linux/drivers/tty/serial/sh-sci.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * SuperH on-chip serial module support.  (SCI with no FIFO / with FIFO)
   4 *
   5 *  Copyright (C) 2002 - 2011  Paul Mundt
   6 *  Copyright (C) 2015 Glider bvba
   7 *  Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
   8 *
   9 * based off of the old drivers/char/sh-sci.c by:
  10 *
  11 *   Copyright (C) 1999, 2000  Niibe Yutaka
  12 *   Copyright (C) 2000  Sugioka Toshinobu
  13 *   Modified to support multiple serial ports. Stuart Menefy (May 2000).
  14 *   Modified to support SecureEdge. David McCullough (2002)
  15 *   Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
  16 *   Removed SH7300 support (Jul 2007).
  17 */
  18#undef DEBUG
  19
  20#include <linux/clk.h>
  21#include <linux/console.h>
  22#include <linux/ctype.h>
  23#include <linux/cpufreq.h>
  24#include <linux/delay.h>
  25#include <linux/dmaengine.h>
  26#include <linux/dma-mapping.h>
  27#include <linux/err.h>
  28#include <linux/errno.h>
  29#include <linux/init.h>
  30#include <linux/interrupt.h>
  31#include <linux/ioport.h>
  32#include <linux/ktime.h>
  33#include <linux/major.h>
  34#include <linux/module.h>
  35#include <linux/mm.h>
  36#include <linux/of.h>
  37#include <linux/of_device.h>
  38#include <linux/platform_device.h>
  39#include <linux/pm_runtime.h>
  40#include <linux/scatterlist.h>
  41#include <linux/serial.h>
  42#include <linux/serial_sci.h>
  43#include <linux/sh_dma.h>
  44#include <linux/slab.h>
  45#include <linux/string.h>
  46#include <linux/sysrq.h>
  47#include <linux/timer.h>
  48#include <linux/tty.h>
  49#include <linux/tty_flip.h>
  50
  51#ifdef CONFIG_SUPERH
  52#include <asm/sh_bios.h>
  53#include <asm/platform_early.h>
  54#endif
  55
  56#include "serial_mctrl_gpio.h"
  57#include "sh-sci.h"
  58
  59/* Offsets into the sci_port->irqs array */
  60enum {
  61        SCIx_ERI_IRQ,
  62        SCIx_RXI_IRQ,
  63        SCIx_TXI_IRQ,
  64        SCIx_BRI_IRQ,
  65        SCIx_DRI_IRQ,
  66        SCIx_TEI_IRQ,
  67        SCIx_NR_IRQS,
  68
  69        SCIx_MUX_IRQ = SCIx_NR_IRQS,    /* special case */
  70};
  71
  72#define SCIx_IRQ_IS_MUXED(port)                 \
  73        ((port)->irqs[SCIx_ERI_IRQ] ==  \
  74         (port)->irqs[SCIx_RXI_IRQ]) || \
  75        ((port)->irqs[SCIx_ERI_IRQ] &&  \
  76         ((port)->irqs[SCIx_RXI_IRQ] < 0))
  77
  78enum SCI_CLKS {
  79        SCI_FCK,                /* Functional Clock */
  80        SCI_SCK,                /* Optional External Clock */
  81        SCI_BRG_INT,            /* Optional BRG Internal Clock Source */
  82        SCI_SCIF_CLK,           /* Optional BRG External Clock Source */
  83        SCI_NUM_CLKS
  84};
  85
  86/* Bit x set means sampling rate x + 1 is supported */
  87#define SCI_SR(x)               BIT((x) - 1)
  88#define SCI_SR_RANGE(x, y)      GENMASK((y) - 1, (x) - 1)
  89
  90#define SCI_SR_SCIFAB           SCI_SR(5) | SCI_SR(7) | SCI_SR(11) | \
  91                                SCI_SR(13) | SCI_SR(16) | SCI_SR(17) | \
  92                                SCI_SR(19) | SCI_SR(27)
  93
  94#define min_sr(_port)           ffs((_port)->sampling_rate_mask)
  95#define max_sr(_port)           fls((_port)->sampling_rate_mask)
  96
  97/* Iterate over all supported sampling rates, from high to low */
  98#define for_each_sr(_sr, _port)                                         \
  99        for ((_sr) = max_sr(_port); (_sr) >= min_sr(_port); (_sr)--)    \
 100                if ((_port)->sampling_rate_mask & SCI_SR((_sr)))
 101
 102struct plat_sci_reg {
 103        u8 offset, size;
 104};
 105
 106struct sci_port_params {
 107        const struct plat_sci_reg regs[SCIx_NR_REGS];
 108        unsigned int fifosize;
 109        unsigned int overrun_reg;
 110        unsigned int overrun_mask;
 111        unsigned int sampling_rate_mask;
 112        unsigned int error_mask;
 113        unsigned int error_clear;
 114};
 115
 116struct sci_port {
 117        struct uart_port        port;
 118
 119        /* Platform configuration */
 120        const struct sci_port_params *params;
 121        const struct plat_sci_port *cfg;
 122        unsigned int            sampling_rate_mask;
 123        resource_size_t         reg_size;
 124        struct mctrl_gpios      *gpios;
 125
 126        /* Clocks */
 127        struct clk              *clks[SCI_NUM_CLKS];
 128        unsigned long           clk_rates[SCI_NUM_CLKS];
 129
 130        int                     irqs[SCIx_NR_IRQS];
 131        char                    *irqstr[SCIx_NR_IRQS];
 132
 133        struct dma_chan                 *chan_tx;
 134        struct dma_chan                 *chan_rx;
 135
 136#ifdef CONFIG_SERIAL_SH_SCI_DMA
 137        struct dma_chan                 *chan_tx_saved;
 138        struct dma_chan                 *chan_rx_saved;
 139        dma_cookie_t                    cookie_tx;
 140        dma_cookie_t                    cookie_rx[2];
 141        dma_cookie_t                    active_rx;
 142        dma_addr_t                      tx_dma_addr;
 143        unsigned int                    tx_dma_len;
 144        struct scatterlist              sg_rx[2];
 145        void                            *rx_buf[2];
 146        size_t                          buf_len_rx;
 147        struct work_struct              work_tx;
 148        struct hrtimer                  rx_timer;
 149        unsigned int                    rx_timeout;     /* microseconds */
 150#endif
 151        unsigned int                    rx_frame;
 152        int                             rx_trigger;
 153        struct timer_list               rx_fifo_timer;
 154        int                             rx_fifo_timeout;
 155        u16                             hscif_tot;
 156
 157        bool has_rtscts;
 158        bool autorts;
 159};
 160
 161#define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
 162
 163static struct sci_port sci_ports[SCI_NPORTS];
 164static unsigned long sci_ports_in_use;
 165static struct uart_driver sci_uart_driver;
 166
 167static inline struct sci_port *
 168to_sci_port(struct uart_port *uart)
 169{
 170        return container_of(uart, struct sci_port, port);
 171}
 172
 173static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
 174        /*
 175         * Common SCI definitions, dependent on the port's regshift
 176         * value.
 177         */
 178        [SCIx_SCI_REGTYPE] = {
 179                .regs = {
 180                        [SCSMR]         = { 0x00,  8 },
 181                        [SCBRR]         = { 0x01,  8 },
 182                        [SCSCR]         = { 0x02,  8 },
 183                        [SCxTDR]        = { 0x03,  8 },
 184                        [SCxSR]         = { 0x04,  8 },
 185                        [SCxRDR]        = { 0x05,  8 },
 186                },
 187                .fifosize = 1,
 188                .overrun_reg = SCxSR,
 189                .overrun_mask = SCI_ORER,
 190                .sampling_rate_mask = SCI_SR(32),
 191                .error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
 192                .error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
 193        },
 194
 195        /*
 196         * Common definitions for legacy IrDA ports.
 197         */
 198        [SCIx_IRDA_REGTYPE] = {
 199                .regs = {
 200                        [SCSMR]         = { 0x00,  8 },
 201                        [SCBRR]         = { 0x02,  8 },
 202                        [SCSCR]         = { 0x04,  8 },
 203                        [SCxTDR]        = { 0x06,  8 },
 204                        [SCxSR]         = { 0x08, 16 },
 205                        [SCxRDR]        = { 0x0a,  8 },
 206                        [SCFCR]         = { 0x0c,  8 },
 207                        [SCFDR]         = { 0x0e, 16 },
 208                },
 209                .fifosize = 1,
 210                .overrun_reg = SCxSR,
 211                .overrun_mask = SCI_ORER,
 212                .sampling_rate_mask = SCI_SR(32),
 213                .error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
 214                .error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
 215        },
 216
 217        /*
 218         * Common SCIFA definitions.
 219         */
 220        [SCIx_SCIFA_REGTYPE] = {
 221                .regs = {
 222                        [SCSMR]         = { 0x00, 16 },
 223                        [SCBRR]         = { 0x04,  8 },
 224                        [SCSCR]         = { 0x08, 16 },
 225                        [SCxTDR]        = { 0x20,  8 },
 226                        [SCxSR]         = { 0x14, 16 },
 227                        [SCxRDR]        = { 0x24,  8 },
 228                        [SCFCR]         = { 0x18, 16 },
 229                        [SCFDR]         = { 0x1c, 16 },
 230                        [SCPCR]         = { 0x30, 16 },
 231                        [SCPDR]         = { 0x34, 16 },
 232                },
 233                .fifosize = 64,
 234                .overrun_reg = SCxSR,
 235                .overrun_mask = SCIFA_ORER,
 236                .sampling_rate_mask = SCI_SR_SCIFAB,
 237                .error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
 238                .error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
 239        },
 240
 241        /*
 242         * Common SCIFB definitions.
 243         */
 244        [SCIx_SCIFB_REGTYPE] = {
 245                .regs = {
 246                        [SCSMR]         = { 0x00, 16 },
 247                        [SCBRR]         = { 0x04,  8 },
 248                        [SCSCR]         = { 0x08, 16 },
 249                        [SCxTDR]        = { 0x40,  8 },
 250                        [SCxSR]         = { 0x14, 16 },
 251                        [SCxRDR]        = { 0x60,  8 },
 252                        [SCFCR]         = { 0x18, 16 },
 253                        [SCTFDR]        = { 0x38, 16 },
 254                        [SCRFDR]        = { 0x3c, 16 },
 255                        [SCPCR]         = { 0x30, 16 },
 256                        [SCPDR]         = { 0x34, 16 },
 257                },
 258                .fifosize = 256,
 259                .overrun_reg = SCxSR,
 260                .overrun_mask = SCIFA_ORER,
 261                .sampling_rate_mask = SCI_SR_SCIFAB,
 262                .error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
 263                .error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
 264        },
 265
 266        /*
 267         * Common SH-2(A) SCIF definitions for ports with FIFO data
 268         * count registers.
 269         */
 270        [SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
 271                .regs = {
 272                        [SCSMR]         = { 0x00, 16 },
 273                        [SCBRR]         = { 0x04,  8 },
 274                        [SCSCR]         = { 0x08, 16 },
 275                        [SCxTDR]        = { 0x0c,  8 },
 276                        [SCxSR]         = { 0x10, 16 },
 277                        [SCxRDR]        = { 0x14,  8 },
 278                        [SCFCR]         = { 0x18, 16 },
 279                        [SCFDR]         = { 0x1c, 16 },
 280                        [SCSPTR]        = { 0x20, 16 },
 281                        [SCLSR]         = { 0x24, 16 },
 282                },
 283                .fifosize = 16,
 284                .overrun_reg = SCLSR,
 285                .overrun_mask = SCLSR_ORER,
 286                .sampling_rate_mask = SCI_SR(32),
 287                .error_mask = SCIF_DEFAULT_ERROR_MASK,
 288                .error_clear = SCIF_ERROR_CLEAR,
 289        },
 290
 291        /*
 292         * The "SCIFA" that is in RZ/T and RZ/A2.
 293         * It looks like a normal SCIF with FIFO data, but with a
 294         * compressed address space. Also, the break out of interrupts
 295         * are different: ERI/BRI, RXI, TXI, TEI, DRI.
 296         */
 297        [SCIx_RZ_SCIFA_REGTYPE] = {
 298                .regs = {
 299                        [SCSMR]         = { 0x00, 16 },
 300                        [SCBRR]         = { 0x02,  8 },
 301                        [SCSCR]         = { 0x04, 16 },
 302                        [SCxTDR]        = { 0x06,  8 },
 303                        [SCxSR]         = { 0x08, 16 },
 304                        [SCxRDR]        = { 0x0A,  8 },
 305                        [SCFCR]         = { 0x0C, 16 },
 306                        [SCFDR]         = { 0x0E, 16 },
 307                        [SCSPTR]        = { 0x10, 16 },
 308                        [SCLSR]         = { 0x12, 16 },
 309                },
 310                .fifosize = 16,
 311                .overrun_reg = SCLSR,
 312                .overrun_mask = SCLSR_ORER,
 313                .sampling_rate_mask = SCI_SR(32),
 314                .error_mask = SCIF_DEFAULT_ERROR_MASK,
 315                .error_clear = SCIF_ERROR_CLEAR,
 316        },
 317
 318        /*
 319         * Common SH-3 SCIF definitions.
 320         */
 321        [SCIx_SH3_SCIF_REGTYPE] = {
 322                .regs = {
 323                        [SCSMR]         = { 0x00,  8 },
 324                        [SCBRR]         = { 0x02,  8 },
 325                        [SCSCR]         = { 0x04,  8 },
 326                        [SCxTDR]        = { 0x06,  8 },
 327                        [SCxSR]         = { 0x08, 16 },
 328                        [SCxRDR]        = { 0x0a,  8 },
 329                        [SCFCR]         = { 0x0c,  8 },
 330                        [SCFDR]         = { 0x0e, 16 },
 331                },
 332                .fifosize = 16,
 333                .overrun_reg = SCLSR,
 334                .overrun_mask = SCLSR_ORER,
 335                .sampling_rate_mask = SCI_SR(32),
 336                .error_mask = SCIF_DEFAULT_ERROR_MASK,
 337                .error_clear = SCIF_ERROR_CLEAR,
 338        },
 339
 340        /*
 341         * Common SH-4(A) SCIF(B) definitions.
 342         */
 343        [SCIx_SH4_SCIF_REGTYPE] = {
 344                .regs = {
 345                        [SCSMR]         = { 0x00, 16 },
 346                        [SCBRR]         = { 0x04,  8 },
 347                        [SCSCR]         = { 0x08, 16 },
 348                        [SCxTDR]        = { 0x0c,  8 },
 349                        [SCxSR]         = { 0x10, 16 },
 350                        [SCxRDR]        = { 0x14,  8 },
 351                        [SCFCR]         = { 0x18, 16 },
 352                        [SCFDR]         = { 0x1c, 16 },
 353                        [SCSPTR]        = { 0x20, 16 },
 354                        [SCLSR]         = { 0x24, 16 },
 355                },
 356                .fifosize = 16,
 357                .overrun_reg = SCLSR,
 358                .overrun_mask = SCLSR_ORER,
 359                .sampling_rate_mask = SCI_SR(32),
 360                .error_mask = SCIF_DEFAULT_ERROR_MASK,
 361                .error_clear = SCIF_ERROR_CLEAR,
 362        },
 363
 364        /*
 365         * Common SCIF definitions for ports with a Baud Rate Generator for
 366         * External Clock (BRG).
 367         */
 368        [SCIx_SH4_SCIF_BRG_REGTYPE] = {
 369                .regs = {
 370                        [SCSMR]         = { 0x00, 16 },
 371                        [SCBRR]         = { 0x04,  8 },
 372                        [SCSCR]         = { 0x08, 16 },
 373                        [SCxTDR]        = { 0x0c,  8 },
 374                        [SCxSR]         = { 0x10, 16 },
 375                        [SCxRDR]        = { 0x14,  8 },
 376                        [SCFCR]         = { 0x18, 16 },
 377                        [SCFDR]         = { 0x1c, 16 },
 378                        [SCSPTR]        = { 0x20, 16 },
 379                        [SCLSR]         = { 0x24, 16 },
 380                        [SCDL]          = { 0x30, 16 },
 381                        [SCCKS]         = { 0x34, 16 },
 382                },
 383                .fifosize = 16,
 384                .overrun_reg = SCLSR,
 385                .overrun_mask = SCLSR_ORER,
 386                .sampling_rate_mask = SCI_SR(32),
 387                .error_mask = SCIF_DEFAULT_ERROR_MASK,
 388                .error_clear = SCIF_ERROR_CLEAR,
 389        },
 390
 391        /*
 392         * Common HSCIF definitions.
 393         */
 394        [SCIx_HSCIF_REGTYPE] = {
 395                .regs = {
 396                        [SCSMR]         = { 0x00, 16 },
 397                        [SCBRR]         = { 0x04,  8 },
 398                        [SCSCR]         = { 0x08, 16 },
 399                        [SCxTDR]        = { 0x0c,  8 },
 400                        [SCxSR]         = { 0x10, 16 },
 401                        [SCxRDR]        = { 0x14,  8 },
 402                        [SCFCR]         = { 0x18, 16 },
 403                        [SCFDR]         = { 0x1c, 16 },
 404                        [SCSPTR]        = { 0x20, 16 },
 405                        [SCLSR]         = { 0x24, 16 },
 406                        [HSSRR]         = { 0x40, 16 },
 407                        [SCDL]          = { 0x30, 16 },
 408                        [SCCKS]         = { 0x34, 16 },
 409                        [HSRTRGR]       = { 0x54, 16 },
 410                        [HSTTRGR]       = { 0x58, 16 },
 411                },
 412                .fifosize = 128,
 413                .overrun_reg = SCLSR,
 414                .overrun_mask = SCLSR_ORER,
 415                .sampling_rate_mask = SCI_SR_RANGE(8, 32),
 416                .error_mask = SCIF_DEFAULT_ERROR_MASK,
 417                .error_clear = SCIF_ERROR_CLEAR,
 418        },
 419
 420        /*
 421         * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
 422         * register.
 423         */
 424        [SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
 425                .regs = {
 426                        [SCSMR]         = { 0x00, 16 },
 427                        [SCBRR]         = { 0x04,  8 },
 428                        [SCSCR]         = { 0x08, 16 },
 429                        [SCxTDR]        = { 0x0c,  8 },
 430                        [SCxSR]         = { 0x10, 16 },
 431                        [SCxRDR]        = { 0x14,  8 },
 432                        [SCFCR]         = { 0x18, 16 },
 433                        [SCFDR]         = { 0x1c, 16 },
 434                        [SCLSR]         = { 0x24, 16 },
 435                },
 436                .fifosize = 16,
 437                .overrun_reg = SCLSR,
 438                .overrun_mask = SCLSR_ORER,
 439                .sampling_rate_mask = SCI_SR(32),
 440                .error_mask = SCIF_DEFAULT_ERROR_MASK,
 441                .error_clear = SCIF_ERROR_CLEAR,
 442        },
 443
 444        /*
 445         * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
 446         * count registers.
 447         */
 448        [SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
 449                .regs = {
 450                        [SCSMR]         = { 0x00, 16 },
 451                        [SCBRR]         = { 0x04,  8 },
 452                        [SCSCR]         = { 0x08, 16 },
 453                        [SCxTDR]        = { 0x0c,  8 },
 454                        [SCxSR]         = { 0x10, 16 },
 455                        [SCxRDR]        = { 0x14,  8 },
 456                        [SCFCR]         = { 0x18, 16 },
 457                        [SCFDR]         = { 0x1c, 16 },
 458                        [SCTFDR]        = { 0x1c, 16 }, /* aliased to SCFDR */
 459                        [SCRFDR]        = { 0x20, 16 },
 460                        [SCSPTR]        = { 0x24, 16 },
 461                        [SCLSR]         = { 0x28, 16 },
 462                },
 463                .fifosize = 16,
 464                .overrun_reg = SCLSR,
 465                .overrun_mask = SCLSR_ORER,
 466                .sampling_rate_mask = SCI_SR(32),
 467                .error_mask = SCIF_DEFAULT_ERROR_MASK,
 468                .error_clear = SCIF_ERROR_CLEAR,
 469        },
 470
 471        /*
 472         * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
 473         * registers.
 474         */
 475        [SCIx_SH7705_SCIF_REGTYPE] = {
 476                .regs = {
 477                        [SCSMR]         = { 0x00, 16 },
 478                        [SCBRR]         = { 0x04,  8 },
 479                        [SCSCR]         = { 0x08, 16 },
 480                        [SCxTDR]        = { 0x20,  8 },
 481                        [SCxSR]         = { 0x14, 16 },
 482                        [SCxRDR]        = { 0x24,  8 },
 483                        [SCFCR]         = { 0x18, 16 },
 484                        [SCFDR]         = { 0x1c, 16 },
 485                },
 486                .fifosize = 64,
 487                .overrun_reg = SCxSR,
 488                .overrun_mask = SCIFA_ORER,
 489                .sampling_rate_mask = SCI_SR(16),
 490                .error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
 491                .error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
 492        },
 493};
 494
 495#define sci_getreg(up, offset)          (&to_sci_port(up)->params->regs[offset])
 496
 497/*
 498 * The "offset" here is rather misleading, in that it refers to an enum
 499 * value relative to the port mapping rather than the fixed offset
 500 * itself, which needs to be manually retrieved from the platform's
 501 * register map for the given port.
 502 */
 503static unsigned int sci_serial_in(struct uart_port *p, int offset)
 504{
 505        const struct plat_sci_reg *reg = sci_getreg(p, offset);
 506
 507        if (reg->size == 8)
 508                return ioread8(p->membase + (reg->offset << p->regshift));
 509        else if (reg->size == 16)
 510                return ioread16(p->membase + (reg->offset << p->regshift));
 511        else
 512                WARN(1, "Invalid register access\n");
 513
 514        return 0;
 515}
 516
 517static void sci_serial_out(struct uart_port *p, int offset, int value)
 518{
 519        const struct plat_sci_reg *reg = sci_getreg(p, offset);
 520
 521        if (reg->size == 8)
 522                iowrite8(value, p->membase + (reg->offset << p->regshift));
 523        else if (reg->size == 16)
 524                iowrite16(value, p->membase + (reg->offset << p->regshift));
 525        else
 526                WARN(1, "Invalid register access\n");
 527}
 528
 529static void sci_port_enable(struct sci_port *sci_port)
 530{
 531        unsigned int i;
 532
 533        if (!sci_port->port.dev)
 534                return;
 535
 536        pm_runtime_get_sync(sci_port->port.dev);
 537
 538        for (i = 0; i < SCI_NUM_CLKS; i++) {
 539                clk_prepare_enable(sci_port->clks[i]);
 540                sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
 541        }
 542        sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
 543}
 544
 545static void sci_port_disable(struct sci_port *sci_port)
 546{
 547        unsigned int i;
 548
 549        if (!sci_port->port.dev)
 550                return;
 551
 552        for (i = SCI_NUM_CLKS; i-- > 0; )
 553                clk_disable_unprepare(sci_port->clks[i]);
 554
 555        pm_runtime_put_sync(sci_port->port.dev);
 556}
 557
 558static inline unsigned long port_rx_irq_mask(struct uart_port *port)
 559{
 560        /*
 561         * Not all ports (such as SCIFA) will support REIE. Rather than
 562         * special-casing the port type, we check the port initialization
 563         * IRQ enable mask to see whether the IRQ is desired at all. If
 564         * it's unset, it's logically inferred that there's no point in
 565         * testing for it.
 566         */
 567        return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
 568}
 569
 570static void sci_start_tx(struct uart_port *port)
 571{
 572        struct sci_port *s = to_sci_port(port);
 573        unsigned short ctrl;
 574
 575#ifdef CONFIG_SERIAL_SH_SCI_DMA
 576        if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
 577                u16 new, scr = serial_port_in(port, SCSCR);
 578                if (s->chan_tx)
 579                        new = scr | SCSCR_TDRQE;
 580                else
 581                        new = scr & ~SCSCR_TDRQE;
 582                if (new != scr)
 583                        serial_port_out(port, SCSCR, new);
 584        }
 585
 586        if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
 587            dma_submit_error(s->cookie_tx)) {
 588                s->cookie_tx = 0;
 589                schedule_work(&s->work_tx);
 590        }
 591#endif
 592
 593        if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
 594                /* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
 595                ctrl = serial_port_in(port, SCSCR);
 596                serial_port_out(port, SCSCR, ctrl | SCSCR_TIE);
 597        }
 598}
 599
 600static void sci_stop_tx(struct uart_port *port)
 601{
 602        unsigned short ctrl;
 603
 604        /* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
 605        ctrl = serial_port_in(port, SCSCR);
 606
 607        if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
 608                ctrl &= ~SCSCR_TDRQE;
 609
 610        ctrl &= ~SCSCR_TIE;
 611
 612        serial_port_out(port, SCSCR, ctrl);
 613}
 614
 615static void sci_start_rx(struct uart_port *port)
 616{
 617        unsigned short ctrl;
 618
 619        ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
 620
 621        if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
 622                ctrl &= ~SCSCR_RDRQE;
 623
 624        serial_port_out(port, SCSCR, ctrl);
 625}
 626
 627static void sci_stop_rx(struct uart_port *port)
 628{
 629        unsigned short ctrl;
 630
 631        ctrl = serial_port_in(port, SCSCR);
 632
 633        if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
 634                ctrl &= ~SCSCR_RDRQE;
 635
 636        ctrl &= ~port_rx_irq_mask(port);
 637
 638        serial_port_out(port, SCSCR, ctrl);
 639}
 640
 641static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
 642{
 643        if (port->type == PORT_SCI) {
 644                /* Just store the mask */
 645                serial_port_out(port, SCxSR, mask);
 646        } else if (to_sci_port(port)->params->overrun_mask == SCIFA_ORER) {
 647                /* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
 648                /* Only clear the status bits we want to clear */
 649                serial_port_out(port, SCxSR,
 650                                serial_port_in(port, SCxSR) & mask);
 651        } else {
 652                /* Store the mask, clear parity/framing errors */
 653                serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
 654        }
 655}
 656
 657#if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
 658    defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
 659
 660#ifdef CONFIG_CONSOLE_POLL
 661static int sci_poll_get_char(struct uart_port *port)
 662{
 663        unsigned short status;
 664        int c;
 665
 666        do {
 667                status = serial_port_in(port, SCxSR);
 668                if (status & SCxSR_ERRORS(port)) {
 669                        sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
 670                        continue;
 671                }
 672                break;
 673        } while (1);
 674
 675        if (!(status & SCxSR_RDxF(port)))
 676                return NO_POLL_CHAR;
 677
 678        c = serial_port_in(port, SCxRDR);
 679
 680        /* Dummy read */
 681        serial_port_in(port, SCxSR);
 682        sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
 683
 684        return c;
 685}
 686#endif
 687
 688static void sci_poll_put_char(struct uart_port *port, unsigned char c)
 689{
 690        unsigned short status;
 691
 692        do {
 693                status = serial_port_in(port, SCxSR);
 694        } while (!(status & SCxSR_TDxE(port)));
 695
 696        serial_port_out(port, SCxTDR, c);
 697        sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
 698}
 699#endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
 700          CONFIG_SERIAL_SH_SCI_EARLYCON */
 701
 702static void sci_init_pins(struct uart_port *port, unsigned int cflag)
 703{
 704        struct sci_port *s = to_sci_port(port);
 705
 706        /*
 707         * Use port-specific handler if provided.
 708         */
 709        if (s->cfg->ops && s->cfg->ops->init_pins) {
 710                s->cfg->ops->init_pins(port, cflag);
 711                return;
 712        }
 713
 714        if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
 715                u16 data = serial_port_in(port, SCPDR);
 716                u16 ctrl = serial_port_in(port, SCPCR);
 717
 718                /* Enable RXD and TXD pin functions */
 719                ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC);
 720                if (to_sci_port(port)->has_rtscts) {
 721                        /* RTS# is output, active low, unless autorts */
 722                        if (!(port->mctrl & TIOCM_RTS)) {
 723                                ctrl |= SCPCR_RTSC;
 724                                data |= SCPDR_RTSD;
 725                        } else if (!s->autorts) {
 726                                ctrl |= SCPCR_RTSC;
 727                                data &= ~SCPDR_RTSD;
 728                        } else {
 729                                /* Enable RTS# pin function */
 730                                ctrl &= ~SCPCR_RTSC;
 731                        }
 732                        /* Enable CTS# pin function */
 733                        ctrl &= ~SCPCR_CTSC;
 734                }
 735                serial_port_out(port, SCPDR, data);
 736                serial_port_out(port, SCPCR, ctrl);
 737        } else if (sci_getreg(port, SCSPTR)->size) {
 738                u16 status = serial_port_in(port, SCSPTR);
 739
 740                /* RTS# is always output; and active low, unless autorts */
 741                status |= SCSPTR_RTSIO;
 742                if (!(port->mctrl & TIOCM_RTS))
 743                        status |= SCSPTR_RTSDT;
 744                else if (!s->autorts)
 745                        status &= ~SCSPTR_RTSDT;
 746                /* CTS# and SCK are inputs */
 747                status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
 748                serial_port_out(port, SCSPTR, status);
 749        }
 750}
 751
 752static int sci_txfill(struct uart_port *port)
 753{
 754        struct sci_port *s = to_sci_port(port);
 755        unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
 756        const struct plat_sci_reg *reg;
 757
 758        reg = sci_getreg(port, SCTFDR);
 759        if (reg->size)
 760                return serial_port_in(port, SCTFDR) & fifo_mask;
 761
 762        reg = sci_getreg(port, SCFDR);
 763        if (reg->size)
 764                return serial_port_in(port, SCFDR) >> 8;
 765
 766        return !(serial_port_in(port, SCxSR) & SCI_TDRE);
 767}
 768
 769static int sci_txroom(struct uart_port *port)
 770{
 771        return port->fifosize - sci_txfill(port);
 772}
 773
 774static int sci_rxfill(struct uart_port *port)
 775{
 776        struct sci_port *s = to_sci_port(port);
 777        unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
 778        const struct plat_sci_reg *reg;
 779
 780        reg = sci_getreg(port, SCRFDR);
 781        if (reg->size)
 782                return serial_port_in(port, SCRFDR) & fifo_mask;
 783
 784        reg = sci_getreg(port, SCFDR);
 785        if (reg->size)
 786                return serial_port_in(port, SCFDR) & fifo_mask;
 787
 788        return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
 789}
 790
 791/* ********************************************************************** *
 792 *                   the interrupt related routines                       *
 793 * ********************************************************************** */
 794
 795static void sci_transmit_chars(struct uart_port *port)
 796{
 797        struct circ_buf *xmit = &port->state->xmit;
 798        unsigned int stopped = uart_tx_stopped(port);
 799        unsigned short status;
 800        unsigned short ctrl;
 801        int count;
 802
 803        status = serial_port_in(port, SCxSR);
 804        if (!(status & SCxSR_TDxE(port))) {
 805                ctrl = serial_port_in(port, SCSCR);
 806                if (uart_circ_empty(xmit))
 807                        ctrl &= ~SCSCR_TIE;
 808                else
 809                        ctrl |= SCSCR_TIE;
 810                serial_port_out(port, SCSCR, ctrl);
 811                return;
 812        }
 813
 814        count = sci_txroom(port);
 815
 816        do {
 817                unsigned char c;
 818
 819                if (port->x_char) {
 820                        c = port->x_char;
 821                        port->x_char = 0;
 822                } else if (!uart_circ_empty(xmit) && !stopped) {
 823                        c = xmit->buf[xmit->tail];
 824                        xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 825                } else {
 826                        break;
 827                }
 828
 829                serial_port_out(port, SCxTDR, c);
 830
 831                port->icount.tx++;
 832        } while (--count > 0);
 833
 834        sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
 835
 836        if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 837                uart_write_wakeup(port);
 838        if (uart_circ_empty(xmit))
 839                sci_stop_tx(port);
 840
 841}
 842
 843/* On SH3, SCIF may read end-of-break as a space->mark char */
 844#define STEPFN(c)  ({int __c = (c); (((__c-1)|(__c)) == -1); })
 845
 846static void sci_receive_chars(struct uart_port *port)
 847{
 848        struct tty_port *tport = &port->state->port;
 849        int i, count, copied = 0;
 850        unsigned short status;
 851        unsigned char flag;
 852
 853        status = serial_port_in(port, SCxSR);
 854        if (!(status & SCxSR_RDxF(port)))
 855                return;
 856
 857        while (1) {
 858                /* Don't copy more bytes than there is room for in the buffer */
 859                count = tty_buffer_request_room(tport, sci_rxfill(port));
 860
 861                /* If for any reason we can't copy more data, we're done! */
 862                if (count == 0)
 863                        break;
 864
 865                if (port->type == PORT_SCI) {
 866                        char c = serial_port_in(port, SCxRDR);
 867                        if (uart_handle_sysrq_char(port, c))
 868                                count = 0;
 869                        else
 870                                tty_insert_flip_char(tport, c, TTY_NORMAL);
 871                } else {
 872                        for (i = 0; i < count; i++) {
 873                                char c;
 874
 875                                if (port->type == PORT_SCIF ||
 876                                    port->type == PORT_HSCIF) {
 877                                        status = serial_port_in(port, SCxSR);
 878                                        c = serial_port_in(port, SCxRDR);
 879                                } else {
 880                                        c = serial_port_in(port, SCxRDR);
 881                                        status = serial_port_in(port, SCxSR);
 882                                }
 883                                if (uart_handle_sysrq_char(port, c)) {
 884                                        count--; i--;
 885                                        continue;
 886                                }
 887
 888                                /* Store data and status */
 889                                if (status & SCxSR_FER(port)) {
 890                                        flag = TTY_FRAME;
 891                                        port->icount.frame++;
 892                                        dev_notice(port->dev, "frame error\n");
 893                                } else if (status & SCxSR_PER(port)) {
 894                                        flag = TTY_PARITY;
 895                                        port->icount.parity++;
 896                                        dev_notice(port->dev, "parity error\n");
 897                                } else
 898                                        flag = TTY_NORMAL;
 899
 900                                tty_insert_flip_char(tport, c, flag);
 901                        }
 902                }
 903
 904                serial_port_in(port, SCxSR); /* dummy read */
 905                sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
 906
 907                copied += count;
 908                port->icount.rx += count;
 909        }
 910
 911        if (copied) {
 912                /* Tell the rest of the system the news. New characters! */
 913                tty_flip_buffer_push(tport);
 914        } else {
 915                /* TTY buffers full; read from RX reg to prevent lockup */
 916                serial_port_in(port, SCxRDR);
 917                serial_port_in(port, SCxSR); /* dummy read */
 918                sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
 919        }
 920}
 921
 922static int sci_handle_errors(struct uart_port *port)
 923{
 924        int copied = 0;
 925        unsigned short status = serial_port_in(port, SCxSR);
 926        struct tty_port *tport = &port->state->port;
 927        struct sci_port *s = to_sci_port(port);
 928
 929        /* Handle overruns */
 930        if (status & s->params->overrun_mask) {
 931                port->icount.overrun++;
 932
 933                /* overrun error */
 934                if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
 935                        copied++;
 936
 937                dev_notice(port->dev, "overrun error\n");
 938        }
 939
 940        if (status & SCxSR_FER(port)) {
 941                /* frame error */
 942                port->icount.frame++;
 943
 944                if (tty_insert_flip_char(tport, 0, TTY_FRAME))
 945                        copied++;
 946
 947                dev_notice(port->dev, "frame error\n");
 948        }
 949
 950        if (status & SCxSR_PER(port)) {
 951                /* parity error */
 952                port->icount.parity++;
 953
 954                if (tty_insert_flip_char(tport, 0, TTY_PARITY))
 955                        copied++;
 956
 957                dev_notice(port->dev, "parity error\n");
 958        }
 959
 960        if (copied)
 961                tty_flip_buffer_push(tport);
 962
 963        return copied;
 964}
 965
 966static int sci_handle_fifo_overrun(struct uart_port *port)
 967{
 968        struct tty_port *tport = &port->state->port;
 969        struct sci_port *s = to_sci_port(port);
 970        const struct plat_sci_reg *reg;
 971        int copied = 0;
 972        u16 status;
 973
 974        reg = sci_getreg(port, s->params->overrun_reg);
 975        if (!reg->size)
 976                return 0;
 977
 978        status = serial_port_in(port, s->params->overrun_reg);
 979        if (status & s->params->overrun_mask) {
 980                status &= ~s->params->overrun_mask;
 981                serial_port_out(port, s->params->overrun_reg, status);
 982
 983                port->icount.overrun++;
 984
 985                tty_insert_flip_char(tport, 0, TTY_OVERRUN);
 986                tty_flip_buffer_push(tport);
 987
 988                dev_dbg(port->dev, "overrun error\n");
 989                copied++;
 990        }
 991
 992        return copied;
 993}
 994
 995static int sci_handle_breaks(struct uart_port *port)
 996{
 997        int copied = 0;
 998        unsigned short status = serial_port_in(port, SCxSR);
 999        struct tty_port *tport = &port->state->port;
1000
1001        if (uart_handle_break(port))
1002                return 0;
1003
1004        if (status & SCxSR_BRK(port)) {
1005                port->icount.brk++;
1006
1007                /* Notify of BREAK */
1008                if (tty_insert_flip_char(tport, 0, TTY_BREAK))
1009                        copied++;
1010
1011                dev_dbg(port->dev, "BREAK detected\n");
1012        }
1013
1014        if (copied)
1015                tty_flip_buffer_push(tport);
1016
1017        copied += sci_handle_fifo_overrun(port);
1018
1019        return copied;
1020}
1021
1022static int scif_set_rtrg(struct uart_port *port, int rx_trig)
1023{
1024        unsigned int bits;
1025
1026        if (rx_trig < 1)
1027                rx_trig = 1;
1028        if (rx_trig >= port->fifosize)
1029                rx_trig = port->fifosize;
1030
1031        /* HSCIF can be set to an arbitrary level. */
1032        if (sci_getreg(port, HSRTRGR)->size) {
1033                serial_port_out(port, HSRTRGR, rx_trig);
1034                return rx_trig;
1035        }
1036
1037        switch (port->type) {
1038        case PORT_SCIF:
1039                if (rx_trig < 4) {
1040                        bits = 0;
1041                        rx_trig = 1;
1042                } else if (rx_trig < 8) {
1043                        bits = SCFCR_RTRG0;
1044                        rx_trig = 4;
1045                } else if (rx_trig < 14) {
1046                        bits = SCFCR_RTRG1;
1047                        rx_trig = 8;
1048                } else {
1049                        bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1050                        rx_trig = 14;
1051                }
1052                break;
1053        case PORT_SCIFA:
1054        case PORT_SCIFB:
1055                if (rx_trig < 16) {
1056                        bits = 0;
1057                        rx_trig = 1;
1058                } else if (rx_trig < 32) {
1059                        bits = SCFCR_RTRG0;
1060                        rx_trig = 16;
1061                } else if (rx_trig < 48) {
1062                        bits = SCFCR_RTRG1;
1063                        rx_trig = 32;
1064                } else {
1065                        bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1066                        rx_trig = 48;
1067                }
1068                break;
1069        default:
1070                WARN(1, "unknown FIFO configuration");
1071                return 1;
1072        }
1073
1074        serial_port_out(port, SCFCR,
1075                (serial_port_in(port, SCFCR) &
1076                ~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
1077
1078        return rx_trig;
1079}
1080
1081static int scif_rtrg_enabled(struct uart_port *port)
1082{
1083        if (sci_getreg(port, HSRTRGR)->size)
1084                return serial_port_in(port, HSRTRGR) != 0;
1085        else
1086                return (serial_port_in(port, SCFCR) &
1087                        (SCFCR_RTRG0 | SCFCR_RTRG1)) != 0;
1088}
1089
1090static void rx_fifo_timer_fn(struct timer_list *t)
1091{
1092        struct sci_port *s = from_timer(s, t, rx_fifo_timer);
1093        struct uart_port *port = &s->port;
1094
1095        dev_dbg(port->dev, "Rx timed out\n");
1096        scif_set_rtrg(port, 1);
1097}
1098
1099static ssize_t rx_fifo_trigger_show(struct device *dev,
1100                                    struct device_attribute *attr, char *buf)
1101{
1102        struct uart_port *port = dev_get_drvdata(dev);
1103        struct sci_port *sci = to_sci_port(port);
1104
1105        return sprintf(buf, "%d\n", sci->rx_trigger);
1106}
1107
1108static ssize_t rx_fifo_trigger_store(struct device *dev,
1109                                     struct device_attribute *attr,
1110                                     const char *buf, size_t count)
1111{
1112        struct uart_port *port = dev_get_drvdata(dev);
1113        struct sci_port *sci = to_sci_port(port);
1114        int ret;
1115        long r;
1116
1117        ret = kstrtol(buf, 0, &r);
1118        if (ret)
1119                return ret;
1120
1121        sci->rx_trigger = scif_set_rtrg(port, r);
1122        if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1123                scif_set_rtrg(port, 1);
1124
1125        return count;
1126}
1127
1128static DEVICE_ATTR_RW(rx_fifo_trigger);
1129
1130static ssize_t rx_fifo_timeout_show(struct device *dev,
1131                               struct device_attribute *attr,
1132                               char *buf)
1133{
1134        struct uart_port *port = dev_get_drvdata(dev);
1135        struct sci_port *sci = to_sci_port(port);
1136        int v;
1137
1138        if (port->type == PORT_HSCIF)
1139                v = sci->hscif_tot >> HSSCR_TOT_SHIFT;
1140        else
1141                v = sci->rx_fifo_timeout;
1142
1143        return sprintf(buf, "%d\n", v);
1144}
1145
1146static ssize_t rx_fifo_timeout_store(struct device *dev,
1147                                struct device_attribute *attr,
1148                                const char *buf,
1149                                size_t count)
1150{
1151        struct uart_port *port = dev_get_drvdata(dev);
1152        struct sci_port *sci = to_sci_port(port);
1153        int ret;
1154        long r;
1155
1156        ret = kstrtol(buf, 0, &r);
1157        if (ret)
1158                return ret;
1159
1160        if (port->type == PORT_HSCIF) {
1161                if (r < 0 || r > 3)
1162                        return -EINVAL;
1163                sci->hscif_tot = r << HSSCR_TOT_SHIFT;
1164        } else {
1165                sci->rx_fifo_timeout = r;
1166                scif_set_rtrg(port, 1);
1167                if (r > 0)
1168                        timer_setup(&sci->rx_fifo_timer, rx_fifo_timer_fn, 0);
1169        }
1170
1171        return count;
1172}
1173
1174static DEVICE_ATTR_RW(rx_fifo_timeout);
1175
1176
1177#ifdef CONFIG_SERIAL_SH_SCI_DMA
1178static void sci_dma_tx_complete(void *arg)
1179{
1180        struct sci_port *s = arg;
1181        struct uart_port *port = &s->port;
1182        struct circ_buf *xmit = &port->state->xmit;
1183        unsigned long flags;
1184
1185        dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1186
1187        spin_lock_irqsave(&port->lock, flags);
1188
1189        xmit->tail += s->tx_dma_len;
1190        xmit->tail &= UART_XMIT_SIZE - 1;
1191
1192        port->icount.tx += s->tx_dma_len;
1193
1194        if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1195                uart_write_wakeup(port);
1196
1197        if (!uart_circ_empty(xmit)) {
1198                s->cookie_tx = 0;
1199                schedule_work(&s->work_tx);
1200        } else {
1201                s->cookie_tx = -EINVAL;
1202                if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1203                        u16 ctrl = serial_port_in(port, SCSCR);
1204                        serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1205                }
1206        }
1207
1208        spin_unlock_irqrestore(&port->lock, flags);
1209}
1210
1211/* Locking: called with port lock held */
1212static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1213{
1214        struct uart_port *port = &s->port;
1215        struct tty_port *tport = &port->state->port;
1216        int copied;
1217
1218        copied = tty_insert_flip_string(tport, buf, count);
1219        if (copied < count)
1220                port->icount.buf_overrun++;
1221
1222        port->icount.rx += copied;
1223
1224        return copied;
1225}
1226
1227static int sci_dma_rx_find_active(struct sci_port *s)
1228{
1229        unsigned int i;
1230
1231        for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1232                if (s->active_rx == s->cookie_rx[i])
1233                        return i;
1234
1235        return -1;
1236}
1237
1238static void sci_dma_rx_chan_invalidate(struct sci_port *s)
1239{
1240        unsigned int i;
1241
1242        s->chan_rx = NULL;
1243        for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1244                s->cookie_rx[i] = -EINVAL;
1245        s->active_rx = 0;
1246}
1247
1248static void sci_dma_rx_release(struct sci_port *s)
1249{
1250        struct dma_chan *chan = s->chan_rx_saved;
1251
1252        s->chan_rx_saved = NULL;
1253        sci_dma_rx_chan_invalidate(s);
1254        dmaengine_terminate_sync(chan);
1255        dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1256                          sg_dma_address(&s->sg_rx[0]));
1257        dma_release_channel(chan);
1258}
1259
1260static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec)
1261{
1262        long sec = usec / 1000000;
1263        long nsec = (usec % 1000000) * 1000;
1264        ktime_t t = ktime_set(sec, nsec);
1265
1266        hrtimer_start(hrt, t, HRTIMER_MODE_REL);
1267}
1268
1269static void sci_dma_rx_reenable_irq(struct sci_port *s)
1270{
1271        struct uart_port *port = &s->port;
1272        u16 scr;
1273
1274        /* Direct new serial port interrupts back to CPU */
1275        scr = serial_port_in(port, SCSCR);
1276        if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1277                scr &= ~SCSCR_RDRQE;
1278                enable_irq(s->irqs[SCIx_RXI_IRQ]);
1279        }
1280        serial_port_out(port, SCSCR, scr | SCSCR_RIE);
1281}
1282
1283static void sci_dma_rx_complete(void *arg)
1284{
1285        struct sci_port *s = arg;
1286        struct dma_chan *chan = s->chan_rx;
1287        struct uart_port *port = &s->port;
1288        struct dma_async_tx_descriptor *desc;
1289        unsigned long flags;
1290        int active, count = 0;
1291
1292        dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1293                s->active_rx);
1294
1295        spin_lock_irqsave(&port->lock, flags);
1296
1297        active = sci_dma_rx_find_active(s);
1298        if (active >= 0)
1299                count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1300
1301        start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1302
1303        if (count)
1304                tty_flip_buffer_push(&port->state->port);
1305
1306        desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1307                                       DMA_DEV_TO_MEM,
1308                                       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1309        if (!desc)
1310                goto fail;
1311
1312        desc->callback = sci_dma_rx_complete;
1313        desc->callback_param = s;
1314        s->cookie_rx[active] = dmaengine_submit(desc);
1315        if (dma_submit_error(s->cookie_rx[active]))
1316                goto fail;
1317
1318        s->active_rx = s->cookie_rx[!active];
1319
1320        dma_async_issue_pending(chan);
1321
1322        spin_unlock_irqrestore(&port->lock, flags);
1323        dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1324                __func__, s->cookie_rx[active], active, s->active_rx);
1325        return;
1326
1327fail:
1328        spin_unlock_irqrestore(&port->lock, flags);
1329        dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1330        /* Switch to PIO */
1331        spin_lock_irqsave(&port->lock, flags);
1332        dmaengine_terminate_async(chan);
1333        sci_dma_rx_chan_invalidate(s);
1334        sci_dma_rx_reenable_irq(s);
1335        spin_unlock_irqrestore(&port->lock, flags);
1336}
1337
1338static void sci_dma_tx_release(struct sci_port *s)
1339{
1340        struct dma_chan *chan = s->chan_tx_saved;
1341
1342        cancel_work_sync(&s->work_tx);
1343        s->chan_tx_saved = s->chan_tx = NULL;
1344        s->cookie_tx = -EINVAL;
1345        dmaengine_terminate_sync(chan);
1346        dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1347                         DMA_TO_DEVICE);
1348        dma_release_channel(chan);
1349}
1350
1351static int sci_dma_rx_submit(struct sci_port *s, bool port_lock_held)
1352{
1353        struct dma_chan *chan = s->chan_rx;
1354        struct uart_port *port = &s->port;
1355        unsigned long flags;
1356        int i;
1357
1358        for (i = 0; i < 2; i++) {
1359                struct scatterlist *sg = &s->sg_rx[i];
1360                struct dma_async_tx_descriptor *desc;
1361
1362                desc = dmaengine_prep_slave_sg(chan,
1363                        sg, 1, DMA_DEV_TO_MEM,
1364                        DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1365                if (!desc)
1366                        goto fail;
1367
1368                desc->callback = sci_dma_rx_complete;
1369                desc->callback_param = s;
1370                s->cookie_rx[i] = dmaengine_submit(desc);
1371                if (dma_submit_error(s->cookie_rx[i]))
1372                        goto fail;
1373
1374        }
1375
1376        s->active_rx = s->cookie_rx[0];
1377
1378        dma_async_issue_pending(chan);
1379        return 0;
1380
1381fail:
1382        /* Switch to PIO */
1383        if (!port_lock_held)
1384                spin_lock_irqsave(&port->lock, flags);
1385        if (i)
1386                dmaengine_terminate_async(chan);
1387        sci_dma_rx_chan_invalidate(s);
1388        sci_start_rx(port);
1389        if (!port_lock_held)
1390                spin_unlock_irqrestore(&port->lock, flags);
1391        return -EAGAIN;
1392}
1393
1394static void sci_dma_tx_work_fn(struct work_struct *work)
1395{
1396        struct sci_port *s = container_of(work, struct sci_port, work_tx);
1397        struct dma_async_tx_descriptor *desc;
1398        struct dma_chan *chan = s->chan_tx;
1399        struct uart_port *port = &s->port;
1400        struct circ_buf *xmit = &port->state->xmit;
1401        unsigned long flags;
1402        dma_addr_t buf;
1403        int head, tail;
1404
1405        /*
1406         * DMA is idle now.
1407         * Port xmit buffer is already mapped, and it is one page... Just adjust
1408         * offsets and lengths. Since it is a circular buffer, we have to
1409         * transmit till the end, and then the rest. Take the port lock to get a
1410         * consistent xmit buffer state.
1411         */
1412        spin_lock_irq(&port->lock);
1413        head = xmit->head;
1414        tail = xmit->tail;
1415        buf = s->tx_dma_addr + (tail & (UART_XMIT_SIZE - 1));
1416        s->tx_dma_len = min_t(unsigned int,
1417                CIRC_CNT(head, tail, UART_XMIT_SIZE),
1418                CIRC_CNT_TO_END(head, tail, UART_XMIT_SIZE));
1419        if (!s->tx_dma_len) {
1420                /* Transmit buffer has been flushed */
1421                spin_unlock_irq(&port->lock);
1422                return;
1423        }
1424
1425        desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1426                                           DMA_MEM_TO_DEV,
1427                                           DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1428        if (!desc) {
1429                spin_unlock_irq(&port->lock);
1430                dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
1431                goto switch_to_pio;
1432        }
1433
1434        dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
1435                                   DMA_TO_DEVICE);
1436
1437        desc->callback = sci_dma_tx_complete;
1438        desc->callback_param = s;
1439        s->cookie_tx = dmaengine_submit(desc);
1440        if (dma_submit_error(s->cookie_tx)) {
1441                spin_unlock_irq(&port->lock);
1442                dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1443                goto switch_to_pio;
1444        }
1445
1446        spin_unlock_irq(&port->lock);
1447        dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
1448                __func__, xmit->buf, tail, head, s->cookie_tx);
1449
1450        dma_async_issue_pending(chan);
1451        return;
1452
1453switch_to_pio:
1454        spin_lock_irqsave(&port->lock, flags);
1455        s->chan_tx = NULL;
1456        sci_start_tx(port);
1457        spin_unlock_irqrestore(&port->lock, flags);
1458        return;
1459}
1460
1461static enum hrtimer_restart sci_dma_rx_timer_fn(struct hrtimer *t)
1462{
1463        struct sci_port *s = container_of(t, struct sci_port, rx_timer);
1464        struct dma_chan *chan = s->chan_rx;
1465        struct uart_port *port = &s->port;
1466        struct dma_tx_state state;
1467        enum dma_status status;
1468        unsigned long flags;
1469        unsigned int read;
1470        int active, count;
1471
1472        dev_dbg(port->dev, "DMA Rx timed out\n");
1473
1474        spin_lock_irqsave(&port->lock, flags);
1475
1476        active = sci_dma_rx_find_active(s);
1477        if (active < 0) {
1478                spin_unlock_irqrestore(&port->lock, flags);
1479                return HRTIMER_NORESTART;
1480        }
1481
1482        status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1483        if (status == DMA_COMPLETE) {
1484                spin_unlock_irqrestore(&port->lock, flags);
1485                dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
1486                        s->active_rx, active);
1487
1488                /* Let packet complete handler take care of the packet */
1489                return HRTIMER_NORESTART;
1490        }
1491
1492        dmaengine_pause(chan);
1493
1494        /*
1495         * sometimes DMA transfer doesn't stop even if it is stopped and
1496         * data keeps on coming until transaction is complete so check
1497         * for DMA_COMPLETE again
1498         * Let packet complete handler take care of the packet
1499         */
1500        status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1501        if (status == DMA_COMPLETE) {
1502                spin_unlock_irqrestore(&port->lock, flags);
1503                dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
1504                return HRTIMER_NORESTART;
1505        }
1506
1507        /* Handle incomplete DMA receive */
1508        dmaengine_terminate_async(s->chan_rx);
1509        read = sg_dma_len(&s->sg_rx[active]) - state.residue;
1510
1511        if (read) {
1512                count = sci_dma_rx_push(s, s->rx_buf[active], read);
1513                if (count)
1514                        tty_flip_buffer_push(&port->state->port);
1515        }
1516
1517        if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1518                sci_dma_rx_submit(s, true);
1519
1520        sci_dma_rx_reenable_irq(s);
1521
1522        spin_unlock_irqrestore(&port->lock, flags);
1523
1524        return HRTIMER_NORESTART;
1525}
1526
1527static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
1528                                             enum dma_transfer_direction dir)
1529{
1530        struct dma_chan *chan;
1531        struct dma_slave_config cfg;
1532        int ret;
1533
1534        chan = dma_request_slave_channel(port->dev,
1535                                         dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1536        if (!chan) {
1537                dev_dbg(port->dev, "dma_request_slave_channel failed\n");
1538                return NULL;
1539        }
1540
1541        memset(&cfg, 0, sizeof(cfg));
1542        cfg.direction = dir;
1543        if (dir == DMA_MEM_TO_DEV) {
1544                cfg.dst_addr = port->mapbase +
1545                        (sci_getreg(port, SCxTDR)->offset << port->regshift);
1546                cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1547        } else {
1548                cfg.src_addr = port->mapbase +
1549                        (sci_getreg(port, SCxRDR)->offset << port->regshift);
1550                cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1551        }
1552
1553        ret = dmaengine_slave_config(chan, &cfg);
1554        if (ret) {
1555                dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
1556                dma_release_channel(chan);
1557                return NULL;
1558        }
1559
1560        return chan;
1561}
1562
1563static void sci_request_dma(struct uart_port *port)
1564{
1565        struct sci_port *s = to_sci_port(port);
1566        struct dma_chan *chan;
1567
1568        dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1569
1570        /*
1571         * DMA on console may interfere with Kernel log messages which use
1572         * plain putchar(). So, simply don't use it with a console.
1573         */
1574        if (uart_console(port))
1575                return;
1576
1577        if (!port->dev->of_node)
1578                return;
1579
1580        s->cookie_tx = -EINVAL;
1581
1582        /*
1583         * Don't request a dma channel if no channel was specified
1584         * in the device tree.
1585         */
1586        if (!of_find_property(port->dev->of_node, "dmas", NULL))
1587                return;
1588
1589        chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
1590        dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1591        if (chan) {
1592                /* UART circular tx buffer is an aligned page. */
1593                s->tx_dma_addr = dma_map_single(chan->device->dev,
1594                                                port->state->xmit.buf,
1595                                                UART_XMIT_SIZE,
1596                                                DMA_TO_DEVICE);
1597                if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1598                        dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1599                        dma_release_channel(chan);
1600                } else {
1601                        dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1602                                __func__, UART_XMIT_SIZE,
1603                                port->state->xmit.buf, &s->tx_dma_addr);
1604
1605                        INIT_WORK(&s->work_tx, sci_dma_tx_work_fn);
1606                        s->chan_tx_saved = s->chan_tx = chan;
1607                }
1608        }
1609
1610        chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);
1611        dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1612        if (chan) {
1613                unsigned int i;
1614                dma_addr_t dma;
1615                void *buf;
1616
1617                s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1618                buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1619                                         &dma, GFP_KERNEL);
1620                if (!buf) {
1621                        dev_warn(port->dev,
1622                                 "Failed to allocate Rx dma buffer, using PIO\n");
1623                        dma_release_channel(chan);
1624                        return;
1625                }
1626
1627                for (i = 0; i < 2; i++) {
1628                        struct scatterlist *sg = &s->sg_rx[i];
1629
1630                        sg_init_table(sg, 1);
1631                        s->rx_buf[i] = buf;
1632                        sg_dma_address(sg) = dma;
1633                        sg_dma_len(sg) = s->buf_len_rx;
1634
1635                        buf += s->buf_len_rx;
1636                        dma += s->buf_len_rx;
1637                }
1638
1639                hrtimer_init(&s->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1640                s->rx_timer.function = sci_dma_rx_timer_fn;
1641
1642                s->chan_rx_saved = s->chan_rx = chan;
1643
1644                if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1645                        sci_dma_rx_submit(s, false);
1646        }
1647}
1648
1649static void sci_free_dma(struct uart_port *port)
1650{
1651        struct sci_port *s = to_sci_port(port);
1652
1653        if (s->chan_tx_saved)
1654                sci_dma_tx_release(s);
1655        if (s->chan_rx_saved)
1656                sci_dma_rx_release(s);
1657}
1658
1659static void sci_flush_buffer(struct uart_port *port)
1660{
1661        struct sci_port *s = to_sci_port(port);
1662
1663        /*
1664         * In uart_flush_buffer(), the xmit circular buffer has just been
1665         * cleared, so we have to reset tx_dma_len accordingly, and stop any
1666         * pending transfers
1667         */
1668        s->tx_dma_len = 0;
1669        if (s->chan_tx) {
1670                dmaengine_terminate_async(s->chan_tx);
1671                s->cookie_tx = -EINVAL;
1672        }
1673}
1674#else /* !CONFIG_SERIAL_SH_SCI_DMA */
1675static inline void sci_request_dma(struct uart_port *port)
1676{
1677}
1678
1679static inline void sci_free_dma(struct uart_port *port)
1680{
1681}
1682
1683#define sci_flush_buffer        NULL
1684#endif /* !CONFIG_SERIAL_SH_SCI_DMA */
1685
1686static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1687{
1688        struct uart_port *port = ptr;
1689        struct sci_port *s = to_sci_port(port);
1690
1691#ifdef CONFIG_SERIAL_SH_SCI_DMA
1692        if (s->chan_rx) {
1693                u16 scr = serial_port_in(port, SCSCR);
1694                u16 ssr = serial_port_in(port, SCxSR);
1695
1696                /* Disable future Rx interrupts */
1697                if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1698                        disable_irq_nosync(irq);
1699                        scr |= SCSCR_RDRQE;
1700                } else {
1701                        if (sci_dma_rx_submit(s, false) < 0)
1702                                goto handle_pio;
1703
1704                        scr &= ~SCSCR_RIE;
1705                }
1706                serial_port_out(port, SCSCR, scr);
1707                /* Clear current interrupt */
1708                serial_port_out(port, SCxSR,
1709                                ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1710                dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u us\n",
1711                        jiffies, s->rx_timeout);
1712                start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1713
1714                return IRQ_HANDLED;
1715        }
1716
1717handle_pio:
1718#endif
1719
1720        if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
1721                if (!scif_rtrg_enabled(port))
1722                        scif_set_rtrg(port, s->rx_trigger);
1723
1724                mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
1725                          s->rx_frame * HZ * s->rx_fifo_timeout, 1000000));
1726        }
1727
1728        /* I think sci_receive_chars has to be called irrespective
1729         * of whether the I_IXOFF is set, otherwise, how is the interrupt
1730         * to be disabled?
1731         */
1732        sci_receive_chars(port);
1733
1734        return IRQ_HANDLED;
1735}
1736
1737static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1738{
1739        struct uart_port *port = ptr;
1740        unsigned long flags;
1741
1742        spin_lock_irqsave(&port->lock, flags);
1743        sci_transmit_chars(port);
1744        spin_unlock_irqrestore(&port->lock, flags);
1745
1746        return IRQ_HANDLED;
1747}
1748
1749static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1750{
1751        struct uart_port *port = ptr;
1752
1753        /* Handle BREAKs */
1754        sci_handle_breaks(port);
1755        sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1756
1757        return IRQ_HANDLED;
1758}
1759
1760static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1761{
1762        struct uart_port *port = ptr;
1763        struct sci_port *s = to_sci_port(port);
1764
1765        if (s->irqs[SCIx_ERI_IRQ] == s->irqs[SCIx_BRI_IRQ]) {
1766                /* Break and Error interrupts are muxed */
1767                unsigned short ssr_status = serial_port_in(port, SCxSR);
1768
1769                /* Break Interrupt */
1770                if (ssr_status & SCxSR_BRK(port))
1771                        sci_br_interrupt(irq, ptr);
1772
1773                /* Break only? */
1774                if (!(ssr_status & SCxSR_ERRORS(port)))
1775                        return IRQ_HANDLED;
1776        }
1777
1778        /* Handle errors */
1779        if (port->type == PORT_SCI) {
1780                if (sci_handle_errors(port)) {
1781                        /* discard character in rx buffer */
1782                        serial_port_in(port, SCxSR);
1783                        sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1784                }
1785        } else {
1786                sci_handle_fifo_overrun(port);
1787                if (!s->chan_rx)
1788                        sci_receive_chars(port);
1789        }
1790
1791        sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1792
1793        /* Kick the transmission */
1794        if (!s->chan_tx)
1795                sci_tx_interrupt(irq, ptr);
1796
1797        return IRQ_HANDLED;
1798}
1799
1800static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1801{
1802        unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1803        struct uart_port *port = ptr;
1804        struct sci_port *s = to_sci_port(port);
1805        irqreturn_t ret = IRQ_NONE;
1806
1807        ssr_status = serial_port_in(port, SCxSR);
1808        scr_status = serial_port_in(port, SCSCR);
1809        if (s->params->overrun_reg == SCxSR)
1810                orer_status = ssr_status;
1811        else if (sci_getreg(port, s->params->overrun_reg)->size)
1812                orer_status = serial_port_in(port, s->params->overrun_reg);
1813
1814        err_enabled = scr_status & port_rx_irq_mask(port);
1815
1816        /* Tx Interrupt */
1817        if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1818            !s->chan_tx)
1819                ret = sci_tx_interrupt(irq, ptr);
1820
1821        /*
1822         * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1823         * DR flags
1824         */
1825        if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1826            (scr_status & SCSCR_RIE))
1827                ret = sci_rx_interrupt(irq, ptr);
1828
1829        /* Error Interrupt */
1830        if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1831                ret = sci_er_interrupt(irq, ptr);
1832
1833        /* Break Interrupt */
1834        if ((ssr_status & SCxSR_BRK(port)) && err_enabled)
1835                ret = sci_br_interrupt(irq, ptr);
1836
1837        /* Overrun Interrupt */
1838        if (orer_status & s->params->overrun_mask) {
1839                sci_handle_fifo_overrun(port);
1840                ret = IRQ_HANDLED;
1841        }
1842
1843        return ret;
1844}
1845
1846static const struct sci_irq_desc {
1847        const char      *desc;
1848        irq_handler_t   handler;
1849} sci_irq_desc[] = {
1850        /*
1851         * Split out handlers, the default case.
1852         */
1853        [SCIx_ERI_IRQ] = {
1854                .desc = "rx err",
1855                .handler = sci_er_interrupt,
1856        },
1857
1858        [SCIx_RXI_IRQ] = {
1859                .desc = "rx full",
1860                .handler = sci_rx_interrupt,
1861        },
1862
1863        [SCIx_TXI_IRQ] = {
1864                .desc = "tx empty",
1865                .handler = sci_tx_interrupt,
1866        },
1867
1868        [SCIx_BRI_IRQ] = {
1869                .desc = "break",
1870                .handler = sci_br_interrupt,
1871        },
1872
1873        [SCIx_DRI_IRQ] = {
1874                .desc = "rx ready",
1875                .handler = sci_rx_interrupt,
1876        },
1877
1878        [SCIx_TEI_IRQ] = {
1879                .desc = "tx end",
1880                .handler = sci_tx_interrupt,
1881        },
1882
1883        /*
1884         * Special muxed handler.
1885         */
1886        [SCIx_MUX_IRQ] = {
1887                .desc = "mux",
1888                .handler = sci_mpxed_interrupt,
1889        },
1890};
1891
1892static int sci_request_irq(struct sci_port *port)
1893{
1894        struct uart_port *up = &port->port;
1895        int i, j, w, ret = 0;
1896
1897        for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1898                const struct sci_irq_desc *desc;
1899                int irq;
1900
1901                /* Check if already registered (muxed) */
1902                for (w = 0; w < i; w++)
1903                        if (port->irqs[w] == port->irqs[i])
1904                                w = i + 1;
1905                if (w > i)
1906                        continue;
1907
1908                if (SCIx_IRQ_IS_MUXED(port)) {
1909                        i = SCIx_MUX_IRQ;
1910                        irq = up->irq;
1911                } else {
1912                        irq = port->irqs[i];
1913
1914                        /*
1915                         * Certain port types won't support all of the
1916                         * available interrupt sources.
1917                         */
1918                        if (unlikely(irq < 0))
1919                                continue;
1920                }
1921
1922                desc = sci_irq_desc + i;
1923                port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1924                                            dev_name(up->dev), desc->desc);
1925                if (!port->irqstr[j]) {
1926                        ret = -ENOMEM;
1927                        goto out_nomem;
1928                }
1929
1930                ret = request_irq(irq, desc->handler, up->irqflags,
1931                                  port->irqstr[j], port);
1932                if (unlikely(ret)) {
1933                        dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1934                        goto out_noirq;
1935                }
1936        }
1937
1938        return 0;
1939
1940out_noirq:
1941        while (--i >= 0)
1942                free_irq(port->irqs[i], port);
1943
1944out_nomem:
1945        while (--j >= 0)
1946                kfree(port->irqstr[j]);
1947
1948        return ret;
1949}
1950
1951static void sci_free_irq(struct sci_port *port)
1952{
1953        int i, j;
1954
1955        /*
1956         * Intentionally in reverse order so we iterate over the muxed
1957         * IRQ first.
1958         */
1959        for (i = 0; i < SCIx_NR_IRQS; i++) {
1960                int irq = port->irqs[i];
1961
1962                /*
1963                 * Certain port types won't support all of the available
1964                 * interrupt sources.
1965                 */
1966                if (unlikely(irq < 0))
1967                        continue;
1968
1969                /* Check if already freed (irq was muxed) */
1970                for (j = 0; j < i; j++)
1971                        if (port->irqs[j] == irq)
1972                                j = i + 1;
1973                if (j > i)
1974                        continue;
1975
1976                free_irq(port->irqs[i], port);
1977                kfree(port->irqstr[i]);
1978
1979                if (SCIx_IRQ_IS_MUXED(port)) {
1980                        /* If there's only one IRQ, we're done. */
1981                        return;
1982                }
1983        }
1984}
1985
1986static unsigned int sci_tx_empty(struct uart_port *port)
1987{
1988        unsigned short status = serial_port_in(port, SCxSR);
1989        unsigned short in_tx_fifo = sci_txfill(port);
1990
1991        return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
1992}
1993
1994static void sci_set_rts(struct uart_port *port, bool state)
1995{
1996        if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1997                u16 data = serial_port_in(port, SCPDR);
1998
1999                /* Active low */
2000                if (state)
2001                        data &= ~SCPDR_RTSD;
2002                else
2003                        data |= SCPDR_RTSD;
2004                serial_port_out(port, SCPDR, data);
2005
2006                /* RTS# is output */
2007                serial_port_out(port, SCPCR,
2008                                serial_port_in(port, SCPCR) | SCPCR_RTSC);
2009        } else if (sci_getreg(port, SCSPTR)->size) {
2010                u16 ctrl = serial_port_in(port, SCSPTR);
2011
2012                /* Active low */
2013                if (state)
2014                        ctrl &= ~SCSPTR_RTSDT;
2015                else
2016                        ctrl |= SCSPTR_RTSDT;
2017                serial_port_out(port, SCSPTR, ctrl);
2018        }
2019}
2020
2021static bool sci_get_cts(struct uart_port *port)
2022{
2023        if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2024                /* Active low */
2025                return !(serial_port_in(port, SCPDR) & SCPDR_CTSD);
2026        } else if (sci_getreg(port, SCSPTR)->size) {
2027                /* Active low */
2028                return !(serial_port_in(port, SCSPTR) & SCSPTR_CTSDT);
2029        }
2030
2031        return true;
2032}
2033
2034/*
2035 * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
2036 * CTS/RTS is supported in hardware by at least one port and controlled
2037 * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
2038 * handled via the ->init_pins() op, which is a bit of a one-way street,
2039 * lacking any ability to defer pin control -- this will later be
2040 * converted over to the GPIO framework).
2041 *
2042 * Other modes (such as loopback) are supported generically on certain
2043 * port types, but not others. For these it's sufficient to test for the
2044 * existence of the support register and simply ignore the port type.
2045 */
2046static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
2047{
2048        struct sci_port *s = to_sci_port(port);
2049
2050        if (mctrl & TIOCM_LOOP) {
2051                const struct plat_sci_reg *reg;
2052
2053                /*
2054                 * Standard loopback mode for SCFCR ports.
2055                 */
2056                reg = sci_getreg(port, SCFCR);
2057                if (reg->size)
2058                        serial_port_out(port, SCFCR,
2059                                        serial_port_in(port, SCFCR) |
2060                                        SCFCR_LOOP);
2061        }
2062
2063        mctrl_gpio_set(s->gpios, mctrl);
2064
2065        if (!s->has_rtscts)
2066                return;
2067
2068        if (!(mctrl & TIOCM_RTS)) {
2069                /* Disable Auto RTS */
2070                serial_port_out(port, SCFCR,
2071                                serial_port_in(port, SCFCR) & ~SCFCR_MCE);
2072
2073                /* Clear RTS */
2074                sci_set_rts(port, 0);
2075        } else if (s->autorts) {
2076                if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2077                        /* Enable RTS# pin function */
2078                        serial_port_out(port, SCPCR,
2079                                serial_port_in(port, SCPCR) & ~SCPCR_RTSC);
2080                }
2081
2082                /* Enable Auto RTS */
2083                serial_port_out(port, SCFCR,
2084                                serial_port_in(port, SCFCR) | SCFCR_MCE);
2085        } else {
2086                /* Set RTS */
2087                sci_set_rts(port, 1);
2088        }
2089}
2090
2091static unsigned int sci_get_mctrl(struct uart_port *port)
2092{
2093        struct sci_port *s = to_sci_port(port);
2094        struct mctrl_gpios *gpios = s->gpios;
2095        unsigned int mctrl = 0;
2096
2097        mctrl_gpio_get(gpios, &mctrl);
2098
2099        /*
2100         * CTS/RTS is handled in hardware when supported, while nothing
2101         * else is wired up.
2102         */
2103        if (s->autorts) {
2104                if (sci_get_cts(port))
2105                        mctrl |= TIOCM_CTS;
2106        } else if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS)) {
2107                mctrl |= TIOCM_CTS;
2108        }
2109        if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR))
2110                mctrl |= TIOCM_DSR;
2111        if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD))
2112                mctrl |= TIOCM_CAR;
2113
2114        return mctrl;
2115}
2116
2117static void sci_enable_ms(struct uart_port *port)
2118{
2119        mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
2120}
2121
2122static void sci_break_ctl(struct uart_port *port, int break_state)
2123{
2124        unsigned short scscr, scsptr;
2125        unsigned long flags;
2126
2127        /* check wheter the port has SCSPTR */
2128        if (!sci_getreg(port, SCSPTR)->size) {
2129                /*
2130                 * Not supported by hardware. Most parts couple break and rx
2131                 * interrupts together, with break detection always enabled.
2132                 */
2133                return;
2134        }
2135
2136        spin_lock_irqsave(&port->lock, flags);
2137        scsptr = serial_port_in(port, SCSPTR);
2138        scscr = serial_port_in(port, SCSCR);
2139
2140        if (break_state == -1) {
2141                scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
2142                scscr &= ~SCSCR_TE;
2143        } else {
2144                scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
2145                scscr |= SCSCR_TE;
2146        }
2147
2148        serial_port_out(port, SCSPTR, scsptr);
2149        serial_port_out(port, SCSCR, scscr);
2150        spin_unlock_irqrestore(&port->lock, flags);
2151}
2152
2153static int sci_startup(struct uart_port *port)
2154{
2155        struct sci_port *s = to_sci_port(port);
2156        int ret;
2157
2158        dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2159
2160        sci_request_dma(port);
2161
2162        ret = sci_request_irq(s);
2163        if (unlikely(ret < 0)) {
2164                sci_free_dma(port);
2165                return ret;
2166        }
2167
2168        return 0;
2169}
2170
2171static void sci_shutdown(struct uart_port *port)
2172{
2173        struct sci_port *s = to_sci_port(port);
2174        unsigned long flags;
2175        u16 scr;
2176
2177        dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2178
2179        s->autorts = false;
2180        mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
2181
2182        spin_lock_irqsave(&port->lock, flags);
2183        sci_stop_rx(port);
2184        sci_stop_tx(port);
2185        /*
2186         * Stop RX and TX, disable related interrupts, keep clock source
2187         * and HSCIF TOT bits
2188         */
2189        scr = serial_port_in(port, SCSCR);
2190        serial_port_out(port, SCSCR, scr &
2191                        (SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
2192        spin_unlock_irqrestore(&port->lock, flags);
2193
2194#ifdef CONFIG_SERIAL_SH_SCI_DMA
2195        if (s->chan_rx_saved) {
2196                dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
2197                        port->line);
2198                hrtimer_cancel(&s->rx_timer);
2199        }
2200#endif
2201
2202        if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0)
2203                del_timer_sync(&s->rx_fifo_timer);
2204        sci_free_irq(s);
2205        sci_free_dma(port);
2206}
2207
2208static int sci_sck_calc(struct sci_port *s, unsigned int bps,
2209                        unsigned int *srr)
2210{
2211        unsigned long freq = s->clk_rates[SCI_SCK];
2212        int err, min_err = INT_MAX;
2213        unsigned int sr;
2214
2215        if (s->port.type != PORT_HSCIF)
2216                freq *= 2;
2217
2218        for_each_sr(sr, s) {
2219                err = DIV_ROUND_CLOSEST(freq, sr) - bps;
2220                if (abs(err) >= abs(min_err))
2221                        continue;
2222
2223                min_err = err;
2224                *srr = sr - 1;
2225
2226                if (!err)
2227                        break;
2228        }
2229
2230        dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
2231                *srr + 1);
2232        return min_err;
2233}
2234
2235static int sci_brg_calc(struct sci_port *s, unsigned int bps,
2236                        unsigned long freq, unsigned int *dlr,
2237                        unsigned int *srr)
2238{
2239        int err, min_err = INT_MAX;
2240        unsigned int sr, dl;
2241
2242        if (s->port.type != PORT_HSCIF)
2243                freq *= 2;
2244
2245        for_each_sr(sr, s) {
2246                dl = DIV_ROUND_CLOSEST(freq, sr * bps);
2247                dl = clamp(dl, 1U, 65535U);
2248
2249                err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
2250                if (abs(err) >= abs(min_err))
2251                        continue;
2252
2253                min_err = err;
2254                *dlr = dl;
2255                *srr = sr - 1;
2256
2257                if (!err)
2258                        break;
2259        }
2260
2261        dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
2262                min_err, *dlr, *srr + 1);
2263        return min_err;
2264}
2265
2266/* calculate sample rate, BRR, and clock select */
2267static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
2268                          unsigned int *brr, unsigned int *srr,
2269                          unsigned int *cks)
2270{
2271        unsigned long freq = s->clk_rates[SCI_FCK];
2272        unsigned int sr, br, prediv, scrate, c;
2273        int err, min_err = INT_MAX;
2274
2275        if (s->port.type != PORT_HSCIF)
2276                freq *= 2;
2277
2278        /*
2279         * Find the combination of sample rate and clock select with the
2280         * smallest deviation from the desired baud rate.
2281         * Prefer high sample rates to maximise the receive margin.
2282         *
2283         * M: Receive margin (%)
2284         * N: Ratio of bit rate to clock (N = sampling rate)
2285         * D: Clock duty (D = 0 to 1.0)
2286         * L: Frame length (L = 9 to 12)
2287         * F: Absolute value of clock frequency deviation
2288         *
2289         *  M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2290         *      (|D - 0.5| / N * (1 + F))|
2291         *  NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2292         */
2293        for_each_sr(sr, s) {
2294                for (c = 0; c <= 3; c++) {
2295                        /* integerized formulas from HSCIF documentation */
2296                        prediv = sr * (1 << (2 * c + 1));
2297
2298                        /*
2299                         * We need to calculate:
2300                         *
2301                         *     br = freq / (prediv * bps) clamped to [1..256]
2302                         *     err = freq / (br * prediv) - bps
2303                         *
2304                         * Watch out for overflow when calculating the desired
2305                         * sampling clock rate!
2306                         */
2307                        if (bps > UINT_MAX / prediv)
2308                                break;
2309
2310                        scrate = prediv * bps;
2311                        br = DIV_ROUND_CLOSEST(freq, scrate);
2312                        br = clamp(br, 1U, 256U);
2313
2314                        err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2315                        if (abs(err) >= abs(min_err))
2316                                continue;
2317
2318                        min_err = err;
2319                        *brr = br - 1;
2320                        *srr = sr - 1;
2321                        *cks = c;
2322
2323                        if (!err)
2324                                goto found;
2325                }
2326        }
2327
2328found:
2329        dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2330                min_err, *brr, *srr + 1, *cks);
2331        return min_err;
2332}
2333
2334static void sci_reset(struct uart_port *port)
2335{
2336        const struct plat_sci_reg *reg;
2337        unsigned int status;
2338        struct sci_port *s = to_sci_port(port);
2339
2340        serial_port_out(port, SCSCR, s->hscif_tot);     /* TE=0, RE=0, CKE1=0 */
2341
2342        reg = sci_getreg(port, SCFCR);
2343        if (reg->size)
2344                serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2345
2346        sci_clear_SCxSR(port,
2347                        SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
2348                        SCxSR_BREAK_CLEAR(port));
2349        if (sci_getreg(port, SCLSR)->size) {
2350                status = serial_port_in(port, SCLSR);
2351                status &= ~(SCLSR_TO | SCLSR_ORER);
2352                serial_port_out(port, SCLSR, status);
2353        }
2354
2355        if (s->rx_trigger > 1) {
2356                if (s->rx_fifo_timeout) {
2357                        scif_set_rtrg(port, 1);
2358                        timer_setup(&s->rx_fifo_timer, rx_fifo_timer_fn, 0);
2359                } else {
2360                        if (port->type == PORT_SCIFA ||
2361                            port->type == PORT_SCIFB)
2362                                scif_set_rtrg(port, 1);
2363                        else
2364                                scif_set_rtrg(port, s->rx_trigger);
2365                }
2366        }
2367}
2368
2369static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2370                            struct ktermios *old)
2371{
2372        unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
2373        unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
2374        unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
2375        struct sci_port *s = to_sci_port(port);
2376        const struct plat_sci_reg *reg;
2377        int min_err = INT_MAX, err;
2378        unsigned long max_freq = 0;
2379        int best_clk = -1;
2380        unsigned long flags;
2381
2382        if ((termios->c_cflag & CSIZE) == CS7)
2383                smr_val |= SCSMR_CHR;
2384        if (termios->c_cflag & PARENB)
2385                smr_val |= SCSMR_PE;
2386        if (termios->c_cflag & PARODD)
2387                smr_val |= SCSMR_PE | SCSMR_ODD;
2388        if (termios->c_cflag & CSTOPB)
2389                smr_val |= SCSMR_STOP;
2390
2391        /*
2392         * earlyprintk comes here early on with port->uartclk set to zero.
2393         * the clock framework is not up and running at this point so here
2394         * we assume that 115200 is the maximum baud rate. please note that
2395         * the baud rate is not programmed during earlyprintk - it is assumed
2396         * that the previous boot loader has enabled required clocks and
2397         * setup the baud rate generator hardware for us already.
2398         */
2399        if (!port->uartclk) {
2400                baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2401                goto done;
2402        }
2403
2404        for (i = 0; i < SCI_NUM_CLKS; i++)
2405                max_freq = max(max_freq, s->clk_rates[i]);
2406
2407        baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
2408        if (!baud)
2409                goto done;
2410
2411        /*
2412         * There can be multiple sources for the sampling clock.  Find the one
2413         * that gives us the smallest deviation from the desired baud rate.
2414         */
2415
2416        /* Optional Undivided External Clock */
2417        if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
2418            port->type != PORT_SCIFB) {
2419                err = sci_sck_calc(s, baud, &srr1);
2420                if (abs(err) < abs(min_err)) {
2421                        best_clk = SCI_SCK;
2422                        scr_val = SCSCR_CKE1;
2423                        sccks = SCCKS_CKS;
2424                        min_err = err;
2425                        srr = srr1;
2426                        if (!err)
2427                                goto done;
2428                }
2429        }
2430
2431        /* Optional BRG Frequency Divided External Clock */
2432        if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
2433                err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
2434                                   &srr1);
2435                if (abs(err) < abs(min_err)) {
2436                        best_clk = SCI_SCIF_CLK;
2437                        scr_val = SCSCR_CKE1;
2438                        sccks = 0;
2439                        min_err = err;
2440                        dl = dl1;
2441                        srr = srr1;
2442                        if (!err)
2443                                goto done;
2444                }
2445        }
2446
2447        /* Optional BRG Frequency Divided Internal Clock */
2448        if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
2449                err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
2450                                   &srr1);
2451                if (abs(err) < abs(min_err)) {
2452                        best_clk = SCI_BRG_INT;
2453                        scr_val = SCSCR_CKE1;
2454                        sccks = SCCKS_XIN;
2455                        min_err = err;
2456                        dl = dl1;
2457                        srr = srr1;
2458                        if (!min_err)
2459                                goto done;
2460                }
2461        }
2462
2463        /* Divided Functional Clock using standard Bit Rate Register */
2464        err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
2465        if (abs(err) < abs(min_err)) {
2466                best_clk = SCI_FCK;
2467                scr_val = 0;
2468                min_err = err;
2469                brr = brr1;
2470                srr = srr1;
2471                cks = cks1;
2472        }
2473
2474done:
2475        if (best_clk >= 0)
2476                dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2477                        s->clks[best_clk], baud, min_err);
2478
2479        sci_port_enable(s);
2480
2481        /*
2482         * Program the optional External Baud Rate Generator (BRG) first.
2483         * It controls the mux to select (H)SCK or frequency divided clock.
2484         */
2485        if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2486                serial_port_out(port, SCDL, dl);
2487                serial_port_out(port, SCCKS, sccks);
2488        }
2489
2490        spin_lock_irqsave(&port->lock, flags);
2491
2492        sci_reset(port);
2493
2494        uart_update_timeout(port, termios->c_cflag, baud);
2495
2496        /* byte size and parity */
2497        switch (termios->c_cflag & CSIZE) {
2498        case CS5:
2499                bits = 7;
2500                break;
2501        case CS6:
2502                bits = 8;
2503                break;
2504        case CS7:
2505                bits = 9;
2506                break;
2507        default:
2508                bits = 10;
2509                break;
2510        }
2511
2512        if (termios->c_cflag & CSTOPB)
2513                bits++;
2514        if (termios->c_cflag & PARENB)
2515                bits++;
2516
2517        if (best_clk >= 0) {
2518                if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
2519                        switch (srr + 1) {
2520                        case 5:  smr_val |= SCSMR_SRC_5;  break;
2521                        case 7:  smr_val |= SCSMR_SRC_7;  break;
2522                        case 11: smr_val |= SCSMR_SRC_11; break;
2523                        case 13: smr_val |= SCSMR_SRC_13; break;
2524                        case 16: smr_val |= SCSMR_SRC_16; break;
2525                        case 17: smr_val |= SCSMR_SRC_17; break;
2526                        case 19: smr_val |= SCSMR_SRC_19; break;
2527                        case 27: smr_val |= SCSMR_SRC_27; break;
2528                        }
2529                smr_val |= cks;
2530                serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2531                serial_port_out(port, SCSMR, smr_val);
2532                serial_port_out(port, SCBRR, brr);
2533                if (sci_getreg(port, HSSRR)->size) {
2534                        unsigned int hssrr = srr | HSCIF_SRE;
2535                        /* Calculate deviation from intended rate at the
2536                         * center of the last stop bit in sampling clocks.
2537                         */
2538                        int last_stop = bits * 2 - 1;
2539                        int deviation = DIV_ROUND_CLOSEST(min_err * last_stop *
2540                                                          (int)(srr + 1),
2541                                                          2 * (int)baud);
2542
2543                        if (abs(deviation) >= 2) {
2544                                /* At least two sampling clocks off at the
2545                                 * last stop bit; we can increase the error
2546                                 * margin by shifting the sampling point.
2547                                 */
2548                                int shift = clamp(deviation / 2, -8, 7);
2549
2550                                hssrr |= (shift << HSCIF_SRHP_SHIFT) &
2551                                         HSCIF_SRHP_MASK;
2552                                hssrr |= HSCIF_SRDE;
2553                        }
2554                        serial_port_out(port, HSSRR, hssrr);
2555                }
2556
2557                /* Wait one bit interval */
2558                udelay((1000000 + (baud - 1)) / baud);
2559        } else {
2560                /* Don't touch the bit rate configuration */
2561                scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
2562                smr_val |= serial_port_in(port, SCSMR) &
2563                           (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
2564                serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2565                serial_port_out(port, SCSMR, smr_val);
2566        }
2567
2568        sci_init_pins(port, termios->c_cflag);
2569
2570        port->status &= ~UPSTAT_AUTOCTS;
2571        s->autorts = false;
2572        reg = sci_getreg(port, SCFCR);
2573        if (reg->size) {
2574                unsigned short ctrl = serial_port_in(port, SCFCR);
2575
2576                if ((port->flags & UPF_HARD_FLOW) &&
2577                    (termios->c_cflag & CRTSCTS)) {
2578                        /* There is no CTS interrupt to restart the hardware */
2579                        port->status |= UPSTAT_AUTOCTS;
2580                        /* MCE is enabled when RTS is raised */
2581                        s->autorts = true;
2582                }
2583
2584                /*
2585                 * As we've done a sci_reset() above, ensure we don't
2586                 * interfere with the FIFOs while toggling MCE. As the
2587                 * reset values could still be set, simply mask them out.
2588                 */
2589                ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2590
2591                serial_port_out(port, SCFCR, ctrl);
2592        }
2593        if (port->flags & UPF_HARD_FLOW) {
2594                /* Refresh (Auto) RTS */
2595                sci_set_mctrl(port, port->mctrl);
2596        }
2597
2598        scr_val |= SCSCR_RE | SCSCR_TE |
2599                   (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0));
2600        serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2601        if ((srr + 1 == 5) &&
2602            (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
2603                /*
2604                 * In asynchronous mode, when the sampling rate is 1/5, first
2605                 * received data may become invalid on some SCIFA and SCIFB.
2606                 * To avoid this problem wait more than 1 serial data time (1
2607                 * bit time x serial data number) after setting SCSCR.RE = 1.
2608                 */
2609                udelay(DIV_ROUND_UP(10 * 1000000, baud));
2610        }
2611
2612        /*
2613         * Calculate delay for 2 DMA buffers (4 FIFO).
2614         * See serial_core.c::uart_update_timeout().
2615         * With 10 bits (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above
2616         * function calculates 1 jiffie for the data plus 5 jiffies for the
2617         * "slop(e)." Then below we calculate 5 jiffies (20ms) for 2 DMA
2618         * buffers (4 FIFO sizes), but when performing a faster transfer, the
2619         * value obtained by this formula is too small. Therefore, if the value
2620         * is smaller than 20ms, use 20ms as the timeout value for DMA.
2621         */
2622        s->rx_frame = (10000 * bits) / (baud / 100);
2623#ifdef CONFIG_SERIAL_SH_SCI_DMA
2624        s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame;
2625        if (s->rx_timeout < 20)
2626                s->rx_timeout = 20;
2627#endif
2628
2629        if ((termios->c_cflag & CREAD) != 0)
2630                sci_start_rx(port);
2631
2632        spin_unlock_irqrestore(&port->lock, flags);
2633
2634        sci_port_disable(s);
2635
2636        if (UART_ENABLE_MS(port, termios->c_cflag))
2637                sci_enable_ms(port);
2638}
2639
2640static void sci_pm(struct uart_port *port, unsigned int state,
2641                   unsigned int oldstate)
2642{
2643        struct sci_port *sci_port = to_sci_port(port);
2644
2645        switch (state) {
2646        case UART_PM_STATE_OFF:
2647                sci_port_disable(sci_port);
2648                break;
2649        default:
2650                sci_port_enable(sci_port);
2651                break;
2652        }
2653}
2654
2655static const char *sci_type(struct uart_port *port)
2656{
2657        switch (port->type) {
2658        case PORT_IRDA:
2659                return "irda";
2660        case PORT_SCI:
2661                return "sci";
2662        case PORT_SCIF:
2663                return "scif";
2664        case PORT_SCIFA:
2665                return "scifa";
2666        case PORT_SCIFB:
2667                return "scifb";
2668        case PORT_HSCIF:
2669                return "hscif";
2670        }
2671
2672        return NULL;
2673}
2674
2675static int sci_remap_port(struct uart_port *port)
2676{
2677        struct sci_port *sport = to_sci_port(port);
2678
2679        /*
2680         * Nothing to do if there's already an established membase.
2681         */
2682        if (port->membase)
2683                return 0;
2684
2685        if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2686                port->membase = ioremap(port->mapbase, sport->reg_size);
2687                if (unlikely(!port->membase)) {
2688                        dev_err(port->dev, "can't remap port#%d\n", port->line);
2689                        return -ENXIO;
2690                }
2691        } else {
2692                /*
2693                 * For the simple (and majority of) cases where we don't
2694                 * need to do any remapping, just cast the cookie
2695                 * directly.
2696                 */
2697                port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2698        }
2699
2700        return 0;
2701}
2702
2703static void sci_release_port(struct uart_port *port)
2704{
2705        struct sci_port *sport = to_sci_port(port);
2706
2707        if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2708                iounmap(port->membase);
2709                port->membase = NULL;
2710        }
2711
2712        release_mem_region(port->mapbase, sport->reg_size);
2713}
2714
2715static int sci_request_port(struct uart_port *port)
2716{
2717        struct resource *res;
2718        struct sci_port *sport = to_sci_port(port);
2719        int ret;
2720
2721        res = request_mem_region(port->mapbase, sport->reg_size,
2722                                 dev_name(port->dev));
2723        if (unlikely(res == NULL)) {
2724                dev_err(port->dev, "request_mem_region failed.");
2725                return -EBUSY;
2726        }
2727
2728        ret = sci_remap_port(port);
2729        if (unlikely(ret != 0)) {
2730                release_resource(res);
2731                return ret;
2732        }
2733
2734        return 0;
2735}
2736
2737static void sci_config_port(struct uart_port *port, int flags)
2738{
2739        if (flags & UART_CONFIG_TYPE) {
2740                struct sci_port *sport = to_sci_port(port);
2741
2742                port->type = sport->cfg->type;
2743                sci_request_port(port);
2744        }
2745}
2746
2747static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2748{
2749        if (ser->baud_base < 2400)
2750                /* No paper tape reader for Mitch.. */
2751                return -EINVAL;
2752
2753        return 0;
2754}
2755
2756static const struct uart_ops sci_uart_ops = {
2757        .tx_empty       = sci_tx_empty,
2758        .set_mctrl      = sci_set_mctrl,
2759        .get_mctrl      = sci_get_mctrl,
2760        .start_tx       = sci_start_tx,
2761        .stop_tx        = sci_stop_tx,
2762        .stop_rx        = sci_stop_rx,
2763        .enable_ms      = sci_enable_ms,
2764        .break_ctl      = sci_break_ctl,
2765        .startup        = sci_startup,
2766        .shutdown       = sci_shutdown,
2767        .flush_buffer   = sci_flush_buffer,
2768        .set_termios    = sci_set_termios,
2769        .pm             = sci_pm,
2770        .type           = sci_type,
2771        .release_port   = sci_release_port,
2772        .request_port   = sci_request_port,
2773        .config_port    = sci_config_port,
2774        .verify_port    = sci_verify_port,
2775#ifdef CONFIG_CONSOLE_POLL
2776        .poll_get_char  = sci_poll_get_char,
2777        .poll_put_char  = sci_poll_put_char,
2778#endif
2779};
2780
2781static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2782{
2783        const char *clk_names[] = {
2784                [SCI_FCK] = "fck",
2785                [SCI_SCK] = "sck",
2786                [SCI_BRG_INT] = "brg_int",
2787                [SCI_SCIF_CLK] = "scif_clk",
2788        };
2789        struct clk *clk;
2790        unsigned int i;
2791
2792        if (sci_port->cfg->type == PORT_HSCIF)
2793                clk_names[SCI_SCK] = "hsck";
2794
2795        for (i = 0; i < SCI_NUM_CLKS; i++) {
2796                clk = devm_clk_get(dev, clk_names[i]);
2797                if (PTR_ERR(clk) == -EPROBE_DEFER)
2798                        return -EPROBE_DEFER;
2799
2800                if (IS_ERR(clk) && i == SCI_FCK) {
2801                        /*
2802                         * "fck" used to be called "sci_ick", and we need to
2803                         * maintain DT backward compatibility.
2804                         */
2805                        clk = devm_clk_get(dev, "sci_ick");
2806                        if (PTR_ERR(clk) == -EPROBE_DEFER)
2807                                return -EPROBE_DEFER;
2808
2809                        if (!IS_ERR(clk))
2810                                goto found;
2811
2812                        /*
2813                         * Not all SH platforms declare a clock lookup entry
2814                         * for SCI devices, in which case we need to get the
2815                         * global "peripheral_clk" clock.
2816                         */
2817                        clk = devm_clk_get(dev, "peripheral_clk");
2818                        if (!IS_ERR(clk))
2819                                goto found;
2820
2821                        dev_err(dev, "failed to get %s (%ld)\n", clk_names[i],
2822                                PTR_ERR(clk));
2823                        return PTR_ERR(clk);
2824                }
2825
2826found:
2827                if (IS_ERR(clk))
2828                        dev_dbg(dev, "failed to get %s (%ld)\n", clk_names[i],
2829                                PTR_ERR(clk));
2830                else
2831                        dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i],
2832                                clk, clk_get_rate(clk));
2833                sci_port->clks[i] = IS_ERR(clk) ? NULL : clk;
2834        }
2835        return 0;
2836}
2837
2838static const struct sci_port_params *
2839sci_probe_regmap(const struct plat_sci_port *cfg)
2840{
2841        unsigned int regtype;
2842
2843        if (cfg->regtype != SCIx_PROBE_REGTYPE)
2844                return &sci_port_params[cfg->regtype];
2845
2846        switch (cfg->type) {
2847        case PORT_SCI:
2848                regtype = SCIx_SCI_REGTYPE;
2849                break;
2850        case PORT_IRDA:
2851                regtype = SCIx_IRDA_REGTYPE;
2852                break;
2853        case PORT_SCIFA:
2854                regtype = SCIx_SCIFA_REGTYPE;
2855                break;
2856        case PORT_SCIFB:
2857                regtype = SCIx_SCIFB_REGTYPE;
2858                break;
2859        case PORT_SCIF:
2860                /*
2861                 * The SH-4 is a bit of a misnomer here, although that's
2862                 * where this particular port layout originated. This
2863                 * configuration (or some slight variation thereof)
2864                 * remains the dominant model for all SCIFs.
2865                 */
2866                regtype = SCIx_SH4_SCIF_REGTYPE;
2867                break;
2868        case PORT_HSCIF:
2869                regtype = SCIx_HSCIF_REGTYPE;
2870                break;
2871        default:
2872                pr_err("Can't probe register map for given port\n");
2873                return NULL;
2874        }
2875
2876        return &sci_port_params[regtype];
2877}
2878
2879static int sci_init_single(struct platform_device *dev,
2880                           struct sci_port *sci_port, unsigned int index,
2881                           const struct plat_sci_port *p, bool early)
2882{
2883        struct uart_port *port = &sci_port->port;
2884        const struct resource *res;
2885        unsigned int i;
2886        int ret;
2887
2888        sci_port->cfg   = p;
2889
2890        port->ops       = &sci_uart_ops;
2891        port->iotype    = UPIO_MEM;
2892        port->line      = index;
2893        port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SH_SCI_CONSOLE);
2894
2895        res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2896        if (res == NULL)
2897                return -ENOMEM;
2898
2899        port->mapbase = res->start;
2900        sci_port->reg_size = resource_size(res);
2901
2902        for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i) {
2903                if (i)
2904                        sci_port->irqs[i] = platform_get_irq_optional(dev, i);
2905                else
2906                        sci_port->irqs[i] = platform_get_irq(dev, i);
2907        }
2908
2909        /* The SCI generates several interrupts. They can be muxed together or
2910         * connected to different interrupt lines. In the muxed case only one
2911         * interrupt resource is specified as there is only one interrupt ID.
2912         * In the non-muxed case, up to 6 interrupt signals might be generated
2913         * from the SCI, however those signals might have their own individual
2914         * interrupt ID numbers, or muxed together with another interrupt.
2915         */
2916        if (sci_port->irqs[0] < 0)
2917                return -ENXIO;
2918
2919        if (sci_port->irqs[1] < 0)
2920                for (i = 1; i < ARRAY_SIZE(sci_port->irqs); i++)
2921                        sci_port->irqs[i] = sci_port->irqs[0];
2922
2923        sci_port->params = sci_probe_regmap(p);
2924        if (unlikely(sci_port->params == NULL))
2925                return -EINVAL;
2926
2927        switch (p->type) {
2928        case PORT_SCIFB:
2929                sci_port->rx_trigger = 48;
2930                break;
2931        case PORT_HSCIF:
2932                sci_port->rx_trigger = 64;
2933                break;
2934        case PORT_SCIFA:
2935                sci_port->rx_trigger = 32;
2936                break;
2937        case PORT_SCIF:
2938                if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
2939                        /* RX triggering not implemented for this IP */
2940                        sci_port->rx_trigger = 1;
2941                else
2942                        sci_port->rx_trigger = 8;
2943                break;
2944        default:
2945                sci_port->rx_trigger = 1;
2946                break;
2947        }
2948
2949        sci_port->rx_fifo_timeout = 0;
2950        sci_port->hscif_tot = 0;
2951
2952        /* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
2953         * match the SoC datasheet, this should be investigated. Let platform
2954         * data override the sampling rate for now.
2955         */
2956        sci_port->sampling_rate_mask = p->sampling_rate
2957                                     ? SCI_SR(p->sampling_rate)
2958                                     : sci_port->params->sampling_rate_mask;
2959
2960        if (!early) {
2961                ret = sci_init_clocks(sci_port, &dev->dev);
2962                if (ret < 0)
2963                        return ret;
2964
2965                port->dev = &dev->dev;
2966
2967                pm_runtime_enable(&dev->dev);
2968        }
2969
2970        port->type              = p->type;
2971        port->flags             = UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
2972        port->fifosize          = sci_port->params->fifosize;
2973
2974        if (port->type == PORT_SCI) {
2975                if (sci_port->reg_size >= 0x20)
2976                        port->regshift = 2;
2977                else
2978                        port->regshift = 1;
2979        }
2980
2981        /*
2982         * The UART port needs an IRQ value, so we peg this to the RX IRQ
2983         * for the multi-IRQ ports, which is where we are primarily
2984         * concerned with the shutdown path synchronization.
2985         *
2986         * For the muxed case there's nothing more to do.
2987         */
2988        port->irq               = sci_port->irqs[SCIx_RXI_IRQ];
2989        port->irqflags          = 0;
2990
2991        port->serial_in         = sci_serial_in;
2992        port->serial_out        = sci_serial_out;
2993
2994        return 0;
2995}
2996
2997static void sci_cleanup_single(struct sci_port *port)
2998{
2999        pm_runtime_disable(port->port.dev);
3000}
3001
3002#if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
3003    defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
3004static void serial_console_putchar(struct uart_port *port, int ch)
3005{
3006        sci_poll_put_char(port, ch);
3007}
3008
3009/*
3010 *      Print a string to the serial port trying not to disturb
3011 *      any possible real use of the port...
3012 */
3013static void serial_console_write(struct console *co, const char *s,
3014                                 unsigned count)
3015{
3016        struct sci_port *sci_port = &sci_ports[co->index];
3017        struct uart_port *port = &sci_port->port;
3018        unsigned short bits, ctrl, ctrl_temp;
3019        unsigned long flags;
3020        int locked = 1;
3021
3022        if (port->sysrq)
3023                locked = 0;
3024        else if (oops_in_progress)
3025                locked = spin_trylock_irqsave(&port->lock, flags);
3026        else
3027                spin_lock_irqsave(&port->lock, flags);
3028
3029        /* first save SCSCR then disable interrupts, keep clock source */
3030        ctrl = serial_port_in(port, SCSCR);
3031        ctrl_temp = SCSCR_RE | SCSCR_TE |
3032                    (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
3033                    (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
3034        serial_port_out(port, SCSCR, ctrl_temp | sci_port->hscif_tot);
3035
3036        uart_console_write(port, s, count, serial_console_putchar);
3037
3038        /* wait until fifo is empty and last bit has been transmitted */
3039        bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
3040        while ((serial_port_in(port, SCxSR) & bits) != bits)
3041                cpu_relax();
3042
3043        /* restore the SCSCR */
3044        serial_port_out(port, SCSCR, ctrl);
3045
3046        if (locked)
3047                spin_unlock_irqrestore(&port->lock, flags);
3048}
3049
3050static int serial_console_setup(struct console *co, char *options)
3051{
3052        struct sci_port *sci_port;
3053        struct uart_port *port;
3054        int baud = 115200;
3055        int bits = 8;
3056        int parity = 'n';
3057        int flow = 'n';
3058        int ret;
3059
3060        /*
3061         * Refuse to handle any bogus ports.
3062         */
3063        if (co->index < 0 || co->index >= SCI_NPORTS)
3064                return -ENODEV;
3065
3066        sci_port = &sci_ports[co->index];
3067        port = &sci_port->port;
3068
3069        /*
3070         * Refuse to handle uninitialized ports.
3071         */
3072        if (!port->ops)
3073                return -ENODEV;
3074
3075        ret = sci_remap_port(port);
3076        if (unlikely(ret != 0))
3077                return ret;
3078
3079        if (options)
3080                uart_parse_options(options, &baud, &parity, &bits, &flow);
3081
3082        return uart_set_options(port, co, baud, parity, bits, flow);
3083}
3084
3085static struct console serial_console = {
3086        .name           = "ttySC",
3087        .device         = uart_console_device,
3088        .write          = serial_console_write,
3089        .setup          = serial_console_setup,
3090        .flags          = CON_PRINTBUFFER,
3091        .index          = -1,
3092        .data           = &sci_uart_driver,
3093};
3094
3095#ifdef CONFIG_SUPERH
3096static struct console early_serial_console = {
3097        .name           = "early_ttySC",
3098        .write          = serial_console_write,
3099        .flags          = CON_PRINTBUFFER,
3100        .index          = -1,
3101};
3102
3103static char early_serial_buf[32];
3104
3105static int sci_probe_earlyprintk(struct platform_device *pdev)
3106{
3107        const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
3108
3109        if (early_serial_console.data)
3110                return -EEXIST;
3111
3112        early_serial_console.index = pdev->id;
3113
3114        sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
3115
3116        serial_console_setup(&early_serial_console, early_serial_buf);
3117
3118        if (!strstr(early_serial_buf, "keep"))
3119                early_serial_console.flags |= CON_BOOT;
3120
3121        register_console(&early_serial_console);
3122        return 0;
3123}
3124#endif
3125
3126#define SCI_CONSOLE     (&serial_console)
3127
3128#else
3129static inline int sci_probe_earlyprintk(struct platform_device *pdev)
3130{
3131        return -EINVAL;
3132}
3133
3134#define SCI_CONSOLE     NULL
3135
3136#endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
3137
3138static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
3139
3140static DEFINE_MUTEX(sci_uart_registration_lock);
3141static struct uart_driver sci_uart_driver = {
3142        .owner          = THIS_MODULE,
3143        .driver_name    = "sci",
3144        .dev_name       = "ttySC",
3145        .major          = SCI_MAJOR,
3146        .minor          = SCI_MINOR_START,
3147        .nr             = SCI_NPORTS,
3148        .cons           = SCI_CONSOLE,
3149};
3150
3151static int sci_remove(struct platform_device *dev)
3152{
3153        struct sci_port *port = platform_get_drvdata(dev);
3154        unsigned int type = port->port.type;    /* uart_remove_... clears it */
3155
3156        sci_ports_in_use &= ~BIT(port->port.line);
3157        uart_remove_one_port(&sci_uart_driver, &port->port);
3158
3159        sci_cleanup_single(port);
3160
3161        if (port->port.fifosize > 1)
3162                device_remove_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3163        if (type == PORT_SCIFA || type == PORT_SCIFB || type == PORT_HSCIF)
3164                device_remove_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3165
3166        return 0;
3167}
3168
3169
3170#define SCI_OF_DATA(type, regtype)      (void *)((type) << 16 | (regtype))
3171#define SCI_OF_TYPE(data)               ((unsigned long)(data) >> 16)
3172#define SCI_OF_REGTYPE(data)            ((unsigned long)(data) & 0xffff)
3173
3174static const struct of_device_id of_sci_match[] = {
3175        /* SoC-specific types */
3176        {
3177                .compatible = "renesas,scif-r7s72100",
3178                .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
3179        },
3180        {
3181                .compatible = "renesas,scif-r7s9210",
3182                .data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3183        },
3184        /* Family-specific types */
3185        {
3186                .compatible = "renesas,rcar-gen1-scif",
3187                .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3188        }, {
3189                .compatible = "renesas,rcar-gen2-scif",
3190                .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3191        }, {
3192                .compatible = "renesas,rcar-gen3-scif",
3193                .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3194        },
3195        /* Generic types */
3196        {
3197                .compatible = "renesas,scif",
3198                .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
3199        }, {
3200                .compatible = "renesas,scifa",
3201                .data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
3202        }, {
3203                .compatible = "renesas,scifb",
3204                .data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
3205        }, {
3206                .compatible = "renesas,hscif",
3207                .data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
3208        }, {
3209                .compatible = "renesas,sci",
3210                .data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
3211        }, {
3212                /* Terminator */
3213        },
3214};
3215MODULE_DEVICE_TABLE(of, of_sci_match);
3216
3217static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
3218                                          unsigned int *dev_id)
3219{
3220        struct device_node *np = pdev->dev.of_node;
3221        struct plat_sci_port *p;
3222        struct sci_port *sp;
3223        const void *data;
3224        int id;
3225
3226        if (!IS_ENABLED(CONFIG_OF) || !np)
3227                return NULL;
3228
3229        data = of_device_get_match_data(&pdev->dev);
3230
3231        p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
3232        if (!p)
3233                return NULL;
3234
3235        /* Get the line number from the aliases node. */
3236        id = of_alias_get_id(np, "serial");
3237        if (id < 0 && ~sci_ports_in_use)
3238                id = ffz(sci_ports_in_use);
3239        if (id < 0) {
3240                dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
3241                return NULL;
3242        }
3243        if (id >= ARRAY_SIZE(sci_ports)) {
3244                dev_err(&pdev->dev, "serial%d out of range\n", id);
3245                return NULL;
3246        }
3247
3248        sp = &sci_ports[id];
3249        *dev_id = id;
3250
3251        p->type = SCI_OF_TYPE(data);
3252        p->regtype = SCI_OF_REGTYPE(data);
3253
3254        sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts");
3255
3256        return p;
3257}
3258
3259static int sci_probe_single(struct platform_device *dev,
3260                                      unsigned int index,
3261                                      struct plat_sci_port *p,
3262                                      struct sci_port *sciport)
3263{
3264        int ret;
3265
3266        /* Sanity check */
3267        if (unlikely(index >= SCI_NPORTS)) {
3268                dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
3269                           index+1, SCI_NPORTS);
3270                dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
3271                return -EINVAL;
3272        }
3273        BUILD_BUG_ON(SCI_NPORTS > sizeof(sci_ports_in_use) * 8);
3274        if (sci_ports_in_use & BIT(index))
3275                return -EBUSY;
3276
3277        mutex_lock(&sci_uart_registration_lock);
3278        if (!sci_uart_driver.state) {
3279                ret = uart_register_driver(&sci_uart_driver);
3280                if (ret) {
3281                        mutex_unlock(&sci_uart_registration_lock);
3282                        return ret;
3283                }
3284        }
3285        mutex_unlock(&sci_uart_registration_lock);
3286
3287        ret = sci_init_single(dev, sciport, index, p, false);
3288        if (ret)
3289                return ret;
3290
3291        sciport->gpios = mctrl_gpio_init(&sciport->port, 0);
3292        if (IS_ERR(sciport->gpios))
3293                return PTR_ERR(sciport->gpios);
3294
3295        if (sciport->has_rtscts) {
3296                if (mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_CTS) ||
3297                    mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_RTS)) {
3298                        dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
3299                        return -EINVAL;
3300                }
3301                sciport->port.flags |= UPF_HARD_FLOW;
3302        }
3303
3304        ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
3305        if (ret) {
3306                sci_cleanup_single(sciport);
3307                return ret;
3308        }
3309
3310        return 0;
3311}
3312
3313static int sci_probe(struct platform_device *dev)
3314{
3315        struct plat_sci_port *p;
3316        struct sci_port *sp;
3317        unsigned int dev_id;
3318        int ret;
3319
3320        /*
3321         * If we've come here via earlyprintk initialization, head off to
3322         * the special early probe. We don't have sufficient device state
3323         * to make it beyond this yet.
3324         */
3325#ifdef CONFIG_SUPERH
3326        if (is_sh_early_platform_device(dev))
3327                return sci_probe_earlyprintk(dev);
3328#endif
3329
3330        if (dev->dev.of_node) {
3331                p = sci_parse_dt(dev, &dev_id);
3332                if (p == NULL)
3333                        return -EINVAL;
3334        } else {
3335                p = dev->dev.platform_data;
3336                if (p == NULL) {
3337                        dev_err(&dev->dev, "no platform data supplied\n");
3338                        return -EINVAL;
3339                }
3340
3341                dev_id = dev->id;
3342        }
3343
3344        sp = &sci_ports[dev_id];
3345        platform_set_drvdata(dev, sp);
3346
3347        ret = sci_probe_single(dev, dev_id, p, sp);
3348        if (ret)
3349                return ret;
3350
3351        if (sp->port.fifosize > 1) {
3352                ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3353                if (ret)
3354                        return ret;
3355        }
3356        if (sp->port.type == PORT_SCIFA || sp->port.type == PORT_SCIFB ||
3357            sp->port.type == PORT_HSCIF) {
3358                ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3359                if (ret) {
3360                        if (sp->port.fifosize > 1) {
3361                                device_remove_file(&dev->dev,
3362                                                   &dev_attr_rx_fifo_trigger);
3363                        }
3364                        return ret;
3365                }
3366        }
3367
3368#ifdef CONFIG_SH_STANDARD_BIOS
3369        sh_bios_gdb_detach();
3370#endif
3371
3372        sci_ports_in_use |= BIT(dev_id);
3373        return 0;
3374}
3375
3376static __maybe_unused int sci_suspend(struct device *dev)
3377{
3378        struct sci_port *sport = dev_get_drvdata(dev);
3379
3380        if (sport)
3381                uart_suspend_port(&sci_uart_driver, &sport->port);
3382
3383        return 0;
3384}
3385
3386static __maybe_unused int sci_resume(struct device *dev)
3387{
3388        struct sci_port *sport = dev_get_drvdata(dev);
3389
3390        if (sport)
3391                uart_resume_port(&sci_uart_driver, &sport->port);
3392
3393        return 0;
3394}
3395
3396static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
3397
3398static struct platform_driver sci_driver = {
3399        .probe          = sci_probe,
3400        .remove         = sci_remove,
3401        .driver         = {
3402                .name   = "sh-sci",
3403                .pm     = &sci_dev_pm_ops,
3404                .of_match_table = of_match_ptr(of_sci_match),
3405        },
3406};
3407
3408static int __init sci_init(void)
3409{
3410        pr_info("%s\n", banner);
3411
3412        return platform_driver_register(&sci_driver);
3413}
3414
3415static void __exit sci_exit(void)
3416{
3417        platform_driver_unregister(&sci_driver);
3418
3419        if (sci_uart_driver.state)
3420                uart_unregister_driver(&sci_uart_driver);
3421}
3422
3423#if defined(CONFIG_SUPERH) && defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
3424sh_early_platform_init_buffer("earlyprintk", &sci_driver,
3425                           early_serial_buf, ARRAY_SIZE(early_serial_buf));
3426#endif
3427#ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
3428static struct plat_sci_port port_cfg __initdata;
3429
3430static int __init early_console_setup(struct earlycon_device *device,
3431                                      int type)
3432{
3433        if (!device->port.membase)
3434                return -ENODEV;
3435
3436        device->port.serial_in = sci_serial_in;
3437        device->port.serial_out = sci_serial_out;
3438        device->port.type = type;
3439        memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
3440        port_cfg.type = type;
3441        sci_ports[0].cfg = &port_cfg;
3442        sci_ports[0].params = sci_probe_regmap(&port_cfg);
3443        port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR);
3444        sci_serial_out(&sci_ports[0].port, SCSCR,
3445                       SCSCR_RE | SCSCR_TE | port_cfg.scscr);
3446
3447        device->con->write = serial_console_write;
3448        return 0;
3449}
3450static int __init sci_early_console_setup(struct earlycon_device *device,
3451                                          const char *opt)
3452{
3453        return early_console_setup(device, PORT_SCI);
3454}
3455static int __init scif_early_console_setup(struct earlycon_device *device,
3456                                          const char *opt)
3457{
3458        return early_console_setup(device, PORT_SCIF);
3459}
3460static int __init rzscifa_early_console_setup(struct earlycon_device *device,
3461                                          const char *opt)
3462{
3463        port_cfg.regtype = SCIx_RZ_SCIFA_REGTYPE;
3464        return early_console_setup(device, PORT_SCIF);
3465}
3466static int __init scifa_early_console_setup(struct earlycon_device *device,
3467                                          const char *opt)
3468{
3469        return early_console_setup(device, PORT_SCIFA);
3470}
3471static int __init scifb_early_console_setup(struct earlycon_device *device,
3472                                          const char *opt)
3473{
3474        return early_console_setup(device, PORT_SCIFB);
3475}
3476static int __init hscif_early_console_setup(struct earlycon_device *device,
3477                                          const char *opt)
3478{
3479        return early_console_setup(device, PORT_HSCIF);
3480}
3481
3482OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
3483OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
3484OF_EARLYCON_DECLARE(scif, "renesas,scif-r7s9210", rzscifa_early_console_setup);
3485OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
3486OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
3487OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
3488#endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
3489
3490module_init(sci_init);
3491module_exit(sci_exit);
3492
3493MODULE_LICENSE("GPL");
3494MODULE_ALIAS("platform:sh-sci");
3495MODULE_AUTHOR("Paul Mundt");
3496MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
3497