linux/drivers/tty/serial/sh-sci.c
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   1/*
   2 * SuperH on-chip serial module support.  (SCI with no FIFO / with FIFO)
   3 *
   4 *  Copyright (C) 2002 - 2011  Paul Mundt
   5 *  Copyright (C) 2015 Glider bvba
   6 *  Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
   7 *
   8 * based off of the old drivers/char/sh-sci.c by:
   9 *
  10 *   Copyright (C) 1999, 2000  Niibe Yutaka
  11 *   Copyright (C) 2000  Sugioka Toshinobu
  12 *   Modified to support multiple serial ports. Stuart Menefy (May 2000).
  13 *   Modified to support SecureEdge. David McCullough (2002)
  14 *   Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
  15 *   Removed SH7300 support (Jul 2007).
  16 *
  17 * This file is subject to the terms and conditions of the GNU General Public
  18 * License.  See the file "COPYING" in the main directory of this archive
  19 * for more details.
  20 */
  21#if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  22#define SUPPORT_SYSRQ
  23#endif
  24
  25#undef DEBUG
  26
  27#include <linux/clk.h>
  28#include <linux/console.h>
  29#include <linux/ctype.h>
  30#include <linux/cpufreq.h>
  31#include <linux/delay.h>
  32#include <linux/dmaengine.h>
  33#include <linux/dma-mapping.h>
  34#include <linux/err.h>
  35#include <linux/errno.h>
  36#include <linux/init.h>
  37#include <linux/interrupt.h>
  38#include <linux/ioport.h>
  39#include <linux/major.h>
  40#include <linux/module.h>
  41#include <linux/mm.h>
  42#include <linux/of.h>
  43#include <linux/platform_device.h>
  44#include <linux/pm_runtime.h>
  45#include <linux/scatterlist.h>
  46#include <linux/serial.h>
  47#include <linux/serial_sci.h>
  48#include <linux/sh_dma.h>
  49#include <linux/slab.h>
  50#include <linux/string.h>
  51#include <linux/sysrq.h>
  52#include <linux/timer.h>
  53#include <linux/tty.h>
  54#include <linux/tty_flip.h>
  55
  56#ifdef CONFIG_SUPERH
  57#include <asm/sh_bios.h>
  58#endif
  59
  60#include "sh-sci.h"
  61
  62/* Offsets into the sci_port->irqs array */
  63enum {
  64        SCIx_ERI_IRQ,
  65        SCIx_RXI_IRQ,
  66        SCIx_TXI_IRQ,
  67        SCIx_BRI_IRQ,
  68        SCIx_NR_IRQS,
  69
  70        SCIx_MUX_IRQ = SCIx_NR_IRQS,    /* special case */
  71};
  72
  73#define SCIx_IRQ_IS_MUXED(port)                 \
  74        ((port)->irqs[SCIx_ERI_IRQ] ==  \
  75         (port)->irqs[SCIx_RXI_IRQ]) || \
  76        ((port)->irqs[SCIx_ERI_IRQ] &&  \
  77         ((port)->irqs[SCIx_RXI_IRQ] < 0))
  78
  79enum SCI_CLKS {
  80        SCI_FCK,                /* Functional Clock */
  81        SCI_SCK,                /* Optional External Clock */
  82        SCI_BRG_INT,            /* Optional BRG Internal Clock Source */
  83        SCI_SCIF_CLK,           /* Optional BRG External Clock Source */
  84        SCI_NUM_CLKS
  85};
  86
  87/* Bit x set means sampling rate x + 1 is supported */
  88#define SCI_SR(x)               BIT((x) - 1)
  89#define SCI_SR_RANGE(x, y)      GENMASK((y) - 1, (x) - 1)
  90
  91#define SCI_SR_SCIFAB           SCI_SR(5) | SCI_SR(7) | SCI_SR(11) | \
  92                                SCI_SR(13) | SCI_SR(16) | SCI_SR(17) | \
  93                                SCI_SR(19) | SCI_SR(27)
  94
  95#define min_sr(_port)           ffs((_port)->sampling_rate_mask)
  96#define max_sr(_port)           fls((_port)->sampling_rate_mask)
  97
  98/* Iterate over all supported sampling rates, from high to low */
  99#define for_each_sr(_sr, _port)                                         \
 100        for ((_sr) = max_sr(_port); (_sr) >= min_sr(_port); (_sr)--)    \
 101                if ((_port)->sampling_rate_mask & SCI_SR((_sr)))
 102
 103struct sci_port {
 104        struct uart_port        port;
 105
 106        /* Platform configuration */
 107        struct plat_sci_port    *cfg;
 108        unsigned int            overrun_reg;
 109        unsigned int            overrun_mask;
 110        unsigned int            error_mask;
 111        unsigned int            error_clear;
 112        unsigned int            sampling_rate_mask;
 113        resource_size_t         reg_size;
 114
 115        /* Break timer */
 116        struct timer_list       break_timer;
 117        int                     break_flag;
 118
 119        /* Clocks */
 120        struct clk              *clks[SCI_NUM_CLKS];
 121        unsigned long           clk_rates[SCI_NUM_CLKS];
 122
 123        int                     irqs[SCIx_NR_IRQS];
 124        char                    *irqstr[SCIx_NR_IRQS];
 125
 126        struct dma_chan                 *chan_tx;
 127        struct dma_chan                 *chan_rx;
 128
 129#ifdef CONFIG_SERIAL_SH_SCI_DMA
 130        dma_cookie_t                    cookie_tx;
 131        dma_cookie_t                    cookie_rx[2];
 132        dma_cookie_t                    active_rx;
 133        dma_addr_t                      tx_dma_addr;
 134        unsigned int                    tx_dma_len;
 135        struct scatterlist              sg_rx[2];
 136        void                            *rx_buf[2];
 137        size_t                          buf_len_rx;
 138        struct work_struct              work_tx;
 139        struct timer_list               rx_timer;
 140        unsigned int                    rx_timeout;
 141#endif
 142};
 143
 144#define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
 145
 146static struct sci_port sci_ports[SCI_NPORTS];
 147static struct uart_driver sci_uart_driver;
 148
 149static inline struct sci_port *
 150to_sci_port(struct uart_port *uart)
 151{
 152        return container_of(uart, struct sci_port, port);
 153}
 154
 155struct plat_sci_reg {
 156        u8 offset, size;
 157};
 158
 159/* Helper for invalidating specific entries of an inherited map. */
 160#define sci_reg_invalid { .offset = 0, .size = 0 }
 161
 162static const struct plat_sci_reg sci_regmap[SCIx_NR_REGTYPES][SCIx_NR_REGS] = {
 163        [SCIx_PROBE_REGTYPE] = {
 164                [0 ... SCIx_NR_REGS - 1] = sci_reg_invalid,
 165        },
 166
 167        /*
 168         * Common SCI definitions, dependent on the port's regshift
 169         * value.
 170         */
 171        [SCIx_SCI_REGTYPE] = {
 172                [SCSMR]         = { 0x00,  8 },
 173                [SCBRR]         = { 0x01,  8 },
 174                [SCSCR]         = { 0x02,  8 },
 175                [SCxTDR]        = { 0x03,  8 },
 176                [SCxSR]         = { 0x04,  8 },
 177                [SCxRDR]        = { 0x05,  8 },
 178                [SCFCR]         = sci_reg_invalid,
 179                [SCFDR]         = sci_reg_invalid,
 180                [SCTFDR]        = sci_reg_invalid,
 181                [SCRFDR]        = sci_reg_invalid,
 182                [SCSPTR]        = sci_reg_invalid,
 183                [SCLSR]         = sci_reg_invalid,
 184                [HSSRR]         = sci_reg_invalid,
 185                [SCPCR]         = sci_reg_invalid,
 186                [SCPDR]         = sci_reg_invalid,
 187                [SCDL]          = sci_reg_invalid,
 188                [SCCKS]         = sci_reg_invalid,
 189        },
 190
 191        /*
 192         * Common definitions for legacy IrDA ports, dependent on
 193         * regshift value.
 194         */
 195        [SCIx_IRDA_REGTYPE] = {
 196                [SCSMR]         = { 0x00,  8 },
 197                [SCBRR]         = { 0x01,  8 },
 198                [SCSCR]         = { 0x02,  8 },
 199                [SCxTDR]        = { 0x03,  8 },
 200                [SCxSR]         = { 0x04,  8 },
 201                [SCxRDR]        = { 0x05,  8 },
 202                [SCFCR]         = { 0x06,  8 },
 203                [SCFDR]         = { 0x07, 16 },
 204                [SCTFDR]        = sci_reg_invalid,
 205                [SCRFDR]        = sci_reg_invalid,
 206                [SCSPTR]        = sci_reg_invalid,
 207                [SCLSR]         = sci_reg_invalid,
 208                [HSSRR]         = sci_reg_invalid,
 209                [SCPCR]         = sci_reg_invalid,
 210                [SCPDR]         = sci_reg_invalid,
 211                [SCDL]          = sci_reg_invalid,
 212                [SCCKS]         = sci_reg_invalid,
 213        },
 214
 215        /*
 216         * Common SCIFA definitions.
 217         */
 218        [SCIx_SCIFA_REGTYPE] = {
 219                [SCSMR]         = { 0x00, 16 },
 220                [SCBRR]         = { 0x04,  8 },
 221                [SCSCR]         = { 0x08, 16 },
 222                [SCxTDR]        = { 0x20,  8 },
 223                [SCxSR]         = { 0x14, 16 },
 224                [SCxRDR]        = { 0x24,  8 },
 225                [SCFCR]         = { 0x18, 16 },
 226                [SCFDR]         = { 0x1c, 16 },
 227                [SCTFDR]        = sci_reg_invalid,
 228                [SCRFDR]        = sci_reg_invalid,
 229                [SCSPTR]        = sci_reg_invalid,
 230                [SCLSR]         = sci_reg_invalid,
 231                [HSSRR]         = sci_reg_invalid,
 232                [SCPCR]         = { 0x30, 16 },
 233                [SCPDR]         = { 0x34, 16 },
 234                [SCDL]          = sci_reg_invalid,
 235                [SCCKS]         = sci_reg_invalid,
 236        },
 237
 238        /*
 239         * Common SCIFB definitions.
 240         */
 241        [SCIx_SCIFB_REGTYPE] = {
 242                [SCSMR]         = { 0x00, 16 },
 243                [SCBRR]         = { 0x04,  8 },
 244                [SCSCR]         = { 0x08, 16 },
 245                [SCxTDR]        = { 0x40,  8 },
 246                [SCxSR]         = { 0x14, 16 },
 247                [SCxRDR]        = { 0x60,  8 },
 248                [SCFCR]         = { 0x18, 16 },
 249                [SCFDR]         = sci_reg_invalid,
 250                [SCTFDR]        = { 0x38, 16 },
 251                [SCRFDR]        = { 0x3c, 16 },
 252                [SCSPTR]        = sci_reg_invalid,
 253                [SCLSR]         = sci_reg_invalid,
 254                [HSSRR]         = sci_reg_invalid,
 255                [SCPCR]         = { 0x30, 16 },
 256                [SCPDR]         = { 0x34, 16 },
 257                [SCDL]          = sci_reg_invalid,
 258                [SCCKS]         = sci_reg_invalid,
 259        },
 260
 261        /*
 262         * Common SH-2(A) SCIF definitions for ports with FIFO data
 263         * count registers.
 264         */
 265        [SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
 266                [SCSMR]         = { 0x00, 16 },
 267                [SCBRR]         = { 0x04,  8 },
 268                [SCSCR]         = { 0x08, 16 },
 269                [SCxTDR]        = { 0x0c,  8 },
 270                [SCxSR]         = { 0x10, 16 },
 271                [SCxRDR]        = { 0x14,  8 },
 272                [SCFCR]         = { 0x18, 16 },
 273                [SCFDR]         = { 0x1c, 16 },
 274                [SCTFDR]        = sci_reg_invalid,
 275                [SCRFDR]        = sci_reg_invalid,
 276                [SCSPTR]        = { 0x20, 16 },
 277                [SCLSR]         = { 0x24, 16 },
 278                [HSSRR]         = sci_reg_invalid,
 279                [SCPCR]         = sci_reg_invalid,
 280                [SCPDR]         = sci_reg_invalid,
 281                [SCDL]          = sci_reg_invalid,
 282                [SCCKS]         = sci_reg_invalid,
 283        },
 284
 285        /*
 286         * Common SH-3 SCIF definitions.
 287         */
 288        [SCIx_SH3_SCIF_REGTYPE] = {
 289                [SCSMR]         = { 0x00,  8 },
 290                [SCBRR]         = { 0x02,  8 },
 291                [SCSCR]         = { 0x04,  8 },
 292                [SCxTDR]        = { 0x06,  8 },
 293                [SCxSR]         = { 0x08, 16 },
 294                [SCxRDR]        = { 0x0a,  8 },
 295                [SCFCR]         = { 0x0c,  8 },
 296                [SCFDR]         = { 0x0e, 16 },
 297                [SCTFDR]        = sci_reg_invalid,
 298                [SCRFDR]        = sci_reg_invalid,
 299                [SCSPTR]        = sci_reg_invalid,
 300                [SCLSR]         = sci_reg_invalid,
 301                [HSSRR]         = sci_reg_invalid,
 302                [SCPCR]         = sci_reg_invalid,
 303                [SCPDR]         = sci_reg_invalid,
 304                [SCDL]          = sci_reg_invalid,
 305                [SCCKS]         = sci_reg_invalid,
 306        },
 307
 308        /*
 309         * Common SH-4(A) SCIF(B) definitions.
 310         */
 311        [SCIx_SH4_SCIF_REGTYPE] = {
 312                [SCSMR]         = { 0x00, 16 },
 313                [SCBRR]         = { 0x04,  8 },
 314                [SCSCR]         = { 0x08, 16 },
 315                [SCxTDR]        = { 0x0c,  8 },
 316                [SCxSR]         = { 0x10, 16 },
 317                [SCxRDR]        = { 0x14,  8 },
 318                [SCFCR]         = { 0x18, 16 },
 319                [SCFDR]         = { 0x1c, 16 },
 320                [SCTFDR]        = sci_reg_invalid,
 321                [SCRFDR]        = sci_reg_invalid,
 322                [SCSPTR]        = { 0x20, 16 },
 323                [SCLSR]         = { 0x24, 16 },
 324                [HSSRR]         = sci_reg_invalid,
 325                [SCPCR]         = sci_reg_invalid,
 326                [SCPDR]         = sci_reg_invalid,
 327                [SCDL]          = sci_reg_invalid,
 328                [SCCKS]         = sci_reg_invalid,
 329        },
 330
 331        /*
 332         * Common SCIF definitions for ports with a Baud Rate Generator for
 333         * External Clock (BRG).
 334         */
 335        [SCIx_SH4_SCIF_BRG_REGTYPE] = {
 336                [SCSMR]         = { 0x00, 16 },
 337                [SCBRR]         = { 0x04,  8 },
 338                [SCSCR]         = { 0x08, 16 },
 339                [SCxTDR]        = { 0x0c,  8 },
 340                [SCxSR]         = { 0x10, 16 },
 341                [SCxRDR]        = { 0x14,  8 },
 342                [SCFCR]         = { 0x18, 16 },
 343                [SCFDR]         = { 0x1c, 16 },
 344                [SCTFDR]        = sci_reg_invalid,
 345                [SCRFDR]        = sci_reg_invalid,
 346                [SCSPTR]        = { 0x20, 16 },
 347                [SCLSR]         = { 0x24, 16 },
 348                [HSSRR]         = sci_reg_invalid,
 349                [SCPCR]         = sci_reg_invalid,
 350                [SCPDR]         = sci_reg_invalid,
 351                [SCDL]          = { 0x30, 16 },
 352                [SCCKS]         = { 0x34, 16 },
 353        },
 354
 355        /*
 356         * Common HSCIF definitions.
 357         */
 358        [SCIx_HSCIF_REGTYPE] = {
 359                [SCSMR]         = { 0x00, 16 },
 360                [SCBRR]         = { 0x04,  8 },
 361                [SCSCR]         = { 0x08, 16 },
 362                [SCxTDR]        = { 0x0c,  8 },
 363                [SCxSR]         = { 0x10, 16 },
 364                [SCxRDR]        = { 0x14,  8 },
 365                [SCFCR]         = { 0x18, 16 },
 366                [SCFDR]         = { 0x1c, 16 },
 367                [SCTFDR]        = sci_reg_invalid,
 368                [SCRFDR]        = sci_reg_invalid,
 369                [SCSPTR]        = { 0x20, 16 },
 370                [SCLSR]         = { 0x24, 16 },
 371                [HSSRR]         = { 0x40, 16 },
 372                [SCPCR]         = sci_reg_invalid,
 373                [SCPDR]         = sci_reg_invalid,
 374                [SCDL]          = { 0x30, 16 },
 375                [SCCKS]         = { 0x34, 16 },
 376        },
 377
 378        /*
 379         * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
 380         * register.
 381         */
 382        [SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
 383                [SCSMR]         = { 0x00, 16 },
 384                [SCBRR]         = { 0x04,  8 },
 385                [SCSCR]         = { 0x08, 16 },
 386                [SCxTDR]        = { 0x0c,  8 },
 387                [SCxSR]         = { 0x10, 16 },
 388                [SCxRDR]        = { 0x14,  8 },
 389                [SCFCR]         = { 0x18, 16 },
 390                [SCFDR]         = { 0x1c, 16 },
 391                [SCTFDR]        = sci_reg_invalid,
 392                [SCRFDR]        = sci_reg_invalid,
 393                [SCSPTR]        = sci_reg_invalid,
 394                [SCLSR]         = { 0x24, 16 },
 395                [HSSRR]         = sci_reg_invalid,
 396                [SCPCR]         = sci_reg_invalid,
 397                [SCPDR]         = sci_reg_invalid,
 398                [SCDL]          = sci_reg_invalid,
 399                [SCCKS]         = sci_reg_invalid,
 400        },
 401
 402        /*
 403         * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
 404         * count registers.
 405         */
 406        [SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
 407                [SCSMR]         = { 0x00, 16 },
 408                [SCBRR]         = { 0x04,  8 },
 409                [SCSCR]         = { 0x08, 16 },
 410                [SCxTDR]        = { 0x0c,  8 },
 411                [SCxSR]         = { 0x10, 16 },
 412                [SCxRDR]        = { 0x14,  8 },
 413                [SCFCR]         = { 0x18, 16 },
 414                [SCFDR]         = { 0x1c, 16 },
 415                [SCTFDR]        = { 0x1c, 16 }, /* aliased to SCFDR */
 416                [SCRFDR]        = { 0x20, 16 },
 417                [SCSPTR]        = { 0x24, 16 },
 418                [SCLSR]         = { 0x28, 16 },
 419                [HSSRR]         = sci_reg_invalid,
 420                [SCPCR]         = sci_reg_invalid,
 421                [SCPDR]         = sci_reg_invalid,
 422                [SCDL]          = sci_reg_invalid,
 423                [SCCKS]         = sci_reg_invalid,
 424        },
 425
 426        /*
 427         * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
 428         * registers.
 429         */
 430        [SCIx_SH7705_SCIF_REGTYPE] = {
 431                [SCSMR]         = { 0x00, 16 },
 432                [SCBRR]         = { 0x04,  8 },
 433                [SCSCR]         = { 0x08, 16 },
 434                [SCxTDR]        = { 0x20,  8 },
 435                [SCxSR]         = { 0x14, 16 },
 436                [SCxRDR]        = { 0x24,  8 },
 437                [SCFCR]         = { 0x18, 16 },
 438                [SCFDR]         = { 0x1c, 16 },
 439                [SCTFDR]        = sci_reg_invalid,
 440                [SCRFDR]        = sci_reg_invalid,
 441                [SCSPTR]        = sci_reg_invalid,
 442                [SCLSR]         = sci_reg_invalid,
 443                [HSSRR]         = sci_reg_invalid,
 444                [SCPCR]         = sci_reg_invalid,
 445                [SCPDR]         = sci_reg_invalid,
 446                [SCDL]          = sci_reg_invalid,
 447                [SCCKS]         = sci_reg_invalid,
 448        },
 449};
 450
 451#define sci_getreg(up, offset)          (sci_regmap[to_sci_port(up)->cfg->regtype] + offset)
 452
 453/*
 454 * The "offset" here is rather misleading, in that it refers to an enum
 455 * value relative to the port mapping rather than the fixed offset
 456 * itself, which needs to be manually retrieved from the platform's
 457 * register map for the given port.
 458 */
 459static unsigned int sci_serial_in(struct uart_port *p, int offset)
 460{
 461        const struct plat_sci_reg *reg = sci_getreg(p, offset);
 462
 463        if (reg->size == 8)
 464                return ioread8(p->membase + (reg->offset << p->regshift));
 465        else if (reg->size == 16)
 466                return ioread16(p->membase + (reg->offset << p->regshift));
 467        else
 468                WARN(1, "Invalid register access\n");
 469
 470        return 0;
 471}
 472
 473static void sci_serial_out(struct uart_port *p, int offset, int value)
 474{
 475        const struct plat_sci_reg *reg = sci_getreg(p, offset);
 476
 477        if (reg->size == 8)
 478                iowrite8(value, p->membase + (reg->offset << p->regshift));
 479        else if (reg->size == 16)
 480                iowrite16(value, p->membase + (reg->offset << p->regshift));
 481        else
 482                WARN(1, "Invalid register access\n");
 483}
 484
 485static int sci_probe_regmap(struct plat_sci_port *cfg)
 486{
 487        switch (cfg->type) {
 488        case PORT_SCI:
 489                cfg->regtype = SCIx_SCI_REGTYPE;
 490                break;
 491        case PORT_IRDA:
 492                cfg->regtype = SCIx_IRDA_REGTYPE;
 493                break;
 494        case PORT_SCIFA:
 495                cfg->regtype = SCIx_SCIFA_REGTYPE;
 496                break;
 497        case PORT_SCIFB:
 498                cfg->regtype = SCIx_SCIFB_REGTYPE;
 499                break;
 500        case PORT_SCIF:
 501                /*
 502                 * The SH-4 is a bit of a misnomer here, although that's
 503                 * where this particular port layout originated. This
 504                 * configuration (or some slight variation thereof)
 505                 * remains the dominant model for all SCIFs.
 506                 */
 507                cfg->regtype = SCIx_SH4_SCIF_REGTYPE;
 508                break;
 509        case PORT_HSCIF:
 510                cfg->regtype = SCIx_HSCIF_REGTYPE;
 511                break;
 512        default:
 513                pr_err("Can't probe register map for given port\n");
 514                return -EINVAL;
 515        }
 516
 517        return 0;
 518}
 519
 520static void sci_port_enable(struct sci_port *sci_port)
 521{
 522        unsigned int i;
 523
 524        if (!sci_port->port.dev)
 525                return;
 526
 527        pm_runtime_get_sync(sci_port->port.dev);
 528
 529        for (i = 0; i < SCI_NUM_CLKS; i++) {
 530                clk_prepare_enable(sci_port->clks[i]);
 531                sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
 532        }
 533        sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
 534}
 535
 536static void sci_port_disable(struct sci_port *sci_port)
 537{
 538        unsigned int i;
 539
 540        if (!sci_port->port.dev)
 541                return;
 542
 543        /* Cancel the break timer to ensure that the timer handler will not try
 544         * to access the hardware with clocks and power disabled. Reset the
 545         * break flag to make the break debouncing state machine ready for the
 546         * next break.
 547         */
 548        del_timer_sync(&sci_port->break_timer);
 549        sci_port->break_flag = 0;
 550
 551        for (i = SCI_NUM_CLKS; i-- > 0; )
 552                clk_disable_unprepare(sci_port->clks[i]);
 553
 554        pm_runtime_put_sync(sci_port->port.dev);
 555}
 556
 557static inline unsigned long port_rx_irq_mask(struct uart_port *port)
 558{
 559        /*
 560         * Not all ports (such as SCIFA) will support REIE. Rather than
 561         * special-casing the port type, we check the port initialization
 562         * IRQ enable mask to see whether the IRQ is desired at all. If
 563         * it's unset, it's logically inferred that there's no point in
 564         * testing for it.
 565         */
 566        return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
 567}
 568
 569static void sci_start_tx(struct uart_port *port)
 570{
 571        struct sci_port *s = to_sci_port(port);
 572        unsigned short ctrl;
 573
 574#ifdef CONFIG_SERIAL_SH_SCI_DMA
 575        if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
 576                u16 new, scr = serial_port_in(port, SCSCR);
 577                if (s->chan_tx)
 578                        new = scr | SCSCR_TDRQE;
 579                else
 580                        new = scr & ~SCSCR_TDRQE;
 581                if (new != scr)
 582                        serial_port_out(port, SCSCR, new);
 583        }
 584
 585        if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
 586            dma_submit_error(s->cookie_tx)) {
 587                s->cookie_tx = 0;
 588                schedule_work(&s->work_tx);
 589        }
 590#endif
 591
 592        if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
 593                /* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
 594                ctrl = serial_port_in(port, SCSCR);
 595                serial_port_out(port, SCSCR, ctrl | SCSCR_TIE);
 596        }
 597}
 598
 599static void sci_stop_tx(struct uart_port *port)
 600{
 601        unsigned short ctrl;
 602
 603        /* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
 604        ctrl = serial_port_in(port, SCSCR);
 605
 606        if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
 607                ctrl &= ~SCSCR_TDRQE;
 608
 609        ctrl &= ~SCSCR_TIE;
 610
 611        serial_port_out(port, SCSCR, ctrl);
 612}
 613
 614static void sci_start_rx(struct uart_port *port)
 615{
 616        unsigned short ctrl;
 617
 618        ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
 619
 620        if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
 621                ctrl &= ~SCSCR_RDRQE;
 622
 623        serial_port_out(port, SCSCR, ctrl);
 624}
 625
 626static void sci_stop_rx(struct uart_port *port)
 627{
 628        unsigned short ctrl;
 629
 630        ctrl = serial_port_in(port, SCSCR);
 631
 632        if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
 633                ctrl &= ~SCSCR_RDRQE;
 634
 635        ctrl &= ~port_rx_irq_mask(port);
 636
 637        serial_port_out(port, SCSCR, ctrl);
 638}
 639
 640static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
 641{
 642        if (port->type == PORT_SCI) {
 643                /* Just store the mask */
 644                serial_port_out(port, SCxSR, mask);
 645        } else if (to_sci_port(port)->overrun_mask == SCIFA_ORER) {
 646                /* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
 647                /* Only clear the status bits we want to clear */
 648                serial_port_out(port, SCxSR,
 649                                serial_port_in(port, SCxSR) & mask);
 650        } else {
 651                /* Store the mask, clear parity/framing errors */
 652                serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
 653        }
 654}
 655
 656#if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
 657    defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
 658
 659#ifdef CONFIG_CONSOLE_POLL
 660static int sci_poll_get_char(struct uart_port *port)
 661{
 662        unsigned short status;
 663        int c;
 664
 665        do {
 666                status = serial_port_in(port, SCxSR);
 667                if (status & SCxSR_ERRORS(port)) {
 668                        sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
 669                        continue;
 670                }
 671                break;
 672        } while (1);
 673
 674        if (!(status & SCxSR_RDxF(port)))
 675                return NO_POLL_CHAR;
 676
 677        c = serial_port_in(port, SCxRDR);
 678
 679        /* Dummy read */
 680        serial_port_in(port, SCxSR);
 681        sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
 682
 683        return c;
 684}
 685#endif
 686
 687static void sci_poll_put_char(struct uart_port *port, unsigned char c)
 688{
 689        unsigned short status;
 690
 691        do {
 692                status = serial_port_in(port, SCxSR);
 693        } while (!(status & SCxSR_TDxE(port)));
 694
 695        serial_port_out(port, SCxTDR, c);
 696        sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
 697}
 698#endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
 699          CONFIG_SERIAL_SH_SCI_EARLYCON */
 700
 701static void sci_init_pins(struct uart_port *port, unsigned int cflag)
 702{
 703        struct sci_port *s = to_sci_port(port);
 704        const struct plat_sci_reg *reg = sci_regmap[s->cfg->regtype] + SCSPTR;
 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        /*
 715         * For the generic path SCSPTR is necessary. Bail out if that's
 716         * unavailable, too.
 717         */
 718        if (!reg->size)
 719                return;
 720
 721        if ((s->cfg->capabilities & SCIx_HAVE_RTSCTS) &&
 722            ((!(cflag & CRTSCTS)))) {
 723                unsigned short status;
 724
 725                status = serial_port_in(port, SCSPTR);
 726                status &= ~SCSPTR_CTSIO;
 727                status |= SCSPTR_RTSIO;
 728                serial_port_out(port, SCSPTR, status); /* Set RTS = 1 */
 729        }
 730}
 731
 732static int sci_txfill(struct uart_port *port)
 733{
 734        const struct plat_sci_reg *reg;
 735
 736        reg = sci_getreg(port, SCTFDR);
 737        if (reg->size)
 738                return serial_port_in(port, SCTFDR) & ((port->fifosize << 1) - 1);
 739
 740        reg = sci_getreg(port, SCFDR);
 741        if (reg->size)
 742                return serial_port_in(port, SCFDR) >> 8;
 743
 744        return !(serial_port_in(port, SCxSR) & SCI_TDRE);
 745}
 746
 747static int sci_txroom(struct uart_port *port)
 748{
 749        return port->fifosize - sci_txfill(port);
 750}
 751
 752static int sci_rxfill(struct uart_port *port)
 753{
 754        const struct plat_sci_reg *reg;
 755
 756        reg = sci_getreg(port, SCRFDR);
 757        if (reg->size)
 758                return serial_port_in(port, SCRFDR) & ((port->fifosize << 1) - 1);
 759
 760        reg = sci_getreg(port, SCFDR);
 761        if (reg->size)
 762                return serial_port_in(port, SCFDR) & ((port->fifosize << 1) - 1);
 763
 764        return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
 765}
 766
 767/*
 768 * SCI helper for checking the state of the muxed port/RXD pins.
 769 */
 770static inline int sci_rxd_in(struct uart_port *port)
 771{
 772        struct sci_port *s = to_sci_port(port);
 773
 774        if (s->cfg->port_reg <= 0)
 775                return 1;
 776
 777        /* Cast for ARM damage */
 778        return !!__raw_readb((void __iomem *)(uintptr_t)s->cfg->port_reg);
 779}
 780
 781/* ********************************************************************** *
 782 *                   the interrupt related routines                       *
 783 * ********************************************************************** */
 784
 785static void sci_transmit_chars(struct uart_port *port)
 786{
 787        struct circ_buf *xmit = &port->state->xmit;
 788        unsigned int stopped = uart_tx_stopped(port);
 789        unsigned short status;
 790        unsigned short ctrl;
 791        int count;
 792
 793        status = serial_port_in(port, SCxSR);
 794        if (!(status & SCxSR_TDxE(port))) {
 795                ctrl = serial_port_in(port, SCSCR);
 796                if (uart_circ_empty(xmit))
 797                        ctrl &= ~SCSCR_TIE;
 798                else
 799                        ctrl |= SCSCR_TIE;
 800                serial_port_out(port, SCSCR, ctrl);
 801                return;
 802        }
 803
 804        count = sci_txroom(port);
 805
 806        do {
 807                unsigned char c;
 808
 809                if (port->x_char) {
 810                        c = port->x_char;
 811                        port->x_char = 0;
 812                } else if (!uart_circ_empty(xmit) && !stopped) {
 813                        c = xmit->buf[xmit->tail];
 814                        xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 815                } else {
 816                        break;
 817                }
 818
 819                serial_port_out(port, SCxTDR, c);
 820
 821                port->icount.tx++;
 822        } while (--count > 0);
 823
 824        sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
 825
 826        if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 827                uart_write_wakeup(port);
 828        if (uart_circ_empty(xmit)) {
 829                sci_stop_tx(port);
 830        } else {
 831                ctrl = serial_port_in(port, SCSCR);
 832
 833                if (port->type != PORT_SCI) {
 834                        serial_port_in(port, SCxSR); /* Dummy read */
 835                        sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
 836                }
 837
 838                ctrl |= SCSCR_TIE;
 839                serial_port_out(port, SCSCR, ctrl);
 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 sci_port *sci_port = to_sci_port(port);
 849        struct tty_port *tport = &port->state->port;
 850        int i, count, copied = 0;
 851        unsigned short status;
 852        unsigned char flag;
 853
 854        status = serial_port_in(port, SCxSR);
 855        if (!(status & SCxSR_RDxF(port)))
 856                return;
 857
 858        while (1) {
 859                /* Don't copy more bytes than there is room for in the buffer */
 860                count = tty_buffer_request_room(tport, sci_rxfill(port));
 861
 862                /* If for any reason we can't copy more data, we're done! */
 863                if (count == 0)
 864                        break;
 865
 866                if (port->type == PORT_SCI) {
 867                        char c = serial_port_in(port, SCxRDR);
 868                        if (uart_handle_sysrq_char(port, c) ||
 869                            sci_port->break_flag)
 870                                count = 0;
 871                        else
 872                                tty_insert_flip_char(tport, c, TTY_NORMAL);
 873                } else {
 874                        for (i = 0; i < count; i++) {
 875                                char c = serial_port_in(port, SCxRDR);
 876
 877                                status = serial_port_in(port, SCxSR);
 878#if defined(CONFIG_CPU_SH3)
 879                                /* Skip "chars" during break */
 880                                if (sci_port->break_flag) {
 881                                        if ((c == 0) &&
 882                                            (status & SCxSR_FER(port))) {
 883                                                count--; i--;
 884                                                continue;
 885                                        }
 886
 887                                        /* Nonzero => end-of-break */
 888                                        dev_dbg(port->dev, "debounce<%02x>\n", c);
 889                                        sci_port->break_flag = 0;
 890
 891                                        if (STEPFN(c)) {
 892                                                count--; i--;
 893                                                continue;
 894                                        }
 895                                }
 896#endif /* CONFIG_CPU_SH3 */
 897                                if (uart_handle_sysrq_char(port, c)) {
 898                                        count--; i--;
 899                                        continue;
 900                                }
 901
 902                                /* Store data and status */
 903                                if (status & SCxSR_FER(port)) {
 904                                        flag = TTY_FRAME;
 905                                        port->icount.frame++;
 906                                        dev_notice(port->dev, "frame error\n");
 907                                } else if (status & SCxSR_PER(port)) {
 908                                        flag = TTY_PARITY;
 909                                        port->icount.parity++;
 910                                        dev_notice(port->dev, "parity error\n");
 911                                } else
 912                                        flag = TTY_NORMAL;
 913
 914                                tty_insert_flip_char(tport, c, flag);
 915                        }
 916                }
 917
 918                serial_port_in(port, SCxSR); /* dummy read */
 919                sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
 920
 921                copied += count;
 922                port->icount.rx += count;
 923        }
 924
 925        if (copied) {
 926                /* Tell the rest of the system the news. New characters! */
 927                tty_flip_buffer_push(tport);
 928        } else {
 929                serial_port_in(port, SCxSR); /* dummy read */
 930                sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
 931        }
 932}
 933
 934#define SCI_BREAK_JIFFIES (HZ/20)
 935
 936/*
 937 * The sci generates interrupts during the break,
 938 * 1 per millisecond or so during the break period, for 9600 baud.
 939 * So dont bother disabling interrupts.
 940 * But dont want more than 1 break event.
 941 * Use a kernel timer to periodically poll the rx line until
 942 * the break is finished.
 943 */
 944static inline void sci_schedule_break_timer(struct sci_port *port)
 945{
 946        mod_timer(&port->break_timer, jiffies + SCI_BREAK_JIFFIES);
 947}
 948
 949/* Ensure that two consecutive samples find the break over. */
 950static void sci_break_timer(unsigned long data)
 951{
 952        struct sci_port *port = (struct sci_port *)data;
 953
 954        if (sci_rxd_in(&port->port) == 0) {
 955                port->break_flag = 1;
 956                sci_schedule_break_timer(port);
 957        } else if (port->break_flag == 1) {
 958                /* break is over. */
 959                port->break_flag = 2;
 960                sci_schedule_break_timer(port);
 961        } else
 962                port->break_flag = 0;
 963}
 964
 965static int sci_handle_errors(struct uart_port *port)
 966{
 967        int copied = 0;
 968        unsigned short status = serial_port_in(port, SCxSR);
 969        struct tty_port *tport = &port->state->port;
 970        struct sci_port *s = to_sci_port(port);
 971
 972        /* Handle overruns */
 973        if (status & s->overrun_mask) {
 974                port->icount.overrun++;
 975
 976                /* overrun error */
 977                if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
 978                        copied++;
 979
 980                dev_notice(port->dev, "overrun error\n");
 981        }
 982
 983        if (status & SCxSR_FER(port)) {
 984                if (sci_rxd_in(port) == 0) {
 985                        /* Notify of BREAK */
 986                        struct sci_port *sci_port = to_sci_port(port);
 987
 988                        if (!sci_port->break_flag) {
 989                                port->icount.brk++;
 990
 991                                sci_port->break_flag = 1;
 992                                sci_schedule_break_timer(sci_port);
 993
 994                                /* Do sysrq handling. */
 995                                if (uart_handle_break(port))
 996                                        return 0;
 997
 998                                dev_dbg(port->dev, "BREAK detected\n");
 999
1000                                if (tty_insert_flip_char(tport, 0, TTY_BREAK))
1001                                        copied++;
1002                        }
1003
1004                } else {
1005                        /* frame error */
1006                        port->icount.frame++;
1007
1008                        if (tty_insert_flip_char(tport, 0, TTY_FRAME))
1009                                copied++;
1010
1011                        dev_notice(port->dev, "frame error\n");
1012                }
1013        }
1014
1015        if (status & SCxSR_PER(port)) {
1016                /* parity error */
1017                port->icount.parity++;
1018
1019                if (tty_insert_flip_char(tport, 0, TTY_PARITY))
1020                        copied++;
1021
1022                dev_notice(port->dev, "parity error\n");
1023        }
1024
1025        if (copied)
1026                tty_flip_buffer_push(tport);
1027
1028        return copied;
1029}
1030
1031static int sci_handle_fifo_overrun(struct uart_port *port)
1032{
1033        struct tty_port *tport = &port->state->port;
1034        struct sci_port *s = to_sci_port(port);
1035        const struct plat_sci_reg *reg;
1036        int copied = 0;
1037        u16 status;
1038
1039        reg = sci_getreg(port, s->overrun_reg);
1040        if (!reg->size)
1041                return 0;
1042
1043        status = serial_port_in(port, s->overrun_reg);
1044        if (status & s->overrun_mask) {
1045                status &= ~s->overrun_mask;
1046                serial_port_out(port, s->overrun_reg, status);
1047
1048                port->icount.overrun++;
1049
1050                tty_insert_flip_char(tport, 0, TTY_OVERRUN);
1051                tty_flip_buffer_push(tport);
1052
1053                dev_dbg(port->dev, "overrun error\n");
1054                copied++;
1055        }
1056
1057        return copied;
1058}
1059
1060static int sci_handle_breaks(struct uart_port *port)
1061{
1062        int copied = 0;
1063        unsigned short status = serial_port_in(port, SCxSR);
1064        struct tty_port *tport = &port->state->port;
1065        struct sci_port *s = to_sci_port(port);
1066
1067        if (uart_handle_break(port))
1068                return 0;
1069
1070        if (!s->break_flag && status & SCxSR_BRK(port)) {
1071#if defined(CONFIG_CPU_SH3)
1072                /* Debounce break */
1073                s->break_flag = 1;
1074#endif
1075
1076                port->icount.brk++;
1077
1078                /* Notify of BREAK */
1079                if (tty_insert_flip_char(tport, 0, TTY_BREAK))
1080                        copied++;
1081
1082                dev_dbg(port->dev, "BREAK detected\n");
1083        }
1084
1085        if (copied)
1086                tty_flip_buffer_push(tport);
1087
1088        copied += sci_handle_fifo_overrun(port);
1089
1090        return copied;
1091}
1092
1093#ifdef CONFIG_SERIAL_SH_SCI_DMA
1094static void sci_dma_tx_complete(void *arg)
1095{
1096        struct sci_port *s = arg;
1097        struct uart_port *port = &s->port;
1098        struct circ_buf *xmit = &port->state->xmit;
1099        unsigned long flags;
1100
1101        dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1102
1103        spin_lock_irqsave(&port->lock, flags);
1104
1105        xmit->tail += s->tx_dma_len;
1106        xmit->tail &= UART_XMIT_SIZE - 1;
1107
1108        port->icount.tx += s->tx_dma_len;
1109
1110        if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1111                uart_write_wakeup(port);
1112
1113        if (!uart_circ_empty(xmit)) {
1114                s->cookie_tx = 0;
1115                schedule_work(&s->work_tx);
1116        } else {
1117                s->cookie_tx = -EINVAL;
1118                if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1119                        u16 ctrl = serial_port_in(port, SCSCR);
1120                        serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1121                }
1122        }
1123
1124        spin_unlock_irqrestore(&port->lock, flags);
1125}
1126
1127/* Locking: called with port lock held */
1128static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1129{
1130        struct uart_port *port = &s->port;
1131        struct tty_port *tport = &port->state->port;
1132        int copied;
1133
1134        copied = tty_insert_flip_string(tport, buf, count);
1135        if (copied < count) {
1136                dev_warn(port->dev, "Rx overrun: dropping %zu bytes\n",
1137                         count - copied);
1138                port->icount.buf_overrun++;
1139        }
1140
1141        port->icount.rx += copied;
1142
1143        return copied;
1144}
1145
1146static int sci_dma_rx_find_active(struct sci_port *s)
1147{
1148        unsigned int i;
1149
1150        for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1151                if (s->active_rx == s->cookie_rx[i])
1152                        return i;
1153
1154        dev_err(s->port.dev, "%s: Rx cookie %d not found!\n", __func__,
1155                s->active_rx);
1156        return -1;
1157}
1158
1159static void sci_rx_dma_release(struct sci_port *s, bool enable_pio)
1160{
1161        struct dma_chan *chan = s->chan_rx;
1162        struct uart_port *port = &s->port;
1163        unsigned long flags;
1164
1165        spin_lock_irqsave(&port->lock, flags);
1166        s->chan_rx = NULL;
1167        s->cookie_rx[0] = s->cookie_rx[1] = -EINVAL;
1168        spin_unlock_irqrestore(&port->lock, flags);
1169        dmaengine_terminate_all(chan);
1170        dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1171                          sg_dma_address(&s->sg_rx[0]));
1172        dma_release_channel(chan);
1173        if (enable_pio)
1174                sci_start_rx(port);
1175}
1176
1177static void sci_dma_rx_complete(void *arg)
1178{
1179        struct sci_port *s = arg;
1180        struct dma_chan *chan = s->chan_rx;
1181        struct uart_port *port = &s->port;
1182        struct dma_async_tx_descriptor *desc;
1183        unsigned long flags;
1184        int active, count = 0;
1185
1186        dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1187                s->active_rx);
1188
1189        spin_lock_irqsave(&port->lock, flags);
1190
1191        active = sci_dma_rx_find_active(s);
1192        if (active >= 0)
1193                count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1194
1195        mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
1196
1197        if (count)
1198                tty_flip_buffer_push(&port->state->port);
1199
1200        desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1201                                       DMA_DEV_TO_MEM,
1202                                       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1203        if (!desc)
1204                goto fail;
1205
1206        desc->callback = sci_dma_rx_complete;
1207        desc->callback_param = s;
1208        s->cookie_rx[active] = dmaengine_submit(desc);
1209        if (dma_submit_error(s->cookie_rx[active]))
1210                goto fail;
1211
1212        s->active_rx = s->cookie_rx[!active];
1213
1214        dma_async_issue_pending(chan);
1215
1216        dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1217                __func__, s->cookie_rx[active], active, s->active_rx);
1218        spin_unlock_irqrestore(&port->lock, flags);
1219        return;
1220
1221fail:
1222        spin_unlock_irqrestore(&port->lock, flags);
1223        dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1224        sci_rx_dma_release(s, true);
1225}
1226
1227static void sci_tx_dma_release(struct sci_port *s, bool enable_pio)
1228{
1229        struct dma_chan *chan = s->chan_tx;
1230        struct uart_port *port = &s->port;
1231        unsigned long flags;
1232
1233        spin_lock_irqsave(&port->lock, flags);
1234        s->chan_tx = NULL;
1235        s->cookie_tx = -EINVAL;
1236        spin_unlock_irqrestore(&port->lock, flags);
1237        dmaengine_terminate_all(chan);
1238        dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1239                         DMA_TO_DEVICE);
1240        dma_release_channel(chan);
1241        if (enable_pio)
1242                sci_start_tx(port);
1243}
1244
1245static void sci_submit_rx(struct sci_port *s)
1246{
1247        struct dma_chan *chan = s->chan_rx;
1248        int i;
1249
1250        for (i = 0; i < 2; i++) {
1251                struct scatterlist *sg = &s->sg_rx[i];
1252                struct dma_async_tx_descriptor *desc;
1253
1254                desc = dmaengine_prep_slave_sg(chan,
1255                        sg, 1, DMA_DEV_TO_MEM,
1256                        DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1257                if (!desc)
1258                        goto fail;
1259
1260                desc->callback = sci_dma_rx_complete;
1261                desc->callback_param = s;
1262                s->cookie_rx[i] = dmaengine_submit(desc);
1263                if (dma_submit_error(s->cookie_rx[i]))
1264                        goto fail;
1265
1266                dev_dbg(s->port.dev, "%s(): cookie %d to #%d\n", __func__,
1267                        s->cookie_rx[i], i);
1268        }
1269
1270        s->active_rx = s->cookie_rx[0];
1271
1272        dma_async_issue_pending(chan);
1273        return;
1274
1275fail:
1276        if (i)
1277                dmaengine_terminate_all(chan);
1278        for (i = 0; i < 2; i++)
1279                s->cookie_rx[i] = -EINVAL;
1280        s->active_rx = -EINVAL;
1281        dev_warn(s->port.dev, "Failed to re-start Rx DMA, using PIO\n");
1282        sci_rx_dma_release(s, true);
1283}
1284
1285static void work_fn_tx(struct work_struct *work)
1286{
1287        struct sci_port *s = container_of(work, struct sci_port, work_tx);
1288        struct dma_async_tx_descriptor *desc;
1289        struct dma_chan *chan = s->chan_tx;
1290        struct uart_port *port = &s->port;
1291        struct circ_buf *xmit = &port->state->xmit;
1292        dma_addr_t buf;
1293
1294        /*
1295         * DMA is idle now.
1296         * Port xmit buffer is already mapped, and it is one page... Just adjust
1297         * offsets and lengths. Since it is a circular buffer, we have to
1298         * transmit till the end, and then the rest. Take the port lock to get a
1299         * consistent xmit buffer state.
1300         */
1301        spin_lock_irq(&port->lock);
1302        buf = s->tx_dma_addr + (xmit->tail & (UART_XMIT_SIZE - 1));
1303        s->tx_dma_len = min_t(unsigned int,
1304                CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE),
1305                CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE));
1306        spin_unlock_irq(&port->lock);
1307
1308        desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1309                                           DMA_MEM_TO_DEV,
1310                                           DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1311        if (!desc) {
1312                dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
1313                /* switch to PIO */
1314                sci_tx_dma_release(s, true);
1315                return;
1316        }
1317
1318        dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
1319                                   DMA_TO_DEVICE);
1320
1321        spin_lock_irq(&port->lock);
1322        desc->callback = sci_dma_tx_complete;
1323        desc->callback_param = s;
1324        spin_unlock_irq(&port->lock);
1325        s->cookie_tx = dmaengine_submit(desc);
1326        if (dma_submit_error(s->cookie_tx)) {
1327                dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1328                /* switch to PIO */
1329                sci_tx_dma_release(s, true);
1330                return;
1331        }
1332
1333        dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
1334                __func__, xmit->buf, xmit->tail, xmit->head, s->cookie_tx);
1335
1336        dma_async_issue_pending(chan);
1337}
1338
1339static void rx_timer_fn(unsigned long arg)
1340{
1341        struct sci_port *s = (struct sci_port *)arg;
1342        struct dma_chan *chan = s->chan_rx;
1343        struct uart_port *port = &s->port;
1344        struct dma_tx_state state;
1345        enum dma_status status;
1346        unsigned long flags;
1347        unsigned int read;
1348        int active, count;
1349        u16 scr;
1350
1351        spin_lock_irqsave(&port->lock, flags);
1352
1353        dev_dbg(port->dev, "DMA Rx timed out\n");
1354
1355        active = sci_dma_rx_find_active(s);
1356        if (active < 0) {
1357                spin_unlock_irqrestore(&port->lock, flags);
1358                return;
1359        }
1360
1361        status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1362        if (status == DMA_COMPLETE) {
1363                dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
1364                        s->active_rx, active);
1365                spin_unlock_irqrestore(&port->lock, flags);
1366
1367                /* Let packet complete handler take care of the packet */
1368                return;
1369        }
1370
1371        dmaengine_pause(chan);
1372
1373        /*
1374         * sometimes DMA transfer doesn't stop even if it is stopped and
1375         * data keeps on coming until transaction is complete so check
1376         * for DMA_COMPLETE again
1377         * Let packet complete handler take care of the packet
1378         */
1379        status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1380        if (status == DMA_COMPLETE) {
1381                spin_unlock_irqrestore(&port->lock, flags);
1382                dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
1383                return;
1384        }
1385
1386        /* Handle incomplete DMA receive */
1387        dmaengine_terminate_all(s->chan_rx);
1388        read = sg_dma_len(&s->sg_rx[active]) - state.residue;
1389        dev_dbg(port->dev, "Read %u bytes with cookie %d\n", read,
1390                s->active_rx);
1391
1392        if (read) {
1393                count = sci_dma_rx_push(s, s->rx_buf[active], read);
1394                if (count)
1395                        tty_flip_buffer_push(&port->state->port);
1396        }
1397
1398        if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1399                sci_submit_rx(s);
1400
1401        /* Direct new serial port interrupts back to CPU */
1402        scr = serial_port_in(port, SCSCR);
1403        if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1404                scr &= ~SCSCR_RDRQE;
1405                enable_irq(s->irqs[SCIx_RXI_IRQ]);
1406        }
1407        serial_port_out(port, SCSCR, scr | SCSCR_RIE);
1408
1409        spin_unlock_irqrestore(&port->lock, flags);
1410}
1411
1412static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
1413                                             enum dma_transfer_direction dir,
1414                                             unsigned int id)
1415{
1416        dma_cap_mask_t mask;
1417        struct dma_chan *chan;
1418        struct dma_slave_config cfg;
1419        int ret;
1420
1421        dma_cap_zero(mask);
1422        dma_cap_set(DMA_SLAVE, mask);
1423
1424        chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
1425                                        (void *)(unsigned long)id, port->dev,
1426                                        dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1427        if (!chan) {
1428                dev_warn(port->dev,
1429                         "dma_request_slave_channel_compat failed\n");
1430                return NULL;
1431        }
1432
1433        memset(&cfg, 0, sizeof(cfg));
1434        cfg.direction = dir;
1435        if (dir == DMA_MEM_TO_DEV) {
1436                cfg.dst_addr = port->mapbase +
1437                        (sci_getreg(port, SCxTDR)->offset << port->regshift);
1438                cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1439        } else {
1440                cfg.src_addr = port->mapbase +
1441                        (sci_getreg(port, SCxRDR)->offset << port->regshift);
1442                cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1443        }
1444
1445        ret = dmaengine_slave_config(chan, &cfg);
1446        if (ret) {
1447                dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
1448                dma_release_channel(chan);
1449                return NULL;
1450        }
1451
1452        return chan;
1453}
1454
1455static void sci_request_dma(struct uart_port *port)
1456{
1457        struct sci_port *s = to_sci_port(port);
1458        struct dma_chan *chan;
1459
1460        dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1461
1462        if (!port->dev->of_node &&
1463            (s->cfg->dma_slave_tx <= 0 || s->cfg->dma_slave_rx <= 0))
1464                return;
1465
1466        s->cookie_tx = -EINVAL;
1467        chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV, s->cfg->dma_slave_tx);
1468        dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1469        if (chan) {
1470                s->chan_tx = chan;
1471                /* UART circular tx buffer is an aligned page. */
1472                s->tx_dma_addr = dma_map_single(chan->device->dev,
1473                                                port->state->xmit.buf,
1474                                                UART_XMIT_SIZE,
1475                                                DMA_TO_DEVICE);
1476                if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1477                        dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1478                        dma_release_channel(chan);
1479                        s->chan_tx = NULL;
1480                } else {
1481                        dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1482                                __func__, UART_XMIT_SIZE,
1483                                port->state->xmit.buf, &s->tx_dma_addr);
1484                }
1485
1486                INIT_WORK(&s->work_tx, work_fn_tx);
1487        }
1488
1489        chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM, s->cfg->dma_slave_rx);
1490        dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1491        if (chan) {
1492                unsigned int i;
1493                dma_addr_t dma;
1494                void *buf;
1495
1496                s->chan_rx = chan;
1497
1498                s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1499                buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1500                                         &dma, GFP_KERNEL);
1501                if (!buf) {
1502                        dev_warn(port->dev,
1503                                 "Failed to allocate Rx dma buffer, using PIO\n");
1504                        dma_release_channel(chan);
1505                        s->chan_rx = NULL;
1506                        return;
1507                }
1508
1509                for (i = 0; i < 2; i++) {
1510                        struct scatterlist *sg = &s->sg_rx[i];
1511
1512                        sg_init_table(sg, 1);
1513                        s->rx_buf[i] = buf;
1514                        sg_dma_address(sg) = dma;
1515                        sg_dma_len(sg) = s->buf_len_rx;
1516
1517                        buf += s->buf_len_rx;
1518                        dma += s->buf_len_rx;
1519                }
1520
1521                setup_timer(&s->rx_timer, rx_timer_fn, (unsigned long)s);
1522
1523                if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1524                        sci_submit_rx(s);
1525        }
1526}
1527
1528static void sci_free_dma(struct uart_port *port)
1529{
1530        struct sci_port *s = to_sci_port(port);
1531
1532        if (s->chan_tx)
1533                sci_tx_dma_release(s, false);
1534        if (s->chan_rx)
1535                sci_rx_dma_release(s, false);
1536}
1537#else
1538static inline void sci_request_dma(struct uart_port *port)
1539{
1540}
1541
1542static inline void sci_free_dma(struct uart_port *port)
1543{
1544}
1545#endif
1546
1547static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1548{
1549#ifdef CONFIG_SERIAL_SH_SCI_DMA
1550        struct uart_port *port = ptr;
1551        struct sci_port *s = to_sci_port(port);
1552
1553        if (s->chan_rx) {
1554                u16 scr = serial_port_in(port, SCSCR);
1555                u16 ssr = serial_port_in(port, SCxSR);
1556
1557                /* Disable future Rx interrupts */
1558                if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1559                        disable_irq_nosync(irq);
1560                        scr |= SCSCR_RDRQE;
1561                } else {
1562                        scr &= ~SCSCR_RIE;
1563                        sci_submit_rx(s);
1564                }
1565                serial_port_out(port, SCSCR, scr);
1566                /* Clear current interrupt */
1567                serial_port_out(port, SCxSR,
1568                                ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1569                dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u jiffies\n",
1570                        jiffies, s->rx_timeout);
1571                mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
1572
1573                return IRQ_HANDLED;
1574        }
1575#endif
1576
1577        /* I think sci_receive_chars has to be called irrespective
1578         * of whether the I_IXOFF is set, otherwise, how is the interrupt
1579         * to be disabled?
1580         */
1581        sci_receive_chars(ptr);
1582
1583        return IRQ_HANDLED;
1584}
1585
1586static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1587{
1588        struct uart_port *port = ptr;
1589        unsigned long flags;
1590
1591        spin_lock_irqsave(&port->lock, flags);
1592        sci_transmit_chars(port);
1593        spin_unlock_irqrestore(&port->lock, flags);
1594
1595        return IRQ_HANDLED;
1596}
1597
1598static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1599{
1600        struct uart_port *port = ptr;
1601        struct sci_port *s = to_sci_port(port);
1602
1603        /* Handle errors */
1604        if (port->type == PORT_SCI) {
1605                if (sci_handle_errors(port)) {
1606                        /* discard character in rx buffer */
1607                        serial_port_in(port, SCxSR);
1608                        sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1609                }
1610        } else {
1611                sci_handle_fifo_overrun(port);
1612                if (!s->chan_rx)
1613                        sci_receive_chars(ptr);
1614        }
1615
1616        sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1617
1618        /* Kick the transmission */
1619        if (!s->chan_tx)
1620                sci_tx_interrupt(irq, ptr);
1621
1622        return IRQ_HANDLED;
1623}
1624
1625static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1626{
1627        struct uart_port *port = ptr;
1628
1629        /* Handle BREAKs */
1630        sci_handle_breaks(port);
1631        sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1632
1633        return IRQ_HANDLED;
1634}
1635
1636static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1637{
1638        unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1639        struct uart_port *port = ptr;
1640        struct sci_port *s = to_sci_port(port);
1641        irqreturn_t ret = IRQ_NONE;
1642
1643        ssr_status = serial_port_in(port, SCxSR);
1644        scr_status = serial_port_in(port, SCSCR);
1645        if (s->overrun_reg == SCxSR)
1646                orer_status = ssr_status;
1647        else {
1648                if (sci_getreg(port, s->overrun_reg)->size)
1649                        orer_status = serial_port_in(port, s->overrun_reg);
1650        }
1651
1652        err_enabled = scr_status & port_rx_irq_mask(port);
1653
1654        /* Tx Interrupt */
1655        if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1656            !s->chan_tx)
1657                ret = sci_tx_interrupt(irq, ptr);
1658
1659        /*
1660         * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1661         * DR flags
1662         */
1663        if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1664            (scr_status & SCSCR_RIE))
1665                ret = sci_rx_interrupt(irq, ptr);
1666
1667        /* Error Interrupt */
1668        if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1669                ret = sci_er_interrupt(irq, ptr);
1670
1671        /* Break Interrupt */
1672        if ((ssr_status & SCxSR_BRK(port)) && err_enabled)
1673                ret = sci_br_interrupt(irq, ptr);
1674
1675        /* Overrun Interrupt */
1676        if (orer_status & s->overrun_mask) {
1677                sci_handle_fifo_overrun(port);
1678                ret = IRQ_HANDLED;
1679        }
1680
1681        return ret;
1682}
1683
1684static const struct sci_irq_desc {
1685        const char      *desc;
1686        irq_handler_t   handler;
1687} sci_irq_desc[] = {
1688        /*
1689         * Split out handlers, the default case.
1690         */
1691        [SCIx_ERI_IRQ] = {
1692                .desc = "rx err",
1693                .handler = sci_er_interrupt,
1694        },
1695
1696        [SCIx_RXI_IRQ] = {
1697                .desc = "rx full",
1698                .handler = sci_rx_interrupt,
1699        },
1700
1701        [SCIx_TXI_IRQ] = {
1702                .desc = "tx empty",
1703                .handler = sci_tx_interrupt,
1704        },
1705
1706        [SCIx_BRI_IRQ] = {
1707                .desc = "break",
1708                .handler = sci_br_interrupt,
1709        },
1710
1711        /*
1712         * Special muxed handler.
1713         */
1714        [SCIx_MUX_IRQ] = {
1715                .desc = "mux",
1716                .handler = sci_mpxed_interrupt,
1717        },
1718};
1719
1720static int sci_request_irq(struct sci_port *port)
1721{
1722        struct uart_port *up = &port->port;
1723        int i, j, ret = 0;
1724
1725        for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1726                const struct sci_irq_desc *desc;
1727                int irq;
1728
1729                if (SCIx_IRQ_IS_MUXED(port)) {
1730                        i = SCIx_MUX_IRQ;
1731                        irq = up->irq;
1732                } else {
1733                        irq = port->irqs[i];
1734
1735                        /*
1736                         * Certain port types won't support all of the
1737                         * available interrupt sources.
1738                         */
1739                        if (unlikely(irq < 0))
1740                                continue;
1741                }
1742
1743                desc = sci_irq_desc + i;
1744                port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1745                                            dev_name(up->dev), desc->desc);
1746                if (!port->irqstr[j])
1747                        goto out_nomem;
1748
1749                ret = request_irq(irq, desc->handler, up->irqflags,
1750                                  port->irqstr[j], port);
1751                if (unlikely(ret)) {
1752                        dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1753                        goto out_noirq;
1754                }
1755        }
1756
1757        return 0;
1758
1759out_noirq:
1760        while (--i >= 0)
1761                free_irq(port->irqs[i], port);
1762
1763out_nomem:
1764        while (--j >= 0)
1765                kfree(port->irqstr[j]);
1766
1767        return ret;
1768}
1769
1770static void sci_free_irq(struct sci_port *port)
1771{
1772        int i;
1773
1774        /*
1775         * Intentionally in reverse order so we iterate over the muxed
1776         * IRQ first.
1777         */
1778        for (i = 0; i < SCIx_NR_IRQS; i++) {
1779                int irq = port->irqs[i];
1780
1781                /*
1782                 * Certain port types won't support all of the available
1783                 * interrupt sources.
1784                 */
1785                if (unlikely(irq < 0))
1786                        continue;
1787
1788                free_irq(port->irqs[i], port);
1789                kfree(port->irqstr[i]);
1790
1791                if (SCIx_IRQ_IS_MUXED(port)) {
1792                        /* If there's only one IRQ, we're done. */
1793                        return;
1794                }
1795        }
1796}
1797
1798static unsigned int sci_tx_empty(struct uart_port *port)
1799{
1800        unsigned short status = serial_port_in(port, SCxSR);
1801        unsigned short in_tx_fifo = sci_txfill(port);
1802
1803        return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
1804}
1805
1806/*
1807 * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
1808 * CTS/RTS is supported in hardware by at least one port and controlled
1809 * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
1810 * handled via the ->init_pins() op, which is a bit of a one-way street,
1811 * lacking any ability to defer pin control -- this will later be
1812 * converted over to the GPIO framework).
1813 *
1814 * Other modes (such as loopback) are supported generically on certain
1815 * port types, but not others. For these it's sufficient to test for the
1816 * existence of the support register and simply ignore the port type.
1817 */
1818static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
1819{
1820        if (mctrl & TIOCM_LOOP) {
1821                const struct plat_sci_reg *reg;
1822
1823                /*
1824                 * Standard loopback mode for SCFCR ports.
1825                 */
1826                reg = sci_getreg(port, SCFCR);
1827                if (reg->size)
1828                        serial_port_out(port, SCFCR,
1829                                        serial_port_in(port, SCFCR) |
1830                                        SCFCR_LOOP);
1831        }
1832}
1833
1834static unsigned int sci_get_mctrl(struct uart_port *port)
1835{
1836        /*
1837         * CTS/RTS is handled in hardware when supported, while nothing
1838         * else is wired up. Keep it simple and simply assert DSR/CAR.
1839         */
1840        return TIOCM_DSR | TIOCM_CAR;
1841}
1842
1843static void sci_break_ctl(struct uart_port *port, int break_state)
1844{
1845        struct sci_port *s = to_sci_port(port);
1846        const struct plat_sci_reg *reg = sci_regmap[s->cfg->regtype] + SCSPTR;
1847        unsigned short scscr, scsptr;
1848
1849        /* check wheter the port has SCSPTR */
1850        if (!reg->size) {
1851                /*
1852                 * Not supported by hardware. Most parts couple break and rx
1853                 * interrupts together, with break detection always enabled.
1854                 */
1855                return;
1856        }
1857
1858        scsptr = serial_port_in(port, SCSPTR);
1859        scscr = serial_port_in(port, SCSCR);
1860
1861        if (break_state == -1) {
1862                scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
1863                scscr &= ~SCSCR_TE;
1864        } else {
1865                scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
1866                scscr |= SCSCR_TE;
1867        }
1868
1869        serial_port_out(port, SCSPTR, scsptr);
1870        serial_port_out(port, SCSCR, scscr);
1871}
1872
1873static int sci_startup(struct uart_port *port)
1874{
1875        struct sci_port *s = to_sci_port(port);
1876        unsigned long flags;
1877        int ret;
1878
1879        dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1880
1881        ret = sci_request_irq(s);
1882        if (unlikely(ret < 0))
1883                return ret;
1884
1885        sci_request_dma(port);
1886
1887        spin_lock_irqsave(&port->lock, flags);
1888        sci_start_tx(port);
1889        sci_start_rx(port);
1890        spin_unlock_irqrestore(&port->lock, flags);
1891
1892        return 0;
1893}
1894
1895static void sci_shutdown(struct uart_port *port)
1896{
1897        struct sci_port *s = to_sci_port(port);
1898        unsigned long flags;
1899
1900        dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1901
1902        spin_lock_irqsave(&port->lock, flags);
1903        sci_stop_rx(port);
1904        sci_stop_tx(port);
1905        spin_unlock_irqrestore(&port->lock, flags);
1906
1907#ifdef CONFIG_SERIAL_SH_SCI_DMA
1908        if (s->chan_rx) {
1909                dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
1910                        port->line);
1911                del_timer_sync(&s->rx_timer);
1912        }
1913#endif
1914
1915        sci_free_dma(port);
1916        sci_free_irq(s);
1917}
1918
1919static int sci_sck_calc(struct sci_port *s, unsigned int bps,
1920                        unsigned int *srr)
1921{
1922        unsigned long freq = s->clk_rates[SCI_SCK];
1923        int err, min_err = INT_MAX;
1924        unsigned int sr;
1925
1926        if (s->port.type != PORT_HSCIF)
1927                freq *= 2;
1928
1929        for_each_sr(sr, s) {
1930                err = DIV_ROUND_CLOSEST(freq, sr) - bps;
1931                if (abs(err) >= abs(min_err))
1932                        continue;
1933
1934                min_err = err;
1935                *srr = sr - 1;
1936
1937                if (!err)
1938                        break;
1939        }
1940
1941        dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
1942                *srr + 1);
1943        return min_err;
1944}
1945
1946static int sci_brg_calc(struct sci_port *s, unsigned int bps,
1947                        unsigned long freq, unsigned int *dlr,
1948                        unsigned int *srr)
1949{
1950        int err, min_err = INT_MAX;
1951        unsigned int sr, dl;
1952
1953        if (s->port.type != PORT_HSCIF)
1954                freq *= 2;
1955
1956        for_each_sr(sr, s) {
1957                dl = DIV_ROUND_CLOSEST(freq, sr * bps);
1958                dl = clamp(dl, 1U, 65535U);
1959
1960                err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
1961                if (abs(err) >= abs(min_err))
1962                        continue;
1963
1964                min_err = err;
1965                *dlr = dl;
1966                *srr = sr - 1;
1967
1968                if (!err)
1969                        break;
1970        }
1971
1972        dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
1973                min_err, *dlr, *srr + 1);
1974        return min_err;
1975}
1976
1977/* calculate sample rate, BRR, and clock select */
1978static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
1979                          unsigned int *brr, unsigned int *srr,
1980                          unsigned int *cks)
1981{
1982        unsigned long freq = s->clk_rates[SCI_FCK];
1983        unsigned int sr, br, prediv, scrate, c;
1984        int err, min_err = INT_MAX;
1985
1986        if (s->port.type != PORT_HSCIF)
1987                freq *= 2;
1988
1989        /*
1990         * Find the combination of sample rate and clock select with the
1991         * smallest deviation from the desired baud rate.
1992         * Prefer high sample rates to maximise the receive margin.
1993         *
1994         * M: Receive margin (%)
1995         * N: Ratio of bit rate to clock (N = sampling rate)
1996         * D: Clock duty (D = 0 to 1.0)
1997         * L: Frame length (L = 9 to 12)
1998         * F: Absolute value of clock frequency deviation
1999         *
2000         *  M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2001         *      (|D - 0.5| / N * (1 + F))|
2002         *  NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2003         */
2004        for_each_sr(sr, s) {
2005                for (c = 0; c <= 3; c++) {
2006                        /* integerized formulas from HSCIF documentation */
2007                        prediv = sr * (1 << (2 * c + 1));
2008
2009                        /*
2010                         * We need to calculate:
2011                         *
2012                         *     br = freq / (prediv * bps) clamped to [1..256]
2013                         *     err = freq / (br * prediv) - bps
2014                         *
2015                         * Watch out for overflow when calculating the desired
2016                         * sampling clock rate!
2017                         */
2018                        if (bps > UINT_MAX / prediv)
2019                                break;
2020
2021                        scrate = prediv * bps;
2022                        br = DIV_ROUND_CLOSEST(freq, scrate);
2023                        br = clamp(br, 1U, 256U);
2024
2025                        err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2026                        if (abs(err) >= abs(min_err))
2027                                continue;
2028
2029                        min_err = err;
2030                        *brr = br - 1;
2031                        *srr = sr - 1;
2032                        *cks = c;
2033
2034                        if (!err)
2035                                goto found;
2036                }
2037        }
2038
2039found:
2040        dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2041                min_err, *brr, *srr + 1, *cks);
2042        return min_err;
2043}
2044
2045static void sci_reset(struct uart_port *port)
2046{
2047        const struct plat_sci_reg *reg;
2048        unsigned int status;
2049
2050        do {
2051                status = serial_port_in(port, SCxSR);
2052        } while (!(status & SCxSR_TEND(port)));
2053
2054        serial_port_out(port, SCSCR, 0x00);     /* TE=0, RE=0, CKE1=0 */
2055
2056        reg = sci_getreg(port, SCFCR);
2057        if (reg->size)
2058                serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2059}
2060
2061static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2062                            struct ktermios *old)
2063{
2064        unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i;
2065        unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
2066        unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
2067        struct sci_port *s = to_sci_port(port);
2068        const struct plat_sci_reg *reg;
2069        int min_err = INT_MAX, err;
2070        unsigned long max_freq = 0;
2071        int best_clk = -1;
2072
2073        if ((termios->c_cflag & CSIZE) == CS7)
2074                smr_val |= SCSMR_CHR;
2075        if (termios->c_cflag & PARENB)
2076                smr_val |= SCSMR_PE;
2077        if (termios->c_cflag & PARODD)
2078                smr_val |= SCSMR_PE | SCSMR_ODD;
2079        if (termios->c_cflag & CSTOPB)
2080                smr_val |= SCSMR_STOP;
2081
2082        /*
2083         * earlyprintk comes here early on with port->uartclk set to zero.
2084         * the clock framework is not up and running at this point so here
2085         * we assume that 115200 is the maximum baud rate. please note that
2086         * the baud rate is not programmed during earlyprintk - it is assumed
2087         * that the previous boot loader has enabled required clocks and
2088         * setup the baud rate generator hardware for us already.
2089         */
2090        if (!port->uartclk) {
2091                baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2092                goto done;
2093        }
2094
2095        for (i = 0; i < SCI_NUM_CLKS; i++)
2096                max_freq = max(max_freq, s->clk_rates[i]);
2097
2098        baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
2099        if (!baud)
2100                goto done;
2101
2102        /*
2103         * There can be multiple sources for the sampling clock.  Find the one
2104         * that gives us the smallest deviation from the desired baud rate.
2105         */
2106
2107        /* Optional Undivided External Clock */
2108        if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
2109            port->type != PORT_SCIFB) {
2110                err = sci_sck_calc(s, baud, &srr1);
2111                if (abs(err) < abs(min_err)) {
2112                        best_clk = SCI_SCK;
2113                        scr_val = SCSCR_CKE1;
2114                        sccks = SCCKS_CKS;
2115                        min_err = err;
2116                        srr = srr1;
2117                        if (!err)
2118                                goto done;
2119                }
2120        }
2121
2122        /* Optional BRG Frequency Divided External Clock */
2123        if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
2124                err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
2125                                   &srr1);
2126                if (abs(err) < abs(min_err)) {
2127                        best_clk = SCI_SCIF_CLK;
2128                        scr_val = SCSCR_CKE1;
2129                        sccks = 0;
2130                        min_err = err;
2131                        dl = dl1;
2132                        srr = srr1;
2133                        if (!err)
2134                                goto done;
2135                }
2136        }
2137
2138        /* Optional BRG Frequency Divided Internal Clock */
2139        if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
2140                err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
2141                                   &srr1);
2142                if (abs(err) < abs(min_err)) {
2143                        best_clk = SCI_BRG_INT;
2144                        scr_val = SCSCR_CKE1;
2145                        sccks = SCCKS_XIN;
2146                        min_err = err;
2147                        dl = dl1;
2148                        srr = srr1;
2149                        if (!min_err)
2150                                goto done;
2151                }
2152        }
2153
2154        /* Divided Functional Clock using standard Bit Rate Register */
2155        err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
2156        if (abs(err) < abs(min_err)) {
2157                best_clk = SCI_FCK;
2158                scr_val = 0;
2159                min_err = err;
2160                brr = brr1;
2161                srr = srr1;
2162                cks = cks1;
2163        }
2164
2165done:
2166        if (best_clk >= 0)
2167                dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2168                        s->clks[best_clk], baud, min_err);
2169
2170        sci_port_enable(s);
2171
2172        /*
2173         * Program the optional External Baud Rate Generator (BRG) first.
2174         * It controls the mux to select (H)SCK or frequency divided clock.
2175         */
2176        if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2177                serial_port_out(port, SCDL, dl);
2178                serial_port_out(port, SCCKS, sccks);
2179        }
2180
2181        sci_reset(port);
2182
2183        uart_update_timeout(port, termios->c_cflag, baud);
2184
2185        if (best_clk >= 0) {
2186                if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
2187                        switch (srr + 1) {
2188                        case 5:  smr_val |= SCSMR_SRC_5;  break;
2189                        case 7:  smr_val |= SCSMR_SRC_7;  break;
2190                        case 11: smr_val |= SCSMR_SRC_11; break;
2191                        case 13: smr_val |= SCSMR_SRC_13; break;
2192                        case 16: smr_val |= SCSMR_SRC_16; break;
2193                        case 17: smr_val |= SCSMR_SRC_17; break;
2194                        case 19: smr_val |= SCSMR_SRC_19; break;
2195                        case 27: smr_val |= SCSMR_SRC_27; break;
2196                        }
2197                smr_val |= cks;
2198                dev_dbg(port->dev,
2199                         "SCR 0x%x SMR 0x%x BRR %u CKS 0x%x DL %u SRR %u\n",
2200                         scr_val, smr_val, brr, sccks, dl, srr);
2201                serial_port_out(port, SCSCR, scr_val);
2202                serial_port_out(port, SCSMR, smr_val);
2203                serial_port_out(port, SCBRR, brr);
2204                if (sci_getreg(port, HSSRR)->size)
2205                        serial_port_out(port, HSSRR, srr | HSCIF_SRE);
2206
2207                /* Wait one bit interval */
2208                udelay((1000000 + (baud - 1)) / baud);
2209        } else {
2210                /* Don't touch the bit rate configuration */
2211                scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
2212                smr_val |= serial_port_in(port, SCSMR) &
2213                           (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
2214                dev_dbg(port->dev, "SCR 0x%x SMR 0x%x\n", scr_val, smr_val);
2215                serial_port_out(port, SCSCR, scr_val);
2216                serial_port_out(port, SCSMR, smr_val);
2217        }
2218
2219        sci_init_pins(port, termios->c_cflag);
2220
2221        reg = sci_getreg(port, SCFCR);
2222        if (reg->size) {
2223                unsigned short ctrl = serial_port_in(port, SCFCR);
2224
2225                if (s->cfg->capabilities & SCIx_HAVE_RTSCTS) {
2226                        if (termios->c_cflag & CRTSCTS)
2227                                ctrl |= SCFCR_MCE;
2228                        else
2229                                ctrl &= ~SCFCR_MCE;
2230                }
2231
2232                /*
2233                 * As we've done a sci_reset() above, ensure we don't
2234                 * interfere with the FIFOs while toggling MCE. As the
2235                 * reset values could still be set, simply mask them out.
2236                 */
2237                ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2238
2239                serial_port_out(port, SCFCR, ctrl);
2240        }
2241
2242        scr_val |= s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0);
2243        dev_dbg(port->dev, "SCSCR 0x%x\n", scr_val);
2244        serial_port_out(port, SCSCR, scr_val);
2245        if ((srr + 1 == 5) &&
2246            (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
2247                /*
2248                 * In asynchronous mode, when the sampling rate is 1/5, first
2249                 * received data may become invalid on some SCIFA and SCIFB.
2250                 * To avoid this problem wait more than 1 serial data time (1
2251                 * bit time x serial data number) after setting SCSCR.RE = 1.
2252                 */
2253                udelay(DIV_ROUND_UP(10 * 1000000, baud));
2254        }
2255
2256#ifdef CONFIG_SERIAL_SH_SCI_DMA
2257        /*
2258         * Calculate delay for 2 DMA buffers (4 FIFO).
2259         * See serial_core.c::uart_update_timeout().
2260         * With 10 bits (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above
2261         * function calculates 1 jiffie for the data plus 5 jiffies for the
2262         * "slop(e)." Then below we calculate 5 jiffies (20ms) for 2 DMA
2263         * buffers (4 FIFO sizes), but when performing a faster transfer, the
2264         * value obtained by this formula is too small. Therefore, if the value
2265         * is smaller than 20ms, use 20ms as the timeout value for DMA.
2266         */
2267        if (s->chan_rx) {
2268                unsigned int bits;
2269
2270                /* byte size and parity */
2271                switch (termios->c_cflag & CSIZE) {
2272                case CS5:
2273                        bits = 7;
2274                        break;
2275                case CS6:
2276                        bits = 8;
2277                        break;
2278                case CS7:
2279                        bits = 9;
2280                        break;
2281                default:
2282                        bits = 10;
2283                        break;
2284                }
2285
2286                if (termios->c_cflag & CSTOPB)
2287                        bits++;
2288                if (termios->c_cflag & PARENB)
2289                        bits++;
2290                s->rx_timeout = DIV_ROUND_UP((s->buf_len_rx * 2 * bits * HZ) /
2291                                             (baud / 10), 10);
2292                dev_dbg(port->dev, "DMA Rx t-out %ums, tty t-out %u jiffies\n",
2293                        s->rx_timeout * 1000 / HZ, port->timeout);
2294                if (s->rx_timeout < msecs_to_jiffies(20))
2295                        s->rx_timeout = msecs_to_jiffies(20);
2296        }
2297#endif
2298
2299        if ((termios->c_cflag & CREAD) != 0)
2300                sci_start_rx(port);
2301
2302        sci_port_disable(s);
2303}
2304
2305static void sci_pm(struct uart_port *port, unsigned int state,
2306                   unsigned int oldstate)
2307{
2308        struct sci_port *sci_port = to_sci_port(port);
2309
2310        switch (state) {
2311        case UART_PM_STATE_OFF:
2312                sci_port_disable(sci_port);
2313                break;
2314        default:
2315                sci_port_enable(sci_port);
2316                break;
2317        }
2318}
2319
2320static const char *sci_type(struct uart_port *port)
2321{
2322        switch (port->type) {
2323        case PORT_IRDA:
2324                return "irda";
2325        case PORT_SCI:
2326                return "sci";
2327        case PORT_SCIF:
2328                return "scif";
2329        case PORT_SCIFA:
2330                return "scifa";
2331        case PORT_SCIFB:
2332                return "scifb";
2333        case PORT_HSCIF:
2334                return "hscif";
2335        }
2336
2337        return NULL;
2338}
2339
2340static int sci_remap_port(struct uart_port *port)
2341{
2342        struct sci_port *sport = to_sci_port(port);
2343
2344        /*
2345         * Nothing to do if there's already an established membase.
2346         */
2347        if (port->membase)
2348                return 0;
2349
2350        if (port->flags & UPF_IOREMAP) {
2351                port->membase = ioremap_nocache(port->mapbase, sport->reg_size);
2352                if (unlikely(!port->membase)) {
2353                        dev_err(port->dev, "can't remap port#%d\n", port->line);
2354                        return -ENXIO;
2355                }
2356        } else {
2357                /*
2358                 * For the simple (and majority of) cases where we don't
2359                 * need to do any remapping, just cast the cookie
2360                 * directly.
2361                 */
2362                port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2363        }
2364
2365        return 0;
2366}
2367
2368static void sci_release_port(struct uart_port *port)
2369{
2370        struct sci_port *sport = to_sci_port(port);
2371
2372        if (port->flags & UPF_IOREMAP) {
2373                iounmap(port->membase);
2374                port->membase = NULL;
2375        }
2376
2377        release_mem_region(port->mapbase, sport->reg_size);
2378}
2379
2380static int sci_request_port(struct uart_port *port)
2381{
2382        struct resource *res;
2383        struct sci_port *sport = to_sci_port(port);
2384        int ret;
2385
2386        res = request_mem_region(port->mapbase, sport->reg_size,
2387                                 dev_name(port->dev));
2388        if (unlikely(res == NULL)) {
2389                dev_err(port->dev, "request_mem_region failed.");
2390                return -EBUSY;
2391        }
2392
2393        ret = sci_remap_port(port);
2394        if (unlikely(ret != 0)) {
2395                release_resource(res);
2396                return ret;
2397        }
2398
2399        return 0;
2400}
2401
2402static void sci_config_port(struct uart_port *port, int flags)
2403{
2404        if (flags & UART_CONFIG_TYPE) {
2405                struct sci_port *sport = to_sci_port(port);
2406
2407                port->type = sport->cfg->type;
2408                sci_request_port(port);
2409        }
2410}
2411
2412static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2413{
2414        if (ser->baud_base < 2400)
2415                /* No paper tape reader for Mitch.. */
2416                return -EINVAL;
2417
2418        return 0;
2419}
2420
2421static struct uart_ops sci_uart_ops = {
2422        .tx_empty       = sci_tx_empty,
2423        .set_mctrl      = sci_set_mctrl,
2424        .get_mctrl      = sci_get_mctrl,
2425        .start_tx       = sci_start_tx,
2426        .stop_tx        = sci_stop_tx,
2427        .stop_rx        = sci_stop_rx,
2428        .break_ctl      = sci_break_ctl,
2429        .startup        = sci_startup,
2430        .shutdown       = sci_shutdown,
2431        .set_termios    = sci_set_termios,
2432        .pm             = sci_pm,
2433        .type           = sci_type,
2434        .release_port   = sci_release_port,
2435        .request_port   = sci_request_port,
2436        .config_port    = sci_config_port,
2437        .verify_port    = sci_verify_port,
2438#ifdef CONFIG_CONSOLE_POLL
2439        .poll_get_char  = sci_poll_get_char,
2440        .poll_put_char  = sci_poll_put_char,
2441#endif
2442};
2443
2444static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2445{
2446        const char *clk_names[] = {
2447                [SCI_FCK] = "fck",
2448                [SCI_SCK] = "sck",
2449                [SCI_BRG_INT] = "brg_int",
2450                [SCI_SCIF_CLK] = "scif_clk",
2451        };
2452        struct clk *clk;
2453        unsigned int i;
2454
2455        if (sci_port->cfg->type == PORT_HSCIF)
2456                clk_names[SCI_SCK] = "hsck";
2457
2458        for (i = 0; i < SCI_NUM_CLKS; i++) {
2459                clk = devm_clk_get(dev, clk_names[i]);
2460                if (PTR_ERR(clk) == -EPROBE_DEFER)
2461                        return -EPROBE_DEFER;
2462
2463                if (IS_ERR(clk) && i == SCI_FCK) {
2464                        /*
2465                         * "fck" used to be called "sci_ick", and we need to
2466                         * maintain DT backward compatibility.
2467                         */
2468                        clk = devm_clk_get(dev, "sci_ick");
2469                        if (PTR_ERR(clk) == -EPROBE_DEFER)
2470                                return -EPROBE_DEFER;
2471
2472                        if (!IS_ERR(clk))
2473                                goto found;
2474
2475                        /*
2476                         * Not all SH platforms declare a clock lookup entry
2477                         * for SCI devices, in which case we need to get the
2478                         * global "peripheral_clk" clock.
2479                         */
2480                        clk = devm_clk_get(dev, "peripheral_clk");
2481                        if (!IS_ERR(clk))
2482                                goto found;
2483
2484                        dev_err(dev, "failed to get %s (%ld)\n", clk_names[i],
2485                                PTR_ERR(clk));
2486                        return PTR_ERR(clk);
2487                }
2488
2489found:
2490                if (IS_ERR(clk))
2491                        dev_dbg(dev, "failed to get %s (%ld)\n", clk_names[i],
2492                                PTR_ERR(clk));
2493                else
2494                        dev_dbg(dev, "clk %s is %pC rate %pCr\n", clk_names[i],
2495                                clk, clk);
2496                sci_port->clks[i] = IS_ERR(clk) ? NULL : clk;
2497        }
2498        return 0;
2499}
2500
2501static int sci_init_single(struct platform_device *dev,
2502                           struct sci_port *sci_port, unsigned int index,
2503                           struct plat_sci_port *p, bool early)
2504{
2505        struct uart_port *port = &sci_port->port;
2506        const struct resource *res;
2507        unsigned int i;
2508        int ret;
2509
2510        sci_port->cfg   = p;
2511
2512        port->ops       = &sci_uart_ops;
2513        port->iotype    = UPIO_MEM;
2514        port->line      = index;
2515
2516        res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2517        if (res == NULL)
2518                return -ENOMEM;
2519
2520        port->mapbase = res->start;
2521        sci_port->reg_size = resource_size(res);
2522
2523        for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i)
2524                sci_port->irqs[i] = platform_get_irq(dev, i);
2525
2526        /* The SCI generates several interrupts. They can be muxed together or
2527         * connected to different interrupt lines. In the muxed case only one
2528         * interrupt resource is specified. In the non-muxed case three or four
2529         * interrupt resources are specified, as the BRI interrupt is optional.
2530         */
2531        if (sci_port->irqs[0] < 0)
2532                return -ENXIO;
2533
2534        if (sci_port->irqs[1] < 0) {
2535                sci_port->irqs[1] = sci_port->irqs[0];
2536                sci_port->irqs[2] = sci_port->irqs[0];
2537                sci_port->irqs[3] = sci_port->irqs[0];
2538        }
2539
2540        if (p->regtype == SCIx_PROBE_REGTYPE) {
2541                ret = sci_probe_regmap(p);
2542                if (unlikely(ret))
2543                        return ret;
2544        }
2545
2546        switch (p->type) {
2547        case PORT_SCIFB:
2548                port->fifosize = 256;
2549                sci_port->overrun_reg = SCxSR;
2550                sci_port->overrun_mask = SCIFA_ORER;
2551                sci_port->sampling_rate_mask = SCI_SR_SCIFAB;
2552                break;
2553        case PORT_HSCIF:
2554                port->fifosize = 128;
2555                sci_port->overrun_reg = SCLSR;
2556                sci_port->overrun_mask = SCLSR_ORER;
2557                sci_port->sampling_rate_mask = SCI_SR_RANGE(8, 32);
2558                break;
2559        case PORT_SCIFA:
2560                port->fifosize = 64;
2561                sci_port->overrun_reg = SCxSR;
2562                sci_port->overrun_mask = SCIFA_ORER;
2563                sci_port->sampling_rate_mask = SCI_SR_SCIFAB;
2564                break;
2565        case PORT_SCIF:
2566                port->fifosize = 16;
2567                if (p->regtype == SCIx_SH7705_SCIF_REGTYPE) {
2568                        sci_port->overrun_reg = SCxSR;
2569                        sci_port->overrun_mask = SCIFA_ORER;
2570                        sci_port->sampling_rate_mask = SCI_SR(16);
2571                } else {
2572                        sci_port->overrun_reg = SCLSR;
2573                        sci_port->overrun_mask = SCLSR_ORER;
2574                        sci_port->sampling_rate_mask = SCI_SR(32);
2575                }
2576                break;
2577        default:
2578                port->fifosize = 1;
2579                sci_port->overrun_reg = SCxSR;
2580                sci_port->overrun_mask = SCI_ORER;
2581                sci_port->sampling_rate_mask = SCI_SR(32);
2582                break;
2583        }
2584
2585        /* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
2586         * match the SoC datasheet, this should be investigated. Let platform
2587         * data override the sampling rate for now.
2588         */
2589        if (p->sampling_rate)
2590                sci_port->sampling_rate_mask = SCI_SR(p->sampling_rate);
2591
2592        if (!early) {
2593                ret = sci_init_clocks(sci_port, &dev->dev);
2594                if (ret < 0)
2595                        return ret;
2596
2597                port->dev = &dev->dev;
2598
2599                pm_runtime_enable(&dev->dev);
2600        }
2601
2602        sci_port->break_timer.data = (unsigned long)sci_port;
2603        sci_port->break_timer.function = sci_break_timer;
2604        init_timer(&sci_port->break_timer);
2605
2606        /*
2607         * Establish some sensible defaults for the error detection.
2608         */
2609        if (p->type == PORT_SCI) {
2610                sci_port->error_mask = SCI_DEFAULT_ERROR_MASK;
2611                sci_port->error_clear = SCI_ERROR_CLEAR;
2612        } else {
2613                sci_port->error_mask = SCIF_DEFAULT_ERROR_MASK;
2614                sci_port->error_clear = SCIF_ERROR_CLEAR;
2615        }
2616
2617        /*
2618         * Make the error mask inclusive of overrun detection, if
2619         * supported.
2620         */
2621        if (sci_port->overrun_reg == SCxSR) {
2622                sci_port->error_mask |= sci_port->overrun_mask;
2623                sci_port->error_clear &= ~sci_port->overrun_mask;
2624        }
2625
2626        port->type              = p->type;
2627        port->flags             = UPF_FIXED_PORT | p->flags;
2628        port->regshift          = p->regshift;
2629
2630        /*
2631         * The UART port needs an IRQ value, so we peg this to the RX IRQ
2632         * for the multi-IRQ ports, which is where we are primarily
2633         * concerned with the shutdown path synchronization.
2634         *
2635         * For the muxed case there's nothing more to do.
2636         */
2637        port->irq               = sci_port->irqs[SCIx_RXI_IRQ];
2638        port->irqflags          = 0;
2639
2640        port->serial_in         = sci_serial_in;
2641        port->serial_out        = sci_serial_out;
2642
2643        if (p->dma_slave_tx > 0 && p->dma_slave_rx > 0)
2644                dev_dbg(port->dev, "DMA tx %d, rx %d\n",
2645                        p->dma_slave_tx, p->dma_slave_rx);
2646
2647        return 0;
2648}
2649
2650static void sci_cleanup_single(struct sci_port *port)
2651{
2652        pm_runtime_disable(port->port.dev);
2653}
2654
2655#if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
2656    defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
2657static void serial_console_putchar(struct uart_port *port, int ch)
2658{
2659        sci_poll_put_char(port, ch);
2660}
2661
2662/*
2663 *      Print a string to the serial port trying not to disturb
2664 *      any possible real use of the port...
2665 */
2666static void serial_console_write(struct console *co, const char *s,
2667                                 unsigned count)
2668{
2669        struct sci_port *sci_port = &sci_ports[co->index];
2670        struct uart_port *port = &sci_port->port;
2671        unsigned short bits, ctrl, ctrl_temp;
2672        unsigned long flags;
2673        int locked = 1;
2674
2675        local_irq_save(flags);
2676#if defined(SUPPORT_SYSRQ)
2677        if (port->sysrq)
2678                locked = 0;
2679        else
2680#endif
2681        if (oops_in_progress)
2682                locked = spin_trylock(&port->lock);
2683        else
2684                spin_lock(&port->lock);
2685
2686        /* first save SCSCR then disable interrupts, keep clock source */
2687        ctrl = serial_port_in(port, SCSCR);
2688        ctrl_temp = (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
2689                    (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
2690        serial_port_out(port, SCSCR, ctrl_temp);
2691
2692        uart_console_write(port, s, count, serial_console_putchar);
2693
2694        /* wait until fifo is empty and last bit has been transmitted */
2695        bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
2696        while ((serial_port_in(port, SCxSR) & bits) != bits)
2697                cpu_relax();
2698
2699        /* restore the SCSCR */
2700        serial_port_out(port, SCSCR, ctrl);
2701
2702        if (locked)
2703                spin_unlock(&port->lock);
2704        local_irq_restore(flags);
2705}
2706
2707static int serial_console_setup(struct console *co, char *options)
2708{
2709        struct sci_port *sci_port;
2710        struct uart_port *port;
2711        int baud = 115200;
2712        int bits = 8;
2713        int parity = 'n';
2714        int flow = 'n';
2715        int ret;
2716
2717        /*
2718         * Refuse to handle any bogus ports.
2719         */
2720        if (co->index < 0 || co->index >= SCI_NPORTS)
2721                return -ENODEV;
2722
2723        sci_port = &sci_ports[co->index];
2724        port = &sci_port->port;
2725
2726        /*
2727         * Refuse to handle uninitialized ports.
2728         */
2729        if (!port->ops)
2730                return -ENODEV;
2731
2732        ret = sci_remap_port(port);
2733        if (unlikely(ret != 0))
2734                return ret;
2735
2736        if (options)
2737                uart_parse_options(options, &baud, &parity, &bits, &flow);
2738
2739        return uart_set_options(port, co, baud, parity, bits, flow);
2740}
2741
2742static struct console serial_console = {
2743        .name           = "ttySC",
2744        .device         = uart_console_device,
2745        .write          = serial_console_write,
2746        .setup          = serial_console_setup,
2747        .flags          = CON_PRINTBUFFER,
2748        .index          = -1,
2749        .data           = &sci_uart_driver,
2750};
2751
2752static struct console early_serial_console = {
2753        .name           = "early_ttySC",
2754        .write          = serial_console_write,
2755        .flags          = CON_PRINTBUFFER,
2756        .index          = -1,
2757};
2758
2759static char early_serial_buf[32];
2760
2761static int sci_probe_earlyprintk(struct platform_device *pdev)
2762{
2763        struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
2764
2765        if (early_serial_console.data)
2766                return -EEXIST;
2767
2768        early_serial_console.index = pdev->id;
2769
2770        sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
2771
2772        serial_console_setup(&early_serial_console, early_serial_buf);
2773
2774        if (!strstr(early_serial_buf, "keep"))
2775                early_serial_console.flags |= CON_BOOT;
2776
2777        register_console(&early_serial_console);
2778        return 0;
2779}
2780
2781#define SCI_CONSOLE     (&serial_console)
2782
2783#else
2784static inline int sci_probe_earlyprintk(struct platform_device *pdev)
2785{
2786        return -EINVAL;
2787}
2788
2789#define SCI_CONSOLE     NULL
2790
2791#endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
2792
2793static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
2794
2795static struct uart_driver sci_uart_driver = {
2796        .owner          = THIS_MODULE,
2797        .driver_name    = "sci",
2798        .dev_name       = "ttySC",
2799        .major          = SCI_MAJOR,
2800        .minor          = SCI_MINOR_START,
2801        .nr             = SCI_NPORTS,
2802        .cons           = SCI_CONSOLE,
2803};
2804
2805static int sci_remove(struct platform_device *dev)
2806{
2807        struct sci_port *port = platform_get_drvdata(dev);
2808
2809        uart_remove_one_port(&sci_uart_driver, &port->port);
2810
2811        sci_cleanup_single(port);
2812
2813        return 0;
2814}
2815
2816
2817#define SCI_OF_DATA(type, regtype)      (void *)((type) << 16 | (regtype))
2818#define SCI_OF_TYPE(data)               ((unsigned long)(data) >> 16)
2819#define SCI_OF_REGTYPE(data)            ((unsigned long)(data) & 0xffff)
2820
2821static const struct of_device_id of_sci_match[] = {
2822        /* SoC-specific types */
2823        {
2824                .compatible = "renesas,scif-r7s72100",
2825                .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
2826        },
2827        /* Family-specific types */
2828        {
2829                .compatible = "renesas,rcar-gen1-scif",
2830                .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
2831        }, {
2832                .compatible = "renesas,rcar-gen2-scif",
2833                .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
2834        }, {
2835                .compatible = "renesas,rcar-gen3-scif",
2836                .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
2837        },
2838        /* Generic types */
2839        {
2840                .compatible = "renesas,scif",
2841                .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
2842        }, {
2843                .compatible = "renesas,scifa",
2844                .data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
2845        }, {
2846                .compatible = "renesas,scifb",
2847                .data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
2848        }, {
2849                .compatible = "renesas,hscif",
2850                .data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
2851        }, {
2852                .compatible = "renesas,sci",
2853                .data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
2854        }, {
2855                /* Terminator */
2856        },
2857};
2858MODULE_DEVICE_TABLE(of, of_sci_match);
2859
2860static struct plat_sci_port *
2861sci_parse_dt(struct platform_device *pdev, unsigned int *dev_id)
2862{
2863        struct device_node *np = pdev->dev.of_node;
2864        const struct of_device_id *match;
2865        struct plat_sci_port *p;
2866        int id;
2867
2868        if (!IS_ENABLED(CONFIG_OF) || !np)
2869                return NULL;
2870
2871        match = of_match_node(of_sci_match, np);
2872        if (!match)
2873                return NULL;
2874
2875        p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
2876        if (!p)
2877                return NULL;
2878
2879        /* Get the line number from the aliases node. */
2880        id = of_alias_get_id(np, "serial");
2881        if (id < 0) {
2882                dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
2883                return NULL;
2884        }
2885
2886        *dev_id = id;
2887
2888        p->flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
2889        p->type = SCI_OF_TYPE(match->data);
2890        p->regtype = SCI_OF_REGTYPE(match->data);
2891        p->scscr = SCSCR_RE | SCSCR_TE;
2892
2893        return p;
2894}
2895
2896static int sci_probe_single(struct platform_device *dev,
2897                                      unsigned int index,
2898                                      struct plat_sci_port *p,
2899                                      struct sci_port *sciport)
2900{
2901        int ret;
2902
2903        /* Sanity check */
2904        if (unlikely(index >= SCI_NPORTS)) {
2905                dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
2906                           index+1, SCI_NPORTS);
2907                dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
2908                return -EINVAL;
2909        }
2910
2911        ret = sci_init_single(dev, sciport, index, p, false);
2912        if (ret)
2913                return ret;
2914
2915        ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
2916        if (ret) {
2917                sci_cleanup_single(sciport);
2918                return ret;
2919        }
2920
2921        return 0;
2922}
2923
2924static int sci_probe(struct platform_device *dev)
2925{
2926        struct plat_sci_port *p;
2927        struct sci_port *sp;
2928        unsigned int dev_id;
2929        int ret;
2930
2931        /*
2932         * If we've come here via earlyprintk initialization, head off to
2933         * the special early probe. We don't have sufficient device state
2934         * to make it beyond this yet.
2935         */
2936        if (is_early_platform_device(dev))
2937                return sci_probe_earlyprintk(dev);
2938
2939        if (dev->dev.of_node) {
2940                p = sci_parse_dt(dev, &dev_id);
2941                if (p == NULL)
2942                        return -EINVAL;
2943        } else {
2944                p = dev->dev.platform_data;
2945                if (p == NULL) {
2946                        dev_err(&dev->dev, "no platform data supplied\n");
2947                        return -EINVAL;
2948                }
2949
2950                dev_id = dev->id;
2951        }
2952
2953        sp = &sci_ports[dev_id];
2954        platform_set_drvdata(dev, sp);
2955
2956        ret = sci_probe_single(dev, dev_id, p, sp);
2957        if (ret)
2958                return ret;
2959
2960#ifdef CONFIG_SH_STANDARD_BIOS
2961        sh_bios_gdb_detach();
2962#endif
2963
2964        return 0;
2965}
2966
2967static __maybe_unused int sci_suspend(struct device *dev)
2968{
2969        struct sci_port *sport = dev_get_drvdata(dev);
2970
2971        if (sport)
2972                uart_suspend_port(&sci_uart_driver, &sport->port);
2973
2974        return 0;
2975}
2976
2977static __maybe_unused int sci_resume(struct device *dev)
2978{
2979        struct sci_port *sport = dev_get_drvdata(dev);
2980
2981        if (sport)
2982                uart_resume_port(&sci_uart_driver, &sport->port);
2983
2984        return 0;
2985}
2986
2987static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
2988
2989static struct platform_driver sci_driver = {
2990        .probe          = sci_probe,
2991        .remove         = sci_remove,
2992        .driver         = {
2993                .name   = "sh-sci",
2994                .pm     = &sci_dev_pm_ops,
2995                .of_match_table = of_match_ptr(of_sci_match),
2996        },
2997};
2998
2999static int __init sci_init(void)
3000{
3001        int ret;
3002
3003        pr_info("%s\n", banner);
3004
3005        ret = uart_register_driver(&sci_uart_driver);
3006        if (likely(ret == 0)) {
3007                ret = platform_driver_register(&sci_driver);
3008                if (unlikely(ret))
3009                        uart_unregister_driver(&sci_uart_driver);
3010        }
3011
3012        return ret;
3013}
3014
3015static void __exit sci_exit(void)
3016{
3017        platform_driver_unregister(&sci_driver);
3018        uart_unregister_driver(&sci_uart_driver);
3019}
3020
3021#ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
3022early_platform_init_buffer("earlyprintk", &sci_driver,
3023                           early_serial_buf, ARRAY_SIZE(early_serial_buf));
3024#endif
3025#ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
3026static struct __init plat_sci_port port_cfg;
3027
3028static int __init early_console_setup(struct earlycon_device *device,
3029                                      int type)
3030{
3031        if (!device->port.membase)
3032                return -ENODEV;
3033
3034        device->port.serial_in = sci_serial_in;
3035        device->port.serial_out = sci_serial_out;
3036        device->port.type = type;
3037        memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
3038        sci_ports[0].cfg = &port_cfg;
3039        sci_ports[0].cfg->type = type;
3040        sci_probe_regmap(sci_ports[0].cfg);
3041        port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR) |
3042                         SCSCR_RE | SCSCR_TE;
3043        sci_serial_out(&sci_ports[0].port, SCSCR, port_cfg.scscr);
3044
3045        device->con->write = serial_console_write;
3046        return 0;
3047}
3048static int __init sci_early_console_setup(struct earlycon_device *device,
3049                                          const char *opt)
3050{
3051        return early_console_setup(device, PORT_SCI);
3052}
3053static int __init scif_early_console_setup(struct earlycon_device *device,
3054                                          const char *opt)
3055{
3056        return early_console_setup(device, PORT_SCIF);
3057}
3058static int __init scifa_early_console_setup(struct earlycon_device *device,
3059                                          const char *opt)
3060{
3061        return early_console_setup(device, PORT_SCIFA);
3062}
3063static int __init scifb_early_console_setup(struct earlycon_device *device,
3064                                          const char *opt)
3065{
3066        return early_console_setup(device, PORT_SCIFB);
3067}
3068static int __init hscif_early_console_setup(struct earlycon_device *device,
3069                                          const char *opt)
3070{
3071        return early_console_setup(device, PORT_HSCIF);
3072}
3073
3074OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
3075OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
3076OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
3077OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
3078OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
3079#endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
3080
3081module_init(sci_init);
3082module_exit(sci_exit);
3083
3084MODULE_LICENSE("GPL");
3085MODULE_ALIAS("platform:sh-sci");
3086MODULE_AUTHOR("Paul Mundt");
3087MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
3088