linux/drivers/tty/serial/samsung.c
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   1/*
   2 * Driver core for Samsung SoC onboard UARTs.
   3 *
   4 * Ben Dooks, Copyright (c) 2003-2008 Simtec Electronics
   5 *      http://armlinux.simtec.co.uk/
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License version 2 as
   9 * published by the Free Software Foundation.
  10*/
  11
  12/* Hote on 2410 error handling
  13 *
  14 * The s3c2410 manual has a love/hate affair with the contents of the
  15 * UERSTAT register in the UART blocks, and keeps marking some of the
  16 * error bits as reserved. Having checked with the s3c2410x01,
  17 * it copes with BREAKs properly, so I am happy to ignore the RESERVED
  18 * feature from the latter versions of the manual.
  19 *
  20 * If it becomes aparrent that latter versions of the 2410 remove these
  21 * bits, then action will have to be taken to differentiate the versions
  22 * and change the policy on BREAK
  23 *
  24 * BJD, 04-Nov-2004
  25*/
  26
  27#if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  28#define SUPPORT_SYSRQ
  29#endif
  30
  31#include <linux/module.h>
  32#include <linux/ioport.h>
  33#include <linux/io.h>
  34#include <linux/platform_device.h>
  35#include <linux/init.h>
  36#include <linux/sysrq.h>
  37#include <linux/console.h>
  38#include <linux/tty.h>
  39#include <linux/tty_flip.h>
  40#include <linux/serial_core.h>
  41#include <linux/serial.h>
  42#include <linux/serial_s3c.h>
  43#include <linux/delay.h>
  44#include <linux/clk.h>
  45#include <linux/cpufreq.h>
  46#include <linux/of.h>
  47
  48#include <asm/irq.h>
  49
  50#ifdef CONFIG_SAMSUNG_CLOCK
  51#include <plat/clock.h>
  52#endif
  53
  54#include "samsung.h"
  55
  56/* UART name and device definitions */
  57
  58#define S3C24XX_SERIAL_NAME     "ttySAC"
  59#define S3C24XX_SERIAL_MAJOR    204
  60#define S3C24XX_SERIAL_MINOR    64
  61
  62/* macros to change one thing to another */
  63
  64#define tx_enabled(port) ((port)->unused[0])
  65#define rx_enabled(port) ((port)->unused[1])
  66
  67/* flag to ignore all characters coming in */
  68#define RXSTAT_DUMMY_READ (0x10000000)
  69
  70static inline struct s3c24xx_uart_port *to_ourport(struct uart_port *port)
  71{
  72        return container_of(port, struct s3c24xx_uart_port, port);
  73}
  74
  75/* translate a port to the device name */
  76
  77static inline const char *s3c24xx_serial_portname(struct uart_port *port)
  78{
  79        return to_platform_device(port->dev)->name;
  80}
  81
  82static int s3c24xx_serial_txempty_nofifo(struct uart_port *port)
  83{
  84        return rd_regl(port, S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXE;
  85}
  86
  87/*
  88 * s3c64xx and later SoC's include the interrupt mask and status registers in
  89 * the controller itself, unlike the s3c24xx SoC's which have these registers
  90 * in the interrupt controller. Check if the port type is s3c64xx or higher.
  91 */
  92static int s3c24xx_serial_has_interrupt_mask(struct uart_port *port)
  93{
  94        return to_ourport(port)->info->type == PORT_S3C6400;
  95}
  96
  97static void s3c24xx_serial_rx_enable(struct uart_port *port)
  98{
  99        unsigned long flags;
 100        unsigned int ucon, ufcon;
 101        int count = 10000;
 102
 103        spin_lock_irqsave(&port->lock, flags);
 104
 105        while (--count && !s3c24xx_serial_txempty_nofifo(port))
 106                udelay(100);
 107
 108        ufcon = rd_regl(port, S3C2410_UFCON);
 109        ufcon |= S3C2410_UFCON_RESETRX;
 110        wr_regl(port, S3C2410_UFCON, ufcon);
 111
 112        ucon = rd_regl(port, S3C2410_UCON);
 113        ucon |= S3C2410_UCON_RXIRQMODE;
 114        wr_regl(port, S3C2410_UCON, ucon);
 115
 116        rx_enabled(port) = 1;
 117        spin_unlock_irqrestore(&port->lock, flags);
 118}
 119
 120static void s3c24xx_serial_rx_disable(struct uart_port *port)
 121{
 122        unsigned long flags;
 123        unsigned int ucon;
 124
 125        spin_lock_irqsave(&port->lock, flags);
 126
 127        ucon = rd_regl(port, S3C2410_UCON);
 128        ucon &= ~S3C2410_UCON_RXIRQMODE;
 129        wr_regl(port, S3C2410_UCON, ucon);
 130
 131        rx_enabled(port) = 0;
 132        spin_unlock_irqrestore(&port->lock, flags);
 133}
 134
 135static void s3c24xx_serial_stop_tx(struct uart_port *port)
 136{
 137        struct s3c24xx_uart_port *ourport = to_ourport(port);
 138
 139        if (tx_enabled(port)) {
 140                if (s3c24xx_serial_has_interrupt_mask(port))
 141                        __set_bit(S3C64XX_UINTM_TXD,
 142                                portaddrl(port, S3C64XX_UINTM));
 143                else
 144                        disable_irq_nosync(ourport->tx_irq);
 145                tx_enabled(port) = 0;
 146                if (port->flags & UPF_CONS_FLOW)
 147                        s3c24xx_serial_rx_enable(port);
 148        }
 149}
 150
 151static void s3c24xx_serial_start_tx(struct uart_port *port)
 152{
 153        struct s3c24xx_uart_port *ourport = to_ourport(port);
 154
 155        if (!tx_enabled(port)) {
 156                if (port->flags & UPF_CONS_FLOW)
 157                        s3c24xx_serial_rx_disable(port);
 158
 159                if (s3c24xx_serial_has_interrupt_mask(port))
 160                        __clear_bit(S3C64XX_UINTM_TXD,
 161                                portaddrl(port, S3C64XX_UINTM));
 162                else
 163                        enable_irq(ourport->tx_irq);
 164                tx_enabled(port) = 1;
 165        }
 166}
 167
 168static void s3c24xx_serial_stop_rx(struct uart_port *port)
 169{
 170        struct s3c24xx_uart_port *ourport = to_ourport(port);
 171
 172        if (rx_enabled(port)) {
 173                dbg("s3c24xx_serial_stop_rx: port=%p\n", port);
 174                if (s3c24xx_serial_has_interrupt_mask(port))
 175                        __set_bit(S3C64XX_UINTM_RXD,
 176                                portaddrl(port, S3C64XX_UINTM));
 177                else
 178                        disable_irq_nosync(ourport->rx_irq);
 179                rx_enabled(port) = 0;
 180        }
 181}
 182
 183static void s3c24xx_serial_enable_ms(struct uart_port *port)
 184{
 185}
 186
 187static inline struct s3c24xx_uart_info *s3c24xx_port_to_info(struct uart_port *port)
 188{
 189        return to_ourport(port)->info;
 190}
 191
 192static inline struct s3c2410_uartcfg *s3c24xx_port_to_cfg(struct uart_port *port)
 193{
 194        struct s3c24xx_uart_port *ourport;
 195
 196        if (port->dev == NULL)
 197                return NULL;
 198
 199        ourport = container_of(port, struct s3c24xx_uart_port, port);
 200        return ourport->cfg;
 201}
 202
 203static int s3c24xx_serial_rx_fifocnt(struct s3c24xx_uart_port *ourport,
 204                                     unsigned long ufstat)
 205{
 206        struct s3c24xx_uart_info *info = ourport->info;
 207
 208        if (ufstat & info->rx_fifofull)
 209                return ourport->port.fifosize;
 210
 211        return (ufstat & info->rx_fifomask) >> info->rx_fifoshift;
 212}
 213
 214
 215/* ? - where has parity gone?? */
 216#define S3C2410_UERSTAT_PARITY (0x1000)
 217
 218static irqreturn_t
 219s3c24xx_serial_rx_chars(int irq, void *dev_id)
 220{
 221        struct s3c24xx_uart_port *ourport = dev_id;
 222        struct uart_port *port = &ourport->port;
 223        unsigned int ufcon, ch, flag, ufstat, uerstat;
 224        unsigned long flags;
 225        int max_count = 64;
 226
 227        spin_lock_irqsave(&port->lock, flags);
 228
 229        while (max_count-- > 0) {
 230                ufcon = rd_regl(port, S3C2410_UFCON);
 231                ufstat = rd_regl(port, S3C2410_UFSTAT);
 232
 233                if (s3c24xx_serial_rx_fifocnt(ourport, ufstat) == 0)
 234                        break;
 235
 236                uerstat = rd_regl(port, S3C2410_UERSTAT);
 237                ch = rd_regb(port, S3C2410_URXH);
 238
 239                if (port->flags & UPF_CONS_FLOW) {
 240                        int txe = s3c24xx_serial_txempty_nofifo(port);
 241
 242                        if (rx_enabled(port)) {
 243                                if (!txe) {
 244                                        rx_enabled(port) = 0;
 245                                        continue;
 246                                }
 247                        } else {
 248                                if (txe) {
 249                                        ufcon |= S3C2410_UFCON_RESETRX;
 250                                        wr_regl(port, S3C2410_UFCON, ufcon);
 251                                        rx_enabled(port) = 1;
 252                                        spin_unlock_irqrestore(&port->lock,
 253                                                        flags);
 254                                        goto out;
 255                                }
 256                                continue;
 257                        }
 258                }
 259
 260                /* insert the character into the buffer */
 261
 262                flag = TTY_NORMAL;
 263                port->icount.rx++;
 264
 265                if (unlikely(uerstat & S3C2410_UERSTAT_ANY)) {
 266                        dbg("rxerr: port ch=0x%02x, rxs=0x%08x\n",
 267                            ch, uerstat);
 268
 269                        /* check for break */
 270                        if (uerstat & S3C2410_UERSTAT_BREAK) {
 271                                dbg("break!\n");
 272                                port->icount.brk++;
 273                                if (uart_handle_break(port))
 274                                        goto ignore_char;
 275                        }
 276
 277                        if (uerstat & S3C2410_UERSTAT_FRAME)
 278                                port->icount.frame++;
 279                        if (uerstat & S3C2410_UERSTAT_OVERRUN)
 280                                port->icount.overrun++;
 281
 282                        uerstat &= port->read_status_mask;
 283
 284                        if (uerstat & S3C2410_UERSTAT_BREAK)
 285                                flag = TTY_BREAK;
 286                        else if (uerstat & S3C2410_UERSTAT_PARITY)
 287                                flag = TTY_PARITY;
 288                        else if (uerstat & (S3C2410_UERSTAT_FRAME |
 289                                            S3C2410_UERSTAT_OVERRUN))
 290                                flag = TTY_FRAME;
 291                }
 292
 293                if (uart_handle_sysrq_char(port, ch))
 294                        goto ignore_char;
 295
 296                uart_insert_char(port, uerstat, S3C2410_UERSTAT_OVERRUN,
 297                                 ch, flag);
 298
 299 ignore_char:
 300                continue;
 301        }
 302
 303        spin_unlock_irqrestore(&port->lock, flags);
 304        tty_flip_buffer_push(&port->state->port);
 305
 306 out:
 307        return IRQ_HANDLED;
 308}
 309
 310static irqreturn_t s3c24xx_serial_tx_chars(int irq, void *id)
 311{
 312        struct s3c24xx_uart_port *ourport = id;
 313        struct uart_port *port = &ourport->port;
 314        struct circ_buf *xmit = &port->state->xmit;
 315        unsigned long flags;
 316        int count = 256;
 317
 318        spin_lock_irqsave(&port->lock, flags);
 319
 320        if (port->x_char) {
 321                wr_regb(port, S3C2410_UTXH, port->x_char);
 322                port->icount.tx++;
 323                port->x_char = 0;
 324                goto out;
 325        }
 326
 327        /* if there isn't anything more to transmit, or the uart is now
 328         * stopped, disable the uart and exit
 329        */
 330
 331        if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
 332                s3c24xx_serial_stop_tx(port);
 333                goto out;
 334        }
 335
 336        /* try and drain the buffer... */
 337
 338        while (!uart_circ_empty(xmit) && count-- > 0) {
 339                if (rd_regl(port, S3C2410_UFSTAT) & ourport->info->tx_fifofull)
 340                        break;
 341
 342                wr_regb(port, S3C2410_UTXH, xmit->buf[xmit->tail]);
 343                xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 344                port->icount.tx++;
 345        }
 346
 347        if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) {
 348                spin_unlock(&port->lock);
 349                uart_write_wakeup(port);
 350                spin_lock(&port->lock);
 351        }
 352
 353        if (uart_circ_empty(xmit))
 354                s3c24xx_serial_stop_tx(port);
 355
 356 out:
 357        spin_unlock_irqrestore(&port->lock, flags);
 358        return IRQ_HANDLED;
 359}
 360
 361/* interrupt handler for s3c64xx and later SoC's.*/
 362static irqreturn_t s3c64xx_serial_handle_irq(int irq, void *id)
 363{
 364        struct s3c24xx_uart_port *ourport = id;
 365        struct uart_port *port = &ourport->port;
 366        unsigned int pend = rd_regl(port, S3C64XX_UINTP);
 367        irqreturn_t ret = IRQ_HANDLED;
 368
 369        if (pend & S3C64XX_UINTM_RXD_MSK) {
 370                ret = s3c24xx_serial_rx_chars(irq, id);
 371                wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_RXD_MSK);
 372        }
 373        if (pend & S3C64XX_UINTM_TXD_MSK) {
 374                ret = s3c24xx_serial_tx_chars(irq, id);
 375                wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_TXD_MSK);
 376        }
 377        return ret;
 378}
 379
 380static unsigned int s3c24xx_serial_tx_empty(struct uart_port *port)
 381{
 382        struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
 383        unsigned long ufstat = rd_regl(port, S3C2410_UFSTAT);
 384        unsigned long ufcon = rd_regl(port, S3C2410_UFCON);
 385
 386        if (ufcon & S3C2410_UFCON_FIFOMODE) {
 387                if ((ufstat & info->tx_fifomask) != 0 ||
 388                    (ufstat & info->tx_fifofull))
 389                        return 0;
 390
 391                return 1;
 392        }
 393
 394        return s3c24xx_serial_txempty_nofifo(port);
 395}
 396
 397/* no modem control lines */
 398static unsigned int s3c24xx_serial_get_mctrl(struct uart_port *port)
 399{
 400        unsigned int umstat = rd_regb(port, S3C2410_UMSTAT);
 401
 402        if (umstat & S3C2410_UMSTAT_CTS)
 403                return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
 404        else
 405                return TIOCM_CAR | TIOCM_DSR;
 406}
 407
 408static void s3c24xx_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
 409{
 410        /* todo - possibly remove AFC and do manual CTS */
 411}
 412
 413static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state)
 414{
 415        unsigned long flags;
 416        unsigned int ucon;
 417
 418        spin_lock_irqsave(&port->lock, flags);
 419
 420        ucon = rd_regl(port, S3C2410_UCON);
 421
 422        if (break_state)
 423                ucon |= S3C2410_UCON_SBREAK;
 424        else
 425                ucon &= ~S3C2410_UCON_SBREAK;
 426
 427        wr_regl(port, S3C2410_UCON, ucon);
 428
 429        spin_unlock_irqrestore(&port->lock, flags);
 430}
 431
 432static void s3c24xx_serial_shutdown(struct uart_port *port)
 433{
 434        struct s3c24xx_uart_port *ourport = to_ourport(port);
 435
 436        if (ourport->tx_claimed) {
 437                if (!s3c24xx_serial_has_interrupt_mask(port))
 438                        free_irq(ourport->tx_irq, ourport);
 439                tx_enabled(port) = 0;
 440                ourport->tx_claimed = 0;
 441        }
 442
 443        if (ourport->rx_claimed) {
 444                if (!s3c24xx_serial_has_interrupt_mask(port))
 445                        free_irq(ourport->rx_irq, ourport);
 446                ourport->rx_claimed = 0;
 447                rx_enabled(port) = 0;
 448        }
 449
 450        /* Clear pending interrupts and mask all interrupts */
 451        if (s3c24xx_serial_has_interrupt_mask(port)) {
 452                free_irq(port->irq, ourport);
 453
 454                wr_regl(port, S3C64XX_UINTP, 0xf);
 455                wr_regl(port, S3C64XX_UINTM, 0xf);
 456        }
 457}
 458
 459static int s3c24xx_serial_startup(struct uart_port *port)
 460{
 461        struct s3c24xx_uart_port *ourport = to_ourport(port);
 462        int ret;
 463
 464        dbg("s3c24xx_serial_startup: port=%p (%08lx,%p)\n",
 465            port->mapbase, port->membase);
 466
 467        rx_enabled(port) = 1;
 468
 469        ret = request_irq(ourport->rx_irq, s3c24xx_serial_rx_chars, 0,
 470                          s3c24xx_serial_portname(port), ourport);
 471
 472        if (ret != 0) {
 473                dev_err(port->dev, "cannot get irq %d\n", ourport->rx_irq);
 474                return ret;
 475        }
 476
 477        ourport->rx_claimed = 1;
 478
 479        dbg("requesting tx irq...\n");
 480
 481        tx_enabled(port) = 1;
 482
 483        ret = request_irq(ourport->tx_irq, s3c24xx_serial_tx_chars, 0,
 484                          s3c24xx_serial_portname(port), ourport);
 485
 486        if (ret) {
 487                dev_err(port->dev, "cannot get irq %d\n", ourport->tx_irq);
 488                goto err;
 489        }
 490
 491        ourport->tx_claimed = 1;
 492
 493        dbg("s3c24xx_serial_startup ok\n");
 494
 495        /* the port reset code should have done the correct
 496         * register setup for the port controls */
 497
 498        return ret;
 499
 500 err:
 501        s3c24xx_serial_shutdown(port);
 502        return ret;
 503}
 504
 505static int s3c64xx_serial_startup(struct uart_port *port)
 506{
 507        struct s3c24xx_uart_port *ourport = to_ourport(port);
 508        int ret;
 509
 510        dbg("s3c64xx_serial_startup: port=%p (%08lx,%p)\n",
 511            port->mapbase, port->membase);
 512
 513        wr_regl(port, S3C64XX_UINTM, 0xf);
 514
 515        ret = request_irq(port->irq, s3c64xx_serial_handle_irq, IRQF_SHARED,
 516                          s3c24xx_serial_portname(port), ourport);
 517        if (ret) {
 518                dev_err(port->dev, "cannot get irq %d\n", port->irq);
 519                return ret;
 520        }
 521
 522        /* For compatibility with s3c24xx Soc's */
 523        rx_enabled(port) = 1;
 524        ourport->rx_claimed = 1;
 525        tx_enabled(port) = 0;
 526        ourport->tx_claimed = 1;
 527
 528        /* Enable Rx Interrupt */
 529        __clear_bit(S3C64XX_UINTM_RXD, portaddrl(port, S3C64XX_UINTM));
 530        dbg("s3c64xx_serial_startup ok\n");
 531        return ret;
 532}
 533
 534/* power power management control */
 535
 536static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level,
 537                              unsigned int old)
 538{
 539        struct s3c24xx_uart_port *ourport = to_ourport(port);
 540
 541        ourport->pm_level = level;
 542
 543        switch (level) {
 544        case 3:
 545                if (!IS_ERR(ourport->baudclk))
 546                        clk_disable_unprepare(ourport->baudclk);
 547
 548                clk_disable_unprepare(ourport->clk);
 549                break;
 550
 551        case 0:
 552                clk_prepare_enable(ourport->clk);
 553
 554                if (!IS_ERR(ourport->baudclk))
 555                        clk_prepare_enable(ourport->baudclk);
 556
 557                break;
 558        default:
 559                dev_err(port->dev, "s3c24xx_serial: unknown pm %d\n", level);
 560        }
 561}
 562
 563/* baud rate calculation
 564 *
 565 * The UARTs on the S3C2410/S3C2440 can take their clocks from a number
 566 * of different sources, including the peripheral clock ("pclk") and an
 567 * external clock ("uclk"). The S3C2440 also adds the core clock ("fclk")
 568 * with a programmable extra divisor.
 569 *
 570 * The following code goes through the clock sources, and calculates the
 571 * baud clocks (and the resultant actual baud rates) and then tries to
 572 * pick the closest one and select that.
 573 *
 574*/
 575
 576#define MAX_CLK_NAME_LENGTH 15
 577
 578static inline int s3c24xx_serial_getsource(struct uart_port *port)
 579{
 580        struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
 581        unsigned int ucon;
 582
 583        if (info->num_clks == 1)
 584                return 0;
 585
 586        ucon = rd_regl(port, S3C2410_UCON);
 587        ucon &= info->clksel_mask;
 588        return ucon >> info->clksel_shift;
 589}
 590
 591static void s3c24xx_serial_setsource(struct uart_port *port,
 592                        unsigned int clk_sel)
 593{
 594        struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
 595        unsigned int ucon;
 596
 597        if (info->num_clks == 1)
 598                return;
 599
 600        ucon = rd_regl(port, S3C2410_UCON);
 601        if ((ucon & info->clksel_mask) >> info->clksel_shift == clk_sel)
 602                return;
 603
 604        ucon &= ~info->clksel_mask;
 605        ucon |= clk_sel << info->clksel_shift;
 606        wr_regl(port, S3C2410_UCON, ucon);
 607}
 608
 609static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
 610                        unsigned int req_baud, struct clk **best_clk,
 611                        unsigned int *clk_num)
 612{
 613        struct s3c24xx_uart_info *info = ourport->info;
 614        struct clk *clk;
 615        unsigned long rate;
 616        unsigned int cnt, baud, quot, clk_sel, best_quot = 0;
 617        char clkname[MAX_CLK_NAME_LENGTH];
 618        int calc_deviation, deviation = (1 << 30) - 1;
 619
 620        clk_sel = (ourport->cfg->clk_sel) ? ourport->cfg->clk_sel :
 621                        ourport->info->def_clk_sel;
 622        for (cnt = 0; cnt < info->num_clks; cnt++) {
 623                if (!(clk_sel & (1 << cnt)))
 624                        continue;
 625
 626                sprintf(clkname, "clk_uart_baud%d", cnt);
 627                clk = clk_get(ourport->port.dev, clkname);
 628                if (IS_ERR(clk))
 629                        continue;
 630
 631                rate = clk_get_rate(clk);
 632                if (!rate)
 633                        continue;
 634
 635                if (ourport->info->has_divslot) {
 636                        unsigned long div = rate / req_baud;
 637
 638                        /* The UDIVSLOT register on the newer UARTs allows us to
 639                         * get a divisor adjustment of 1/16th on the baud clock.
 640                         *
 641                         * We don't keep the UDIVSLOT value (the 16ths we
 642                         * calculated by not multiplying the baud by 16) as it
 643                         * is easy enough to recalculate.
 644                         */
 645
 646                        quot = div / 16;
 647                        baud = rate / div;
 648                } else {
 649                        quot = (rate + (8 * req_baud)) / (16 * req_baud);
 650                        baud = rate / (quot * 16);
 651                }
 652                quot--;
 653
 654                calc_deviation = req_baud - baud;
 655                if (calc_deviation < 0)
 656                        calc_deviation = -calc_deviation;
 657
 658                if (calc_deviation < deviation) {
 659                        *best_clk = clk;
 660                        best_quot = quot;
 661                        *clk_num = cnt;
 662                        deviation = calc_deviation;
 663                }
 664        }
 665
 666        return best_quot;
 667}
 668
 669/* udivslot_table[]
 670 *
 671 * This table takes the fractional value of the baud divisor and gives
 672 * the recommended setting for the UDIVSLOT register.
 673 */
 674static u16 udivslot_table[16] = {
 675        [0] = 0x0000,
 676        [1] = 0x0080,
 677        [2] = 0x0808,
 678        [3] = 0x0888,
 679        [4] = 0x2222,
 680        [5] = 0x4924,
 681        [6] = 0x4A52,
 682        [7] = 0x54AA,
 683        [8] = 0x5555,
 684        [9] = 0xD555,
 685        [10] = 0xD5D5,
 686        [11] = 0xDDD5,
 687        [12] = 0xDDDD,
 688        [13] = 0xDFDD,
 689        [14] = 0xDFDF,
 690        [15] = 0xFFDF,
 691};
 692
 693static void s3c24xx_serial_set_termios(struct uart_port *port,
 694                                       struct ktermios *termios,
 695                                       struct ktermios *old)
 696{
 697        struct s3c2410_uartcfg *cfg = s3c24xx_port_to_cfg(port);
 698        struct s3c24xx_uart_port *ourport = to_ourport(port);
 699        struct clk *clk = ERR_PTR(-EINVAL);
 700        unsigned long flags;
 701        unsigned int baud, quot, clk_sel = 0;
 702        unsigned int ulcon;
 703        unsigned int umcon;
 704        unsigned int udivslot = 0;
 705
 706        /*
 707         * We don't support modem control lines.
 708         */
 709        termios->c_cflag &= ~(HUPCL | CMSPAR);
 710        termios->c_cflag |= CLOCAL;
 711
 712        /*
 713         * Ask the core to calculate the divisor for us.
 714         */
 715
 716        baud = uart_get_baud_rate(port, termios, old, 0, 115200*8);
 717        quot = s3c24xx_serial_getclk(ourport, baud, &clk, &clk_sel);
 718        if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
 719                quot = port->custom_divisor;
 720        if (IS_ERR(clk))
 721                return;
 722
 723        /* check to see if we need  to change clock source */
 724
 725        if (ourport->baudclk != clk) {
 726                s3c24xx_serial_setsource(port, clk_sel);
 727
 728                if (!IS_ERR(ourport->baudclk)) {
 729                        clk_disable_unprepare(ourport->baudclk);
 730                        ourport->baudclk = ERR_PTR(-EINVAL);
 731                }
 732
 733                clk_prepare_enable(clk);
 734
 735                ourport->baudclk = clk;
 736                ourport->baudclk_rate = clk ? clk_get_rate(clk) : 0;
 737        }
 738
 739        if (ourport->info->has_divslot) {
 740                unsigned int div = ourport->baudclk_rate / baud;
 741
 742                if (cfg->has_fracval) {
 743                        udivslot = (div & 15);
 744                        dbg("fracval = %04x\n", udivslot);
 745                } else {
 746                        udivslot = udivslot_table[div & 15];
 747                        dbg("udivslot = %04x (div %d)\n", udivslot, div & 15);
 748                }
 749        }
 750
 751        switch (termios->c_cflag & CSIZE) {
 752        case CS5:
 753                dbg("config: 5bits/char\n");
 754                ulcon = S3C2410_LCON_CS5;
 755                break;
 756        case CS6:
 757                dbg("config: 6bits/char\n");
 758                ulcon = S3C2410_LCON_CS6;
 759                break;
 760        case CS7:
 761                dbg("config: 7bits/char\n");
 762                ulcon = S3C2410_LCON_CS7;
 763                break;
 764        case CS8:
 765        default:
 766                dbg("config: 8bits/char\n");
 767                ulcon = S3C2410_LCON_CS8;
 768                break;
 769        }
 770
 771        /* preserve original lcon IR settings */
 772        ulcon |= (cfg->ulcon & S3C2410_LCON_IRM);
 773
 774        if (termios->c_cflag & CSTOPB)
 775                ulcon |= S3C2410_LCON_STOPB;
 776
 777        umcon = (termios->c_cflag & CRTSCTS) ? S3C2410_UMCOM_AFC : 0;
 778
 779        if (termios->c_cflag & PARENB) {
 780                if (termios->c_cflag & PARODD)
 781                        ulcon |= S3C2410_LCON_PODD;
 782                else
 783                        ulcon |= S3C2410_LCON_PEVEN;
 784        } else {
 785                ulcon |= S3C2410_LCON_PNONE;
 786        }
 787
 788        spin_lock_irqsave(&port->lock, flags);
 789
 790        dbg("setting ulcon to %08x, brddiv to %d, udivslot %08x\n",
 791            ulcon, quot, udivslot);
 792
 793        wr_regl(port, S3C2410_ULCON, ulcon);
 794        wr_regl(port, S3C2410_UBRDIV, quot);
 795        wr_regl(port, S3C2410_UMCON, umcon);
 796
 797        if (ourport->info->has_divslot)
 798                wr_regl(port, S3C2443_DIVSLOT, udivslot);
 799
 800        dbg("uart: ulcon = 0x%08x, ucon = 0x%08x, ufcon = 0x%08x\n",
 801            rd_regl(port, S3C2410_ULCON),
 802            rd_regl(port, S3C2410_UCON),
 803            rd_regl(port, S3C2410_UFCON));
 804
 805        /*
 806         * Update the per-port timeout.
 807         */
 808        uart_update_timeout(port, termios->c_cflag, baud);
 809
 810        /*
 811         * Which character status flags are we interested in?
 812         */
 813        port->read_status_mask = S3C2410_UERSTAT_OVERRUN;
 814        if (termios->c_iflag & INPCK)
 815                port->read_status_mask |= S3C2410_UERSTAT_FRAME | S3C2410_UERSTAT_PARITY;
 816
 817        /*
 818         * Which character status flags should we ignore?
 819         */
 820        port->ignore_status_mask = 0;
 821        if (termios->c_iflag & IGNPAR)
 822                port->ignore_status_mask |= S3C2410_UERSTAT_OVERRUN;
 823        if (termios->c_iflag & IGNBRK && termios->c_iflag & IGNPAR)
 824                port->ignore_status_mask |= S3C2410_UERSTAT_FRAME;
 825
 826        /*
 827         * Ignore all characters if CREAD is not set.
 828         */
 829        if ((termios->c_cflag & CREAD) == 0)
 830                port->ignore_status_mask |= RXSTAT_DUMMY_READ;
 831
 832        spin_unlock_irqrestore(&port->lock, flags);
 833}
 834
 835static const char *s3c24xx_serial_type(struct uart_port *port)
 836{
 837        switch (port->type) {
 838        case PORT_S3C2410:
 839                return "S3C2410";
 840        case PORT_S3C2440:
 841                return "S3C2440";
 842        case PORT_S3C2412:
 843                return "S3C2412";
 844        case PORT_S3C6400:
 845                return "S3C6400/10";
 846        default:
 847                return NULL;
 848        }
 849}
 850
 851#define MAP_SIZE (0x100)
 852
 853static void s3c24xx_serial_release_port(struct uart_port *port)
 854{
 855        release_mem_region(port->mapbase, MAP_SIZE);
 856}
 857
 858static int s3c24xx_serial_request_port(struct uart_port *port)
 859{
 860        const char *name = s3c24xx_serial_portname(port);
 861        return request_mem_region(port->mapbase, MAP_SIZE, name) ? 0 : -EBUSY;
 862}
 863
 864static void s3c24xx_serial_config_port(struct uart_port *port, int flags)
 865{
 866        struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
 867
 868        if (flags & UART_CONFIG_TYPE &&
 869            s3c24xx_serial_request_port(port) == 0)
 870                port->type = info->type;
 871}
 872
 873/*
 874 * verify the new serial_struct (for TIOCSSERIAL).
 875 */
 876static int
 877s3c24xx_serial_verify_port(struct uart_port *port, struct serial_struct *ser)
 878{
 879        struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
 880
 881        if (ser->type != PORT_UNKNOWN && ser->type != info->type)
 882                return -EINVAL;
 883
 884        return 0;
 885}
 886
 887
 888#ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
 889
 890static struct console s3c24xx_serial_console;
 891
 892static int __init s3c24xx_serial_console_init(void)
 893{
 894        register_console(&s3c24xx_serial_console);
 895        return 0;
 896}
 897console_initcall(s3c24xx_serial_console_init);
 898
 899#define S3C24XX_SERIAL_CONSOLE &s3c24xx_serial_console
 900#else
 901#define S3C24XX_SERIAL_CONSOLE NULL
 902#endif
 903
 904#if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
 905static int s3c24xx_serial_get_poll_char(struct uart_port *port);
 906static void s3c24xx_serial_put_poll_char(struct uart_port *port,
 907                         unsigned char c);
 908#endif
 909
 910static struct uart_ops s3c24xx_serial_ops = {
 911        .pm             = s3c24xx_serial_pm,
 912        .tx_empty       = s3c24xx_serial_tx_empty,
 913        .get_mctrl      = s3c24xx_serial_get_mctrl,
 914        .set_mctrl      = s3c24xx_serial_set_mctrl,
 915        .stop_tx        = s3c24xx_serial_stop_tx,
 916        .start_tx       = s3c24xx_serial_start_tx,
 917        .stop_rx        = s3c24xx_serial_stop_rx,
 918        .enable_ms      = s3c24xx_serial_enable_ms,
 919        .break_ctl      = s3c24xx_serial_break_ctl,
 920        .startup        = s3c24xx_serial_startup,
 921        .shutdown       = s3c24xx_serial_shutdown,
 922        .set_termios    = s3c24xx_serial_set_termios,
 923        .type           = s3c24xx_serial_type,
 924        .release_port   = s3c24xx_serial_release_port,
 925        .request_port   = s3c24xx_serial_request_port,
 926        .config_port    = s3c24xx_serial_config_port,
 927        .verify_port    = s3c24xx_serial_verify_port,
 928#if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
 929        .poll_get_char = s3c24xx_serial_get_poll_char,
 930        .poll_put_char = s3c24xx_serial_put_poll_char,
 931#endif
 932};
 933
 934static struct uart_driver s3c24xx_uart_drv = {
 935        .owner          = THIS_MODULE,
 936        .driver_name    = "s3c2410_serial",
 937        .nr             = CONFIG_SERIAL_SAMSUNG_UARTS,
 938        .cons           = S3C24XX_SERIAL_CONSOLE,
 939        .dev_name       = S3C24XX_SERIAL_NAME,
 940        .major          = S3C24XX_SERIAL_MAJOR,
 941        .minor          = S3C24XX_SERIAL_MINOR,
 942};
 943
 944static struct s3c24xx_uart_port s3c24xx_serial_ports[CONFIG_SERIAL_SAMSUNG_UARTS] = {
 945        [0] = {
 946                .port = {
 947                        .lock           = __SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[0].port.lock),
 948                        .iotype         = UPIO_MEM,
 949                        .uartclk        = 0,
 950                        .fifosize       = 16,
 951                        .ops            = &s3c24xx_serial_ops,
 952                        .flags          = UPF_BOOT_AUTOCONF,
 953                        .line           = 0,
 954                }
 955        },
 956        [1] = {
 957                .port = {
 958                        .lock           = __SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[1].port.lock),
 959                        .iotype         = UPIO_MEM,
 960                        .uartclk        = 0,
 961                        .fifosize       = 16,
 962                        .ops            = &s3c24xx_serial_ops,
 963                        .flags          = UPF_BOOT_AUTOCONF,
 964                        .line           = 1,
 965                }
 966        },
 967#if CONFIG_SERIAL_SAMSUNG_UARTS > 2
 968
 969        [2] = {
 970                .port = {
 971                        .lock           = __SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[2].port.lock),
 972                        .iotype         = UPIO_MEM,
 973                        .uartclk        = 0,
 974                        .fifosize       = 16,
 975                        .ops            = &s3c24xx_serial_ops,
 976                        .flags          = UPF_BOOT_AUTOCONF,
 977                        .line           = 2,
 978                }
 979        },
 980#endif
 981#if CONFIG_SERIAL_SAMSUNG_UARTS > 3
 982        [3] = {
 983                .port = {
 984                        .lock           = __SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[3].port.lock),
 985                        .iotype         = UPIO_MEM,
 986                        .uartclk        = 0,
 987                        .fifosize       = 16,
 988                        .ops            = &s3c24xx_serial_ops,
 989                        .flags          = UPF_BOOT_AUTOCONF,
 990                        .line           = 3,
 991                }
 992        }
 993#endif
 994};
 995
 996/* s3c24xx_serial_resetport
 997 *
 998 * reset the fifos and other the settings.
 999*/
1000
1001static void s3c24xx_serial_resetport(struct uart_port *port,
1002                                   struct s3c2410_uartcfg *cfg)
1003{
1004        struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1005        unsigned long ucon = rd_regl(port, S3C2410_UCON);
1006        unsigned int ucon_mask;
1007
1008        ucon_mask = info->clksel_mask;
1009        if (info->type == PORT_S3C2440)
1010                ucon_mask |= S3C2440_UCON0_DIVMASK;
1011
1012        ucon &= ucon_mask;
1013        wr_regl(port, S3C2410_UCON,  ucon | cfg->ucon);
1014
1015        /* reset both fifos */
1016        wr_regl(port, S3C2410_UFCON, cfg->ufcon | S3C2410_UFCON_RESETBOTH);
1017        wr_regl(port, S3C2410_UFCON, cfg->ufcon);
1018
1019        /* some delay is required after fifo reset */
1020        udelay(1);
1021}
1022
1023
1024#ifdef CONFIG_CPU_FREQ
1025
1026static int s3c24xx_serial_cpufreq_transition(struct notifier_block *nb,
1027                                             unsigned long val, void *data)
1028{
1029        struct s3c24xx_uart_port *port;
1030        struct uart_port *uport;
1031
1032        port = container_of(nb, struct s3c24xx_uart_port, freq_transition);
1033        uport = &port->port;
1034
1035        /* check to see if port is enabled */
1036
1037        if (port->pm_level != 0)
1038                return 0;
1039
1040        /* try and work out if the baudrate is changing, we can detect
1041         * a change in rate, but we do not have support for detecting
1042         * a disturbance in the clock-rate over the change.
1043         */
1044
1045        if (IS_ERR(port->baudclk))
1046                goto exit;
1047
1048        if (port->baudclk_rate == clk_get_rate(port->baudclk))
1049                goto exit;
1050
1051        if (val == CPUFREQ_PRECHANGE) {
1052                /* we should really shut the port down whilst the
1053                 * frequency change is in progress. */
1054
1055        } else if (val == CPUFREQ_POSTCHANGE) {
1056                struct ktermios *termios;
1057                struct tty_struct *tty;
1058
1059                if (uport->state == NULL)
1060                        goto exit;
1061
1062                tty = uport->state->port.tty;
1063
1064                if (tty == NULL)
1065                        goto exit;
1066
1067                termios = &tty->termios;
1068
1069                if (termios == NULL) {
1070                        dev_warn(uport->dev, "%s: no termios?\n", __func__);
1071                        goto exit;
1072                }
1073
1074                s3c24xx_serial_set_termios(uport, termios, NULL);
1075        }
1076
1077 exit:
1078        return 0;
1079}
1080
1081static inline int s3c24xx_serial_cpufreq_register(struct s3c24xx_uart_port *port)
1082{
1083        port->freq_transition.notifier_call = s3c24xx_serial_cpufreq_transition;
1084
1085        return cpufreq_register_notifier(&port->freq_transition,
1086                                         CPUFREQ_TRANSITION_NOTIFIER);
1087}
1088
1089static inline void s3c24xx_serial_cpufreq_deregister(struct s3c24xx_uart_port *port)
1090{
1091        cpufreq_unregister_notifier(&port->freq_transition,
1092                                    CPUFREQ_TRANSITION_NOTIFIER);
1093}
1094
1095#else
1096static inline int s3c24xx_serial_cpufreq_register(struct s3c24xx_uart_port *port)
1097{
1098        return 0;
1099}
1100
1101static inline void s3c24xx_serial_cpufreq_deregister(struct s3c24xx_uart_port *port)
1102{
1103}
1104#endif
1105
1106/* s3c24xx_serial_init_port
1107 *
1108 * initialise a single serial port from the platform device given
1109 */
1110
1111static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
1112                                    struct platform_device *platdev)
1113{
1114        struct uart_port *port = &ourport->port;
1115        struct s3c2410_uartcfg *cfg = ourport->cfg;
1116        struct resource *res;
1117        int ret;
1118
1119        dbg("s3c24xx_serial_init_port: port=%p, platdev=%p\n", port, platdev);
1120
1121        if (platdev == NULL)
1122                return -ENODEV;
1123
1124        if (port->mapbase != 0)
1125                return 0;
1126
1127        /* setup info for port */
1128        port->dev       = &platdev->dev;
1129
1130        /* Startup sequence is different for s3c64xx and higher SoC's */
1131        if (s3c24xx_serial_has_interrupt_mask(port))
1132                s3c24xx_serial_ops.startup = s3c64xx_serial_startup;
1133
1134        port->uartclk = 1;
1135
1136        if (cfg->uart_flags & UPF_CONS_FLOW) {
1137                dbg("s3c24xx_serial_init_port: enabling flow control\n");
1138                port->flags |= UPF_CONS_FLOW;
1139        }
1140
1141        /* sort our the physical and virtual addresses for each UART */
1142
1143        res = platform_get_resource(platdev, IORESOURCE_MEM, 0);
1144        if (res == NULL) {
1145                dev_err(port->dev, "failed to find memory resource for uart\n");
1146                return -EINVAL;
1147        }
1148
1149        dbg("resource %p (%lx..%lx)\n", res, res->start, res->end);
1150
1151        port->membase = devm_ioremap(port->dev, res->start, resource_size(res));
1152        if (!port->membase) {
1153                dev_err(port->dev, "failed to remap controller address\n");
1154                return -EBUSY;
1155        }
1156
1157        port->mapbase = res->start;
1158        ret = platform_get_irq(platdev, 0);
1159        if (ret < 0)
1160                port->irq = 0;
1161        else {
1162                port->irq = ret;
1163                ourport->rx_irq = ret;
1164                ourport->tx_irq = ret + 1;
1165        }
1166
1167        ret = platform_get_irq(platdev, 1);
1168        if (ret > 0)
1169                ourport->tx_irq = ret;
1170
1171        ourport->clk    = clk_get(&platdev->dev, "uart");
1172        if (IS_ERR(ourport->clk)) {
1173                pr_err("%s: Controller clock not found\n",
1174                                dev_name(&platdev->dev));
1175                return PTR_ERR(ourport->clk);
1176        }
1177
1178        ret = clk_prepare_enable(ourport->clk);
1179        if (ret) {
1180                pr_err("uart: clock failed to prepare+enable: %d\n", ret);
1181                clk_put(ourport->clk);
1182                return ret;
1183        }
1184
1185        /* Keep all interrupts masked and cleared */
1186        if (s3c24xx_serial_has_interrupt_mask(port)) {
1187                wr_regl(port, S3C64XX_UINTM, 0xf);
1188                wr_regl(port, S3C64XX_UINTP, 0xf);
1189                wr_regl(port, S3C64XX_UINTSP, 0xf);
1190        }
1191
1192        dbg("port: map=%08x, mem=%08x, irq=%d (%d,%d), clock=%ld\n",
1193            port->mapbase, port->membase, port->irq,
1194            ourport->rx_irq, ourport->tx_irq, port->uartclk);
1195
1196        /* reset the fifos (and setup the uart) */
1197        s3c24xx_serial_resetport(port, cfg);
1198        clk_disable_unprepare(ourport->clk);
1199        return 0;
1200}
1201
1202#ifdef CONFIG_SAMSUNG_CLOCK
1203static ssize_t s3c24xx_serial_show_clksrc(struct device *dev,
1204                                          struct device_attribute *attr,
1205                                          char *buf)
1206{
1207        struct uart_port *port = s3c24xx_dev_to_port(dev);
1208        struct s3c24xx_uart_port *ourport = to_ourport(port);
1209
1210        if (IS_ERR(ourport->baudclk))
1211                return -EINVAL;
1212
1213        return snprintf(buf, PAGE_SIZE, "* %s\n",
1214                        ourport->baudclk->name ?: "(null)");
1215}
1216
1217static DEVICE_ATTR(clock_source, S_IRUGO, s3c24xx_serial_show_clksrc, NULL);
1218#endif
1219
1220/* Device driver serial port probe */
1221
1222static const struct of_device_id s3c24xx_uart_dt_match[];
1223static int probe_index;
1224
1225static inline struct s3c24xx_serial_drv_data *s3c24xx_get_driver_data(
1226                        struct platform_device *pdev)
1227{
1228#ifdef CONFIG_OF
1229        if (pdev->dev.of_node) {
1230                const struct of_device_id *match;
1231                match = of_match_node(s3c24xx_uart_dt_match, pdev->dev.of_node);
1232                return (struct s3c24xx_serial_drv_data *)match->data;
1233        }
1234#endif
1235        return (struct s3c24xx_serial_drv_data *)
1236                        platform_get_device_id(pdev)->driver_data;
1237}
1238
1239static int s3c24xx_serial_probe(struct platform_device *pdev)
1240{
1241        struct s3c24xx_uart_port *ourport;
1242        int ret;
1243
1244        dbg("s3c24xx_serial_probe(%p) %d\n", pdev, probe_index);
1245
1246        ourport = &s3c24xx_serial_ports[probe_index];
1247
1248        ourport->drv_data = s3c24xx_get_driver_data(pdev);
1249        if (!ourport->drv_data) {
1250                dev_err(&pdev->dev, "could not find driver data\n");
1251                return -ENODEV;
1252        }
1253
1254        ourport->baudclk = ERR_PTR(-EINVAL);
1255        ourport->info = ourport->drv_data->info;
1256        ourport->cfg = (dev_get_platdata(&pdev->dev)) ?
1257                        (struct s3c2410_uartcfg *)dev_get_platdata(&pdev->dev) :
1258                        ourport->drv_data->def_cfg;
1259
1260        ourport->port.fifosize = (ourport->info->fifosize) ?
1261                ourport->info->fifosize :
1262                ourport->drv_data->fifosize[probe_index];
1263
1264        probe_index++;
1265
1266        dbg("%s: initialising port %p...\n", __func__, ourport);
1267
1268        ret = s3c24xx_serial_init_port(ourport, pdev);
1269        if (ret < 0)
1270                goto probe_err;
1271
1272        dbg("%s: adding port\n", __func__);
1273        uart_add_one_port(&s3c24xx_uart_drv, &ourport->port);
1274        platform_set_drvdata(pdev, &ourport->port);
1275
1276#ifdef CONFIG_SAMSUNG_CLOCK
1277        ret = device_create_file(&pdev->dev, &dev_attr_clock_source);
1278        if (ret < 0)
1279                dev_err(&pdev->dev, "failed to add clock source attr.\n");
1280#endif
1281
1282        ret = s3c24xx_serial_cpufreq_register(ourport);
1283        if (ret < 0)
1284                dev_err(&pdev->dev, "failed to add cpufreq notifier\n");
1285
1286        return 0;
1287
1288 probe_err:
1289        return ret;
1290}
1291
1292static int s3c24xx_serial_remove(struct platform_device *dev)
1293{
1294        struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
1295
1296        if (port) {
1297                s3c24xx_serial_cpufreq_deregister(to_ourport(port));
1298#ifdef CONFIG_SAMSUNG_CLOCK
1299                device_remove_file(&dev->dev, &dev_attr_clock_source);
1300#endif
1301                uart_remove_one_port(&s3c24xx_uart_drv, port);
1302        }
1303
1304        return 0;
1305}
1306
1307/* UART power management code */
1308#ifdef CONFIG_PM_SLEEP
1309static int s3c24xx_serial_suspend(struct device *dev)
1310{
1311        struct uart_port *port = s3c24xx_dev_to_port(dev);
1312
1313        if (port)
1314                uart_suspend_port(&s3c24xx_uart_drv, port);
1315
1316        return 0;
1317}
1318
1319static int s3c24xx_serial_resume(struct device *dev)
1320{
1321        struct uart_port *port = s3c24xx_dev_to_port(dev);
1322        struct s3c24xx_uart_port *ourport = to_ourport(port);
1323
1324        if (port) {
1325                clk_prepare_enable(ourport->clk);
1326                s3c24xx_serial_resetport(port, s3c24xx_port_to_cfg(port));
1327                clk_disable_unprepare(ourport->clk);
1328
1329                uart_resume_port(&s3c24xx_uart_drv, port);
1330        }
1331
1332        return 0;
1333}
1334
1335static int s3c24xx_serial_resume_noirq(struct device *dev)
1336{
1337        struct uart_port *port = s3c24xx_dev_to_port(dev);
1338
1339        if (port) {
1340                /* restore IRQ mask */
1341                if (s3c24xx_serial_has_interrupt_mask(port)) {
1342                        unsigned int uintm = 0xf;
1343                        if (tx_enabled(port))
1344                                uintm &= ~S3C64XX_UINTM_TXD_MSK;
1345                        if (rx_enabled(port))
1346                                uintm &= ~S3C64XX_UINTM_RXD_MSK;
1347                        wr_regl(port, S3C64XX_UINTM, uintm);
1348                }
1349        }
1350
1351        return 0;
1352}
1353
1354static const struct dev_pm_ops s3c24xx_serial_pm_ops = {
1355        .suspend = s3c24xx_serial_suspend,
1356        .resume = s3c24xx_serial_resume,
1357        .resume_noirq = s3c24xx_serial_resume_noirq,
1358};
1359#define SERIAL_SAMSUNG_PM_OPS   (&s3c24xx_serial_pm_ops)
1360
1361#else /* !CONFIG_PM_SLEEP */
1362
1363#define SERIAL_SAMSUNG_PM_OPS   NULL
1364#endif /* CONFIG_PM_SLEEP */
1365
1366/* Console code */
1367
1368#ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
1369
1370static struct uart_port *cons_uart;
1371
1372static int
1373s3c24xx_serial_console_txrdy(struct uart_port *port, unsigned int ufcon)
1374{
1375        struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1376        unsigned long ufstat, utrstat;
1377
1378        if (ufcon & S3C2410_UFCON_FIFOMODE) {
1379                /* fifo mode - check amount of data in fifo registers... */
1380
1381                ufstat = rd_regl(port, S3C2410_UFSTAT);
1382                return (ufstat & info->tx_fifofull) ? 0 : 1;
1383        }
1384
1385        /* in non-fifo mode, we go and use the tx buffer empty */
1386
1387        utrstat = rd_regl(port, S3C2410_UTRSTAT);
1388        return (utrstat & S3C2410_UTRSTAT_TXE) ? 1 : 0;
1389}
1390
1391static bool
1392s3c24xx_port_configured(unsigned int ucon)
1393{
1394        /* consider the serial port configured if the tx/rx mode set */
1395        return (ucon & 0xf) != 0;
1396}
1397
1398#ifdef CONFIG_CONSOLE_POLL
1399/*
1400 * Console polling routines for writing and reading from the uart while
1401 * in an interrupt or debug context.
1402 */
1403
1404static int s3c24xx_serial_get_poll_char(struct uart_port *port)
1405{
1406        struct s3c24xx_uart_port *ourport = to_ourport(port);
1407        unsigned int ufstat;
1408
1409        ufstat = rd_regl(port, S3C2410_UFSTAT);
1410        if (s3c24xx_serial_rx_fifocnt(ourport, ufstat) == 0)
1411                return NO_POLL_CHAR;
1412
1413        return rd_regb(port, S3C2410_URXH);
1414}
1415
1416static void s3c24xx_serial_put_poll_char(struct uart_port *port,
1417                unsigned char c)
1418{
1419        unsigned int ufcon = rd_regl(cons_uart, S3C2410_UFCON);
1420        unsigned int ucon = rd_regl(cons_uart, S3C2410_UCON);
1421
1422        /* not possible to xmit on unconfigured port */
1423        if (!s3c24xx_port_configured(ucon))
1424                return;
1425
1426        while (!s3c24xx_serial_console_txrdy(port, ufcon))
1427                cpu_relax();
1428        wr_regb(cons_uart, S3C2410_UTXH, c);
1429}
1430
1431#endif /* CONFIG_CONSOLE_POLL */
1432
1433static void
1434s3c24xx_serial_console_putchar(struct uart_port *port, int ch)
1435{
1436        unsigned int ufcon = rd_regl(cons_uart, S3C2410_UFCON);
1437        unsigned int ucon = rd_regl(cons_uart, S3C2410_UCON);
1438
1439        /* not possible to xmit on unconfigured port */
1440        if (!s3c24xx_port_configured(ucon))
1441                return;
1442
1443        while (!s3c24xx_serial_console_txrdy(port, ufcon))
1444                barrier();
1445        wr_regb(cons_uart, S3C2410_UTXH, ch);
1446}
1447
1448static void
1449s3c24xx_serial_console_write(struct console *co, const char *s,
1450                             unsigned int count)
1451{
1452        uart_console_write(cons_uart, s, count, s3c24xx_serial_console_putchar);
1453}
1454
1455static void __init
1456s3c24xx_serial_get_options(struct uart_port *port, int *baud,
1457                           int *parity, int *bits)
1458{
1459        struct clk *clk;
1460        unsigned int ulcon;
1461        unsigned int ucon;
1462        unsigned int ubrdiv;
1463        unsigned long rate;
1464        unsigned int clk_sel;
1465        char clk_name[MAX_CLK_NAME_LENGTH];
1466
1467        ulcon  = rd_regl(port, S3C2410_ULCON);
1468        ucon   = rd_regl(port, S3C2410_UCON);
1469        ubrdiv = rd_regl(port, S3C2410_UBRDIV);
1470
1471        dbg("s3c24xx_serial_get_options: port=%p\n"
1472            "registers: ulcon=%08x, ucon=%08x, ubdriv=%08x\n",
1473            port, ulcon, ucon, ubrdiv);
1474
1475        if (s3c24xx_port_configured(ucon)) {
1476                switch (ulcon & S3C2410_LCON_CSMASK) {
1477                case S3C2410_LCON_CS5:
1478                        *bits = 5;
1479                        break;
1480                case S3C2410_LCON_CS6:
1481                        *bits = 6;
1482                        break;
1483                case S3C2410_LCON_CS7:
1484                        *bits = 7;
1485                        break;
1486                default:
1487                case S3C2410_LCON_CS8:
1488                        *bits = 8;
1489                        break;
1490                }
1491
1492                switch (ulcon & S3C2410_LCON_PMASK) {
1493                case S3C2410_LCON_PEVEN:
1494                        *parity = 'e';
1495                        break;
1496
1497                case S3C2410_LCON_PODD:
1498                        *parity = 'o';
1499                        break;
1500
1501                case S3C2410_LCON_PNONE:
1502                default:
1503                        *parity = 'n';
1504                }
1505
1506                /* now calculate the baud rate */
1507
1508                clk_sel = s3c24xx_serial_getsource(port);
1509                sprintf(clk_name, "clk_uart_baud%d", clk_sel);
1510
1511                clk = clk_get(port->dev, clk_name);
1512                if (!IS_ERR(clk))
1513                        rate = clk_get_rate(clk);
1514                else
1515                        rate = 1;
1516
1517                *baud = rate / (16 * (ubrdiv + 1));
1518                dbg("calculated baud %d\n", *baud);
1519        }
1520
1521}
1522
1523static int __init
1524s3c24xx_serial_console_setup(struct console *co, char *options)
1525{
1526        struct uart_port *port;
1527        int baud = 9600;
1528        int bits = 8;
1529        int parity = 'n';
1530        int flow = 'n';
1531
1532        dbg("s3c24xx_serial_console_setup: co=%p (%d), %s\n",
1533            co, co->index, options);
1534
1535        /* is this a valid port */
1536
1537        if (co->index == -1 || co->index >= CONFIG_SERIAL_SAMSUNG_UARTS)
1538                co->index = 0;
1539
1540        port = &s3c24xx_serial_ports[co->index].port;
1541
1542        /* is the port configured? */
1543
1544        if (port->mapbase == 0x0)
1545                return -ENODEV;
1546
1547        cons_uart = port;
1548
1549        dbg("s3c24xx_serial_console_setup: port=%p (%d)\n", port, co->index);
1550
1551        /*
1552         * Check whether an invalid uart number has been specified, and
1553         * if so, search for the first available port that does have
1554         * console support.
1555         */
1556        if (options)
1557                uart_parse_options(options, &baud, &parity, &bits, &flow);
1558        else
1559                s3c24xx_serial_get_options(port, &baud, &parity, &bits);
1560
1561        dbg("s3c24xx_serial_console_setup: baud %d\n", baud);
1562
1563        return uart_set_options(port, co, baud, parity, bits, flow);
1564}
1565
1566static struct console s3c24xx_serial_console = {
1567        .name           = S3C24XX_SERIAL_NAME,
1568        .device         = uart_console_device,
1569        .flags          = CON_PRINTBUFFER,
1570        .index          = -1,
1571        .write          = s3c24xx_serial_console_write,
1572        .setup          = s3c24xx_serial_console_setup,
1573        .data           = &s3c24xx_uart_drv,
1574};
1575#endif /* CONFIG_SERIAL_SAMSUNG_CONSOLE */
1576
1577#ifdef CONFIG_CPU_S3C2410
1578static struct s3c24xx_serial_drv_data s3c2410_serial_drv_data = {
1579        .info = &(struct s3c24xx_uart_info) {
1580                .name           = "Samsung S3C2410 UART",
1581                .type           = PORT_S3C2410,
1582                .fifosize       = 16,
1583                .rx_fifomask    = S3C2410_UFSTAT_RXMASK,
1584                .rx_fifoshift   = S3C2410_UFSTAT_RXSHIFT,
1585                .rx_fifofull    = S3C2410_UFSTAT_RXFULL,
1586                .tx_fifofull    = S3C2410_UFSTAT_TXFULL,
1587                .tx_fifomask    = S3C2410_UFSTAT_TXMASK,
1588                .tx_fifoshift   = S3C2410_UFSTAT_TXSHIFT,
1589                .def_clk_sel    = S3C2410_UCON_CLKSEL0,
1590                .num_clks       = 2,
1591                .clksel_mask    = S3C2410_UCON_CLKMASK,
1592                .clksel_shift   = S3C2410_UCON_CLKSHIFT,
1593        },
1594        .def_cfg = &(struct s3c2410_uartcfg) {
1595                .ucon           = S3C2410_UCON_DEFAULT,
1596                .ufcon          = S3C2410_UFCON_DEFAULT,
1597        },
1598};
1599#define S3C2410_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c2410_serial_drv_data)
1600#else
1601#define S3C2410_SERIAL_DRV_DATA (kernel_ulong_t)NULL
1602#endif
1603
1604#ifdef CONFIG_CPU_S3C2412
1605static struct s3c24xx_serial_drv_data s3c2412_serial_drv_data = {
1606        .info = &(struct s3c24xx_uart_info) {
1607                .name           = "Samsung S3C2412 UART",
1608                .type           = PORT_S3C2412,
1609                .fifosize       = 64,
1610                .has_divslot    = 1,
1611                .rx_fifomask    = S3C2440_UFSTAT_RXMASK,
1612                .rx_fifoshift   = S3C2440_UFSTAT_RXSHIFT,
1613                .rx_fifofull    = S3C2440_UFSTAT_RXFULL,
1614                .tx_fifofull    = S3C2440_UFSTAT_TXFULL,
1615                .tx_fifomask    = S3C2440_UFSTAT_TXMASK,
1616                .tx_fifoshift   = S3C2440_UFSTAT_TXSHIFT,
1617                .def_clk_sel    = S3C2410_UCON_CLKSEL2,
1618                .num_clks       = 4,
1619                .clksel_mask    = S3C2412_UCON_CLKMASK,
1620                .clksel_shift   = S3C2412_UCON_CLKSHIFT,
1621        },
1622        .def_cfg = &(struct s3c2410_uartcfg) {
1623                .ucon           = S3C2410_UCON_DEFAULT,
1624                .ufcon          = S3C2410_UFCON_DEFAULT,
1625        },
1626};
1627#define S3C2412_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c2412_serial_drv_data)
1628#else
1629#define S3C2412_SERIAL_DRV_DATA (kernel_ulong_t)NULL
1630#endif
1631
1632#if defined(CONFIG_CPU_S3C2440) || defined(CONFIG_CPU_S3C2416) || \
1633        defined(CONFIG_CPU_S3C2443) || defined(CONFIG_CPU_S3C2442)
1634static struct s3c24xx_serial_drv_data s3c2440_serial_drv_data = {
1635        .info = &(struct s3c24xx_uart_info) {
1636                .name           = "Samsung S3C2440 UART",
1637                .type           = PORT_S3C2440,
1638                .fifosize       = 64,
1639                .has_divslot    = 1,
1640                .rx_fifomask    = S3C2440_UFSTAT_RXMASK,
1641                .rx_fifoshift   = S3C2440_UFSTAT_RXSHIFT,
1642                .rx_fifofull    = S3C2440_UFSTAT_RXFULL,
1643                .tx_fifofull    = S3C2440_UFSTAT_TXFULL,
1644                .tx_fifomask    = S3C2440_UFSTAT_TXMASK,
1645                .tx_fifoshift   = S3C2440_UFSTAT_TXSHIFT,
1646                .def_clk_sel    = S3C2410_UCON_CLKSEL2,
1647                .num_clks       = 4,
1648                .clksel_mask    = S3C2412_UCON_CLKMASK,
1649                .clksel_shift   = S3C2412_UCON_CLKSHIFT,
1650        },
1651        .def_cfg = &(struct s3c2410_uartcfg) {
1652                .ucon           = S3C2410_UCON_DEFAULT,
1653                .ufcon          = S3C2410_UFCON_DEFAULT,
1654        },
1655};
1656#define S3C2440_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c2440_serial_drv_data)
1657#else
1658#define S3C2440_SERIAL_DRV_DATA (kernel_ulong_t)NULL
1659#endif
1660
1661#if defined(CONFIG_CPU_S3C6400) || defined(CONFIG_CPU_S3C6410) || \
1662        defined(CONFIG_CPU_S5P6440) || defined(CONFIG_CPU_S5P6450) || \
1663        defined(CONFIG_CPU_S5PC100)
1664static struct s3c24xx_serial_drv_data s3c6400_serial_drv_data = {
1665        .info = &(struct s3c24xx_uart_info) {
1666                .name           = "Samsung S3C6400 UART",
1667                .type           = PORT_S3C6400,
1668                .fifosize       = 64,
1669                .has_divslot    = 1,
1670                .rx_fifomask    = S3C2440_UFSTAT_RXMASK,
1671                .rx_fifoshift   = S3C2440_UFSTAT_RXSHIFT,
1672                .rx_fifofull    = S3C2440_UFSTAT_RXFULL,
1673                .tx_fifofull    = S3C2440_UFSTAT_TXFULL,
1674                .tx_fifomask    = S3C2440_UFSTAT_TXMASK,
1675                .tx_fifoshift   = S3C2440_UFSTAT_TXSHIFT,
1676                .def_clk_sel    = S3C2410_UCON_CLKSEL2,
1677                .num_clks       = 4,
1678                .clksel_mask    = S3C6400_UCON_CLKMASK,
1679                .clksel_shift   = S3C6400_UCON_CLKSHIFT,
1680        },
1681        .def_cfg = &(struct s3c2410_uartcfg) {
1682                .ucon           = S3C2410_UCON_DEFAULT,
1683                .ufcon          = S3C2410_UFCON_DEFAULT,
1684        },
1685};
1686#define S3C6400_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c6400_serial_drv_data)
1687#else
1688#define S3C6400_SERIAL_DRV_DATA (kernel_ulong_t)NULL
1689#endif
1690
1691#ifdef CONFIG_CPU_S5PV210
1692static struct s3c24xx_serial_drv_data s5pv210_serial_drv_data = {
1693        .info = &(struct s3c24xx_uart_info) {
1694                .name           = "Samsung S5PV210 UART",
1695                .type           = PORT_S3C6400,
1696                .has_divslot    = 1,
1697                .rx_fifomask    = S5PV210_UFSTAT_RXMASK,
1698                .rx_fifoshift   = S5PV210_UFSTAT_RXSHIFT,
1699                .rx_fifofull    = S5PV210_UFSTAT_RXFULL,
1700                .tx_fifofull    = S5PV210_UFSTAT_TXFULL,
1701                .tx_fifomask    = S5PV210_UFSTAT_TXMASK,
1702                .tx_fifoshift   = S5PV210_UFSTAT_TXSHIFT,
1703                .def_clk_sel    = S3C2410_UCON_CLKSEL0,
1704                .num_clks       = 2,
1705                .clksel_mask    = S5PV210_UCON_CLKMASK,
1706                .clksel_shift   = S5PV210_UCON_CLKSHIFT,
1707        },
1708        .def_cfg = &(struct s3c2410_uartcfg) {
1709                .ucon           = S5PV210_UCON_DEFAULT,
1710                .ufcon          = S5PV210_UFCON_DEFAULT,
1711        },
1712        .fifosize = { 256, 64, 16, 16 },
1713};
1714#define S5PV210_SERIAL_DRV_DATA ((kernel_ulong_t)&s5pv210_serial_drv_data)
1715#else
1716#define S5PV210_SERIAL_DRV_DATA (kernel_ulong_t)NULL
1717#endif
1718
1719#if defined(CONFIG_ARCH_EXYNOS)
1720static struct s3c24xx_serial_drv_data exynos4210_serial_drv_data = {
1721        .info = &(struct s3c24xx_uart_info) {
1722                .name           = "Samsung Exynos4 UART",
1723                .type           = PORT_S3C6400,
1724                .has_divslot    = 1,
1725                .rx_fifomask    = S5PV210_UFSTAT_RXMASK,
1726                .rx_fifoshift   = S5PV210_UFSTAT_RXSHIFT,
1727                .rx_fifofull    = S5PV210_UFSTAT_RXFULL,
1728                .tx_fifofull    = S5PV210_UFSTAT_TXFULL,
1729                .tx_fifomask    = S5PV210_UFSTAT_TXMASK,
1730                .tx_fifoshift   = S5PV210_UFSTAT_TXSHIFT,
1731                .def_clk_sel    = S3C2410_UCON_CLKSEL0,
1732                .num_clks       = 1,
1733                .clksel_mask    = 0,
1734                .clksel_shift   = 0,
1735        },
1736        .def_cfg = &(struct s3c2410_uartcfg) {
1737                .ucon           = S5PV210_UCON_DEFAULT,
1738                .ufcon          = S5PV210_UFCON_DEFAULT,
1739                .has_fracval    = 1,
1740        },
1741        .fifosize = { 256, 64, 16, 16 },
1742};
1743#define EXYNOS4210_SERIAL_DRV_DATA ((kernel_ulong_t)&exynos4210_serial_drv_data)
1744#else
1745#define EXYNOS4210_SERIAL_DRV_DATA (kernel_ulong_t)NULL
1746#endif
1747
1748static struct platform_device_id s3c24xx_serial_driver_ids[] = {
1749        {
1750                .name           = "s3c2410-uart",
1751                .driver_data    = S3C2410_SERIAL_DRV_DATA,
1752        }, {
1753                .name           = "s3c2412-uart",
1754                .driver_data    = S3C2412_SERIAL_DRV_DATA,
1755        }, {
1756                .name           = "s3c2440-uart",
1757                .driver_data    = S3C2440_SERIAL_DRV_DATA,
1758        }, {
1759                .name           = "s3c6400-uart",
1760                .driver_data    = S3C6400_SERIAL_DRV_DATA,
1761        }, {
1762                .name           = "s5pv210-uart",
1763                .driver_data    = S5PV210_SERIAL_DRV_DATA,
1764        }, {
1765                .name           = "exynos4210-uart",
1766                .driver_data    = EXYNOS4210_SERIAL_DRV_DATA,
1767        },
1768        { },
1769};
1770MODULE_DEVICE_TABLE(platform, s3c24xx_serial_driver_ids);
1771
1772#ifdef CONFIG_OF
1773static const struct of_device_id s3c24xx_uart_dt_match[] = {
1774        { .compatible = "samsung,s3c2410-uart",
1775                .data = (void *)S3C2410_SERIAL_DRV_DATA },
1776        { .compatible = "samsung,s3c2412-uart",
1777                .data = (void *)S3C2412_SERIAL_DRV_DATA },
1778        { .compatible = "samsung,s3c2440-uart",
1779                .data = (void *)S3C2440_SERIAL_DRV_DATA },
1780        { .compatible = "samsung,s3c6400-uart",
1781                .data = (void *)S3C6400_SERIAL_DRV_DATA },
1782        { .compatible = "samsung,s5pv210-uart",
1783                .data = (void *)S5PV210_SERIAL_DRV_DATA },
1784        { .compatible = "samsung,exynos4210-uart",
1785                .data = (void *)EXYNOS4210_SERIAL_DRV_DATA },
1786        {},
1787};
1788MODULE_DEVICE_TABLE(of, s3c24xx_uart_dt_match);
1789#endif
1790
1791static struct platform_driver samsung_serial_driver = {
1792        .probe          = s3c24xx_serial_probe,
1793        .remove         = s3c24xx_serial_remove,
1794        .id_table       = s3c24xx_serial_driver_ids,
1795        .driver         = {
1796                .name   = "samsung-uart",
1797                .owner  = THIS_MODULE,
1798                .pm     = SERIAL_SAMSUNG_PM_OPS,
1799                .of_match_table = of_match_ptr(s3c24xx_uart_dt_match),
1800        },
1801};
1802
1803/* module initialisation code */
1804
1805static int __init s3c24xx_serial_modinit(void)
1806{
1807        int ret;
1808
1809        ret = uart_register_driver(&s3c24xx_uart_drv);
1810        if (ret < 0) {
1811                pr_err("Failed to register Samsung UART driver\n");
1812                return ret;
1813        }
1814
1815        ret = platform_driver_register(&samsung_serial_driver);
1816        if (ret < 0) {
1817                pr_err("Failed to register platform driver\n");
1818                uart_unregister_driver(&s3c24xx_uart_drv);
1819        }
1820
1821        return ret;
1822}
1823
1824static void __exit s3c24xx_serial_modexit(void)
1825{
1826        platform_driver_unregister(&samsung_serial_driver);
1827        uart_unregister_driver(&s3c24xx_uart_drv);
1828}
1829
1830module_init(s3c24xx_serial_modinit);
1831module_exit(s3c24xx_serial_modexit);
1832
1833MODULE_ALIAS("platform:samsung-uart");
1834MODULE_DESCRIPTION("Samsung SoC Serial port driver");
1835MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
1836MODULE_LICENSE("GPL v2");
1837