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        unsigned int umcon = rd_regl(port, S3C2410_UMCON);
 411
 412        if (mctrl & TIOCM_RTS)
 413                umcon |= S3C2410_UMCOM_RTS_LOW;
 414        else
 415                umcon &= ~S3C2410_UMCOM_RTS_LOW;
 416
 417        wr_regl(port, S3C2410_UMCON, umcon);
 418}
 419
 420static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state)
 421{
 422        unsigned long flags;
 423        unsigned int ucon;
 424
 425        spin_lock_irqsave(&port->lock, flags);
 426
 427        ucon = rd_regl(port, S3C2410_UCON);
 428
 429        if (break_state)
 430                ucon |= S3C2410_UCON_SBREAK;
 431        else
 432                ucon &= ~S3C2410_UCON_SBREAK;
 433
 434        wr_regl(port, S3C2410_UCON, ucon);
 435
 436        spin_unlock_irqrestore(&port->lock, flags);
 437}
 438
 439static void s3c24xx_serial_shutdown(struct uart_port *port)
 440{
 441        struct s3c24xx_uart_port *ourport = to_ourport(port);
 442
 443        if (ourport->tx_claimed) {
 444                if (!s3c24xx_serial_has_interrupt_mask(port))
 445                        free_irq(ourport->tx_irq, ourport);
 446                tx_enabled(port) = 0;
 447                ourport->tx_claimed = 0;
 448        }
 449
 450        if (ourport->rx_claimed) {
 451                if (!s3c24xx_serial_has_interrupt_mask(port))
 452                        free_irq(ourport->rx_irq, ourport);
 453                ourport->rx_claimed = 0;
 454                rx_enabled(port) = 0;
 455        }
 456
 457        /* Clear pending interrupts and mask all interrupts */
 458        if (s3c24xx_serial_has_interrupt_mask(port)) {
 459                free_irq(port->irq, ourport);
 460
 461                wr_regl(port, S3C64XX_UINTP, 0xf);
 462                wr_regl(port, S3C64XX_UINTM, 0xf);
 463        }
 464}
 465
 466static int s3c24xx_serial_startup(struct uart_port *port)
 467{
 468        struct s3c24xx_uart_port *ourport = to_ourport(port);
 469        int ret;
 470
 471        dbg("s3c24xx_serial_startup: port=%p (%08lx,%p)\n",
 472            port->mapbase, port->membase);
 473
 474        rx_enabled(port) = 1;
 475
 476        ret = request_irq(ourport->rx_irq, s3c24xx_serial_rx_chars, 0,
 477                          s3c24xx_serial_portname(port), ourport);
 478
 479        if (ret != 0) {
 480                dev_err(port->dev, "cannot get irq %d\n", ourport->rx_irq);
 481                return ret;
 482        }
 483
 484        ourport->rx_claimed = 1;
 485
 486        dbg("requesting tx irq...\n");
 487
 488        tx_enabled(port) = 1;
 489
 490        ret = request_irq(ourport->tx_irq, s3c24xx_serial_tx_chars, 0,
 491                          s3c24xx_serial_portname(port), ourport);
 492
 493        if (ret) {
 494                dev_err(port->dev, "cannot get irq %d\n", ourport->tx_irq);
 495                goto err;
 496        }
 497
 498        ourport->tx_claimed = 1;
 499
 500        dbg("s3c24xx_serial_startup ok\n");
 501
 502        /* the port reset code should have done the correct
 503         * register setup for the port controls */
 504
 505        return ret;
 506
 507 err:
 508        s3c24xx_serial_shutdown(port);
 509        return ret;
 510}
 511
 512static int s3c64xx_serial_startup(struct uart_port *port)
 513{
 514        struct s3c24xx_uart_port *ourport = to_ourport(port);
 515        int ret;
 516
 517        dbg("s3c64xx_serial_startup: port=%p (%08lx,%p)\n",
 518            port->mapbase, port->membase);
 519
 520        wr_regl(port, S3C64XX_UINTM, 0xf);
 521
 522        ret = request_irq(port->irq, s3c64xx_serial_handle_irq, IRQF_SHARED,
 523                          s3c24xx_serial_portname(port), ourport);
 524        if (ret) {
 525                dev_err(port->dev, "cannot get irq %d\n", port->irq);
 526                return ret;
 527        }
 528
 529        /* For compatibility with s3c24xx Soc's */
 530        rx_enabled(port) = 1;
 531        ourport->rx_claimed = 1;
 532        tx_enabled(port) = 0;
 533        ourport->tx_claimed = 1;
 534
 535        /* Enable Rx Interrupt */
 536        __clear_bit(S3C64XX_UINTM_RXD, portaddrl(port, S3C64XX_UINTM));
 537        dbg("s3c64xx_serial_startup ok\n");
 538        return ret;
 539}
 540
 541/* power power management control */
 542
 543static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level,
 544                              unsigned int old)
 545{
 546        struct s3c24xx_uart_port *ourport = to_ourport(port);
 547
 548        ourport->pm_level = level;
 549
 550        switch (level) {
 551        case 3:
 552                if (!IS_ERR(ourport->baudclk))
 553                        clk_disable_unprepare(ourport->baudclk);
 554
 555                clk_disable_unprepare(ourport->clk);
 556                break;
 557
 558        case 0:
 559                clk_prepare_enable(ourport->clk);
 560
 561                if (!IS_ERR(ourport->baudclk))
 562                        clk_prepare_enable(ourport->baudclk);
 563
 564                break;
 565        default:
 566                dev_err(port->dev, "s3c24xx_serial: unknown pm %d\n", level);
 567        }
 568}
 569
 570/* baud rate calculation
 571 *
 572 * The UARTs on the S3C2410/S3C2440 can take their clocks from a number
 573 * of different sources, including the peripheral clock ("pclk") and an
 574 * external clock ("uclk"). The S3C2440 also adds the core clock ("fclk")
 575 * with a programmable extra divisor.
 576 *
 577 * The following code goes through the clock sources, and calculates the
 578 * baud clocks (and the resultant actual baud rates) and then tries to
 579 * pick the closest one and select that.
 580 *
 581*/
 582
 583#define MAX_CLK_NAME_LENGTH 15
 584
 585static inline int s3c24xx_serial_getsource(struct uart_port *port)
 586{
 587        struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
 588        unsigned int ucon;
 589
 590        if (info->num_clks == 1)
 591                return 0;
 592
 593        ucon = rd_regl(port, S3C2410_UCON);
 594        ucon &= info->clksel_mask;
 595        return ucon >> info->clksel_shift;
 596}
 597
 598static void s3c24xx_serial_setsource(struct uart_port *port,
 599                        unsigned int clk_sel)
 600{
 601        struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
 602        unsigned int ucon;
 603
 604        if (info->num_clks == 1)
 605                return;
 606
 607        ucon = rd_regl(port, S3C2410_UCON);
 608        if ((ucon & info->clksel_mask) >> info->clksel_shift == clk_sel)
 609                return;
 610
 611        ucon &= ~info->clksel_mask;
 612        ucon |= clk_sel << info->clksel_shift;
 613        wr_regl(port, S3C2410_UCON, ucon);
 614}
 615
 616static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
 617                        unsigned int req_baud, struct clk **best_clk,
 618                        unsigned int *clk_num)
 619{
 620        struct s3c24xx_uart_info *info = ourport->info;
 621        struct clk *clk;
 622        unsigned long rate;
 623        unsigned int cnt, baud, quot, clk_sel, best_quot = 0;
 624        char clkname[MAX_CLK_NAME_LENGTH];
 625        int calc_deviation, deviation = (1 << 30) - 1;
 626
 627        clk_sel = (ourport->cfg->clk_sel) ? ourport->cfg->clk_sel :
 628                        ourport->info->def_clk_sel;
 629        for (cnt = 0; cnt < info->num_clks; cnt++) {
 630                if (!(clk_sel & (1 << cnt)))
 631                        continue;
 632
 633                sprintf(clkname, "clk_uart_baud%d", cnt);
 634                clk = clk_get(ourport->port.dev, clkname);
 635                if (IS_ERR(clk))
 636                        continue;
 637
 638                rate = clk_get_rate(clk);
 639                if (!rate)
 640                        continue;
 641
 642                if (ourport->info->has_divslot) {
 643                        unsigned long div = rate / req_baud;
 644
 645                        /* The UDIVSLOT register on the newer UARTs allows us to
 646                         * get a divisor adjustment of 1/16th on the baud clock.
 647                         *
 648                         * We don't keep the UDIVSLOT value (the 16ths we
 649                         * calculated by not multiplying the baud by 16) as it
 650                         * is easy enough to recalculate.
 651                         */
 652
 653                        quot = div / 16;
 654                        baud = rate / div;
 655                } else {
 656                        quot = (rate + (8 * req_baud)) / (16 * req_baud);
 657                        baud = rate / (quot * 16);
 658                }
 659                quot--;
 660
 661                calc_deviation = req_baud - baud;
 662                if (calc_deviation < 0)
 663                        calc_deviation = -calc_deviation;
 664
 665                if (calc_deviation < deviation) {
 666                        *best_clk = clk;
 667                        best_quot = quot;
 668                        *clk_num = cnt;
 669                        deviation = calc_deviation;
 670                }
 671        }
 672
 673        return best_quot;
 674}
 675
 676/* udivslot_table[]
 677 *
 678 * This table takes the fractional value of the baud divisor and gives
 679 * the recommended setting for the UDIVSLOT register.
 680 */
 681static u16 udivslot_table[16] = {
 682        [0] = 0x0000,
 683        [1] = 0x0080,
 684        [2] = 0x0808,
 685        [3] = 0x0888,
 686        [4] = 0x2222,
 687        [5] = 0x4924,
 688        [6] = 0x4A52,
 689        [7] = 0x54AA,
 690        [8] = 0x5555,
 691        [9] = 0xD555,
 692        [10] = 0xD5D5,
 693        [11] = 0xDDD5,
 694        [12] = 0xDDDD,
 695        [13] = 0xDFDD,
 696        [14] = 0xDFDF,
 697        [15] = 0xFFDF,
 698};
 699
 700static void s3c24xx_serial_set_termios(struct uart_port *port,
 701                                       struct ktermios *termios,
 702                                       struct ktermios *old)
 703{
 704        struct s3c2410_uartcfg *cfg = s3c24xx_port_to_cfg(port);
 705        struct s3c24xx_uart_port *ourport = to_ourport(port);
 706        struct clk *clk = ERR_PTR(-EINVAL);
 707        unsigned long flags;
 708        unsigned int baud, quot, clk_sel = 0;
 709        unsigned int ulcon;
 710        unsigned int umcon;
 711        unsigned int udivslot = 0;
 712
 713        /*
 714         * We don't support modem control lines.
 715         */
 716        termios->c_cflag &= ~(HUPCL | CMSPAR);
 717        termios->c_cflag |= CLOCAL;
 718
 719        /*
 720         * Ask the core to calculate the divisor for us.
 721         */
 722
 723        baud = uart_get_baud_rate(port, termios, old, 0, 115200*8);
 724        quot = s3c24xx_serial_getclk(ourport, baud, &clk, &clk_sel);
 725        if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
 726                quot = port->custom_divisor;
 727        if (IS_ERR(clk))
 728                return;
 729
 730        /* check to see if we need  to change clock source */
 731
 732        if (ourport->baudclk != clk) {
 733                s3c24xx_serial_setsource(port, clk_sel);
 734
 735                if (!IS_ERR(ourport->baudclk)) {
 736                        clk_disable_unprepare(ourport->baudclk);
 737                        ourport->baudclk = ERR_PTR(-EINVAL);
 738                }
 739
 740                clk_prepare_enable(clk);
 741
 742                ourport->baudclk = clk;
 743                ourport->baudclk_rate = clk ? clk_get_rate(clk) : 0;
 744        }
 745
 746        if (ourport->info->has_divslot) {
 747                unsigned int div = ourport->baudclk_rate / baud;
 748
 749                if (cfg->has_fracval) {
 750                        udivslot = (div & 15);
 751                        dbg("fracval = %04x\n", udivslot);
 752                } else {
 753                        udivslot = udivslot_table[div & 15];
 754                        dbg("udivslot = %04x (div %d)\n", udivslot, div & 15);
 755                }
 756        }
 757
 758        switch (termios->c_cflag & CSIZE) {
 759        case CS5:
 760                dbg("config: 5bits/char\n");
 761                ulcon = S3C2410_LCON_CS5;
 762                break;
 763        case CS6:
 764                dbg("config: 6bits/char\n");
 765                ulcon = S3C2410_LCON_CS6;
 766                break;
 767        case CS7:
 768                dbg("config: 7bits/char\n");
 769                ulcon = S3C2410_LCON_CS7;
 770                break;
 771        case CS8:
 772        default:
 773                dbg("config: 8bits/char\n");
 774                ulcon = S3C2410_LCON_CS8;
 775                break;
 776        }
 777
 778        /* preserve original lcon IR settings */
 779        ulcon |= (cfg->ulcon & S3C2410_LCON_IRM);
 780
 781        if (termios->c_cflag & CSTOPB)
 782                ulcon |= S3C2410_LCON_STOPB;
 783
 784        if (termios->c_cflag & PARENB) {
 785                if (termios->c_cflag & PARODD)
 786                        ulcon |= S3C2410_LCON_PODD;
 787                else
 788                        ulcon |= S3C2410_LCON_PEVEN;
 789        } else {
 790                ulcon |= S3C2410_LCON_PNONE;
 791        }
 792
 793        spin_lock_irqsave(&port->lock, flags);
 794
 795        dbg("setting ulcon to %08x, brddiv to %d, udivslot %08x\n",
 796            ulcon, quot, udivslot);
 797
 798        wr_regl(port, S3C2410_ULCON, ulcon);
 799        wr_regl(port, S3C2410_UBRDIV, quot);
 800
 801        umcon = rd_regl(port, S3C2410_UMCON);
 802        if (termios->c_cflag & CRTSCTS) {
 803                umcon |= S3C2410_UMCOM_AFC;
 804                /* Disable RTS when RX FIFO contains 63 bytes */
 805                umcon &= ~S3C2412_UMCON_AFC_8;
 806        } else {
 807                umcon &= ~S3C2410_UMCOM_AFC;
 808        }
 809        wr_regl(port, S3C2410_UMCON, umcon);
 810
 811        if (ourport->info->has_divslot)
 812                wr_regl(port, S3C2443_DIVSLOT, udivslot);
 813
 814        dbg("uart: ulcon = 0x%08x, ucon = 0x%08x, ufcon = 0x%08x\n",
 815            rd_regl(port, S3C2410_ULCON),
 816            rd_regl(port, S3C2410_UCON),
 817            rd_regl(port, S3C2410_UFCON));
 818
 819        /*
 820         * Update the per-port timeout.
 821         */
 822        uart_update_timeout(port, termios->c_cflag, baud);
 823
 824        /*
 825         * Which character status flags are we interested in?
 826         */
 827        port->read_status_mask = S3C2410_UERSTAT_OVERRUN;
 828        if (termios->c_iflag & INPCK)
 829                port->read_status_mask |= S3C2410_UERSTAT_FRAME | S3C2410_UERSTAT_PARITY;
 830
 831        /*
 832         * Which character status flags should we ignore?
 833         */
 834        port->ignore_status_mask = 0;
 835        if (termios->c_iflag & IGNPAR)
 836                port->ignore_status_mask |= S3C2410_UERSTAT_OVERRUN;
 837        if (termios->c_iflag & IGNBRK && termios->c_iflag & IGNPAR)
 838                port->ignore_status_mask |= S3C2410_UERSTAT_FRAME;
 839
 840        /*
 841         * Ignore all characters if CREAD is not set.
 842         */
 843        if ((termios->c_cflag & CREAD) == 0)
 844                port->ignore_status_mask |= RXSTAT_DUMMY_READ;
 845
 846        spin_unlock_irqrestore(&port->lock, flags);
 847}
 848
 849static const char *s3c24xx_serial_type(struct uart_port *port)
 850{
 851        switch (port->type) {
 852        case PORT_S3C2410:
 853                return "S3C2410";
 854        case PORT_S3C2440:
 855                return "S3C2440";
 856        case PORT_S3C2412:
 857                return "S3C2412";
 858        case PORT_S3C6400:
 859                return "S3C6400/10";
 860        default:
 861                return NULL;
 862        }
 863}
 864
 865#define MAP_SIZE (0x100)
 866
 867static void s3c24xx_serial_release_port(struct uart_port *port)
 868{
 869        release_mem_region(port->mapbase, MAP_SIZE);
 870}
 871
 872static int s3c24xx_serial_request_port(struct uart_port *port)
 873{
 874        const char *name = s3c24xx_serial_portname(port);
 875        return request_mem_region(port->mapbase, MAP_SIZE, name) ? 0 : -EBUSY;
 876}
 877
 878static void s3c24xx_serial_config_port(struct uart_port *port, int flags)
 879{
 880        struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
 881
 882        if (flags & UART_CONFIG_TYPE &&
 883            s3c24xx_serial_request_port(port) == 0)
 884                port->type = info->type;
 885}
 886
 887/*
 888 * verify the new serial_struct (for TIOCSSERIAL).
 889 */
 890static int
 891s3c24xx_serial_verify_port(struct uart_port *port, struct serial_struct *ser)
 892{
 893        struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
 894
 895        if (ser->type != PORT_UNKNOWN && ser->type != info->type)
 896                return -EINVAL;
 897
 898        return 0;
 899}
 900
 901
 902#ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
 903
 904static struct console s3c24xx_serial_console;
 905
 906static int __init s3c24xx_serial_console_init(void)
 907{
 908        register_console(&s3c24xx_serial_console);
 909        return 0;
 910}
 911console_initcall(s3c24xx_serial_console_init);
 912
 913#define S3C24XX_SERIAL_CONSOLE &s3c24xx_serial_console
 914#else
 915#define S3C24XX_SERIAL_CONSOLE NULL
 916#endif
 917
 918#if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
 919static int s3c24xx_serial_get_poll_char(struct uart_port *port);
 920static void s3c24xx_serial_put_poll_char(struct uart_port *port,
 921                         unsigned char c);
 922#endif
 923
 924static struct uart_ops s3c24xx_serial_ops = {
 925        .pm             = s3c24xx_serial_pm,
 926        .tx_empty       = s3c24xx_serial_tx_empty,
 927        .get_mctrl      = s3c24xx_serial_get_mctrl,
 928        .set_mctrl      = s3c24xx_serial_set_mctrl,
 929        .stop_tx        = s3c24xx_serial_stop_tx,
 930        .start_tx       = s3c24xx_serial_start_tx,
 931        .stop_rx        = s3c24xx_serial_stop_rx,
 932        .enable_ms      = s3c24xx_serial_enable_ms,
 933        .break_ctl      = s3c24xx_serial_break_ctl,
 934        .startup        = s3c24xx_serial_startup,
 935        .shutdown       = s3c24xx_serial_shutdown,
 936        .set_termios    = s3c24xx_serial_set_termios,
 937        .type           = s3c24xx_serial_type,
 938        .release_port   = s3c24xx_serial_release_port,
 939        .request_port   = s3c24xx_serial_request_port,
 940        .config_port    = s3c24xx_serial_config_port,
 941        .verify_port    = s3c24xx_serial_verify_port,
 942#if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
 943        .poll_get_char = s3c24xx_serial_get_poll_char,
 944        .poll_put_char = s3c24xx_serial_put_poll_char,
 945#endif
 946};
 947
 948static struct uart_driver s3c24xx_uart_drv = {
 949        .owner          = THIS_MODULE,
 950        .driver_name    = "s3c2410_serial",
 951        .nr             = CONFIG_SERIAL_SAMSUNG_UARTS,
 952        .cons           = S3C24XX_SERIAL_CONSOLE,
 953        .dev_name       = S3C24XX_SERIAL_NAME,
 954        .major          = S3C24XX_SERIAL_MAJOR,
 955        .minor          = S3C24XX_SERIAL_MINOR,
 956};
 957
 958static struct s3c24xx_uart_port s3c24xx_serial_ports[CONFIG_SERIAL_SAMSUNG_UARTS] = {
 959        [0] = {
 960                .port = {
 961                        .lock           = __SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[0].port.lock),
 962                        .iotype         = UPIO_MEM,
 963                        .uartclk        = 0,
 964                        .fifosize       = 16,
 965                        .ops            = &s3c24xx_serial_ops,
 966                        .flags          = UPF_BOOT_AUTOCONF,
 967                        .line           = 0,
 968                }
 969        },
 970        [1] = {
 971                .port = {
 972                        .lock           = __SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[1].port.lock),
 973                        .iotype         = UPIO_MEM,
 974                        .uartclk        = 0,
 975                        .fifosize       = 16,
 976                        .ops            = &s3c24xx_serial_ops,
 977                        .flags          = UPF_BOOT_AUTOCONF,
 978                        .line           = 1,
 979                }
 980        },
 981#if CONFIG_SERIAL_SAMSUNG_UARTS > 2
 982
 983        [2] = {
 984                .port = {
 985                        .lock           = __SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[2].port.lock),
 986                        .iotype         = UPIO_MEM,
 987                        .uartclk        = 0,
 988                        .fifosize       = 16,
 989                        .ops            = &s3c24xx_serial_ops,
 990                        .flags          = UPF_BOOT_AUTOCONF,
 991                        .line           = 2,
 992                }
 993        },
 994#endif
 995#if CONFIG_SERIAL_SAMSUNG_UARTS > 3
 996        [3] = {
 997                .port = {
 998                        .lock           = __SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[3].port.lock),
 999                        .iotype         = UPIO_MEM,
1000                        .uartclk        = 0,
1001                        .fifosize       = 16,
1002                        .ops            = &s3c24xx_serial_ops,
1003                        .flags          = UPF_BOOT_AUTOCONF,
1004                        .line           = 3,
1005                }
1006        }
1007#endif
1008};
1009
1010/* s3c24xx_serial_resetport
1011 *
1012 * reset the fifos and other the settings.
1013*/
1014
1015static void s3c24xx_serial_resetport(struct uart_port *port,
1016                                   struct s3c2410_uartcfg *cfg)
1017{
1018        struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1019        unsigned long ucon = rd_regl(port, S3C2410_UCON);
1020        unsigned int ucon_mask;
1021
1022        ucon_mask = info->clksel_mask;
1023        if (info->type == PORT_S3C2440)
1024                ucon_mask |= S3C2440_UCON0_DIVMASK;
1025
1026        ucon &= ucon_mask;
1027        wr_regl(port, S3C2410_UCON,  ucon | cfg->ucon);
1028
1029        /* reset both fifos */
1030        wr_regl(port, S3C2410_UFCON, cfg->ufcon | S3C2410_UFCON_RESETBOTH);
1031        wr_regl(port, S3C2410_UFCON, cfg->ufcon);
1032
1033        /* some delay is required after fifo reset */
1034        udelay(1);
1035}
1036
1037
1038#ifdef CONFIG_CPU_FREQ
1039
1040static int s3c24xx_serial_cpufreq_transition(struct notifier_block *nb,
1041                                             unsigned long val, void *data)
1042{
1043        struct s3c24xx_uart_port *port;
1044        struct uart_port *uport;
1045
1046        port = container_of(nb, struct s3c24xx_uart_port, freq_transition);
1047        uport = &port->port;
1048
1049        /* check to see if port is enabled */
1050
1051        if (port->pm_level != 0)
1052                return 0;
1053
1054        /* try and work out if the baudrate is changing, we can detect
1055         * a change in rate, but we do not have support for detecting
1056         * a disturbance in the clock-rate over the change.
1057         */
1058
1059        if (IS_ERR(port->baudclk))
1060                goto exit;
1061
1062        if (port->baudclk_rate == clk_get_rate(port->baudclk))
1063                goto exit;
1064
1065        if (val == CPUFREQ_PRECHANGE) {
1066                /* we should really shut the port down whilst the
1067                 * frequency change is in progress. */
1068
1069        } else if (val == CPUFREQ_POSTCHANGE) {
1070                struct ktermios *termios;
1071                struct tty_struct *tty;
1072
1073                if (uport->state == NULL)
1074                        goto exit;
1075
1076                tty = uport->state->port.tty;
1077
1078                if (tty == NULL)
1079                        goto exit;
1080
1081                termios = &tty->termios;
1082
1083                if (termios == NULL) {
1084                        dev_warn(uport->dev, "%s: no termios?\n", __func__);
1085                        goto exit;
1086                }
1087
1088                s3c24xx_serial_set_termios(uport, termios, NULL);
1089        }
1090
1091 exit:
1092        return 0;
1093}
1094
1095static inline int s3c24xx_serial_cpufreq_register(struct s3c24xx_uart_port *port)
1096{
1097        port->freq_transition.notifier_call = s3c24xx_serial_cpufreq_transition;
1098
1099        return cpufreq_register_notifier(&port->freq_transition,
1100                                         CPUFREQ_TRANSITION_NOTIFIER);
1101}
1102
1103static inline void s3c24xx_serial_cpufreq_deregister(struct s3c24xx_uart_port *port)
1104{
1105        cpufreq_unregister_notifier(&port->freq_transition,
1106                                    CPUFREQ_TRANSITION_NOTIFIER);
1107}
1108
1109#else
1110static inline int s3c24xx_serial_cpufreq_register(struct s3c24xx_uart_port *port)
1111{
1112        return 0;
1113}
1114
1115static inline void s3c24xx_serial_cpufreq_deregister(struct s3c24xx_uart_port *port)
1116{
1117}
1118#endif
1119
1120/* s3c24xx_serial_init_port
1121 *
1122 * initialise a single serial port from the platform device given
1123 */
1124
1125static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
1126                                    struct platform_device *platdev)
1127{
1128        struct uart_port *port = &ourport->port;
1129        struct s3c2410_uartcfg *cfg = ourport->cfg;
1130        struct resource *res;
1131        int ret;
1132
1133        dbg("s3c24xx_serial_init_port: port=%p, platdev=%p\n", port, platdev);
1134
1135        if (platdev == NULL)
1136                return -ENODEV;
1137
1138        if (port->mapbase != 0)
1139                return 0;
1140
1141        /* setup info for port */
1142        port->dev       = &platdev->dev;
1143
1144        /* Startup sequence is different for s3c64xx and higher SoC's */
1145        if (s3c24xx_serial_has_interrupt_mask(port))
1146                s3c24xx_serial_ops.startup = s3c64xx_serial_startup;
1147
1148        port->uartclk = 1;
1149
1150        if (cfg->uart_flags & UPF_CONS_FLOW) {
1151                dbg("s3c24xx_serial_init_port: enabling flow control\n");
1152                port->flags |= UPF_CONS_FLOW;
1153        }
1154
1155        /* sort our the physical and virtual addresses for each UART */
1156
1157        res = platform_get_resource(platdev, IORESOURCE_MEM, 0);
1158        if (res == NULL) {
1159                dev_err(port->dev, "failed to find memory resource for uart\n");
1160                return -EINVAL;
1161        }
1162
1163        dbg("resource %p (%lx..%lx)\n", res, res->start, res->end);
1164
1165        port->membase = devm_ioremap(port->dev, res->start, resource_size(res));
1166        if (!port->membase) {
1167                dev_err(port->dev, "failed to remap controller address\n");
1168                return -EBUSY;
1169        }
1170
1171        port->mapbase = res->start;
1172        ret = platform_get_irq(platdev, 0);
1173        if (ret < 0)
1174                port->irq = 0;
1175        else {
1176                port->irq = ret;
1177                ourport->rx_irq = ret;
1178                ourport->tx_irq = ret + 1;
1179        }
1180
1181        ret = platform_get_irq(platdev, 1);
1182        if (ret > 0)
1183                ourport->tx_irq = ret;
1184
1185        ourport->clk    = clk_get(&platdev->dev, "uart");
1186        if (IS_ERR(ourport->clk)) {
1187                pr_err("%s: Controller clock not found\n",
1188                                dev_name(&platdev->dev));
1189                return PTR_ERR(ourport->clk);
1190        }
1191
1192        ret = clk_prepare_enable(ourport->clk);
1193        if (ret) {
1194                pr_err("uart: clock failed to prepare+enable: %d\n", ret);
1195                clk_put(ourport->clk);
1196                return ret;
1197        }
1198
1199        /* Keep all interrupts masked and cleared */
1200        if (s3c24xx_serial_has_interrupt_mask(port)) {
1201                wr_regl(port, S3C64XX_UINTM, 0xf);
1202                wr_regl(port, S3C64XX_UINTP, 0xf);
1203                wr_regl(port, S3C64XX_UINTSP, 0xf);
1204        }
1205
1206        dbg("port: map=%08x, mem=%08x, irq=%d (%d,%d), clock=%ld\n",
1207            port->mapbase, port->membase, port->irq,
1208            ourport->rx_irq, ourport->tx_irq, port->uartclk);
1209
1210        /* reset the fifos (and setup the uart) */
1211        s3c24xx_serial_resetport(port, cfg);
1212        clk_disable_unprepare(ourport->clk);
1213        return 0;
1214}
1215
1216#ifdef CONFIG_SAMSUNG_CLOCK
1217static ssize_t s3c24xx_serial_show_clksrc(struct device *dev,
1218                                          struct device_attribute *attr,
1219                                          char *buf)
1220{
1221        struct uart_port *port = s3c24xx_dev_to_port(dev);
1222        struct s3c24xx_uart_port *ourport = to_ourport(port);
1223
1224        if (IS_ERR(ourport->baudclk))
1225                return -EINVAL;
1226
1227        return snprintf(buf, PAGE_SIZE, "* %s\n",
1228                        ourport->baudclk->name ?: "(null)");
1229}
1230
1231static DEVICE_ATTR(clock_source, S_IRUGO, s3c24xx_serial_show_clksrc, NULL);
1232#endif
1233
1234/* Device driver serial port probe */
1235
1236static const struct of_device_id s3c24xx_uart_dt_match[];
1237static int probe_index;
1238
1239static inline struct s3c24xx_serial_drv_data *s3c24xx_get_driver_data(
1240                        struct platform_device *pdev)
1241{
1242#ifdef CONFIG_OF
1243        if (pdev->dev.of_node) {
1244                const struct of_device_id *match;
1245                match = of_match_node(s3c24xx_uart_dt_match, pdev->dev.of_node);
1246                return (struct s3c24xx_serial_drv_data *)match->data;
1247        }
1248#endif
1249        return (struct s3c24xx_serial_drv_data *)
1250                        platform_get_device_id(pdev)->driver_data;
1251}
1252
1253static int s3c24xx_serial_probe(struct platform_device *pdev)
1254{
1255        struct s3c24xx_uart_port *ourport;
1256        int ret;
1257
1258        dbg("s3c24xx_serial_probe(%p) %d\n", pdev, probe_index);
1259
1260        ourport = &s3c24xx_serial_ports[probe_index];
1261
1262        ourport->drv_data = s3c24xx_get_driver_data(pdev);
1263        if (!ourport->drv_data) {
1264                dev_err(&pdev->dev, "could not find driver data\n");
1265                return -ENODEV;
1266        }
1267
1268        ourport->baudclk = ERR_PTR(-EINVAL);
1269        ourport->info = ourport->drv_data->info;
1270        ourport->cfg = (dev_get_platdata(&pdev->dev)) ?
1271                        dev_get_platdata(&pdev->dev) :
1272                        ourport->drv_data->def_cfg;
1273
1274        ourport->port.fifosize = (ourport->info->fifosize) ?
1275                ourport->info->fifosize :
1276                ourport->drv_data->fifosize[probe_index];
1277
1278        probe_index++;
1279
1280        dbg("%s: initialising port %p...\n", __func__, ourport);
1281
1282        ret = s3c24xx_serial_init_port(ourport, pdev);
1283        if (ret < 0)
1284                goto probe_err;
1285
1286        dbg("%s: adding port\n", __func__);
1287        uart_add_one_port(&s3c24xx_uart_drv, &ourport->port);
1288        platform_set_drvdata(pdev, &ourport->port);
1289
1290#ifdef CONFIG_SAMSUNG_CLOCK
1291        ret = device_create_file(&pdev->dev, &dev_attr_clock_source);
1292        if (ret < 0)
1293                dev_err(&pdev->dev, "failed to add clock source attr.\n");
1294#endif
1295
1296        ret = s3c24xx_serial_cpufreq_register(ourport);
1297        if (ret < 0)
1298                dev_err(&pdev->dev, "failed to add cpufreq notifier\n");
1299
1300        return 0;
1301
1302 probe_err:
1303        return ret;
1304}
1305
1306static int s3c24xx_serial_remove(struct platform_device *dev)
1307{
1308        struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
1309
1310        if (port) {
1311                s3c24xx_serial_cpufreq_deregister(to_ourport(port));
1312#ifdef CONFIG_SAMSUNG_CLOCK
1313                device_remove_file(&dev->dev, &dev_attr_clock_source);
1314#endif
1315                uart_remove_one_port(&s3c24xx_uart_drv, port);
1316        }
1317
1318        return 0;
1319}
1320
1321/* UART power management code */
1322#ifdef CONFIG_PM_SLEEP
1323static int s3c24xx_serial_suspend(struct device *dev)
1324{
1325        struct uart_port *port = s3c24xx_dev_to_port(dev);
1326
1327        if (port)
1328                uart_suspend_port(&s3c24xx_uart_drv, port);
1329
1330        return 0;
1331}
1332
1333static int s3c24xx_serial_resume(struct device *dev)
1334{
1335        struct uart_port *port = s3c24xx_dev_to_port(dev);
1336        struct s3c24xx_uart_port *ourport = to_ourport(port);
1337
1338        if (port) {
1339                clk_prepare_enable(ourport->clk);
1340                s3c24xx_serial_resetport(port, s3c24xx_port_to_cfg(port));
1341                clk_disable_unprepare(ourport->clk);
1342
1343                uart_resume_port(&s3c24xx_uart_drv, port);
1344        }
1345
1346        return 0;
1347}
1348
1349static int s3c24xx_serial_resume_noirq(struct device *dev)
1350{
1351        struct uart_port *port = s3c24xx_dev_to_port(dev);
1352
1353        if (port) {
1354                /* restore IRQ mask */
1355                if (s3c24xx_serial_has_interrupt_mask(port)) {
1356                        unsigned int uintm = 0xf;
1357                        if (tx_enabled(port))
1358                                uintm &= ~S3C64XX_UINTM_TXD_MSK;
1359                        if (rx_enabled(port))
1360                                uintm &= ~S3C64XX_UINTM_RXD_MSK;
1361                        wr_regl(port, S3C64XX_UINTM, uintm);
1362                }
1363        }
1364
1365        return 0;
1366}
1367
1368static const struct dev_pm_ops s3c24xx_serial_pm_ops = {
1369        .suspend = s3c24xx_serial_suspend,
1370        .resume = s3c24xx_serial_resume,
1371        .resume_noirq = s3c24xx_serial_resume_noirq,
1372};
1373#define SERIAL_SAMSUNG_PM_OPS   (&s3c24xx_serial_pm_ops)
1374
1375#else /* !CONFIG_PM_SLEEP */
1376
1377#define SERIAL_SAMSUNG_PM_OPS   NULL
1378#endif /* CONFIG_PM_SLEEP */
1379
1380/* Console code */
1381
1382#ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
1383
1384static struct uart_port *cons_uart;
1385
1386static int
1387s3c24xx_serial_console_txrdy(struct uart_port *port, unsigned int ufcon)
1388{
1389        struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1390        unsigned long ufstat, utrstat;
1391
1392        if (ufcon & S3C2410_UFCON_FIFOMODE) {
1393                /* fifo mode - check amount of data in fifo registers... */
1394
1395                ufstat = rd_regl(port, S3C2410_UFSTAT);
1396                return (ufstat & info->tx_fifofull) ? 0 : 1;
1397        }
1398
1399        /* in non-fifo mode, we go and use the tx buffer empty */
1400
1401        utrstat = rd_regl(port, S3C2410_UTRSTAT);
1402        return (utrstat & S3C2410_UTRSTAT_TXE) ? 1 : 0;
1403}
1404
1405static bool
1406s3c24xx_port_configured(unsigned int ucon)
1407{
1408        /* consider the serial port configured if the tx/rx mode set */
1409        return (ucon & 0xf) != 0;
1410}
1411
1412#ifdef CONFIG_CONSOLE_POLL
1413/*
1414 * Console polling routines for writing and reading from the uart while
1415 * in an interrupt or debug context.
1416 */
1417
1418static int s3c24xx_serial_get_poll_char(struct uart_port *port)
1419{
1420        struct s3c24xx_uart_port *ourport = to_ourport(port);
1421        unsigned int ufstat;
1422
1423        ufstat = rd_regl(port, S3C2410_UFSTAT);
1424        if (s3c24xx_serial_rx_fifocnt(ourport, ufstat) == 0)
1425                return NO_POLL_CHAR;
1426
1427        return rd_regb(port, S3C2410_URXH);
1428}
1429
1430static void s3c24xx_serial_put_poll_char(struct uart_port *port,
1431                unsigned char c)
1432{
1433        unsigned int ufcon = rd_regl(cons_uart, S3C2410_UFCON);
1434        unsigned int ucon = rd_regl(cons_uart, S3C2410_UCON);
1435
1436        /* not possible to xmit on unconfigured port */
1437        if (!s3c24xx_port_configured(ucon))
1438                return;
1439
1440        while (!s3c24xx_serial_console_txrdy(port, ufcon))
1441                cpu_relax();
1442        wr_regb(cons_uart, S3C2410_UTXH, c);
1443}
1444
1445#endif /* CONFIG_CONSOLE_POLL */
1446
1447static void
1448s3c24xx_serial_console_putchar(struct uart_port *port, int ch)
1449{
1450        unsigned int ufcon = rd_regl(cons_uart, S3C2410_UFCON);
1451        unsigned int ucon = rd_regl(cons_uart, S3C2410_UCON);
1452
1453        /* not possible to xmit on unconfigured port */
1454        if (!s3c24xx_port_configured(ucon))
1455                return;
1456
1457        while (!s3c24xx_serial_console_txrdy(port, ufcon))
1458                barrier();
1459        wr_regb(cons_uart, S3C2410_UTXH, ch);
1460}
1461
1462static void
1463s3c24xx_serial_console_write(struct console *co, const char *s,
1464                             unsigned int count)
1465{
1466        uart_console_write(cons_uart, s, count, s3c24xx_serial_console_putchar);
1467}
1468
1469static void __init
1470s3c24xx_serial_get_options(struct uart_port *port, int *baud,
1471                           int *parity, int *bits)
1472{
1473        struct clk *clk;
1474        unsigned int ulcon;
1475        unsigned int ucon;
1476        unsigned int ubrdiv;
1477        unsigned long rate;
1478        unsigned int clk_sel;
1479        char clk_name[MAX_CLK_NAME_LENGTH];
1480
1481        ulcon  = rd_regl(port, S3C2410_ULCON);
1482        ucon   = rd_regl(port, S3C2410_UCON);
1483        ubrdiv = rd_regl(port, S3C2410_UBRDIV);
1484
1485        dbg("s3c24xx_serial_get_options: port=%p\n"
1486            "registers: ulcon=%08x, ucon=%08x, ubdriv=%08x\n",
1487            port, ulcon, ucon, ubrdiv);
1488
1489        if (s3c24xx_port_configured(ucon)) {
1490                switch (ulcon & S3C2410_LCON_CSMASK) {
1491                case S3C2410_LCON_CS5:
1492                        *bits = 5;
1493                        break;
1494                case S3C2410_LCON_CS6:
1495                        *bits = 6;
1496                        break;
1497                case S3C2410_LCON_CS7:
1498                        *bits = 7;
1499                        break;
1500                default:
1501                case S3C2410_LCON_CS8:
1502                        *bits = 8;
1503                        break;
1504                }
1505
1506                switch (ulcon & S3C2410_LCON_PMASK) {
1507                case S3C2410_LCON_PEVEN:
1508                        *parity = 'e';
1509                        break;
1510
1511                case S3C2410_LCON_PODD:
1512                        *parity = 'o';
1513                        break;
1514
1515                case S3C2410_LCON_PNONE:
1516                default:
1517                        *parity = 'n';
1518                }
1519
1520                /* now calculate the baud rate */
1521
1522                clk_sel = s3c24xx_serial_getsource(port);
1523                sprintf(clk_name, "clk_uart_baud%d", clk_sel);
1524
1525                clk = clk_get(port->dev, clk_name);
1526                if (!IS_ERR(clk))
1527                        rate = clk_get_rate(clk);
1528                else
1529                        rate = 1;
1530
1531                *baud = rate / (16 * (ubrdiv + 1));
1532                dbg("calculated baud %d\n", *baud);
1533        }
1534
1535}
1536
1537static int __init
1538s3c24xx_serial_console_setup(struct console *co, char *options)
1539{
1540        struct uart_port *port;
1541        int baud = 9600;
1542        int bits = 8;
1543        int parity = 'n';
1544        int flow = 'n';
1545
1546        dbg("s3c24xx_serial_console_setup: co=%p (%d), %s\n",
1547            co, co->index, options);
1548
1549        /* is this a valid port */
1550
1551        if (co->index == -1 || co->index >= CONFIG_SERIAL_SAMSUNG_UARTS)
1552                co->index = 0;
1553
1554        port = &s3c24xx_serial_ports[co->index].port;
1555
1556        /* is the port configured? */
1557
1558        if (port->mapbase == 0x0)
1559                return -ENODEV;
1560
1561        cons_uart = port;
1562
1563        dbg("s3c24xx_serial_console_setup: port=%p (%d)\n", port, co->index);
1564
1565        /*
1566         * Check whether an invalid uart number has been specified, and
1567         * if so, search for the first available port that does have
1568         * console support.
1569         */
1570        if (options)
1571                uart_parse_options(options, &baud, &parity, &bits, &flow);
1572        else
1573                s3c24xx_serial_get_options(port, &baud, &parity, &bits);
1574
1575        dbg("s3c24xx_serial_console_setup: baud %d\n", baud);
1576
1577        return uart_set_options(port, co, baud, parity, bits, flow);
1578}
1579
1580static struct console s3c24xx_serial_console = {
1581        .name           = S3C24XX_SERIAL_NAME,
1582        .device         = uart_console_device,
1583        .flags          = CON_PRINTBUFFER,
1584        .index          = -1,
1585        .write          = s3c24xx_serial_console_write,
1586        .setup          = s3c24xx_serial_console_setup,
1587        .data           = &s3c24xx_uart_drv,
1588};
1589#endif /* CONFIG_SERIAL_SAMSUNG_CONSOLE */
1590
1591#ifdef CONFIG_CPU_S3C2410
1592static struct s3c24xx_serial_drv_data s3c2410_serial_drv_data = {
1593        .info = &(struct s3c24xx_uart_info) {
1594                .name           = "Samsung S3C2410 UART",
1595                .type           = PORT_S3C2410,
1596                .fifosize       = 16,
1597                .rx_fifomask    = S3C2410_UFSTAT_RXMASK,
1598                .rx_fifoshift   = S3C2410_UFSTAT_RXSHIFT,
1599                .rx_fifofull    = S3C2410_UFSTAT_RXFULL,
1600                .tx_fifofull    = S3C2410_UFSTAT_TXFULL,
1601                .tx_fifomask    = S3C2410_UFSTAT_TXMASK,
1602                .tx_fifoshift   = S3C2410_UFSTAT_TXSHIFT,
1603                .def_clk_sel    = S3C2410_UCON_CLKSEL0,
1604                .num_clks       = 2,
1605                .clksel_mask    = S3C2410_UCON_CLKMASK,
1606                .clksel_shift   = S3C2410_UCON_CLKSHIFT,
1607        },
1608        .def_cfg = &(struct s3c2410_uartcfg) {
1609                .ucon           = S3C2410_UCON_DEFAULT,
1610                .ufcon          = S3C2410_UFCON_DEFAULT,
1611        },
1612};
1613#define S3C2410_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c2410_serial_drv_data)
1614#else
1615#define S3C2410_SERIAL_DRV_DATA (kernel_ulong_t)NULL
1616#endif
1617
1618#ifdef CONFIG_CPU_S3C2412
1619static struct s3c24xx_serial_drv_data s3c2412_serial_drv_data = {
1620        .info = &(struct s3c24xx_uart_info) {
1621                .name           = "Samsung S3C2412 UART",
1622                .type           = PORT_S3C2412,
1623                .fifosize       = 64,
1624                .has_divslot    = 1,
1625                .rx_fifomask    = S3C2440_UFSTAT_RXMASK,
1626                .rx_fifoshift   = S3C2440_UFSTAT_RXSHIFT,
1627                .rx_fifofull    = S3C2440_UFSTAT_RXFULL,
1628                .tx_fifofull    = S3C2440_UFSTAT_TXFULL,
1629                .tx_fifomask    = S3C2440_UFSTAT_TXMASK,
1630                .tx_fifoshift   = S3C2440_UFSTAT_TXSHIFT,
1631                .def_clk_sel    = S3C2410_UCON_CLKSEL2,
1632                .num_clks       = 4,
1633                .clksel_mask    = S3C2412_UCON_CLKMASK,
1634                .clksel_shift   = S3C2412_UCON_CLKSHIFT,
1635        },
1636        .def_cfg = &(struct s3c2410_uartcfg) {
1637                .ucon           = S3C2410_UCON_DEFAULT,
1638                .ufcon          = S3C2410_UFCON_DEFAULT,
1639        },
1640};
1641#define S3C2412_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c2412_serial_drv_data)
1642#else
1643#define S3C2412_SERIAL_DRV_DATA (kernel_ulong_t)NULL
1644#endif
1645
1646#if defined(CONFIG_CPU_S3C2440) || defined(CONFIG_CPU_S3C2416) || \
1647        defined(CONFIG_CPU_S3C2443) || defined(CONFIG_CPU_S3C2442)
1648static struct s3c24xx_serial_drv_data s3c2440_serial_drv_data = {
1649        .info = &(struct s3c24xx_uart_info) {
1650                .name           = "Samsung S3C2440 UART",
1651                .type           = PORT_S3C2440,
1652                .fifosize       = 64,
1653                .has_divslot    = 1,
1654                .rx_fifomask    = S3C2440_UFSTAT_RXMASK,
1655                .rx_fifoshift   = S3C2440_UFSTAT_RXSHIFT,
1656                .rx_fifofull    = S3C2440_UFSTAT_RXFULL,
1657                .tx_fifofull    = S3C2440_UFSTAT_TXFULL,
1658                .tx_fifomask    = S3C2440_UFSTAT_TXMASK,
1659                .tx_fifoshift   = S3C2440_UFSTAT_TXSHIFT,
1660                .def_clk_sel    = S3C2410_UCON_CLKSEL2,
1661                .num_clks       = 4,
1662                .clksel_mask    = S3C2412_UCON_CLKMASK,
1663                .clksel_shift   = S3C2412_UCON_CLKSHIFT,
1664        },
1665        .def_cfg = &(struct s3c2410_uartcfg) {
1666                .ucon           = S3C2410_UCON_DEFAULT,
1667                .ufcon          = S3C2410_UFCON_DEFAULT,
1668        },
1669};
1670#define S3C2440_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c2440_serial_drv_data)
1671#else
1672#define S3C2440_SERIAL_DRV_DATA (kernel_ulong_t)NULL
1673#endif
1674
1675#if defined(CONFIG_CPU_S3C6400) || defined(CONFIG_CPU_S3C6410) || \
1676        defined(CONFIG_CPU_S5P6440) || defined(CONFIG_CPU_S5P6450) || \
1677        defined(CONFIG_CPU_S5PC100)
1678static struct s3c24xx_serial_drv_data s3c6400_serial_drv_data = {
1679        .info = &(struct s3c24xx_uart_info) {
1680                .name           = "Samsung S3C6400 UART",
1681                .type           = PORT_S3C6400,
1682                .fifosize       = 64,
1683                .has_divslot    = 1,
1684                .rx_fifomask    = S3C2440_UFSTAT_RXMASK,
1685                .rx_fifoshift   = S3C2440_UFSTAT_RXSHIFT,
1686                .rx_fifofull    = S3C2440_UFSTAT_RXFULL,
1687                .tx_fifofull    = S3C2440_UFSTAT_TXFULL,
1688                .tx_fifomask    = S3C2440_UFSTAT_TXMASK,
1689                .tx_fifoshift   = S3C2440_UFSTAT_TXSHIFT,
1690                .def_clk_sel    = S3C2410_UCON_CLKSEL2,
1691                .num_clks       = 4,
1692                .clksel_mask    = S3C6400_UCON_CLKMASK,
1693                .clksel_shift   = S3C6400_UCON_CLKSHIFT,
1694        },
1695        .def_cfg = &(struct s3c2410_uartcfg) {
1696                .ucon           = S3C2410_UCON_DEFAULT,
1697                .ufcon          = S3C2410_UFCON_DEFAULT,
1698        },
1699};
1700#define S3C6400_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c6400_serial_drv_data)
1701#else
1702#define S3C6400_SERIAL_DRV_DATA (kernel_ulong_t)NULL
1703#endif
1704
1705#ifdef CONFIG_CPU_S5PV210
1706static struct s3c24xx_serial_drv_data s5pv210_serial_drv_data = {
1707        .info = &(struct s3c24xx_uart_info) {
1708                .name           = "Samsung S5PV210 UART",
1709                .type           = PORT_S3C6400,
1710                .has_divslot    = 1,
1711                .rx_fifomask    = S5PV210_UFSTAT_RXMASK,
1712                .rx_fifoshift   = S5PV210_UFSTAT_RXSHIFT,
1713                .rx_fifofull    = S5PV210_UFSTAT_RXFULL,
1714                .tx_fifofull    = S5PV210_UFSTAT_TXFULL,
1715                .tx_fifomask    = S5PV210_UFSTAT_TXMASK,
1716                .tx_fifoshift   = S5PV210_UFSTAT_TXSHIFT,
1717                .def_clk_sel    = S3C2410_UCON_CLKSEL0,
1718                .num_clks       = 2,
1719                .clksel_mask    = S5PV210_UCON_CLKMASK,
1720                .clksel_shift   = S5PV210_UCON_CLKSHIFT,
1721        },
1722        .def_cfg = &(struct s3c2410_uartcfg) {
1723                .ucon           = S5PV210_UCON_DEFAULT,
1724                .ufcon          = S5PV210_UFCON_DEFAULT,
1725        },
1726        .fifosize = { 256, 64, 16, 16 },
1727};
1728#define S5PV210_SERIAL_DRV_DATA ((kernel_ulong_t)&s5pv210_serial_drv_data)
1729#else
1730#define S5PV210_SERIAL_DRV_DATA (kernel_ulong_t)NULL
1731#endif
1732
1733#if defined(CONFIG_ARCH_EXYNOS)
1734static struct s3c24xx_serial_drv_data exynos4210_serial_drv_data = {
1735        .info = &(struct s3c24xx_uart_info) {
1736                .name           = "Samsung Exynos4 UART",
1737                .type           = PORT_S3C6400,
1738                .has_divslot    = 1,
1739                .rx_fifomask    = S5PV210_UFSTAT_RXMASK,
1740                .rx_fifoshift   = S5PV210_UFSTAT_RXSHIFT,
1741                .rx_fifofull    = S5PV210_UFSTAT_RXFULL,
1742                .tx_fifofull    = S5PV210_UFSTAT_TXFULL,
1743                .tx_fifomask    = S5PV210_UFSTAT_TXMASK,
1744                .tx_fifoshift   = S5PV210_UFSTAT_TXSHIFT,
1745                .def_clk_sel    = S3C2410_UCON_CLKSEL0,
1746                .num_clks       = 1,
1747                .clksel_mask    = 0,
1748                .clksel_shift   = 0,
1749        },
1750        .def_cfg = &(struct s3c2410_uartcfg) {
1751                .ucon           = S5PV210_UCON_DEFAULT,
1752                .ufcon          = S5PV210_UFCON_DEFAULT,
1753                .has_fracval    = 1,
1754        },
1755        .fifosize = { 256, 64, 16, 16 },
1756};
1757#define EXYNOS4210_SERIAL_DRV_DATA ((kernel_ulong_t)&exynos4210_serial_drv_data)
1758#else
1759#define EXYNOS4210_SERIAL_DRV_DATA (kernel_ulong_t)NULL
1760#endif
1761
1762static struct platform_device_id s3c24xx_serial_driver_ids[] = {
1763        {
1764                .name           = "s3c2410-uart",
1765                .driver_data    = S3C2410_SERIAL_DRV_DATA,
1766        }, {
1767                .name           = "s3c2412-uart",
1768                .driver_data    = S3C2412_SERIAL_DRV_DATA,
1769        }, {
1770                .name           = "s3c2440-uart",
1771                .driver_data    = S3C2440_SERIAL_DRV_DATA,
1772        }, {
1773                .name           = "s3c6400-uart",
1774                .driver_data    = S3C6400_SERIAL_DRV_DATA,
1775        }, {
1776                .name           = "s5pv210-uart",
1777                .driver_data    = S5PV210_SERIAL_DRV_DATA,
1778        }, {
1779                .name           = "exynos4210-uart",
1780                .driver_data    = EXYNOS4210_SERIAL_DRV_DATA,
1781        },
1782        { },
1783};
1784MODULE_DEVICE_TABLE(platform, s3c24xx_serial_driver_ids);
1785
1786#ifdef CONFIG_OF
1787static const struct of_device_id s3c24xx_uart_dt_match[] = {
1788        { .compatible = "samsung,s3c2410-uart",
1789                .data = (void *)S3C2410_SERIAL_DRV_DATA },
1790        { .compatible = "samsung,s3c2412-uart",
1791                .data = (void *)S3C2412_SERIAL_DRV_DATA },
1792        { .compatible = "samsung,s3c2440-uart",
1793                .data = (void *)S3C2440_SERIAL_DRV_DATA },
1794        { .compatible = "samsung,s3c6400-uart",
1795                .data = (void *)S3C6400_SERIAL_DRV_DATA },
1796        { .compatible = "samsung,s5pv210-uart",
1797                .data = (void *)S5PV210_SERIAL_DRV_DATA },
1798        { .compatible = "samsung,exynos4210-uart",
1799                .data = (void *)EXYNOS4210_SERIAL_DRV_DATA },
1800        {},
1801};
1802MODULE_DEVICE_TABLE(of, s3c24xx_uart_dt_match);
1803#endif
1804
1805static struct platform_driver samsung_serial_driver = {
1806        .probe          = s3c24xx_serial_probe,
1807        .remove         = s3c24xx_serial_remove,
1808        .id_table       = s3c24xx_serial_driver_ids,
1809        .driver         = {
1810                .name   = "samsung-uart",
1811                .owner  = THIS_MODULE,
1812                .pm     = SERIAL_SAMSUNG_PM_OPS,
1813                .of_match_table = of_match_ptr(s3c24xx_uart_dt_match),
1814        },
1815};
1816
1817/* module initialisation code */
1818
1819static int __init s3c24xx_serial_modinit(void)
1820{
1821        int ret;
1822
1823        ret = uart_register_driver(&s3c24xx_uart_drv);
1824        if (ret < 0) {
1825                pr_err("Failed to register Samsung UART driver\n");
1826                return ret;
1827        }
1828
1829        ret = platform_driver_register(&samsung_serial_driver);
1830        if (ret < 0) {
1831                pr_err("Failed to register platform driver\n");
1832                uart_unregister_driver(&s3c24xx_uart_drv);
1833        }
1834
1835        return ret;
1836}
1837
1838static void __exit s3c24xx_serial_modexit(void)
1839{
1840        platform_driver_unregister(&samsung_serial_driver);
1841        uart_unregister_driver(&s3c24xx_uart_drv);
1842}
1843
1844module_init(s3c24xx_serial_modinit);
1845module_exit(s3c24xx_serial_modexit);
1846
1847MODULE_ALIAS("platform:samsung-uart");
1848MODULE_DESCRIPTION("Samsung SoC Serial port driver");
1849MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
1850MODULE_LICENSE("GPL v2");
1851