linux/drivers/tty/serial/amba-pl010.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 *  Driver for AMBA serial ports
   4 *
   5 *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
   6 *
   7 *  Copyright 1999 ARM Limited
   8 *  Copyright (C) 2000 Deep Blue Solutions Ltd.
   9 *
  10 * This is a generic driver for ARM AMBA-type serial ports.  They
  11 * have a lot of 16550-like features, but are not register compatible.
  12 * Note that although they do have CTS, DCD and DSR inputs, they do
  13 * not have an RI input, nor do they have DTR or RTS outputs.  If
  14 * required, these have to be supplied via some other means (eg, GPIO)
  15 * and hooked into this driver.
  16 */
  17
  18#include <linux/module.h>
  19#include <linux/ioport.h>
  20#include <linux/init.h>
  21#include <linux/console.h>
  22#include <linux/sysrq.h>
  23#include <linux/device.h>
  24#include <linux/tty.h>
  25#include <linux/tty_flip.h>
  26#include <linux/serial_core.h>
  27#include <linux/serial.h>
  28#include <linux/amba/bus.h>
  29#include <linux/amba/serial.h>
  30#include <linux/clk.h>
  31#include <linux/slab.h>
  32#include <linux/io.h>
  33
  34#define UART_NR         8
  35
  36#define SERIAL_AMBA_MAJOR       204
  37#define SERIAL_AMBA_MINOR       16
  38#define SERIAL_AMBA_NR          UART_NR
  39
  40#define AMBA_ISR_PASS_LIMIT     256
  41
  42#define UART_RX_DATA(s)         (((s) & UART01x_FR_RXFE) == 0)
  43#define UART_TX_READY(s)        (((s) & UART01x_FR_TXFF) == 0)
  44
  45#define UART_DUMMY_RSR_RX       256
  46#define UART_PORT_SIZE          64
  47
  48/*
  49 * We wrap our port structure around the generic uart_port.
  50 */
  51struct uart_amba_port {
  52        struct uart_port        port;
  53        struct clk              *clk;
  54        struct amba_device      *dev;
  55        struct amba_pl010_data  *data;
  56        unsigned int            old_status;
  57};
  58
  59static void pl010_stop_tx(struct uart_port *port)
  60{
  61        struct uart_amba_port *uap =
  62                container_of(port, struct uart_amba_port, port);
  63        unsigned int cr;
  64
  65        cr = readb(uap->port.membase + UART010_CR);
  66        cr &= ~UART010_CR_TIE;
  67        writel(cr, uap->port.membase + UART010_CR);
  68}
  69
  70static void pl010_start_tx(struct uart_port *port)
  71{
  72        struct uart_amba_port *uap =
  73                container_of(port, struct uart_amba_port, port);
  74        unsigned int cr;
  75
  76        cr = readb(uap->port.membase + UART010_CR);
  77        cr |= UART010_CR_TIE;
  78        writel(cr, uap->port.membase + UART010_CR);
  79}
  80
  81static void pl010_stop_rx(struct uart_port *port)
  82{
  83        struct uart_amba_port *uap =
  84                container_of(port, struct uart_amba_port, port);
  85        unsigned int cr;
  86
  87        cr = readb(uap->port.membase + UART010_CR);
  88        cr &= ~(UART010_CR_RIE | UART010_CR_RTIE);
  89        writel(cr, uap->port.membase + UART010_CR);
  90}
  91
  92static void pl010_disable_ms(struct uart_port *port)
  93{
  94        struct uart_amba_port *uap = (struct uart_amba_port *)port;
  95        unsigned int cr;
  96
  97        cr = readb(uap->port.membase + UART010_CR);
  98        cr &= ~UART010_CR_MSIE;
  99        writel(cr, uap->port.membase + UART010_CR);
 100}
 101
 102static void pl010_enable_ms(struct uart_port *port)
 103{
 104        struct uart_amba_port *uap =
 105                container_of(port, struct uart_amba_port, port);
 106        unsigned int cr;
 107
 108        cr = readb(uap->port.membase + UART010_CR);
 109        cr |= UART010_CR_MSIE;
 110        writel(cr, uap->port.membase + UART010_CR);
 111}
 112
 113static void pl010_rx_chars(struct uart_amba_port *uap)
 114{
 115        unsigned int status, ch, flag, rsr, max_count = 256;
 116
 117        status = readb(uap->port.membase + UART01x_FR);
 118        while (UART_RX_DATA(status) && max_count--) {
 119                ch = readb(uap->port.membase + UART01x_DR);
 120                flag = TTY_NORMAL;
 121
 122                uap->port.icount.rx++;
 123
 124                /*
 125                 * Note that the error handling code is
 126                 * out of the main execution path
 127                 */
 128                rsr = readb(uap->port.membase + UART01x_RSR) | UART_DUMMY_RSR_RX;
 129                if (unlikely(rsr & UART01x_RSR_ANY)) {
 130                        writel(0, uap->port.membase + UART01x_ECR);
 131
 132                        if (rsr & UART01x_RSR_BE) {
 133                                rsr &= ~(UART01x_RSR_FE | UART01x_RSR_PE);
 134                                uap->port.icount.brk++;
 135                                if (uart_handle_break(&uap->port))
 136                                        goto ignore_char;
 137                        } else if (rsr & UART01x_RSR_PE)
 138                                uap->port.icount.parity++;
 139                        else if (rsr & UART01x_RSR_FE)
 140                                uap->port.icount.frame++;
 141                        if (rsr & UART01x_RSR_OE)
 142                                uap->port.icount.overrun++;
 143
 144                        rsr &= uap->port.read_status_mask;
 145
 146                        if (rsr & UART01x_RSR_BE)
 147                                flag = TTY_BREAK;
 148                        else if (rsr & UART01x_RSR_PE)
 149                                flag = TTY_PARITY;
 150                        else if (rsr & UART01x_RSR_FE)
 151                                flag = TTY_FRAME;
 152                }
 153
 154                if (uart_handle_sysrq_char(&uap->port, ch))
 155                        goto ignore_char;
 156
 157                uart_insert_char(&uap->port, rsr, UART01x_RSR_OE, ch, flag);
 158
 159        ignore_char:
 160                status = readb(uap->port.membase + UART01x_FR);
 161        }
 162        spin_unlock(&uap->port.lock);
 163        tty_flip_buffer_push(&uap->port.state->port);
 164        spin_lock(&uap->port.lock);
 165}
 166
 167static void pl010_tx_chars(struct uart_amba_port *uap)
 168{
 169        struct circ_buf *xmit = &uap->port.state->xmit;
 170        int count;
 171
 172        if (uap->port.x_char) {
 173                writel(uap->port.x_char, uap->port.membase + UART01x_DR);
 174                uap->port.icount.tx++;
 175                uap->port.x_char = 0;
 176                return;
 177        }
 178        if (uart_circ_empty(xmit) || uart_tx_stopped(&uap->port)) {
 179                pl010_stop_tx(&uap->port);
 180                return;
 181        }
 182
 183        count = uap->port.fifosize >> 1;
 184        do {
 185                writel(xmit->buf[xmit->tail], uap->port.membase + UART01x_DR);
 186                xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 187                uap->port.icount.tx++;
 188                if (uart_circ_empty(xmit))
 189                        break;
 190        } while (--count > 0);
 191
 192        if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 193                uart_write_wakeup(&uap->port);
 194
 195        if (uart_circ_empty(xmit))
 196                pl010_stop_tx(&uap->port);
 197}
 198
 199static void pl010_modem_status(struct uart_amba_port *uap)
 200{
 201        unsigned int status, delta;
 202
 203        writel(0, uap->port.membase + UART010_ICR);
 204
 205        status = readb(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
 206
 207        delta = status ^ uap->old_status;
 208        uap->old_status = status;
 209
 210        if (!delta)
 211                return;
 212
 213        if (delta & UART01x_FR_DCD)
 214                uart_handle_dcd_change(&uap->port, status & UART01x_FR_DCD);
 215
 216        if (delta & UART01x_FR_DSR)
 217                uap->port.icount.dsr++;
 218
 219        if (delta & UART01x_FR_CTS)
 220                uart_handle_cts_change(&uap->port, status & UART01x_FR_CTS);
 221
 222        wake_up_interruptible(&uap->port.state->port.delta_msr_wait);
 223}
 224
 225static irqreturn_t pl010_int(int irq, void *dev_id)
 226{
 227        struct uart_amba_port *uap = dev_id;
 228        unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
 229        int handled = 0;
 230
 231        spin_lock(&uap->port.lock);
 232
 233        status = readb(uap->port.membase + UART010_IIR);
 234        if (status) {
 235                do {
 236                        if (status & (UART010_IIR_RTIS | UART010_IIR_RIS))
 237                                pl010_rx_chars(uap);
 238                        if (status & UART010_IIR_MIS)
 239                                pl010_modem_status(uap);
 240                        if (status & UART010_IIR_TIS)
 241                                pl010_tx_chars(uap);
 242
 243                        if (pass_counter-- == 0)
 244                                break;
 245
 246                        status = readb(uap->port.membase + UART010_IIR);
 247                } while (status & (UART010_IIR_RTIS | UART010_IIR_RIS |
 248                                   UART010_IIR_TIS));
 249                handled = 1;
 250        }
 251
 252        spin_unlock(&uap->port.lock);
 253
 254        return IRQ_RETVAL(handled);
 255}
 256
 257static unsigned int pl010_tx_empty(struct uart_port *port)
 258{
 259        struct uart_amba_port *uap =
 260                container_of(port, struct uart_amba_port, port);
 261        unsigned int status = readb(uap->port.membase + UART01x_FR);
 262        return status & UART01x_FR_BUSY ? 0 : TIOCSER_TEMT;
 263}
 264
 265static unsigned int pl010_get_mctrl(struct uart_port *port)
 266{
 267        struct uart_amba_port *uap =
 268                container_of(port, struct uart_amba_port, port);
 269        unsigned int result = 0;
 270        unsigned int status;
 271
 272        status = readb(uap->port.membase + UART01x_FR);
 273        if (status & UART01x_FR_DCD)
 274                result |= TIOCM_CAR;
 275        if (status & UART01x_FR_DSR)
 276                result |= TIOCM_DSR;
 277        if (status & UART01x_FR_CTS)
 278                result |= TIOCM_CTS;
 279
 280        return result;
 281}
 282
 283static void pl010_set_mctrl(struct uart_port *port, unsigned int mctrl)
 284{
 285        struct uart_amba_port *uap =
 286                container_of(port, struct uart_amba_port, port);
 287
 288        if (uap->data)
 289                uap->data->set_mctrl(uap->dev, uap->port.membase, mctrl);
 290}
 291
 292static void pl010_break_ctl(struct uart_port *port, int break_state)
 293{
 294        struct uart_amba_port *uap =
 295                container_of(port, struct uart_amba_port, port);
 296        unsigned long flags;
 297        unsigned int lcr_h;
 298
 299        spin_lock_irqsave(&uap->port.lock, flags);
 300        lcr_h = readb(uap->port.membase + UART010_LCRH);
 301        if (break_state == -1)
 302                lcr_h |= UART01x_LCRH_BRK;
 303        else
 304                lcr_h &= ~UART01x_LCRH_BRK;
 305        writel(lcr_h, uap->port.membase + UART010_LCRH);
 306        spin_unlock_irqrestore(&uap->port.lock, flags);
 307}
 308
 309static int pl010_startup(struct uart_port *port)
 310{
 311        struct uart_amba_port *uap =
 312                container_of(port, struct uart_amba_port, port);
 313        int retval;
 314
 315        /*
 316         * Try to enable the clock producer.
 317         */
 318        retval = clk_prepare_enable(uap->clk);
 319        if (retval)
 320                goto out;
 321
 322        uap->port.uartclk = clk_get_rate(uap->clk);
 323
 324        /*
 325         * Allocate the IRQ
 326         */
 327        retval = request_irq(uap->port.irq, pl010_int, 0, "uart-pl010", uap);
 328        if (retval)
 329                goto clk_dis;
 330
 331        /*
 332         * initialise the old status of the modem signals
 333         */
 334        uap->old_status = readb(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
 335
 336        /*
 337         * Finally, enable interrupts
 338         */
 339        writel(UART01x_CR_UARTEN | UART010_CR_RIE | UART010_CR_RTIE,
 340               uap->port.membase + UART010_CR);
 341
 342        return 0;
 343
 344 clk_dis:
 345        clk_disable_unprepare(uap->clk);
 346 out:
 347        return retval;
 348}
 349
 350static void pl010_shutdown(struct uart_port *port)
 351{
 352        struct uart_amba_port *uap =
 353                container_of(port, struct uart_amba_port, port);
 354
 355        /*
 356         * Free the interrupt
 357         */
 358        free_irq(uap->port.irq, uap);
 359
 360        /*
 361         * disable all interrupts, disable the port
 362         */
 363        writel(0, uap->port.membase + UART010_CR);
 364
 365        /* disable break condition and fifos */
 366        writel(readb(uap->port.membase + UART010_LCRH) &
 367                ~(UART01x_LCRH_BRK | UART01x_LCRH_FEN),
 368               uap->port.membase + UART010_LCRH);
 369
 370        /*
 371         * Shut down the clock producer
 372         */
 373        clk_disable_unprepare(uap->clk);
 374}
 375
 376static void
 377pl010_set_termios(struct uart_port *port, struct ktermios *termios,
 378                     struct ktermios *old)
 379{
 380        struct uart_amba_port *uap =
 381                container_of(port, struct uart_amba_port, port);
 382        unsigned int lcr_h, old_cr;
 383        unsigned long flags;
 384        unsigned int baud, quot;
 385
 386        /*
 387         * Ask the core to calculate the divisor for us.
 388         */
 389        baud = uart_get_baud_rate(port, termios, old, 0, uap->port.uartclk/16); 
 390        quot = uart_get_divisor(port, baud);
 391
 392        switch (termios->c_cflag & CSIZE) {
 393        case CS5:
 394                lcr_h = UART01x_LCRH_WLEN_5;
 395                break;
 396        case CS6:
 397                lcr_h = UART01x_LCRH_WLEN_6;
 398                break;
 399        case CS7:
 400                lcr_h = UART01x_LCRH_WLEN_7;
 401                break;
 402        default: // CS8
 403                lcr_h = UART01x_LCRH_WLEN_8;
 404                break;
 405        }
 406        if (termios->c_cflag & CSTOPB)
 407                lcr_h |= UART01x_LCRH_STP2;
 408        if (termios->c_cflag & PARENB) {
 409                lcr_h |= UART01x_LCRH_PEN;
 410                if (!(termios->c_cflag & PARODD))
 411                        lcr_h |= UART01x_LCRH_EPS;
 412        }
 413        if (uap->port.fifosize > 1)
 414                lcr_h |= UART01x_LCRH_FEN;
 415
 416        spin_lock_irqsave(&uap->port.lock, flags);
 417
 418        /*
 419         * Update the per-port timeout.
 420         */
 421        uart_update_timeout(port, termios->c_cflag, baud);
 422
 423        uap->port.read_status_mask = UART01x_RSR_OE;
 424        if (termios->c_iflag & INPCK)
 425                uap->port.read_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
 426        if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
 427                uap->port.read_status_mask |= UART01x_RSR_BE;
 428
 429        /*
 430         * Characters to ignore
 431         */
 432        uap->port.ignore_status_mask = 0;
 433        if (termios->c_iflag & IGNPAR)
 434                uap->port.ignore_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
 435        if (termios->c_iflag & IGNBRK) {
 436                uap->port.ignore_status_mask |= UART01x_RSR_BE;
 437                /*
 438                 * If we're ignoring parity and break indicators,
 439                 * ignore overruns too (for real raw support).
 440                 */
 441                if (termios->c_iflag & IGNPAR)
 442                        uap->port.ignore_status_mask |= UART01x_RSR_OE;
 443        }
 444
 445        /*
 446         * Ignore all characters if CREAD is not set.
 447         */
 448        if ((termios->c_cflag & CREAD) == 0)
 449                uap->port.ignore_status_mask |= UART_DUMMY_RSR_RX;
 450
 451        /* first, disable everything */
 452        old_cr = readb(uap->port.membase + UART010_CR) & ~UART010_CR_MSIE;
 453
 454        if (UART_ENABLE_MS(port, termios->c_cflag))
 455                old_cr |= UART010_CR_MSIE;
 456
 457        writel(0, uap->port.membase + UART010_CR);
 458
 459        /* Set baud rate */
 460        quot -= 1;
 461        writel((quot & 0xf00) >> 8, uap->port.membase + UART010_LCRM);
 462        writel(quot & 0xff, uap->port.membase + UART010_LCRL);
 463
 464        /*
 465         * ----------v----------v----------v----------v-----
 466         * NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L
 467         * ----------^----------^----------^----------^-----
 468         */
 469        writel(lcr_h, uap->port.membase + UART010_LCRH);
 470        writel(old_cr, uap->port.membase + UART010_CR);
 471
 472        spin_unlock_irqrestore(&uap->port.lock, flags);
 473}
 474
 475static void pl010_set_ldisc(struct uart_port *port, struct ktermios *termios)
 476{
 477        if (termios->c_line == N_PPS) {
 478                port->flags |= UPF_HARDPPS_CD;
 479                spin_lock_irq(&port->lock);
 480                pl010_enable_ms(port);
 481                spin_unlock_irq(&port->lock);
 482        } else {
 483                port->flags &= ~UPF_HARDPPS_CD;
 484                if (!UART_ENABLE_MS(port, termios->c_cflag)) {
 485                        spin_lock_irq(&port->lock);
 486                        pl010_disable_ms(port);
 487                        spin_unlock_irq(&port->lock);
 488                }
 489        }
 490}
 491
 492static const char *pl010_type(struct uart_port *port)
 493{
 494        return port->type == PORT_AMBA ? "AMBA" : NULL;
 495}
 496
 497/*
 498 * Release the memory region(s) being used by 'port'
 499 */
 500static void pl010_release_port(struct uart_port *port)
 501{
 502        release_mem_region(port->mapbase, UART_PORT_SIZE);
 503}
 504
 505/*
 506 * Request the memory region(s) being used by 'port'
 507 */
 508static int pl010_request_port(struct uart_port *port)
 509{
 510        return request_mem_region(port->mapbase, UART_PORT_SIZE, "uart-pl010")
 511                        != NULL ? 0 : -EBUSY;
 512}
 513
 514/*
 515 * Configure/autoconfigure the port.
 516 */
 517static void pl010_config_port(struct uart_port *port, int flags)
 518{
 519        if (flags & UART_CONFIG_TYPE) {
 520                port->type = PORT_AMBA;
 521                pl010_request_port(port);
 522        }
 523}
 524
 525/*
 526 * verify the new serial_struct (for TIOCSSERIAL).
 527 */
 528static int pl010_verify_port(struct uart_port *port, struct serial_struct *ser)
 529{
 530        int ret = 0;
 531        if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA)
 532                ret = -EINVAL;
 533        if (ser->irq < 0 || ser->irq >= nr_irqs)
 534                ret = -EINVAL;
 535        if (ser->baud_base < 9600)
 536                ret = -EINVAL;
 537        return ret;
 538}
 539
 540static const struct uart_ops amba_pl010_pops = {
 541        .tx_empty       = pl010_tx_empty,
 542        .set_mctrl      = pl010_set_mctrl,
 543        .get_mctrl      = pl010_get_mctrl,
 544        .stop_tx        = pl010_stop_tx,
 545        .start_tx       = pl010_start_tx,
 546        .stop_rx        = pl010_stop_rx,
 547        .enable_ms      = pl010_enable_ms,
 548        .break_ctl      = pl010_break_ctl,
 549        .startup        = pl010_startup,
 550        .shutdown       = pl010_shutdown,
 551        .set_termios    = pl010_set_termios,
 552        .set_ldisc      = pl010_set_ldisc,
 553        .type           = pl010_type,
 554        .release_port   = pl010_release_port,
 555        .request_port   = pl010_request_port,
 556        .config_port    = pl010_config_port,
 557        .verify_port    = pl010_verify_port,
 558};
 559
 560static struct uart_amba_port *amba_ports[UART_NR];
 561
 562#ifdef CONFIG_SERIAL_AMBA_PL010_CONSOLE
 563
 564static void pl010_console_putchar(struct uart_port *port, int ch)
 565{
 566        struct uart_amba_port *uap =
 567                container_of(port, struct uart_amba_port, port);
 568        unsigned int status;
 569
 570        do {
 571                status = readb(uap->port.membase + UART01x_FR);
 572                barrier();
 573        } while (!UART_TX_READY(status));
 574        writel(ch, uap->port.membase + UART01x_DR);
 575}
 576
 577static void
 578pl010_console_write(struct console *co, const char *s, unsigned int count)
 579{
 580        struct uart_amba_port *uap = amba_ports[co->index];
 581        unsigned int status, old_cr;
 582
 583        clk_enable(uap->clk);
 584
 585        /*
 586         *      First save the CR then disable the interrupts
 587         */
 588        old_cr = readb(uap->port.membase + UART010_CR);
 589        writel(UART01x_CR_UARTEN, uap->port.membase + UART010_CR);
 590
 591        uart_console_write(&uap->port, s, count, pl010_console_putchar);
 592
 593        /*
 594         *      Finally, wait for transmitter to become empty
 595         *      and restore the TCR
 596         */
 597        do {
 598                status = readb(uap->port.membase + UART01x_FR);
 599                barrier();
 600        } while (status & UART01x_FR_BUSY);
 601        writel(old_cr, uap->port.membase + UART010_CR);
 602
 603        clk_disable(uap->clk);
 604}
 605
 606static void __init
 607pl010_console_get_options(struct uart_amba_port *uap, int *baud,
 608                             int *parity, int *bits)
 609{
 610        if (readb(uap->port.membase + UART010_CR) & UART01x_CR_UARTEN) {
 611                unsigned int lcr_h, quot;
 612                lcr_h = readb(uap->port.membase + UART010_LCRH);
 613
 614                *parity = 'n';
 615                if (lcr_h & UART01x_LCRH_PEN) {
 616                        if (lcr_h & UART01x_LCRH_EPS)
 617                                *parity = 'e';
 618                        else
 619                                *parity = 'o';
 620                }
 621
 622                if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7)
 623                        *bits = 7;
 624                else
 625                        *bits = 8;
 626
 627                quot = readb(uap->port.membase + UART010_LCRL) |
 628                       readb(uap->port.membase + UART010_LCRM) << 8;
 629                *baud = uap->port.uartclk / (16 * (quot + 1));
 630        }
 631}
 632
 633static int __init pl010_console_setup(struct console *co, char *options)
 634{
 635        struct uart_amba_port *uap;
 636        int baud = 38400;
 637        int bits = 8;
 638        int parity = 'n';
 639        int flow = 'n';
 640        int ret;
 641
 642        /*
 643         * Check whether an invalid uart number has been specified, and
 644         * if so, search for the first available port that does have
 645         * console support.
 646         */
 647        if (co->index >= UART_NR)
 648                co->index = 0;
 649        uap = amba_ports[co->index];
 650        if (!uap)
 651                return -ENODEV;
 652
 653        ret = clk_prepare(uap->clk);
 654        if (ret)
 655                return ret;
 656
 657        uap->port.uartclk = clk_get_rate(uap->clk);
 658
 659        if (options)
 660                uart_parse_options(options, &baud, &parity, &bits, &flow);
 661        else
 662                pl010_console_get_options(uap, &baud, &parity, &bits);
 663
 664        return uart_set_options(&uap->port, co, baud, parity, bits, flow);
 665}
 666
 667static struct uart_driver amba_reg;
 668static struct console amba_console = {
 669        .name           = "ttyAM",
 670        .write          = pl010_console_write,
 671        .device         = uart_console_device,
 672        .setup          = pl010_console_setup,
 673        .flags          = CON_PRINTBUFFER,
 674        .index          = -1,
 675        .data           = &amba_reg,
 676};
 677
 678#define AMBA_CONSOLE    &amba_console
 679#else
 680#define AMBA_CONSOLE    NULL
 681#endif
 682
 683static DEFINE_MUTEX(amba_reg_lock);
 684static struct uart_driver amba_reg = {
 685        .owner                  = THIS_MODULE,
 686        .driver_name            = "ttyAM",
 687        .dev_name               = "ttyAM",
 688        .major                  = SERIAL_AMBA_MAJOR,
 689        .minor                  = SERIAL_AMBA_MINOR,
 690        .nr                     = UART_NR,
 691        .cons                   = AMBA_CONSOLE,
 692};
 693
 694static int pl010_probe(struct amba_device *dev, const struct amba_id *id)
 695{
 696        struct uart_amba_port *uap;
 697        void __iomem *base;
 698        int i, ret;
 699
 700        for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
 701                if (amba_ports[i] == NULL)
 702                        break;
 703
 704        if (i == ARRAY_SIZE(amba_ports))
 705                return -EBUSY;
 706
 707        uap = devm_kzalloc(&dev->dev, sizeof(struct uart_amba_port),
 708                           GFP_KERNEL);
 709        if (!uap)
 710                return -ENOMEM;
 711
 712        base = devm_ioremap(&dev->dev, dev->res.start,
 713                            resource_size(&dev->res));
 714        if (!base)
 715                return -ENOMEM;
 716
 717        uap->clk = devm_clk_get(&dev->dev, NULL);
 718        if (IS_ERR(uap->clk))
 719                return PTR_ERR(uap->clk);
 720
 721        uap->port.dev = &dev->dev;
 722        uap->port.mapbase = dev->res.start;
 723        uap->port.membase = base;
 724        uap->port.iotype = UPIO_MEM;
 725        uap->port.irq = dev->irq[0];
 726        uap->port.fifosize = 16;
 727        uap->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_AMBA_PL010_CONSOLE);
 728        uap->port.ops = &amba_pl010_pops;
 729        uap->port.flags = UPF_BOOT_AUTOCONF;
 730        uap->port.line = i;
 731        uap->dev = dev;
 732        uap->data = dev_get_platdata(&dev->dev);
 733
 734        amba_ports[i] = uap;
 735
 736        amba_set_drvdata(dev, uap);
 737
 738        mutex_lock(&amba_reg_lock);
 739        if (!amba_reg.state) {
 740                ret = uart_register_driver(&amba_reg);
 741                if (ret < 0) {
 742                        mutex_unlock(&amba_reg_lock);
 743                        dev_err(uap->port.dev,
 744                                "Failed to register AMBA-PL010 driver\n");
 745                        return ret;
 746                }
 747        }
 748        mutex_unlock(&amba_reg_lock);
 749
 750        ret = uart_add_one_port(&amba_reg, &uap->port);
 751        if (ret)
 752                amba_ports[i] = NULL;
 753
 754        return ret;
 755}
 756
 757static int pl010_remove(struct amba_device *dev)
 758{
 759        struct uart_amba_port *uap = amba_get_drvdata(dev);
 760        int i;
 761        bool busy = false;
 762
 763        uart_remove_one_port(&amba_reg, &uap->port);
 764
 765        for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
 766                if (amba_ports[i] == uap)
 767                        amba_ports[i] = NULL;
 768                else if (amba_ports[i])
 769                        busy = true;
 770
 771        if (!busy)
 772                uart_unregister_driver(&amba_reg);
 773
 774        return 0;
 775}
 776
 777#ifdef CONFIG_PM_SLEEP
 778static int pl010_suspend(struct device *dev)
 779{
 780        struct uart_amba_port *uap = dev_get_drvdata(dev);
 781
 782        if (uap)
 783                uart_suspend_port(&amba_reg, &uap->port);
 784
 785        return 0;
 786}
 787
 788static int pl010_resume(struct device *dev)
 789{
 790        struct uart_amba_port *uap = dev_get_drvdata(dev);
 791
 792        if (uap)
 793                uart_resume_port(&amba_reg, &uap->port);
 794
 795        return 0;
 796}
 797#endif
 798
 799static SIMPLE_DEV_PM_OPS(pl010_dev_pm_ops, pl010_suspend, pl010_resume);
 800
 801static const struct amba_id pl010_ids[] = {
 802        {
 803                .id     = 0x00041010,
 804                .mask   = 0x000fffff,
 805        },
 806        { 0, 0 },
 807};
 808
 809MODULE_DEVICE_TABLE(amba, pl010_ids);
 810
 811static struct amba_driver pl010_driver = {
 812        .drv = {
 813                .name   = "uart-pl010",
 814                .pm     = &pl010_dev_pm_ops,
 815        },
 816        .id_table       = pl010_ids,
 817        .probe          = pl010_probe,
 818        .remove         = pl010_remove,
 819};
 820
 821static int __init pl010_init(void)
 822{
 823        printk(KERN_INFO "Serial: AMBA driver\n");
 824
 825        return  amba_driver_register(&pl010_driver);
 826}
 827
 828static void __exit pl010_exit(void)
 829{
 830        amba_driver_unregister(&pl010_driver);
 831}
 832
 833module_init(pl010_init);
 834module_exit(pl010_exit);
 835
 836MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd");
 837MODULE_DESCRIPTION("ARM AMBA serial port driver");
 838MODULE_LICENSE("GPL");
 839