linux/drivers/tty/serial/efm32-uart.c
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   1#if defined(CONFIG_SERIAL_EFM32_UART_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
   2#define SUPPORT_SYSRQ
   3#endif
   4
   5#include <linux/kernel.h>
   6#include <linux/module.h>
   7#include <linux/io.h>
   8#include <linux/platform_device.h>
   9#include <linux/console.h>
  10#include <linux/sysrq.h>
  11#include <linux/serial_core.h>
  12#include <linux/tty_flip.h>
  13#include <linux/slab.h>
  14#include <linux/clk.h>
  15#include <linux/of.h>
  16#include <linux/of_device.h>
  17
  18#include <linux/platform_data/efm32-uart.h>
  19
  20#define DRIVER_NAME "efm32-uart"
  21#define DEV_NAME "ttyefm"
  22
  23#define UARTn_CTRL              0x00
  24#define UARTn_CTRL_SYNC         0x0001
  25#define UARTn_CTRL_TXBIL                0x1000
  26
  27#define UARTn_FRAME             0x04
  28#define UARTn_FRAME_DATABITS__MASK      0x000f
  29#define UARTn_FRAME_DATABITS(n)         ((n) - 3)
  30#define UARTn_FRAME_PARITY_NONE         0x0000
  31#define UARTn_FRAME_PARITY_EVEN         0x0200
  32#define UARTn_FRAME_PARITY_ODD          0x0300
  33#define UARTn_FRAME_STOPBITS_HALF       0x0000
  34#define UARTn_FRAME_STOPBITS_ONE        0x1000
  35#define UARTn_FRAME_STOPBITS_TWO        0x3000
  36
  37#define UARTn_CMD               0x0c
  38#define UARTn_CMD_RXEN                  0x0001
  39#define UARTn_CMD_RXDIS         0x0002
  40#define UARTn_CMD_TXEN                  0x0004
  41#define UARTn_CMD_TXDIS         0x0008
  42
  43#define UARTn_STATUS            0x10
  44#define UARTn_STATUS_TXENS              0x0002
  45#define UARTn_STATUS_TXC                0x0020
  46#define UARTn_STATUS_TXBL               0x0040
  47#define UARTn_STATUS_RXDATAV            0x0080
  48
  49#define UARTn_CLKDIV            0x14
  50
  51#define UARTn_RXDATAX           0x18
  52#define UARTn_RXDATAX_RXDATA__MASK      0x01ff
  53#define UARTn_RXDATAX_PERR              0x4000
  54#define UARTn_RXDATAX_FERR              0x8000
  55/*
  56 * This is a software only flag used for ignore_status_mask and
  57 * read_status_mask! It's used for breaks that the hardware doesn't report
  58 * explicitly.
  59 */
  60#define SW_UARTn_RXDATAX_BERR           0x2000
  61
  62#define UARTn_TXDATA            0x34
  63
  64#define UARTn_IF                0x40
  65#define UARTn_IF_TXC                    0x0001
  66#define UARTn_IF_TXBL                   0x0002
  67#define UARTn_IF_RXDATAV                0x0004
  68#define UARTn_IF_RXOF                   0x0010
  69
  70#define UARTn_IFS               0x44
  71#define UARTn_IFC               0x48
  72#define UARTn_IEN               0x4c
  73
  74#define UARTn_ROUTE             0x54
  75#define UARTn_ROUTE_LOCATION__MASK      0x0700
  76#define UARTn_ROUTE_LOCATION(n)         (((n) << 8) & UARTn_ROUTE_LOCATION__MASK)
  77#define UARTn_ROUTE_RXPEN               0x0001
  78#define UARTn_ROUTE_TXPEN               0x0002
  79
  80struct efm32_uart_port {
  81        struct uart_port port;
  82        unsigned int txirq;
  83        struct clk *clk;
  84        struct efm32_uart_pdata pdata;
  85};
  86#define to_efm_port(_port) container_of(_port, struct efm32_uart_port, port)
  87#define efm_debug(efm_port, format, arg...)                     \
  88        dev_dbg(efm_port->port.dev, format, ##arg)
  89
  90static void efm32_uart_write32(struct efm32_uart_port *efm_port,
  91                u32 value, unsigned offset)
  92{
  93        writel_relaxed(value, efm_port->port.membase + offset);
  94}
  95
  96static u32 efm32_uart_read32(struct efm32_uart_port *efm_port,
  97                unsigned offset)
  98{
  99        return readl_relaxed(efm_port->port.membase + offset);
 100}
 101
 102static unsigned int efm32_uart_tx_empty(struct uart_port *port)
 103{
 104        struct efm32_uart_port *efm_port = to_efm_port(port);
 105        u32 status = efm32_uart_read32(efm_port, UARTn_STATUS);
 106
 107        if (status & UARTn_STATUS_TXC)
 108                return TIOCSER_TEMT;
 109        else
 110                return 0;
 111}
 112
 113static void efm32_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
 114{
 115        /* sorry, neither handshaking lines nor loop functionallity */
 116}
 117
 118static unsigned int efm32_uart_get_mctrl(struct uart_port *port)
 119{
 120        /* sorry, no handshaking lines available */
 121        return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR;
 122}
 123
 124static void efm32_uart_stop_tx(struct uart_port *port)
 125{
 126        struct efm32_uart_port *efm_port = to_efm_port(port);
 127        u32 ien = efm32_uart_read32(efm_port,  UARTn_IEN);
 128
 129        efm32_uart_write32(efm_port, UARTn_CMD_TXDIS, UARTn_CMD);
 130        ien &= ~(UARTn_IF_TXC | UARTn_IF_TXBL);
 131        efm32_uart_write32(efm_port, ien, UARTn_IEN);
 132}
 133
 134static void efm32_uart_tx_chars(struct efm32_uart_port *efm_port)
 135{
 136        struct uart_port *port = &efm_port->port;
 137        struct circ_buf *xmit = &port->state->xmit;
 138
 139        while (efm32_uart_read32(efm_port, UARTn_STATUS) &
 140                        UARTn_STATUS_TXBL) {
 141                if (port->x_char) {
 142                        port->icount.tx++;
 143                        efm32_uart_write32(efm_port, port->x_char,
 144                                        UARTn_TXDATA);
 145                        port->x_char = 0;
 146                        continue;
 147                }
 148                if (!uart_circ_empty(xmit) && !uart_tx_stopped(port)) {
 149                        port->icount.tx++;
 150                        efm32_uart_write32(efm_port, xmit->buf[xmit->tail],
 151                                        UARTn_TXDATA);
 152                        xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 153                } else
 154                        break;
 155        }
 156
 157        if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 158                uart_write_wakeup(port);
 159
 160        if (!port->x_char && uart_circ_empty(xmit) &&
 161                        efm32_uart_read32(efm_port, UARTn_STATUS) &
 162                                UARTn_STATUS_TXC)
 163                efm32_uart_stop_tx(port);
 164}
 165
 166static void efm32_uart_start_tx(struct uart_port *port)
 167{
 168        struct efm32_uart_port *efm_port = to_efm_port(port);
 169        u32 ien;
 170
 171        efm32_uart_write32(efm_port,
 172                        UARTn_IF_TXBL | UARTn_IF_TXC, UARTn_IFC);
 173        ien = efm32_uart_read32(efm_port, UARTn_IEN);
 174        efm32_uart_write32(efm_port,
 175                        ien | UARTn_IF_TXBL | UARTn_IF_TXC, UARTn_IEN);
 176        efm32_uart_write32(efm_port, UARTn_CMD_TXEN, UARTn_CMD);
 177
 178        efm32_uart_tx_chars(efm_port);
 179}
 180
 181static void efm32_uart_stop_rx(struct uart_port *port)
 182{
 183        struct efm32_uart_port *efm_port = to_efm_port(port);
 184
 185        efm32_uart_write32(efm_port, UARTn_CMD_RXDIS, UARTn_CMD);
 186}
 187
 188static void efm32_uart_enable_ms(struct uart_port *port)
 189{
 190        /* no handshake lines, no modem status interrupts */
 191}
 192
 193static void efm32_uart_break_ctl(struct uart_port *port, int ctl)
 194{
 195        /* not possible without fiddling with gpios */
 196}
 197
 198static void efm32_uart_rx_chars(struct efm32_uart_port *efm_port)
 199{
 200        struct uart_port *port = &efm_port->port;
 201
 202        while (efm32_uart_read32(efm_port, UARTn_STATUS) &
 203                        UARTn_STATUS_RXDATAV) {
 204                u32 rxdata = efm32_uart_read32(efm_port, UARTn_RXDATAX);
 205                int flag = 0;
 206
 207                /*
 208                 * This is a reserved bit and I only saw it read as 0. But to be
 209                 * sure not to be confused too much by new devices adhere to the
 210                 * warning in the reference manual that reserverd bits might
 211                 * read as 1 in the future.
 212                 */
 213                rxdata &= ~SW_UARTn_RXDATAX_BERR;
 214
 215                port->icount.rx++;
 216
 217                if ((rxdata & UARTn_RXDATAX_FERR) &&
 218                                !(rxdata & UARTn_RXDATAX_RXDATA__MASK)) {
 219                        rxdata |= SW_UARTn_RXDATAX_BERR;
 220                        port->icount.brk++;
 221                        if (uart_handle_break(port))
 222                                continue;
 223                } else if (rxdata & UARTn_RXDATAX_PERR)
 224                        port->icount.parity++;
 225                else if (rxdata & UARTn_RXDATAX_FERR)
 226                        port->icount.frame++;
 227
 228                rxdata &= port->read_status_mask;
 229
 230                if (rxdata & SW_UARTn_RXDATAX_BERR)
 231                        flag = TTY_BREAK;
 232                else if (rxdata & UARTn_RXDATAX_PERR)
 233                        flag = TTY_PARITY;
 234                else if (rxdata & UARTn_RXDATAX_FERR)
 235                        flag = TTY_FRAME;
 236                else if (uart_handle_sysrq_char(port,
 237                                        rxdata & UARTn_RXDATAX_RXDATA__MASK))
 238                        continue;
 239
 240                if ((rxdata & port->ignore_status_mask) == 0)
 241                        tty_insert_flip_char(&port->state->port,
 242                                        rxdata & UARTn_RXDATAX_RXDATA__MASK, flag);
 243        }
 244}
 245
 246static irqreturn_t efm32_uart_rxirq(int irq, void *data)
 247{
 248        struct efm32_uart_port *efm_port = data;
 249        u32 irqflag = efm32_uart_read32(efm_port, UARTn_IF);
 250        int handled = IRQ_NONE;
 251        struct uart_port *port = &efm_port->port;
 252        struct tty_port *tport = &port->state->port;
 253
 254        spin_lock(&port->lock);
 255
 256        if (irqflag & UARTn_IF_RXDATAV) {
 257                efm32_uart_write32(efm_port, UARTn_IF_RXDATAV, UARTn_IFC);
 258                efm32_uart_rx_chars(efm_port);
 259
 260                handled = IRQ_HANDLED;
 261        }
 262
 263        if (irqflag & UARTn_IF_RXOF) {
 264                efm32_uart_write32(efm_port, UARTn_IF_RXOF, UARTn_IFC);
 265                port->icount.overrun++;
 266                tty_insert_flip_char(tport, 0, TTY_OVERRUN);
 267
 268                handled = IRQ_HANDLED;
 269        }
 270
 271        spin_unlock(&port->lock);
 272
 273        tty_flip_buffer_push(tport);
 274
 275        return handled;
 276}
 277
 278static irqreturn_t efm32_uart_txirq(int irq, void *data)
 279{
 280        struct efm32_uart_port *efm_port = data;
 281        u32 irqflag = efm32_uart_read32(efm_port, UARTn_IF);
 282
 283        /* TXBL doesn't need to be cleared */
 284        if (irqflag & UARTn_IF_TXC)
 285                efm32_uart_write32(efm_port, UARTn_IF_TXC, UARTn_IFC);
 286
 287        if (irqflag & (UARTn_IF_TXC | UARTn_IF_TXBL)) {
 288                efm32_uart_tx_chars(efm_port);
 289                return IRQ_HANDLED;
 290        } else
 291                return IRQ_NONE;
 292}
 293
 294static int efm32_uart_startup(struct uart_port *port)
 295{
 296        struct efm32_uart_port *efm_port = to_efm_port(port);
 297        int ret;
 298
 299        ret = clk_enable(efm_port->clk);
 300        if (ret) {
 301                efm_debug(efm_port, "failed to enable clk\n");
 302                goto err_clk_enable;
 303        }
 304        port->uartclk = clk_get_rate(efm_port->clk);
 305
 306        /* Enable pins at configured location */
 307        efm32_uart_write32(efm_port,
 308                        UARTn_ROUTE_LOCATION(efm_port->pdata.location) |
 309                        UARTn_ROUTE_RXPEN | UARTn_ROUTE_TXPEN,
 310                        UARTn_ROUTE);
 311
 312        ret = request_irq(port->irq, efm32_uart_rxirq, 0,
 313                        DRIVER_NAME, efm_port);
 314        if (ret) {
 315                efm_debug(efm_port, "failed to register rxirq\n");
 316                goto err_request_irq_rx;
 317        }
 318
 319        /* disable all irqs */
 320        efm32_uart_write32(efm_port, 0, UARTn_IEN);
 321
 322        ret = request_irq(efm_port->txirq, efm32_uart_txirq, 0,
 323                        DRIVER_NAME, efm_port);
 324        if (ret) {
 325                efm_debug(efm_port, "failed to register txirq\n");
 326                free_irq(port->irq, efm_port);
 327err_request_irq_rx:
 328
 329                clk_disable(efm_port->clk);
 330        } else {
 331                efm32_uart_write32(efm_port,
 332                                UARTn_IF_RXDATAV | UARTn_IF_RXOF, UARTn_IEN);
 333                efm32_uart_write32(efm_port, UARTn_CMD_RXEN, UARTn_CMD);
 334        }
 335
 336err_clk_enable:
 337        return ret;
 338}
 339
 340static void efm32_uart_shutdown(struct uart_port *port)
 341{
 342        struct efm32_uart_port *efm_port = to_efm_port(port);
 343
 344        efm32_uart_write32(efm_port, 0, UARTn_IEN);
 345        free_irq(port->irq, efm_port);
 346
 347        clk_disable(efm_port->clk);
 348}
 349
 350static void efm32_uart_set_termios(struct uart_port *port,
 351                struct ktermios *new, struct ktermios *old)
 352{
 353        struct efm32_uart_port *efm_port = to_efm_port(port);
 354        unsigned long flags;
 355        unsigned baud;
 356        u32 clkdiv;
 357        u32 frame = 0;
 358
 359        /* no modem control lines */
 360        new->c_cflag &= ~(CRTSCTS | CMSPAR);
 361
 362        baud = uart_get_baud_rate(port, new, old,
 363                        DIV_ROUND_CLOSEST(port->uartclk, 16 * 8192),
 364                        DIV_ROUND_CLOSEST(port->uartclk, 16));
 365
 366        switch (new->c_cflag & CSIZE) {
 367        case CS5:
 368                frame |= UARTn_FRAME_DATABITS(5);
 369                break;
 370        case CS6:
 371                frame |= UARTn_FRAME_DATABITS(6);
 372                break;
 373        case CS7:
 374                frame |= UARTn_FRAME_DATABITS(7);
 375                break;
 376        case CS8:
 377                frame |= UARTn_FRAME_DATABITS(8);
 378                break;
 379        }
 380
 381        if (new->c_cflag & CSTOPB)
 382                /* the receiver only verifies the first stop bit */
 383                frame |= UARTn_FRAME_STOPBITS_TWO;
 384        else
 385                frame |= UARTn_FRAME_STOPBITS_ONE;
 386
 387        if (new->c_cflag & PARENB) {
 388                if (new->c_cflag & PARODD)
 389                        frame |= UARTn_FRAME_PARITY_ODD;
 390                else
 391                        frame |= UARTn_FRAME_PARITY_EVEN;
 392        } else
 393                frame |= UARTn_FRAME_PARITY_NONE;
 394
 395        /*
 396         * the 6 lowest bits of CLKDIV are dc, bit 6 has value 0.25.
 397         * port->uartclk <= 14e6, so 4 * port->uartclk doesn't overflow.
 398         */
 399        clkdiv = (DIV_ROUND_CLOSEST(4 * port->uartclk, 16 * baud) - 4) << 6;
 400
 401        spin_lock_irqsave(&port->lock, flags);
 402
 403        efm32_uart_write32(efm_port,
 404                        UARTn_CMD_TXDIS | UARTn_CMD_RXDIS, UARTn_CMD);
 405
 406        port->read_status_mask = UARTn_RXDATAX_RXDATA__MASK;
 407        if (new->c_iflag & INPCK)
 408                port->read_status_mask |=
 409                        UARTn_RXDATAX_FERR | UARTn_RXDATAX_PERR;
 410        if (new->c_iflag & (BRKINT | PARMRK))
 411                port->read_status_mask |= SW_UARTn_RXDATAX_BERR;
 412
 413        port->ignore_status_mask = 0;
 414        if (new->c_iflag & IGNPAR)
 415                port->ignore_status_mask |=
 416                        UARTn_RXDATAX_FERR | UARTn_RXDATAX_PERR;
 417        if (new->c_iflag & IGNBRK)
 418                port->ignore_status_mask |= SW_UARTn_RXDATAX_BERR;
 419
 420        uart_update_timeout(port, new->c_cflag, baud);
 421
 422        efm32_uart_write32(efm_port, UARTn_CTRL_TXBIL, UARTn_CTRL);
 423        efm32_uart_write32(efm_port, frame, UARTn_FRAME);
 424        efm32_uart_write32(efm_port, clkdiv, UARTn_CLKDIV);
 425
 426        efm32_uart_write32(efm_port, UARTn_CMD_TXEN | UARTn_CMD_RXEN,
 427                        UARTn_CMD);
 428
 429        spin_unlock_irqrestore(&port->lock, flags);
 430}
 431
 432static const char *efm32_uart_type(struct uart_port *port)
 433{
 434        return port->type == PORT_EFMUART ? "efm32-uart" : NULL;
 435}
 436
 437static void efm32_uart_release_port(struct uart_port *port)
 438{
 439        struct efm32_uart_port *efm_port = to_efm_port(port);
 440
 441        clk_unprepare(efm_port->clk);
 442        clk_put(efm_port->clk);
 443        iounmap(port->membase);
 444}
 445
 446static int efm32_uart_request_port(struct uart_port *port)
 447{
 448        struct efm32_uart_port *efm_port = to_efm_port(port);
 449        int ret;
 450
 451        port->membase = ioremap(port->mapbase, 60);
 452        if (!efm_port->port.membase) {
 453                ret = -ENOMEM;
 454                efm_debug(efm_port, "failed to remap\n");
 455                goto err_ioremap;
 456        }
 457
 458        efm_port->clk = clk_get(port->dev, NULL);
 459        if (IS_ERR(efm_port->clk)) {
 460                ret = PTR_ERR(efm_port->clk);
 461                efm_debug(efm_port, "failed to get clock\n");
 462                goto err_clk_get;
 463        }
 464
 465        ret = clk_prepare(efm_port->clk);
 466        if (ret) {
 467                clk_put(efm_port->clk);
 468err_clk_get:
 469
 470                iounmap(port->membase);
 471err_ioremap:
 472                return ret;
 473        }
 474        return 0;
 475}
 476
 477static void efm32_uart_config_port(struct uart_port *port, int type)
 478{
 479        if (type & UART_CONFIG_TYPE &&
 480                        !efm32_uart_request_port(port))
 481                port->type = PORT_EFMUART;
 482}
 483
 484static int efm32_uart_verify_port(struct uart_port *port,
 485                struct serial_struct *serinfo)
 486{
 487        int ret = 0;
 488
 489        if (serinfo->type != PORT_UNKNOWN && serinfo->type != PORT_EFMUART)
 490                ret = -EINVAL;
 491
 492        return ret;
 493}
 494
 495static struct uart_ops efm32_uart_pops = {
 496        .tx_empty = efm32_uart_tx_empty,
 497        .set_mctrl = efm32_uart_set_mctrl,
 498        .get_mctrl = efm32_uart_get_mctrl,
 499        .stop_tx = efm32_uart_stop_tx,
 500        .start_tx = efm32_uart_start_tx,
 501        .stop_rx = efm32_uart_stop_rx,
 502        .enable_ms = efm32_uart_enable_ms,
 503        .break_ctl = efm32_uart_break_ctl,
 504        .startup = efm32_uart_startup,
 505        .shutdown = efm32_uart_shutdown,
 506        .set_termios = efm32_uart_set_termios,
 507        .type = efm32_uart_type,
 508        .release_port = efm32_uart_release_port,
 509        .request_port = efm32_uart_request_port,
 510        .config_port = efm32_uart_config_port,
 511        .verify_port = efm32_uart_verify_port,
 512};
 513
 514static struct efm32_uart_port *efm32_uart_ports[5];
 515
 516#ifdef CONFIG_SERIAL_EFM32_UART_CONSOLE
 517static void efm32_uart_console_putchar(struct uart_port *port, int ch)
 518{
 519        struct efm32_uart_port *efm_port = to_efm_port(port);
 520        unsigned int timeout = 0x400;
 521        u32 status;
 522
 523        while (1) {
 524                status = efm32_uart_read32(efm_port, UARTn_STATUS);
 525
 526                if (status & UARTn_STATUS_TXBL)
 527                        break;
 528                if (!timeout--)
 529                        return;
 530        }
 531        efm32_uart_write32(efm_port, ch, UARTn_TXDATA);
 532}
 533
 534static void efm32_uart_console_write(struct console *co, const char *s,
 535                unsigned int count)
 536{
 537        struct efm32_uart_port *efm_port = efm32_uart_ports[co->index];
 538        u32 status = efm32_uart_read32(efm_port, UARTn_STATUS);
 539        unsigned int timeout = 0x400;
 540
 541        if (!(status & UARTn_STATUS_TXENS))
 542                efm32_uart_write32(efm_port, UARTn_CMD_TXEN, UARTn_CMD);
 543
 544        uart_console_write(&efm_port->port, s, count,
 545                        efm32_uart_console_putchar);
 546
 547        /* Wait for the transmitter to become empty */
 548        while (1) {
 549                u32 status = efm32_uart_read32(efm_port, UARTn_STATUS);
 550                if (status & UARTn_STATUS_TXC)
 551                        break;
 552                if (!timeout--)
 553                        break;
 554        }
 555
 556        if (!(status & UARTn_STATUS_TXENS))
 557                efm32_uart_write32(efm_port, UARTn_CMD_TXDIS, UARTn_CMD);
 558}
 559
 560static void efm32_uart_console_get_options(struct efm32_uart_port *efm_port,
 561                int *baud, int *parity, int *bits)
 562{
 563        u32 ctrl = efm32_uart_read32(efm_port, UARTn_CTRL);
 564        u32 route, clkdiv, frame;
 565
 566        if (ctrl & UARTn_CTRL_SYNC)
 567                /* not operating in async mode */
 568                return;
 569
 570        route = efm32_uart_read32(efm_port, UARTn_ROUTE);
 571        if (!(route & UARTn_ROUTE_TXPEN))
 572                /* tx pin not routed */
 573                return;
 574
 575        clkdiv = efm32_uart_read32(efm_port, UARTn_CLKDIV);
 576
 577        *baud = DIV_ROUND_CLOSEST(4 * efm_port->port.uartclk,
 578                        16 * (4 + (clkdiv >> 6)));
 579
 580        frame = efm32_uart_read32(efm_port, UARTn_FRAME);
 581        if (frame & UARTn_FRAME_PARITY_ODD)
 582                *parity = 'o';
 583        else if (frame & UARTn_FRAME_PARITY_EVEN)
 584                *parity = 'e';
 585        else
 586                *parity = 'n';
 587
 588        *bits = (frame & UARTn_FRAME_DATABITS__MASK) -
 589                        UARTn_FRAME_DATABITS(4) + 4;
 590
 591        efm_debug(efm_port, "get_opts: options=%d%c%d\n",
 592                        *baud, *parity, *bits);
 593}
 594
 595static int efm32_uart_console_setup(struct console *co, char *options)
 596{
 597        struct efm32_uart_port *efm_port;
 598        int baud = 115200;
 599        int bits = 8;
 600        int parity = 'n';
 601        int flow = 'n';
 602        int ret;
 603
 604        if (co->index < 0 || co->index >= ARRAY_SIZE(efm32_uart_ports)) {
 605                unsigned i;
 606                for (i = 0; i < ARRAY_SIZE(efm32_uart_ports); ++i) {
 607                        if (efm32_uart_ports[i]) {
 608                                pr_warn("efm32-console: fall back to console index %u (from %hhi)\n",
 609                                                i, co->index);
 610                                co->index = i;
 611                                break;
 612                        }
 613                }
 614        }
 615
 616        efm_port = efm32_uart_ports[co->index];
 617        if (!efm_port) {
 618                pr_warn("efm32-console: No port at %d\n", co->index);
 619                return -ENODEV;
 620        }
 621
 622        ret = clk_prepare(efm_port->clk);
 623        if (ret) {
 624                dev_warn(efm_port->port.dev,
 625                                "console: clk_prepare failed: %d\n", ret);
 626                return ret;
 627        }
 628
 629        efm_port->port.uartclk = clk_get_rate(efm_port->clk);
 630
 631        if (options)
 632                uart_parse_options(options, &baud, &parity, &bits, &flow);
 633        else
 634                efm32_uart_console_get_options(efm_port,
 635                                &baud, &parity, &bits);
 636
 637        return uart_set_options(&efm_port->port, co, baud, parity, bits, flow);
 638}
 639
 640static struct uart_driver efm32_uart_reg;
 641
 642static struct console efm32_uart_console = {
 643        .name = DEV_NAME,
 644        .write = efm32_uart_console_write,
 645        .device = uart_console_device,
 646        .setup = efm32_uart_console_setup,
 647        .flags = CON_PRINTBUFFER,
 648        .index = -1,
 649        .data = &efm32_uart_reg,
 650};
 651
 652#else
 653#define efm32_uart_console (*(struct console *)NULL)
 654#endif /* ifdef CONFIG_SERIAL_EFM32_UART_CONSOLE / else */
 655
 656static struct uart_driver efm32_uart_reg = {
 657        .owner = THIS_MODULE,
 658        .driver_name = DRIVER_NAME,
 659        .dev_name = DEV_NAME,
 660        .nr = ARRAY_SIZE(efm32_uart_ports),
 661        .cons = &efm32_uart_console,
 662};
 663
 664static int efm32_uart_probe_dt(struct platform_device *pdev,
 665                struct efm32_uart_port *efm_port)
 666{
 667        struct device_node *np = pdev->dev.of_node;
 668        u32 location;
 669        int ret;
 670
 671        if (!np)
 672                return 1;
 673
 674        ret = of_property_read_u32(np, "location", &location);
 675        if (!ret) {
 676                if (location > 5) {
 677                        dev_err(&pdev->dev, "invalid location\n");
 678                        return -EINVAL;
 679                }
 680                efm_debug(efm_port, "using location %u\n", location);
 681                efm_port->pdata.location = location;
 682        } else {
 683                efm_debug(efm_port, "fall back to location 0\n");
 684        }
 685
 686        ret = of_alias_get_id(np, "serial");
 687        if (ret < 0) {
 688                dev_err(&pdev->dev, "failed to get alias id: %d\n", ret);
 689                return ret;
 690        } else {
 691                efm_port->port.line = ret;
 692                return 0;
 693        }
 694
 695}
 696
 697static int efm32_uart_probe(struct platform_device *pdev)
 698{
 699        struct efm32_uart_port *efm_port;
 700        struct resource *res;
 701        unsigned int line;
 702        int ret;
 703
 704        efm_port = kzalloc(sizeof(*efm_port), GFP_KERNEL);
 705        if (!efm_port) {
 706                dev_dbg(&pdev->dev, "failed to allocate private data\n");
 707                return -ENOMEM;
 708        }
 709
 710        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 711        if (!res) {
 712                ret = -ENODEV;
 713                dev_dbg(&pdev->dev, "failed to determine base address\n");
 714                goto err_get_base;
 715        }
 716
 717        if (resource_size(res) < 60) {
 718                ret = -EINVAL;
 719                dev_dbg(&pdev->dev, "memory resource too small\n");
 720                goto err_too_small;
 721        }
 722
 723        ret = platform_get_irq(pdev, 0);
 724        if (ret <= 0) {
 725                dev_dbg(&pdev->dev, "failed to get rx irq\n");
 726                goto err_get_rxirq;
 727        }
 728
 729        efm_port->port.irq = ret;
 730
 731        ret = platform_get_irq(pdev, 1);
 732        if (ret <= 0)
 733                ret = efm_port->port.irq + 1;
 734
 735        efm_port->txirq = ret;
 736
 737        efm_port->port.dev = &pdev->dev;
 738        efm_port->port.mapbase = res->start;
 739        efm_port->port.type = PORT_EFMUART;
 740        efm_port->port.iotype = UPIO_MEM32;
 741        efm_port->port.fifosize = 2;
 742        efm_port->port.ops = &efm32_uart_pops;
 743        efm_port->port.flags = UPF_BOOT_AUTOCONF;
 744
 745        ret = efm32_uart_probe_dt(pdev, efm_port);
 746        if (ret > 0) {
 747                /* not created by device tree */
 748                const struct efm32_uart_pdata *pdata = dev_get_platdata(&pdev->dev);
 749
 750                efm_port->port.line = pdev->id;
 751
 752                if (pdata)
 753                        efm_port->pdata = *pdata;
 754        } else if (ret < 0)
 755                goto err_probe_dt;
 756
 757        line = efm_port->port.line;
 758
 759        if (line >= 0 && line < ARRAY_SIZE(efm32_uart_ports))
 760                efm32_uart_ports[line] = efm_port;
 761
 762        ret = uart_add_one_port(&efm32_uart_reg, &efm_port->port);
 763        if (ret) {
 764                dev_dbg(&pdev->dev, "failed to add port: %d\n", ret);
 765
 766                if (line >= 0 && line < ARRAY_SIZE(efm32_uart_ports))
 767                        efm32_uart_ports[line] = NULL;
 768err_probe_dt:
 769err_get_rxirq:
 770err_too_small:
 771err_get_base:
 772                kfree(efm_port);
 773        } else {
 774                platform_set_drvdata(pdev, efm_port);
 775                dev_dbg(&pdev->dev, "\\o/\n");
 776        }
 777
 778        return ret;
 779}
 780
 781static int efm32_uart_remove(struct platform_device *pdev)
 782{
 783        struct efm32_uart_port *efm_port = platform_get_drvdata(pdev);
 784        unsigned int line = efm_port->port.line;
 785
 786        uart_remove_one_port(&efm32_uart_reg, &efm_port->port);
 787
 788        if (line >= 0 && line < ARRAY_SIZE(efm32_uart_ports))
 789                efm32_uart_ports[line] = NULL;
 790
 791        kfree(efm_port);
 792
 793        return 0;
 794}
 795
 796static const struct of_device_id efm32_uart_dt_ids[] = {
 797        {
 798                .compatible = "efm32,uart",
 799        }, {
 800                /* sentinel */
 801        }
 802};
 803MODULE_DEVICE_TABLE(of, efm32_uart_dt_ids);
 804
 805static struct platform_driver efm32_uart_driver = {
 806        .probe = efm32_uart_probe,
 807        .remove = efm32_uart_remove,
 808
 809        .driver = {
 810                .name = DRIVER_NAME,
 811                .owner = THIS_MODULE,
 812                .of_match_table = efm32_uart_dt_ids,
 813        },
 814};
 815
 816static int __init efm32_uart_init(void)
 817{
 818        int ret;
 819
 820        ret = uart_register_driver(&efm32_uart_reg);
 821        if (ret)
 822                return ret;
 823
 824        ret = platform_driver_register(&efm32_uart_driver);
 825        if (ret)
 826                uart_unregister_driver(&efm32_uart_reg);
 827
 828        pr_info("EFM32 UART/USART driver\n");
 829
 830        return ret;
 831}
 832module_init(efm32_uart_init);
 833
 834static void __exit efm32_uart_exit(void)
 835{
 836        platform_driver_unregister(&efm32_uart_driver);
 837        uart_unregister_driver(&efm32_uart_reg);
 838}
 839
 840MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>");
 841MODULE_DESCRIPTION("EFM32 UART/USART driver");
 842MODULE_LICENSE("GPL v2");
 843MODULE_ALIAS("platform:" DRIVER_NAME);
 844