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_break_ctl(struct uart_port *port, int ctl)
 189{
 190        /* not possible without fiddling with gpios */
 191}
 192
 193static void efm32_uart_rx_chars(struct efm32_uart_port *efm_port)
 194{
 195        struct uart_port *port = &efm_port->port;
 196
 197        while (efm32_uart_read32(efm_port, UARTn_STATUS) &
 198                        UARTn_STATUS_RXDATAV) {
 199                u32 rxdata = efm32_uart_read32(efm_port, UARTn_RXDATAX);
 200                int flag = 0;
 201
 202                /*
 203                 * This is a reserved bit and I only saw it read as 0. But to be
 204                 * sure not to be confused too much by new devices adhere to the
 205                 * warning in the reference manual that reserverd bits might
 206                 * read as 1 in the future.
 207                 */
 208                rxdata &= ~SW_UARTn_RXDATAX_BERR;
 209
 210                port->icount.rx++;
 211
 212                if ((rxdata & UARTn_RXDATAX_FERR) &&
 213                                !(rxdata & UARTn_RXDATAX_RXDATA__MASK)) {
 214                        rxdata |= SW_UARTn_RXDATAX_BERR;
 215                        port->icount.brk++;
 216                        if (uart_handle_break(port))
 217                                continue;
 218                } else if (rxdata & UARTn_RXDATAX_PERR)
 219                        port->icount.parity++;
 220                else if (rxdata & UARTn_RXDATAX_FERR)
 221                        port->icount.frame++;
 222
 223                rxdata &= port->read_status_mask;
 224
 225                if (rxdata & SW_UARTn_RXDATAX_BERR)
 226                        flag = TTY_BREAK;
 227                else if (rxdata & UARTn_RXDATAX_PERR)
 228                        flag = TTY_PARITY;
 229                else if (rxdata & UARTn_RXDATAX_FERR)
 230                        flag = TTY_FRAME;
 231                else if (uart_handle_sysrq_char(port,
 232                                        rxdata & UARTn_RXDATAX_RXDATA__MASK))
 233                        continue;
 234
 235                if ((rxdata & port->ignore_status_mask) == 0)
 236                        tty_insert_flip_char(&port->state->port,
 237                                        rxdata & UARTn_RXDATAX_RXDATA__MASK, flag);
 238        }
 239}
 240
 241static irqreturn_t efm32_uart_rxirq(int irq, void *data)
 242{
 243        struct efm32_uart_port *efm_port = data;
 244        u32 irqflag = efm32_uart_read32(efm_port, UARTn_IF);
 245        int handled = IRQ_NONE;
 246        struct uart_port *port = &efm_port->port;
 247        struct tty_port *tport = &port->state->port;
 248
 249        spin_lock(&port->lock);
 250
 251        if (irqflag & UARTn_IF_RXDATAV) {
 252                efm32_uart_write32(efm_port, UARTn_IF_RXDATAV, UARTn_IFC);
 253                efm32_uart_rx_chars(efm_port);
 254
 255                handled = IRQ_HANDLED;
 256        }
 257
 258        if (irqflag & UARTn_IF_RXOF) {
 259                efm32_uart_write32(efm_port, UARTn_IF_RXOF, UARTn_IFC);
 260                port->icount.overrun++;
 261                tty_insert_flip_char(tport, 0, TTY_OVERRUN);
 262
 263                handled = IRQ_HANDLED;
 264        }
 265
 266        spin_unlock(&port->lock);
 267
 268        tty_flip_buffer_push(tport);
 269
 270        return handled;
 271}
 272
 273static irqreturn_t efm32_uart_txirq(int irq, void *data)
 274{
 275        struct efm32_uart_port *efm_port = data;
 276        u32 irqflag = efm32_uart_read32(efm_port, UARTn_IF);
 277
 278        /* TXBL doesn't need to be cleared */
 279        if (irqflag & UARTn_IF_TXC)
 280                efm32_uart_write32(efm_port, UARTn_IF_TXC, UARTn_IFC);
 281
 282        if (irqflag & (UARTn_IF_TXC | UARTn_IF_TXBL)) {
 283                efm32_uart_tx_chars(efm_port);
 284                return IRQ_HANDLED;
 285        } else
 286                return IRQ_NONE;
 287}
 288
 289static int efm32_uart_startup(struct uart_port *port)
 290{
 291        struct efm32_uart_port *efm_port = to_efm_port(port);
 292        int ret;
 293
 294        ret = clk_enable(efm_port->clk);
 295        if (ret) {
 296                efm_debug(efm_port, "failed to enable clk\n");
 297                goto err_clk_enable;
 298        }
 299        port->uartclk = clk_get_rate(efm_port->clk);
 300
 301        /* Enable pins at configured location */
 302        efm32_uart_write32(efm_port,
 303                        UARTn_ROUTE_LOCATION(efm_port->pdata.location) |
 304                        UARTn_ROUTE_RXPEN | UARTn_ROUTE_TXPEN,
 305                        UARTn_ROUTE);
 306
 307        ret = request_irq(port->irq, efm32_uart_rxirq, 0,
 308                        DRIVER_NAME, efm_port);
 309        if (ret) {
 310                efm_debug(efm_port, "failed to register rxirq\n");
 311                goto err_request_irq_rx;
 312        }
 313
 314        /* disable all irqs */
 315        efm32_uart_write32(efm_port, 0, UARTn_IEN);
 316
 317        ret = request_irq(efm_port->txirq, efm32_uart_txirq, 0,
 318                        DRIVER_NAME, efm_port);
 319        if (ret) {
 320                efm_debug(efm_port, "failed to register txirq\n");
 321                free_irq(port->irq, efm_port);
 322err_request_irq_rx:
 323
 324                clk_disable(efm_port->clk);
 325        } else {
 326                efm32_uart_write32(efm_port,
 327                                UARTn_IF_RXDATAV | UARTn_IF_RXOF, UARTn_IEN);
 328                efm32_uart_write32(efm_port, UARTn_CMD_RXEN, UARTn_CMD);
 329        }
 330
 331err_clk_enable:
 332        return ret;
 333}
 334
 335static void efm32_uart_shutdown(struct uart_port *port)
 336{
 337        struct efm32_uart_port *efm_port = to_efm_port(port);
 338
 339        efm32_uart_write32(efm_port, 0, UARTn_IEN);
 340        free_irq(port->irq, efm_port);
 341
 342        clk_disable(efm_port->clk);
 343}
 344
 345static void efm32_uart_set_termios(struct uart_port *port,
 346                struct ktermios *new, struct ktermios *old)
 347{
 348        struct efm32_uart_port *efm_port = to_efm_port(port);
 349        unsigned long flags;
 350        unsigned baud;
 351        u32 clkdiv;
 352        u32 frame = 0;
 353
 354        /* no modem control lines */
 355        new->c_cflag &= ~(CRTSCTS | CMSPAR);
 356
 357        baud = uart_get_baud_rate(port, new, old,
 358                        DIV_ROUND_CLOSEST(port->uartclk, 16 * 8192),
 359                        DIV_ROUND_CLOSEST(port->uartclk, 16));
 360
 361        switch (new->c_cflag & CSIZE) {
 362        case CS5:
 363                frame |= UARTn_FRAME_DATABITS(5);
 364                break;
 365        case CS6:
 366                frame |= UARTn_FRAME_DATABITS(6);
 367                break;
 368        case CS7:
 369                frame |= UARTn_FRAME_DATABITS(7);
 370                break;
 371        case CS8:
 372                frame |= UARTn_FRAME_DATABITS(8);
 373                break;
 374        }
 375
 376        if (new->c_cflag & CSTOPB)
 377                /* the receiver only verifies the first stop bit */
 378                frame |= UARTn_FRAME_STOPBITS_TWO;
 379        else
 380                frame |= UARTn_FRAME_STOPBITS_ONE;
 381
 382        if (new->c_cflag & PARENB) {
 383                if (new->c_cflag & PARODD)
 384                        frame |= UARTn_FRAME_PARITY_ODD;
 385                else
 386                        frame |= UARTn_FRAME_PARITY_EVEN;
 387        } else
 388                frame |= UARTn_FRAME_PARITY_NONE;
 389
 390        /*
 391         * the 6 lowest bits of CLKDIV are dc, bit 6 has value 0.25.
 392         * port->uartclk <= 14e6, so 4 * port->uartclk doesn't overflow.
 393         */
 394        clkdiv = (DIV_ROUND_CLOSEST(4 * port->uartclk, 16 * baud) - 4) << 6;
 395
 396        spin_lock_irqsave(&port->lock, flags);
 397
 398        efm32_uart_write32(efm_port,
 399                        UARTn_CMD_TXDIS | UARTn_CMD_RXDIS, UARTn_CMD);
 400
 401        port->read_status_mask = UARTn_RXDATAX_RXDATA__MASK;
 402        if (new->c_iflag & INPCK)
 403                port->read_status_mask |=
 404                        UARTn_RXDATAX_FERR | UARTn_RXDATAX_PERR;
 405        if (new->c_iflag & (IGNBRK | BRKINT | PARMRK))
 406                port->read_status_mask |= SW_UARTn_RXDATAX_BERR;
 407
 408        port->ignore_status_mask = 0;
 409        if (new->c_iflag & IGNPAR)
 410                port->ignore_status_mask |=
 411                        UARTn_RXDATAX_FERR | UARTn_RXDATAX_PERR;
 412        if (new->c_iflag & IGNBRK)
 413                port->ignore_status_mask |= SW_UARTn_RXDATAX_BERR;
 414
 415        uart_update_timeout(port, new->c_cflag, baud);
 416
 417        efm32_uart_write32(efm_port, UARTn_CTRL_TXBIL, UARTn_CTRL);
 418        efm32_uart_write32(efm_port, frame, UARTn_FRAME);
 419        efm32_uart_write32(efm_port, clkdiv, UARTn_CLKDIV);
 420
 421        efm32_uart_write32(efm_port, UARTn_CMD_TXEN | UARTn_CMD_RXEN,
 422                        UARTn_CMD);
 423
 424        spin_unlock_irqrestore(&port->lock, flags);
 425}
 426
 427static const char *efm32_uart_type(struct uart_port *port)
 428{
 429        return port->type == PORT_EFMUART ? "efm32-uart" : NULL;
 430}
 431
 432static void efm32_uart_release_port(struct uart_port *port)
 433{
 434        struct efm32_uart_port *efm_port = to_efm_port(port);
 435
 436        clk_unprepare(efm_port->clk);
 437        clk_put(efm_port->clk);
 438        iounmap(port->membase);
 439}
 440
 441static int efm32_uart_request_port(struct uart_port *port)
 442{
 443        struct efm32_uart_port *efm_port = to_efm_port(port);
 444        int ret;
 445
 446        port->membase = ioremap(port->mapbase, 60);
 447        if (!efm_port->port.membase) {
 448                ret = -ENOMEM;
 449                efm_debug(efm_port, "failed to remap\n");
 450                goto err_ioremap;
 451        }
 452
 453        efm_port->clk = clk_get(port->dev, NULL);
 454        if (IS_ERR(efm_port->clk)) {
 455                ret = PTR_ERR(efm_port->clk);
 456                efm_debug(efm_port, "failed to get clock\n");
 457                goto err_clk_get;
 458        }
 459
 460        ret = clk_prepare(efm_port->clk);
 461        if (ret) {
 462                clk_put(efm_port->clk);
 463err_clk_get:
 464
 465                iounmap(port->membase);
 466err_ioremap:
 467                return ret;
 468        }
 469        return 0;
 470}
 471
 472static void efm32_uart_config_port(struct uart_port *port, int type)
 473{
 474        if (type & UART_CONFIG_TYPE &&
 475                        !efm32_uart_request_port(port))
 476                port->type = PORT_EFMUART;
 477}
 478
 479static int efm32_uart_verify_port(struct uart_port *port,
 480                struct serial_struct *serinfo)
 481{
 482        int ret = 0;
 483
 484        if (serinfo->type != PORT_UNKNOWN && serinfo->type != PORT_EFMUART)
 485                ret = -EINVAL;
 486
 487        return ret;
 488}
 489
 490static struct uart_ops efm32_uart_pops = {
 491        .tx_empty = efm32_uart_tx_empty,
 492        .set_mctrl = efm32_uart_set_mctrl,
 493        .get_mctrl = efm32_uart_get_mctrl,
 494        .stop_tx = efm32_uart_stop_tx,
 495        .start_tx = efm32_uart_start_tx,
 496        .stop_rx = efm32_uart_stop_rx,
 497        .break_ctl = efm32_uart_break_ctl,
 498        .startup = efm32_uart_startup,
 499        .shutdown = efm32_uart_shutdown,
 500        .set_termios = efm32_uart_set_termios,
 501        .type = efm32_uart_type,
 502        .release_port = efm32_uart_release_port,
 503        .request_port = efm32_uart_request_port,
 504        .config_port = efm32_uart_config_port,
 505        .verify_port = efm32_uart_verify_port,
 506};
 507
 508static struct efm32_uart_port *efm32_uart_ports[5];
 509
 510#ifdef CONFIG_SERIAL_EFM32_UART_CONSOLE
 511static void efm32_uart_console_putchar(struct uart_port *port, int ch)
 512{
 513        struct efm32_uart_port *efm_port = to_efm_port(port);
 514        unsigned int timeout = 0x400;
 515        u32 status;
 516
 517        while (1) {
 518                status = efm32_uart_read32(efm_port, UARTn_STATUS);
 519
 520                if (status & UARTn_STATUS_TXBL)
 521                        break;
 522                if (!timeout--)
 523                        return;
 524        }
 525        efm32_uart_write32(efm_port, ch, UARTn_TXDATA);
 526}
 527
 528static void efm32_uart_console_write(struct console *co, const char *s,
 529                unsigned int count)
 530{
 531        struct efm32_uart_port *efm_port = efm32_uart_ports[co->index];
 532        u32 status = efm32_uart_read32(efm_port, UARTn_STATUS);
 533        unsigned int timeout = 0x400;
 534
 535        if (!(status & UARTn_STATUS_TXENS))
 536                efm32_uart_write32(efm_port, UARTn_CMD_TXEN, UARTn_CMD);
 537
 538        uart_console_write(&efm_port->port, s, count,
 539                        efm32_uart_console_putchar);
 540
 541        /* Wait for the transmitter to become empty */
 542        while (1) {
 543                u32 status = efm32_uart_read32(efm_port, UARTn_STATUS);
 544                if (status & UARTn_STATUS_TXC)
 545                        break;
 546                if (!timeout--)
 547                        break;
 548        }
 549
 550        if (!(status & UARTn_STATUS_TXENS))
 551                efm32_uart_write32(efm_port, UARTn_CMD_TXDIS, UARTn_CMD);
 552}
 553
 554static void efm32_uart_console_get_options(struct efm32_uart_port *efm_port,
 555                int *baud, int *parity, int *bits)
 556{
 557        u32 ctrl = efm32_uart_read32(efm_port, UARTn_CTRL);
 558        u32 route, clkdiv, frame;
 559
 560        if (ctrl & UARTn_CTRL_SYNC)
 561                /* not operating in async mode */
 562                return;
 563
 564        route = efm32_uart_read32(efm_port, UARTn_ROUTE);
 565        if (!(route & UARTn_ROUTE_TXPEN))
 566                /* tx pin not routed */
 567                return;
 568
 569        clkdiv = efm32_uart_read32(efm_port, UARTn_CLKDIV);
 570
 571        *baud = DIV_ROUND_CLOSEST(4 * efm_port->port.uartclk,
 572                        16 * (4 + (clkdiv >> 6)));
 573
 574        frame = efm32_uart_read32(efm_port, UARTn_FRAME);
 575        if (frame & UARTn_FRAME_PARITY_ODD)
 576                *parity = 'o';
 577        else if (frame & UARTn_FRAME_PARITY_EVEN)
 578                *parity = 'e';
 579        else
 580                *parity = 'n';
 581
 582        *bits = (frame & UARTn_FRAME_DATABITS__MASK) -
 583                        UARTn_FRAME_DATABITS(4) + 4;
 584
 585        efm_debug(efm_port, "get_opts: options=%d%c%d\n",
 586                        *baud, *parity, *bits);
 587}
 588
 589static int efm32_uart_console_setup(struct console *co, char *options)
 590{
 591        struct efm32_uart_port *efm_port;
 592        int baud = 115200;
 593        int bits = 8;
 594        int parity = 'n';
 595        int flow = 'n';
 596        int ret;
 597
 598        if (co->index < 0 || co->index >= ARRAY_SIZE(efm32_uart_ports)) {
 599                unsigned i;
 600                for (i = 0; i < ARRAY_SIZE(efm32_uart_ports); ++i) {
 601                        if (efm32_uart_ports[i]) {
 602                                pr_warn("efm32-console: fall back to console index %u (from %hhi)\n",
 603                                                i, co->index);
 604                                co->index = i;
 605                                break;
 606                        }
 607                }
 608        }
 609
 610        efm_port = efm32_uart_ports[co->index];
 611        if (!efm_port) {
 612                pr_warn("efm32-console: No port at %d\n", co->index);
 613                return -ENODEV;
 614        }
 615
 616        ret = clk_prepare(efm_port->clk);
 617        if (ret) {
 618                dev_warn(efm_port->port.dev,
 619                                "console: clk_prepare failed: %d\n", ret);
 620                return ret;
 621        }
 622
 623        efm_port->port.uartclk = clk_get_rate(efm_port->clk);
 624
 625        if (options)
 626                uart_parse_options(options, &baud, &parity, &bits, &flow);
 627        else
 628                efm32_uart_console_get_options(efm_port,
 629                                &baud, &parity, &bits);
 630
 631        return uart_set_options(&efm_port->port, co, baud, parity, bits, flow);
 632}
 633
 634static struct uart_driver efm32_uart_reg;
 635
 636static struct console efm32_uart_console = {
 637        .name = DEV_NAME,
 638        .write = efm32_uart_console_write,
 639        .device = uart_console_device,
 640        .setup = efm32_uart_console_setup,
 641        .flags = CON_PRINTBUFFER,
 642        .index = -1,
 643        .data = &efm32_uart_reg,
 644};
 645
 646#else
 647#define efm32_uart_console (*(struct console *)NULL)
 648#endif /* ifdef CONFIG_SERIAL_EFM32_UART_CONSOLE / else */
 649
 650static struct uart_driver efm32_uart_reg = {
 651        .owner = THIS_MODULE,
 652        .driver_name = DRIVER_NAME,
 653        .dev_name = DEV_NAME,
 654        .nr = ARRAY_SIZE(efm32_uart_ports),
 655        .cons = &efm32_uart_console,
 656};
 657
 658static int efm32_uart_probe_dt(struct platform_device *pdev,
 659                struct efm32_uart_port *efm_port)
 660{
 661        struct device_node *np = pdev->dev.of_node;
 662        u32 location;
 663        int ret;
 664
 665        if (!np)
 666                return 1;
 667
 668        ret = of_property_read_u32(np, "energymicro,location", &location);
 669
 670        if (ret)
 671                /* fall back to wrongly namespaced property */
 672                ret = of_property_read_u32(np, "efm32,location", &location);
 673
 674        if (ret)
 675                /* fall back to old and (wrongly) generic property "location" */
 676                ret = of_property_read_u32(np, "location", &location);
 677
 678        if (!ret) {
 679                if (location > 5) {
 680                        dev_err(&pdev->dev, "invalid location\n");
 681                        return -EINVAL;
 682                }
 683                efm_debug(efm_port, "using location %u\n", location);
 684                efm_port->pdata.location = location;
 685        } else {
 686                efm_debug(efm_port, "fall back to location 0\n");
 687        }
 688
 689        ret = of_alias_get_id(np, "serial");
 690        if (ret < 0) {
 691                dev_err(&pdev->dev, "failed to get alias id: %d\n", ret);
 692                return ret;
 693        } else {
 694                efm_port->port.line = ret;
 695                return 0;
 696        }
 697
 698}
 699
 700static int efm32_uart_probe(struct platform_device *pdev)
 701{
 702        struct efm32_uart_port *efm_port;
 703        struct resource *res;
 704        unsigned int line;
 705        int ret;
 706
 707        efm_port = kzalloc(sizeof(*efm_port), GFP_KERNEL);
 708        if (!efm_port) {
 709                dev_dbg(&pdev->dev, "failed to allocate private data\n");
 710                return -ENOMEM;
 711        }
 712
 713        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 714        if (!res) {
 715                ret = -ENODEV;
 716                dev_dbg(&pdev->dev, "failed to determine base address\n");
 717                goto err_get_base;
 718        }
 719
 720        if (resource_size(res) < 60) {
 721                ret = -EINVAL;
 722                dev_dbg(&pdev->dev, "memory resource too small\n");
 723                goto err_too_small;
 724        }
 725
 726        ret = platform_get_irq(pdev, 0);
 727        if (ret <= 0) {
 728                dev_dbg(&pdev->dev, "failed to get rx irq\n");
 729                goto err_get_rxirq;
 730        }
 731
 732        efm_port->port.irq = ret;
 733
 734        ret = platform_get_irq(pdev, 1);
 735        if (ret <= 0)
 736                ret = efm_port->port.irq + 1;
 737
 738        efm_port->txirq = ret;
 739
 740        efm_port->port.dev = &pdev->dev;
 741        efm_port->port.mapbase = res->start;
 742        efm_port->port.type = PORT_EFMUART;
 743        efm_port->port.iotype = UPIO_MEM32;
 744        efm_port->port.fifosize = 2;
 745        efm_port->port.ops = &efm32_uart_pops;
 746        efm_port->port.flags = UPF_BOOT_AUTOCONF;
 747
 748        ret = efm32_uart_probe_dt(pdev, efm_port);
 749        if (ret > 0) {
 750                /* not created by device tree */
 751                const struct efm32_uart_pdata *pdata = dev_get_platdata(&pdev->dev);
 752
 753                efm_port->port.line = pdev->id;
 754
 755                if (pdata)
 756                        efm_port->pdata = *pdata;
 757        } else if (ret < 0)
 758                goto err_probe_dt;
 759
 760        line = efm_port->port.line;
 761
 762        if (line >= 0 && line < ARRAY_SIZE(efm32_uart_ports))
 763                efm32_uart_ports[line] = efm_port;
 764
 765        ret = uart_add_one_port(&efm32_uart_reg, &efm_port->port);
 766        if (ret) {
 767                dev_dbg(&pdev->dev, "failed to add port: %d\n", ret);
 768
 769                if (line >= 0 && line < ARRAY_SIZE(efm32_uart_ports))
 770                        efm32_uart_ports[line] = NULL;
 771err_probe_dt:
 772err_get_rxirq:
 773err_too_small:
 774err_get_base:
 775                kfree(efm_port);
 776        } else {
 777                platform_set_drvdata(pdev, efm_port);
 778                dev_dbg(&pdev->dev, "\\o/\n");
 779        }
 780
 781        return ret;
 782}
 783
 784static int efm32_uart_remove(struct platform_device *pdev)
 785{
 786        struct efm32_uart_port *efm_port = platform_get_drvdata(pdev);
 787        unsigned int line = efm_port->port.line;
 788
 789        uart_remove_one_port(&efm32_uart_reg, &efm_port->port);
 790
 791        if (line >= 0 && line < ARRAY_SIZE(efm32_uart_ports))
 792                efm32_uart_ports[line] = NULL;
 793
 794        kfree(efm_port);
 795
 796        return 0;
 797}
 798
 799static const struct of_device_id efm32_uart_dt_ids[] = {
 800        {
 801                .compatible = "energymicro,efm32-uart",
 802        }, {
 803                /* doesn't follow the "vendor,device" scheme, don't use */
 804                .compatible = "efm32,uart",
 805        }, {
 806                /* sentinel */
 807        }
 808};
 809MODULE_DEVICE_TABLE(of, efm32_uart_dt_ids);
 810
 811static struct platform_driver efm32_uart_driver = {
 812        .probe = efm32_uart_probe,
 813        .remove = efm32_uart_remove,
 814
 815        .driver = {
 816                .name = DRIVER_NAME,
 817                .of_match_table = efm32_uart_dt_ids,
 818        },
 819};
 820
 821static int __init efm32_uart_init(void)
 822{
 823        int ret;
 824
 825        ret = uart_register_driver(&efm32_uart_reg);
 826        if (ret)
 827                return ret;
 828
 829        ret = platform_driver_register(&efm32_uart_driver);
 830        if (ret)
 831                uart_unregister_driver(&efm32_uart_reg);
 832
 833        pr_info("EFM32 UART/USART driver\n");
 834
 835        return ret;
 836}
 837module_init(efm32_uart_init);
 838
 839static void __exit efm32_uart_exit(void)
 840{
 841        platform_driver_unregister(&efm32_uart_driver);
 842        uart_unregister_driver(&efm32_uart_reg);
 843}
 844module_exit(efm32_uart_exit);
 845
 846MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>");
 847MODULE_DESCRIPTION("EFM32 UART/USART driver");
 848MODULE_LICENSE("GPL v2");
 849MODULE_ALIAS("platform:" DRIVER_NAME);
 850