target/linux/ramips/patches-3.18/0050-SPI-ralink-add-Ralink-SoC-spi-driver.patch

   1 From fc006d0622ab8c43086b2c9018c03012db332033 Mon Sep 17 00:00:00 2001
   2 From: John Crispin <blogic@openwrt.org>
   3 Date: Sun, 27 Jul 2014 11:15:12 +0100
   4 Subject: [PATCH 50/57] SPI: ralink: add Ralink SoC spi driver
   5
   6 Add the driver needed to make SPI work on Ralink SoC.
   7
   8 Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
   9 Acked-by: John Crispin <blogic@openwrt.org>
  10 ---
  11  drivers/spi/Kconfig      |    6 +
  12  drivers/spi/Makefile     |    1 +
  13  drivers/spi/spi-rt2880.c |  432 ++++++++++++++++++++++++++++++++++++++++++++++
  14  3 files changed, 439 insertions(+)
  15  create mode 100644 drivers/spi/spi-rt2880.c
  16
  17 --- a/drivers/spi/Kconfig
  18 +++ b/drivers/spi/Kconfig
  19 @@ -433,6 +433,12 @@ config SPI_QUP
  20           This driver can also be built as a module.  If so, the module
  21           will be called spi_qup.
  22
  23 +config SPI_RT2880
  24 +       tristate "Ralink RT288x SPI Controller"
  25 +       depends on RALINK
  26 +       help
  27 +         This selects a driver for the Ralink RT288x/RT305x SPI Controller.
  28 +
  29  config SPI_S3C24XX
  30         tristate "Samsung S3C24XX series SPI"
  31         depends on ARCH_S3C24XX
  32 --- a/drivers/spi/Makefile
  33 +++ b/drivers/spi/Makefile
  34 @@ -65,6 +65,7 @@ obj-$(CONFIG_SPI_PXA2XX_PCI)          += spi-pxa
  35  obj-$(CONFIG_SPI_QUP)                  += spi-qup.o
  36  obj-$(CONFIG_SPI_ROCKCHIP)             += spi-rockchip.o
  37  obj-$(CONFIG_SPI_RSPI)                 += spi-rspi.o
  38 +obj-$(CONFIG_SPI_RT2880)               += spi-rt2880.o
  39  obj-$(CONFIG_SPI_S3C24XX)              += spi-s3c24xx-hw.o
  40  spi-s3c24xx-hw-y                       := spi-s3c24xx.o
  41  spi-s3c24xx-hw-$(CONFIG_SPI_S3C24XX_FIQ) += spi-s3c24xx-fiq.o
  42 --- /dev/null
  43 +++ b/drivers/spi/spi-rt2880.c
  44 @@ -0,0 +1,539 @@
  45 +/*
  46 + * spi-rt2880.c -- Ralink RT288x/RT305x SPI controller driver
  47 + *
  48 + * Copyright (C) 2011 Sergiy <piratfm@gmail.com>
  49 + * Copyright (C) 2011-2013 Gabor Juhos <juhosg@openwrt.org>
  50 + *
  51 + * Some parts are based on spi-orion.c:
  52 + *   Author: Shadi Ammouri <shadi@marvell.com>
  53 + *   Copyright (C) 2007-2008 Marvell Ltd.
  54 + *
  55 + * This program is free software; you can redistribute it and/or modify
  56 + * it under the terms of the GNU General Public License version 2 as
  57 + * published by the Free Software Foundation.
  58 + */
  59 +
  60 +#include <linux/init.h>
  61 +#include <linux/module.h>
  62 +#include <linux/clk.h>
  63 +#include <linux/err.h>
  64 +#include <linux/delay.h>
  65 +#include <linux/io.h>
  66 +#include <linux/reset.h>
  67 +#include <linux/spi/spi.h>
  68 +#include <linux/platform_device.h>
  69 +
  70 +#define DRIVER_NAME                    "spi-rt2880"
  71 +/* only one slave is supported*/
  72 +#define RALINK_NUM_CHIPSELECTS         1
  73 +
  74 +#define RAMIPS_SPI_STAT                        0x00
  75 +#define RAMIPS_SPI_CFG                 0x10
  76 +#define RAMIPS_SPI_CTL                 0x14
  77 +#define RAMIPS_SPI_DATA                        0x20
  78 +#define RAMIPS_SPI_ADDR                        0x24
  79 +#define RAMIPS_SPI_BS                  0x28
  80 +#define RAMIPS_SPI_USER                        0x2C
  81 +#define RAMIPS_SPI_TXFIFO              0x30
  82 +#define RAMIPS_SPI_RXFIFO              0x34
  83 +#define RAMIPS_SPI_FIFO_STAT           0x38
  84 +#define RAMIPS_SPI_MODE                        0x3C
  85 +#define RAMIPS_SPI_DEV_OFFSET          0x40
  86 +#define RAMIPS_SPI_DMA                 0x80
  87 +#define RAMIPS_SPI_DMASTAT             0x84
  88 +#define RAMIPS_SPI_ARBITER             0xF0
  89 +
  90 +/* SPISTAT register bit field */
  91 +#define SPISTAT_BUSY                   BIT(0)
  92 +
  93 +/* SPICFG register bit field */
  94 +#define SPICFG_ADDRMODE                        BIT(12)
  95 +#define SPICFG_RXENVDIS                        BIT(11)
  96 +#define SPICFG_RXCAP                   BIT(10)
  97 +#define SPICFG_SPIENMODE               BIT(9)
  98 +#define SPICFG_MSBFIRST                        BIT(8)
  99 +#define SPICFG_SPICLKPOL               BIT(6)
 100 +#define SPICFG_RXCLKEDGE_FALLING       BIT(5)
 101 +#define SPICFG_TXCLKEDGE_FALLING       BIT(4)
 102 +#define SPICFG_HIZSPI                  BIT(3)
 103 +#define SPICFG_SPICLK_PRESCALE_MASK    0x7
 104 +#define SPICFG_SPICLK_DIV2             0
 105 +#define SPICFG_SPICLK_DIV4             1
 106 +#define SPICFG_SPICLK_DIV8             2
 107 +#define SPICFG_SPICLK_DIV16            3
 108 +#define SPICFG_SPICLK_DIV32            4
 109 +#define SPICFG_SPICLK_DIV64            5
 110 +#define SPICFG_SPICLK_DIV128           6
 111 +#define SPICFG_SPICLK_DISABLE          7
 112 +
 113 +/* SPICTL register bit field */
 114 +#define SPICTL_START                   BIT(4)
 115 +#define SPICTL_HIZSDO                  BIT(3)
 116 +#define SPICTL_STARTWR                 BIT(2)
 117 +#define SPICTL_STARTRD                 BIT(1)
 118 +#define SPICTL_SPIENA                  BIT(0)
 119 +
 120 +/* SPIUSER register bit field */
 121 +#define SPIUSER_USERMODE               BIT(21)
 122 +#define SPIUSER_INSTR_PHASE            BIT(20)
 123 +#define SPIUSER_ADDR_PHASE_MASK                0x7
 124 +#define SPIUSER_ADDR_PHASE_OFFSET      17
 125 +#define SPIUSER_MODE_PHASE             BIT(16)
 126 +#define SPIUSER_DUMMY_PHASE_MASK       0x3
 127 +#define SPIUSER_DUMMY_PHASE_OFFSET     14
 128 +#define SPIUSER_DATA_PHASE_MASK                0x3
 129 +#define SPIUSER_DATA_PHASE_OFFSET      12
 130 +#define SPIUSER_DATA_READ              (BIT(0) << SPIUSER_DATA_PHASE_OFFSET)
 131 +#define SPIUSER_DATA_WRITE             (BIT(1) << SPIUSER_DATA_PHASE_OFFSET)
 132 +#define SPIUSER_ADDR_TYPE_OFFSET       9
 133 +#define SPIUSER_MODE_TYPE_OFFSET       6
 134 +#define SPIUSER_DUMMY_TYPE_OFFSET      3
 135 +#define SPIUSER_DATA_TYPE_OFFSET       0
 136 +#define SPIUSER_TRANSFER_MASK          0x7
 137 +#define SPIUSER_TRANSFER_SINGLE                BIT(0)
 138 +#define SPIUSER_TRANSFER_DUAL          BIT(1)
 139 +#define SPIUSER_TRANSFER_QUAD          BIT(2)
 140 +
 141 +#define SPIUSER_TRANSFER_TYPE(type) ( \
 142 +       (type << SPIUSER_ADDR_TYPE_OFFSET) | \
 143 +       (type << SPIUSER_MODE_TYPE_OFFSET) | \
 144 +       (type << SPIUSER_DUMMY_TYPE_OFFSET) | \
 145 +       (type << SPIUSER_DATA_TYPE_OFFSET) \
 146 +)
 147 +
 148 +/* SPIFIFOSTAT register bit field */
 149 +#define SPIFIFOSTAT_TXEMPTY            BIT(19)
 150 +#define SPIFIFOSTAT_RXEMPTY            BIT(18)
 151 +#define SPIFIFOSTAT_TXFULL             BIT(17)
 152 +#define SPIFIFOSTAT_RXFULL             BIT(16)
 153 +#define SPIFIFOSTAT_FIFO_MASK          0xff
 154 +#define SPIFIFOSTAT_TX_OFFSET          8
 155 +#define SPIFIFOSTAT_RX_OFFSET          0
 156 +
 157 +#define SPI_FIFO_DEPTH                 16
 158 +
 159 +/* SPIMODE register bit field */
 160 +#define SPIMODE_MODE_OFFSET            24
 161 +#define SPIMODE_DUMMY_OFFSET           0
 162 +
 163 +/* SPIARB register bit field */
 164 +#define SPICTL_ARB_EN                  BIT(31)
 165 +#define SPICTL_CSCTL1                  BIT(16)
 166 +#define SPI1_POR                       BIT(1)
 167 +#define SPI0_POR                       BIT(0)
 168 +
 169 +#define RT2880_SPI_MODE_BITS   (SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST | \
 170 +               SPI_CS_HIGH)
 171 +
 172 +struct rt2880_spi {
 173 +       struct spi_master       *master;
 174 +       void __iomem            *base;
 175 +       unsigned int            sys_freq;
 176 +       unsigned int            speed;
 177 +       u16                     wait_loops;
 178 +       u16                     mode;
 179 +       struct clk              *clk;
 180 +};
 181 +
 182 +static inline struct rt2880_spi *spidev_to_rt2880_spi(struct spi_device *spi)
 183 +{
 184 +       return spi_master_get_devdata(spi->master);
 185 +}
 186 +
 187 +static inline u32 rt2880_spi_read(struct rt2880_spi *rs, u32 reg)
 188 +{
 189 +       return ioread32(rs->base + reg);
 190 +}
 191 +
 192 +static inline void rt2880_spi_write(struct rt2880_spi *rs, u32 reg,
 193 +               const u32 val)
 194 +{
 195 +       iowrite32(val, rs->base + reg);
 196 +}
 197 +
 198 +static inline void rt2880_spi_setbits(struct rt2880_spi *rs, u32 reg, u32 mask)
 199 +{
 200 +       void __iomem *addr = rs->base + reg;
 201 +
 202 +       iowrite32((ioread32(addr) | mask), addr);
 203 +}
 204 +
 205 +static inline void rt2880_spi_clrbits(struct rt2880_spi *rs, u32 reg, u32 mask)
 206 +{
 207 +       void __iomem *addr = rs->base + reg;
 208 +
 209 +       iowrite32((ioread32(addr) & ~mask), addr);
 210 +}
 211 +
 212 +static int rt2880_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
 213 +{
 214 +       struct rt2880_spi *rs = spidev_to_rt2880_spi(spi);
 215 +       u32 rate;
 216 +       u32 prescale;
 217 +       u32 reg;
 218 +
 219 +       dev_dbg(&spi->dev, "speed:%u\n", speed);
 220 +
 221 +       /*
 222 +        * the supported rates are: 2, 4, 8, ... 128
 223 +        * round up as we look for equal or less speed
 224 +        */
 225 +       rate = DIV_ROUND_UP(rs->sys_freq, speed);
 226 +       dev_dbg(&spi->dev, "rate-1:%u\n", rate);
 227 +       rate = roundup_pow_of_two(rate);
 228 +       dev_dbg(&spi->dev, "rate-2:%u\n", rate);
 229 +
 230 +       /* Convert the rate to SPI clock divisor value. */
 231 +       prescale = ilog2(rate / 2);
 232 +       dev_dbg(&spi->dev, "prescale:%u\n", prescale);
 233 +
 234 +       reg = rt2880_spi_read(rs, RAMIPS_SPI_CFG);
 235 +       reg = ((reg & ~SPICFG_SPICLK_PRESCALE_MASK) | prescale);
 236 +       rt2880_spi_write(rs, RAMIPS_SPI_CFG, reg);
 237 +
 238 +       /* some tolerance. double and add 100 */
 239 +       rs->wait_loops = (8 * HZ * loops_per_jiffy) /
 240 +               (clk_get_rate(rs->clk) / rate);
 241 +       rs->wait_loops = (rs->wait_loops << 1) + 100;
 242 +       rs->speed = speed;
 243 +       return 0;
 244 +}
 245 +
 246 +/*
 247 + * called only when no transfer is active on the bus
 248 + */
 249 +static int
 250 +rt2880_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
 251 +{
 252 +       struct rt2880_spi *rs = spidev_to_rt2880_spi(spi);
 253 +       unsigned int speed = spi->max_speed_hz;
 254 +       int rc;
 255 +
 256 +       if ((t != NULL) && t->speed_hz)
 257 +               speed = t->speed_hz;
 258 +
 259 +       if (rs->speed != speed) {
 260 +               dev_dbg(&spi->dev, "speed_hz:%u\n", speed);
 261 +               rc = rt2880_spi_baudrate_set(spi, speed);
 262 +               if (rc)
 263 +                       return rc;
 264 +       }
 265 +
 266 +       return 0;
 267 +}
 268 +
 269 +static u32 get_arbiter_offset(struct spi_master *master)
 270 +{
 271 +       u32 offset;
 272 +
 273 +       offset = RAMIPS_SPI_ARBITER;
 274 +       if (master->bus_num == 1)
 275 +               offset -= RAMIPS_SPI_DEV_OFFSET;
 276 +
 277 +       return offset;
 278 +}
 279 +
 280 +static void rt2880_spi_set_cs(struct rt2880_spi *rs, int enable)
 281 +{
 282 +       if (enable)
 283 +               rt2880_spi_clrbits(rs, RAMIPS_SPI_CTL, SPICTL_SPIENA);
 284 +       else
 285 +               rt2880_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_SPIENA);
 286 +}
 287 +
 288 +static int rt2880_spi_wait_ready(struct rt2880_spi *rs, int len)
 289 +{
 290 +       int loop = rs->wait_loops * len;
 291 +
 292 +       while ((rt2880_spi_read(rs, RAMIPS_SPI_STAT) & SPISTAT_BUSY) && --loop)
 293 +               cpu_relax();
 294 +
 295 +       if (loop)
 296 +               return 0;
 297 +
 298 +       return -ETIMEDOUT;
 299 +}
 300 +
 301 +static unsigned int
 302 +rt2880_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
 303 +{
 304 +       struct rt2880_spi *rs = spidev_to_rt2880_spi(spi);
 305 +       unsigned count = 0;
 306 +       u8 *rx = xfer->rx_buf;
 307 +       const u8 *tx = xfer->tx_buf;
 308 +       int err;
 309 +
 310 +       dev_dbg(&spi->dev, "read (%d): %s %s\n", xfer->len,
 311 +                 (tx != NULL) ? "tx" : "  ",
 312 +                 (rx != NULL) ? "rx" : "  ");
 313 +
 314 +       if (tx) {
 315 +               for (count = 0; count < xfer->len; count++) {
 316 +                       rt2880_spi_write(rs, RAMIPS_SPI_DATA, tx[count]);
 317 +                       rt2880_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_STARTWR);
 318 +                       err = rt2880_spi_wait_ready(rs, 1);
 319 +                       if (err) {
 320 +                               dev_err(&spi->dev, "TX failed, err=%d\n", err);
 321 +                               goto out;
 322 +                       }
 323 +               }
 324 +       }
 325 +
 326 +       if (rx) {
 327 +               for (count = 0; count < xfer->len; count++) {
 328 +                       rt2880_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_STARTRD);
 329 +                       err = rt2880_spi_wait_ready(rs, 1);
 330 +                       if (err) {
 331 +                               dev_err(&spi->dev, "RX failed, err=%d\n", err);
 332 +                               goto out;
 333 +                       }
 334 +                       rx[count] = (u8) rt2880_spi_read(rs, RAMIPS_SPI_DATA);
 335 +               }
 336 +       }
 337 +
 338 +out:
 339 +       return count;
 340 +}
 341 +
 342 +static int rt2880_spi_transfer_one_message(struct spi_master *master,
 343 +                                          struct spi_message *m)
 344 +{
 345 +       struct rt2880_spi *rs = spi_master_get_devdata(master);
 346 +       struct spi_device *spi = m->spi;
 347 +       struct spi_transfer *t = NULL;
 348 +       int par_override = 0;
 349 +       int status = 0;
 350 +       int cs_active = 0;
 351 +
 352 +       /* Load defaults */
 353 +       status = rt2880_spi_setup_transfer(spi, NULL);
 354 +       if (status < 0)
 355 +               goto msg_done;
 356 +
 357 +       list_for_each_entry(t, &m->transfers, transfer_list) {
 358 +               if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
 359 +                       dev_err(&spi->dev,
 360 +                               "message rejected: invalid transfer data buffers\n");
 361 +                       status = -EIO;
 362 +                       goto msg_done;
 363 +               }
 364 +
 365 +               if (t->speed_hz && t->speed_hz < (rs->sys_freq / 128)) {
 366 +                       dev_err(&spi->dev,
 367 +                               "message rejected: device min speed (%d Hz) exceeds required transfer speed (%d Hz)\n",
 368 +                               (rs->sys_freq / 128), t->speed_hz);
 369 +                       status = -EIO;
 370 +                       goto msg_done;
 371 +               }
 372 +
 373 +               if (par_override || t->speed_hz || t->bits_per_word) {
 374 +                       par_override = 1;
 375 +                       status = rt2880_spi_setup_transfer(spi, t);
 376 +                       if (status < 0)
 377 +                               goto msg_done;
 378 +                       if (!t->speed_hz && !t->bits_per_word)
 379 +                               par_override = 0;
 380 +               }
 381 +
 382 +               if (!cs_active) {
 383 +                       rt2880_spi_set_cs(rs, 1);
 384 +                       cs_active = 1;
 385 +               }
 386 +
 387 +               if (t->len)
 388 +                       m->actual_length += rt2880_spi_write_read(spi, t);
 389 +
 390 +               if (t->delay_usecs)
 391 +                       udelay(t->delay_usecs);
 392 +
 393 +               if (t->cs_change) {
 394 +                       rt2880_spi_set_cs(rs, 0);
 395 +                       cs_active = 0;
 396 +               }
 397 +       }
 398 +
 399 +msg_done:
 400 +       if (cs_active)
 401 +               rt2880_spi_set_cs(rs, 0);
 402 +
 403 +       m->status = status;
 404 +       spi_finalize_current_message(master);
 405 +
 406 +       return 0;
 407 +}
 408 +
 409 +static int rt2880_spi_setup(struct spi_device *spi)
 410 +{
 411 +       struct spi_master *master = spi->master;
 412 +       struct rt2880_spi *rs = spi_master_get_devdata(master);
 413 +       u32 reg, old_reg, arbit_off;
 414 +
 415 +       if ((spi->max_speed_hz > master->max_speed_hz) ||
 416 +                       (spi->max_speed_hz < master->min_speed_hz)) {
 417 +               dev_err(&spi->dev, "invalide requested speed %d Hz\n",
 418 +                               spi->max_speed_hz);
 419 +               return -EINVAL;
 420 +       }
 421 +
 422 +       if (!(master->bits_per_word_mask &
 423 +                               BIT(spi->bits_per_word - 1))) {
 424 +               dev_err(&spi->dev, "invalide bits_per_word %d\n",
 425 +                               spi->bits_per_word);
 426 +               return -EINVAL;
 427 +       }
 428 +
 429 +       /* the hardware seems can't work on mode0 force it to mode3 */
 430 +       if ((spi->mode & (SPI_CPOL | SPI_CPHA)) == SPI_MODE_0) {
 431 +               dev_warn(&spi->dev, "force spi mode3\n");
 432 +               spi->mode |= SPI_MODE_3;
 433 +       }
 434 +
 435 +       /* chip polarity */
 436 +       arbit_off = get_arbiter_offset(master);
 437 +       reg = old_reg = rt2880_spi_read(rs, arbit_off);
 438 +       if (spi->mode & SPI_CS_HIGH) {
 439 +               switch (master->bus_num) {
 440 +               case 1:
 441 +                       reg |= SPI1_POR;
 442 +                       break;
 443 +               default:
 444 +                       reg |= SPI0_POR;
 445 +                       break;
 446 +               }
 447 +       } else {
 448 +               switch (master->bus_num) {
 449 +               case 1:
 450 +                       reg &= ~SPI1_POR;
 451 +                       break;
 452 +               default:
 453 +                       reg &= ~SPI0_POR;
 454 +                       break;
 455 +               }
 456 +       }
 457 +
 458 +       /* enable spi1 */
 459 +       if (master->bus_num == 1)
 460 +               reg |= SPICTL_ARB_EN;
 461 +
 462 +       if (reg != old_reg)
 463 +               rt2880_spi_write(rs, arbit_off, reg);
 464 +
 465 +       return 0;
 466 +}
 467 +
 468 +static void rt2880_spi_reset(struct rt2880_spi *rs)
 469 +{
 470 +       rt2880_spi_write(rs, RAMIPS_SPI_CFG,
 471 +                        SPICFG_MSBFIRST | SPICFG_TXCLKEDGE_FALLING |
 472 +                        SPICFG_SPICLK_DIV16 | SPICFG_SPICLKPOL);
 473 +       rt2880_spi_write(rs, RAMIPS_SPI_CTL, SPICTL_HIZSDO | SPICTL_SPIENA);
 474 +}
 475 +
 476 +static int rt2880_spi_probe(struct platform_device *pdev)
 477 +{
 478 +       struct spi_master *master;
 479 +       struct rt2880_spi *rs;
 480 +       void __iomem *base;
 481 +       struct resource *r;
 482 +       struct clk *clk;
 483 +       int ret;
 484 +
 485 +       r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 486 +       base = devm_ioremap_resource(&pdev->dev, r);
 487 +       if (IS_ERR(base))
 488 +               return PTR_ERR(base);
 489 +
 490 +       clk = devm_clk_get(&pdev->dev, NULL);
 491 +       if (IS_ERR(clk)) {
 492 +               dev_err(&pdev->dev, "unable to get SYS clock\n");
 493 +               return PTR_ERR(clk);
 494 +       }
 495 +
 496 +       ret = clk_prepare_enable(clk);
 497 +       if (ret)
 498 +               goto err_clk;
 499 +
 500 +       master = spi_alloc_master(&pdev->dev, sizeof(*rs));
 501 +       if (master == NULL) {
 502 +               dev_dbg(&pdev->dev, "master allocation failed\n");
 503 +               ret = -ENOMEM;
 504 +               goto err_clk;
 505 +       }
 506 +
 507 +       master->dev.of_node = pdev->dev.of_node;
 508 +       master->mode_bits = RT2880_SPI_MODE_BITS;
 509 +       master->bits_per_word_mask = SPI_BPW_MASK(8);
 510 +       master->min_speed_hz = clk_get_rate(clk) / 128;
 511 +       master->max_speed_hz = clk_get_rate(clk) / 2;
 512 +       master->flags = SPI_MASTER_HALF_DUPLEX;
 513 +       master->setup = rt2880_spi_setup;
 514 +       master->transfer_one_message = rt2880_spi_transfer_one_message;
 515 +       master->num_chipselect = RALINK_NUM_CHIPSELECTS;
 516 +
 517 +       dev_set_drvdata(&pdev->dev, master);
 518 +
 519 +       rs = spi_master_get_devdata(master);
 520 +       rs->master = master;
 521 +       rs->base = base;
 522 +       rs->clk = clk;
 523 +       rs->sys_freq = clk_get_rate(rs->clk);
 524 +       dev_dbg(&pdev->dev, "sys_freq: %u\n", rs->sys_freq);
 525 +
 526 +       device_reset(&pdev->dev);
 527 +
 528 +       rt2880_spi_reset(rs);
 529 +
 530 +       ret = devm_spi_register_master(&pdev->dev, master);
 531 +       if (ret < 0) {
 532 +               dev_err(&pdev->dev, "devm_spi_register_master error.\n");
 533 +               goto err_master;
 534 +       }
 535 +
 536 +       return ret;
 537 +
 538 +err_master:
 539 +       spi_master_put(master);
 540 +       kfree(master);
 541 +err_clk:
 542 +       clk_disable_unprepare(clk);
 543 +
 544 +       return ret;
 545 +}
 546 +
 547 +static int rt2880_spi_remove(struct platform_device *pdev)
 548 +{
 549 +       struct spi_master *master;
 550 +       struct rt2880_spi *rs;
 551 +
 552 +       master = dev_get_drvdata(&pdev->dev);
 553 +       rs = spi_master_get_devdata(master);
 554 +
 555 +       clk_disable_unprepare(rs->clk);
 556 +
 557 +       return 0;
 558 +}
 559 +
 560 +MODULE_ALIAS("platform:" DRIVER_NAME);
 561 +
 562 +static const struct of_device_id rt2880_spi_match[] = {
 563 +       { .compatible = "ralink,rt2880-spi" },
 564 +       {},
 565 +};
 566 +MODULE_DEVICE_TABLE(of, rt2880_spi_match);
 567 +
 568 +static struct platform_driver rt2880_spi_driver = {
 569 +       .driver = {
 570 +               .name = DRIVER_NAME,
 571 +               .owner = THIS_MODULE,
 572 +               .of_match_table = rt2880_spi_match,
 573 +       },
 574 +       .probe = rt2880_spi_probe,
 575 +       .remove = rt2880_spi_remove,
 576 +};
 577 +
 578 +module_platform_driver(rt2880_spi_driver);
 579 +
 580 +MODULE_DESCRIPTION("Ralink SPI driver");
 581 +MODULE_AUTHOR("Sergiy <piratfm@gmail.com>");
 582 +MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
 583 +MODULE_LICENSE("GPL");