drivers/spi/spi-ti-qspi.c

   1 /*
   2  * TI QSPI driver
   3  *
   4  * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
   5  * Author: Sourav Poddar <sourav.poddar@ti.com>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GPLv2.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR /PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/init.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/module.h>
  20 #include <linux/device.h>
  21 #include <linux/delay.h>
  22 #include <linux/dma-mapping.h>
  23 #include <linux/dmaengine.h>
  24 #include <linux/omap-dma.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/err.h>
  27 #include <linux/clk.h>
  28 #include <linux/io.h>
  29 #include <linux/slab.h>
  30 #include <linux/pm_runtime.h>
  31 #include <linux/of.h>
  32 #include <linux/of_device.h>
  33 #include <linux/pinctrl/consumer.h>
  34 #include <linux/mfd/syscon.h>
  35 #include <linux/regmap.h>
  36
  37 #include <linux/spi/spi.h>
  38
  39 struct ti_qspi_regs {
  40         u32 clkctrl;
  41 };
  42
  43 struct ti_qspi {
  44         /* list synchronization */
  45         struct mutex            list_lock;
  46
  47         struct spi_master       *master;
  48         void __iomem            *base;
  49         void __iomem            *mmap_base;
  50         struct regmap           *ctrl_base;
  51         unsigned int            ctrl_reg;
  52         struct clk              *fclk;
  53         struct device           *dev;
  54
  55         struct ti_qspi_regs     ctx_reg;
  56
  57         u32 spi_max_frequency;
  58         u32 cmd;
  59         u32 dc;
  60
  61         bool mmap_enabled;
  62 };
  63
  64 #define QSPI_PID                        (0x0)
  65 #define QSPI_SYSCONFIG                  (0x10)
  66 #define QSPI_SPI_CLOCK_CNTRL_REG        (0x40)
  67 #define QSPI_SPI_DC_REG                 (0x44)
  68 #define QSPI_SPI_CMD_REG                (0x48)
  69 #define QSPI_SPI_STATUS_REG             (0x4c)
  70 #define QSPI_SPI_DATA_REG               (0x50)
  71 #define QSPI_SPI_SETUP_REG(n)           ((0x54 + 4 * n))
  72 #define QSPI_SPI_SWITCH_REG             (0x64)
  73 #define QSPI_SPI_DATA_REG_1             (0x68)
  74 #define QSPI_SPI_DATA_REG_2             (0x6c)
  75 #define QSPI_SPI_DATA_REG_3             (0x70)
  76
  77 #define QSPI_COMPLETION_TIMEOUT         msecs_to_jiffies(2000)
  78
  79 #define QSPI_FCLK                       192000000
  80
  81 /* Clock Control */
  82 #define QSPI_CLK_EN                     (1 << 31)
  83 #define QSPI_CLK_DIV_MAX                0xffff
  84
  85 /* Command */
  86 #define QSPI_EN_CS(n)                   (n << 28)
  87 #define QSPI_WLEN(n)                    ((n - 1) << 19)
  88 #define QSPI_3_PIN                      (1 << 18)
  89 #define QSPI_RD_SNGL                    (1 << 16)
  90 #define QSPI_WR_SNGL                    (2 << 16)
  91 #define QSPI_RD_DUAL                    (3 << 16)
  92 #define QSPI_RD_QUAD                    (7 << 16)
  93 #define QSPI_INVAL                      (4 << 16)
  94 #define QSPI_FLEN(n)                    ((n - 1) << 0)
  95 #define QSPI_WLEN_MAX_BITS              128
  96 #define QSPI_WLEN_MAX_BYTES             16
  97
  98 /* STATUS REGISTER */
  99 #define BUSY                            0x01
 100 #define WC                              0x02
 101
 102 /* Device Control */
 103 #define QSPI_DD(m, n)                   (m << (3 + n * 8))
 104 #define QSPI_CKPHA(n)                   (1 << (2 + n * 8))
 105 #define QSPI_CSPOL(n)                   (1 << (1 + n * 8))
 106 #define QSPI_CKPOL(n)                   (1 << (n * 8))
 107
 108 #define QSPI_FRAME                      4096
 109
 110 #define QSPI_AUTOSUSPEND_TIMEOUT         2000
 111
 112 #define MEM_CS_EN(n)                    ((n + 1) << 8)
 113 #define MEM_CS_MASK                     (7 << 8)
 114
 115 #define MM_SWITCH                       0x1
 116
 117 #define QSPI_SETUP_RD_NORMAL            (0x0 << 12)
 118 #define QSPI_SETUP_RD_DUAL              (0x1 << 12)
 119 #define QSPI_SETUP_RD_QUAD              (0x3 << 12)
 120 #define QSPI_SETUP_ADDR_SHIFT           8
 121 #define QSPI_SETUP_DUMMY_SHIFT          10
 122
 123 static inline unsigned long ti_qspi_read(struct ti_qspi *qspi,
 124                 unsigned long reg)
 125 {
 126         return readl(qspi->base + reg);
 127 }
 128
 129 static inline void ti_qspi_write(struct ti_qspi *qspi,
 130                 unsigned long val, unsigned long reg)
 131 {
 132         writel(val, qspi->base + reg);
 133 }
 134
 135 static int ti_qspi_setup(struct spi_device *spi)
 136 {
 137         struct ti_qspi  *qspi = spi_master_get_devdata(spi->master);
 138         struct ti_qspi_regs *ctx_reg = &qspi->ctx_reg;
 139         int clk_div = 0, ret;
 140         u32 clk_ctrl_reg, clk_rate, clk_mask;
 141
 142         if (spi->master->busy) {
 143                 dev_dbg(qspi->dev, "master busy doing other trasnfers\n");
 144                 return -EBUSY;
 145         }
 146
 147         if (!qspi->spi_max_frequency) {
 148                 dev_err(qspi->dev, "spi max frequency not defined\n");
 149                 return -EINVAL;
 150         }
 151
 152         clk_rate = clk_get_rate(qspi->fclk);
 153
 154         clk_div = DIV_ROUND_UP(clk_rate, qspi->spi_max_frequency) - 1;
 155
 156         if (clk_div < 0) {
 157                 dev_dbg(qspi->dev, "clock divider < 0, using /1 divider\n");
 158                 return -EINVAL;
 159         }
 160
 161         if (clk_div > QSPI_CLK_DIV_MAX) {
 162                 dev_dbg(qspi->dev, "clock divider >%d , using /%d divider\n",
 163                                 QSPI_CLK_DIV_MAX, QSPI_CLK_DIV_MAX + 1);
 164                 return -EINVAL;
 165         }
 166
 167         dev_dbg(qspi->dev, "hz: %d, clock divider %d\n",
 168                         qspi->spi_max_frequency, clk_div);
 169
 170         ret = pm_runtime_get_sync(qspi->dev);
 171         if (ret < 0) {
 172                 dev_err(qspi->dev, "pm_runtime_get_sync() failed\n");
 173                 return ret;
 174         }
 175
 176         clk_ctrl_reg = ti_qspi_read(qspi, QSPI_SPI_CLOCK_CNTRL_REG);
 177
 178         clk_ctrl_reg &= ~QSPI_CLK_EN;
 179
 180         /* disable SCLK */
 181         ti_qspi_write(qspi, clk_ctrl_reg, QSPI_SPI_CLOCK_CNTRL_REG);
 182
 183         /* enable SCLK */
 184         clk_mask = QSPI_CLK_EN | clk_div;
 185         ti_qspi_write(qspi, clk_mask, QSPI_SPI_CLOCK_CNTRL_REG);
 186         ctx_reg->clkctrl = clk_mask;
 187
 188         pm_runtime_mark_last_busy(qspi->dev);
 189         ret = pm_runtime_put_autosuspend(qspi->dev);
 190         if (ret < 0) {
 191                 dev_err(qspi->dev, "pm_runtime_put_autosuspend() failed\n");
 192                 return ret;
 193         }
 194
 195         return 0;
 196 }
 197
 198 static void ti_qspi_restore_ctx(struct ti_qspi *qspi)
 199 {
 200         struct ti_qspi_regs *ctx_reg = &qspi->ctx_reg;
 201
 202         ti_qspi_write(qspi, ctx_reg->clkctrl, QSPI_SPI_CLOCK_CNTRL_REG);
 203 }
 204
 205 static inline u32 qspi_is_busy(struct ti_qspi *qspi)
 206 {
 207         u32 stat;
 208         unsigned long timeout = jiffies + QSPI_COMPLETION_TIMEOUT;
 209
 210         stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
 211         while ((stat & BUSY) && time_after(timeout, jiffies)) {
 212                 cpu_relax();
 213                 stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
 214         }
 215
 216         WARN(stat & BUSY, "qspi busy\n");
 217         return stat & BUSY;
 218 }
 219
 220 static inline int ti_qspi_poll_wc(struct ti_qspi *qspi)
 221 {
 222         u32 stat;
 223         unsigned long timeout = jiffies + QSPI_COMPLETION_TIMEOUT;
 224
 225         do {
 226                 stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
 227                 if (stat & WC)
 228                         return 0;
 229                 cpu_relax();
 230         } while (time_after(timeout, jiffies));
 231
 232         stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
 233         if (stat & WC)
 234                 return 0;
 235         return  -ETIMEDOUT;
 236 }
 237
 238 static int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t)
 239 {
 240         int wlen, count, xfer_len;
 241         unsigned int cmd;
 242         const u8 *txbuf;
 243         u32 data;
 244
 245         txbuf = t->tx_buf;
 246         cmd = qspi->cmd | QSPI_WR_SNGL;
 247         count = t->len;
 248         wlen = t->bits_per_word >> 3;   /* in bytes */
 249         xfer_len = wlen;
 250
 251         while (count) {
 252                 if (qspi_is_busy(qspi))
 253                         return -EBUSY;
 254
 255                 switch (wlen) {
 256                 case 1:
 257                         dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %02x\n",
 258                                         cmd, qspi->dc, *txbuf);
 259                         if (count >= QSPI_WLEN_MAX_BYTES) {
 260                                 u32 *txp = (u32 *)txbuf;
 261
 262                                 data = cpu_to_be32(*txp++);
 263                                 writel(data, qspi->base +
 264                                        QSPI_SPI_DATA_REG_3);
 265                                 data = cpu_to_be32(*txp++);
 266                                 writel(data, qspi->base +
 267                                        QSPI_SPI_DATA_REG_2);
 268                                 data = cpu_to_be32(*txp++);
 269                                 writel(data, qspi->base +
 270                                        QSPI_SPI_DATA_REG_1);
 271                                 data = cpu_to_be32(*txp++);
 272                                 writel(data, qspi->base +
 273                                        QSPI_SPI_DATA_REG);
 274                                 xfer_len = QSPI_WLEN_MAX_BYTES;
 275                                 cmd |= QSPI_WLEN(QSPI_WLEN_MAX_BITS);
 276                         } else {
 277                                 writeb(*txbuf, qspi->base + QSPI_SPI_DATA_REG);
 278                                 cmd = qspi->cmd | QSPI_WR_SNGL;
 279                                 xfer_len = wlen;
 280                                 cmd |= QSPI_WLEN(wlen);
 281                         }
 282                         break;
 283                 case 2:
 284                         dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %04x\n",
 285                                         cmd, qspi->dc, *txbuf);
 286                         writew(*((u16 *)txbuf), qspi->base + QSPI_SPI_DATA_REG);
 287                         break;
 288                 case 4:
 289                         dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %08x\n",
 290                                         cmd, qspi->dc, *txbuf);
 291                         writel(*((u32 *)txbuf), qspi->base + QSPI_SPI_DATA_REG);
 292                         break;
 293                 }
 294
 295                 ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
 296                 if (ti_qspi_poll_wc(qspi)) {
 297                         dev_err(qspi->dev, "write timed out\n");
 298                         return -ETIMEDOUT;
 299                 }
 300                 txbuf += xfer_len;
 301                 count -= xfer_len;
 302         }
 303
 304         return 0;
 305 }
 306
 307 static int qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t)
 308 {
 309         int wlen, count;
 310         unsigned int cmd;
 311         u8 *rxbuf;
 312
 313         rxbuf = t->rx_buf;
 314         cmd = qspi->cmd;
 315         switch (t->rx_nbits) {
 316         case SPI_NBITS_DUAL:
 317                 cmd |= QSPI_RD_DUAL;
 318                 break;
 319         case SPI_NBITS_QUAD:
 320                 cmd |= QSPI_RD_QUAD;
 321                 break;
 322         default:
 323                 cmd |= QSPI_RD_SNGL;
 324                 break;
 325         }
 326         count = t->len;
 327         wlen = t->bits_per_word >> 3;   /* in bytes */
 328
 329         while (count) {
 330                 dev_dbg(qspi->dev, "rx cmd %08x dc %08x\n", cmd, qspi->dc);
 331                 if (qspi_is_busy(qspi))
 332                         return -EBUSY;
 333
 334                 ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
 335                 if (ti_qspi_poll_wc(qspi)) {
 336                         dev_err(qspi->dev, "read timed out\n");
 337                         return -ETIMEDOUT;
 338                 }
 339                 switch (wlen) {
 340                 case 1:
 341                         *rxbuf = readb(qspi->base + QSPI_SPI_DATA_REG);
 342                         break;
 343                 case 2:
 344                         *((u16 *)rxbuf) = readw(qspi->base + QSPI_SPI_DATA_REG);
 345                         break;
 346                 case 4:
 347                         *((u32 *)rxbuf) = readl(qspi->base + QSPI_SPI_DATA_REG);
 348                         break;
 349                 }
 350                 rxbuf += wlen;
 351                 count -= wlen;
 352         }
 353
 354         return 0;
 355 }
 356
 357 static int qspi_transfer_msg(struct ti_qspi *qspi, struct spi_transfer *t)
 358 {
 359         int ret;
 360
 361         if (t->tx_buf) {
 362                 ret = qspi_write_msg(qspi, t);
 363                 if (ret) {
 364                         dev_dbg(qspi->dev, "Error while writing\n");
 365                         return ret;
 366                 }
 367         }
 368
 369         if (t->rx_buf) {
 370                 ret = qspi_read_msg(qspi, t);
 371                 if (ret) {
 372                         dev_dbg(qspi->dev, "Error while reading\n");
 373                         return ret;
 374                 }
 375         }
 376
 377         return 0;
 378 }
 379
 380 static void ti_qspi_enable_memory_map(struct spi_device *spi)
 381 {
 382         struct ti_qspi  *qspi = spi_master_get_devdata(spi->master);
 383
 384         ti_qspi_write(qspi, MM_SWITCH, QSPI_SPI_SWITCH_REG);
 385         if (qspi->ctrl_base) {
 386                 regmap_update_bits(qspi->ctrl_base, qspi->ctrl_reg,
 387                                    MEM_CS_EN(spi->chip_select),
 388                                    MEM_CS_MASK);
 389         }
 390         qspi->mmap_enabled = true;
 391 }
 392
 393 static void ti_qspi_disable_memory_map(struct spi_device *spi)
 394 {
 395         struct ti_qspi  *qspi = spi_master_get_devdata(spi->master);
 396
 397         ti_qspi_write(qspi, 0, QSPI_SPI_SWITCH_REG);
 398         if (qspi->ctrl_base)
 399                 regmap_update_bits(qspi->ctrl_base, qspi->ctrl_reg,
 400                                    0, MEM_CS_MASK);
 401         qspi->mmap_enabled = false;
 402 }
 403
 404 static void ti_qspi_setup_mmap_read(struct spi_device *spi,
 405                                     struct spi_flash_read_message *msg)
 406 {
 407         struct ti_qspi  *qspi = spi_master_get_devdata(spi->master);
 408         u32 memval = msg->read_opcode;
 409
 410         switch (msg->data_nbits) {
 411         case SPI_NBITS_QUAD:
 412                 memval |= QSPI_SETUP_RD_QUAD;
 413                 break;
 414         case SPI_NBITS_DUAL:
 415                 memval |= QSPI_SETUP_RD_DUAL;
 416                 break;
 417         default:
 418                 memval |= QSPI_SETUP_RD_NORMAL;
 419                 break;
 420         }
 421         memval |= ((msg->addr_width - 1) << QSPI_SETUP_ADDR_SHIFT |
 422                    msg->dummy_bytes << QSPI_SETUP_DUMMY_SHIFT);
 423         ti_qspi_write(qspi, memval,
 424                       QSPI_SPI_SETUP_REG(spi->chip_select));
 425 }
 426
 427 static int ti_qspi_spi_flash_read(struct  spi_device *spi,
 428                                   struct spi_flash_read_message *msg)
 429 {
 430         struct ti_qspi *qspi = spi_master_get_devdata(spi->master);
 431         int ret = 0;
 432
 433         mutex_lock(&qspi->list_lock);
 434
 435         if (!qspi->mmap_enabled)
 436                 ti_qspi_enable_memory_map(spi);
 437         ti_qspi_setup_mmap_read(spi, msg);
 438         memcpy_fromio(msg->buf, qspi->mmap_base + msg->from, msg->len);
 439         msg->retlen = msg->len;
 440
 441         mutex_unlock(&qspi->list_lock);
 442
 443         return ret;
 444 }
 445
 446 static int ti_qspi_start_transfer_one(struct spi_master *master,
 447                 struct spi_message *m)
 448 {
 449         struct ti_qspi *qspi = spi_master_get_devdata(master);
 450         struct spi_device *spi = m->spi;
 451         struct spi_transfer *t;
 452         int status = 0, ret;
 453         int frame_length;
 454
 455         /* setup device control reg */
 456         qspi->dc = 0;
 457
 458         if (spi->mode & SPI_CPHA)
 459                 qspi->dc |= QSPI_CKPHA(spi->chip_select);
 460         if (spi->mode & SPI_CPOL)
 461                 qspi->dc |= QSPI_CKPOL(spi->chip_select);
 462         if (spi->mode & SPI_CS_HIGH)
 463                 qspi->dc |= QSPI_CSPOL(spi->chip_select);
 464
 465         frame_length = (m->frame_length << 3) / spi->bits_per_word;
 466
 467         frame_length = clamp(frame_length, 0, QSPI_FRAME);
 468
 469         /* setup command reg */
 470         qspi->cmd = 0;
 471         qspi->cmd |= QSPI_EN_CS(spi->chip_select);
 472         qspi->cmd |= QSPI_FLEN(frame_length);
 473
 474         ti_qspi_write(qspi, qspi->dc, QSPI_SPI_DC_REG);
 475
 476         mutex_lock(&qspi->list_lock);
 477
 478         if (qspi->mmap_enabled)
 479                 ti_qspi_disable_memory_map(spi);
 480
 481         list_for_each_entry(t, &m->transfers, transfer_list) {
 482                 qspi->cmd |= QSPI_WLEN(t->bits_per_word);
 483
 484                 ret = qspi_transfer_msg(qspi, t);
 485                 if (ret) {
 486                         dev_dbg(qspi->dev, "transfer message failed\n");
 487                         mutex_unlock(&qspi->list_lock);
 488                         return -EINVAL;
 489                 }
 490
 491                 m->actual_length += t->len;
 492         }
 493
 494         mutex_unlock(&qspi->list_lock);
 495
 496         ti_qspi_write(qspi, qspi->cmd | QSPI_INVAL, QSPI_SPI_CMD_REG);
 497         m->status = status;
 498         spi_finalize_current_message(master);
 499
 500         return status;
 501 }
 502
 503 static int ti_qspi_runtime_resume(struct device *dev)
 504 {
 505         struct ti_qspi      *qspi;
 506
 507         qspi = dev_get_drvdata(dev);
 508         ti_qspi_restore_ctx(qspi);
 509
 510         return 0;
 511 }
 512
 513 static const struct of_device_id ti_qspi_match[] = {
 514         {.compatible = "ti,dra7xxx-qspi" },
 515         {.compatible = "ti,am4372-qspi" },
 516         {},
 517 };
 518 MODULE_DEVICE_TABLE(of, ti_qspi_match);
 519
 520 static int ti_qspi_probe(struct platform_device *pdev)
 521 {
 522         struct  ti_qspi *qspi;
 523         struct spi_master *master;
 524         struct resource         *r, *res_mmap;
 525         struct device_node *np = pdev->dev.of_node;
 526         u32 max_freq;
 527         int ret = 0, num_cs, irq;
 528
 529         master = spi_alloc_master(&pdev->dev, sizeof(*qspi));
 530         if (!master)
 531                 return -ENOMEM;
 532
 533         master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_RX_DUAL | SPI_RX_QUAD;
 534
 535         master->flags = SPI_MASTER_HALF_DUPLEX;
 536         master->setup = ti_qspi_setup;
 537         master->auto_runtime_pm = true;
 538         master->transfer_one_message = ti_qspi_start_transfer_one;
 539         master->dev.of_node = pdev->dev.of_node;
 540         master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
 541                                      SPI_BPW_MASK(8);
 542
 543         if (!of_property_read_u32(np, "num-cs", &num_cs))
 544                 master->num_chipselect = num_cs;
 545
 546         qspi = spi_master_get_devdata(master);
 547         qspi->master = master;
 548         qspi->dev = &pdev->dev;
 549         platform_set_drvdata(pdev, qspi);
 550
 551         r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi_base");
 552         if (r == NULL) {
 553                 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 554                 if (r == NULL) {
 555                         dev_err(&pdev->dev, "missing platform data\n");
 556                         return -ENODEV;
 557                 }
 558         }
 559
 560         res_mmap = platform_get_resource_byname(pdev,
 561                         IORESOURCE_MEM, "qspi_mmap");
 562         if (res_mmap == NULL) {
 563                 res_mmap = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 564                 if (res_mmap == NULL) {
 565                         dev_err(&pdev->dev,
 566                                 "memory mapped resource not required\n");
 567                 }
 568         }
 569
 570         irq = platform_get_irq(pdev, 0);
 571         if (irq < 0) {
 572                 dev_err(&pdev->dev, "no irq resource?\n");
 573                 return irq;
 574         }
 575
 576         mutex_init(&qspi->list_lock);
 577
 578         qspi->base = devm_ioremap_resource(&pdev->dev, r);
 579         if (IS_ERR(qspi->base)) {
 580                 ret = PTR_ERR(qspi->base);
 581                 goto free_master;
 582         }
 583
 584         if (res_mmap) {
 585                 qspi->mmap_base = devm_ioremap_resource(&pdev->dev,
 586                                                         res_mmap);
 587                 master->spi_flash_read = ti_qspi_spi_flash_read;
 588                 if (IS_ERR(qspi->mmap_base)) {
 589                         dev_err(&pdev->dev,
 590                                 "falling back to PIO mode\n");
 591                         master->spi_flash_read = NULL;
 592                 }
 593         }
 594         qspi->mmap_enabled = false;
 595
 596         if (of_property_read_bool(np, "syscon-chipselects")) {
 597                 qspi->ctrl_base =
 598                 syscon_regmap_lookup_by_phandle(np,
 599                                                 "syscon-chipselects");
 600                 if (IS_ERR(qspi->ctrl_base))
 601                         return PTR_ERR(qspi->ctrl_base);
 602                 ret = of_property_read_u32_index(np,
 603                                                  "syscon-chipselects",
 604                                                  1, &qspi->ctrl_reg);
 605                 if (ret) {
 606                         dev_err(&pdev->dev,
 607                                 "couldn't get ctrl_mod reg index\n");
 608                         return ret;
 609                 }
 610         }
 611
 612         qspi->fclk = devm_clk_get(&pdev->dev, "fck");
 613         if (IS_ERR(qspi->fclk)) {
 614                 ret = PTR_ERR(qspi->fclk);
 615                 dev_err(&pdev->dev, "could not get clk: %d\n", ret);
 616         }
 617
 618         pm_runtime_use_autosuspend(&pdev->dev);
 619         pm_runtime_set_autosuspend_delay(&pdev->dev, QSPI_AUTOSUSPEND_TIMEOUT);
 620         pm_runtime_enable(&pdev->dev);
 621
 622         if (!of_property_read_u32(np, "spi-max-frequency", &max_freq))
 623                 qspi->spi_max_frequency = max_freq;
 624
 625         ret = devm_spi_register_master(&pdev->dev, master);
 626         if (ret)
 627                 goto free_master;
 628
 629         return 0;
 630
 631 free_master:
 632         spi_master_put(master);
 633         return ret;
 634 }
 635
 636 static int ti_qspi_remove(struct platform_device *pdev)
 637 {
 638         pm_runtime_put_sync(&pdev->dev);
 639         pm_runtime_disable(&pdev->dev);
 640
 641         return 0;
 642 }
 643
 644 static const struct dev_pm_ops ti_qspi_pm_ops = {
 645         .runtime_resume = ti_qspi_runtime_resume,
 646 };
 647
 648 static struct platform_driver ti_qspi_driver = {
 649         .probe  = ti_qspi_probe,
 650         .remove = ti_qspi_remove,
 651         .driver = {
 652                 .name   = "ti-qspi",
 653                 .pm =   &ti_qspi_pm_ops,
 654                 .of_match_table = ti_qspi_match,
 655         }
 656 };
 657
 658 module_platform_driver(ti_qspi_driver);
 659
 660 MODULE_AUTHOR("Sourav Poddar <sourav.poddar@ti.com>");
 661 MODULE_LICENSE("GPL v2");
 662 MODULE_DESCRIPTION("TI QSPI controller driver");
 663 MODULE_ALIAS("platform:ti-qspi");