kernel/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
  35 #include <linux/spi/spi.h>
  36
  37 struct ti_qspi_regs {
  38         u32 clkctrl;
  39 };
  40
  41 struct ti_qspi {
  42         /* list synchronization */
  43         struct mutex            list_lock;
  44
  45         struct spi_master       *master;
  46         void __iomem            *base;
  47         void __iomem            *ctrl_base;
  48         void __iomem            *mmap_base;
  49         struct clk              *fclk;
  50         struct device           *dev;
  51
  52         struct ti_qspi_regs     ctx_reg;
  53
  54         u32 spi_max_frequency;
  55         u32 cmd;
  56         u32 dc;
  57
  58         bool ctrl_mod;
  59 };
  60
  61 #define QSPI_PID                        (0x0)
  62 #define QSPI_SYSCONFIG                  (0x10)
  63 #define QSPI_SPI_CLOCK_CNTRL_REG        (0x40)
  64 #define QSPI_SPI_DC_REG                 (0x44)
  65 #define QSPI_SPI_CMD_REG                (0x48)
  66 #define QSPI_SPI_STATUS_REG             (0x4c)
  67 #define QSPI_SPI_DATA_REG               (0x50)
  68 #define QSPI_SPI_SETUP0_REG             (0x54)
  69 #define QSPI_SPI_SWITCH_REG             (0x64)
  70 #define QSPI_SPI_SETUP1_REG             (0x58)
  71 #define QSPI_SPI_SETUP2_REG             (0x5c)
  72 #define QSPI_SPI_SETUP3_REG             (0x60)
  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 static inline unsigned long ti_qspi_read(struct ti_qspi *qspi,
 113                 unsigned long reg)
 114 {
 115         return readl(qspi->base + reg);
 116 }
 117
 118 static inline void ti_qspi_write(struct ti_qspi *qspi,
 119                 unsigned long val, unsigned long reg)
 120 {
 121         writel(val, qspi->base + reg);
 122 }
 123
 124 static int ti_qspi_setup(struct spi_device *spi)
 125 {
 126         struct ti_qspi  *qspi = spi_master_get_devdata(spi->master);
 127         struct ti_qspi_regs *ctx_reg = &qspi->ctx_reg;
 128         int clk_div = 0, ret;
 129         u32 clk_ctrl_reg, clk_rate, clk_mask;
 130
 131         if (spi->master->busy) {
 132                 dev_dbg(qspi->dev, "master busy doing other trasnfers\n");
 133                 return -EBUSY;
 134         }
 135
 136         if (!qspi->spi_max_frequency) {
 137                 dev_err(qspi->dev, "spi max frequency not defined\n");
 138                 return -EINVAL;
 139         }
 140
 141         clk_rate = clk_get_rate(qspi->fclk);
 142
 143         clk_div = DIV_ROUND_UP(clk_rate, qspi->spi_max_frequency) - 1;
 144
 145         if (clk_div < 0) {
 146                 dev_dbg(qspi->dev, "clock divider < 0, using /1 divider\n");
 147                 return -EINVAL;
 148         }
 149
 150         if (clk_div > QSPI_CLK_DIV_MAX) {
 151                 dev_dbg(qspi->dev, "clock divider >%d , using /%d divider\n",
 152                                 QSPI_CLK_DIV_MAX, QSPI_CLK_DIV_MAX + 1);
 153                 return -EINVAL;
 154         }
 155
 156         dev_dbg(qspi->dev, "hz: %d, clock divider %d\n",
 157                         qspi->spi_max_frequency, clk_div);
 158
 159         ret = pm_runtime_get_sync(qspi->dev);
 160         if (ret < 0) {
 161                 dev_err(qspi->dev, "pm_runtime_get_sync() failed\n");
 162                 return ret;
 163         }
 164
 165         clk_ctrl_reg = ti_qspi_read(qspi, QSPI_SPI_CLOCK_CNTRL_REG);
 166
 167         clk_ctrl_reg &= ~QSPI_CLK_EN;
 168
 169         /* disable SCLK */
 170         ti_qspi_write(qspi, clk_ctrl_reg, QSPI_SPI_CLOCK_CNTRL_REG);
 171
 172         /* enable SCLK */
 173         clk_mask = QSPI_CLK_EN | clk_div;
 174         ti_qspi_write(qspi, clk_mask, QSPI_SPI_CLOCK_CNTRL_REG);
 175         ctx_reg->clkctrl = clk_mask;
 176
 177         pm_runtime_mark_last_busy(qspi->dev);
 178         ret = pm_runtime_put_autosuspend(qspi->dev);
 179         if (ret < 0) {
 180                 dev_err(qspi->dev, "pm_runtime_put_autosuspend() failed\n");
 181                 return ret;
 182         }
 183
 184         return 0;
 185 }
 186
 187 static void ti_qspi_restore_ctx(struct ti_qspi *qspi)
 188 {
 189         struct ti_qspi_regs *ctx_reg = &qspi->ctx_reg;
 190
 191         ti_qspi_write(qspi, ctx_reg->clkctrl, QSPI_SPI_CLOCK_CNTRL_REG);
 192 }
 193
 194 static inline u32 qspi_is_busy(struct ti_qspi *qspi)
 195 {
 196         u32 stat;
 197         unsigned long timeout = jiffies + QSPI_COMPLETION_TIMEOUT;
 198
 199         stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
 200         while ((stat & BUSY) && time_after(timeout, jiffies)) {
 201                 cpu_relax();
 202                 stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
 203         }
 204
 205         WARN(stat & BUSY, "qspi busy\n");
 206         return stat & BUSY;
 207 }
 208
 209 static inline int ti_qspi_poll_wc(struct ti_qspi *qspi)
 210 {
 211         u32 stat;
 212         unsigned long timeout = jiffies + QSPI_COMPLETION_TIMEOUT;
 213
 214         do {
 215                 stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
 216                 if (stat & WC)
 217                         return 0;
 218                 cpu_relax();
 219         } while (time_after(timeout, jiffies));
 220
 221         stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
 222         if (stat & WC)
 223                 return 0;
 224         return  -ETIMEDOUT;
 225 }
 226
 227 static int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t)
 228 {
 229         int wlen, count, xfer_len;
 230         unsigned int cmd;
 231         const u8 *txbuf;
 232         u32 data;
 233
 234         txbuf = t->tx_buf;
 235         cmd = qspi->cmd | QSPI_WR_SNGL;
 236         count = t->len;
 237         wlen = t->bits_per_word >> 3;   /* in bytes */
 238         xfer_len = wlen;
 239
 240         while (count) {
 241                 if (qspi_is_busy(qspi))
 242                         return -EBUSY;
 243
 244                 switch (wlen) {
 245                 case 1:
 246                         dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %02x\n",
 247                                         cmd, qspi->dc, *txbuf);
 248                         if (count >= QSPI_WLEN_MAX_BYTES) {
 249                                 u32 *txp = (u32 *)txbuf;
 250
 251                                 data = cpu_to_be32(*txp++);
 252                                 writel(data, qspi->base +
 253                                        QSPI_SPI_DATA_REG_3);
 254                                 data = cpu_to_be32(*txp++);
 255                                 writel(data, qspi->base +
 256                                        QSPI_SPI_DATA_REG_2);
 257                                 data = cpu_to_be32(*txp++);
 258                                 writel(data, qspi->base +
 259                                        QSPI_SPI_DATA_REG_1);
 260                                 data = cpu_to_be32(*txp++);
 261                                 writel(data, qspi->base +
 262                                        QSPI_SPI_DATA_REG);
 263                                 xfer_len = QSPI_WLEN_MAX_BYTES;
 264                                 cmd |= QSPI_WLEN(QSPI_WLEN_MAX_BITS);
 265                         } else {
 266                                 writeb(*txbuf, qspi->base + QSPI_SPI_DATA_REG);
 267                                 cmd = qspi->cmd | QSPI_WR_SNGL;
 268                                 xfer_len = wlen;
 269                                 cmd |= QSPI_WLEN(wlen);
 270                         }
 271                         break;
 272                 case 2:
 273                         dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %04x\n",
 274                                         cmd, qspi->dc, *txbuf);
 275                         writew(*((u16 *)txbuf), qspi->base + QSPI_SPI_DATA_REG);
 276                         break;
 277                 case 4:
 278                         dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %08x\n",
 279                                         cmd, qspi->dc, *txbuf);
 280                         writel(*((u32 *)txbuf), qspi->base + QSPI_SPI_DATA_REG);
 281                         break;
 282                 }
 283
 284                 ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
 285                 if (ti_qspi_poll_wc(qspi)) {
 286                         dev_err(qspi->dev, "write timed out\n");
 287                         return -ETIMEDOUT;
 288                 }
 289                 txbuf += xfer_len;
 290                 count -= xfer_len;
 291         }
 292
 293         return 0;
 294 }
 295
 296 static int qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t)
 297 {
 298         int wlen, count;
 299         unsigned int cmd;
 300         u8 *rxbuf;
 301
 302         rxbuf = t->rx_buf;
 303         cmd = qspi->cmd;
 304         switch (t->rx_nbits) {
 305         case SPI_NBITS_DUAL:
 306                 cmd |= QSPI_RD_DUAL;
 307                 break;
 308         case SPI_NBITS_QUAD:
 309                 cmd |= QSPI_RD_QUAD;
 310                 break;
 311         default:
 312                 cmd |= QSPI_RD_SNGL;
 313                 break;
 314         }
 315         count = t->len;
 316         wlen = t->bits_per_word >> 3;   /* in bytes */
 317
 318         while (count) {
 319                 dev_dbg(qspi->dev, "rx cmd %08x dc %08x\n", cmd, qspi->dc);
 320                 if (qspi_is_busy(qspi))
 321                         return -EBUSY;
 322
 323                 ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
 324                 if (ti_qspi_poll_wc(qspi)) {
 325                         dev_err(qspi->dev, "read timed out\n");
 326                         return -ETIMEDOUT;
 327                 }
 328                 switch (wlen) {
 329                 case 1:
 330                         *rxbuf = readb(qspi->base + QSPI_SPI_DATA_REG);
 331                         break;
 332                 case 2:
 333                         *((u16 *)rxbuf) = readw(qspi->base + QSPI_SPI_DATA_REG);
 334                         break;
 335                 case 4:
 336                         *((u32 *)rxbuf) = readl(qspi->base + QSPI_SPI_DATA_REG);
 337                         break;
 338                 }
 339                 rxbuf += wlen;
 340                 count -= wlen;
 341         }
 342
 343         return 0;
 344 }
 345
 346 static int qspi_transfer_msg(struct ti_qspi *qspi, struct spi_transfer *t)
 347 {
 348         int ret;
 349
 350         if (t->tx_buf) {
 351                 ret = qspi_write_msg(qspi, t);
 352                 if (ret) {
 353                         dev_dbg(qspi->dev, "Error while writing\n");
 354                         return ret;
 355                 }
 356         }
 357
 358         if (t->rx_buf) {
 359                 ret = qspi_read_msg(qspi, t);
 360                 if (ret) {
 361                         dev_dbg(qspi->dev, "Error while reading\n");
 362                         return ret;
 363                 }
 364         }
 365
 366         return 0;
 367 }
 368
 369 static int ti_qspi_start_transfer_one(struct spi_master *master,
 370                 struct spi_message *m)
 371 {
 372         struct ti_qspi *qspi = spi_master_get_devdata(master);
 373         struct spi_device *spi = m->spi;
 374         struct spi_transfer *t;
 375         int status = 0, ret;
 376         int frame_length;
 377
 378         /* setup device control reg */
 379         qspi->dc = 0;
 380
 381         if (spi->mode & SPI_CPHA)
 382                 qspi->dc |= QSPI_CKPHA(spi->chip_select);
 383         if (spi->mode & SPI_CPOL)
 384                 qspi->dc |= QSPI_CKPOL(spi->chip_select);
 385         if (spi->mode & SPI_CS_HIGH)
 386                 qspi->dc |= QSPI_CSPOL(spi->chip_select);
 387
 388         frame_length = (m->frame_length << 3) / spi->bits_per_word;
 389
 390         frame_length = clamp(frame_length, 0, QSPI_FRAME);
 391
 392         /* setup command reg */
 393         qspi->cmd = 0;
 394         qspi->cmd |= QSPI_EN_CS(spi->chip_select);
 395         qspi->cmd |= QSPI_FLEN(frame_length);
 396
 397         ti_qspi_write(qspi, qspi->dc, QSPI_SPI_DC_REG);
 398
 399         mutex_lock(&qspi->list_lock);
 400
 401         list_for_each_entry(t, &m->transfers, transfer_list) {
 402                 qspi->cmd |= QSPI_WLEN(t->bits_per_word);
 403
 404                 ret = qspi_transfer_msg(qspi, t);
 405                 if (ret) {
 406                         dev_dbg(qspi->dev, "transfer message failed\n");
 407                         mutex_unlock(&qspi->list_lock);
 408                         return -EINVAL;
 409                 }
 410
 411                 m->actual_length += t->len;
 412         }
 413
 414         mutex_unlock(&qspi->list_lock);
 415
 416         ti_qspi_write(qspi, qspi->cmd | QSPI_INVAL, QSPI_SPI_CMD_REG);
 417         m->status = status;
 418         spi_finalize_current_message(master);
 419
 420         return status;
 421 }
 422
 423 static int ti_qspi_runtime_resume(struct device *dev)
 424 {
 425         struct ti_qspi      *qspi;
 426
 427         qspi = dev_get_drvdata(dev);
 428         ti_qspi_restore_ctx(qspi);
 429
 430         return 0;
 431 }
 432
 433 static const struct of_device_id ti_qspi_match[] = {
 434         {.compatible = "ti,dra7xxx-qspi" },
 435         {.compatible = "ti,am4372-qspi" },
 436         {},
 437 };
 438 MODULE_DEVICE_TABLE(of, ti_qspi_match);
 439
 440 static int ti_qspi_probe(struct platform_device *pdev)
 441 {
 442         struct  ti_qspi *qspi;
 443         struct spi_master *master;
 444         struct resource         *r, *res_ctrl, *res_mmap;
 445         struct device_node *np = pdev->dev.of_node;
 446         u32 max_freq;
 447         int ret = 0, num_cs, irq;
 448
 449         master = spi_alloc_master(&pdev->dev, sizeof(*qspi));
 450         if (!master)
 451                 return -ENOMEM;
 452
 453         master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_RX_DUAL | SPI_RX_QUAD;
 454
 455         master->flags = SPI_MASTER_HALF_DUPLEX;
 456         master->setup = ti_qspi_setup;
 457         master->auto_runtime_pm = true;
 458         master->transfer_one_message = ti_qspi_start_transfer_one;
 459         master->dev.of_node = pdev->dev.of_node;
 460         master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
 461                                      SPI_BPW_MASK(8);
 462
 463         if (!of_property_read_u32(np, "num-cs", &num_cs))
 464                 master->num_chipselect = num_cs;
 465
 466         qspi = spi_master_get_devdata(master);
 467         qspi->master = master;
 468         qspi->dev = &pdev->dev;
 469         platform_set_drvdata(pdev, qspi);
 470
 471         r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi_base");
 472         if (r == NULL) {
 473                 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 474                 if (r == NULL) {
 475                         dev_err(&pdev->dev, "missing platform data\n");
 476                         return -ENODEV;
 477                 }
 478         }
 479
 480         res_mmap = platform_get_resource_byname(pdev,
 481                         IORESOURCE_MEM, "qspi_mmap");
 482         if (res_mmap == NULL) {
 483                 res_mmap = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 484                 if (res_mmap == NULL) {
 485                         dev_err(&pdev->dev,
 486                                 "memory mapped resource not required\n");
 487                 }
 488         }
 489
 490         res_ctrl = platform_get_resource_byname(pdev,
 491                         IORESOURCE_MEM, "qspi_ctrlmod");
 492         if (res_ctrl == NULL) {
 493                 res_ctrl = platform_get_resource(pdev, IORESOURCE_MEM, 2);
 494                 if (res_ctrl == NULL) {
 495                         dev_dbg(&pdev->dev,
 496                                 "control module resources not required\n");
 497                 }
 498         }
 499
 500         irq = platform_get_irq(pdev, 0);
 501         if (irq < 0) {
 502                 dev_err(&pdev->dev, "no irq resource?\n");
 503                 return irq;
 504         }
 505
 506         mutex_init(&qspi->list_lock);
 507
 508         qspi->base = devm_ioremap_resource(&pdev->dev, r);
 509         if (IS_ERR(qspi->base)) {
 510                 ret = PTR_ERR(qspi->base);
 511                 goto free_master;
 512         }
 513
 514         if (res_ctrl) {
 515                 qspi->ctrl_mod = true;
 516                 qspi->ctrl_base = devm_ioremap_resource(&pdev->dev, res_ctrl);
 517                 if (IS_ERR(qspi->ctrl_base)) {
 518                         ret = PTR_ERR(qspi->ctrl_base);
 519                         goto free_master;
 520                 }
 521         }
 522
 523         if (res_mmap) {
 524                 qspi->mmap_base = devm_ioremap_resource(&pdev->dev, res_mmap);
 525                 if (IS_ERR(qspi->mmap_base)) {
 526                         ret = PTR_ERR(qspi->mmap_base);
 527                         goto free_master;
 528                 }
 529         }
 530
 531         qspi->fclk = devm_clk_get(&pdev->dev, "fck");
 532         if (IS_ERR(qspi->fclk)) {
 533                 ret = PTR_ERR(qspi->fclk);
 534                 dev_err(&pdev->dev, "could not get clk: %d\n", ret);
 535         }
 536
 537         pm_runtime_use_autosuspend(&pdev->dev);
 538         pm_runtime_set_autosuspend_delay(&pdev->dev, QSPI_AUTOSUSPEND_TIMEOUT);
 539         pm_runtime_enable(&pdev->dev);
 540
 541         if (!of_property_read_u32(np, "spi-max-frequency", &max_freq))
 542                 qspi->spi_max_frequency = max_freq;
 543
 544         ret = devm_spi_register_master(&pdev->dev, master);
 545         if (ret)
 546                 goto free_master;
 547
 548         return 0;
 549
 550 free_master:
 551         spi_master_put(master);
 552         return ret;
 553 }
 554
 555 static int ti_qspi_remove(struct platform_device *pdev)
 556 {
 557         pm_runtime_put_sync(&pdev->dev);
 558         pm_runtime_disable(&pdev->dev);
 559
 560         return 0;
 561 }
 562
 563 static const struct dev_pm_ops ti_qspi_pm_ops = {
 564         .runtime_resume = ti_qspi_runtime_resume,
 565 };
 566
 567 static struct platform_driver ti_qspi_driver = {
 568         .probe  = ti_qspi_probe,
 569         .remove = ti_qspi_remove,
 570         .driver = {
 571                 .name   = "ti-qspi",
 572                 .pm =   &ti_qspi_pm_ops,
 573                 .of_match_table = ti_qspi_match,
 574         }
 575 };
 576
 577 module_platform_driver(ti_qspi_driver);
 578
 579 MODULE_AUTHOR("Sourav Poddar <sourav.poddar@ti.com>");
 580 MODULE_LICENSE("GPL v2");
 581 MODULE_DESCRIPTION("TI QSPI controller driver");
 582 MODULE_ALIAS("platform:ti-qspi");