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         struct completion       transfer_complete;
  43
  44         /* list synchronization */
  45         struct mutex            list_lock;
  46
  47         struct spi_master       *master;
  48         void __iomem            *base;
  49         void __iomem            *ctrl_base;
  50         void __iomem            *mmap_base;
  51         struct clk              *fclk;
  52         struct device           *dev;
  53
  54         struct ti_qspi_regs     ctx_reg;
  55
  56         u32 spi_max_frequency;
  57         u32 cmd;
  58         u32 dc;
  59
  60         bool ctrl_mod;
  61 };
  62
  63 #define QSPI_PID                        (0x0)
  64 #define QSPI_SYSCONFIG                  (0x10)
  65 #define QSPI_INTR_STATUS_RAW_SET        (0x20)
  66 #define QSPI_INTR_STATUS_ENABLED_CLEAR  (0x24)
  67 #define QSPI_INTR_ENABLE_SET_REG        (0x28)
  68 #define QSPI_INTR_ENABLE_CLEAR_REG      (0x2c)
  69 #define QSPI_SPI_CLOCK_CNTRL_REG        (0x40)
  70 #define QSPI_SPI_DC_REG                 (0x44)
  71 #define QSPI_SPI_CMD_REG                (0x48)
  72 #define QSPI_SPI_STATUS_REG             (0x4c)
  73 #define QSPI_SPI_DATA_REG               (0x50)
  74 #define QSPI_SPI_SETUP0_REG             (0x54)
  75 #define QSPI_SPI_SWITCH_REG             (0x64)
  76 #define QSPI_SPI_SETUP1_REG             (0x58)
  77 #define QSPI_SPI_SETUP2_REG             (0x5c)
  78 #define QSPI_SPI_SETUP3_REG             (0x60)
  79 #define QSPI_SPI_DATA_REG_1             (0x68)
  80 #define QSPI_SPI_DATA_REG_2             (0x6c)
  81 #define QSPI_SPI_DATA_REG_3             (0x70)
  82
  83 #define QSPI_COMPLETION_TIMEOUT         msecs_to_jiffies(2000)
  84
  85 #define QSPI_FCLK                       192000000
  86
  87 /* Clock Control */
  88 #define QSPI_CLK_EN                     (1 << 31)
  89 #define QSPI_CLK_DIV_MAX                0xffff
  90
  91 /* Command */
  92 #define QSPI_EN_CS(n)                   (n << 28)
  93 #define QSPI_WLEN(n)                    ((n - 1) << 19)
  94 #define QSPI_3_PIN                      (1 << 18)
  95 #define QSPI_RD_SNGL                    (1 << 16)
  96 #define QSPI_WR_SNGL                    (2 << 16)
  97 #define QSPI_RD_DUAL                    (3 << 16)
  98 #define QSPI_RD_QUAD                    (7 << 16)
  99 #define QSPI_INVAL                      (4 << 16)
 100 #define QSPI_WC_CMD_INT_EN                      (1 << 14)
 101 #define QSPI_FLEN(n)                    ((n - 1) << 0)
 102
 103 /* STATUS REGISTER */
 104 #define BUSY                            0x01
 105 #define WC                              0x02
 106
 107 /* INTERRUPT REGISTER */
 108 #define QSPI_WC_INT_EN                          (1 << 1)
 109 #define QSPI_WC_INT_DISABLE                     (1 << 1)
 110
 111 /* Device Control */
 112 #define QSPI_DD(m, n)                   (m << (3 + n * 8))
 113 #define QSPI_CKPHA(n)                   (1 << (2 + n * 8))
 114 #define QSPI_CSPOL(n)                   (1 << (1 + n * 8))
 115 #define QSPI_CKPOL(n)                   (1 << (n * 8))
 116
 117 #define QSPI_FRAME                      4096
 118
 119 #define QSPI_AUTOSUSPEND_TIMEOUT         2000
 120
 121 static inline unsigned long ti_qspi_read(struct ti_qspi *qspi,
 122                 unsigned long reg)
 123 {
 124         return readl(qspi->base + reg);
 125 }
 126
 127 static inline void ti_qspi_write(struct ti_qspi *qspi,
 128                 unsigned long val, unsigned long reg)
 129 {
 130         writel(val, qspi->base + reg);
 131 }
 132
 133 static int ti_qspi_setup(struct spi_device *spi)
 134 {
 135         struct ti_qspi  *qspi = spi_master_get_devdata(spi->master);
 136         struct ti_qspi_regs *ctx_reg = &qspi->ctx_reg;
 137         int clk_div = 0, ret;
 138         u32 clk_ctrl_reg, clk_rate, clk_mask;
 139
 140         if (spi->master->busy) {
 141                 dev_dbg(qspi->dev, "master busy doing other trasnfers\n");
 142                 return -EBUSY;
 143         }
 144
 145         if (!qspi->spi_max_frequency) {
 146                 dev_err(qspi->dev, "spi max frequency not defined\n");
 147                 return -EINVAL;
 148         }
 149
 150         clk_rate = clk_get_rate(qspi->fclk);
 151
 152         clk_div = DIV_ROUND_UP(clk_rate, qspi->spi_max_frequency) - 1;
 153
 154         if (clk_div < 0) {
 155                 dev_dbg(qspi->dev, "clock divider < 0, using /1 divider\n");
 156                 return -EINVAL;
 157         }
 158
 159         if (clk_div > QSPI_CLK_DIV_MAX) {
 160                 dev_dbg(qspi->dev, "clock divider >%d , using /%d divider\n",
 161                                 QSPI_CLK_DIV_MAX, QSPI_CLK_DIV_MAX + 1);
 162                 return -EINVAL;
 163         }
 164
 165         dev_dbg(qspi->dev, "hz: %d, clock divider %d\n",
 166                         qspi->spi_max_frequency, clk_div);
 167
 168         ret = pm_runtime_get_sync(qspi->dev);
 169         if (ret < 0) {
 170                 dev_err(qspi->dev, "pm_runtime_get_sync() failed\n");
 171                 return ret;
 172         }
 173
 174         clk_ctrl_reg = ti_qspi_read(qspi, QSPI_SPI_CLOCK_CNTRL_REG);
 175
 176         clk_ctrl_reg &= ~QSPI_CLK_EN;
 177
 178         /* disable SCLK */
 179         ti_qspi_write(qspi, clk_ctrl_reg, QSPI_SPI_CLOCK_CNTRL_REG);
 180
 181         /* enable SCLK */
 182         clk_mask = QSPI_CLK_EN | clk_div;
 183         ti_qspi_write(qspi, clk_mask, QSPI_SPI_CLOCK_CNTRL_REG);
 184         ctx_reg->clkctrl = clk_mask;
 185
 186         pm_runtime_mark_last_busy(qspi->dev);
 187         ret = pm_runtime_put_autosuspend(qspi->dev);
 188         if (ret < 0) {
 189                 dev_err(qspi->dev, "pm_runtime_put_autosuspend() failed\n");
 190                 return ret;
 191         }
 192
 193         return 0;
 194 }
 195
 196 static void ti_qspi_restore_ctx(struct ti_qspi *qspi)
 197 {
 198         struct ti_qspi_regs *ctx_reg = &qspi->ctx_reg;
 199
 200         ti_qspi_write(qspi, ctx_reg->clkctrl, QSPI_SPI_CLOCK_CNTRL_REG);
 201 }
 202
 203 static inline u32 qspi_is_busy(struct ti_qspi *qspi)
 204 {
 205         u32 stat;
 206         unsigned long timeout = jiffies + QSPI_COMPLETION_TIMEOUT;
 207
 208         stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
 209         while ((stat & BUSY) && time_after(timeout, jiffies)) {
 210                 cpu_relax();
 211                 stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
 212         }
 213
 214         WARN(stat & BUSY, "qspi busy\n");
 215         return stat & BUSY;
 216 }
 217
 218 static int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t)
 219 {
 220         int wlen, count;
 221         unsigned int cmd;
 222         const u8 *txbuf;
 223
 224         txbuf = t->tx_buf;
 225         cmd = qspi->cmd | QSPI_WR_SNGL;
 226         count = t->len;
 227         wlen = t->bits_per_word >> 3;   /* in bytes */
 228
 229         while (count) {
 230                 if (qspi_is_busy(qspi))
 231                         return -EBUSY;
 232
 233                 switch (wlen) {
 234                 case 1:
 235                         dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %02x\n",
 236                                         cmd, qspi->dc, *txbuf);
 237                         writeb(*txbuf, qspi->base + QSPI_SPI_DATA_REG);
 238                         break;
 239                 case 2:
 240                         dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %04x\n",
 241                                         cmd, qspi->dc, *txbuf);
 242                         writew(*((u16 *)txbuf), qspi->base + QSPI_SPI_DATA_REG);
 243                         break;
 244                 case 4:
 245                         dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %08x\n",
 246                                         cmd, qspi->dc, *txbuf);
 247                         writel(*((u32 *)txbuf), qspi->base + QSPI_SPI_DATA_REG);
 248                         break;
 249                 }
 250
 251                 ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
 252                 if (!wait_for_completion_timeout(&qspi->transfer_complete,
 253                                                  QSPI_COMPLETION_TIMEOUT)) {
 254                         dev_err(qspi->dev, "write timed out\n");
 255                         return -ETIMEDOUT;
 256                 }
 257                 txbuf += wlen;
 258                 count -= wlen;
 259         }
 260
 261         return 0;
 262 }
 263
 264 static int qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t)
 265 {
 266         int wlen, count;
 267         unsigned int cmd;
 268         u8 *rxbuf;
 269
 270         rxbuf = t->rx_buf;
 271         cmd = qspi->cmd;
 272         switch (t->rx_nbits) {
 273         case SPI_NBITS_DUAL:
 274                 cmd |= QSPI_RD_DUAL;
 275                 break;
 276         case SPI_NBITS_QUAD:
 277                 cmd |= QSPI_RD_QUAD;
 278                 break;
 279         default:
 280                 cmd |= QSPI_RD_SNGL;
 281                 break;
 282         }
 283         count = t->len;
 284         wlen = t->bits_per_word >> 3;   /* in bytes */
 285
 286         while (count) {
 287                 dev_dbg(qspi->dev, "rx cmd %08x dc %08x\n", cmd, qspi->dc);
 288                 if (qspi_is_busy(qspi))
 289                         return -EBUSY;
 290
 291                 ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
 292                 if (!wait_for_completion_timeout(&qspi->transfer_complete,
 293                                                  QSPI_COMPLETION_TIMEOUT)) {
 294                         dev_err(qspi->dev, "read timed out\n");
 295                         return -ETIMEDOUT;
 296                 }
 297                 switch (wlen) {
 298                 case 1:
 299                         *rxbuf = readb(qspi->base + QSPI_SPI_DATA_REG);
 300                         break;
 301                 case 2:
 302                         *((u16 *)rxbuf) = readw(qspi->base + QSPI_SPI_DATA_REG);
 303                         break;
 304                 case 4:
 305                         *((u32 *)rxbuf) = readl(qspi->base + QSPI_SPI_DATA_REG);
 306                         break;
 307                 }
 308                 rxbuf += wlen;
 309                 count -= wlen;
 310         }
 311
 312         return 0;
 313 }
 314
 315 static int qspi_transfer_msg(struct ti_qspi *qspi, struct spi_transfer *t)
 316 {
 317         int ret;
 318
 319         if (t->tx_buf) {
 320                 ret = qspi_write_msg(qspi, t);
 321                 if (ret) {
 322                         dev_dbg(qspi->dev, "Error while writing\n");
 323                         return ret;
 324                 }
 325         }
 326
 327         if (t->rx_buf) {
 328                 ret = qspi_read_msg(qspi, t);
 329                 if (ret) {
 330                         dev_dbg(qspi->dev, "Error while reading\n");
 331                         return ret;
 332                 }
 333         }
 334
 335         return 0;
 336 }
 337
 338 static int ti_qspi_start_transfer_one(struct spi_master *master,
 339                 struct spi_message *m)
 340 {
 341         struct ti_qspi *qspi = spi_master_get_devdata(master);
 342         struct spi_device *spi = m->spi;
 343         struct spi_transfer *t;
 344         int status = 0, ret;
 345         int frame_length;
 346
 347         /* setup device control reg */
 348         qspi->dc = 0;
 349
 350         if (spi->mode & SPI_CPHA)
 351                 qspi->dc |= QSPI_CKPHA(spi->chip_select);
 352         if (spi->mode & SPI_CPOL)
 353                 qspi->dc |= QSPI_CKPOL(spi->chip_select);
 354         if (spi->mode & SPI_CS_HIGH)
 355                 qspi->dc |= QSPI_CSPOL(spi->chip_select);
 356
 357         frame_length = (m->frame_length << 3) / spi->bits_per_word;
 358
 359         frame_length = clamp(frame_length, 0, QSPI_FRAME);
 360
 361         /* setup command reg */
 362         qspi->cmd = 0;
 363         qspi->cmd |= QSPI_EN_CS(spi->chip_select);
 364         qspi->cmd |= QSPI_FLEN(frame_length);
 365         qspi->cmd |= QSPI_WC_CMD_INT_EN;
 366
 367         ti_qspi_write(qspi, QSPI_WC_INT_EN, QSPI_INTR_ENABLE_SET_REG);
 368         ti_qspi_write(qspi, qspi->dc, QSPI_SPI_DC_REG);
 369
 370         mutex_lock(&qspi->list_lock);
 371
 372         list_for_each_entry(t, &m->transfers, transfer_list) {
 373                 qspi->cmd |= QSPI_WLEN(t->bits_per_word);
 374
 375                 ret = qspi_transfer_msg(qspi, t);
 376                 if (ret) {
 377                         dev_dbg(qspi->dev, "transfer message failed\n");
 378                         mutex_unlock(&qspi->list_lock);
 379                         return -EINVAL;
 380                 }
 381
 382                 m->actual_length += t->len;
 383         }
 384
 385         mutex_unlock(&qspi->list_lock);
 386
 387         m->status = status;
 388         spi_finalize_current_message(master);
 389
 390         ti_qspi_write(qspi, qspi->cmd | QSPI_INVAL, QSPI_SPI_CMD_REG);
 391
 392         return status;
 393 }
 394
 395 static irqreturn_t ti_qspi_isr(int irq, void *dev_id)
 396 {
 397         struct ti_qspi *qspi = dev_id;
 398         u16 int_stat;
 399         u32 stat;
 400
 401         irqreturn_t ret = IRQ_HANDLED;
 402
 403         int_stat = ti_qspi_read(qspi, QSPI_INTR_STATUS_ENABLED_CLEAR);
 404         stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
 405
 406         if (!int_stat) {
 407                 dev_dbg(qspi->dev, "No IRQ triggered\n");
 408                 ret = IRQ_NONE;
 409                 goto out;
 410         }
 411
 412         ti_qspi_write(qspi, QSPI_WC_INT_DISABLE,
 413                                 QSPI_INTR_STATUS_ENABLED_CLEAR);
 414         if (stat & WC)
 415                 complete(&qspi->transfer_complete);
 416 out:
 417         return ret;
 418 }
 419
 420 static int ti_qspi_runtime_resume(struct device *dev)
 421 {
 422         struct ti_qspi      *qspi;
 423
 424         qspi = dev_get_drvdata(dev);
 425         ti_qspi_restore_ctx(qspi);
 426
 427         return 0;
 428 }
 429
 430 static const struct of_device_id ti_qspi_match[] = {
 431         {.compatible = "ti,dra7xxx-qspi" },
 432         {.compatible = "ti,am4372-qspi" },
 433         {},
 434 };
 435 MODULE_DEVICE_TABLE(of, ti_qspi_match);
 436
 437 static int ti_qspi_probe(struct platform_device *pdev)
 438 {
 439         struct  ti_qspi *qspi;
 440         struct spi_master *master;
 441         struct resource         *r, *res_ctrl, *res_mmap;
 442         struct device_node *np = pdev->dev.of_node;
 443         u32 max_freq;
 444         int ret = 0, num_cs, irq;
 445
 446         master = spi_alloc_master(&pdev->dev, sizeof(*qspi));
 447         if (!master)
 448                 return -ENOMEM;
 449
 450         master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_RX_DUAL | SPI_RX_QUAD;
 451
 452         master->flags = SPI_MASTER_HALF_DUPLEX;
 453         master->setup = ti_qspi_setup;
 454         master->auto_runtime_pm = true;
 455         master->transfer_one_message = ti_qspi_start_transfer_one;
 456         master->dev.of_node = pdev->dev.of_node;
 457         master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
 458                                      SPI_BPW_MASK(8);
 459
 460         if (!of_property_read_u32(np, "num-cs", &num_cs))
 461                 master->num_chipselect = num_cs;
 462
 463         qspi = spi_master_get_devdata(master);
 464         qspi->master = master;
 465         qspi->dev = &pdev->dev;
 466         platform_set_drvdata(pdev, qspi);
 467
 468         r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi_base");
 469         if (r == NULL) {
 470                 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 471                 if (r == NULL) {
 472                         dev_err(&pdev->dev, "missing platform data\n");
 473                         return -ENODEV;
 474                 }
 475         }
 476
 477         res_mmap = platform_get_resource_byname(pdev,
 478                         IORESOURCE_MEM, "qspi_mmap");
 479         if (res_mmap == NULL) {
 480                 res_mmap = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 481                 if (res_mmap == NULL) {
 482                         dev_err(&pdev->dev,
 483                                 "memory mapped resource not required\n");
 484                 }
 485         }
 486
 487         res_ctrl = platform_get_resource_byname(pdev,
 488                         IORESOURCE_MEM, "qspi_ctrlmod");
 489         if (res_ctrl == NULL) {
 490                 res_ctrl = platform_get_resource(pdev, IORESOURCE_MEM, 2);
 491                 if (res_ctrl == NULL) {
 492                         dev_dbg(&pdev->dev,
 493                                 "control module resources not required\n");
 494                 }
 495         }
 496
 497         irq = platform_get_irq(pdev, 0);
 498         if (irq < 0) {
 499                 dev_err(&pdev->dev, "no irq resource?\n");
 500                 return irq;
 501         }
 502
 503         mutex_init(&qspi->list_lock);
 504
 505         qspi->base = devm_ioremap_resource(&pdev->dev, r);
 506         if (IS_ERR(qspi->base)) {
 507                 ret = PTR_ERR(qspi->base);
 508                 goto free_master;
 509         }
 510
 511         if (res_ctrl) {
 512                 qspi->ctrl_mod = true;
 513                 qspi->ctrl_base = devm_ioremap_resource(&pdev->dev, res_ctrl);
 514                 if (IS_ERR(qspi->ctrl_base)) {
 515                         ret = PTR_ERR(qspi->ctrl_base);
 516                         goto free_master;
 517                 }
 518         }
 519
 520         if (res_mmap) {
 521                 qspi->mmap_base = devm_ioremap_resource(&pdev->dev, res_mmap);
 522                 if (IS_ERR(qspi->mmap_base)) {
 523                         ret = PTR_ERR(qspi->mmap_base);
 524                         goto free_master;
 525                 }
 526         }
 527
 528         ret = devm_request_irq(&pdev->dev, irq, ti_qspi_isr, 0,
 529                         dev_name(&pdev->dev), qspi);
 530         if (ret < 0) {
 531                 dev_err(&pdev->dev, "Failed to register ISR for IRQ %d\n",
 532                                 irq);
 533                 goto free_master;
 534         }
 535
 536         qspi->fclk = devm_clk_get(&pdev->dev, "fck");
 537         if (IS_ERR(qspi->fclk)) {
 538                 ret = PTR_ERR(qspi->fclk);
 539                 dev_err(&pdev->dev, "could not get clk: %d\n", ret);
 540         }
 541
 542         init_completion(&qspi->transfer_complete);
 543
 544         pm_runtime_use_autosuspend(&pdev->dev);
 545         pm_runtime_set_autosuspend_delay(&pdev->dev, QSPI_AUTOSUSPEND_TIMEOUT);
 546         pm_runtime_enable(&pdev->dev);
 547
 548         if (!of_property_read_u32(np, "spi-max-frequency", &max_freq))
 549                 qspi->spi_max_frequency = max_freq;
 550
 551         ret = devm_spi_register_master(&pdev->dev, master);
 552         if (ret)
 553                 goto free_master;
 554
 555         return 0;
 556
 557 free_master:
 558         spi_master_put(master);
 559         return ret;
 560 }
 561
 562 static int ti_qspi_remove(struct platform_device *pdev)
 563 {
 564         struct ti_qspi *qspi = platform_get_drvdata(pdev);
 565         int ret;
 566
 567         ret = pm_runtime_get_sync(qspi->dev);
 568         if (ret < 0) {
 569                 dev_err(qspi->dev, "pm_runtime_get_sync() failed\n");
 570                 return ret;
 571         }
 572
 573         ti_qspi_write(qspi, QSPI_WC_INT_DISABLE, QSPI_INTR_ENABLE_CLEAR_REG);
 574
 575         pm_runtime_put(qspi->dev);
 576         pm_runtime_disable(&pdev->dev);
 577
 578         return 0;
 579 }
 580
 581 static const struct dev_pm_ops ti_qspi_pm_ops = {
 582         .runtime_resume = ti_qspi_runtime_resume,
 583 };
 584
 585 static struct platform_driver ti_qspi_driver = {
 586         .probe  = ti_qspi_probe,
 587         .remove = ti_qspi_remove,
 588         .driver = {
 589                 .name   = "ti-qspi",
 590                 .pm =   &ti_qspi_pm_ops,
 591                 .of_match_table = ti_qspi_match,
 592         }
 593 };
 594
 595 module_platform_driver(ti_qspi_driver);
 596
 597 MODULE_AUTHOR("Sourav Poddar <sourav.poddar@ti.com>");
 598 MODULE_LICENSE("GPL v2");
 599 MODULE_DESCRIPTION("TI QSPI controller driver");
 600 MODULE_ALIAS("platform:ti-qspi");