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