drivers/spi/spi-sh.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * SH SPI bus driver
   4  *
   5  * Copyright (C) 2011  Renesas Solutions Corp.
   6  *
   7  * Based on pxa2xx_spi.c:
   8  * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/kernel.h>
  13 #include <linux/sched.h>
  14 #include <linux/errno.h>
  15 #include <linux/timer.h>
  16 #include <linux/delay.h>
  17 #include <linux/list.h>
  18 #include <linux/workqueue.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/io.h>
  22 #include <linux/spi/spi.h>
  23
  24 #define SPI_SH_TBR              0x00
  25 #define SPI_SH_RBR              0x00
  26 #define SPI_SH_CR1              0x08
  27 #define SPI_SH_CR2              0x10
  28 #define SPI_SH_CR3              0x18
  29 #define SPI_SH_CR4              0x20
  30 #define SPI_SH_CR5              0x28
  31
  32 /* CR1 */
  33 #define SPI_SH_TBE              0x80
  34 #define SPI_SH_TBF              0x40
  35 #define SPI_SH_RBE              0x20
  36 #define SPI_SH_RBF              0x10
  37 #define SPI_SH_PFONRD           0x08
  38 #define SPI_SH_SSDB             0x04
  39 #define SPI_SH_SSD              0x02
  40 #define SPI_SH_SSA              0x01
  41
  42 /* CR2 */
  43 #define SPI_SH_RSTF             0x80
  44 #define SPI_SH_LOOPBK           0x40
  45 #define SPI_SH_CPOL             0x20
  46 #define SPI_SH_CPHA             0x10
  47 #define SPI_SH_L1M0             0x08
  48
  49 /* CR3 */
  50 #define SPI_SH_MAX_BYTE         0xFF
  51
  52 /* CR4 */
  53 #define SPI_SH_TBEI             0x80
  54 #define SPI_SH_TBFI             0x40
  55 #define SPI_SH_RBEI             0x20
  56 #define SPI_SH_RBFI             0x10
  57 #define SPI_SH_WPABRT           0x04
  58 #define SPI_SH_SSS              0x01
  59
  60 /* CR8 */
  61 #define SPI_SH_P1L0             0x80
  62 #define SPI_SH_PP1L0            0x40
  63 #define SPI_SH_MUXI             0x20
  64 #define SPI_SH_MUXIRQ           0x10
  65
  66 #define SPI_SH_FIFO_SIZE        32
  67 #define SPI_SH_SEND_TIMEOUT     (3 * HZ)
  68 #define SPI_SH_RECEIVE_TIMEOUT  (HZ >> 3)
  69
  70 #undef DEBUG
  71
  72 struct spi_sh_data {
  73         void __iomem *addr;
  74         int irq;
  75         struct spi_master *master;
  76         unsigned long cr1;
  77         wait_queue_head_t wait;
  78         int width;
  79 };
  80
  81 static void spi_sh_write(struct spi_sh_data *ss, unsigned long data,
  82                              unsigned long offset)
  83 {
  84         if (ss->width == 8)
  85                 iowrite8(data, ss->addr + (offset >> 2));
  86         else if (ss->width == 32)
  87                 iowrite32(data, ss->addr + offset);
  88 }
  89
  90 static unsigned long spi_sh_read(struct spi_sh_data *ss, unsigned long offset)
  91 {
  92         if (ss->width == 8)
  93                 return ioread8(ss->addr + (offset >> 2));
  94         else if (ss->width == 32)
  95                 return ioread32(ss->addr + offset);
  96         else
  97                 return 0;
  98 }
  99
 100 static void spi_sh_set_bit(struct spi_sh_data *ss, unsigned long val,
 101                                 unsigned long offset)
 102 {
 103         unsigned long tmp;
 104
 105         tmp = spi_sh_read(ss, offset);
 106         tmp |= val;
 107         spi_sh_write(ss, tmp, offset);
 108 }
 109
 110 static void spi_sh_clear_bit(struct spi_sh_data *ss, unsigned long val,
 111                                 unsigned long offset)
 112 {
 113         unsigned long tmp;
 114
 115         tmp = spi_sh_read(ss, offset);
 116         tmp &= ~val;
 117         spi_sh_write(ss, tmp, offset);
 118 }
 119
 120 static void clear_fifo(struct spi_sh_data *ss)
 121 {
 122         spi_sh_set_bit(ss, SPI_SH_RSTF, SPI_SH_CR2);
 123         spi_sh_clear_bit(ss, SPI_SH_RSTF, SPI_SH_CR2);
 124 }
 125
 126 static int spi_sh_wait_receive_buffer(struct spi_sh_data *ss)
 127 {
 128         int timeout = 100000;
 129
 130         while (spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_RBE) {
 131                 udelay(10);
 132                 if (timeout-- < 0)
 133                         return -ETIMEDOUT;
 134         }
 135         return 0;
 136 }
 137
 138 static int spi_sh_wait_write_buffer_empty(struct spi_sh_data *ss)
 139 {
 140         int timeout = 100000;
 141
 142         while (!(spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_TBE)) {
 143                 udelay(10);
 144                 if (timeout-- < 0)
 145                         return -ETIMEDOUT;
 146         }
 147         return 0;
 148 }
 149
 150 static int spi_sh_send(struct spi_sh_data *ss, struct spi_message *mesg,
 151                         struct spi_transfer *t)
 152 {
 153         int i, retval = 0;
 154         int remain = t->len;
 155         int cur_len;
 156         unsigned char *data;
 157         long ret;
 158
 159         if (t->len)
 160                 spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
 161
 162         data = (unsigned char *)t->tx_buf;
 163         while (remain > 0) {
 164                 cur_len = min(SPI_SH_FIFO_SIZE, remain);
 165                 for (i = 0; i < cur_len &&
 166                                 !(spi_sh_read(ss, SPI_SH_CR4) &
 167                                                         SPI_SH_WPABRT) &&
 168                                 !(spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_TBF);
 169                                 i++)
 170                         spi_sh_write(ss, (unsigned long)data[i], SPI_SH_TBR);
 171
 172                 if (spi_sh_read(ss, SPI_SH_CR4) & SPI_SH_WPABRT) {
 173                         /* Abort SPI operation */
 174                         spi_sh_set_bit(ss, SPI_SH_WPABRT, SPI_SH_CR4);
 175                         retval = -EIO;
 176                         break;
 177                 }
 178
 179                 cur_len = i;
 180
 181                 remain -= cur_len;
 182                 data += cur_len;
 183
 184                 if (remain > 0) {
 185                         ss->cr1 &= ~SPI_SH_TBE;
 186                         spi_sh_set_bit(ss, SPI_SH_TBE, SPI_SH_CR4);
 187                         ret = wait_event_interruptible_timeout(ss->wait,
 188                                                  ss->cr1 & SPI_SH_TBE,
 189                                                  SPI_SH_SEND_TIMEOUT);
 190                         if (ret == 0 && !(ss->cr1 & SPI_SH_TBE)) {
 191                                 printk(KERN_ERR "%s: timeout\n", __func__);
 192                                 return -ETIMEDOUT;
 193                         }
 194                 }
 195         }
 196
 197         if (list_is_last(&t->transfer_list, &mesg->transfers)) {
 198                 spi_sh_clear_bit(ss, SPI_SH_SSD | SPI_SH_SSDB, SPI_SH_CR1);
 199                 spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
 200
 201                 ss->cr1 &= ~SPI_SH_TBE;
 202                 spi_sh_set_bit(ss, SPI_SH_TBE, SPI_SH_CR4);
 203                 ret = wait_event_interruptible_timeout(ss->wait,
 204                                          ss->cr1 & SPI_SH_TBE,
 205                                          SPI_SH_SEND_TIMEOUT);
 206                 if (ret == 0 && (ss->cr1 & SPI_SH_TBE)) {
 207                         printk(KERN_ERR "%s: timeout\n", __func__);
 208                         return -ETIMEDOUT;
 209                 }
 210         }
 211
 212         return retval;
 213 }
 214
 215 static int spi_sh_receive(struct spi_sh_data *ss, struct spi_message *mesg,
 216                           struct spi_transfer *t)
 217 {
 218         int i;
 219         int remain = t->len;
 220         int cur_len;
 221         unsigned char *data;
 222         long ret;
 223
 224         if (t->len > SPI_SH_MAX_BYTE)
 225                 spi_sh_write(ss, SPI_SH_MAX_BYTE, SPI_SH_CR3);
 226         else
 227                 spi_sh_write(ss, t->len, SPI_SH_CR3);
 228
 229         spi_sh_clear_bit(ss, SPI_SH_SSD | SPI_SH_SSDB, SPI_SH_CR1);
 230         spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
 231
 232         spi_sh_wait_write_buffer_empty(ss);
 233
 234         data = (unsigned char *)t->rx_buf;
 235         while (remain > 0) {
 236                 if (remain >= SPI_SH_FIFO_SIZE) {
 237                         ss->cr1 &= ~SPI_SH_RBF;
 238                         spi_sh_set_bit(ss, SPI_SH_RBF, SPI_SH_CR4);
 239                         ret = wait_event_interruptible_timeout(ss->wait,
 240                                                  ss->cr1 & SPI_SH_RBF,
 241                                                  SPI_SH_RECEIVE_TIMEOUT);
 242                         if (ret == 0 &&
 243                             spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_RBE) {
 244                                 printk(KERN_ERR "%s: timeout\n", __func__);
 245                                 return -ETIMEDOUT;
 246                         }
 247                 }
 248
 249                 cur_len = min(SPI_SH_FIFO_SIZE, remain);
 250                 for (i = 0; i < cur_len; i++) {
 251                         if (spi_sh_wait_receive_buffer(ss))
 252                                 break;
 253                         data[i] = (unsigned char)spi_sh_read(ss, SPI_SH_RBR);
 254                 }
 255
 256                 remain -= cur_len;
 257                 data += cur_len;
 258         }
 259
 260         /* deassert CS when SPI is receiving. */
 261         if (t->len > SPI_SH_MAX_BYTE) {
 262                 clear_fifo(ss);
 263                 spi_sh_write(ss, 1, SPI_SH_CR3);
 264         } else {
 265                 spi_sh_write(ss, 0, SPI_SH_CR3);
 266         }
 267
 268         return 0;
 269 }
 270
 271 static int spi_sh_transfer_one_message(struct spi_controller *ctlr,
 272                                         struct spi_message *mesg)
 273 {
 274         struct spi_sh_data *ss = spi_controller_get_devdata(ctlr);
 275         struct spi_transfer *t;
 276         int ret;
 277
 278         pr_debug("%s: enter\n", __func__);
 279
 280         spi_sh_clear_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
 281
 282         list_for_each_entry(t, &mesg->transfers, transfer_list) {
 283                 pr_debug("tx_buf = %p, rx_buf = %p\n",
 284                          t->tx_buf, t->rx_buf);
 285                 pr_debug("len = %d, delay.value = %d\n",
 286                          t->len, t->delay.value);
 287
 288                 if (t->tx_buf) {
 289                         ret = spi_sh_send(ss, mesg, t);
 290                         if (ret < 0)
 291                                 goto error;
 292                 }
 293                 if (t->rx_buf) {
 294                         ret = spi_sh_receive(ss, mesg, t);
 295                         if (ret < 0)
 296                                 goto error;
 297                 }
 298                 mesg->actual_length += t->len;
 299         }
 300
 301         mesg->status = 0;
 302         spi_finalize_current_message(ctlr);
 303
 304         clear_fifo(ss);
 305         spi_sh_set_bit(ss, SPI_SH_SSD, SPI_SH_CR1);
 306         udelay(100);
 307
 308         spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
 309                          SPI_SH_CR1);
 310
 311         clear_fifo(ss);
 312
 313         return 0;
 314
 315  error:
 316         mesg->status = ret;
 317         spi_finalize_current_message(ctlr);
 318         if (mesg->complete)
 319                 mesg->complete(mesg->context);
 320
 321         spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
 322                          SPI_SH_CR1);
 323         clear_fifo(ss);
 324
 325         return ret;
 326 }
 327
 328 static int spi_sh_setup(struct spi_device *spi)
 329 {
 330         struct spi_sh_data *ss = spi_master_get_devdata(spi->master);
 331
 332         pr_debug("%s: enter\n", __func__);
 333
 334         spi_sh_write(ss, 0xfe, SPI_SH_CR1);     /* SPI sycle stop */
 335         spi_sh_write(ss, 0x00, SPI_SH_CR1);     /* CR1 init */
 336         spi_sh_write(ss, 0x00, SPI_SH_CR3);     /* CR3 init */
 337
 338         clear_fifo(ss);
 339
 340         /* 1/8 clock */
 341         spi_sh_write(ss, spi_sh_read(ss, SPI_SH_CR2) | 0x07, SPI_SH_CR2);
 342         udelay(10);
 343
 344         return 0;
 345 }
 346
 347 static void spi_sh_cleanup(struct spi_device *spi)
 348 {
 349         struct spi_sh_data *ss = spi_master_get_devdata(spi->master);
 350
 351         pr_debug("%s: enter\n", __func__);
 352
 353         spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
 354                          SPI_SH_CR1);
 355 }
 356
 357 static irqreturn_t spi_sh_irq(int irq, void *_ss)
 358 {
 359         struct spi_sh_data *ss = (struct spi_sh_data *)_ss;
 360         unsigned long cr1;
 361
 362         cr1 = spi_sh_read(ss, SPI_SH_CR1);
 363         if (cr1 & SPI_SH_TBE)
 364                 ss->cr1 |= SPI_SH_TBE;
 365         if (cr1 & SPI_SH_TBF)
 366                 ss->cr1 |= SPI_SH_TBF;
 367         if (cr1 & SPI_SH_RBE)
 368                 ss->cr1 |= SPI_SH_RBE;
 369         if (cr1 & SPI_SH_RBF)
 370                 ss->cr1 |= SPI_SH_RBF;
 371
 372         if (ss->cr1) {
 373                 spi_sh_clear_bit(ss, ss->cr1, SPI_SH_CR4);
 374                 wake_up(&ss->wait);
 375         }
 376
 377         return IRQ_HANDLED;
 378 }
 379
 380 static void spi_sh_remove(struct platform_device *pdev)
 381 {
 382         struct spi_sh_data *ss = platform_get_drvdata(pdev);
 383
 384         spi_unregister_master(ss->master);
 385         free_irq(ss->irq, ss);
 386 }
 387
 388 static int spi_sh_probe(struct platform_device *pdev)
 389 {
 390         struct resource *res;
 391         struct spi_master *master;
 392         struct spi_sh_data *ss;
 393         int ret, irq;
 394
 395         /* get base addr */
 396         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 397         if (unlikely(res == NULL)) {
 398                 dev_err(&pdev->dev, "invalid resource\n");
 399                 return -EINVAL;
 400         }
 401
 402         irq = platform_get_irq(pdev, 0);
 403         if (irq < 0)
 404                 return irq;
 405
 406         master = devm_spi_alloc_master(&pdev->dev, sizeof(struct spi_sh_data));
 407         if (master == NULL) {
 408                 dev_err(&pdev->dev, "spi_alloc_master error.\n");
 409                 return -ENOMEM;
 410         }
 411
 412         ss = spi_master_get_devdata(master);
 413         platform_set_drvdata(pdev, ss);
 414
 415         switch (res->flags & IORESOURCE_MEM_TYPE_MASK) {
 416         case IORESOURCE_MEM_8BIT:
 417                 ss->width = 8;
 418                 break;
 419         case IORESOURCE_MEM_32BIT:
 420                 ss->width = 32;
 421                 break;
 422         default:
 423                 dev_err(&pdev->dev, "No support width\n");
 424                 return -ENODEV;
 425         }
 426         ss->irq = irq;
 427         ss->master = master;
 428         ss->addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
 429         if (ss->addr == NULL) {
 430                 dev_err(&pdev->dev, "ioremap error.\n");
 431                 return -ENOMEM;
 432         }
 433         init_waitqueue_head(&ss->wait);
 434
 435         ret = request_irq(irq, spi_sh_irq, 0, "spi_sh", ss);
 436         if (ret < 0) {
 437                 dev_err(&pdev->dev, "request_irq error\n");
 438                 return ret;
 439         }
 440
 441         master->num_chipselect = 2;
 442         master->bus_num = pdev->id;
 443         master->setup = spi_sh_setup;
 444         master->transfer_one_message = spi_sh_transfer_one_message;
 445         master->cleanup = spi_sh_cleanup;
 446
 447         ret = spi_register_master(master);
 448         if (ret < 0) {
 449                 printk(KERN_ERR "spi_register_master error.\n");
 450                 goto error3;
 451         }
 452
 453         return 0;
 454
 455  error3:
 456         free_irq(irq, ss);
 457         return ret;
 458 }
 459
 460 static struct platform_driver spi_sh_driver = {
 461         .probe = spi_sh_probe,
 462         .remove_new = spi_sh_remove,
 463         .driver = {
 464                 .name = "sh_spi",
 465         },
 466 };
 467 module_platform_driver(spi_sh_driver);
 468
 469 MODULE_DESCRIPTION("SH SPI bus driver");
 470 MODULE_LICENSE("GPL v2");
 471 MODULE_AUTHOR("Yoshihiro Shimoda");
 472 MODULE_ALIAS("platform:sh_spi");