drivers/spi/spi-sh.c

   1 /*
   2  * SH SPI bus driver
   3  *
   4  * Copyright (C) 2011  Renesas Solutions Corp.
   5  *
   6  * Based on pxa2xx_spi.c:
   7  * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; version 2 of the License.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  21  *
  22  */
  23
  24 #include <linux/module.h>
  25 #include <linux/kernel.h>
  26 #include <linux/sched.h>
  27 #include <linux/errno.h>
  28 #include <linux/timer.h>
  29 #include <linux/delay.h>
  30 #include <linux/list.h>
  31 #include <linux/workqueue.h>
  32 #include <linux/interrupt.h>
  33 #include <linux/platform_device.h>
  34 #include <linux/io.h>
  35 #include <linux/spi/spi.h>
  36
  37 #define SPI_SH_TBR              0x00
  38 #define SPI_SH_RBR              0x00
  39 #define SPI_SH_CR1              0x08
  40 #define SPI_SH_CR2              0x10
  41 #define SPI_SH_CR3              0x18
  42 #define SPI_SH_CR4              0x20
  43 #define SPI_SH_CR5              0x28
  44
  45 /* CR1 */
  46 #define SPI_SH_TBE              0x80
  47 #define SPI_SH_TBF              0x40
  48 #define SPI_SH_RBE              0x20
  49 #define SPI_SH_RBF              0x10
  50 #define SPI_SH_PFONRD           0x08
  51 #define SPI_SH_SSDB             0x04
  52 #define SPI_SH_SSD              0x02
  53 #define SPI_SH_SSA              0x01
  54
  55 /* CR2 */
  56 #define SPI_SH_RSTF             0x80
  57 #define SPI_SH_LOOPBK           0x40
  58 #define SPI_SH_CPOL             0x20
  59 #define SPI_SH_CPHA             0x10
  60 #define SPI_SH_L1M0             0x08
  61
  62 /* CR3 */
  63 #define SPI_SH_MAX_BYTE         0xFF
  64
  65 /* CR4 */
  66 #define SPI_SH_TBEI             0x80
  67 #define SPI_SH_TBFI             0x40
  68 #define SPI_SH_RBEI             0x20
  69 #define SPI_SH_RBFI             0x10
  70 #define SPI_SH_WPABRT           0x04
  71 #define SPI_SH_SSS              0x01
  72
  73 /* CR8 */
  74 #define SPI_SH_P1L0             0x80
  75 #define SPI_SH_PP1L0            0x40
  76 #define SPI_SH_MUXI             0x20
  77 #define SPI_SH_MUXIRQ           0x10
  78
  79 #define SPI_SH_FIFO_SIZE        32
  80 #define SPI_SH_SEND_TIMEOUT     (3 * HZ)
  81 #define SPI_SH_RECEIVE_TIMEOUT  (HZ >> 3)
  82
  83 #undef DEBUG
  84
  85 struct spi_sh_data {
  86         void __iomem *addr;
  87         int irq;
  88         struct spi_master *master;
  89         struct list_head queue;
  90         struct workqueue_struct *workqueue;
  91         struct work_struct ws;
  92         unsigned long cr1;
  93         wait_queue_head_t wait;
  94         spinlock_t lock;
  95         int width;
  96 };
  97
  98 static void spi_sh_write(struct spi_sh_data *ss, unsigned long data,
  99                              unsigned long offset)
 100 {
 101         if (ss->width == 8)
 102                 iowrite8(data, ss->addr + (offset >> 2));
 103         else if (ss->width == 32)
 104                 iowrite32(data, ss->addr + offset);
 105 }
 106
 107 static unsigned long spi_sh_read(struct spi_sh_data *ss, unsigned long offset)
 108 {
 109         if (ss->width == 8)
 110                 return ioread8(ss->addr + (offset >> 2));
 111         else if (ss->width == 32)
 112                 return ioread32(ss->addr + offset);
 113         else
 114                 return 0;
 115 }
 116
 117 static void spi_sh_set_bit(struct spi_sh_data *ss, unsigned long val,
 118                                 unsigned long offset)
 119 {
 120         unsigned long tmp;
 121
 122         tmp = spi_sh_read(ss, offset);
 123         tmp |= val;
 124         spi_sh_write(ss, tmp, offset);
 125 }
 126
 127 static void spi_sh_clear_bit(struct spi_sh_data *ss, unsigned long val,
 128                                 unsigned long offset)
 129 {
 130         unsigned long tmp;
 131
 132         tmp = spi_sh_read(ss, offset);
 133         tmp &= ~val;
 134         spi_sh_write(ss, tmp, offset);
 135 }
 136
 137 static void clear_fifo(struct spi_sh_data *ss)
 138 {
 139         spi_sh_set_bit(ss, SPI_SH_RSTF, SPI_SH_CR2);
 140         spi_sh_clear_bit(ss, SPI_SH_RSTF, SPI_SH_CR2);
 141 }
 142
 143 static int spi_sh_wait_receive_buffer(struct spi_sh_data *ss)
 144 {
 145         int timeout = 100000;
 146
 147         while (spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_RBE) {
 148                 udelay(10);
 149                 if (timeout-- < 0)
 150                         return -ETIMEDOUT;
 151         }
 152         return 0;
 153 }
 154
 155 static int spi_sh_wait_write_buffer_empty(struct spi_sh_data *ss)
 156 {
 157         int timeout = 100000;
 158
 159         while (!(spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_TBE)) {
 160                 udelay(10);
 161                 if (timeout-- < 0)
 162                         return -ETIMEDOUT;
 163         }
 164         return 0;
 165 }
 166
 167 static int spi_sh_send(struct spi_sh_data *ss, struct spi_message *mesg,
 168                         struct spi_transfer *t)
 169 {
 170         int i, retval = 0;
 171         int remain = t->len;
 172         int cur_len;
 173         unsigned char *data;
 174         unsigned long tmp;
 175         long ret;
 176
 177         if (t->len)
 178                 spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
 179
 180         data = (unsigned char *)t->tx_buf;
 181         while (remain > 0) {
 182                 cur_len = min(SPI_SH_FIFO_SIZE, remain);
 183                 for (i = 0; i < cur_len &&
 184                                 !(spi_sh_read(ss, SPI_SH_CR4) &
 185                                                         SPI_SH_WPABRT) &&
 186                                 !(spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_TBF);
 187                                 i++)
 188                         spi_sh_write(ss, (unsigned long)data[i], SPI_SH_TBR);
 189
 190                 if (spi_sh_read(ss, SPI_SH_CR4) & SPI_SH_WPABRT) {
 191                         /* Abort SPI operation */
 192                         spi_sh_set_bit(ss, SPI_SH_WPABRT, SPI_SH_CR4);
 193                         retval = -EIO;
 194                         break;
 195                 }
 196
 197                 cur_len = i;
 198
 199                 remain -= cur_len;
 200                 data += cur_len;
 201
 202                 if (remain > 0) {
 203                         ss->cr1 &= ~SPI_SH_TBE;
 204                         spi_sh_set_bit(ss, SPI_SH_TBE, SPI_SH_CR4);
 205                         ret = wait_event_interruptible_timeout(ss->wait,
 206                                                  ss->cr1 & SPI_SH_TBE,
 207                                                  SPI_SH_SEND_TIMEOUT);
 208                         if (ret == 0 && !(ss->cr1 & SPI_SH_TBE)) {
 209                                 printk(KERN_ERR "%s: timeout\n", __func__);
 210                                 return -ETIMEDOUT;
 211                         }
 212                 }
 213         }
 214
 215         if (list_is_last(&t->transfer_list, &mesg->transfers)) {
 216                 tmp = spi_sh_read(ss, SPI_SH_CR1);
 217                 tmp = tmp & ~(SPI_SH_SSD | SPI_SH_SSDB);
 218                 spi_sh_write(ss, tmp, SPI_SH_CR1);
 219                 spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
 220
 221                 ss->cr1 &= ~SPI_SH_TBE;
 222                 spi_sh_set_bit(ss, SPI_SH_TBE, SPI_SH_CR4);
 223                 ret = wait_event_interruptible_timeout(ss->wait,
 224                                          ss->cr1 & SPI_SH_TBE,
 225                                          SPI_SH_SEND_TIMEOUT);
 226                 if (ret == 0 && (ss->cr1 & SPI_SH_TBE)) {
 227                         printk(KERN_ERR "%s: timeout\n", __func__);
 228                         return -ETIMEDOUT;
 229                 }
 230         }
 231
 232         return retval;
 233 }
 234
 235 static int spi_sh_receive(struct spi_sh_data *ss, struct spi_message *mesg,
 236                           struct spi_transfer *t)
 237 {
 238         int i;
 239         int remain = t->len;
 240         int cur_len;
 241         unsigned char *data;
 242         unsigned long tmp;
 243         long ret;
 244
 245         if (t->len > SPI_SH_MAX_BYTE)
 246                 spi_sh_write(ss, SPI_SH_MAX_BYTE, SPI_SH_CR3);
 247         else
 248                 spi_sh_write(ss, t->len, SPI_SH_CR3);
 249
 250         tmp = spi_sh_read(ss, SPI_SH_CR1);
 251         tmp = tmp & ~(SPI_SH_SSD | SPI_SH_SSDB);
 252         spi_sh_write(ss, tmp, SPI_SH_CR1);
 253         spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
 254
 255         spi_sh_wait_write_buffer_empty(ss);
 256
 257         data = (unsigned char *)t->rx_buf;
 258         while (remain > 0) {
 259                 if (remain >= SPI_SH_FIFO_SIZE) {
 260                         ss->cr1 &= ~SPI_SH_RBF;
 261                         spi_sh_set_bit(ss, SPI_SH_RBF, SPI_SH_CR4);
 262                         ret = wait_event_interruptible_timeout(ss->wait,
 263                                                  ss->cr1 & SPI_SH_RBF,
 264                                                  SPI_SH_RECEIVE_TIMEOUT);
 265                         if (ret == 0 &&
 266                             spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_RBE) {
 267                                 printk(KERN_ERR "%s: timeout\n", __func__);
 268                                 return -ETIMEDOUT;
 269                         }
 270                 }
 271
 272                 cur_len = min(SPI_SH_FIFO_SIZE, remain);
 273                 for (i = 0; i < cur_len; i++) {
 274                         if (spi_sh_wait_receive_buffer(ss))
 275                                 break;
 276                         data[i] = (unsigned char)spi_sh_read(ss, SPI_SH_RBR);
 277                 }
 278
 279                 remain -= cur_len;
 280                 data += cur_len;
 281         }
 282
 283         /* deassert CS when SPI is receiving. */
 284         if (t->len > SPI_SH_MAX_BYTE) {
 285                 clear_fifo(ss);
 286                 spi_sh_write(ss, 1, SPI_SH_CR3);
 287         } else {
 288                 spi_sh_write(ss, 0, SPI_SH_CR3);
 289         }
 290
 291         return 0;
 292 }
 293
 294 static void spi_sh_work(struct work_struct *work)
 295 {
 296         struct spi_sh_data *ss = container_of(work, struct spi_sh_data, ws);
 297         struct spi_message *mesg;
 298         struct spi_transfer *t;
 299         unsigned long flags;
 300         int ret;
 301
 302         pr_debug("%s: enter\n", __func__);
 303
 304         spin_lock_irqsave(&ss->lock, flags);
 305         while (!list_empty(&ss->queue)) {
 306                 mesg = list_entry(ss->queue.next, struct spi_message, queue);
 307                 list_del_init(&mesg->queue);
 308
 309                 spin_unlock_irqrestore(&ss->lock, flags);
 310                 list_for_each_entry(t, &mesg->transfers, transfer_list) {
 311                         pr_debug("tx_buf = %p, rx_buf = %p\n",
 312                                         t->tx_buf, t->rx_buf);
 313                         pr_debug("len = %d, delay_usecs = %d\n",
 314                                         t->len, t->delay_usecs);
 315
 316                         if (t->tx_buf) {
 317                                 ret = spi_sh_send(ss, mesg, t);
 318                                 if (ret < 0)
 319                                         goto error;
 320                         }
 321                         if (t->rx_buf) {
 322                                 ret = spi_sh_receive(ss, mesg, t);
 323                                 if (ret < 0)
 324                                         goto error;
 325                         }
 326                         mesg->actual_length += t->len;
 327                 }
 328                 spin_lock_irqsave(&ss->lock, flags);
 329
 330                 mesg->status = 0;
 331                 mesg->complete(mesg->context);
 332         }
 333
 334         clear_fifo(ss);
 335         spi_sh_set_bit(ss, SPI_SH_SSD, SPI_SH_CR1);
 336         udelay(100);
 337
 338         spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
 339                          SPI_SH_CR1);
 340
 341         clear_fifo(ss);
 342
 343         spin_unlock_irqrestore(&ss->lock, flags);
 344
 345         return;
 346
 347  error:
 348         mesg->status = ret;
 349         mesg->complete(mesg->context);
 350
 351         spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
 352                          SPI_SH_CR1);
 353         clear_fifo(ss);
 354
 355 }
 356
 357 static int spi_sh_setup(struct spi_device *spi)
 358 {
 359         struct spi_sh_data *ss = spi_master_get_devdata(spi->master);
 360
 361         if (!spi->bits_per_word)
 362                 spi->bits_per_word = 8;
 363
 364         pr_debug("%s: enter\n", __func__);
 365
 366         spi_sh_write(ss, 0xfe, SPI_SH_CR1);     /* SPI sycle stop */
 367         spi_sh_write(ss, 0x00, SPI_SH_CR1);     /* CR1 init */
 368         spi_sh_write(ss, 0x00, SPI_SH_CR3);     /* CR3 init */
 369
 370         clear_fifo(ss);
 371
 372         /* 1/8 clock */
 373         spi_sh_write(ss, spi_sh_read(ss, SPI_SH_CR2) | 0x07, SPI_SH_CR2);
 374         udelay(10);
 375
 376         return 0;
 377 }
 378
 379 static int spi_sh_transfer(struct spi_device *spi, struct spi_message *mesg)
 380 {
 381         struct spi_sh_data *ss = spi_master_get_devdata(spi->master);
 382         unsigned long flags;
 383
 384         pr_debug("%s: enter\n", __func__);
 385         pr_debug("\tmode = %02x\n", spi->mode);
 386
 387         spin_lock_irqsave(&ss->lock, flags);
 388
 389         mesg->actual_length = 0;
 390         mesg->status = -EINPROGRESS;
 391
 392         spi_sh_clear_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
 393
 394         list_add_tail(&mesg->queue, &ss->queue);
 395         queue_work(ss->workqueue, &ss->ws);
 396
 397         spin_unlock_irqrestore(&ss->lock, flags);
 398
 399         return 0;
 400 }
 401
 402 static void spi_sh_cleanup(struct spi_device *spi)
 403 {
 404         struct spi_sh_data *ss = spi_master_get_devdata(spi->master);
 405
 406         pr_debug("%s: enter\n", __func__);
 407
 408         spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
 409                          SPI_SH_CR1);
 410 }
 411
 412 static irqreturn_t spi_sh_irq(int irq, void *_ss)
 413 {
 414         struct spi_sh_data *ss = (struct spi_sh_data *)_ss;
 415         unsigned long cr1;
 416
 417         cr1 = spi_sh_read(ss, SPI_SH_CR1);
 418         if (cr1 & SPI_SH_TBE)
 419                 ss->cr1 |= SPI_SH_TBE;
 420         if (cr1 & SPI_SH_TBF)
 421                 ss->cr1 |= SPI_SH_TBF;
 422         if (cr1 & SPI_SH_RBE)
 423                 ss->cr1 |= SPI_SH_RBE;
 424         if (cr1 & SPI_SH_RBF)
 425                 ss->cr1 |= SPI_SH_RBF;
 426
 427         if (ss->cr1) {
 428                 spi_sh_clear_bit(ss, ss->cr1, SPI_SH_CR4);
 429                 wake_up(&ss->wait);
 430         }
 431
 432         return IRQ_HANDLED;
 433 }
 434
 435 static int __devexit spi_sh_remove(struct platform_device *pdev)
 436 {
 437         struct spi_sh_data *ss = dev_get_drvdata(&pdev->dev);
 438
 439         spi_unregister_master(ss->master);
 440         destroy_workqueue(ss->workqueue);
 441         free_irq(ss->irq, ss);
 442         iounmap(ss->addr);
 443
 444         return 0;
 445 }
 446
 447 static int __devinit spi_sh_probe(struct platform_device *pdev)
 448 {
 449         struct resource *res;
 450         struct spi_master *master;
 451         struct spi_sh_data *ss;
 452         int ret, irq;
 453
 454         /* get base addr */
 455         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 456         if (unlikely(res == NULL)) {
 457                 dev_err(&pdev->dev, "invalid resource\n");
 458                 return -EINVAL;
 459         }
 460
 461         irq = platform_get_irq(pdev, 0);
 462         if (irq < 0) {
 463                 dev_err(&pdev->dev, "platform_get_irq error\n");
 464                 return -ENODEV;
 465         }
 466
 467         master = spi_alloc_master(&pdev->dev, sizeof(struct spi_sh_data));
 468         if (master == NULL) {
 469                 dev_err(&pdev->dev, "spi_alloc_master error.\n");
 470                 return -ENOMEM;
 471         }
 472
 473         ss = spi_master_get_devdata(master);
 474         dev_set_drvdata(&pdev->dev, ss);
 475
 476         switch (res->flags & IORESOURCE_MEM_TYPE_MASK) {
 477         case IORESOURCE_MEM_8BIT:
 478                 ss->width = 8;
 479                 break;
 480         case IORESOURCE_MEM_32BIT:
 481                 ss->width = 32;
 482                 break;
 483         default:
 484                 dev_err(&pdev->dev, "No support width\n");
 485                 ret = -ENODEV;
 486                 goto error1;
 487         }
 488         ss->irq = irq;
 489         ss->master = master;
 490         ss->addr = ioremap(res->start, resource_size(res));
 491         if (ss->addr == NULL) {
 492                 dev_err(&pdev->dev, "ioremap error.\n");
 493                 ret = -ENOMEM;
 494                 goto error1;
 495         }
 496         INIT_LIST_HEAD(&ss->queue);
 497         spin_lock_init(&ss->lock);
 498         INIT_WORK(&ss->ws, spi_sh_work);
 499         init_waitqueue_head(&ss->wait);
 500         ss->workqueue = create_singlethread_workqueue(
 501                                         dev_name(master->dev.parent));
 502         if (ss->workqueue == NULL) {
 503                 dev_err(&pdev->dev, "create workqueue error\n");
 504                 ret = -EBUSY;
 505                 goto error2;
 506         }
 507
 508         ret = request_irq(irq, spi_sh_irq, 0, "spi_sh", ss);
 509         if (ret < 0) {
 510                 dev_err(&pdev->dev, "request_irq error\n");
 511                 goto error3;
 512         }
 513
 514         master->num_chipselect = 2;
 515         master->bus_num = pdev->id;
 516         master->setup = spi_sh_setup;
 517         master->transfer = spi_sh_transfer;
 518         master->cleanup = spi_sh_cleanup;
 519
 520         ret = spi_register_master(master);
 521         if (ret < 0) {
 522                 printk(KERN_ERR "spi_register_master error.\n");
 523                 goto error4;
 524         }
 525
 526         return 0;
 527
 528  error4:
 529         free_irq(irq, ss);
 530  error3:
 531         destroy_workqueue(ss->workqueue);
 532  error2:
 533         iounmap(ss->addr);
 534  error1:
 535         spi_master_put(master);
 536
 537         return ret;
 538 }
 539
 540 static struct platform_driver spi_sh_driver = {
 541         .probe = spi_sh_probe,
 542         .remove = __devexit_p(spi_sh_remove),
 543         .driver = {
 544                 .name = "sh_spi",
 545                 .owner = THIS_MODULE,
 546         },
 547 };
 548 module_platform_driver(spi_sh_driver);
 549
 550 MODULE_DESCRIPTION("SH SPI bus driver");
 551 MODULE_LICENSE("GPL");
 552 MODULE_AUTHOR("Yoshihiro Shimoda");
 553 MODULE_ALIAS("platform:sh_spi");