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         long ret;
 175
 176         if (t->len)
 177                 spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
 178
 179         data = (unsigned char *)t->tx_buf;
 180         while (remain > 0) {
 181                 cur_len = min(SPI_SH_FIFO_SIZE, remain);
 182                 for (i = 0; i < cur_len &&
 183                                 !(spi_sh_read(ss, SPI_SH_CR4) &
 184                                                         SPI_SH_WPABRT) &&
 185                                 !(spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_TBF);
 186                                 i++)
 187                         spi_sh_write(ss, (unsigned long)data[i], SPI_SH_TBR);
 188
 189                 if (spi_sh_read(ss, SPI_SH_CR4) & SPI_SH_WPABRT) {
 190                         /* Abort SPI operation */
 191                         spi_sh_set_bit(ss, SPI_SH_WPABRT, SPI_SH_CR4);
 192                         retval = -EIO;
 193                         break;
 194                 }
 195
 196                 cur_len = i;
 197
 198                 remain -= cur_len;
 199                 data += cur_len;
 200
 201                 if (remain > 0) {
 202                         ss->cr1 &= ~SPI_SH_TBE;
 203                         spi_sh_set_bit(ss, SPI_SH_TBE, SPI_SH_CR4);
 204                         ret = wait_event_interruptible_timeout(ss->wait,
 205                                                  ss->cr1 & SPI_SH_TBE,
 206                                                  SPI_SH_SEND_TIMEOUT);
 207                         if (ret == 0 && !(ss->cr1 & SPI_SH_TBE)) {
 208                                 printk(KERN_ERR "%s: timeout\n", __func__);
 209                                 return -ETIMEDOUT;
 210                         }
 211                 }
 212         }
 213
 214         if (list_is_last(&t->transfer_list, &mesg->transfers)) {
 215                 spi_sh_clear_bit(ss, SPI_SH_SSD | SPI_SH_SSDB, SPI_SH_CR1);
 216                 spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
 217
 218                 ss->cr1 &= ~SPI_SH_TBE;
 219                 spi_sh_set_bit(ss, SPI_SH_TBE, SPI_SH_CR4);
 220                 ret = wait_event_interruptible_timeout(ss->wait,
 221                                          ss->cr1 & SPI_SH_TBE,
 222                                          SPI_SH_SEND_TIMEOUT);
 223                 if (ret == 0 && (ss->cr1 & SPI_SH_TBE)) {
 224                         printk(KERN_ERR "%s: timeout\n", __func__);
 225                         return -ETIMEDOUT;
 226                 }
 227         }
 228
 229         return retval;
 230 }
 231
 232 static int spi_sh_receive(struct spi_sh_data *ss, struct spi_message *mesg,
 233                           struct spi_transfer *t)
 234 {
 235         int i;
 236         int remain = t->len;
 237         int cur_len;
 238         unsigned char *data;
 239         long ret;
 240
 241         if (t->len > SPI_SH_MAX_BYTE)
 242                 spi_sh_write(ss, SPI_SH_MAX_BYTE, SPI_SH_CR3);
 243         else
 244                 spi_sh_write(ss, t->len, SPI_SH_CR3);
 245
 246         spi_sh_clear_bit(ss, SPI_SH_SSD | SPI_SH_SSDB, SPI_SH_CR1);
 247         spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
 248
 249         spi_sh_wait_write_buffer_empty(ss);
 250
 251         data = (unsigned char *)t->rx_buf;
 252         while (remain > 0) {
 253                 if (remain >= SPI_SH_FIFO_SIZE) {
 254                         ss->cr1 &= ~SPI_SH_RBF;
 255                         spi_sh_set_bit(ss, SPI_SH_RBF, SPI_SH_CR4);
 256                         ret = wait_event_interruptible_timeout(ss->wait,
 257                                                  ss->cr1 & SPI_SH_RBF,
 258                                                  SPI_SH_RECEIVE_TIMEOUT);
 259                         if (ret == 0 &&
 260                             spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_RBE) {
 261                                 printk(KERN_ERR "%s: timeout\n", __func__);
 262                                 return -ETIMEDOUT;
 263                         }
 264                 }
 265
 266                 cur_len = min(SPI_SH_FIFO_SIZE, remain);
 267                 for (i = 0; i < cur_len; i++) {
 268                         if (spi_sh_wait_receive_buffer(ss))
 269                                 break;
 270                         data[i] = (unsigned char)spi_sh_read(ss, SPI_SH_RBR);
 271                 }
 272
 273                 remain -= cur_len;
 274                 data += cur_len;
 275         }
 276
 277         /* deassert CS when SPI is receiving. */
 278         if (t->len > SPI_SH_MAX_BYTE) {
 279                 clear_fifo(ss);
 280                 spi_sh_write(ss, 1, SPI_SH_CR3);
 281         } else {
 282                 spi_sh_write(ss, 0, SPI_SH_CR3);
 283         }
 284
 285         return 0;
 286 }
 287
 288 static void spi_sh_work(struct work_struct *work)
 289 {
 290         struct spi_sh_data *ss = container_of(work, struct spi_sh_data, ws);
 291         struct spi_message *mesg;
 292         struct spi_transfer *t;
 293         unsigned long flags;
 294         int ret;
 295
 296         pr_debug("%s: enter\n", __func__);
 297
 298         spin_lock_irqsave(&ss->lock, flags);
 299         while (!list_empty(&ss->queue)) {
 300                 mesg = list_entry(ss->queue.next, struct spi_message, queue);
 301                 list_del_init(&mesg->queue);
 302
 303                 spin_unlock_irqrestore(&ss->lock, flags);
 304                 list_for_each_entry(t, &mesg->transfers, transfer_list) {
 305                         pr_debug("tx_buf = %p, rx_buf = %p\n",
 306                                         t->tx_buf, t->rx_buf);
 307                         pr_debug("len = %d, delay_usecs = %d\n",
 308                                         t->len, t->delay_usecs);
 309
 310                         if (t->tx_buf) {
 311                                 ret = spi_sh_send(ss, mesg, t);
 312                                 if (ret < 0)
 313                                         goto error;
 314                         }
 315                         if (t->rx_buf) {
 316                                 ret = spi_sh_receive(ss, mesg, t);
 317                                 if (ret < 0)
 318                                         goto error;
 319                         }
 320                         mesg->actual_length += t->len;
 321                 }
 322                 spin_lock_irqsave(&ss->lock, flags);
 323
 324                 mesg->status = 0;
 325                 if (mesg->complete)
 326                         mesg->complete(mesg->context);
 327         }
 328
 329         clear_fifo(ss);
 330         spi_sh_set_bit(ss, SPI_SH_SSD, SPI_SH_CR1);
 331         udelay(100);
 332
 333         spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
 334                          SPI_SH_CR1);
 335
 336         clear_fifo(ss);
 337
 338         spin_unlock_irqrestore(&ss->lock, flags);
 339
 340         return;
 341
 342  error:
 343         mesg->status = ret;
 344         if (mesg->complete)
 345                 mesg->complete(mesg->context);
 346
 347         spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
 348                          SPI_SH_CR1);
 349         clear_fifo(ss);
 350
 351 }
 352
 353 static int spi_sh_setup(struct spi_device *spi)
 354 {
 355         struct spi_sh_data *ss = spi_master_get_devdata(spi->master);
 356
 357         pr_debug("%s: enter\n", __func__);
 358
 359         spi_sh_write(ss, 0xfe, SPI_SH_CR1);     /* SPI sycle stop */
 360         spi_sh_write(ss, 0x00, SPI_SH_CR1);     /* CR1 init */
 361         spi_sh_write(ss, 0x00, SPI_SH_CR3);     /* CR3 init */
 362
 363         clear_fifo(ss);
 364
 365         /* 1/8 clock */
 366         spi_sh_write(ss, spi_sh_read(ss, SPI_SH_CR2) | 0x07, SPI_SH_CR2);
 367         udelay(10);
 368
 369         return 0;
 370 }
 371
 372 static int spi_sh_transfer(struct spi_device *spi, struct spi_message *mesg)
 373 {
 374         struct spi_sh_data *ss = spi_master_get_devdata(spi->master);
 375         unsigned long flags;
 376
 377         pr_debug("%s: enter\n", __func__);
 378         pr_debug("\tmode = %02x\n", spi->mode);
 379
 380         spin_lock_irqsave(&ss->lock, flags);
 381
 382         mesg->actual_length = 0;
 383         mesg->status = -EINPROGRESS;
 384
 385         spi_sh_clear_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
 386
 387         list_add_tail(&mesg->queue, &ss->queue);
 388         queue_work(ss->workqueue, &ss->ws);
 389
 390         spin_unlock_irqrestore(&ss->lock, flags);
 391
 392         return 0;
 393 }
 394
 395 static void spi_sh_cleanup(struct spi_device *spi)
 396 {
 397         struct spi_sh_data *ss = spi_master_get_devdata(spi->master);
 398
 399         pr_debug("%s: enter\n", __func__);
 400
 401         spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
 402                          SPI_SH_CR1);
 403 }
 404
 405 static irqreturn_t spi_sh_irq(int irq, void *_ss)
 406 {
 407         struct spi_sh_data *ss = (struct spi_sh_data *)_ss;
 408         unsigned long cr1;
 409
 410         cr1 = spi_sh_read(ss, SPI_SH_CR1);
 411         if (cr1 & SPI_SH_TBE)
 412                 ss->cr1 |= SPI_SH_TBE;
 413         if (cr1 & SPI_SH_TBF)
 414                 ss->cr1 |= SPI_SH_TBF;
 415         if (cr1 & SPI_SH_RBE)
 416                 ss->cr1 |= SPI_SH_RBE;
 417         if (cr1 & SPI_SH_RBF)
 418                 ss->cr1 |= SPI_SH_RBF;
 419
 420         if (ss->cr1) {
 421                 spi_sh_clear_bit(ss, ss->cr1, SPI_SH_CR4);
 422                 wake_up(&ss->wait);
 423         }
 424
 425         return IRQ_HANDLED;
 426 }
 427
 428 static int spi_sh_remove(struct platform_device *pdev)
 429 {
 430         struct spi_sh_data *ss = platform_get_drvdata(pdev);
 431
 432         spi_unregister_master(ss->master);
 433         destroy_workqueue(ss->workqueue);
 434         free_irq(ss->irq, ss);
 435
 436         return 0;
 437 }
 438
 439 static int spi_sh_probe(struct platform_device *pdev)
 440 {
 441         struct resource *res;
 442         struct spi_master *master;
 443         struct spi_sh_data *ss;
 444         int ret, irq;
 445
 446         /* get base addr */
 447         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 448         if (unlikely(res == NULL)) {
 449                 dev_err(&pdev->dev, "invalid resource\n");
 450                 return -EINVAL;
 451         }
 452
 453         irq = platform_get_irq(pdev, 0);
 454         if (irq < 0) {
 455                 dev_err(&pdev->dev, "platform_get_irq error\n");
 456                 return -ENODEV;
 457         }
 458
 459         master = spi_alloc_master(&pdev->dev, sizeof(struct spi_sh_data));
 460         if (master == NULL) {
 461                 dev_err(&pdev->dev, "spi_alloc_master error.\n");
 462                 return -ENOMEM;
 463         }
 464
 465         ss = spi_master_get_devdata(master);
 466         platform_set_drvdata(pdev, ss);
 467
 468         switch (res->flags & IORESOURCE_MEM_TYPE_MASK) {
 469         case IORESOURCE_MEM_8BIT:
 470                 ss->width = 8;
 471                 break;
 472         case IORESOURCE_MEM_32BIT:
 473                 ss->width = 32;
 474                 break;
 475         default:
 476                 dev_err(&pdev->dev, "No support width\n");
 477                 ret = -ENODEV;
 478                 goto error1;
 479         }
 480         ss->irq = irq;
 481         ss->master = master;
 482         ss->addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
 483         if (ss->addr == NULL) {
 484                 dev_err(&pdev->dev, "ioremap error.\n");
 485                 ret = -ENOMEM;
 486                 goto error1;
 487         }
 488         INIT_LIST_HEAD(&ss->queue);
 489         spin_lock_init(&ss->lock);
 490         INIT_WORK(&ss->ws, spi_sh_work);
 491         init_waitqueue_head(&ss->wait);
 492         ss->workqueue = create_singlethread_workqueue(
 493                                         dev_name(master->dev.parent));
 494         if (ss->workqueue == NULL) {
 495                 dev_err(&pdev->dev, "create workqueue error\n");
 496                 ret = -EBUSY;
 497                 goto error1;
 498         }
 499
 500         ret = request_irq(irq, spi_sh_irq, 0, "spi_sh", ss);
 501         if (ret < 0) {
 502                 dev_err(&pdev->dev, "request_irq error\n");
 503                 goto error2;
 504         }
 505
 506         master->num_chipselect = 2;
 507         master->bus_num = pdev->id;
 508         master->setup = spi_sh_setup;
 509         master->transfer = spi_sh_transfer;
 510         master->cleanup = spi_sh_cleanup;
 511
 512         ret = spi_register_master(master);
 513         if (ret < 0) {
 514                 printk(KERN_ERR "spi_register_master error.\n");
 515                 goto error3;
 516         }
 517
 518         return 0;
 519
 520  error3:
 521         free_irq(irq, ss);
 522  error2:
 523         destroy_workqueue(ss->workqueue);
 524  error1:
 525         spi_master_put(master);
 526
 527         return ret;
 528 }
 529
 530 static struct platform_driver spi_sh_driver = {
 531         .probe = spi_sh_probe,
 532         .remove = spi_sh_remove,
 533         .driver = {
 534                 .name = "sh_spi",
 535                 .owner = THIS_MODULE,
 536         },
 537 };
 538 module_platform_driver(spi_sh_driver);
 539
 540 MODULE_DESCRIPTION("SH SPI bus driver");
 541 MODULE_LICENSE("GPL");
 542 MODULE_AUTHOR("Yoshihiro Shimoda");
 543 MODULE_ALIAS("platform:sh_spi");