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