linux/drivers/spi/spi-sh.c
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   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
  72struct spi_sh_data {
  73        void __iomem *addr;
  74        int irq;
  75        struct spi_master *master;
  76        struct list_head queue;
  77        struct work_struct ws;
  78        unsigned long cr1;
  79        wait_queue_head_t wait;
  80        spinlock_t lock;
  81        int width;
  82};
  83
  84static void spi_sh_write(struct spi_sh_data *ss, unsigned long data,
  85                             unsigned long offset)
  86{
  87        if (ss->width == 8)
  88                iowrite8(data, ss->addr + (offset >> 2));
  89        else if (ss->width == 32)
  90                iowrite32(data, ss->addr + offset);
  91}
  92
  93static unsigned long spi_sh_read(struct spi_sh_data *ss, unsigned long offset)
  94{
  95        if (ss->width == 8)
  96                return ioread8(ss->addr + (offset >> 2));
  97        else if (ss->width == 32)
  98                return ioread32(ss->addr + offset);
  99        else
 100                return 0;
 101}
 102
 103static void spi_sh_set_bit(struct spi_sh_data *ss, unsigned long val,
 104                                unsigned long offset)
 105{
 106        unsigned long tmp;
 107
 108        tmp = spi_sh_read(ss, offset);
 109        tmp |= val;
 110        spi_sh_write(ss, tmp, offset);
 111}
 112
 113static void spi_sh_clear_bit(struct spi_sh_data *ss, unsigned long val,
 114                                unsigned long offset)
 115{
 116        unsigned long tmp;
 117
 118        tmp = spi_sh_read(ss, offset);
 119        tmp &= ~val;
 120        spi_sh_write(ss, tmp, offset);
 121}
 122
 123static void clear_fifo(struct spi_sh_data *ss)
 124{
 125        spi_sh_set_bit(ss, SPI_SH_RSTF, SPI_SH_CR2);
 126        spi_sh_clear_bit(ss, SPI_SH_RSTF, SPI_SH_CR2);
 127}
 128
 129static int spi_sh_wait_receive_buffer(struct spi_sh_data *ss)
 130{
 131        int timeout = 100000;
 132
 133        while (spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_RBE) {
 134                udelay(10);
 135                if (timeout-- < 0)
 136                        return -ETIMEDOUT;
 137        }
 138        return 0;
 139}
 140
 141static int spi_sh_wait_write_buffer_empty(struct spi_sh_data *ss)
 142{
 143        int timeout = 100000;
 144
 145        while (!(spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_TBE)) {
 146                udelay(10);
 147                if (timeout-- < 0)
 148                        return -ETIMEDOUT;
 149        }
 150        return 0;
 151}
 152
 153static int spi_sh_send(struct spi_sh_data *ss, struct spi_message *mesg,
 154                        struct spi_transfer *t)
 155{
 156        int i, retval = 0;
 157        int remain = t->len;
 158        int cur_len;
 159        unsigned char *data;
 160        long ret;
 161
 162        if (t->len)
 163                spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
 164
 165        data = (unsigned char *)t->tx_buf;
 166        while (remain > 0) {
 167                cur_len = min(SPI_SH_FIFO_SIZE, remain);
 168                for (i = 0; i < cur_len &&
 169                                !(spi_sh_read(ss, SPI_SH_CR4) &
 170                                                        SPI_SH_WPABRT) &&
 171                                !(spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_TBF);
 172                                i++)
 173                        spi_sh_write(ss, (unsigned long)data[i], SPI_SH_TBR);
 174
 175                if (spi_sh_read(ss, SPI_SH_CR4) & SPI_SH_WPABRT) {
 176                        /* Abort SPI operation */
 177                        spi_sh_set_bit(ss, SPI_SH_WPABRT, SPI_SH_CR4);
 178                        retval = -EIO;
 179                        break;
 180                }
 181
 182                cur_len = i;
 183
 184                remain -= cur_len;
 185                data += cur_len;
 186
 187                if (remain > 0) {
 188                        ss->cr1 &= ~SPI_SH_TBE;
 189                        spi_sh_set_bit(ss, SPI_SH_TBE, SPI_SH_CR4);
 190                        ret = wait_event_interruptible_timeout(ss->wait,
 191                                                 ss->cr1 & SPI_SH_TBE,
 192                                                 SPI_SH_SEND_TIMEOUT);
 193                        if (ret == 0 && !(ss->cr1 & SPI_SH_TBE)) {
 194                                printk(KERN_ERR "%s: timeout\n", __func__);
 195                                return -ETIMEDOUT;
 196                        }
 197                }
 198        }
 199
 200        if (list_is_last(&t->transfer_list, &mesg->transfers)) {
 201                spi_sh_clear_bit(ss, SPI_SH_SSD | SPI_SH_SSDB, SPI_SH_CR1);
 202                spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
 203
 204                ss->cr1 &= ~SPI_SH_TBE;
 205                spi_sh_set_bit(ss, SPI_SH_TBE, SPI_SH_CR4);
 206                ret = wait_event_interruptible_timeout(ss->wait,
 207                                         ss->cr1 & SPI_SH_TBE,
 208                                         SPI_SH_SEND_TIMEOUT);
 209                if (ret == 0 && (ss->cr1 & SPI_SH_TBE)) {
 210                        printk(KERN_ERR "%s: timeout\n", __func__);
 211                        return -ETIMEDOUT;
 212                }
 213        }
 214
 215        return retval;
 216}
 217
 218static int spi_sh_receive(struct spi_sh_data *ss, struct spi_message *mesg,
 219                          struct spi_transfer *t)
 220{
 221        int i;
 222        int remain = t->len;
 223        int cur_len;
 224        unsigned char *data;
 225        long ret;
 226
 227        if (t->len > SPI_SH_MAX_BYTE)
 228                spi_sh_write(ss, SPI_SH_MAX_BYTE, SPI_SH_CR3);
 229        else
 230                spi_sh_write(ss, t->len, SPI_SH_CR3);
 231
 232        spi_sh_clear_bit(ss, SPI_SH_SSD | SPI_SH_SSDB, SPI_SH_CR1);
 233        spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
 234
 235        spi_sh_wait_write_buffer_empty(ss);
 236
 237        data = (unsigned char *)t->rx_buf;
 238        while (remain > 0) {
 239                if (remain >= SPI_SH_FIFO_SIZE) {
 240                        ss->cr1 &= ~SPI_SH_RBF;
 241                        spi_sh_set_bit(ss, SPI_SH_RBF, SPI_SH_CR4);
 242                        ret = wait_event_interruptible_timeout(ss->wait,
 243                                                 ss->cr1 & SPI_SH_RBF,
 244                                                 SPI_SH_RECEIVE_TIMEOUT);
 245                        if (ret == 0 &&
 246                            spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_RBE) {
 247                                printk(KERN_ERR "%s: timeout\n", __func__);
 248                                return -ETIMEDOUT;
 249                        }
 250                }
 251
 252                cur_len = min(SPI_SH_FIFO_SIZE, remain);
 253                for (i = 0; i < cur_len; i++) {
 254                        if (spi_sh_wait_receive_buffer(ss))
 255                                break;
 256                        data[i] = (unsigned char)spi_sh_read(ss, SPI_SH_RBR);
 257                }
 258
 259                remain -= cur_len;
 260                data += cur_len;
 261        }
 262
 263        /* deassert CS when SPI is receiving. */
 264        if (t->len > SPI_SH_MAX_BYTE) {
 265                clear_fifo(ss);
 266                spi_sh_write(ss, 1, SPI_SH_CR3);
 267        } else {
 268                spi_sh_write(ss, 0, SPI_SH_CR3);
 269        }
 270
 271        return 0;
 272}
 273
 274static void spi_sh_work(struct work_struct *work)
 275{
 276        struct spi_sh_data *ss = container_of(work, struct spi_sh_data, ws);
 277        struct spi_message *mesg;
 278        struct spi_transfer *t;
 279        unsigned long flags;
 280        int ret;
 281
 282        pr_debug("%s: enter\n", __func__);
 283
 284        spin_lock_irqsave(&ss->lock, flags);
 285        while (!list_empty(&ss->queue)) {
 286                mesg = list_entry(ss->queue.next, struct spi_message, queue);
 287                list_del_init(&mesg->queue);
 288
 289                spin_unlock_irqrestore(&ss->lock, flags);
 290                list_for_each_entry(t, &mesg->transfers, transfer_list) {
 291                        pr_debug("tx_buf = %p, rx_buf = %p\n",
 292                                        t->tx_buf, t->rx_buf);
 293                        pr_debug("len = %d, delay_usecs = %d\n",
 294                                        t->len, t->delay_usecs);
 295
 296                        if (t->tx_buf) {
 297                                ret = spi_sh_send(ss, mesg, t);
 298                                if (ret < 0)
 299                                        goto error;
 300                        }
 301                        if (t->rx_buf) {
 302                                ret = spi_sh_receive(ss, mesg, t);
 303                                if (ret < 0)
 304                                        goto error;
 305                        }
 306                        mesg->actual_length += t->len;
 307                }
 308                spin_lock_irqsave(&ss->lock, flags);
 309
 310                mesg->status = 0;
 311                if (mesg->complete)
 312                        mesg->complete(mesg->context);
 313        }
 314
 315        clear_fifo(ss);
 316        spi_sh_set_bit(ss, SPI_SH_SSD, SPI_SH_CR1);
 317        udelay(100);
 318
 319        spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
 320                         SPI_SH_CR1);
 321
 322        clear_fifo(ss);
 323
 324        spin_unlock_irqrestore(&ss->lock, flags);
 325
 326        return;
 327
 328 error:
 329        mesg->status = ret;
 330        if (mesg->complete)
 331                mesg->complete(mesg->context);
 332
 333        spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
 334                         SPI_SH_CR1);
 335        clear_fifo(ss);
 336
 337}
 338
 339static int spi_sh_setup(struct spi_device *spi)
 340{
 341        struct spi_sh_data *ss = spi_master_get_devdata(spi->master);
 342
 343        pr_debug("%s: enter\n", __func__);
 344
 345        spi_sh_write(ss, 0xfe, SPI_SH_CR1);     /* SPI sycle stop */
 346        spi_sh_write(ss, 0x00, SPI_SH_CR1);     /* CR1 init */
 347        spi_sh_write(ss, 0x00, SPI_SH_CR3);     /* CR3 init */
 348
 349        clear_fifo(ss);
 350
 351        /* 1/8 clock */
 352        spi_sh_write(ss, spi_sh_read(ss, SPI_SH_CR2) | 0x07, SPI_SH_CR2);
 353        udelay(10);
 354
 355        return 0;
 356}
 357
 358static int spi_sh_transfer(struct spi_device *spi, struct spi_message *mesg)
 359{
 360        struct spi_sh_data *ss = spi_master_get_devdata(spi->master);
 361        unsigned long flags;
 362
 363        pr_debug("%s: enter\n", __func__);
 364        pr_debug("\tmode = %02x\n", spi->mode);
 365
 366        spin_lock_irqsave(&ss->lock, flags);
 367
 368        mesg->actual_length = 0;
 369        mesg->status = -EINPROGRESS;
 370
 371        spi_sh_clear_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
 372
 373        list_add_tail(&mesg->queue, &ss->queue);
 374        schedule_work(&ss->ws);
 375
 376        spin_unlock_irqrestore(&ss->lock, flags);
 377
 378        return 0;
 379}
 380
 381static void spi_sh_cleanup(struct spi_device *spi)
 382{
 383        struct spi_sh_data *ss = spi_master_get_devdata(spi->master);
 384
 385        pr_debug("%s: enter\n", __func__);
 386
 387        spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
 388                         SPI_SH_CR1);
 389}
 390
 391static irqreturn_t spi_sh_irq(int irq, void *_ss)
 392{
 393        struct spi_sh_data *ss = (struct spi_sh_data *)_ss;
 394        unsigned long cr1;
 395
 396        cr1 = spi_sh_read(ss, SPI_SH_CR1);
 397        if (cr1 & SPI_SH_TBE)
 398                ss->cr1 |= SPI_SH_TBE;
 399        if (cr1 & SPI_SH_TBF)
 400                ss->cr1 |= SPI_SH_TBF;
 401        if (cr1 & SPI_SH_RBE)
 402                ss->cr1 |= SPI_SH_RBE;
 403        if (cr1 & SPI_SH_RBF)
 404                ss->cr1 |= SPI_SH_RBF;
 405
 406        if (ss->cr1) {
 407                spi_sh_clear_bit(ss, ss->cr1, SPI_SH_CR4);
 408                wake_up(&ss->wait);
 409        }
 410
 411        return IRQ_HANDLED;
 412}
 413
 414static int spi_sh_remove(struct platform_device *pdev)
 415{
 416        struct spi_sh_data *ss = platform_get_drvdata(pdev);
 417
 418        spi_unregister_master(ss->master);
 419        flush_work(&ss->ws);
 420        free_irq(ss->irq, ss);
 421
 422        return 0;
 423}
 424
 425static int spi_sh_probe(struct platform_device *pdev)
 426{
 427        struct resource *res;
 428        struct spi_master *master;
 429        struct spi_sh_data *ss;
 430        int ret, irq;
 431
 432        /* get base addr */
 433        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 434        if (unlikely(res == NULL)) {
 435                dev_err(&pdev->dev, "invalid resource\n");
 436                return -EINVAL;
 437        }
 438
 439        irq = platform_get_irq(pdev, 0);
 440        if (irq < 0)
 441                return irq;
 442
 443        master = spi_alloc_master(&pdev->dev, sizeof(struct spi_sh_data));
 444        if (master == NULL) {
 445                dev_err(&pdev->dev, "spi_alloc_master error.\n");
 446                return -ENOMEM;
 447        }
 448
 449        ss = spi_master_get_devdata(master);
 450        platform_set_drvdata(pdev, ss);
 451
 452        switch (res->flags & IORESOURCE_MEM_TYPE_MASK) {
 453        case IORESOURCE_MEM_8BIT:
 454                ss->width = 8;
 455                break;
 456        case IORESOURCE_MEM_32BIT:
 457                ss->width = 32;
 458                break;
 459        default:
 460                dev_err(&pdev->dev, "No support width\n");
 461                ret = -ENODEV;
 462                goto error1;
 463        }
 464        ss->irq = irq;
 465        ss->master = master;
 466        ss->addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
 467        if (ss->addr == NULL) {
 468                dev_err(&pdev->dev, "ioremap error.\n");
 469                ret = -ENOMEM;
 470                goto error1;
 471        }
 472        INIT_LIST_HEAD(&ss->queue);
 473        spin_lock_init(&ss->lock);
 474        INIT_WORK(&ss->ws, spi_sh_work);
 475        init_waitqueue_head(&ss->wait);
 476
 477        ret = request_irq(irq, spi_sh_irq, 0, "spi_sh", ss);
 478        if (ret < 0) {
 479                dev_err(&pdev->dev, "request_irq error\n");
 480                goto error1;
 481        }
 482
 483        master->num_chipselect = 2;
 484        master->bus_num = pdev->id;
 485        master->setup = spi_sh_setup;
 486        master->transfer = spi_sh_transfer;
 487        master->cleanup = spi_sh_cleanup;
 488
 489        ret = spi_register_master(master);
 490        if (ret < 0) {
 491                printk(KERN_ERR "spi_register_master error.\n");
 492                goto error3;
 493        }
 494
 495        return 0;
 496
 497 error3:
 498        free_irq(irq, ss);
 499 error1:
 500        spi_master_put(master);
 501
 502        return ret;
 503}
 504
 505static struct platform_driver spi_sh_driver = {
 506        .probe = spi_sh_probe,
 507        .remove = spi_sh_remove,
 508        .driver = {
 509                .name = "sh_spi",
 510        },
 511};
 512module_platform_driver(spi_sh_driver);
 513
 514MODULE_DESCRIPTION("SH SPI bus driver");
 515MODULE_LICENSE("GPL v2");
 516MODULE_AUTHOR("Yoshihiro Shimoda");
 517MODULE_ALIAS("platform:sh_spi");
 518