drivers/spi/spi-coldfire-qspi.c

   1 /*
   2  * Freescale/Motorola Coldfire Queued SPI driver
   3  *
   4  * Copyright 2010 Steven King <sfking@fdwdc.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA
  19  *
  20 */
  21
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/errno.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/sched.h>
  28 #include <linux/delay.h>
  29 #include <linux/io.h>
  30 #include <linux/clk.h>
  31 #include <linux/err.h>
  32 #include <linux/spi/spi.h>
  33 #include <linux/pm_runtime.h>
  34
  35 #include <asm/coldfire.h>
  36 #include <asm/mcfsim.h>
  37 #include <asm/mcfqspi.h>
  38
  39 #define DRIVER_NAME "mcfqspi"
  40
  41 #define MCFQSPI_BUSCLK                  (MCF_BUSCLK / 2)
  42
  43 #define MCFQSPI_QMR                     0x00
  44 #define         MCFQSPI_QMR_MSTR        0x8000
  45 #define         MCFQSPI_QMR_CPOL        0x0200
  46 #define         MCFQSPI_QMR_CPHA        0x0100
  47 #define MCFQSPI_QDLYR                   0x04
  48 #define         MCFQSPI_QDLYR_SPE       0x8000
  49 #define MCFQSPI_QWR                     0x08
  50 #define         MCFQSPI_QWR_HALT        0x8000
  51 #define         MCFQSPI_QWR_WREN        0x4000
  52 #define         MCFQSPI_QWR_CSIV        0x1000
  53 #define MCFQSPI_QIR                     0x0C
  54 #define         MCFQSPI_QIR_WCEFB       0x8000
  55 #define         MCFQSPI_QIR_ABRTB       0x4000
  56 #define         MCFQSPI_QIR_ABRTL       0x1000
  57 #define         MCFQSPI_QIR_WCEFE       0x0800
  58 #define         MCFQSPI_QIR_ABRTE       0x0400
  59 #define         MCFQSPI_QIR_SPIFE       0x0100
  60 #define         MCFQSPI_QIR_WCEF        0x0008
  61 #define         MCFQSPI_QIR_ABRT        0x0004
  62 #define         MCFQSPI_QIR_SPIF        0x0001
  63 #define MCFQSPI_QAR                     0x010
  64 #define         MCFQSPI_QAR_TXBUF       0x00
  65 #define         MCFQSPI_QAR_RXBUF       0x10
  66 #define         MCFQSPI_QAR_CMDBUF      0x20
  67 #define MCFQSPI_QDR                     0x014
  68 #define MCFQSPI_QCR                     0x014
  69 #define         MCFQSPI_QCR_CONT        0x8000
  70 #define         MCFQSPI_QCR_BITSE       0x4000
  71 #define         MCFQSPI_QCR_DT          0x2000
  72
  73 struct mcfqspi {
  74         void __iomem *iobase;
  75         int irq;
  76         struct clk *clk;
  77         struct mcfqspi_cs_control *cs_control;
  78
  79         wait_queue_head_t waitq;
  80 };
  81
  82 static void mcfqspi_wr_qmr(struct mcfqspi *mcfqspi, u16 val)
  83 {
  84         writew(val, mcfqspi->iobase + MCFQSPI_QMR);
  85 }
  86
  87 static void mcfqspi_wr_qdlyr(struct mcfqspi *mcfqspi, u16 val)
  88 {
  89         writew(val, mcfqspi->iobase + MCFQSPI_QDLYR);
  90 }
  91
  92 static u16 mcfqspi_rd_qdlyr(struct mcfqspi *mcfqspi)
  93 {
  94         return readw(mcfqspi->iobase + MCFQSPI_QDLYR);
  95 }
  96
  97 static void mcfqspi_wr_qwr(struct mcfqspi *mcfqspi, u16 val)
  98 {
  99         writew(val, mcfqspi->iobase + MCFQSPI_QWR);
 100 }
 101
 102 static void mcfqspi_wr_qir(struct mcfqspi *mcfqspi, u16 val)
 103 {
 104         writew(val, mcfqspi->iobase + MCFQSPI_QIR);
 105 }
 106
 107 static void mcfqspi_wr_qar(struct mcfqspi *mcfqspi, u16 val)
 108 {
 109         writew(val, mcfqspi->iobase + MCFQSPI_QAR);
 110 }
 111
 112 static void mcfqspi_wr_qdr(struct mcfqspi *mcfqspi, u16 val)
 113 {
 114         writew(val, mcfqspi->iobase + MCFQSPI_QDR);
 115 }
 116
 117 static u16 mcfqspi_rd_qdr(struct mcfqspi *mcfqspi)
 118 {
 119         return readw(mcfqspi->iobase + MCFQSPI_QDR);
 120 }
 121
 122 static void mcfqspi_cs_select(struct mcfqspi *mcfqspi, u8 chip_select,
 123                             bool cs_high)
 124 {
 125         mcfqspi->cs_control->select(mcfqspi->cs_control, chip_select, cs_high);
 126 }
 127
 128 static void mcfqspi_cs_deselect(struct mcfqspi *mcfqspi, u8 chip_select,
 129                                 bool cs_high)
 130 {
 131         mcfqspi->cs_control->deselect(mcfqspi->cs_control, chip_select, cs_high);
 132 }
 133
 134 static int mcfqspi_cs_setup(struct mcfqspi *mcfqspi)
 135 {
 136         return (mcfqspi->cs_control->setup) ?
 137                 mcfqspi->cs_control->setup(mcfqspi->cs_control) : 0;
 138 }
 139
 140 static void mcfqspi_cs_teardown(struct mcfqspi *mcfqspi)
 141 {
 142         if (mcfqspi->cs_control->teardown)
 143                 mcfqspi->cs_control->teardown(mcfqspi->cs_control);
 144 }
 145
 146 static u8 mcfqspi_qmr_baud(u32 speed_hz)
 147 {
 148         return clamp((MCFQSPI_BUSCLK + speed_hz - 1) / speed_hz, 2u, 255u);
 149 }
 150
 151 static bool mcfqspi_qdlyr_spe(struct mcfqspi *mcfqspi)
 152 {
 153         return mcfqspi_rd_qdlyr(mcfqspi) & MCFQSPI_QDLYR_SPE;
 154 }
 155
 156 static irqreturn_t mcfqspi_irq_handler(int this_irq, void *dev_id)
 157 {
 158         struct mcfqspi *mcfqspi = dev_id;
 159
 160         /* clear interrupt */
 161         mcfqspi_wr_qir(mcfqspi, MCFQSPI_QIR_SPIFE | MCFQSPI_QIR_SPIF);
 162         wake_up(&mcfqspi->waitq);
 163
 164         return IRQ_HANDLED;
 165 }
 166
 167 static void mcfqspi_transfer_msg8(struct mcfqspi *mcfqspi, unsigned count,
 168                                   const u8 *txbuf, u8 *rxbuf)
 169 {
 170         unsigned i, n, offset = 0;
 171
 172         n = min(count, 16u);
 173
 174         mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_CMDBUF);
 175         for (i = 0; i < n; ++i)
 176                 mcfqspi_wr_qdr(mcfqspi, MCFQSPI_QCR_BITSE);
 177
 178         mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_TXBUF);
 179         if (txbuf)
 180                 for (i = 0; i < n; ++i)
 181                         mcfqspi_wr_qdr(mcfqspi, *txbuf++);
 182         else
 183                 for (i = 0; i < count; ++i)
 184                         mcfqspi_wr_qdr(mcfqspi, 0);
 185
 186         count -= n;
 187         if (count) {
 188                 u16 qwr = 0xf08;
 189                 mcfqspi_wr_qwr(mcfqspi, 0x700);
 190                 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
 191
 192                 do {
 193                         wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
 194                         mcfqspi_wr_qwr(mcfqspi, qwr);
 195                         mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
 196                         if (rxbuf) {
 197                                 mcfqspi_wr_qar(mcfqspi,
 198                                                MCFQSPI_QAR_RXBUF + offset);
 199                                 for (i = 0; i < 8; ++i)
 200                                         *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
 201                         }
 202                         n = min(count, 8u);
 203                         if (txbuf) {
 204                                 mcfqspi_wr_qar(mcfqspi,
 205                                                MCFQSPI_QAR_TXBUF + offset);
 206                                 for (i = 0; i < n; ++i)
 207                                         mcfqspi_wr_qdr(mcfqspi, *txbuf++);
 208                         }
 209                         qwr = (offset ? 0x808 : 0) + ((n - 1) << 8);
 210                         offset ^= 8;
 211                         count -= n;
 212                 } while (count);
 213                 wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
 214                 mcfqspi_wr_qwr(mcfqspi, qwr);
 215                 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
 216                 if (rxbuf) {
 217                         mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
 218                         for (i = 0; i < 8; ++i)
 219                                 *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
 220                         offset ^= 8;
 221                 }
 222         } else {
 223                 mcfqspi_wr_qwr(mcfqspi, (n - 1) << 8);
 224                 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
 225         }
 226         wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
 227         if (rxbuf) {
 228                 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
 229                 for (i = 0; i < n; ++i)
 230                         *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
 231         }
 232 }
 233
 234 static void mcfqspi_transfer_msg16(struct mcfqspi *mcfqspi, unsigned count,
 235                                    const u16 *txbuf, u16 *rxbuf)
 236 {
 237         unsigned i, n, offset = 0;
 238
 239         n = min(count, 16u);
 240
 241         mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_CMDBUF);
 242         for (i = 0; i < n; ++i)
 243                 mcfqspi_wr_qdr(mcfqspi, MCFQSPI_QCR_BITSE);
 244
 245         mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_TXBUF);
 246         if (txbuf)
 247                 for (i = 0; i < n; ++i)
 248                         mcfqspi_wr_qdr(mcfqspi, *txbuf++);
 249         else
 250                 for (i = 0; i < count; ++i)
 251                         mcfqspi_wr_qdr(mcfqspi, 0);
 252
 253         count -= n;
 254         if (count) {
 255                 u16 qwr = 0xf08;
 256                 mcfqspi_wr_qwr(mcfqspi, 0x700);
 257                 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
 258
 259                 do {
 260                         wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
 261                         mcfqspi_wr_qwr(mcfqspi, qwr);
 262                         mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
 263                         if (rxbuf) {
 264                                 mcfqspi_wr_qar(mcfqspi,
 265                                                MCFQSPI_QAR_RXBUF + offset);
 266                                 for (i = 0; i < 8; ++i)
 267                                         *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
 268                         }
 269                         n = min(count, 8u);
 270                         if (txbuf) {
 271                                 mcfqspi_wr_qar(mcfqspi,
 272                                                MCFQSPI_QAR_TXBUF + offset);
 273                                 for (i = 0; i < n; ++i)
 274                                         mcfqspi_wr_qdr(mcfqspi, *txbuf++);
 275                         }
 276                         qwr = (offset ? 0x808 : 0x000) + ((n - 1) << 8);
 277                         offset ^= 8;
 278                         count -= n;
 279                 } while (count);
 280                 wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
 281                 mcfqspi_wr_qwr(mcfqspi, qwr);
 282                 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
 283                 if (rxbuf) {
 284                         mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
 285                         for (i = 0; i < 8; ++i)
 286                                 *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
 287                         offset ^= 8;
 288                 }
 289         } else {
 290                 mcfqspi_wr_qwr(mcfqspi, (n - 1) << 8);
 291                 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
 292         }
 293         wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
 294         if (rxbuf) {
 295                 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
 296                 for (i = 0; i < n; ++i)
 297                         *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
 298         }
 299 }
 300
 301 static void mcfqspi_set_cs(struct spi_device *spi, bool enable)
 302 {
 303         struct mcfqspi *mcfqspi = spi_master_get_devdata(spi->master);
 304         bool cs_high = spi->mode & SPI_CS_HIGH;
 305
 306         if (enable)
 307                 mcfqspi_cs_select(mcfqspi, spi->chip_select, cs_high);
 308         else
 309                 mcfqspi_cs_deselect(mcfqspi, spi->chip_select, cs_high);
 310 }
 311
 312 static int mcfqspi_transfer_one(struct spi_master *master,
 313                                 struct spi_device *spi,
 314                                 struct spi_transfer *t)
 315 {
 316         struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
 317         u16 qmr = MCFQSPI_QMR_MSTR;
 318
 319         qmr |= t->bits_per_word << 10;
 320         if (spi->mode & SPI_CPHA)
 321                 qmr |= MCFQSPI_QMR_CPHA;
 322         if (spi->mode & SPI_CPOL)
 323                 qmr |= MCFQSPI_QMR_CPOL;
 324         qmr |= mcfqspi_qmr_baud(t->speed_hz);
 325         mcfqspi_wr_qmr(mcfqspi, qmr);
 326
 327         mcfqspi_wr_qir(mcfqspi, MCFQSPI_QIR_SPIFE);
 328         if (t->bits_per_word == 8)
 329                 mcfqspi_transfer_msg8(mcfqspi, t->len, t->tx_buf, t->rx_buf);
 330         else
 331                 mcfqspi_transfer_msg16(mcfqspi, t->len / 2, t->tx_buf,
 332                                        t->rx_buf);
 333         mcfqspi_wr_qir(mcfqspi, 0);
 334
 335         return 0;
 336 }
 337
 338 static int mcfqspi_setup(struct spi_device *spi)
 339 {
 340         mcfqspi_cs_deselect(spi_master_get_devdata(spi->master),
 341                             spi->chip_select, spi->mode & SPI_CS_HIGH);
 342
 343         dev_dbg(&spi->dev,
 344                         "bits per word %d, chip select %d, speed %d KHz\n",
 345                         spi->bits_per_word, spi->chip_select,
 346                         (MCFQSPI_BUSCLK / mcfqspi_qmr_baud(spi->max_speed_hz))
 347                         / 1000);
 348
 349         return 0;
 350 }
 351
 352 static int mcfqspi_probe(struct platform_device *pdev)
 353 {
 354         struct spi_master *master;
 355         struct mcfqspi *mcfqspi;
 356         struct resource *res;
 357         struct mcfqspi_platform_data *pdata;
 358         int status;
 359
 360         pdata = dev_get_platdata(&pdev->dev);
 361         if (!pdata) {
 362                 dev_dbg(&pdev->dev, "platform data is missing\n");
 363                 return -ENOENT;
 364         }
 365
 366         if (!pdata->cs_control) {
 367                 dev_dbg(&pdev->dev, "pdata->cs_control is NULL\n");
 368                 return -EINVAL;
 369         }
 370
 371         master = spi_alloc_master(&pdev->dev, sizeof(*mcfqspi));
 372         if (master == NULL) {
 373                 dev_dbg(&pdev->dev, "spi_alloc_master failed\n");
 374                 return -ENOMEM;
 375         }
 376
 377         mcfqspi = spi_master_get_devdata(master);
 378
 379         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 380         mcfqspi->iobase = devm_ioremap_resource(&pdev->dev, res);
 381         if (IS_ERR(mcfqspi->iobase)) {
 382                 status = PTR_ERR(mcfqspi->iobase);
 383                 goto fail0;
 384         }
 385
 386         mcfqspi->irq = platform_get_irq(pdev, 0);
 387         if (mcfqspi->irq < 0) {
 388                 dev_dbg(&pdev->dev, "platform_get_irq failed\n");
 389                 status = -ENXIO;
 390                 goto fail0;
 391         }
 392
 393         status = devm_request_irq(&pdev->dev, mcfqspi->irq, mcfqspi_irq_handler,
 394                                 0, pdev->name, mcfqspi);
 395         if (status) {
 396                 dev_dbg(&pdev->dev, "request_irq failed\n");
 397                 goto fail0;
 398         }
 399
 400         mcfqspi->clk = devm_clk_get(&pdev->dev, "qspi_clk");
 401         if (IS_ERR(mcfqspi->clk)) {
 402                 dev_dbg(&pdev->dev, "clk_get failed\n");
 403                 status = PTR_ERR(mcfqspi->clk);
 404                 goto fail0;
 405         }
 406         clk_enable(mcfqspi->clk);
 407
 408         master->bus_num = pdata->bus_num;
 409         master->num_chipselect = pdata->num_chipselect;
 410
 411         mcfqspi->cs_control = pdata->cs_control;
 412         status = mcfqspi_cs_setup(mcfqspi);
 413         if (status) {
 414                 dev_dbg(&pdev->dev, "error initializing cs_control\n");
 415                 goto fail1;
 416         }
 417
 418         init_waitqueue_head(&mcfqspi->waitq);
 419
 420         master->mode_bits = SPI_CS_HIGH | SPI_CPOL | SPI_CPHA;
 421         master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 16);
 422         master->setup = mcfqspi_setup;
 423         master->set_cs = mcfqspi_set_cs;
 424         master->transfer_one = mcfqspi_transfer_one;
 425         master->auto_runtime_pm = true;
 426
 427         platform_set_drvdata(pdev, master);
 428
 429         status = devm_spi_register_master(&pdev->dev, master);
 430         if (status) {
 431                 dev_dbg(&pdev->dev, "spi_register_master failed\n");
 432                 goto fail2;
 433         }
 434         pm_runtime_enable(&pdev->dev);
 435
 436         dev_info(&pdev->dev, "Coldfire QSPI bus driver\n");
 437
 438         return 0;
 439
 440 fail2:
 441         mcfqspi_cs_teardown(mcfqspi);
 442 fail1:
 443         clk_disable(mcfqspi->clk);
 444 fail0:
 445         spi_master_put(master);
 446
 447         dev_dbg(&pdev->dev, "Coldfire QSPI probe failed\n");
 448
 449         return status;
 450 }
 451
 452 static int mcfqspi_remove(struct platform_device *pdev)
 453 {
 454         struct spi_master *master = platform_get_drvdata(pdev);
 455         struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
 456
 457         pm_runtime_disable(&pdev->dev);
 458         /* disable the hardware (set the baud rate to 0) */
 459         mcfqspi_wr_qmr(mcfqspi, MCFQSPI_QMR_MSTR);
 460
 461         mcfqspi_cs_teardown(mcfqspi);
 462         clk_disable(mcfqspi->clk);
 463
 464         return 0;
 465 }
 466
 467 #ifdef CONFIG_PM_SLEEP
 468 static int mcfqspi_suspend(struct device *dev)
 469 {
 470         struct spi_master *master = dev_get_drvdata(dev);
 471         struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
 472         int ret;
 473
 474         ret = spi_master_suspend(master);
 475         if (ret)
 476                 return ret;
 477
 478         clk_disable(mcfqspi->clk);
 479
 480         return 0;
 481 }
 482
 483 static int mcfqspi_resume(struct device *dev)
 484 {
 485         struct spi_master *master = dev_get_drvdata(dev);
 486         struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
 487
 488         clk_enable(mcfqspi->clk);
 489
 490         return spi_master_resume(master);
 491 }
 492 #endif
 493
 494 #ifdef CONFIG_PM_RUNTIME
 495 static int mcfqspi_runtime_suspend(struct device *dev)
 496 {
 497         struct spi_master *master = dev_get_drvdata(dev);
 498         struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
 499
 500         clk_disable(mcfqspi->clk);
 501
 502         return 0;
 503 }
 504
 505 static int mcfqspi_runtime_resume(struct device *dev)
 506 {
 507         struct spi_master *master = dev_get_drvdata(dev);
 508         struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
 509
 510         clk_enable(mcfqspi->clk);
 511
 512         return 0;
 513 }
 514 #endif
 515
 516 static const struct dev_pm_ops mcfqspi_pm = {
 517         SET_SYSTEM_SLEEP_PM_OPS(mcfqspi_suspend, mcfqspi_resume)
 518         SET_RUNTIME_PM_OPS(mcfqspi_runtime_suspend, mcfqspi_runtime_resume,
 519                         NULL)
 520 };
 521
 522 static struct platform_driver mcfqspi_driver = {
 523         .driver.name    = DRIVER_NAME,
 524         .driver.owner   = THIS_MODULE,
 525         .driver.pm      = &mcfqspi_pm,
 526         .probe          = mcfqspi_probe,
 527         .remove         = mcfqspi_remove,
 528 };
 529 module_platform_driver(mcfqspi_driver);
 530
 531 MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
 532 MODULE_DESCRIPTION("Coldfire QSPI Controller Driver");
 533 MODULE_LICENSE("GPL");
 534 MODULE_ALIAS("platform:" DRIVER_NAME);