drivers/spi/mpc52xx_psc_spi.c

   1 /*
   2  * MPC52xx SPC in SPI mode driver.
   3  *
   4  * Maintainer: Dragos Carp
   5  *
   6  * Copyright (C) 2006 TOPTICA Photonics AG.
   7  *
   8  * This program is free software; you can redistribute  it and/or modify it
   9  * under  the terms of  the GNU General  Public License as published by the
  10  * Free Software Foundation;  either version 2 of the  License, or (at your
  11  * option) any later version.
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/errno.h>
  17 #include <linux/interrupt.h>
  18
  19 #if defined(CONFIG_PPC_MERGE)
  20 #include <asm/of_platform.h>
  21 #else
  22 #include <linux/platform_device.h>
  23 #endif
  24
  25 #include <linux/workqueue.h>
  26 #include <linux/completion.h>
  27 #include <linux/io.h>
  28 #include <linux/delay.h>
  29 #include <linux/spi/spi.h>
  30 #include <linux/fsl_devices.h>
  31
  32 #include <asm/mpc52xx.h>
  33 #include <asm/mpc52xx_psc.h>
  34
  35 #define MCLK 20000000 /* PSC port MClk in hz */
  36
  37 struct mpc52xx_psc_spi {
  38         /* fsl_spi_platform data */
  39         void (*activate_cs)(u8, u8);
  40         void (*deactivate_cs)(u8, u8);
  41         u32 sysclk;
  42
  43         /* driver internal data */
  44         struct mpc52xx_psc __iomem *psc;
  45         unsigned int irq;
  46         u8 bits_per_word;
  47         u8 busy;
  48
  49         struct workqueue_struct *workqueue;
  50         struct work_struct work;
  51
  52         struct list_head queue;
  53         spinlock_t lock;
  54
  55         struct completion done;
  56 };
  57
  58 /* controller state */
  59 struct mpc52xx_psc_spi_cs {
  60         int bits_per_word;
  61         int speed_hz;
  62 };
  63
  64 /* set clock freq, clock ramp, bits per work
  65  * if t is NULL then reset the values to the default values
  66  */
  67 static int mpc52xx_psc_spi_transfer_setup(struct spi_device *spi,
  68                 struct spi_transfer *t)
  69 {
  70         struct mpc52xx_psc_spi_cs *cs = spi->controller_state;
  71
  72         cs->speed_hz = (t && t->speed_hz)
  73                         ? t->speed_hz : spi->max_speed_hz;
  74         cs->bits_per_word = (t && t->bits_per_word)
  75                         ? t->bits_per_word : spi->bits_per_word;
  76         cs->bits_per_word = ((cs->bits_per_word + 7) / 8) * 8;
  77         return 0;
  78 }
  79
  80 static void mpc52xx_psc_spi_activate_cs(struct spi_device *spi)
  81 {
  82         struct mpc52xx_psc_spi_cs *cs = spi->controller_state;
  83         struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
  84         struct mpc52xx_psc __iomem *psc = mps->psc;
  85         u32 sicr;
  86         u16 ccr;
  87
  88         sicr = in_be32(&psc->sicr);
  89
  90         /* Set clock phase and polarity */
  91         if (spi->mode & SPI_CPHA)
  92                 sicr |= 0x00001000;
  93         else
  94                 sicr &= ~0x00001000;
  95         if (spi->mode & SPI_CPOL)
  96                 sicr |= 0x00002000;
  97         else
  98                 sicr &= ~0x00002000;
  99
 100         if (spi->mode & SPI_LSB_FIRST)
 101                 sicr |= 0x10000000;
 102         else
 103                 sicr &= ~0x10000000;
 104         out_be32(&psc->sicr, sicr);
 105
 106         /* Set clock frequency and bits per word
 107          * Because psc->ccr is defined as 16bit register instead of 32bit
 108          * just set the lower byte of BitClkDiv
 109          */
 110         ccr = in_be16(&psc->ccr);
 111         ccr &= 0xFF00;
 112         if (cs->speed_hz)
 113                 ccr |= (MCLK / cs->speed_hz - 1) & 0xFF;
 114         else /* by default SPI Clk 1MHz */
 115                 ccr |= (MCLK / 1000000 - 1) & 0xFF;
 116         out_be16(&psc->ccr, ccr);
 117         mps->bits_per_word = cs->bits_per_word;
 118
 119         if (mps->activate_cs)
 120                 mps->activate_cs(spi->chip_select,
 121                                 (spi->mode & SPI_CS_HIGH) ? 1 : 0);
 122 }
 123
 124 static void mpc52xx_psc_spi_deactivate_cs(struct spi_device *spi)
 125 {
 126         struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
 127
 128         if (mps->deactivate_cs)
 129                 mps->deactivate_cs(spi->chip_select,
 130                                 (spi->mode & SPI_CS_HIGH) ? 1 : 0);
 131 }
 132
 133 #define MPC52xx_PSC_BUFSIZE (MPC52xx_PSC_RFNUM_MASK + 1)
 134 /* wake up when 80% fifo full */
 135 #define MPC52xx_PSC_RFALARM (MPC52xx_PSC_BUFSIZE * 20 / 100)
 136
 137 static int mpc52xx_psc_spi_transfer_rxtx(struct spi_device *spi,
 138                                                 struct spi_transfer *t)
 139 {
 140         struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
 141         struct mpc52xx_psc __iomem *psc = mps->psc;
 142         unsigned rb = 0;        /* number of bytes receieved */
 143         unsigned sb = 0;        /* number of bytes sent */
 144         unsigned char *rx_buf = (unsigned char *)t->rx_buf;
 145         unsigned char *tx_buf = (unsigned char *)t->tx_buf;
 146         unsigned rfalarm;
 147         unsigned send_at_once = MPC52xx_PSC_BUFSIZE;
 148         unsigned recv_at_once;
 149         unsigned bpw = mps->bits_per_word / 8;
 150
 151         if (!t->tx_buf && !t->rx_buf && t->len)
 152                 return -EINVAL;
 153
 154         /* enable transmiter/receiver */
 155         out_8(&psc->command, MPC52xx_PSC_TX_ENABLE | MPC52xx_PSC_RX_ENABLE);
 156         while (rb < t->len) {
 157                 if (t->len - rb > MPC52xx_PSC_BUFSIZE) {
 158                         rfalarm = MPC52xx_PSC_RFALARM;
 159                 } else {
 160                         send_at_once = t->len - sb;
 161                         rfalarm = MPC52xx_PSC_BUFSIZE - (t->len - rb);
 162                 }
 163
 164                 dev_dbg(&spi->dev, "send %d bytes...\n", send_at_once);
 165                 if (tx_buf) {
 166                         for (; send_at_once; sb++, send_at_once--) {
 167                                 /* set EOF flag */
 168                                 if (mps->bits_per_word
 169                                                 && (sb + 1) % bpw == 0)
 170                                         out_8(&psc->ircr2, 0x01);
 171                                 out_8(&psc->mpc52xx_psc_buffer_8, tx_buf[sb]);
 172                         }
 173                 } else {
 174                         for (; send_at_once; sb++, send_at_once--) {
 175                                 /* set EOF flag */
 176                                 if (mps->bits_per_word
 177                                                 && ((sb + 1) % bpw) == 0)
 178                                         out_8(&psc->ircr2, 0x01);
 179                                 out_8(&psc->mpc52xx_psc_buffer_8, 0);
 180                         }
 181                 }
 182
 183
 184                 /* enable interrupts and wait for wake up
 185                  * if just one byte is expected the Rx FIFO genererates no
 186                  * FFULL interrupt, so activate the RxRDY interrupt
 187                  */
 188                 out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1);
 189                 if (t->len - rb == 1) {
 190                         out_8(&psc->mode, 0);
 191                 } else {
 192                         out_8(&psc->mode, MPC52xx_PSC_MODE_FFULL);
 193                         out_be16(&psc->rfalarm, rfalarm);
 194                 }
 195                 out_be16(&psc->mpc52xx_psc_imr, MPC52xx_PSC_IMR_RXRDY);
 196                 wait_for_completion(&mps->done);
 197                 recv_at_once = in_be16(&psc->rfnum);
 198                 dev_dbg(&spi->dev, "%d bytes received\n", recv_at_once);
 199
 200                 send_at_once = recv_at_once;
 201                 if (rx_buf) {
 202                         for (; recv_at_once; rb++, recv_at_once--)
 203                                 rx_buf[rb] = in_8(&psc->mpc52xx_psc_buffer_8);
 204                 } else {
 205                         for (; recv_at_once; rb++, recv_at_once--)
 206                                 in_8(&psc->mpc52xx_psc_buffer_8);
 207                 }
 208         }
 209         /* disable transmiter/receiver */
 210         out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE);
 211
 212         return 0;
 213 }
 214
 215 static void mpc52xx_psc_spi_work(struct work_struct *work)
 216 {
 217         struct mpc52xx_psc_spi *mps =
 218                 container_of(work, struct mpc52xx_psc_spi, work);
 219
 220         spin_lock_irq(&mps->lock);
 221         mps->busy = 1;
 222         while (!list_empty(&mps->queue)) {
 223                 struct spi_message *m;
 224                 struct spi_device *spi;
 225                 struct spi_transfer *t = NULL;
 226                 unsigned cs_change;
 227                 int status;
 228
 229                 m = container_of(mps->queue.next, struct spi_message, queue);
 230                 list_del_init(&m->queue);
 231                 spin_unlock_irq(&mps->lock);
 232
 233                 spi = m->spi;
 234                 cs_change = 1;
 235                 status = 0;
 236                 list_for_each_entry (t, &m->transfers, transfer_list) {
 237                         if (t->bits_per_word || t->speed_hz) {
 238                                 status = mpc52xx_psc_spi_transfer_setup(spi, t);
 239                                 if (status < 0)
 240                                         break;
 241                         }
 242
 243                         if (cs_change)
 244                                 mpc52xx_psc_spi_activate_cs(spi);
 245                         cs_change = t->cs_change;
 246
 247                         status = mpc52xx_psc_spi_transfer_rxtx(spi, t);
 248                         if (status)
 249                                 break;
 250                         m->actual_length += t->len;
 251
 252                         if (t->delay_usecs)
 253                                 udelay(t->delay_usecs);
 254
 255                         if (cs_change)
 256                                 mpc52xx_psc_spi_deactivate_cs(spi);
 257                 }
 258
 259                 m->status = status;
 260                 m->complete(m->context);
 261
 262                 if (status || !cs_change)
 263                         mpc52xx_psc_spi_deactivate_cs(spi);
 264
 265                 mpc52xx_psc_spi_transfer_setup(spi, NULL);
 266
 267                 spin_lock_irq(&mps->lock);
 268         }
 269         mps->busy = 0;
 270         spin_unlock_irq(&mps->lock);
 271 }
 272
 273 /* the spi->mode bits understood by this driver: */
 274 #define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST)
 275
 276 static int mpc52xx_psc_spi_setup(struct spi_device *spi)
 277 {
 278         struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
 279         struct mpc52xx_psc_spi_cs *cs = spi->controller_state;
 280         unsigned long flags;
 281
 282         if (spi->bits_per_word%8)
 283                 return -EINVAL;
 284
 285         if (spi->mode & ~MODEBITS) {
 286                 dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
 287                         spi->mode & ~MODEBITS);
 288                 return -EINVAL;
 289         }
 290
 291         if (!cs) {
 292                 cs = kzalloc(sizeof *cs, GFP_KERNEL);
 293                 if (!cs)
 294                         return -ENOMEM;
 295                 spi->controller_state = cs;
 296         }
 297
 298         cs->bits_per_word = spi->bits_per_word;
 299         cs->speed_hz = spi->max_speed_hz;
 300
 301         spin_lock_irqsave(&mps->lock, flags);
 302         if (!mps->busy)
 303                 mpc52xx_psc_spi_deactivate_cs(spi);
 304         spin_unlock_irqrestore(&mps->lock, flags);
 305
 306         return 0;
 307 }
 308
 309 static int mpc52xx_psc_spi_transfer(struct spi_device *spi,
 310                 struct spi_message *m)
 311 {
 312         struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
 313         unsigned long flags;
 314
 315         m->actual_length = 0;
 316         m->status = -EINPROGRESS;
 317
 318         spin_lock_irqsave(&mps->lock, flags);
 319         list_add_tail(&m->queue, &mps->queue);
 320         queue_work(mps->workqueue, &mps->work);
 321         spin_unlock_irqrestore(&mps->lock, flags);
 322
 323         return 0;
 324 }
 325
 326 static void mpc52xx_psc_spi_cleanup(struct spi_device *spi)
 327 {
 328         kfree(spi->controller_state);
 329 }
 330
 331 static int mpc52xx_psc_spi_port_config(int psc_id, struct mpc52xx_psc_spi *mps)
 332 {
 333         struct mpc52xx_psc __iomem *psc = mps->psc;
 334         u32 mclken_div;
 335         int ret = 0;
 336
 337         /* default sysclk is 512MHz */
 338         mclken_div = (mps->sysclk ? mps->sysclk : 512000000) / MCLK;
 339         mpc52xx_set_psc_clkdiv(psc_id, mclken_div);
 340
 341         /* Reset the PSC into a known state */
 342         out_8(&psc->command, MPC52xx_PSC_RST_RX);
 343         out_8(&psc->command, MPC52xx_PSC_RST_TX);
 344         out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE);
 345
 346         /* Disable interrupts, interrupts are based on alarm level */
 347         out_be16(&psc->mpc52xx_psc_imr, 0);
 348         out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1);
 349         out_8(&psc->rfcntl, 0);
 350         out_8(&psc->mode, MPC52xx_PSC_MODE_FFULL);
 351
 352         /* Configure 8bit codec mode as a SPI master and use EOF flags */
 353         /* SICR_SIM_CODEC8|SICR_GENCLK|SICR_SPI|SICR_MSTR|SICR_USEEOF */
 354         out_be32(&psc->sicr, 0x0180C800);
 355         out_be16(&psc->ccr, 0x070F); /* by default SPI Clk 1MHz */
 356
 357         /* Set 2ms DTL delay */
 358         out_8(&psc->ctur, 0x00);
 359         out_8(&psc->ctlr, 0x84);
 360
 361         mps->bits_per_word = 8;
 362
 363         return ret;
 364 }
 365
 366 static irqreturn_t mpc52xx_psc_spi_isr(int irq, void *dev_id)
 367 {
 368         struct mpc52xx_psc_spi *mps = (struct mpc52xx_psc_spi *)dev_id;
 369         struct mpc52xx_psc __iomem *psc = mps->psc;
 370
 371         /* disable interrupt and wake up the work queue */
 372         if (in_be16(&psc->mpc52xx_psc_isr) & MPC52xx_PSC_IMR_RXRDY) {
 373                 out_be16(&psc->mpc52xx_psc_imr, 0);
 374                 complete(&mps->done);
 375                 return IRQ_HANDLED;
 376         }
 377         return IRQ_NONE;
 378 }
 379
 380 /* bus_num is used only for the case dev->platform_data == NULL */
 381 static int __init mpc52xx_psc_spi_do_probe(struct device *dev, u32 regaddr,
 382                                 u32 size, unsigned int irq, s16 bus_num)
 383 {
 384         struct fsl_spi_platform_data *pdata = dev->platform_data;
 385         struct mpc52xx_psc_spi *mps;
 386         struct spi_master *master;
 387         int ret;
 388
 389         master = spi_alloc_master(dev, sizeof *mps);
 390         if (master == NULL)
 391                 return -ENOMEM;
 392
 393         dev_set_drvdata(dev, master);
 394         mps = spi_master_get_devdata(master);
 395
 396         mps->irq = irq;
 397         if (pdata == NULL) {
 398                 dev_warn(dev, "probe called without platform data, no "
 399                                 "(de)activate_cs function will be called\n");
 400                 mps->activate_cs = NULL;
 401                 mps->deactivate_cs = NULL;
 402                 mps->sysclk = 0;
 403                 master->bus_num = bus_num;
 404                 master->num_chipselect = 255;
 405         } else {
 406                 mps->activate_cs = pdata->activate_cs;
 407                 mps->deactivate_cs = pdata->deactivate_cs;
 408                 mps->sysclk = pdata->sysclk;
 409                 master->bus_num = pdata->bus_num;
 410                 master->num_chipselect = pdata->max_chipselect;
 411         }
 412         master->setup = mpc52xx_psc_spi_setup;
 413         master->transfer = mpc52xx_psc_spi_transfer;
 414         master->cleanup = mpc52xx_psc_spi_cleanup;
 415
 416         mps->psc = ioremap(regaddr, size);
 417         if (!mps->psc) {
 418                 dev_err(dev, "could not ioremap I/O port range\n");
 419                 ret = -EFAULT;
 420                 goto free_master;
 421         }
 422
 423         ret = request_irq(mps->irq, mpc52xx_psc_spi_isr, 0, "mpc52xx-psc-spi",
 424                                 mps);
 425         if (ret)
 426                 goto free_master;
 427
 428         ret = mpc52xx_psc_spi_port_config(master->bus_num, mps);
 429         if (ret < 0)
 430                 goto free_irq;
 431
 432         spin_lock_init(&mps->lock);
 433         init_completion(&mps->done);
 434         INIT_WORK(&mps->work, mpc52xx_psc_spi_work);
 435         INIT_LIST_HEAD(&mps->queue);
 436
 437         mps->workqueue = create_singlethread_workqueue(
 438                 master->dev.parent->bus_id);
 439         if (mps->workqueue == NULL) {
 440                 ret = -EBUSY;
 441                 goto free_irq;
 442         }
 443
 444         ret = spi_register_master(master);
 445         if (ret < 0)
 446                 goto unreg_master;
 447
 448         return ret;
 449
 450 unreg_master:
 451         destroy_workqueue(mps->workqueue);
 452 free_irq:
 453         free_irq(mps->irq, mps);
 454 free_master:
 455         if (mps->psc)
 456                 iounmap(mps->psc);
 457         spi_master_put(master);
 458
 459         return ret;
 460 }
 461
 462 static int __exit mpc52xx_psc_spi_do_remove(struct device *dev)
 463 {
 464         struct spi_master *master = dev_get_drvdata(dev);
 465         struct mpc52xx_psc_spi *mps = spi_master_get_devdata(master);
 466
 467         flush_workqueue(mps->workqueue);
 468         destroy_workqueue(mps->workqueue);
 469         spi_unregister_master(master);
 470         free_irq(mps->irq, mps);
 471         if (mps->psc)
 472                 iounmap(mps->psc);
 473
 474         return 0;
 475 }
 476
 477 #if !defined(CONFIG_PPC_MERGE)
 478 static int __init mpc52xx_psc_spi_probe(struct platform_device *dev)
 479 {
 480         switch(dev->id) {
 481         case 1:
 482         case 2:
 483         case 3:
 484         case 6:
 485                 return mpc52xx_psc_spi_do_probe(&dev->dev,
 486                         MPC52xx_PA(MPC52xx_PSCx_OFFSET(dev->id)),
 487                         MPC52xx_PSC_SIZE, platform_get_irq(dev, 0), dev->id);
 488         default:
 489                 return -EINVAL;
 490         }
 491 }
 492
 493 static int __exit mpc52xx_psc_spi_remove(struct platform_device *dev)
 494 {
 495         return mpc52xx_psc_spi_do_remove(&dev->dev);
 496 }
 497
 498 static struct platform_driver mpc52xx_psc_spi_platform_driver = {
 499         .remove = __exit_p(mpc52xx_psc_spi_remove),
 500         .driver = {
 501                 .name = "mpc52xx-psc-spi",
 502                 .owner = THIS_MODULE,
 503         },
 504 };
 505
 506 static int __init mpc52xx_psc_spi_init(void)
 507 {
 508         return platform_driver_probe(&mpc52xx_psc_spi_platform_driver,
 509                         mpc52xx_psc_spi_probe);
 510 }
 511 module_init(mpc52xx_psc_spi_init);
 512
 513 static void __exit mpc52xx_psc_spi_exit(void)
 514 {
 515         platform_driver_unregister(&mpc52xx_psc_spi_platform_driver);
 516 }
 517 module_exit(mpc52xx_psc_spi_exit);
 518
 519 #else   /* defined(CONFIG_PPC_MERGE) */
 520
 521 static int __init mpc52xx_psc_spi_of_probe(struct of_device *op,
 522         const struct of_device_id *match)
 523 {
 524         const u32 *regaddr_p;
 525         u64 regaddr64, size64;
 526         s16 id = -1;
 527
 528         regaddr_p = of_get_address(op->node, 0, &size64, NULL);
 529         if (!regaddr_p) {
 530                 printk(KERN_ERR "Invalid PSC address\n");
 531                 return -EINVAL;
 532         }
 533         regaddr64 = of_translate_address(op->node, regaddr_p);
 534
 535         /* get PSC id (1..6, used by port_config) */
 536         if (op->dev.platform_data == NULL) {
 537                 const u32 *psc_nump;
 538
 539                 psc_nump = of_get_property(op->node, "cell-index", NULL);
 540                 if (!psc_nump || *psc_nump > 5) {
 541                         printk(KERN_ERR "mpc52xx_psc_spi: Device node %s has invalid "
 542                                         "cell-index property\n", op->node->full_name);
 543                         return -EINVAL;
 544                 }
 545                 id = *psc_nump + 1;
 546         }
 547
 548         return mpc52xx_psc_spi_do_probe(&op->dev, (u32)regaddr64, (u32)size64,
 549                                         irq_of_parse_and_map(op->node, 0), id);
 550 }
 551
 552 static int __exit mpc52xx_psc_spi_of_remove(struct of_device *op)
 553 {
 554         return mpc52xx_psc_spi_do_remove(&op->dev);
 555 }
 556
 557 static struct of_device_id mpc52xx_psc_spi_of_match[] = {
 558         { .compatible = "fsl,mpc5200-psc-spi", },
 559         { .compatible = "mpc5200-psc-spi", }, /* old */
 560         {}
 561 };
 562
 563 MODULE_DEVICE_TABLE(of, mpc52xx_psc_spi_of_match);
 564
 565 static struct of_platform_driver mpc52xx_psc_spi_of_driver = {
 566         .owner = THIS_MODULE,
 567         .name = "mpc52xx-psc-spi",
 568         .match_table = mpc52xx_psc_spi_of_match,
 569         .probe = mpc52xx_psc_spi_of_probe,
 570         .remove = __exit_p(mpc52xx_psc_spi_of_remove),
 571         .driver = {
 572                 .name = "mpc52xx-psc-spi",
 573                 .owner = THIS_MODULE,
 574         },
 575 };
 576
 577 static int __init mpc52xx_psc_spi_init(void)
 578 {
 579         return of_register_platform_driver(&mpc52xx_psc_spi_of_driver);
 580 }
 581 module_init(mpc52xx_psc_spi_init);
 582
 583 static void __exit mpc52xx_psc_spi_exit(void)
 584 {
 585         of_unregister_platform_driver(&mpc52xx_psc_spi_of_driver);
 586 }
 587 module_exit(mpc52xx_psc_spi_exit);
 588
 589 #endif  /* defined(CONFIG_PPC_MERGE) */
 590
 591 MODULE_AUTHOR("Dragos Carp");
 592 MODULE_DESCRIPTION("MPC52xx PSC SPI Driver");
 593 MODULE_LICENSE("GPL");