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         struct mpc52xx_psc_fifo __iomem *fifo;
  46         unsigned int irq;
  47         u8 bits_per_word;
  48         u8 busy;
  49
  50         struct workqueue_struct *workqueue;
  51         struct work_struct work;
  52
  53         struct list_head queue;
  54         spinlock_t lock;
  55
  56         struct completion done;
  57 };
  58
  59 /* controller state */
  60 struct mpc52xx_psc_spi_cs {
  61         int bits_per_word;
  62         int speed_hz;
  63 };
  64
  65 /* set clock freq, clock ramp, bits per work
  66  * if t is NULL then reset the values to the default values
  67  */
  68 static int mpc52xx_psc_spi_transfer_setup(struct spi_device *spi,
  69                 struct spi_transfer *t)
  70 {
  71         struct mpc52xx_psc_spi_cs *cs = spi->controller_state;
  72
  73         cs->speed_hz = (t && t->speed_hz)
  74                         ? t->speed_hz : spi->max_speed_hz;
  75         cs->bits_per_word = (t && t->bits_per_word)
  76                         ? t->bits_per_word : spi->bits_per_word;
  77         cs->bits_per_word = ((cs->bits_per_word + 7) / 8) * 8;
  78         return 0;
  79 }
  80
  81 static void mpc52xx_psc_spi_activate_cs(struct spi_device *spi)
  82 {
  83         struct mpc52xx_psc_spi_cs *cs = spi->controller_state;
  84         struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
  85         struct mpc52xx_psc __iomem *psc = mps->psc;
  86         u32 sicr;
  87         u16 ccr;
  88
  89         sicr = in_be32(&psc->sicr);
  90
  91         /* Set clock phase and polarity */
  92         if (spi->mode & SPI_CPHA)
  93                 sicr |= 0x00001000;
  94         else
  95                 sicr &= ~0x00001000;
  96         if (spi->mode & SPI_CPOL)
  97                 sicr |= 0x00002000;
  98         else
  99                 sicr &= ~0x00002000;
 100
 101         if (spi->mode & SPI_LSB_FIRST)
 102                 sicr |= 0x10000000;
 103         else
 104                 sicr &= ~0x10000000;
 105         out_be32(&psc->sicr, sicr);
 106
 107         /* Set clock frequency and bits per word
 108          * Because psc->ccr is defined as 16bit register instead of 32bit
 109          * just set the lower byte of BitClkDiv
 110          */
 111         ccr = in_be16(&psc->ccr);
 112         ccr &= 0xFF00;
 113         if (cs->speed_hz)
 114                 ccr |= (MCLK / cs->speed_hz - 1) & 0xFF;
 115         else /* by default SPI Clk 1MHz */
 116                 ccr |= (MCLK / 1000000 - 1) & 0xFF;
 117         out_be16(&psc->ccr, ccr);
 118         mps->bits_per_word = cs->bits_per_word;
 119
 120         if (mps->activate_cs)
 121                 mps->activate_cs(spi->chip_select,
 122                                 (spi->mode & SPI_CS_HIGH) ? 1 : 0);
 123 }
 124
 125 static void mpc52xx_psc_spi_deactivate_cs(struct spi_device *spi)
 126 {
 127         struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
 128
 129         if (mps->deactivate_cs)
 130                 mps->deactivate_cs(spi->chip_select,
 131                                 (spi->mode & SPI_CS_HIGH) ? 1 : 0);
 132 }
 133
 134 #define MPC52xx_PSC_BUFSIZE (MPC52xx_PSC_RFNUM_MASK + 1)
 135 /* wake up when 80% fifo full */
 136 #define MPC52xx_PSC_RFALARM (MPC52xx_PSC_BUFSIZE * 20 / 100)
 137
 138 static int mpc52xx_psc_spi_transfer_rxtx(struct spi_device *spi,
 139                                                 struct spi_transfer *t)
 140 {
 141         struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
 142         struct mpc52xx_psc __iomem *psc = mps->psc;
 143         struct mpc52xx_psc_fifo __iomem *fifo = mps->fifo;
 144         unsigned rb = 0;        /* number of bytes receieved */
 145         unsigned sb = 0;        /* number of bytes sent */
 146         unsigned char *rx_buf = (unsigned char *)t->rx_buf;
 147         unsigned char *tx_buf = (unsigned char *)t->tx_buf;
 148         unsigned rfalarm;
 149         unsigned send_at_once = MPC52xx_PSC_BUFSIZE;
 150         unsigned recv_at_once;
 151         unsigned bpw = mps->bits_per_word / 8;
 152
 153         if (!t->tx_buf && !t->rx_buf && t->len)
 154                 return -EINVAL;
 155
 156         /* enable transmiter/receiver */
 157         out_8(&psc->command, MPC52xx_PSC_TX_ENABLE | MPC52xx_PSC_RX_ENABLE);
 158         while (rb < t->len) {
 159                 if (t->len - rb > MPC52xx_PSC_BUFSIZE) {
 160                         rfalarm = MPC52xx_PSC_RFALARM;
 161                 } else {
 162                         send_at_once = t->len - sb;
 163                         rfalarm = MPC52xx_PSC_BUFSIZE - (t->len - rb);
 164                 }
 165
 166                 dev_dbg(&spi->dev, "send %d bytes...\n", send_at_once);
 167                 if (tx_buf) {
 168                         for (; send_at_once; sb++, send_at_once--) {
 169                                 /* set EOF flag */
 170                                 if (mps->bits_per_word
 171                                                 && (sb + 1) % bpw == 0)
 172                                         out_8(&psc->ircr2, 0x01);
 173                                 out_8(&psc->mpc52xx_psc_buffer_8, tx_buf[sb]);
 174                         }
 175                 } else {
 176                         for (; send_at_once; sb++, send_at_once--) {
 177                                 /* set EOF flag */
 178                                 if (mps->bits_per_word
 179                                                 && ((sb + 1) % bpw) == 0)
 180                                         out_8(&psc->ircr2, 0x01);
 181                                 out_8(&psc->mpc52xx_psc_buffer_8, 0);
 182                         }
 183                 }
 184
 185
 186                 /* enable interrupts and wait for wake up
 187                  * if just one byte is expected the Rx FIFO genererates no
 188                  * FFULL interrupt, so activate the RxRDY interrupt
 189                  */
 190                 out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1);
 191                 if (t->len - rb == 1) {
 192                         out_8(&psc->mode, 0);
 193                 } else {
 194                         out_8(&psc->mode, MPC52xx_PSC_MODE_FFULL);
 195                         out_be16(&fifo->rfalarm, rfalarm);
 196                 }
 197                 out_be16(&psc->mpc52xx_psc_imr, MPC52xx_PSC_IMR_RXRDY);
 198                 wait_for_completion(&mps->done);
 199                 recv_at_once = in_be16(&fifo->rfnum);
 200                 dev_dbg(&spi->dev, "%d bytes received\n", recv_at_once);
 201
 202                 send_at_once = recv_at_once;
 203                 if (rx_buf) {
 204                         for (; recv_at_once; rb++, recv_at_once--)
 205                                 rx_buf[rb] = in_8(&psc->mpc52xx_psc_buffer_8);
 206                 } else {
 207                         for (; recv_at_once; rb++, recv_at_once--)
 208                                 in_8(&psc->mpc52xx_psc_buffer_8);
 209                 }
 210         }
 211         /* disable transmiter/receiver */
 212         out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE);
 213
 214         return 0;
 215 }
 216
 217 static void mpc52xx_psc_spi_work(struct work_struct *work)
 218 {
 219         struct mpc52xx_psc_spi *mps =
 220                 container_of(work, struct mpc52xx_psc_spi, work);
 221
 222         spin_lock_irq(&mps->lock);
 223         mps->busy = 1;
 224         while (!list_empty(&mps->queue)) {
 225                 struct spi_message *m;
 226                 struct spi_device *spi;
 227                 struct spi_transfer *t = NULL;
 228                 unsigned cs_change;
 229                 int status;
 230
 231                 m = container_of(mps->queue.next, struct spi_message, queue);
 232                 list_del_init(&m->queue);
 233                 spin_unlock_irq(&mps->lock);
 234
 235                 spi = m->spi;
 236                 cs_change = 1;
 237                 status = 0;
 238                 list_for_each_entry (t, &m->transfers, transfer_list) {
 239                         if (t->bits_per_word || t->speed_hz) {
 240                                 status = mpc52xx_psc_spi_transfer_setup(spi, t);
 241                                 if (status < 0)
 242                                         break;
 243                         }
 244
 245                         if (cs_change)
 246                                 mpc52xx_psc_spi_activate_cs(spi);
 247                         cs_change = t->cs_change;
 248
 249                         status = mpc52xx_psc_spi_transfer_rxtx(spi, t);
 250                         if (status)
 251                                 break;
 252                         m->actual_length += t->len;
 253
 254                         if (t->delay_usecs)
 255                                 udelay(t->delay_usecs);
 256
 257                         if (cs_change)
 258                                 mpc52xx_psc_spi_deactivate_cs(spi);
 259                 }
 260
 261                 m->status = status;
 262                 m->complete(m->context);
 263
 264                 if (status || !cs_change)
 265                         mpc52xx_psc_spi_deactivate_cs(spi);
 266
 267                 mpc52xx_psc_spi_transfer_setup(spi, NULL);
 268
 269                 spin_lock_irq(&mps->lock);
 270         }
 271         mps->busy = 0;
 272         spin_unlock_irq(&mps->lock);
 273 }
 274
 275 /* the spi->mode bits understood by this driver: */
 276 #define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST)
 277
 278 static int mpc52xx_psc_spi_setup(struct spi_device *spi)
 279 {
 280         struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
 281         struct mpc52xx_psc_spi_cs *cs = spi->controller_state;
 282         unsigned long flags;
 283
 284         if (spi->bits_per_word%8)
 285                 return -EINVAL;
 286
 287         if (spi->mode & ~MODEBITS) {
 288                 dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
 289                         spi->mode & ~MODEBITS);
 290                 return -EINVAL;
 291         }
 292
 293         if (!cs) {
 294                 cs = kzalloc(sizeof *cs, GFP_KERNEL);
 295                 if (!cs)
 296                         return -ENOMEM;
 297                 spi->controller_state = cs;
 298         }
 299
 300         cs->bits_per_word = spi->bits_per_word;
 301         cs->speed_hz = spi->max_speed_hz;
 302
 303         spin_lock_irqsave(&mps->lock, flags);
 304         if (!mps->busy)
 305                 mpc52xx_psc_spi_deactivate_cs(spi);
 306         spin_unlock_irqrestore(&mps->lock, flags);
 307
 308         return 0;
 309 }
 310
 311 static int mpc52xx_psc_spi_transfer(struct spi_device *spi,
 312                 struct spi_message *m)
 313 {
 314         struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
 315         unsigned long flags;
 316
 317         m->actual_length = 0;
 318         m->status = -EINPROGRESS;
 319
 320         spin_lock_irqsave(&mps->lock, flags);
 321         list_add_tail(&m->queue, &mps->queue);
 322         queue_work(mps->workqueue, &mps->work);
 323         spin_unlock_irqrestore(&mps->lock, flags);
 324
 325         return 0;
 326 }
 327
 328 static void mpc52xx_psc_spi_cleanup(struct spi_device *spi)
 329 {
 330         kfree(spi->controller_state);
 331 }
 332
 333 static int mpc52xx_psc_spi_port_config(int psc_id, struct mpc52xx_psc_spi *mps)
 334 {
 335         struct mpc52xx_psc __iomem *psc = mps->psc;
 336         struct mpc52xx_psc_fifo __iomem *fifo = mps->fifo;
 337         u32 mclken_div;
 338         int ret = 0;
 339
 340         /* default sysclk is 512MHz */
 341         mclken_div = (mps->sysclk ? mps->sysclk : 512000000) / MCLK;
 342         mpc52xx_set_psc_clkdiv(psc_id, mclken_div);
 343
 344         /* Reset the PSC into a known state */
 345         out_8(&psc->command, MPC52xx_PSC_RST_RX);
 346         out_8(&psc->command, MPC52xx_PSC_RST_TX);
 347         out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE);
 348
 349         /* Disable interrupts, interrupts are based on alarm level */
 350         out_be16(&psc->mpc52xx_psc_imr, 0);
 351         out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1);
 352         out_8(&fifo->rfcntl, 0);
 353         out_8(&psc->mode, MPC52xx_PSC_MODE_FFULL);
 354
 355         /* Configure 8bit codec mode as a SPI master and use EOF flags */
 356         /* SICR_SIM_CODEC8|SICR_GENCLK|SICR_SPI|SICR_MSTR|SICR_USEEOF */
 357         out_be32(&psc->sicr, 0x0180C800);
 358         out_be16(&psc->ccr, 0x070F); /* by default SPI Clk 1MHz */
 359
 360         /* Set 2ms DTL delay */
 361         out_8(&psc->ctur, 0x00);
 362         out_8(&psc->ctlr, 0x84);
 363
 364         mps->bits_per_word = 8;
 365
 366         return ret;
 367 }
 368
 369 static irqreturn_t mpc52xx_psc_spi_isr(int irq, void *dev_id)
 370 {
 371         struct mpc52xx_psc_spi *mps = (struct mpc52xx_psc_spi *)dev_id;
 372         struct mpc52xx_psc __iomem *psc = mps->psc;
 373
 374         /* disable interrupt and wake up the work queue */
 375         if (in_be16(&psc->mpc52xx_psc_isr) & MPC52xx_PSC_IMR_RXRDY) {
 376                 out_be16(&psc->mpc52xx_psc_imr, 0);
 377                 complete(&mps->done);
 378                 return IRQ_HANDLED;
 379         }
 380         return IRQ_NONE;
 381 }
 382
 383 /* bus_num is used only for the case dev->platform_data == NULL */
 384 static int __init mpc52xx_psc_spi_do_probe(struct device *dev, u32 regaddr,
 385                                 u32 size, unsigned int irq, s16 bus_num)
 386 {
 387         struct fsl_spi_platform_data *pdata = dev->platform_data;
 388         struct mpc52xx_psc_spi *mps;
 389         struct spi_master *master;
 390         int ret;
 391
 392         master = spi_alloc_master(dev, sizeof *mps);
 393         if (master == NULL)
 394                 return -ENOMEM;
 395
 396         dev_set_drvdata(dev, master);
 397         mps = spi_master_get_devdata(master);
 398
 399         mps->irq = irq;
 400         if (pdata == NULL) {
 401                 dev_warn(dev, "probe called without platform data, no "
 402                                 "(de)activate_cs function will be called\n");
 403                 mps->activate_cs = NULL;
 404                 mps->deactivate_cs = NULL;
 405                 mps->sysclk = 0;
 406                 master->bus_num = bus_num;
 407                 master->num_chipselect = 255;
 408         } else {
 409                 mps->activate_cs = pdata->activate_cs;
 410                 mps->deactivate_cs = pdata->deactivate_cs;
 411                 mps->sysclk = pdata->sysclk;
 412                 master->bus_num = pdata->bus_num;
 413                 master->num_chipselect = pdata->max_chipselect;
 414         }
 415         master->setup = mpc52xx_psc_spi_setup;
 416         master->transfer = mpc52xx_psc_spi_transfer;
 417         master->cleanup = mpc52xx_psc_spi_cleanup;
 418
 419         mps->psc = ioremap(regaddr, size);
 420         if (!mps->psc) {
 421                 dev_err(dev, "could not ioremap I/O port range\n");
 422                 ret = -EFAULT;
 423                 goto free_master;
 424         }
 425         /* On the 5200, fifo regs are immediately ajacent to the psc regs */
 426         mps->fifo = ((void __iomem *)mps->psc) + sizeof(struct mpc52xx_psc);
 427
 428         ret = request_irq(mps->irq, mpc52xx_psc_spi_isr, 0, "mpc52xx-psc-spi",
 429                                 mps);
 430         if (ret)
 431                 goto free_master;
 432
 433         ret = mpc52xx_psc_spi_port_config(master->bus_num, mps);
 434         if (ret < 0)
 435                 goto free_irq;
 436
 437         spin_lock_init(&mps->lock);
 438         init_completion(&mps->done);
 439         INIT_WORK(&mps->work, mpc52xx_psc_spi_work);
 440         INIT_LIST_HEAD(&mps->queue);
 441
 442         mps->workqueue = create_singlethread_workqueue(
 443                 master->dev.parent->bus_id);
 444         if (mps->workqueue == NULL) {
 445                 ret = -EBUSY;
 446                 goto free_irq;
 447         }
 448
 449         ret = spi_register_master(master);
 450         if (ret < 0)
 451                 goto unreg_master;
 452
 453         return ret;
 454
 455 unreg_master:
 456         destroy_workqueue(mps->workqueue);
 457 free_irq:
 458         free_irq(mps->irq, mps);
 459 free_master:
 460         if (mps->psc)
 461                 iounmap(mps->psc);
 462         spi_master_put(master);
 463
 464         return ret;
 465 }
 466
 467 static int __exit mpc52xx_psc_spi_do_remove(struct device *dev)
 468 {
 469         struct spi_master *master = dev_get_drvdata(dev);
 470         struct mpc52xx_psc_spi *mps = spi_master_get_devdata(master);
 471
 472         flush_workqueue(mps->workqueue);
 473         destroy_workqueue(mps->workqueue);
 474         spi_unregister_master(master);
 475         free_irq(mps->irq, mps);
 476         if (mps->psc)
 477                 iounmap(mps->psc);
 478
 479         return 0;
 480 }
 481
 482 #if !defined(CONFIG_PPC_MERGE)
 483 static int __init mpc52xx_psc_spi_probe(struct platform_device *dev)
 484 {
 485         switch(dev->id) {
 486         case 1:
 487         case 2:
 488         case 3:
 489         case 6:
 490                 return mpc52xx_psc_spi_do_probe(&dev->dev,
 491                         MPC52xx_PA(MPC52xx_PSCx_OFFSET(dev->id)),
 492                         MPC52xx_PSC_SIZE, platform_get_irq(dev, 0), dev->id);
 493         default:
 494                 return -EINVAL;
 495         }
 496 }
 497
 498 static int __exit mpc52xx_psc_spi_remove(struct platform_device *dev)
 499 {
 500         return mpc52xx_psc_spi_do_remove(&dev->dev);
 501 }
 502
 503 static struct platform_driver mpc52xx_psc_spi_platform_driver = {
 504         .remove = __exit_p(mpc52xx_psc_spi_remove),
 505         .driver = {
 506                 .name = "mpc52xx-psc-spi",
 507                 .owner = THIS_MODULE,
 508         },
 509 };
 510
 511 static int __init mpc52xx_psc_spi_init(void)
 512 {
 513         return platform_driver_probe(&mpc52xx_psc_spi_platform_driver,
 514                         mpc52xx_psc_spi_probe);
 515 }
 516 module_init(mpc52xx_psc_spi_init);
 517
 518 static void __exit mpc52xx_psc_spi_exit(void)
 519 {
 520         platform_driver_unregister(&mpc52xx_psc_spi_platform_driver);
 521 }
 522 module_exit(mpc52xx_psc_spi_exit);
 523
 524 #else   /* defined(CONFIG_PPC_MERGE) */
 525
 526 static int __init mpc52xx_psc_spi_of_probe(struct of_device *op,
 527         const struct of_device_id *match)
 528 {
 529         const u32 *regaddr_p;
 530         u64 regaddr64, size64;
 531         s16 id = -1;
 532
 533         regaddr_p = of_get_address(op->node, 0, &size64, NULL);
 534         if (!regaddr_p) {
 535                 printk(KERN_ERR "Invalid PSC address\n");
 536                 return -EINVAL;
 537         }
 538         regaddr64 = of_translate_address(op->node, regaddr_p);
 539
 540         /* get PSC id (1..6, used by port_config) */
 541         if (op->dev.platform_data == NULL) {
 542                 const u32 *psc_nump;
 543
 544                 psc_nump = of_get_property(op->node, "cell-index", NULL);
 545                 if (!psc_nump || *psc_nump > 5) {
 546                         printk(KERN_ERR "mpc52xx_psc_spi: Device node %s has invalid "
 547                                         "cell-index property\n", op->node->full_name);
 548                         return -EINVAL;
 549                 }
 550                 id = *psc_nump + 1;
 551         }
 552
 553         return mpc52xx_psc_spi_do_probe(&op->dev, (u32)regaddr64, (u32)size64,
 554                                         irq_of_parse_and_map(op->node, 0), id);
 555 }
 556
 557 static int __exit mpc52xx_psc_spi_of_remove(struct of_device *op)
 558 {
 559         return mpc52xx_psc_spi_do_remove(&op->dev);
 560 }
 561
 562 static struct of_device_id mpc52xx_psc_spi_of_match[] = {
 563         { .compatible = "fsl,mpc5200-psc-spi", },
 564         { .compatible = "mpc5200-psc-spi", }, /* old */
 565         {}
 566 };
 567
 568 MODULE_DEVICE_TABLE(of, mpc52xx_psc_spi_of_match);
 569
 570 static struct of_platform_driver mpc52xx_psc_spi_of_driver = {
 571         .owner = THIS_MODULE,
 572         .name = "mpc52xx-psc-spi",
 573         .match_table = mpc52xx_psc_spi_of_match,
 574         .probe = mpc52xx_psc_spi_of_probe,
 575         .remove = __exit_p(mpc52xx_psc_spi_of_remove),
 576         .driver = {
 577                 .name = "mpc52xx-psc-spi",
 578                 .owner = THIS_MODULE,
 579         },
 580 };
 581
 582 static int __init mpc52xx_psc_spi_init(void)
 583 {
 584         return of_register_platform_driver(&mpc52xx_psc_spi_of_driver);
 585 }
 586 module_init(mpc52xx_psc_spi_init);
 587
 588 static void __exit mpc52xx_psc_spi_exit(void)
 589 {
 590         of_unregister_platform_driver(&mpc52xx_psc_spi_of_driver);
 591 }
 592 module_exit(mpc52xx_psc_spi_exit);
 593
 594 #endif  /* defined(CONFIG_PPC_MERGE) */
 595
 596 MODULE_AUTHOR("Dragos Carp");
 597 MODULE_DESCRIPTION("MPC52xx PSC SPI Driver");
 598 MODULE_LICENSE("GPL");