drivers/spi/mpc512x_psc_spi.c

   1 /*
   2  * MPC512x PSC in SPI mode driver.
   3  *
   4  * Copyright (C) 2007,2008 Freescale Semiconductor Inc.
   5  * Original port from 52xx driver:
   6  *      Hongjun Chen <hong-jun.chen@freescale.com>
   7  *
   8  * Fork of mpc52xx_psc_spi.c:
   9  *      Copyright (C) 2006 TOPTICA Photonics AG., Dragos Carp
  10  *
  11  * This program is free software; you can redistribute  it and/or modify it
  12  * under  the terms of  the GNU General  Public License as published by the
  13  * Free Software Foundation;  either version 2 of the  License, or (at your
  14  * option) any later version.
  15  */
  16
  17 #include <linux/module.h>
  18 #include <linux/kernel.h>
  19 #include <linux/init.h>
  20 #include <linux/errno.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/of_address.h>
  23 #include <linux/of_platform.h>
  24 #include <linux/workqueue.h>
  25 #include <linux/completion.h>
  26 #include <linux/io.h>
  27 #include <linux/delay.h>
  28 #include <linux/clk.h>
  29 #include <linux/spi/spi.h>
  30 #include <linux/fsl_devices.h>
  31 #include <asm/mpc52xx_psc.h>
  32
  33 struct mpc512x_psc_spi {
  34         void (*cs_control)(struct spi_device *spi, bool on);
  35         u32 sysclk;
  36
  37         /* driver internal data */
  38         struct mpc52xx_psc __iomem *psc;
  39         struct mpc512x_psc_fifo __iomem *fifo;
  40         unsigned int irq;
  41         u8 bits_per_word;
  42         u8 busy;
  43         u32 mclk;
  44         u8 eofbyte;
  45
  46         struct workqueue_struct *workqueue;
  47         struct work_struct work;
  48
  49         struct list_head queue;
  50         spinlock_t lock;        /* Message queue lock */
  51
  52         struct completion done;
  53 };
  54
  55 /* controller state */
  56 struct mpc512x_psc_spi_cs {
  57         int bits_per_word;
  58         int speed_hz;
  59 };
  60
  61 /* set clock freq, clock ramp, bits per work
  62  * if t is NULL then reset the values to the default values
  63  */
  64 static int mpc512x_psc_spi_transfer_setup(struct spi_device *spi,
  65                                           struct spi_transfer *t)
  66 {
  67         struct mpc512x_psc_spi_cs *cs = spi->controller_state;
  68
  69         cs->speed_hz = (t && t->speed_hz)
  70             ? t->speed_hz : spi->max_speed_hz;
  71         cs->bits_per_word = (t && t->bits_per_word)
  72             ? t->bits_per_word : spi->bits_per_word;
  73         cs->bits_per_word = ((cs->bits_per_word + 7) / 8) * 8;
  74         return 0;
  75 }
  76
  77 static void mpc512x_psc_spi_activate_cs(struct spi_device *spi)
  78 {
  79         struct mpc512x_psc_spi_cs *cs = spi->controller_state;
  80         struct mpc512x_psc_spi *mps = spi_master_get_devdata(spi->master);
  81         struct mpc52xx_psc __iomem *psc = mps->psc;
  82         u32 sicr;
  83         u32 ccr;
  84         u16 bclkdiv;
  85
  86         sicr = in_be32(&psc->sicr);
  87
  88         /* Set clock phase and polarity */
  89         if (spi->mode & SPI_CPHA)
  90                 sicr |= 0x00001000;
  91         else
  92                 sicr &= ~0x00001000;
  93
  94         if (spi->mode & SPI_CPOL)
  95                 sicr |= 0x00002000;
  96         else
  97                 sicr &= ~0x00002000;
  98
  99         if (spi->mode & SPI_LSB_FIRST)
 100                 sicr |= 0x10000000;
 101         else
 102                 sicr &= ~0x10000000;
 103         out_be32(&psc->sicr, sicr);
 104
 105         ccr = in_be32(&psc->ccr);
 106         ccr &= 0xFF000000;
 107         if (cs->speed_hz)
 108                 bclkdiv = (mps->mclk / cs->speed_hz) - 1;
 109         else
 110                 bclkdiv = (mps->mclk / 1000000) - 1;    /* default 1MHz */
 111
 112         ccr |= (((bclkdiv & 0xff) << 16) | (((bclkdiv >> 8) & 0xff) << 8));
 113         out_be32(&psc->ccr, ccr);
 114         mps->bits_per_word = cs->bits_per_word;
 115
 116         if (mps->cs_control)
 117                 mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 1 : 0);
 118 }
 119
 120 static void mpc512x_psc_spi_deactivate_cs(struct spi_device *spi)
 121 {
 122         struct mpc512x_psc_spi *mps = spi_master_get_devdata(spi->master);
 123
 124         if (mps->cs_control)
 125                 mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 0 : 1);
 126
 127 }
 128
 129 /* extract and scale size field in txsz or rxsz */
 130 #define MPC512x_PSC_FIFO_SZ(sz) ((sz & 0x7ff) << 2);
 131
 132 #define EOFBYTE 1
 133
 134 static int mpc512x_psc_spi_transfer_rxtx(struct spi_device *spi,
 135                                          struct spi_transfer *t)
 136 {
 137         struct mpc512x_psc_spi *mps = spi_master_get_devdata(spi->master);
 138         struct mpc52xx_psc __iomem *psc = mps->psc;
 139         struct mpc512x_psc_fifo __iomem *fifo = mps->fifo;
 140         size_t len = t->len;
 141         u8 *tx_buf = (u8 *)t->tx_buf;
 142         u8 *rx_buf = (u8 *)t->rx_buf;
 143
 144         if (!tx_buf && !rx_buf && t->len)
 145                 return -EINVAL;
 146
 147         /* Zero MR2 */
 148         in_8(&psc->mode);
 149         out_8(&psc->mode, 0x0);
 150
 151         while (len) {
 152                 int count;
 153                 int i;
 154                 u8 data;
 155                 size_t fifosz;
 156                 int rxcount;
 157
 158                 /*
 159                  * The number of bytes that can be sent at a time
 160                  * depends on the fifo size.
 161                  */
 162                 fifosz = MPC512x_PSC_FIFO_SZ(in_be32(&fifo->txsz));
 163                 count = min(fifosz, len);
 164
 165                 for (i = count; i > 0; i--) {
 166                         data = tx_buf ? *tx_buf++ : 0;
 167                         if (len == EOFBYTE)
 168                                 setbits32(&fifo->txcmd, MPC512x_PSC_FIFO_EOF);
 169                         out_8(&fifo->txdata_8, data);
 170                         len--;
 171                 }
 172
 173                 INIT_COMPLETION(mps->done);
 174
 175                 /* interrupt on tx fifo empty */
 176                 out_be32(&fifo->txisr, MPC512x_PSC_FIFO_EMPTY);
 177                 out_be32(&fifo->tximr, MPC512x_PSC_FIFO_EMPTY);
 178
 179                 /* enable transmiter/receiver */
 180                 out_8(&psc->command,
 181                       MPC52xx_PSC_TX_ENABLE | MPC52xx_PSC_RX_ENABLE);
 182
 183                 wait_for_completion(&mps->done);
 184
 185                 mdelay(1);
 186
 187                 /* rx fifo should have count bytes in it */
 188                 rxcount = in_be32(&fifo->rxcnt);
 189                 if (rxcount != count)
 190                         mdelay(1);
 191
 192                 rxcount = in_be32(&fifo->rxcnt);
 193                 if (rxcount != count) {
 194                         dev_warn(&spi->dev, "expected %d bytes in rx fifo "
 195                                  "but got %d\n", count, rxcount);
 196                 }
 197
 198                 rxcount = min(rxcount, count);
 199                 for (i = rxcount; i > 0; i--) {
 200                         data = in_8(&fifo->rxdata_8);
 201                         if (rx_buf)
 202                                 *rx_buf++ = data;
 203                 }
 204                 while (in_be32(&fifo->rxcnt)) {
 205                         in_8(&fifo->rxdata_8);
 206                 }
 207
 208                 out_8(&psc->command,
 209                       MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE);
 210         }
 211         /* disable transmiter/receiver and fifo interrupt */
 212         out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE);
 213         out_be32(&fifo->tximr, 0);
 214         return 0;
 215 }
 216
 217 static void mpc512x_psc_spi_work(struct work_struct *work)
 218 {
 219         struct mpc512x_psc_spi *mps = container_of(work,
 220                                                    struct mpc512x_psc_spi,
 221                                                    work);
 222
 223         spin_lock_irq(&mps->lock);
 224         mps->busy = 1;
 225         while (!list_empty(&mps->queue)) {
 226                 struct spi_message *m;
 227                 struct spi_device *spi;
 228                 struct spi_transfer *t = NULL;
 229                 unsigned cs_change;
 230                 int status;
 231
 232                 m = container_of(mps->queue.next, struct spi_message, queue);
 233                 list_del_init(&m->queue);
 234                 spin_unlock_irq(&mps->lock);
 235
 236                 spi = m->spi;
 237                 cs_change = 1;
 238                 status = 0;
 239                 list_for_each_entry(t, &m->transfers, transfer_list) {
 240                         if (t->bits_per_word || t->speed_hz) {
 241                                 status = mpc512x_psc_spi_transfer_setup(spi, t);
 242                                 if (status < 0)
 243                                         break;
 244                         }
 245
 246                         if (cs_change)
 247                                 mpc512x_psc_spi_activate_cs(spi);
 248                         cs_change = t->cs_change;
 249
 250                         status = mpc512x_psc_spi_transfer_rxtx(spi, t);
 251                         if (status)
 252                                 break;
 253                         m->actual_length += t->len;
 254
 255                         if (t->delay_usecs)
 256                                 udelay(t->delay_usecs);
 257
 258                         if (cs_change)
 259                                 mpc512x_psc_spi_deactivate_cs(spi);
 260                 }
 261
 262                 m->status = status;
 263                 m->complete(m->context);
 264
 265                 if (status || !cs_change)
 266                         mpc512x_psc_spi_deactivate_cs(spi);
 267
 268                 mpc512x_psc_spi_transfer_setup(spi, NULL);
 269
 270                 spin_lock_irq(&mps->lock);
 271         }
 272         mps->busy = 0;
 273         spin_unlock_irq(&mps->lock);
 274 }
 275
 276 static int mpc512x_psc_spi_setup(struct spi_device *spi)
 277 {
 278         struct mpc512x_psc_spi *mps = spi_master_get_devdata(spi->master);
 279         struct mpc512x_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 (!cs) {
 286                 cs = kzalloc(sizeof *cs, GFP_KERNEL);
 287                 if (!cs)
 288                         return -ENOMEM;
 289                 spi->controller_state = cs;
 290         }
 291
 292         cs->bits_per_word = spi->bits_per_word;
 293         cs->speed_hz = spi->max_speed_hz;
 294
 295         spin_lock_irqsave(&mps->lock, flags);
 296         if (!mps->busy)
 297                 mpc512x_psc_spi_deactivate_cs(spi);
 298         spin_unlock_irqrestore(&mps->lock, flags);
 299
 300         return 0;
 301 }
 302
 303 static int mpc512x_psc_spi_transfer(struct spi_device *spi,
 304                                     struct spi_message *m)
 305 {
 306         struct mpc512x_psc_spi *mps = spi_master_get_devdata(spi->master);
 307         unsigned long flags;
 308
 309         m->actual_length = 0;
 310         m->status = -EINPROGRESS;
 311
 312         spin_lock_irqsave(&mps->lock, flags);
 313         list_add_tail(&m->queue, &mps->queue);
 314         queue_work(mps->workqueue, &mps->work);
 315         spin_unlock_irqrestore(&mps->lock, flags);
 316
 317         return 0;
 318 }
 319
 320 static void mpc512x_psc_spi_cleanup(struct spi_device *spi)
 321 {
 322         kfree(spi->controller_state);
 323 }
 324
 325 static int mpc512x_psc_spi_port_config(struct spi_master *master,
 326                                        struct mpc512x_psc_spi *mps)
 327 {
 328         struct mpc52xx_psc __iomem *psc = mps->psc;
 329         struct mpc512x_psc_fifo __iomem *fifo = mps->fifo;
 330         struct clk *spiclk;
 331         int ret = 0;
 332         char name[32];
 333         u32 sicr;
 334         u32 ccr;
 335         u16 bclkdiv;
 336
 337         sprintf(name, "psc%d_mclk", master->bus_num);
 338         spiclk = clk_get(&master->dev, name);
 339         clk_enable(spiclk);
 340         mps->mclk = clk_get_rate(spiclk);
 341         clk_put(spiclk);
 342
 343         /* Reset the PSC into a known state */
 344         out_8(&psc->command, MPC52xx_PSC_RST_RX);
 345         out_8(&psc->command, MPC52xx_PSC_RST_TX);
 346         out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE);
 347
 348         /* Disable psc interrupts all useful interrupts are in fifo */
 349         out_be16(&psc->isr_imr.imr, 0);
 350
 351         /* Disable fifo interrupts, will be enabled later */
 352         out_be32(&fifo->tximr, 0);
 353         out_be32(&fifo->rximr, 0);
 354
 355         /* Setup fifo slice address and size */
 356         /*out_be32(&fifo->txsz, 0x0fe00004);*/
 357         /*out_be32(&fifo->rxsz, 0x0ff00004);*/
 358
 359         sicr =  0x01000000 |    /* SIM = 0001 -- 8 bit */
 360                 0x00800000 |    /* GenClk = 1 -- internal clk */
 361                 0x00008000 |    /* SPI = 1 */
 362                 0x00004000 |    /* MSTR = 1   -- SPI master */
 363                 0x00000800;     /* UseEOF = 1 -- SS low until EOF */
 364
 365         out_be32(&psc->sicr, sicr);
 366
 367         ccr = in_be32(&psc->ccr);
 368         ccr &= 0xFF000000;
 369         bclkdiv = (mps->mclk / 1000000) - 1;    /* default 1MHz */
 370         ccr |= (((bclkdiv & 0xff) << 16) | (((bclkdiv >> 8) & 0xff) << 8));
 371         out_be32(&psc->ccr, ccr);
 372
 373         /* Set 2ms DTL delay */
 374         out_8(&psc->ctur, 0x00);
 375         out_8(&psc->ctlr, 0x82);
 376
 377         /* we don't use the alarms */
 378         out_be32(&fifo->rxalarm, 0xfff);
 379         out_be32(&fifo->txalarm, 0);
 380
 381         /* Enable FIFO slices for Rx/Tx */
 382         out_be32(&fifo->rxcmd,
 383                  MPC512x_PSC_FIFO_ENABLE_SLICE | MPC512x_PSC_FIFO_ENABLE_DMA);
 384         out_be32(&fifo->txcmd,
 385                  MPC512x_PSC_FIFO_ENABLE_SLICE | MPC512x_PSC_FIFO_ENABLE_DMA);
 386
 387         mps->bits_per_word = 8;
 388
 389         return ret;
 390 }
 391
 392 static irqreturn_t mpc512x_psc_spi_isr(int irq, void *dev_id)
 393 {
 394         struct mpc512x_psc_spi *mps = (struct mpc512x_psc_spi *)dev_id;
 395         struct mpc512x_psc_fifo __iomem *fifo = mps->fifo;
 396
 397         /* clear interrupt and wake up the work queue */
 398         if (in_be32(&fifo->txisr) &
 399             in_be32(&fifo->tximr) & MPC512x_PSC_FIFO_EMPTY) {
 400                 out_be32(&fifo->txisr, MPC512x_PSC_FIFO_EMPTY);
 401                 out_be32(&fifo->tximr, 0);
 402                 complete(&mps->done);
 403                 return IRQ_HANDLED;
 404         }
 405         return IRQ_NONE;
 406 }
 407
 408 /* bus_num is used only for the case dev->platform_data == NULL */
 409 static int __devinit mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
 410                                               u32 size, unsigned int irq,
 411                                               s16 bus_num)
 412 {
 413         struct fsl_spi_platform_data *pdata = dev->platform_data;
 414         struct mpc512x_psc_spi *mps;
 415         struct spi_master *master;
 416         int ret;
 417         void *tempp;
 418
 419         master = spi_alloc_master(dev, sizeof *mps);
 420         if (master == NULL)
 421                 return -ENOMEM;
 422
 423         dev_set_drvdata(dev, master);
 424         mps = spi_master_get_devdata(master);
 425         mps->irq = irq;
 426
 427         if (pdata == NULL) {
 428                 dev_err(dev, "probe called without platform data, no "
 429                         "cs_control function will be called\n");
 430                 mps->cs_control = NULL;
 431                 mps->sysclk = 0;
 432                 master->bus_num = bus_num;
 433                 master->num_chipselect = 255;
 434         } else {
 435                 mps->cs_control = pdata->cs_control;
 436                 mps->sysclk = pdata->sysclk;
 437                 master->bus_num = pdata->bus_num;
 438                 master->num_chipselect = pdata->max_chipselect;
 439         }
 440
 441         master->setup = mpc512x_psc_spi_setup;
 442         master->transfer = mpc512x_psc_spi_transfer;
 443         master->cleanup = mpc512x_psc_spi_cleanup;
 444         master->dev.of_node = dev->of_node;
 445
 446         tempp = ioremap(regaddr, size);
 447         if (!tempp) {
 448                 dev_err(dev, "could not ioremap I/O port range\n");
 449                 ret = -EFAULT;
 450                 goto free_master;
 451         }
 452         mps->psc = tempp;
 453         mps->fifo =
 454                 (struct mpc512x_psc_fifo *)(tempp + sizeof(struct mpc52xx_psc));
 455
 456         ret = request_irq(mps->irq, mpc512x_psc_spi_isr, IRQF_SHARED,
 457                           "mpc512x-psc-spi", mps);
 458         if (ret)
 459                 goto free_master;
 460
 461         ret = mpc512x_psc_spi_port_config(master, mps);
 462         if (ret < 0)
 463                 goto free_irq;
 464
 465         spin_lock_init(&mps->lock);
 466         init_completion(&mps->done);
 467         INIT_WORK(&mps->work, mpc512x_psc_spi_work);
 468         INIT_LIST_HEAD(&mps->queue);
 469
 470         mps->workqueue =
 471                 create_singlethread_workqueue(dev_name(master->dev.parent));
 472         if (mps->workqueue == NULL) {
 473                 ret = -EBUSY;
 474                 goto free_irq;
 475         }
 476
 477         ret = spi_register_master(master);
 478         if (ret < 0)
 479                 goto unreg_master;
 480
 481         return ret;
 482
 483 unreg_master:
 484         destroy_workqueue(mps->workqueue);
 485 free_irq:
 486         free_irq(mps->irq, mps);
 487 free_master:
 488         if (mps->psc)
 489                 iounmap(mps->psc);
 490         spi_master_put(master);
 491
 492         return ret;
 493 }
 494
 495 static int __devexit mpc512x_psc_spi_do_remove(struct device *dev)
 496 {
 497         struct spi_master *master = dev_get_drvdata(dev);
 498         struct mpc512x_psc_spi *mps = spi_master_get_devdata(master);
 499
 500         flush_workqueue(mps->workqueue);
 501         destroy_workqueue(mps->workqueue);
 502         spi_unregister_master(master);
 503         free_irq(mps->irq, mps);
 504         if (mps->psc)
 505                 iounmap(mps->psc);
 506
 507         return 0;
 508 }
 509
 510 static int __devinit mpc512x_psc_spi_of_probe(struct platform_device *op,
 511                                               const struct of_device_id *match)
 512 {
 513         const u32 *regaddr_p;
 514         u64 regaddr64, size64;
 515         s16 id = -1;
 516
 517         regaddr_p = of_get_address(op->dev.of_node, 0, &size64, NULL);
 518         if (!regaddr_p) {
 519                 dev_err(&op->dev, "Invalid PSC address\n");
 520                 return -EINVAL;
 521         }
 522         regaddr64 = of_translate_address(op->dev.of_node, regaddr_p);
 523
 524         /* get PSC id (0..11, used by port_config) */
 525         if (op->dev.platform_data == NULL) {
 526                 const u32 *psc_nump;
 527
 528                 psc_nump = of_get_property(op->dev.of_node, "cell-index", NULL);
 529                 if (!psc_nump || *psc_nump > 11) {
 530                         dev_err(&op->dev, "mpc512x_psc_spi: Device node %s "
 531                                 "has invalid cell-index property\n",
 532                                 op->dev.of_node->full_name);
 533                         return -EINVAL;
 534                 }
 535                 id = *psc_nump;
 536         }
 537
 538         return mpc512x_psc_spi_do_probe(&op->dev, (u32) regaddr64, (u32) size64,
 539                                 irq_of_parse_and_map(op->dev.of_node, 0), id);
 540 }
 541
 542 static int __devexit mpc512x_psc_spi_of_remove(struct platform_device *op)
 543 {
 544         return mpc512x_psc_spi_do_remove(&op->dev);
 545 }
 546
 547 static struct of_device_id mpc512x_psc_spi_of_match[] = {
 548         { .compatible = "fsl,mpc5121-psc-spi", },
 549         {},
 550 };
 551
 552 MODULE_DEVICE_TABLE(of, mpc512x_psc_spi_of_match);
 553
 554 static struct of_platform_driver mpc512x_psc_spi_of_driver = {
 555         .probe = mpc512x_psc_spi_of_probe,
 556         .remove = __devexit_p(mpc512x_psc_spi_of_remove),
 557         .driver = {
 558                 .name = "mpc512x-psc-spi",
 559                 .owner = THIS_MODULE,
 560                 .of_match_table = mpc512x_psc_spi_of_match,
 561         },
 562 };
 563
 564 static int __init mpc512x_psc_spi_init(void)
 565 {
 566         return of_register_platform_driver(&mpc512x_psc_spi_of_driver);
 567 }
 568 module_init(mpc512x_psc_spi_init);
 569
 570 static void __exit mpc512x_psc_spi_exit(void)
 571 {
 572         of_unregister_platform_driver(&mpc512x_psc_spi_of_driver);
 573 }
 574 module_exit(mpc512x_psc_spi_exit);
 575
 576 MODULE_AUTHOR("John Rigby");
 577 MODULE_DESCRIPTION("MPC512x PSC SPI Driver");
 578 MODULE_LICENSE("GPL");