drivers/spi/dw_spi.c

   1 /*
   2  * dw_spi.c - Designware SPI core controller driver (refer pxa2xx_spi.c)
   3  *
   4  * Copyright (c) 2009, Intel Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2, as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along with
  16  * this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #include <linux/dma-mapping.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/highmem.h>
  23 #include <linux/delay.h>
  24
  25 #include <linux/spi/dw_spi.h>
  26 #include <linux/spi/spi.h>
  27
  28 #ifdef CONFIG_DEBUG_FS
  29 #include <linux/debugfs.h>
  30 #endif
  31
  32 #define START_STATE     ((void *)0)
  33 #define RUNNING_STATE   ((void *)1)
  34 #define DONE_STATE      ((void *)2)
  35 #define ERROR_STATE     ((void *)-1)
  36
  37 #define QUEUE_RUNNING   0
  38 #define QUEUE_STOPPED   1
  39
  40 #define MRST_SPI_DEASSERT       0
  41 #define MRST_SPI_ASSERT         1
  42
  43 /* Slave spi_dev related */
  44 struct chip_data {
  45         u16 cr0;
  46         u8 cs;                  /* chip select pin */
  47         u8 n_bytes;             /* current is a 1/2/4 byte op */
  48         u8 tmode;               /* TR/TO/RO/EEPROM */
  49         u8 type;                /* SPI/SSP/MicroWire */
  50
  51         u8 poll_mode;           /* 1 means use poll mode */
  52
  53         u32 dma_width;
  54         u32 rx_threshold;
  55         u32 tx_threshold;
  56         u8 enable_dma;
  57         u8 bits_per_word;
  58         u16 clk_div;            /* baud rate divider */
  59         u32 speed_hz;           /* baud rate */
  60         int (*write)(struct dw_spi *dws);
  61         int (*read)(struct dw_spi *dws);
  62         void (*cs_control)(u32 command);
  63 };
  64
  65 #ifdef CONFIG_DEBUG_FS
  66 static int spi_show_regs_open(struct inode *inode, struct file *file)
  67 {
  68         file->private_data = inode->i_private;
  69         return 0;
  70 }
  71
  72 #define SPI_REGS_BUFSIZE        1024
  73 static ssize_t  spi_show_regs(struct file *file, char __user *user_buf,
  74                                 size_t count, loff_t *ppos)
  75 {
  76         struct dw_spi *dws;
  77         char *buf;
  78         u32 len = 0;
  79         ssize_t ret;
  80
  81         dws = file->private_data;
  82
  83         buf = kzalloc(SPI_REGS_BUFSIZE, GFP_KERNEL);
  84         if (!buf)
  85                 return 0;
  86
  87         len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
  88                         "MRST SPI0 registers:\n");
  89         len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
  90                         "=================================\n");
  91         len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
  92                         "CTRL0: \t\t0x%08x\n", dw_readl(dws, ctrl0));
  93         len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
  94                         "CTRL1: \t\t0x%08x\n", dw_readl(dws, ctrl1));
  95         len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
  96                         "SSIENR: \t0x%08x\n", dw_readl(dws, ssienr));
  97         len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
  98                         "SER: \t\t0x%08x\n", dw_readl(dws, ser));
  99         len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
 100                         "BAUDR: \t\t0x%08x\n", dw_readl(dws, baudr));
 101         len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
 102                         "TXFTLR: \t0x%08x\n", dw_readl(dws, txfltr));
 103         len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
 104                         "RXFTLR: \t0x%08x\n", dw_readl(dws, rxfltr));
 105         len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
 106                         "TXFLR: \t\t0x%08x\n", dw_readl(dws, txflr));
 107         len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
 108                         "RXFLR: \t\t0x%08x\n", dw_readl(dws, rxflr));
 109         len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
 110                         "SR: \t\t0x%08x\n", dw_readl(dws, sr));
 111         len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
 112                         "IMR: \t\t0x%08x\n", dw_readl(dws, imr));
 113         len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
 114                         "ISR: \t\t0x%08x\n", dw_readl(dws, isr));
 115         len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
 116                         "DMACR: \t\t0x%08x\n", dw_readl(dws, dmacr));
 117         len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
 118                         "DMATDLR: \t0x%08x\n", dw_readl(dws, dmatdlr));
 119         len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
 120                         "DMARDLR: \t0x%08x\n", dw_readl(dws, dmardlr));
 121         len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
 122                         "=================================\n");
 123
 124         ret =  simple_read_from_buffer(user_buf, count, ppos, buf, len);
 125         kfree(buf);
 126         return ret;
 127 }
 128
 129 static const struct file_operations mrst_spi_regs_ops = {
 130         .owner          = THIS_MODULE,
 131         .open           = spi_show_regs_open,
 132         .read           = spi_show_regs,
 133 };
 134
 135 static int mrst_spi_debugfs_init(struct dw_spi *dws)
 136 {
 137         dws->debugfs = debugfs_create_dir("mrst_spi", NULL);
 138         if (!dws->debugfs)
 139                 return -ENOMEM;
 140
 141         debugfs_create_file("registers", S_IFREG | S_IRUGO,
 142                 dws->debugfs, (void *)dws, &mrst_spi_regs_ops);
 143         return 0;
 144 }
 145
 146 static void mrst_spi_debugfs_remove(struct dw_spi *dws)
 147 {
 148         if (dws->debugfs)
 149                 debugfs_remove_recursive(dws->debugfs);
 150 }
 151
 152 #else
 153 static inline int mrst_spi_debugfs_init(struct dw_spi *dws)
 154 {
 155         return 0;
 156 }
 157
 158 static inline void mrst_spi_debugfs_remove(struct dw_spi *dws)
 159 {
 160 }
 161 #endif /* CONFIG_DEBUG_FS */
 162
 163 static void wait_till_not_busy(struct dw_spi *dws)
 164 {
 165         unsigned long end = jiffies + 1 + usecs_to_jiffies(1000);
 166
 167         while (time_before(jiffies, end)) {
 168                 if (!(dw_readw(dws, sr) & SR_BUSY))
 169                         return;
 170         }
 171         dev_err(&dws->master->dev,
 172                 "DW SPI: Status keeps busy for 1000us after a read/write!\n");
 173 }
 174
 175 static void flush(struct dw_spi *dws)
 176 {
 177         while (dw_readw(dws, sr) & SR_RF_NOT_EMPT)
 178                 dw_readw(dws, dr);
 179
 180         wait_till_not_busy(dws);
 181 }
 182
 183 static void null_cs_control(u32 command)
 184 {
 185 }
 186
 187 static int null_writer(struct dw_spi *dws)
 188 {
 189         u8 n_bytes = dws->n_bytes;
 190
 191         if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL)
 192                 || (dws->tx == dws->tx_end))
 193                 return 0;
 194         dw_writew(dws, dr, 0);
 195         dws->tx += n_bytes;
 196
 197         wait_till_not_busy(dws);
 198         return 1;
 199 }
 200
 201 static int null_reader(struct dw_spi *dws)
 202 {
 203         u8 n_bytes = dws->n_bytes;
 204
 205         while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT)
 206                 && (dws->rx < dws->rx_end)) {
 207                 dw_readw(dws, dr);
 208                 dws->rx += n_bytes;
 209         }
 210         wait_till_not_busy(dws);
 211         return dws->rx == dws->rx_end;
 212 }
 213
 214 static int u8_writer(struct dw_spi *dws)
 215 {
 216         if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL)
 217                 || (dws->tx == dws->tx_end))
 218                 return 0;
 219
 220         dw_writew(dws, dr, *(u8 *)(dws->tx));
 221         ++dws->tx;
 222
 223         wait_till_not_busy(dws);
 224         return 1;
 225 }
 226
 227 static int u8_reader(struct dw_spi *dws)
 228 {
 229         while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT)
 230                 && (dws->rx < dws->rx_end)) {
 231                 *(u8 *)(dws->rx) = dw_readw(dws, dr);
 232                 ++dws->rx;
 233         }
 234
 235         wait_till_not_busy(dws);
 236         return dws->rx == dws->rx_end;
 237 }
 238
 239 static int u16_writer(struct dw_spi *dws)
 240 {
 241         if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL)
 242                 || (dws->tx == dws->tx_end))
 243                 return 0;
 244
 245         dw_writew(dws, dr, *(u16 *)(dws->tx));
 246         dws->tx += 2;
 247
 248         wait_till_not_busy(dws);
 249         return 1;
 250 }
 251
 252 static int u16_reader(struct dw_spi *dws)
 253 {
 254         u16 temp;
 255
 256         while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT)
 257                 && (dws->rx < dws->rx_end)) {
 258                 temp = dw_readw(dws, dr);
 259                 *(u16 *)(dws->rx) = temp;
 260                 dws->rx += 2;
 261         }
 262
 263         wait_till_not_busy(dws);
 264         return dws->rx == dws->rx_end;
 265 }
 266
 267 static void *next_transfer(struct dw_spi *dws)
 268 {
 269         struct spi_message *msg = dws->cur_msg;
 270         struct spi_transfer *trans = dws->cur_transfer;
 271
 272         /* Move to next transfer */
 273         if (trans->transfer_list.next != &msg->transfers) {
 274                 dws->cur_transfer =
 275                         list_entry(trans->transfer_list.next,
 276                                         struct spi_transfer,
 277                                         transfer_list);
 278                 return RUNNING_STATE;
 279         } else
 280                 return DONE_STATE;
 281 }
 282
 283 /*
 284  * Note: first step is the protocol driver prepares
 285  * a dma-capable memory, and this func just need translate
 286  * the virt addr to physical
 287  */
 288 static int map_dma_buffers(struct dw_spi *dws)
 289 {
 290         if (!dws->cur_msg->is_dma_mapped || !dws->dma_inited
 291                 || !dws->cur_chip->enable_dma)
 292                 return 0;
 293
 294         if (dws->cur_transfer->tx_dma)
 295                 dws->tx_dma = dws->cur_transfer->tx_dma;
 296
 297         if (dws->cur_transfer->rx_dma)
 298                 dws->rx_dma = dws->cur_transfer->rx_dma;
 299
 300         return 1;
 301 }
 302
 303 /* Caller already set message->status; dma and pio irqs are blocked */
 304 static void giveback(struct dw_spi *dws)
 305 {
 306         struct spi_transfer *last_transfer;
 307         unsigned long flags;
 308         struct spi_message *msg;
 309
 310         spin_lock_irqsave(&dws->lock, flags);
 311         msg = dws->cur_msg;
 312         dws->cur_msg = NULL;
 313         dws->cur_transfer = NULL;
 314         dws->prev_chip = dws->cur_chip;
 315         dws->cur_chip = NULL;
 316         dws->dma_mapped = 0;
 317         queue_work(dws->workqueue, &dws->pump_messages);
 318         spin_unlock_irqrestore(&dws->lock, flags);
 319
 320         last_transfer = list_entry(msg->transfers.prev,
 321                                         struct spi_transfer,
 322                                         transfer_list);
 323
 324         if (!last_transfer->cs_change)
 325                 dws->cs_control(MRST_SPI_DEASSERT);
 326
 327         msg->state = NULL;
 328         if (msg->complete)
 329                 msg->complete(msg->context);
 330 }
 331
 332 static void int_error_stop(struct dw_spi *dws, const char *msg)
 333 {
 334         /* Stop and reset hw */
 335         flush(dws);
 336         spi_enable_chip(dws, 0);
 337
 338         dev_err(&dws->master->dev, "%s\n", msg);
 339         dws->cur_msg->state = ERROR_STATE;
 340         tasklet_schedule(&dws->pump_transfers);
 341 }
 342
 343 static void transfer_complete(struct dw_spi *dws)
 344 {
 345         /* Update total byte transfered return count actual bytes read */
 346         dws->cur_msg->actual_length += dws->len;
 347
 348         /* Move to next transfer */
 349         dws->cur_msg->state = next_transfer(dws);
 350
 351         /* Handle end of message */
 352         if (dws->cur_msg->state == DONE_STATE) {
 353                 dws->cur_msg->status = 0;
 354                 giveback(dws);
 355         } else
 356                 tasklet_schedule(&dws->pump_transfers);
 357 }
 358
 359 static irqreturn_t interrupt_transfer(struct dw_spi *dws)
 360 {
 361         u16 irq_status, irq_mask = 0x3f;
 362         u32 int_level = dws->fifo_len / 2;
 363         u32 left;
 364
 365         irq_status = dw_readw(dws, isr) & irq_mask;
 366         /* Error handling */
 367         if (irq_status & (SPI_INT_TXOI | SPI_INT_RXOI | SPI_INT_RXUI)) {
 368                 dw_readw(dws, txoicr);
 369                 dw_readw(dws, rxoicr);
 370                 dw_readw(dws, rxuicr);
 371                 int_error_stop(dws, "interrupt_transfer: fifo overrun");
 372                 return IRQ_HANDLED;
 373         }
 374
 375         if (irq_status & SPI_INT_TXEI) {
 376                 spi_mask_intr(dws, SPI_INT_TXEI);
 377
 378                 left = (dws->tx_end - dws->tx) / dws->n_bytes;
 379                 left = (left > int_level) ? int_level : left;
 380
 381                 while (left--)
 382                         dws->write(dws);
 383                 dws->read(dws);
 384
 385                 /* Re-enable the IRQ if there is still data left to tx */
 386                 if (dws->tx_end > dws->tx)
 387                         spi_umask_intr(dws, SPI_INT_TXEI);
 388                 else
 389                         transfer_complete(dws);
 390         }
 391
 392         return IRQ_HANDLED;
 393 }
 394
 395 static irqreturn_t dw_spi_irq(int irq, void *dev_id)
 396 {
 397         struct dw_spi *dws = dev_id;
 398
 399         if (!dws->cur_msg) {
 400                 spi_mask_intr(dws, SPI_INT_TXEI);
 401                 /* Never fail */
 402                 return IRQ_HANDLED;
 403         }
 404
 405         return dws->transfer_handler(dws);
 406 }
 407
 408 /* Must be called inside pump_transfers() */
 409 static void poll_transfer(struct dw_spi *dws)
 410 {
 411         while (dws->write(dws))
 412                 dws->read(dws);
 413
 414         transfer_complete(dws);
 415 }
 416
 417 static void dma_transfer(struct dw_spi *dws, int cs_change)
 418 {
 419 }
 420
 421 static void pump_transfers(unsigned long data)
 422 {
 423         struct dw_spi *dws = (struct dw_spi *)data;
 424         struct spi_message *message = NULL;
 425         struct spi_transfer *transfer = NULL;
 426         struct spi_transfer *previous = NULL;
 427         struct spi_device *spi = NULL;
 428         struct chip_data *chip = NULL;
 429         u8 bits = 0;
 430         u8 imask = 0;
 431         u8 cs_change = 0;
 432         u16 txint_level = 0;
 433         u16 clk_div = 0;
 434         u32 speed = 0;
 435         u32 cr0 = 0;
 436
 437         /* Get current state information */
 438         message = dws->cur_msg;
 439         transfer = dws->cur_transfer;
 440         chip = dws->cur_chip;
 441         spi = message->spi;
 442
 443         if (unlikely(!chip->clk_div))
 444                 chip->clk_div = dws->max_freq / chip->speed_hz;
 445
 446         if (message->state == ERROR_STATE) {
 447                 message->status = -EIO;
 448                 goto early_exit;
 449         }
 450
 451         /* Handle end of message */
 452         if (message->state == DONE_STATE) {
 453                 message->status = 0;
 454                 goto early_exit;
 455         }
 456
 457         /* Delay if requested at end of transfer*/
 458         if (message->state == RUNNING_STATE) {
 459                 previous = list_entry(transfer->transfer_list.prev,
 460                                         struct spi_transfer,
 461                                         transfer_list);
 462                 if (previous->delay_usecs)
 463                         udelay(previous->delay_usecs);
 464         }
 465
 466         dws->n_bytes = chip->n_bytes;
 467         dws->dma_width = chip->dma_width;
 468         dws->cs_control = chip->cs_control;
 469
 470         dws->rx_dma = transfer->rx_dma;
 471         dws->tx_dma = transfer->tx_dma;
 472         dws->tx = (void *)transfer->tx_buf;
 473         dws->tx_end = dws->tx + transfer->len;
 474         dws->rx = transfer->rx_buf;
 475         dws->rx_end = dws->rx + transfer->len;
 476         dws->write = dws->tx ? chip->write : null_writer;
 477         dws->read = dws->rx ? chip->read : null_reader;
 478         dws->cs_change = transfer->cs_change;
 479         dws->len = dws->cur_transfer->len;
 480         if (chip != dws->prev_chip)
 481                 cs_change = 1;
 482
 483         cr0 = chip->cr0;
 484
 485         /* Handle per transfer options for bpw and speed */
 486         if (transfer->speed_hz) {
 487                 speed = chip->speed_hz;
 488
 489                 if (transfer->speed_hz != speed) {
 490                         speed = transfer->speed_hz;
 491                         if (speed > dws->max_freq) {
 492                                 printk(KERN_ERR "MRST SPI0: unsupported"
 493                                         "freq: %dHz\n", speed);
 494                                 message->status = -EIO;
 495                                 goto early_exit;
 496                         }
 497
 498                         /* clk_div doesn't support odd number */
 499                         clk_div = dws->max_freq / speed;
 500                         clk_div = (clk_div + 1) & 0xfffe;
 501
 502                         chip->speed_hz = speed;
 503                         chip->clk_div = clk_div;
 504                 }
 505         }
 506         if (transfer->bits_per_word) {
 507                 bits = transfer->bits_per_word;
 508
 509                 switch (bits) {
 510                 case 8:
 511                         dws->n_bytes = 1;
 512                         dws->dma_width = 1;
 513                         dws->read = (dws->read != null_reader) ?
 514                                         u8_reader : null_reader;
 515                         dws->write = (dws->write != null_writer) ?
 516                                         u8_writer : null_writer;
 517                         break;
 518                 case 16:
 519                         dws->n_bytes = 2;
 520                         dws->dma_width = 2;
 521                         dws->read = (dws->read != null_reader) ?
 522                                         u16_reader : null_reader;
 523                         dws->write = (dws->write != null_writer) ?
 524                                         u16_writer : null_writer;
 525                         break;
 526                 default:
 527                         printk(KERN_ERR "MRST SPI0: unsupported bits:"
 528                                 "%db\n", bits);
 529                         message->status = -EIO;
 530                         goto early_exit;
 531                 }
 532
 533                 cr0 = (bits - 1)
 534                         | (chip->type << SPI_FRF_OFFSET)
 535                         | (spi->mode << SPI_MODE_OFFSET)
 536                         | (chip->tmode << SPI_TMOD_OFFSET);
 537         }
 538         message->state = RUNNING_STATE;
 539
 540         /*
 541          * Adjust transfer mode if necessary. Requires platform dependent
 542          * chipselect mechanism.
 543          */
 544         if (dws->cs_control) {
 545                 if (dws->rx && dws->tx)
 546                         chip->tmode = 0x00;
 547                 else if (dws->rx)
 548                         chip->tmode = 0x02;
 549                 else
 550                         chip->tmode = 0x01;
 551
 552                 cr0 &= ~(0x3 << SPI_MODE_OFFSET);
 553                 cr0 |= (chip->tmode << SPI_TMOD_OFFSET);
 554         }
 555
 556         /* Check if current transfer is a DMA transaction */
 557         dws->dma_mapped = map_dma_buffers(dws);
 558
 559         /*
 560          * Interrupt mode
 561          * we only need set the TXEI IRQ, as TX/RX always happen syncronizely
 562          */
 563         if (!dws->dma_mapped && !chip->poll_mode) {
 564                 int templen = dws->len / dws->n_bytes;
 565                 txint_level = dws->fifo_len / 2;
 566                 txint_level = (templen > txint_level) ? txint_level : templen;
 567
 568                 imask |= SPI_INT_TXEI;
 569                 dws->transfer_handler = interrupt_transfer;
 570         }
 571
 572         /*
 573          * Reprogram registers only if
 574          *      1. chip select changes
 575          *      2. clk_div is changed
 576          *      3. control value changes
 577          */
 578         if (dw_readw(dws, ctrl0) != cr0 || cs_change || clk_div || imask) {
 579                 spi_enable_chip(dws, 0);
 580
 581                 if (dw_readw(dws, ctrl0) != cr0)
 582                         dw_writew(dws, ctrl0, cr0);
 583
 584                 spi_set_clk(dws, clk_div ? clk_div : chip->clk_div);
 585                 spi_chip_sel(dws, spi->chip_select);
 586
 587                 /* Set the interrupt mask, for poll mode just diable all int */
 588                 spi_mask_intr(dws, 0xff);
 589                 if (imask)
 590                         spi_umask_intr(dws, imask);
 591                 if (txint_level)
 592                         dw_writew(dws, txfltr, txint_level);
 593
 594                 spi_enable_chip(dws, 1);
 595                 if (cs_change)
 596                         dws->prev_chip = chip;
 597         }
 598
 599         if (dws->dma_mapped)
 600                 dma_transfer(dws, cs_change);
 601
 602         if (chip->poll_mode)
 603                 poll_transfer(dws);
 604
 605         return;
 606
 607 early_exit:
 608         giveback(dws);
 609         return;
 610 }
 611
 612 static void pump_messages(struct work_struct *work)
 613 {
 614         struct dw_spi *dws =
 615                 container_of(work, struct dw_spi, pump_messages);
 616         unsigned long flags;
 617
 618         /* Lock queue and check for queue work */
 619         spin_lock_irqsave(&dws->lock, flags);
 620         if (list_empty(&dws->queue) || dws->run == QUEUE_STOPPED) {
 621                 dws->busy = 0;
 622                 spin_unlock_irqrestore(&dws->lock, flags);
 623                 return;
 624         }
 625
 626         /* Make sure we are not already running a message */
 627         if (dws->cur_msg) {
 628                 spin_unlock_irqrestore(&dws->lock, flags);
 629                 return;
 630         }
 631
 632         /* Extract head of queue */
 633         dws->cur_msg = list_entry(dws->queue.next, struct spi_message, queue);
 634         list_del_init(&dws->cur_msg->queue);
 635
 636         /* Initial message state*/
 637         dws->cur_msg->state = START_STATE;
 638         dws->cur_transfer = list_entry(dws->cur_msg->transfers.next,
 639                                                 struct spi_transfer,
 640                                                 transfer_list);
 641         dws->cur_chip = spi_get_ctldata(dws->cur_msg->spi);
 642
 643         /* Mark as busy and launch transfers */
 644         tasklet_schedule(&dws->pump_transfers);
 645
 646         dws->busy = 1;
 647         spin_unlock_irqrestore(&dws->lock, flags);
 648 }
 649
 650 /* spi_device use this to queue in their spi_msg */
 651 static int dw_spi_transfer(struct spi_device *spi, struct spi_message *msg)
 652 {
 653         struct dw_spi *dws = spi_master_get_devdata(spi->master);
 654         unsigned long flags;
 655
 656         spin_lock_irqsave(&dws->lock, flags);
 657
 658         if (dws->run == QUEUE_STOPPED) {
 659                 spin_unlock_irqrestore(&dws->lock, flags);
 660                 return -ESHUTDOWN;
 661         }
 662
 663         msg->actual_length = 0;
 664         msg->status = -EINPROGRESS;
 665         msg->state = START_STATE;
 666
 667         list_add_tail(&msg->queue, &dws->queue);
 668
 669         if (dws->run == QUEUE_RUNNING && !dws->busy) {
 670
 671                 if (dws->cur_transfer || dws->cur_msg)
 672                         queue_work(dws->workqueue,
 673                                         &dws->pump_messages);
 674                 else {
 675                         /* If no other data transaction in air, just go */
 676                         spin_unlock_irqrestore(&dws->lock, flags);
 677                         pump_messages(&dws->pump_messages);
 678                         return 0;
 679                 }
 680         }
 681
 682         spin_unlock_irqrestore(&dws->lock, flags);
 683         return 0;
 684 }
 685
 686 /* This may be called twice for each spi dev */
 687 static int dw_spi_setup(struct spi_device *spi)
 688 {
 689         struct dw_spi_chip *chip_info = NULL;
 690         struct chip_data *chip;
 691
 692         if (spi->bits_per_word != 8 && spi->bits_per_word != 16)
 693                 return -EINVAL;
 694
 695         /* Only alloc on first setup */
 696         chip = spi_get_ctldata(spi);
 697         if (!chip) {
 698                 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
 699                 if (!chip)
 700                         return -ENOMEM;
 701
 702                 chip->cs_control = null_cs_control;
 703                 chip->enable_dma = 0;
 704         }
 705
 706         /*
 707          * Protocol drivers may change the chip settings, so...
 708          * if chip_info exists, use it
 709          */
 710         chip_info = spi->controller_data;
 711
 712         /* chip_info doesn't always exist */
 713         if (chip_info) {
 714                 if (chip_info->cs_control)
 715                         chip->cs_control = chip_info->cs_control;
 716
 717                 chip->poll_mode = chip_info->poll_mode;
 718                 chip->type = chip_info->type;
 719
 720                 chip->rx_threshold = 0;
 721                 chip->tx_threshold = 0;
 722
 723                 chip->enable_dma = chip_info->enable_dma;
 724         }
 725
 726         if (spi->bits_per_word <= 8) {
 727                 chip->n_bytes = 1;
 728                 chip->dma_width = 1;
 729                 chip->read = u8_reader;
 730                 chip->write = u8_writer;
 731         } else if (spi->bits_per_word <= 16) {
 732                 chip->n_bytes = 2;
 733                 chip->dma_width = 2;
 734                 chip->read = u16_reader;
 735                 chip->write = u16_writer;
 736         } else {
 737                 /* Never take >16b case for MRST SPIC */
 738                 dev_err(&spi->dev, "invalid wordsize\n");
 739                 return -EINVAL;
 740         }
 741         chip->bits_per_word = spi->bits_per_word;
 742
 743         if (!spi->max_speed_hz) {
 744                 dev_err(&spi->dev, "No max speed HZ parameter\n");
 745                 return -EINVAL;
 746         }
 747         chip->speed_hz = spi->max_speed_hz;
 748
 749         chip->tmode = 0; /* Tx & Rx */
 750         /* Default SPI mode is SCPOL = 0, SCPH = 0 */
 751         chip->cr0 = (chip->bits_per_word - 1)
 752                         | (chip->type << SPI_FRF_OFFSET)
 753                         | (spi->mode  << SPI_MODE_OFFSET)
 754                         | (chip->tmode << SPI_TMOD_OFFSET);
 755
 756         spi_set_ctldata(spi, chip);
 757         return 0;
 758 }
 759
 760 static void dw_spi_cleanup(struct spi_device *spi)
 761 {
 762         struct chip_data *chip = spi_get_ctldata(spi);
 763         kfree(chip);
 764 }
 765
 766 static int __devinit init_queue(struct dw_spi *dws)
 767 {
 768         INIT_LIST_HEAD(&dws->queue);
 769         spin_lock_init(&dws->lock);
 770
 771         dws->run = QUEUE_STOPPED;
 772         dws->busy = 0;
 773
 774         tasklet_init(&dws->pump_transfers,
 775                         pump_transfers, (unsigned long)dws);
 776
 777         INIT_WORK(&dws->pump_messages, pump_messages);
 778         dws->workqueue = create_singlethread_workqueue(
 779                                         dev_name(dws->master->dev.parent));
 780         if (dws->workqueue == NULL)
 781                 return -EBUSY;
 782
 783         return 0;
 784 }
 785
 786 static int start_queue(struct dw_spi *dws)
 787 {
 788         unsigned long flags;
 789
 790         spin_lock_irqsave(&dws->lock, flags);
 791
 792         if (dws->run == QUEUE_RUNNING || dws->busy) {
 793                 spin_unlock_irqrestore(&dws->lock, flags);
 794                 return -EBUSY;
 795         }
 796
 797         dws->run = QUEUE_RUNNING;
 798         dws->cur_msg = NULL;
 799         dws->cur_transfer = NULL;
 800         dws->cur_chip = NULL;
 801         dws->prev_chip = NULL;
 802         spin_unlock_irqrestore(&dws->lock, flags);
 803
 804         queue_work(dws->workqueue, &dws->pump_messages);
 805
 806         return 0;
 807 }
 808
 809 static int stop_queue(struct dw_spi *dws)
 810 {
 811         unsigned long flags;
 812         unsigned limit = 50;
 813         int status = 0;
 814
 815         spin_lock_irqsave(&dws->lock, flags);
 816         dws->run = QUEUE_STOPPED;
 817         while (!list_empty(&dws->queue) && dws->busy && limit--) {
 818                 spin_unlock_irqrestore(&dws->lock, flags);
 819                 msleep(10);
 820                 spin_lock_irqsave(&dws->lock, flags);
 821         }
 822
 823         if (!list_empty(&dws->queue) || dws->busy)
 824                 status = -EBUSY;
 825         spin_unlock_irqrestore(&dws->lock, flags);
 826
 827         return status;
 828 }
 829
 830 static int destroy_queue(struct dw_spi *dws)
 831 {
 832         int status;
 833
 834         status = stop_queue(dws);
 835         if (status != 0)
 836                 return status;
 837         destroy_workqueue(dws->workqueue);
 838         return 0;
 839 }
 840
 841 /* Restart the controller, disable all interrupts, clean rx fifo */
 842 static void spi_hw_init(struct dw_spi *dws)
 843 {
 844         spi_enable_chip(dws, 0);
 845         spi_mask_intr(dws, 0xff);
 846         spi_enable_chip(dws, 1);
 847         flush(dws);
 848
 849         /*
 850          * Try to detect the FIFO depth if not set by interface driver,
 851          * the depth could be from 2 to 256 from HW spec
 852          */
 853         if (!dws->fifo_len) {
 854                 u32 fifo;
 855                 for (fifo = 2; fifo <= 257; fifo++) {
 856                         dw_writew(dws, txfltr, fifo);
 857                         if (fifo != dw_readw(dws, txfltr))
 858                                 break;
 859                 }
 860
 861                 dws->fifo_len = (fifo == 257) ? 0 : fifo;
 862                 dw_writew(dws, txfltr, 0);
 863         }
 864 }
 865
 866 int __devinit dw_spi_add_host(struct dw_spi *dws)
 867 {
 868         struct spi_master *master;
 869         int ret;
 870
 871         BUG_ON(dws == NULL);
 872
 873         master = spi_alloc_master(dws->parent_dev, 0);
 874         if (!master) {
 875                 ret = -ENOMEM;
 876                 goto exit;
 877         }
 878
 879         dws->master = master;
 880         dws->type = SSI_MOTO_SPI;
 881         dws->prev_chip = NULL;
 882         dws->dma_inited = 0;
 883         dws->dma_addr = (dma_addr_t)(dws->paddr + 0x60);
 884
 885         ret = request_irq(dws->irq, dw_spi_irq, 0,
 886                         "dw_spi", dws);
 887         if (ret < 0) {
 888                 dev_err(&master->dev, "can not get IRQ\n");
 889                 goto err_free_master;
 890         }
 891
 892         master->mode_bits = SPI_CPOL | SPI_CPHA;
 893         master->bus_num = dws->bus_num;
 894         master->num_chipselect = dws->num_cs;
 895         master->cleanup = dw_spi_cleanup;
 896         master->setup = dw_spi_setup;
 897         master->transfer = dw_spi_transfer;
 898
 899         dws->dma_inited = 0;
 900
 901         /* Basic HW init */
 902         spi_hw_init(dws);
 903
 904         /* Initial and start queue */
 905         ret = init_queue(dws);
 906         if (ret) {
 907                 dev_err(&master->dev, "problem initializing queue\n");
 908                 goto err_diable_hw;
 909         }
 910         ret = start_queue(dws);
 911         if (ret) {
 912                 dev_err(&master->dev, "problem starting queue\n");
 913                 goto err_diable_hw;
 914         }
 915
 916         spi_master_set_devdata(master, dws);
 917         ret = spi_register_master(master);
 918         if (ret) {
 919                 dev_err(&master->dev, "problem registering spi master\n");
 920                 goto err_queue_alloc;
 921         }
 922
 923         mrst_spi_debugfs_init(dws);
 924         return 0;
 925
 926 err_queue_alloc:
 927         destroy_queue(dws);
 928 err_diable_hw:
 929         spi_enable_chip(dws, 0);
 930         free_irq(dws->irq, dws);
 931 err_free_master:
 932         spi_master_put(master);
 933 exit:
 934         return ret;
 935 }
 936 EXPORT_SYMBOL(dw_spi_add_host);
 937
 938 void __devexit dw_spi_remove_host(struct dw_spi *dws)
 939 {
 940         int status = 0;
 941
 942         if (!dws)
 943                 return;
 944         mrst_spi_debugfs_remove(dws);
 945
 946         /* Remove the queue */
 947         status = destroy_queue(dws);
 948         if (status != 0)
 949                 dev_err(&dws->master->dev, "dw_spi_remove: workqueue will not "
 950                         "complete, message memory not freed\n");
 951
 952         spi_enable_chip(dws, 0);
 953         /* Disable clk */
 954         spi_set_clk(dws, 0);
 955         free_irq(dws->irq, dws);
 956
 957         /* Disconnect from the SPI framework */
 958         spi_unregister_master(dws->master);
 959 }
 960 EXPORT_SYMBOL(dw_spi_remove_host);
 961
 962 int dw_spi_suspend_host(struct dw_spi *dws)
 963 {
 964         int ret = 0;
 965
 966         ret = stop_queue(dws);
 967         if (ret)
 968                 return ret;
 969         spi_enable_chip(dws, 0);
 970         spi_set_clk(dws, 0);
 971         return ret;
 972 }
 973 EXPORT_SYMBOL(dw_spi_suspend_host);
 974
 975 int dw_spi_resume_host(struct dw_spi *dws)
 976 {
 977         int ret;
 978
 979         spi_hw_init(dws);
 980         ret = start_queue(dws);
 981         if (ret)
 982                 dev_err(&dws->master->dev, "fail to start queue (%d)\n", ret);
 983         return ret;
 984 }
 985 EXPORT_SYMBOL(dw_spi_resume_host);
 986
 987 MODULE_AUTHOR("Feng Tang <feng.tang@intel.com>");
 988 MODULE_DESCRIPTION("Driver for DesignWare SPI controller core");
 989 MODULE_LICENSE("GPL v2");