git.oblomov.eu Git - linux-2.6/blob - drivers/mmc/host/atmel-mci.c

   1 /*
   2  * Atmel MultiMedia Card Interface driver
   3  *
   4  * Copyright (C) 2004-2008 Atmel Corporation
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10 #include <linux/blkdev.h>
  11 #include <linux/clk.h>
  12 #include <linux/debugfs.h>
  13 #include <linux/device.h>
  14 #include <linux/dmaengine.h>
  15 #include <linux/dma-mapping.h>
  16 #include <linux/err.h>
  17 #include <linux/gpio.h>
  18 #include <linux/init.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/ioport.h>
  21 #include <linux/module.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/scatterlist.h>
  24 #include <linux/seq_file.h>
  25 #include <linux/stat.h>
  26
  27 #include <linux/mmc/host.h>
  28
  29 #include <asm/atmel-mci.h>
  30 #include <asm/io.h>
  31 #include <asm/unaligned.h>
  32
  33 #include <mach/board.h>
  34
  35 #include "atmel-mci-regs.h"
  36
  37 #define ATMCI_DATA_ERROR_FLAGS  (MCI_DCRCE | MCI_DTOE | MCI_OVRE | MCI_UNRE)
  38 #define ATMCI_DMA_THRESHOLD     16
  39
  40 enum {
  41         EVENT_CMD_COMPLETE = 0,
  42         EVENT_XFER_COMPLETE,
  43         EVENT_DATA_COMPLETE,
  44         EVENT_DATA_ERROR,
  45 };
  46
  47 enum atmel_mci_state {
  48         STATE_IDLE = 0,
  49         STATE_SENDING_CMD,
  50         STATE_SENDING_DATA,
  51         STATE_DATA_BUSY,
  52         STATE_SENDING_STOP,
  53         STATE_DATA_ERROR,
  54 };
  55
  56 struct atmel_mci_dma {
  57 #ifdef CONFIG_MMC_ATMELMCI_DMA
  58         struct dma_client               client;
  59         struct dma_chan                 *chan;
  60         struct dma_async_tx_descriptor  *data_desc;
  61 #endif
  62 };
  63
  64 /**
  65  * struct atmel_mci - MMC controller state shared between all slots
  66  * @lock: Spinlock protecting the queue and associated data.
  67  * @regs: Pointer to MMIO registers.
  68  * @sg: Scatterlist entry currently being processed by PIO code, if any.
  69  * @pio_offset: Offset into the current scatterlist entry.
  70  * @cur_slot: The slot which is currently using the controller.
  71  * @mrq: The request currently being processed on @cur_slot,
  72  *      or NULL if the controller is idle.
  73  * @cmd: The command currently being sent to the card, or NULL.
  74  * @data: The data currently being transferred, or NULL if no data
  75  *      transfer is in progress.
  76  * @dma: DMA client state.
  77  * @data_chan: DMA channel being used for the current data transfer.
  78  * @cmd_status: Snapshot of SR taken upon completion of the current
  79  *      command. Only valid when EVENT_CMD_COMPLETE is pending.
  80  * @data_status: Snapshot of SR taken upon completion of the current
  81  *      data transfer. Only valid when EVENT_DATA_COMPLETE or
  82  *      EVENT_DATA_ERROR is pending.
  83  * @stop_cmdr: Value to be loaded into CMDR when the stop command is
  84  *      to be sent.
  85  * @tasklet: Tasklet running the request state machine.
  86  * @pending_events: Bitmask of events flagged by the interrupt handler
  87  *      to be processed by the tasklet.
  88  * @completed_events: Bitmask of events which the state machine has
  89  *      processed.
  90  * @state: Tasklet state.
  91  * @queue: List of slots waiting for access to the controller.
  92  * @need_clock_update: Update the clock rate before the next request.
  93  * @need_reset: Reset controller before next request.
  94  * @mode_reg: Value of the MR register.
  95  * @bus_hz: The rate of @mck in Hz. This forms the basis for MMC bus
  96  *      rate and timeout calculations.
  97  * @mapbase: Physical address of the MMIO registers.
  98  * @mck: The peripheral bus clock hooked up to the MMC controller.
  99  * @pdev: Platform device associated with the MMC controller.
 100  * @slot: Slots sharing this MMC controller.
 101  *
 102  * Locking
 103  * =======
 104  *
 105  * @lock is a softirq-safe spinlock protecting @queue as well as
 106  * @cur_slot, @mrq and @state. These must always be updated
 107  * at the same time while holding @lock.
 108  *
 109  * @lock also protects mode_reg and need_clock_update since these are
 110  * used to synchronize mode register updates with the queue
 111  * processing.
 112  *
 113  * The @mrq field of struct atmel_mci_slot is also protected by @lock,
 114  * and must always be written at the same time as the slot is added to
 115  * @queue.
 116  *
 117  * @pending_events and @completed_events are accessed using atomic bit
 118  * operations, so they don't need any locking.
 119  *
 120  * None of the fields touched by the interrupt handler need any
 121  * locking. However, ordering is important: Before EVENT_DATA_ERROR or
 122  * EVENT_DATA_COMPLETE is set in @pending_events, all data-related
 123  * interrupts must be disabled and @data_status updated with a
 124  * snapshot of SR. Similarly, before EVENT_CMD_COMPLETE is set, the
 125  * CMDRDY interupt must be disabled and @cmd_status updated with a
 126  * snapshot of SR, and before EVENT_XFER_COMPLETE can be set, the
 127  * bytes_xfered field of @data must be written. This is ensured by
 128  * using barriers.
 129  */
 130 struct atmel_mci {
 131         spinlock_t              lock;
 132         void __iomem            *regs;
 133
 134         struct scatterlist      *sg;
 135         unsigned int            pio_offset;
 136
 137         struct atmel_mci_slot   *cur_slot;
 138         struct mmc_request      *mrq;
 139         struct mmc_command      *cmd;
 140         struct mmc_data         *data;
 141
 142         struct atmel_mci_dma    dma;
 143         struct dma_chan         *data_chan;
 144
 145         u32                     cmd_status;
 146         u32                     data_status;
 147         u32                     stop_cmdr;
 148
 149         struct tasklet_struct   tasklet;
 150         unsigned long           pending_events;
 151         unsigned long           completed_events;
 152         enum atmel_mci_state    state;
 153         struct list_head        queue;
 154
 155         bool                    need_clock_update;
 156         bool                    need_reset;
 157         u32                     mode_reg;
 158         unsigned long           bus_hz;
 159         unsigned long           mapbase;
 160         struct clk              *mck;
 161         struct platform_device  *pdev;
 162
 163         struct atmel_mci_slot   *slot[ATMEL_MCI_MAX_NR_SLOTS];
 164 };
 165
 166 /**
 167  * struct atmel_mci_slot - MMC slot state
 168  * @mmc: The mmc_host representing this slot.
 169  * @host: The MMC controller this slot is using.
 170  * @sdc_reg: Value of SDCR to be written before using this slot.
 171  * @mrq: mmc_request currently being processed or waiting to be
 172  *      processed, or NULL when the slot is idle.
 173  * @queue_node: List node for placing this node in the @queue list of
 174  *      &struct atmel_mci.
 175  * @clock: Clock rate configured by set_ios(). Protected by host->lock.
 176  * @flags: Random state bits associated with the slot.
 177  * @detect_pin: GPIO pin used for card detection, or negative if not
 178  *      available.
 179  * @wp_pin: GPIO pin used for card write protect sending, or negative
 180  *      if not available.
 181  * @detect_timer: Timer used for debouncing @detect_pin interrupts.
 182  */
 183 struct atmel_mci_slot {
 184         struct mmc_host         *mmc;
 185         struct atmel_mci        *host;
 186
 187         u32                     sdc_reg;
 188
 189         struct mmc_request      *mrq;
 190         struct list_head        queue_node;
 191
 192         unsigned int            clock;
 193         unsigned long           flags;
 194 #define ATMCI_CARD_PRESENT      0
 195 #define ATMCI_CARD_NEED_INIT    1
 196 #define ATMCI_SHUTDOWN          2
 197
 198         int                     detect_pin;
 199         int                     wp_pin;
 200
 201         struct timer_list       detect_timer;
 202 };
 203
 204 #define atmci_test_and_clear_pending(host, event)               \
 205         test_and_clear_bit(event, &host->pending_events)
 206 #define atmci_set_completed(host, event)                        \
 207         set_bit(event, &host->completed_events)
 208 #define atmci_set_pending(host, event)                          \
 209         set_bit(event, &host->pending_events)
 210
 211 /*
 212  * The debugfs stuff below is mostly optimized away when
 213  * CONFIG_DEBUG_FS is not set.
 214  */
 215 static int atmci_req_show(struct seq_file *s, void *v)
 216 {
 217         struct atmel_mci_slot   *slot = s->private;
 218         struct mmc_request      *mrq;
 219         struct mmc_command      *cmd;
 220         struct mmc_command      *stop;
 221         struct mmc_data         *data;
 222
 223         /* Make sure we get a consistent snapshot */
 224         spin_lock_bh(&slot->host->lock);
 225         mrq = slot->mrq;
 226
 227         if (mrq) {
 228                 cmd = mrq->cmd;
 229                 data = mrq->data;
 230                 stop = mrq->stop;
 231
 232                 if (cmd)
 233                         seq_printf(s,
 234                                 "CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
 235                                 cmd->opcode, cmd->arg, cmd->flags,
 236                                 cmd->resp[0], cmd->resp[1], cmd->resp[2],
 237                                 cmd->resp[2], cmd->error);
 238                 if (data)
 239                         seq_printf(s, "DATA %u / %u * %u flg %x err %d\n",
 240                                 data->bytes_xfered, data->blocks,
 241                                 data->blksz, data->flags, data->error);
 242                 if (stop)
 243                         seq_printf(s,
 244                                 "CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
 245                                 stop->opcode, stop->arg, stop->flags,
 246                                 stop->resp[0], stop->resp[1], stop->resp[2],
 247                                 stop->resp[2], stop->error);
 248         }
 249
 250         spin_unlock_bh(&slot->host->lock);
 251
 252         return 0;
 253 }
 254
 255 static int atmci_req_open(struct inode *inode, struct file *file)
 256 {
 257         return single_open(file, atmci_req_show, inode->i_private);
 258 }
 259
 260 static const struct file_operations atmci_req_fops = {
 261         .owner          = THIS_MODULE,
 262         .open           = atmci_req_open,
 263         .read           = seq_read,
 264         .llseek         = seq_lseek,
 265         .release        = single_release,
 266 };
 267
 268 static void atmci_show_status_reg(struct seq_file *s,
 269                 const char *regname, u32 value)
 270 {
 271         static const char       *sr_bit[] = {
 272                 [0]     = "CMDRDY",
 273                 [1]     = "RXRDY",
 274                 [2]     = "TXRDY",
 275                 [3]     = "BLKE",
 276                 [4]     = "DTIP",
 277                 [5]     = "NOTBUSY",
 278                 [8]     = "SDIOIRQA",
 279                 [9]     = "SDIOIRQB",
 280                 [16]    = "RINDE",
 281                 [17]    = "RDIRE",
 282                 [18]    = "RCRCE",
 283                 [19]    = "RENDE",
 284                 [20]    = "RTOE",
 285                 [21]    = "DCRCE",
 286                 [22]    = "DTOE",
 287                 [30]    = "OVRE",
 288                 [31]    = "UNRE",
 289         };
 290         unsigned int            i;
 291
 292         seq_printf(s, "%s:\t0x%08x", regname, value);
 293         for (i = 0; i < ARRAY_SIZE(sr_bit); i++) {
 294                 if (value & (1 << i)) {
 295                         if (sr_bit[i])
 296                                 seq_printf(s, " %s", sr_bit[i]);
 297                         else
 298                                 seq_puts(s, " UNKNOWN");
 299                 }
 300         }
 301         seq_putc(s, '\n');
 302 }
 303
 304 static int atmci_regs_show(struct seq_file *s, void *v)
 305 {
 306         struct atmel_mci        *host = s->private;
 307         u32                     *buf;
 308
 309         buf = kmalloc(MCI_REGS_SIZE, GFP_KERNEL);
 310         if (!buf)
 311                 return -ENOMEM;
 312
 313         /*
 314          * Grab a more or less consistent snapshot. Note that we're
 315          * not disabling interrupts, so IMR and SR may not be
 316          * consistent.
 317          */
 318         spin_lock_bh(&host->lock);
 319         clk_enable(host->mck);
 320         memcpy_fromio(buf, host->regs, MCI_REGS_SIZE);
 321         clk_disable(host->mck);
 322         spin_unlock_bh(&host->lock);
 323
 324         seq_printf(s, "MR:\t0x%08x%s%s CLKDIV=%u\n",
 325                         buf[MCI_MR / 4],
 326                         buf[MCI_MR / 4] & MCI_MR_RDPROOF ? " RDPROOF" : "",
 327                         buf[MCI_MR / 4] & MCI_MR_WRPROOF ? " WRPROOF" : "",
 328                         buf[MCI_MR / 4] & 0xff);
 329         seq_printf(s, "DTOR:\t0x%08x\n", buf[MCI_DTOR / 4]);
 330         seq_printf(s, "SDCR:\t0x%08x\n", buf[MCI_SDCR / 4]);
 331         seq_printf(s, "ARGR:\t0x%08x\n", buf[MCI_ARGR / 4]);
 332         seq_printf(s, "BLKR:\t0x%08x BCNT=%u BLKLEN=%u\n",
 333                         buf[MCI_BLKR / 4],
 334                         buf[MCI_BLKR / 4] & 0xffff,
 335                         (buf[MCI_BLKR / 4] >> 16) & 0xffff);
 336
 337         /* Don't read RSPR and RDR; it will consume the data there */
 338
 339         atmci_show_status_reg(s, "SR", buf[MCI_SR / 4]);
 340         atmci_show_status_reg(s, "IMR", buf[MCI_IMR / 4]);
 341
 342         kfree(buf);
 343
 344         return 0;
 345 }
 346
 347 static int atmci_regs_open(struct inode *inode, struct file *file)
 348 {
 349         return single_open(file, atmci_regs_show, inode->i_private);
 350 }
 351
 352 static const struct file_operations atmci_regs_fops = {
 353         .owner          = THIS_MODULE,
 354         .open           = atmci_regs_open,
 355         .read           = seq_read,
 356         .llseek         = seq_lseek,
 357         .release        = single_release,
 358 };
 359
 360 static void atmci_init_debugfs(struct atmel_mci_slot *slot)
 361 {
 362         struct mmc_host         *mmc = slot->mmc;
 363         struct atmel_mci        *host = slot->host;
 364         struct dentry           *root;
 365         struct dentry           *node;
 366
 367         root = mmc->debugfs_root;
 368         if (!root)
 369                 return;
 370
 371         node = debugfs_create_file("regs", S_IRUSR, root, host,
 372                         &atmci_regs_fops);
 373         if (IS_ERR(node))
 374                 return;
 375         if (!node)
 376                 goto err;
 377
 378         node = debugfs_create_file("req", S_IRUSR, root, slot, &atmci_req_fops);
 379         if (!node)
 380                 goto err;
 381
 382         node = debugfs_create_u32("state", S_IRUSR, root, (u32 *)&host->state);
 383         if (!node)
 384                 goto err;
 385
 386         node = debugfs_create_x32("pending_events", S_IRUSR, root,
 387                                      (u32 *)&host->pending_events);
 388         if (!node)
 389                 goto err;
 390
 391         node = debugfs_create_x32("completed_events", S_IRUSR, root,
 392                                      (u32 *)&host->completed_events);
 393         if (!node)
 394                 goto err;
 395
 396         return;
 397
 398 err:
 399         dev_err(&mmc->class_dev, "failed to initialize debugfs for slot\n");
 400 }
 401
 402 static inline unsigned int ns_to_clocks(struct atmel_mci *host,
 403                                         unsigned int ns)
 404 {
 405         return (ns * (host->bus_hz / 1000000) + 999) / 1000;
 406 }
 407
 408 static void atmci_set_timeout(struct atmel_mci *host,
 409                 struct atmel_mci_slot *slot, struct mmc_data *data)
 410 {
 411         static unsigned dtomul_to_shift[] = {
 412                 0, 4, 7, 8, 10, 12, 16, 20
 413         };
 414         unsigned        timeout;
 415         unsigned        dtocyc;
 416         unsigned        dtomul;
 417
 418         timeout = ns_to_clocks(host, data->timeout_ns) + data->timeout_clks;
 419
 420         for (dtomul = 0; dtomul < 8; dtomul++) {
 421                 unsigned shift = dtomul_to_shift[dtomul];
 422                 dtocyc = (timeout + (1 << shift) - 1) >> shift;
 423                 if (dtocyc < 15)
 424                         break;
 425         }
 426
 427         if (dtomul >= 8) {
 428                 dtomul = 7;
 429                 dtocyc = 15;
 430         }
 431
 432         dev_vdbg(&slot->mmc->class_dev, "setting timeout to %u cycles\n",
 433                         dtocyc << dtomul_to_shift[dtomul]);
 434         mci_writel(host, DTOR, (MCI_DTOMUL(dtomul) | MCI_DTOCYC(dtocyc)));
 435 }
 436
 437 /*
 438  * Return mask with command flags to be enabled for this command.
 439  */
 440 static u32 atmci_prepare_command(struct mmc_host *mmc,
 441                                  struct mmc_command *cmd)
 442 {
 443         struct mmc_data *data;
 444         u32             cmdr;
 445
 446         cmd->error = -EINPROGRESS;
 447
 448         cmdr = MCI_CMDR_CMDNB(cmd->opcode);
 449
 450         if (cmd->flags & MMC_RSP_PRESENT) {
 451                 if (cmd->flags & MMC_RSP_136)
 452                         cmdr |= MCI_CMDR_RSPTYP_136BIT;
 453                 else
 454                         cmdr |= MCI_CMDR_RSPTYP_48BIT;
 455         }
 456
 457         /*
 458          * This should really be MAXLAT_5 for CMD2 and ACMD41, but
 459          * it's too difficult to determine whether this is an ACMD or
 460          * not. Better make it 64.
 461          */
 462         cmdr |= MCI_CMDR_MAXLAT_64CYC;
 463
 464         if (mmc->ios.bus_mode == MMC_BUSMODE_OPENDRAIN)
 465                 cmdr |= MCI_CMDR_OPDCMD;
 466
 467         data = cmd->data;
 468         if (data) {
 469                 cmdr |= MCI_CMDR_START_XFER;
 470                 if (data->flags & MMC_DATA_STREAM)
 471                         cmdr |= MCI_CMDR_STREAM;
 472                 else if (data->blocks > 1)
 473                         cmdr |= MCI_CMDR_MULTI_BLOCK;
 474                 else
 475                         cmdr |= MCI_CMDR_BLOCK;
 476
 477                 if (data->flags & MMC_DATA_READ)
 478                         cmdr |= MCI_CMDR_TRDIR_READ;
 479         }
 480
 481         return cmdr;
 482 }
 483
 484 static void atmci_start_command(struct atmel_mci *host,
 485                 struct mmc_command *cmd, u32 cmd_flags)
 486 {
 487         WARN_ON(host->cmd);
 488         host->cmd = cmd;
 489
 490         dev_vdbg(&host->pdev->dev,
 491                         "start command: ARGR=0x%08x CMDR=0x%08x\n",
 492                         cmd->arg, cmd_flags);
 493
 494         mci_writel(host, ARGR, cmd->arg);
 495         mci_writel(host, CMDR, cmd_flags);
 496 }
 497
 498 static void send_stop_cmd(struct atmel_mci *host, struct mmc_data *data)
 499 {
 500         atmci_start_command(host, data->stop, host->stop_cmdr);
 501         mci_writel(host, IER, MCI_CMDRDY);
 502 }
 503
 504 #ifdef CONFIG_MMC_ATMELMCI_DMA
 505 static void atmci_dma_cleanup(struct atmel_mci *host)
 506 {
 507         struct mmc_data                 *data = host->data;
 508
 509         dma_unmap_sg(&host->pdev->dev, data->sg, data->sg_len,
 510                      ((data->flags & MMC_DATA_WRITE)
 511                       ? DMA_TO_DEVICE : DMA_FROM_DEVICE));
 512 }
 513
 514 static void atmci_stop_dma(struct atmel_mci *host)
 515 {
 516         struct dma_chan *chan = host->data_chan;
 517
 518         if (chan) {
 519                 chan->device->device_terminate_all(chan);
 520                 atmci_dma_cleanup(host);
 521         } else {
 522                 /* Data transfer was stopped by the interrupt handler */
 523                 atmci_set_pending(host, EVENT_XFER_COMPLETE);
 524                 mci_writel(host, IER, MCI_NOTBUSY);
 525         }
 526 }
 527
 528 /* This function is called by the DMA driver from tasklet context. */
 529 static void atmci_dma_complete(void *arg)
 530 {
 531         struct atmel_mci        *host = arg;
 532         struct mmc_data         *data = host->data;
 533
 534         dev_vdbg(&host->pdev->dev, "DMA complete\n");
 535
 536         atmci_dma_cleanup(host);
 537
 538         /*
 539          * If the card was removed, data will be NULL. No point trying
 540          * to send the stop command or waiting for NBUSY in this case.
 541          */
 542         if (data) {
 543                 atmci_set_pending(host, EVENT_XFER_COMPLETE);
 544                 tasklet_schedule(&host->tasklet);
 545
 546                 /*
 547                  * Regardless of what the documentation says, we have
 548                  * to wait for NOTBUSY even after block read
 549                  * operations.
 550                  *
 551                  * When the DMA transfer is complete, the controller
 552                  * may still be reading the CRC from the card, i.e.
 553                  * the data transfer is still in progress and we
 554                  * haven't seen all the potential error bits yet.
 555                  *
 556                  * The interrupt handler will schedule a different
 557                  * tasklet to finish things up when the data transfer
 558                  * is completely done.
 559                  *
 560                  * We may not complete the mmc request here anyway
 561                  * because the mmc layer may call back and cause us to
 562                  * violate the "don't submit new operations from the
 563                  * completion callback" rule of the dma engine
 564                  * framework.
 565                  */
 566                 mci_writel(host, IER, MCI_NOTBUSY);
 567         }
 568 }
 569
 570 static int
 571 atmci_submit_data_dma(struct atmel_mci *host, struct mmc_data *data)
 572 {
 573         struct dma_chan                 *chan;
 574         struct dma_async_tx_descriptor  *desc;
 575         struct scatterlist              *sg;
 576         unsigned int                    i;
 577         enum dma_data_direction         direction;
 578
 579         /*
 580          * We don't do DMA on "complex" transfers, i.e. with
 581          * non-word-aligned buffers or lengths. Also, we don't bother
 582          * with all the DMA setup overhead for short transfers.
 583          */
 584         if (data->blocks * data->blksz < ATMCI_DMA_THRESHOLD)
 585                 return -EINVAL;
 586         if (data->blksz & 3)
 587                 return -EINVAL;
 588
 589         for_each_sg(data->sg, sg, data->sg_len, i) {
 590                 if (sg->offset & 3 || sg->length & 3)
 591                         return -EINVAL;
 592         }
 593
 594         /* If we don't have a channel, we can't do DMA */
 595         chan = host->dma.chan;
 596         if (chan) {
 597                 dma_chan_get(chan);
 598                 host->data_chan = chan;
 599         }
 600
 601         if (!chan)
 602                 return -ENODEV;
 603
 604         if (data->flags & MMC_DATA_READ)
 605                 direction = DMA_FROM_DEVICE;
 606         else
 607                 direction = DMA_TO_DEVICE;
 608
 609         desc = chan->device->device_prep_slave_sg(chan,
 610                         data->sg, data->sg_len, direction,
 611                         DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 612         if (!desc)
 613                 return -ENOMEM;
 614
 615         host->dma.data_desc = desc;
 616         desc->callback = atmci_dma_complete;
 617         desc->callback_param = host;
 618         desc->tx_submit(desc);
 619
 620         /* Go! */
 621         chan->device->device_issue_pending(chan);
 622
 623         return 0;
 624 }
 625
 626 #else /* CONFIG_MMC_ATMELMCI_DMA */
 627
 628 static int atmci_submit_data_dma(struct atmel_mci *host, struct mmc_data *data)
 629 {
 630         return -ENOSYS;
 631 }
 632
 633 static void atmci_stop_dma(struct atmel_mci *host)
 634 {
 635         /* Data transfer was stopped by the interrupt handler */
 636         atmci_set_pending(host, EVENT_XFER_COMPLETE);
 637         mci_writel(host, IER, MCI_NOTBUSY);
 638 }
 639
 640 #endif /* CONFIG_MMC_ATMELMCI_DMA */
 641
 642 /*
 643  * Returns a mask of interrupt flags to be enabled after the whole
 644  * request has been prepared.
 645  */
 646 static u32 atmci_submit_data(struct atmel_mci *host, struct mmc_data *data)
 647 {
 648         u32 iflags;
 649
 650         data->error = -EINPROGRESS;
 651
 652         WARN_ON(host->data);
 653         host->sg = NULL;
 654         host->data = data;
 655
 656         iflags = ATMCI_DATA_ERROR_FLAGS;
 657         if (atmci_submit_data_dma(host, data)) {
 658                 host->data_chan = NULL;
 659
 660                 /*
 661                  * Errata: MMC data write operation with less than 12
 662                  * bytes is impossible.
 663                  *
 664                  * Errata: MCI Transmit Data Register (TDR) FIFO
 665                  * corruption when length is not multiple of 4.
 666                  */
 667                 if (data->blocks * data->blksz < 12
 668                                 || (data->blocks * data->blksz) & 3)
 669                         host->need_reset = true;
 670
 671                 host->sg = data->sg;
 672                 host->pio_offset = 0;
 673                 if (data->flags & MMC_DATA_READ)
 674                         iflags |= MCI_RXRDY;
 675                 else
 676                         iflags |= MCI_TXRDY;
 677         }
 678
 679         return iflags;
 680 }
 681
 682 static void atmci_start_request(struct atmel_mci *host,
 683                 struct atmel_mci_slot *slot)
 684 {
 685         struct mmc_request      *mrq;
 686         struct mmc_command      *cmd;
 687         struct mmc_data         *data;
 688         u32                     iflags;
 689         u32                     cmdflags;
 690
 691         mrq = slot->mrq;
 692         host->cur_slot = slot;
 693         host->mrq = mrq;
 694
 695         host->pending_events = 0;
 696         host->completed_events = 0;
 697         host->data_status = 0;
 698
 699         if (host->need_reset) {
 700                 mci_writel(host, CR, MCI_CR_SWRST);
 701                 mci_writel(host, CR, MCI_CR_MCIEN);
 702                 mci_writel(host, MR, host->mode_reg);
 703                 host->need_reset = false;
 704         }
 705         mci_writel(host, SDCR, slot->sdc_reg);
 706
 707         iflags = mci_readl(host, IMR);
 708         if (iflags)
 709                 dev_warn(&slot->mmc->class_dev, "WARNING: IMR=0x%08x\n",
 710                                 iflags);
 711
 712         if (unlikely(test_and_clear_bit(ATMCI_CARD_NEED_INIT, &slot->flags))) {
 713                 /* Send init sequence (74 clock cycles) */
 714                 mci_writel(host, CMDR, MCI_CMDR_SPCMD_INIT);
 715                 while (!(mci_readl(host, SR) & MCI_CMDRDY))
 716                         cpu_relax();
 717         }
 718         data = mrq->data;
 719         if (data) {
 720                 atmci_set_timeout(host, slot, data);
 721
 722                 /* Must set block count/size before sending command */
 723                 mci_writel(host, BLKR, MCI_BCNT(data->blocks)
 724                                 | MCI_BLKLEN(data->blksz));
 725                 dev_vdbg(&slot->mmc->class_dev, "BLKR=0x%08x\n",
 726                         MCI_BCNT(data->blocks) | MCI_BLKLEN(data->blksz));
 727         }
 728
 729         iflags = MCI_CMDRDY;
 730         cmd = mrq->cmd;
 731         cmdflags = atmci_prepare_command(slot->mmc, cmd);
 732         atmci_start_command(host, cmd, cmdflags);
 733
 734         if (data)
 735                 iflags |= atmci_submit_data(host, data);
 736
 737         if (mrq->stop) {
 738                 host->stop_cmdr = atmci_prepare_command(slot->mmc, mrq->stop);
 739                 host->stop_cmdr |= MCI_CMDR_STOP_XFER;
 740                 if (!(data->flags & MMC_DATA_WRITE))
 741                         host->stop_cmdr |= MCI_CMDR_TRDIR_READ;
 742                 if (data->flags & MMC_DATA_STREAM)
 743                         host->stop_cmdr |= MCI_CMDR_STREAM;
 744                 else
 745                         host->stop_cmdr |= MCI_CMDR_MULTI_BLOCK;
 746         }
 747
 748         /*
 749          * We could have enabled interrupts earlier, but I suspect
 750          * that would open up a nice can of interesting race
 751          * conditions (e.g. command and data complete, but stop not
 752          * prepared yet.)
 753          */
 754         mci_writel(host, IER, iflags);
 755 }
 756
 757 static void atmci_queue_request(struct atmel_mci *host,
 758                 struct atmel_mci_slot *slot, struct mmc_request *mrq)
 759 {
 760         dev_vdbg(&slot->mmc->class_dev, "queue request: state=%d\n",
 761                         host->state);
 762
 763         spin_lock_bh(&host->lock);
 764         slot->mrq = mrq;
 765         if (host->state == STATE_IDLE) {
 766                 host->state = STATE_SENDING_CMD;
 767                 atmci_start_request(host, slot);
 768         } else {
 769                 list_add_tail(&slot->queue_node, &host->queue);
 770         }
 771         spin_unlock_bh(&host->lock);
 772 }
 773
 774 static void atmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
 775 {
 776         struct atmel_mci_slot   *slot = mmc_priv(mmc);
 777         struct atmel_mci        *host = slot->host;
 778         struct mmc_data         *data;
 779
 780         WARN_ON(slot->mrq);
 781
 782         /*
 783          * We may "know" the card is gone even though there's still an
 784          * electrical connection. If so, we really need to communicate
 785          * this to the MMC core since there won't be any more
 786          * interrupts as the card is completely removed. Otherwise,
 787          * the MMC core might believe the card is still there even
 788          * though the card was just removed very slowly.
 789          */
 790         if (!test_bit(ATMCI_CARD_PRESENT, &slot->flags)) {
 791                 mrq->cmd->error = -ENOMEDIUM;
 792                 mmc_request_done(mmc, mrq);
 793                 return;
 794         }
 795
 796         /* We don't support multiple blocks of weird lengths. */
 797         data = mrq->data;
 798         if (data && data->blocks > 1 && data->blksz & 3) {
 799                 mrq->cmd->error = -EINVAL;
 800                 mmc_request_done(mmc, mrq);
 801         }
 802
 803         atmci_queue_request(host, slot, mrq);
 804 }
 805
 806 static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 807 {
 808         struct atmel_mci_slot   *slot = mmc_priv(mmc);
 809         struct atmel_mci        *host = slot->host;
 810         unsigned int            i;
 811
 812         slot->sdc_reg &= ~MCI_SDCBUS_MASK;
 813         switch (ios->bus_width) {
 814         case MMC_BUS_WIDTH_1:
 815                 slot->sdc_reg |= MCI_SDCBUS_1BIT;
 816                 break;
 817         case MMC_BUS_WIDTH_4:
 818                 slot->sdc_reg = MCI_SDCBUS_4BIT;
 819                 break;
 820         }
 821
 822         if (ios->clock) {
 823                 unsigned int clock_min = ~0U;
 824                 u32 clkdiv;
 825
 826                 spin_lock_bh(&host->lock);
 827                 if (!host->mode_reg) {
 828                         clk_enable(host->mck);
 829                         mci_writel(host, CR, MCI_CR_SWRST);
 830                         mci_writel(host, CR, MCI_CR_MCIEN);
 831                 }
 832
 833                 /*
 834                  * Use mirror of ios->clock to prevent race with mmc
 835                  * core ios update when finding the minimum.
 836                  */
 837                 slot->clock = ios->clock;
 838                 for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) {
 839                         if (host->slot[i] && host->slot[i]->clock
 840                                         && host->slot[i]->clock < clock_min)
 841                                 clock_min = host->slot[i]->clock;
 842                 }
 843
 844                 /* Calculate clock divider */
 845                 clkdiv = DIV_ROUND_UP(host->bus_hz, 2 * clock_min) - 1;
 846                 if (clkdiv > 255) {
 847                         dev_warn(&mmc->class_dev,
 848                                 "clock %u too slow; using %lu\n",
 849                                 clock_min, host->bus_hz / (2 * 256));
 850                         clkdiv = 255;
 851                 }
 852
 853                 /*
 854                  * WRPROOF and RDPROOF prevent overruns/underruns by
 855                  * stopping the clock when the FIFO is full/empty.
 856                  * This state is not expected to last for long.
 857                  */
 858                 host->mode_reg = MCI_MR_CLKDIV(clkdiv) | MCI_MR_WRPROOF
 859                                         | MCI_MR_RDPROOF;
 860
 861                 if (list_empty(&host->queue))
 862                         mci_writel(host, MR, host->mode_reg);
 863                 else
 864                         host->need_clock_update = true;
 865
 866                 spin_unlock_bh(&host->lock);
 867         } else {
 868                 bool any_slot_active = false;
 869
 870                 spin_lock_bh(&host->lock);
 871                 slot->clock = 0;
 872                 for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) {
 873                         if (host->slot[i] && host->slot[i]->clock) {
 874                                 any_slot_active = true;
 875                                 break;
 876                         }
 877                 }
 878                 if (!any_slot_active) {
 879                         mci_writel(host, CR, MCI_CR_MCIDIS);
 880                         if (host->mode_reg) {
 881                                 mci_readl(host, MR);
 882                                 clk_disable(host->mck);
 883                         }
 884                         host->mode_reg = 0;
 885                 }
 886                 spin_unlock_bh(&host->lock);
 887         }
 888
 889         switch (ios->power_mode) {
 890         case MMC_POWER_UP:
 891                 set_bit(ATMCI_CARD_NEED_INIT, &slot->flags);
 892                 break;
 893         default:
 894                 /*
 895                  * TODO: None of the currently available AVR32-based
 896                  * boards allow MMC power to be turned off. Implement
 897                  * power control when this can be tested properly.
 898                  *
 899                  * We also need to hook this into the clock management
 900                  * somehow so that newly inserted cards aren't
 901                  * subjected to a fast clock before we have a chance
 902                  * to figure out what the maximum rate is. Currently,
 903                  * there's no way to avoid this, and there never will
 904                  * be for boards that don't support power control.
 905                  */
 906                 break;
 907         }
 908 }
 909
 910 static int atmci_get_ro(struct mmc_host *mmc)
 911 {
 912         int                     read_only = -ENOSYS;
 913         struct atmel_mci_slot   *slot = mmc_priv(mmc);
 914
 915         if (gpio_is_valid(slot->wp_pin)) {
 916                 read_only = gpio_get_value(slot->wp_pin);
 917                 dev_dbg(&mmc->class_dev, "card is %s\n",
 918                                 read_only ? "read-only" : "read-write");
 919         }
 920
 921         return read_only;
 922 }
 923
 924 static int atmci_get_cd(struct mmc_host *mmc)
 925 {
 926         int                     present = -ENOSYS;
 927         struct atmel_mci_slot   *slot = mmc_priv(mmc);
 928
 929         if (gpio_is_valid(slot->detect_pin)) {
 930                 present = !gpio_get_value(slot->detect_pin);
 931                 dev_dbg(&mmc->class_dev, "card is %spresent\n",
 932                                 present ? "" : "not ");
 933         }
 934
 935         return present;
 936 }
 937
 938 static const struct mmc_host_ops atmci_ops = {
 939         .request        = atmci_request,
 940         .set_ios        = atmci_set_ios,
 941         .get_ro         = atmci_get_ro,
 942         .get_cd         = atmci_get_cd,
 943 };
 944
 945 /* Called with host->lock held */
 946 static void atmci_request_end(struct atmel_mci *host, struct mmc_request *mrq)
 947         __releases(&host->lock)
 948         __acquires(&host->lock)
 949 {
 950         struct atmel_mci_slot   *slot = NULL;
 951         struct mmc_host         *prev_mmc = host->cur_slot->mmc;
 952
 953         WARN_ON(host->cmd || host->data);
 954
 955         /*
 956          * Update the MMC clock rate if necessary. This may be
 957          * necessary if set_ios() is called when a different slot is
 958          * busy transfering data.
 959          */
 960         if (host->need_clock_update)
 961                 mci_writel(host, MR, host->mode_reg);
 962
 963         host->cur_slot->mrq = NULL;
 964         host->mrq = NULL;
 965         if (!list_empty(&host->queue)) {
 966                 slot = list_entry(host->queue.next,
 967                                 struct atmel_mci_slot, queue_node);
 968                 list_del(&slot->queue_node);
 969                 dev_vdbg(&host->pdev->dev, "list not empty: %s is next\n",
 970                                 mmc_hostname(slot->mmc));
 971                 host->state = STATE_SENDING_CMD;
 972                 atmci_start_request(host, slot);
 973         } else {
 974                 dev_vdbg(&host->pdev->dev, "list empty\n");
 975                 host->state = STATE_IDLE;
 976         }
 977
 978         spin_unlock(&host->lock);
 979         mmc_request_done(prev_mmc, mrq);
 980         spin_lock(&host->lock);
 981 }
 982
 983 static void atmci_command_complete(struct atmel_mci *host,
 984                         struct mmc_command *cmd)
 985 {
 986         u32             status = host->cmd_status;
 987
 988         /* Read the response from the card (up to 16 bytes) */
 989         cmd->resp[0] = mci_readl(host, RSPR);
 990         cmd->resp[1] = mci_readl(host, RSPR);
 991         cmd->resp[2] = mci_readl(host, RSPR);
 992         cmd->resp[3] = mci_readl(host, RSPR);
 993
 994         if (status & MCI_RTOE)
 995                 cmd->error = -ETIMEDOUT;
 996         else if ((cmd->flags & MMC_RSP_CRC) && (status & MCI_RCRCE))
 997                 cmd->error = -EILSEQ;
 998         else if (status & (MCI_RINDE | MCI_RDIRE | MCI_RENDE))
 999                 cmd->error = -EIO;
1000         else
1001                 cmd->error = 0;
1002
1003         if (cmd->error) {
1004                 dev_dbg(&host->pdev->dev,
1005                         "command error: status=0x%08x\n", status);
1006
1007                 if (cmd->data) {
1008                         host->data = NULL;
1009                         atmci_stop_dma(host);
1010                         mci_writel(host, IDR, MCI_NOTBUSY
1011                                         | MCI_TXRDY | MCI_RXRDY
1012                                         | ATMCI_DATA_ERROR_FLAGS);
1013                 }
1014         }
1015 }
1016
1017 static void atmci_detect_change(unsigned long data)
1018 {
1019         struct atmel_mci_slot   *slot = (struct atmel_mci_slot *)data;
1020         bool                    present;
1021         bool                    present_old;
1022
1023         /*
1024          * atmci_cleanup_slot() sets the ATMCI_SHUTDOWN flag before
1025          * freeing the interrupt. We must not re-enable the interrupt
1026          * if it has been freed, and if we're shutting down, it
1027          * doesn't really matter whether the card is present or not.
1028          */
1029         smp_rmb();
1030         if (test_bit(ATMCI_SHUTDOWN, &slot->flags))
1031                 return;
1032
1033         enable_irq(gpio_to_irq(slot->detect_pin));
1034         present = !gpio_get_value(slot->detect_pin);
1035         present_old = test_bit(ATMCI_CARD_PRESENT, &slot->flags);
1036
1037         dev_vdbg(&slot->mmc->class_dev, "detect change: %d (was %d)\n",
1038                         present, present_old);
1039
1040         if (present != present_old) {
1041                 struct atmel_mci        *host = slot->host;
1042                 struct mmc_request      *mrq;
1043
1044                 dev_dbg(&slot->mmc->class_dev, "card %s\n",
1045                         present ? "inserted" : "removed");
1046
1047                 spin_lock(&host->lock);
1048
1049                 if (!present)
1050                         clear_bit(ATMCI_CARD_PRESENT, &slot->flags);
1051                 else
1052                         set_bit(ATMCI_CARD_PRESENT, &slot->flags);
1053
1054                 /* Clean up queue if present */
1055                 mrq = slot->mrq;
1056                 if (mrq) {
1057                         if (mrq == host->mrq) {
1058                                 /*
1059                                  * Reset controller to terminate any ongoing
1060                                  * commands or data transfers.
1061                                  */
1062                                 mci_writel(host, CR, MCI_CR_SWRST);
1063                                 mci_writel(host, CR, MCI_CR_MCIEN);
1064                                 mci_writel(host, MR, host->mode_reg);
1065
1066                                 host->data = NULL;
1067                                 host->cmd = NULL;
1068
1069                                 switch (host->state) {
1070                                 case STATE_IDLE:
1071                                         break;
1072                                 case STATE_SENDING_CMD:
1073                                         mrq->cmd->error = -ENOMEDIUM;
1074                                         if (!mrq->data)
1075                                                 break;
1076                                         /* fall through */
1077                                 case STATE_SENDING_DATA:
1078                                         mrq->data->error = -ENOMEDIUM;
1079                                         atmci_stop_dma(host);
1080                                         break;
1081                                 case STATE_DATA_BUSY:
1082                                 case STATE_DATA_ERROR:
1083                                         if (mrq->data->error == -EINPROGRESS)
1084                                                 mrq->data->error = -ENOMEDIUM;
1085                                         if (!mrq->stop)
1086                                                 break;
1087                                         /* fall through */
1088                                 case STATE_SENDING_STOP:
1089                                         mrq->stop->error = -ENOMEDIUM;
1090                                         break;
1091                                 }
1092
1093                                 atmci_request_end(host, mrq);
1094                         } else {
1095                                 list_del(&slot->queue_node);
1096                                 mrq->cmd->error = -ENOMEDIUM;
1097                                 if (mrq->data)
1098                                         mrq->data->error = -ENOMEDIUM;
1099                                 if (mrq->stop)
1100                                         mrq->stop->error = -ENOMEDIUM;
1101
1102                                 spin_unlock(&host->lock);
1103                                 mmc_request_done(slot->mmc, mrq);
1104                                 spin_lock(&host->lock);
1105                         }
1106                 }
1107                 spin_unlock(&host->lock);
1108
1109                 mmc_detect_change(slot->mmc, 0);
1110         }
1111 }
1112
1113 static void atmci_tasklet_func(unsigned long priv)
1114 {
1115         struct atmel_mci        *host = (struct atmel_mci *)priv;
1116         struct mmc_request      *mrq = host->mrq;
1117         struct mmc_data         *data = host->data;
1118         struct mmc_command      *cmd = host->cmd;
1119         enum atmel_mci_state    state = host->state;
1120         enum atmel_mci_state    prev_state;
1121         u32                     status;
1122
1123         spin_lock(&host->lock);
1124
1125         state = host->state;
1126
1127         dev_vdbg(&host->pdev->dev,
1128                 "tasklet: state %u pending/completed/mask %lx/%lx/%x\n",
1129                 state, host->pending_events, host->completed_events,
1130                 mci_readl(host, IMR));
1131
1132         do {
1133                 prev_state = state;
1134
1135                 switch (state) {
1136                 case STATE_IDLE:
1137                         break;
1138
1139                 case STATE_SENDING_CMD:
1140                         if (!atmci_test_and_clear_pending(host,
1141                                                 EVENT_CMD_COMPLETE))
1142                                 break;
1143
1144                         host->cmd = NULL;
1145                         atmci_set_completed(host, EVENT_CMD_COMPLETE);
1146                         atmci_command_complete(host, mrq->cmd);
1147                         if (!mrq->data || cmd->error) {
1148                                 atmci_request_end(host, host->mrq);
1149                                 goto unlock;
1150                         }
1151
1152                         prev_state = state = STATE_SENDING_DATA;
1153                         /* fall through */
1154
1155                 case STATE_SENDING_DATA:
1156                         if (atmci_test_and_clear_pending(host,
1157                                                 EVENT_DATA_ERROR)) {
1158                                 atmci_stop_dma(host);
1159                                 if (data->stop)
1160                                         send_stop_cmd(host, data);
1161                                 state = STATE_DATA_ERROR;
1162                                 break;
1163                         }
1164
1165                         if (!atmci_test_and_clear_pending(host,
1166                                                 EVENT_XFER_COMPLETE))
1167                                 break;
1168
1169                         atmci_set_completed(host, EVENT_XFER_COMPLETE);
1170                         prev_state = state = STATE_DATA_BUSY;
1171                         /* fall through */
1172
1173                 case STATE_DATA_BUSY:
1174                         if (!atmci_test_and_clear_pending(host,
1175                                                 EVENT_DATA_COMPLETE))
1176                                 break;
1177
1178                         host->data = NULL;
1179                         atmci_set_completed(host, EVENT_DATA_COMPLETE);
1180                         status = host->data_status;
1181                         if (unlikely(status & ATMCI_DATA_ERROR_FLAGS)) {
1182                                 if (status & MCI_DTOE) {
1183                                         dev_dbg(&host->pdev->dev,
1184                                                         "data timeout error\n");
1185                                         data->error = -ETIMEDOUT;
1186                                 } else if (status & MCI_DCRCE) {
1187                                         dev_dbg(&host->pdev->dev,
1188                                                         "data CRC error\n");
1189                                         data->error = -EILSEQ;
1190                                 } else {
1191                                         dev_dbg(&host->pdev->dev,
1192                                                 "data FIFO error (status=%08x)\n",
1193                                                 status);
1194                                         data->error = -EIO;
1195                                 }
1196                         } else {
1197                                 data->bytes_xfered = data->blocks * data->blksz;
1198                                 data->error = 0;
1199                         }
1200
1201                         if (!data->stop) {
1202                                 atmci_request_end(host, host->mrq);
1203                                 goto unlock;
1204                         }
1205
1206                         prev_state = state = STATE_SENDING_STOP;
1207                         if (!data->error)
1208                                 send_stop_cmd(host, data);
1209                         /* fall through */
1210
1211                 case STATE_SENDING_STOP:
1212                         if (!atmci_test_and_clear_pending(host,
1213                                                 EVENT_CMD_COMPLETE))
1214                                 break;
1215
1216                         host->cmd = NULL;
1217                         atmci_command_complete(host, mrq->stop);
1218                         atmci_request_end(host, host->mrq);
1219                         goto unlock;
1220
1221                 case STATE_DATA_ERROR:
1222                         if (!atmci_test_and_clear_pending(host,
1223                                                 EVENT_XFER_COMPLETE))
1224                                 break;
1225
1226                         state = STATE_DATA_BUSY;
1227                         break;
1228                 }
1229         } while (state != prev_state);
1230
1231         host->state = state;
1232
1233 unlock:
1234         spin_unlock(&host->lock);
1235 }
1236
1237 static void atmci_read_data_pio(struct atmel_mci *host)
1238 {
1239         struct scatterlist      *sg = host->sg;
1240         void                    *buf = sg_virt(sg);
1241         unsigned int            offset = host->pio_offset;
1242         struct mmc_data         *data = host->data;
1243         u32                     value;
1244         u32                     status;
1245         unsigned int            nbytes = 0;
1246
1247         do {
1248                 value = mci_readl(host, RDR);
1249                 if (likely(offset + 4 <= sg->length)) {
1250                         put_unaligned(value, (u32 *)(buf + offset));
1251
1252                         offset += 4;
1253                         nbytes += 4;
1254
1255                         if (offset == sg->length) {
1256                                 host->sg = sg = sg_next(sg);
1257                                 if (!sg)
1258                                         goto done;
1259
1260                                 offset = 0;
1261                                 buf = sg_virt(sg);
1262                         }
1263                 } else {
1264                         unsigned int remaining = sg->length - offset;
1265                         memcpy(buf + offset, &value, remaining);
1266                         nbytes += remaining;
1267
1268                         flush_dcache_page(sg_page(sg));
1269                         host->sg = sg = sg_next(sg);
1270                         if (!sg)
1271                                 goto done;
1272
1273                         offset = 4 - remaining;
1274                         buf = sg_virt(sg);
1275                         memcpy(buf, (u8 *)&value + remaining, offset);
1276                         nbytes += offset;
1277                 }
1278
1279                 status = mci_readl(host, SR);
1280                 if (status & ATMCI_DATA_ERROR_FLAGS) {
1281                         mci_writel(host, IDR, (MCI_NOTBUSY | MCI_RXRDY
1282                                                 | ATMCI_DATA_ERROR_FLAGS));
1283                         host->data_status = status;
1284                         data->bytes_xfered += nbytes;
1285                         smp_wmb();
1286                         atmci_set_pending(host, EVENT_DATA_ERROR);
1287                         tasklet_schedule(&host->tasklet);
1288                         return;
1289                 }
1290         } while (status & MCI_RXRDY);
1291
1292         host->pio_offset = offset;
1293         data->bytes_xfered += nbytes;
1294
1295         return;
1296
1297 done:
1298         mci_writel(host, IDR, MCI_RXRDY);
1299         mci_writel(host, IER, MCI_NOTBUSY);
1300         data->bytes_xfered += nbytes;
1301         smp_wmb();
1302         atmci_set_pending(host, EVENT_XFER_COMPLETE);
1303 }
1304
1305 static void atmci_write_data_pio(struct atmel_mci *host)
1306 {
1307         struct scatterlist      *sg = host->sg;
1308         void                    *buf = sg_virt(sg);
1309         unsigned int            offset = host->pio_offset;
1310         struct mmc_data         *data = host->data;
1311         u32                     value;
1312         u32                     status;
1313         unsigned int            nbytes = 0;
1314
1315         do {
1316                 if (likely(offset + 4 <= sg->length)) {
1317                         value = get_unaligned((u32 *)(buf + offset));
1318                         mci_writel(host, TDR, value);
1319
1320                         offset += 4;
1321                         nbytes += 4;
1322                         if (offset == sg->length) {
1323                                 host->sg = sg = sg_next(sg);
1324                                 if (!sg)
1325                                         goto done;
1326
1327                                 offset = 0;
1328                                 buf = sg_virt(sg);
1329                         }
1330                 } else {
1331                         unsigned int remaining = sg->length - offset;
1332
1333                         value = 0;
1334                         memcpy(&value, buf + offset, remaining);
1335                         nbytes += remaining;
1336
1337                         host->sg = sg = sg_next(sg);
1338                         if (!sg) {
1339                                 mci_writel(host, TDR, value);
1340                                 goto done;
1341                         }
1342
1343                         offset = 4 - remaining;
1344                         buf = sg_virt(sg);
1345                         memcpy((u8 *)&value + remaining, buf, offset);
1346                         mci_writel(host, TDR, value);
1347                         nbytes += offset;
1348                 }
1349
1350                 status = mci_readl(host, SR);
1351                 if (status & ATMCI_DATA_ERROR_FLAGS) {
1352                         mci_writel(host, IDR, (MCI_NOTBUSY | MCI_TXRDY
1353                                                 | ATMCI_DATA_ERROR_FLAGS));
1354                         host->data_status = status;
1355                         data->bytes_xfered += nbytes;
1356                         smp_wmb();
1357                         atmci_set_pending(host, EVENT_DATA_ERROR);
1358                         tasklet_schedule(&host->tasklet);
1359                         return;
1360                 }
1361         } while (status & MCI_TXRDY);
1362
1363         host->pio_offset = offset;
1364         data->bytes_xfered += nbytes;
1365
1366         return;
1367
1368 done:
1369         mci_writel(host, IDR, MCI_TXRDY);
1370         mci_writel(host, IER, MCI_NOTBUSY);
1371         data->bytes_xfered += nbytes;
1372         smp_wmb();
1373         atmci_set_pending(host, EVENT_XFER_COMPLETE);
1374 }
1375
1376 static void atmci_cmd_interrupt(struct atmel_mci *host, u32 status)
1377 {
1378         mci_writel(host, IDR, MCI_CMDRDY);
1379
1380         host->cmd_status = status;
1381         smp_wmb();
1382         atmci_set_pending(host, EVENT_CMD_COMPLETE);
1383         tasklet_schedule(&host->tasklet);
1384 }
1385
1386 static irqreturn_t atmci_interrupt(int irq, void *dev_id)
1387 {
1388         struct atmel_mci        *host = dev_id;
1389         u32                     status, mask, pending;
1390         unsigned int            pass_count = 0;
1391
1392         do {
1393                 status = mci_readl(host, SR);
1394                 mask = mci_readl(host, IMR);
1395                 pending = status & mask;
1396                 if (!pending)
1397                         break;
1398
1399                 if (pending & ATMCI_DATA_ERROR_FLAGS) {
1400                         mci_writel(host, IDR, ATMCI_DATA_ERROR_FLAGS
1401                                         | MCI_RXRDY | MCI_TXRDY);
1402                         pending &= mci_readl(host, IMR);
1403
1404                         host->data_status = status;
1405                         smp_wmb();
1406                         atmci_set_pending(host, EVENT_DATA_ERROR);
1407                         tasklet_schedule(&host->tasklet);
1408                 }
1409                 if (pending & MCI_NOTBUSY) {
1410                         mci_writel(host, IDR,
1411                                         ATMCI_DATA_ERROR_FLAGS | MCI_NOTBUSY);
1412                         if (!host->data_status)
1413                                 host->data_status = status;
1414                         smp_wmb();
1415                         atmci_set_pending(host, EVENT_DATA_COMPLETE);
1416                         tasklet_schedule(&host->tasklet);
1417                 }
1418                 if (pending & MCI_RXRDY)
1419                         atmci_read_data_pio(host);
1420                 if (pending & MCI_TXRDY)
1421                         atmci_write_data_pio(host);
1422
1423                 if (pending & MCI_CMDRDY)
1424                         atmci_cmd_interrupt(host, status);
1425         } while (pass_count++ < 5);
1426
1427         return pass_count ? IRQ_HANDLED : IRQ_NONE;
1428 }
1429
1430 static irqreturn_t atmci_detect_interrupt(int irq, void *dev_id)
1431 {
1432         struct atmel_mci_slot   *slot = dev_id;
1433
1434         /*
1435          * Disable interrupts until the pin has stabilized and check
1436          * the state then. Use mod_timer() since we may be in the
1437          * middle of the timer routine when this interrupt triggers.
1438          */
1439         disable_irq_nosync(irq);
1440         mod_timer(&slot->detect_timer, jiffies + msecs_to_jiffies(20));
1441
1442         return IRQ_HANDLED;
1443 }
1444
1445 #ifdef CONFIG_MMC_ATMELMCI_DMA
1446
1447 static inline struct atmel_mci *
1448 dma_client_to_atmel_mci(struct dma_client *client)
1449 {
1450         return container_of(client, struct atmel_mci, dma.client);
1451 }
1452
1453 static enum dma_state_client atmci_dma_event(struct dma_client *client,
1454                 struct dma_chan *chan, enum dma_state state)
1455 {
1456         struct atmel_mci        *host;
1457         enum dma_state_client   ret = DMA_NAK;
1458
1459         host = dma_client_to_atmel_mci(client);
1460
1461         switch (state) {
1462         case DMA_RESOURCE_AVAILABLE:
1463                 spin_lock_bh(&host->lock);
1464                 if (!host->dma.chan) {
1465                         host->dma.chan = chan;
1466                         ret = DMA_ACK;
1467                 }
1468                 spin_unlock_bh(&host->lock);
1469
1470                 if (ret == DMA_ACK)
1471                         dev_info(&host->pdev->dev,
1472                                         "Using %s for DMA transfers\n",
1473                                         chan->dev.bus_id);
1474                 break;
1475
1476         case DMA_RESOURCE_REMOVED:
1477                 spin_lock_bh(&host->lock);
1478                 if (host->dma.chan == chan) {
1479                         host->dma.chan = NULL;
1480                         ret = DMA_ACK;
1481                 }
1482                 spin_unlock_bh(&host->lock);
1483
1484                 if (ret == DMA_ACK)
1485                         dev_info(&host->pdev->dev,
1486                                         "Lost %s, falling back to PIO\n",
1487                                         chan->dev.bus_id);
1488                 break;
1489
1490         default:
1491                 break;
1492         }
1493
1494
1495         return ret;
1496 }
1497 #endif /* CONFIG_MMC_ATMELMCI_DMA */
1498
1499 static int __init atmci_init_slot(struct atmel_mci *host,
1500                 struct mci_slot_pdata *slot_data, unsigned int id,
1501                 u32 sdc_reg)
1502 {
1503         struct mmc_host                 *mmc;
1504         struct atmel_mci_slot           *slot;
1505
1506         mmc = mmc_alloc_host(sizeof(struct atmel_mci_slot), &host->pdev->dev);
1507         if (!mmc)
1508                 return -ENOMEM;
1509
1510         slot = mmc_priv(mmc);
1511         slot->mmc = mmc;
1512         slot->host = host;
1513         slot->detect_pin = slot_data->detect_pin;
1514         slot->wp_pin = slot_data->wp_pin;
1515         slot->sdc_reg = sdc_reg;
1516
1517         mmc->ops = &atmci_ops;
1518         mmc->f_min = DIV_ROUND_UP(host->bus_hz, 512);
1519         mmc->f_max = host->bus_hz / 2;
1520         mmc->ocr_avail  = MMC_VDD_32_33 | MMC_VDD_33_34;
1521         if (slot_data->bus_width >= 4)
1522                 mmc->caps |= MMC_CAP_4_BIT_DATA;
1523
1524         mmc->max_hw_segs = 64;
1525         mmc->max_phys_segs = 64;
1526         mmc->max_req_size = 32768 * 512;
1527         mmc->max_blk_size = 32768;
1528         mmc->max_blk_count = 512;
1529
1530         /* Assume card is present initially */
1531         set_bit(ATMCI_CARD_PRESENT, &slot->flags);
1532         if (gpio_is_valid(slot->detect_pin)) {
1533                 if (gpio_request(slot->detect_pin, "mmc_detect")) {
1534                         dev_dbg(&mmc->class_dev, "no detect pin available\n");
1535                         slot->detect_pin = -EBUSY;
1536                 } else if (gpio_get_value(slot->detect_pin)) {
1537                         clear_bit(ATMCI_CARD_PRESENT, &slot->flags);
1538                 }
1539         }
1540
1541         if (!gpio_is_valid(slot->detect_pin))
1542                 mmc->caps |= MMC_CAP_NEEDS_POLL;
1543
1544         if (gpio_is_valid(slot->wp_pin)) {
1545                 if (gpio_request(slot->wp_pin, "mmc_wp")) {
1546                         dev_dbg(&mmc->class_dev, "no WP pin available\n");
1547                         slot->wp_pin = -EBUSY;
1548                 }
1549         }
1550
1551         host->slot[id] = slot;
1552         mmc_add_host(mmc);
1553
1554         if (gpio_is_valid(slot->detect_pin)) {
1555                 int ret;
1556
1557                 setup_timer(&slot->detect_timer, atmci_detect_change,
1558                                 (unsigned long)slot);
1559
1560                 ret = request_irq(gpio_to_irq(slot->detect_pin),
1561                                 atmci_detect_interrupt,
1562                                 IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
1563                                 "mmc-detect", slot);
1564                 if (ret) {
1565                         dev_dbg(&mmc->class_dev,
1566                                 "could not request IRQ %d for detect pin\n",
1567                                 gpio_to_irq(slot->detect_pin));
1568                         gpio_free(slot->detect_pin);
1569                         slot->detect_pin = -EBUSY;
1570                 }
1571         }
1572
1573         atmci_init_debugfs(slot);
1574
1575         return 0;
1576 }
1577
1578 static void __exit atmci_cleanup_slot(struct atmel_mci_slot *slot,
1579                 unsigned int id)
1580 {
1581         /* Debugfs stuff is cleaned up by mmc core */
1582
1583         set_bit(ATMCI_SHUTDOWN, &slot->flags);
1584         smp_wmb();
1585
1586         mmc_remove_host(slot->mmc);
1587
1588         if (gpio_is_valid(slot->detect_pin)) {
1589                 int pin = slot->detect_pin;
1590
1591                 free_irq(gpio_to_irq(pin), slot);
1592                 del_timer_sync(&slot->detect_timer);
1593                 gpio_free(pin);
1594         }
1595         if (gpio_is_valid(slot->wp_pin))
1596                 gpio_free(slot->wp_pin);
1597
1598         slot->host->slot[id] = NULL;
1599         mmc_free_host(slot->mmc);
1600 }
1601
1602 static int __init atmci_probe(struct platform_device *pdev)
1603 {
1604         struct mci_platform_data        *pdata;
1605         struct atmel_mci                *host;
1606         struct resource                 *regs;
1607         unsigned int                    nr_slots;
1608         int                             irq;
1609         int                             ret;
1610
1611         regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1612         if (!regs)
1613                 return -ENXIO;
1614         pdata = pdev->dev.platform_data;
1615         if (!pdata)
1616                 return -ENXIO;
1617         irq = platform_get_irq(pdev, 0);
1618         if (irq < 0)
1619                 return irq;
1620
1621         host = kzalloc(sizeof(struct atmel_mci), GFP_KERNEL);
1622         if (!host)
1623                 return -ENOMEM;
1624
1625         host->pdev = pdev;
1626         spin_lock_init(&host->lock);
1627         INIT_LIST_HEAD(&host->queue);
1628
1629         host->mck = clk_get(&pdev->dev, "mci_clk");
1630         if (IS_ERR(host->mck)) {
1631                 ret = PTR_ERR(host->mck);
1632                 goto err_clk_get;
1633         }
1634
1635         ret = -ENOMEM;
1636         host->regs = ioremap(regs->start, regs->end - regs->start + 1);
1637         if (!host->regs)
1638                 goto err_ioremap;
1639
1640         clk_enable(host->mck);
1641         mci_writel(host, CR, MCI_CR_SWRST);
1642         host->bus_hz = clk_get_rate(host->mck);
1643         clk_disable(host->mck);
1644
1645         host->mapbase = regs->start;
1646
1647         tasklet_init(&host->tasklet, atmci_tasklet_func, (unsigned long)host);
1648
1649         ret = request_irq(irq, atmci_interrupt, 0, pdev->dev.bus_id, host);
1650         if (ret)
1651                 goto err_request_irq;
1652
1653 #ifdef CONFIG_MMC_ATMELMCI_DMA
1654         if (pdata->dma_slave) {
1655                 struct dma_slave *slave = pdata->dma_slave;
1656
1657                 slave->tx_reg = regs->start + MCI_TDR;
1658                 slave->rx_reg = regs->start + MCI_RDR;
1659
1660                 /* Try to grab a DMA channel */
1661                 host->dma.client.event_callback = atmci_dma_event;
1662                 dma_cap_set(DMA_SLAVE, host->dma.client.cap_mask);
1663                 host->dma.client.slave = slave;
1664
1665                 dma_async_client_register(&host->dma.client);
1666                 dma_async_client_chan_request(&host->dma.client);
1667         } else {
1668                 dev_notice(&pdev->dev, "DMA not available, using PIO\n");
1669         }
1670 #endif /* CONFIG_MMC_ATMELMCI_DMA */
1671
1672         platform_set_drvdata(pdev, host);
1673
1674         /* We need at least one slot to succeed */
1675         nr_slots = 0;
1676         ret = -ENODEV;
1677         if (pdata->slot[0].bus_width) {
1678                 ret = atmci_init_slot(host, &pdata->slot[0],
1679                                 MCI_SDCSEL_SLOT_A, 0);
1680                 if (!ret)
1681                         nr_slots++;
1682         }
1683         if (pdata->slot[1].bus_width) {
1684                 ret = atmci_init_slot(host, &pdata->slot[1],
1685                                 MCI_SDCSEL_SLOT_B, 1);
1686                 if (!ret)
1687                         nr_slots++;
1688         }
1689
1690         if (!nr_slots)
1691                 goto err_init_slot;
1692
1693         dev_info(&pdev->dev,
1694                         "Atmel MCI controller at 0x%08lx irq %d, %u slots\n",
1695                         host->mapbase, irq, nr_slots);
1696
1697         return 0;
1698
1699 err_init_slot:
1700 #ifdef CONFIG_MMC_ATMELMCI_DMA
1701         if (pdata->dma_slave)
1702                 dma_async_client_unregister(&host->dma.client);
1703 #endif
1704         free_irq(irq, host);
1705 err_request_irq:
1706         iounmap(host->regs);
1707 err_ioremap:
1708         clk_put(host->mck);
1709 err_clk_get:
1710         kfree(host);
1711         return ret;
1712 }
1713
1714 static int __exit atmci_remove(struct platform_device *pdev)
1715 {
1716         struct atmel_mci        *host = platform_get_drvdata(pdev);
1717         unsigned int            i;
1718
1719         platform_set_drvdata(pdev, NULL);
1720
1721         for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) {
1722                 if (host->slot[i])
1723                         atmci_cleanup_slot(host->slot[i], i);
1724         }
1725
1726         clk_enable(host->mck);
1727         mci_writel(host, IDR, ~0UL);
1728         mci_writel(host, CR, MCI_CR_MCIDIS);
1729         mci_readl(host, SR);
1730         clk_disable(host->mck);
1731
1732 #ifdef CONFIG_MMC_ATMELMCI_DMA
1733         if (host->dma.client.slave)
1734                 dma_async_client_unregister(&host->dma.client);
1735 #endif
1736
1737         free_irq(platform_get_irq(pdev, 0), host);
1738         iounmap(host->regs);
1739
1740         clk_put(host->mck);
1741         kfree(host);
1742
1743         return 0;
1744 }
1745
1746 static struct platform_driver atmci_driver = {
1747         .remove         = __exit_p(atmci_remove),
1748         .driver         = {
1749                 .name           = "atmel_mci",
1750         },
1751 };
1752
1753 static int __init atmci_init(void)
1754 {
1755         return platform_driver_probe(&atmci_driver, atmci_probe);
1756 }
1757
1758 static void __exit atmci_exit(void)
1759 {
1760         platform_driver_unregister(&atmci_driver);
1761 }
1762
1763 module_init(atmci_init);
1764 module_exit(atmci_exit);
1765
1766 MODULE_DESCRIPTION("Atmel Multimedia Card Interface driver");
1767 MODULE_AUTHOR("Haavard Skinnemoen <haavard.skinnemoen@atmel.com>");
1768 MODULE_LICENSE("GPL v2");