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/device.h>
  13 #include <linux/init.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/ioport.h>
  16 #include <linux/module.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/scatterlist.h>
  19
  20 #include <linux/mmc/host.h>
  21
  22 #include <asm/atmel-mci.h>
  23 #include <asm/io.h>
  24 #include <asm/unaligned.h>
  25
  26 #include <asm/arch/board.h>
  27 #include <asm/arch/gpio.h>
  28
  29 #include "atmel-mci-regs.h"
  30
  31 #define ATMCI_DATA_ERROR_FLAGS  (MCI_DCRCE | MCI_DTOE | MCI_OVRE | MCI_UNRE)
  32
  33 enum {
  34         EVENT_CMD_COMPLETE = 0,
  35         EVENT_DATA_ERROR,
  36         EVENT_DATA_COMPLETE,
  37         EVENT_STOP_SENT,
  38         EVENT_STOP_COMPLETE,
  39         EVENT_XFER_COMPLETE,
  40 };
  41
  42 struct atmel_mci {
  43         struct mmc_host         *mmc;
  44         void __iomem            *regs;
  45
  46         struct scatterlist      *sg;
  47         unsigned int            pio_offset;
  48
  49         struct mmc_request      *mrq;
  50         struct mmc_command      *cmd;
  51         struct mmc_data         *data;
  52
  53         u32                     cmd_status;
  54         u32                     data_status;
  55         u32                     stop_status;
  56         u32                     stop_cmdr;
  57
  58         u32                     mode_reg;
  59         u32                     sdc_reg;
  60
  61         struct tasklet_struct   tasklet;
  62         unsigned long           pending_events;
  63         unsigned long           completed_events;
  64
  65         int                     present;
  66         int                     detect_pin;
  67         int                     wp_pin;
  68
  69         /* For detect pin debouncing */
  70         struct timer_list       detect_timer;
  71
  72         unsigned long           bus_hz;
  73         unsigned long           mapbase;
  74         struct clk              *mck;
  75         struct platform_device  *pdev;
  76 };
  77
  78 #define atmci_is_completed(host, event)                         \
  79         test_bit(event, &host->completed_events)
  80 #define atmci_test_and_clear_pending(host, event)               \
  81         test_and_clear_bit(event, &host->pending_events)
  82 #define atmci_test_and_set_completed(host, event)               \
  83         test_and_set_bit(event, &host->completed_events)
  84 #define atmci_set_completed(host, event)                        \
  85         set_bit(event, &host->completed_events)
  86 #define atmci_set_pending(host, event)                          \
  87         set_bit(event, &host->pending_events)
  88 #define atmci_clear_pending(host, event)                        \
  89         clear_bit(event, &host->pending_events)
  90
  91
  92 static void atmci_enable(struct atmel_mci *host)
  93 {
  94         clk_enable(host->mck);
  95         mci_writel(host, CR, MCI_CR_MCIEN);
  96         mci_writel(host, MR, host->mode_reg);
  97         mci_writel(host, SDCR, host->sdc_reg);
  98 }
  99
 100 static void atmci_disable(struct atmel_mci *host)
 101 {
 102         mci_writel(host, CR, MCI_CR_SWRST);
 103
 104         /* Stall until write is complete, then disable the bus clock */
 105         mci_readl(host, SR);
 106         clk_disable(host->mck);
 107 }
 108
 109 static inline unsigned int ns_to_clocks(struct atmel_mci *host,
 110                                         unsigned int ns)
 111 {
 112         return (ns * (host->bus_hz / 1000000) + 999) / 1000;
 113 }
 114
 115 static void atmci_set_timeout(struct atmel_mci *host,
 116                               struct mmc_data *data)
 117 {
 118         static unsigned dtomul_to_shift[] = {
 119                 0, 4, 7, 8, 10, 12, 16, 20
 120         };
 121         unsigned        timeout;
 122         unsigned        dtocyc;
 123         unsigned        dtomul;
 124
 125         timeout = ns_to_clocks(host, data->timeout_ns) + data->timeout_clks;
 126
 127         for (dtomul = 0; dtomul < 8; dtomul++) {
 128                 unsigned shift = dtomul_to_shift[dtomul];
 129                 dtocyc = (timeout + (1 << shift) - 1) >> shift;
 130                 if (dtocyc < 15)
 131                         break;
 132         }
 133
 134         if (dtomul >= 8) {
 135                 dtomul = 7;
 136                 dtocyc = 15;
 137         }
 138
 139         dev_vdbg(&host->mmc->class_dev, "setting timeout to %u cycles\n",
 140                         dtocyc << dtomul_to_shift[dtomul]);
 141         mci_writel(host, DTOR, (MCI_DTOMUL(dtomul) | MCI_DTOCYC(dtocyc)));
 142 }
 143
 144 /*
 145  * Return mask with command flags to be enabled for this command.
 146  */
 147 static u32 atmci_prepare_command(struct mmc_host *mmc,
 148                                  struct mmc_command *cmd)
 149 {
 150         struct mmc_data *data;
 151         u32             cmdr;
 152
 153         cmd->error = -EINPROGRESS;
 154
 155         cmdr = MCI_CMDR_CMDNB(cmd->opcode);
 156
 157         if (cmd->flags & MMC_RSP_PRESENT) {
 158                 if (cmd->flags & MMC_RSP_136)
 159                         cmdr |= MCI_CMDR_RSPTYP_136BIT;
 160                 else
 161                         cmdr |= MCI_CMDR_RSPTYP_48BIT;
 162         }
 163
 164         /*
 165          * This should really be MAXLAT_5 for CMD2 and ACMD41, but
 166          * it's too difficult to determine whether this is an ACMD or
 167          * not. Better make it 64.
 168          */
 169         cmdr |= MCI_CMDR_MAXLAT_64CYC;
 170
 171         if (mmc->ios.bus_mode == MMC_BUSMODE_OPENDRAIN)
 172                 cmdr |= MCI_CMDR_OPDCMD;
 173
 174         data = cmd->data;
 175         if (data) {
 176                 cmdr |= MCI_CMDR_START_XFER;
 177                 if (data->flags & MMC_DATA_STREAM)
 178                         cmdr |= MCI_CMDR_STREAM;
 179                 else if (data->blocks > 1)
 180                         cmdr |= MCI_CMDR_MULTI_BLOCK;
 181                 else
 182                         cmdr |= MCI_CMDR_BLOCK;
 183
 184                 if (data->flags & MMC_DATA_READ)
 185                         cmdr |= MCI_CMDR_TRDIR_READ;
 186         }
 187
 188         return cmdr;
 189 }
 190
 191 static void atmci_start_command(struct atmel_mci *host,
 192                                 struct mmc_command *cmd,
 193                                 u32 cmd_flags)
 194 {
 195         /* Must read host->cmd after testing event flags */
 196         smp_rmb();
 197         WARN_ON(host->cmd);
 198         host->cmd = cmd;
 199
 200         dev_vdbg(&host->mmc->class_dev,
 201                         "start command: ARGR=0x%08x CMDR=0x%08x\n",
 202                         cmd->arg, cmd_flags);
 203
 204         mci_writel(host, ARGR, cmd->arg);
 205         mci_writel(host, CMDR, cmd_flags);
 206 }
 207
 208 static void send_stop_cmd(struct mmc_host *mmc, struct mmc_data *data)
 209 {
 210         struct atmel_mci *host = mmc_priv(mmc);
 211
 212         atmci_start_command(host, data->stop, host->stop_cmdr);
 213         mci_writel(host, IER, MCI_CMDRDY);
 214 }
 215
 216 static void atmci_request_end(struct mmc_host *mmc, struct mmc_request *mrq)
 217 {
 218         struct atmel_mci *host = mmc_priv(mmc);
 219
 220         WARN_ON(host->cmd || host->data);
 221         host->mrq = NULL;
 222
 223         atmci_disable(host);
 224
 225         mmc_request_done(mmc, mrq);
 226 }
 227
 228 /*
 229  * Returns a mask of interrupt flags to be enabled after the whole
 230  * request has been prepared.
 231  */
 232 static u32 atmci_submit_data(struct mmc_host *mmc, struct mmc_data *data)
 233 {
 234         struct atmel_mci        *host = mmc_priv(mmc);
 235         u32                     iflags;
 236
 237         data->error = -EINPROGRESS;
 238
 239         WARN_ON(host->data);
 240         host->sg = NULL;
 241         host->data = data;
 242
 243         mci_writel(host, BLKR, MCI_BCNT(data->blocks)
 244                         | MCI_BLKLEN(data->blksz));
 245         dev_vdbg(&mmc->class_dev, "BLKR=0x%08x\n",
 246                         MCI_BCNT(data->blocks) | MCI_BLKLEN(data->blksz));
 247
 248         iflags = ATMCI_DATA_ERROR_FLAGS;
 249         host->sg = data->sg;
 250         host->pio_offset = 0;
 251         if (data->flags & MMC_DATA_READ)
 252                 iflags |= MCI_RXRDY;
 253         else
 254                 iflags |= MCI_TXRDY;
 255
 256         return iflags;
 257 }
 258
 259 static void atmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
 260 {
 261         struct atmel_mci        *host = mmc_priv(mmc);
 262         struct mmc_data         *data;
 263         struct mmc_command      *cmd;
 264         u32                     iflags;
 265         u32                     cmdflags = 0;
 266
 267         iflags = mci_readl(host, IMR);
 268         if (iflags)
 269                 dev_warn(&mmc->class_dev, "WARNING: IMR=0x%08x\n",
 270                                 mci_readl(host, IMR));
 271
 272         WARN_ON(host->mrq != NULL);
 273
 274         /*
 275          * We may "know" the card is gone even though there's still an
 276          * electrical connection. If so, we really need to communicate
 277          * this to the MMC core since there won't be any more
 278          * interrupts as the card is completely removed. Otherwise,
 279          * the MMC core might believe the card is still there even
 280          * though the card was just removed very slowly.
 281          */
 282         if (!host->present) {
 283                 mrq->cmd->error = -ENOMEDIUM;
 284                 mmc_request_done(mmc, mrq);
 285                 return;
 286         }
 287
 288         host->mrq = mrq;
 289         host->pending_events = 0;
 290         host->completed_events = 0;
 291
 292         atmci_enable(host);
 293
 294         /* We don't support multiple blocks of weird lengths. */
 295         data = mrq->data;
 296         if (data) {
 297                 if (data->blocks > 1 && data->blksz & 3)
 298                         goto fail;
 299                 atmci_set_timeout(host, data);
 300         }
 301
 302         iflags = MCI_CMDRDY;
 303         cmd = mrq->cmd;
 304         cmdflags = atmci_prepare_command(mmc, cmd);
 305         atmci_start_command(host, cmd, cmdflags);
 306
 307         if (data)
 308                 iflags |= atmci_submit_data(mmc, data);
 309
 310         if (mrq->stop) {
 311                 host->stop_cmdr = atmci_prepare_command(mmc, mrq->stop);
 312                 host->stop_cmdr |= MCI_CMDR_STOP_XFER;
 313                 if (!(data->flags & MMC_DATA_WRITE))
 314                         host->stop_cmdr |= MCI_CMDR_TRDIR_READ;
 315                 if (data->flags & MMC_DATA_STREAM)
 316                         host->stop_cmdr |= MCI_CMDR_STREAM;
 317                 else
 318                         host->stop_cmdr |= MCI_CMDR_MULTI_BLOCK;
 319         }
 320
 321         /*
 322          * We could have enabled interrupts earlier, but I suspect
 323          * that would open up a nice can of interesting race
 324          * conditions (e.g. command and data complete, but stop not
 325          * prepared yet.)
 326          */
 327         mci_writel(host, IER, iflags);
 328
 329         return;
 330
 331 fail:
 332         atmci_disable(host);
 333         host->mrq = NULL;
 334         mrq->cmd->error = -EINVAL;
 335         mmc_request_done(mmc, mrq);
 336 }
 337
 338 static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 339 {
 340         struct atmel_mci        *host = mmc_priv(mmc);
 341
 342         if (ios->clock) {
 343                 u32 clkdiv;
 344
 345                 /* Set clock rate */
 346                 clkdiv = DIV_ROUND_UP(host->bus_hz, 2 * ios->clock) - 1;
 347                 if (clkdiv > 255) {
 348                         dev_warn(&mmc->class_dev,
 349                                 "clock %u too slow; using %lu\n",
 350                                 ios->clock, host->bus_hz / (2 * 256));
 351                         clkdiv = 255;
 352                 }
 353
 354                 host->mode_reg = MCI_MR_CLKDIV(clkdiv) | MCI_MR_WRPROOF
 355                                         | MCI_MR_RDPROOF;
 356         }
 357
 358         switch (ios->bus_width) {
 359         case MMC_BUS_WIDTH_1:
 360                 host->sdc_reg = 0;
 361                 break;
 362         case MMC_BUS_WIDTH_4:
 363                 host->sdc_reg = MCI_SDCBUS_4BIT;
 364                 break;
 365         }
 366
 367         switch (ios->power_mode) {
 368         case MMC_POWER_ON:
 369                 /* Send init sequence (74 clock cycles) */
 370                 atmci_enable(host);
 371                 mci_writel(host, CMDR, MCI_CMDR_SPCMD_INIT);
 372                 while (!(mci_readl(host, SR) & MCI_CMDRDY))
 373                         cpu_relax();
 374                 atmci_disable(host);
 375                 break;
 376         default:
 377                 /*
 378                  * TODO: None of the currently available AVR32-based
 379                  * boards allow MMC power to be turned off. Implement
 380                  * power control when this can be tested properly.
 381                  */
 382                 break;
 383         }
 384 }
 385
 386 static int atmci_get_ro(struct mmc_host *mmc)
 387 {
 388         int                     read_only = 0;
 389         struct atmel_mci        *host = mmc_priv(mmc);
 390
 391         if (host->wp_pin >= 0) {
 392                 read_only = gpio_get_value(host->wp_pin);
 393                 dev_dbg(&mmc->class_dev, "card is %s\n",
 394                                 read_only ? "read-only" : "read-write");
 395         } else {
 396                 dev_dbg(&mmc->class_dev,
 397                         "no pin for checking read-only switch."
 398                         " Assuming write-enable.\n");
 399         }
 400
 401         return read_only;
 402 }
 403
 404 static struct mmc_host_ops atmci_ops = {
 405         .request        = atmci_request,
 406         .set_ios        = atmci_set_ios,
 407         .get_ro         = atmci_get_ro,
 408 };
 409
 410 static void atmci_command_complete(struct atmel_mci *host,
 411                         struct mmc_command *cmd, u32 status)
 412 {
 413         /* Read the response from the card (up to 16 bytes) */
 414         cmd->resp[0] = mci_readl(host, RSPR);
 415         cmd->resp[1] = mci_readl(host, RSPR);
 416         cmd->resp[2] = mci_readl(host, RSPR);
 417         cmd->resp[3] = mci_readl(host, RSPR);
 418
 419         if (status & MCI_RTOE)
 420                 cmd->error = -ETIMEDOUT;
 421         else if ((cmd->flags & MMC_RSP_CRC) && (status & MCI_RCRCE))
 422                 cmd->error = -EILSEQ;
 423         else if (status & (MCI_RINDE | MCI_RDIRE | MCI_RENDE))
 424                 cmd->error = -EIO;
 425         else
 426                 cmd->error = 0;
 427
 428         if (cmd->error) {
 429                 dev_dbg(&host->mmc->class_dev,
 430                         "command error: status=0x%08x\n", status);
 431
 432                 if (cmd->data) {
 433                         host->data = NULL;
 434                         mci_writel(host, IDR, MCI_NOTBUSY
 435                                         | MCI_TXRDY | MCI_RXRDY
 436                                         | ATMCI_DATA_ERROR_FLAGS);
 437                 }
 438         }
 439 }
 440
 441 static void atmci_detect_change(unsigned long data)
 442 {
 443         struct atmel_mci *host = (struct atmel_mci *)data;
 444         struct mmc_request *mrq = host->mrq;
 445         int present;
 446
 447         /*
 448          * atmci_remove() sets detect_pin to -1 before freeing the
 449          * interrupt. We must not re-enable the interrupt if it has
 450          * been freed.
 451          */
 452         smp_rmb();
 453         if (host->detect_pin < 0)
 454                 return;
 455
 456         enable_irq(gpio_to_irq(host->detect_pin));
 457         present = !gpio_get_value(host->detect_pin);
 458
 459         dev_vdbg(&host->pdev->dev, "detect change: %d (was %d)\n",
 460                         present, host->present);
 461
 462         if (present != host->present) {
 463                 dev_dbg(&host->mmc->class_dev, "card %s\n",
 464                         present ? "inserted" : "removed");
 465                 host->present = present;
 466
 467                 /* Reset controller if card is gone */
 468                 if (!present) {
 469                         mci_writel(host, CR, MCI_CR_SWRST);
 470                         mci_writel(host, IDR, ~0UL);
 471                         mci_writel(host, CR, MCI_CR_MCIEN);
 472                 }
 473
 474                 /* Clean up queue if present */
 475                 if (mrq) {
 476                         /*
 477                          * Reset controller to terminate any ongoing
 478                          * commands or data transfers.
 479                          */
 480                         mci_writel(host, CR, MCI_CR_SWRST);
 481
 482                         if (!atmci_is_completed(host, EVENT_CMD_COMPLETE))
 483                                 mrq->cmd->error = -ENOMEDIUM;
 484
 485                         if (mrq->data && !atmci_is_completed(host,
 486                                                 EVENT_DATA_COMPLETE)) {
 487                                 host->data = NULL;
 488                                 mrq->data->error = -ENOMEDIUM;
 489                         }
 490                         if (mrq->stop && !atmci_is_completed(host,
 491                                                 EVENT_STOP_COMPLETE))
 492                                 mrq->stop->error = -ENOMEDIUM;
 493
 494                         host->cmd = NULL;
 495                         atmci_request_end(host->mmc, mrq);
 496                 }
 497
 498                 mmc_detect_change(host->mmc, 0);
 499         }
 500 }
 501
 502 static void atmci_tasklet_func(unsigned long priv)
 503 {
 504         struct mmc_host         *mmc = (struct mmc_host *)priv;
 505         struct atmel_mci        *host = mmc_priv(mmc);
 506         struct mmc_request      *mrq = host->mrq;
 507         struct mmc_data         *data = host->data;
 508
 509         dev_vdbg(&mmc->class_dev,
 510                 "tasklet: pending/completed/mask %lx/%lx/%x\n",
 511                 host->pending_events, host->completed_events,
 512                 mci_readl(host, IMR));
 513
 514         if (atmci_test_and_clear_pending(host, EVENT_CMD_COMPLETE)) {
 515                 /*
 516                  * host->cmd must be set to NULL before the interrupt
 517                  * handler sees EVENT_CMD_COMPLETE
 518                  */
 519                 host->cmd = NULL;
 520                 smp_wmb();
 521                 atmci_set_completed(host, EVENT_CMD_COMPLETE);
 522                 atmci_command_complete(host, mrq->cmd, host->cmd_status);
 523
 524                 if (!mrq->cmd->error && mrq->stop
 525                                 && atmci_is_completed(host, EVENT_XFER_COMPLETE)
 526                                 && !atmci_test_and_set_completed(host,
 527                                         EVENT_STOP_SENT))
 528                         send_stop_cmd(host->mmc, mrq->data);
 529         }
 530         if (atmci_test_and_clear_pending(host, EVENT_STOP_COMPLETE)) {
 531                 /*
 532                  * host->cmd must be set to NULL before the interrupt
 533                  * handler sees EVENT_STOP_COMPLETE
 534                  */
 535                 host->cmd = NULL;
 536                 smp_wmb();
 537                 atmci_set_completed(host, EVENT_STOP_COMPLETE);
 538                 atmci_command_complete(host, mrq->stop, host->stop_status);
 539         }
 540         if (atmci_test_and_clear_pending(host, EVENT_DATA_ERROR)) {
 541                 u32 status = host->data_status;
 542
 543                 dev_vdbg(&mmc->class_dev, "data error: status=%08x\n", status);
 544
 545                 atmci_set_completed(host, EVENT_DATA_ERROR);
 546                 atmci_set_completed(host, EVENT_DATA_COMPLETE);
 547
 548                 if (status & MCI_DTOE) {
 549                         dev_dbg(&mmc->class_dev,
 550                                         "data timeout error\n");
 551                         data->error = -ETIMEDOUT;
 552                 } else if (status & MCI_DCRCE) {
 553                         dev_dbg(&mmc->class_dev, "data CRC error\n");
 554                         data->error = -EILSEQ;
 555                 } else {
 556                         dev_dbg(&mmc->class_dev,
 557                                         "data FIFO error (status=%08x)\n",
 558                                         status);
 559                         data->error = -EIO;
 560                 }
 561
 562                 if (host->present && data->stop
 563                                 && atmci_is_completed(host, EVENT_CMD_COMPLETE)
 564                                 && !atmci_test_and_set_completed(
 565                                         host, EVENT_STOP_SENT))
 566                         send_stop_cmd(host->mmc, data);
 567
 568                 host->data = NULL;
 569         }
 570         if (atmci_test_and_clear_pending(host, EVENT_DATA_COMPLETE)) {
 571                 atmci_set_completed(host, EVENT_DATA_COMPLETE);
 572
 573                 if (!atmci_is_completed(host, EVENT_DATA_ERROR)) {
 574                         data->bytes_xfered = data->blocks * data->blksz;
 575                         data->error = 0;
 576                 }
 577
 578                 host->data = NULL;
 579         }
 580
 581         if (host->mrq && !host->cmd && !host->data)
 582                 atmci_request_end(mmc, host->mrq);
 583 }
 584
 585 static void atmci_read_data_pio(struct atmel_mci *host)
 586 {
 587         struct scatterlist      *sg = host->sg;
 588         void                    *buf = sg_virt(sg);
 589         unsigned int            offset = host->pio_offset;
 590         struct mmc_data         *data = host->data;
 591         u32                     value;
 592         u32                     status;
 593         unsigned int            nbytes = 0;
 594
 595         do {
 596                 value = mci_readl(host, RDR);
 597                 if (likely(offset + 4 <= sg->length)) {
 598                         put_unaligned(value, (u32 *)(buf + offset));
 599
 600                         offset += 4;
 601                         nbytes += 4;
 602
 603                         if (offset == sg->length) {
 604                                 host->sg = sg = sg_next(sg);
 605                                 if (!sg)
 606                                         goto done;
 607
 608                                 offset = 0;
 609                                 buf = sg_virt(sg);
 610                         }
 611                 } else {
 612                         unsigned int remaining = sg->length - offset;
 613                         memcpy(buf + offset, &value, remaining);
 614                         nbytes += remaining;
 615
 616                         flush_dcache_page(sg_page(sg));
 617                         host->sg = sg = sg_next(sg);
 618                         if (!sg)
 619                                 goto done;
 620
 621                         offset = 4 - remaining;
 622                         buf = sg_virt(sg);
 623                         memcpy(buf, (u8 *)&value + remaining, offset);
 624                         nbytes += offset;
 625                 }
 626
 627                 status = mci_readl(host, SR);
 628                 if (status & ATMCI_DATA_ERROR_FLAGS) {
 629                         mci_writel(host, IDR, (MCI_NOTBUSY | MCI_RXRDY
 630                                                 | ATMCI_DATA_ERROR_FLAGS));
 631                         host->data_status = status;
 632                         atmci_set_pending(host, EVENT_DATA_ERROR);
 633                         tasklet_schedule(&host->tasklet);
 634                         break;
 635                 }
 636         } while (status & MCI_RXRDY);
 637
 638         host->pio_offset = offset;
 639         data->bytes_xfered += nbytes;
 640
 641         return;
 642
 643 done:
 644         mci_writel(host, IDR, MCI_RXRDY);
 645         mci_writel(host, IER, MCI_NOTBUSY);
 646         data->bytes_xfered += nbytes;
 647         atmci_set_completed(host, EVENT_XFER_COMPLETE);
 648         if (data->stop && atmci_is_completed(host, EVENT_CMD_COMPLETE)
 649                         && !atmci_test_and_set_completed(host, EVENT_STOP_SENT))
 650                 send_stop_cmd(host->mmc, data);
 651 }
 652
 653 static void atmci_write_data_pio(struct atmel_mci *host)
 654 {
 655         struct scatterlist      *sg = host->sg;
 656         void                    *buf = sg_virt(sg);
 657         unsigned int            offset = host->pio_offset;
 658         struct mmc_data         *data = host->data;
 659         u32                     value;
 660         u32                     status;
 661         unsigned int            nbytes = 0;
 662
 663         do {
 664                 if (likely(offset + 4 <= sg->length)) {
 665                         value = get_unaligned((u32 *)(buf + offset));
 666                         mci_writel(host, TDR, value);
 667
 668                         offset += 4;
 669                         nbytes += 4;
 670                         if (offset == sg->length) {
 671                                 host->sg = sg = sg_next(sg);
 672                                 if (!sg)
 673                                         goto done;
 674
 675                                 offset = 0;
 676                                 buf = sg_virt(sg);
 677                         }
 678                 } else {
 679                         unsigned int remaining = sg->length - offset;
 680
 681                         value = 0;
 682                         memcpy(&value, buf + offset, remaining);
 683                         nbytes += remaining;
 684
 685                         host->sg = sg = sg_next(sg);
 686                         if (!sg) {
 687                                 mci_writel(host, TDR, value);
 688                                 goto done;
 689                         }
 690
 691                         offset = 4 - remaining;
 692                         buf = sg_virt(sg);
 693                         memcpy((u8 *)&value + remaining, buf, offset);
 694                         mci_writel(host, TDR, value);
 695                         nbytes += offset;
 696                 }
 697
 698                 status = mci_readl(host, SR);
 699                 if (status & ATMCI_DATA_ERROR_FLAGS) {
 700                         mci_writel(host, IDR, (MCI_NOTBUSY | MCI_TXRDY
 701                                                 | ATMCI_DATA_ERROR_FLAGS));
 702                         host->data_status = status;
 703                         atmci_set_pending(host, EVENT_DATA_ERROR);
 704                         tasklet_schedule(&host->tasklet);
 705                         break;
 706                 }
 707         } while (status & MCI_TXRDY);
 708
 709         host->pio_offset = offset;
 710         data->bytes_xfered += nbytes;
 711
 712         return;
 713
 714 done:
 715         mci_writel(host, IDR, MCI_TXRDY);
 716         mci_writel(host, IER, MCI_NOTBUSY);
 717         data->bytes_xfered += nbytes;
 718         atmci_set_completed(host, EVENT_XFER_COMPLETE);
 719         if (data->stop && atmci_is_completed(host, EVENT_CMD_COMPLETE)
 720                         && !atmci_test_and_set_completed(host, EVENT_STOP_SENT))
 721                 send_stop_cmd(host->mmc, data);
 722 }
 723
 724 static void atmci_cmd_interrupt(struct mmc_host *mmc, u32 status)
 725 {
 726         struct atmel_mci        *host = mmc_priv(mmc);
 727
 728         mci_writel(host, IDR, MCI_CMDRDY);
 729
 730         if (atmci_is_completed(host, EVENT_STOP_SENT)) {
 731                 host->stop_status = status;
 732                 atmci_set_pending(host, EVENT_STOP_COMPLETE);
 733         } else {
 734                 host->cmd_status = status;
 735                 atmci_set_pending(host, EVENT_CMD_COMPLETE);
 736         }
 737
 738         tasklet_schedule(&host->tasklet);
 739 }
 740
 741 static irqreturn_t atmci_interrupt(int irq, void *dev_id)
 742 {
 743         struct mmc_host         *mmc = dev_id;
 744         struct atmel_mci        *host = mmc_priv(mmc);
 745         u32                     status, mask, pending;
 746         unsigned int            pass_count = 0;
 747
 748         spin_lock(&mmc->lock);
 749
 750         do {
 751                 status = mci_readl(host, SR);
 752                 mask = mci_readl(host, IMR);
 753                 pending = status & mask;
 754                 if (!pending)
 755                         break;
 756
 757                 if (pending & ATMCI_DATA_ERROR_FLAGS) {
 758                         mci_writel(host, IDR, ATMCI_DATA_ERROR_FLAGS
 759                                         | MCI_RXRDY | MCI_TXRDY);
 760                         pending &= mci_readl(host, IMR);
 761                         host->data_status = status;
 762                         atmci_set_pending(host, EVENT_DATA_ERROR);
 763                         tasklet_schedule(&host->tasklet);
 764                 }
 765                 if (pending & MCI_NOTBUSY) {
 766                         mci_writel(host, IDR, (MCI_NOTBUSY
 767                                                | ATMCI_DATA_ERROR_FLAGS));
 768                         atmci_set_pending(host, EVENT_DATA_COMPLETE);
 769                         tasklet_schedule(&host->tasklet);
 770                 }
 771                 if (pending & MCI_RXRDY)
 772                         atmci_read_data_pio(host);
 773                 if (pending & MCI_TXRDY)
 774                         atmci_write_data_pio(host);
 775
 776                 if (pending & MCI_CMDRDY)
 777                         atmci_cmd_interrupt(mmc, status);
 778         } while (pass_count++ < 5);
 779
 780         spin_unlock(&mmc->lock);
 781
 782         return pass_count ? IRQ_HANDLED : IRQ_NONE;
 783 }
 784
 785 static irqreturn_t atmci_detect_interrupt(int irq, void *dev_id)
 786 {
 787         struct mmc_host         *mmc = dev_id;
 788         struct atmel_mci        *host = mmc_priv(mmc);
 789
 790         /*
 791          * Disable interrupts until the pin has stabilized and check
 792          * the state then. Use mod_timer() since we may be in the
 793          * middle of the timer routine when this interrupt triggers.
 794          */
 795         disable_irq_nosync(irq);
 796         mod_timer(&host->detect_timer, jiffies + msecs_to_jiffies(20));
 797
 798         return IRQ_HANDLED;
 799 }
 800
 801 static int __init atmci_probe(struct platform_device *pdev)
 802 {
 803         struct mci_platform_data        *pdata;
 804         struct atmel_mci *host;
 805         struct mmc_host *mmc;
 806         struct resource *regs;
 807         int irq;
 808         int ret;
 809
 810         regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 811         if (!regs)
 812                 return -ENXIO;
 813         pdata = pdev->dev.platform_data;
 814         if (!pdata)
 815                 return -ENXIO;
 816         irq = platform_get_irq(pdev, 0);
 817         if (irq < 0)
 818                 return irq;
 819
 820         mmc = mmc_alloc_host(sizeof(struct atmel_mci), &pdev->dev);
 821         if (!mmc)
 822                 return -ENOMEM;
 823
 824         host = mmc_priv(mmc);
 825         host->pdev = pdev;
 826         host->mmc = mmc;
 827         host->detect_pin = pdata->detect_pin;
 828         host->wp_pin = pdata->wp_pin;
 829
 830         host->mck = clk_get(&pdev->dev, "mci_clk");
 831         if (IS_ERR(host->mck)) {
 832                 ret = PTR_ERR(host->mck);
 833                 goto err_clk_get;
 834         }
 835
 836         ret = -ENOMEM;
 837         host->regs = ioremap(regs->start, regs->end - regs->start + 1);
 838         if (!host->regs)
 839                 goto err_ioremap;
 840
 841         clk_enable(host->mck);
 842         mci_writel(host, CR, MCI_CR_SWRST);
 843         host->bus_hz = clk_get_rate(host->mck);
 844         clk_disable(host->mck);
 845
 846         host->mapbase = regs->start;
 847
 848         mmc->ops = &atmci_ops;
 849         mmc->f_min = (host->bus_hz + 511) / 512;
 850         mmc->f_max = host->bus_hz / 2;
 851         mmc->ocr_avail  = MMC_VDD_32_33 | MMC_VDD_33_34;
 852         mmc->caps |= MMC_CAP_4_BIT_DATA;
 853
 854         mmc->max_hw_segs = 64;
 855         mmc->max_phys_segs = 64;
 856         mmc->max_req_size = 32768 * 512;
 857         mmc->max_blk_size = 32768;
 858         mmc->max_blk_count = 512;
 859
 860         tasklet_init(&host->tasklet, atmci_tasklet_func, (unsigned long)mmc);
 861
 862         ret = request_irq(irq, atmci_interrupt, 0, pdev->dev.bus_id, mmc);
 863         if (ret)
 864                 goto err_request_irq;
 865
 866         /* Assume card is present if we don't have a detect pin */
 867         host->present = 1;
 868         if (host->detect_pin >= 0) {
 869                 if (gpio_request(host->detect_pin, "mmc_detect")) {
 870                         dev_dbg(&mmc->class_dev, "no detect pin available\n");
 871                         host->detect_pin = -1;
 872                 } else {
 873                         host->present = !gpio_get_value(host->detect_pin);
 874                 }
 875         }
 876         if (host->wp_pin >= 0) {
 877                 if (gpio_request(host->wp_pin, "mmc_wp")) {
 878                         dev_dbg(&mmc->class_dev, "no WP pin available\n");
 879                         host->wp_pin = -1;
 880                 }
 881         }
 882
 883         platform_set_drvdata(pdev, host);
 884
 885         mmc_add_host(mmc);
 886
 887         if (host->detect_pin >= 0) {
 888                 setup_timer(&host->detect_timer, atmci_detect_change,
 889                                 (unsigned long)host);
 890
 891                 ret = request_irq(gpio_to_irq(host->detect_pin),
 892                                 atmci_detect_interrupt,
 893                                 IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
 894                                 "mmc-detect", mmc);
 895                 if (ret) {
 896                         dev_dbg(&mmc->class_dev,
 897                                 "could not request IRQ %d for detect pin\n",
 898                                 gpio_to_irq(host->detect_pin));
 899                         gpio_free(host->detect_pin);
 900                         host->detect_pin = -1;
 901                 }
 902         }
 903
 904         dev_info(&mmc->class_dev,
 905                         "Atmel MCI controller at 0x%08lx irq %d\n",
 906                         host->mapbase, irq);
 907
 908         return 0;
 909
 910 err_request_irq:
 911         iounmap(host->regs);
 912 err_ioremap:
 913         clk_put(host->mck);
 914 err_clk_get:
 915         mmc_free_host(mmc);
 916         return ret;
 917 }
 918
 919 static int __exit atmci_remove(struct platform_device *pdev)
 920 {
 921         struct atmel_mci *host = platform_get_drvdata(pdev);
 922
 923         platform_set_drvdata(pdev, NULL);
 924
 925         if (host) {
 926                 if (host->detect_pin >= 0) {
 927                         int pin = host->detect_pin;
 928
 929                         /* Make sure the timer doesn't enable the interrupt */
 930                         host->detect_pin = -1;
 931                         smp_wmb();
 932
 933                         free_irq(gpio_to_irq(pin), host->mmc);
 934                         del_timer_sync(&host->detect_timer);
 935                         gpio_free(pin);
 936                 }
 937
 938                 mmc_remove_host(host->mmc);
 939
 940                 clk_enable(host->mck);
 941                 mci_writel(host, IDR, ~0UL);
 942                 mci_writel(host, CR, MCI_CR_MCIDIS);
 943                 mci_readl(host, SR);
 944                 clk_disable(host->mck);
 945
 946                 if (host->wp_pin >= 0)
 947                         gpio_free(host->wp_pin);
 948
 949                 free_irq(platform_get_irq(pdev, 0), host->mmc);
 950                 iounmap(host->regs);
 951
 952                 clk_put(host->mck);
 953
 954                 mmc_free_host(host->mmc);
 955         }
 956         return 0;
 957 }
 958
 959 static struct platform_driver atmci_driver = {
 960         .remove         = __exit_p(atmci_remove),
 961         .driver         = {
 962                 .name           = "atmel_mci",
 963         },
 964 };
 965
 966 static int __init atmci_init(void)
 967 {
 968         return platform_driver_probe(&atmci_driver, atmci_probe);
 969 }
 970
 971 static void __exit atmci_exit(void)
 972 {
 973         platform_driver_unregister(&atmci_driver);
 974 }
 975
 976 module_init(atmci_init);
 977 module_exit(atmci_exit);
 978
 979 MODULE_DESCRIPTION("Atmel Multimedia Card Interface driver");
 980 MODULE_AUTHOR("Haavard Skinnemoen <haavard.skinnemoen@atmel.com>");
 981 MODULE_LICENSE("GPL v2");