linux/drivers/mmc/host/bcm2835.c
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   1/*
   2 * bcm2835 sdhost driver.
   3 *
   4 * The 2835 has two SD controllers: The Arasan sdhci controller
   5 * (supported by the iproc driver) and a custom sdhost controller
   6 * (supported by this driver).
   7 *
   8 * The sdhci controller supports both sdcard and sdio.  The sdhost
   9 * controller supports the sdcard only, but has better performance.
  10 * Also note that the rpi3 has sdio wifi, so driving the sdcard with
  11 * the sdhost controller allows to use the sdhci controller for wifi
  12 * support.
  13 *
  14 * The configuration is done by devicetree via pin muxing.  Both
  15 * SD controller are available on the same pins (2 pin groups = pin 22
  16 * to 27 + pin 48 to 53).  So it's possible to use both SD controllers
  17 * at the same time with different pin groups.
  18 *
  19 * Author:      Phil Elwell <phil@raspberrypi.org>
  20 *              Copyright (C) 2015-2016 Raspberry Pi (Trading) Ltd.
  21 *
  22 * Based on
  23 *  mmc-bcm2835.c by Gellert Weisz
  24 * which is, in turn, based on
  25 *  sdhci-bcm2708.c by Broadcom
  26 *  sdhci-bcm2835.c by Stephen Warren and Oleksandr Tymoshenko
  27 *  sdhci.c and sdhci-pci.c by Pierre Ossman
  28 *
  29 * This program is free software; you can redistribute it and/or modify it
  30 * under the terms and conditions of the GNU General Public License,
  31 * version 2, as published by the Free Software Foundation.
  32 *
  33 * This program is distributed in the hope it will be useful, but WITHOUT
  34 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  35 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  36 * more details.
  37 *
  38 * You should have received a copy of the GNU General Public License
  39 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  40 */
  41#include <linux/clk.h>
  42#include <linux/delay.h>
  43#include <linux/device.h>
  44#include <linux/dmaengine.h>
  45#include <linux/dma-mapping.h>
  46#include <linux/err.h>
  47#include <linux/highmem.h>
  48#include <linux/interrupt.h>
  49#include <linux/io.h>
  50#include <linux/iopoll.h>
  51#include <linux/module.h>
  52#include <linux/of_address.h>
  53#include <linux/of_irq.h>
  54#include <linux/platform_device.h>
  55#include <linux/scatterlist.h>
  56#include <linux/time.h>
  57#include <linux/workqueue.h>
  58
  59#include <linux/mmc/host.h>
  60#include <linux/mmc/mmc.h>
  61#include <linux/mmc/sd.h>
  62
  63#define SDCMD  0x00 /* Command to SD card              - 16 R/W */
  64#define SDARG  0x04 /* Argument to SD card             - 32 R/W */
  65#define SDTOUT 0x08 /* Start value for timeout counter - 32 R/W */
  66#define SDCDIV 0x0c /* Start value for clock divider   - 11 R/W */
  67#define SDRSP0 0x10 /* SD card response (31:0)         - 32 R   */
  68#define SDRSP1 0x14 /* SD card response (63:32)        - 32 R   */
  69#define SDRSP2 0x18 /* SD card response (95:64)        - 32 R   */
  70#define SDRSP3 0x1c /* SD card response (127:96)       - 32 R   */
  71#define SDHSTS 0x20 /* SD host status                  - 11 R/W */
  72#define SDVDD  0x30 /* SD card power control           -  1 R/W */
  73#define SDEDM  0x34 /* Emergency Debug Mode            - 13 R/W */
  74#define SDHCFG 0x38 /* Host configuration              -  2 R/W */
  75#define SDHBCT 0x3c /* Host byte count (debug)         - 32 R/W */
  76#define SDDATA 0x40 /* Data to/from SD card            - 32 R/W */
  77#define SDHBLC 0x50 /* Host block count (SDIO/SDHC)    -  9 R/W */
  78
  79#define SDCMD_NEW_FLAG                  0x8000
  80#define SDCMD_FAIL_FLAG                 0x4000
  81#define SDCMD_BUSYWAIT                  0x800
  82#define SDCMD_NO_RESPONSE               0x400
  83#define SDCMD_LONG_RESPONSE             0x200
  84#define SDCMD_WRITE_CMD                 0x80
  85#define SDCMD_READ_CMD                  0x40
  86#define SDCMD_CMD_MASK                  0x3f
  87
  88#define SDCDIV_MAX_CDIV                 0x7ff
  89
  90#define SDHSTS_BUSY_IRPT                0x400
  91#define SDHSTS_BLOCK_IRPT               0x200
  92#define SDHSTS_SDIO_IRPT                0x100
  93#define SDHSTS_REW_TIME_OUT             0x80
  94#define SDHSTS_CMD_TIME_OUT             0x40
  95#define SDHSTS_CRC16_ERROR              0x20
  96#define SDHSTS_CRC7_ERROR               0x10
  97#define SDHSTS_FIFO_ERROR               0x08
  98/* Reserved */
  99/* Reserved */
 100#define SDHSTS_DATA_FLAG                0x01
 101
 102#define SDHSTS_TRANSFER_ERROR_MASK      (SDHSTS_CRC7_ERROR | \
 103                                         SDHSTS_CRC16_ERROR | \
 104                                         SDHSTS_REW_TIME_OUT | \
 105                                         SDHSTS_FIFO_ERROR)
 106
 107#define SDHSTS_ERROR_MASK               (SDHSTS_CMD_TIME_OUT | \
 108                                         SDHSTS_TRANSFER_ERROR_MASK)
 109
 110#define SDHCFG_BUSY_IRPT_EN     BIT(10)
 111#define SDHCFG_BLOCK_IRPT_EN    BIT(8)
 112#define SDHCFG_SDIO_IRPT_EN     BIT(5)
 113#define SDHCFG_DATA_IRPT_EN     BIT(4)
 114#define SDHCFG_SLOW_CARD        BIT(3)
 115#define SDHCFG_WIDE_EXT_BUS     BIT(2)
 116#define SDHCFG_WIDE_INT_BUS     BIT(1)
 117#define SDHCFG_REL_CMD_LINE     BIT(0)
 118
 119#define SDVDD_POWER_OFF         0
 120#define SDVDD_POWER_ON          1
 121
 122#define SDEDM_FORCE_DATA_MODE   BIT(19)
 123#define SDEDM_CLOCK_PULSE       BIT(20)
 124#define SDEDM_BYPASS            BIT(21)
 125
 126#define SDEDM_WRITE_THRESHOLD_SHIFT     9
 127#define SDEDM_READ_THRESHOLD_SHIFT      14
 128#define SDEDM_THRESHOLD_MASK            0x1f
 129
 130#define SDEDM_FSM_MASK          0xf
 131#define SDEDM_FSM_IDENTMODE     0x0
 132#define SDEDM_FSM_DATAMODE      0x1
 133#define SDEDM_FSM_READDATA      0x2
 134#define SDEDM_FSM_WRITEDATA     0x3
 135#define SDEDM_FSM_READWAIT      0x4
 136#define SDEDM_FSM_READCRC       0x5
 137#define SDEDM_FSM_WRITECRC      0x6
 138#define SDEDM_FSM_WRITEWAIT1    0x7
 139#define SDEDM_FSM_POWERDOWN     0x8
 140#define SDEDM_FSM_POWERUP       0x9
 141#define SDEDM_FSM_WRITESTART1   0xa
 142#define SDEDM_FSM_WRITESTART2   0xb
 143#define SDEDM_FSM_GENPULSES     0xc
 144#define SDEDM_FSM_WRITEWAIT2    0xd
 145#define SDEDM_FSM_STARTPOWDOWN  0xf
 146
 147#define SDDATA_FIFO_WORDS       16
 148
 149#define FIFO_READ_THRESHOLD     4
 150#define FIFO_WRITE_THRESHOLD    4
 151#define SDDATA_FIFO_PIO_BURST   8
 152
 153#define PIO_THRESHOLD   1  /* Maximum block count for PIO (0 = always DMA) */
 154
 155struct bcm2835_host {
 156        spinlock_t              lock;
 157        struct mutex            mutex;
 158
 159        void __iomem            *ioaddr;
 160        u32                     phys_addr;
 161
 162        struct mmc_host         *mmc;
 163        struct platform_device  *pdev;
 164
 165        int                     clock;          /* Current clock speed */
 166        unsigned int            max_clk;        /* Max possible freq */
 167        struct work_struct      dma_work;
 168        struct delayed_work     timeout_work;   /* Timer for timeouts */
 169        struct sg_mapping_iter  sg_miter;       /* SG state for PIO */
 170        unsigned int            blocks;         /* remaining PIO blocks */
 171        int                     irq;            /* Device IRQ */
 172
 173        u32                     ns_per_fifo_word;
 174
 175        /* cached registers */
 176        u32                     hcfg;
 177        u32                     cdiv;
 178
 179        struct mmc_request      *mrq;           /* Current request */
 180        struct mmc_command      *cmd;           /* Current command */
 181        struct mmc_data         *data;          /* Current data request */
 182        bool                    data_complete:1;/* Data finished before cmd */
 183        bool                    use_busy:1;     /* Wait for busy interrupt */
 184        bool                    use_sbc:1;      /* Send CMD23 */
 185
 186        /* for threaded irq handler */
 187        bool                    irq_block;
 188        bool                    irq_busy;
 189        bool                    irq_data;
 190
 191        /* DMA part */
 192        struct dma_chan         *dma_chan_rxtx;
 193        struct dma_chan         *dma_chan;
 194        struct dma_slave_config dma_cfg_rx;
 195        struct dma_slave_config dma_cfg_tx;
 196        struct dma_async_tx_descriptor  *dma_desc;
 197        u32                     dma_dir;
 198        u32                     drain_words;
 199        struct page             *drain_page;
 200        u32                     drain_offset;
 201        bool                    use_dma;
 202};
 203
 204static void bcm2835_dumpcmd(struct bcm2835_host *host, struct mmc_command *cmd,
 205                            const char *label)
 206{
 207        struct device *dev = &host->pdev->dev;
 208
 209        if (!cmd)
 210                return;
 211
 212        dev_dbg(dev, "%c%s op %d arg 0x%x flags 0x%x - resp %08x %08x %08x %08x, err %d\n",
 213                (cmd == host->cmd) ? '>' : ' ',
 214                label, cmd->opcode, cmd->arg, cmd->flags,
 215                cmd->resp[0], cmd->resp[1], cmd->resp[2], cmd->resp[3],
 216                cmd->error);
 217}
 218
 219static void bcm2835_dumpregs(struct bcm2835_host *host)
 220{
 221        struct mmc_request *mrq = host->mrq;
 222        struct device *dev = &host->pdev->dev;
 223
 224        if (mrq) {
 225                bcm2835_dumpcmd(host, mrq->sbc, "sbc");
 226                bcm2835_dumpcmd(host, mrq->cmd, "cmd");
 227                if (mrq->data) {
 228                        dev_dbg(dev, "data blocks %x blksz %x - err %d\n",
 229                                mrq->data->blocks,
 230                                mrq->data->blksz,
 231                                mrq->data->error);
 232                }
 233                bcm2835_dumpcmd(host, mrq->stop, "stop");
 234        }
 235
 236        dev_dbg(dev, "=========== REGISTER DUMP ===========\n");
 237        dev_dbg(dev, "SDCMD  0x%08x\n", readl(host->ioaddr + SDCMD));
 238        dev_dbg(dev, "SDARG  0x%08x\n", readl(host->ioaddr + SDARG));
 239        dev_dbg(dev, "SDTOUT 0x%08x\n", readl(host->ioaddr + SDTOUT));
 240        dev_dbg(dev, "SDCDIV 0x%08x\n", readl(host->ioaddr + SDCDIV));
 241        dev_dbg(dev, "SDRSP0 0x%08x\n", readl(host->ioaddr + SDRSP0));
 242        dev_dbg(dev, "SDRSP1 0x%08x\n", readl(host->ioaddr + SDRSP1));
 243        dev_dbg(dev, "SDRSP2 0x%08x\n", readl(host->ioaddr + SDRSP2));
 244        dev_dbg(dev, "SDRSP3 0x%08x\n", readl(host->ioaddr + SDRSP3));
 245        dev_dbg(dev, "SDHSTS 0x%08x\n", readl(host->ioaddr + SDHSTS));
 246        dev_dbg(dev, "SDVDD  0x%08x\n", readl(host->ioaddr + SDVDD));
 247        dev_dbg(dev, "SDEDM  0x%08x\n", readl(host->ioaddr + SDEDM));
 248        dev_dbg(dev, "SDHCFG 0x%08x\n", readl(host->ioaddr + SDHCFG));
 249        dev_dbg(dev, "SDHBCT 0x%08x\n", readl(host->ioaddr + SDHBCT));
 250        dev_dbg(dev, "SDHBLC 0x%08x\n", readl(host->ioaddr + SDHBLC));
 251        dev_dbg(dev, "===========================================\n");
 252}
 253
 254static void bcm2835_reset_internal(struct bcm2835_host *host)
 255{
 256        u32 temp;
 257
 258        writel(SDVDD_POWER_OFF, host->ioaddr + SDVDD);
 259        writel(0, host->ioaddr + SDCMD);
 260        writel(0, host->ioaddr + SDARG);
 261        writel(0xf00000, host->ioaddr + SDTOUT);
 262        writel(0, host->ioaddr + SDCDIV);
 263        writel(0x7f8, host->ioaddr + SDHSTS); /* Write 1s to clear */
 264        writel(0, host->ioaddr + SDHCFG);
 265        writel(0, host->ioaddr + SDHBCT);
 266        writel(0, host->ioaddr + SDHBLC);
 267
 268        /* Limit fifo usage due to silicon bug */
 269        temp = readl(host->ioaddr + SDEDM);
 270        temp &= ~((SDEDM_THRESHOLD_MASK << SDEDM_READ_THRESHOLD_SHIFT) |
 271                  (SDEDM_THRESHOLD_MASK << SDEDM_WRITE_THRESHOLD_SHIFT));
 272        temp |= (FIFO_READ_THRESHOLD << SDEDM_READ_THRESHOLD_SHIFT) |
 273                (FIFO_WRITE_THRESHOLD << SDEDM_WRITE_THRESHOLD_SHIFT);
 274        writel(temp, host->ioaddr + SDEDM);
 275        msleep(20);
 276        writel(SDVDD_POWER_ON, host->ioaddr + SDVDD);
 277        msleep(20);
 278        host->clock = 0;
 279        writel(host->hcfg, host->ioaddr + SDHCFG);
 280        writel(host->cdiv, host->ioaddr + SDCDIV);
 281}
 282
 283static void bcm2835_reset(struct mmc_host *mmc)
 284{
 285        struct bcm2835_host *host = mmc_priv(mmc);
 286
 287        if (host->dma_chan)
 288                dmaengine_terminate_sync(host->dma_chan);
 289        bcm2835_reset_internal(host);
 290}
 291
 292static void bcm2835_finish_command(struct bcm2835_host *host);
 293
 294static void bcm2835_wait_transfer_complete(struct bcm2835_host *host)
 295{
 296        int timediff;
 297        u32 alternate_idle;
 298
 299        alternate_idle = (host->mrq->data->flags & MMC_DATA_READ) ?
 300                SDEDM_FSM_READWAIT : SDEDM_FSM_WRITESTART1;
 301
 302        timediff = 0;
 303
 304        while (1) {
 305                u32 edm, fsm;
 306
 307                edm = readl(host->ioaddr + SDEDM);
 308                fsm = edm & SDEDM_FSM_MASK;
 309
 310                if ((fsm == SDEDM_FSM_IDENTMODE) ||
 311                    (fsm == SDEDM_FSM_DATAMODE))
 312                        break;
 313                if (fsm == alternate_idle) {
 314                        writel(edm | SDEDM_FORCE_DATA_MODE,
 315                               host->ioaddr + SDEDM);
 316                        break;
 317                }
 318
 319                timediff++;
 320                if (timediff == 100000) {
 321                        dev_err(&host->pdev->dev,
 322                                "wait_transfer_complete - still waiting after %d retries\n",
 323                                timediff);
 324                        bcm2835_dumpregs(host);
 325                        host->mrq->data->error = -ETIMEDOUT;
 326                        return;
 327                }
 328                cpu_relax();
 329        }
 330}
 331
 332static void bcm2835_dma_complete(void *param)
 333{
 334        struct bcm2835_host *host = param;
 335
 336        schedule_work(&host->dma_work);
 337}
 338
 339static void bcm2835_transfer_block_pio(struct bcm2835_host *host, bool is_read)
 340{
 341        unsigned long flags;
 342        size_t blksize;
 343        unsigned long wait_max;
 344
 345        blksize = host->data->blksz;
 346
 347        wait_max = jiffies + msecs_to_jiffies(500);
 348
 349        local_irq_save(flags);
 350
 351        while (blksize) {
 352                int copy_words;
 353                u32 hsts = 0;
 354                size_t len;
 355                u32 *buf;
 356
 357                if (!sg_miter_next(&host->sg_miter)) {
 358                        host->data->error = -EINVAL;
 359                        break;
 360                }
 361
 362                len = min(host->sg_miter.length, blksize);
 363                if (len % 4) {
 364                        host->data->error = -EINVAL;
 365                        break;
 366                }
 367
 368                blksize -= len;
 369                host->sg_miter.consumed = len;
 370
 371                buf = (u32 *)host->sg_miter.addr;
 372
 373                copy_words = len / 4;
 374
 375                while (copy_words) {
 376                        int burst_words, words;
 377                        u32 edm;
 378
 379                        burst_words = min(SDDATA_FIFO_PIO_BURST, copy_words);
 380                        edm = readl(host->ioaddr + SDEDM);
 381                        if (is_read)
 382                                words = ((edm >> 4) & 0x1f);
 383                        else
 384                                words = SDDATA_FIFO_WORDS - ((edm >> 4) & 0x1f);
 385
 386                        if (words < burst_words) {
 387                                int fsm_state = (edm & SDEDM_FSM_MASK);
 388                                struct device *dev = &host->pdev->dev;
 389
 390                                if ((is_read &&
 391                                     (fsm_state != SDEDM_FSM_READDATA &&
 392                                      fsm_state != SDEDM_FSM_READWAIT &&
 393                                      fsm_state != SDEDM_FSM_READCRC)) ||
 394                                    (!is_read &&
 395                                     (fsm_state != SDEDM_FSM_WRITEDATA &&
 396                                      fsm_state != SDEDM_FSM_WRITESTART1 &&
 397                                      fsm_state != SDEDM_FSM_WRITESTART2))) {
 398                                        hsts = readl(host->ioaddr + SDHSTS);
 399                                        dev_err(dev, "fsm %x, hsts %08x\n",
 400                                                fsm_state, hsts);
 401                                        if (hsts & SDHSTS_ERROR_MASK)
 402                                                break;
 403                                }
 404
 405                                if (time_after(jiffies, wait_max)) {
 406                                        dev_err(dev, "PIO %s timeout - EDM %08x\n",
 407                                                is_read ? "read" : "write",
 408                                                edm);
 409                                        hsts = SDHSTS_REW_TIME_OUT;
 410                                        break;
 411                                }
 412                                ndelay((burst_words - words) *
 413                                       host->ns_per_fifo_word);
 414                                continue;
 415                        } else if (words > copy_words) {
 416                                words = copy_words;
 417                        }
 418
 419                        copy_words -= words;
 420
 421                        while (words) {
 422                                if (is_read)
 423                                        *(buf++) = readl(host->ioaddr + SDDATA);
 424                                else
 425                                        writel(*(buf++), host->ioaddr + SDDATA);
 426                                words--;
 427                        }
 428                }
 429
 430                if (hsts & SDHSTS_ERROR_MASK)
 431                        break;
 432        }
 433
 434        sg_miter_stop(&host->sg_miter);
 435
 436        local_irq_restore(flags);
 437}
 438
 439static void bcm2835_transfer_pio(struct bcm2835_host *host)
 440{
 441        struct device *dev = &host->pdev->dev;
 442        u32 sdhsts;
 443        bool is_read;
 444
 445        is_read = (host->data->flags & MMC_DATA_READ) != 0;
 446        bcm2835_transfer_block_pio(host, is_read);
 447
 448        sdhsts = readl(host->ioaddr + SDHSTS);
 449        if (sdhsts & (SDHSTS_CRC16_ERROR |
 450                      SDHSTS_CRC7_ERROR |
 451                      SDHSTS_FIFO_ERROR)) {
 452                dev_err(dev, "%s transfer error - HSTS %08x\n",
 453                        is_read ? "read" : "write", sdhsts);
 454                host->data->error = -EILSEQ;
 455        } else if ((sdhsts & (SDHSTS_CMD_TIME_OUT |
 456                              SDHSTS_REW_TIME_OUT))) {
 457                dev_err(dev, "%s timeout error - HSTS %08x\n",
 458                        is_read ? "read" : "write", sdhsts);
 459                host->data->error = -ETIMEDOUT;
 460        }
 461}
 462
 463static
 464void bcm2835_prepare_dma(struct bcm2835_host *host, struct mmc_data *data)
 465{
 466        int len, dir_data, dir_slave;
 467        struct dma_async_tx_descriptor *desc = NULL;
 468        struct dma_chan *dma_chan;
 469
 470        dma_chan = host->dma_chan_rxtx;
 471        if (data->flags & MMC_DATA_READ) {
 472                dir_data = DMA_FROM_DEVICE;
 473                dir_slave = DMA_DEV_TO_MEM;
 474        } else {
 475                dir_data = DMA_TO_DEVICE;
 476                dir_slave = DMA_MEM_TO_DEV;
 477        }
 478
 479        /* The block doesn't manage the FIFO DREQs properly for
 480         * multi-block transfers, so don't attempt to DMA the final
 481         * few words.  Unfortunately this requires the final sg entry
 482         * to be trimmed.  N.B. This code demands that the overspill
 483         * is contained in a single sg entry.
 484         */
 485
 486        host->drain_words = 0;
 487        if ((data->blocks > 1) && (dir_data == DMA_FROM_DEVICE)) {
 488                struct scatterlist *sg;
 489                u32 len;
 490                int i;
 491
 492                len = min((u32)(FIFO_READ_THRESHOLD - 1) * 4,
 493                          (u32)data->blocks * data->blksz);
 494
 495                for_each_sg(data->sg, sg, data->sg_len, i) {
 496                        if (sg_is_last(sg)) {
 497                                WARN_ON(sg->length < len);
 498                                sg->length -= len;
 499                                host->drain_page = sg_page(sg);
 500                                host->drain_offset = sg->offset + sg->length;
 501                        }
 502                }
 503                host->drain_words = len / 4;
 504        }
 505
 506        /* The parameters have already been validated, so this will not fail */
 507        (void)dmaengine_slave_config(dma_chan,
 508                                     (dir_data == DMA_FROM_DEVICE) ?
 509                                     &host->dma_cfg_rx :
 510                                     &host->dma_cfg_tx);
 511
 512        len = dma_map_sg(dma_chan->device->dev, data->sg, data->sg_len,
 513                         dir_data);
 514
 515        if (len > 0) {
 516                desc = dmaengine_prep_slave_sg(dma_chan, data->sg,
 517                                               len, dir_slave,
 518                                               DMA_PREP_INTERRUPT |
 519                                               DMA_CTRL_ACK);
 520        }
 521
 522        if (desc) {
 523                desc->callback = bcm2835_dma_complete;
 524                desc->callback_param = host;
 525                host->dma_desc = desc;
 526                host->dma_chan = dma_chan;
 527                host->dma_dir = dir_data;
 528        }
 529}
 530
 531static void bcm2835_start_dma(struct bcm2835_host *host)
 532{
 533        dmaengine_submit(host->dma_desc);
 534        dma_async_issue_pending(host->dma_chan);
 535}
 536
 537static void bcm2835_set_transfer_irqs(struct bcm2835_host *host)
 538{
 539        u32 all_irqs = SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN |
 540                SDHCFG_BUSY_IRPT_EN;
 541
 542        if (host->dma_desc) {
 543                host->hcfg = (host->hcfg & ~all_irqs) |
 544                        SDHCFG_BUSY_IRPT_EN;
 545        } else {
 546                host->hcfg = (host->hcfg & ~all_irqs) |
 547                        SDHCFG_DATA_IRPT_EN |
 548                        SDHCFG_BUSY_IRPT_EN;
 549        }
 550
 551        writel(host->hcfg, host->ioaddr + SDHCFG);
 552}
 553
 554static
 555void bcm2835_prepare_data(struct bcm2835_host *host, struct mmc_command *cmd)
 556{
 557        struct mmc_data *data = cmd->data;
 558
 559        WARN_ON(host->data);
 560
 561        host->data = data;
 562        if (!data)
 563                return;
 564
 565        host->data_complete = false;
 566        host->data->bytes_xfered = 0;
 567
 568        if (!host->dma_desc) {
 569                /* Use PIO */
 570                int flags = SG_MITER_ATOMIC;
 571
 572                if (data->flags & MMC_DATA_READ)
 573                        flags |= SG_MITER_TO_SG;
 574                else
 575                        flags |= SG_MITER_FROM_SG;
 576                sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags);
 577                host->blocks = data->blocks;
 578        }
 579
 580        bcm2835_set_transfer_irqs(host);
 581
 582        writel(data->blksz, host->ioaddr + SDHBCT);
 583        writel(data->blocks, host->ioaddr + SDHBLC);
 584}
 585
 586static u32 bcm2835_read_wait_sdcmd(struct bcm2835_host *host, u32 max_ms)
 587{
 588        struct device *dev = &host->pdev->dev;
 589        u32 value;
 590        int ret;
 591
 592        ret = readl_poll_timeout(host->ioaddr + SDCMD, value,
 593                                 !(value & SDCMD_NEW_FLAG), 1, 10);
 594        if (ret == -ETIMEDOUT)
 595                /* if it takes a while make poll interval bigger */
 596                ret = readl_poll_timeout(host->ioaddr + SDCMD, value,
 597                                         !(value & SDCMD_NEW_FLAG),
 598                                         10, max_ms * 1000);
 599        if (ret == -ETIMEDOUT)
 600                dev_err(dev, "%s: timeout (%d ms)\n", __func__, max_ms);
 601
 602        return value;
 603}
 604
 605static void bcm2835_finish_request(struct bcm2835_host *host)
 606{
 607        struct dma_chan *terminate_chan = NULL;
 608        struct mmc_request *mrq;
 609
 610        cancel_delayed_work(&host->timeout_work);
 611
 612        mrq = host->mrq;
 613
 614        host->mrq = NULL;
 615        host->cmd = NULL;
 616        host->data = NULL;
 617
 618        host->dma_desc = NULL;
 619        terminate_chan = host->dma_chan;
 620        host->dma_chan = NULL;
 621
 622        if (terminate_chan) {
 623                int err = dmaengine_terminate_all(terminate_chan);
 624
 625                if (err)
 626                        dev_err(&host->pdev->dev,
 627                                "failed to terminate DMA (%d)\n", err);
 628        }
 629
 630        mmc_request_done(host->mmc, mrq);
 631}
 632
 633static
 634bool bcm2835_send_command(struct bcm2835_host *host, struct mmc_command *cmd)
 635{
 636        struct device *dev = &host->pdev->dev;
 637        u32 sdcmd, sdhsts;
 638        unsigned long timeout;
 639
 640        WARN_ON(host->cmd);
 641
 642        sdcmd = bcm2835_read_wait_sdcmd(host, 100);
 643        if (sdcmd & SDCMD_NEW_FLAG) {
 644                dev_err(dev, "previous command never completed.\n");
 645                bcm2835_dumpregs(host);
 646                cmd->error = -EILSEQ;
 647                bcm2835_finish_request(host);
 648                return false;
 649        }
 650
 651        if (!cmd->data && cmd->busy_timeout > 9000)
 652                timeout = DIV_ROUND_UP(cmd->busy_timeout, 1000) * HZ + HZ;
 653        else
 654                timeout = 10 * HZ;
 655        schedule_delayed_work(&host->timeout_work, timeout);
 656
 657        host->cmd = cmd;
 658
 659        /* Clear any error flags */
 660        sdhsts = readl(host->ioaddr + SDHSTS);
 661        if (sdhsts & SDHSTS_ERROR_MASK)
 662                writel(sdhsts, host->ioaddr + SDHSTS);
 663
 664        if ((cmd->flags & MMC_RSP_136) && (cmd->flags & MMC_RSP_BUSY)) {
 665                dev_err(dev, "unsupported response type!\n");
 666                cmd->error = -EINVAL;
 667                bcm2835_finish_request(host);
 668                return false;
 669        }
 670
 671        bcm2835_prepare_data(host, cmd);
 672
 673        writel(cmd->arg, host->ioaddr + SDARG);
 674
 675        sdcmd = cmd->opcode & SDCMD_CMD_MASK;
 676
 677        host->use_busy = false;
 678        if (!(cmd->flags & MMC_RSP_PRESENT)) {
 679                sdcmd |= SDCMD_NO_RESPONSE;
 680        } else {
 681                if (cmd->flags & MMC_RSP_136)
 682                        sdcmd |= SDCMD_LONG_RESPONSE;
 683                if (cmd->flags & MMC_RSP_BUSY) {
 684                        sdcmd |= SDCMD_BUSYWAIT;
 685                        host->use_busy = true;
 686                }
 687        }
 688
 689        if (cmd->data) {
 690                if (cmd->data->flags & MMC_DATA_WRITE)
 691                        sdcmd |= SDCMD_WRITE_CMD;
 692                if (cmd->data->flags & MMC_DATA_READ)
 693                        sdcmd |= SDCMD_READ_CMD;
 694        }
 695
 696        writel(sdcmd | SDCMD_NEW_FLAG, host->ioaddr + SDCMD);
 697
 698        return true;
 699}
 700
 701static void bcm2835_transfer_complete(struct bcm2835_host *host)
 702{
 703        struct mmc_data *data;
 704
 705        WARN_ON(!host->data_complete);
 706
 707        data = host->data;
 708        host->data = NULL;
 709
 710        /* Need to send CMD12 if -
 711         * a) open-ended multiblock transfer (no CMD23)
 712         * b) error in multiblock transfer
 713         */
 714        if (host->mrq->stop && (data->error || !host->use_sbc)) {
 715                if (bcm2835_send_command(host, host->mrq->stop)) {
 716                        /* No busy, so poll for completion */
 717                        if (!host->use_busy)
 718                                bcm2835_finish_command(host);
 719                }
 720        } else {
 721                bcm2835_wait_transfer_complete(host);
 722                bcm2835_finish_request(host);
 723        }
 724}
 725
 726static void bcm2835_finish_data(struct bcm2835_host *host)
 727{
 728        struct device *dev = &host->pdev->dev;
 729        struct mmc_data *data;
 730
 731        data = host->data;
 732
 733        host->hcfg &= ~(SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN);
 734        writel(host->hcfg, host->ioaddr + SDHCFG);
 735
 736        data->bytes_xfered = data->error ? 0 : (data->blksz * data->blocks);
 737
 738        host->data_complete = true;
 739
 740        if (host->cmd) {
 741                /* Data managed to finish before the
 742                 * command completed. Make sure we do
 743                 * things in the proper order.
 744                 */
 745                dev_dbg(dev, "Finished early - HSTS %08x\n",
 746                        readl(host->ioaddr + SDHSTS));
 747        } else {
 748                bcm2835_transfer_complete(host);
 749        }
 750}
 751
 752static void bcm2835_finish_command(struct bcm2835_host *host)
 753{
 754        struct device *dev = &host->pdev->dev;
 755        struct mmc_command *cmd = host->cmd;
 756        u32 sdcmd;
 757
 758        sdcmd = bcm2835_read_wait_sdcmd(host, 100);
 759
 760        /* Check for errors */
 761        if (sdcmd & SDCMD_NEW_FLAG) {
 762                dev_err(dev, "command never completed.\n");
 763                bcm2835_dumpregs(host);
 764                host->cmd->error = -EIO;
 765                bcm2835_finish_request(host);
 766                return;
 767        } else if (sdcmd & SDCMD_FAIL_FLAG) {
 768                u32 sdhsts = readl(host->ioaddr + SDHSTS);
 769
 770                /* Clear the errors */
 771                writel(SDHSTS_ERROR_MASK, host->ioaddr + SDHSTS);
 772
 773                if (!(sdhsts & SDHSTS_CRC7_ERROR) ||
 774                    (host->cmd->opcode != MMC_SEND_OP_COND)) {
 775                        if (sdhsts & SDHSTS_CMD_TIME_OUT) {
 776                                host->cmd->error = -ETIMEDOUT;
 777                        } else {
 778                                dev_err(dev, "unexpected command %d error\n",
 779                                        host->cmd->opcode);
 780                                bcm2835_dumpregs(host);
 781                                host->cmd->error = -EILSEQ;
 782                        }
 783                        bcm2835_finish_request(host);
 784                        return;
 785                }
 786        }
 787
 788        if (cmd->flags & MMC_RSP_PRESENT) {
 789                if (cmd->flags & MMC_RSP_136) {
 790                        int i;
 791
 792                        for (i = 0; i < 4; i++) {
 793                                cmd->resp[3 - i] =
 794                                        readl(host->ioaddr + SDRSP0 + i * 4);
 795                        }
 796                } else {
 797                        cmd->resp[0] = readl(host->ioaddr + SDRSP0);
 798                }
 799        }
 800
 801        if (cmd == host->mrq->sbc) {
 802                /* Finished CMD23, now send actual command. */
 803                host->cmd = NULL;
 804                if (bcm2835_send_command(host, host->mrq->cmd)) {
 805                        if (host->data && host->dma_desc)
 806                                /* DMA transfer starts now, PIO starts
 807                                 * after irq
 808                                 */
 809                                bcm2835_start_dma(host);
 810
 811                        if (!host->use_busy)
 812                                bcm2835_finish_command(host);
 813                }
 814        } else if (cmd == host->mrq->stop) {
 815                /* Finished CMD12 */
 816                bcm2835_finish_request(host);
 817        } else {
 818                /* Processed actual command. */
 819                host->cmd = NULL;
 820                if (!host->data)
 821                        bcm2835_finish_request(host);
 822                else if (host->data_complete)
 823                        bcm2835_transfer_complete(host);
 824        }
 825}
 826
 827static void bcm2835_timeout(struct work_struct *work)
 828{
 829        struct delayed_work *d = to_delayed_work(work);
 830        struct bcm2835_host *host =
 831                container_of(d, struct bcm2835_host, timeout_work);
 832        struct device *dev = &host->pdev->dev;
 833
 834        mutex_lock(&host->mutex);
 835
 836        if (host->mrq) {
 837                dev_err(dev, "timeout waiting for hardware interrupt.\n");
 838                bcm2835_dumpregs(host);
 839
 840                if (host->data) {
 841                        host->data->error = -ETIMEDOUT;
 842                        bcm2835_finish_data(host);
 843                } else {
 844                        if (host->cmd)
 845                                host->cmd->error = -ETIMEDOUT;
 846                        else
 847                                host->mrq->cmd->error = -ETIMEDOUT;
 848
 849                        bcm2835_finish_request(host);
 850                }
 851        }
 852
 853        mutex_unlock(&host->mutex);
 854}
 855
 856static bool bcm2835_check_cmd_error(struct bcm2835_host *host, u32 intmask)
 857{
 858        struct device *dev = &host->pdev->dev;
 859
 860        if (!(intmask & SDHSTS_ERROR_MASK))
 861                return false;
 862
 863        if (!host->cmd)
 864                return true;
 865
 866        dev_err(dev, "sdhost_busy_irq: intmask %08x\n", intmask);
 867        if (intmask & SDHSTS_CRC7_ERROR) {
 868                host->cmd->error = -EILSEQ;
 869        } else if (intmask & (SDHSTS_CRC16_ERROR |
 870                              SDHSTS_FIFO_ERROR)) {
 871                if (host->mrq->data)
 872                        host->mrq->data->error = -EILSEQ;
 873                else
 874                        host->cmd->error = -EILSEQ;
 875        } else if (intmask & SDHSTS_REW_TIME_OUT) {
 876                if (host->mrq->data)
 877                        host->mrq->data->error = -ETIMEDOUT;
 878                else
 879                        host->cmd->error = -ETIMEDOUT;
 880        } else if (intmask & SDHSTS_CMD_TIME_OUT) {
 881                host->cmd->error = -ETIMEDOUT;
 882        }
 883        bcm2835_dumpregs(host);
 884        return true;
 885}
 886
 887static void bcm2835_check_data_error(struct bcm2835_host *host, u32 intmask)
 888{
 889        if (!host->data)
 890                return;
 891        if (intmask & (SDHSTS_CRC16_ERROR | SDHSTS_FIFO_ERROR))
 892                host->data->error = -EILSEQ;
 893        if (intmask & SDHSTS_REW_TIME_OUT)
 894                host->data->error = -ETIMEDOUT;
 895}
 896
 897static void bcm2835_busy_irq(struct bcm2835_host *host)
 898{
 899        if (WARN_ON(!host->cmd)) {
 900                bcm2835_dumpregs(host);
 901                return;
 902        }
 903
 904        if (WARN_ON(!host->use_busy)) {
 905                bcm2835_dumpregs(host);
 906                return;
 907        }
 908        host->use_busy = false;
 909
 910        bcm2835_finish_command(host);
 911}
 912
 913static void bcm2835_data_irq(struct bcm2835_host *host, u32 intmask)
 914{
 915        /* There are no dedicated data/space available interrupt
 916         * status bits, so it is necessary to use the single shared
 917         * data/space available FIFO status bits. It is therefore not
 918         * an error to get here when there is no data transfer in
 919         * progress.
 920         */
 921        if (!host->data)
 922                return;
 923
 924        bcm2835_check_data_error(host, intmask);
 925        if (host->data->error)
 926                goto finished;
 927
 928        if (host->data->flags & MMC_DATA_WRITE) {
 929                /* Use the block interrupt for writes after the first block */
 930                host->hcfg &= ~(SDHCFG_DATA_IRPT_EN);
 931                host->hcfg |= SDHCFG_BLOCK_IRPT_EN;
 932                writel(host->hcfg, host->ioaddr + SDHCFG);
 933                bcm2835_transfer_pio(host);
 934        } else {
 935                bcm2835_transfer_pio(host);
 936                host->blocks--;
 937                if ((host->blocks == 0) || host->data->error)
 938                        goto finished;
 939        }
 940        return;
 941
 942finished:
 943        host->hcfg &= ~(SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN);
 944        writel(host->hcfg, host->ioaddr + SDHCFG);
 945}
 946
 947static void bcm2835_data_threaded_irq(struct bcm2835_host *host)
 948{
 949        if (!host->data)
 950                return;
 951        if ((host->blocks == 0) || host->data->error)
 952                bcm2835_finish_data(host);
 953}
 954
 955static void bcm2835_block_irq(struct bcm2835_host *host)
 956{
 957        if (WARN_ON(!host->data)) {
 958                bcm2835_dumpregs(host);
 959                return;
 960        }
 961
 962        if (!host->dma_desc) {
 963                WARN_ON(!host->blocks);
 964                if (host->data->error || (--host->blocks == 0))
 965                        bcm2835_finish_data(host);
 966                else
 967                        bcm2835_transfer_pio(host);
 968        } else if (host->data->flags & MMC_DATA_WRITE) {
 969                bcm2835_finish_data(host);
 970        }
 971}
 972
 973static irqreturn_t bcm2835_irq(int irq, void *dev_id)
 974{
 975        irqreturn_t result = IRQ_NONE;
 976        struct bcm2835_host *host = dev_id;
 977        u32 intmask;
 978
 979        spin_lock(&host->lock);
 980
 981        intmask = readl(host->ioaddr + SDHSTS);
 982
 983        writel(SDHSTS_BUSY_IRPT |
 984               SDHSTS_BLOCK_IRPT |
 985               SDHSTS_SDIO_IRPT |
 986               SDHSTS_DATA_FLAG,
 987               host->ioaddr + SDHSTS);
 988
 989        if (intmask & SDHSTS_BLOCK_IRPT) {
 990                bcm2835_check_data_error(host, intmask);
 991                host->irq_block = true;
 992                result = IRQ_WAKE_THREAD;
 993        }
 994
 995        if (intmask & SDHSTS_BUSY_IRPT) {
 996                if (!bcm2835_check_cmd_error(host, intmask)) {
 997                        host->irq_busy = true;
 998                        result = IRQ_WAKE_THREAD;
 999                } else {
1000                        result = IRQ_HANDLED;
1001                }
1002        }
1003
1004        /* There is no true data interrupt status bit, so it is
1005         * necessary to qualify the data flag with the interrupt
1006         * enable bit.
1007         */
1008        if ((intmask & SDHSTS_DATA_FLAG) &&
1009            (host->hcfg & SDHCFG_DATA_IRPT_EN)) {
1010                bcm2835_data_irq(host, intmask);
1011                host->irq_data = true;
1012                result = IRQ_WAKE_THREAD;
1013        }
1014
1015        spin_unlock(&host->lock);
1016
1017        return result;
1018}
1019
1020static irqreturn_t bcm2835_threaded_irq(int irq, void *dev_id)
1021{
1022        struct bcm2835_host *host = dev_id;
1023        unsigned long flags;
1024        bool block, busy, data;
1025
1026        spin_lock_irqsave(&host->lock, flags);
1027
1028        block = host->irq_block;
1029        busy  = host->irq_busy;
1030        data  = host->irq_data;
1031        host->irq_block = false;
1032        host->irq_busy  = false;
1033        host->irq_data  = false;
1034
1035        spin_unlock_irqrestore(&host->lock, flags);
1036
1037        mutex_lock(&host->mutex);
1038
1039        if (block)
1040                bcm2835_block_irq(host);
1041        if (busy)
1042                bcm2835_busy_irq(host);
1043        if (data)
1044                bcm2835_data_threaded_irq(host);
1045
1046        mutex_unlock(&host->mutex);
1047
1048        return IRQ_HANDLED;
1049}
1050
1051static void bcm2835_dma_complete_work(struct work_struct *work)
1052{
1053        struct bcm2835_host *host =
1054                container_of(work, struct bcm2835_host, dma_work);
1055        struct mmc_data *data = host->data;
1056
1057        mutex_lock(&host->mutex);
1058
1059        if (host->dma_chan) {
1060                dma_unmap_sg(host->dma_chan->device->dev,
1061                             data->sg, data->sg_len,
1062                             host->dma_dir);
1063
1064                host->dma_chan = NULL;
1065        }
1066
1067        if (host->drain_words) {
1068                unsigned long flags;
1069                void *page;
1070                u32 *buf;
1071
1072                if (host->drain_offset & PAGE_MASK) {
1073                        host->drain_page += host->drain_offset >> PAGE_SHIFT;
1074                        host->drain_offset &= ~PAGE_MASK;
1075                }
1076                local_irq_save(flags);
1077                page = kmap_atomic(host->drain_page);
1078                buf = page + host->drain_offset;
1079
1080                while (host->drain_words) {
1081                        u32 edm = readl(host->ioaddr + SDEDM);
1082
1083                        if ((edm >> 4) & 0x1f)
1084                                *(buf++) = readl(host->ioaddr + SDDATA);
1085                        host->drain_words--;
1086                }
1087
1088                kunmap_atomic(page);
1089                local_irq_restore(flags);
1090        }
1091
1092        bcm2835_finish_data(host);
1093
1094        mutex_unlock(&host->mutex);
1095}
1096
1097static void bcm2835_set_clock(struct bcm2835_host *host, unsigned int clock)
1098{
1099        int div;
1100
1101        /* The SDCDIV register has 11 bits, and holds (div - 2).  But
1102         * in data mode the max is 50MHz wihout a minimum, and only
1103         * the bottom 3 bits are used. Since the switch over is
1104         * automatic (unless we have marked the card as slow...),
1105         * chosen values have to make sense in both modes.  Ident mode
1106         * must be 100-400KHz, so can range check the requested
1107         * clock. CMD15 must be used to return to data mode, so this
1108         * can be monitored.
1109         *
1110         * clock 250MHz -> 0->125MHz, 1->83.3MHz, 2->62.5MHz, 3->50.0MHz
1111         *                 4->41.7MHz, 5->35.7MHz, 6->31.3MHz, 7->27.8MHz
1112         *
1113         *               623->400KHz/27.8MHz
1114         *               reset value (507)->491159/50MHz
1115         *
1116         * BUT, the 3-bit clock divisor in data mode is too small if
1117         * the core clock is higher than 250MHz, so instead use the
1118         * SLOW_CARD configuration bit to force the use of the ident
1119         * clock divisor at all times.
1120         */
1121
1122        if (clock < 100000) {
1123                /* Can't stop the clock, but make it as slow as possible
1124                 * to show willing
1125                 */
1126                host->cdiv = SDCDIV_MAX_CDIV;
1127                writel(host->cdiv, host->ioaddr + SDCDIV);
1128                return;
1129        }
1130
1131        div = host->max_clk / clock;
1132        if (div < 2)
1133                div = 2;
1134        if ((host->max_clk / div) > clock)
1135                div++;
1136        div -= 2;
1137
1138        if (div > SDCDIV_MAX_CDIV)
1139                div = SDCDIV_MAX_CDIV;
1140
1141        clock = host->max_clk / (div + 2);
1142        host->mmc->actual_clock = clock;
1143
1144        /* Calibrate some delays */
1145
1146        host->ns_per_fifo_word = (1000000000 / clock) *
1147                ((host->mmc->caps & MMC_CAP_4_BIT_DATA) ? 8 : 32);
1148
1149        host->cdiv = div;
1150        writel(host->cdiv, host->ioaddr + SDCDIV);
1151
1152        /* Set the timeout to 500ms */
1153        writel(host->mmc->actual_clock / 2, host->ioaddr + SDTOUT);
1154}
1155
1156static void bcm2835_request(struct mmc_host *mmc, struct mmc_request *mrq)
1157{
1158        struct bcm2835_host *host = mmc_priv(mmc);
1159        struct device *dev = &host->pdev->dev;
1160        u32 edm, fsm;
1161
1162        /* Reset the error statuses in case this is a retry */
1163        if (mrq->sbc)
1164                mrq->sbc->error = 0;
1165        if (mrq->cmd)
1166                mrq->cmd->error = 0;
1167        if (mrq->data)
1168                mrq->data->error = 0;
1169        if (mrq->stop)
1170                mrq->stop->error = 0;
1171
1172        if (mrq->data && !is_power_of_2(mrq->data->blksz)) {
1173                dev_err(dev, "unsupported block size (%d bytes)\n",
1174                        mrq->data->blksz);
1175
1176                if (mrq->cmd)
1177                        mrq->cmd->error = -EINVAL;
1178
1179                mmc_request_done(mmc, mrq);
1180                return;
1181        }
1182
1183        if (host->use_dma && mrq->data && (mrq->data->blocks > PIO_THRESHOLD))
1184                bcm2835_prepare_dma(host, mrq->data);
1185
1186        mutex_lock(&host->mutex);
1187
1188        WARN_ON(host->mrq);
1189        host->mrq = mrq;
1190
1191        edm = readl(host->ioaddr + SDEDM);
1192        fsm = edm & SDEDM_FSM_MASK;
1193
1194        if ((fsm != SDEDM_FSM_IDENTMODE) &&
1195            (fsm != SDEDM_FSM_DATAMODE)) {
1196                dev_err(dev, "previous command (%d) not complete (EDM %08x)\n",
1197                        readl(host->ioaddr + SDCMD) & SDCMD_CMD_MASK,
1198                        edm);
1199                bcm2835_dumpregs(host);
1200
1201                if (mrq->cmd)
1202                        mrq->cmd->error = -EILSEQ;
1203
1204                bcm2835_finish_request(host);
1205                mutex_unlock(&host->mutex);
1206                return;
1207        }
1208
1209        host->use_sbc = !!mrq->sbc && host->mrq->data &&
1210                        (host->mrq->data->flags & MMC_DATA_READ);
1211        if (host->use_sbc) {
1212                if (bcm2835_send_command(host, mrq->sbc)) {
1213                        if (!host->use_busy)
1214                                bcm2835_finish_command(host);
1215                }
1216        } else if (mrq->cmd && bcm2835_send_command(host, mrq->cmd)) {
1217                if (host->data && host->dma_desc) {
1218                        /* DMA transfer starts now, PIO starts after irq */
1219                        bcm2835_start_dma(host);
1220                }
1221
1222                if (!host->use_busy)
1223                        bcm2835_finish_command(host);
1224        }
1225
1226        mutex_unlock(&host->mutex);
1227}
1228
1229static void bcm2835_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
1230{
1231        struct bcm2835_host *host = mmc_priv(mmc);
1232
1233        mutex_lock(&host->mutex);
1234
1235        if (!ios->clock || ios->clock != host->clock) {
1236                bcm2835_set_clock(host, ios->clock);
1237                host->clock = ios->clock;
1238        }
1239
1240        /* set bus width */
1241        host->hcfg &= ~SDHCFG_WIDE_EXT_BUS;
1242        if (ios->bus_width == MMC_BUS_WIDTH_4)
1243                host->hcfg |= SDHCFG_WIDE_EXT_BUS;
1244
1245        host->hcfg |= SDHCFG_WIDE_INT_BUS;
1246
1247        /* Disable clever clock switching, to cope with fast core clocks */
1248        host->hcfg |= SDHCFG_SLOW_CARD;
1249
1250        writel(host->hcfg, host->ioaddr + SDHCFG);
1251
1252        mutex_unlock(&host->mutex);
1253}
1254
1255static const struct mmc_host_ops bcm2835_ops = {
1256        .request = bcm2835_request,
1257        .set_ios = bcm2835_set_ios,
1258        .hw_reset = bcm2835_reset,
1259};
1260
1261static int bcm2835_add_host(struct bcm2835_host *host)
1262{
1263        struct mmc_host *mmc = host->mmc;
1264        struct device *dev = &host->pdev->dev;
1265        char pio_limit_string[20];
1266        int ret;
1267
1268        mmc->f_max = host->max_clk;
1269        mmc->f_min = host->max_clk / SDCDIV_MAX_CDIV;
1270
1271        mmc->max_busy_timeout = ~0 / (mmc->f_max / 1000);
1272
1273        dev_dbg(dev, "f_max %d, f_min %d, max_busy_timeout %d\n",
1274                mmc->f_max, mmc->f_min, mmc->max_busy_timeout);
1275
1276        /* host controller capabilities */
1277        mmc->caps |= MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED |
1278                     MMC_CAP_NEEDS_POLL | MMC_CAP_HW_RESET | MMC_CAP_ERASE |
1279                     MMC_CAP_CMD23;
1280
1281        spin_lock_init(&host->lock);
1282        mutex_init(&host->mutex);
1283
1284        if (IS_ERR_OR_NULL(host->dma_chan_rxtx)) {
1285                dev_warn(dev, "unable to initialise DMA channel. Falling back to PIO\n");
1286                host->use_dma = false;
1287        } else {
1288                host->use_dma = true;
1289
1290                host->dma_cfg_tx.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1291                host->dma_cfg_tx.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1292                host->dma_cfg_tx.slave_id = 13;         /* DREQ channel */
1293                host->dma_cfg_tx.direction = DMA_MEM_TO_DEV;
1294                host->dma_cfg_tx.src_addr = 0;
1295                host->dma_cfg_tx.dst_addr = host->phys_addr + SDDATA;
1296
1297                host->dma_cfg_rx.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1298                host->dma_cfg_rx.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1299                host->dma_cfg_rx.slave_id = 13;         /* DREQ channel */
1300                host->dma_cfg_rx.direction = DMA_DEV_TO_MEM;
1301                host->dma_cfg_rx.src_addr = host->phys_addr + SDDATA;
1302                host->dma_cfg_rx.dst_addr = 0;
1303
1304                if (dmaengine_slave_config(host->dma_chan_rxtx,
1305                                           &host->dma_cfg_tx) != 0 ||
1306                    dmaengine_slave_config(host->dma_chan_rxtx,
1307                                           &host->dma_cfg_rx) != 0)
1308                        host->use_dma = false;
1309        }
1310
1311        mmc->max_segs = 128;
1312        mmc->max_req_size = 524288;
1313        mmc->max_seg_size = mmc->max_req_size;
1314        mmc->max_blk_size = 1024;
1315        mmc->max_blk_count =  65535;
1316
1317        /* report supported voltage ranges */
1318        mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
1319
1320        INIT_WORK(&host->dma_work, bcm2835_dma_complete_work);
1321        INIT_DELAYED_WORK(&host->timeout_work, bcm2835_timeout);
1322
1323        /* Set interrupt enables */
1324        host->hcfg = SDHCFG_BUSY_IRPT_EN;
1325
1326        bcm2835_reset_internal(host);
1327
1328        ret = request_threaded_irq(host->irq, bcm2835_irq,
1329                                   bcm2835_threaded_irq,
1330                                   0, mmc_hostname(mmc), host);
1331        if (ret) {
1332                dev_err(dev, "failed to request IRQ %d: %d\n", host->irq, ret);
1333                return ret;
1334        }
1335
1336        ret = mmc_add_host(mmc);
1337        if (ret) {
1338                free_irq(host->irq, host);
1339                return ret;
1340        }
1341
1342        pio_limit_string[0] = '\0';
1343        if (host->use_dma && (PIO_THRESHOLD > 0))
1344                sprintf(pio_limit_string, " (>%d)", PIO_THRESHOLD);
1345        dev_info(dev, "loaded - DMA %s%s\n",
1346                 host->use_dma ? "enabled" : "disabled", pio_limit_string);
1347
1348        return 0;
1349}
1350
1351static int bcm2835_probe(struct platform_device *pdev)
1352{
1353        struct device *dev = &pdev->dev;
1354        struct clk *clk;
1355        struct resource *iomem;
1356        struct bcm2835_host *host;
1357        struct mmc_host *mmc;
1358        const __be32 *regaddr_p;
1359        int ret;
1360
1361        dev_dbg(dev, "%s\n", __func__);
1362        mmc = mmc_alloc_host(sizeof(*host), dev);
1363        if (!mmc)
1364                return -ENOMEM;
1365
1366        mmc->ops = &bcm2835_ops;
1367        host = mmc_priv(mmc);
1368        host->mmc = mmc;
1369        host->pdev = pdev;
1370        spin_lock_init(&host->lock);
1371
1372        iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1373        host->ioaddr = devm_ioremap_resource(dev, iomem);
1374        if (IS_ERR(host->ioaddr)) {
1375                ret = PTR_ERR(host->ioaddr);
1376                goto err;
1377        }
1378
1379        /* Parse OF address directly to get the physical address for
1380         * DMA to our registers.
1381         */
1382        regaddr_p = of_get_address(pdev->dev.of_node, 0, NULL, NULL);
1383        if (!regaddr_p) {
1384                dev_err(dev, "Can't get phys address\n");
1385                ret = -EINVAL;
1386                goto err;
1387        }
1388
1389        host->phys_addr = be32_to_cpup(regaddr_p);
1390
1391        host->dma_chan = NULL;
1392        host->dma_desc = NULL;
1393
1394        host->dma_chan_rxtx = dma_request_slave_channel(dev, "rx-tx");
1395
1396        clk = devm_clk_get(dev, NULL);
1397        if (IS_ERR(clk)) {
1398                ret = PTR_ERR(clk);
1399                if (ret != -EPROBE_DEFER)
1400                        dev_err(dev, "could not get clk: %d\n", ret);
1401                goto err;
1402        }
1403
1404        host->max_clk = clk_get_rate(clk);
1405
1406        host->irq = platform_get_irq(pdev, 0);
1407        if (host->irq <= 0) {
1408                dev_err(dev, "get IRQ failed\n");
1409                ret = -EINVAL;
1410                goto err;
1411        }
1412
1413        ret = mmc_of_parse(mmc);
1414        if (ret)
1415                goto err;
1416
1417        ret = bcm2835_add_host(host);
1418        if (ret)
1419                goto err;
1420
1421        platform_set_drvdata(pdev, host);
1422
1423        dev_dbg(dev, "%s -> OK\n", __func__);
1424
1425        return 0;
1426
1427err:
1428        dev_dbg(dev, "%s -> err %d\n", __func__, ret);
1429        mmc_free_host(mmc);
1430
1431        return ret;
1432}
1433
1434static int bcm2835_remove(struct platform_device *pdev)
1435{
1436        struct bcm2835_host *host = platform_get_drvdata(pdev);
1437
1438        mmc_remove_host(host->mmc);
1439
1440        writel(SDVDD_POWER_OFF, host->ioaddr + SDVDD);
1441
1442        free_irq(host->irq, host);
1443
1444        cancel_work_sync(&host->dma_work);
1445        cancel_delayed_work_sync(&host->timeout_work);
1446
1447        mmc_free_host(host->mmc);
1448        platform_set_drvdata(pdev, NULL);
1449
1450        return 0;
1451}
1452
1453static const struct of_device_id bcm2835_match[] = {
1454        { .compatible = "brcm,bcm2835-sdhost" },
1455        { }
1456};
1457MODULE_DEVICE_TABLE(of, bcm2835_match);
1458
1459static struct platform_driver bcm2835_driver = {
1460        .probe      = bcm2835_probe,
1461        .remove     = bcm2835_remove,
1462        .driver     = {
1463                .name           = "sdhost-bcm2835",
1464                .of_match_table = bcm2835_match,
1465        },
1466};
1467module_platform_driver(bcm2835_driver);
1468
1469MODULE_ALIAS("platform:sdhost-bcm2835");
1470MODULE_DESCRIPTION("BCM2835 SDHost driver");
1471MODULE_LICENSE("GPL v2");
1472MODULE_AUTHOR("Phil Elwell");
1473