linux/drivers/mmc/host/imxmmc.c
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   1/*
   2 *  linux/drivers/mmc/host/imxmmc.c - Motorola i.MX MMCI driver
   3 *
   4 *  Copyright (C) 2004 Sascha Hauer, Pengutronix <sascha@saschahauer.de>
   5 *  Copyright (C) 2006 Pavel Pisa, PiKRON <ppisa@pikron.com>
   6 *
   7 *  derived from pxamci.c by Russell King
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License version 2 as
  11 * published by the Free Software Foundation.
  12 *
  13 */
  14
  15#include <linux/module.h>
  16#include <linux/init.h>
  17#include <linux/ioport.h>
  18#include <linux/platform_device.h>
  19#include <linux/interrupt.h>
  20#include <linux/blkdev.h>
  21#include <linux/dma-mapping.h>
  22#include <linux/mmc/host.h>
  23#include <linux/mmc/card.h>
  24#include <linux/delay.h>
  25#include <linux/clk.h>
  26#include <linux/io.h>
  27
  28#include <asm/dma.h>
  29#include <asm/irq.h>
  30#include <asm/sizes.h>
  31#include <mach/mmc.h>
  32#include <mach/imx-dma.h>
  33
  34#include "imxmmc.h"
  35
  36#define DRIVER_NAME "imx-mmc"
  37
  38#define IMXMCI_INT_MASK_DEFAULT (INT_MASK_BUF_READY | INT_MASK_DATA_TRAN | \
  39                                 INT_MASK_WRITE_OP_DONE | INT_MASK_END_CMD_RES | \
  40                                 INT_MASK_AUTO_CARD_DETECT | INT_MASK_DAT0_EN | INT_MASK_SDIO)
  41
  42struct imxmci_host {
  43        struct mmc_host         *mmc;
  44        spinlock_t              lock;
  45        struct resource         *res;
  46        void __iomem            *base;
  47        int                     irq;
  48        imx_dmach_t             dma;
  49        volatile unsigned int   imask;
  50        unsigned int            power_mode;
  51        unsigned int            present;
  52        struct imxmmc_platform_data *pdata;
  53
  54        struct mmc_request      *req;
  55        struct mmc_command      *cmd;
  56        struct mmc_data         *data;
  57
  58        struct timer_list       timer;
  59        struct tasklet_struct   tasklet;
  60        unsigned int            status_reg;
  61        unsigned long           pending_events;
  62        /* Next two fields are there for CPU driven transfers to overcome SDHC deficiencies */
  63        u16                     *data_ptr;
  64        unsigned int            data_cnt;
  65        atomic_t                stuck_timeout;
  66
  67        unsigned int            dma_nents;
  68        unsigned int            dma_size;
  69        unsigned int            dma_dir;
  70        int                     dma_allocated;
  71
  72        unsigned char           actual_bus_width;
  73
  74        int                     prev_cmd_code;
  75
  76        struct clk              *clk;
  77};
  78
  79#define IMXMCI_PEND_IRQ_b       0
  80#define IMXMCI_PEND_DMA_END_b   1
  81#define IMXMCI_PEND_DMA_ERR_b   2
  82#define IMXMCI_PEND_WAIT_RESP_b 3
  83#define IMXMCI_PEND_DMA_DATA_b  4
  84#define IMXMCI_PEND_CPU_DATA_b  5
  85#define IMXMCI_PEND_CARD_XCHG_b 6
  86#define IMXMCI_PEND_SET_INIT_b  7
  87#define IMXMCI_PEND_STARTED_b   8
  88
  89#define IMXMCI_PEND_IRQ_m       (1 << IMXMCI_PEND_IRQ_b)
  90#define IMXMCI_PEND_DMA_END_m   (1 << IMXMCI_PEND_DMA_END_b)
  91#define IMXMCI_PEND_DMA_ERR_m   (1 << IMXMCI_PEND_DMA_ERR_b)
  92#define IMXMCI_PEND_WAIT_RESP_m (1 << IMXMCI_PEND_WAIT_RESP_b)
  93#define IMXMCI_PEND_DMA_DATA_m  (1 << IMXMCI_PEND_DMA_DATA_b)
  94#define IMXMCI_PEND_CPU_DATA_m  (1 << IMXMCI_PEND_CPU_DATA_b)
  95#define IMXMCI_PEND_CARD_XCHG_m (1 << IMXMCI_PEND_CARD_XCHG_b)
  96#define IMXMCI_PEND_SET_INIT_m  (1 << IMXMCI_PEND_SET_INIT_b)
  97#define IMXMCI_PEND_STARTED_m   (1 << IMXMCI_PEND_STARTED_b)
  98
  99static void imxmci_stop_clock(struct imxmci_host *host)
 100{
 101        int i = 0;
 102        u16 reg;
 103
 104        reg = readw(host->base + MMC_REG_STR_STP_CLK);
 105        writew(reg & ~STR_STP_CLK_START_CLK, host->base + MMC_REG_STR_STP_CLK);
 106        while (i < 0x1000) {
 107                if (!(i & 0x7f)) {
 108                        reg = readw(host->base + MMC_REG_STR_STP_CLK);
 109                        writew(reg | STR_STP_CLK_STOP_CLK,
 110                                        host->base + MMC_REG_STR_STP_CLK);
 111                }
 112
 113                reg = readw(host->base + MMC_REG_STATUS);
 114                if (!(reg & STATUS_CARD_BUS_CLK_RUN)) {
 115                        /* Check twice before cut */
 116                        reg = readw(host->base + MMC_REG_STATUS);
 117                        if (!(reg & STATUS_CARD_BUS_CLK_RUN))
 118                                return;
 119                }
 120
 121                i++;
 122        }
 123        dev_dbg(mmc_dev(host->mmc), "imxmci_stop_clock blocked, no luck\n");
 124}
 125
 126static int imxmci_start_clock(struct imxmci_host *host)
 127{
 128        unsigned int trials = 0;
 129        unsigned int delay_limit = 128;
 130        unsigned long flags;
 131        u16 reg;
 132
 133        reg = readw(host->base + MMC_REG_STR_STP_CLK);
 134        writew(reg & ~STR_STP_CLK_STOP_CLK, host->base + MMC_REG_STR_STP_CLK);
 135
 136        clear_bit(IMXMCI_PEND_STARTED_b, &host->pending_events);
 137
 138        /*
 139         * Command start of the clock, this usually succeeds in less
 140         * then 6 delay loops, but during card detection (low clockrate)
 141         * it takes up to 5000 delay loops and sometimes fails for the first time
 142         */
 143        reg = readw(host->base + MMC_REG_STR_STP_CLK);
 144        writew(reg | STR_STP_CLK_START_CLK, host->base + MMC_REG_STR_STP_CLK);
 145
 146        do {
 147                unsigned int delay = delay_limit;
 148
 149                while (delay--) {
 150                        reg = readw(host->base + MMC_REG_STATUS);
 151                        if (reg & STATUS_CARD_BUS_CLK_RUN) {
 152                                /* Check twice before cut */
 153                                reg = readw(host->base + MMC_REG_STATUS);
 154                                if (reg & STATUS_CARD_BUS_CLK_RUN)
 155                                        return 0;
 156                        }
 157
 158                        if (test_bit(IMXMCI_PEND_STARTED_b, &host->pending_events))
 159                                return 0;
 160                }
 161
 162                local_irq_save(flags);
 163                /*
 164                 * Ensure, that request is not doubled under all possible circumstances.
 165                 * It is possible, that cock running state is missed, because some other
 166                 * IRQ or schedule delays this function execution and the clocks has
 167                 * been already stopped by other means (response processing, SDHC HW)
 168                 */
 169                if (!test_bit(IMXMCI_PEND_STARTED_b, &host->pending_events)) {
 170                        reg = readw(host->base + MMC_REG_STR_STP_CLK);
 171                        writew(reg | STR_STP_CLK_START_CLK,
 172                                        host->base + MMC_REG_STR_STP_CLK);
 173                }
 174                local_irq_restore(flags);
 175
 176        } while (++trials < 256);
 177
 178        dev_err(mmc_dev(host->mmc), "imxmci_start_clock blocked, no luck\n");
 179
 180        return -1;
 181}
 182
 183static void imxmci_softreset(struct imxmci_host *host)
 184{
 185        int i;
 186
 187        /* reset sequence */
 188        writew(0x08, host->base + MMC_REG_STR_STP_CLK);
 189        writew(0x0D, host->base + MMC_REG_STR_STP_CLK);
 190
 191        for (i = 0; i < 8; i++)
 192                writew(0x05, host->base + MMC_REG_STR_STP_CLK);
 193
 194        writew(0xff, host->base + MMC_REG_RES_TO);
 195        writew(512, host->base + MMC_REG_BLK_LEN);
 196        writew(1, host->base + MMC_REG_NOB);
 197}
 198
 199static int imxmci_busy_wait_for_status(struct imxmci_host *host,
 200                                       unsigned int *pstat, unsigned int stat_mask,
 201                                       int timeout, const char *where)
 202{
 203        int loops = 0;
 204
 205        while (!(*pstat & stat_mask)) {
 206                loops += 2;
 207                if (loops >= timeout) {
 208                        dev_dbg(mmc_dev(host->mmc), "busy wait timeout in %s, STATUS = 0x%x (0x%x)\n",
 209                                where, *pstat, stat_mask);
 210                        return -1;
 211                }
 212                udelay(2);
 213                *pstat |= readw(host->base + MMC_REG_STATUS);
 214        }
 215        if (!loops)
 216                return 0;
 217
 218        /* The busy-wait is expected there for clock <8MHz due to SDHC hardware flaws */
 219        if (!(stat_mask & STATUS_END_CMD_RESP) || (host->mmc->ios.clock >= 8000000))
 220                dev_info(mmc_dev(host->mmc), "busy wait for %d usec in %s, STATUS = 0x%x (0x%x)\n",
 221                         loops, where, *pstat, stat_mask);
 222        return loops;
 223}
 224
 225static void imxmci_setup_data(struct imxmci_host *host, struct mmc_data *data)
 226{
 227        unsigned int nob = data->blocks;
 228        unsigned int blksz = data->blksz;
 229        unsigned int datasz = nob * blksz;
 230        int i;
 231
 232        if (data->flags & MMC_DATA_STREAM)
 233                nob = 0xffff;
 234
 235        host->data = data;
 236        data->bytes_xfered = 0;
 237
 238        writew(nob, host->base + MMC_REG_NOB);
 239        writew(blksz, host->base + MMC_REG_BLK_LEN);
 240
 241        /*
 242         * DMA cannot be used for small block sizes, we have to use CPU driven transfers otherwise.
 243         * We are in big troubles for non-512 byte transfers according to note in the paragraph
 244         * 20.6.7 of User Manual anyway, but we need to be able to transfer SCR at least.
 245         * The situation is even more complex in reality. The SDHC in not able to handle wll
 246         * partial FIFO fills and reads. The length has to be rounded up to burst size multiple.
 247         * This is required for SCR read at least.
 248         */
 249        if (datasz < 512) {
 250                host->dma_size = datasz;
 251                if (data->flags & MMC_DATA_READ) {
 252                        host->dma_dir = DMA_FROM_DEVICE;
 253
 254                        /* Hack to enable read SCR */
 255                        writew(1, host->base + MMC_REG_NOB);
 256                        writew(512, host->base + MMC_REG_BLK_LEN);
 257                } else {
 258                        host->dma_dir = DMA_TO_DEVICE;
 259                }
 260
 261                /* Convert back to virtual address */
 262                host->data_ptr = (u16 *)sg_virt(data->sg);
 263                host->data_cnt = 0;
 264
 265                clear_bit(IMXMCI_PEND_DMA_DATA_b, &host->pending_events);
 266                set_bit(IMXMCI_PEND_CPU_DATA_b, &host->pending_events);
 267
 268                return;
 269        }
 270
 271        if (data->flags & MMC_DATA_READ) {
 272                host->dma_dir = DMA_FROM_DEVICE;
 273                host->dma_nents = dma_map_sg(mmc_dev(host->mmc), data->sg,
 274                                             data->sg_len,  host->dma_dir);
 275
 276                imx_dma_setup_sg(host->dma, data->sg, data->sg_len, datasz,
 277                                 host->res->start + MMC_REG_BUFFER_ACCESS,
 278                                 DMA_MODE_READ);
 279
 280                /*imx_dma_setup_mem2dev_ccr(host->dma, DMA_MODE_READ, IMX_DMA_WIDTH_16, CCR_REN);*/
 281                CCR(host->dma) = CCR_DMOD_LINEAR | CCR_DSIZ_32 | CCR_SMOD_FIFO | CCR_SSIZ_16 | CCR_REN;
 282        } else {
 283                host->dma_dir = DMA_TO_DEVICE;
 284
 285                host->dma_nents = dma_map_sg(mmc_dev(host->mmc), data->sg,
 286                                             data->sg_len,  host->dma_dir);
 287
 288                imx_dma_setup_sg(host->dma, data->sg, data->sg_len, datasz,
 289                                 host->res->start + MMC_REG_BUFFER_ACCESS,
 290                                 DMA_MODE_WRITE);
 291
 292                /*imx_dma_setup_mem2dev_ccr(host->dma, DMA_MODE_WRITE, IMX_DMA_WIDTH_16, CCR_REN);*/
 293                CCR(host->dma) = CCR_SMOD_LINEAR | CCR_SSIZ_32 | CCR_DMOD_FIFO | CCR_DSIZ_16 | CCR_REN;
 294        }
 295
 296#if 1   /* This code is there only for consistency checking and can be disabled in future */
 297        host->dma_size = 0;
 298        for (i = 0; i < host->dma_nents; i++)
 299                host->dma_size += data->sg[i].length;
 300
 301        if (datasz > host->dma_size) {
 302                dev_err(mmc_dev(host->mmc), "imxmci_setup_data datasz 0x%x > 0x%x dm_size\n",
 303                        datasz, host->dma_size);
 304        }
 305#endif
 306
 307        host->dma_size = datasz;
 308
 309        wmb();
 310
 311        set_bit(IMXMCI_PEND_DMA_DATA_b, &host->pending_events);
 312        clear_bit(IMXMCI_PEND_CPU_DATA_b, &host->pending_events);
 313
 314        /* start DMA engine for read, write is delayed after initial response */
 315        if (host->dma_dir == DMA_FROM_DEVICE)
 316                imx_dma_enable(host->dma);
 317}
 318
 319static void imxmci_start_cmd(struct imxmci_host *host, struct mmc_command *cmd, unsigned int cmdat)
 320{
 321        unsigned long flags;
 322        u32 imask;
 323
 324        WARN_ON(host->cmd != NULL);
 325        host->cmd = cmd;
 326
 327        /* Ensure, that clock are stopped else command programming and start fails */
 328        imxmci_stop_clock(host);
 329
 330        if (cmd->flags & MMC_RSP_BUSY)
 331                cmdat |= CMD_DAT_CONT_BUSY;
 332
 333        switch (mmc_resp_type(cmd)) {
 334        case MMC_RSP_R1: /* short CRC, OPCODE */
 335        case MMC_RSP_R1B:/* short CRC, OPCODE, BUSY */
 336                cmdat |= CMD_DAT_CONT_RESPONSE_FORMAT_R1;
 337                break;
 338        case MMC_RSP_R2: /* long 136 bit + CRC */
 339                cmdat |= CMD_DAT_CONT_RESPONSE_FORMAT_R2;
 340                break;
 341        case MMC_RSP_R3: /* short */
 342                cmdat |= CMD_DAT_CONT_RESPONSE_FORMAT_R3;
 343                break;
 344        default:
 345                break;
 346        }
 347
 348        if (test_and_clear_bit(IMXMCI_PEND_SET_INIT_b, &host->pending_events))
 349                cmdat |= CMD_DAT_CONT_INIT; /* This command needs init */
 350
 351        if (host->actual_bus_width == MMC_BUS_WIDTH_4)
 352                cmdat |= CMD_DAT_CONT_BUS_WIDTH_4;
 353
 354        writew(cmd->opcode, host->base + MMC_REG_CMD);
 355        writew(cmd->arg >> 16, host->base + MMC_REG_ARGH);
 356        writew(cmd->arg & 0xffff, host->base + MMC_REG_ARGL);
 357        writew(cmdat, host->base + MMC_REG_CMD_DAT_CONT);
 358
 359        atomic_set(&host->stuck_timeout, 0);
 360        set_bit(IMXMCI_PEND_WAIT_RESP_b, &host->pending_events);
 361
 362
 363        imask = IMXMCI_INT_MASK_DEFAULT;
 364        imask &= ~INT_MASK_END_CMD_RES;
 365        if (cmdat & CMD_DAT_CONT_DATA_ENABLE) {
 366                /* imask &= ~INT_MASK_BUF_READY; */
 367                imask &= ~INT_MASK_DATA_TRAN;
 368                if (cmdat & CMD_DAT_CONT_WRITE)
 369                        imask &= ~INT_MASK_WRITE_OP_DONE;
 370                if (test_bit(IMXMCI_PEND_CPU_DATA_b, &host->pending_events))
 371                        imask &= ~INT_MASK_BUF_READY;
 372        }
 373
 374        spin_lock_irqsave(&host->lock, flags);
 375        host->imask = imask;
 376        writew(host->imask, host->base + MMC_REG_INT_MASK);
 377        spin_unlock_irqrestore(&host->lock, flags);
 378
 379        dev_dbg(mmc_dev(host->mmc), "CMD%02d (0x%02x) mask set to 0x%04x\n",
 380                cmd->opcode, cmd->opcode, imask);
 381
 382        imxmci_start_clock(host);
 383}
 384
 385static void imxmci_finish_request(struct imxmci_host *host, struct mmc_request *req)
 386{
 387        unsigned long flags;
 388
 389        spin_lock_irqsave(&host->lock, flags);
 390
 391        host->pending_events &= ~(IMXMCI_PEND_WAIT_RESP_m | IMXMCI_PEND_DMA_END_m |
 392                                  IMXMCI_PEND_DMA_DATA_m | IMXMCI_PEND_CPU_DATA_m);
 393
 394        host->imask = IMXMCI_INT_MASK_DEFAULT;
 395        writew(host->imask, host->base + MMC_REG_INT_MASK);
 396
 397        spin_unlock_irqrestore(&host->lock, flags);
 398
 399        if (req && req->cmd)
 400                host->prev_cmd_code = req->cmd->opcode;
 401
 402        host->req = NULL;
 403        host->cmd = NULL;
 404        host->data = NULL;
 405        mmc_request_done(host->mmc, req);
 406}
 407
 408static int imxmci_finish_data(struct imxmci_host *host, unsigned int stat)
 409{
 410        struct mmc_data *data = host->data;
 411        int data_error;
 412
 413        if (test_and_clear_bit(IMXMCI_PEND_DMA_DATA_b, &host->pending_events)) {
 414                imx_dma_disable(host->dma);
 415                dma_unmap_sg(mmc_dev(host->mmc), data->sg, host->dma_nents,
 416                             host->dma_dir);
 417        }
 418
 419        if (stat & STATUS_ERR_MASK) {
 420                dev_dbg(mmc_dev(host->mmc), "request failed. status: 0x%08x\n", stat);
 421                if (stat & (STATUS_CRC_READ_ERR | STATUS_CRC_WRITE_ERR))
 422                        data->error = -EILSEQ;
 423                else if (stat & STATUS_TIME_OUT_READ)
 424                        data->error = -ETIMEDOUT;
 425                else
 426                        data->error = -EIO;
 427        } else {
 428                data->bytes_xfered = host->dma_size;
 429        }
 430
 431        data_error = data->error;
 432
 433        host->data = NULL;
 434
 435        return data_error;
 436}
 437
 438static int imxmci_cmd_done(struct imxmci_host *host, unsigned int stat)
 439{
 440        struct mmc_command *cmd = host->cmd;
 441        int i;
 442        u32 a, b, c;
 443        struct mmc_data *data = host->data;
 444
 445        if (!cmd)
 446                return 0;
 447
 448        host->cmd = NULL;
 449
 450        if (stat & STATUS_TIME_OUT_RESP) {
 451                dev_dbg(mmc_dev(host->mmc), "CMD TIMEOUT\n");
 452                cmd->error = -ETIMEDOUT;
 453        } else if (stat & STATUS_RESP_CRC_ERR && cmd->flags & MMC_RSP_CRC) {
 454                dev_dbg(mmc_dev(host->mmc), "cmd crc error\n");
 455                cmd->error = -EILSEQ;
 456        }
 457
 458        if (cmd->flags & MMC_RSP_PRESENT) {
 459                if (cmd->flags & MMC_RSP_136) {
 460                        for (i = 0; i < 4; i++) {
 461                                a = readw(host->base + MMC_REG_RES_FIFO);
 462                                b = readw(host->base + MMC_REG_RES_FIFO);
 463                                cmd->resp[i] = a << 16 | b;
 464                        }
 465                } else {
 466                        a = readw(host->base + MMC_REG_RES_FIFO);
 467                        b = readw(host->base + MMC_REG_RES_FIFO);
 468                        c = readw(host->base + MMC_REG_RES_FIFO);
 469                        cmd->resp[0] = a << 24 | b << 8 | c >> 8;
 470                }
 471        }
 472
 473        dev_dbg(mmc_dev(host->mmc), "RESP 0x%08x, 0x%08x, 0x%08x, 0x%08x, error %d\n",
 474                cmd->resp[0], cmd->resp[1], cmd->resp[2], cmd->resp[3], cmd->error);
 475
 476        if (data && !cmd->error && !(stat & STATUS_ERR_MASK)) {
 477                if (host->req->data->flags & MMC_DATA_WRITE) {
 478
 479                        /* Wait for FIFO to be empty before starting DMA write */
 480
 481                        stat = readw(host->base + MMC_REG_STATUS);
 482                        if (imxmci_busy_wait_for_status(host, &stat,
 483                                                        STATUS_APPL_BUFF_FE,
 484                                                        40, "imxmci_cmd_done DMA WR") < 0) {
 485                                cmd->error = -EIO;
 486                                imxmci_finish_data(host, stat);
 487                                if (host->req)
 488                                        imxmci_finish_request(host, host->req);
 489                                dev_warn(mmc_dev(host->mmc), "STATUS = 0x%04x\n",
 490                                         stat);
 491                                return 0;
 492                        }
 493
 494                        if (test_bit(IMXMCI_PEND_DMA_DATA_b, &host->pending_events))
 495                                imx_dma_enable(host->dma);
 496                }
 497        } else {
 498                struct mmc_request *req;
 499                imxmci_stop_clock(host);
 500                req = host->req;
 501
 502                if (data)
 503                        imxmci_finish_data(host, stat);
 504
 505                if (req)
 506                        imxmci_finish_request(host, req);
 507                else
 508                        dev_warn(mmc_dev(host->mmc), "imxmci_cmd_done: no request to finish\n");
 509        }
 510
 511        return 1;
 512}
 513
 514static int imxmci_data_done(struct imxmci_host *host, unsigned int stat)
 515{
 516        struct mmc_data *data = host->data;
 517        int data_error;
 518
 519        if (!data)
 520                return 0;
 521
 522        data_error = imxmci_finish_data(host, stat);
 523
 524        if (host->req->stop) {
 525                imxmci_stop_clock(host);
 526                imxmci_start_cmd(host, host->req->stop, 0);
 527        } else {
 528                struct mmc_request *req;
 529                req = host->req;
 530                if (req)
 531                        imxmci_finish_request(host, req);
 532                else
 533                        dev_warn(mmc_dev(host->mmc), "imxmci_data_done: no request to finish\n");
 534        }
 535
 536        return 1;
 537}
 538
 539static int imxmci_cpu_driven_data(struct imxmci_host *host, unsigned int *pstat)
 540{
 541        int i;
 542        int burst_len;
 543        int trans_done = 0;
 544        unsigned int stat = *pstat;
 545
 546        if (host->actual_bus_width != MMC_BUS_WIDTH_4)
 547                burst_len = 16;
 548        else
 549                burst_len = 64;
 550
 551        /* This is unfortunately required */
 552        dev_dbg(mmc_dev(host->mmc), "imxmci_cpu_driven_data running STATUS = 0x%x\n",
 553                stat);
 554
 555        udelay(20);     /* required for clocks < 8MHz*/
 556
 557        if (host->dma_dir == DMA_FROM_DEVICE) {
 558                imxmci_busy_wait_for_status(host, &stat,
 559                                            STATUS_APPL_BUFF_FF | STATUS_DATA_TRANS_DONE |
 560                                            STATUS_TIME_OUT_READ,
 561                                            50, "imxmci_cpu_driven_data read");
 562
 563                while ((stat & (STATUS_APPL_BUFF_FF | STATUS_DATA_TRANS_DONE)) &&
 564                       !(stat & STATUS_TIME_OUT_READ) &&
 565                       (host->data_cnt < 512)) {
 566
 567                        udelay(20);     /* required for clocks < 8MHz*/
 568
 569                        for (i = burst_len; i >= 2 ; i -= 2) {
 570                                u16 data;
 571                                data = readw(host->base + MMC_REG_BUFFER_ACCESS);
 572                                udelay(10);     /* required for clocks < 8MHz*/
 573                                if (host->data_cnt+2 <= host->dma_size) {
 574                                        *(host->data_ptr++) = data;
 575                                } else {
 576                                        if (host->data_cnt < host->dma_size)
 577                                                *(u8 *)(host->data_ptr) = data;
 578                                }
 579                                host->data_cnt += 2;
 580                        }
 581
 582                        stat = readw(host->base + MMC_REG_STATUS);
 583
 584                        dev_dbg(mmc_dev(host->mmc), "imxmci_cpu_driven_data read %d burst %d STATUS = 0x%x\n",
 585                                host->data_cnt, burst_len, stat);
 586                }
 587
 588                if ((stat & STATUS_DATA_TRANS_DONE) && (host->data_cnt >= 512))
 589                        trans_done = 1;
 590
 591                if (host->dma_size & 0x1ff)
 592                        stat &= ~STATUS_CRC_READ_ERR;
 593
 594                if (stat & STATUS_TIME_OUT_READ) {
 595                        dev_dbg(mmc_dev(host->mmc), "imxmci_cpu_driven_data read timeout STATUS = 0x%x\n",
 596                                stat);
 597                        trans_done = -1;
 598                }
 599
 600        } else {
 601                imxmci_busy_wait_for_status(host, &stat,
 602                                            STATUS_APPL_BUFF_FE,
 603                                            20, "imxmci_cpu_driven_data write");
 604
 605                while ((stat & STATUS_APPL_BUFF_FE) &&
 606                       (host->data_cnt < host->dma_size)) {
 607                        if (burst_len >= host->dma_size - host->data_cnt) {
 608                                burst_len = host->dma_size - host->data_cnt;
 609                                host->data_cnt = host->dma_size;
 610                                trans_done = 1;
 611                        } else {
 612                                host->data_cnt += burst_len;
 613                        }
 614
 615                        for (i = burst_len; i > 0 ; i -= 2)
 616                                writew(*(host->data_ptr++), host->base + MMC_REG_BUFFER_ACCESS);
 617
 618                        stat = readw(host->base + MMC_REG_STATUS);
 619
 620                        dev_dbg(mmc_dev(host->mmc), "imxmci_cpu_driven_data write burst %d STATUS = 0x%x\n",
 621                                burst_len, stat);
 622                }
 623        }
 624
 625        *pstat = stat;
 626
 627        return trans_done;
 628}
 629
 630static void imxmci_dma_irq(int dma, void *devid)
 631{
 632        struct imxmci_host *host = devid;
 633        u32 stat = readw(host->base + MMC_REG_STATUS);
 634
 635        atomic_set(&host->stuck_timeout, 0);
 636        host->status_reg = stat;
 637        set_bit(IMXMCI_PEND_DMA_END_b, &host->pending_events);
 638        tasklet_schedule(&host->tasklet);
 639}
 640
 641static irqreturn_t imxmci_irq(int irq, void *devid)
 642{
 643        struct imxmci_host *host = devid;
 644        u32 stat = readw(host->base + MMC_REG_STATUS);
 645        int handled = 1;
 646
 647        writew(host->imask | INT_MASK_SDIO | INT_MASK_AUTO_CARD_DETECT,
 648                        host->base + MMC_REG_INT_MASK);
 649
 650        atomic_set(&host->stuck_timeout, 0);
 651        host->status_reg = stat;
 652        set_bit(IMXMCI_PEND_IRQ_b, &host->pending_events);
 653        set_bit(IMXMCI_PEND_STARTED_b, &host->pending_events);
 654        tasklet_schedule(&host->tasklet);
 655
 656        return IRQ_RETVAL(handled);
 657}
 658
 659static void imxmci_tasklet_fnc(unsigned long data)
 660{
 661        struct imxmci_host *host = (struct imxmci_host *)data;
 662        u32 stat;
 663        unsigned int data_dir_mask = 0; /* STATUS_WR_CRC_ERROR_CODE_MASK */
 664        int timeout = 0;
 665
 666        if (atomic_read(&host->stuck_timeout) > 4) {
 667                char *what;
 668                timeout = 1;
 669                stat = readw(host->base + MMC_REG_STATUS);
 670                host->status_reg = stat;
 671                if (test_bit(IMXMCI_PEND_WAIT_RESP_b, &host->pending_events))
 672                        if (test_bit(IMXMCI_PEND_DMA_DATA_b, &host->pending_events))
 673                                what = "RESP+DMA";
 674                        else
 675                                what = "RESP";
 676                else
 677                        if (test_bit(IMXMCI_PEND_DMA_DATA_b, &host->pending_events))
 678                                if (test_bit(IMXMCI_PEND_DMA_END_b, &host->pending_events))
 679                                        what = "DATA";
 680                                else
 681                                        what = "DMA";
 682                        else
 683                                what = "???";
 684
 685                dev_err(mmc_dev(host->mmc),
 686                        "%s TIMEOUT, hardware stucked STATUS = 0x%04x IMASK = 0x%04x\n",
 687                        what, stat,
 688                        readw(host->base + MMC_REG_INT_MASK));
 689                dev_err(mmc_dev(host->mmc),
 690                        "CMD_DAT_CONT = 0x%04x, MMC_BLK_LEN = 0x%04x, MMC_NOB = 0x%04x, DMA_CCR = 0x%08x\n",
 691                        readw(host->base + MMC_REG_CMD_DAT_CONT),
 692                        readw(host->base + MMC_REG_BLK_LEN),
 693                        readw(host->base + MMC_REG_NOB),
 694                        CCR(host->dma));
 695                dev_err(mmc_dev(host->mmc), "CMD%d, prevCMD%d, bus %d-bit, dma_size = 0x%x\n",
 696                        host->cmd ? host->cmd->opcode : 0,
 697                        host->prev_cmd_code,
 698                        1 << host->actual_bus_width, host->dma_size);
 699        }
 700
 701        if (!host->present || timeout)
 702                host->status_reg = STATUS_TIME_OUT_RESP | STATUS_TIME_OUT_READ |
 703                        STATUS_CRC_READ_ERR | STATUS_CRC_WRITE_ERR;
 704
 705        if (test_bit(IMXMCI_PEND_IRQ_b, &host->pending_events) || timeout) {
 706                clear_bit(IMXMCI_PEND_IRQ_b, &host->pending_events);
 707
 708                stat = readw(host->base + MMC_REG_STATUS);
 709                /*
 710                 * This is not required in theory, but there is chance to miss some flag
 711                 * which clears automatically by mask write, FreeScale original code keeps
 712                 * stat from IRQ time so do I
 713                 */
 714                stat |= host->status_reg;
 715
 716                if (test_bit(IMXMCI_PEND_CPU_DATA_b, &host->pending_events))
 717                        stat &= ~STATUS_CRC_READ_ERR;
 718
 719                if (test_bit(IMXMCI_PEND_WAIT_RESP_b, &host->pending_events)) {
 720                        imxmci_busy_wait_for_status(host, &stat,
 721                                                    STATUS_END_CMD_RESP | STATUS_ERR_MASK,
 722                                                    20, "imxmci_tasklet_fnc resp (ERRATUM #4)");
 723                }
 724
 725                if (stat & (STATUS_END_CMD_RESP | STATUS_ERR_MASK)) {
 726                        if (test_and_clear_bit(IMXMCI_PEND_WAIT_RESP_b, &host->pending_events))
 727                                imxmci_cmd_done(host, stat);
 728                        if (host->data && (stat & STATUS_ERR_MASK))
 729                                imxmci_data_done(host, stat);
 730                }
 731
 732                if (test_bit(IMXMCI_PEND_CPU_DATA_b, &host->pending_events)) {
 733                        stat |= readw(host->base + MMC_REG_STATUS);
 734                        if (imxmci_cpu_driven_data(host, &stat)) {
 735                                if (test_and_clear_bit(IMXMCI_PEND_WAIT_RESP_b, &host->pending_events))
 736                                        imxmci_cmd_done(host, stat);
 737                                atomic_clear_mask(IMXMCI_PEND_IRQ_m|IMXMCI_PEND_CPU_DATA_m,
 738                                                  &host->pending_events);
 739                                imxmci_data_done(host, stat);
 740                        }
 741                }
 742        }
 743
 744        if (test_bit(IMXMCI_PEND_DMA_END_b, &host->pending_events) &&
 745            !test_bit(IMXMCI_PEND_WAIT_RESP_b, &host->pending_events)) {
 746
 747                stat = readw(host->base + MMC_REG_STATUS);
 748                /* Same as above */
 749                stat |= host->status_reg;
 750
 751                if (host->dma_dir == DMA_TO_DEVICE)
 752                        data_dir_mask = STATUS_WRITE_OP_DONE;
 753                else
 754                        data_dir_mask = STATUS_DATA_TRANS_DONE;
 755
 756                if (stat & data_dir_mask) {
 757                        clear_bit(IMXMCI_PEND_DMA_END_b, &host->pending_events);
 758                        imxmci_data_done(host, stat);
 759                }
 760        }
 761
 762        if (test_and_clear_bit(IMXMCI_PEND_CARD_XCHG_b, &host->pending_events)) {
 763
 764                if (host->cmd)
 765                        imxmci_cmd_done(host, STATUS_TIME_OUT_RESP);
 766
 767                if (host->data)
 768                        imxmci_data_done(host, STATUS_TIME_OUT_READ |
 769                                         STATUS_CRC_READ_ERR | STATUS_CRC_WRITE_ERR);
 770
 771                if (host->req)
 772                        imxmci_finish_request(host, host->req);
 773
 774                mmc_detect_change(host->mmc, msecs_to_jiffies(100));
 775
 776        }
 777}
 778
 779static void imxmci_request(struct mmc_host *mmc, struct mmc_request *req)
 780{
 781        struct imxmci_host *host = mmc_priv(mmc);
 782        unsigned int cmdat;
 783
 784        WARN_ON(host->req != NULL);
 785
 786        host->req = req;
 787
 788        cmdat = 0;
 789
 790        if (req->data) {
 791                imxmci_setup_data(host, req->data);
 792
 793                cmdat |= CMD_DAT_CONT_DATA_ENABLE;
 794
 795                if (req->data->flags & MMC_DATA_WRITE)
 796                        cmdat |= CMD_DAT_CONT_WRITE;
 797
 798                if (req->data->flags & MMC_DATA_STREAM)
 799                        cmdat |= CMD_DAT_CONT_STREAM_BLOCK;
 800        }
 801
 802        imxmci_start_cmd(host, req->cmd, cmdat);
 803}
 804
 805#define CLK_RATE 19200000
 806
 807static void imxmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 808{
 809        struct imxmci_host *host = mmc_priv(mmc);
 810        int prescaler;
 811
 812        if (ios->bus_width == MMC_BUS_WIDTH_4) {
 813                host->actual_bus_width = MMC_BUS_WIDTH_4;
 814                imx_gpio_mode(PB11_PF_SD_DAT3);
 815                BLR(host->dma) = 0;     /* burst 64 byte read/write */
 816        } else {
 817                host->actual_bus_width = MMC_BUS_WIDTH_1;
 818                imx_gpio_mode(GPIO_PORTB | GPIO_IN | GPIO_PUEN | 11);
 819                BLR(host->dma) = 16;    /* burst 16 byte read/write */
 820        }
 821
 822        if (host->power_mode != ios->power_mode) {
 823                switch (ios->power_mode) {
 824                case MMC_POWER_OFF:
 825                        break;
 826                case MMC_POWER_UP:
 827                        set_bit(IMXMCI_PEND_SET_INIT_b, &host->pending_events);
 828                        break;
 829                case MMC_POWER_ON:
 830                        break;
 831                }
 832                host->power_mode = ios->power_mode;
 833        }
 834
 835        if (ios->clock) {
 836                unsigned int clk;
 837                u16 reg;
 838
 839                /* The prescaler is 5 for PERCLK2 equal to 96MHz
 840                 * then 96MHz / 5 = 19.2 MHz
 841                 */
 842                clk = clk_get_rate(host->clk);
 843                prescaler = (clk + (CLK_RATE * 7) / 8) / CLK_RATE;
 844                switch (prescaler) {
 845                case 0:
 846                case 1: prescaler = 0;
 847                        break;
 848                case 2: prescaler = 1;
 849                        break;
 850                case 3: prescaler = 2;
 851                        break;
 852                case 4: prescaler = 4;
 853                        break;
 854                default:
 855                case 5: prescaler = 5;
 856                        break;
 857                }
 858
 859                dev_dbg(mmc_dev(host->mmc), "PERCLK2 %d MHz -> prescaler %d\n",
 860                        clk, prescaler);
 861
 862                for (clk = 0; clk < 8; clk++) {
 863                        int x;
 864                        x = CLK_RATE / (1 << clk);
 865                        if (x <= ios->clock)
 866                                break;
 867                }
 868
 869                /* enable controller */
 870                reg = readw(host->base + MMC_REG_STR_STP_CLK);
 871                writew(reg | STR_STP_CLK_ENABLE,
 872                                host->base + MMC_REG_STR_STP_CLK);
 873
 874                imxmci_stop_clock(host);
 875                writew((prescaler << 3) | clk, host->base + MMC_REG_CLK_RATE);
 876                /*
 877                 * Under my understanding, clock should not be started there, because it would
 878                 * initiate SDHC sequencer and send last or random command into card
 879                 */
 880                /* imxmci_start_clock(host); */
 881
 882                dev_dbg(mmc_dev(host->mmc),
 883                        "MMC_CLK_RATE: 0x%08x\n",
 884                        readw(host->base + MMC_REG_CLK_RATE));
 885        } else {
 886                imxmci_stop_clock(host);
 887        }
 888}
 889
 890static int imxmci_get_ro(struct mmc_host *mmc)
 891{
 892        struct imxmci_host *host = mmc_priv(mmc);
 893
 894        if (host->pdata && host->pdata->get_ro)
 895                return !!host->pdata->get_ro(mmc_dev(mmc));
 896        /*
 897         * Board doesn't support read only detection; let the mmc core
 898         * decide what to do.
 899         */
 900        return -ENOSYS;
 901}
 902
 903
 904static const struct mmc_host_ops imxmci_ops = {
 905        .request        = imxmci_request,
 906        .set_ios        = imxmci_set_ios,
 907        .get_ro         = imxmci_get_ro,
 908};
 909
 910static void imxmci_check_status(unsigned long data)
 911{
 912        struct imxmci_host *host = (struct imxmci_host *)data;
 913
 914        if (host->pdata && host->pdata->card_present &&
 915            host->pdata->card_present(mmc_dev(host->mmc)) != host->present) {
 916                host->present ^= 1;
 917                dev_info(mmc_dev(host->mmc), "card %s\n",
 918                      host->present ? "inserted" : "removed");
 919
 920                set_bit(IMXMCI_PEND_CARD_XCHG_b, &host->pending_events);
 921                tasklet_schedule(&host->tasklet);
 922        }
 923
 924        if (test_bit(IMXMCI_PEND_WAIT_RESP_b, &host->pending_events) ||
 925            test_bit(IMXMCI_PEND_DMA_DATA_b, &host->pending_events)) {
 926                atomic_inc(&host->stuck_timeout);
 927                if (atomic_read(&host->stuck_timeout) > 4)
 928                        tasklet_schedule(&host->tasklet);
 929        } else {
 930                atomic_set(&host->stuck_timeout, 0);
 931
 932        }
 933
 934        mod_timer(&host->timer, jiffies + (HZ>>1));
 935}
 936
 937static int __init imxmci_probe(struct platform_device *pdev)
 938{
 939        struct mmc_host *mmc;
 940        struct imxmci_host *host = NULL;
 941        struct resource *r;
 942        int ret = 0, irq;
 943        u16 rev_no;
 944
 945        pr_info("i.MX mmc driver\n");
 946
 947        r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 948        irq = platform_get_irq(pdev, 0);
 949        if (!r || irq < 0)
 950                return -ENXIO;
 951
 952        r = request_mem_region(r->start, resource_size(r), pdev->name);
 953        if (!r)
 954                return -EBUSY;
 955
 956        mmc = mmc_alloc_host(sizeof(struct imxmci_host), &pdev->dev);
 957        if (!mmc) {
 958                ret = -ENOMEM;
 959                goto out;
 960        }
 961
 962        mmc->ops = &imxmci_ops;
 963        mmc->f_min = 150000;
 964        mmc->f_max = CLK_RATE/2;
 965        mmc->ocr_avail = MMC_VDD_32_33;
 966        mmc->caps = MMC_CAP_4_BIT_DATA;
 967
 968        /* MMC core transfer sizes tunable parameters */
 969        mmc->max_segs = 64;
 970        mmc->max_seg_size = 64*512;     /* default PAGE_CACHE_SIZE */
 971        mmc->max_req_size = 64*512;     /* default PAGE_CACHE_SIZE */
 972        mmc->max_blk_size = 2048;
 973        mmc->max_blk_count = 65535;
 974
 975        host = mmc_priv(mmc);
 976        host->base = ioremap(r->start, resource_size(r));
 977        if (!host->base) {
 978                ret = -ENOMEM;
 979                goto out;
 980        }
 981
 982        host->mmc = mmc;
 983        host->dma_allocated = 0;
 984        host->pdata = pdev->dev.platform_data;
 985        if (!host->pdata)
 986                dev_warn(&pdev->dev, "No platform data provided!\n");
 987
 988        spin_lock_init(&host->lock);
 989        host->res = r;
 990        host->irq = irq;
 991
 992        host->clk = clk_get(&pdev->dev, "perclk2");
 993        if (IS_ERR(host->clk)) {
 994                ret = PTR_ERR(host->clk);
 995                goto out;
 996        }
 997        clk_enable(host->clk);
 998
 999        imx_gpio_mode(PB8_PF_SD_DAT0);
1000        imx_gpio_mode(PB9_PF_SD_DAT1);
1001        imx_gpio_mode(PB10_PF_SD_DAT2);
1002        /* Configured as GPIO with pull-up to ensure right MCC card mode */
1003        /* Switched to PB11_PF_SD_DAT3 if 4 bit bus is configured */
1004        imx_gpio_mode(GPIO_PORTB | GPIO_IN | GPIO_PUEN | 11);
1005        /* imx_gpio_mode(PB11_PF_SD_DAT3); */
1006        imx_gpio_mode(PB12_PF_SD_CLK);
1007        imx_gpio_mode(PB13_PF_SD_CMD);
1008
1009        imxmci_softreset(host);
1010
1011        rev_no = readw(host->base + MMC_REG_REV_NO);
1012        if (rev_no != 0x390) {
1013                dev_err(mmc_dev(host->mmc), "wrong rev.no. 0x%08x. aborting.\n",
1014                        readw(host->base + MMC_REG_REV_NO));
1015                goto out;
1016        }
1017
1018        /* recommended in data sheet */
1019        writew(0x2db4, host->base + MMC_REG_READ_TO);
1020
1021        host->imask = IMXMCI_INT_MASK_DEFAULT;
1022        writew(host->imask, host->base + MMC_REG_INT_MASK);
1023
1024        host->dma = imx_dma_request_by_prio(DRIVER_NAME, DMA_PRIO_LOW);
1025        if(host->dma < 0) {
1026                dev_err(mmc_dev(host->mmc), "imx_dma_request_by_prio failed\n");
1027                ret = -EBUSY;
1028                goto out;
1029        }
1030        host->dma_allocated = 1;
1031        imx_dma_setup_handlers(host->dma, imxmci_dma_irq, NULL, host);
1032        RSSR(host->dma) = DMA_REQ_SDHC;
1033
1034        tasklet_init(&host->tasklet, imxmci_tasklet_fnc, (unsigned long)host);
1035        host->status_reg=0;
1036        host->pending_events=0;
1037
1038        ret = request_irq(host->irq, imxmci_irq, 0, DRIVER_NAME, host);
1039        if (ret)
1040                goto out;
1041
1042        if (host->pdata && host->pdata->card_present)
1043                host->present = host->pdata->card_present(mmc_dev(mmc));
1044        else    /* if there is no way to detect assume that card is present */
1045                host->present = 1;
1046
1047        init_timer(&host->timer);
1048        host->timer.data = (unsigned long)host;
1049        host->timer.function = imxmci_check_status;
1050        add_timer(&host->timer);
1051        mod_timer(&host->timer, jiffies + (HZ >> 1));
1052
1053        platform_set_drvdata(pdev, mmc);
1054
1055        mmc_add_host(mmc);
1056
1057        return 0;
1058
1059out:
1060        if (host) {
1061                if (host->dma_allocated) {
1062                        imx_dma_free(host->dma);
1063                        host->dma_allocated = 0;
1064                }
1065                if (host->clk) {
1066                        clk_disable(host->clk);
1067                        clk_put(host->clk);
1068                }
1069                if (host->base)
1070                        iounmap(host->base);
1071        }
1072        if (mmc)
1073                mmc_free_host(mmc);
1074        release_mem_region(r->start, resource_size(r));
1075        return ret;
1076}
1077
1078static int __exit imxmci_remove(struct platform_device *pdev)
1079{
1080        struct mmc_host *mmc = platform_get_drvdata(pdev);
1081
1082        platform_set_drvdata(pdev, NULL);
1083
1084        if (mmc) {
1085                struct imxmci_host *host = mmc_priv(mmc);
1086
1087                tasklet_disable(&host->tasklet);
1088
1089                del_timer_sync(&host->timer);
1090                mmc_remove_host(mmc);
1091
1092                free_irq(host->irq, host);
1093                iounmap(host->base);
1094                if (host->dma_allocated) {
1095                        imx_dma_free(host->dma);
1096                        host->dma_allocated = 0;
1097                }
1098
1099                tasklet_kill(&host->tasklet);
1100
1101                clk_disable(host->clk);
1102                clk_put(host->clk);
1103
1104                release_mem_region(host->res->start, resource_size(host->res));
1105
1106                mmc_free_host(mmc);
1107        }
1108        return 0;
1109}
1110
1111#ifdef CONFIG_PM
1112static int imxmci_suspend(struct platform_device *dev, pm_message_t state)
1113{
1114        struct mmc_host *mmc = platform_get_drvdata(dev);
1115        int ret = 0;
1116
1117        if (mmc)
1118                ret = mmc_suspend_host(mmc);
1119
1120        return ret;
1121}
1122
1123static int imxmci_resume(struct platform_device *dev)
1124{
1125        struct mmc_host *mmc = platform_get_drvdata(dev);
1126        struct imxmci_host *host;
1127        int ret = 0;
1128
1129        if (mmc) {
1130                host = mmc_priv(mmc);
1131                if (host)
1132                        set_bit(IMXMCI_PEND_SET_INIT_b, &host->pending_events);
1133                ret = mmc_resume_host(mmc);
1134        }
1135
1136        return ret;
1137}
1138#else
1139#define imxmci_suspend  NULL
1140#define imxmci_resume   NULL
1141#endif /* CONFIG_PM */
1142
1143static struct platform_driver imxmci_driver = {
1144        .remove         = __exit_p(imxmci_remove),
1145        .suspend        = imxmci_suspend,
1146        .resume         = imxmci_resume,
1147        .driver         = {
1148                .name           = DRIVER_NAME,
1149                .owner          = THIS_MODULE,
1150        }
1151};
1152
1153static int __init imxmci_init(void)
1154{
1155        return platform_driver_probe(&imxmci_driver, imxmci_probe);
1156}
1157
1158static void __exit imxmci_exit(void)
1159{
1160        platform_driver_unregister(&imxmci_driver);
1161}
1162
1163module_init(imxmci_init);
1164module_exit(imxmci_exit);
1165
1166MODULE_DESCRIPTION("i.MX Multimedia Card Interface Driver");
1167MODULE_AUTHOR("Sascha Hauer, Pengutronix");
1168MODULE_LICENSE("GPL");
1169MODULE_ALIAS("platform:imx-mmc");
1170