2 * linux/drivers/mmc/mmc.c
4 * Copyright (C) 2003-2004 Russell King, All Rights Reserved.
5 * SD support Copyright (C) 2004 Ian Molton, All Rights Reserved.
6 * SD support Copyright (C) 2005 Pierre Ossman, All Rights Reserved.
7 * MMCv4 support Copyright (C) 2006 Philip Langdale, All Rights Reserved.
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.
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
16 #include <linux/completion.h>
17 #include <linux/device.h>
18 #include <linux/delay.h>
19 #include <linux/pagemap.h>
20 #include <linux/err.h>
21 #include <asm/scatterlist.h>
22 #include <linux/scatterlist.h>
24 #include <linux/mmc/card.h>
25 #include <linux/mmc/host.h>
26 #include <linux/mmc/protocol.h>
33 * OCR Bit positions to 10s of Vdd mV.
35 static const unsigned short mmc_ocr_bit_to_vdd[] = {
36 150, 155, 160, 165, 170, 180, 190, 200,
37 210, 220, 230, 240, 250, 260, 270, 280,
38 290, 300, 310, 320, 330, 340, 350, 360
41 static const unsigned int tran_exp[] = {
42 10000, 100000, 1000000, 10000000,
46 static const unsigned char tran_mant[] = {
47 0, 10, 12, 13, 15, 20, 25, 30,
48 35, 40, 45, 50, 55, 60, 70, 80,
51 static const unsigned int tacc_exp[] = {
52 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000,
55 static const unsigned int tacc_mant[] = {
56 0, 10, 12, 13, 15, 20, 25, 30,
57 35, 40, 45, 50, 55, 60, 70, 80,
62 * mmc_request_done - finish processing an MMC request
63 * @host: MMC host which completed request
64 * @mrq: MMC request which request
66 * MMC drivers should call this function when they have completed
67 * their processing of a request.
69 void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
71 struct mmc_command *cmd = mrq->cmd;
74 pr_debug("%s: req done (CMD%u): %d/%d/%d: %08x %08x %08x %08x\n",
75 mmc_hostname(host), cmd->opcode, err,
76 mrq->data ? mrq->data->error : 0,
77 mrq->stop ? mrq->stop->error : 0,
78 cmd->resp[0], cmd->resp[1], cmd->resp[2], cmd->resp[3]);
80 if (err && cmd->retries) {
83 host->ops->request(host, mrq);
84 } else if (mrq->done) {
89 EXPORT_SYMBOL(mmc_request_done);
92 * mmc_start_request - start a command on a host
93 * @host: MMC host to start command on
94 * @mrq: MMC request to start
96 * Queue a command on the specified host. We expect the
97 * caller to be holding the host lock with interrupts disabled.
100 mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
102 #ifdef CONFIG_MMC_DEBUG
106 pr_debug("%s: starting CMD%u arg %08x flags %08x\n",
107 mmc_hostname(host), mrq->cmd->opcode,
108 mrq->cmd->arg, mrq->cmd->flags);
110 WARN_ON(!host->claimed);
115 BUG_ON(mrq->data->blksz > host->max_blk_size);
116 BUG_ON(mrq->data->blocks > host->max_blk_count);
117 BUG_ON(mrq->data->blocks * mrq->data->blksz >
120 #ifdef CONFIG_MMC_DEBUG
122 for (i = 0;i < mrq->data->sg_len;i++)
123 sz += mrq->data->sg[i].length;
124 BUG_ON(sz != mrq->data->blocks * mrq->data->blksz);
127 mrq->cmd->data = mrq->data;
128 mrq->data->error = 0;
129 mrq->data->mrq = mrq;
131 mrq->data->stop = mrq->stop;
132 mrq->stop->error = 0;
133 mrq->stop->mrq = mrq;
136 host->ops->request(host, mrq);
139 EXPORT_SYMBOL(mmc_start_request);
141 static void mmc_wait_done(struct mmc_request *mrq)
143 complete(mrq->done_data);
146 int mmc_wait_for_req(struct mmc_host *host, struct mmc_request *mrq)
148 DECLARE_COMPLETION_ONSTACK(complete);
150 mrq->done_data = &complete;
151 mrq->done = mmc_wait_done;
153 mmc_start_request(host, mrq);
155 wait_for_completion(&complete);
160 EXPORT_SYMBOL(mmc_wait_for_req);
163 * mmc_wait_for_cmd - start a command and wait for completion
164 * @host: MMC host to start command
165 * @cmd: MMC command to start
166 * @retries: maximum number of retries
168 * Start a new MMC command for a host, and wait for the command
169 * to complete. Return any error that occurred while the command
170 * was executing. Do not attempt to parse the response.
172 int mmc_wait_for_cmd(struct mmc_host *host, struct mmc_command *cmd, int retries)
174 struct mmc_request mrq;
176 BUG_ON(!host->claimed);
178 memset(&mrq, 0, sizeof(struct mmc_request));
180 memset(cmd->resp, 0, sizeof(cmd->resp));
181 cmd->retries = retries;
186 mmc_wait_for_req(host, &mrq);
191 EXPORT_SYMBOL(mmc_wait_for_cmd);
194 * mmc_wait_for_app_cmd - start an application command and wait for
196 * @host: MMC host to start command
197 * @rca: RCA to send MMC_APP_CMD to
198 * @cmd: MMC command to start
199 * @retries: maximum number of retries
201 * Sends a MMC_APP_CMD, checks the card response, sends the command
202 * in the parameter and waits for it to complete. Return any error
203 * that occurred while the command was executing. Do not attempt to
204 * parse the response.
206 int mmc_wait_for_app_cmd(struct mmc_host *host, unsigned int rca,
207 struct mmc_command *cmd, int retries)
209 struct mmc_request mrq;
210 struct mmc_command appcmd;
214 BUG_ON(!host->claimed);
217 err = MMC_ERR_INVALID;
220 * We have to resend MMC_APP_CMD for each attempt so
221 * we cannot use the retries field in mmc_command.
223 for (i = 0;i <= retries;i++) {
224 memset(&mrq, 0, sizeof(struct mmc_request));
226 appcmd.opcode = MMC_APP_CMD;
227 appcmd.arg = rca << 16;
228 appcmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
230 memset(appcmd.resp, 0, sizeof(appcmd.resp));
236 mmc_wait_for_req(host, &mrq);
243 /* Check that card supported application commands */
244 if (!(appcmd.resp[0] & R1_APP_CMD))
245 return MMC_ERR_FAILED;
247 memset(&mrq, 0, sizeof(struct mmc_request));
249 memset(cmd->resp, 0, sizeof(cmd->resp));
255 mmc_wait_for_req(host, &mrq);
258 if (cmd->error == MMC_ERR_NONE)
265 EXPORT_SYMBOL(mmc_wait_for_app_cmd);
268 * mmc_set_data_timeout - set the timeout for a data command
269 * @data: data phase for command
270 * @card: the MMC card associated with the data transfer
271 * @write: flag to differentiate reads from writes
273 void mmc_set_data_timeout(struct mmc_data *data, const struct mmc_card *card,
279 * SD cards use a 100 multiplier rather than 10
281 mult = mmc_card_sd(card) ? 100 : 10;
284 * Scale up the multiplier (and therefore the timeout) by
285 * the r2w factor for writes.
288 mult <<= card->csd.r2w_factor;
290 data->timeout_ns = card->csd.tacc_ns * mult;
291 data->timeout_clks = card->csd.tacc_clks * mult;
294 * SD cards also have an upper limit on the timeout.
296 if (mmc_card_sd(card)) {
297 unsigned int timeout_us, limit_us;
299 timeout_us = data->timeout_ns / 1000;
300 timeout_us += data->timeout_clks * 1000 /
301 (card->host->ios.clock / 1000);
309 * SDHC cards always use these fixed values.
311 if (timeout_us > limit_us || mmc_card_blockaddr(card)) {
312 data->timeout_ns = limit_us * 1000;
313 data->timeout_clks = 0;
317 EXPORT_SYMBOL(mmc_set_data_timeout);
319 static int mmc_select_card(struct mmc_host *host, struct mmc_card *card);
322 * __mmc_claim_host - exclusively claim a host
323 * @host: mmc host to claim
324 * @card: mmc card to claim host for
326 * Claim a host for a set of operations. If a valid card
327 * is passed and this wasn't the last card selected, select
328 * the card before returning.
330 * Note: you should use mmc_card_claim_host or mmc_claim_host.
332 int __mmc_claim_host(struct mmc_host *host, struct mmc_card *card)
334 DECLARE_WAITQUEUE(wait, current);
338 add_wait_queue(&host->wq, &wait);
339 spin_lock_irqsave(&host->lock, flags);
341 set_current_state(TASK_UNINTERRUPTIBLE);
344 spin_unlock_irqrestore(&host->lock, flags);
346 spin_lock_irqsave(&host->lock, flags);
348 set_current_state(TASK_RUNNING);
350 spin_unlock_irqrestore(&host->lock, flags);
351 remove_wait_queue(&host->wq, &wait);
353 if (card != (void *)-1) {
354 err = mmc_select_card(host, card);
355 if (err != MMC_ERR_NONE)
362 EXPORT_SYMBOL(__mmc_claim_host);
365 * mmc_release_host - release a host
366 * @host: mmc host to release
368 * Release a MMC host, allowing others to claim the host
369 * for their operations.
371 void mmc_release_host(struct mmc_host *host)
375 BUG_ON(!host->claimed);
377 spin_lock_irqsave(&host->lock, flags);
379 spin_unlock_irqrestore(&host->lock, flags);
384 EXPORT_SYMBOL(mmc_release_host);
386 static inline void mmc_set_ios(struct mmc_host *host)
388 struct mmc_ios *ios = &host->ios;
390 pr_debug("%s: clock %uHz busmode %u powermode %u cs %u Vdd %u "
391 "width %u timing %u\n",
392 mmc_hostname(host), ios->clock, ios->bus_mode,
393 ios->power_mode, ios->chip_select, ios->vdd,
394 ios->bus_width, ios->timing);
396 host->ops->set_ios(host, ios);
399 static int mmc_select_card(struct mmc_host *host, struct mmc_card *card)
402 struct mmc_command cmd;
404 BUG_ON(!host->claimed);
406 if (host->card_selected == card)
409 host->card_selected = card;
411 cmd.opcode = MMC_SELECT_CARD;
412 cmd.arg = card->rca << 16;
413 cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
415 err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
416 if (err != MMC_ERR_NONE)
420 * We can only change the bus width of SD cards when
421 * they are selected so we have to put the handling
424 * The card is in 1 bit mode by default so
425 * we only need to change if it supports the
428 if (mmc_card_sd(card) &&
429 (card->scr.bus_widths & SD_SCR_BUS_WIDTH_4)) {
432 * Default bus width is 1 bit.
434 host->ios.bus_width = MMC_BUS_WIDTH_1;
436 if (host->caps & MMC_CAP_4_BIT_DATA) {
437 struct mmc_command cmd;
438 cmd.opcode = SD_APP_SET_BUS_WIDTH;
439 cmd.arg = SD_BUS_WIDTH_4;
440 cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
442 err = mmc_wait_for_app_cmd(host, card->rca, &cmd,
444 if (err != MMC_ERR_NONE)
447 host->ios.bus_width = MMC_BUS_WIDTH_4;
457 * Ensure that no card is selected.
459 static void mmc_deselect_cards(struct mmc_host *host)
461 struct mmc_command cmd;
463 if (host->card_selected) {
464 host->card_selected = NULL;
466 cmd.opcode = MMC_SELECT_CARD;
468 cmd.flags = MMC_RSP_NONE | MMC_CMD_AC;
470 mmc_wait_for_cmd(host, &cmd, 0);
475 static inline void mmc_delay(unsigned int ms)
477 if (ms < 1000 / HZ) {
486 * Mask off any voltages we don't support and select
489 static u32 mmc_select_voltage(struct mmc_host *host, u32 ocr)
493 ocr &= host->ocr_avail;
510 #define UNSTUFF_BITS(resp,start,size) \
512 const int __size = size; \
513 const u32 __mask = (__size < 32 ? 1 << __size : 0) - 1; \
514 const int __off = 3 - ((start) / 32); \
515 const int __shft = (start) & 31; \
518 __res = resp[__off] >> __shft; \
519 if (__size + __shft > 32) \
520 __res |= resp[__off-1] << ((32 - __shft) % 32); \
525 * Given the decoded CSD structure, decode the raw CID to our CID structure.
527 static void mmc_decode_cid(struct mmc_card *card)
529 u32 *resp = card->raw_cid;
531 memset(&card->cid, 0, sizeof(struct mmc_cid));
533 if (mmc_card_sd(card)) {
535 * SD doesn't currently have a version field so we will
536 * have to assume we can parse this.
538 card->cid.manfid = UNSTUFF_BITS(resp, 120, 8);
539 card->cid.oemid = UNSTUFF_BITS(resp, 104, 16);
540 card->cid.prod_name[0] = UNSTUFF_BITS(resp, 96, 8);
541 card->cid.prod_name[1] = UNSTUFF_BITS(resp, 88, 8);
542 card->cid.prod_name[2] = UNSTUFF_BITS(resp, 80, 8);
543 card->cid.prod_name[3] = UNSTUFF_BITS(resp, 72, 8);
544 card->cid.prod_name[4] = UNSTUFF_BITS(resp, 64, 8);
545 card->cid.hwrev = UNSTUFF_BITS(resp, 60, 4);
546 card->cid.fwrev = UNSTUFF_BITS(resp, 56, 4);
547 card->cid.serial = UNSTUFF_BITS(resp, 24, 32);
548 card->cid.year = UNSTUFF_BITS(resp, 12, 8);
549 card->cid.month = UNSTUFF_BITS(resp, 8, 4);
551 card->cid.year += 2000; /* SD cards year offset */
554 * The selection of the format here is based upon published
555 * specs from sandisk and from what people have reported.
557 switch (card->csd.mmca_vsn) {
558 case 0: /* MMC v1.0 - v1.2 */
559 case 1: /* MMC v1.4 */
560 card->cid.manfid = UNSTUFF_BITS(resp, 104, 24);
561 card->cid.prod_name[0] = UNSTUFF_BITS(resp, 96, 8);
562 card->cid.prod_name[1] = UNSTUFF_BITS(resp, 88, 8);
563 card->cid.prod_name[2] = UNSTUFF_BITS(resp, 80, 8);
564 card->cid.prod_name[3] = UNSTUFF_BITS(resp, 72, 8);
565 card->cid.prod_name[4] = UNSTUFF_BITS(resp, 64, 8);
566 card->cid.prod_name[5] = UNSTUFF_BITS(resp, 56, 8);
567 card->cid.prod_name[6] = UNSTUFF_BITS(resp, 48, 8);
568 card->cid.hwrev = UNSTUFF_BITS(resp, 44, 4);
569 card->cid.fwrev = UNSTUFF_BITS(resp, 40, 4);
570 card->cid.serial = UNSTUFF_BITS(resp, 16, 24);
571 card->cid.month = UNSTUFF_BITS(resp, 12, 4);
572 card->cid.year = UNSTUFF_BITS(resp, 8, 4) + 1997;
575 case 2: /* MMC v2.0 - v2.2 */
576 case 3: /* MMC v3.1 - v3.3 */
578 card->cid.manfid = UNSTUFF_BITS(resp, 120, 8);
579 card->cid.oemid = UNSTUFF_BITS(resp, 104, 16);
580 card->cid.prod_name[0] = UNSTUFF_BITS(resp, 96, 8);
581 card->cid.prod_name[1] = UNSTUFF_BITS(resp, 88, 8);
582 card->cid.prod_name[2] = UNSTUFF_BITS(resp, 80, 8);
583 card->cid.prod_name[3] = UNSTUFF_BITS(resp, 72, 8);
584 card->cid.prod_name[4] = UNSTUFF_BITS(resp, 64, 8);
585 card->cid.prod_name[5] = UNSTUFF_BITS(resp, 56, 8);
586 card->cid.serial = UNSTUFF_BITS(resp, 16, 32);
587 card->cid.month = UNSTUFF_BITS(resp, 12, 4);
588 card->cid.year = UNSTUFF_BITS(resp, 8, 4) + 1997;
592 printk("%s: card has unknown MMCA version %d\n",
593 mmc_hostname(card->host), card->csd.mmca_vsn);
594 mmc_card_set_bad(card);
601 * Given a 128-bit response, decode to our card CSD structure.
603 static void mmc_decode_csd(struct mmc_card *card)
605 struct mmc_csd *csd = &card->csd;
606 unsigned int e, m, csd_struct;
607 u32 *resp = card->raw_csd;
609 if (mmc_card_sd(card)) {
610 csd_struct = UNSTUFF_BITS(resp, 126, 2);
612 switch (csd_struct) {
614 m = UNSTUFF_BITS(resp, 115, 4);
615 e = UNSTUFF_BITS(resp, 112, 3);
616 csd->tacc_ns = (tacc_exp[e] * tacc_mant[m] + 9) / 10;
617 csd->tacc_clks = UNSTUFF_BITS(resp, 104, 8) * 100;
619 m = UNSTUFF_BITS(resp, 99, 4);
620 e = UNSTUFF_BITS(resp, 96, 3);
621 csd->max_dtr = tran_exp[e] * tran_mant[m];
622 csd->cmdclass = UNSTUFF_BITS(resp, 84, 12);
624 e = UNSTUFF_BITS(resp, 47, 3);
625 m = UNSTUFF_BITS(resp, 62, 12);
626 csd->capacity = (1 + m) << (e + 2);
628 csd->read_blkbits = UNSTUFF_BITS(resp, 80, 4);
629 csd->read_partial = UNSTUFF_BITS(resp, 79, 1);
630 csd->write_misalign = UNSTUFF_BITS(resp, 78, 1);
631 csd->read_misalign = UNSTUFF_BITS(resp, 77, 1);
632 csd->r2w_factor = UNSTUFF_BITS(resp, 26, 3);
633 csd->write_blkbits = UNSTUFF_BITS(resp, 22, 4);
634 csd->write_partial = UNSTUFF_BITS(resp, 21, 1);
638 * This is a block-addressed SDHC card. Most
639 * interesting fields are unused and have fixed
640 * values. To avoid getting tripped by buggy cards,
641 * we assume those fixed values ourselves.
643 mmc_card_set_blockaddr(card);
645 csd->tacc_ns = 0; /* Unused */
646 csd->tacc_clks = 0; /* Unused */
648 m = UNSTUFF_BITS(resp, 99, 4);
649 e = UNSTUFF_BITS(resp, 96, 3);
650 csd->max_dtr = tran_exp[e] * tran_mant[m];
651 csd->cmdclass = UNSTUFF_BITS(resp, 84, 12);
653 m = UNSTUFF_BITS(resp, 48, 22);
654 csd->capacity = (1 + m) << 10;
656 csd->read_blkbits = 9;
657 csd->read_partial = 0;
658 csd->write_misalign = 0;
659 csd->read_misalign = 0;
660 csd->r2w_factor = 4; /* Unused */
661 csd->write_blkbits = 9;
662 csd->write_partial = 0;
665 printk("%s: unrecognised CSD structure version %d\n",
666 mmc_hostname(card->host), csd_struct);
667 mmc_card_set_bad(card);
672 * We only understand CSD structure v1.1 and v1.2.
673 * v1.2 has extra information in bits 15, 11 and 10.
675 csd_struct = UNSTUFF_BITS(resp, 126, 2);
676 if (csd_struct != 1 && csd_struct != 2) {
677 printk("%s: unrecognised CSD structure version %d\n",
678 mmc_hostname(card->host), csd_struct);
679 mmc_card_set_bad(card);
683 csd->mmca_vsn = UNSTUFF_BITS(resp, 122, 4);
684 m = UNSTUFF_BITS(resp, 115, 4);
685 e = UNSTUFF_BITS(resp, 112, 3);
686 csd->tacc_ns = (tacc_exp[e] * tacc_mant[m] + 9) / 10;
687 csd->tacc_clks = UNSTUFF_BITS(resp, 104, 8) * 100;
689 m = UNSTUFF_BITS(resp, 99, 4);
690 e = UNSTUFF_BITS(resp, 96, 3);
691 csd->max_dtr = tran_exp[e] * tran_mant[m];
692 csd->cmdclass = UNSTUFF_BITS(resp, 84, 12);
694 e = UNSTUFF_BITS(resp, 47, 3);
695 m = UNSTUFF_BITS(resp, 62, 12);
696 csd->capacity = (1 + m) << (e + 2);
698 csd->read_blkbits = UNSTUFF_BITS(resp, 80, 4);
699 csd->read_partial = UNSTUFF_BITS(resp, 79, 1);
700 csd->write_misalign = UNSTUFF_BITS(resp, 78, 1);
701 csd->read_misalign = UNSTUFF_BITS(resp, 77, 1);
702 csd->r2w_factor = UNSTUFF_BITS(resp, 26, 3);
703 csd->write_blkbits = UNSTUFF_BITS(resp, 22, 4);
704 csd->write_partial = UNSTUFF_BITS(resp, 21, 1);
709 * Given a 64-bit response, decode to our card SCR structure.
711 static void mmc_decode_scr(struct mmc_card *card)
713 struct sd_scr *scr = &card->scr;
714 unsigned int scr_struct;
717 BUG_ON(!mmc_card_sd(card));
719 resp[3] = card->raw_scr[1];
720 resp[2] = card->raw_scr[0];
722 scr_struct = UNSTUFF_BITS(resp, 60, 4);
723 if (scr_struct != 0) {
724 printk("%s: unrecognised SCR structure version %d\n",
725 mmc_hostname(card->host), scr_struct);
726 mmc_card_set_bad(card);
730 scr->sda_vsn = UNSTUFF_BITS(resp, 56, 4);
731 scr->bus_widths = UNSTUFF_BITS(resp, 48, 4);
735 * Locate a MMC card on this MMC host given a raw CID.
737 static struct mmc_card *mmc_find_card(struct mmc_host *host, u32 *raw_cid)
739 struct mmc_card *card;
741 list_for_each_entry(card, &host->cards, node) {
742 if (memcmp(card->raw_cid, raw_cid, sizeof(card->raw_cid)) == 0)
749 * Allocate a new MMC card, and assign a unique RCA.
751 static struct mmc_card *
752 mmc_alloc_card(struct mmc_host *host, u32 *raw_cid, unsigned int *frca)
754 struct mmc_card *card, *c;
755 unsigned int rca = *frca;
757 card = kmalloc(sizeof(struct mmc_card), GFP_KERNEL);
759 return ERR_PTR(-ENOMEM);
761 mmc_init_card(card, host);
762 memcpy(card->raw_cid, raw_cid, sizeof(card->raw_cid));
765 list_for_each_entry(c, &host->cards, node)
779 * Tell attached cards to go to IDLE state
781 static void mmc_idle_cards(struct mmc_host *host)
783 struct mmc_command cmd;
785 host->ios.chip_select = MMC_CS_HIGH;
790 cmd.opcode = MMC_GO_IDLE_STATE;
792 cmd.flags = MMC_RSP_NONE | MMC_CMD_BC;
794 mmc_wait_for_cmd(host, &cmd, 0);
798 host->ios.chip_select = MMC_CS_DONTCARE;
805 * Apply power to the MMC stack. This is a two-stage process.
806 * First, we enable power to the card without the clock running.
807 * We then wait a bit for the power to stabilise. Finally,
808 * enable the bus drivers and clock to the card.
810 * We must _NOT_ enable the clock prior to power stablising.
812 * If a host does all the power sequencing itself, ignore the
813 * initial MMC_POWER_UP stage.
815 static void mmc_power_up(struct mmc_host *host)
817 int bit = fls(host->ocr_avail) - 1;
820 host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;
821 host->ios.chip_select = MMC_CS_DONTCARE;
822 host->ios.power_mode = MMC_POWER_UP;
823 host->ios.bus_width = MMC_BUS_WIDTH_1;
824 host->ios.timing = MMC_TIMING_LEGACY;
829 host->ios.clock = host->f_min;
830 host->ios.power_mode = MMC_POWER_ON;
836 static void mmc_power_off(struct mmc_host *host)
840 host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;
841 host->ios.chip_select = MMC_CS_DONTCARE;
842 host->ios.power_mode = MMC_POWER_OFF;
843 host->ios.bus_width = MMC_BUS_WIDTH_1;
844 host->ios.timing = MMC_TIMING_LEGACY;
848 static int mmc_send_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
850 struct mmc_command cmd;
853 cmd.opcode = MMC_SEND_OP_COND;
855 cmd.flags = MMC_RSP_R3 | MMC_CMD_BCR;
857 for (i = 100; i; i--) {
858 err = mmc_wait_for_cmd(host, &cmd, 0);
859 if (err != MMC_ERR_NONE)
862 if (cmd.resp[0] & MMC_CARD_BUSY || ocr == 0)
865 err = MMC_ERR_TIMEOUT;
876 static int mmc_send_app_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
878 struct mmc_command cmd;
881 cmd.opcode = SD_APP_OP_COND;
883 cmd.flags = MMC_RSP_R3 | MMC_CMD_BCR;
885 for (i = 100; i; i--) {
886 err = mmc_wait_for_app_cmd(host, 0, &cmd, CMD_RETRIES);
887 if (err != MMC_ERR_NONE)
890 if (cmd.resp[0] & MMC_CARD_BUSY || ocr == 0)
893 err = MMC_ERR_TIMEOUT;
904 static int mmc_send_if_cond(struct mmc_host *host, u32 ocr, int *rsd2)
906 struct mmc_command cmd;
908 static const u8 test_pattern = 0xAA;
911 * To support SD 2.0 cards, we must always invoke SD_SEND_IF_COND
912 * before SD_APP_OP_COND. This command will harmlessly fail for
915 cmd.opcode = SD_SEND_IF_COND;
916 cmd.arg = ((ocr & 0xFF8000) != 0) << 8 | test_pattern;
917 cmd.flags = MMC_RSP_R7 | MMC_CMD_BCR;
919 err = mmc_wait_for_cmd(host, &cmd, 0);
920 if (err == MMC_ERR_NONE) {
921 if ((cmd.resp[0] & 0xFF) == test_pattern) {
925 err = MMC_ERR_FAILED;
929 * Treat errors as SD 1.0 card.
940 * Discover cards by requesting their CID. If this command
941 * times out, it is not an error; there are no further cards
942 * to be discovered. Add new cards to the list.
944 * Create a mmc_card entry for each discovered card, assigning
945 * it an RCA, and save the raw CID for decoding later.
947 static void mmc_discover_cards(struct mmc_host *host)
949 struct mmc_card *card;
950 unsigned int first_rca = 1, err;
953 struct mmc_command cmd;
955 cmd.opcode = MMC_ALL_SEND_CID;
957 cmd.flags = MMC_RSP_R2 | MMC_CMD_BCR;
959 err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
960 if (err == MMC_ERR_TIMEOUT) {
964 if (err != MMC_ERR_NONE) {
965 printk(KERN_ERR "%s: error requesting CID: %d\n",
966 mmc_hostname(host), err);
970 card = mmc_find_card(host, cmd.resp);
972 card = mmc_alloc_card(host, cmd.resp, &first_rca);
977 list_add(&card->node, &host->cards);
980 card->state &= ~MMC_STATE_DEAD;
982 if (host->mode == MMC_MODE_SD) {
983 card->type = MMC_TYPE_SD;
985 cmd.opcode = SD_SEND_RELATIVE_ADDR;
987 cmd.flags = MMC_RSP_R6 | MMC_CMD_BCR;
989 err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
990 if (err != MMC_ERR_NONE)
991 mmc_card_set_dead(card);
993 card->rca = cmd.resp[0] >> 16;
995 if (!host->ops->get_ro) {
996 printk(KERN_WARNING "%s: host does not "
997 "support reading read-only "
998 "switch. assuming write-enable.\n",
1001 if (host->ops->get_ro(host))
1002 mmc_card_set_readonly(card);
1006 card->type = MMC_TYPE_MMC;
1007 cmd.opcode = MMC_SET_RELATIVE_ADDR;
1008 cmd.arg = card->rca << 16;
1009 cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
1011 err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
1012 if (err != MMC_ERR_NONE)
1013 mmc_card_set_dead(card);
1018 static void mmc_read_csds(struct mmc_host *host)
1020 struct mmc_card *card;
1022 list_for_each_entry(card, &host->cards, node) {
1023 struct mmc_command cmd;
1026 if (card->state & (MMC_STATE_DEAD|MMC_STATE_PRESENT))
1029 cmd.opcode = MMC_SEND_CSD;
1030 cmd.arg = card->rca << 16;
1031 cmd.flags = MMC_RSP_R2 | MMC_CMD_AC;
1033 err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
1034 if (err != MMC_ERR_NONE) {
1035 mmc_card_set_dead(card);
1039 memcpy(card->raw_csd, cmd.resp, sizeof(card->raw_csd));
1041 mmc_decode_csd(card);
1042 mmc_decode_cid(card);
1046 static void mmc_process_ext_csds(struct mmc_host *host)
1049 struct mmc_card *card;
1051 struct mmc_request mrq;
1052 struct mmc_command cmd;
1053 struct mmc_data data;
1055 struct scatterlist sg;
1058 * As the ext_csd is so large and mostly unused, we don't store the
1059 * raw block in mmc_card.
1062 ext_csd = kmalloc(512, GFP_KERNEL);
1064 printk("%s: could not allocate a buffer to receive the ext_csd."
1065 "mmc v4 cards will be treated as v3.\n",
1066 mmc_hostname(host));
1070 list_for_each_entry(card, &host->cards, node) {
1071 if (card->state & (MMC_STATE_DEAD|MMC_STATE_PRESENT))
1073 if (mmc_card_sd(card))
1075 if (card->csd.mmca_vsn < CSD_SPEC_VER_4)
1078 err = mmc_select_card(host, card);
1079 if (err != MMC_ERR_NONE) {
1080 mmc_card_set_dead(card);
1084 memset(&cmd, 0, sizeof(struct mmc_command));
1086 cmd.opcode = MMC_SEND_EXT_CSD;
1088 cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
1090 memset(&data, 0, sizeof(struct mmc_data));
1092 mmc_set_data_timeout(&data, card, 0);
1096 data.flags = MMC_DATA_READ;
1100 memset(&mrq, 0, sizeof(struct mmc_request));
1105 sg_init_one(&sg, ext_csd, 512);
1107 mmc_wait_for_req(host, &mrq);
1109 if (cmd.error != MMC_ERR_NONE || data.error != MMC_ERR_NONE) {
1110 if (card->csd.capacity == (4096 * 512)) {
1111 printk(KERN_ERR "%s: unable to read EXT_CSD "
1112 "on a possible high capacity card. "
1113 "Card will be ignored.\n",
1114 mmc_hostname(card->host));
1115 mmc_card_set_dead(card);
1117 printk(KERN_WARNING "%s: unable to read "
1118 "EXT_CSD, performance might "
1120 mmc_hostname(card->host));
1125 card->ext_csd.sectors =
1126 ext_csd[EXT_CSD_SEC_CNT + 0] << 0 |
1127 ext_csd[EXT_CSD_SEC_CNT + 1] << 8 |
1128 ext_csd[EXT_CSD_SEC_CNT + 2] << 16 |
1129 ext_csd[EXT_CSD_SEC_CNT + 3] << 24;
1130 if (card->ext_csd.sectors)
1131 mmc_card_set_blockaddr(card);
1133 switch (ext_csd[EXT_CSD_CARD_TYPE]) {
1134 case EXT_CSD_CARD_TYPE_52 | EXT_CSD_CARD_TYPE_26:
1135 card->ext_csd.hs_max_dtr = 52000000;
1137 case EXT_CSD_CARD_TYPE_26:
1138 card->ext_csd.hs_max_dtr = 26000000;
1141 /* MMC v4 spec says this cannot happen */
1142 printk("%s: card is mmc v4 but doesn't support "
1143 "any high-speed modes.\n",
1144 mmc_hostname(card->host));
1148 if (host->caps & MMC_CAP_MMC_HIGHSPEED) {
1149 /* Activate highspeed support. */
1150 cmd.opcode = MMC_SWITCH;
1151 cmd.arg = (MMC_SWITCH_MODE_WRITE_BYTE << 24) |
1152 (EXT_CSD_HS_TIMING << 16) |
1154 EXT_CSD_CMD_SET_NORMAL;
1155 cmd.flags = MMC_RSP_R1B | MMC_CMD_AC;
1157 err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
1158 if (err != MMC_ERR_NONE) {
1159 printk("%s: failed to switch card to mmc v4 "
1160 "high-speed mode.\n",
1161 mmc_hostname(card->host));
1165 mmc_card_set_highspeed(card);
1167 host->ios.timing = MMC_TIMING_MMC_HS;
1171 /* Check for host support for wide-bus modes. */
1172 if (host->caps & MMC_CAP_4_BIT_DATA) {
1173 /* Activate 4-bit support. */
1174 cmd.opcode = MMC_SWITCH;
1175 cmd.arg = (MMC_SWITCH_MODE_WRITE_BYTE << 24) |
1176 (EXT_CSD_BUS_WIDTH << 16) |
1177 (EXT_CSD_BUS_WIDTH_4 << 8) |
1178 EXT_CSD_CMD_SET_NORMAL;
1179 cmd.flags = MMC_RSP_R1B | MMC_CMD_AC;
1181 err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
1182 if (err != MMC_ERR_NONE) {
1183 printk("%s: failed to switch card to "
1184 "mmc v4 4-bit bus mode.\n",
1185 mmc_hostname(card->host));
1189 host->ios.bus_width = MMC_BUS_WIDTH_4;
1196 mmc_deselect_cards(host);
1199 static void mmc_read_scrs(struct mmc_host *host)
1202 struct mmc_card *card;
1203 struct mmc_request mrq;
1204 struct mmc_command cmd;
1205 struct mmc_data data;
1206 struct scatterlist sg;
1208 list_for_each_entry(card, &host->cards, node) {
1209 if (card->state & (MMC_STATE_DEAD|MMC_STATE_PRESENT))
1211 if (!mmc_card_sd(card))
1214 err = mmc_select_card(host, card);
1215 if (err != MMC_ERR_NONE) {
1216 mmc_card_set_dead(card);
1220 memset(&cmd, 0, sizeof(struct mmc_command));
1222 cmd.opcode = MMC_APP_CMD;
1223 cmd.arg = card->rca << 16;
1224 cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
1226 err = mmc_wait_for_cmd(host, &cmd, 0);
1227 if ((err != MMC_ERR_NONE) || !(cmd.resp[0] & R1_APP_CMD)) {
1228 mmc_card_set_dead(card);
1232 memset(&cmd, 0, sizeof(struct mmc_command));
1234 cmd.opcode = SD_APP_SEND_SCR;
1236 cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
1238 memset(&data, 0, sizeof(struct mmc_data));
1240 mmc_set_data_timeout(&data, card, 0);
1242 data.blksz = 1 << 3;
1244 data.flags = MMC_DATA_READ;
1248 memset(&mrq, 0, sizeof(struct mmc_request));
1253 sg_init_one(&sg, (u8*)card->raw_scr, 8);
1255 mmc_wait_for_req(host, &mrq);
1257 if (cmd.error != MMC_ERR_NONE || data.error != MMC_ERR_NONE) {
1258 mmc_card_set_dead(card);
1262 card->raw_scr[0] = ntohl(card->raw_scr[0]);
1263 card->raw_scr[1] = ntohl(card->raw_scr[1]);
1265 mmc_decode_scr(card);
1268 mmc_deselect_cards(host);
1271 static void mmc_read_switch_caps(struct mmc_host *host)
1274 struct mmc_card *card;
1275 struct mmc_request mrq;
1276 struct mmc_command cmd;
1277 struct mmc_data data;
1278 unsigned char *status;
1279 struct scatterlist sg;
1281 if (!(host->caps & MMC_CAP_SD_HIGHSPEED))
1284 status = kmalloc(64, GFP_KERNEL);
1286 printk(KERN_WARNING "%s: Unable to allocate buffer for "
1287 "reading switch capabilities.\n",
1288 mmc_hostname(host));
1292 list_for_each_entry(card, &host->cards, node) {
1293 if (card->state & (MMC_STATE_DEAD|MMC_STATE_PRESENT))
1295 if (!mmc_card_sd(card))
1297 if (card->scr.sda_vsn < SCR_SPEC_VER_1)
1300 err = mmc_select_card(host, card);
1301 if (err != MMC_ERR_NONE) {
1302 mmc_card_set_dead(card);
1306 memset(&cmd, 0, sizeof(struct mmc_command));
1308 cmd.opcode = SD_SWITCH;
1309 cmd.arg = 0x00FFFFF1;
1310 cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
1312 memset(&data, 0, sizeof(struct mmc_data));
1314 mmc_set_data_timeout(&data, card, 0);
1318 data.flags = MMC_DATA_READ;
1322 memset(&mrq, 0, sizeof(struct mmc_request));
1327 sg_init_one(&sg, status, 64);
1329 mmc_wait_for_req(host, &mrq);
1331 if (cmd.error != MMC_ERR_NONE || data.error != MMC_ERR_NONE) {
1332 printk("%s: unable to read switch capabilities, "
1333 "performance might suffer.\n",
1334 mmc_hostname(card->host));
1338 if (status[13] & 0x02)
1339 card->sw_caps.hs_max_dtr = 50000000;
1341 memset(&cmd, 0, sizeof(struct mmc_command));
1343 cmd.opcode = SD_SWITCH;
1344 cmd.arg = 0x80FFFFF1;
1345 cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
1347 memset(&data, 0, sizeof(struct mmc_data));
1349 mmc_set_data_timeout(&data, card, 0);
1353 data.flags = MMC_DATA_READ;
1357 memset(&mrq, 0, sizeof(struct mmc_request));
1362 sg_init_one(&sg, status, 64);
1364 mmc_wait_for_req(host, &mrq);
1366 if (cmd.error != MMC_ERR_NONE || data.error != MMC_ERR_NONE ||
1367 (status[16] & 0xF) != 1) {
1368 printk(KERN_WARNING "%s: Problem switching card "
1369 "into high-speed mode!\n",
1370 mmc_hostname(host));
1374 mmc_card_set_highspeed(card);
1376 host->ios.timing = MMC_TIMING_SD_HS;
1382 mmc_deselect_cards(host);
1385 static unsigned int mmc_calculate_clock(struct mmc_host *host)
1387 struct mmc_card *card;
1388 unsigned int max_dtr = host->f_max;
1390 list_for_each_entry(card, &host->cards, node)
1391 if (!mmc_card_dead(card)) {
1392 if (mmc_card_highspeed(card) && mmc_card_sd(card)) {
1393 if (max_dtr > card->sw_caps.hs_max_dtr)
1394 max_dtr = card->sw_caps.hs_max_dtr;
1395 } else if (mmc_card_highspeed(card) && !mmc_card_sd(card)) {
1396 if (max_dtr > card->ext_csd.hs_max_dtr)
1397 max_dtr = card->ext_csd.hs_max_dtr;
1398 } else if (max_dtr > card->csd.max_dtr) {
1399 max_dtr = card->csd.max_dtr;
1403 pr_debug("%s: selected %d.%03dMHz transfer rate\n",
1405 max_dtr / 1000000, (max_dtr / 1000) % 1000);
1411 * Check whether cards we already know about are still present.
1412 * We do this by requesting status, and checking whether a card
1415 * A request for status does not cause a state change in data
1418 static void mmc_check_cards(struct mmc_host *host)
1420 struct list_head *l, *n;
1422 mmc_deselect_cards(host);
1424 list_for_each_safe(l, n, &host->cards) {
1425 struct mmc_card *card = mmc_list_to_card(l);
1426 struct mmc_command cmd;
1429 cmd.opcode = MMC_SEND_STATUS;
1430 cmd.arg = card->rca << 16;
1431 cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
1433 err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
1434 if (err == MMC_ERR_NONE)
1437 mmc_card_set_dead(card);
1441 static void mmc_setup(struct mmc_host *host)
1443 if (host->ios.power_mode != MMC_POWER_ON) {
1447 host->mode = MMC_MODE_SD;
1450 mmc_idle_cards(host);
1452 err = mmc_send_if_cond(host, host->ocr_avail, NULL);
1453 if (err != MMC_ERR_NONE) {
1456 err = mmc_send_app_op_cond(host, 0, &ocr);
1459 * If we fail to detect any SD cards then try
1460 * searching for MMC cards.
1462 if (err != MMC_ERR_NONE) {
1463 host->mode = MMC_MODE_MMC;
1465 err = mmc_send_op_cond(host, 0, &ocr);
1466 if (err != MMC_ERR_NONE)
1470 host->ocr = mmc_select_voltage(host, ocr);
1473 * Since we're changing the OCR value, we seem to
1474 * need to tell some cards to go back to the idle
1475 * state. We wait 1ms to give cards time to
1479 mmc_idle_cards(host);
1481 host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;
1482 host->ios.clock = host->f_min;
1486 * We should remember the OCR mask from the existing
1487 * cards, and detect the new cards OCR mask, combine
1488 * the two and re-select the VDD. However, if we do
1489 * change VDD, we should do an idle, and then do a
1490 * full re-initialisation. We would need to notify
1491 * drivers so that they can re-setup the cards as
1492 * well, while keeping their queues at bay.
1494 * For the moment, we take the easy way out - if the
1495 * new cards don't like our currently selected VDD,
1496 * they drop off the bus.
1504 * Send the selected OCR multiple times... until the cards
1505 * all get the idea that they should be ready for CMD2.
1506 * (My SanDisk card seems to need this.)
1508 if (host->mode == MMC_MODE_SD) {
1510 err = mmc_send_if_cond(host, host->ocr, &sd2);
1511 if (err == MMC_ERR_NONE) {
1513 * If SD_SEND_IF_COND indicates an SD 2.0
1514 * compliant card and we should set bit 30
1515 * of the ocr to indicate that we can handle
1516 * block-addressed SDHC cards.
1518 mmc_send_app_op_cond(host, host->ocr | (sd2 << 30), NULL);
1521 /* The extra bit indicates that we support high capacity */
1522 mmc_send_op_cond(host, host->ocr | (1 << 30), NULL);
1525 mmc_discover_cards(host);
1528 * Ok, now switch to push-pull mode.
1530 host->ios.bus_mode = MMC_BUSMODE_PUSHPULL;
1533 mmc_read_csds(host);
1535 if (host->mode == MMC_MODE_SD) {
1536 mmc_read_scrs(host);
1537 mmc_read_switch_caps(host);
1539 mmc_process_ext_csds(host);
1544 * mmc_detect_change - process change of state on a MMC socket
1545 * @host: host which changed state.
1546 * @delay: optional delay to wait before detection (jiffies)
1548 * All we know is that card(s) have been inserted or removed
1549 * from the socket(s). We don't know which socket or cards.
1551 void mmc_detect_change(struct mmc_host *host, unsigned long delay)
1553 #ifdef CONFIG_MMC_DEBUG
1554 mmc_claim_host(host);
1555 BUG_ON(host->removed);
1556 mmc_release_host(host);
1559 mmc_schedule_delayed_work(&host->detect, delay);
1562 EXPORT_SYMBOL(mmc_detect_change);
1565 static void mmc_rescan(struct work_struct *work)
1567 struct mmc_host *host =
1568 container_of(work, struct mmc_host, detect.work);
1569 struct list_head *l, *n;
1570 unsigned char power_mode;
1572 mmc_claim_host(host);
1575 * Check for removed cards and newly inserted ones. We check for
1576 * removed cards first so we can intelligently re-select the VDD.
1578 power_mode = host->ios.power_mode;
1579 if (power_mode == MMC_POWER_ON)
1580 mmc_check_cards(host);
1585 * Some broken cards process CMD1 even in stand-by state. There is
1586 * no reply, but an ILLEGAL_COMMAND error is cached and returned
1587 * after next command. We poll for card status here to clear any
1588 * possibly pending error.
1590 if (power_mode == MMC_POWER_ON)
1591 mmc_check_cards(host);
1593 if (!list_empty(&host->cards)) {
1595 * (Re-)calculate the fastest clock rate which the
1596 * attached cards and the host support.
1598 host->ios.clock = mmc_calculate_clock(host);
1602 mmc_release_host(host);
1604 list_for_each_safe(l, n, &host->cards) {
1605 struct mmc_card *card = mmc_list_to_card(l);
1608 * If this is a new and good card, register it.
1610 if (!mmc_card_present(card) && !mmc_card_dead(card)) {
1611 if (mmc_register_card(card))
1612 mmc_card_set_dead(card);
1616 * If this card is dead, destroy it.
1618 if (mmc_card_dead(card)) {
1619 list_del(&card->node);
1620 mmc_remove_card(card);
1625 * If we discover that there are no cards on the
1626 * bus, turn off the clock and power down.
1628 if (list_empty(&host->cards))
1629 mmc_power_off(host);
1634 * mmc_alloc_host - initialise the per-host structure.
1635 * @extra: sizeof private data structure
1636 * @dev: pointer to host device model structure
1638 * Initialise the per-host structure.
1640 struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
1642 struct mmc_host *host;
1644 host = mmc_alloc_host_sysfs(extra, dev);
1646 spin_lock_init(&host->lock);
1647 init_waitqueue_head(&host->wq);
1648 INIT_LIST_HEAD(&host->cards);
1649 INIT_DELAYED_WORK(&host->detect, mmc_rescan);
1652 * By default, hosts do not support SGIO or large requests.
1653 * They have to set these according to their abilities.
1655 host->max_hw_segs = 1;
1656 host->max_phys_segs = 1;
1657 host->max_seg_size = PAGE_CACHE_SIZE;
1659 host->max_req_size = PAGE_CACHE_SIZE;
1660 host->max_blk_size = 512;
1661 host->max_blk_count = PAGE_CACHE_SIZE / 512;
1667 EXPORT_SYMBOL(mmc_alloc_host);
1670 * mmc_add_host - initialise host hardware
1673 int mmc_add_host(struct mmc_host *host)
1677 ret = mmc_add_host_sysfs(host);
1679 mmc_power_off(host);
1680 mmc_detect_change(host, 0);
1686 EXPORT_SYMBOL(mmc_add_host);
1689 * mmc_remove_host - remove host hardware
1692 * Unregister and remove all cards associated with this host,
1693 * and power down the MMC bus.
1695 void mmc_remove_host(struct mmc_host *host)
1697 struct list_head *l, *n;
1699 #ifdef CONFIG_MMC_DEBUG
1700 mmc_claim_host(host);
1702 mmc_release_host(host);
1705 mmc_flush_scheduled_work();
1707 list_for_each_safe(l, n, &host->cards) {
1708 struct mmc_card *card = mmc_list_to_card(l);
1710 mmc_remove_card(card);
1713 mmc_power_off(host);
1714 mmc_remove_host_sysfs(host);
1717 EXPORT_SYMBOL(mmc_remove_host);
1720 * mmc_free_host - free the host structure
1723 * Free the host once all references to it have been dropped.
1725 void mmc_free_host(struct mmc_host *host)
1727 mmc_free_host_sysfs(host);
1730 EXPORT_SYMBOL(mmc_free_host);
1735 * mmc_suspend_host - suspend a host
1737 * @state: suspend mode (PM_SUSPEND_xxx)
1739 int mmc_suspend_host(struct mmc_host *host, pm_message_t state)
1741 mmc_claim_host(host);
1742 mmc_deselect_cards(host);
1743 mmc_power_off(host);
1744 mmc_release_host(host);
1749 EXPORT_SYMBOL(mmc_suspend_host);
1752 * mmc_resume_host - resume a previously suspended host
1755 int mmc_resume_host(struct mmc_host *host)
1757 mmc_rescan(&host->detect.work);
1762 EXPORT_SYMBOL(mmc_resume_host);
1766 MODULE_LICENSE("GPL");