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Commit 52ef7c19 authored by Maya Erez's avatar Maya Erez
Browse files

mmc: core: add partial initialization support 



This change adds the ability to partially initialize
the MMC card by using card Sleep/Awake sequence (CMD5).
Card will be sent to Sleep state during runtime/system suspend
and will be woken up during runtime/system resume.
By using this sequence the card doesn't need full initialization
which gives time reduction in system/runtime resume path.

Change-Id: Id8dadf03ef4226f7c4675fadbacac7bb15c0289e
Signed-off-by: default avatarTalel Shenhar <tatias@codeaurora.org>
Signed-off-by: default avatarMaya Erez <merez@codeaurora.org>
parent ee630a97

drivers/mmc/core/mmc.c

+162 −13
Original line number Diff line number Diff line
@@ -1405,7 +1405,7 @@ static int mmc_select_cmdq(struct mmc_card *card) 
	}



	mmc_host_clk_release(card->host);

	pr_info("%s: CMDQ enabled on card\n", mmc_hostname(host));

	pr_info_once("%s: CMDQ enabled on card\n", mmc_hostname(host));

out:

	return ret;

}
@@ -2049,24 +2049,28 @@ err: 
	return err;

}



static int mmc_can_sleep(struct mmc_card *card)

static int mmc_can_sleepawake(struct mmc_host *host)

{

	return (card && card->ext_csd.rev >= 3);

	return host && (host->caps2 & MMC_CAP2_SLEEP_AWAKE) && host->card &&

		(host->card->ext_csd.rev >= 3);

}



static int mmc_sleep(struct mmc_host *host)

static int mmc_sleepawake(struct mmc_host *host, bool sleep)

{

	struct mmc_command cmd = {0};

	struct mmc_card *card = host->card;

	unsigned int timeout_ms = DIV_ROUND_UP(card->ext_csd.sa_timeout, 10000);

	int err;



	if (sleep) {

		err = mmc_deselect_cards(host);

		if (err)

			return err;

	}



	cmd.opcode = MMC_SLEEP_AWAKE;

	cmd.arg = card->rca << 16;

	if (sleep)

		cmd.arg |= 1 << 15;



	/*
@@ -2095,6 +2099,9 @@ static int mmc_sleep(struct mmc_host *host) 
	if (!cmd.busy_timeout || !(host->caps & MMC_CAP_WAIT_WHILE_BUSY))

		mmc_delay(timeout_ms);



	if (!sleep)

		err = mmc_select_card(card);



	return err;

}
@@ -2203,6 +2210,69 @@ static void mmc_detect(struct mmc_host *host) 
	}

}



static int mmc_cache_card_ext_csd(struct mmc_host *host)

{

	int err;

	u8 *ext_csd;

	struct mmc_card *card = host->card;



	err = mmc_get_ext_csd(card, &ext_csd);

	if (err || !ext_csd) {

		pr_err("%s: %s: mmc_get_ext_csd failed (%d)\n",

			mmc_hostname(host), __func__, err);

		return err;

	}



	/* only cache read/write fields that the sw changes */

	card->ext_csd.raw_ext_csd_cmdq = ext_csd[EXT_CSD_CMDQ];

	card->ext_csd.raw_ext_csd_cache_ctrl = ext_csd[EXT_CSD_CACHE_CTRL];

	card->ext_csd.raw_ext_csd_bus_width = ext_csd[EXT_CSD_BUS_WIDTH];

	card->ext_csd.raw_ext_csd_hs_timing = ext_csd[EXT_CSD_HS_TIMING];



	mmc_free_ext_csd(ext_csd);



	return 0;

}



static int mmc_test_awake_ext_csd(struct mmc_host *host)

{

	int err;

	u8 *ext_csd;

	struct mmc_card *card = host->card;



	err = mmc_get_ext_csd(card, &ext_csd);

	if (err) {

		pr_err("%s: %s: mmc_get_ext_csd failed (%d)\n",

			mmc_hostname(host), __func__, err);

		return err;

	}



	/* only compare read/write fields that the sw changes */

	pr_debug("%s: %s: type(cached:current) cmdq(%d:%d) cache_ctrl(%d:%d) bus_width (%d:%d) timing(%d:%d)\n",

		mmc_hostname(host), __func__,

		card->ext_csd.raw_ext_csd_cmdq,

		ext_csd[EXT_CSD_CMDQ],

		card->ext_csd.raw_ext_csd_cache_ctrl,

		ext_csd[EXT_CSD_CACHE_CTRL],

		card->ext_csd.raw_ext_csd_bus_width,

		ext_csd[EXT_CSD_BUS_WIDTH],

		card->ext_csd.raw_ext_csd_hs_timing,

		ext_csd[EXT_CSD_HS_TIMING]);



	err = !((card->ext_csd.raw_ext_csd_cmdq ==

			ext_csd[EXT_CSD_CMDQ]) &&

		(card->ext_csd.raw_ext_csd_cache_ctrl ==

			ext_csd[EXT_CSD_CACHE_CTRL]) &&

		(card->ext_csd.raw_ext_csd_bus_width ==

			ext_csd[EXT_CSD_BUS_WIDTH]) &&

		(card->ext_csd.raw_ext_csd_hs_timing ==

			ext_csd[EXT_CSD_HS_TIMING]));



	mmc_free_ext_csd(ext_csd);



	return err;

}



static int _mmc_suspend(struct mmc_host *host, bool is_suspend)

{

	int err = 0;
@@ -2254,10 +2324,13 @@ static int _mmc_suspend(struct mmc_host *host, bool is_suspend) 
	if (err)

		goto out;



	if (mmc_can_sleep(host->card))

		err = mmc_sleep(host);

	else if (!mmc_host_is_spi(host))

	if (mmc_can_sleepawake(host)) {

		memcpy(&host->cached_ios, &host->ios, sizeof(host->cached_ios));

		mmc_cache_card_ext_csd(host);

		err = mmc_sleepawake(host, true);

	} else if (!mmc_host_is_spi(host)) {

		err = mmc_deselect_cards(host);

	}



	if (!err) {

		mmc_power_off(host);
@@ -2272,6 +2345,71 @@ out: 
	return err;

}



static int mmc_partial_init(struct mmc_host *host)

{

	int err = 0;

	struct mmc_card *card = host->card;



	pr_debug("%s: %s: starting partial init\n",

		mmc_hostname(host), __func__);



	mmc_set_bus_width(host, host->cached_ios.bus_width);

	mmc_set_timing(host, host->cached_ios.timing);

	mmc_set_clock(host, host->cached_ios.clock);

	mmc_set_bus_mode(host, host->cached_ios.bus_mode);



	mmc_host_clk_hold(host);



	if (mmc_card_hs200(card) || mmc_card_hs400(card)) {

		if (card->ext_csd.strobe_support && host->ops->enhanced_strobe)

			err = host->ops->enhanced_strobe(host);

		else

			err = host->ops->execute_tuning(host,

				MMC_SEND_TUNING_BLOCK_HS200);

		if (err)

			pr_warn("%s: %s: tuning execution failed (%d)\n",

				mmc_hostname(host), __func__, err);

	}



	/*

	 * The ext_csd is read to make sure the card did not went through

	 * Power-failure during sleep period.

	 * A subset of the W/E_P, W/C_P register will be tested. In case

	 * these registers values are different from the values that were

	 * cached during suspend, we will conclude that a Power-failure occurred

	 * and will do full initialization sequence.

	 * In addition, full init sequence also transfer ext_csd before moving

	 * to CMDQ mode which has a side affect of configuring SDHCI registers

	 * which needed to be done before moving to CMDQ mode. The same

	 * registers need to be configured for partial init.

	 */

	err = mmc_test_awake_ext_csd(host);

	if (err) {

		pr_debug("%s: %s: fail on ext_csd read (%d)\n",

			mmc_hostname(host), __func__, err);

		goto out;

	}

	pr_debug("%s: %s: reading and comparing ext_csd successful\n",

		mmc_hostname(host), __func__);



	if (card->ext_csd.cmdq_support && (card->host->caps2 &

					   MMC_CAP2_CMD_QUEUE)) {

		err = mmc_select_cmdq(card);

		if (err) {

			pr_warn("%s: %s: enabling CMDQ mode failed (%d)\n",

					mmc_hostname(card->host),

					__func__, err);

		}

	}

out:

	mmc_host_clk_release(host);



	pr_debug("%s: %s: done partial init (%d)\n",

		mmc_hostname(host), __func__, err);



	return err;

}



/*

 * Suspend callback

 */
@@ -2297,7 +2435,7 @@ static int mmc_suspend(struct mmc_host *host) 
 */

static int _mmc_resume(struct mmc_host *host)

{

	int err = 0;

	int err = -ENOSYS;

	int retries;



	BUG_ON(!host);
@@ -2313,7 +2451,18 @@ static int _mmc_resume(struct mmc_host *host) 
	mmc_power_up(host, host->card->ocr);

	retries = 3;

	while (retries) {

		if (mmc_can_sleepawake(host)) {

			err = mmc_sleepawake(host, false);

			if (!err)

				err = mmc_partial_init(host);

			if (err)

				pr_err("%s: %s: awake failed (%d), fallback to full init\n",

					mmc_hostname(host), __func__, err);

		}



		if (err)

			err = mmc_init_card(host, host->card->ocr, host->card);



		if (err) {

			pr_err("%s: MMC card re-init failed rc = %d (retries = %d)\n",

			       mmc_hostname(host), err, retries);

include/linux/mmc/card.h

+4 −0
Original line number Diff line number Diff line
@@ -93,12 +93,16 @@ struct mmc_ext_csd { 
	unsigned int            data_tag_unit_size;     /* DATA TAG UNIT size */

	unsigned int		boot_ro_lock;		/* ro lock support */

	bool			boot_ro_lockable;

	u8			raw_ext_csd_cmdq;	/* 15 */

	u8			raw_ext_csd_cache_ctrl;	/* 33 */

	u8			raw_exception_status;	/* 54 */

	u8			raw_partition_support;	/* 160 */

	u8			raw_rpmb_size_mult;	/* 168 */

	u8			raw_erased_mem_count;	/* 181 */

	u8			raw_ext_csd_bus_width;	/* 183 */

	u8			strobe_support;		/* 184 */

#define MMC_STROBE_SUPPORT	(1 << 0)

	u8			raw_ext_csd_hs_timing;	/* 185 */

	u8			raw_ext_csd_structure;	/* 194 */

	u8			raw_card_type;		/* 196 */

	u8			raw_drive_strength;	/* 197 */

include/linux/mmc/host.h

+3 −0
Original line number Diff line number Diff line
@@ -433,6 +433,8 @@ struct mmc_host { 
#define MMC_CAP2_NONHOTPLUG	(1 << 25)	/*Don't support hotplug*/

#define MMC_CAP2_CMD_QUEUE	(1 << 26)	/* support eMMC command queue */

#define MMC_CAP2_SANITIZE       (1 << 27)               /* Support Sanitize */

#define MMC_CAP2_SLEEP_AWAKE	(1 << 28)	/* Use Sleep/Awake (CMD5) */



	mmc_pm_flag_t		pm_caps;	/* supported pm features */



#ifdef CONFIG_MMC_CLKGATE
@@ -460,6 +462,7 @@ struct mmc_host { 
	spinlock_t		lock;		/* lock for claim and bus ops */



	struct mmc_ios		ios;		/* current io bus settings */

	struct mmc_ios		cached_ios;



	/* group bitfields together to minimize padding */

	unsigned int		use_spi_crc:1;