mmc: core: Fixup broken suspend and eMMC4.5 power off notify

This patch fixes up the broken suspend sequence for eMMC with sleep
support. Additionally it reworks the eMMC4.5 Power Off Notification
feature so it fits together with the existing sleep feature.

The CMD0 based re-initialization of the eMMC at resume is re-introduced
to maintain compatiblity for devices using sleep.

A host shall use MMC_CAP2_POWEROFF_NOTIFY to enable the Power Off
Notification feature. We might be able to remove this cap later on,
if we think that Power Off Notification always is preferred over
sleep, even if the host is not able to cut the eMMC VCCQ power.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Saugata Das <saugata.das@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/core/core.c

@@ -1273,48 +1273,6 @@ void mmc_set_driver_type(struct mmc_host *host, unsigned int drv_type)
 	mmc_host_clk_release(host);
 }
 
-static void mmc_poweroff_notify(struct mmc_host *host)
-{
-	struct mmc_card *card;
-	unsigned int timeout;
-	unsigned int notify_type = EXT_CSD_NO_POWER_NOTIFICATION;
-	int err = 0;
-
-	card = host->card;
-	mmc_claim_host(host);
-
-	/*
-	 * Send power notify command only if card
-	 * is mmc and notify state is powered ON
-	 */
-	if (card && mmc_card_mmc(card) &&
-	    (card->poweroff_notify_state == MMC_POWERED_ON)) {
-
-		if (host->power_notify_type == MMC_HOST_PW_NOTIFY_SHORT) {
-			notify_type = EXT_CSD_POWER_OFF_SHORT;
-			timeout = card->ext_csd.generic_cmd6_time;
-			card->poweroff_notify_state = MMC_POWEROFF_SHORT;
-		} else {
-			notify_type = EXT_CSD_POWER_OFF_LONG;
-			timeout = card->ext_csd.power_off_longtime;
-			card->poweroff_notify_state = MMC_POWEROFF_LONG;
-		}
-
-		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
-				 EXT_CSD_POWER_OFF_NOTIFICATION,
-				 notify_type, timeout);
-
-		if (err && err != -EBADMSG)
-			pr_err("Device failed to respond within %d poweroff "
-			       "time. Forcefully powering down the device\n",
-			       timeout);
-
-		/* Set the card state to no notification after the poweroff */
-		card->poweroff_notify_state = MMC_NO_POWER_NOTIFICATION;
-	}
-	mmc_release_host(host);
-}
-
 /*
  * Apply power to the MMC stack.  This is a two-stage process.
  * First, we enable power to the card without the clock running.
@@ -1377,8 +1335,6 @@ static void mmc_power_up(struct mmc_host *host)
 
 void mmc_power_off(struct mmc_host *host)
 {
-	int err = 0;
-
 	if (host->ios.power_mode == MMC_POWER_OFF)
 		return;
 
@@ -1387,22 +1343,6 @@ void mmc_power_off(struct mmc_host *host)
 	host->ios.clock = 0;
 	host->ios.vdd = 0;
 
-	/*
-	 * For eMMC 4.5 device send AWAKE command before
-	 * POWER_OFF_NOTIFY command, because in sleep state
-	 * eMMC 4.5 devices respond to only RESET and AWAKE cmd
-	 */
-	if (host->card && mmc_card_is_sleep(host->card) &&
-	    host->bus_ops->resume) {
-		err = host->bus_ops->resume(host);
-
-		if (!err)
-			mmc_poweroff_notify(host);
-		else
-			pr_warning("%s: error %d during resume "
-				   "(continue with poweroff sequence)\n",
-				   mmc_hostname(host), err);
-	}
 
 	/*
 	 * Reset ocr mask to be the highest possible voltage supported for
@@ -2579,7 +2519,6 @@ int mmc_pm_notify(struct notifier_block *notify_block,
 
 		spin_lock_irqsave(&host->lock, flags);
 		host->rescan_disable = 1;
-		host->power_notify_type = MMC_HOST_PW_NOTIFY_SHORT;
 		spin_unlock_irqrestore(&host->lock, flags);
 		cancel_delayed_work_sync(&host->detect);
 
@@ -2603,7 +2542,6 @@ int mmc_pm_notify(struct notifier_block *notify_block,
 
 		spin_lock_irqsave(&host->lock, flags);
 		host->rescan_disable = 0;
-		host->power_notify_type = MMC_HOST_PW_NOTIFY_LONG;
 		spin_unlock_irqrestore(&host->lock, flags);
 		mmc_detect_change(host, 0);
 

drivers/mmc/core/mmc.c

@@ -1007,7 +1007,7 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
 		 * so check for success and update the flag
 		 */
 		if (!err)
-			card->poweroff_notify_state = MMC_POWERED_ON;
+			card->ext_csd.power_off_notification = EXT_CSD_POWER_ON;
 	}
 
 	/*
@@ -1273,6 +1273,35 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
 	return err;
 }
 
+static int mmc_can_poweroff_notify(const struct mmc_card *card)
+{
+	return card &&
+		mmc_card_mmc(card) &&
+		(card->ext_csd.power_off_notification == EXT_CSD_POWER_ON);
+}
+
+static int mmc_poweroff_notify(struct mmc_card *card, unsigned int notify_type)
+{
+	unsigned int timeout = card->ext_csd.generic_cmd6_time;
+	int err;
+
+	/* Use EXT_CSD_POWER_OFF_SHORT as default notification type. */
+	if (notify_type == EXT_CSD_POWER_OFF_LONG)
+		timeout = card->ext_csd.power_off_longtime;
+
+	err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+			 EXT_CSD_POWER_OFF_NOTIFICATION,
+			 notify_type, timeout);
+	if (err)
+		pr_err("%s: Power Off Notification timed out, %u\n",
+		       mmc_hostname(card->host), timeout);
+
+	/* Disable the power off notification after the switch operation. */
+	card->ext_csd.power_off_notification = EXT_CSD_NO_POWER_NOTIFICATION;
+
+	return err;
+}
+
 /*
  * Host is being removed. Free up the current card.
  */
@@ -1333,11 +1362,11 @@ static int mmc_suspend(struct mmc_host *host)
 	BUG_ON(!host->card);
 
 	mmc_claim_host(host);
-	if (mmc_card_can_sleep(host)) {
+	if (mmc_can_poweroff_notify(host->card))
+		err = mmc_poweroff_notify(host->card, EXT_CSD_POWER_OFF_SHORT);
+	else if (mmc_card_can_sleep(host))
 		err = mmc_card_sleep(host);
-		if (!err)
-			mmc_card_set_sleep(host->card);
-	} else if (!mmc_host_is_spi(host))
+	else if (!mmc_host_is_spi(host))
 		err = mmc_deselect_cards(host);
 	host->card->state &= ~(MMC_STATE_HIGHSPEED | MMC_STATE_HIGHSPEED_200);
 	mmc_release_host(host);
@@ -1359,11 +1388,7 @@ static int mmc_resume(struct mmc_host *host)
 	BUG_ON(!host->card);
 
 	mmc_claim_host(host);
-	if (mmc_card_is_sleep(host->card)) {
-		err = mmc_card_awake(host);
-		mmc_card_clr_sleep(host->card);
-	} else
-		err = mmc_init_card(host, host->ocr, host->card);
+	err = mmc_init_card(host, host->ocr, host->card);
 	mmc_release_host(host);
 
 	return err;
@@ -1374,7 +1399,6 @@ static int mmc_power_restore(struct mmc_host *host)
 	int ret;
 
 	host->card->state &= ~(MMC_STATE_HIGHSPEED | MMC_STATE_HIGHSPEED_200);
-	mmc_card_clr_sleep(host->card);
 	mmc_claim_host(host);
 	ret = mmc_init_card(host, host->ocr, host->card);
 	mmc_release_host(host);

drivers/mmc/host/dw_mmc.c

@@ -1885,11 +1885,6 @@ static int dw_mci_init_slot(struct dw_mci *host, unsigned int id)
 	if (host->pdata->quirks & DW_MCI_QUIRK_HIGHSPEED)
 		mmc->caps |= MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED;
 
-	if (mmc->caps2 & MMC_CAP2_POWEROFF_NOTIFY)
-		mmc->power_notify_type = MMC_HOST_PW_NOTIFY_SHORT;
-	else
-		mmc->power_notify_type = MMC_HOST_PW_NOTIFY_NONE;
-
 	if (host->pdata->blk_settings) {
 		mmc->max_segs = host->pdata->blk_settings->max_segs;
 		mmc->max_blk_size = host->pdata->blk_settings->max_blk_size;

drivers/mmc/host/sdhci.c

@@ -2886,15 +2886,6 @@ int sdhci_add_host(struct sdhci_host *host)
 	if (caps[1] & SDHCI_DRIVER_TYPE_D)
 		mmc->caps |= MMC_CAP_DRIVER_TYPE_D;
 
-	/*
-	 * If Power Off Notify capability is enabled by the host,
-	 * set notify to short power off notify timeout value.
-	 */
-	if (mmc->caps2 & MMC_CAP2_POWEROFF_NOTIFY)
-		mmc->power_notify_type = MMC_HOST_PW_NOTIFY_SHORT;
-	else
-		mmc->power_notify_type = MMC_HOST_PW_NOTIFY_NONE;
-
 	/* Initial value for re-tuning timer count */
 	host->tuning_count = (caps[1] & SDHCI_RETUNING_TIMER_COUNT_MASK) >>
 			      SDHCI_RETUNING_TIMER_COUNT_SHIFT;

include/linux/mmc/card.h

@@ -57,6 +57,7 @@ struct mmc_ext_csd {
 	unsigned int		sa_timeout;		/* Units: 100ns */
 	unsigned int		generic_cmd6_time;	/* Units: 10ms */
 	unsigned int            power_off_longtime;     /* Units: ms */
+	u8			power_off_notification;	/* state */
 	unsigned int		hs_max_dtr;
 #define MMC_HIGH_26_MAX_DTR	26000000
 #define MMC_HIGH_52_MAX_DTR	52000000
@@ -229,7 +230,6 @@ struct mmc_card {
 #define MMC_CARD_SDXC		(1<<6)		/* card is SDXC */
 #define MMC_CARD_REMOVED	(1<<7)		/* card has been removed */
 #define MMC_STATE_HIGHSPEED_200	(1<<8)		/* card is in HS200 mode */
-#define MMC_STATE_SLEEP		(1<<9)		/* card is in sleep state */
 #define MMC_STATE_DOING_BKOPS	(1<<10)		/* card is doing BKOPS */
 	unsigned int		quirks; 	/* card quirks */
 #define MMC_QUIRK_LENIENT_FN0	(1<<0)		/* allow SDIO FN0 writes outside of the VS CCCR range */
@@ -246,11 +246,6 @@ struct mmc_card {
 #define MMC_QUIRK_LONG_READ_TIME (1<<9)		/* Data read time > CSD says */
 #define MMC_QUIRK_SEC_ERASE_TRIM_BROKEN (1<<10)	/* Skip secure for erase/trim */
 						/* byte mode */
-	unsigned int    poweroff_notify_state;	/* eMMC4.5 notify feature */
-#define MMC_NO_POWER_NOTIFICATION	0
-#define MMC_POWERED_ON			1
-#define MMC_POWEROFF_SHORT		2
-#define MMC_POWEROFF_LONG		3
 
 	unsigned int		erase_size;	/* erase size in sectors */
  	unsigned int		erase_shift;	/* if erase unit is power 2 */
@@ -397,7 +392,6 @@ static inline void __maybe_unused remove_quirk(struct mmc_card *card, int data)
 #define mmc_sd_card_uhs(c)	((c)->state & MMC_STATE_ULTRAHIGHSPEED)
 #define mmc_card_ext_capacity(c) ((c)->state & MMC_CARD_SDXC)
 #define mmc_card_removed(c)	((c) && ((c)->state & MMC_CARD_REMOVED))
-#define mmc_card_is_sleep(c)	((c)->state & MMC_STATE_SLEEP)
 #define mmc_card_doing_bkops(c)	((c)->state & MMC_STATE_DOING_BKOPS)
 
 #define mmc_card_set_present(c)	((c)->state |= MMC_STATE_PRESENT)
@@ -410,11 +404,9 @@ static inline void __maybe_unused remove_quirk(struct mmc_card *card, int data)
 #define mmc_sd_card_set_uhs(c) ((c)->state |= MMC_STATE_ULTRAHIGHSPEED)
 #define mmc_card_set_ext_capacity(c) ((c)->state |= MMC_CARD_SDXC)
 #define mmc_card_set_removed(c) ((c)->state |= MMC_CARD_REMOVED)
-#define mmc_card_set_sleep(c)	((c)->state |= MMC_STATE_SLEEP)
 #define mmc_card_set_doing_bkops(c)	((c)->state |= MMC_STATE_DOING_BKOPS)
-
 #define mmc_card_clr_doing_bkops(c)	((c)->state &= ~MMC_STATE_DOING_BKOPS)
-#define mmc_card_clr_sleep(c)	((c)->state &= ~MMC_STATE_SLEEP)
+
 /*
  * Quirk add/remove for MMC products.
  */

include/linux/mmc/host.h

@@ -259,10 +259,6 @@ struct mmc_host {
 #define MMC_CAP2_RO_ACTIVE_HIGH	(1 << 11)	/* Write-protect signal active high */
 
 	mmc_pm_flag_t		pm_caps;	/* supported pm features */
-	unsigned int        power_notify_type;
-#define MMC_HOST_PW_NOTIFY_NONE		0
-#define MMC_HOST_PW_NOTIFY_SHORT	1
-#define MMC_HOST_PW_NOTIFY_LONG		2
 
 #ifdef CONFIG_MMC_CLKGATE
 	int			clk_requests;	/* internal reference counter */