mmc: core: Fix PowerOff Notify suspend/resume

Modified the mmc_poweroff to resume before sending the poweroff
notification command. In sleep mode only AWAKE and RESET commands are
allowed, so before sending the poweroff notification command resume from
sleep mode and then send the notification command.

PowerOff Notify is tested on a Synopsis Designware Host Controller
(eMMC 4.5). The suspend to RAM and resume works fine.

Signed-off-by: Girish K S <girish.shivananjappa@linaro.org>
Tested-by: Girish K S <girish.shivananjappa@linaro.org>
Reviewed-by: Saugata Das <saugata.das@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 1866155..690255c 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1256,6 +1256,7 @@
 	int err = 0;
 
 	card = host->card;
+	mmc_claim_host(host);
 
 	/*
 	 * Send power notify command only if card
@@ -1286,6 +1287,7 @@
 		/* Set the card state to no notification after the poweroff */
 		card->poweroff_notify_state = MMC_NO_POWER_NOTIFICATION;
 	}
+	mmc_release_host(host);
 }
 
 /*
@@ -1344,12 +1346,28 @@
 
 void mmc_power_off(struct mmc_host *host)
 {
+	int err = 0;
 	mmc_host_clk_hold(host);
 
 	host->ios.clock = 0;
 	host->ios.vdd = 0;
 
-	mmc_poweroff_notify(host);
+	/*
+	 * 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
@@ -2403,12 +2421,6 @@
 		 */
 		if (mmc_try_claim_host(host)) {
 			if (host->bus_ops->suspend) {
-				/*
-				 * For eMMC 4.5 device send notify command
-				 * before sleep, because in sleep state eMMC 4.5
-				 * devices respond to only RESET and AWAKE cmd
-				 */
-				mmc_poweroff_notify(host);
 				err = host->bus_ops->suspend(host);
 			}
 			mmc_do_release_host(host);