mmc: core: Fixup suspend/resume issues for UHS-I cards

Even if cards supports 1.8V I/O voltage those should anyway be
initialized at 3.3V I/O according to (e)MMC, SD and SDIO specs.
Some eMMC and embedded SDIO devices are able to be initialized
at 1.8V as well, but it is better to be safe.

Do note that initialization in this context means that the card
has been completely powered off, otherwise the card will remain
at the last I/O voltage level that were negotitiated.

Due to the above being taken care of the suspend/resume issues
for UHS-I SD-cards has been fixed.

Signed-off-by: Ulf Hansson <ulf.hansson@stericsson.com>
Acked-by: Philip Rakity <prakity@marvell.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

4 files changed, 17 insertions, 5 deletions

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 690255c7d4d..132378b89d7 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2068,6 +2068,9 @@ static int mmc_rescan_try_freq(struct mmc_host *host, unsigned freq)
 	 */
 	mmc_hw_reset_for_init(host);
 
+	/* Initialization should be done at 3.3 V I/O voltage. */
+	mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330, 0);
+
 	/*
 	 * sdio_reset sends CMD52 to reset card.  Since we do not know
 	 * if the card is being re-initialized, just send it.  CMD52
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index a48066344fa..2b9ed1401dc 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -816,6 +816,9 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
 	if (!mmc_host_is_spi(host))
 		mmc_set_bus_mode(host, MMC_BUSMODE_OPENDRAIN);
 
+	/* Initialization should be done at 3.3 V I/O voltage. */
+	mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330, 0);
+
 	/*
 	 * Since we're changing the OCR value, we seem to
 	 * need to tell some cards to go back to the idle
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 5017f9354ce..c272c6868ec 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -911,6 +911,9 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
 	BUG_ON(!host);
 	WARN_ON(!host->claimed);
 
+	/* The initialization should be done at 3.3 V I/O voltage. */
+	mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330, 0);
+
 	err = mmc_sd_get_cid(host, ocr, cid, &rocr);
 	if (err)
 		return err;
@@ -1156,11 +1159,6 @@ int mmc_attach_sd(struct mmc_host *host)
 	BUG_ON(!host);
 	WARN_ON(!host->claimed);
 
-	/* Make sure we are at 3.3V signalling voltage */
-	err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330, false);
-	if (err)
-		return err;
-
 	/* Disable preset value enable if already set since last time */
 	if (host->ops->enable_preset_value) {
 		mmc_host_clk_hold(host);
diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 12cde6ee17f..2c7c83f832d 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -585,6 +585,9 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
 	 * Inform the card of the voltage
 	 */
 	if (!powered_resume) {
+		/* The initialization should be done at 3.3 V I/O voltage. */
+		mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330, 0);
+
 		err = mmc_send_io_op_cond(host, host->ocr, &ocr);
 		if (err)
 			goto err;
@@ -996,6 +999,11 @@ static int mmc_sdio_power_restore(struct mmc_host *host)
 	 * With these steps taken, mmc_select_voltage() is also required to
 	 * restore the correct voltage setting of the card.
 	 */
+
+	/* The initialization should be done at 3.3 V I/O voltage. */
+	if (!mmc_card_keep_power(host))
+		mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330, 0);
+
 	sdio_reset(host);
 	mmc_go_idle(host);
 	mmc_send_if_cond(host, host->ocr_avail);