mmc: core: Break out start_signal_voltage_switch

Allow callers to access the start_signal_voltage_switch host_ops
member without going through any cmd11 logic. This is mostly a
preparation for the following signal voltage switch patch.

Also, reset ios.signal_voltage to its original value if
start_signal_voltage_switch fails.

Signed-off-by: Johan Rudholm <johan.rudholm@stericsson.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Wei WANG <wei_wang@realsil.com.cn>
Signed-off-by: Chris Ball <cjb@laptop.org>

5 files changed, 31 insertions, 21 deletions

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 789056fbfc93..bb794c784597 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1317,7 +1317,26 @@ u32 mmc_select_voltage(struct mmc_host *host, u32 ocr)
         return ocr;
 }
 
-int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage, bool cmd11)
+int __mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage)
+{
+        int err = 0;
+        int old_signal_voltage = host->ios.signal_voltage;
+
+        host->ios.signal_voltage = signal_voltage;
+        if (host->ops->start_signal_voltage_switch) {
+                mmc_host_clk_hold(host);
+                err = host->ops->start_signal_voltage_switch(host, &host->ios);
+                mmc_host_clk_release(host);
+        }
+
+        if (err)
+                host->ios.signal_voltage = old_signal_voltage;
+
+        return err;
+
+}
+
+int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage)
 {
         struct mmc_command cmd = {0};
         int err = 0;
@@ -1328,7 +1347,7 @@ int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage, bool cmd11
          * Send CMD11 only if the request is to switch the card to
          * 1.8V signalling.
          */
-        if ((signal_voltage != MMC_SIGNAL_VOLTAGE_330) && cmd11) {
+        if (signal_voltage != MMC_SIGNAL_VOLTAGE_330) {
                 cmd.opcode = SD_SWITCH_VOLTAGE;
                 cmd.arg = 0;
                 cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
@@ -1341,15 +1360,7 @@ int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage, bool cmd11
                         return -EIO;
         }
 
-        host->ios.signal_voltage = signal_voltage;
-
-        if (host->ops->start_signal_voltage_switch) {
-                mmc_host_clk_hold(host);
-                err = host->ops->start_signal_voltage_switch(host, &host->ios);
-                mmc_host_clk_release(host);
-        }
-
-        return err;
+        return __mmc_set_signal_voltage(host, signal_voltage);
 }
 
 /*
@@ -1412,7 +1423,7 @@ static void mmc_power_up(struct mmc_host *host)
         mmc_set_ios(host);
 
         /* Set signal voltage to 3.3V */
-        mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330, false);
+        __mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330);
 
         /*
          * This delay should be sufficient to allow the power supply
diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
index 9007de74d8a9..b9f18a2a8874 100644
--- a/drivers/mmc/core/core.h
+++ b/drivers/mmc/core/core.h
@@ -40,8 +40,8 @@ void mmc_set_ungated(struct mmc_host *host);
 void mmc_set_bus_mode(struct mmc_host *host, unsigned int mode);
 void mmc_set_bus_width(struct mmc_host *host, unsigned int width);
 u32 mmc_select_voltage(struct mmc_host *host, u32 ocr);
-int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage,
-                           bool cmd11);
+int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage);
+int __mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage);
 void mmc_set_timing(struct mmc_host *host, unsigned int timing);
 void mmc_set_driver_type(struct mmc_host *host, unsigned int drv_type);
 void mmc_power_off(struct mmc_host *host);
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 0d7a9795a6da..8a3ad602a877 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -769,11 +769,11 @@ static int mmc_select_hs200(struct mmc_card *card)
 
         if (card->ext_csd.card_type & EXT_CSD_CARD_TYPE_SDR_1_2V &&
                         host->caps2 & MMC_CAP2_HS200_1_2V_SDR)
-                err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120, 0);
+                err = __mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120);
 
         if (err && card->ext_csd.card_type & EXT_CSD_CARD_TYPE_SDR_1_8V &&
                         host->caps2 & MMC_CAP2_HS200_1_8V_SDR)
-                err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180, 0);
+                err = __mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180);
 
         /* If fails try again during next card power cycle */
         if (err)
@@ -1221,8 +1221,8 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
                          * WARNING: eMMC rules are NOT the same as SD DDR
                          */
                         if (ddr == MMC_1_2V_DDR_MODE) {
-                                err = mmc_set_signal_voltage(host,
-                                        MMC_SIGNAL_VOLTAGE_120, 0);
+                                err = __mmc_set_signal_voltage(host,
+                                        MMC_SIGNAL_VOLTAGE_120);
                                 if (err)
                                         goto err;
                         }
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 937363948079..9a59fcd55a75 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -757,7 +757,7 @@ try_again:
          */
         if (!mmc_host_is_spi(host) && rocr &&
            ((*rocr & 0x41000000) == 0x41000000)) {
-                err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180, true);
+                err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180);
                 if (err) {
                         ocr &= ~SD_OCR_S18R;
                         goto try_again;
diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 3a64933466b8..1a726aef211d 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -647,8 +647,7 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
          * it.
          */
         if ((ocr & R4_18V_PRESENT) && mmc_host_uhs(host)) {
-                err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180,
-                                true);
+                err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180);
                 if (err) {
                         ocr &= ~R4_18V_PRESENT;
                         host->ocr &= ~R4_18V_PRESENT;