mmc: core: Share internal function to set initial signal voltage

Move the corresponding code for setting the initial signal voltage, from
mmc_power_up() into a new function, mmc_set_initial_signal_voltage().

Make the function internally available to the mmc core, as to allow the
following changes to make use of it.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Quentin Schulz <quentin.schulz@bootlin.com>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>

drivers/mmc/core/core.c

@@ -1484,6 +1484,17 @@ int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage)
 
 }
 
+void mmc_set_initial_signal_voltage(struct mmc_host *host)
+{
+	/* Try to set signal voltage to 3.3V but fall back to 1.8v or 1.2v */
+	if (!mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330))
+		dev_dbg(mmc_dev(host), "Initial signal voltage of 3.3v\n");
+	else if (!mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180))
+		dev_dbg(mmc_dev(host), "Initial signal voltage of 1.8v\n");
+	else if (!mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120))
+		dev_dbg(mmc_dev(host), "Initial signal voltage of 1.2v\n");
+}
+
 int mmc_host_set_uhs_voltage(struct mmc_host *host)
 {
 	u32 clock;
@@ -1646,13 +1657,7 @@ void mmc_power_up(struct mmc_host *host, u32 ocr)
 	/* Set initial state and call mmc_set_ios */
 	mmc_set_initial_state(host);
 
-	/* Try to set signal voltage to 3.3V but fall back to 1.8v or 1.2v */
-	if (!mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330))
-		dev_dbg(mmc_dev(host), "Initial signal voltage of 3.3v\n");
-	else if (!mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180))
-		dev_dbg(mmc_dev(host), "Initial signal voltage of 1.8v\n");
-	else if (!mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120))
-		dev_dbg(mmc_dev(host), "Initial signal voltage of 1.2v\n");
+	mmc_set_initial_signal_voltage(host);
 
 	/*
 	 * This delay should be sufficient to allow the power supply

drivers/mmc/core/core.h

@@ -52,6 +52,7 @@ u32 mmc_select_voltage(struct mmc_host *host, u32 ocr);
 int mmc_set_uhs_voltage(struct mmc_host *host, u32 ocr);
 int mmc_host_set_uhs_voltage(struct mmc_host *host);
 int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage);
+void mmc_set_initial_signal_voltage(struct mmc_host *host);
 void mmc_set_timing(struct mmc_host *host, unsigned int timing);
 void mmc_set_driver_type(struct mmc_host *host, unsigned int drv_type);
 int mmc_select_drive_strength(struct mmc_card *card, unsigned int max_dtr,