mmc: host: Prepare host drivers for mmc_regulator_set_vqmmc() returning > 0

Patch all drivers which use mmc_regulator_set_vqmmc() and prepare them for
the fact that mmc_regulator_set_vqmmc() can return a value > 0, which would
happen if the signal voltage switch did NOT happen, because the voltage was
already set correctly.
Signed-off-by: Marek Vasut <marex@denx.de>
Link: https://lore.kernel.org/r/20200416163649.336967-1-marex@denx.de
[Ulf: Re-worked/simplified the code a bit]
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/dw_mmc-k3.c

@@ -424,7 +424,7 @@ static int dw_mci_hi3660_switch_voltage(struct mmc_host *mmc,
 
 	if (!IS_ERR(mmc->supply.vqmmc)) {
 		ret = mmc_regulator_set_vqmmc(mmc, ios);
-		if (ret) {
+		if (ret < 0) {
 			dev_err(host->dev, "Regulator set error %d\n", ret);
 			return ret;
 		}

drivers/mmc/host/dw_mmc.c

@@ -1546,8 +1546,7 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
 
 	if (!IS_ERR(mmc->supply.vqmmc)) {
 		ret = mmc_regulator_set_vqmmc(mmc, ios);
-
-		if (ret) {
+		if (ret < 0) {
 			dev_dbg(&mmc->class_dev,
 					 "Regulator set error %d - %s V\n",
 					 ret, uhs & v18 ? "1.8" : "3.3");

drivers/mmc/host/meson-gx-mmc.c

@@ -1004,6 +1004,8 @@ static int meson_mmc_card_busy(struct mmc_host *mmc)
 
 static int meson_mmc_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
 {
+	int ret;
+
 	/* vqmmc regulator is available */
 	if (!IS_ERR(mmc->supply.vqmmc)) {
 		/*
@@ -1013,7 +1015,8 @@ static int meson_mmc_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
 		 * to 1.8v. Please make sure the regulator framework is aware
 		 * of your own regulator constraints
 		 */
-		return mmc_regulator_set_vqmmc(mmc, ios);
+		ret = mmc_regulator_set_vqmmc(mmc, ios);
+		return ret < 0 ? ret : 0;
 	}
 
 	/* no vqmmc regulator, assume fixed regulator at 3/3.3V */

drivers/mmc/host/mtk-sd.c

@@ -1369,7 +1369,7 @@ static void msdc_set_buswidth(struct msdc_host *host, u32 width)
 static int msdc_ops_switch_volt(struct mmc_host *mmc, struct mmc_ios *ios)
 {
 	struct msdc_host *host = mmc_priv(mmc);
-	int ret = 0;
+	int ret;
 
 	if (!IS_ERR(mmc->supply.vqmmc)) {
 		if (ios->signal_voltage != MMC_SIGNAL_VOLTAGE_330 &&
@@ -1379,18 +1379,19 @@ static int msdc_ops_switch_volt(struct mmc_host *mmc, struct mmc_ios *ios)
 		}
 
 		ret = mmc_regulator_set_vqmmc(mmc, ios);
-		if (ret) {
+		if (ret < 0) {
 			dev_dbg(host->dev, "Regulator set error %d (%d)\n",
 				ret, ios->signal_voltage);
-		} else {
-			/* Apply different pinctrl settings for different signal voltage */
-			if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180)
-				pinctrl_select_state(host->pinctrl, host->pins_uhs);
-			else
-				pinctrl_select_state(host->pinctrl, host->pins_default);
+			return ret;
 		}
+
+		/* Apply different pinctrl settings for different signal voltage */
+		if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180)
+			pinctrl_select_state(host->pinctrl, host->pins_uhs);
+		else
+			pinctrl_select_state(host->pinctrl, host->pins_default);
 	}
-	return ret;
+	return 0;
 }
 
 static int msdc_card_busy(struct mmc_host *mmc)

drivers/mmc/host/renesas_sdhi_core.c

@@ -237,7 +237,7 @@ static int renesas_sdhi_start_signal_voltage_switch(struct mmc_host *mmc,
 			MMC_SIGNAL_VOLTAGE_330 ? 0 : -EINVAL;
 
 	ret = mmc_regulator_set_vqmmc(host->mmc, ios);
-	if (ret)
+	if (ret < 0)
 		return ret;
 
 	return pinctrl_select_state(priv->pinctrl, pin_state);

drivers/mmc/host/sdhci-sprd.c

@@ -434,7 +434,7 @@ static int sdhci_sprd_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
 
 	if (!IS_ERR(mmc->supply.vqmmc)) {
 		ret = mmc_regulator_set_vqmmc(mmc, ios);
-		if (ret) {
+		if (ret < 0) {
 			pr_err("%s: Switching signalling voltage failed\n",
 			       mmc_hostname(mmc));
 			return ret;

drivers/mmc/host/sdhci.c

@@ -2411,7 +2411,7 @@ int sdhci_start_signal_voltage_switch(struct mmc_host *mmc,
 
 		if (!IS_ERR(mmc->supply.vqmmc)) {
 			ret = mmc_regulator_set_vqmmc(mmc, ios);
-			if (ret) {
+			if (ret < 0) {
 				pr_warn("%s: Switching to 3.3V signalling voltage failed\n",
 					mmc_hostname(mmc));
 				return -EIO;
@@ -2434,7 +2434,7 @@ int sdhci_start_signal_voltage_switch(struct mmc_host *mmc,
 			return -EINVAL;
 		if (!IS_ERR(mmc->supply.vqmmc)) {
 			ret = mmc_regulator_set_vqmmc(mmc, ios);
-			if (ret) {
+			if (ret < 0) {
 				pr_warn("%s: Switching to 1.8V signalling voltage failed\n",
 					mmc_hostname(mmc));
 				return -EIO;
@@ -2466,7 +2466,7 @@ int sdhci_start_signal_voltage_switch(struct mmc_host *mmc,
 			return -EINVAL;
 		if (!IS_ERR(mmc->supply.vqmmc)) {
 			ret = mmc_regulator_set_vqmmc(mmc, ios);
-			if (ret) {
+			if (ret < 0) {
 				pr_warn("%s: Switching to 1.2V signalling voltage failed\n",
 					mmc_hostname(mmc));
 				return -EIO;

drivers/mmc/host/sunxi-mmc.c

@@ -951,9 +951,13 @@ static void sunxi_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 
 static int sunxi_mmc_volt_switch(struct mmc_host *mmc, struct mmc_ios *ios)
 {
+	int ret;
+
 	/* vqmmc regulator is available */
-	if (!IS_ERR(mmc->supply.vqmmc))
-		return mmc_regulator_set_vqmmc(mmc, ios);
+	if (!IS_ERR(mmc->supply.vqmmc)) {
+		ret = mmc_regulator_set_vqmmc(mmc, ios);
+		return ret < 0 ? ret : 0;
+	}
 
 	/* no vqmmc regulator, assume fixed regulator at 3/3.3V */
 	if (mmc->ios.signal_voltage == MMC_SIGNAL_VOLTAGE_330)