diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index a0dc3e1..47732a2 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -43,7 +43,9 @@
 #define CORE_PWRCTL_IO_LOW	BIT(2)
 #define CORE_PWRCTL_IO_HIGH	BIT(3)
 #define CORE_PWRCTL_BUS_SUCCESS BIT(0)
+#define CORE_PWRCTL_BUS_FAIL    BIT(1)
 #define CORE_PWRCTL_IO_SUCCESS	BIT(2)
+#define CORE_PWRCTL_IO_FAIL     BIT(3)
 #define REQ_BUS_OFF		BIT(0)
 #define REQ_BUS_ON		BIT(1)
 #define REQ_IO_LOW		BIT(2)
@@ -236,6 +238,14 @@ struct sdhci_msm_variant_info {
 	const struct sdhci_msm_offset *offset;
 };
 
+/* Holds voltage regulator information to be used by the driver*/
+struct sdhci_msm_vreg_info {
+	bool vmmc_load;
+	u32 vmmc_level[2];
+	bool vqmmc_load;
+	u32 vqmmc_level[2];
+};
+
 struct sdhci_msm_host {
 	struct platform_device *pdev;
 	void __iomem *core_mem;	/* MSM SDCC mapped address */
@@ -258,6 +268,8 @@ struct sdhci_msm_host {
 	bool mci_removed;
 	const struct sdhci_msm_variant_ops *var_ops;
 	const struct sdhci_msm_offset *offset;
+	struct sdhci_msm_vreg_info vreg_info;
+	bool pltfm_init_done;
 };
 
 static const struct sdhci_msm_offset *sdhci_priv_msm_offset(struct sdhci_host *host)
@@ -1314,11 +1326,13 @@ static void sdhci_msm_handle_pwr_irq(struct sdhci_host *host, int irq)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
+	struct mmc_host *mmc = host->mmc;
 	u32 irq_status, irq_ack = 0;
-	int retry = 10;
+	int retry = 10, ret = 0;
 	u32 pwr_state = 0, io_level = 0;
 	u32 config;
 	const struct sdhci_msm_offset *msm_offset = msm_host->offset;
+	struct sdhci_msm_vreg_info vreg_info = msm_host->vreg_info;
 
 	irq_status = msm_host_readl(msm_host, host,
 			msm_offset->core_pwrctl_status);
@@ -1351,14 +1365,91 @@ static void sdhci_msm_handle_pwr_irq(struct sdhci_host *host, int irq)
 
 	/* Handle BUS ON/OFF*/
 	if (irq_status & CORE_PWRCTL_BUS_ON) {
-		pwr_state = REQ_BUS_ON;
-		io_level = REQ_IO_HIGH;
-		irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
+		if (!IS_ERR(mmc->supply.vmmc)) {
+			if (vreg_info.vmmc_load)
+				ret = regulator_set_load(mmc->supply.vmmc,
+						vreg_info.vmmc_level[1]);
+			ret |= mmc_regulator_set_ocr(mmc, mmc->supply.vmmc,
+					mmc->ios.vdd);
+			if (ret)
+				pr_err("%s: vmmc enable failed: %d\n",
+						mmc_hostname(mmc), ret);
+		}
+
+		if (!IS_ERR(mmc->supply.vqmmc) && !ret) {
+			struct mmc_ios ios;
+
+			if (vreg_info.vqmmc_load)
+				ret = regulator_set_load(mmc->supply.vqmmc,
+						vreg_info.vqmmc_level[1]);
+			/*
+			 * The IO voltage regulator maynot always support
+			 * a voltage close to vdd. Set IO voltage based on
+			 * capability of the regulator.
+			 */
+			if (msm_host->caps_0 & CORE_3_0V_SUPPORT)
+				ios.signal_voltage = MMC_SIGNAL_VOLTAGE_330;
+			else if (msm_host->caps_0 & CORE_1_8V_SUPPORT)
+				ios.signal_voltage = MMC_SIGNAL_VOLTAGE_180;
+			if (msm_host->caps_0 & CORE_VOLT_SUPPORT) {
+				pr_err("%s: %s: setting signal voltage: %d\n",
+						mmc_hostname(mmc), __func__,
+						ios.signal_voltage);
+				ret |= mmc_regulator_set_vqmmc(mmc, &ios);
+			}
+
+			if (!ret)
+				ret = regulator_enable(mmc->supply.vqmmc);
+			if (ret)
+				pr_err("%s: vqmmc enable failed: %d\n",
+						mmc_hostname(mmc), ret);
+		}
+		if (!ret) {
+			pwr_state = REQ_BUS_ON;
+			io_level = REQ_IO_HIGH;
+			irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
+		} else {
+			pr_err("%s: BUS_ON req failed(%d). irq_status: 0x%08x\n",
+					mmc_hostname(mmc), ret, irq_status);
+			irq_ack |= CORE_PWRCTL_BUS_FAIL;
+		}
 	}
 	if (irq_status & CORE_PWRCTL_BUS_OFF) {
-		pwr_state = REQ_BUS_OFF;
-		io_level = REQ_IO_LOW;
-		irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
+		/*
+		 * During platform initialization, we may get BUS_OFF request
+		 * and turn off the supply. EMMC devices expect Power off
+		 * notification before being turned off. So wait till platform
+		 * initialization is over to actually turn off power.
+		 */
+		if (!IS_ERR(mmc->supply.vmmc) && msm_host->pltfm_init_done) {
+			if (vreg_info.vmmc_load)
+				ret = regulator_set_load(mmc->supply.vmmc,
+						vreg_info.vmmc_level[0]);
+			ret |= mmc_regulator_set_ocr(mmc, mmc->supply.vmmc,
+					mmc->ios.vdd);
+			if (ret)
+				pr_err("%s: vmmc disabling failed: %d\n",
+						mmc_hostname(mmc), ret);
+		}
+		if (!IS_ERR(mmc->supply.vqmmc) && msm_host->pltfm_init_done &&
+				!ret) {
+			if (vreg_info.vqmmc_load)
+				ret = regulator_set_load(mmc->supply.vqmmc,
+						vreg_info.vqmmc_level[0]);
+			ret |= regulator_disable(mmc->supply.vqmmc);
+			if (ret)
+				pr_err("%s: vqmmc disabling failed: %d\n",
+						mmc_hostname(mmc), ret);
+		}
+		if (!ret) {
+			pwr_state = REQ_BUS_OFF;
+			io_level = REQ_IO_LOW;
+			irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
+		} else {
+			pr_err("%s: BUS_ON req failed(%d). irq_status: 0x%08x\n",
+					mmc_hostname(mmc), ret, irq_status);
+			irq_ack |= CORE_PWRCTL_BUS_FAIL;
+		}
 	}
 	/* Handle IO LOW/HIGH */
 	if (irq_status & CORE_PWRCTL_IO_LOW) {
@@ -1370,6 +1461,15 @@ static void sdhci_msm_handle_pwr_irq(struct sdhci_host *host, int irq)
 		irq_ack |= CORE_PWRCTL_IO_SUCCESS;
 	}
 
+	if (io_level && !IS_ERR(mmc->supply.vqmmc) && !pwr_state) {
+		ret = mmc_regulator_set_vqmmc(mmc, &mmc->ios);
+		if (ret)
+			pr_err("%s: IO_level setting failed(%d). signal_voltage: %d, vdd: %d irq_status: 0x%08x\n",
+					mmc_hostname(mmc), ret,
+					mmc->ios.signal_voltage, mmc->ios.vdd,
+					irq_status);
+	}
+
 	/*
 	 * The driver has to acknowledge the interrupt, switch voltages and
 	 * report back if it succeded or not to this register. The voltage
@@ -1415,10 +1515,9 @@ static void sdhci_msm_handle_pwr_irq(struct sdhci_host *host, int irq)
 		msm_host->curr_pwr_state = pwr_state;
 	if (io_level)
 		msm_host->curr_io_level = io_level;
-
 	pr_debug("%s: %s: Handled IRQ(%d), irq_status=0x%x, ack=0x%x\n",
-		mmc_hostname(msm_host->mmc), __func__, irq, irq_status,
-		irq_ack);
+			mmc_hostname(msm_host->mmc), __func__,
+			irq, irq_status, irq_ack);
 }
 
 static irqreturn_t sdhci_msm_pwr_irq(int irq, void *data)
@@ -1563,6 +1662,13 @@ static void sdhci_msm_writeb(struct sdhci_host *host, u8 val, int reg)
 		sdhci_msm_check_power_status(host, req_type);
 }
 
+static void sdhci_msm_set_power(struct sdhci_host *host, unsigned char mode,
+		     unsigned short vdd)
+{
+	sdhci_set_power_noreg(host, mode, vdd);
+
+}
+
 static void sdhci_msm_set_regulator_caps(struct sdhci_msm_host *msm_host)
 {
 	struct mmc_host *mmc = msm_host->mmc;
@@ -1605,6 +1711,91 @@ static void sdhci_msm_set_regulator_caps(struct sdhci_msm_host *msm_host)
 	pr_debug("%s: supported caps: 0x%08x\n", mmc_hostname(mmc), caps);
 }
 
+static int sdhci_msm_register_vreg(struct sdhci_msm_host *msm_host)
+{
+	int ret = 0;
+
+	ret = mmc_regulator_get_supply(msm_host->mmc);
+	if (ret)
+		return ret;
+	if (device_property_read_u32_array(&msm_host->pdev->dev,
+			"vmmc-current-level",
+			msm_host->vreg_info.vmmc_level, 2) >= 0)
+		msm_host->vreg_info.vmmc_load = true;
+	if (device_property_read_u32_array(&msm_host->pdev->dev,
+			"vqmmc-current-level",
+			msm_host->vreg_info.vqmmc_level, 2) >= 0)
+		msm_host->vreg_info.vqmmc_load = true;
+
+	sdhci_msm_set_regulator_caps(msm_host);
+
+	return 0;
+
+}
+
+static int sdhci_msm_start_signal_voltage_switch(struct mmc_host *mmc,
+				      struct mmc_ios *ios)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	u16 ctrl;
+
+	/*
+	 * Signal Voltage Switching is only applicable for Host Controllers
+	 * v3.00 and above.
+	 */
+	if (host->version < SDHCI_SPEC_300)
+		return 0;
+
+	ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+
+	switch (ios->signal_voltage) {
+	case MMC_SIGNAL_VOLTAGE_330:
+		if (!(host->flags & SDHCI_SIGNALING_330))
+			return -EINVAL;
+		/* Set 1.8V Signal Enable in the Host Control2 register to 0 */
+		ctrl &= ~SDHCI_CTRL_VDD_180;
+		sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
+
+		/* 3.3V regulator output should be stable within 5 ms */
+		ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+		if (!(ctrl & SDHCI_CTRL_VDD_180))
+			return 0;
+
+		pr_warn("%s: 3.3V regulator output did not became stable\n",
+			mmc_hostname(mmc));
+
+		return -EAGAIN;
+	case MMC_SIGNAL_VOLTAGE_180:
+		if (!(host->flags & SDHCI_SIGNALING_180))
+			return -EINVAL;
+
+		/*
+		 * Enable 1.8V Signal Enable in the Host Control2
+		 * register
+		 */
+		ctrl |= SDHCI_CTRL_VDD_180;
+		sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
+
+		/* 1.8V regulator output should be stable within 5 ms */
+		ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+		if (ctrl & SDHCI_CTRL_VDD_180)
+			return 0;
+
+		pr_warn("%s: 1.8V regulator output did not became stable\n",
+			mmc_hostname(mmc));
+
+		return -EAGAIN;
+	case MMC_SIGNAL_VOLTAGE_120:
+		if (!(host->flags & SDHCI_SIGNALING_120))
+			return -EINVAL;
+		return 0;
+	default:
+		/* No signal voltage switch required */
+		return 0;
+	}
+
+}
+
 static const struct sdhci_msm_variant_ops mci_var_ops = {
 	.msm_readl_relaxed = sdhci_msm_mci_variant_readl_relaxed,
 	.msm_writel_relaxed = sdhci_msm_mci_variant_writel_relaxed,
@@ -1644,6 +1835,7 @@ static void sdhci_msm_set_regulator_caps(struct sdhci_msm_host *msm_host)
 	.set_uhs_signaling = sdhci_msm_set_uhs_signaling,
 	.write_w = sdhci_msm_writew,
 	.write_b = sdhci_msm_writeb,
+	.set_power = sdhci_msm_set_power,
 };
 
 static const struct sdhci_pltfm_data sdhci_msm_pdata = {
@@ -1672,6 +1864,8 @@ static int sdhci_msm_probe(struct platform_device *pdev)
 	if (IS_ERR(host))
 		return PTR_ERR(host);
 
+	host->mmc_host_ops.start_signal_voltage_switch =
+		sdhci_msm_start_signal_voltage_switch;
 	host->sdma_boundary = 0;
 	pltfm_host = sdhci_priv(host);
 	msm_host = sdhci_pltfm_priv(pltfm_host);
@@ -1819,6 +2013,10 @@ static int sdhci_msm_probe(struct platform_device *pdev)
 				msm_offset->core_vendor_spec_capabilities0);
 	}
 
+	ret = sdhci_msm_register_vreg(msm_host);
+	if (ret == -EPROBE_DEFER)
+		goto clk_disable;
+
 	/*
 	 * Power on reset state may trigger power irq if previous status of
 	 * PWRCTL was either BUS_ON or IO_HIGH_V. So before enabling pwr irq
@@ -1867,7 +2065,7 @@ static int sdhci_msm_probe(struct platform_device *pdev)
 	ret = sdhci_add_host(host);
 	if (ret)
 		goto pm_runtime_disable;
-	sdhci_msm_set_regulator_caps(msm_host);
+	msm_host->pltfm_init_done = true;
 
 	pm_runtime_mark_last_busy(&pdev->dev);
 	pm_runtime_put_autosuspend(&pdev->dev);
