mmc: sdhci-msm: Configuring IO_PAD support for sdhci-msm

index c283291..a822f10 100644
@@ -21,6 +21,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/slab.h>
 #include <linux/iopoll.h>
+#include <linux/regulator/consumer.h>
 
 #include "sdhci-pltfm.h"
 

@@ -81,6 +82,9 @@
 #define CORE_HC_SELECT_IN_HS400	(6 << 19)
 #define CORE_HC_SELECT_IN_MASK	(7 << 19)
 
+#define CORE_3_0V_SUPPORT	(1 << 25)
+#define CORE_1_8V_SUPPORT	(1 << 26)
+
 #define CORE_CSR_CDC_CTLR_CFG0		0x130
 #define CORE_SW_TRIG_FULL_CALIB		BIT(16)
 #define CORE_HW_AUTOCAL_ENA		BIT(17)

@@ -148,6 +152,7 @@ struct sdhci_msm_host {
 	u32 curr_io_level;
 	wait_queue_head_t pwr_irq_wait;
 	bool pwr_irq_flag;
+	u32 caps_0;
 };
 
 static unsigned int msm_get_clock_rate_for_bus_mode(struct sdhci_host *host,

@@ -1103,7 +1108,7 @@ static void sdhci_msm_handle_pwr_irq(struct sdhci_host *host, int irq)
 	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
 	u32 irq_status, irq_ack = 0;
 	int retry = 10;
-	int pwr_state = 0, io_level = 0;
+	u32 pwr_state = 0, io_level = 0;
 
 
 	irq_status = readl_relaxed(msm_host->core_mem + CORE_PWRCTL_STATUS);

@@ -1313,6 +1318,31 @@ static void sdhci_msm_writeb(struct sdhci_host *host, u8 val, int reg)
 		sdhci_msm_check_power_status(host, req_type);
 }
 
+static int sdhci_msm_set_regulator_caps(struct sdhci_msm_host *msm_host)
+{
+	struct mmc_host *mmc = msm_host->mmc;
+	struct regulator *supply = mmc->supply.vqmmc;
+	u32 caps = 0;
+
+	if (!IS_ERR(mmc->supply.vqmmc)) {
+		if (regulator_is_supported_voltage(supply, 1700000, 1950000))
+			caps |= CORE_1_8V_SUPPORT;
+		if (regulator_is_supported_voltage(supply, 2700000, 3600000))
+			caps |= CORE_3_0V_SUPPORT;
+
+		if (!caps)
+			pr_warn("%s: %s: 1.8/3V not supported for vqmmc\n",
+					mmc_hostname(mmc), __func__);
+	}
+
+	msm_host->caps_0 |= caps;
+	pr_debug("%s: %s: supported caps: 0x%08x\n", mmc_hostname(mmc),
+			__func__, caps);
+
+	return 0;
+}
+
+
 static const struct of_device_id sdhci_msm_dt_match[] = {
 	{ .compatible = "qcom,sdhci-msm-v4" },
 	{},

@@ -1530,6 +1560,10 @@ static int sdhci_msm_probe(struct platform_device *pdev)
 	ret = sdhci_add_host(host);
 	if (ret)
 		goto pm_runtime_disable;
+	ret = sdhci_msm_set_regulator_caps(msm_host);
+	if (ret)
+		dev_err(&pdev->dev, "Failed to set regulator caps: %d\n",
+				ret);
 
 	pm_runtime_mark_last_busy(&pdev->dev);
 	pm_runtime_put_autosuspend(&pdev->dev);

index a822f10..2ffb7bb 100644
@@ -78,12 +78,15 @@
 #define CORE_HC_MCLK_SEL_DFLT	(2 << 8)
 #define CORE_HC_MCLK_SEL_HS400	(3 << 8)
 #define CORE_HC_MCLK_SEL_MASK	(3 << 8)
+#define CORE_IO_PAD_PWR_SWITCH_EN	(1 << 15)
+#define CORE_IO_PAD_PWR_SWITCH  (1 << 16)
 #define CORE_HC_SELECT_IN_EN	BIT(18)
 #define CORE_HC_SELECT_IN_HS400	(6 << 19)
 #define CORE_HC_SELECT_IN_MASK	(7 << 19)
 
 #define CORE_3_0V_SUPPORT	(1 << 25)
 #define CORE_1_8V_SUPPORT	(1 << 26)
+#define CORE_VOLT_SUPPORT	(CORE_3_0V_SUPPORT | CORE_1_8V_SUPPORT)
 
 #define CORE_CSR_CDC_CTLR_CFG0		0x130
 #define CORE_SW_TRIG_FULL_CALIB		BIT(16)

@@ -1109,7 +1112,7 @@ static void sdhci_msm_handle_pwr_irq(struct sdhci_host *host, int irq)
 	u32 irq_status, irq_ack = 0;
 	int retry = 10;
 	u32 pwr_state = 0, io_level = 0;
-
+	u32 config;
 
 	irq_status = readl_relaxed(msm_host->core_mem + CORE_PWRCTL_STATUS);
 	irq_status &= INT_MASK;

@@ -1166,11 +1169,51 @@ static void sdhci_msm_handle_pwr_irq(struct sdhci_host *host, int irq)
 	 */
 	writel_relaxed(irq_ack, msm_host->core_mem + CORE_PWRCTL_CTL);
 
+	/*
+	 * If we don't have info regarding the voltage levels supported by
+	 * regulators, don't change the IO PAD PWR SWITCH.
+	 */
+	if (msm_host->caps_0 & CORE_VOLT_SUPPORT) {
+		/* Ensure order between core_mem and hc_mem */
+		mb();
+		/*
+		 * We should unset IO PAD PWR switch only if the register write
+		 * can set IO lines high and the regulator also switches to 3 V.
+		 * Else, we should keep the IO PAD PWR switch set.
+		 * This is applicable to certain targets where eMMC vccq supply
+		 * is only 1.8V. In such targets, even during REQ_IO_HIGH, the
+		 * IO PAD PWR switch must be kept set to reflect actual
+		 * regulator voltage. This way, during initialization of
+		 * controllers with only 1.8V, we will set the IO PAD bit
+		 * without waiting for a REQ_IO_LOW.
+		 */
+		config = readl_relaxed(host->ioaddr + CORE_VENDOR_SPEC);
+
+		if (((io_level & REQ_IO_HIGH) && (msm_host->caps_0 &
+				CORE_3_0V_SUPPORT)) &&
+				(config & CORE_IO_PAD_PWR_SWITCH)) {
+			config &= ~CORE_IO_PAD_PWR_SWITCH;
+			writel_relaxed(config,
+					host->ioaddr + CORE_VENDOR_SPEC);
+			/* IO PAD register is in different memory space */
+			mb();
+		} else if (((io_level & REQ_IO_LOW) ||
+				(msm_host->caps_0 & CORE_1_8V_SUPPORT)) &&
+				!(config & CORE_IO_PAD_PWR_SWITCH)) {
+			config |= CORE_IO_PAD_PWR_SWITCH;
+			writel_relaxed(config,
+					host->ioaddr + CORE_VENDOR_SPEC);
+			/* IO PAD bit is in different memory space */
+			mb();
+		}
+	}
+
 	if (pwr_state)
 		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);

@@ -1322,7 +1365,8 @@ static int sdhci_msm_set_regulator_caps(struct sdhci_msm_host *msm_host)
 {
 	struct mmc_host *mmc = msm_host->mmc;
 	struct regulator *supply = mmc->supply.vqmmc;
-	u32 caps = 0;
+	u32 caps = 0, config;
+	struct sdhci_host *host = mmc_priv(mmc);
 
 	if (!IS_ERR(mmc->supply.vqmmc)) {
 		if (regulator_is_supported_voltage(supply, 1700000, 1950000))

@@ -1335,6 +1379,23 @@ static int sdhci_msm_set_regulator_caps(struct sdhci_msm_host *msm_host)
 					mmc_hostname(mmc), __func__);
 	}
 
+	if (caps) {
+		/*
+		 * Set the PAD_PWR_SWITCH_EN bit so that the PAD_PWR_SWITCH
+		 * bit can be used as required later on.
+		 */
+		u32 io_level = msm_host->curr_io_level;
+
+		config = readl_relaxed(host->ioaddr + CORE_VENDOR_SPEC);
+		config |= CORE_IO_PAD_PWR_SWITCH_EN;
+
+		if ((io_level & REQ_IO_HIGH) && (caps &	CORE_3_0V_SUPPORT))
+			config &= ~CORE_IO_PAD_PWR_SWITCH;
+		else if ((io_level & REQ_IO_LOW) || (caps & CORE_1_8V_SUPPORT))
+			config |= CORE_IO_PAD_PWR_SWITCH;
+
+		writel_relaxed(config, host->ioaddr + CORE_VENDOR_SPEC);
+	}
 	msm_host->caps_0 |= caps;
 	pr_debug("%s: %s: supported caps: 0x%08x\n", mmc_hostname(mmc),
 			__func__, caps);