[PATCH 1/2] mmc: xenon: set signal voltage and max base clock

[Pali Rohár]

From: Evan Wang <xswang at marvell.com>

- The SDIO signal voltage and max base clock frequency
  setting are missing in driver, which causes SDIO
  not working.
- The patch adds SDIO signal voltage switch support,
  which is based on regulator-gpio of vqmmc-supply, and
  sets the max base clock frequency.
- Fix the zero clock value in call to sdhci_setup_cfg()
  function.

Change-Id: I79c8860c65b8db166f4f70db56ede4097f71f1fa
Signed-off-by: Evan Wang <xswang at marvell.com>
Reviewed-on: http://vgitil04.il.marvell.com:8080/53589
Reviewed-by: Hua Jing <jinghua at marvell.com>
Tested-by: Hua Jing <jinghua at marvell.com>
[pali: Amended fixup patch]
Signed-off-by: Pali Rohár <pali at kernel.org>
---
 drivers/mmc/xenon_sdhci.c | 79 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 78 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/xenon_sdhci.c b/drivers/mmc/xenon_sdhci.c
index 356dd9846d..7f9a579c83 100644
--- a/drivers/mmc/xenon_sdhci.c
+++ b/drivers/mmc/xenon_sdhci.c
@@ -22,6 +22,7 @@
 #include <linux/libfdt.h>
 #include <malloc.h>
 #include <sdhci.h>
+#include <power/regulator.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -42,6 +43,14 @@ DECLARE_GLOBAL_DATA_PTR;
 #define SDHC_SYS_EXT_OP_CTRL			0x010C
 #define MASK_CMD_CONFLICT_ERROR			BIT(8)
 
+#define SDHC_SLOT_EMMC_CTRL			0x0130
+#define ENABLE_DATA_STROBE_SHIFT		24
+#define SET_EMMC_RSTN_SHIFT			16
+#define EMMC_VCCQ_MASK				0x3
+#define EMMC_VCCQ_1_8V				0x1
+#define EMMC_VCCQ_1_2V				0x2
+#define	EMMC_VCCQ_3_3V				0x3
+
 #define SDHC_SLOT_RETUNING_REQ_CTRL		0x0144
 /* retuning compatible */
 #define RETUNING_COMPATIBLE			0x1
@@ -108,6 +117,8 @@ DECLARE_GLOBAL_DATA_PTR;
 #define MMC_TIMING_MMC_HS400	10
 
 #define XENON_MMC_MAX_CLK	400000000
+#define XENON_MMC_3V3_UV	3300000
+#define XENON_MMC_1V8_UV	1800000
 
 enum soc_pad_ctrl_type {
 	SOC_PAD_SD,
@@ -128,6 +139,8 @@ struct xenon_sdhci_priv {
 
 	void *pad_ctrl_reg;
 	int pad_type;
+
+	struct udevice *vqmmc;
 };
 
 static int xenon_mmc_phy_init(struct sdhci_host *host)
@@ -208,6 +221,51 @@ static void armada_3700_soc_pad_voltage_set(struct sdhci_host *host)
 		writel(ARMADA_3700_SOC_PAD_3_3V, priv->pad_ctrl_reg);
 }
 
+static int xenon_mmc_start_signal_voltage_switch(struct sdhci_host *host)
+{
+	struct xenon_sdhci_priv *priv = host->mmc->priv;
+	u8 voltage;
+	u32 ctrl;
+	int ret = 0;
+
+	/* If there is no vqmmc regulator, return */
+	if (!priv->vqmmc)
+		return 0;
+
+	if (priv->pad_type == SOC_PAD_FIXED_1_8V) {
+		/* Switch to 1.8v */
+		ret = regulator_set_value(priv->vqmmc,
+					  XENON_MMC_1V8_UV);
+	} else if (priv->pad_type == SOC_PAD_SD) {
+		/* Get voltage info */
+		voltage = sdhci_readb(host, SDHCI_POWER_CONTROL);
+		voltage &= ~SDHCI_POWER_ON;
+
+		if (voltage == SDHCI_POWER_330) {
+			/* Switch to 3.3v */
+			ret = regulator_set_value(priv->vqmmc,
+						  XENON_MMC_3V3_UV);
+		} else {
+			/* Switch to 1.8v */
+			ret = regulator_set_value(priv->vqmmc,
+						  XENON_MMC_1V8_UV);
+		}
+	}
+
+	/* Set VCCQ, eMMC mode: 1.8V; SD/SDIO mode: 3.3V */
+	ctrl = sdhci_readl(host, SDHC_SLOT_EMMC_CTRL);
+	if (IS_SD(host->mmc))
+		ctrl |= EMMC_VCCQ_3_3V;
+	else
+		ctrl |= EMMC_VCCQ_1_8V;
+	sdhci_writel(host, ctrl, SDHC_SLOT_EMMC_CTRL);
+
+	if (ret)
+		printf("Signal voltage switch fail\n");
+
+	return ret;
+}
+
 static void xenon_mmc_phy_set(struct sdhci_host *host)
 {
 	struct xenon_sdhci_priv *priv = host->mmc->priv;
@@ -334,6 +392,13 @@ static int xenon_sdhci_set_ios_post(struct sdhci_host *host)
 	uint speed = host->mmc->tran_speed;
 	int pwr_18v = 0;
 
+	/*
+	 * Signal Voltage Switching is only applicable for Host Controllers
+	 * v3.00 and above.
+	 */
+	if (SDHCI_GET_VERSION(host) >= SDHCI_SPEC_300)
+		xenon_mmc_start_signal_voltage_switch(host);
+
 	if ((sdhci_readb(host, SDHCI_POWER_CONTROL) & ~SDHCI_POWER_ON) ==
 	    SDHCI_POWER_180)
 		pwr_18v = 1;
@@ -394,6 +459,18 @@ static int xenon_sdhci_probe(struct udevice *dev)
 	/* Set default timing */
 	priv->timing = MMC_TIMING_LEGACY;
 
+	/* Get the vqmmc regulator if there is */
+	device_get_supply_regulator(dev, "vqmmc-supply", &priv->vqmmc);
+	/* Set the initial voltage value to 3.3V if there is regulator */
+	if (priv->vqmmc) {
+		ret = regulator_set_value(priv->vqmmc,
+					  XENON_MMC_3V3_UV);
+		if (ret) {
+			printf("Failed to set VQMMC regulator to 3.3V\n");
+			return ret;
+		}
+	}
+
 	/* Disable auto clock gating during init */
 	xenon_mmc_set_acg(host, false);
 
@@ -426,7 +503,7 @@ static int xenon_sdhci_probe(struct udevice *dev)
 	host->ops = &xenon_sdhci_ops;
 
 	host->max_clk = XENON_MMC_MAX_CLK;
-	ret = sdhci_setup_cfg(&plat->cfg, host, 0, 0);
+	ret = sdhci_setup_cfg(&plat->cfg, host, XENON_MMC_MAX_CLK, 0);
 	if (ret)
 		return ret;
 
-- 
2.20.1