From 3c29a5673617c8f03e0494febca310c2ea1f7ed9 Mon Sep 17 00:00:00 2001
From: Adam Ford <aford173@gmail.com>
Date: Thu, 24 Jan 2019 14:33:36 -0600
Subject: regulator: pbias: Handle extended drain IO when changing omap36 PBIAS

The OMAP36 and DM37 TRM state to disable extneded drain IO before
changing the PBIAS.  This patch does this before pmic writes if
the CONFIG_MMC_OMAP36XX_PINS flag is set and the cpu family is
omap36xx

Signed-off-by: Adam Ford <aford173@gmail.com>
---
 drivers/power/regulator/pbias_regulator.c | 49 +++++++++++++++++++++++++++++--
 1 file changed, 47 insertions(+), 2 deletions(-)

(limited to 'drivers/power')

diff --git a/drivers/power/regulator/pbias_regulator.c b/drivers/power/regulator/pbias_regulator.c
index 366f97b38b..4ed3c94e03 100644
--- a/drivers/power/regulator/pbias_regulator.c
+++ b/drivers/power/regulator/pbias_regulator.c
@@ -14,6 +14,11 @@
 #include <linux/bitops.h>
 #include <linux/ioport.h>
 #include <dm/read.h>
+#ifdef CONFIG_MMC_OMAP36XX_PINS
+#include <asm/arch/sys_proto.h>
+#include <asm/io.h>
+#include <asm/arch/mux.h>
+#endif
 
 struct pbias_reg_info {
 	u32 enable;
@@ -223,8 +228,11 @@ static int pbias_regulator_get_value(struct udevice *dev)
 static int pbias_regulator_set_value(struct udevice *dev, int uV)
 {
 	const struct pbias_reg_info *p = dev_get_priv(dev);
-	int rc;
+	int rc, ret;
 	u32 reg;
+#ifdef CONFIG_MMC_OMAP36XX_PINS
+	u32 wkup_ctrl = readl(OMAP34XX_CTRL_WKUP_CTRL);
+#endif
 
 	rc = pmic_read(dev->parent, 0, (uint8_t *)&reg, sizeof(reg));
 	if (rc)
@@ -240,7 +248,23 @@ static int pbias_regulator_set_value(struct udevice *dev, int uV)
 	debug("Setting %s voltage to %s\n", p->name,
 	      (reg & p->vmode) ? "3.0v" : "1.8v");
 
-	return pmic_write(dev->parent, 0, (uint8_t *)&reg, sizeof(reg));
+#ifdef CONFIG_MMC_OMAP36XX_PINS
+	if (get_cpu_family() == CPU_OMAP36XX) {
+		/* Disable extended drain IO before changing PBIAS */
+		wkup_ctrl &= ~OMAP34XX_CTRL_WKUP_CTRL_GPIO_IO_PWRDNZ;
+		writel(wkup_ctrl, OMAP34XX_CTRL_WKUP_CTRL);
+	}
+#endif
+	ret = pmic_write(dev->parent, 0, (uint8_t *)&reg, sizeof(reg));
+#ifdef CONFIG_MMC_OMAP36XX_PINS
+	if (get_cpu_family() == CPU_OMAP36XX) {
+		/* Enable extended drain IO after changing PBIAS */
+		writel(wkup_ctrl |
+				OMAP34XX_CTRL_WKUP_CTRL_GPIO_IO_PWRDNZ,
+				OMAP34XX_CTRL_WKUP_CTRL);
+	}
+#endif
+	return ret;
 }
 
 static int pbias_regulator_get_enable(struct udevice *dev)
@@ -264,9 +288,20 @@ static int pbias_regulator_set_enable(struct udevice *dev, bool enable)
 	const struct pbias_reg_info *p = dev_get_priv(dev);
 	int rc;
 	u32 reg;
+#ifdef CONFIG_MMC_OMAP36XX_PINS
+	u32 wkup_ctrl = readl(OMAP34XX_CTRL_WKUP_CTRL);
+#endif
 
 	debug("Turning %s %s\n", enable ? "on" : "off", p->name);
 
+#ifdef CONFIG_MMC_OMAP36XX_PINS
+	if (get_cpu_family() == CPU_OMAP36XX) {
+		/* Disable extended drain IO before changing PBIAS */
+		wkup_ctrl &= ~OMAP34XX_CTRL_WKUP_CTRL_GPIO_IO_PWRDNZ;
+		writel(wkup_ctrl, OMAP34XX_CTRL_WKUP_CTRL);
+	}
+#endif
+
 	rc = pmic_read(dev->parent, 0, (uint8_t *)&reg, sizeof(reg));
 	if (rc)
 		return rc;
@@ -278,6 +313,16 @@ static int pbias_regulator_set_enable(struct udevice *dev, bool enable)
 		reg |= p->disable_val;
 
 	rc = pmic_write(dev->parent, 0, (uint8_t *)&reg, sizeof(reg));
+
+#ifdef CONFIG_MMC_OMAP36XX_PINS
+	if (get_cpu_family() == CPU_OMAP36XX) {
+		/* Enable extended drain IO after changing PBIAS */
+		writel(wkup_ctrl |
+				OMAP34XX_CTRL_WKUP_CTRL_GPIO_IO_PWRDNZ,
+				OMAP34XX_CTRL_WKUP_CTRL);
+	}
+#endif
+
 	if (rc)
 		return rc;
 
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