[PATCH 2/4] regulator: claim the enable GPIO at probe time, not in of_to_plat()

[Mehmet Fide <mehmet.fide@gmail.com>]

From: Mehmet Fide <mehmet.fide@screeningeagle.com>

regulator_common_of_to_plat() requests the enable GPIO, which probes
the GPIO controller and claims the pin while the consumer's platform
data is still being read. of_to_plat() must not do either: it runs
before the device's pinctrl state is applied, so on SoCs where the
direction lives in the pad register - the output enable on Vybrid is
one - the pinctrl undoes the direction the early claim just set, and a
fixed regulator configured as always-on powers nothing.

Parse the GPIO into the platform data in of_to_plat() and request it in
the new regulator_common_probe(), called from the fixed and fixed-clock
regulator probe methods. The gpio regulator's voltage-control GPIO has
the same problem and moves the same way.

Signed-off-by: Mehmet Fide <mehmet.fide@screeningeagle.com>
---
 drivers/power/regulator/fixed.c            | 11 ++++++++++
 drivers/power/regulator/gpio-regulator.c   | 21 +++++++++++++++---
 drivers/power/regulator/regulator_common.c | 25 ++++++++++++++++++----
 drivers/power/regulator/regulator_common.h |  3 +++
 4 files changed, 53 insertions(+), 7 deletions(-)

diff --git a/drivers/power/regulator/fixed.c b/drivers/power/regulator/fixed.c
index 1dd137f493e..b8e3af0f0ca 100644
--- a/drivers/power/regulator/fixed.c
+++ b/drivers/power/regulator/fixed.c
@@ -38,6 +38,11 @@ static int fixed_regulator_of_to_plat(struct udevice *dev)
 	return regulator_common_of_to_plat(dev, plat, gpios ? "gpios" : "gpio");
 }
 
+static int fixed_regulator_probe(struct udevice *dev)
+{
+	return regulator_common_probe(dev, dev_get_plat(dev));
+}
+
 static int fixed_regulator_get_value(struct udevice *dev)
 {
 	struct dm_regulator_uclass_plat *uc_pdata;
@@ -115,6 +120,11 @@ static int fixed_clock_regulator_set_enable(struct udevice *dev, bool enable)
 static int fixed_clock_regulator_probe(struct udevice *dev)
 {
 	struct fixed_clock_regulator_priv *priv = dev_get_priv(dev);
+	int ret;
+
+	ret = regulator_common_probe(dev, dev_get_plat(dev));
+	if (ret)
+		return ret;
 
 	priv->enable_clock = devm_clk_get(dev, NULL);
 	if (IS_ERR(priv->enable_clock))
@@ -150,6 +160,7 @@ U_BOOT_DRIVER(regulator_fixed) = {
 	.id = UCLASS_REGULATOR,
 	.ops = &fixed_regulator_ops,
 	.of_match = fixed_regulator_ids,
+	.probe = fixed_regulator_probe,
 	.of_to_plat = fixed_regulator_of_to_plat,
 	.plat_auto = sizeof(struct regulator_common_plat),
 };
diff --git a/drivers/power/regulator/gpio-regulator.c b/drivers/power/regulator/gpio-regulator.c
index 787f8170234..703a96ff095 100644
--- a/drivers/power/regulator/gpio-regulator.c
+++ b/drivers/power/regulator/gpio-regulator.c
@@ -19,6 +19,7 @@
 
 struct gpio_regulator_plat {
 	struct regulator_common_plat common;
+	struct gpio_dt_desc gpio_dt; /* parsed voltage GPIO, requested in probe */
 	struct gpio_desc gpio; /* GPIO for regulator voltage control */
 	int states[GPIO_REGULATOR_MAX_STATES];
 	int voltages[GPIO_REGULATOR_MAX_STATES];
@@ -28,7 +29,6 @@ static int gpio_regulator_of_to_plat(struct udevice *dev)
 {
 	struct dm_regulator_uclass_plat *uc_pdata;
 	struct gpio_regulator_plat *plat;
-	struct gpio_desc *gpio;
 	int ret, count, i, j;
 	u32 states_array[GPIO_REGULATOR_MAX_STATES * 2];
 
@@ -47,8 +47,8 @@ static int gpio_regulator_of_to_plat(struct udevice *dev)
 	 * per gpio-regulator. As of now no instance with multiple
 	 * gpios is presnt
 	 */
-	gpio = &plat->gpio;
-	ret = gpio_request_by_name(dev, "gpios", 0, gpio, GPIOD_IS_OUT);
+	ret = gpio_parse_by_name(dev, "gpios", 0, GPIOD_IS_OUT,
+				 &plat->gpio_dt);
 	if (ret)
 		debug("regulator gpio - not found! Error: %d", ret);
 
@@ -76,6 +76,20 @@ static int gpio_regulator_of_to_plat(struct udevice *dev)
 	return regulator_common_of_to_plat(dev, &plat->common, "enable-gpios");
 }
 
+static int gpio_regulator_probe(struct udevice *dev)
+{
+	struct gpio_regulator_plat *plat = dev_get_plat(dev);
+	int ret;
+
+	if (plat->gpio_dt.present) {
+		ret = gpio_request_parsed(dev, &plat->gpio_dt, &plat->gpio);
+		if (ret)
+			return ret;
+	}
+
+	return regulator_common_probe(dev, &plat->common);
+}
+
 static int gpio_regulator_get_value(struct udevice *dev)
 {
 	struct dm_regulator_uclass_plat *uc_pdata;
@@ -153,6 +167,7 @@ U_BOOT_DRIVER(gpio_regulator) = {
 	.id = UCLASS_REGULATOR,
 	.ops = &gpio_regulator_ops,
 	.of_match = gpio_regulator_ids,
+	.probe = gpio_regulator_probe,
 	.of_to_plat = gpio_regulator_of_to_plat,
 	.plat_auto	= sizeof(struct gpio_regulator_plat),
 };
diff --git a/drivers/power/regulator/regulator_common.c b/drivers/power/regulator/regulator_common.c
index c0387eff4fc..99a3cde436e 100644
--- a/drivers/power/regulator/regulator_common.c
+++ b/drivers/power/regulator/regulator_common.c
@@ -16,7 +16,6 @@ int regulator_common_of_to_plat(struct udevice *dev,
 				struct regulator_common_plat *plat,
 				const char *enable_gpio_name)
 {
-	struct gpio_desc *gpio;
 	int flags = GPIOD_IS_OUT;
 	int ret;
 
@@ -25,10 +24,10 @@ int regulator_common_of_to_plat(struct udevice *dev,
 	if (dev_read_bool(dev, "regulator-boot-on"))
 		flags |= GPIOD_IS_OUT_ACTIVE;
 
-	/* Get optional enable GPIO desc */
-	gpio = &plat->gpio;
+	/* Read the optional enable GPIO; it is requested in probe() */
 	if (CONFIG_IS_ENABLED(DM_GPIO)) {
-		ret = gpio_request_by_name(dev, enable_gpio_name, 0, gpio, flags);
+		ret = gpio_parse_by_name(dev, enable_gpio_name, 0, flags,
+					 &plat->gpio_dt);
 		if (ret) {
 			debug("Regulator '%s' optional enable GPIO - not found! Error: %d\n",
 			      dev->name, ret);
@@ -49,6 +48,24 @@ int regulator_common_of_to_plat(struct udevice *dev,
 	return 0;
 }
 
+int regulator_common_probe(struct udevice *dev,
+			   struct regulator_common_plat *plat)
+{
+	int ret;
+
+	if (!CONFIG_IS_ENABLED(DM_GPIO) || !plat->gpio_dt.present)
+		return 0;
+
+	ret = gpio_request_parsed(dev, &plat->gpio_dt, &plat->gpio);
+	if (ret) {
+		debug("Regulator '%s' enable GPIO request failed: %d\n",
+		      dev->name, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
 int regulator_common_get_enable(const struct udevice *dev,
 	struct regulator_common_plat *plat)
 {
diff --git a/drivers/power/regulator/regulator_common.h b/drivers/power/regulator/regulator_common.h
index d4962899d83..43e32ac48f6 100644
--- a/drivers/power/regulator/regulator_common.h
+++ b/drivers/power/regulator/regulator_common.h
@@ -10,6 +10,7 @@
 #include <asm/gpio.h>
 
 struct regulator_common_plat {
+	struct gpio_dt_desc gpio_dt; /* parsed enable GPIO, requested in probe */
 	struct gpio_desc gpio; /* GPIO for regulator enable control */
 	unsigned int startup_delay_us;
 	unsigned int off_on_delay_us;
@@ -19,6 +20,8 @@ struct regulator_common_plat {
 int regulator_common_of_to_plat(struct udevice *dev,
 				struct regulator_common_plat *plat, const
 				char *enable_gpio_name);
+int regulator_common_probe(struct udevice *dev,
+			   struct regulator_common_plat *plat);
 int regulator_common_get_enable(const struct udevice *dev,
 	struct regulator_common_plat *plat);
 /*
-- 
2.54.0