linux-kernel - [PATCH v2 2/2] regulator: core: Allow enable GPIO to be specified using GPIOD

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Date:   Tue, 29 Nov 2016 11:50:04 +0000
From:   Charles Keepax <ckeepax@...nsource.wolfsonmicro.com>
To:     <broonie@...nel.org>
CC:     <lgirdwood@...il.com>, <linux-kernel@...r.kernel.org>,
        <patches@...nsource.wolfsonmicro.com>
Subject: [PATCH v2 2/2] regulator: core: Allow enable GPIO to be specified using GPIOD

The regulator subsystem has used GPIOs internally for a while, however,
end drivers must still specify their enable GPIO using a GPIO number. This
patch allows the end drivers to specify the enable GPIO using GPIOD
directly.

Signed-off-by: Charles Keepax <ckeepax@...nsource.wolfsonmicro.com>
---

Changes since v1:
 - Make a small correction to the error path, where we were calling
   desc_to_gpio on something that might not be zero.

Thanks,
Charles

 drivers/regulator/core.c         | 43 ++++++++++++++++++++++++++--------------
 include/linux/regulator/driver.h | 14 ++++++++-----
 2 files changed, 37 insertions(+), 20 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index b3417ac..9e8def2 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1929,6 +1929,16 @@ void regulator_bulk_unregister_supply_alias(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(regulator_bulk_unregister_supply_alias);
 
+static bool regulator_ena_gpio_valid(const struct regulator_config *config)
+{
+	if (config->ena_gpiod)
+		return true;
+
+	if (config->ena_gpio || config->ena_gpio_initialized)
+		return gpio_is_valid(config->ena_gpio);
+
+	return false;
+}
 
 /* Manage enable GPIO list. Same GPIO pin can be shared among regulators */
 static int regulator_ena_gpio_request(struct regulator_dev *rdev,
@@ -1938,7 +1948,10 @@ static int regulator_ena_gpio_request(struct regulator_dev *rdev,
 	struct gpio_desc *gpiod;
 	int ret;
 
-	gpiod = gpio_to_desc(config->ena_gpio);
+	if (config->ena_gpiod)
+		gpiod = config->ena_gpiod;
+	else
+		gpiod = gpio_to_desc(config->ena_gpio);
 
 	list_for_each_entry(pin, &regulator_ena_gpio_list, list) {
 		if (pin->gpiod == gpiod) {
@@ -1948,16 +1961,20 @@ static int regulator_ena_gpio_request(struct regulator_dev *rdev,
 		}
 	}
 
-	ret = gpio_request_one(config->ena_gpio,
-				GPIOF_DIR_OUT | config->ena_gpio_flags,
-				rdev_get_name(rdev));
-	if (ret)
-		return ret;
-
 	pin = kzalloc(sizeof(struct regulator_enable_gpio), GFP_KERNEL);
-	if (pin == NULL) {
-		gpio_free(config->ena_gpio);
+	if (!pin)
 		return -ENOMEM;
+
+	if (!config->ena_gpiod) {
+		ret = gpio_request_one(config->ena_gpio,
+				       GPIOF_DIR_OUT | config->ena_gpio_flags,
+				       rdev_get_name(rdev));
+		if (ret) {
+			kfree(pin);
+			rdev_err(rdev, "Failed to request enable GPIO%d: %d\n",
+				 config->ena_gpio, ret);
+			return ret;
+		}
 	}
 
 	pin->gpiod = gpiod;
@@ -4027,16 +4044,12 @@ regulator_register(const struct regulator_desc *regulator_desc,
 			goto clean;
 	}
 
-	if ((config->ena_gpio || config->ena_gpio_initialized) &&
-	    gpio_is_valid(config->ena_gpio)) {
+	if (regulator_ena_gpio_valid(config)) {
 		mutex_lock(&regulator_list_mutex);
 		ret = regulator_ena_gpio_request(rdev, config);
 		mutex_unlock(&regulator_list_mutex);
-		if (ret != 0) {
-			rdev_err(rdev, "Failed to request enable GPIO%d: %d\n",
-				 config->ena_gpio, ret);
+		if (ret != 0)
 			goto clean;
-		}
 	}
 
 	/* register with sysfs */
diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index dac8e7b1..0a3f3a0 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -367,11 +367,13 @@ struct regulator_desc {
  *           NULL).
  * @regmap: regmap to use for core regmap helpers if dev_get_regmap() is
  *          insufficient.
- * @ena_gpio_initialized: GPIO controlling regulator enable was properly
- *                        initialized, meaning that >= 0 is a valid gpio
- *                        identifier and < 0 is a non existent gpio.
- * @ena_gpio: GPIO controlling regulator enable.
+ * @ena_gpiod: GPIO controlling regulator enable.
  * @ena_gpio_invert: Sense for GPIO enable control.
+ * @ena_gpio_initialized: ena_gpio enable was properly initialized,
+ *                        meaning that >= 0 is a valid gpio identifier
+ *                        and < 0 is a non existent gpio.
+ * @ena_gpio: GPIO controlling regulator enable, deprecated in favour of
+ *            ena_gpiod.
  * @ena_gpio_flags: Flags to use when calling gpio_request_one()
  */
 struct regulator_config {
@@ -381,9 +383,11 @@ struct regulator_config {
 	struct device_node *of_node;
 	struct regmap *regmap;
 
+	struct gpio_desc *ena_gpiod;
+	unsigned int ena_gpio_invert:1;
+
 	bool ena_gpio_initialized;
 	int ena_gpio;
-	unsigned int ena_gpio_invert:1;
 	unsigned int ena_gpio_flags;
 };
 
-- 
2.1.4