linux-kernel - [PATCH 06/15 v3] regulator: max8973: Let core handle GPIO descriptor

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Date:   Wed,  5 Dec 2018 13:47:12 +0100
From:   Linus Walleij <linus.walleij@...aro.org>
To:     Liam Girdwood <lgirdwood@...il.com>,
        Mark Brown <broonie@...nel.org>
Cc:     linux-kernel@...r.kernel.org,
        Charles Keepax <ckeepax@...nsource.cirrus.com>,
        Bartosz Golaszewski <bgolaszewski@...libre.com>,
        Marek Szyprowski <m.szyprowski@...sung.com>,
        Linus Walleij <linus.walleij@...aro.org>
Subject: [PATCH 06/15 v3] regulator: max8973: Let core handle GPIO descriptor

Use the gpiod_get() rather than the devm_* version so that the
regulator core can handle the lifecycle of these descriptors.

Fixes: e7d2be696faa ("regulator: max8973: Pass descriptor instead of GPIO number")
Signed-off-by: Linus Walleij <linus.walleij@...aro.org>
---
ChangeLog v2->v3:
- Resending.
ChangeLog v1->v2:
- Drop the gpiod_put() on the errorpath after devm_regulator_register()
  as this will be handled by the regulator core.
- Fix the second case of devm_gpiod_get()
- Put a comment in the code so maintainers knows not to
  use managed resources (devm*)
---
 drivers/regulator/max8973-regulator.c | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/drivers/regulator/max8973-regulator.c b/drivers/regulator/max8973-regulator.c
index e7a58b509032..ef8f4789a517 100644
--- a/drivers/regulator/max8973-regulator.c
+++ b/drivers/regulator/max8973-regulator.c
@@ -632,7 +632,7 @@ static int max8973_probe(struct i2c_client *client,
 	struct max8973_chip *max;
 	bool pdata_from_dt = false;
 	unsigned int chip_id;
-	struct gpio_desc *gpiod;
+	struct gpio_desc *gpiod = NULL;
 	enum gpiod_flags gflags;
 	int ret;
 
@@ -759,9 +759,13 @@ static int max8973_probe(struct i2c_client *client,
 		else
 			gflags = GPIOD_OUT_LOW;
 		gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE;
-		gpiod = devm_gpiod_get_optional(&client->dev,
-						"maxim,enable",
-						gflags);
+		/*
+		 * Do not use devm* here: the regulator core takes over the
+		 * lifecycle management of the GPIO descriptor.
+		 */
+		gpiod = gpiod_get_optional(&client->dev,
+					   "maxim,enable",
+					   gflags);
 		if (IS_ERR(gpiod))
 			return PTR_ERR(gpiod);
 		if (gpiod) {
@@ -775,10 +779,13 @@ static int max8973_probe(struct i2c_client *client,
 		/*
 		 * We do not let the core switch this regulator on/off,
 		 * we just leave it on.
+		 *
+		 * Do not use devm* here: the regulator core takes over the
+		 * lifecycle management of the GPIO descriptor.
 		 */
-		gpiod = devm_gpiod_get_optional(&client->dev,
-						"maxim,enable",
-						GPIOD_OUT_HIGH);
+		gpiod = gpiod_get_optional(&client->dev,
+					   "maxim,enable",
+					   GPIOD_OUT_HIGH);
 		if (IS_ERR(gpiod))
 			return PTR_ERR(gpiod);
 		if (gpiod)
@@ -798,6 +805,8 @@ static int max8973_probe(struct i2c_client *client,
 
 	ret = max8973_init_dcdc(max, pdata);
 	if (ret < 0) {
+		if (gpiod)
+			gpiod_put(gpiod);
 		dev_err(max->dev, "Max8973 Init failed, err = %d\n", ret);
 		return ret;
 	}
-- 
2.19.2