linux-kernel - [PATCH] regulator: wm8994: Don't use devres for enable GPIOs

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Date:   Tue, 20 Nov 2018 17:01:52 +0000
From:   Charles Keepax <ckeepax@...nsource.cirrus.com>
To:     <broonie@...nel.org>
CC:     <linus.walleij@...aro.org>, <lgirdwood@...il.com>,
        <m.szyprowski@...sung.com>, <linux-kernel@...r.kernel.org>,
        <patches@...nsource.cirrus.com>
Subject: [PATCH] regulator: wm8994: Don't use devres for enable GPIOs

We need to manage the life time of the enable GPIO against the regulator
device but the OF node lives on the parent MFD device. As such we can't
use the devm functions which assume the same device will be used for
both.

Reported-by: Marek Szyprowski <m.szyprowski@...sung.com>
Signed-off-by: Charles Keepax <ckeepax@...nsource.cirrus.com>
---

This patch is only build tested so it would be good to get a
tested by from Marek before applying.

Thanks,
Charles

 drivers/regulator/wm8994-regulator.c | 28 +++++++++++++++++++++++-----
 1 file changed, 23 insertions(+), 5 deletions(-)

diff --git a/drivers/regulator/wm8994-regulator.c b/drivers/regulator/wm8994-regulator.c
index d7fec533c403..f2592c30d0ca 100644
--- a/drivers/regulator/wm8994-regulator.c
+++ b/drivers/regulator/wm8994-regulator.c
@@ -31,6 +31,7 @@ struct wm8994_ldo {
 	struct wm8994 *wm8994;
 	struct regulator_consumer_supply supply;
 	struct regulator_init_data init_data;
+	struct gpio_desc *ena_gpiod;
 };
 
 #define WM8994_LDO1_MAX_SELECTOR 0x7
@@ -147,14 +148,19 @@ static int wm8994_ldo_probe(struct platform_device *pdev)
 	config.regmap = wm8994->regmap;
 	config.init_data = &ldo->init_data;
 
-	/* Look up LDO enable GPIO from the parent device node */
-	gpiod = devm_gpiod_get_optional(pdev->dev.parent,
-					id ? "wlf,ldo2ena" : "wlf,ldo1ena",
-					GPIOD_OUT_LOW |
-					GPIOD_FLAGS_BIT_NONEXCLUSIVE);
+	/*
+	 * Look up LDO enable GPIO from the parent device node, we can't
+	 * use devm because it assumes the device we want to allocate
+	 * against is the same one that holds the OF node
+	 */
+	gpiod = gpiod_get_optional(pdev->dev.parent,
+				   id ? "wlf,ldo2ena" : "wlf,ldo1ena",
+				   GPIOD_OUT_LOW |
+				   GPIOD_FLAGS_BIT_NONEXCLUSIVE);
 	if (IS_ERR(gpiod))
 		return PTR_ERR(gpiod);
 	config.ena_gpiod = gpiod;
+	ldo->ena_gpiod = gpiod;
 
 	/* Use default constraints if none set up */
 	if (!pdata || !pdata->ldo[id].init_data || wm8994->dev->of_node) {
@@ -184,11 +190,23 @@ static int wm8994_ldo_probe(struct platform_device *pdev)
 	return 0;
 
 err:
+	gpiod_put(gpiod);
 	return ret;
 }
 
+static int wm8994_ldo_remove(struct platform_device *pdev)
+{
+	struct wm8994_ldo *ldo = platform_get_drvdata(pdev);
+
+	if (ldo->ena_gpiod)
+		gpiod_put(ldo->ena_gpiod);
+
+	return 0;
+}
+
 static struct platform_driver wm8994_ldo_driver = {
 	.probe = wm8994_ldo_probe,
+	.remove = wm8994_ldo_remove,
 	.driver		= {
 		.name	= "wm8994-ldo",
 	},
-- 
2.11.0