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authorLinus Walleij <linus.walleij@linaro.org>2018-12-06 15:43:46 +0300
committerMark Brown <broonie@kernel.org>2018-12-11 04:04:23 +0300
commit891ddbc79a61eb5b919cf56202ecaf7259878cb2 (patch)
treee4b1a683a2b5761d77b4525368f251897644b0a6 /drivers/gpio
parentcb28ee388e465a956b05ada682f9ef90e776a9b7 (diff)
downloadlinux-891ddbc79a61eb5b919cf56202ecaf7259878cb2.tar.xz
gpio: Add devm_gpiod_unhinge()
This adds a function named devm_gpiod_unhinge() that removes the resource management from a GPIO descriptor. I am not sure if this is the best anglosaxon name for the function, no other managed resources have an equivalent currently, but I chose "unhinge" as the closest intuitive thing I could imagine that fits Rusty Russell's API design criterions "the obvious use is the correct one" and "the name tells you how to use it". The idea came out of a remark from Mark Brown that it should be possible to handle over management of a resource from devres to the regulator core, and indeed we can do that. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/gpio')
-rw-r--r--drivers/gpio/gpiolib-devres.c30
1 files changed, 30 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib-devres.c b/drivers/gpio/gpiolib-devres.c
index f9591b5c9748..0acc2cc6e868 100644
--- a/drivers/gpio/gpiolib-devres.c
+++ b/drivers/gpio/gpiolib-devres.c
@@ -347,6 +347,36 @@ void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)
EXPORT_SYMBOL(devm_gpiod_put);
/**
+ * devm_gpiod_unhinge - Remove resource management from a gpio descriptor
+ * @dev: GPIO consumer
+ * @desc: GPIO descriptor to remove resource management from
+ *
+ * Remove resource management from a GPIO descriptor. This is needed when
+ * you want to hand over lifecycle management of a descriptor to another
+ * mechanism.
+ */
+
+void devm_gpiod_unhinge(struct device *dev, struct gpio_desc *desc)
+{
+ int ret;
+
+ if (IS_ERR_OR_NULL(desc))
+ return;
+ ret = devres_destroy(dev, devm_gpiod_release,
+ devm_gpiod_match, &desc);
+ /*
+ * If the GPIO descriptor is requested as nonexclusive, we
+ * may call this function several times on the same descriptor
+ * so it is OK if devres_destroy() returns -ENOENT.
+ */
+ if (ret == -ENOENT)
+ return;
+ /* Anything else we should warn about */
+ WARN_ON(ret);
+}
+EXPORT_SYMBOL(devm_gpiod_unhinge);
+
+/**
* devm_gpiod_put_array - Resource-managed gpiod_put_array()
* @dev: GPIO consumer
* @descs: GPIO descriptor array to dispose of