gpio: devres: Handle nonexclusive GPIOs
When we get a nonexeclusive GPIO descriptor using managed
resources, we should only add it to the list of managed
resources once: on the first user. Augment the
devm_gpiod_get_index() and devm_gpiod_get_from_of_node()
calls to account for this by checking if the descriptor
is already resource managed before we proceed to allocate
a new resource management struct.
Fixes: b0ce7b29bfcd ("regulator/gpio: Allow nonexclusive GPIO access")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
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>
diff --git a/drivers/gpio/gpiolib-devres.c b/drivers/gpio/gpiolib-devres.c
index 0195936..f9591b5 100644
--- a/drivers/gpio/gpiolib-devres.c
+++ b/drivers/gpio/gpiolib-devres.c
@@ -98,15 +98,28 @@ struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,
struct gpio_desc **dr;
struct gpio_desc *desc;
+ desc = gpiod_get_index(dev, con_id, idx, flags);
+ if (IS_ERR(desc))
+ return desc;
+
+ /*
+ * For non-exclusive GPIO descriptors, check if this descriptor is
+ * already under resource management by this device.
+ */
+ if (flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
+ struct devres *dres;
+
+ dres = devres_find(dev, devm_gpiod_release,
+ devm_gpiod_match, &desc);
+ if (dres)
+ return desc;
+ }
+
dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
GFP_KERNEL);
- if (!dr)
+ if (!dr) {
+ gpiod_put(desc);
return ERR_PTR(-ENOMEM);
-
- desc = gpiod_get_index(dev, con_id, idx, flags);
- if (IS_ERR(desc)) {
- devres_free(dr);
- return desc;
}
*dr = desc;
@@ -140,15 +153,28 @@ struct gpio_desc *devm_gpiod_get_from_of_node(struct device *dev,
struct gpio_desc **dr;
struct gpio_desc *desc;
+ desc = gpiod_get_from_of_node(node, propname, index, dflags, label);
+ if (IS_ERR(desc))
+ return desc;
+
+ /*
+ * For non-exclusive GPIO descriptors, check if this descriptor is
+ * already under resource management by this device.
+ */
+ if (dflags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
+ struct devres *dres;
+
+ dres = devres_find(dev, devm_gpiod_release,
+ devm_gpiod_match, &desc);
+ if (dres)
+ return desc;
+ }
+
dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
GFP_KERNEL);
- if (!dr)
+ if (!dr) {
+ gpiod_put(desc);
return ERR_PTR(-ENOMEM);
-
- desc = gpiod_get_from_of_node(node, propname, index, dflags, label);
- if (IS_ERR(desc)) {
- devres_free(dr);
- return desc;
}
*dr = desc;