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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: b0ce7b29bf ("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>
This commit is contained in:
Linus Walleij 2018-12-06 13:43:45 +01:00 committed by Mark Brown
parent ec757001c8
commit cb28ee388e
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 38 additions and 12 deletions
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50
drivers/gpio/gpiolib-devres.c
View File

@ -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;