drivers: gpio: Add a managed API to get a GPIO from the device-tree

Add managed functions to get a gpio from the devce-tree, based on a
property name (minus the '-gpios' suffix) and optionally an index.

When the device is unbound, the GPIO is automatically released and the
data structure is freed.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
This commit is contained in:
Jean-Jacques Hiblot 2020-09-11 13:43:34 +05:30 committed by Tom Rini
parent bad2433151
commit d4b722e3a8
2 changed files with 118 additions and 0 deletions

View file

@ -6,6 +6,8 @@
#include <common.h>
#include <dm.h>
#include <log.h>
#include <dm/devres.h>
#include <dm/device_compat.h>
#include <dm/device-internal.h>
#include <dm/lists.h>
#include <dm/uclass-internal.h>
@ -1209,6 +1211,75 @@ int gpio_dev_request_index(struct udevice *dev, const char *nodename,
flags, 0, dev);
}
static void devm_gpiod_release(struct udevice *dev, void *res)
{
dm_gpio_free(dev, res);
}
static int devm_gpiod_match(struct udevice *dev, void *res, void *data)
{
return res == data;
}
struct gpio_desc *devm_gpiod_get_index(struct udevice *dev, const char *id,
unsigned int index, int flags)
{
int rc;
struct gpio_desc *desc;
char *propname;
static const char suffix[] = "-gpios";
propname = malloc(strlen(id) + sizeof(suffix));
if (!propname) {
rc = -ENOMEM;
goto end;
}
strcpy(propname, id);
strcat(propname, suffix);
desc = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc),
__GFP_ZERO);
if (unlikely(!desc)) {
rc = -ENOMEM;
goto end;
}
rc = gpio_request_by_name(dev, propname, index, desc, flags);
end:
if (propname)
free(propname);
if (rc)
return ERR_PTR(rc);
devres_add(dev, desc);
return desc;
}
struct gpio_desc *devm_gpiod_get_index_optional(struct udevice *dev,
const char *id,
unsigned int index,
int flags)
{
struct gpio_desc *desc = devm_gpiod_get_index(dev, id, index, flags);
if (IS_ERR(desc))
return NULL;
return desc;
}
void devm_gpiod_put(struct udevice *dev, struct gpio_desc *desc)
{
int rc;
rc = devres_release(dev, devm_gpiod_release, devm_gpiod_match, desc);
WARN_ON(rc);
}
static int gpio_post_bind(struct udevice *dev)
{
struct udevice *child;

View file

@ -701,4 +701,51 @@ int gpio_get_number(const struct gpio_desc *desc);
*/
int gpio_get_acpi(const struct gpio_desc *desc, struct acpi_gpio *gpio);
/**
* devm_gpiod_get_index - Resource-managed gpiod_get()
* @dev: GPIO consumer
* @con_id: function within the GPIO consumer
* @index: index of the GPIO to obtain in the consumer
* @flags: optional GPIO initialization flags
*
* Managed gpiod_get(). GPIO descriptors returned from this function are
* automatically disposed on device unbind.
* Return the GPIO descriptor corresponding to the function con_id of device
* dev, -ENOENT if no GPIO has been assigned to the requested function, or
* another IS_ERR() code if an error occurred while trying to acquire the GPIO.
*/
struct gpio_desc *devm_gpiod_get_index(struct udevice *dev, const char *id,
unsigned int index, int flags);
#define devm_gpiod_get(dev, id, flags) devm_gpiod_get_index(dev, id, 0, flags)
/**
* gpiod_get_optional - obtain an optional GPIO for a given GPIO function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
* @index: index of the GPIO to obtain in the consumer
* @flags: optional GPIO initialization flags
*
* This is equivalent to devm_gpiod_get(), except that when no GPIO was
* assigned to the requested function it will return NULL. This is convenient
* for drivers that need to handle optional GPIOs.
*/
struct gpio_desc *devm_gpiod_get_index_optional(struct udevice *dev,
const char *id,
unsigned int index,
int flags);
#define devm_gpiod_get_optional(dev, id, flags) \
devm_gpiod_get_index_optional(dev, id, 0, flags)
/**
* devm_gpiod_put - Resource-managed gpiod_put()
* @dev: GPIO consumer
* @desc: GPIO descriptor to dispose of
*
* Dispose of a GPIO descriptor obtained with devm_gpiod_get() or
* devm_gpiod_get_index(). Normally this function will not be called as the GPIO
* will be disposed of by the resource management code.
*/
void devm_gpiod_put(struct udevice *dev, struct gpio_desc *desc);
#endif /* _ASM_GENERIC_GPIO_H_ */