diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpio/devres.c | 32 | ||||
| -rw-r--r-- | drivers/gpio/gpiolib.c | 55 |
2 files changed, 87 insertions, 0 deletions
diff --git a/drivers/gpio/devres.c b/drivers/gpio/devres.c index 954b9f6b0ef8..13dbd3dfc33a 100644 --- a/drivers/gpio/devres.c +++ b/drivers/gpio/devres.c @@ -109,6 +109,38 @@ struct gpio_desc *__must_check __devm_gpiod_get_index(struct device *dev, EXPORT_SYMBOL(__devm_gpiod_get_index); /** + * devm_get_gpiod_from_child - get a GPIO descriptor from a device's child node + * @dev: GPIO consumer + * @child: firmware node (child of @dev) + * + * GPIO descriptors returned from this function are automatically disposed on + * driver detach. + */ +struct gpio_desc *devm_get_gpiod_from_child(struct device *dev, + struct fwnode_handle *child) +{ + struct gpio_desc **dr; + struct gpio_desc *desc; + + dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *), + GFP_KERNEL); + if (!dr) + return ERR_PTR(-ENOMEM); + + desc = fwnode_get_named_gpiod(child, "gpios"); + if (IS_ERR(desc)) { + devres_free(dr); + return desc; + } + + *dr = desc; + devres_add(dev, dr); + + return desc; +} +EXPORT_SYMBOL(devm_get_gpiod_from_child); + +/** * devm_gpiod_get_index_optional - Resource-managed gpiod_get_index_optional() * @dev: GPIO consumer * @con_id: function within the GPIO consumer diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 15e452c98981..1a7ef2c576e8 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2536,6 +2536,61 @@ struct gpio_desc *__must_check __gpiod_get_index(struct device *dev, EXPORT_SYMBOL_GPL(__gpiod_get_index); /** + * fwnode_get_named_gpiod - obtain a GPIO from firmware node + * @fwnode: handle of the firmware node + * @propname: name of the firmware property representing the GPIO + * + * This function can be used for drivers that get their configuration + * from firmware. + * + * Function properly finds the corresponding GPIO using whatever is the + * underlying firmware interface and then makes sure that the GPIO + * descriptor is requested before it is returned to the caller. + * + * In case of error an ERR_PTR() is returned. + */ +struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode, + const char *propname) +{ + struct gpio_desc *desc = ERR_PTR(-ENODEV); + bool active_low = false; + int ret; + + if (!fwnode) + return ERR_PTR(-EINVAL); + + if (is_of_node(fwnode)) { + enum of_gpio_flags flags; + + desc = of_get_named_gpiod_flags(of_node(fwnode), propname, 0, + &flags); + if (!IS_ERR(desc)) + active_low = flags & OF_GPIO_ACTIVE_LOW; + } else if (is_acpi_node(fwnode)) { + struct acpi_gpio_info info; + + desc = acpi_get_gpiod_by_index(acpi_node(fwnode), propname, 0, + &info); + if (!IS_ERR(desc)) + active_low = info.active_low; + } + + if (IS_ERR(desc)) + return desc; + + ret = gpiod_request(desc, NULL); + if (ret) + return ERR_PTR(ret); + + /* Only value flag can be set from both DT and ACPI is active_low */ + if (active_low) + set_bit(FLAG_ACTIVE_LOW, &desc->flags); + + return desc; +} +EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod); + +/** * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO * function * @dev: GPIO consumer, can be NULL for system-global GPIOs |