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Commit 6392cca4 authored by Linus Walleij's avatar Linus Walleij
Browse files

gpio: Break out code to get a descriptor from a DT node 



Sometimes a GPIO needs to be taken from a node without
a device associated with it. The fwnode accessor does this,
let's however break out the DT code for now.

Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 6a537d48

drivers/gpio/gpiolib.c

+86 −37
Original line number Diff line number Diff line
@@ -3668,65 +3668,48 @@ 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

 * @index:	index of the GPIO to obtain in the consumer

 * gpiod_get_from_of_node() - obtain a GPIO from an OF node

 * @node:	handle of the OF node

 * @propname:	name of the DT property representing the GPIO

 * @index:	index of the GPIO to obtain for the consumer

 * @dflags:	GPIO initialization flags

 * @label:	label to attach to the requested 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.

 *

 * Returns:

 * On successful request the GPIO pin is configured in accordance with

 * provided @dflags.

 * provided @dflags. If the node does not have the requested GPIO

 * property, NULL is returned.

 *

 * In case of error an ERR_PTR() is returned.

 */

struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,

static struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,

						const char *propname, int index,

						enum gpiod_flags dflags,

						const char *label)

{

	struct gpio_desc *desc = ERR_PTR(-ENODEV);

	unsigned long lflags = 0;

	enum of_gpio_flags flags;

	bool active_low = false;

	bool single_ended = false;

	bool open_drain = false;

	bool transitory = false;

	int ret;



	if (!fwnode)

		return ERR_PTR(-EINVAL);

	desc = of_get_named_gpiod_flags(node, propname,

					index, &flags);



	if (is_of_node(fwnode)) {

		enum of_gpio_flags flags;

	if (!desc || IS_ERR(desc)) {

		/* If it is not there, just return NULL */

		if (PTR_ERR(desc) == -ENOENT)

			return NULL;

		return desc;

	}



		desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname,

						index, &flags);

		if (!IS_ERR(desc)) {

	active_low = flags & OF_GPIO_ACTIVE_LOW;

	single_ended = flags & OF_GPIO_SINGLE_ENDED;

	open_drain = flags & OF_GPIO_OPEN_DRAIN;

	transitory = flags & OF_GPIO_TRANSITORY;

		}

	} else if (is_acpi_node(fwnode)) {

		struct acpi_gpio_info info;



		desc = acpi_node_get_gpiod(fwnode, propname, index, &info);

		if (!IS_ERR(desc)) {

			active_low = info.polarity == GPIO_ACTIVE_LOW;

			acpi_gpio_update_gpiod_flags(&dflags, &info);

		}

	}



	if (IS_ERR(desc))

		return desc;



	ret = gpiod_request(desc, label);

	if (ret)
@@ -3753,6 +3736,72 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode, 


	return desc;

}



/**

 * 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

 * @index:	index of the GPIO to obtain for the consumer

 * @dflags:	GPIO initialization flags

 * @label:	label to attach to the requested GPIO

 *

 * This function can be used for drivers that get their configuration

 * from opaque firmware.

 *

 * The 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.

 *

 * Returns:

 * On successful request the GPIO pin is configured in accordance with

 * provided @dflags.

 *

 * In case of error an ERR_PTR() is returned.

 */

struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,

					 const char *propname, int index,

					 enum gpiod_flags dflags,

					 const char *label)

{

	struct gpio_desc *desc = ERR_PTR(-ENODEV);

	unsigned long lflags = 0;

	int ret;



	if (!fwnode)

		return ERR_PTR(-EINVAL);



	if (is_of_node(fwnode)) {

		desc = gpiod_get_from_of_node(to_of_node(fwnode),

					      propname, index,

					      dflags,

					      label);

		return desc;

	} else if (is_acpi_node(fwnode)) {

		struct acpi_gpio_info info;



		desc = acpi_node_get_gpiod(fwnode, propname, index, &info);

		if (IS_ERR(desc))

			return desc;



		acpi_gpio_update_gpiod_flags(&dflags, &info);



		if (info.polarity == GPIO_ACTIVE_LOW)

			lflags |= GPIO_ACTIVE_LOW;

	}



	/* Currently only ACPI takes this path */

	ret = gpiod_request(desc, label);

	if (ret)

		return ERR_PTR(ret);



	ret = gpiod_configure_flags(desc, propname, lflags, dflags);

	if (ret < 0) {

		gpiod_put(desc);

		return ERR_PTR(ret);

	}



	return desc;

}

EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);



/**