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

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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: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Linus Walleij 2017-12-29 02:07:54 +01:00
parent 6a537d4846
commit 6392cca42d
1 changed files with 88 additions and 39 deletions
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127
drivers/gpio/gpiolib.c
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@ -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,
const char *propname, int index,
enum gpiod_flags dflags,
const char *label)
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;
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 (!desc || IS_ERR(desc)) {
/* If it is not there, just return NULL */
if (PTR_ERR(desc) == -ENOENT)
return NULL;
return desc;
}
if (IS_ERR(desc))
return 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;
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);
/**