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authorLinus Walleij <linus.walleij@linaro.org>2017-12-29 04:07:54 +0300
committerLinus Walleij <linus.walleij@linaro.org>2018-01-12 13:05:18 +0300
commit6392cca42de603d49c2d929c838c92801d4ee761 (patch)
treefa70a00049c700d6ac8f7ce03ba95c3dce0b9784 /drivers
parent6a537d48461deacc57c07ed86d9915e5aa4b3539 (diff)
downloadlinux-6392cca42de603d49c2d929c838c92801d4ee761.tar.xz
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: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/gpio/gpiolib.c123
1 files changed, 86 insertions, 37 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 94a5575d1ebe..6df94492e93e 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -3668,17 +3668,87 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
EXPORT_SYMBOL_GPL(gpiod_get_index);
/**
+ * 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
+ *
+ * Returns:
+ * On successful request the GPIO pin is configured in accordance with
+ * provided @dflags. If the node does not have the requested GPIO
+ * property, NULL is returned.
+ *
+ * In case of error an ERR_PTR() is returned.
+ */
+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;
+
+ desc = of_get_named_gpiod_flags(node, propname,
+ index, &flags);
+
+ if (!desc || IS_ERR(desc)) {
+ /* If it is not there, just return NULL */
+ if (PTR_ERR(desc) == -ENOENT)
+ return NULL;
+ 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)
+ return ERR_PTR(ret);
+
+ if (active_low)
+ lflags |= GPIO_ACTIVE_LOW;
+
+ if (single_ended) {
+ if (open_drain)
+ lflags |= GPIO_OPEN_DRAIN;
+ else
+ lflags |= GPIO_OPEN_SOURCE;
+ }
+
+ if (transitory)
+ lflags |= GPIO_TRANSITORY;
+
+ ret = gpiod_configure_flags(desc, propname, lflags, dflags);
+ if (ret < 0) {
+ gpiod_put(desc);
+ return ERR_PTR(ret);
+ }
+
+ 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 in the consumer
+ * @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.
+ * from opaque firmware.
*
- * Function properly finds the corresponding GPIO using whatever is the
+ * 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.
*
@@ -3695,56 +3765,35 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
{
struct gpio_desc *desc = ERR_PTR(-ENODEV);
unsigned long lflags = 0;
- bool active_low = false;
- bool single_ended = false;
- bool open_drain = false;
- bool transitory = 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(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;
- }
+ 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)) {
- active_low = info.polarity == GPIO_ACTIVE_LOW;
- acpi_gpio_update_gpiod_flags(&dflags, &info);
- }
- }
+ if (IS_ERR(desc))
+ return desc;
- 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);
- if (active_low)
- lflags |= GPIO_ACTIVE_LOW;
-
- if (single_ended) {
- if (open_drain)
- lflags |= GPIO_OPEN_DRAIN;
- else
- lflags |= GPIO_OPEN_SOURCE;
- }
-
- if (transitory)
- lflags |= GPIO_TRANSITORY;
-
ret = gpiod_configure_flags(desc, propname, lflags, dflags);
if (ret < 0) {
gpiod_put(desc);