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path: root/drivers/gpio/gpiolib.c
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Diffstat (limited to 'drivers/gpio/gpiolib.c')
-rw-r--r--drivers/gpio/gpiolib.c85
1 files changed, 81 insertions, 4 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index e8e98ca..58659db 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1505,14 +1505,36 @@ static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id,
unsigned int idx,
enum gpio_lookup_flags *flags)
{
+ static const char * const suffixes[] = { "gpios", "gpio" };
+ struct acpi_device *adev = ACPI_COMPANION(dev);
struct acpi_gpio_info info;
struct gpio_desc *desc;
+ char propname[32];
+ int i;
- desc = acpi_get_gpiod_by_index(dev, idx, &info);
- if (IS_ERR(desc))
- return desc;
+ /* Try first from _DSD */
+ for (i = 0; i < ARRAY_SIZE(suffixes); i++) {
+ if (con_id && strcmp(con_id, "gpios")) {
+ snprintf(propname, sizeof(propname), "%s-%s",
+ con_id, suffixes[i]);
+ } else {
+ snprintf(propname, sizeof(propname), "%s",
+ suffixes[i]);
+ }
+
+ desc = acpi_get_gpiod_by_index(adev, propname, idx, &info);
+ if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
+ break;
+ }
- if (info.gpioint && info.active_low)
+ /* Then from plain _CRS GPIOs */
+ if (IS_ERR(desc)) {
+ desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info);
+ if (IS_ERR(desc))
+ return desc;
+ }
+
+ if (info.active_low)
*flags |= GPIO_ACTIVE_LOW;
return desc;
@@ -1713,6 +1735,61 @@ 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