gpiolib: Add and use OF_GPIO_SINGLE_ENDED flag

The flag matches the DT GPIO_SINGLE_ENDED flag and allows drivers to
parse and use the DT flag to handle single-ended (open-drain or
open-source) GPIOs.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 1615cc9..6798355 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1831,6 +1831,13 @@ static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
        if (of_flags & OF_GPIO_ACTIVE_LOW)
                *flags |= GPIO_ACTIVE_LOW;
 
+       if (of_flags & OF_GPIO_SINGLE_ENDED) {
+               if (of_flags & OF_GPIO_ACTIVE_LOW)
+                       *flags |= GPIO_OPEN_DRAIN;
+               else
+                       *flags |= GPIO_OPEN_SOURCE;
+       }
+
        return desc;
 }
 
@@ -2184,6 +2191,7 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
 {
        struct gpio_desc *desc = ERR_PTR(-ENODEV);
        bool active_low = false;
+       bool single_ended = false;
        int ret;
 
        if (!fwnode)
@@ -2194,8 +2202,10 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
 
                desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname, 0,
                                                &flags);
-               if (!IS_ERR(desc))
+               if (!IS_ERR(desc)) {
                        active_low = flags & OF_GPIO_ACTIVE_LOW;
+                       single_ended = flags & OF_GPIO_SINGLE_ENDED;
+               }
        } else if (is_acpi_node(fwnode)) {
                struct acpi_gpio_info info;
 
@@ -2208,10 +2218,16 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
        if (IS_ERR(desc))
                return desc;
 
-       /* Only value flag can be set from both DT and ACPI is active_low */
        if (active_low)
                set_bit(FLAG_ACTIVE_LOW, &desc->flags);
 
+       if (single_ended) {
+               if (active_low)
+                       set_bit(FLAG_OPEN_DRAIN, &desc->flags);
+               else
+                       set_bit(FLAG_OPEN_SOURCE, &desc->flags);
+       }
+
        ret = gpiod_request(desc, NULL);
        if (ret)
                return ERR_PTR(ret);

diff --git a/include/linux/of_gpio.h b/include/linux/of_gpio.h
index f319182..87d6d16 100644 (file)
--- a/include/linux/of_gpio.h
+++ b/include/linux/of_gpio.h
@@ -29,6 +29,7 @@ struct device_node;
  */
 enum of_gpio_flags {
        OF_GPIO_ACTIVE_LOW = 0x1,
+       OF_GPIO_SINGLE_ENDED = 0x2,
 };
 
 #ifdef CONFIG_OF_GPIO