[PATCH 08/10] gpiolib: factor out finding gpio property

[Ahmad Fatoum]

The GPIO property may end with -gpios or -gpio or if there's only a
single GPIO, may have no dash at all. We will add more functions that
need to find the gpio property, so let's factor this out into
of_find_gpio_property.

This introduces functional change: When a foo-gpios property is found,
but points at an invalid GPIO, that failure will be propagated instead
of trying foo-gpio. This is deemed acceptable as this sounds like the
saner choice anyway.

Signed-off-by: Ahmad Fatoum <a.fat...@pengutronix.de>
---
 drivers/gpio/gpiolib.c | 61 +++++++++++++++++++++++++++---------------
 1 file changed, 39 insertions(+), 22 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 25d91d250dc8..3e57cf6239c3 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -794,21 +794,12 @@ static const char *gpio_suffixes[] = {
        "gpio",
 };
 
-/* Linux compatibility helper: Get a GPIO descriptor from device tree */
-struct gpio_desc *dev_gpiod_get_index(struct device *dev,
-                       struct device_node *np,
-                       const char *_con_id, int index,
-                       enum gpiod_flags flags,
-                       const char *label)
+static struct property *of_find_gpio_property(struct device_node *np,
+                                             const char *_con_id)
 {
-       struct gpio_desc *desc = NULL;
-       enum of_gpio_flags of_flags;
-       char *buf = NULL, *con_id;
-       int gpio;
-       int ret, i;
-
-       if (!np)
-               return ERR_PTR(-ENODEV);
+       struct property *pp = NULL;
+       char *con_id;
+       int i;
 
        for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
                if (_con_id)
@@ -819,26 +810,52 @@ struct gpio_desc *dev_gpiod_get_index(struct device *dev,
                if (!con_id)
                        return ERR_PTR(-ENOMEM);
 
-               gpio = of_get_named_gpio_flags(np, con_id, index, &of_flags);
+               pp = of_find_property(np, con_id, NULL);
                free(con_id);
 
-               if (gpio_is_valid(gpio)) {
-                       desc = gpio_to_desc(gpio);
-                       break;
-               }
+               if (pp)
+                       return pp;
        }
 
-       if (!desc)
+       return NULL;
+}
+
+/* Linux compatibility helper: Get a GPIO descriptor from device tree */
+struct gpio_desc *dev_gpiod_get_index(struct device *dev,
+                       struct device_node *np,
+                       const char *con_id, int index,
+                       enum gpiod_flags flags,
+                       const char *label)
+{
+       struct gpio_desc *desc = NULL;
+       enum of_gpio_flags of_flags;
+       struct property *pp;
+       char *buf = NULL;
+       int gpio;
+       int ret;
+
+       if (!np)
+               return ERR_PTR(-ENODEV);
+
+       pp = of_find_gpio_property(np, con_id);
+       if (!pp)
+               return ERR_PTR(-ENOENT);
+
+       gpio = of_get_named_gpio_flags(dev->device_node, pp->name,
+                                      index, &of_flags);
+       if (!gpio_is_valid(gpio))
                return ERR_PTR(gpio < 0 ? gpio : -EINVAL);
 
+       desc = gpio_to_desc(gpio);
+
        if (of_flags & OF_GPIO_ACTIVE_LOW)
                flags |= GPIOF_ACTIVE_LOW;
 
        buf = NULL;
 
        if (!label) {
-               if (_con_id)
-                       label = buf = basprintf("%s-%s", dev_name(dev), 
_con_id);
+               if (con_id)
+                       label = buf = basprintf("%s-%s", dev_name(dev), con_id);
                else
                        label = dev_name(dev);
        }
-- 
2.39.2