gpiolib: Use GPIO name from names array for gpio descriptor

This patch adds GPIO names to the GPIO descriptors when initializing the
gpiochip. It also introduces a check whether any of the new names will
conflict with an existing GPIO name.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 697c409832465b048ffd45414d80c6bb3954e317..2341bfce235e7af7b239e8f8d51cfc40d424399d 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -250,6 +250,38 @@ static int gpiochip_add_to_list(struct gpio_chip *chip)
        return err;
 }
 
+/*
+ * Takes the names from gc->names and checks if they are all unique. If they
+ * are, they are assigned to their gpio descriptors.
+ *
+ * Returns -EEXIST if one of the names is already used for a different GPIO.
+ */
+static int gpiochip_set_desc_names(struct gpio_chip *gc)
+{
+       int i;
+
+       if (!gc->names)
+               return 0;
+
+       /* First check all names if they are unique */
+       for (i = 0; i != gc->ngpio; ++i) {
+               struct gpio_desc *gpio;
+
+               gpio = gpio_name_to_desc(gc->names[i]);
+               if (gpio) {
+                       dev_err(gc->dev, "Detected name collision for GPIO name '%s'\n",
+                               gc->names[i]);
+                       return -EEXIST;
+               }
+       }
+
+       /* Then add all names to the GPIO descriptors */
+       for (i = 0; i != gc->ngpio; ++i)
+               gc->desc[i].name = gc->names[i];
+
+       return 0;
+}
+
 /**
  * gpiochip_add() - register a gpio_chip
  * @chip: the chip to register, with chip->base initialized
@@ -322,6 +354,10 @@ int gpiochip_add(struct gpio_chip *chip)
        if (!chip->owner && chip->dev && chip->dev->driver)
                chip->owner = chip->dev->driver->owner;
 
+       status = gpiochip_set_desc_names(chip);
+       if (status)
+               goto err_remove_from_list;
+
        status = of_gpiochip_add(chip);
        if (status)
                goto err_remove_chip;
@@ -342,6 +378,7 @@ err_remove_chip:
        acpi_gpiochip_remove(chip);
        gpiochip_free_hogs(chip);
        of_gpiochip_remove(chip);
+err_remove_from_list:
        spin_lock_irqsave(&gpio_lock, flags);
        list_del(&chip->list);
        spin_unlock_irqrestore(&gpio_lock, flags);