gpiolib: separation of pin concerns

The fact that of_gpiochip_add_pin_range() and
gpiochip_add_pin_range() share too much code is fragile and
will invariably mean that bugs need to be fixed in two places
instead of one.

So separate the concerns of gpiolib.c and gpiolib-of.c and
have the latter call the former as back-end. This is necessary
also when going forward with other device descriptions such
as ACPI.

This is done by:

- Adding a return code to gpiochip_add_pin_range() so we can
  reliably check whether this succeeds.

- Get rid of the custom of_pinctrl_add_gpio_range() from
  pinctrl. Instead create of_pinctrl_get() to just retrive the
  pin controller per se from an OF node. This composite
  function was just begging to be deleted, it was way to
  purpose-specific.

- Use pinctrl_dev_get_name() to get the name of the retrieved
  pin controller and use that to call back into the generic
  gpiochip_add_pin_range().

Now the pin range is only allocated and tied to a pin
controller from the core implementation in gpiolib.c.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index 2e60de4265ac..50d995e7e44a 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -63,8 +63,8 @@ struct gpio_pin_range {
 	struct pinctrl_gpio_range range;
 };
 
-void gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
-			    unsigned int pin_base, unsigned int npins);
+int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
+			   unsigned int pin_base, unsigned int npins);
 void gpiochip_remove_pin_ranges(struct gpio_chip *chip);
 
 #endif