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>

2 files changed, 3 insertions, 6 deletions

diff --git a/include/linux/gpio.h b/include/linux/gpio.h
index 21d28b930dc7..81bbfe5b5de6 100644
--- a/include/linux/gpio.h
+++ b/include/linux/gpio.h
@@ -233,7 +233,7 @@ static inline int irq_to_gpio(unsigned irq)
 
 #ifdef CONFIG_PINCTRL
 
-static inline void
+static inline int
 gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
 		       unsigned int pin_base, unsigned int npins)
 {
diff --git a/include/linux/pinctrl/pinctrl.h b/include/linux/pinctrl/pinctrl.h
index 434e5a94e131..4a58428bc793 100644
--- a/include/linux/pinctrl/pinctrl.h
+++ b/include/linux/pinctrl/pinctrl.h
@@ -141,16 +141,13 @@ extern struct pinctrl_dev *find_pinctrl_and_add_gpio_range(const char *devname,
 		struct pinctrl_gpio_range *range);
 
 #ifdef CONFIG_OF
-extern struct pinctrl_dev *of_pinctrl_add_gpio_range(struct device_node *np,
-		struct pinctrl_gpio_range *range);
+extern struct pinctrl_dev *of_pinctrl_get(struct device_node *np);
 #else
 static inline
-struct pinctrl_dev *of_pinctrl_add_gpio_range(struct device_node *np,
-		struct pinctrl_gpio_range *range)
+struct pinctrl_dev *of_pinctrl_get(struct device_node *np)
 {
 	return NULL;
 }
-
 #endif /* CONFIG_OF */
 
 extern const char *pinctrl_dev_get_name(struct pinctrl_dev *pctldev);