[PATCH] gpiolib: fix linker errors when GPIOLIB is disabled

[Pierluigi Passaro <pierluigi.p@variscite.com>]

Both the functions gpiochip_request_own_desc and
gpiochip_free_own_desc are exported from
    drivers/gpio/gpiolib.c
but this file is compiled only when CONFIG_GPIOLIB is enabled.
Move the protototypes under "#ifdef CONFIG_GPIOLIB" and provide
reasonable definitions in the "#else" branch.

Signed-off-by: Pierluigi Passaro <pierluigi.p@variscite.com>
Reported-by: kernel test robot <lkp@intel.com>
---
 include/linux/gpio/driver.h | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index 44783fc16125..ed77c6fc0beb 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -758,6 +758,8 @@ gpiochip_remove_pin_ranges(struct gpio_chip *gc)
 
 #endif /* CONFIG_PINCTRL */
 
+#ifdef CONFIG_GPIOLIB
+
 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
 					    unsigned int hwnum,
 					    const char *label,
@@ -765,8 +767,6 @@ struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
 					    enum gpiod_flags dflags);
 void gpiochip_free_own_desc(struct gpio_desc *desc);
 
-#ifdef CONFIG_GPIOLIB
-
 /* lock/unlock as IRQ */
 int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset);
 void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset);
@@ -776,6 +776,22 @@ struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);
 
 #else /* CONFIG_GPIOLIB */
 
+static inline struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
+					    unsigned int hwnum,
+					    const char *label,
+					    enum gpio_lookup_flags lflags,
+					    enum gpiod_flags dflags)
+{
+	/* GPIO can never have been requested */
+	WARN_ON(1);
+	return ERR_PTR(-ENODEV);
+}
+
+static inline void gpiochip_free_own_desc(struct gpio_desc *desc)
+{
+	WARN_ON(1);
+}
+
 static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
 {
 	/* GPIO can never have been requested */
-- 
2.37.2