of_gpio: add support of of_gpio_named_count to be able to count named gpio

Signed-off-by: NJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: devicetree-discuss@lists.ozlabs.org
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

drivers/of/gpio.c

@@ -78,8 +78,9 @@ int of_get_named_gpio_flags(struct device_node *np, const char *propname,
 EXPORT_SYMBOL(of_get_named_gpio_flags);
 
 /**
- * of_gpio_count - Count GPIOs for a device
+ * of_gpio_named_count - Count GPIOs for a device
  * @np:		device node to count GPIOs for
+ * @propname:	property name containing gpio specifier(s)
  *
  * The function returns the count of GPIOs specified for a node.
  *
@@ -93,14 +94,14 @@ EXPORT_SYMBOL(of_get_named_gpio_flags);
  * defines four GPIOs (so this function will return 4), two of which
  * are not specified.
  */
-unsigned int of_gpio_count(struct device_node *np)
+unsigned int of_gpio_named_count(struct device_node *np, const char* propname)
 {
 	unsigned int cnt = 0;
 
 	do {
 		int ret;
 
-		ret = of_parse_phandle_with_args(np, "gpios", "#gpio-cells",
+		ret = of_parse_phandle_with_args(np, propname, "#gpio-cells",
 						 cnt, NULL);
 		/* A hole in the gpios = <> counts anyway. */
 		if (ret < 0 && ret != -EEXIST)
@@ -109,7 +110,7 @@ unsigned int of_gpio_count(struct device_node *np)
 
 	return cnt;
 }
-EXPORT_SYMBOL(of_gpio_count);
+EXPORT_SYMBOL(of_gpio_named_count);
 
 /**
  * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags

include/linux/of_gpio.h

@@ -50,7 +50,8 @@ static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc)
 extern int of_get_named_gpio_flags(struct device_node *np,
 		const char *list_name, int index, enum of_gpio_flags *flags);
 
-extern unsigned int of_gpio_count(struct device_node *np);
+extern unsigned int of_gpio_named_count(struct device_node *np,
+					const char* propname);
 
 extern int of_mm_gpiochip_add(struct device_node *np,
 			      struct of_mm_gpio_chip *mm_gc);
@@ -71,7 +72,8 @@ static inline int of_get_named_gpio_flags(struct device_node *np,
 	return -ENOSYS;
 }
 
-static inline unsigned int of_gpio_count(struct device_node *np)
+static inline unsigned int of_gpio_named_count(struct device_node *np,
+					const char* propname)
 {
 	return 0;
 }
@@ -88,6 +90,27 @@ static inline void of_gpiochip_remove(struct gpio_chip *gc) { }
 
 #endif /* CONFIG_OF_GPIO */
 
+/**
+ * of_gpio_count - Count GPIOs for a device
+ * @np:		device node to count GPIOs for
+ *
+ * The function returns the count of GPIOs specified for a node.
+ *
+ * Note that the empty GPIO specifiers counts too. For example,
+ *
+ * gpios = <0
+ *          &pio1 1 2
+ *          0
+ *          &pio2 3 4>;
+ *
+ * defines four GPIOs (so this function will return 4), two of which
+ * are not specified.
+ */
+static inline unsigned int of_gpio_count(struct device_node *np)
+{
+	return of_gpio_named_count(np, "gpios");
+}
+
 /**
  * of_get_gpio_flags() - Get a GPIO number and flags to use with GPIO API
  * @np:		device node to get GPIO from