i2c: i2c_gpio: add devicetree support

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 55 insertions, 0 deletions

diff --git a/include/of_gpio.h b/include/of_gpio.h
index d42b18e63f..95a454c683 100644
--- a/include/of_gpio.h
+++ b/include/of_gpio.h
@@ -35,10 +35,65 @@ static inline int of_get_named_gpio_flags(struct device_node *np,
 
 #endif /* CONFIG_OF_GPIO */
 
+/**
+ * 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.
+ * Note that the empty GPIO specifiers count too. Returns either
+ *   Number of gpios defined in property,
+ *   -EINVAL for an incorrectly formed gpios property, or
+ *   -ENOENT for a missing gpios property
+ *
+ * Example:
+ * gpios = <0
+ *          &gpio1 1 2
+ *          0
+ *          &gpio2 3 4>;
+ *
+ * The above example defines four GPIOs, two of which are not specified.
+ * This function will return '4'
+ */
+static inline int of_gpio_named_count(struct device_node *np, const char* propname)
+{
+	return of_count_phandle_with_args(np, propname, "#gpio-cells");
+}
+
+/**
+ * of_gpio_count() - Count GPIOs for a device
+ * @np:		device node to count GPIOs for
+ *
+ * Same as of_gpio_named_count, but hard coded to use the 'gpios' property
+ */
+static inline int of_gpio_count(struct device_node *np)
+{
+	return of_gpio_named_count(np, "gpios");
+}
+
+static inline int of_get_gpio_flags(struct device_node *np, int index,
+		      enum of_gpio_flags *flags)
+{
+	return of_get_named_gpio_flags(np, "gpios", index, flags);
+}
+
 static inline int of_get_named_gpio(struct device_node *np,
 				const char *list_name, int index)
 {
 	return of_get_named_gpio_flags(np, list_name, index, NULL);
 }
 
+/**
+ * of_get_gpio() - Get a GPIO number to use with GPIO API
+ * @np:		device node to get GPIO from
+ * @index:	index of the GPIO
+ *
+ * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
+ * value on the error condition.
+ */
+static inline int of_get_gpio(struct device_node *np, int index)
+{
+	return of_get_gpio_flags(np, index, NULL);
+}
+
 #endif