of/gpio: Implement of_gpio_count()

[linux-2.6-omap-h63xx.git] / drivers / of / gpio.c

diff --git a/drivers/of/gpio.c b/drivers/of/gpio.c
index a4ba217116eb4bdc81810c51890d14f010ae7523..6eea601a92043b69f3c95c86aa06ae077327c03a 100644 (file)
--- a/drivers/of/gpio.c
+++ b/drivers/of/gpio.c
@@ -79,6 +79,40 @@ err0:
 }
 EXPORT_SYMBOL(of_get_gpio_flags);
 
+/**
+ * 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.
+ */
+unsigned int of_gpio_count(struct device_node *np)
+{
+       unsigned int cnt = 0;
+
+       do {
+               int ret;
+
+               ret = of_parse_phandles_with_args(np, "gpios", "#gpio-cells",
+                                                 cnt, NULL, NULL);
+               /* A hole in the gpios = <> counts anyway. */
+               if (ret < 0 && ret != -EEXIST)
+                       break;
+       } while (++cnt);
+
+       return cnt;
+}
+EXPORT_SYMBOL(of_gpio_count);
+
 /**
  * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags
  * @of_gc:     pointer to the of_gpio_chip structure