[PATCH v1 1/5] gpiolib: Introduce gpiochip_count() helper

[Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>]

The gpiochip_count() helper iterates over the device child nodes that have
the "gpio-controller" property set. It returns the number of such nodes
under given device.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
 include/linux/gpio/driver.h | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index 894eab753fdf..52918ef5d288 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -9,6 +9,7 @@
 #include <linux/lockdep.h>
 #include <linux/pinctrl/pinctrl.h>
 #include <linux/pinctrl/pinconf-generic.h>
+#include <linux/property.h>
 #include <linux/types.h>
 
 struct gpio_desc;
@@ -750,4 +751,17 @@ static inline void gpiochip_unlock_as_irq(struct gpio_chip *gc,
 }
 #endif /* CONFIG_GPIOLIB */
 
+static inline unsigned int gpiochip_count(struct device *dev)
+{
+	struct fwnode_handle *child;
+	unsigned int count = 0;
+
+	device_for_each_child_node(dev, child) {
+		if (device_property_read_bool(child, "gpio-controller"))
+			count++;
+	}
+
+	return count;
+}
+
 #endif /* __LINUX_GPIO_DRIVER_H */
-- 
2.35.1