Commit 74982092 authored by Anton Vorontsov's avatar Anton Vorontsov Committed by Paul Mackerras
Browse files

of/gpio: Implement of_gpio_count() 



This function is used to count how many GPIOs are specified for
a device node.

Signed-off-by: default avatarAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 7736a3db

drivers/of/gpio.c

+34 −0
Original line number Diff line number Diff line
@@ -79,6 +79,40 @@ int of_get_gpio_flags(struct device_node *np, int index, 
}

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

include/linux/of_gpio.h

+6 −0
Original line number Diff line number Diff line
@@ -65,6 +65,7 @@ static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc) 


extern int of_get_gpio_flags(struct device_node *np, int index,

			     enum of_gpio_flags *flags);

extern unsigned int of_gpio_count(struct device_node *np);



extern int of_mm_gpiochip_add(struct device_node *np,

			      struct of_mm_gpio_chip *mm_gc);
@@ -81,6 +82,11 @@ static inline int of_get_gpio_flags(struct device_node *np, int index, 
	return -ENOSYS;

}



static inline unsigned int of_gpio_count(struct device_node *np)

{

	return 0;

}



#endif /* CONFIG_OF_GPIO */



/**