diff options
| author | Anton Vorontsov <avorontsov@ru.mvista.com> | 2008-12-05 11:15:54 +0300 |
|---|---|---|
| committer | Paul Mackerras <paulus@samba.org> | 2008-12-21 06:21:14 +0300 |
| commit | 749820928a2fd47ff536773d869d2c3f8038b7d1 (patch) | |
| tree | 69f7f37a63f9c194f33fb7a16d12f62b583da6c8 /drivers/of | |
| parent | 7736a3db98bed028d0e5235f8958a730acfd822e (diff) | |
| download | linux-749820928a2fd47ff536773d869d2c3f8038b7d1.tar.xz | |
of/gpio: Implement of_gpio_count()
This function is used to count how many GPIOs are specified for
a device node.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'drivers/of')
| -rw-r--r-- | drivers/of/gpio.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/drivers/of/gpio.c b/drivers/of/gpio.c index a4ba217116eb..6eea601a9204 100644 --- a/drivers/of/gpio.c +++ b/drivers/of/gpio.c @@ -80,6 +80,40 @@ 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 * @np: device node of the GPIO chip |