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authorAnton Vorontsov <avorontsov@ru.mvista.com>2008-12-05 03:15:54 -0500
committerPaul Mackerras <paulus@samba.org>2008-12-20 22:21:14 -0500
commit749820928a2fd47ff536773d869d2c3f8038b7d1 (patch)
tree69f7f37a63f9c194f33fb7a16d12f62b583da6c8 /drivers/of
parent7736a3db98bed028d0e5235f8958a730acfd822e (diff)
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.c34
1 files changed, 34 insertions, 0 deletions
diff --git a/drivers/of/gpio.c b/drivers/of/gpio.c
index a4ba217116e..6eea601a920 100644
--- a/drivers/of/gpio.c
+++ b/drivers/of/gpio.c
@@ -80,6 +80,40 @@ err0:
80EXPORT_SYMBOL(of_get_gpio_flags); 80EXPORT_SYMBOL(of_get_gpio_flags);
81 81
82/** 82/**
83 * of_gpio_count - Count GPIOs for a device
84 * @np: device node to count GPIOs for
85 *
86 * The function returns the count of GPIOs specified for a node.
87 *
88 * Note that the empty GPIO specifiers counts too. For example,
89 *
90 * gpios = <0
91 * &pio1 1 2
92 * 0
93 * &pio2 3 4>;
94 *
95 * defines four GPIOs (so this function will return 4), two of which
96 * are not specified.
97 */
98unsigned int of_gpio_count(struct device_node *np)
99{
100 unsigned int cnt = 0;
101
102 do {
103 int ret;
104
105 ret = of_parse_phandles_with_args(np, "gpios", "#gpio-cells",
106 cnt, NULL, NULL);
107 /* A hole in the gpios = <> counts anyway. */
108 if (ret < 0 && ret != -EEXIST)
109 break;
110 } while (++cnt);
111
112 return cnt;
113}
114EXPORT_SYMBOL(of_gpio_count);
115
116/**
83 * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags 117 * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags
84 * @of_gc: pointer to the of_gpio_chip structure 118 * @of_gc: pointer to the of_gpio_chip structure
85 * @np: device node of the GPIO chip 119 * @np: device node of the GPIO chip