diff options
Diffstat (limited to 'drivers/of/gpio.c')
-rw-r--r-- | drivers/of/gpio.c | 70 |
1 files changed, 63 insertions, 7 deletions
diff --git a/drivers/of/gpio.c b/drivers/of/gpio.c index 7cd7301b5839..6eea601a9204 100644 --- a/drivers/of/gpio.c +++ b/drivers/of/gpio.c | |||
@@ -19,14 +19,17 @@ | |||
19 | #include <asm/prom.h> | 19 | #include <asm/prom.h> |
20 | 20 | ||
21 | /** | 21 | /** |
22 | * of_get_gpio - Get a GPIO number from the device tree to use with GPIO API | 22 | * of_get_gpio_flags - Get a GPIO number and flags to use with GPIO API |
23 | * @np: device node to get GPIO from | 23 | * @np: device node to get GPIO from |
24 | * @index: index of the GPIO | 24 | * @index: index of the GPIO |
25 | * @flags: a flags pointer to fill in | ||
25 | * | 26 | * |
26 | * Returns GPIO number to use with Linux generic GPIO API, or one of the errno | 27 | * Returns GPIO number to use with Linux generic GPIO API, or one of the errno |
27 | * value on the error condition. | 28 | * value on the error condition. If @flags is not NULL the function also fills |
29 | * in flags for the GPIO. | ||
28 | */ | 30 | */ |
29 | int of_get_gpio(struct device_node *np, int index) | 31 | int of_get_gpio_flags(struct device_node *np, int index, |
32 | enum of_gpio_flags *flags) | ||
30 | { | 33 | { |
31 | int ret; | 34 | int ret; |
32 | struct device_node *gc; | 35 | struct device_node *gc; |
@@ -59,7 +62,11 @@ int of_get_gpio(struct device_node *np, int index) | |||
59 | goto err1; | 62 | goto err1; |
60 | } | 63 | } |
61 | 64 | ||
62 | ret = of_gc->xlate(of_gc, np, gpio_spec); | 65 | /* .xlate might decide to not fill in the flags, so clear it. */ |
66 | if (flags) | ||
67 | *flags = 0; | ||
68 | |||
69 | ret = of_gc->xlate(of_gc, np, gpio_spec, flags); | ||
63 | if (ret < 0) | 70 | if (ret < 0) |
64 | goto err1; | 71 | goto err1; |
65 | 72 | ||
@@ -70,26 +77,75 @@ err0: | |||
70 | pr_debug("%s exited with status %d\n", __func__, ret); | 77 | pr_debug("%s exited with status %d\n", __func__, ret); |
71 | return ret; | 78 | return ret; |
72 | } | 79 | } |
73 | EXPORT_SYMBOL(of_get_gpio); | 80 | EXPORT_SYMBOL(of_get_gpio_flags); |
74 | 81 | ||
75 | /** | 82 | /** |
76 | * of_gpio_simple_xlate - translate gpio_spec to the GPIO number | 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 | */ | ||
98 | unsigned 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 | } | ||
114 | EXPORT_SYMBOL(of_gpio_count); | ||
115 | |||
116 | /** | ||
117 | * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags | ||
77 | * @of_gc: pointer to the of_gpio_chip structure | 118 | * @of_gc: pointer to the of_gpio_chip structure |
78 | * @np: device node of the GPIO chip | 119 | * @np: device node of the GPIO chip |
79 | * @gpio_spec: gpio specifier as found in the device tree | 120 | * @gpio_spec: gpio specifier as found in the device tree |
121 | * @flags: a flags pointer to fill in | ||
80 | * | 122 | * |
81 | * This is simple translation function, suitable for the most 1:1 mapped | 123 | * This is simple translation function, suitable for the most 1:1 mapped |
82 | * gpio chips. This function performs only one sanity check: whether gpio | 124 | * gpio chips. This function performs only one sanity check: whether gpio |
83 | * is less than ngpios (that is specified in the gpio_chip). | 125 | * is less than ngpios (that is specified in the gpio_chip). |
84 | */ | 126 | */ |
85 | int of_gpio_simple_xlate(struct of_gpio_chip *of_gc, struct device_node *np, | 127 | int of_gpio_simple_xlate(struct of_gpio_chip *of_gc, struct device_node *np, |
86 | const void *gpio_spec) | 128 | const void *gpio_spec, enum of_gpio_flags *flags) |
87 | { | 129 | { |
88 | const u32 *gpio = gpio_spec; | 130 | const u32 *gpio = gpio_spec; |
89 | 131 | ||
132 | /* | ||
133 | * We're discouraging gpio_cells < 2, since that way you'll have to | ||
134 | * write your own xlate function (that will have to retrive the GPIO | ||
135 | * number and the flags from a single gpio cell -- this is possible, | ||
136 | * but not recommended). | ||
137 | */ | ||
138 | if (of_gc->gpio_cells < 2) { | ||
139 | WARN_ON(1); | ||
140 | return -EINVAL; | ||
141 | } | ||
142 | |||
90 | if (*gpio > of_gc->gc.ngpio) | 143 | if (*gpio > of_gc->gc.ngpio) |
91 | return -EINVAL; | 144 | return -EINVAL; |
92 | 145 | ||
146 | if (flags) | ||
147 | *flags = gpio[1]; | ||
148 | |||
93 | return *gpio; | 149 | return *gpio; |
94 | } | 150 | } |
95 | EXPORT_SYMBOL(of_gpio_simple_xlate); | 151 | EXPORT_SYMBOL(of_gpio_simple_xlate); |