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path: root/drivers/of/gpio.c
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Diffstat (limited to 'drivers/of/gpio.c')
-rw-r--r--drivers/of/gpio.c70
1 files changed, 63 insertions, 7 deletions
diff --git a/drivers/of/gpio.c b/drivers/of/gpio.c
index 7cd7301b583..6eea601a920 100644
--- a/drivers/of/gpio.c
+++ b/drivers/of/gpio.c
@@ -19,14 +19,17 @@
#include <asm/prom.h>
/**
- * of_get_gpio - Get a GPIO number from the device tree to use with GPIO API
+ * of_get_gpio_flags - Get a GPIO number and flags to use with GPIO API
* @np: device node to get GPIO from
* @index: index of the GPIO
+ * @flags: a flags pointer to fill in
*
* Returns GPIO number to use with Linux generic GPIO API, or one of the errno
- * value on the error condition.
+ * value on the error condition. If @flags is not NULL the function also fills
+ * in flags for the GPIO.
*/
-int of_get_gpio(struct device_node *np, int index)
+int of_get_gpio_flags(struct device_node *np, int index,
+ enum of_gpio_flags *flags)
{
int ret;
struct device_node *gc;
@@ -59,7 +62,11 @@ int of_get_gpio(struct device_node *np, int index)
goto err1;
}
- ret = of_gc->xlate(of_gc, np, gpio_spec);
+ /* .xlate might decide to not fill in the flags, so clear it. */
+ if (flags)
+ *flags = 0;
+
+ ret = of_gc->xlate(of_gc, np, gpio_spec, flags);
if (ret < 0)
goto err1;
@@ -70,26 +77,75 @@ err0:
pr_debug("%s exited with status %d\n", __func__, ret);
return ret;
}
-EXPORT_SYMBOL(of_get_gpio);
+EXPORT_SYMBOL(of_get_gpio_flags);
/**
- * of_gpio_simple_xlate - translate gpio_spec to the GPIO number
+ * 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
* @gpio_spec: gpio specifier as found in the device tree
+ * @flags: a flags pointer to fill in
*
* This is simple translation function, suitable for the most 1:1 mapped
* gpio chips. This function performs only one sanity check: whether gpio
* is less than ngpios (that is specified in the gpio_chip).
*/
int of_gpio_simple_xlate(struct of_gpio_chip *of_gc, struct device_node *np,
- const void *gpio_spec)
+ const void *gpio_spec, enum of_gpio_flags *flags)
{
const u32 *gpio = gpio_spec;
+ /*
+ * We're discouraging gpio_cells < 2, since that way you'll have to
+ * write your own xlate function (that will have to retrive the GPIO
+ * number and the flags from a single gpio cell -- this is possible,
+ * but not recommended).
+ */
+ if (of_gc->gpio_cells < 2) {
+ WARN_ON(1);
+ return -EINVAL;
+ }
+
if (*gpio > of_gc->gc.ngpio)
return -EINVAL;
+ if (flags)
+ *flags = gpio[1];
+
return *gpio;
}
EXPORT_SYMBOL(of_gpio_simple_xlate);