of/gpio: Implement of_get_gpio_flags()
This adds a new function, of_get_gpio_flags, which is like
of_get_gpio(), but accepts a new "flags" argument. This new function
will be used by the drivers that need to retrieve additional GPIO
information, such as active-low flag.
Also, this changes the default ("simple") .xlate routine to warn about
bogus (< 2) #gpio-cells usage: the second cell should always be present
for GPIO flags.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/drivers/of/gpio.c b/drivers/of/gpio.c
index 7cd7301..a4ba217 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 @@
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 +77,41 @@
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_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);