dm: gpio: Add a driver GPIO translation method
Only the GPIO driver knows about the full GPIO device tree binding used by
a device. Add a method to allow the driver to provide this information to the
uclass, including the GPIO offset within the device and flags such as the
polarity.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index a827a56..c08c963 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -171,6 +171,8 @@
int gpio_requestf(unsigned gpio, const char *fmt, ...)
__attribute__ ((format (__printf__, 2, 3)));
+struct fdtdec_phandle_args;
+
/**
* struct struct dm_gpio_ops - Driver model GPIO operations
*
@@ -214,6 +216,33 @@
* @return current function - GPIOF_...
*/
int (*get_function)(struct udevice *dev, unsigned offset);
+
+ /**
+ * xlate() - Translate phandle arguments into a GPIO description
+ *
+ * This function should set up the fields in desc according to the
+ * information in the arguments. The uclass will have set up:
+ *
+ * @desc->dev to @dev
+ * @desc->flags to 0
+ * @desc->offset to the value of the first argument in args, if any,
+ * otherwise -1 (which is invalid)
+ *
+ * This method is optional so if the above defaults suit it can be
+ * omitted. Typical behaviour is to set up the GPIOD_ACTIVE_LOW flag
+ * in desc->flags.
+ *
+ * Note that @dev is passed in as a parameter to follow driver model
+ * uclass conventions, even though it is already available as
+ * desc->dev.
+ *
+ * @dev: GPIO device
+ * @desc: Place to put GPIO description
+ * @args: Arguments provided in descripion
+ * @return 0 if OK, -ve on error
+ */
+ int (*xlate)(struct udevice *dev, struct gpio_desc *desc,
+ struct fdtdec_phandle_args *args);
};
/**