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dm: gpio: Add a driver GPIO translation method

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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>
This commit is contained in:
Simon Glass 2015-01-05 20:05:28 -07:00
parent ae7123f876
commit 0dac4d51f5
2 changed files with 45 additions and 0 deletions
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16
drivers/gpio/gpio-uclass.c
View File

@ -7,6 +7,7 @@
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <fdtdec.h>
#include <malloc.h>
#include <asm/gpio.h>
#include <linux/ctype.h>
@ -91,6 +92,21 @@ int gpio_lookup_name(const char *name, struct udevice **devp,
return 0;
}
int gpio_find_and_xlate(struct gpio_desc *desc,
struct fdtdec_phandle_args *args)
{
struct dm_gpio_ops *ops = gpio_get_ops(desc->dev);
/* Use the first argument as the offset by default */
if (args->args_count > 0)
desc->offset = args->args[0];
else
desc->offset = -1;
desc->flags = 0;
return ops->xlate ? ops->xlate(desc->dev, desc, args) : 0;
}
static int dm_gpio_request(struct gpio_desc *desc, const char *label)
{
struct udevice *dev = desc->dev;

29
include/asm-generic/gpio.h
View File

@ -171,6 +171,8 @@ int gpio_get_raw_function(struct udevice *dev, int offset, const char **namep);
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 @@ struct dm_gpio_ops {
* @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);
};
/**