Many drivers use a common form of offset + flags for device tree nodes. e.g.: <&gpio1 2 GPIO_ACTIVE_LOW>
This patch adds a common implementation of this type of parsing and calls it when a gpio driver doesn't supply its' own xlate routine.
This will allow removal of the driver-specific versions in a handful of drivers and simplify the addition of new drivers.
Signed-off-by: Eric Nelson eric@nelint.com --- V2 removes parsing of offset from the gpio_find_and_xlate routine, and only parses the offset and GPIO_ACTIVE_LOW flag when a driver-specific xlate is unavailable.
V3 re-works tests of the argument count as suggested by Stephen Warren and will allow parsing of nodes with no flags field: <&gpio1 2>
drivers/gpio/gpio-uclass.c | 30 +++++++++++++++++++++++------- include/asm-generic/gpio.h | 19 ++++++++++++++----- 2 files changed, 37 insertions(+), 12 deletions(-)
diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c index b58d4e6..3e83cec 100644 --- a/drivers/gpio/gpio-uclass.c +++ b/drivers/gpio/gpio-uclass.c @@ -6,6 +6,7 @@
#include <common.h> #include <dm.h> +#include <dt-bindings/gpio/gpio.h> #include <errno.h> #include <fdtdec.h> #include <malloc.h> @@ -113,19 +114,33 @@ int gpio_lookup_name(const char *name, struct udevice **devp, return 0; }
+int gpio_xlate_offs_flags(struct udevice *dev, + struct gpio_desc *desc, + struct fdtdec_phandle_args *args) +{ + if (args->args_count < 1) + return -EINVAL; + + desc->offset = args->args[0]; + + if (args->args_count < 2) + return 0; + + if (args->args[1] & GPIO_ACTIVE_LOW) + desc->flags = GPIOD_ACTIVE_LOW; + + return 0; +} + static 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]; + if (ops->xlate) + return ops->xlate(desc->dev, desc, args); else - desc->offset = -1; - desc->flags = 0; - - return ops->xlate ? ops->xlate(desc->dev, desc, args) : 0; + return gpio_xlate_offs_flags(desc->dev, desc, args); }
int dm_gpio_request(struct gpio_desc *desc, const char *label) @@ -605,6 +620,7 @@ static int _gpio_request_by_name_nodev(const void *blob, int node,
desc->dev = NULL; desc->offset = 0; + desc->flags = 0; ret = fdtdec_parse_phandle_with_args(blob, node, list_name, "#gpio-cells", 0, index, &args); if (ret) { diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index 68b5f0b..2500c10 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -207,6 +207,16 @@ int gpio_requestf(unsigned gpio, const char *fmt, ...) struct fdtdec_phandle_args;
/** + * gpio_xlate_offs_flags() - implementation for common use of dm_gpio_ops.xlate + * + * This routine sets the offset field to args[0] and the flags field to + * GPIOD_ACTIVE_LOW if the GPIO_ACTIVE_LOW flag is present in args[1]. + * + */ +int gpio_xlate_offs_flags(struct udevice *dev, struct gpio_desc *desc, + struct fdtdec_phandle_args *args); + +/** * struct struct dm_gpio_ops - Driver model GPIO operations * * Refer to functions above for description. These function largely copy @@ -258,12 +268,11 @@ struct dm_gpio_ops { * * @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) + * @desc->offset to 0 * - * 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. + * This method is optional and defaults to gpio_xlate_offs_flags, + * which will parse offset and the GPIO_ACTIVE_LOW flag in the first + * two arguments. * * Note that @dev is passed in as a parameter to follow driver model * uclass conventions, even though it is already available as