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authorAlexandre Courbot <acourbot@nvidia.com>2014-07-25 18:38:36 +0400
committerLinus Walleij <linus.walleij@linaro.org>2014-07-28 14:28:05 +0400
commit39b2bbe3d715cf5013b5c48695ccdd25bd3bf120 (patch)
tree019129dbc7b1cc10200342602fe7eac47230219e /include/linux/gpio
parent9b5b33f6256a941d9d34f219b508ba7140a39dba (diff)
downloadlinux-39b2bbe3d715cf5013b5c48695ccdd25bd3bf120.tar.xz
gpio: add flags argument to gpiod_get*() functions
The huge majority of GPIOs have their direction and initial value set right after being obtained by one of the gpiod_get() functions. The integer GPIO API had gpio_request_one() that took a convenience flags parameter allowing to specify an direction and value applied to the returned GPIO. This feature greatly simplifies client code and ensures errors are always handled properly. A similar feature has been requested for the gpiod API. Since setting the direction of a GPIO is so often the very next action done after obtaining its descriptor, we prefer to extend the existing functions instead of introducing new functions that would raise the number of gpiod getters to 16 (!). The drawback of this approach is that all gpiod clients need to be updated. To limit the pain, temporary macros are introduced that allow gpiod_get*() to be called with or without the extra flags argument. They will be removed once all consumer code has been updated. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Mark Brown <broonie@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'include/linux/gpio')
-rw-r--r--include/linux/gpio/consumer.h81
1 files changed, 65 insertions, 16 deletions
diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
index 05e53ccb708b..b7ce0c64c6f3 100644
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -18,30 +18,79 @@ struct gpio_desc;
#ifdef CONFIG_GPIOLIB
+#define GPIOD_FLAGS_BIT_DIR_SET BIT(0)
+#define GPIOD_FLAGS_BIT_DIR_OUT BIT(1)
+#define GPIOD_FLAGS_BIT_DIR_VAL BIT(2)
+
+/**
+ * Optional flags that can be passed to one of gpiod_* to configure direction
+ * and output value. These values cannot be OR'd.
+ */
+enum gpiod_flags {
+ GPIOD_ASIS = 0,
+ GPIOD_IN = GPIOD_FLAGS_BIT_DIR_SET,
+ GPIOD_OUT_LOW = GPIOD_FLAGS_BIT_DIR_SET | GPIOD_FLAGS_BIT_DIR_OUT,
+ GPIOD_OUT_HIGH = GPIOD_FLAGS_BIT_DIR_SET | GPIOD_FLAGS_BIT_DIR_OUT |
+ GPIOD_FLAGS_BIT_DIR_VAL,
+};
+
/* Acquire and dispose GPIOs */
-struct gpio_desc *__must_check gpiod_get(struct device *dev,
- const char *con_id);
-struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
+struct gpio_desc *__must_check __gpiod_get(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags);
+#define __gpiod_get(dev, con_id, flags, ...) __gpiod_get(dev, con_id, flags)
+#define gpiod_get(varargs...) __gpiod_get(varargs, 0)
+struct gpio_desc *__must_check __gpiod_get_index(struct device *dev,
const char *con_id,
- unsigned int idx);
-struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
- const char *con_id);
-struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
+ unsigned int idx,
+ enum gpiod_flags flags);
+#define __gpiod_get_index(dev, con_id, index, flags, ...) \
+ __gpiod_get_index(dev, con_id, index, flags)
+#define gpiod_get_index(varargs...) __gpiod_get_index(varargs, 0)
+struct gpio_desc *__must_check __gpiod_get_optional(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags);
+#define __gpiod_get_optional(dev, con_id, flags, ...) \
+ __gpiod_get_optional(dev, con_id, flags)
+#define gpiod_get_optional(varargs...) __gpiod_get_optional(varargs, 0)
+struct gpio_desc *__must_check __gpiod_get_index_optional(struct device *dev,
const char *con_id,
- unsigned int index);
+ unsigned int index,
+ enum gpiod_flags flags);
+#define __gpiod_get_index_optional(dev, con_id, index, flags, ...) \
+ __gpiod_get_index_optional(dev, con_id, index, flags)
+#define gpiod_get_index_optional(varargs...) \
+ __gpiod_get_index_optional(varargs, 0)
void gpiod_put(struct gpio_desc *desc);
-struct gpio_desc *__must_check devm_gpiod_get(struct device *dev,
- const char *con_id);
-struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,
+struct gpio_desc *__must_check __devm_gpiod_get(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags);
+#define __devm_gpiod_get(dev, con_id, flags, ...) \
+ __devm_gpiod_get(dev, con_id, flags)
+#define devm_gpiod_get(varargs...) __devm_gpiod_get(varargs, 0)
+struct gpio_desc *__must_check __devm_gpiod_get_index(struct device *dev,
const char *con_id,
- unsigned int idx);
-struct gpio_desc *__must_check devm_gpiod_get_optional(struct device *dev,
- const char *con_id);
+ unsigned int idx,
+ enum gpiod_flags flags);
+#define __devm_gpiod_get_index(dev, con_id, index, flags, ...) \
+ __devm_gpiod_get_index(dev, con_id, index, flags)
+#define devm_gpiod_get_index(varargs...) __devm_gpiod_get_index(varargs, 0)
+struct gpio_desc *__must_check __devm_gpiod_get_optional(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags);
+#define __devm_gpiod_get_optional(dev, con_id, flags, ...) \
+ __devm_gpiod_get_optional(dev, con_id, flags)
+#define devm_gpiod_get_optional(varargs...) \
+ __devm_gpiod_get_optional(varargs, 0)
struct gpio_desc *__must_check
-devm_gpiod_get_index_optional(struct device *dev, const char *con_id,
- unsigned int index);
+__devm_gpiod_get_index_optional(struct device *dev, const char *con_id,
+ unsigned int index, enum gpiod_flags flags);
+#define __devm_gpiod_get_index_optional(dev, con_id, index, flags, ...) \
+ __devm_gpiod_get_index_optional(dev, con_id, index, flags)
+#define devm_gpiod_get_index_optional(varargs...) \
+ __devm_gpiod_get_index_optional(varargs, 0)
void devm_gpiod_put(struct device *dev, struct gpio_desc *desc);