From eec1d566cdf94b57e8f5ba9fe60eea214929bcfc Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Thu, 12 Oct 2017 12:40:10 +0200 Subject: gpio: Introduce ->get_multiple callback SPI-attached GPIO controllers typically read out all inputs in one go. If callers desire the values of multipe inputs, ideally a single readout should take place to return the desired values. However the current driver API only offers a ->get callback but no ->get_multiple (unlike ->set_multiple, which is present). Thus, to read multiple inputs, a full readout needs to be performed for every single value (barring driver-internal caching), which is inefficient. In fact, the lack of a ->get_multiple callback has been bemoaned repeatedly by the gpio subsystem maintainer: http://www.spinics.net/lists/linux-gpio/msg10571.html http://www.spinics.net/lists/devicetree/msg121734.html Introduce the missing callback. Add corresponding consumer functions such as gpiod_get_array_value(). Amend linehandle_ioctl() to take advantage of the newly added infrastructure. Update the documentation. Cc: Rojhalat Ibrahim Signed-off-by: Lukas Wunner Signed-off-by: Linus Walleij --- include/linux/gpio/consumer.h | 43 +++++++++++++++++++++++++++++++++++++++++++ include/linux/gpio/driver.h | 5 +++++ 2 files changed, 48 insertions(+) (limited to 'include/linux') diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h index 8f702fcbe485..d4920ec1f1da 100644 --- a/include/linux/gpio/consumer.h +++ b/include/linux/gpio/consumer.h @@ -99,10 +99,15 @@ int gpiod_direction_output_raw(struct gpio_desc *desc, int value); /* Value get/set from non-sleeping context */ int gpiod_get_value(const struct gpio_desc *desc); +int gpiod_get_array_value(unsigned int array_size, + struct gpio_desc **desc_array, int *value_array); void gpiod_set_value(struct gpio_desc *desc, int value); void gpiod_set_array_value(unsigned int array_size, struct gpio_desc **desc_array, int *value_array); int gpiod_get_raw_value(const struct gpio_desc *desc); +int gpiod_get_raw_array_value(unsigned int array_size, + struct gpio_desc **desc_array, + int *value_array); void gpiod_set_raw_value(struct gpio_desc *desc, int value); void gpiod_set_raw_array_value(unsigned int array_size, struct gpio_desc **desc_array, @@ -110,11 +115,17 @@ void gpiod_set_raw_array_value(unsigned int array_size, /* Value get/set from sleeping context */ int gpiod_get_value_cansleep(const struct gpio_desc *desc); +int gpiod_get_array_value_cansleep(unsigned int array_size, + struct gpio_desc **desc_array, + int *value_array); void gpiod_set_value_cansleep(struct gpio_desc *desc, int value); void gpiod_set_array_value_cansleep(unsigned int array_size, struct gpio_desc **desc_array, int *value_array); int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc); +int gpiod_get_raw_array_value_cansleep(unsigned int array_size, + struct gpio_desc **desc_array, + int *value_array); void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value); void gpiod_set_raw_array_value_cansleep(unsigned int array_size, struct gpio_desc **desc_array, @@ -305,6 +316,14 @@ static inline int gpiod_get_value(const struct gpio_desc *desc) WARN_ON(1); return 0; } +static inline int gpiod_get_array_value(unsigned int array_size, + struct gpio_desc **desc_array, + int *value_array) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return 0; +} static inline void gpiod_set_value(struct gpio_desc *desc, int value) { /* GPIO can never have been requested */ @@ -323,6 +342,14 @@ static inline int gpiod_get_raw_value(const struct gpio_desc *desc) WARN_ON(1); return 0; } +static inline int gpiod_get_raw_array_value(unsigned int array_size, + struct gpio_desc **desc_array, + int *value_array) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return 0; +} static inline void gpiod_set_raw_value(struct gpio_desc *desc, int value) { /* GPIO can never have been requested */ @@ -342,6 +369,14 @@ static inline int gpiod_get_value_cansleep(const struct gpio_desc *desc) WARN_ON(1); return 0; } +static inline int gpiod_get_array_value_cansleep(unsigned int array_size, + struct gpio_desc **desc_array, + int *value_array) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return 0; +} static inline void gpiod_set_value_cansleep(struct gpio_desc *desc, int value) { /* GPIO can never have been requested */ @@ -360,6 +395,14 @@ static inline int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc) WARN_ON(1); return 0; } +static inline int gpiod_get_raw_array_value_cansleep(unsigned int array_size, + struct gpio_desc **desc_array, + int *value_array) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return 0; +} static inline void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value) { diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index 6bbda879fb8b..bda95a9b7b8c 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -35,6 +35,8 @@ struct module; * @direction_input: configures signal "offset" as input, or returns error * @direction_output: configures signal "offset" as output, or returns error * @get: returns value for signal "offset", 0=low, 1=high, or negative error + * @get_multiple: reads values for multiple signals defined by "mask" and + * stores them in "bits", returns 0 on success or negative error * @set: assigns output value for signal "offset" * @set_multiple: assigns output values for multiple signals defined by "mask" * @set_config: optional hook for all kinds of settings. Uses the same @@ -125,6 +127,9 @@ struct gpio_chip { unsigned offset, int value); int (*get)(struct gpio_chip *chip, unsigned offset); + int (*get_multiple)(struct gpio_chip *chip, + unsigned long *mask, + unsigned long *bits); void (*set)(struct gpio_chip *chip, unsigned offset, int value); void (*set_multiple)(struct gpio_chip *chip, -- cgit v1.2.3