Kernel/linux-next
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git synced 2025-01-18 14:25:25 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity
linux-next/include/linux/gpio/consumer.h
Rojhalat Ibrahim 5f42424354 gpiolib: allow simultaneous setting of multiple GPIO outputs 
Introduce new functions gpiod_set_array & gpiod_set_raw_array to the consumer
interface which allow setting multiple outputs with just one function call.
Also add an optional set_multiple function to the driver interface. Without an
implementation of that function in the chip driver outputs are set
sequentially.

Implementing the set_multiple function in a chip driver allows for:
- Improved performance for certain use cases. The original motivation for this
  was the task of configuring an FPGA. In that specific case, where 9 GPIO
  lines have to be set many times, configuration time goes down from 48 s to
  20 s when using the new function.
- Simultaneous glitch-free setting of multiple pins on any kind of parallel
  bus attached to GPIOs provided they all reside on the same chip and bank.

Limitations:
  Performance is only improved for normal high-low outputs. Open drain and
  open source outputs are always set separately from each other. Those kinds
  of outputs could probably be accelerated in a similar way if we could
  forgo the error checking when setting GPIO directions.

Change log:
  v6: - rebase on current linux-gpio devel branch
  v5: - check can_sleep property per chip
      - remove superfluous checks
      - supplement documentation
  v4: - add gpiod_set_array function for setting logical values
      - change interface of the set_multiple driver function to use
        unsigned long as type for the bit fields
      - use generic bitops (which also use unsigned long for bit fields)
      - do not use ARCH_NR_GPIOS any more
  v3: - add documentation
      - change commit message
  v2: - use descriptor interface
      - allow arbitrary groups of GPIOs spanning multiple chips

Signed-off-by: Rojhalat Ibrahim <imr@rtschenk.de>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-11-27 15:01:18 +01:00

396 lines
11 KiB
C
Raw Blame History

#ifndef __LINUX_GPIO_CONSUMER_H
#define __LINUX_GPIO_CONSUMER_H
#include <linux/bug.h>
#include <linux/err.h>
#include <linux/kernel.h>
struct device;
/**
* Opaque descriptor for a GPIO. These are obtained using gpiod_get() and are
* preferable to the old integer-based handles.
*
* Contrary to integers, a pointer to a gpio_desc is guaranteed to be valid
* until the GPIO is released.
*/
struct gpio_desc;
#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,
};
#ifdef CONFIG_GPIOLIB
/* Acquire and dispose GPIOs */
struct gpio_desc *__must_check __gpiod_get(struct device *dev,
const char *con_id,
enum gpiod_flags flags);
struct gpio_desc *__must_check __gpiod_get_index(struct device *dev,
const char *con_id,
unsigned int idx,
enum gpiod_flags flags);
struct gpio_desc *__must_check __gpiod_get_optional(struct device *dev,
const char *con_id,
enum gpiod_flags flags);
struct gpio_desc *__must_check __gpiod_get_index_optional(struct device *dev,
const char *con_id,
unsigned int index,
enum gpiod_flags flags);
void gpiod_put(struct gpio_desc *desc);
struct gpio_desc *__must_check __devm_gpiod_get(struct device *dev,
const char *con_id,
enum gpiod_flags flags);
struct gpio_desc *__must_check __devm_gpiod_get_index(struct device *dev,
const char *con_id,
unsigned int idx,
enum gpiod_flags flags);
struct gpio_desc *__must_check __devm_gpiod_get_optional(struct device *dev,
const char *con_id,
enum gpiod_flags flags);
struct gpio_desc *__must_check
__devm_gpiod_get_index_optional(struct device *dev, const char *con_id,
unsigned int index, enum gpiod_flags flags);
void devm_gpiod_put(struct device *dev, struct gpio_desc *desc);
int gpiod_get_direction(const struct gpio_desc *desc);
int gpiod_direction_input(struct gpio_desc *desc);
int gpiod_direction_output(struct gpio_desc *desc, int value);
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);
void gpiod_set_value(struct gpio_desc *desc, int value);
void gpiod_set_array(unsigned int array_size,
struct gpio_desc **desc_array, int *value_array);
int gpiod_get_raw_value(const struct gpio_desc *desc);
void gpiod_set_raw_value(struct gpio_desc *desc, int value);
void gpiod_set_raw_array(unsigned int array_size,
struct gpio_desc **desc_array, int *value_array);
/* Value get/set from sleeping context */
int gpiod_get_value_cansleep(const struct gpio_desc *desc);
void gpiod_set_value_cansleep(struct gpio_desc *desc, int value);
void gpiod_set_array_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
int *value_array);
int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc);
void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value);
void gpiod_set_raw_array_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
int *value_array);
int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce);
int gpiod_is_active_low(const struct gpio_desc *desc);
int gpiod_cansleep(const struct gpio_desc *desc);
int gpiod_to_irq(const struct gpio_desc *desc);
/* Convert between the old gpio_ and new gpiod_ interfaces */
struct gpio_desc *gpio_to_desc(unsigned gpio);
int desc_to_gpio(const struct gpio_desc *desc);
#else /* CONFIG_GPIOLIB */
static inline struct gpio_desc *__must_check __gpiod_get(struct device *dev,
const char *con_id,
enum gpiod_flags flags)
{
return ERR_PTR(-ENOSYS);
}
static inline struct gpio_desc *__must_check
__gpiod_get_index(struct device *dev,
const char *con_id,
unsigned int idx,
enum gpiod_flags flags)
{
return ERR_PTR(-ENOSYS);
}
static inline struct gpio_desc *__must_check
__gpiod_get_optional(struct device *dev, const char *con_id,
enum gpiod_flags flags)
{
return ERR_PTR(-ENOSYS);
}
static inline struct gpio_desc *__must_check
__gpiod_get_index_optional(struct device *dev, const char *con_id,
unsigned int index, enum gpiod_flags flags)
{
return ERR_PTR(-ENOSYS);
}
static inline void gpiod_put(struct gpio_desc *desc)
{
might_sleep();
/* GPIO can never have been requested */
WARN_ON(1);
}
static inline struct gpio_desc *__must_check
__devm_gpiod_get(struct device *dev,
const char *con_id,
enum gpiod_flags flags)
{
return ERR_PTR(-ENOSYS);
}
static inline
struct gpio_desc *__must_check
__devm_gpiod_get_index(struct device *dev,
const char *con_id,
unsigned int idx,
enum gpiod_flags flags)
{
return ERR_PTR(-ENOSYS);
}
static inline struct gpio_desc *__must_check
__devm_gpiod_get_optional(struct device *dev, const char *con_id,
enum gpiod_flags flags)
{
return ERR_PTR(-ENOSYS);
}
static inline struct gpio_desc *__must_check
__devm_gpiod_get_index_optional(struct device *dev, const char *con_id,
unsigned int index, enum gpiod_flags flags)
{
return ERR_PTR(-ENOSYS);
}
static inline void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)
{
might_sleep();
/* GPIO can never have been requested */
WARN_ON(1);
}
static inline int gpiod_get_direction(const struct gpio_desc *desc)
{
/* GPIO can never have been requested */
WARN_ON(1);
return -ENOSYS;
}
static inline int gpiod_direction_input(struct gpio_desc *desc)
{
/* GPIO can never have been requested */
WARN_ON(1);
return -ENOSYS;
}
static inline int gpiod_direction_output(struct gpio_desc *desc, int value)
{
/* GPIO can never have been requested */
WARN_ON(1);
return -ENOSYS;
}
static inline int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
{
/* GPIO can never have been requested */
WARN_ON(1);
return -ENOSYS;
}
static inline int gpiod_get_value(const struct gpio_desc *desc)
{
/* 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 */
WARN_ON(1);
}
static inline void gpiod_set_array(unsigned int array_size,
struct gpio_desc **desc_array,
int *value_array)
{
/* GPIO can never have been requested */
WARN_ON(1);
}
static inline int gpiod_get_raw_value(const struct gpio_desc *desc)
{
/* 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 */
WARN_ON(1);
}
static inline void gpiod_set_raw_array(unsigned int array_size,
struct gpio_desc **desc_array,
int *value_array)
{
/* GPIO can never have been requested */
WARN_ON(1);
}
static inline int gpiod_get_value_cansleep(const struct gpio_desc *desc)
{
/* 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 */
WARN_ON(1);
}
static inline void gpiod_set_array_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
int *value_array)
{
/* GPIO can never have been requested */
WARN_ON(1);
}
static inline int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
{
/* 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)
{
/* GPIO can never have been requested */
WARN_ON(1);
}
static inline void gpiod_set_raw_array_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
int *value_array)
{
/* GPIO can never have been requested */
WARN_ON(1);
}
static inline int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
{
/* GPIO can never have been requested */
WARN_ON(1);
return -ENOSYS;
}
static inline int gpiod_is_active_low(const struct gpio_desc *desc)
{
/* GPIO can never have been requested */
WARN_ON(1);
return 0;
}
static inline int gpiod_cansleep(const struct gpio_desc *desc)
{
/* GPIO can never have been requested */
WARN_ON(1);
return 0;
}
static inline int gpiod_to_irq(const struct gpio_desc *desc)
{
/* GPIO can never have been requested */
WARN_ON(1);
return -EINVAL;
}
static inline struct gpio_desc *gpio_to_desc(unsigned gpio)
{
return ERR_PTR(-EINVAL);
}
static inline int desc_to_gpio(const struct gpio_desc *desc)
{
/* GPIO can never have been requested */
WARN_ON(1);
return -EINVAL;
}
#endif /* CONFIG_GPIOLIB */
/*
* Vararg-hacks! This is done to transition the kernel to always pass
* the options flags argument to the below functions. During a transition
* phase these vararg macros make both old-and-newstyle code compile,
* but when all calls to the elder API are removed, these should go away
* and the __gpiod_get() etc functions above be renamed just gpiod_get()
* etc.
*/
#define __gpiod_get(dev, con_id, flags, ...) __gpiod_get(dev, con_id, flags)
#define gpiod_get(varargs...) __gpiod_get(varargs, 0)
#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)
#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)
#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)
#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)
#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)
#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)
#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)
#if IS_ENABLED(CONFIG_GPIOLIB) && IS_ENABLED(CONFIG_GPIO_SYSFS)
int gpiod_export(struct gpio_desc *desc, bool direction_may_change);
int gpiod_export_link(struct device *dev, const char *name,
struct gpio_desc *desc);
int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value);
void gpiod_unexport(struct gpio_desc *desc);
#else /* CONFIG_GPIOLIB && CONFIG_GPIO_SYSFS */
static inline int gpiod_export(struct gpio_desc *desc,
bool direction_may_change)
{
return -ENOSYS;
}
static inline int gpiod_export_link(struct device *dev, const char *name,
struct gpio_desc *desc)
{
return -ENOSYS;
}
static inline int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value)
{
return -ENOSYS;
}
static inline void gpiod_unexport(struct gpio_desc *desc)
{
}
#endif /* CONFIG_GPIOLIB && CONFIG_GPIO_SYSFS */
#endif
Reference in New Issue View Git Blame Copy Permalink