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								#ifndef _ASM_GENERIC_GPIO_H
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								#define _ASM_GENERIC_GPIO_H
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								#include <linux/kernel.h>
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								#include <linux/types.h>
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								#include <linux/errno.h>
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								#include <linux/of.h>
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								#include <linux/pinctrl/pinctrl.h>
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											2008-07-25 01:46:11 -07:00
										 
									 
								 
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								#ifdef CONFIG_GPIOLIB
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								#include <linux/compiler.h>
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								#include <linux/gpio/driver.h>
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								#include <linux/gpio/consumer.h>
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								/* Platforms may implement their GPIO interface with library code,
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								 * at a small performance cost for non-inlined operations and some
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								 * extra memory (for code and for per-GPIO table entries).
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								 *
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								 * While the GPIO programming interface defines valid GPIO numbers
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								 * to be in the range 0..MAX_INT, this library restricts them to the
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								 * smaller range 0..ARCH_NR_GPIOS-1.
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								 *
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								 * ARCH_NR_GPIOS is somewhat arbitrary; it usually reflects the sum of
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								 * builtin/SoC GPIOs plus a number of GPIOs on expanders; the latter is
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								 * actually an estimate of a board-specific value.
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								 */
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								#ifndef ARCH_NR_GPIOS
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								#define ARCH_NR_GPIOS		256
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								#endif
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								/*
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								 * "valid" GPIO numbers are nonnegative and may be passed to
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								 * setup routines like gpio_request().  only some valid numbers
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								 * can successfully be requested and used.
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								 *
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								 * Invalid GPIO numbers are useful for indicating no-such-GPIO in
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								 * platform data and other tables.
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								 */
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								static inline bool gpio_is_valid(int number)
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								{
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									return number >= 0 && number < ARCH_NR_GPIOS;
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								}
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								struct device;
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								struct gpio;
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								struct seq_file;
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								struct module;
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								struct device_node;
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								struct gpio_desc;
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								/* caller holds gpio_lock *OR* gpio is marked as requested */
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								static inline struct gpio_chip *gpio_to_chip(unsigned gpio)
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								{
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									return gpiod_to_chip(gpio_to_desc(gpio));
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								}
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								/* Always use the library code for GPIO management calls,
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								 * or when sleeping may be involved.
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								 */
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								extern int gpio_request(unsigned gpio, const char *label);
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								extern void gpio_free(unsigned gpio);
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								static inline int gpio_direction_input(unsigned gpio)
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								{
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									return gpiod_direction_input(gpio_to_desc(gpio));
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								}
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								static inline int gpio_direction_output(unsigned gpio, int value)
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								{
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									return gpiod_direction_output_raw(gpio_to_desc(gpio), value);
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								}
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								static inline int gpio_set_debounce(unsigned gpio, unsigned debounce)
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								{
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									return gpiod_set_debounce(gpio_to_desc(gpio), debounce);
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								}
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								static inline int gpio_get_value_cansleep(unsigned gpio)
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								{
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									return gpiod_get_raw_value_cansleep(gpio_to_desc(gpio));
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								}
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								static inline void gpio_set_value_cansleep(unsigned gpio, int value)
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								{
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									return gpiod_set_raw_value_cansleep(gpio_to_desc(gpio), value);
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								}
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								/* A platform's <asm/gpio.h> code may want to inline the I/O calls when
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								 * the GPIO is constant and refers to some always-present controller,
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								 * giving direct access to chip registers and tight bitbanging loops.
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								 */
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								static inline int __gpio_get_value(unsigned gpio)
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								{
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									return gpiod_get_raw_value(gpio_to_desc(gpio));
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								}
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								static inline void __gpio_set_value(unsigned gpio, int value)
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								{
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									return gpiod_set_raw_value(gpio_to_desc(gpio), value);
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								}
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								static inline int __gpio_cansleep(unsigned gpio)
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								{
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									return gpiod_cansleep(gpio_to_desc(gpio));
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								}
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								static inline int __gpio_to_irq(unsigned gpio)
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								{
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									return gpiod_to_irq(gpio_to_desc(gpio));
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								}
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								extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
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								extern int gpio_request_array(const struct gpio *array, size_t num);
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								extern void gpio_free_array(const struct gpio *array, size_t num);
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												gpio: sysfs interface
This adds a simple sysfs interface for GPIOs.
    /sys/class/gpio
    	/export ... asks the kernel to export a GPIO to userspace
    	/unexport ... to return a GPIO to the kernel
        /gpioN ... for each exported GPIO #N
	    /value ... always readable, writes fail for input GPIOs
	    /direction ... r/w as: in, out (default low); write high, low
	/gpiochipN ... for each gpiochip; #N is its first GPIO
	    /base ... (r/o) same as N
	    /label ... (r/o) descriptive, not necessarily unique
	    /ngpio ... (r/o) number of GPIOs; numbered N .. N+(ngpio - 1)
GPIOs claimed by kernel code may be exported by its owner using a new
gpio_export() call, which should be most useful for driver debugging.
Such exports may optionally be done without a "direction" attribute.
Userspace may ask to take over a GPIO by writing to a sysfs control file,
helping to cope with incomplete board support or other "one-off"
requirements that don't merit full kernel support:
  echo 23 > /sys/class/gpio/export
	... will gpio_request(23, "sysfs") and gpio_export(23);
	use /sys/class/gpio/gpio-23/direction to (re)configure it,
	when that GPIO can be used as both input and output.
  echo 23 > /sys/class/gpio/unexport
	... will gpio_free(23), when it was exported as above
The extra D-space footprint is a few hundred bytes, except for the sysfs
resources associated with each exported GPIO.  The additional I-space
footprint is about two thirds of the current size of gpiolib (!).  Since
no /dev node creation is involved, no "udev" support is needed.
Related changes:
  * This adds a device pointer to "struct gpio_chip".  When GPIO
    providers initialize that, sysfs gpio class devices become children of
    that device instead of being "virtual" devices.
  * The (few) gpio_chip providers which have such a device node have
    been updated.
  * Some gpio_chip drivers also needed to update their module "owner"
    field ...  for which missing kerneldoc was added.
  * Some gpio_chips don't support input GPIOs.  Those GPIOs are now
    flagged appropriately when the chip is registered.
Based on previous patches, and discussion both on and off LKML.
A Documentation/ABI/testing/sysfs-gpio update is ready to submit once this
merges to mainline.
[akpm@linux-foundation.org: a few maintenance build fixes]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de>
Cc: Greg KH <greg@kroah.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
											
										 
										
											2008-07-25 01:46:07 -07:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								/*
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								 * A sysfs interface can be exported by individual drivers if they want,
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								 * but more typically is configured entirely from userspace.
							 | 
						
					
						
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							 | 
							
								
							 | 
							
								
							 | 
							
							
								 */
							 | 
						
					
						
							
								
									
										
										
										
											2013-10-17 10:21:36 -07:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								static inline int gpio_export(unsigned gpio, bool direction_may_change)
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								{
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
									return gpiod_export(gpio_to_desc(gpio), direction_may_change);
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								}
							 | 
						
					
						
							
								
									
										
											 
										 
										
											
												gpio: sysfs interface
This adds a simple sysfs interface for GPIOs.
    /sys/class/gpio
    	/export ... asks the kernel to export a GPIO to userspace
    	/unexport ... to return a GPIO to the kernel
        /gpioN ... for each exported GPIO #N
	    /value ... always readable, writes fail for input GPIOs
	    /direction ... r/w as: in, out (default low); write high, low
	/gpiochipN ... for each gpiochip; #N is its first GPIO
	    /base ... (r/o) same as N
	    /label ... (r/o) descriptive, not necessarily unique
	    /ngpio ... (r/o) number of GPIOs; numbered N .. N+(ngpio - 1)
GPIOs claimed by kernel code may be exported by its owner using a new
gpio_export() call, which should be most useful for driver debugging.
Such exports may optionally be done without a "direction" attribute.
Userspace may ask to take over a GPIO by writing to a sysfs control file,
helping to cope with incomplete board support or other "one-off"
requirements that don't merit full kernel support:
  echo 23 > /sys/class/gpio/export
	... will gpio_request(23, "sysfs") and gpio_export(23);
	use /sys/class/gpio/gpio-23/direction to (re)configure it,
	when that GPIO can be used as both input and output.
  echo 23 > /sys/class/gpio/unexport
	... will gpio_free(23), when it was exported as above
The extra D-space footprint is a few hundred bytes, except for the sysfs
resources associated with each exported GPIO.  The additional I-space
footprint is about two thirds of the current size of gpiolib (!).  Since
no /dev node creation is involved, no "udev" support is needed.
Related changes:
  * This adds a device pointer to "struct gpio_chip".  When GPIO
    providers initialize that, sysfs gpio class devices become children of
    that device instead of being "virtual" devices.
  * The (few) gpio_chip providers which have such a device node have
    been updated.
  * Some gpio_chip drivers also needed to update their module "owner"
    field ...  for which missing kerneldoc was added.
  * Some gpio_chips don't support input GPIOs.  Those GPIOs are now
    flagged appropriately when the chip is registered.
Based on previous patches, and discussion both on and off LKML.
A Documentation/ABI/testing/sysfs-gpio update is ready to submit once this
merges to mainline.
[akpm@linux-foundation.org: a few maintenance build fixes]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de>
Cc: Greg KH <greg@kroah.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
											
										 
										
											2008-07-25 01:46:07 -07:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							
								
									
										
										
										
											2013-10-17 10:21:36 -07:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								static inline int gpio_export_link(struct device *dev, const char *name,
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
												   unsigned gpio)
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								{
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
									return gpiod_export_link(dev, name, gpio_to_desc(gpio));
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								}
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								static inline int gpio_sysfs_set_active_low(unsigned gpio, int value)
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								{
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
									return gpiod_sysfs_set_active_low(gpio_to_desc(gpio), value);
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								}
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								static inline void gpio_unexport(unsigned gpio)
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								{
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
									gpiod_unexport(gpio_to_desc(gpio));
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								}
							 | 
						
					
						
							
								
									
										
											 
										 
										
											
												gpio: sysfs interface
This adds a simple sysfs interface for GPIOs.
    /sys/class/gpio
    	/export ... asks the kernel to export a GPIO to userspace
    	/unexport ... to return a GPIO to the kernel
        /gpioN ... for each exported GPIO #N
	    /value ... always readable, writes fail for input GPIOs
	    /direction ... r/w as: in, out (default low); write high, low
	/gpiochipN ... for each gpiochip; #N is its first GPIO
	    /base ... (r/o) same as N
	    /label ... (r/o) descriptive, not necessarily unique
	    /ngpio ... (r/o) number of GPIOs; numbered N .. N+(ngpio - 1)
GPIOs claimed by kernel code may be exported by its owner using a new
gpio_export() call, which should be most useful for driver debugging.
Such exports may optionally be done without a "direction" attribute.
Userspace may ask to take over a GPIO by writing to a sysfs control file,
helping to cope with incomplete board support or other "one-off"
requirements that don't merit full kernel support:
  echo 23 > /sys/class/gpio/export
	... will gpio_request(23, "sysfs") and gpio_export(23);
	use /sys/class/gpio/gpio-23/direction to (re)configure it,
	when that GPIO can be used as both input and output.
  echo 23 > /sys/class/gpio/unexport
	... will gpio_free(23), when it was exported as above
The extra D-space footprint is a few hundred bytes, except for the sysfs
resources associated with each exported GPIO.  The additional I-space
footprint is about two thirds of the current size of gpiolib (!).  Since
no /dev node creation is involved, no "udev" support is needed.
Related changes:
  * This adds a device pointer to "struct gpio_chip".  When GPIO
    providers initialize that, sysfs gpio class devices become children of
    that device instead of being "virtual" devices.
  * The (few) gpio_chip providers which have such a device node have
    been updated.
  * Some gpio_chip drivers also needed to update their module "owner"
    field ...  for which missing kerneldoc was added.
  * Some gpio_chips don't support input GPIOs.  Those GPIOs are now
    flagged appropriately when the chip is registered.
Based on previous patches, and discussion both on and off LKML.
A Documentation/ABI/testing/sysfs-gpio update is ready to submit once this
merges to mainline.
[akpm@linux-foundation.org: a few maintenance build fixes]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de>
Cc: Greg KH <greg@kroah.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
											
										 
										
											2008-07-25 01:46:07 -07:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							
								
									
										
										
										
											2013-01-17 22:03:22 +08:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								#ifdef CONFIG_PINCTRL
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								/**
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								 * struct gpio_pin_range - pin range controlled by a gpio chip
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								 * @head: list for maintaining set of pin ranges, used internally
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								 * @pctldev: pinctrl device which handles corresponding pins
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								 * @range: actual range of pins controlled by a gpio controller
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								 */
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								struct gpio_pin_range {
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
									struct list_head node;
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
									struct pinctrl_dev *pctldev;
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
									struct pinctrl_gpio_range range;
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								};
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
											   unsigned int gpio_offset, unsigned int pin_offset,
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
											   unsigned int npins);
							 | 
						
					
						
							
								
									
										
										
										
											2013-10-15 15:37:54 +02:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								int gpiochip_add_pingroup_range(struct gpio_chip *chip,
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
											struct pinctrl_dev *pctldev,
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
											unsigned int gpio_offset, const char *pin_group);
							 | 
						
					
						
							
								
									
										
										
										
											2013-01-17 22:03:22 +08:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								void gpiochip_remove_pin_ranges(struct gpio_chip *chip);
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								#else
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								static inline int
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
										       unsigned int gpio_offset, unsigned int pin_offset,
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
										       unsigned int npins)
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								{
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
									return 0;
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								}
							 | 
						
					
						
							
								
									
										
										
										
											2013-10-15 15:37:54 +02:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								static inline int
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								gpiochip_add_pingroup_range(struct gpio_chip *chip,
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
											struct pinctrl_dev *pctldev,
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
											unsigned int gpio_offset, const char *pin_group)
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								{
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
									return 0;
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								}
							 | 
						
					
						
							
								
									
										
										
										
											2013-01-17 22:03:22 +08:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								static inline void
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								gpiochip_remove_pin_ranges(struct gpio_chip *chip)
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								{
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								}
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								#endif /* CONFIG_PINCTRL */
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							
								
									
										
										
										
											2010-10-27 15:33:16 -07:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								#else	/* !CONFIG_GPIOLIB */
							 | 
						
					
						
							
								
									
										
										
										
											2008-02-04 22:28:20 -08:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							
								
									
										
										
										
											2011-05-10 16:23:07 -07:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								static inline bool gpio_is_valid(int number)
							 | 
						
					
						
							
								
									
										
										
										
											2008-04-28 02:14:46 -07:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								{
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
									/* only non-negative numbers are valid */
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
									return number >= 0;
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								}
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							
								
									
										
										
										
											2007-02-12 00:53:11 -08:00
										 
									 
								 
							 | 
							
								
							 | 
							
								
							 | 
							
							
								/* platforms that don't directly support access to GPIOs through I2C, SPI,
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								 * or other blocking infrastructure can use these wrappers.
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								 */
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								static inline int gpio_cansleep(unsigned gpio)
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								{
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
									return 0;
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								}
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								static inline int gpio_get_value_cansleep(unsigned gpio)
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								{
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
									might_sleep();
							 | 
						
					
						
							
								
									
										
										
										
											2011-10-21 09:38:32 +08:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
									return __gpio_get_value(gpio);
							 | 
						
					
						
							
								
									
										
										
										
											2007-02-12 00:53:11 -08:00
										 
									 
								 
							 | 
							
								
							 | 
							
								
							 | 
							
							
								}
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								static inline void gpio_set_value_cansleep(unsigned gpio, int value)
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								{
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
									might_sleep();
							 | 
						
					
						
							
								
									
										
										
										
											2011-10-21 09:38:32 +08:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
									__gpio_set_value(gpio, value);
							 | 
						
					
						
							
								
									
										
										
										
											2007-02-12 00:53:11 -08:00
										 
									 
								 
							 | 
							
								
							 | 
							
								
							 | 
							
							
								}
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							
								
									
										
										
										
											2010-10-27 15:33:16 -07:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								#endif /* !CONFIG_GPIOLIB */
							 | 
						
					
						
							
								
									
										
											 
										 
										
											
												gpio: sysfs interface
This adds a simple sysfs interface for GPIOs.
    /sys/class/gpio
    	/export ... asks the kernel to export a GPIO to userspace
    	/unexport ... to return a GPIO to the kernel
        /gpioN ... for each exported GPIO #N
	    /value ... always readable, writes fail for input GPIOs
	    /direction ... r/w as: in, out (default low); write high, low
	/gpiochipN ... for each gpiochip; #N is its first GPIO
	    /base ... (r/o) same as N
	    /label ... (r/o) descriptive, not necessarily unique
	    /ngpio ... (r/o) number of GPIOs; numbered N .. N+(ngpio - 1)
GPIOs claimed by kernel code may be exported by its owner using a new
gpio_export() call, which should be most useful for driver debugging.
Such exports may optionally be done without a "direction" attribute.
Userspace may ask to take over a GPIO by writing to a sysfs control file,
helping to cope with incomplete board support or other "one-off"
requirements that don't merit full kernel support:
  echo 23 > /sys/class/gpio/export
	... will gpio_request(23, "sysfs") and gpio_export(23);
	use /sys/class/gpio/gpio-23/direction to (re)configure it,
	when that GPIO can be used as both input and output.
  echo 23 > /sys/class/gpio/unexport
	... will gpio_free(23), when it was exported as above
The extra D-space footprint is a few hundred bytes, except for the sysfs
resources associated with each exported GPIO.  The additional I-space
footprint is about two thirds of the current size of gpiolib (!).  Since
no /dev node creation is involved, no "udev" support is needed.
Related changes:
  * This adds a device pointer to "struct gpio_chip".  When GPIO
    providers initialize that, sysfs gpio class devices become children of
    that device instead of being "virtual" devices.
  * The (few) gpio_chip providers which have such a device node have
    been updated.
  * Some gpio_chip drivers also needed to update their module "owner"
    field ...  for which missing kerneldoc was added.
  * Some gpio_chips don't support input GPIOs.  Those GPIOs are now
    flagged appropriately when the chip is registered.
Based on previous patches, and discussion both on and off LKML.
A Documentation/ABI/testing/sysfs-gpio update is ready to submit once this
merges to mainline.
[akpm@linux-foundation.org: a few maintenance build fixes]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de>
Cc: Greg KH <greg@kroah.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
											
										 
										
											2008-07-25 01:46:07 -07:00
										 
									 
								 
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											2007-02-12 00:53:11 -08:00
										 
									 
								 
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								#endif /* _ASM_GENERIC_GPIO_H */
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