2007-02-12 16:53:11 +08:00
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#ifndef _ASM_GENERIC_GPIO_H
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#define _ASM_GENERIC_GPIO_H
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2009-10-02 06:43:56 +08:00
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#include <linux/kernel.h>
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2008-05-24 04:04:58 +08:00
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#include <linux/types.h>
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2008-07-29 06:46:38 +08:00
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#include <linux/errno.h>
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2011-12-13 00:25:57 +08:00
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#include <linux/of.h>
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2012-10-27 17:51:36 +08:00
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#include <linux/pinctrl/pinctrl.h>
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2008-05-24 04:04:58 +08:00
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2008-07-25 16:46:11 +08:00
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#ifdef CONFIG_GPIOLIB
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2008-02-05 14:28:20 +08:00
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2008-05-24 04:04:58 +08:00
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#include <linux/compiler.h>
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2008-02-05 14:28:20 +08:00
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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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2008-07-27 06:22:26 +08:00
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* smaller range 0..ARCH_NR_GPIOS-1.
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2010-09-10 07:38:03 +08:00
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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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2008-02-05 14:28:20 +08:00
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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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2010-09-10 07:38:03 +08:00
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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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2011-05-11 07:23:07 +08:00
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static inline bool gpio_is_valid(int number)
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2008-04-28 17:14:46 +08:00
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{
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2011-05-11 07:23:07 +08:00
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return number >= 0 && number < ARCH_NR_GPIOS;
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2008-04-28 17:14:46 +08:00
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}
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2009-12-09 19:53:39 +08:00
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struct device;
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2011-10-24 21:24:10 +08:00
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struct gpio;
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2008-02-05 14:28:20 +08:00
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struct seq_file;
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2008-04-28 17:14:44 +08:00
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struct module;
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2010-06-08 21:48:16 +08:00
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struct device_node;
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2008-02-05 14:28:20 +08:00
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/**
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* struct gpio_chip - abstract a GPIO controller
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* @label: for diagnostics
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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 16:46:07 +08:00
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* @dev: optional device providing the GPIOs
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* @owner: helps prevent removal of modules exporting active GPIOs
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2013-02-03 00:29:24 +08:00
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* @list: links gpio_chips together for traversal
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2008-10-16 13:03:16 +08:00
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* @request: optional hook for chip-specific activation, such as
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* enabling module power and clock; may sleep
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* @free: optional hook for chip-specific deactivation, such as
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* disabling module power and clock; may sleep
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2012-10-24 22:25:27 +08:00
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* @get_direction: returns direction for signal "offset", 0=out, 1=in,
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* (same as GPIOF_DIR_XXX), or negative error
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2008-02-05 14:28:20 +08:00
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* @direction_input: configures signal "offset" as input, or returns error
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* @get: returns value for signal "offset"; for output signals this
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* returns either the value actually sensed, or zero
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* @direction_output: configures signal "offset" as output, or returns error
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2012-09-25 15:56:14 +08:00
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* @set_debounce: optional hook for setting debounce time for specified gpio in
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* interrupt triggered gpio chips
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2008-02-05 14:28:20 +08:00
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* @set: assigns output value for signal "offset"
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2008-10-16 13:03:14 +08:00
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* @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
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* implementation may not sleep
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2008-02-05 14:28:20 +08:00
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* @dbg_show: optional routine to show contents in debugfs; default code
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* will be used when this is omitted, but custom code can show extra
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* state (such as pullup/pulldown configuration).
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* @base: identifies the first GPIO number handled by this chip; or, if
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* negative during registration, requests dynamic ID allocation.
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* @ngpio: the number of GPIOs handled by this controller; the last GPIO
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* handled is (base + ngpio - 1).
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* @can_sleep: flag must be set iff get()/set() methods sleep, as they
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* must while accessing GPIO expander chips over I2C or SPI
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2009-04-03 07:57:05 +08:00
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* @names: if set, must be an array of strings to use as alternative
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* names for the GPIOs in this chip. Any entry in the array
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* may be NULL if there is no alias for the GPIO, however the
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2010-05-27 05:42:18 +08:00
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* array must be @ngpio entries long. A name can include a single printk
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* format specifier for an unsigned int. It is substituted by the actual
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* number of the gpio.
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2008-02-05 14:28:20 +08:00
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*
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* A gpio_chip can help platforms abstract various sources of GPIOs so
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* they can all be accessed through a common programing interface.
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* Example sources would be SOC controllers, FPGAs, multifunction
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* chips, dedicated GPIO expanders, and so on.
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*
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* Each chip controls a number of signals, identified in method calls
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* by "offset" values in the range 0..(@ngpio - 1). When those signals
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* are referenced through calls like gpio_get_value(gpio), the offset
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* is calculated by subtracting @base from the gpio number.
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*/
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struct gpio_chip {
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2008-10-16 13:03:10 +08:00
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const char *label;
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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 16:46:07 +08:00
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struct device *dev;
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2008-04-28 17:14:44 +08:00
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struct module *owner;
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2013-02-03 00:29:24 +08:00
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struct list_head list;
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2008-02-05 14:28:20 +08:00
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2008-10-16 13:03:16 +08:00
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int (*request)(struct gpio_chip *chip,
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unsigned offset);
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void (*free)(struct gpio_chip *chip,
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unsigned offset);
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2012-10-24 22:25:27 +08:00
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int (*get_direction)(struct gpio_chip *chip,
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unsigned offset);
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2008-02-05 14:28:20 +08:00
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int (*direction_input)(struct gpio_chip *chip,
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unsigned offset);
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int (*get)(struct gpio_chip *chip,
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unsigned offset);
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int (*direction_output)(struct gpio_chip *chip,
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unsigned offset, int value);
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2010-05-27 05:42:23 +08:00
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int (*set_debounce)(struct gpio_chip *chip,
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unsigned offset, unsigned debounce);
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2008-02-05 14:28:20 +08:00
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void (*set)(struct gpio_chip *chip,
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unsigned offset, int value);
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2008-10-16 13:03:14 +08:00
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int (*to_irq)(struct gpio_chip *chip,
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unsigned offset);
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2008-02-05 14:28:20 +08:00
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void (*dbg_show)(struct seq_file *s,
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struct gpio_chip *chip);
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int base;
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u16 ngpio;
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2010-05-27 05:42:17 +08:00
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const char *const *names;
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2008-02-05 14:28:20 +08:00
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unsigned can_sleep:1;
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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 16:46:07 +08:00
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unsigned exported:1;
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2010-06-08 21:48:16 +08:00
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#if defined(CONFIG_OF_GPIO)
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/*
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* If CONFIG_OF is enabled, then all GPIO controllers described in the
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* device tree automatically may have an OF translation
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*/
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struct device_node *of_node;
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int of_gpio_n_cells;
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2011-12-13 00:25:57 +08:00
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int (*of_xlate)(struct gpio_chip *gc,
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const struct of_phandle_args *gpiospec, u32 *flags);
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2010-06-08 21:48:16 +08:00
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#endif
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2012-10-27 17:51:36 +08:00
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#ifdef CONFIG_PINCTRL
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/*
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* If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
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* describe the actual pin range which they serve in an SoC. This
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* information would be used by pinctrl subsystem to configure
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* corresponding pins for gpio usage.
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*/
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struct list_head pin_ranges;
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#endif
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2008-02-05 14:28:20 +08:00
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};
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extern const char *gpiochip_is_requested(struct gpio_chip *chip,
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unsigned offset);
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2011-12-13 00:25:57 +08:00
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extern struct gpio_chip *gpio_to_chip(unsigned gpio);
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2008-02-05 14:28:20 +08:00
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/* add/remove chips */
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extern int gpiochip_add(struct gpio_chip *chip);
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extern int __must_check gpiochip_remove(struct gpio_chip *chip);
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2012-05-19 13:01:05 +08:00
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extern struct gpio_chip *gpiochip_find(void *data,
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2010-06-08 21:48:16 +08:00
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int (*match)(struct gpio_chip *chip,
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2012-05-18 03:54:40 +08:00
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void *data));
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2008-02-05 14:28:20 +08:00
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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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2011-01-14 09:26:46 +08:00
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extern int gpio_request(unsigned gpio, const char *label);
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2008-02-05 14:28:20 +08:00
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extern void gpio_free(unsigned gpio);
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2011-01-14 09:26:46 +08:00
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extern int gpio_direction_input(unsigned gpio);
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extern int gpio_direction_output(unsigned gpio, int value);
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2008-02-05 14:28:20 +08:00
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2010-05-27 05:42:23 +08:00
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extern int gpio_set_debounce(unsigned gpio, unsigned debounce);
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2008-02-05 14:28:20 +08:00
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extern int gpio_get_value_cansleep(unsigned gpio);
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extern void gpio_set_value_cansleep(unsigned gpio, int value);
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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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extern int __gpio_get_value(unsigned gpio);
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extern void __gpio_set_value(unsigned gpio, int value);
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extern int __gpio_cansleep(unsigned gpio);
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2008-10-16 13:03:14 +08:00
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extern int __gpio_to_irq(unsigned gpio);
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2008-02-05 14:28:20 +08:00
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2011-01-14 09:26:46 +08:00
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extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
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2011-05-26 07:20:31 +08:00
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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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2010-03-06 05:44:35 +08:00
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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 16:46:07 +08:00
|
|
|
#ifdef CONFIG_GPIO_SYSFS
|
|
|
|
|
|
|
|
/*
|
|
|
|
* A sysfs interface can be exported by individual drivers if they want,
|
|
|
|
* but more typically is configured entirely from userspace.
|
|
|
|
*/
|
|
|
|
extern int gpio_export(unsigned gpio, bool direction_may_change);
|
2009-09-23 07:46:33 +08:00
|
|
|
extern int gpio_export_link(struct device *dev, const char *name,
|
|
|
|
unsigned gpio);
|
2009-12-16 08:46:20 +08:00
|
|
|
extern int gpio_sysfs_set_active_low(unsigned gpio, int value);
|
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 16:46:07 +08:00
|
|
|
extern void gpio_unexport(unsigned gpio);
|
|
|
|
|
|
|
|
#endif /* CONFIG_GPIO_SYSFS */
|
|
|
|
|
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);
|
|
|
|
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;
|
|
|
|
}
|
|
|
|
|
|
|
|
static inline void
|
|
|
|
gpiochip_remove_pin_ranges(struct gpio_chip *chip)
|
|
|
|
{
|
|
|
|
}
|
|
|
|
|
|
|
|
#endif /* CONFIG_PINCTRL */
|
|
|
|
|
2010-10-28 06:33:16 +08:00
|
|
|
#else /* !CONFIG_GPIOLIB */
|
2008-02-05 14:28:20 +08:00
|
|
|
|
2011-05-11 07:23:07 +08:00
|
|
|
static inline bool gpio_is_valid(int number)
|
2008-04-28 17:14:46 +08:00
|
|
|
{
|
|
|
|
/* only non-negative numbers are valid */
|
|
|
|
return number >= 0;
|
|
|
|
}
|
|
|
|
|
2007-02-12 16:53:11 +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 16:53:11 +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 16:53:11 +08:00
|
|
|
}
|
|
|
|
|
2010-10-28 06:33:16 +08:00
|
|
|
#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 16:46:07 +08:00
|
|
|
|
|
|
|
#ifndef CONFIG_GPIO_SYSFS
|
|
|
|
|
2009-12-09 19:53:39 +08:00
|
|
|
struct device;
|
|
|
|
|
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 16:46:07 +08:00
|
|
|
/* sysfs support is only available with gpiolib, where it's optional */
|
|
|
|
|
|
|
|
static inline int gpio_export(unsigned gpio, bool direction_may_change)
|
|
|
|
{
|
|
|
|
return -ENOSYS;
|
|
|
|
}
|
|
|
|
|
2009-09-23 07:46:33 +08:00
|
|
|
static inline int gpio_export_link(struct device *dev, const char *name,
|
|
|
|
unsigned gpio)
|
|
|
|
{
|
|
|
|
return -ENOSYS;
|
|
|
|
}
|
|
|
|
|
2009-12-16 08:46:20 +08:00
|
|
|
static inline int gpio_sysfs_set_active_low(unsigned gpio, int value)
|
|
|
|
{
|
|
|
|
return -ENOSYS;
|
|
|
|
}
|
|
|
|
|
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 16:46:07 +08:00
|
|
|
static inline void gpio_unexport(unsigned gpio)
|
|
|
|
{
|
|
|
|
}
|
|
|
|
#endif /* CONFIG_GPIO_SYSFS */
|
2008-02-05 14:28:20 +08:00
|
|
|
|
2007-02-12 16:53:11 +08:00
|
|
|
#endif /* _ASM_GENERIC_GPIO_H */
|