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path: root/drivers/gpio/pca953x.c
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* gpio: sysfs interfaceDavid Brownell2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* gpio: pca953x (i2c) handles max7310 tooDavid Brownell2008-07-04
| | | | | | | | | | The pca953x driver can handle another 8-bit I/O expander, the max7310. This patch adds that chip to the list of supported IDs in that driver, and expands the Kconfig helptext accordingly. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* gpio: pca953x driver handles pca9554 tooDavid Brownell2008-05-24
| | | | | | | | Teach drivers/gpio/pca953x.c about PCA9554, another compatible chip. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* gpio: pca953x: add support for pca9555 I2C I/O expanderWill Newton2008-05-01
| | | | | | | | | | | Add support for pca9555 I2C I/O expander. As the comment suggests this part is software compatible with the pca9539. Signed-off-by: Will Newton <will.newton@imgtec.com> Cc: "eric miao" <eric.miao@marvell.com> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* i2c: Convert most new-style drivers to use module aliasingJean Delvare2008-04-29
| | | | | | | | | | | | | | Based on earlier work by Jon Smirl and Jochen Friedrich. Update most new-style i2c drivers to use standard module aliasing instead of the old driver_name/type driver matching scheme. I've left the video drivers apart (except for SoC camera drivers) as they're a bit more diffcult to deal with, they'll have their own patch later. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Jon Smirl <jonsmirl@gmail.com> Cc: Jochen Friedrich <jochen@scram.de>
* i2c: Add support for device alias namesJean Delvare2008-04-29
| | | | | | | | | | | | | | Based on earlier work by Jon Smirl and Jochen Friedrich. This patch allows new-style i2c chip drivers to have alias names using the official kernel aliasing system and MODULE_DEVICE_TABLE(). At this point, the old i2c driver binding scheme (driver_name/type) is still supported. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Jochen Friedrich <jochen@scram.de> Cc: Jon Smirl <jonsmirl@gmail.com> Cc: Kay Sievers <kay.sievers@vrfy.org>
* gpiolib: i2c/spi drivers: handle rmmod betterGuennadi Liakhovetski2008-04-28
| | | | | | | | | | | | Use the newly introduced owner field in struct gpio_chip to protect the current (small) set of non-SOC GPIO drivers from being unloaded while any of their GPIOs are in use. Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de> [ add mcp23s08 and pcf857x ] Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* gpio/pca953x bugfix: mark as can_sleepArnaud Patard2008-03-10
| | | | | | | | | | | | | The pca953x driver is an I2C driver so gpio_chip->can_sleep should be set. This lets upper layers know they should use the gpio_*_cansleep() calls to access values, and may not access them from nonsleeping contexts. Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: "eric miao" <eric.y.miao@gmail.com> Cc: Jean Delvare <khali@linux-fr.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* gpio: handle pca953{4,5,6,7,8} tooGuennadi Liakhovetski2008-02-06
| | | | | | | | | | | | | | This third part of an extension to support more pca953x chips updates the logic to handle the smaller register widths used by the 4-bit and 8-bit parts, and to use the chip type to determine how many GPIOs it provides. As long as we don't support interrupt and reset capabilities, those size issues are the only software-visible differences between these parts. Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* gpio: rename pca953x symbolsGuennadi Liakhovetski2008-02-06
| | | | | | | | | | | This second part of an extension to support more pca953x chips renames the C and Kconfig symbols. All affected files were updated by sed, except for a couple of obvious exceptions. It also updates the Kconfig helptext. Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* gpio: rename pca9539 driverGuennadi Liakhovetski2008-02-06
First part of an extension to let the pca9539 driver support more chips, starting with pca9534, pca9535, pca9536, pca9537, and pca9538. This renames the files and modifies the Makefile. Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>