aboutsummaryrefslogtreecommitdiff
path: root/drivers/gpio/pca953x.c
AgeCommit message (Collapse)Author
2009-01-15gpio: fix probe() error return in gpio driver probesBen Dooks
A number of drivers in drivers/gpio return -ENODEV when confronted with missing setup parameters such as the platform data. However, returning -ENODEV causes the driver layer to silently ignore the driver as it assumes the probe did not find anything and was only speculative. To make life easier to discern why a driver is not being attached, change to returning -EINVAL, which is a better description of the fact that the driver data was not valid. Also add a set of dev_dbg() statements to the error paths to provide an better explanation of the error as there may be more that one point in the driver. Signed-off-by: Ben Dooks <ben-linux@fluff.org> 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>
2009-01-06gpio: pca953x handles more chips, i2c fault codesDavid Brownell
Minor updates to the pca953x GPIO expander driver: handle several more compatible parts, and stop assuming that the I2C layer's return codes are garbage (that's now been fixed). Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Eric Miao <eric.miao@marvell.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16gpio: i2c expanders use subsys_initDavid Brownell
Make the I2C external GPIO expander drivers register themselves at subsys_initcall() time when they're statically linked. SOC-integrated GPIOs are available starting very early -- early in arch_initcall() at latest, but often even before initcalls start to run -- so this improves consistency, so more subsystems can rely on GPIOs in their own subsys_initcall() code. (This isn't a theoretical problem. This is one of several patches needed to resolve oopsing observed when statically linking kernels on a DaVinci EVM. Its pcf857x GPIOs needed to be available well before some other drivers initialized.) Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> 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>
2008-07-25gpio: sysfs interfaceDavid Brownell
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>
2008-07-04gpio: pca953x (i2c) handles max7310 tooDavid Brownell
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>
2008-05-24gpio: pca953x driver handles pca9554 tooDavid Brownell
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>
2008-05-01gpio: pca953x: add support for pca9555 I2C I/O expanderWill Newton
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>
2008-04-29i2c: Convert most new-style drivers to use module aliasingJean Delvare
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>
2008-04-29i2c: Add support for device alias namesJean Delvare
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>
2008-04-28gpiolib: i2c/spi drivers: handle rmmod betterGuennadi Liakhovetski
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>
2008-03-10gpio/pca953x bugfix: mark as can_sleepArnaud Patard
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>
2008-02-06gpio: handle pca953{4,5,6,7,8} tooGuennadi Liakhovetski
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>
2008-02-06gpio: rename pca953x symbolsGuennadi Liakhovetski
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>
2008-02-06gpio: rename pca9539 driverGuennadi Liakhovetski
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>