MAX7315 is pin and software compatible with PCA9534, so add it to the I2C
device ID table of pca953x driver.
http://www.datasheetcatalog.org/datasheet/maxim/MAX7315.pdfSigned-off-by: NAlek Du <alek.du@intel.com>
Acked-by: NDavid Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

PCA9556 is the software-compatible predecessor to the PCA9557, so add it
to the supported I2C device ID table.
Signed-off-by: NNate Case <ncase@xes-inc.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

On OpenFirmware platforms, it makes the most sense to get platform_data
from the device tree.  Make an attempt to translate OF node properties
into platform_data struct before bailing out.

Note that the implementation approach taken differs from other device
drivers that make use of device tree information.  This is because I2C
chips are already registered automatically by of_i2c, so we can get by
with a small translator function in the driver.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: kfree(NULL) is legal]
Signed-off-by: NNate Case <ncase@xes-inc.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support to the PCA953x driver to use the GPIOLIB naming facility for
GPIOs.
Signed-off-by: NDaniel Silverstone <dsilvers@simtec.co.uk>
Cc: Ben Gardner <bgardner@wabtec.com>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NBen Dooks <ben-linux@fluff.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Eric Miao <eric.miao@marvell.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NDavid 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: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Teach drivers/gpio/pca953x.c about PCA9554, another compatible chip.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support for pca9555 I2C I/O expander.  As the comment suggests this part
is software compatible with the pca9539.
Signed-off-by: NWill Newton <will.newton@imgtec.com>
Cc: "eric miao" <eric.miao@marvell.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NJean Delvare <khali@linux-fr.org>
Cc: Jon Smirl <jonsmirl@gmail.com>
Cc: Jochen Friedrich <jochen@scram.de>

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: NJean Delvare <khali@linux-fr.org>
Cc: Jochen Friedrich <jochen@scram.de>
Cc: Jon Smirl <jonsmirl@gmail.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>

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: NGuennadi Liakhovetski <g.liakhovetski@pengutronix.de>
[ add mcp23s08 and pcf857x ]
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NArnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Acked-by: N"eric miao" <eric.y.miao@gmail.com>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NGuennadi Liakhovetski <g.liakhovetski@pengutronix.de>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NGuennadi Liakhovetski <g.liakhovetski@pengutronix.de>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NGuennadi Liakhovetski <g.liakhovetski@pengutronix.de>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This adds a new-style I2C driver with basic support for the sixteen bit
PCA9539 GPIO expanders.  These chips have multiple registers, push-pull output
drivers, and (not supported in this patch) pin change interrupts.

Board-specific code must provide "pca9539_platform_data" with each chip's
"i2c_board_info".  That provides the GPIO numbers to be used by that chip, and
callbacks for board-specific setup/teardown logic.

Derived from drivers/i2c/chips/pca9539.c (which has no current known users).
This is faster and simpler; it uses 16-bit register access, and cache the
OUTPUT and DIRECTION registers for fast access
Signed-off-by: Neric miao <eric.miao@marvell.com>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Acked-by: NJean Delvare <khali@linux-fr.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Philipp Zabel <philipp.zabel@gmail.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ben Gardner <bgardner@wabtec.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>