Commit Graph

40 Commits

Author SHA1 Message Date
Grant Likely
07ce8ec730 gpiolib: Remove 'const' from data argument of gpiochip_find()
Commit 3d0f7cf0 "gpio: Adjust of_xlate API to support multiple GPIO
chips" changed the api of gpiochip_find to drop const from the data
parameter of the match hook, but didn't also drop const from data
causing a build warning.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-05-18 23:01:05 -06:00
Grant Likely
3d0f7cf0f3 gpio: Adjust of_xlate API to support multiple GPIO chips
This patch changes the of_xlate API to make it possible for multiple
gpio_chips to refer to the same device tree node.  This is useful for
banked GPIO controllers that use multiple gpio_chips for a single
device.  With this change the core code will try calling of_xlate on
each gpio_chip that references the device_node and will return the
gpio number for the first one to return 'true'.

Tested-by: Roland Stigge <stigge@antcom.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-05-18 16:48:36 -06:00
Mark Brown
09d71ff194 gpiolib: Implement devm_gpio_request_one()
Allow drivers to use the modern request and configure idiom together
with devres.

As with plain gpio_request() and gpio_request_one() we can't implement
the old school version in terms of _one() as this would force the
explicit selection of a direction in gpio_request() which could break
systems if we pick the wrong one.  Implementing devm_gpio_request_one()
in terms of devm_gpio_request() would needlessly complicate things or
lead to duplication from the unmanaged version depending on how it's
done.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-05-18 16:48:35 -06:00
Grant Likely
6e2cf65140 gpio: constify the data parameter to gpiochip_find()
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-03-02 15:56:03 -07:00
John Crispin
1a0703ede4 GPIO: add bindings for managed devices
This patch adds 2 functions that allow managed devices to request GPIOs.
These GPIOs will then be managed by drivers/base/devres.c.

Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-01-04 11:37:42 -07:00
Grant Likely
15c9a0acc3 of: create of_phandle_args to simplify return of phandle parsing data
of_parse_phandle_with_args() needs to return quite a bit of data.  Rather
than making each datum a separate **out_ argument, this patch creates
struct of_phandle_args to contain all the returned data and reworks the
user of the function.  This patch also enables of_parse_phandle_with_args()
to return the device node pointer for the phandle node.

This patch also ends up being fairly major surgery to
of_parse_handle_with_args().  The existing structure didn't work well
when extending to use of_phandle_args, and I discovered bugs during testing.
I also took the opportunity to rename the function to be like the
existing of_parse_phandle().

v2: - moved declaration of of_phandle_args to fix compile on non-DT builds
    - fixed incorrect index in example usage
    - fixed incorrect return code handling for empty entries

Reviewed-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-12-12 13:40:16 -07:00
Grant Likely
1a2d397a6e gpio/powerpc: Eliminate duplication of of_get_named_gpio_flags()
A large chunk of qe_pin_request() is unnecessarily cut-and-paste
directly from of_get_named_gpio_flags().  This patch cuts out the
duplicate code and replaces it with a call to of_get_gpio().

v2: fixed compile error due to missing gpio_to_chip()

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Kumar Gala <galak@kernel.crashing.org>
2011-12-12 13:40:16 -07:00
Hamo
eb9ae7f2a3 gpio: fix build error in include/asm-generic/gpio.h
Should call the platform-specific __gpio_{get,set}_value
instead of generic gpio_{get,set}_value

Signed-off-by: Yang Bai <hamo.by@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-10-26 23:15:28 +02:00
Mark Brown
feb8369924 gpiolib: Ensure struct gpio is always defined
Currently struct gpio is only defined when using gpiolib which makes the
stub gpio_request_array() much less useful in drivers than is ideal as
they can't work with struct gpio.  Since there are no other definitions
in kernel instead make the define always available no matter if gpiolib
is selectable or selected, ensuring that drivers can always use the
type.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-10-24 16:04:06 +02:00
Randy Dunlap
c001fb72a7 gpio: add GPIOF_ values regardless on kconfig settings
Make GPIOF_ defined values available even when GPIOLIB nor GENERIC_GPIO
is enabled by moving them to <linux/gpio.h>.

Fixes these build errors in linux-next:
sound/soc/codecs/ak4641.c:524: error: 'GPIOF_OUT_INIT_LOW' undeclared (first use in this function)
sound/soc/codecs/wm8915.c:2921: error: 'GPIOF_OUT_INIT_LOW' undeclared (first use in this function)

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-06-16 08:40:52 -06:00
Lars-Peter Clausen
7c295975a8 gpio: make gpio_{request,free}_array gpio array parameter const
gpio_{request,free}_array should not (and do not) modify the passed gpio
array, so make the parameter const.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Eric Miao <eric.y.miao@gmail.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-05-27 17:56:45 -06:00
Joe Perches
3474cb3cc0 gpio: Convert gpio_is_valid to return bool
Make the code a bit more readable.

Instead of casting an int to an unsigned then comparing to
MAX_NR_GPIOS, add a >= 0 test and let the compiler optimizer
do the conversion to unsigned.

The generated code should be the same.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-05-26 21:02:43 -06:00
Linus Torvalds
d8a3515e2a Revert "gpiolib: annotate gpio-intialization with __must_check"
This reverts commit 0fdae42d36, which
wasn't really supposed to go in, and causes lots of annoying warnings.

Quoth Andrew:
  "Complete brainfart - I meant to drop that patch ages ago."

Quoth Greg:
  "Ick, yeah, that patch isn't ok to go in as-is, all of the callers
   need to be fixed up first, which is what I thought we had agreed on..."

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 17:26:46 -08:00
Wolfram Sang
0fdae42d36 gpiolib: annotate gpio-intialization with __must_check
Because GPIOs can have crucial functions especially in embedded systems,
we are better safe than sorry regarding their configuration.  For
gpio_request, the documentation is simply enforced: <quote>"The return
value of gpio_request() must be checked."</quote> For gpio_direction_* and
gpio_request_*, we now act accordingly.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Greg KH <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 08:03:14 -08:00
Anton Vorontsov
09cd9527d6 gpiolib: fix HAVE_GPIO_LIB leftovers in asm-generic/gpio.h
commit 7444a72eff ("gpiolib: allow user-selection")
removed HAVE_GPIO_LIB Kconfig symbol, but the header file still uses the
name [to confuse readers wrt #ifdef/#else/#endif location].

The real Kconfig symbol nowadays is CONFIG_GPIOLIB.

Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.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>
2010-10-27 18:03:06 -07:00
David Brownell
c956126c13 gpio: doc updates
There's been some recent confusion about error checking GPIO numbers.
briefly, it should be handled mostly during setup, when gpio_request() is
called, and NEVER by expectig gpio_is_valid to report more than
never-usable GPIO numbers.

[akpm@linux-foundation.org: terminate unterminated comment]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Eric Miao" <eric.y.miao@gmail.com>
Cc: "Ryan Mallon" <ryan@bluewatersys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-09 18:57:24 -07:00
Grant Likely
594fa265e0 of/gpio: stop using device_node data pointer to find gpio_chip
Currently the kernel uses the struct device_node.data pointer to resolve
a struct gpio_chip pointer from a device tree node.  However, the .data
member doesn't provide any type checking and there aren't any rules
enforced on what it should be used for.  There's no guarantee that the
data stored in it actually points to an gpio_chip pointer.

Instead of relying on the .data pointer, this patch modifies the code
to add a lookup function which scans through the registered gpio_chips
and returns the gpio_chip that has a pointer to the specified
device_node.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Anton Vorontsov <avorontsov@ru.mvista.com>
CC: Grant Likely <grant.likely@secretlab.ca>
CC: David Brownell <dbrownell@users.sourceforge.net>
CC: Bill Gatliff <bgat@billgatliff.com>
CC: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Jean Delvare <khali@linux-fr.org>
CC: linux-kernel@vger.kernel.org
CC: devicetree-discuss@lists.ozlabs.org
2010-07-05 16:14:30 -06:00
Anton Vorontsov
a19e3da5bc of/gpio: Kill of_gpio_chip and add members directly to gpio_chip
The OF gpio infrastructure is great for describing GPIO connections within
the device tree.  However, using a GPIO binding still requires changes to
the gpio controller just to add an of_gpio structure.  In most cases, the
gpio controller doesn't actually need any special support and the simple
OF gpio mapping function is more than sufficient.  Additional, the current
scheme of using of_gpio_chip requires a convoluted scheme to maintain
1:1 mappings between of_gpio_chip and gpio_chip instances.

If the struct of_gpio_chip data members were moved into struct gpio_chip,
then it would simplify the processing of OF gpio bindings, and it would
make it trivial to use device tree OF connections on existing gpiolib
controller drivers.

This patch eliminates the of_gpio_chip structure and moves the relevant
fields into struct gpio_chip (conditional on CONFIG_OF_GPIO).  This move
simplifies the existing code and prepares for adding automatic device tree
support to existing drivers.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Bill Gatliff <bgat@billgatliff.com>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jean Delvare <khali@linux-fr.org>
2010-07-05 16:14:30 -06:00
Felipe Balbi
c4b5be98fe gpiolib: introduce set_debounce method
A few architectures, like OMAP, allow you to set a debouncing time for the
gpio before generating the IRQ.  Teach gpiolib about that.

Mark said:
: This would be generally useful for embedded systems, especially where
: the interrupt concerned is a wake source.  It allows drivers to avoid
: spurious interrupts from noisy sources so if the hardware supports it
: the driver can avoid having to explicitly wait for the signal to become
: stable and software has to cope with fewer events.  We've lived without
: it for quite some time, though.

David said:
: I looked at adding debounce support to the generic GPIO calls (and thus
: gpiolib) some time back, but decided against it.  I forget why at this
: time (check list archives) but it wasn't because of lack of utility in
: certain contexts.
:
: One thing to watch out for is just how variable the hardware capabilities
: are.  Atmel GPIOs have something like a fixed number of 32K clock cycles
: for debounce, twl4030 had something odd, OMAPs were more like the Atmel
: chips but with a different clock.  In some cases debouncing had to be
: ganged, not per-GPIO.  And so forth.

Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: David Brownell <david-b@pacbell.net>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:42 -07:00
Uwe Kleine-König
7839ec7821 gpiolib: document that names can contain printk format specifiers
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
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>
2010-05-27 09:12:41 -07:00
Uwe Kleine-König
62154991a8 gpiolib: make names array and its values const
gpiolib doesn't need to modify the names and I assume most initializers
use string constants that shouldn't be modified anyhow.

[akpm@linux-foundation.org: fix drivers/gpio/cs5535-gpio.c]
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Kevin Wells <kevin.wells@nxp.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>
2010-05-27 09:12:41 -07:00
Eric Miao
3e45f1d115 gpio: introduce gpio_request_one() and friends
gpio_request() without initial configuration of the GPIO is normally
useless, introduce gpio_request_one() together with GPIOF_ flags for
input/output direction and initial output level.

gpio_{request,free}_array() for multiple GPIOs.

Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Ben Nizette <bn@niasdigital.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-06 11:26:48 -08:00
Jani Nikula
0769746183 gpiolib: add support for changing value polarity in sysfs
Drivers may use gpiolib sysfs as part of their public user space
interface. The GPIO number and polarity might change from board to
board. The gpio_export_link() call can be used to hide the GPIO number
from user space. Add support for also hiding the GPIO line polarity
changes from user space.

Signed-off-by: Jani Nikula <ext-jani.1.nikula@nokia.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>
2009-12-16 07:20:01 -08:00
Mike Frysinger
1f018c8d0d asm-generic/gpio.h: add some forward decls of the device struct
After the recent commit a4177ee7f, attempting to include asm-generic/gpio.h
in otherwise "slim" code results in ugly warnings like so:

  CC      arch/blackfin/kernel/bfin_gpio.o
In file included from arch/blackfin/include/asm/gpio.h:278,
                 from arch/blackfin/kernel/bfin_gpio.c:15:
include/asm-generic/gpio.h:193: warning:
‘struct device’ declared inside parameter list
its scope is only this definition or declaration, which is probably not what you want

So add simple C forward decls of the struct device to avoid these.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2009-12-10 22:18:33 +01:00
Mike Frysinger
b3db4a8ad1 asm-generic/gpio.h: pull in linux/kernel.h for might_sleep()
The asm-generic/gpio.h header uses the might_sleep() macro but doesn't
include the header for it, so any source code that might include
linux/gpio.h before linux/kernel.h can easily lead to a build failure.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01 16:11:11 -07:00