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path: root/include/asm-generic/gpio.h
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2013-02-11gpiolib: let gpio_chip reference its descriptorsAlexandre Courbot
Add a pointer to the gpio_chip structure that references the array of GPIO descriptors belonging to the chip, and update gpiolib code to use this pointer instead of the global gpio_desc[] array. This is another step towards the removal of the gpio_desc[] global array. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.orh> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2013-02-09gpiolib: link all gpio_chips using a listAlexandre Courbot
Add a list member to gpio_chip that allows all chips to be parsed quickly. The current method requires parsing the entire GPIO integer space, which is painfully slow. Using a list makes many chip operations that involve lookup or parsing faster, and also simplifies the code. It is also necessary to eventually get rid of the global gpio_desc[] array. The list of gpio_chips is always ordered by base GPIO number to ensure chips traversal is done in the right order. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2013-02-04gpiolib: remove gpiochip_reserve()Alexandre Courbot
gpiochip_reserve() has no user and stands in the way of the removal of the static gpio_desc[] array. Remove this function as well as the now unneeded RESERVED flag of struct gpio_desc. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-01-22gpio: devm_gpio_* support should not depend on GPIOLIBShawn Guo
Some architectures (e.g. blackfin) provide gpio API without requiring GPIOLIB support (ARCH_WANT_OPTIONAL_GPIOLIB). devm_gpio_* functions should also work for these architectures, since they do not really depend on GPIOLIB. Add a new option GPIO_DEVRES (enabled by default) to control the build of devres.c. It also removes the empty version of devm_gpio_* functions for !GENERIC_GPIO build from linux/gpio.h, and moves the function declarations from asm-generic/gpio.h into linux/gpio.h. Signed-off-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-01-22gpio: fix warning of 'struct gpio_chip' declarationShawn Guo
The struct gpio_chip is only defined inside #ifdef CONFIG_GPIOLIB, but it's referenced by gpiochip_add_pin_range() and gpiochip_remove_pin_ranges() which are outside #ifdef CONFIG_GPIOLIB. Thus, we see the following warning when building blackfin image, where GPIOLIB is not required. CC arch/blackfin/kernel/bfin_gpio.o CC init/version.o In file included from arch/blackfin/include/asm/gpio.h:321, from arch/blackfin/kernel/bfin_gpio.c:15: include/asm-generic/gpio.h:298: warning: 'struct gpio_chip' declared inside parameter list include/asm-generic/gpio.h:298: warning: its scope is only this definition or declaration, which is probably not what you want include/asm-generic/gpio.h:304: warning: 'struct gpio_chip' declared inside parameter list Move pinctrl trunk into #ifdef CONFIG_GPIOLIB to fix the warning, since it appears that pinctrl gpio range support depends on GPIOLIB. Signed-off-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-12-11Merge tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux-2.6Linus Torvalds
Pull GPIO updates from Grant Likely: "GPIO follow up patch and type change for v3.5 merge window Primarily device driver additions, features and bug fixes. Not much touching gpio common subsystem support. Should not be scary." * tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux-2.6: (34 commits) gpio: Provide the STMPE GPIO driver with its own IRQ Domain gpio: add TS-5500 DIO blocks support gpio: pcf857x: use client->irq for gpio_to_irq() gpio: stmpe: Add DT support for stmpe gpio gpio: pl061 depends on ARM gpio/pl061: remove old comment gpio: SPEAr: add spi chipselect control driver gpio: gpio-max710x: Support device tree probing gpio: twl4030: Use only TWL4030_MODULE_LED for LED configuration gpio: tegra: read output value when gpio is set in direction_out gpio: pca953x: Add compatible strings to gpio-pca953x driver gpio: pca953x: Register an IRQ domain gpio: mvebu: Set free callback for gpio_chip gpio: tegra: Drop exporting static functions gpio: tegra: Staticize non-exported symbols gpio: tegra: fix suspend/resume apis gpio-pch: Set parent dev for gpio chip gpio: em: Fix build errors GPIO: clps711x: use platform_device_unregister in gpio_clps711x_init() gpio/tc3589x: convert to use the simple irqdomain ...
2012-11-21gpiolib: rename pin range argumentsLinus Walleij
To be crystal clear on what the arguments mean in this funtion dealing with both GPIO and PIN ranges with confusing naming, we now have gpio_offset and pin_offset and we are on the clear that these are offsets into the specific GPIO and pin controller respectively. The GPIO chip itself will of course keep track of the base offset into the global GPIO number space. Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-11-21gpiolib: let gpiochip_add_pin_range() specify offsetLinus Walleij
Like with commit 3c739ad0df5eb41cd7adad879eda6aa09879eb76 it is not always enough to specify all the pins of a gpio_chip from offset zero to be added to a pin map range, since the mapping from GPIO to pin controller may not be linear at all, but need to be broken into a few consecutive sub-ranges or 1-pin entries for complicated cases. The ranges may also be sparse. This alters the signature of the function to accept offsets into both the GPIO-chip local pinspace and the pin controller local pinspace. Reviewed-by: Stephen Warren <swarren@nvidia.com> Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-11-11gpiolib: iron out include ladder mistakesLinus Walleij
The <*/gpio.h> includes are updated again: now we need to account for the problem introduced by commit: 595679a8038584df7b9398bf34f61db3c038bfea "gpiolib: fix up function prototypes etc" Actually we need static inlines in include/asm-generic/gpio.h as well since we may have GPIOLIB but not PINCTRL. Make sure to move all the CONFIG_PINCTRL business to the end of the file so we are sure we have declared struct gpio_chip. And we need to keep the static inlines in <linux/gpio.h> but here for the !CONFIG_GENERIC_GPIO case, and then we may as well throw in a few warnings like the other prototypes there, if someone would have the bad taste of compiling without GENERIC_GPIO even. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-11-11gpiolib: separation of pin concernsLinus Walleij
The fact that of_gpiochip_add_pin_range() and gpiochip_add_pin_range() share too much code is fragile and will invariably mean that bugs need to be fixed in two places instead of one. So separate the concerns of gpiolib.c and gpiolib-of.c and have the latter call the former as back-end. This is necessary also when going forward with other device descriptions such as ACPI. This is done by: - Adding a return code to gpiochip_add_pin_range() so we can reliably check whether this succeeds. - Get rid of the custom of_pinctrl_add_gpio_range() from pinctrl. Instead create of_pinctrl_get() to just retrive the pin controller per se from an OF node. This composite function was just begging to be deleted, it was way to purpose-specific. - Use pinctrl_dev_get_name() to get the name of the retrieved pin controller and use that to call back into the generic gpiochip_add_pin_range(). Now the pin range is only allocated and tied to a pin controller from the core implementation in gpiolib.c. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-11-11gpiolib: fix up function prototypes etcLinus Walleij
Commit 69e1601bca88809dc118abd1becb02c15a02ec71 "gpiolib: provide provision to register pin ranges" Got most of it's function prototypes wrong, so fix this up by: - Moving the void declarations into static inlines in <linux/gpio.h> (previously the actual prototypes were declared here...) - Declare the gpiochip_add_pin_range() and gpiochip_remove_pin_ranges() functions in <asm-generic/gpio.h> together with the pin range struct declaration itself. - Actually only implement these very functions in gpiolib.c if CONFIG_PINCTRL is set. - Additionally export the symbols since modules will need to be able to do this. Reviewed-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-11-11gpiolib: provide provision to register pin rangesShiraz Hashim
pinctrl subsystem needs gpio chip base to prepare set of gpio pin ranges, which a given pinctrl driver can handle. This is important to handle pinctrl gpio request calls in order to program a given pin properly for gpio operation. As gpio base is allocated dynamically during gpiochip registration, presently there exists no clean way to pass this information to the pinctrl subsystem. After few discussions from [1], it was concluded that may be gpio controller reporting the pin range it supports, is a better way than pinctrl subsystem directly registering it. [1] http://comments.gmane.org/gmane.linux.ports.arm.kernel/184816 Cc: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Shiraz Hashim <shiraz.hashim@st.com> [Edited documentation a bit] Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-10-26gpiolib: add gpio get direction callback supportMathias Nyman
Add .get_direction callback to gpio_chip. This allows gpiolib to check the current direction of a gpio. Used to show the correct gpio direction in sysfs and debug entries. If callback is not set then gpiolib will work as previously; e.g. guessing everything is input until a direction is set. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-09-30gpio: Document device_node's det_debounceRoland Stigge
This patch adds documentation for set_debounce in struct device_node. Signed-off-by: Roland Stigge <stigge@antcom.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-05-19gpiolib: Remove 'const' from data argument of gpiochip_find()Grant Likely
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>
2012-05-18gpio: Adjust of_xlate API to support multiple GPIO chipsGrant Likely
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>
2012-05-18gpiolib: Implement devm_gpio_request_one()Mark Brown
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>
2012-03-02gpio: constify the data parameter to gpiochip_find()Grant Likely
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-01-04GPIO: add bindings for managed devicesJohn Crispin
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>
2011-12-12of: create of_phandle_args to simplify return of phandle parsing dataGrant Likely
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>
2011-12-12gpio/powerpc: Eliminate duplication of of_get_named_gpio_flags()Grant Likely
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>
2011-10-26gpio: fix build error in include/asm-generic/gpio.hHamo
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>
2011-10-24gpiolib: Ensure struct gpio is always definedMark Brown
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>
2011-06-16gpio: add GPIOF_ values regardless on kconfig settingsRandy Dunlap
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>
2011-05-27gpio: make gpio_{request,free}_array gpio array parameter constLars-Peter Clausen
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>
2011-05-27gpio: Convert gpio_is_valid to return boolJoe Perches
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>
2011-01-14Revert "gpiolib: annotate gpio-intialization with __must_check"Linus Torvalds
This reverts commit 0fdae42d361bbb431ca0ab0efed5126a94821177, 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>
2011-01-13gpiolib: annotate gpio-intialization with __must_checkWolfram Sang
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>
2010-10-28gpiolib: fix HAVE_GPIO_LIB leftovers in asm-generic/gpio.hAnton Vorontsov
commit 7444a72effa632fcd8edc566f88 ("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>
2010-09-10gpio: doc updatesDavid Brownell
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>
2010-07-05of/gpio: stop using device_node data pointer to find gpio_chipGrant Likely
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
2010-07-05of/gpio: Kill of_gpio_chip and add members directly to gpio_chipAnton Vorontsov
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>
2010-05-27gpiolib: introduce set_debounce methodFelipe Balbi
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>
2010-05-27gpiolib: document that names can contain printk format specifiersUwe Kleine-König
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>
2010-05-27gpiolib: make names array and its values constUwe Kleine-König
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>
2010-03-06gpio: introduce gpio_request_one() and friendsEric Miao
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>
2009-12-16gpiolib: add support for changing value polarity in sysfsJani Nikula
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>
2009-12-10asm-generic/gpio.h: add some forward decls of the device structMike Frysinger
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>
2009-10-01asm-generic/gpio.h: pull in linux/kernel.h for might_sleep()Mike Frysinger
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>
2009-09-23gpiolib: allow exported GPIO nodes to be named using sysfs linksJani Nikula
Commit 926b663ce8215ba448960e1ff6e58b67a2c3b99b (gpiolib: allow GPIOs to be named) already provides naming on the chip level. This patch provides more flexibility by allowing multiple names where ever in sysfs on a per GPIO basis. Adapted from David Brownell's comments on a similar concept: http://lkml.org/lkml/2009/4/20/203. [randy.dunlap@oracle.com: fix build for CONFIG_GENERIC_GPIO=n] Signed-off-by: Jani Nikula <ext-jani.1.nikula@nokia.com> Acked-by: David Brownell <david-b@pacbell.net> Cc: Daniel Silverstone <dsilvers@simtec.co.uk> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-03gpiolib: allow GPIOs to be namedDaniel Silverstone
Allow GPIOs in GPIOLIB chips to be named. This name is then used when the GPIO is exported to sysfs, although it could be used elsewhere if deemed useful. Signed-off-by: Daniel Silverstone <dsilvers@simtec.co.uk> 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>
2008-10-16gpiolib: request/free hooksDavid Brownell
Add a new internal mechanism to gpiolib to support low power operations by letting gpio_chip instances see when their GPIOs are in use. When no GPIOs are active, chips may be able to enter lower powered runtime states by disabling clocks and/or power domains. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: "Magnus Damm" <magnus.damm@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16gpiolib: gpio_to_irq() hooksDavid Brownell
Add a new gpiolib mechanism: gpio_chip instances can provide mappings between their (input) GPIOs and any associated IRQs. This makes it easier for platforms to support IRQs that are provided by board-specific external chips instead of as part of their core (such as SOC-integrated GPIOs). Also update the irq_to_gpio() description, saying to avoid it because it's not always supported. 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>
2008-10-16gpio: make gpiochip label constDmitry Baryshkov
Mark gpiochip label as a const char pointer. Fixes things like arch/arm/common/scoop.c: In function `scoop_probe': arch/arm/common/scoop.c:250: warning: assignment discards qualifiers from pointer target type Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com> Acked-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>
2008-07-28gpio: fix build on CONFIG_GPIO_SYSFS=nAtsushi Nemoto
If CONFIG_GENERIC_GPIO=y && CONFIG_GPIO_SYSFS=n, gpio_export() in asm-generic/gpio.h refers -ENOSYS and causes build error. Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Acked-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>
2008-07-27gpiolib: fix typo in commentMichael Buesch
This fixes an off-by-one error in a comment. Signed-off-by: Michael Buesch <mb@bu3sch.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>
2008-07-25gpiolib: allow user-selectionMichael Buesch
This patch adds functionality to the gpio-lib subsystem to make it possible to enable the gpio-lib code even if the architecture code didn't request to get it built in. The archtitecture code does still need to implement the gpiolib accessor functions in its asm/gpio.h file. This patch adds the implementations for x86 and PPC. With these changes it is possible to run generic GPIO expansion cards on every architecture that implements the trivial wrapper functions. Support for more architectures can easily be added. Signed-off-by: Michael Buesch <mb@bu3sch.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: David Brownell <david-b@pacbell.net> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jean Delvare <khali@linux-fr.org> Cc: Samuel Ortiz <sameo@openedhand.com> Cc: Kumar Gala <galak@gate.crashing.org> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Adrian Bunk <bunk@stusta.de> 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>
2008-05-24gpio: build fixesDavid Brownell
This fixes various gpio-related build errors (mostly potential) reported in part by Russell King and Uwe Kleine-König. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Arnaud Patard <arnaud.patard@rtp-net.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28gpiochip_reserve()Anton Vorontsov
Add a new function gpiochip_reserve() to reserve ranges of gpios that platform code has pre-allocated. That is, this marks gpio numbers which will be claimed by drivers that haven't yet been loaded, and thus are not available for dynamic gpio number allocation. [akpm@linux-foundation.org: remove unneeded __must_check] [david-b@pacbell.net: don't export gpiochip_reserve (section fix)] Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> 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>