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path: root/drivers/gpio/mcp23s08.c
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2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2009-09-23gpio: include <linux/gpio.h> not <asm/gpio.h>H Hartley Sweeten
Drivers should be including <linux/gpio.h> not <asm/gpio.h>. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.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>
2009-09-23spi: prefix modalias with "spi:"Anton Vorontsov
This makes it consistent with other buses (platform, i2c, vio, ...). I'm not sure why we use the prefixes, but there must be a reason. This was easy enough to do it, and I did it. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Cc: David Brownell <dbrownell@users.sourceforge.net> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Grant Likely <grant.likely@secretlab.ca> Cc: Jean Delvare <khali@linux-fr.org> Cc: Ben Dooks <ben-linux@fluff.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dmitry Torokhov <dtor@mail.ru> Cc: Samuel Ortiz <sameo@openedhand.com> Cc: "John W. Linville" <linville@tuxdriver.com> Acked-by: Mike Frysinger <vapier.adi@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
2008-10-16spi: core and gpio expanders use subsys_initDavid Brownell
Make the SPI external GPIO expander drivers register themselves at subsys_initcall() time when they're statically linked, and make the SPI core do its driver model initialization earlier so that's safe. SOC-integrated GPIOs are available starting very early -- often before initcalls start to run, or earily in arch_initcall() at latest -- so this improves consistency, letting more subsystems rely on GPIOs being usable by their own subsys_initcall() code. 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>
2008-07-25gpio: mcp23s08 handles multiple chips per chipselectDavid Brownell
Teach the mcp23s08 driver about a curious feature of these chips: up to four of them can share the same chipselect, with the SPI signals wired in parallel, by matching two bits in the first protocol byte against two address lines on the chip. This is handled by three software changes: * Platform data now holds an array of per-chip structs, not just one chip's address and pullup configuration. * Probe() and remove() now use another level of structure, wrapping an instance of the original structure for each mcp23s08 chip sharing that chipselect. * The HAEN bit is set, so that the hardware address bits can no longer be ignored (boot firmware may not have enabled them). The "one struct per chip" preserves the guts of the current code, but platform_data will need minor changes. OLD: /* incorrect "slave" ID may not have mattered */ .slave = 3, .pullups = BIT(3) | BIT(1) | BIT(0), NEW: /* slave address _must_ match chip's wiring */ .chip[3] = { .is_present = true, .pullups = BIT(3) | BIT(1) | BIT(0), }, There's no change in how things _behave_ for spi_device nodes with a single mcp23s08 chip. New multi-chip configurations assign GPIOs in sequence, without holes. The spi_device just resembles a bigger controller, but internally it has multiple gpio_chip instances. 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>
2008-07-25gpio: 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: mcp23s08 debug fixRoel Kluin
The return value of mcp23s08_read_regs() can only be evaluated when signed Signed-off-by: Roel Kluin <12o3l@tiscali.nl> 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>
2008-04-28gpiolib: 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>
2008-02-05mcp23s08 spi gpio expander supportDavid Brownell
Basic driver for 8-bit SPI based MCP23S08 GPIO expander, without support for IRQs or the shared chipselect mechanism. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Jean Delvare <khali@linux-fr.org> Cc: Eric Miao <eric.miao@marvell.com> 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>