Bill Gatliff reported the following bug when using the irq_chip facility
of the pca953x driver on a PPC platform:
BUG: scheduling while atomic: insmod/1530/0x00000002
He traced it back to an i2c transaction in pca953x_irq_set_type(), which
can be called with interrupt disabled (from __setup_irq()). As the i2c
controller can sleep while sending a message, this qualifies as a bad
idea.
This patch moves the i2c transaction to pca953x_irq_bus_sync_unlock(),
where it is actually safe to send an i2c message.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Marc Zyngier <maz@misterjones.org>
Reported-by: Bill Gatliff <bgat@billgatliff.com>
Cc: Eric Miao <eric.y.miao@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
Most of the GPIO expanders controlled by the pca953x driver are able to
report changes on the input pins through an *INT pin.
This patch implements the irq_chip functionality (edge detection only).
The driver has been tested on an Arcom Zeus.
[akpm@linux-foundation.org: the compiler does inlining for us nowadays]
Signed-off-by: Marc Zyngier <maz@misterjones.org>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Haojian Zhuang <haojian.zhuang@gmail.com>
Cc: David Brownell <david-b@pacbell.net>
Cc: Nate Case <ncase@xes-inc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
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.pdf
Signed-off-by: Alek Du <alek.du@intel.com>
Acked-by: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: Nate Case <ncase@xes-inc.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>
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: Nate Case <ncase@xes-inc.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>
Add support to the PCA953x driver to use the GPIOLIB naming facility for
GPIOs.
Signed-off-by: Daniel 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: 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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
