2139 Commits

Author SHA1 Message Date
Grygorii Strashko
84f28998cc gpio: pcf857x: handle only enabled irqs
Now pcf857x_irq() IRQ's dispatcher will try to run nested
IRQ handlers for each GPIO pin which state has changed.
Such IRQs are, actually, spurious and nested IRQ handlers
have to be called only for IRQs wich were enabled by users.
This is not critical issue - just  /proc/interrupts
will display counters for unused IRQS:
399:          4          0   pcf857x   0 Edge
428:          1          0   pcf857x  13 Edge
430:          1          0   pcf857x  15 Edge

Hence, fix it by adding irq_enabled field in struct pcf857x to track
enabled GPIO IRQs and corresponding callbacks in pcf857x_irq_chip.

Similar functionality was presented in pcf857x driver, commit
21fd3cd1874a ('gpio: pcf857x: call the gpio user handler iff...')

and then it was removed by commit
 a39294bdf4b0 ('gpio: pcf857x: Switch to use gpiolib irqchip...')

Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Fixes: a39294bdf4b0 ('gpio: pcf857x: Switch to use gpiolib irqchip helpers')
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-06-16 10:57:58 +02:00
Mika Westerberg
f35bbf61ab gpio / ACPI: Return -EPROBE_DEFER if the gpiochip was not found
If a driver requests a GPIO described in its _CRS but the GPIO host
controller (gpiochip) driver providing the GPIO has not been loaded yet
acpi_get_gpiod() returns -ENODEV which causes the calling driver to fail.

If the gpiochip driver is loaded afterwards the driver requesting the GPIO
will not notice this.

Better approach is to return -EPROBE_DEFER in such case. Then when the
gpiochip driver appears the driver requesting the GPIO will be probed
again. This also aligns ACPI GPIO lookup code closer to DT as it does
pretty much the same when no gpiochip driver was found.

Reported-by: Tobias Diedrich <tobiasdiedrich@gmail.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Tobias Diedrich <ranma+kernel@tdiedrich.de>
Reviewed-by: Amos Kong <kongjianjun@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-06-11 10:17:32 +02:00
Hanjun Guo
2b528fff09 GPIO / ACPI: export acpi_gpiochip_request(free)_interrupts for module use
acpi_gpiochip_request(free)_interrupts can be used for modules,
so export them. This also fixs a compile error when xgene-sb
configured as kernel module.

Fixes: 733cf014f020 "gpio: xgene: add ACPI support for APM X-Gene GPIO standby driver"
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
2015-06-10 15:29:30 +02:00
Linus Walleij
a713890d32 gpio: improve error reporting on own descriptors
When requesting own descriptors through hogs, it is useful to
get some details about what's going on if we encounter problems.

Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-06-10 10:15:46 +02:00
Linus Walleij
8405f20894 gpio: promote own request failure to pr_err()
These error messages are helpful to see that we fail to get
hogs. Promote them to real errors so they appear in the boot
crawl.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-06-10 10:14:25 +02:00
Anurag Kumar Vulisha
bdf7a4ae37 gpio: Added support to Zynq Ultrascale+ MPSoC
Added support to Zynq Ultrascale+ MPSoC on the existing zynq
gpio driver.

Signed-off-by: Anurag Kumar Vulisha <anuragku@xilinx.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-06-10 09:44:17 +02:00
Rabin Vincent
d342571efe gpio: add ETRAXFS GPIO driver
Add a GPIO driver for the General I/O block on Axis ETRAX FS SoCs.

Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-06-10 09:11:10 +02:00
Gregory Fong
3b0213d56e gpio: Add GPIO support for Broadcom STB SoCs
This adds support for the GPIO IP "UPG GIO" used on
Broadcom STB SoCs (BCM7XXX and some others). Uses
basic_mmio_gpio to instantiate a gpio_chip for each bank.
The driver assumes that it handles the base set of GPIOs
on the system and that it can start its numbering sequence
from 0, so any GPIO expanders used with it must dynamically
assign GPIO numbers after this driver has finished
registering its GPIOs.

Does not implement the interrupt-controller portion yet,
will be done in a future commit.

v2:
- change include to use <linux/gpio/driver.h> instead of
  <linux/gpio.h>
- get rid of unnecessary imask member in struct bank
- rename GPIO_PER_BANK -> MAX_GPIO_PER_BANK
- always have 32 GPIOs per bank and add 'width' member in
  struct bank to hold actual number of GPIOs in use
- mark of_match table as const

List-usage-fixed-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Gregory Fong <gregory.0xf0@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-06-02 15:36:22 +02:00
Y Vo
733cf014f0 gpio: xgene: add ACPI support for APM X-Gene GPIO standby driver
Add ACPI support for APM X-Gene GPIO standby driver.

Signed-off-by: Y Vo <yvo@apm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-06-02 14:52:00 +02:00
Axel Lin
81d49ce8a8 gpio: tb10x: Drop unneeded free_irq() call
Current code uses devm_request_irq() in .probe, so drop the unneeded
free_irq() call in .remove.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Christian Ruppert <christian.ruppert@alitech.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-06-02 11:25:42 +02:00
Aaron Lu
61e749d7e1 gpio: crystalcove: set IRQCHIP_SKIP_SET_WAKE for the irqchip
The CrystalCove GPIO irqchip doesn't have irq_set_wake callback defined
so we should set IRQCHIP_SKIP_SET_WAKE for it or it would cause an irq
desc's wake_depth unbalanced warning during system resume phase from the
gpio_keys driver, which is the driver for the power button of the ASUS
T100 laptop.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-06-02 11:22:07 +02:00
Martin Blumenstingl
50f0907393 gpio: stp-xway: Use the of_property_read_u32 helper
This removes some redundant code but does not have any functional impact.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-06-02 11:22:02 +02:00
Geert Uytterhoeven
ffb8e44bd7 gpio: pcf857x: Check for irq_set_irq_wake() failures
If an interrupt controller doesn't support wake-up configuration,
irq_set_irq_wake() returns an error code.  Then any subsequent call
trying to deconfigure wake-up will cause an imbalance, and a warning
will be printed:

    WARNING: CPU: 1 PID: 1341 at kernel/irq/manage.c:540 irq_set_irq_wake+0x
    Unbalanced IRQ 26 wake disable

To fix this, refrain from any further parent interrupt controller
(de)configuration if irq_set_irq_wake() failed.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-06-01 16:55:25 +02:00
Martin Blumenstingl
08b085a07e gpio-stp-xway: Fix enabling the highest bit of the PHY LEDs
0x3 only masks two bits, but three bits have to be allowed. This fixes
GPHY0 LED2 (which is the highest bit of phy2) on my board.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-06-01 16:53:55 +02:00
Joshua Scott
b6ac1280b6 gpio: Prevent an integer overflow in the pca953x driver
Interrupts were missed if an 8-bit integer overflow occurred. This was
observed when bank0,pin7 and bank1,pin7 changed simultaniously.

As the 8-bit totals were only checked against zero, replace them with
booleans. Name the booleans so that their purpose is clear.

Signed-off-by: Joshua Scott <joshua.scott@alliedtelesis.co.nz>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-06-01 16:53:55 +02:00
Grygorii Strashko
121dcb7604 gpio: omap: rework omap_gpio_irq_startup to handle current pin state properly
The omap_gpio_irq_startup() can be called at time when:
- corresponding GPIO has been requested already and in this case
it has to be configured as input already. If not - return with -EINVAL
and do not try to re-configure it as it could be unsafe.
- corresponding GPIO is free: reconfigure GPIO as input.

In addition, call omap_enable_gpio_module directly as all needed
checks are already present inside it.

Signed-off-by: Grygorii Strashko <grygorii.strashko@linaro.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-06-01 16:53:54 +02:00
Grygorii Strashko
c351817212 gpio: omap: rework omap_gpio_request to touch only gpio specific registers
The GPIO Chip and GPIO IRQ Chip functionality are essentially orthogonal,
so GPIO Chip implementation shouldn't touch GPIO IRQ specific registers
and vise versa.

Hence, rework omap_gpio_request:
- don't reset GPIO IRQ triggering type to IRQ_TYPE_NONE, because
  GPIO irqchip should be responsible for that;
- call directly omap_enable_gpio_module as all needed checks are already
  present inside it.

Signed-off-by: Grygorii Strashko <grygorii.strashko@linaro.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-06-01 16:53:50 +02:00
Grygorii Strashko
6e96c1b5e5 gpio: omap: rework omap_x_irq_shutdown to touch only irqs specific registers
The GPIO Chip and GPIO IRQ Chip functionality are essentially orthogonal,
so GPIO IRQ Chip implementation shouldn't touch GPIO specific
registers and vise versa.

Hence, rework omap_gpio_irq_shutdown and try to touch only irqs specific
registers:
- don't configure GPIO as input (it, actually, should be already configured
  as input).
- don't clear debounce configuration if GPIO is still used as GPIO.
  We need to take in to account here commit c9c55d921115
  ("gpio/omap: fix off-mode bug: clear debounce settings on free/reset").

Also remove omap_reset_gpio() function as it is not used any more.

Signed-off-by: Grygorii Strashko <grygorii.strashko@linaro.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-06-01 16:53:46 +02:00
Grygorii Strashko
1562e4618d gpio: omap: fix error handling in omap_gpio_irq_type
The GPIO bank will be kept powered in case if input parameters
are invalid or error occurred in omap_gpio_irq_type.

Hence, fix it by ensuring that GPIO bank will be unpowered
in case of errors and add additional check of value returned
from omap_set_gpio_triggering().

Signed-off-by: Grygorii Strashko <grygorii.strashko@linaro.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-06-01 16:51:16 +02:00
Grygorii Strashko
5f982c70a7 gpio: omap: fix omap_gpio_free to not clean up irq configuration
This patch fixes following issue:
- GPIOn is used as IRQ by some dev, for example PCF8575.INT ->  gpio6.11
- PCFx driver knows nothing about type of IRQ line (GPIO or not)
  so it doesn't request gpio and just do request_irq()
- If gpio6.11 will be exported through the sysfs and then un-xeported
then IRQs from PCFx will not be received any more, because
IRQ configuration for gpio6.11 will be cleaned up unconditionally
in omap_gpio_free.

Fix this by removing all GPIO IRQ specific code from omap_gpio_free()
and also do GPIO clean up (change direction to 'in' and disable debounce)
only if corresponding GPIO is not used as IRQ too.
GPIO IRQ will be properly cleaned up by GPIO irqchip code.

Signed-off-by: Grygorii Strashko <grygorii.strashko@linaro.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-06-01 16:50:49 +02:00
Geert Uytterhoeven
501ef0f95a gpio: rcar: Check for irq_set_irq_wake() failures
If an interrupt controller doesn't support wake-up configuration,
irq_set_irq_wake() returns an error code.  Then any subsequent call
trying to deconfigure wake-up will cause an imbalance, and a warning
will be printed:

    WARNING: CPU: 1 PID: 1341 at kernel/irq/manage.c:540 irq_set_irq_wake+0x9c/0xf8()
    Unbalanced IRQ 26 wake disable

To fix this, refrain from any further parent interrupt controller
(de)configuration if irq_set_irq_wake() failed.

Alternative fixes would be:
  - calling "gic_set_irqchip_flags(IRQCHIP_SKIP_SET_WAKE)" from the
    platform code,
  - setting "gic_chip.flags = IRQCHIP_SKIP_SET_WAKE" in the GIC driver
    code,
but these were withheld as the GIC hardware doesn't really support
wake-up interrupts.

Fixes: ab82fa7da4dce5c7 ("gpio: rcar: Prevent module clock disable when wake-up is enabled")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-06-01 15:10:09 +02:00
Rojhalat Ibrahim
3fff99bc4e gpiolib: rename gpiod_set_array to gpiod_set_array_value
There have been concerns that the function names gpiod_set_array() and
gpiod_get_array() might be confusing to users. One might expect
gpiod_get_array() to return array values, while it is actually the array
counterpart of gpiod_get(). To be consistent with the single descriptor API
we could rename gpiod_set_array() to gpiod_set_array_value(). This makes
some function names a bit lengthy: gpiod_set_raw_array_value_cansleep().

Signed-off-by: Rojhalat Ibrahim <imr@rtschenk.de>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-06-01 15:10:09 +02:00
Colin Cronin
20a8a96873 Drivers: gpio: Fix spelling errors
Fixed several spelling errors in gpio-lynxpoint, gpio-pca953x,
gpio-tegra, gpio-zynq, gpiolib-of, gpiolib.

Signed-off-by: Colin Cronin <colinpatrickcronin@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-19 16:52:30 +02:00
Dmitry Eremin-Solenikov
25e4fe92a2 gpiolib: cleanup chained handler and data
Clean up chained handler and handler data if they were set by
gpiochip_set_chained_irqchip().

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-13 13:02:36 +02:00
Johan Hovold
8864afaa63 gpio: dln2: fix build breakage
The dln2 driver was initialising a gpiolib private field, which is now
gone.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-13 10:02:12 +02:00
Michael Brunner
f230e8ffc0 gpio: gpio-kempld: Fix get_direction return value
This patch fixes an inverted return value of the gpio get_direction
function.

The wrong value causes the direction sysfs entry and GPIO debugfs file
to indicate incorrect GPIO direction settings. In some cases it also
prevents setting GPIO output values.

The problem is also present in all other stable kernel versions since
linux-3.12.

Cc: Stable <stable@vger.kernel.org> # v3.12+
Reported-by: Jochen Henneberg <jh@henneberg-systemdesign.com>
Signed-off-by: Michael Brunner <michael.brunner@kontron.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 13:49:13 +02:00
Axel Lin
b8a3f52e98 gpio: xlp: Add missing .owner and .label settings for gpio_chip
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 13:23:24 +02:00
Johan Hovold
6d86750ce6 gpio: fix gpio leak in gpiochip_add error path
Make sure to free any hogged gpios on errors in gpiochip_add.

Also move all forward declarations to the top of the file.

Fixes: f625d4601759 ("gpio: add GPIO hogging mechanism")
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:56:28 +02:00
Johan Hovold
cef1717b7f gpio: sysfs: move irq trigger flags to class-device data
Move irq trigger flags, which as sysfs-interface specific, to the class
device data.

This avoids accessing the gpio-descriptor flags field using non-atomic
operations without any locking, and allows for a more clear separation
of the sysfs interface from gpiolib core.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:47:57 +02:00
Johan Hovold
427fdeef50 gpio: sysfs: remove FLAG_SYSFS_DIR
Remove FLAG_SYSFS_DIR, which is sysfs-interface specific, and store it
in the class-device data instead.

Note that the flag is only used during export.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:47:52 +02:00
Johan Hovold
2f323b8567 gpio: sysfs: rename active-low helper
Rename active-low helper using common prefix.

Also remove unnecessary manipulation of value argument.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:47:48 +02:00
Johan Hovold
72eba6f66a gpio: sysfs: fix race between gpiod export and unexport
Make sure to deregister the class device (and release the irq) while
holding the sysfs lock in gpio_unexport to prevent racing with
gpio_export.

Note that this requires the recently introduced per-gpio locking to
avoid a deadlock with the kernfs active protection when waiting for the
attribute operations to drain during deregistration.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:47:44 +02:00
Johan Hovold
6ffcb79714 gpio: sysfs: use per-gpio locking
Add a per-gpio mutex to serialise attribute operations rather than use
one global mutex for all gpios and chips.

Having a single global lock for all gpios in a system adds unnecessary
latency to the sysfs interface, and especially when having gpio
controllers connected over slow buses.

Now that the global gpio-sysfs interrupt table is gone and with per-gpio
data in place, we can easily switch to using a more fine-grained locking
scheme.

Keep the global mutex to serialise the global (class) operations of gpio
export and unexport and chip removal.

Also document the locking assumptions made.

Note that this is also needed to fix a race between gpiod_export and
gpiod_unexport.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:47:39 +02:00
Johan Hovold
56d30ec14c gpio: sysfs: clean up gpiod_export_link locking
Drop unnecessary locking from gpiod_export_link. If the class device has
not already been unregistered, class_find_device returns the ref-counted
class device so there's no need for locking.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:47:35 +02:00
Johan Hovold
e4339ce323 gpio: sysfs: clean up edge_store
Remove goto from success path.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:47:31 +02:00
Johan Hovold
2ec74a9593 gpio: sysfs: split irq allocation and deallocation
Add separate helper functions for irq request and free.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:47:27 +02:00
Johan Hovold
b91e18076f gpio: sysfs: only call irq helper if needed
Only call irq helper if actually reconfiguring interrupt state.

This is a preparatory step in introducing separate gpio-irq request and
free functions.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:47:23 +02:00
Johan Hovold
a08f5c21f4 gpio: sysfs: clean up interrupt-interface implementation
Store the value sysfs entry in the gpiod data rather than in a global
table accessed through an index stored in the overloaded gpio-descriptor
flag field.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:47:19 +02:00
Johan Hovold
0f62850808 gpio: sysfs: remove redundant gpio-descriptor parameters
Remove redundant gpio-descriptor parameters from sysfs_set_active_low and
gpio_setup_irq.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:47:16 +02:00
Johan Hovold
c43960fbcc gpio: sysfs: add gpiod class-device data
Add gpiod class-device data.

This is a first step in getting rid of the insane gpio-descriptor flag
overloading, backward irq-interface implementation, and course grained
sysfs-interface locking (a single static mutex for every operation on
all exported gpios in a system).

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:47:12 +02:00
Johan Hovold
f0b7866a02 gpio: sysfs: remove redundant export tests
The attribute operations will never be called for an unregistered device
so remove redundant checks for FLAG_EXPORT.

Note that kernfs will also guarantee that any active sysfs operation has
finished before the attribute is removed during deregistration.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:47:08 +02:00
Johan Hovold
54d9acd754 gpio: sysfs: release irq after class-device deregistration
Make sure to release any irq only after the class device has been
deregistered.

This avoids a race between gpiod_unexport and edge_store, where an irq
could be allocated just before the gpio class device is deregistered
without relying on FLAG_EXPORT and the global sysfs lock.

Note that there is no need to hold the sysfs lock when releasing the irq
after the class device is gone as kernfs will prevent further attribute
operations.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:47:03 +02:00
Johan Hovold
6beac9d1aa gpio: sysfs: use DEVICE_ATTR macros
Use DEVICE_ATTR_RO and DEVICE_ATTR_RW rather than specifying masks and
callbacks directly.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:46:59 +02:00
Johan Hovold
166a85e442 gpio: remove gpiod_sysfs_set_active_low
Remove gpiod_sysfs_set_active_low (and gpio_sysfs_set_active_low) which
allowed code to change the polarity of a gpio line even after it had
been exported through sysfs.

Drivers should not care, and generally does not know, about gpio-line
polarity which is a hardware feature that needs to be described by
firmware.

It is currently possible to define gpio-line polarity in device-tree and
acpi firmware or using platform data. Userspace can also change the
polarity through sysfs.

Note that drivers using the legacy gpio interface could still use
GPIOF_ACTIVE_LOW to change the polarity before exporting the gpio.

There are no in-kernel users of this interface.

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Harry Wei <harryxiyou@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@zh-kernel.org
Cc: linux-arch@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:46:53 +02:00
Johan Hovold
426577bd88 gpio: sysfs: rename gpiochip registration functions
Rename the gpio-chip export/unexport functions to the more descriptive
names gpiochip_sysfs_register and gpiochip_sysfs_unregister.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:46:49 +02:00
Johan Hovold
6a4b6b0a3b gpio: sysfs: clean up chip class-device handling
Clean gpio-chip class device registration and deregistration.

The class device is registered when a gpio-chip is added (or from
gpiolib_sysfs_init post-core init call), and deregistered when the chip
is removed.

Store the class device in struct gpio_chip directly rather than do a
class-device lookup on deregistration. This also removes the need for
the exported flag.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:46:44 +02:00
Johan Hovold
3ff74be5c1 gpio: sysfs: reduce gpiochip-export locking scope
Reduce scope of sysfs_lock protection during chip export and unexport,
which is only needed to prevent gpiod (re-)exports during chip removal.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:46:40 +02:00
Johan Hovold
cecf58ab55 gpio: sysfs: preparatory clean ups
Put the recently introduced gpio-chip pointer to some more use in
gpiod_export.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:46:36 +02:00
Johan Hovold
52176d0d3b gpio: sysfs: fix redundant lock-as-irq handling
Drivers should call gpiochip_lock_as_irq (which prevents the pin
direction from being changed) in their irq_request_resources callbacks
but some drivers currently fail to do so.

Instead a second, explicit and often redundant call to lock-as-irq is
made by the sysfs-interface implementation after an irq has been
requested.

Move the explicit call before the irq-request to match the unlock done
after the irq is later released. Note that this also fixes an irq leak,
should the explicit call ever have failed.

Also add a comment about removing the redundant call once the broken
drivers have been fixed.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:46:31 +02:00
Johan Hovold
fab28b89a1 gpio: clean up gpiochip_remove
Clean up gpiochip_remove somewhat and only output warning about removing
chip with GPIOs requested once.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:46:15 +02:00