Commit Graph

2346 Commits

Author SHA1 Message Date
Geert Uytterhoeven
40c8eabac4 gpio: Propagate all errors in devm_get_gpiod_from_child()
devm_get_gpiod_from_child() tries several property suffixes to find a
GPIO descriptor. If all suffixes fail and no probe deferral has been
detected, it returns the error of the last try.

However, if any but the last try fails with a real error (e.g. -EBUSY),
this error is not propagated, and -ENOENT will be returned.
This confuses drivers that e.g. want to detect if a GPIO is already in
use.

To fix this, change the loop logic to continue on -ENOENT, which
indicates the property was not found and the next suffix should be
tried, and propagate all other detected errors.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-25 10:04:25 +01:00
Linus Walleij
9d8cc89c31 gpio: fixup line flags for userspace ABI
This fixes the wrongly indicated lines in the userspace
ABI: test for the right BITS, do not treat bit numbers as
bitmasks.

Reported-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-22 13:44:53 +01:00
Bamvor Jian Zhang
bd203bd56d gpiolib: fix crash when gpiochip removed
Commit cb464a88e1ed ("gpio: make the gpiochip a real device") call
gpiochip_sysfs_unregister after the gpiochip is empty. It lead to the
following crash:

[  163.503994] Unable to handle kernel NULL pointer dereference at virtual address 0000007c
[...]
[  163.525394] [<ffffffc0003719a0>] gpiochip_sysfs_unregister+0x44/0xa4
[  163.525611] [<ffffffc00036f6a0>] gpiochip_remove+0x24/0x154
[  163.525861] [<ffffffbffc00f0a4>] mockup_gpio_remove+0x38/0x64 [gpio_mockup]
[  163.526101] [<ffffffc00042b4b4>] platform_drv_remove+0x24/0x64
[  163.526313] [<ffffffc000429cc8>] __device_release_driver+0x7c/0xfc
[  163.526525] [<ffffffc000429e54>] driver_detach+0xbc/0xc0
[  163.526700] [<ffffffc000429014>] bus_remove_driver+0x58/0xac
[  163.526883] [<ffffffc00042a4cc>] driver_unregister+0x2c/0x4c
[  163.527067] [<ffffffc00042b5c0>] platform_driver_unregister+0x10/0x18
[  163.527284] [<ffffffbffc00f340>] mock_device_exit+0x10/0x38 [gpio_mockup]
[  163.527593] [<ffffffc00011cefc>] SyS_delete_module+0x1b8/0x1fc
[  163.527799] [<ffffffc000085d8c>] __sys_trace_return+0x0/0x4
[  163.528049] Code: 940d74b4 f9019abf aa1303e0 940d7439 (7940fac0)
[  163.536273] ---[ end trace 3d1329be504af609 ]---

This patch fix this by changing the code back.

Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-20 12:48:34 +01:00
Sudip Mukherjee
3e089d9f55 gpio: pisosr: add missing unlock
If spi_read() fails then we just returned but we missed unlocking the
mutex.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-19 12:56:13 +01:00
Quan Nguyen
1013fc417c gpio: xgene: Enable X-Gene standby GPIO as interrupt controller
Enable X-Gene standby GPIO controller as interrupt controller to provide
its own resources. This avoids ambiguity where GIC interrupt resource is
use as X-Gene standby GPIO interrupt resource in user driver.

Signed-off-by: Y Vo <yvo@apm.com>
Signed-off-by: Quan Nguyen <qnguyen@apm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-19 10:10:41 +01:00
Linus Walleij
521a2ad6f8 gpio: add userspace ABI for GPIO line information
This adds a GPIO line ABI for getting name, label and a few select
flags from the kernel.

This hides the kernel internals and only tells userspace what it
may need to know: the different in-kernel consumers are masked
behind the flag "kernel" and that is all userspace needs to know.

However electric characteristics like active low, open drain etc
are reflected to userspace, as this is important information.

We provide information on all lines on all chips, later on we will
likely add a flag for the chardev consumer so we can filter and
display only the lines userspace actually uses in e.g. lsgpio,
but then we first need an ABI for userspace to grab and use
(get/set/select direction) a GPIO line.

Sample output from "lsgpio" on ux500:

GPIO chip: gpiochip7, "8011e000.gpio", 32 GPIO lines
        line 0: unnamed unlabeled
        line 1: unnamed unlabeled
(...)
        line 25: unnamed "SFH7741 Proximity Sensor" [kernel output open-drain]
        line 26: unnamed unlabeled
(...)

Tested-by: Michael Welling <mwelling@ieee.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-19 09:48:46 +01:00
Linus Walleij
df4878e969 gpio: store reflect the label to userspace
The gpio_chip label is useful for userspace to understand what
kind of GPIO chip it is dealing with. Let's store a copy of this
label in the gpio_device, add it to the struct passed to userspace
for GPIO_GET_CHIPINFO_IOCTL and modify lsgpio to show it.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-19 09:48:41 +01:00
Linus Walleij
0a7439ef75 gpio: tps65218: remove unused #include
Just as it says: after adding the proper interfaces to gpiolib,
this is no longer needed.

Suggested-by: Nicolas Saenz Julienne <nicolassaenzj@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-19 09:22:41 +01:00
Arnd Bergmann
d7f7764e02 gpio: ks8695: remove irq_to_gpio function
The ks8695 gpio driver has its own copy of the irq_to_gpio()
function. This is completely unused in the mainline kernel
after we converted all remaining users several years ago,
so we can remove the definition as well.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-19 00:20:30 +01:00
Josh Cartwright
969f07b445 gpio: use kzalloc to allocate gpio_device
The use of kmalloc() to allocate the gpio_device leaves the contained struct
device object in an unknown state.  Calling dev_set_name() on a struct device
of unknown state can trigger the free() of an invalid pointer, as seen in the
following backtrace (collected by Tony Lindgren):

  kfree
  kobject_set_name_vargs
  dev_set_name
  gpiochip_add_data
  omap_gpio_probe
  platform_drv_probe
  ...

Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reported-by: Michael Welling <mwelling@ieee.org>
Reported-by: Tony Lindgren <tony@atomide.com>
Tested-by: Michael Welling <mwelling@ieee.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Josh Cartwright <joshc@ni.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-18 20:45:25 +01:00
Insu Yun
aaf2b3afb9 gpio-mcp23s08: correctly handling failed allocation
Since devm_kzalloc can be failed in memory pressure,
it needs to check and return -ENOMEM

Signed-off-by: Insu Yun <wuninsu@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16 16:36:22 +01:00
Axel Lin
818cc6a5f8 gpio: tps65218: Make tps65218_gpio_output set proper output level
The .direction_output callback should set proper output level.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16 15:58:32 +01:00
Axel Lin
ce02d18fc1 gpio: tpic2810: Make tpic2810_direction_output set proper output level
The .direction_output callback should set proper output level.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16 15:56:51 +01:00
Linus Walleij
143b65d677 gpio: create an API to detect open drain/source on lines
My left hand merges code to privatize the descriptor handling
while my right hand merges drivers that poke around and
disrespect with the same gpiolib internals.

So let's expose the proper APIs for drivers to ask the gpiolib
core if a line is marked as open drain or open source and
get some order around things so this driver compiles again.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Nicolas Saenz Julienne <nicolassaenzj@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16 15:41:42 +01:00
Nicholas Krause
d6f434e858 gpio: davinci: Fix possible NULL pointer deference
This fixes a possible NULL pointer deference in the function,
davinci_gpio_probe due to the function, gpio2regs being able
to return a NULL pointer if it rans to get the registers for
the gpio devices on a davinci board. Furthermore if this does
arise return -ENXIO to signal callers that this case has arisen
and avoiding setting the regs or other pointer values on the

Signed-off-by: Nicholas Krause <xerofoify@gmail.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16 00:20:04 +01:00
Bjorn Helgaas
288e6eaa06 gpio: Include linux/gpio.h instead of asm/gpio.h
Most arches have an asm/gpio.h that merely includes linux/gpio.h.  The
others select ARCH_HAVE_CUSTOM_GPIO_H, and when that's selected,
linux/gpio.h includes asm/gpio.h.

Therefore, code should include linux/gpio.h instead of including asm/gpio.h
directly.

Remove includes of asm/gpio.h, adding an include of linux/gpio.h when
necessary.

This is a follow-on to 7563bbf89d ("gpiolib/arches: Centralise
bolierplate asm/gpio.h").

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16 00:20:03 +01:00
Julien Grossholtz
047b2f62cd gpio: TS-4800: remove useless bgpio_init flags
No flags are required for bgpio_init in the TS-4800 gpio driver. This
patch set zero instead. The driver will have the same behaviour since
the & operator between the flags already resulted to zero.

Fixes: 5041e79144 ("gpio: add TS-4800 fpga GPIO support")
Signed-off-by: Julien Grossholtz <julien.grossholtz@savoirfairelinux.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16 00:20:03 +01:00
Linus Walleij
43c54ecade gpio: move the subdriver data pointer into gpio_device
We move to manage this pointer under gpiolib control rather than
leave it in the subdevice's gpio_chip. We can not NULL it after
gpiochip_remove so at to keep things tight.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16 00:20:02 +01:00
Linus Walleij
20ec3e39fc gpio: move the pin ranges into gpio_device
Instead of keeping this reference to the pin ranges in the
client driver-supplied gpio_chip, move it to the internal
gpio_device as the drivers have no need to inspect this.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16 00:20:02 +01:00
William Breathitt Gray
148ad68b3d gpio: ws16c48: Use devm_request_region
By the time request_region is called in the WinSystems WS16C48 GPIO
driver, a corresponding device structure has already been allocated. The
devm_request_region function should be used to help simplify the cleanup
code and reduce the possible points of failure.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16 00:19:54 +01:00
William Breathitt Gray
1344145785 gpio: sch311x: Use devm_request_region
By the time request_region is called in the SMSC SCH311x GPIO driver, a
corresponding device structure has already been allocated. The
devm_request_region function should be used to help simplify the cleanup
code and reduce the possible points of failure.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16 00:19:53 +01:00
William Breathitt Gray
8a06b08ec3 gpio: ich: Use devm_request_region
By the time request_region is called in the Intel ICH series GPIO
driver, a corresponding device structure has already been allocated. The
devm_request_region function should be used to help simplify the cleanup
code and reduce the possible points of failure.

Cc: Peter Tyser <ptyser@xes-inc.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16 00:19:53 +01:00
William Breathitt Gray
35568c40bd gpio: amd8111: Use devm_request_region
By the time request_region is called in the AMD 8111 GPIO driver, a
corresponding device structure has already been allocated. The
devm_request_region function should be used to help simplify the cleanup
code and reduce the possible points of failure.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16 00:19:52 +01:00
William Breathitt Gray
cb32389cb9 gpio: 104-idio-16: Use devm_request_region
By the time request_region is called in the ACCES 104-IDIO-16 GPIO
driver, a corresponding device structure has already been allocated. The
devm_request_region function should be used to help simplify the cleanup
code and reduce the possible points of failure.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16 00:19:52 +01:00
William Breathitt Gray
5cfc05761b gpio: 104-idi-48: Use devm_request_region
By the time request_region is called in the ACCES 104-IDI-48 GPIO
driver, a corresponding device structure has already been allocated. The
devm_request_region function should be used to help simplify the cleanup
code and reduce the possible points of failure.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16 00:19:51 +01:00
William Breathitt Gray
aa6c360226 gpio: 104-dio-48e: Use devm_request_region
By the time request_region is called in the ACCES 104-DIO-48E GPIO
driver, a corresponding device structure has already been allocated. The
devm_request_region function should be used to help simplify the cleanup
code and reduce the possible points of failure.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16 00:19:51 +01:00
William Breathitt Gray
22aeddb58d gpio: misc: Pass correct license string to MODULE_LICENSE
The GPIO driver copyright boilerplate lacks the "or
later" verbiage regarding GPL compliant distribution. The MODULE_LICENSE
string should reflect the actual copyright license terms used.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16 00:19:50 +01:00
Linus Walleij
33a68e86fd gpio: reference count the gpio device for each desc
Every time a descriptor is retrieved from the gpiolib, we issue
module_get() to reference count the module supplying the GPIOs.
We also need to call device_get() and device_put() as we also
reference the backing gpio_device when doing this.

Since the sysfs GPIO interface is using gpiod_get() this will
also reference count the sysfs requests until all GPIOs are
unexported.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-11 20:29:46 +01:00
Linus Walleij
fdeb8e1547 gpio: reflect base and ngpio into gpio_device
Some information about the GPIO chip need to stay around also
after the gpio_chip has been removed and only the gpio_device
persist. The base and ngpio are such things, for example we
don't want a new chip arriving to overlap the number space
of a dangling gpio_device, and the chardev may still query
the device for the number of lines etc.

Note that the code that assigns base and insert gpio_device
into the global list no longer check for a missing gpio_chip:
we respect the number space allocated by any other gpio_device.

As a consequence of the gdev being referenced directly from
the gpio_desc, we need to verify it differently from all
in-kernel API calls that fall through to direct queries to
the gpio_chip vtable: we first check that desc is !NULL, then
that desc->gdev is !NULL, then, if desc->gdev->chip is NULL,
we *BAIL OUT* without any error, so as to manage the case
where operations are requested on a device that is gone.

These checks were non-uniform and partly missing in the past:
so to simplify: create the macros VALIDATE_DESC() that will
return -EINVAL if the desc or desc->gdev is missing and just
0 if the chip is gone, and conversely VALIDATE_DESC_VOID()
for the case where the function does not return an error.
By using these macros, we get warning messages about missing
gdev with reference to the right function in the kernel log.

Despite the macro business this simplifies the code and make
it more readable than if we copy/paste the same descriptor
checking code into all code ABI call sites (IMHO).

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-11 20:29:46 +01:00
Linus Walleij
6cee3821e4 gpio/pinctrl: sunxi: stop poking around in private vars
This kind of hacks disturbs the refactoring of the gpiolib.

The descriptor table belongs to the gpiolib, if we want to know
something about something in it, use or define the proper accessor
functions. Let's add this gpiochip_lins_is_irq() to do what the
sunxi driver is trying at so we can privatize the descriptors
properly.

Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-11 20:29:45 +01:00
Linus Walleij
1c3cdb1861 gpio: move descriptors into gpio_device
We need gpio_device to hold the descriptors so that they can
be lifecycled with the struct gpio_device held from userspace.
Move the descriptor array into gpio_device. Also rename it from
"desc" (singularis) to "descs" (pluralis) to reflect the fact
that it is an array.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-11 20:29:45 +01:00
Linus Walleij
afbc4f312b gpio: move sysfs mock device to the gpio_device
Since gpio_device is the struct that survives if the backing
gpio_chip is removed, move the sysfs mock device to this state
container so it becomes part of the dangling state of the
GPIO device on removal.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-11 18:16:54 +01:00
Linus Walleij
9efd9e6956 gpio: remember to finally free gpio_device
When the device core reference count for the device goes to
0 and it calls .release() we free resources and so can also
finally free up the GPIO state container, struct gpio_device.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-11 18:16:53 +01:00
Nicolas Saenz Julienne
c366c76a2c gpio: add tps65218 gpio
Driver for the GPIO block found in ti's tps65218 pmics.

The device has two GPIOs and one GPO pin which can be configured as follows:
GPIO1:
	-general-purpose, open-drain output controlled by GPO1 user bit and/or
	 sequencer
	-DDR3 reset input signal from SOC. Signal is either latched or
	 passed-trough to GPO2 pin. See below for details.
GPO2:
	-general-purpose output controlled by GPO2 user bit
	-DDR3 reset output signal. Signal is controlled by GPIO1 and PGOOD.
	 See below for details.
	-Output buffer can be configured as open-drain or push-pull.
GPIO3:
	-general-purpose, open-drain output controlled by GPO3 user bit and/or
	 sequencer
	-reset input-signal for DCDC1 and DCDC2.

The input configurations are not meant to be used by the user so the driver
only offers GPOs.

v2: Added request routine that evaluates the fw config flags and removed module
    owner
v3: Added .direction_input() routine, and took care of all Linus Walleij
suggestions (clamp to bool, use proper include)

Signed-off-by: Nicolas Saenz Julienne <nicolassaenzj@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-11 12:25:16 +01:00
Andrew F. Davis
b866526d0c gpio: Add driver for TI TPIC2810
Add driver for TI TPIC2810 8-Bit LED Driver with I2C Interface.

The TPIC2810 has 8 open-drain outputs that can but used to drive
LEDs and other low-side switched resistive loads.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-10 15:22:06 +01:00
Andrew F. Davis
df6df93c8a gpio: Add driver for SPI serializers
Add generic parallel-in/serial-out shift register GPIO driver.

This includes SPI compatible devices like SN74165 serial-out shift
registers and the SN65HVS88x series of industrial serializers that can
be read over the SPI bus and used for GPI (General Purpose Input).

Signed-off-by: Andrew F. Davis <afd@ti.com>
Tested-by: Sean Nyekjaer <sean.nyekjaer@prevas.dk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-10 15:15:51 +01:00
Alban Bedel
28be55dfed gpio: ath79: Update the copyright notice
Add myself to the copyright list and remove the reference to Atheros'
BSP as nothing is left of this code.

Signed-off-by: Alban Bedel <albeu@free.fr>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-10 11:38:21 +01:00
Alban Bedel
2b8f89e19b gpio: ath79: Add support for the interrupt controller
Add support for the interrupt controller using GPIOLIB_IRQCHIP.
Both edges isn't supported by the chip and has to be emulated
by switching the polarity on each interrupt.

Signed-off-by: Alban Bedel <albeu@free.fr>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-10 11:15:24 +01:00
Alban Bedel
2f890cf0df gpio: ath79: Make the driver removable
As we now allow the driver to be built as a module it should be
removable.

Signed-off-by: Alban Bedel <albeu@free.fr>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-10 11:14:08 +01:00
Alban Bedel
409d87838d gpio: ath79: Allow building in compile tests
To allow building the driver in compile tests we must drop the
dependency on asm/mach-ath79/ar71xx_regs.h. For this we replace the
include with local definition of the registers needed for this driver.

Signed-off-by: Alban Bedel <albeu@free.fr>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-10 11:08:31 +01:00
Alban Bedel
ab32770ec8 gpio: ath79: Move to the generic GPIO driver
Drop most of the code in favor of the generic MMIO GPIO driver.
As the driver now depend on CONFIG_GPIO_GENERIC also add a Kconfig
entry to make the driver optional.

We leave the base pointer and lock in the data struct because they are
needed for the IRQ support.

Signed-off-by: Alban Bedel <albeu@free.fr>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-10 11:07:24 +01:00
Linus Walleij
60afe31d1f Merge branch 'chardev' into devel 2016-02-09 12:58:19 +01:00
Linus Walleij
3c702e9987 gpio: add a userspace chardev ABI for GPIOs
A new chardev that is to be used for userspace GPIO access is
added in this patch. It is intended to gradually replace the
horribly broken sysfs ABI.

Using a chardev has many upsides:

- All operations are per-gpiochip, which is the actual
  device underlying the GPIOs, making us tie in to the
  kernel device model properly.

- Hotpluggable GPIO controllers can come and go, as this
  kind of problem has been know to userspace for character
  devices since ages, and if a gpiochip handle is held in
  userspace we know we will break something, whereas the
  sysfs is stateless.

- The one-value-per-file rule of sysfs is really hard to
  maintain when you want to twist more than one knob at a time,
  for example have in-kernel APIs to switch several GPIO
  lines at the same time, and this will be possible to do
  with a single ioctl() from userspace, saving a lot of
  context switching.

We also need to add a new bus type for GPIO. This is
necessary for example for userspace coldplug, where sysfs is
traversed to find the boot-time device nodes and create the
character devices in /dev.

This new chardev ABI is *non* *optional* and can be counted
on to be present in the future, emphasizing the preference
of this ABI.

The ABI only implements one single ioctl() to get the name
and number of GPIO lines of a chip. Even this is debatable:
see it as a minimal example for review. This ABI shall be
ruthlessly reviewed and etched in stone.

The old /sys/class/gpio is still optional to compile in,
but will be deprecated.

Unique device IDs are created using IDR, which is overkill
and insanely scalable, but also well tested.

Cc: Johan Hovold <johan@kernel.org>
Cc: Michael Welling <mwelling@ieee.org>
Cc: Markus Pargmann <mpa@pengutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-09 11:09:35 +01:00
Linus Walleij
34ffd85d9c gpio: refer to gpio device in prints and debugfs
We use the new struct device inside gpio_chip to related debug
prints and warnings, and we also add it to the debugfs dump.

Cc: Johan Hovold <johan@kernel.org>
Cc: Michael Welling <mwelling@ieee.org>
Cc: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-09 11:09:30 +01:00
Linus Walleij
ff2b135922 gpio: make the gpiochip a real device
GPIO chips have been around for years, but were never real devices,
instead they were piggy-backing on a parent device (such as a
platform_device or amba_device) but this was always optional.
GPIO chips could also exist without any device at all, with its
struct device *parent (ex *dev) pointer being set to null.

When sysfs was in use, a mock device would be created, with the
optional parent assigned, or just floating orphaned with NULL
as parent.

If sysfs is active, it will use this device as parent.

We now create a gpio_device struct containing a real
struct device and move the subsystem over to using that. The
list of struct gpio_chip:s is augmented to hold struct
gpio_device:s and we find gpio_chips:s by first looking up
the struct gpio_device.

The struct gpio_device is designed to stay around even if the
gpio_chip is removed, so as to satisfy users in userspace
that need a backing data structure to hold the state of the
session initiated with e.g. a character device even if there is
no physical chip anymore.

From this point on, gpiochips are devices.

Cc: Johan Hovold <johan@kernel.org>
Cc: Michael Welling <mwelling@ieee.org>
Cc: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-09 11:03:53 +01:00
Liu Gang
42178e2a1e drivers/gpio: Switch gpio-mpc8xxx to use gpio-generic
The new Layerscape platforms has the same ip block/controller
as GPIO on PowerPC platforms(MPC8XXX), but the GPIO registers
may be big or little endian. So the code needs to get the
endian property from DTB, then make additional functions to
fit all the PowerPC/Layerscape GPIO register read/write
operations.

gpio-generic.c provides an universal infrastructure for both
big and little endian register operations. So switch the
gpio-mpc8xxx to use gpio-generic can simplify the driver and
reduce a lot of code.

The IRQ and some workaround parts in gpio-mpc8xxx.c will be
updated with the new API interfaces but following the
original functionalities.

Signed-off-by: Liu Gang <Gang.Liu@nxp.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-08 18:32:58 +01:00
Julien Grossholtz
5041e79144 gpio: add TS-4800 fpga GPIO support
The TS-4800 GPIO driver provide support for the GPIOs available
on the Technologic Sytems board FPGA. It allows to set
direction and read/write states.

It uses the generic gpio driver.

Signed-off-by: Julien Grossholtz <julien.grossholtz@savoirfairelinux.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-05 15:11:08 +01:00
Geliang Tang
ccdbddfeff gpio: davinci: use irq_data_get_chip_type
Use irq_data_get_chip_type() instead of container_of().

Signed-off-by: Geliang Tang <geliangtang@163.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-01-28 15:28:59 +01:00
Liu Gang
5df7fd46b7 gpio/qoriq: Add qoriq platforms support
The gpio-mpc8xxx.c should can support qoriq and
Layerscape platforms.

Signed-off-by: Liu Gang <Gang.Liu@nxp.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-01-28 10:56:47 +01:00
Peter Hung
1920906f59 gpio-f7188x: Add F81866 GPIO supports
Add F81866 GPIO supports

Fintek F81866 is a SuperIO. It contains HWMON/GPIO/Serial Ports.
and it has totally 72(9x8 sets) gpio pins.

Here is the PDF spec:
http://www.alldatasheet.com/datasheet-pdf/pdf/459085/FINTEK/F81866AD-I.html

The control method is the same with F7188x, but we should care the address
of GPIO8x.

GPIO address is below:
    GPIO0x based: 0xf0
    GPIO1x based: 0xe0
    GPIO2x based: 0xd0
    GPIO3x based: 0xc0
    GPIO4x based: 0xb0
    GPIO5x based: 0xa0
    GPIO6x based: 0x90
    GPIO7x based: 0x80
    GPIO8x based: 0x88 <-- not 0x70.

Signed-off-by: Peter Hung <hpeter+linux_kernel@gmail.com>
Acked-by: Simon Guinot <simon.guinot@sequanux.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-01-28 10:06:12 +01:00