The bgpio_get_set() call should return a value clamped to [0,1],
the current code will return a negative value if reading
bit 31, which turns the value negative as this is a signed value
and thus gets interpreted as an error by the gpiolib core.
Found on the gpio-mxc but applies to any MMIO driver.

Cc: stable@vger.kernel.org # 4.3+
Cc: kernel@pengutronix.de
Cc: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Fixes:  e20538b8 ("gpio: Propagate errors from chip->get()")
Reported-by: NClemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Returning an error instead of NULL in bgpio_map if
platform_get_resource_byname does not find a resource was introduced with
commit cf3f2a2c ("gpio: generic: improve error handling in bgpio_map").
This results in several qemu runtime failures with default and non-default
configurations, if attempts are made to boot from mmcblk0. Examples for
failures with multi_v7_defconfig are

Machine: vexpress-a9	dtb: vexpress-v2p-ca9
Machine: vexpress-a15	dtb: vexpress-v2p-ca15-tc1

Crash:

VFS: Cannot open root device "mmcblk0" or unknown-block(0,0): error -6
Please append a correct "root=" boot option; here are the available partitions:
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)

Looking into the code, always returning an error if bgpio_map fails
does not appear to make much sense, since the code in bgpio_setup_io
specifically supports some of the resources to be NULL.

Fixes: cf3f2a2c ("gpio: generic: improve error handling in bgpio_map")
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Use the ERRPTR standard way to return an error code in a pointer
thus simplifiying the code.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Replace devm_request_mem_region / devm_ioremap with devm_ioremap_resource.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

If bgpio_map returns NULL then err should always be set.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Allow chips to indicates that they are input-only and thus cannot set
the output value.  This will be used by the gpio-etraxfs driver.
Signed-off-by: NRabin Vincent <rabin@rab.in>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Allow to determine the current direction configuration by
reading back from the direction register.
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Acked-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The change introduces BGPIOF_READ_OUTPUT_REG_SET flag for gpio-generic
GPIO chip implementation, which allows to get correct configured value
from reg_set register, input value is still get from reg_dat.
Signed-off-by: NVladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add set_multiple functions to the generic driver for memory-mapped GPIO
controllers to improve performance when setting multiple outputs
simultaneously.
Signed-off-by: NRojhalat Ibrahim <imr@rtschenk.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Signed-off-by: Nabdoulaye berthe <berthe.ab@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

gpiolib will require all gpio drivers to expicitly set the request
function pointer in the future. To encourage gpio driver developers
to adhere to this standard gpio-generic.c now sets this function
pointer.
Signed-off-by: NAnthony Fee <anthony.fee@emutex.com>
Acked-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The generic GPIO would return 0 for low generic GPIO, and
something != 0 for high GPIO. Let's make this sane by clamping
the returned value to [0,1].
Reported-by: NEvgeny Boger <boger@contactless.ru>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

When registering more than one platform device, it is
useful to set the gpio chip label in the platform data.
Signed-off-by: NPawel Moll <pawel.moll@arm.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Memory for basic-mmio-gpio driver is allocated by the driver
using it, whether it's the generic GPIO driver itself or another
driver. In either case, the owner shall allocate and free the
struct bgpio_chip it is using, preferably using a managed
resource.
Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

There is no general support for 64-bit big endian accesses, so that is
left unsupported.
Signed-off-by: NAndreas Larsson <andreas@gaisler.com>
Acked-by: NAnton Vorontsov <anton@enomsg.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

CONFIG_HOTPLUG is going away as an option so __devexit is no
longer needed.
Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Cc: Grant Likely <grant.likely@secretlab.ca>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Cc: Peter Tyser <ptyser@xes-inc.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

CONFIG_HOTPLUG is going away as an option so __devinit is no longer
needed.
Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Peter Tyser <ptyser@xes-inc.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

CONFIG_HOTPLUG is going away as an option so __devexit_p is no longer
needed.
Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Peter Tyser <ptyser@xes-inc.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It fixes the issue in gpio-generic that commit fb149218 (gpio/mxc: add
missing initialization of basic_mmio_gpio shadow variables) manged to
fix in gpio-mxc driver, so that other platform specific drivers do not
suffer from the same problem over and over again.

Changes since v1:
* Turn the last parameter of bgpio_init() "bool big_endian" into
  "unsigned long flags" and give those really quirky hardwares a
  chance to tell that reg_set and reg_dir are unreadable.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
[grant.likely: Fix big-endian usage to explicitly set BBGPIOF_BIG_ENDIAN]
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Where appropriate factor out some boilerplate code for platform device
registration into module_platform_driver. Drivers that don't use the
standard module_init initcall haven't been converted.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Building a kernel with hotplug disabled results in a link failure:

  `bgpio_remove' referenced in section `___ksymtab_gpl+bgpio_remove' of drivers/built-in.o: defined in discarded section `.devexit.text' of drivers/built-in.o

This is because of bgpio_remove() is exported.  It is illegal to export
symbols which are discarded either at link time or as part of an
init/exit section.

Fix this by dropping the __devexit attributation from bgpio_remove().
Also drop the __devinit attributation from bgpio_init().
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Sort the gpio makefile and enforce the naming convention gpio-*.c for
gpio drivers.

v2: cleaned up filenames in Kconfig and comment blocks
v3: fixup use of BASIC_MMIO to GENERIC_GPIO for mxc
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Allow GPIO_BASIC_MMIO_CORE to be used to provide an accessor library
for implementing GPIO drivers whilst abstracting the register access
detail.  Based on a patch from Anton Vorontsov[1] and adapted to allow
bgpio_chip to be embedded in another structure.

Changes since v1:
	- Register the gpio_chip in the platform device probe

1. https://lkml.org/lkml/2011/4/19/401Signed-off-by: NAnton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: NJamie Iles <jamie@jamieiles.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

The __raw_* accessors don't include memory barriers and can cause
problems when writes get stuck in write buffers.
Suggested-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NAnton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: NJamie Iles <jamie@jamieiles.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Most controllers require the direction of a GPIO to be set by writing to
a direction register.  Add support for either an input direction
register or an output direction register.
Signed-off-by: NJamie Iles <jamie@jamieiles.com>
Acked-by: NAnton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Some controllers have separate input and output registers.  For these
controllers, use "set" for the output and "dat" for the input.

Changes since v2: reuse "set" for output and "dat" for input rather than
adding a new "in" register.
Signed-off-by: NJamie Iles <jamie@jamieiles.com>
Acked-by: NAnton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Rather than detecting the output method each time in the .set()
callback, do it at probe time and set the appropriate callback.

Changes since v2: moved the reg_dat initialization into
bgpio_setup_io().
Signed-off-by: NJamie Iles <jamie@jamieiles.com>
Acked-by: NAnton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Make sure that we get the register regions with request_mem_region()
before ioremap() to make sure we have exclusive access.
Signed-off-by: NJamie Iles <jamie@jamieiles.com>
Acked-by: NAnton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Some platforms may have a number of GPIO that is less than the register
width of the peripheral.
Signed-off-by: NJamie Iles <jamie@jamieiles.com>
Acked-by: NAnton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Use the platform drvdata helpers rather than working on the struct
device itself.
Signed-off-by: NJamie Iles <jamie@jamieiles.com>
Acked-by: NAnton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Remove endianness/width calculations at runtime by installing function
pointers for bit-to-mask conversion and register accessors.
Reported-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJamie Iles <jamie@jamieiles.com>
Acked-by: NAnton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

The basic GPIO controllers may be found in various on-board FPGA and ASIC
solutions that are used to control board's switches, LEDs, chip-selects,
Ethernet/USB PHY power, etc.

These controllers may not provide any means of pin setup
(in/out/open drain).

The driver supports:
- 8/16/32/64 bits registers;
- GPIO controllers with clear/set registers;
- GPIO controllers with a single "data" register;
- Big endian bits/GPIOs ordering (mostly used on PowerPC).
Signed-off-by: NAnton Vorontsov <cbouatmailru@gmail.com>
Reviewed-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Cc: David Brownell <david-b@pacbell.net>
Cc: Samuel Ortiz <sameo@linux.intel.com>,
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>