Instead of using the name directly from the I2C client
to name the gpio_chip, use dev_name() on the client->dev,
so we get the sometimes more unique device name, as I2C has
a mechanism for naming its devices explicitly in e.g.
board data.

This is a prerequisite for being able to reference
uniquely any I2C GPIO expander defined in a board file
when setting up GPIO descriptor tables.
Reviewed-by: NRobert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Don't warn about missing interrupts support when the parent interrupt is
not defined. Enabling interrupts support would not make it work anyway.
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This is a GPIO driver, include only <linux/gpio/driver.h>.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The register constants are so far defined in a way that they fit
for the pcal9555a when shifted by the number of banks, i.e. are
multiplied by 2 in the accessor function.

Now, the pcal6524 has 3 banks which means the relative offset
is multiplied by 4 for the standard registers.

Simply applying the bit shift to the extended registers gives
a wrong result, since the base offset is already included in
the offset.

Therefore, we have to add code to the 24 bit accessor functions
that adjusts the register number for these exended registers.

The formula finally used was developed and proposed by
Andy Shevchenko <andy.shevchenko@gmail.com>.
Suggested-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NH. Nikolaus Schaller <hns@goldelico.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

These mask bits are to be used to map the extended register
addresses (which are defined for an unsupported 8-bit pcal chip)
to 16 and 24 bit chips (pcal6524).
Signed-off-by: NH. Nikolaus Schaller <hns@goldelico.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The of_device_table is missing the PCA_PCAL flag so the
pcal6524 would be operated in tca6424 compatibility mode which
does not handle the new interrupt mask registers.
Suggested-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NH. Nikolaus Schaller <hns@goldelico.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The driver stores the result of irq_set_type() in the internal variables
irq_trig_raise and irq_trig_fall, which later are used to determine
the GPIOs that must be re-configured as input. These variables retain their
value between gpiolib's  export / unexport, resulting in an incorrect
state in some cases. The corresponding bits in the variables
irq_trig_raise and irq_trig_fall should be cleared in irq_shutdown().
Signed-off-by: NDenis Grigoryev <grigoryev@fastwel.ru>
Acked-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The pcal6524 has another set of registers to fine control
the interrupt handling.
Signed-off-by: NH. Nikolaus Schaller <hns@goldelico.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

PCAL chips ("L" seems to stand for "latched") have additional
registers starting at address 0x40 to control the latches,
interrupt mask, pull-up and pull down etc.
Signed-off-by: NH. Nikolaus Schaller <hns@goldelico.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

which makes it easier to match them with the data sheets.
Signed-off-by: NH. Nikolaus Schaller <hns@goldelico.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Use of_device_get_match_data() instead of open-coding it.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The Pyra-Handheld originally used the tca6424 but recently we have
replaced it by the pin and package compatible pcal6524. So let's
add this to the bindings and the driver.

And while we are at it, the pcal9555a does not have a compatible entry
either but is already supported by the device id table.
Signed-off-by: NH. Nikolaus Schaller <hns@goldelico.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Despite commit 55020c80 ("of: Add vendor prefix for ON Semiconductor
Corp.") was made long ago, the latter commit 9f49f6dd ("gpio: pca953x:
add onsemi,pca9654 id") made use of another, undocumented vendor prefix.
Since such prefix doesn't seem to be used in any device trees, I think we
can just fix the "compatible" string in the driver and the bindings and be
done with that...

Fixes: 9f49f6dd ("gpio: pca953x: add onsemi,pca9654 id")
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

In order to consolidate the multiple ways to associate an IRQ chip with
a GPIO chip, move more fields into the new struct gpio_irq_chip.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Acked-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

i2c_smbus commands handle the correct byte order for smbus transactions
internally. This will currently result in incorrect operation on big
endian systems.
Suggested-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The TCA9554 doesn't work with the pcf857x driver, trying to change the direction
gives a NAK bailout error.

TCA9554 is similar to the PCA9554, thus change the driver.
Signed-off-by: NAnders Darander <anders@chargestorm.se>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

GPIO ACPI library is going to be stricter about resources, thus, expand
comment regarding "reset" GPIO resource in this driver to clarify its
usage in ACPI case.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

For sake of better maintenance sort the headers by alphabetical order.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Introduce ->get_direction() callback for the driver.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
[Removed use of GPIOF_DIR* flags]
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add optional reset-gpios pin control. If present, de-assert the
specified reset gpio pin to bring the chip out of reset.

v2:
- Specify that reset signal to PCA953x chip is active low, in
  binding doc.
- reorder includes in gpio-pca953x.c.
- remove dev_err() on devm_gpiod_get_optional() error return.

Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: linux-gpio@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NSteve Longerbeam <steve_longerbeam@mentor.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: NVladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This tries to simplify the use of CONFIG_GPIOLIB_IRQCHIP when
using threaded interrupts: add a new call
gpiochip_irqchip_add_nested() to indicate that we're dealing
with a nested rather than a chained irqchip, then create a
separate gpiochip_set_nested_irqchip() to mirror
the gpiochip_set_chained_irqchip() call to connect the
parent and child interrupts.

In the nested case gpiochip_set_nested_irqchip() does nothing
more than call irq_set_parent() on each valid child interrupt,
which has little semantic effect in the kernel, but this is
probably still formally correct.

Update all drivers using nested interrupts to use
gpiochip_irqchip_add_nested() so we can now see clearly
which these users are.

The DLN2 driver can drop its specific hack with
.irq_not_threaded as we now recognize whether a chip is
threaded or not from its use of gpiochip_irqchip_add_nested()
signature rather than from inspecting .can_sleep.

We rename the .irq_parent to .irq_chained_parent since this
parent IRQ is only really kept around for the chained
interrupt handlers.

Cc: Lars Poeschel <poeschel@lemonage.de>
Cc: Octavian Purdila <octavian.purdila@intel.com>
Cc: Daniel Baluta <daniel.baluta@intel.com>
Cc: Bin Gao <bin.gao@linux.intel.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>
Cc: Semen Protsenko <semen.protsenko@globallogic.com>
Cc: Alexander Stein <alexander.stein@systec-electronic.com>
Cc: Phil Reid <preid@electromag.com.au>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Need to ensure that reg_output is not updated while setting multiple
bits. This makes the mutex locking behaviour for the set_multiple call
consistent with that of the set_value call.

Cc: stable@vger.kernel.org
Fixes: b4818afe ("gpio: pca953x: Add set_multiple to allow multiple")
Signed-off-by: NPhil Reid <preid@electromag.com.au>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

gpiod_set_array_value_complex does not clear the bits field.
Therefore when the drivers set_multiple funciton is called bits outside
the mask are undefined and can be either set or not. So bank_val needs
to be masked with bank_mask before or with the reg_val cache.

Cc: stable@vger.kernel.org
Fixes: b4818afe ("gpio: pca953x: Add set_multiple to allow multiple")
Signed-off-by: NPhil Reid <preid@electromag.com.au>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add compatible string for the MAX7318 part. This is a two bank,
16 lines, I2C GPIO expander with interrupt line.
Signed-off-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This is a follow-up to commit 559b4699 ("gpio: pca953x: fix an
incorrect lockdep warning"). The reason for calling
lockdep_set_subclass() in pca953x_probe() is not explained in
the code.

Add a comment describing the problem, partial solution and required
future extensions.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

sparse  rightfully said:

drivers/gpio/gpio-pca953x.c:771:45: warning: symbol 'id' shadows an earlier one
drivers/gpio/gpio-pca953x.c:742:36: originally declared here

So, name them explicitly 'i2c_id' and 'acpi_id' to avoid any confusion.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

If an I2C GPIO multiplexer is driven by a GPIO provided by an expander
when there's a second expander using the same device driver on one of
the I2C bus segments, lockdep prints a deadlock warning when trying to
set the direction or the value of the GPIOs provided by the second
expander.

The below diagram presents the setup:

                                               - - - - -
 -------             ---------  Bus segment 1 |         |
|       |           |         |---------------  Devices
|       | SCL/SDA   |         |               |         |
| Linux |-----------| I2C MUX |                - - - - -
|       |    |      |         | Bus segment 2
|       |    |      |         |-------------------
 -------     |       ---------                    |
             |           |                    - - - - -
        ------------     | MUX GPIO          |         |
       |            |    |                     Devices
       |    GPIO    |    |                   |         |
       | Expander 1 |----                     - - - - -
       |            |                             |
        ------------                              | SCL/SDA
                                                  |
                                             ------------
                                            |            |
                                            |    GPIO    |
                                            | Expander 2 |
                                            |            |
                                             ------------

The reason for lockdep warning is that we take the chip->i2c_lock in
pca953x_gpio_set_value() or pca953x_gpio_direction_output() and then
come right back to pca953x_gpio_set_value() when the GPIO mux kicks
in. The locks actually protect different expanders, but for lockdep
both are of the same class, so it says:

  Possible unsafe locking scenario:

        CPU0
        ----
   lock(&chip->i2c_lock);
   lock(&chip->i2c_lock);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

In order to get rid of the warning, retrieve the adapter nesting depth
and use it as lockdep subclass for chip->i2c_lock.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: NPeter Rosin <peda@axentia.se>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This reverts commit 313b9a99.

This was already fixed by
commit bf62efeb
"gpio: pca954x: fix undefined error code from remove"

The latter is a better fix since it makes it easier to detect
erronous code by not assigning a default error code.
Reported-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

ret is not initialized so it contains garbage.  Ensure garbage
is not returned in the case that pdata && pdata->teardown is false
by initializing ret to 0.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

pca953x_gpio_set_multiple() has some coding style issues that make it
harder to read. Tweak the code a bit.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The chip_type variable in struct pca953x_chip is no longer required.

Remove it.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Avoid the unnecessary if-else in pca953x_read_regs() by spltting the
routine into smaller, specialized functions and calling the right one
via a function pointer held in struct pca953x.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Avoid the unnecessary if-else in pca953x_write_regs() by splitting
the routine into smaller, specialized functions and calling the right
one via a function pointer held in struct pca953x_chip.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

There are multiple places in the driver code where a
switch (chip->chip_type) is used to determine the proper register
offset.

Unduplicate the code by adding a simple structure holding the possible
offsets that differ between the pca953x and pca957x chip families and
use it to avoid the checks.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The recent addition of the regulator support has led to the pca953x_remove
function returning uninitialized data when no platform data pointer is
provided, as gcc warns when using -Wmaybe-uninitialized:

drivers/gpio/gpio-pca953x.c: In function 'pca953x_remove':
drivers/gpio/gpio-pca953x.c:860:9: error: 'ret' may be used uninitialized in this function [-Werror=maybe-uninitialized]

This restores the previous behavior, returning 0 on success.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Fixes: e23efa31 ("gpio: pca954x: Add vcc regulator and enable it")
Acked-by: NPhil Reid <preid@electromag.com.au>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Some i2c gpio devices are connected to a switchable power supply
which needs to be enabled prior to probing the device. This patch
allows the drive to enable the devices vcc regulator prior to probing.
Signed-off-by: NPhil Reid <preid@electromag.com.au>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Intel Edison board has 4 GPIO expanders PCA9555a connected to I2C bus. Add an
ID to support them.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

NBANK() macro assumes that ngpios is a multiple of 8(BANK_SZ) and
hence results in 0 banks for PCA9536 which has just 4 gpios. This is
wrong as PCA9356 has 1 bank with 4 gpios. This results in uninitialized
PCA953X_INVERT register. Fix this by using DIV_ROUND_UP macro in
NBANK().

Cc: stable@vger.kernel.org
Signed-off-by: NVignesh R <vigneshr@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The commit 9b8e3ec3 ("gpio: pca953x: Use correct u16 value for register
word write") fixed regression in pca953x_write_regs(). At the same time the
solution introduced a sparse warning:

drivers/gpio/gpio-pca953x.c:168:39: warning: incorrect type in argument 3 (different base types)
drivers/gpio/gpio-pca953x.c:168:39:    expected unsigned short [unsigned] [usertype] value
drivers/gpio/gpio-pca953x.c:168:39:    got restricted __le16 [usertype] <noident>

Fix the code by enforcing the type of i2c_smbus_write_word_data() parameter.

Cc: Yong Li <sdliyong@gmail.com>
Cc: Phil Reid <preid@electromag.com.au>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

There are few redundant assignments of ret variable which is updated anyway.
Remove them for good.

While here, correct indentation of the constant definition and remove one empty
line.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>