Currently probing of the mcp23s08 results in an error message
"detected irqchip that is shared with multiple gpiochips:
please fix the driver"

This is due to the following:

Call to mcp23s08_irqchip_setup() with call hierarchy:
mcp23s08_irqchip_setup()
  gpiochip_irqchip_add_nested()
    gpiochip_irqchip_add_key()
      gpiochip_set_irq_hooks()

Call to devm_gpiochip_add_data() with call hierarchy:
devm_gpiochip_add_data()
  gpiochip_add_data_with_key()
    gpiochip_add_irqchip()
      gpiochip_set_irq_hooks()

The gpiochip_add_irqchip() returns immediately if there isn't a irqchip
but we added a irqchip due to the previous mcp23s08_irqchip_setup()
call. So it calls gpiochip_set_irq_hooks() a second time.

Fix this by moving the call to devm_gpiochip_add_data before
the call to mcp23s08_irqchip_setup

Fixes: 02e389e6 ("pinctrl: mcp23s08: fix irq setup order")
Suggested-by: NMarco Felsch <m.felsch@pengutronix.de>
Signed-off-by: NPhil Reid <preid@electromag.com.au>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add SPDX license identifiers to all files which:

 - Have no license information of any form

 - Have MODULE_LICENCE("GPL*") inside which was used in the initial
   scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It is expected that some of these operations won't work on each and
every HW. Previously, even a simple `cat
/sys/kernel/debug/pinctrl/spi1.1/pinconf-pins` caused excessive dmesg
output.
Signed-off-by: NJan Kundrát <jan.kundrat@cesnet.cz>
Cc: Phil Reid <preid@electromag.com.au>
Cc: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The comment for this dbg_show says that it is supposed to return more
than what the generic code is showing, including de-glitching. That's
wrong because:

- this chip does not support deglitching,
- the code does not print anything extra compared to the generic
handler,
- its behavior is different because it skips unrequested GPIOs; the
generic code prints their names if they're assigned

There is an important difference, though. Previously, dbg_show would
re-check some registers to see if they still match what the regmap
thinks should be in there. This was semi-useful when develpoing the HW
board because it immediately pointed to SPI wiring problem if a CS
connection was missing (0xffs are easy to see). However, I do not think
that this makes much sense -- and one could always do this in some other
way if needed.
Signed-off-by: NJan Kundrát <jan.kundrat@cesnet.cz>
Cc: Phil Reid <preid@electromag.com.au>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Keeping the irq_chip definition static shares it with multiple instances
of the mcp23s08 gpiochip in the system. This is bad and now we get this
warning from gpiolib core:

"detected irqchip that is shared with multiple gpiochips: please fix the
driver."

Hence, move the irq_chip definition from being driver static into the
struct mcp23s08. So a unique irq_chip is used for each gpiochip
instance.
Signed-off-by: NLars Poeschel <poeschel@lemonage.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Fixes issue created by 9b3e4207.

It wasn't possible for one_regmap_config to be non-NULL at the point
it was tested for mcp23s18 devices.

Applied the same pattern of allocating one_regmap_config using
devm_kmemdump() and then initializing the local regmap structure
from that.
Signed-off-by: NJason Kridner <jdk@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
    int stuff;
    void *entry[];
};

instance = devm_kzalloc(dev, sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = devm_kzalloc(dev, struct_size(instance, entry, count), GFP_KERNEL);

This code was detected with the help of Coccinelle.
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Since 'commit 02e389e6 ("pinctrl: mcp23s08: fix irq setup order")' the
irq request isn't the last devm_* allocation. Without a deeper look at
the irq and testing this isn't a good solution. Since this driver relies
on the devm mechanism, requesting a interrupt should be the last thing
to avoid memory corruptions during unbinding.

'Commit 02e389e6 ("pinctrl: mcp23s08: fix irq setup order")' fixed the
order for the interrupt-controller use case only. The
mcp23s08_irq_setup() must be split into two to fix it for the
interrupt-controller use case and to register the irq at last. So the
irq will be freed first during unbind.

Cc: stable@vger.kernel.org
Cc: Jan Kundrát <jan.kundrat@cesnet.cz>
Cc: Dmitry Mastykin <mastichi@gmail.com>
Cc: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Fixes: 82039d24 ("pinctrl: mcp23s08: add pinconf support")
Fixes: 02e389e6 ("pinctrl: mcp23s08: fix irq setup order")
Signed-off-by: NMarco Felsch <m.felsch@pengutronix.de>
Tested-by: NPhil Reid <preid@electromag.com.au>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

These drivers are GPIO drivers, and the do not need to use the
legacy header in <linux/gpio.h>, go directly for
<linux/gpio/driver.h> instead.

Replace any use of GPIOF_* with 0/1, these flags are for
consumers, not drivers.

Get rid of a few gpio_to_irq() users that was littering
around the place, use local callbacks or avoid using it at
all.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Apart from the usual stuff, the debugfs code is currently also used for
one non-obvious side effect. It attempts to check whether the chip's
registers are still set to an expected value, and if not, re-initializes
them. It seems that the driver has "always" done so.

The code, however, also checks the INTF register which normally
indicates which pins have caused the recent interrupt. That's a volatile
register, and the datasheet says that writes are ignored in there.

When I'm just cat-ing /sys/kernel/debug/gpio with no SPI traffic and no
nosie on the GPIO lines, I'm not getting any warnings. Once I actually
use these GPIOs and cat that file in parallel, I always seem to get a:

  mcp23s08 spi1.1: restoring reg 0x07 from 0x0000 to 0xffff (power-loss?)

This might be a sign that I should not leave my unused inputs floating,
but the code should not be checking a volatile register, anyway. Let's
simply skip this last item in the iteration. I was also considering
removing this enitre re-initialization because it's non-obvious, but the
code survived various refactorings already and has sign-offs by people
who know more than I do, so let's leave it as-is. For now :).
Signed-off-by: NJan Kundrát <jan.kundrat@cesnet.cz>
Reviewed-by: NPhil Reid <preid@electromag.com.au>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The mcp23s08 series device can be configured for wired and interrupts
using an external pull-up and open drain output via the IOCON_ODR bit.
And "drive-open-drain" property to enable this.
Reviewed-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: NPhil Reid <preid@electromag.com.au>
Reviewed-by: NJan Kundrát <jan.kundrat@cesnet.cz>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

one_regmap_config is always null if mcp type is MCP_TYPE_S18.
Remove the null check so that the mcp23s18 will probe.

Fixes: 1781af56 ("pinctrl: mcp23s08: spi: Fix duplicate pinctrl debugfs entries")
Signed-off-by: NPhil Reid <preid@electromag.com.au>
Reviewed-by: NJan Kundrát <jan.kundrat@cesnet.cz>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This is a bit more involved because the pinctrl core so far always
assumed that one device (with a unique dev_name) only contains a single
pinctrl thing. This is not true for the mcp23s08 driver for chips
connected over SPI. They have a "logical address" which means that
several chips can share one physical CS signal.

A downside of this patch are some possibly ugly names for the debugfs
entries, such as "spi1.1-mcp23xxx-pinctrl.2", etc.
Signed-off-by: NJan Kundrát <jan.kundrat@cesnet.cz>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

When several devices are sharing one hardware SPI CS, there is no visual
clue in `lsgpio` or in /sys/kernel/debug/gpio about which one is which
one. Stuff depends on the enumeration order, and therefore lower chip
addresses always go first, but that's just an implementation detail.
This change includes the device-specific address in the debug output:

  gpiochip4: GPIOs 464-479, parent: spi/spi1.1, mcp23s17.2, can sleep:
  gpiochip3: GPIOs 480-495, parent: spi/spi1.1, mcp23s17.1, can sleep:
Signed-off-by: NJan Kundrát <jan.kundrat@cesnet.cz>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The SPI version of this chip allows several devices to be present on the
same SPI bus via a local address. If this is in action and if the kernel
has debugfs, however, the code attempts to create duplicate entries for
the regmap's debugfs:

  mcp23s08 spi1.1: Failed to create debugfs directory

This patch simply assigns a local name matching the device logical
address to the `struct regmap_config`.

No changes are needed for MCP23S18 because that device does not support
any logical addressing. Similarly, I2C devices do not need any action,
either, because they are already different in their I2C address.

A similar problem is present for the pinctrl debugfs instance, but that
one is not addressed by this patch.
Signed-off-by: NJan Kundrát <jan.kundrat@cesnet.cz>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

When using mcp23s08 module with gpio-keys, often (50% of boots)
it fails to get irq numbers with message:
"gpio-keys keys: Unable to get irq number for GPIO 0, error -6".
Seems that irqs must be setup before devm_gpiochip_add_data().

Cc: stable@vger.kernel.org
Signed-off-by: NDmitry Mastykin <mastichi@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

* Print a line break together with other data in a single function call.

* Adjust indentation.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

* Add a jump target so that a call of the function "mutex_unlock" is stored
  only twice in this function implementation.

* Replace five calls by goto statements.

* Adjust five condition checks.

This issue was detected by using the Coccinelle software.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
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>

This adds the required definitions for the mcp23018 which is the i2c
variant of the mcp23s18.
Signed-off-by: NPhil Reid <preid@electromag.com.au>
Reviewed-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

interrupt handling was broken with conversion to using regmap caching.
cached_gpio value was updated by boolean status instead of gpio reading.

Fixes: 8f38910b ("pinctrl: mcp23s08: switch to regmap caching")
Tested-by: NPhil Reid <preid@electromag.com.au>
Signed-off-by: NDmitry Mastykin <mastichi@gmail.com>
Reviewed-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Variable mask and val are not used in the mcp_pinconf_set().
Signed-off-by: NPhil Reid <preid@electromag.com.au>
Reviewed-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The driver supports using mcp23xxx as interrupt controller, so
let's drop all comments stating otherwise.
Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This moves irq property handling from spi/i2c specific code into
the generic mcp23s08_probe_one. This is possible because the
device properties are named equally.

As a side-effect this drops support for setting the properties via
pdata, which has no mainline users. If boardcode wants to enable
the chip as interrupt controller it can attach the device properties
instead.
Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Simplify spi pdata handling, so that it uses pdata when available
and falls back to reading device properties otherwise.
Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Simplify i2c pdata handling, so that it uses pdata when available
and falls back to reading device properties otherwise.
Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Switching to devm_gpiochip_add_data simplifies the driver's
cleanup routine and safes a few loc.
Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Let's remove a few lines of code by using managed memory for mcp
variable.
Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

i2c-core and spi-core already assign the irq, so we
can drop the additional call from the mcp driver.
Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Instead of using custom caching, this switches to regmap based
caching. Before the conversion the debugfs file used uncached
values, so that it was easily possible to see power-loss related
problems. The new code will check and recover at this place.

The patch will also ensure, that irqs are not cleared by checking
register status in debugfs.
Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

mcp23s08 support configuration of the pullups using the
pinconf framework. This removes the custom pullup configuration
from platform data, which has no upstream users.
Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

mcp23xxx device have configurable 100k pullup resistors. This adds
support for enabling them using pinctrl's pinconf interface.
Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>
Tested-by: NEnric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This moves the mcp23s08 driver from gpio to pinctrl. Actual
pinctrl support for configuration of the pull-up resistors
follows in its own patch.
Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>
Acked-by: NSylvain Lemieux <slemieux.tyco@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

When an interrupt occurs on an MCP23S08 chip, the INTF register will only
contain one bit as causing the interrupt.  If more than two pins change at
the same time on the chip, this causes one of the pins to not be reported.
This patch fixes the logic for checking if a pin has changed, so that
multiple pins will always cause more than one change.

Cc: stable@vger.kernel.org
Signed-off-by: NRobert Middleton <robert.middleton@rm5248.com>
Tested-by: NPhil Reid <preid@electromag.com.au>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Use regmap API to save some lines of codes and have
debugfs support for all of the MCP's registers.
Signed-off-by: NSebastian Reichel <sre@kernel.org>
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>

The MCP23S08 driver certainly accesses fields inside the
struct gpio_chip that are only available under CONFIG_OF_GPIO
not just CONFIG_OF, so update the Kconfig and driver to reflect
this.

Cc: Alexander Stein <alexander.stein@systec-electronic.com>
Cc: Phil Reid <preid@electromag.com.au>
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The interrupt for the corresponding pin is configured to trigger when the
pin state changes compared to a preconfigured state (Bit set in INTCON).
This state is set by setting/clearing the bit in DEFVAL.
In the interrupt handler we need also to check if the bit in INTCON is set
for level triggered interrupts.
Signed-off-by: NAlexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

When using the GPIOLIB_IRQCHIP the gpiolib provides a
straight-forward implementation of request/release resources,
rely on that instead.

Cc: Phil Reid <preid@electromag.com.au>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>