watchdog: wm831x_wdt: Remove GPIO handling

An attempt to convert the driver to using GPIO descriptors
(see Link tag) was discouraged in favor of deleting the
handling of the update GPIO altogehter since there are
no in-tree users.

This patch deletes the GPIO handling instead.

Cc: Richard Fitzgerald <rf@opensource.cirrus.com>
Cc: Charles Keepax <ckeepax@opensource.cirrus.com>
Cc: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/linux-watchdog/20200210102209.289379-1-linus.walleij@linaro.org/
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20200229115046.57781-1-linus.walleij@linaro.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

regulator: wm831x: Convert to use GPIO descriptors

This converts the Wolfson Micro WM831x DCDC converter to use
a GPIO descriptor for the GPIO driving the DVS pin.

There is just one (non-DT) machine in the kernel using this, and
that is the Wolfson Micro (now Cirrus) Cragganmore 6410 so we
patch this board to pass a descriptor table and fix up the driver
accordingly.

Cc: Charles Keepax <ckeepax@opensource.cirrus.com>
Cc: Richard Fitzgerald <rf@opensource.cirrus.com>
Cc: patches@opensource.cirrus.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix typo milivolt => millivolt

Signed-off-by: Thomas Weber <thomas@tweber.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

mfd: Support software initiated shutdown of WM831x PMICs

In systems where there is no hardware signal from the processor to the
PMIC to initiate the final power off sequence we must initiate the
shutdown with a register write to the PMIC. Support such systems in the
driver. Since this may prevent a full shutdown of the system platform
data is used to enable the feature.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

mfd: Support software initiated shutdown of WM831x PMICs

In systems where there is no hardware signal from the processor to the
PMIC to initiate the final power off sequence we must initiate the
shutdown with a register write to the PMIC. Support such systems in the
driver. Since this may prevent a full shutdown of the system platform
data is used to enable the feature.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

mfd: Allow touchscreen to be disabled on wm831x devices

Allow platform data to flag the touchscreen as disabled so that if the
touch driver is built in we don't end up causing lots of work by spuriously
detecting touchscreen activity on systems where it isn't in use.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

mfd: Provide platform data for WM831x GPIO configuration

Allow the GPIO mode of WM831x devices to be configured using platform data.
Users may provide a table of GPIO register values in gpio_defaults[]. In
order to allow 0 to be set explicitly out of range values are accepted and
masked off, with a WM831X_GPIO_CONFIGURE define provided to set an out of
range value.

This can be used to configure higher numbered GPIOs or override values set
in OTP for GPIOs configured using OTP.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Input: wm831x-ts - allow IRQ flags to be specified

This allows maximum flexibility for configuring the direct GPIO based
interrupts.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

mfd: Add platform data to support multiple WM831x devices per board

If a system contains multiple WM831x devices we need to pass a device
number through to the MFD so that we use unique device IDs when we
instantiate child devices. In order to get support for this into 2.6.39
add some platform data to support the configuration, but no implementation
as yet.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

mfd: Support configuration of WM831x /IRQ output in CMOS mode

Provide platform data allowing the system to set the /IRQ pin into
CMOS mode rather than the default open drain. The default value of
this platform data reflects the default hardware configuration so
there should be no change to existing users.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Input: wm831x - add driver for Wolfson WM831x PMIC touchscreen controllers

Some of the WM831x series of PMICs from Wolfson Microelectronics include
a resistive touchscreen controller. Implement support for these controllers
within the input API.

Platform data is supported to allow configuration of system parameters such
as selection between four and five wire touchscreens and for specification
of optional direct to CPU IRQs for sample availability and for pen down.
Use of this feature for at least the data IRQ is strongly recommended.

Thanks to Julien Boibessot for extensive testing and detailed feedback.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Tested-by: Julien Boibessot <julien.boibessot@armadeus.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

regulator: Implement WM831x BuckWise DC-DC convertor DVS support

The BuckWise DC-DC convertors in WM831x devices support switching to
a second output voltage using the logic level on one of the device
pins. This is intended to allow rapid voltage switching for uses like
cpufreq, replacing the I2C or SPI write used to configure the voltage
of the regulator with a much faster GPIO status change.

This is implemented by keeping the DVS voltage configured as the
maximum voltage permitted for the regulator. If a request is made
for the maximum voltage then the GPIO is used to switch to the DVS
voltage, otherwise the normal ON voltage is updated and used. This
follows the idiom used by most cpufreq drivers, which drop the
minimum voltage as the core frequency is dropped but use a constant
maximum - raising the voltage should normally be fast, but lowering
it may be slower.

Configuration of the DVS MFP on the device should be done externally,
for example via OTP.

Support is present in the hardware for monitoring the status of the
transition using a second GPIO. This is not currently implemented
but platform data is provided for it - the driver currently assumes
that the device will be configured to transition immediately - but
platform data is provided to reduce merge issues once it is.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

mfd: Move WM831x to generic IRQ

Replace the wm831x-local IRQ infrastructure with genirq, allowing access
to the diagnostic infrastructure of genirq and allowing us to implement
interrupt support for the GPIOs. The switchover is done within the
wm831x specific IRQ API, further patches will convert the individual
drivers to use genirq directly.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

mfd: Conditionally add WM831x backlight subdevice

The WM831x backlight driver requires at least the specification of the
current sink to use and a maximum current to allow them to function and
will actively interfere with other users of the regulators it uses if
misconfigured so only register the subdevice for it if this platform
data has been supplied.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

mfd: Initial core support for WM831x series devices

The WM831x series of devices are register compatible processor power
management subsystems, providing regulator and power path management
facilities along with other services like watchdog, RTC and touch
panel controllers.

This patch adds very basic support, providing basic single register
I2C access, handling of the security key and registration of the
devices.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>