HID: i2c-hid: add more DRM dependencies

When a symbol is selected that has extra dependencies,
anything that selects it must have the same dependencies.
With the added CONFIG_DRM reference from I2C_HID_CORE,
this broke a couple of drivers that now also depend
on DRM:

WARNING: unmet direct dependencies detected for I2C_HID_CORE
Depends on [m]: HID_SUPPORT [=y] && I2C_HID [=y] && (DRM [=m] || !DRM [=m])
Selected by [y]:
- I2C_HID_OF [=y] && HID_SUPPORT [=y] && I2C_HID [=y]
- I2C_HID_ACPI [=y] && HID_SUPPORT [=y] && I2C_HID [=y] && ACPI [=y]
- I2C_HID_OF_GOODIX [=y] && HID_SUPPORT [=y] && I2C_HID [=y] && OF [=y]
x86_64-linux-ld: vmlinux.o: in function `i2c_hid_core_remove':
(.text+0xfc8826): undefined reference to `drm_panel_remove_follower'
x86_64-linux-ld: vmlinux.o: in function `i2c_hid_core_probe':
(.text+0xfc8da0): undefined reference to `drm_is_panel_follower'

Add the corresponding DRM||!DRM dependencies on each one that
is affected.

Fixes: 96a37bfd232ae ("HID: i2c-hid: Support being a panel follower")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230802124947.1355415-1-arnd@kernel.org

HID: i2c-hid: Support being a panel follower

As talked about in the patch ("drm/panel: Add a way for other devices
to follow panel state"), we really want to keep the power states of a
touchscreen and the panel it's attached to in sync with each other. In
that spirit, add support to i2c-hid to be a panel follower. This will
let the i2c-hid driver get informed when the panel is powered on and
off. From there we can match the i2c-hid device's power state to that
of the panel.

NOTE: this patch specifically _doesn't_ use pm_runtime to keep track
of / manage the power state of the i2c-hid device, even though my
first instinct said that would be the way to go. Specific problems
with using pm_runtime():
* The initial power up couldn't happen in a runtime resume function
since it create sub-devices and, apparently, that's not good to do
in your resume function.
* Managing our power state with pm_runtime meant fighting to make the
right thing happen at system suspend to prevent the system from
trying to resume us only to suspend us again. While this might be
able to be solved, it added complexity.
Overall the code without pm_runtime() ended up being smaller and
easier to understand.

Reviewed-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Benjamin Tissoires <bentiss@kernel.org>
Acked-by: Benjamin Tissoires <bentiss@kernel.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230727101636.v4.9.Ib1a98309c455cd7e26b931c69993d4fba33bbe15@changeid

HID: i2c-hid-of: Allow using i2c-hid-of on non OF platforms

There are some x86 tablets / 2-in-1s which ship with Android as their
factory OS image. These have pretty broken ACPI tables, relying on
everything being hardcoded in the factory kernel image.

platform/x86/x86-android-tablets.c manually instantiates i2c-clients for
i2c devices on these tablets to make them work with the mainline kernel.

The Lenovo Yoga Book 1 (yb1-x90f/l) is such a 2-in-1. It has 2 I2C-HID
devices its main touchscreen and a Wacom digitizer. Its main touchscreen
can alternatively also be used in HiDeep's native protocol mode but
for the Wacom digitizer we really need I2C-HID.

This patch allows using i2c-hid-of on non OF platforms so that it can
bind to a non ACPI instantiated i2c_client on x86 for the Wacom digitizer.
Note the driver already has an "i2c-over-hid" i2c_device_id (rather then
an of_device_id).

Besides enabling building on non-OF platforms this also replaces
the only of_property_read_u32() call with device_property_read_u32() note
that other properties where already read using device_property_read_...().

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20230413093625.71146-3-hdegoede@redhat.com
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

HID: stop drivers from selecting CONFIG_HID

There is a mix of drivers using either 'depends on HID' or 'select HID',
which causes both circular dependencies and missed dependencies for
a 'select':

WARNING: unment direct dependencies for HID
Depends on [m]: HID_SUPPORT [=y] && INPUT [=m]
Selected by [y]:
- AMD_SFH_HID [=y] && HID_SUPPORT [=y] && (X86_64 || COMPILE_TEST [=y]) && PCI [=y]
Selected by [m]:
- I2C_HID_CORE [=m] && HID_SUPPORT [=y]

WARNING: unmet direct dependencies detected for INPUT_FF_MEMLESS
Depends on [m]: INPUT [=m]
Selected by [y]:
- DRAGONRISE_FF [=y] && HID_SUPPORT [=y] && HID [=y] && HID_DRAGONRISE [=y]
- HID_MICROSOFT [=y] && HID_SUPPORT [=y] && HID [=y]
- GREENASIA_FF [=y] && HID_SUPPORT [=y] && HID [=y] && HID_GREENASIA [=y]
Selected by [m]:
- INPUT_ARIZONA_HAPTICS [=m] && INPUT [=m] && INPUT_MISC [=y] && MFD_ARIZONA [=y] && SND_SOC [=m]
- INPUT_PM8XXX_VIBRATOR [=m] && INPUT [=m] && INPUT_MISC [=y] && (MFD_PM8XXX [=m] || MFD_SPMI_PMIC [=n])
- INPUT_MAX8997_HAPTIC [=m] && INPUT [=m] && INPUT_MISC [=y] && PWM [=y] && MFD_MAX8997 [=y]
- INPUT_GPIO_VIBRA [=m] && INPUT [=m] && INPUT_MISC [=y] && (GPIOLIB [=y] || COMPILE_TEST [=y])
- INPUT_REGULATOR_HAPTIC [=m] && INPUT [=m] && INPUT_MISC [=y] && REGULATOR [=y]
- INPUT_TWL6040_VIBRA [=m] && INPUT [=m] && INPUT_MISC [=y] && TWL6040_CORE [=y]
- INPUT_PWM_VIBRA [=m] && INPUT [=m] && INPUT_MISC [=y] && PWM [=y]
- INPUT_DRV260X_HAPTICS [=m] && INPUT_MISC [=y] && INPUT [=m] && I2C [=y] && (GPIOLIB [=y] || COMPILE_TEST [=y])
- INPUT_DRV2665_HAPTICS [=m] && INPUT_MISC [=y] && INPUT [=m] && I2C [=y]
- INPUT_DRV2667_HAPTICS [=m] && INPUT_MISC [=y] && INPUT [=m] && I2C [=y]
- INPUT_SC27XX_VIBRA [=m] && INPUT [=m] && INPUT_MISC [=y] && (MFD_SC27XX_PMIC [=y] || COMPILE_TEST [=y])
- HID_MAYFLASH [=m] && HID_SUPPORT [=y] && HID [=y]

Avoid this by changing all HID client drivers to use 'depends on HID'.
For I2C_HID, this requires a larger rework of the Kconfig description,
but it hopefully becomes easier to understand without the complex
I2C_HID_CORE definition.

Fixes: 25621bcc8976 ("HID: Kconfig: split HID support and hid-core compilation")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

HID: fix I2C_HID not selected when I2C_HID_OF_ELAN is

When I2C_HID_OF_ELAN is set, we need to turn on I2C_HID_CORE to
ensure we get all the HID requirements.

Fixes: bd3cba00dcc6 ("HID: i2c-hid: elan: Add support for Elan eKTH6915 i2c-hid touchscreens")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

HID: i2c-hid: elan: Add support for Elan eKTH6915 i2c-hid touchscreens

Like many i2c-hid touchscreen controllers, the Elan eKTH6915 has a
reset GPIO hooked up to it. According to the datasheet, the way we're
supposed to turn the touchscreen on is:

1. Turn on the 3.3V supply.
2. Turn on the IO supply. It's OK if this is hardwired to the 3.3V
supply, but if it's not then it must be turned on _after_ the 3.3V
supply.
3. Wait >= 1 ms.
4. Deassert the reset GPIO (reset GPIO is active low, so there would
be a leakage path if this was deasserted _before_ the IO supply).
5. Wait 300 ms.

Much of the above can be handled by the generic i2c-hid-of driver, but
the "reset" GPIO is not supported by that driver. Thus we'll do the
same as we did for Goodix and add a new tiny driver that uses the
i2c-hid core.

NOTE: support for this new touchscreen could theorically fit into the
Goodix driver. I've made it a separate driver because the Elan driver
supports _two_ regulators and it's unclear exactly how that would fit
in with commit 18eeef46d359 ("HID: i2c-hid: goodix: Tie the reset line
to true state of the regulator").

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

HID: i2c-hid: Introduce goodix-i2c-hid using i2c-hid core

Goodix i2c-hid touchscreens are mostly i2c-hid compliant but have some
special power sequencing requirements, including the need to drive a
reset line during the sequencing.

Let's use the new rejiggering of i2c-hid to support this with a thin
wrapper driver to support the first Goodix i2c-hid touchscreen:
GT7375P

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

HID: i2c-hid: Reorganize so ACPI and OF are separate modules

This patch rejiggers the i2c-hid code so that the OF (Open Firmware
aka Device Tree) and ACPI support is separated out a bit. The OF and
ACPI drivers are now separate modules that wrap the core module.

Essentially, what we're doing here:
* Make "power up" and "power down" a function that can be (optionally)
implemented by a given user of the i2c-hid core.
* The OF and ACPI modules are drivers on their own, so they implement
probe / remove / suspend / resume / shutdown. The core code
provides implementations that OF and ACPI can call into.

We'll organize this so that we now have 3 modules: the old i2c-hid
module becomes the "core" module and two new modules will depend on
it, handling probing the specific device.

As part of this work, we'll remove the i2c-hid "platform data"
concept since it's not needed.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

treewide: replace '---help---' in Kconfig files with 'help'

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

a) 4 spaces + '---help---'
b) 7 spaces + '---help---'
c) 8 spaces + '---help---'
d) 1 space + 1 tab + '---help---'
e) 1 tab + '---help---' (correct indentation)
f) 1 tab + 1 space + '---help---'
g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

$ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

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

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

HID: i2c-hid: enhance Kconfig

The "comment" part can never be displayed, so we can remove it.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

HID: i2c-hid: introduce HID over i2c specification implementation

Microsoft published the protocol specification of HID over i2c:
http://msdn.microsoft.com/en-us/library/windows/hardware/hh852380.aspx

This patch introduces an implementation of this protocol.

This implementation does not includes the ACPI part of the specification.
This will come when ACPI 5.0 devices enumeration will be available.

Once the ACPI part is done, OEM will not have to declare HID over I2C
devices in their platform specific driver.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>