Input: synaptics-rmi4 - make rmi_bus_type const

Now that the driver core can properly handle constant struct bus_type,
move the variable rmi_bus_type to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.

Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Link: https://lore.kernel.org/r/20240210-bus_cleanup-input2-v1-1-0daef7e034e0@marliere.net
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 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 version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Input: synaptics-rmi4 - convert irq distribution to irq_domain

Convert the RMI driver to use the standard mechanism for
distributing IRQs to the various functions.

Tested on:
* S7300 (F11, F34, F54)
* S7817 (F12, F34, F54)

Signed-off-by: Nick Dyer <nick@shmanahar.org>
Acked-by: Christopher Heiny <cheiny@synaptics.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: synaptics-rmi4 - add SMBus support

Code obtained from https://raw.githubusercontent.com/mightybigcar/synaptics-rmi4/jf/drivers/input/rmi4/rmi_smbus.c
and updated to match upstream. And fixed to make it work.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Andrew Duggan <aduggan@synaptics.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: synaptics-rmi4 - add device tree support for RMI4 I2C devices

Add devicetree binding for I2C devices and add bindings for optional
parameters in the function drivers. Parameters for function drivers are
defined in child nodes for each of the functions.

Signed-off-by: Andrew Duggan <aduggan@synaptics.com>
Acked-by: Rob Herring <robh@kernel.org>
Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: synaptics-rmi4 - add support for Synaptics RMI4 devices

Synaptics uses the Register Mapped Interface (RMI) protocol as a
communications interface for their devices. This driver adds the core
functionality needed to interface with RMI4 devices.

RMI devices can be connected to the host via several transport protocols
and can supports a wide variety of functionality defined by RMI functions.
Support for transport protocols and RMI functions are implemented in
individual drivers. The RMI4 core driver uses a bus architecture to
facilitate the various combinations of transport and function drivers
needed by a particular device.

Signed-off-by: Andrew Duggan <aduggan@synaptics.com>
Signed-off-by: Christopher Heiny <cheiny@synaptics.com>
Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>