Revert "Input: psmouse - add delay when deactivating for SMBus mode"

This reverts commit 92e24e0e57f72e06c2df87116557331fd2d4dda2.

While the patch itself is correct, it uncovered an issue with fallback
to PS/2 mode, where we were leaving psmouse->fast_reconnect handler set
to psmouse_smbus_reconnect(), which caused crashes.

While discussing various approaches to fix the issue it was noted that
this patch ass undesired delay in the "fast" resume path of PS/2 device,
and it would be better to actually use "reset_delay" option defined in
struct rmi_device_platform_data and have RMI code handle it for SMBus
transport as well. So this patch is being reverted to deal with crashes
and a better solution will be merged shortly.

Reported-by: Thorsten Leemhuis <linux@leemhuis.info>
Closes: https://lore.kernel.org/all/ca0109fa-c64b-43c1-a651-75b294d750a1@leemhuis.info/
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: psmouse - add delay when deactivating for SMBus mode

There is a period of time between the psmouse deactivate and the
ability to communicate with the SMBus companion. Insert a
sleep after the deactivate to account for the delay and ensure
the SMBus companion is responsive.

Attempting to read from the SMBus companion too quickly was causing
the touchpad on machines with an i801_smbus companion to stop working
after a sleep/resume cycle.

On resume the rmi4_smbus would fail with errors reading the SMBus version
number:
```
[5454] i2c_i801:i801_check_post:414: i801_smbus 0000:00:1f.3: No response
smbus_result: i2c-0 a=02c f=0000 c=fd BYTE_DATA rd res=-6
rmi4_smbus 0-002c: failed to get SMBus version number!
...
rmi4_f01 rmi4-00.fn01: Failed to restore normal operation: -6.
rmi4_f01 rmi4-00.fn01: Resume failed with code -6.
rmi4_physical rmi4-00: Failed to suspend functions: -6
rmi4_smbus 0-002c: Failed to resume device: -6
```
In this case the rmi_smb_get_version fails with -ENXIO if it happens too
soon after the preceding serio_resume -> psmouse_deactivate call.

On boot this issue could cause the touchpad to stay in the limited PS/2
mode. This only reproduced in 1 in 10 boots on the Lenovo T440p.
Failures in the log on boot would show up as:
```
psmouse serio1: synaptics: Trying to set up SMBus access
[122] i2c_i801:i801_check_post:437: i801_smbus 0000:00:1f.3: No response
psmouse serio1: synaptics: SMbus companion is not ready yet
```

Experimentation on the Lenovo T440p showed that a delay of 7-12ms on
resume allowed the companion to respond.

The 30ms delay in this patch was chosen based on the linux-input message:
Link: https://lore.kernel.org/all/BYAPR03MB47572F2C65E52ED673238D41B2439@BYAPR03MB4757.namprd03.prod.outlook.com/

Signed-off-by: Jeffery Miller <jefferymiller@google.com>
Link: https://lore.kernel.org/r/20230726025256.81174-1-jefferymiller@google.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: psmouse-smbus - avoid flush_scheduled_work() usage

Flushing system-wide workqueues is dangerous and will be forbidden.
Replace system_wq with local psmouse_wq.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Link: https://lore.kernel.org/r/25e2b787-cb2c-fb0d-d62c-6577ad1cd9df@I-love.SAKURA.ne.jp
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: psmouse - set up dependency between PS/2 and SMBus companions

When we switch from emulated PS/2 to native (RMI4 or Elan) protocols, we
create SMBus companion devices that are attached to I2C/SMBus controllers.
However, when suspending and resuming, we also need to make sure that we
take into account the PS/2 device they are associated with, so that PS/2
device is suspended after the companion and resumed before it, otherwise
companions will not work properly. Before I2C devices were marked for
asynchronous suspend/resume, this ordering happened naturally, but now we
need to enforce it by establishing device links, with PS/2 devices being
suppliers and SMBus companions being consumers.

Fixes: 172d931910e1 ("i2c: enable async suspend/resume on i2c client devices")
Reported-and-tested-by: Hugh Dickins <hughd@google.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Link: https://lore.kernel.org/r/89456fcd-a113-4c82-4b10-a9bcaefac68f@google.com
Link: https://lore.kernel.org/r/YgwQN8ynO88CPMju@google.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: psmouse - switch to using i2c_new_scanned_device()

Move from the deprecated i2c_new_probed_device() to the new
i2c_new_scanned_device(). Make use of the new ERRPTR if suitable.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20200210165902.5250-1-wsa+renesas@sang-engineering.com
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: psmouse-smbus - allow to control psmouse_deactivate

This seems to be Synaptics specific, as some Elan touchpads are not
correctly switching to SMBus if we call deactivate before switching to
SMBus on cold boot and on resume.

Tested with the T480s

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: KT Liao <kt.liao@emc.com.tw>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: elantech - add support for SMBus devices

Many of the Elantech devices are connected through PS/2 and a different
bus (SMBus or plain I2C).

To not break any existing device, we only enable SMBus based
on a module parameter. If some laptops require the quirk to
be set, we will have to rely on a list of PNPIds or MDI matching
to individually expose those hardware over SMBus.
the parameter mentioned above is elantech_smbus from the psmouse
module.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: KT Liao <kt.liao@emc.com.tw>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: psmouse - use i2c_client_type to locate i2c clients

Now that i2c_client_type structure is exported, we can use it, instead
of i2c_adapter_type, when looking for devices that are i2c clients.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: psmouse - fix cleaning up SMBus companions

When trying to destroy platform data after destruction of SMbus companion,
we need to make sure that we are actually dealing with an SMB companion
device, and not some random I2C client device.

Fixes: 8eb92e5c9133 ("Input: psmouse - add support for SMBus companions")
Reported-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: psmouse - add support for SMBus companions

This provides glue between PS/2 devices that enumerate the RMI4 devices
and Elan touchpads to the RMI4 (or Elan) SMBus driver.

The SMBus devices keep their PS/2 connection alive. If the initialization
process goes too far (psmouse_activate called), the device disconnects
from the I2C bus and stays on the PS/2 bus, that is why we explicitly
disable PS/2 device reporting (by calling psmouse_deactivate) before
trying to register SMBus companion device.

The HID over I2C devices are enumerated through the ACPI DSDT, and
their PS/2 device also exports the InterTouch bit in the extended
capability 0x0C. However, the firmware keeps its I2C connection open
even after going further in the PS/2 initialization. We don't need
to take extra precautions with those device, especially because they
block their PS/2 communication when HID over I2C is used.

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