[PATCH v2 0/3] Bind RMI4 over SMBus from PS/2

From: Benjamin Tissoires
Date: Thu Feb 16 2017 - 12:51:15 EST

Hi Dmitry,

quoting your last email about this topic:

> I think that by trying to "unwind" unsuccessful SMbus initialization you
> make the code much more complicated and fragile. I think we should
> select a path (PS/2 or SMbus) and commit to it. If we commit to SMBus
> then we need to communicate that fact to psmouse core so that it does
> not create input devices or psmouse attributes, and "short-circuit" the
> reconnect() routines to simply ignore requests and always report
> success.

I have tried in the past to unwind the psmouse input devices, and it was a pain.
So I thought of using a dummy serio driver that basically just calls
PSMOUSE_CMD_DISABLE at connect and returns 0 everywhere else.

I tried this in the past without much luck but I think I found a reliable
way today.

The good thing is that it seems that in that case, the rmi4_smbus driver
doesn't need any changes now that most serio states are ignored.

The new ps2smbus driver gets a little bit more complex, especially because
of kseriod. We need to wait for the .connect() of the serio driver to end
and have a stable PS/2 connection before starting the smbus work.

>From the tests I made today, it seems reliable: cold boot & suspend/resume
works, various "rescan" with drvctl with different synaptics_intertouch
parameter state work too.

I hope you'll find this solution acceptable.


Benjamin Tissoires (3):
input: serio - allow others to specify a driver for a serio device
Input: synaptics - allocate a Synaptics Intertouch device
Input: add a PS/2 to SMBus platform module

drivers/input/misc/Kconfig | 11 ++
drivers/input/misc/Makefile | 1 +
drivers/input/misc/ps2_smbus.c | 382 ++++++++++++++++++++++++++++++++++++++++
drivers/input/mouse/synaptics.c | 106 +++++++++++
drivers/input/mouse/synaptics.h | 1 +
drivers/input/rmi4/Kconfig | 1 +
drivers/input/serio/serio.c | 20 +++
include/linux/serio.h | 5 +
8 files changed, 527 insertions(+)
create mode 100644 drivers/input/misc/ps2_smbus.c