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

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.

Cheers,
Benjamin

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

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2.9.3