On Wed, Aug 18, 2010 at 05:38:38PM -0400, Neil Leeder wrote:

Hi Dmitry,

On 8/17/2010 2:05 PM, Dmitry Torokhov wrote:

quoted

That suggests that the device responds to at least basic PS/2 queries.

quoted

I can see data being passed through the serio driver but the logitech
driver can't process it.

What about loading psmouse module with proto=bare?

Could you also dump the data received from touchpad during probing?

It appears the controller does somewhat respond as a PS/2 device.
The first problem is it only responds to CMD_GETID correctly about
50% of the time. Sometimes it responds well with a 0x00, other times
with 0xfa, which causes psmouse_probe to not recognize it as a
pointing device.

[    1.037223] wpce775x_send len=1 data=f2
[    1.054412] wpce775x_recv ... data_in=fa fa 64 0 0 0 0 0 fa 0 0 0
0 0 0 0

It also doesn't respond well to CMD_GETINFO, which is why it gets
mis-detected as the wrong device type. As an aside, I'm not sure if
combining separate commands into one i2c packet is correct, but
separating them didn't seem to produce better results either.

[    1.723943] wpce775x_send len=3 data=e8 3 e6
[    1.735666] wpce775x_recv ... data_in=fa fa 64 0 0 0 0 0 fa 0 0 0
0 0 0 0
[    1.735892] wpce775x_send len=3 data=e6 e6 e9
[    1.748281] wpce775x_recv ... data_in=fe fa 64 0 0 0 0 0 fa 0 0 0
0 0 0 0
[    1.748500] wpce775x_send len=3 data=e8 0 e6
[    1.760233] wpce775x_recv ... data_in=fa fa 64 0 0 0 0 0 fa 0 0 0
0 0 0 0
[    1.760457] wpce775x_send len=3 data=e6 e6 e9
[    1.772876] wpce775x_recv ... data_in=fe fa 64 0 0 0 0 0 fa 0 0 0
0 0 0 0

Using proto=bare gets around the GETINFO failure, but doesn't help
with the more important GETID failure.

Does it help if you change write() to transmit (and read) 1 byte at a time?

The other issue is that when the serio driver requests up to 16
bytes over i2c, the controller responds with 16 bytes of data, which
appear to be the 3 flags/X/Y regs plus 13 bytes of irrelevant data.
This all gets passed to psmouse which interprets it 3 bytes at a
time as movement data. Not only does the extra data get interpreted
as movement info, but it causes subsequent real data to be
mis-aligned and wrongly interpreted.

[  115.915558] wpce775x_recv ... data_in=28 1 ff 0 0 0 0 0 9c 0 0 0 0 0 0 0
[  115.915649] psmouse_process_byte data=28 01 ff rel_x=1 rel_y=1
<--- OK
[  115.915688] psmouse_process_byte data=00 00 00 rel_x=0 rel_y=0
[  115.915714] psmouse_process_byte data=00 00 9c rel_x=0 rel_y=-156
<--- bad
[  115.915745] psmouse_process_byte data=00 00 00 rel_x=0 rel_y=0
[  115.915771] psmouse_process_byte data=00 00 00 rel_x=0 rel_y=0
[  115.928269] wpce775x_recv ... data_in=28 1 fe 0 0 0 0 0 9c 0 0 0 0 0 0 0
[  115.928357] psmouse_process_byte data=00 28 01 rel_x=40 rel_y=-1
<--- wrong
[  115.928396] psmouse_process_byte data=fe 00 00 rel_x=0 rel_y=0
<--- wrong
[  115.928426] psmouse_process_byte data=00 00 00 rel_x=0 rel_y=0
[  115.928457] psmouse_process_byte data=9c 00 00 rel_x=0 rel_y=0
[  115.928484] psmouse_process_byte data=00 00 00 rel_x=0 rel_y=0
[  115.939728] wpce775x_recv ... data_in=28 1 ff 0 0 0 0 0 9c 0 0 0 0 0 0 0
[  115.939818] psmouse_process_byte data=00 00 28 rel_x=0 rel_y=-40
<--- wrong
[  115.939857] psmouse_process_byte data=01 ff 00 rel_x=255 rel_y=0
<--- wrong
[  115.939889] psmouse_process_byte data=00 00 00 rel_x=0 rel_y=0
[  115.939916] psmouse_process_byte data=00 9c 00 rel_x=156 rel_y=0
<--- bad
[  115.939947] psmouse_process_byte data=00 00 00 rel_x=0 rel_y=0
[  115.939972] psmouse_process_byte data=00 00 00 rel_x=0 rel_y=0

Is there a way to get the serio driver to only read 3 bytes of data
per interrupt?

One way would be to look for PSMOUSE_CMD_ENABLE/PSMOUSE_CMD_DISABLE
(0xf4/0xf5) in ->write() method to switch between 1 and 3-byte transfers.

Thanks.

-- 
Dmitry