Re: [PATCH 01/14] Input: atmel_mxt_ts - do not pass suspend mode in platform data
From: Dmitry Torokhov
Date: Thu Mar 15 2018 - 19:56:32 EST
On Wed, Mar 14, 2018 at 08:51:24PM +0000, Nick Dyer wrote:
> Hi Dmitry-
>
> Thanks for sending these patches!
>
> On Mon, Mar 12, 2018 at 12:08:54PM -0700, Dmitry Torokhov wrote:
> > The way we are supposed to put controller to sleep and wake it up does not
> > depend on the platform, but rather on controller itself. Controllers using
> > T9 require manipulating T9 control register, while others, using newer
> > T100, should be put to sleep by adjusting T7 power config.
>
> I'm afraid this is actually a misconception. If you look at object table
> for the older T9 device, you'll find it has the T7 object and it in fact
> works exactly the same way as the T100-based device.
>
> The MXT_SUSPEND_T9_CTRL is in there because on your older Pixel devices
> the config saved into NVRAM on the touch controller has a zero byte in
> the T9 CTRL setting, meaning the touch controller will never wake up
> unless the driver knows to write 0x83 into it.
Ah, OK, I see. I would really like to drop this pdata->suspend_mode
stuff and I do not want to create "pixel-screwed-up" property either...
I guess for the time being I'll put a DMI quirk for Link to restore T9
control method, and then look into cleaning it all up. We have quite a
bit different code in chromeos kernel trees and I'd like to reconcile
it.
Thanks.
--
Dmitry