linux-kernel - Re: [PATCH 2/2] Input: ili210x

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Message-ID: <f4390226-055b-3667-e156-78695ae911e5@denx.de>
Date:   Mon, 4 Nov 2019 10:13:31 +0100
From:   Marek Vasut <marex@...x.de>
To:     Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Sven Van Asbroeck <thesven73@...il.com>
Cc:     Adam Ford <aford173@...il.com>, linux-input@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] Input: ili210x - add ILI2117 support

On 11/4/19 8:01 AM, Dmitry Torokhov wrote:
> Hi Sven,
> 
> On Fri, Nov 01, 2019 at 04:48:01PM -0400, Sven Van Asbroeck wrote:
>> Dmitry / Marek,
>>
>> There have been two attempts to add ILI2117 touch controller support.
>> I was about to add a third, but luckily I checked the mailing list
>> before writing any code :)
>>
>> Adding this support would clearly be beneficial for the common good.
>> What can we do to get this in motion again?
>>
>> Last time I checked, Marek posted a patch which added the 2117, but Dmitry
>> objected, because the code became too unwieldy. Dmitry then posted a cleanup
>> patch, which did not work for Marek. So everything came to a halt.
>> See:
>> https://patchwork.kernel.org/patch/10836651/
>> https://www.spinics.net/lists/linux-input/msg62670.html
>>
>> Dmitry, would you perhaps be willing to accept Marek's patch, and perform the
>> cleanup later?
>>
>> Marek, would you perhaps be willing to invest some time to debug Dmitry's
>> cleanup patch?
>>
>> On my end, I've reviewed Dmitry's patch and it looks mostly ok. I saw one
>> difference with ILI210X which could explain Marek's results, but I can't be
>> sure - because I could not locate the 210X's register layout on the web.
>>
>> In Dmitry's patch, we see:
>>
>> 	touch = ili210x_report_events(priv, touchdata);
>> 	if (touch || chip->continue_polling(touchdata))
>> 		schedule_delayed_work(&priv->dwork,
>> 				      msecs_to_jiffies(priv->poll_period));
>>
>> but this is not exactly equivalent to the original. Because in the original,
>> the 210X's decision to kick off delayed work is completely independent of
>> the value of touch.
> 
> No, it is not independent really. Bits 0 and 1 in the first byte
> correspond to touches with first and 2nd finger, so checking for touch
> in addition to 0xf3 mask is not incorrect.
> 
> Can you please tell me what device you have? Do the patches work for
> you?
> 
> Marek, sorry for letting the patches linger. Can you please tell me what
> touch controller did you test with that failed for you?

See Message-ID <20190917032842.GL237523@...r-ws> . I tested the ILI2117
with these two patches and it works. With the additional two patches
from you on top, it failed, unless I reverted:
Input: ili210x - define and use chip operations structure

> I think I see at
> least one issue in ili251x_read_touch_data() - the check whether we
> should read the second part of the packet should check if data[0] == 2,
> not 0.

But that's not a problem of this particular patch, so maybe this patch
can finally be applied and then we can debug the subsequent patches ?