linux-kernel - Re: [-next, 1/2] Input: synaptics-rmi4 - add support for F55 sensor tuning

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Message-ID: <1477006119.5714.46.camel@synaptics.com>
Date:   Thu, 20 Oct 2016 16:28:39 -0700
From:   Christopher Heiny <cheiny@...aptics.com>
To:     Nick Dyer <nick@...anahar.org>, Guenter Roeck <linux@...ck-us.net>
CC:     Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Chris Healy <cphealy@...il.com>,
        Andrew Duggan <aduggan@...aptics.com>,
        "Mauro Carvalho Chehab" <mchehab@...nel.org>,
        Hans Verkuil <hans.verkuil@...co.com>,
        <linux-kernel@...r.kernel.org>, <linux-input@...r.kernel.org>
Subject: Re: [-next, 1/2] Input: synaptics-rmi4 - add support for F55 sensor
 tuning

On Thu, 2016-10-20 at 23:51 +0100, Nick Dyer wrote:
> On Mon, Oct 17, 2016 at 02:30:08PM -0700, Guenter Roeck wrote:
> > 
> > On Fri, Sep 30, 2016 at 08:22:47PM -0700, Guenter Roeck wrote:
> > > 
> > > Sensor tuning support is needed to determine the number of
> > > enabled
> > > tx and rx electrodes for use in F54 functions.
> > > 
> > > The number of enabled electrodes is not identical to the total
> > > number
> > > of electrodes as reported with F55:Query0 and F55:Query1. It has
> > > to be
> > > calculated by analyzing F55:Ctrl1 (sensor receiver assignment)
> > > and
> > > F55:Ctrl2 (sensor transmitter assignment).
> > > 
> > > Support for additional sensor tuning functions may be added
> > > later.
> > > 
> > > Signed-off-by: Guenter Roeck <linux@...ck-us.net>
> > 
> > Ping ... any comments on this patch and on
> > https://patchwork.kernel.org/patch/9359061/ ?
> > 
> > Both patches now apply to mainline.
> > 
> > Thanks,
> > Guenter
> 
> Hi Guenter-
> 
> I've reviewed and tested (on S7300 and S7813) both these patches now
> - you can add my sign-off.
> 
> However, on the S7813 firmware, F55 is on PDT page 3, and nothing
> on page 2, so the default behaviour of the mainline driver means it
> is
> not initialised.
> 
> So I think we need to revert this change in mainline:
> https://patchwork.kernel.org/patch/3796971/
> 
> See below the PDT scan with it reverted and some debug added.
> 
> Christopher/Andrew: is there a better heuristic than scanning all 255
> pages, given that some firmwares contain gaps?

It's difficult to say.  It is against the RMI4 spec for there to be
gaps in the pages - you're supposed to be able to scan until you hit a
page with an empty PDT, and then stop.

Since F55 is hardcoded to page 3 for this firmware, it may be a
customer specific deviation.  This may have been done to accommodate a
customer-written driver that did not scan the PDT, but instead always
looked for F55 on page 3.  This idea is supported by the existence of
the F51 custom function on page 4, since F51 almost always requires
customer driver code to handle it.

In my opinion, the Non-standard bit should have been set in the PDT to
indicate that special handling was required, but that wasn't done in
this case.

Anyway, given that this sort of thing has escaped into the wild, I'm
unsure what to advise.  Just off the top of my head, one possibility is
to have a "keep-going" option to scan the first 128 pages (0x00 through
0x7F), regardless of whether an empty page is encountered.  This could
be triggered either by a product ID on the "known goofy list", or by a
boot/load time flag.  I'm sure there are other possibilities, though.

					Cheers,
						Chris


> 
> cheers
> 
> Nick
> 
> [    2.181199] rmi4_physical rmi4-00: Creating functions.
> [    2.181210] rmi4_physical rmi4-00: rmi_scan_pdt page 0
> [    2.181221] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 233
> [    2.182218] rmi4_physical rmi4-00: rmi_read_pdt_entry: F34 V2
> [    2.182230] rmi4_physical rmi4-00: Initializing F34.
> [    2.182325] rmi4_physical rmi4-00: Registered F34.
> [    2.182337] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 227
> [    2.183003] rmi4_physical rmi4-00: rmi_read_pdt_entry: F01 V0
> [    2.183014] rmi4_physical rmi4-00: Initializing F01.
> [    2.187358] rmi4_f01 rmi4-00.fn01: found RMI device, manufacturer:
> Synaptics, product: s7813, fw id: 2174259
> [    2.198822] rmi4_physical rmi4-00: Registered F01.
> [    2.198834] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 221
> [    2.199494] rmi4_physical rmi4-00: rmi_read_pdt_entry: F12 V0
> [    2.199505] rmi4_physical rmi4-00: Initializing F12.
> [    2.199612] rmi4_f12 rmi4-00.fn12: rmi_f12_probe
> [    2.210721] rmi4_physical rmi4-00: Registered F12.
> [    2.210732] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 215
> [    2.211393] rmi4_physical rmi4-00: rmi_read_pdt_entry: F00 V0
> [    2.211404] rmi4_physical rmi4-00: rmi_scan_pdt_page end of page
> [    2.211414] rmi4_physical rmi4-00: rmi_scan_pdt page 1
> [    2.211424] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 489
> [    2.212419] rmi4_physical rmi4-00: rmi_read_pdt_entry: F54 V0
> [    2.212431] rmi4_physical rmi4-00: Initializing F54.
> [    2.214241] rmi4_f54 rmi4-00.fn54: F54 num_rx_electrodes: 60
> [    2.214253] rmi4_f54 rmi4-00.fn54: F54 num_tx_electrodes: 36
> [    2.214263] rmi4_f54 rmi4-00.fn54: F54 capabilities: 0x44
> [    2.214274] rmi4_f54 rmi4-00.fn54: F54 clock rate: 0x5aa0
> [    2.214283] rmi4_f54 rmi4-00.fn54: F54 family: 0x2
> [    2.214695] rmi4_physical rmi4-00: Registered F54.
> [    2.214708] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 483
> [    2.215372] rmi4_physical rmi4-00: rmi_read_pdt_entry: F00 V0
> [    2.215384] rmi4_physical rmi4-00: rmi_scan_pdt_page end of page
> [    2.215395] rmi4_physical rmi4-00: rmi_scan_pdt page 2
> [    2.215405] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 745
> [    2.216404] rmi4_physical rmi4-00: rmi_read_pdt_entry: F00 V0
> [    2.216415] rmi4_physical rmi4-00: rmi_scan_pdt_page end of page
> [    2.216426] rmi4_physical rmi4-00: rmi_scan_pdt page 3
> [    2.216436] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 1001
> [    2.217431] rmi4_physical rmi4-00: rmi_read_pdt_entry: F55 V0
> [    2.217442] rmi4_physical rmi4-00: Initializing F55.
> [    2.224189] rmi4_f55 rmi4-00.fn55: F55 num_rx_electrodes: 48 (raw
> 60)
> [    2.224201] rmi4_f55 rmi4-00.fn55: F55 num_tx_electrodes: 30 (raw
> 36)
> [    2.224220] rmi4_physical rmi4-00: Registered F55.
> [    2.224231] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 995
> [    2.224889] rmi4_physical rmi4-00: rmi_read_pdt_entry: F00 V0
> [    2.224900] rmi4_physical rmi4-00: rmi_scan_pdt_page end of page
> [    2.224911] rmi4_physical rmi4-00: rmi_scan_pdt page 4
> [    2.224921] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 1257
> [    2.225915] rmi4_physical rmi4-00: rmi_read_pdt_entry: F51 V1
> [    2.225927] rmi4_physical rmi4-00: Initializing F51.
> [    2.226005] rmi4_physical rmi4-00: Registered F51.
> [    2.226016] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 1251
> [    2.226677] rmi4_physical rmi4-00: rmi_read_pdt_entry: F00 V0
> [    2.226689] rmi4_physical rmi4-00: rmi_scan_pdt_page end of page
> [    2.226699] rmi4_physical rmi4-00: rmi_scan_pdt page 5