From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Kemnade Subject: Re: [RFC PATCH 00/10] Netronix embedded controller driver for Kobo and Tolino ebook readers Date: Mon, 6 Jul 2020 21:28:48 +0200 Message-ID: <20200706212848.7e19886b@aktux> References: <20200620223915.1311485-1-j.neuschaefer@gmx.net> <20200630084051.66feadea@aktux> <20200630071523.GA2983@latitude> <20200630221447.3e03ae28@aktux> <20200704205808.GD2578@latitude> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Return-path: Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45892 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725892AbgGFT3X (ORCPT ); Mon, 6 Jul 2020 15:29:23 -0400 In-Reply-To: <20200704205808.GD2578@latitude> Sender: linux-pwm-owner@vger.kernel.org List-Id: linux-pwm@vger.kernel.org To: Jonathan =?UTF-8?B?TmV1c2Now6RmZXI=?= Cc: linux-kernel@vger.kernel.org, Lee Jones , Rob Herring , Thierry Reding , Uwe =?UTF-8?B?S2xlaW5lLUvDtm5pZw==?= , Alessandro Zummo , Alexandre Belloni , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , NXP Linux Team , Sam Ravnborg , Linus Walleij , Heiko Stuebner , Stephan Gerhold , Lubomir Rintel , Mark Brown , allen On Sat, 4 Jul 2020 22:58:08 +0200 Jonathan Neusch=C3=A4fer wrote: > On Tue, Jun 30, 2020 at 10:14:47PM +0200, Andreas Kemnade wrote: > > On Tue, 30 Jun 2020 09:15:23 +0200 > > Jonathan Neusch=C3=A4fer wrote: > > =20 > > > On Tue, Jun 30, 2020 at 08:40:51AM +0200, Andreas Kemnade wrote: > > > [...] =20 > > > > got a chance to test it on a Tolino Shine 2 HD. > > > > It uses the RTC from the RC5T619 but backlight seems to go via MSP4= 30 > > > > EC. > > > >=20 > > > > I got this. > > > >=20 > > > > [ 1.453603] ntxec 0-0043: Netronix embedded controller version f= 110 detected. > > > > [ 10.723638] ntxec-rtc 21a0000.i2c:embedded-controller@43:rtc: re= gistered as rtc0 > > > > [ 10.775276] ntxec-pwm: probe of 21a0000.i2c:embedded-controller@= 43:pwm failed with error -5 =20 > > >=20 > > > Hmm, -EIO from the PWM driver. > > > =20 > > turing debugging on: =20 >=20 > (edited for compactness:) > > [ 330.332971] i2c i2c-0: write slave address: addr=3D0x86 ACK receiv= ed > > [ 330.334420] i2c i2c-0: write byte: B0=3D0xA3 ACK receiv= ed > > [ 330.334790] i2c i2c-0: write byte: B1=3D0x0 No ACK =20 >=20 > > [ 330.352339] i2c i2c-0: write slave address: addr=3D0x86 ACK receiv= ed > > [ 330.362208] i2c i2c-0: write byte: B0=3D0xA1 ACK receiv= ed > > [ 330.362479] i2c i2c-0: write byte: B1=3D0xFF No ACK =20 >=20 > > [ 330.363112] i2c i2c-0: write slave address: addr=3D0x86 ACK receiv= ed > > [ 330.363362] i2c i2c-0: write byte: B0=3D0xA2 ACK receiv= ed > > [ 330.363608] i2c i2c-0: write byte: B1=3D0xFF No ACK =20 >=20 > Hmm, it doesn't ack the writes to 0xA3, 0xA1 and 0xA2, which should > disable the PWM output and then disable the auto-off timer (according to > the vendor kernel). >=20 > And you said in your other mail that you can actually toggle the light > with writes to 0xA3, so I suspect a bug in the EC firmware here (which > may have gone unnoticed because the vendor kernel doesn't check if the > i2c transfers succeed). :/ >=20 That is a also my theory. > IMHO we should get this driver merged first, and perhaps add a quirk to > deal with the missing ACKs later (unless a better solution is found). >=20 Yes, that can be done separately (after the Tolino Shine 2 HD dtb is in, I am polishing it right now). Regards, Andreas