From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756582AbdEROpe (ORCPT ); Thu, 18 May 2017 10:45:34 -0400 Received: from galahad.ideasonboard.com ([185.26.127.97]:56377 "EHLO galahad.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756500AbdEROpb (ORCPT ); Thu, 18 May 2017 10:45:31 -0400 From: Laurent Pinchart To: Eric Anholt Cc: Rob Herring , dri-devel , Thierry Reding , Mark Rutland , Archit Taneja , Andrzej Hajda , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 2/4] dt-bindings: Document the Raspberry Pi Touchscreen nodes. Date: Thu, 18 May 2017 17:45:40 +0300 Message-ID: <5108517.4KFRtigegR@avalon> User-Agent: KMail/4.14.10 (Linux/4.9.16-gentoo; KDE/4.14.32; x86_64; ; ) In-Reply-To: <87shk4iqr7.fsf@eliezer.anholt.net> References: <20170511235625.22427-1-eric@anholt.net> <3768334.nZM7df9y4L@avalon> <87shk4iqr7.fsf@eliezer.anholt.net> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Eric, On Tuesday 16 May 2017 11:46:36 Eric Anholt wrote: [snip] > In terms of physical connections: > > [15-pin "DSI" connector on 2835] > > | I2C | DSI > / \ SPI | > [TS] [Atmel]------[TC358762] > \ | > \PWM | > \ | DPI > [some backlight]------[some unknown panel] > > The binding I'm trying to create is to expose what's necessary for a > driver that talks I2C to the Atmel, which then controls the PWM and does > the command sequence over SPI to the Toshiba that sets up its end of the > DSI link. According to the documentation I've been able to find, the TC358762 has an SPI master port through which it can output the commands DCS received from the DSI port, and an I2C slave port through which it can be configured by an external device. If the connection between the microcontroller and the TC358762 is indeed SPI and not I2C, I assume it's used by the microcontroller to receive the DCS commands and perform control of the backlight (and possibly other components) accordingly. By the way, is there any place where I can find a leaked version of the non-public panel schematics ? ;-) As far as I can tell from your patch series, you don't need to send any command to the TC358762 over DSI. In that case I would model the panel in DT as an I2C device, as all control goes through the I2C bus. The DSI video data connection should then be modelled using the OF graph DT bindings. The result will be a black box panel with a custom black box panel driver, using a single DT node. There's no need for a separate bridge instance. That's the cleanest option I can come up with so far, and I agree that splitting TC358762 support into a standalone bridge driver makes no sense in this case. -- Regards, Laurent Pinchart From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Pinchart Subject: Re: [PATCH 2/4] dt-bindings: Document the Raspberry Pi Touchscreen nodes. Date: Thu, 18 May 2017 17:45:40 +0300 Message-ID: <5108517.4KFRtigegR@avalon> References: <20170511235625.22427-1-eric@anholt.net> <3768334.nZM7df9y4L@avalon> <87shk4iqr7.fsf@eliezer.anholt.net> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <87shk4iqr7.fsf@eliezer.anholt.net> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Eric Anholt Cc: Mark Rutland , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , dri-devel , Rob Herring List-Id: devicetree@vger.kernel.org SGkgRXJpYywKCk9uIFR1ZXNkYXkgMTYgTWF5IDIwMTcgMTE6NDY6MzYgRXJpYyBBbmhvbHQgd3Jv dGU6Cgpbc25pcF0KCj4gSW4gdGVybXMgb2YgcGh5c2ljYWwgY29ubmVjdGlvbnM6Cj4gCj4gICAg WzE1LXBpbiAiRFNJIiBjb25uZWN0b3Igb24gMjgzNV0KPiAKPiAgICAgfCBJMkMgICAgICAgICAg ICAgICB8IERTSQo+ICAgIC8gXCAgICAgICAgU1BJICAgICAgIHwKPiBbVFNdICBbQXRtZWxdLS0t LS0tW1RDMzU4NzYyXQo+ICAgICAgICBcICAgICAgICAgICAgICAgIHwKPiAgICAgICAgIFxQV00g ICAgICAgICAgICB8Cj4gICAgICAgICAgXCAgICAgICAgICAgICAgfCBEUEkKPiBbc29tZSBiYWNr bGlnaHRdLS0tLS0tW3NvbWUgdW5rbm93biBwYW5lbF0KPiAKPiBUaGUgYmluZGluZyBJJ20gdHJ5 aW5nIHRvIGNyZWF0ZSBpcyB0byBleHBvc2Ugd2hhdCdzIG5lY2Vzc2FyeSBmb3IgYQo+IGRyaXZl ciB0aGF0IHRhbGtzIEkyQyB0byB0aGUgQXRtZWwsIHdoaWNoIHRoZW4gY29udHJvbHMgdGhlIFBX TSBhbmQgZG9lcwo+IHRoZSBjb21tYW5kIHNlcXVlbmNlIG92ZXIgU1BJIHRvIHRoZSBUb3NoaWJh IHRoYXQgc2V0cyB1cCBpdHMgZW5kIG9mIHRoZQo+IERTSSBsaW5rLgoKQWNjb3JkaW5nIHRvIHRo ZSBkb2N1bWVudGF0aW9uIEkndmUgYmVlbiBhYmxlIHRvIGZpbmQsIHRoZSBUQzM1ODc2MiBoYXMg YW4gU1BJIAptYXN0ZXIgcG9ydCB0aHJvdWdoIHdoaWNoIGl0IGNhbiBvdXRwdXQgdGhlIGNvbW1h bmRzIERDUyByZWNlaXZlZCBmcm9tIHRoZSBEU0kgCnBvcnQsIGFuZCBhbiBJMkMgc2xhdmUgcG9y dCB0aHJvdWdoIHdoaWNoIGl0IGNhbiBiZSBjb25maWd1cmVkIGJ5IGFuIGV4dGVybmFsIApkZXZp Y2UuIElmIHRoZSBjb25uZWN0aW9uIGJldHdlZW4gdGhlIG1pY3JvY29udHJvbGxlciBhbmQgdGhl IFRDMzU4NzYyIGlzIAppbmRlZWQgU1BJIGFuZCBub3QgSTJDLCBJIGFzc3VtZSBpdCdzIHVzZWQg YnkgdGhlIG1pY3JvY29udHJvbGxlciB0byByZWNlaXZlIAp0aGUgRENTIGNvbW1hbmRzIGFuZCBw ZXJmb3JtIGNvbnRyb2wgb2YgdGhlIGJhY2tsaWdodCAoYW5kIHBvc3NpYmx5IG90aGVyIApjb21w b25lbnRzKSBhY2NvcmRpbmdseS4gQnkgdGhlIHdheSwgaXMgdGhlcmUgYW55IHBsYWNlIHdoZXJl IEkgY2FuIGZpbmQgYSAKbGVha2VkIHZlcnNpb24gb2YgdGhlIG5vbi1wdWJsaWMgcGFuZWwgc2No ZW1hdGljcyA/IDstKQoKQXMgZmFyIGFzIEkgY2FuIHRlbGwgZnJvbSB5b3VyIHBhdGNoIHNlcmll cywgeW91IGRvbid0IG5lZWQgdG8gc2VuZCBhbnkgCmNvbW1hbmQgdG8gdGhlIFRDMzU4NzYyIG92 ZXIgRFNJLiBJbiB0aGF0IGNhc2UgSSB3b3VsZCBtb2RlbCB0aGUgcGFuZWwgaW4gRFQgCmFzIGFu IEkyQyBkZXZpY2UsIGFzIGFsbCBjb250cm9sIGdvZXMgdGhyb3VnaCB0aGUgSTJDIGJ1cy4gVGhl IERTSSB2aWRlbyBkYXRhIApjb25uZWN0aW9uIHNob3VsZCB0aGVuIGJlIG1vZGVsbGVkIHVzaW5n IHRoZSBPRiBncmFwaCBEVCBiaW5kaW5ncy4gVGhlIHJlc3VsdCAKd2lsbCBiZSBhIGJsYWNrIGJv eCBwYW5lbCB3aXRoIGEgY3VzdG9tIGJsYWNrIGJveCBwYW5lbCBkcml2ZXIsIHVzaW5nIGEgc2lu Z2xlIApEVCBub2RlLiBUaGVyZSdzIG5vIG5lZWQgZm9yIGEgc2VwYXJhdGUgYnJpZGdlIGluc3Rh bmNlLiBUaGF0J3MgdGhlIGNsZWFuZXN0IApvcHRpb24gSSBjYW4gY29tZSB1cCB3aXRoIHNvIGZh ciwgYW5kIEkgYWdyZWUgdGhhdCBzcGxpdHRpbmcgVEMzNTg3NjIgc3VwcG9ydCAKaW50byBhIHN0 YW5kYWxvbmUgYnJpZGdlIGRyaXZlciBtYWtlcyBubyBzZW5zZSBpbiB0aGlzIGNhc2UuCgotLSAK UmVnYXJkcywKCkxhdXJlbnQgUGluY2hhcnQKCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fCmRyaS1kZXZlbCBtYWlsaW5nIGxpc3QKZHJpLWRldmVsQGxpc3Rz LmZyZWVkZXNrdG9wLm9yZwpodHRwczovL2xpc3RzLmZyZWVkZXNrdG9wLm9yZy9tYWlsbWFuL2xp c3RpbmZvL2RyaS1kZXZlbAo=