From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753383AbdEPQrz (ORCPT ); Tue, 16 May 2017 12:47:55 -0400 Received: from anholt.net ([50.246.234.109]:58268 "EHLO anholt.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751815AbdEPQrw (ORCPT ); Tue, 16 May 2017 12:47:52 -0400 From: Eric Anholt To: Rob Herring Cc: Laurent Pinchart , 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. In-Reply-To: References: <20170511235625.22427-1-eric@anholt.net> <20170511235625.22427-3-eric@anholt.net> <1579603.xgvSgGFBs8@avalon> <87shk53bxq.fsf@eliezer.anholt.net> User-Agent: Notmuch/0.22.2+1~gb0bcfaa (http://notmuchmail.org) Emacs/24.5.1 (x86_64-pc-linux-gnu) Date: Tue, 16 May 2017 09:47:49 -0700 Message-ID: <87h90ku4sq.fsf@eliezer.anholt.net> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha512; protocol="application/pgp-signature" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-=-= Content-Type: text/plain Rob Herring writes: > On Mon, May 15, 2017 at 7:03 PM, Eric Anholt wrote: >> Laurent Pinchart writes: >> >>> Hi Eric, >>> >>> Thank you for the patch. >>> >>> On Thursday 11 May 2017 16:56:23 Eric Anholt wrote: >>>> The Raspberry Pi 7" Touchscreen is a DPI touchscreen panel with >>>> DSI->DPI bridge and touchscreen controller integrated, that connects >>>> to the Raspberry Pi through its 15-pin "DSI" connector (some lines are >>>> DSI, some lines are I2C). >>>> >>>> This device is represented in the DT as three nodes (DSI device, I2C >>>> device, panel). Input will be left to a separate binding later, as it >>>> will be a basic I2C client device. >>>> >>>> Signed-off-by: Eric Anholt >>>> --- >>>> .../raspberrypi,7inch-touchscreen-bridge.txt | 68 +++++++++++++++++++ >>>> .../panel/raspberrypi,7inch-touchscreen-panel.txt | 7 +++ >>>> 2 files changed, 75 insertions(+) >>>> create mode 100644 >>>> Documentation/devicetree/bindings/display/bridge/raspberrypi,7inch-touchscr >>>> een-bridge.txt create mode 100644 >>>> Documentation/devicetree/bindings/display/panel/raspberrypi,7inch-touchscre >>>> en-panel.txt >>>> >>>> diff --git >>>> a/Documentation/devicetree/bindings/display/bridge/raspberrypi,7inch-touchs >>>> creen-bridge.txt >>>> b/Documentation/devicetree/bindings/display/bridge/raspberrypi,7inch-touchs >>>> creen-bridge.txt new file mode 100644 >>>> index 000000000000..a5669beaf68f >>>> --- /dev/null >>>> +++ >>>> b/Documentation/devicetree/bindings/display/bridge/raspberrypi,7inch-touchs >>>> creen-bridge.txt @@ -0,0 +1,68 @@ >>>> +Official 7" (800x480) Raspberry Pi touchscreen panel's bridge. >>>> + >>>> +This DSI panel contains: >>>> + >>>> +- TC358762 DSI->DPI bridge >>>> +- Atmel microcontroller on I2C for power sequencing the DSI bridge and >>>> + controlling backlight >>>> +- Touchscreen controller on I2C for touch input >>>> + >>>> +and this covers the TC358762 bridge and Atmel microcontroller, while >>>> +../panel/raspberrypi,7inch-touchscreen-panel.txt covers the panel. >>> >>> The TC358762 is a standalone bridge that doesn't depend on the ATTiny >>> microcontroller used by the RPI. As it's usable standalone, I believe this >>> binding should be split in two. >> >> Do you have a plan for how I would implement a driver on top of that >> binding change, though? Note that we don't program the Toshiba >> directly, we only send commands to the Atmel. > > I agree. If it is a black box and the interface to the host is defined > by the Atmel uC firmware, then that's what the DT should describe. > Perhaps a diagram here or pointer to one would help and remove > mentioning what kind of bridge chip it is. It's a *very* black box. I have some non-public schematics that don't even say what panel is involved, and no documentation of the uc interface. The driver code is just replicating the firmware's programming sequence. I would certainly love to be building a generic TC358762 driver, which would be a lot more satisfying. I just don't think it's doable for this panel. Given that, what do I need to do to the DT? Should I just drop mention of the Toshiba and talk about this being a bridge with a custom microcontroller firmware? --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEE/JuuFDWp9/ZkuCBXtdYpNtH8nugFAlkbLTUACgkQtdYpNtH8 nuhD0RAAoyUZKCYtVx5DePA2RZGz4aF3hxmS783MMF6z+x3T59MFELMauXFP8wHX JY2zTavX8Vh0cQ/wXPYSNOj5LW/wUkRx2kzoFgXSxH+kF9GvX4Raqzb4smxNm55W lVS9sWZRN1E2lfcw5XQZDDu4tU/wapHuAXoutz0ajRL92pGB07ji/bad8HhbCiig aaUahNTQjU4z/85Hr8dKlrOfaTSxWMvbk81xsAmrWcwGiRCvjSVk1/HJzwtH8Taz 2OwyoON/laekoxpu05ZuLdJ6WP9gva25n04nMSfIwMfUJysiYuaD85FwWxZocl2t LFgWxIf/D15GJ+MtEC2zEHgwi2l9/ayCICcgtNXWogIom1iSslvKL6goqS4nIxjo RxtgemHR6803VtWXfU38i30Myxqi7oxSZ8rqw4aqBbvBkyavUVkpB/FNIAGniNHL slmdgEMQm+HQSoTamFjf9To2Y3wrPNGunAmWWzgDW1vS5O3mEccDiQv7k+9wjcJK uqAjpeIm4c8LwktU5AaI2N9+i9O16Tq3nWA8mbvFmL9S9nayzHVxAcobRvQ3Bd3V v1f9c/7krf5v8wC+qtKIPUfQb5AaUZx1i9F5V//toQi4iOju+AYUmp12jbvTYWa3 D71fKh4m6fdYSItX4TtLzcbY/8H3Bzt6dOE2IWXWSFEJs+XlaIM= =yElQ -----END PGP SIGNATURE----- --=-=-=-- From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Anholt Subject: Re: [PATCH 2/4] dt-bindings: Document the Raspberry Pi Touchscreen nodes. Date: Tue, 16 May 2017 09:47:49 -0700 Message-ID: <87h90ku4sq.fsf@eliezer.anholt.net> References: <20170511235625.22427-1-eric@anholt.net> <20170511235625.22427-3-eric@anholt.net> <1579603.xgvSgGFBs8@avalon> <87shk53bxq.fsf@eliezer.anholt.net> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha512; protocol="application/pgp-signature" Return-path: In-Reply-To: Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Rob Herring Cc: Laurent Pinchart , dri-devel , Thierry Reding , Mark Rutland , Archit Taneja , Andrzej Hajda , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" List-Id: devicetree@vger.kernel.org --=-=-= Content-Type: text/plain Rob Herring writes: > On Mon, May 15, 2017 at 7:03 PM, Eric Anholt wrote: >> Laurent Pinchart writes: >> >>> Hi Eric, >>> >>> Thank you for the patch. >>> >>> On Thursday 11 May 2017 16:56:23 Eric Anholt wrote: >>>> The Raspberry Pi 7" Touchscreen is a DPI touchscreen panel with >>>> DSI->DPI bridge and touchscreen controller integrated, that connects >>>> to the Raspberry Pi through its 15-pin "DSI" connector (some lines are >>>> DSI, some lines are I2C). >>>> >>>> This device is represented in the DT as three nodes (DSI device, I2C >>>> device, panel). Input will be left to a separate binding later, as it >>>> will be a basic I2C client device. >>>> >>>> Signed-off-by: Eric Anholt >>>> --- >>>> .../raspberrypi,7inch-touchscreen-bridge.txt | 68 +++++++++++++++++++ >>>> .../panel/raspberrypi,7inch-touchscreen-panel.txt | 7 +++ >>>> 2 files changed, 75 insertions(+) >>>> create mode 100644 >>>> Documentation/devicetree/bindings/display/bridge/raspberrypi,7inch-touchscr >>>> een-bridge.txt create mode 100644 >>>> Documentation/devicetree/bindings/display/panel/raspberrypi,7inch-touchscre >>>> en-panel.txt >>>> >>>> diff --git >>>> a/Documentation/devicetree/bindings/display/bridge/raspberrypi,7inch-touchs >>>> creen-bridge.txt >>>> b/Documentation/devicetree/bindings/display/bridge/raspberrypi,7inch-touchs >>>> creen-bridge.txt new file mode 100644 >>>> index 000000000000..a5669beaf68f >>>> --- /dev/null >>>> +++ >>>> b/Documentation/devicetree/bindings/display/bridge/raspberrypi,7inch-touchs >>>> creen-bridge.txt @@ -0,0 +1,68 @@ >>>> +Official 7" (800x480) Raspberry Pi touchscreen panel's bridge. >>>> + >>>> +This DSI panel contains: >>>> + >>>> +- TC358762 DSI->DPI bridge >>>> +- Atmel microcontroller on I2C for power sequencing the DSI bridge and >>>> + controlling backlight >>>> +- Touchscreen controller on I2C for touch input >>>> + >>>> +and this covers the TC358762 bridge and Atmel microcontroller, while >>>> +../panel/raspberrypi,7inch-touchscreen-panel.txt covers the panel. >>> >>> The TC358762 is a standalone bridge that doesn't depend on the ATTiny >>> microcontroller used by the RPI. As it's usable standalone, I believe this >>> binding should be split in two. >> >> Do you have a plan for how I would implement a driver on top of that >> binding change, though? Note that we don't program the Toshiba >> directly, we only send commands to the Atmel. > > I agree. If it is a black box and the interface to the host is defined > by the Atmel uC firmware, then that's what the DT should describe. > Perhaps a diagram here or pointer to one would help and remove > mentioning what kind of bridge chip it is. It's a *very* black box. I have some non-public schematics that don't even say what panel is involved, and no documentation of the uc interface. The driver code is just replicating the firmware's programming sequence. I would certainly love to be building a generic TC358762 driver, which would be a lot more satisfying. I just don't think it's doable for this panel. Given that, what do I need to do to the DT? Should I just drop mention of the Toshiba and talk about this being a bridge with a custom microcontroller firmware? --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEE/JuuFDWp9/ZkuCBXtdYpNtH8nugFAlkbLTUACgkQtdYpNtH8 nuhD0RAAoyUZKCYtVx5DePA2RZGz4aF3hxmS783MMF6z+x3T59MFELMauXFP8wHX JY2zTavX8Vh0cQ/wXPYSNOj5LW/wUkRx2kzoFgXSxH+kF9GvX4Raqzb4smxNm55W lVS9sWZRN1E2lfcw5XQZDDu4tU/wapHuAXoutz0ajRL92pGB07ji/bad8HhbCiig aaUahNTQjU4z/85Hr8dKlrOfaTSxWMvbk81xsAmrWcwGiRCvjSVk1/HJzwtH8Taz 2OwyoON/laekoxpu05ZuLdJ6WP9gva25n04nMSfIwMfUJysiYuaD85FwWxZocl2t LFgWxIf/D15GJ+MtEC2zEHgwi2l9/ayCICcgtNXWogIom1iSslvKL6goqS4nIxjo RxtgemHR6803VtWXfU38i30Myxqi7oxSZ8rqw4aqBbvBkyavUVkpB/FNIAGniNHL slmdgEMQm+HQSoTamFjf9To2Y3wrPNGunAmWWzgDW1vS5O3mEccDiQv7k+9wjcJK uqAjpeIm4c8LwktU5AaI2N9+i9O16Tq3nWA8mbvFmL9S9nayzHVxAcobRvQ3Bd3V v1f9c/7krf5v8wC+qtKIPUfQb5AaUZx1i9F5V//toQi4iOju+AYUmp12jbvTYWa3 D71fKh4m6fdYSItX4TtLzcbY/8H3Bzt6dOE2IWXWSFEJs+XlaIM= =yElQ -----END PGP SIGNATURE----- --=-=-=-- -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html