Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753006AbdIXVoa (ORCPT ); Sun, 24 Sep 2017 17:44:30 -0400 Received: from gate2.alliedtelesis.co.nz ([202.36.163.20]:44782 "EHLO gate2.alliedtelesis.co.nz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752874AbdIXVo1 (ORCPT ); Sun, 24 Sep 2017 17:44:27 -0400 From: Kalyan Kinthada To: Gregory CLEMENT CC: "devicetree@vger.kernel.org" , "wsa@the-dreams.de" , "robh+dt@kernel.org" , "pawel.moll@arm.com" , "mark.rutland@arm.com" , "ijc+devicetree@hellion.org.uk" , "galak@codeaurora.org" , "linux-i2c@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Chris Packham Subject: Re: [PATCH] dt-bindings: i2c: Add armada-38x i2c binding Thread-Topic: [PATCH] dt-bindings: i2c: Add armada-38x i2c binding Thread-Index: AQHTM0clf+HOSDwxcUGJff8P6E1bWKLAgu/wgAQQlgY= Date: Sun, 24 Sep 2017 21:44:21 +0000 Message-ID: <1506289460890.34765@alliedtelesis.co.nz> References: <20170922020429.20941-1-kalyan.kinthada@alliedtelesis.co.nz>,<87377fmbpw.fsf@free-electrons.com> In-Reply-To: <87377fmbpw.fsf@free-electrons.com> Accept-Language: en-NZ, en-US Content-Language: en-NZ X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.32.1.10] Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id v8OLicJq029510 Content-Length: 2790 Lines: 74 Hi Gregory, I got this information from Armada-38x functional errata document. I can add the "marvell,mv78230-i2c" compatible string to the appropriate device tree files but the i2c-mv64xxx driver enables an additional feature (offload i2c transactions) based on the compatible string "marvell,mv78230-i2c". I am not sure if this feature (offload i2c transactions) should be enabled for Armada-38x devices. That is the reason I felt for the need of a new compatible string specifically for Armada-38x SoCs. Thanks, Kalyan ________________________________________ From: Gregory CLEMENT Sent: Friday, 22 September 2017 7:30 p.m. To: Kalyan Kinthada Cc: devicetree@vger.kernel.org; wsa@the-dreams.de; robh+dt@kernel.org; pawel.moll@arm.com; mark.rutland@arm.com; ijc+devicetree@hellion.org.uk; galak@codeaurora.org; linux-i2c@vger.kernel.org; linux-kernel@vger.kernel.org; Chris Packham Subject: Re: [PATCH] dt-bindings: i2c: Add armada-38x i2c binding Hi Kalyan, On ven., sept. 22 2017, Kalyan Kinthada wrote: > All armada-38x variants(380, 385, 388) SoCs have an issue > in i2c controller which violates the i2c repeated start timing. Did you had an issue with one of the SoC ? If yes what was your setting ? On my side I never managed to have this sort of issue on Armada 38x. > > This errata is fixed in the i2c-mv64xxx driver but enabled > only for devices with compatible string "marvell,mv78230-i2c". In this case why not just adding the "marvell,mv78230-i2c" as compatible string in the appropriate device tree files ? Gregory > > This patch introduces a new compatible string > "marvell,armada-38x-i2c" for the i2c controller on armada-38x SoCs > so that the workaound is enabled. > > Signed-off-by: Kalyan Kinthada > --- > Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt > index 5c30026921..fc100b6bdb 100644 > --- a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt > +++ b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt > @@ -14,6 +14,7 @@ Required properties : > very rare, initial version of the SoC which > had broken offload support. Linux > auto-detects this and sets it appropriately. > + - "marvell,armada-38x-i2c" > - interrupts : The interrupt number > > Optional properties : > -- > 2.14.1 > -- Gregory Clement, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com