From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0FBC5C4741F for ; Mon, 28 Sep 2020 19:03:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A4C6420809 for ; Mon, 28 Sep 2020 19:03:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726600AbgI1TDw (ORCPT ); Mon, 28 Sep 2020 15:03:52 -0400 Received: from asavdk3.altibox.net ([109.247.116.14]:42150 "EHLO asavdk3.altibox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726328AbgI1TDv (ORCPT ); Mon, 28 Sep 2020 15:03:51 -0400 Received: from ravnborg.org (unknown [188.228.123.71]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by asavdk3.altibox.net (Postfix) with ESMTPS id 62EBC20058; Mon, 28 Sep 2020 21:03:42 +0200 (CEST) Date: Mon, 28 Sep 2020 21:03:41 +0200 From: Sam Ravnborg To: "Alex G." Cc: dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, Jernej Skrabec , Mauro Carvalho Chehab , Neil Armstrong , David Airlie , Mark Brown , Jonas Karlman , linux-kernel@vger.kernel.org, Andrzej Hajda , Rob Herring , Thomas Bogendoerfer , Laurent Pinchart Subject: Re: [PATCH 1/2] drm/bridge: sii902x: Enable I/O and core VCC supplies if present Message-ID: <20200928190341.GA673726@ravnborg.org> References: <20200924200507.1175888-1-mr.nuke.me@gmail.com> <20200926184919.GB98875@ravnborg.org> <9c3ce766-743c-705f-7926-21e753c2d02d@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9c3ce766-743c-705f-7926-21e753c2d02d@gmail.com> X-CMAE-Score: 0 X-CMAE-Analysis: v=2.3 cv=CaYmGojl c=1 sm=1 tr=0 a=S6zTFyMACwkrwXSdXUNehg==:117 a=S6zTFyMACwkrwXSdXUNehg==:17 a=kj9zAlcOel0A:10 a=pGLkceISAAAA:8 a=n0pIf5krzdTGiaSpMTQA:9 a=CjuIK1q_8ugA:10 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Alex. On Mon, Sep 28, 2020 at 12:35:01PM -0500, Alex G. wrote: > On 9/26/20 1:49 PM, Sam Ravnborg wrote: > > Hi Alexandru > > > > On Thu, Sep 24, 2020 at 03:05:05PM -0500, Alexandru Gagniuc wrote: > > > On the SII9022, the IOVCC and CVCC12 supplies must reach the correct > > > voltage before the reset sequence is initiated. On most boards, this > > > assumption is true at boot-up, so initialization succeeds. > > > > > > However, when we try to initialize the chip with incorrect supply > > > voltages, it will not respond to I2C requests. sii902x_probe() fails > > > with -ENXIO. > > > > > > To resolve this, look for the "iovcc" and "cvcc12" regulators, and > > > make sure they are enabled before starting the reset sequence. If > > > these supplies are not available in devicetree, then they will default > > > to dummy-regulator. In that case everything will work like before. > > > > > > This was observed on a STM32MP157C-DK2 booting in u-boot falcon mode. > > > On this board, the supplies would be set by the second stage > > > bootloader, which does not run in falcon mode. > > > > > > Signed-off-by: Alexandru Gagniuc > > > > One nitpick here. The binding should be present in the tree before > > you start using it. So this patch should be applied after the binding. > > It is :) > * arch/arm/boot/dts/stm32mp15xx-dkx.dtsi This is the device tree. So essentially there is part of the device tree that is not yet documented - so in a perfect world all parts of the device tree is documented in bindings (Documentation/devicetree/bindings/* ) before the device tree is committed. Sam From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5D32BC47420 for ; Mon, 28 Sep 2020 19:03:53 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F098B2080C for ; Mon, 28 Sep 2020 19:03:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F098B2080C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ravnborg.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id EDC7289F6B; Mon, 28 Sep 2020 19:03:51 +0000 (UTC) Received: from asavdk3.altibox.net (asavdk3.altibox.net [109.247.116.14]) by gabe.freedesktop.org (Postfix) with ESMTPS id 58A7989F6B for ; Mon, 28 Sep 2020 19:03:50 +0000 (UTC) Received: from ravnborg.org (unknown [188.228.123.71]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by asavdk3.altibox.net (Postfix) with ESMTPS id 62EBC20058; Mon, 28 Sep 2020 21:03:42 +0200 (CEST) Date: Mon, 28 Sep 2020 21:03:41 +0200 From: Sam Ravnborg To: "Alex G." Subject: Re: [PATCH 1/2] drm/bridge: sii902x: Enable I/O and core VCC supplies if present Message-ID: <20200928190341.GA673726@ravnborg.org> References: <20200924200507.1175888-1-mr.nuke.me@gmail.com> <20200926184919.GB98875@ravnborg.org> <9c3ce766-743c-705f-7926-21e753c2d02d@gmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <9c3ce766-743c-705f-7926-21e753c2d02d@gmail.com> X-CMAE-Score: 0 X-CMAE-Analysis: v=2.3 cv=CaYmGojl c=1 sm=1 tr=0 a=S6zTFyMACwkrwXSdXUNehg==:117 a=S6zTFyMACwkrwXSdXUNehg==:17 a=kj9zAlcOel0A:10 a=pGLkceISAAAA:8 a=n0pIf5krzdTGiaSpMTQA:9 a=CjuIK1q_8ugA:10 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, Jernej Skrabec , Thomas Bogendoerfer , Rob Herring , Neil Armstrong , Mauro Carvalho Chehab , Jonas Karlman , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Andrzej Hajda , David Airlie , Mark Brown , Laurent Pinchart Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Alex. On Mon, Sep 28, 2020 at 12:35:01PM -0500, Alex G. wrote: > On 9/26/20 1:49 PM, Sam Ravnborg wrote: > > Hi Alexandru > > > > On Thu, Sep 24, 2020 at 03:05:05PM -0500, Alexandru Gagniuc wrote: > > > On the SII9022, the IOVCC and CVCC12 supplies must reach the correct > > > voltage before the reset sequence is initiated. On most boards, this > > > assumption is true at boot-up, so initialization succeeds. > > > > > > However, when we try to initialize the chip with incorrect supply > > > voltages, it will not respond to I2C requests. sii902x_probe() fails > > > with -ENXIO. > > > > > > To resolve this, look for the "iovcc" and "cvcc12" regulators, and > > > make sure they are enabled before starting the reset sequence. If > > > these supplies are not available in devicetree, then they will default > > > to dummy-regulator. In that case everything will work like before. > > > > > > This was observed on a STM32MP157C-DK2 booting in u-boot falcon mode. > > > On this board, the supplies would be set by the second stage > > > bootloader, which does not run in falcon mode. > > > > > > Signed-off-by: Alexandru Gagniuc > > > > One nitpick here. The binding should be present in the tree before > > you start using it. So this patch should be applied after the binding. > > It is :) > * arch/arm/boot/dts/stm32mp15xx-dkx.dtsi This is the device tree. So essentially there is part of the device tree that is not yet documented - so in a perfect world all parts of the device tree is documented in bindings (Documentation/devicetree/bindings/* ) before the device tree is committed. Sam _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel