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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F0F54C43217 for ; Wed, 2 Feb 2022 10:32:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245642AbiBBKcW convert rfc822-to-8bit (ORCPT ); Wed, 2 Feb 2022 05:32:22 -0500 Received: from aposti.net ([89.234.176.197]:46030 "EHLO aposti.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232194AbiBBKcV (ORCPT ); Wed, 2 Feb 2022 05:32:21 -0500 Date: Wed, 02 Feb 2022 10:32:01 +0000 From: Paul Cercueil Subject: Re: [PATCH v12 7/9] drm/bridge: display-connector: add ddc-en gpio support To: "H. Nikolaus Schaller" Cc: Rob Herring , Mark Rutland , Thomas Bogendoerfer , Geert Uytterhoeven , Kees Cook , "Eric W. Biederman" , Miquel Raynal , David Airlie , Daniel Vetter , Neil Armstrong , Robert Foss , Laurent Pinchart , Jernej Skrabec , Harry Wentland , Sam Ravnborg , Maxime Ripard , Hans Verkuil , Liam Girdwood , Mark Brown , Paul Boddie , Andrzej Hajda , Kieran Bingham , devicetree@vger.kernel.org, linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, letux-kernel@openphoenux.org, Jonas Karlman , dri-devel@lists.freedesktop.org Message-Id: In-Reply-To: <77a7a1daaf381e1651be38adb62f9af9dd6c8fc5.1643632014.git.hns@goldelico.com> References: <77a7a1daaf381e1651be38adb62f9af9dd6c8fc5.1643632014.git.hns@goldelico.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Hi Nikolaus, Le lun., janv. 31 2022 at 13:26:53 +0100, H. Nikolaus Schaller a écrit : > "hdmi-connector.yaml" bindings defines an optional property > "ddc-en-gpios" for a single gpio to enable DDC operation. > > Usually this controls +5V power on the HDMI connector. > This +5V may also be needed for HPD. > > This was not reflected in code. > > Now, the driver activates the ddc gpio after probe and > deactivates after remove so it is "almost on". > > But only if this driver is loaded (and not e.g. blacklisted > as module). > > Signed-off-by: H. Nikolaus Schaller > --- > drivers/gpu/drm/bridge/display-connector.c | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/drivers/gpu/drm/bridge/display-connector.c > b/drivers/gpu/drm/bridge/display-connector.c > index d24f5b90feabf..555395e301096 100644 > --- a/drivers/gpu/drm/bridge/display-connector.c > +++ b/drivers/gpu/drm/bridge/display-connector.c > @@ -24,6 +24,7 @@ struct display_connector { > int hpd_irq; > > struct regulator *dp_pwr; > + struct gpio_desc *ddc_en; > }; > > static inline struct display_connector * > @@ -345,6 +346,19 @@ static int display_connector_probe(struct > platform_device *pdev) > } > } > > + /* enable DDC */ > + if (type == DRM_MODE_CONNECTOR_HDMIA) { > + conn->ddc_en = devm_gpiod_get_optional(&pdev->dev, "ddc-en", > + GPIOD_OUT_HIGH); > + > + if (IS_ERR(conn->ddc_en)) { > + dev_err(&pdev->dev, "Couldn't get ddc-en gpio\n"); > + return PTR_ERR(conn->ddc_en); > + } > + > + gpiod_set_value(conn->ddc_en, 1); You already requested the gpio with the GPIOD_OUT_HIGH flag, so this can be removed. > + } > + > conn->bridge.funcs = &display_connector_bridge_funcs; > conn->bridge.of_node = pdev->dev.of_node; > > @@ -373,6 +387,9 @@ static int display_connector_remove(struct > platform_device *pdev) > { > struct display_connector *conn = platform_get_drvdata(pdev); > > + if (conn->ddc_en) > + gpiod_set_value(conn->ddc_en, 0); Note that gpiod_set_value() already does the null-check internally. I actually do prefer your solution, so this is fine with me, but maintainers may have a different opinion. Cheers, -Paul > + > if (conn->dp_pwr) > regulator_disable(conn->dp_pwr); > > -- > 2.33.0 >