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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham 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 3C9B7C2D0C9 for ; Sat, 14 Dec 2019 10:24:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1C96D24658 for ; Sat, 14 Dec 2019 10:24:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726072AbfLNKX7 (ORCPT ); Sat, 14 Dec 2019 05:23:59 -0500 Received: from asavdk4.altibox.net ([109.247.116.15]:44204 "EHLO asavdk4.altibox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725872AbfLNKX6 (ORCPT ); Sat, 14 Dec 2019 05:23:58 -0500 Received: from ravnborg.org (unknown [158.248.194.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by asavdk4.altibox.net (Postfix) with ESMTPS id A8A518050E; Sat, 14 Dec 2019 11:23:55 +0100 (CET) Date: Sat, 14 Dec 2019 11:23:54 +0100 From: Sam Ravnborg To: Miquel Raynal Cc: Thierry Reding , David Airlie , Daniel Vetter , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Paul Kocialkowski , Maxime Chevallier , Thomas Petazzoni Subject: Re: [PATCH] drm/panel: simple: Support reset GPIOs Message-ID: <20191214102354.GB2967@ravnborg.org> References: <20191213181325.26228-1-miquel.raynal@bootlin.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191213181325.26228-1-miquel.raynal@bootlin.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CMAE-Score: 0 X-CMAE-Analysis: v=2.3 cv=VcLZwmh9 c=1 sm=1 tr=0 a=UWs3HLbX/2nnQ3s7vZ42gw==:117 a=UWs3HLbX/2nnQ3s7vZ42gw==:17 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=kj9zAlcOel0A:10 a=P-IC7800AAAA:8 a=rgyZEuhkcDeh9zHs8M0A:9 a=CjuIK1q_8ugA:10 a=d3PnA9EDa4IxuAV0gXij:22 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Miquel. On Fri, Dec 13, 2019 at 07:13:25PM +0100, Miquel Raynal wrote: > The panel common bindings provide a gpios-reset property which is > active low by default. Let's support it in the simple driver. > > De-asserting the reset pin implies a physical high, which in turns is > a logic low. > > Signed-off-by: Miquel Raynal Code looks fine - but I fail to see why simple panels would require a reset pin. Do you have any simple panels that requires this, or did you add it because you saw it in the panel-common.yaml file? Sam > --- > drivers/gpu/drm/panel/panel-simple.c | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c > index 5d487686d25c..15dd495c347d 100644 > --- a/drivers/gpu/drm/panel/panel-simple.c > +++ b/drivers/gpu/drm/panel/panel-simple.c > @@ -110,6 +110,7 @@ struct panel_simple { > struct i2c_adapter *ddc; > > struct gpio_desc *enable_gpio; > + struct gpio_desc *reset_gpio; > > struct drm_display_mode override_mode; > }; > @@ -433,12 +434,21 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc) > if (IS_ERR(panel->supply)) > return PTR_ERR(panel->supply); > > + panel->reset_gpio = devm_gpiod_get_optional(dev, "reset", > + GPIOD_OUT_LOW); > + if (IS_ERR(panel->reset_gpio)) { > + err = PTR_ERR(panel->reset_gpio); > + if (err != -EPROBE_DEFER) > + dev_err(dev, "failed to request reset pin: %d\n", err); > + return err; > + } > + > panel->enable_gpio = devm_gpiod_get_optional(dev, "enable", > GPIOD_OUT_LOW); > if (IS_ERR(panel->enable_gpio)) { > err = PTR_ERR(panel->enable_gpio); > if (err != -EPROBE_DEFER) > - dev_err(dev, "failed to request GPIO: %d\n", err); > + dev_err(dev, "failed to request enable pin: %d\n", err); > return err; > } > > -- > 2.20.1