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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 524B5C43381 for ; Fri, 15 Mar 2019 13:48:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 295FC217F5 for ; Fri, 15 Mar 2019 13:48:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729159AbfCONsN (ORCPT ); Fri, 15 Mar 2019 09:48:13 -0400 Received: from relay1-d.mail.gandi.net ([217.70.183.193]:56031 "EHLO relay1-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727705AbfCONsN (ORCPT ); Fri, 15 Mar 2019 09:48:13 -0400 X-Originating-IP: 90.88.22.102 Received: from aptenodytes (aaubervilliers-681-1-80-102.w90-88.abo.wanadoo.fr [90.88.22.102]) (Authenticated sender: paul.kocialkowski@bootlin.com) by relay1-d.mail.gandi.net (Postfix) with ESMTPSA id 3D92224000E; Fri, 15 Mar 2019 13:48:08 +0000 (UTC) Message-ID: <3206b448f031ce22acc2db979781f19c1dded20c.camel@bootlin.com> Subject: Re: [linux-sunxi] [PATCH 3/6] drm/sun4i: dsi: Add bridge support From: Paul Kocialkowski To: Maxime Ripard Cc: jagan@amarulasolutions.com, Andrzej Hajda , Laurent Pinchart , Chen-Yu Tsai , David Airlie , Daniel Vetter , Rob Herring , Mark Rutland , Michael Trimarchi , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@googlegroups.com, linux-amarula@amarulasolutions.com Date: Fri, 15 Mar 2019 14:48:07 +0100 In-Reply-To: <20190315134555.ekpywymjx3xqmdhf@flea> References: <20190315130825.9005-1-jagan@amarulasolutions.com> <20190315130825.9005-4-jagan@amarulasolutions.com> <20190315134555.ekpywymjx3xqmdhf@flea> Organization: Bootlin Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.30.5 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Fri, 2019-03-15 at 14:45 +0100, Maxime Ripard wrote: > On Fri, Mar 15, 2019 at 02:32:55PM +0100, Paul Kocialkowski wrote: > > Hi, > > > > On Fri, 2019-03-15 at 18:38 +0530, Jagan Teki wrote: > > > Some display panels would come up with a non-DSI output which > > > can have an option to connect DSI interface by means of bridge > > > convertor. > > > > > > This DSI to non-DSI bridge convertor would require a bridge > > > driver that would communicate the DSI controller for bridge > > > functionalities. > > > > > > So, add support for bridge functionalities in Allwinner DSI > > > controller. > > > > See a few comments below. > > > > > Signed-off-by: Jagan Teki > > > --- > > > drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 65 +++++++++++++++++++------- > > > drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h | 1 + > > > 2 files changed, 49 insertions(+), 17 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c > > > index 0960b96b62cc..64d74313b842 100644 > > > --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c > > > +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c > > > @@ -781,6 +781,9 @@ static void sun6i_dsi_encoder_enable(struct drm_encoder *encoder) > > > if (!IS_ERR(dsi->panel)) > > > drm_panel_prepare(dsi->panel); > > > > > > + if (!IS_ERR(dsi->bridge)) > > > + drm_bridge_pre_enable(dsi->bridge); > > > + > > > /* > > > * FIXME: This should be moved after the switch to HS mode. > > > * > > > @@ -796,6 +799,9 @@ static void sun6i_dsi_encoder_enable(struct drm_encoder *encoder) > > > if (!IS_ERR(dsi->panel)) > > > drm_panel_enable(dsi->panel); > > > > > > + if (!IS_ERR(dsi->bridge)) > > > + drm_bridge_enable(dsi->bridge); > > > + > > > sun6i_dsi_start(dsi, DSI_START_HSC); > > > > > > udelay(1000); > > > @@ -812,6 +818,9 @@ static void sun6i_dsi_encoder_disable(struct drm_encoder *encoder) > > > if (!IS_ERR(dsi->panel)) { > > > drm_panel_disable(dsi->panel); > > > drm_panel_unprepare(dsi->panel); > > > + } else if (!IS_ERR(dsi->bridge)) { > > > + drm_bridge_disable(dsi->bridge); > > > + drm_bridge_post_disable(dsi->bridge); > > > } > > > > > > phy_power_off(dsi->dphy); > > > @@ -973,11 +982,16 @@ static int sun6i_dsi_attach(struct mipi_dsi_host *host, > > > struct sun6i_dsi *dsi = host_to_sun6i_dsi(host); > > > > > > dsi->device = device; > > > - dsi->panel = of_drm_find_panel(device->dev.of_node); > > > - if (IS_ERR(dsi->panel)) > > > - return PTR_ERR(dsi->panel); > > > > > > - dev_info(host->dev, "Attached device %s\n", device->name); > > > + dsi->bridge = of_drm_find_bridge(device->dev.of_node); > > > + if (!dsi->bridge) { > > > > You are using IS_ERR to check that the bridge is alive in the changes > > above, but switch to checking that it's non-NULL at this point. > > > > Are both guaranteed to be interchangeable? > > They aren't. Any ERR_PTR will be !NULL > > > > + dsi->panel = of_drm_find_panel(device->dev.of_node); > > > + if (IS_ERR(dsi->panel)) > > > + return PTR_ERR(dsi->panel); > > > + } > > > > You should probably use drm_of_find_panel_or_bridge instead of > > duplicating the logic here. > > Or we can even use the drm_panel_bridge_add to simplify things. Indeed, I was just looking at that and it seems to be specifically tailored for this use case. Cheers, Paul -- Paul Kocialkowski, Bootlin Embedded Linux and kernel engineering https://bootlin.com