From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Pinchart Subject: Re: [PATCH v3 2/2] drm/tegra: output: rgb: Support LVDS encoder bridge Date: Thu, 16 Apr 2020 20:41:12 +0300 Message-ID: <20200416174112.GS4796@pendragon.ideasonboard.com> References: <20200416172405.5051-1-digetx@gmail.com> <20200416172405.5051-3-digetx@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: <20200416172405.5051-3-digetx-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Dmitry Osipenko Cc: Thierry Reding , Sam Ravnborg , dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-tegra@vger.kernel.org Hi Dmitry, Thank you for the patch. On Thu, Apr 16, 2020 at 08:24:05PM +0300, Dmitry Osipenko wrote: > Newer Tegra device-trees will specify a video output graph that involves > LVDS encoder bridge, This patch adds support for the LVDS encoder bridge > to the RGB output, allowing us to model display hardware properly. > > Signed-off-by: Dmitry Osipenko > --- > drivers/gpu/drm/tegra/drm.h | 2 ++ > drivers/gpu/drm/tegra/output.c | 10 ++++++++++ > drivers/gpu/drm/tegra/rgb.c | 34 ++++++++++++++++++++++++++++++++++ > 3 files changed, 46 insertions(+) > > diff --git a/drivers/gpu/drm/tegra/drm.h b/drivers/gpu/drm/tegra/drm.h > index 804869799305..cccd368b6752 100644 > --- a/drivers/gpu/drm/tegra/drm.h > +++ b/drivers/gpu/drm/tegra/drm.h > @@ -12,6 +12,7 @@ > #include > > #include > +#include > #include > #include > #include > @@ -116,6 +117,7 @@ struct tegra_output { > struct device_node *of_node; > struct device *dev; > > + struct drm_bridge *bridge; > struct drm_panel *panel; > struct i2c_adapter *ddc; > const struct edid *edid; > diff --git a/drivers/gpu/drm/tegra/output.c b/drivers/gpu/drm/tegra/output.c > index a6a711d54e88..37fc6b8c173f 100644 > --- a/drivers/gpu/drm/tegra/output.c > +++ b/drivers/gpu/drm/tegra/output.c > @@ -180,6 +180,16 @@ int tegra_output_init(struct drm_device *drm, struct tegra_output *output) > int connector_type; > int err; > > + if (output->bridge) { > + err = drm_bridge_attach(&output->encoder, output->bridge, > + NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR); Using DRM_BRIDGE_ATTACH_NO_CONNECTOR is definitely the way to go, but please be aware that it will require creating a connector and an encoder manually (which I think this driver already does), and using the bridge operations to implement the connector operations. I highly recommend using the DRM bridge connector helper for this purpose. > + if (err) { > + dev_err(output->dev, "cannot connect bridge: %d\n", > + err); > + return err; > + } > + } > + > if (output->panel) { May I also recommend switching to the DRM panel bridge helper ? It will simplify the code. > err = drm_panel_attach(output->panel, &output->connector); > if (err < 0) > diff --git a/drivers/gpu/drm/tegra/rgb.c b/drivers/gpu/drm/tegra/rgb.c > index 0562a7eb793f..0df213e92664 100644 > --- a/drivers/gpu/drm/tegra/rgb.c > +++ b/drivers/gpu/drm/tegra/rgb.c > @@ -5,6 +5,7 @@ > */ > > #include > +#include > > #include > #include > @@ -210,6 +211,7 @@ static const struct drm_encoder_helper_funcs tegra_rgb_encoder_helper_funcs = { > > int tegra_dc_rgb_probe(struct tegra_dc *dc) > { > + const unsigned int encoder_port = 0, panel_port = 1; > struct device_node *np; > struct tegra_rgb *rgb; > int err; > @@ -226,6 +228,38 @@ int tegra_dc_rgb_probe(struct tegra_dc *dc) > rgb->output.of_node = np; > rgb->dc = dc; > > + /* > + * Tegra devices that have LVDS panel utilize LVDS-encoder bridge > + * for converting 24/18 RGB data-lanes into 8 lanes. Encoder usually > + * have a powerdown control which needs to be enabled in order to > + * transfer data to the panel. Historically devices that use an older > + * device-tree version didn't model the bridge, assuming that encoder > + * is turned ON by default, while today's DRM allows us to model LVDS > + * encoder properly. > + * > + * Newer device-trees may utilize output->encoder->panel graph. > + * > + * For older device-trees we fall back to use nvidia,panel phandle. > + */ > + np = of_graph_get_remote_node(rgb->output.of_node, encoder_port, -1); > + if (np) { > + rgb->output.bridge = of_drm_find_bridge(np); > + of_node_put(np); > + > + if (!rgb->output.bridge) > + return -EPROBE_DEFER; > + > + np = of_graph_get_remote_node(rgb->output.bridge->of_node, > + panel_port, -1); This shouldn't be needed, the LVDS codec bridge driver should already get the panel and handle it internally. You only need to handle panels in this driver when they're connected directly to the RGB input. > + if (np) { > + rgb->output.panel = of_drm_find_panel(np); > + of_node_put(np); > + > + if (IS_ERR(rgb->output.panel)) > + return PTR_ERR(rgb->output.panel); > + } > + } > + > err = tegra_output_probe(&rgb->output); > if (err < 0) > return err; -- Regards, Laurent Pinchart 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=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 6175EC2BB55 for ; Thu, 16 Apr 2020 17:41:28 +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 36B682078B for ; Thu, 16 Apr 2020 17:41:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="pKsGoMuc" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 36B682078B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ideasonboard.com 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 BFF866E935; Thu, 16 Apr 2020 17:41:27 +0000 (UTC) Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by gabe.freedesktop.org (Postfix) with ESMTPS id 22CFE6E935 for ; Thu, 16 Apr 2020 17:41:26 +0000 (UTC) Received: from pendragon.ideasonboard.com (81-175-216-236.bb.dnainternet.fi [81.175.216.236]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 86B0597D; Thu, 16 Apr 2020 19:41:24 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1587058884; bh=4BIA7LGF6ywJGURewccfXyn3A/kH2tNbw0kqlU/g4oY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=pKsGoMucWMzZY1JkPjTUTlsoic6cvvluNNp1XmxsmlE6t1FEhpucOYSHK78YVqMMY /MVTIgTrAdkZe7sqWO9mZNxU/4kKMfZzdbQ5zFhl2XKIVbvr7U39K5jcQc10f2zbik QlC8K7/IMLn9HgS9ASu2zET4pb7IzXbFjD6mbpR0= Date: Thu, 16 Apr 2020 20:41:12 +0300 From: Laurent Pinchart To: Dmitry Osipenko Subject: Re: [PATCH v3 2/2] drm/tegra: output: rgb: Support LVDS encoder bridge Message-ID: <20200416174112.GS4796@pendragon.ideasonboard.com> References: <20200416172405.5051-1-digetx@gmail.com> <20200416172405.5051-3-digetx@gmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200416172405.5051-3-digetx@gmail.com> 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: linux-tegra@vger.kernel.org, Thierry Reding , Sam Ravnborg , dri-devel@lists.freedesktop.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Dmitry, Thank you for the patch. On Thu, Apr 16, 2020 at 08:24:05PM +0300, Dmitry Osipenko wrote: > Newer Tegra device-trees will specify a video output graph that involves > LVDS encoder bridge, This patch adds support for the LVDS encoder bridge > to the RGB output, allowing us to model display hardware properly. > > Signed-off-by: Dmitry Osipenko > --- > drivers/gpu/drm/tegra/drm.h | 2 ++ > drivers/gpu/drm/tegra/output.c | 10 ++++++++++ > drivers/gpu/drm/tegra/rgb.c | 34 ++++++++++++++++++++++++++++++++++ > 3 files changed, 46 insertions(+) > > diff --git a/drivers/gpu/drm/tegra/drm.h b/drivers/gpu/drm/tegra/drm.h > index 804869799305..cccd368b6752 100644 > --- a/drivers/gpu/drm/tegra/drm.h > +++ b/drivers/gpu/drm/tegra/drm.h > @@ -12,6 +12,7 @@ > #include > > #include > +#include > #include > #include > #include > @@ -116,6 +117,7 @@ struct tegra_output { > struct device_node *of_node; > struct device *dev; > > + struct drm_bridge *bridge; > struct drm_panel *panel; > struct i2c_adapter *ddc; > const struct edid *edid; > diff --git a/drivers/gpu/drm/tegra/output.c b/drivers/gpu/drm/tegra/output.c > index a6a711d54e88..37fc6b8c173f 100644 > --- a/drivers/gpu/drm/tegra/output.c > +++ b/drivers/gpu/drm/tegra/output.c > @@ -180,6 +180,16 @@ int tegra_output_init(struct drm_device *drm, struct tegra_output *output) > int connector_type; > int err; > > + if (output->bridge) { > + err = drm_bridge_attach(&output->encoder, output->bridge, > + NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR); Using DRM_BRIDGE_ATTACH_NO_CONNECTOR is definitely the way to go, but please be aware that it will require creating a connector and an encoder manually (which I think this driver already does), and using the bridge operations to implement the connector operations. I highly recommend using the DRM bridge connector helper for this purpose. > + if (err) { > + dev_err(output->dev, "cannot connect bridge: %d\n", > + err); > + return err; > + } > + } > + > if (output->panel) { May I also recommend switching to the DRM panel bridge helper ? It will simplify the code. > err = drm_panel_attach(output->panel, &output->connector); > if (err < 0) > diff --git a/drivers/gpu/drm/tegra/rgb.c b/drivers/gpu/drm/tegra/rgb.c > index 0562a7eb793f..0df213e92664 100644 > --- a/drivers/gpu/drm/tegra/rgb.c > +++ b/drivers/gpu/drm/tegra/rgb.c > @@ -5,6 +5,7 @@ > */ > > #include > +#include > > #include > #include > @@ -210,6 +211,7 @@ static const struct drm_encoder_helper_funcs tegra_rgb_encoder_helper_funcs = { > > int tegra_dc_rgb_probe(struct tegra_dc *dc) > { > + const unsigned int encoder_port = 0, panel_port = 1; > struct device_node *np; > struct tegra_rgb *rgb; > int err; > @@ -226,6 +228,38 @@ int tegra_dc_rgb_probe(struct tegra_dc *dc) > rgb->output.of_node = np; > rgb->dc = dc; > > + /* > + * Tegra devices that have LVDS panel utilize LVDS-encoder bridge > + * for converting 24/18 RGB data-lanes into 8 lanes. Encoder usually > + * have a powerdown control which needs to be enabled in order to > + * transfer data to the panel. Historically devices that use an older > + * device-tree version didn't model the bridge, assuming that encoder > + * is turned ON by default, while today's DRM allows us to model LVDS > + * encoder properly. > + * > + * Newer device-trees may utilize output->encoder->panel graph. > + * > + * For older device-trees we fall back to use nvidia,panel phandle. > + */ > + np = of_graph_get_remote_node(rgb->output.of_node, encoder_port, -1); > + if (np) { > + rgb->output.bridge = of_drm_find_bridge(np); > + of_node_put(np); > + > + if (!rgb->output.bridge) > + return -EPROBE_DEFER; > + > + np = of_graph_get_remote_node(rgb->output.bridge->of_node, > + panel_port, -1); This shouldn't be needed, the LVDS codec bridge driver should already get the panel and handle it internally. You only need to handle panels in this driver when they're connected directly to the RGB input. > + if (np) { > + rgb->output.panel = of_drm_find_panel(np); > + of_node_put(np); > + > + if (IS_ERR(rgb->output.panel)) > + return PTR_ERR(rgb->output.panel); > + } > + } > + > err = tegra_output_probe(&rgb->output); > if (err < 0) > return err; -- Regards, Laurent Pinchart _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel