From: Sam Ravnborg <sam@ravnborg.org>
To: Dmitry Osipenko <digetx@gmail.com>, g@ravnborg.org
Cc: devicetree@vger.kernel.org, dri-devel@lists.freedesktop.org,
linux-kernel@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
Thierry Reding <thierry.reding@gmail.com>,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
linux-tegra@vger.kernel.org,
Frank Rowand <frowand.list@gmail.com>
Subject: Re: [PATCH v5 5/6] drm/tegra: output: rgb: Support LVDS encoder bridge
Date: Wed, 6 May 2020 18:45:17 +0200 [thread overview]
Message-ID: <20200506164517.GE19296@ravnborg.org> (raw)
In-Reply-To: <20200418170703.1583-6-digetx@gmail.com>
On Sat, Apr 18, 2020 at 08:07:02PM +0300, Dmitry Osipenko wrote:
> Newer Tegra device-trees will specify a video output graph, which involves
> LVDS encoder bridge. This patch adds support for the LVDS encoder bridge
> to the RGB output, allowing us to model the display hardware properly.
>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
> ---
> drivers/gpu/drm/tegra/rgb.c | 58 +++++++++++++++++++++++++++++++------
> 1 file changed, 49 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/tegra/rgb.c b/drivers/gpu/drm/tegra/rgb.c
> index 0562a7eb793f..9a7024ec96bc 100644
> --- a/drivers/gpu/drm/tegra/rgb.c
> +++ b/drivers/gpu/drm/tegra/rgb.c
> @@ -7,6 +7,7 @@
> #include <linux/clk.h>
>
> #include <drm/drm_atomic_helper.h>
> +#include <drm/drm_bridge_connector.h>
> #include <drm/drm_panel.h>
> #include <drm/drm_simple_kms_helper.h>
>
> @@ -267,24 +268,63 @@ int tegra_dc_rgb_remove(struct tegra_dc *dc)
> int tegra_dc_rgb_init(struct drm_device *drm, struct tegra_dc *dc)
> {
> struct tegra_output *output = dc->rgb;
> + struct drm_connector *connector;
> int err;
>
> if (!dc->rgb)
> return -ENODEV;
>
> - drm_connector_init(drm, &output->connector, &tegra_rgb_connector_funcs,
> - DRM_MODE_CONNECTOR_LVDS);
> - drm_connector_helper_add(&output->connector,
> - &tegra_rgb_connector_helper_funcs);
> - output->connector.dpms = DRM_MODE_DPMS_OFF;
> -
> drm_simple_encoder_init(drm, &output->encoder, DRM_MODE_ENCODER_LVDS);
> drm_encoder_helper_add(&output->encoder,
> &tegra_rgb_encoder_helper_funcs);
>
> - drm_connector_attach_encoder(&output->connector,
> - &output->encoder);
> - drm_connector_register(&output->connector);
> + /*
> + * Tegra devices that have LVDS panel utilize LVDS encoder bridge
> + * for converting up to 28 LCD LVTTL lanes into 5/4 LVDS lanes that
> + * go to display panel's receiver.
> + *
> + * Encoder usually have a power-down control which needs to be enabled
> + * in order to transmit 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 utilize LVDS encoder bridge, which provides
> + * us with a connector and handles the display panel.
> + *
> + * For older device-trees we fall back to our own connector and use
> + * nvidia,panel phandle.
> + */
> + if (output->bridge) {
> + err = drm_bridge_attach(&output->encoder, output->bridge,
> + NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> + if (err) {
> + dev_err(output->dev, "failed to attach bridge: %d\n",
> + err);
> + return err;
> + }
> +
> + connector = drm_bridge_connector_init(drm, &output->encoder);
> + if (IS_ERR(connector)) {
> + dev_err(output->dev,
> + "failed to initialize bridge connector: %pe\n",
> + connector);
> + return PTR_ERR(connector);
> + }
> +
> + drm_connector_attach_encoder(connector, &output->encoder);
> + } else {
> + drm_connector_init(drm, &output->connector,
> + &tegra_rgb_connector_funcs,
> + DRM_MODE_CONNECTOR_LVDS);
> + drm_connector_helper_add(&output->connector,
> + &tegra_rgb_connector_helper_funcs);
> + output->connector.dpms = DRM_MODE_DPMS_OFF;
> +
> + drm_connector_attach_encoder(&output->connector,
> + &output->encoder);
> + drm_connector_register(&output->connector);
> + }
>
> err = tegra_output_init(drm, output);
> if (err < 0) {
> --
> 2.26.0
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2020-05-06 16:45 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-18 17:06 [PATCH v5 0/6] Support DRM bridges on NVIDIA Tegra Dmitry Osipenko
2020-04-18 17:06 ` [PATCH v5 1/6] of_graph: add of_graph_get_local_port() Dmitry Osipenko
2020-04-30 14:10 ` Rob Herring
2020-05-06 16:32 ` Sam Ravnborg
2020-05-11 20:27 ` Rob Herring
2020-04-18 17:06 ` [PATCH v5 2/6] drm/of: Make drm_of_find_panel_or_bridge() to check graph's presence Dmitry Osipenko
2020-05-06 16:41 ` Sam Ravnborg
2020-05-06 17:05 ` Dmitry Osipenko
2020-04-18 17:07 ` [PATCH v5 3/6] drm/tegra: output: Don't leak OF node on error Dmitry Osipenko
2020-05-06 16:42 ` Sam Ravnborg
2020-04-18 17:07 ` [PATCH v5 4/6] drm/tegra: output: Support DRM bridges Dmitry Osipenko
2020-05-06 16:43 ` Sam Ravnborg
2020-04-18 17:07 ` [PATCH v5 5/6] drm/tegra: output: rgb: Support LVDS encoder bridge Dmitry Osipenko
2020-05-06 16:45 ` Sam Ravnborg [this message]
2020-04-18 17:07 ` [PATCH v5 6/6] drm/tegra: output: rgb: Wrap directly-connected panel into DRM bridge Dmitry Osipenko
2020-04-25 17:02 ` Sam Ravnborg
2020-04-25 21:51 ` Dmitry Osipenko
2020-05-24 18:41 ` [PATCH v5 0/6] Support DRM bridges on NVIDIA Tegra Dmitry Osipenko
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200506164517.GE19296@ravnborg.org \
--to=sam@ravnborg.org \
--cc=devicetree@vger.kernel.org \
--cc=digetx@gmail.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=frowand.list@gmail.com \
--cc=g@ravnborg.org \
--cc=laurent.pinchart@ideasonboard.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tegra@vger.kernel.org \
--cc=robh+dt@kernel.org \
--cc=thierry.reding@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).