Hi Bjorn
On 2021-10-05 16:13, Bjorn Andersson wrote:
> eDP panels might need some power sequencing and backlight management,
> so make it possible to associate a drm_panel with an eDP instance and
> prepare and enable the panel accordingly.
>
> Now that we know which hardware instance is DP and which is eDP,
> parser->parse() is passed the connector_type and the parser is limited
> to only search for a panel in the eDP case.
>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> ---
>
> Changes since v3:
> - Previously posted separately, now added to series
> - Make the search for a panel conditional on it being an eDP connector
> - Move the search to of_graph port 1 (was 2 to distinguish from DP
> link to USB-C connector)
>
> drivers/gpu/drm/msm/dp/dp_display.c | 9 ++++++---
> drivers/gpu/drm/msm/dp/dp_display.h | 1 +
> drivers/gpu/drm/msm/dp/dp_drm.c | 11 +++++++++++
> drivers/gpu/drm/msm/dp/dp_parser.c | 30 ++++++++++++++++++++++++++++-
> drivers/gpu/drm/msm/dp/dp_parser.h | 3 ++-
> 5 files changed, 49 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c
> b/drivers/gpu/drm/msm/dp/dp_display.c
> index eaf08f9e7d87..bdaf227f05dc 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -10,6 +10,7 @@
> #include <linux/component.h>
> #include <linux/of_irq.h>
> #include <linux/delay.h>
> +#include <drm/drm_panel.h>
>
> #include "msm_drv.h"
> #include "msm_kms.h"
> @@ -230,12 +231,14 @@ static int dp_display_bind(struct device *dev,
> struct device *master,
> priv = drm->dev_private;
> priv->dp = &(dp->dp_display);
>
> - rc = dp->parser->parse(dp->parser);
> + rc = dp->parser->parse(dp->parser, dp->dp_display.connector_type);
> if (rc) {
> DRM_ERROR("device tree parsing failed\n");
> goto end;
> }
>
> + dp->dp_display.panel_bridge = dp->parser->panel_bridge;
> +
> dp->aux->drm_dev = drm;
> rc = dp_aux_register(dp->aux);
> if (rc) {
> @@ -822,7 +825,7 @@ static int dp_display_set_mode(struct msm_dp
> *dp_display,
> return 0;
> }
>
> -static int dp_display_prepare(struct msm_dp *dp)
> +static int dp_display_prepare(struct msm_dp *dp_display)
> {
> return 0;
> }
> @@ -896,7 +899,7 @@ static int dp_display_disable(struct
> dp_display_private *dp, u32 data)
> return 0;
> }
>
> -static int dp_display_unprepare(struct msm_dp *dp)
> +static int dp_display_unprepare(struct msm_dp *dp_display)
> {
> return 0;
> }
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.h
> b/drivers/gpu/drm/msm/dp/dp_display.h
> index 02999408c052..24aefca66029 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.h
> +++ b/drivers/gpu/drm/msm/dp/dp_display.h
> @@ -15,6 +15,7 @@ struct msm_dp {
> struct device *codec_dev;
> struct drm_connector *connector;
> struct drm_encoder *encoder;
> + struct drm_bridge *panel_bridge;
> bool is_connected;
> bool audio_enabled;
> bool power_on;
> diff --git a/drivers/gpu/drm/msm/dp/dp_drm.c
> b/drivers/gpu/drm/msm/dp/dp_drm.c
> index f33e31523f56..76856c4ee1d6 100644
> --- a/drivers/gpu/drm/msm/dp/dp_drm.c
> +++ b/drivers/gpu/drm/msm/dp/dp_drm.c
> @@ -5,6 +5,7 @@
>
> #include <drm/drm_atomic_helper.h>
> #include <drm/drm_atomic.h>
> +#include <drm/drm_bridge.h>
> #include <drm/drm_crtc.h>
>
> #include "msm_drv.h"
> @@ -160,5 +161,15 @@ struct drm_connector
> *dp_drm_connector_init(struct msm_dp *dp_display)
>
> drm_connector_attach_encoder(connector, dp_display->encoder);
>
> + if (dp_display->panel_bridge) {
> + ret = drm_bridge_attach(dp_display->encoder,
> + dp_display->panel_bridge, NULL,
> + DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> + if (ret < 0) {
> + DRM_ERROR("failed to attach panel bridge: %d\n", ret);
> + return ERR_PTR(ret);
> + }
> + }
> +
> return connector;
> }
> diff --git a/drivers/gpu/drm/msm/dp/dp_parser.c
> b/drivers/gpu/drm/msm/dp/dp_parser.c
> index 4d6e047f803d..eb6bbfbea484 100644
> --- a/drivers/gpu/drm/msm/dp/dp_parser.c
> +++ b/drivers/gpu/drm/msm/dp/dp_parser.c
> @@ -6,6 +6,7 @@
> #include <linux/of_gpio.h>
> #include <linux/phy/phy.h>
>
> +#include <drm/drm_of.h>
> #include <drm/drm_print.h>
>
> #include "dp_parser.h"
> @@ -263,7 +264,28 @@ static int dp_parser_clock(struct dp_parser
> *parser)
> return 0;
> }
>
> -static int dp_parser_parse(struct dp_parser *parser)
> +static int dp_parser_find_panel(struct dp_parser *parser)
> +{
> + struct device *dev = &parser->pdev->dev;
> + struct drm_panel *panel;
> + int rc;
> +
> + rc = drm_of_find_panel_or_bridge(dev->of_node, 1, 0, &panel, NULL);
> + if (rc) {
> + DRM_ERROR("failed to acquire DRM panel: %d\n", rc);
> + return rc;
> + }
> +
> + parser->panel_bridge = devm_drm_panel_bridge_add(dev, panel);
> + if (IS_ERR(parser->panel_bridge)) {
> + DRM_ERROR("failed to create panel bridge\n");
> + return PTR_ERR(parser->panel_bridge);
> + }
When we add a bridge using devm_drm_panel_bridge_add(), it will
register
with default bridge functions which is fine
because we need the panel power to be controlled here.
140 static const struct drm_bridge_funcs panel_bridge_bridge_funcs = {
141 .attach = panel_bridge_attach,
142 .detach = panel_bridge_detach,
143 .pre_enable = panel_bridge_pre_enable,
144 .enable = panel_bridge_enable,
145 .disable = panel_bridge_disable,
146 .post_disable = panel_bridge_post_disable,
147 .get_modes = panel_bridge_get_modes,
But what about the EDID related things, the DP/eDP driver already
reads the
EDID and gets the modes so we need to skip
that in this case as otherwise it will end up calling the
panel_get_modes in
the eDP panel which will be redundant.
Let me know if I am missing something in this proposal.
