Quoting Bjorn Andersson (2021-07-26 16:13:51) > eDP panels might need some power sequencing and backlight management, > so make it possible to associate a drm_panel with a DP instance and > prepare and enable the panel accordingly. > > Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx> > --- > > This solves my immediate problem on my 8cx laptops, of indirectly controlling > the backlight during DPMS. But my panel is powered when I boot it and as such I > get the hpd interrupt and I don't actually have to deal with a power on > sequence - so I'm posting this as an RFC, hoping to get some input on these > other aspects. > > If this is acceptable I'd be happy to write up an accompanying DT binding > change that marks port 2 of the DP controller's of_graph as a reference to the > attached panel. dianders@ mentioned creating a connector (and maybe a bridge) for the DP connector (not eDP)[1]. I'm not sure that's directly related, but I think with the aux bus code the panel isn't managed in the encoder driver. Instead the encoder sees a bridge and tries to power it up and then query things over the aux bus? It's all a little too fuzzy to me right now so I could be spewing nonsense but I think we want to take this bridge route if possible. -Stephen [1] https://lore.kernel.org/r/CAD=FV=Xd9fizYdxfXYOkpJ_1fZcHp3-ROJ7k4iPg0g0RQ_+A3Q@xxxxxxxxxxxxxx/ > > drivers/gpu/drm/msm/dp/dp_display.c | 15 +++++++++++++-- > drivers/gpu/drm/msm/dp/dp_display.h | 1 + > drivers/gpu/drm/msm/dp/dp_parser.c | 19 +++++++++++++++++++ > drivers/gpu/drm/msm/dp/dp_parser.h | 1 + > 4 files changed, 34 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c > index 206bf7806f51..1db5a3f752d2 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" > @@ -252,6 +253,8 @@ static int dp_display_bind(struct device *dev, struct device *master, > goto end; > } > > + dp->dp_display.drm_panel = dp->parser->drm_panel; > + > rc = dp_aux_register(dp->aux, drm); > if (rc) { > DRM_ERROR("DRM DP AUX register failed\n"); > @@ -867,8 +870,10 @@ 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) > { > + drm_panel_prepare(dp_display->drm_panel); > + > return 0; > } > > @@ -886,6 +891,8 @@ static int dp_display_enable(struct dp_display_private *dp, u32 data) > if (!rc) > dp_display->power_on = true; > > + drm_panel_enable(dp_display->drm_panel); > + > return rc; > } > > @@ -915,6 +922,8 @@ static int dp_display_disable(struct dp_display_private *dp, u32 data) > if (!dp_display->power_on) > return 0; > > + drm_panel_disable(dp_display->drm_panel); > + > /* wait only if audio was enabled */ > if (dp_display->audio_enabled) { > /* signal the disconnect event */ > @@ -939,8 +948,10 @@ 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) > { > + drm_panel_unprepare(dp_display->drm_panel); > + > return 0; > } > > diff --git a/drivers/gpu/drm/msm/dp/dp_display.h b/drivers/gpu/drm/msm/dp/dp_display.h > index 8b47cdabb67e..ce337824c95d 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_panel *drm_panel; > bool is_connected; > bool audio_enabled; > bool power_on; > diff --git a/drivers/gpu/drm/msm/dp/dp_parser.c b/drivers/gpu/drm/msm/dp/dp_parser.c > index fc8a6452f641..e6a6e9007bfd 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" > @@ -276,6 +277,20 @@ static int dp_parser_clock(struct dp_parser *parser) > return 0; > } > > +static int dp_parser_find_panel(struct dp_parser *parser) > +{ > + struct device_node *np = parser->pdev->dev.of_node; > + int rc; > + > + rc = drm_of_find_panel_or_bridge(np, 2, 0, &parser->drm_panel, NULL); > + if (rc == -ENODEV) > + rc = 0; > + else if (rc) > + DRM_ERROR("failed to acquire DRM panel: %d\n", rc); > + > + return rc; > +} > + > static int dp_parser_parse(struct dp_parser *parser) > { > int rc = 0; > @@ -297,6 +312,10 @@ static int dp_parser_parse(struct dp_parser *parser) > if (rc) > return rc; > > + rc = dp_parser_find_panel(parser); > + if (rc) > + return rc; > + > /* Map the corresponding regulator information according to > * version. Currently, since we only have one supported platform, > * mapping the regulator directly. > diff --git a/drivers/gpu/drm/msm/dp/dp_parser.h b/drivers/gpu/drm/msm/dp/dp_parser.h > index 3266b529c090..994ca9336acd 100644 > --- a/drivers/gpu/drm/msm/dp/dp_parser.h > +++ b/drivers/gpu/drm/msm/dp/dp_parser.h > @@ -122,6 +122,7 @@ struct dp_parser { > struct dp_display_data disp_data; > const struct dp_regulator_cfg *regulator_cfg; > u32 max_dp_lanes; > + struct drm_panel *drm_panel; > > int (*parse)(struct dp_parser *parser); > }; > --
