On Thu 29 Jul 04:59 CDT 2021, Dmitry Baryshkov wrote:
> On 27/07/2021 02:13, Bjorn Andersson wrote:
> > 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>
>
> The idea looks good from my point of view.
Thanks.
> For v1 could you please extend it with the `if (panel)` checks and
> handling of the error codes.
Passing NULL to the drm_panel_* api is valid and a nop, and I run the
same code for both eDP and DP.
Would you still like it to indicate to a future reader that this might
be NULL?
Regards,
Bjorn
>
> > ---
> >
> > 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.
> >
> > 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);
> > };
> >
>
>
> --
> With best wishes
> Dmitry
