Re: [Freedreno] [PATCH v4 4/7] drm/msm/dp: Allow attaching a drm_panel

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@linaro.org

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.

• return 0;

+}

+static int dp_parser_parse(struct dp_parser *parser, int connector_type) { int rc = 0;

@@ -284,6 +306,12 @@ static int dp_parser_parse(struct dp_parser *parser) if (rc) return rc;

• if (connector_type == DRM_MODE_CONNECTOR_eDP) {

• 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 dac10923abde..3172da089421 100644 --- a/drivers/gpu/drm/msm/dp/dp_parser.h +++ b/drivers/gpu/drm/msm/dp/dp_parser.h @@ -123,8 +123,9 @@ struct dp_parser { struct dp_display_data disp_data; const struct dp_regulator_cfg *regulator_cfg; u32 max_dp_lanes;

• struct drm_bridge *panel_bridge;

• int (*parse)(struct dp_parser *parser);

• int (*parse)(struct dp_parser *parser, int connector_type);

};

/**