Re: [Freedreno] [PATCH v4 4/7] drm/msm/dp: Allow attaching a drm_panel
From: abhinavk
Date: Tue Oct 05 2021 - 20:35:55 EST
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.
+
+ 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);
};
/**