[PATCH 5/5] drm/bridge: simple-bridge: Add next panel support

Liu Ying
2025-03-04T10:15:02Z

The next bridge connected to a simple bridge could be a panel, e.g.,
a DPI panel connected to a DPI color encoder. Add the next panel support,
instead of supporting non-panel next bridge only.

Signed-off-by: Liu Ying <victor.liu@nxp.com>
---
drivers/gpu/drm/bridge/Kconfig | 1 +
drivers/gpu/drm/bridge/simple-bridge.c | 32 ++++++++++++++++----------
2 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index d20f1646dac2..92187dbdd32b 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -310,6 +310,7 @@ config DRM_SIMPLE_BRIDGE
tristate "Simple DRM bridge support"
depends on OF
select DRM_KMS_HELPER
+ select DRM_PANEL_BRIDGE
help
Support for non-programmable DRM bridges, such as ADI ADV7123, TI
THS8134 and THS8135 or passive resistor ladder DACs.
diff --git a/drivers/gpu/drm/bridge/simple-bridge.c b/drivers/gpu/drm/bridge/simple-bridge.c
index c0445bd20e07..4c585e5583ca 100644
--- a/drivers/gpu/drm/bridge/simple-bridge.c
+++ b/drivers/gpu/drm/bridge/simple-bridge.c
@@ -19,6 +19,7 @@
#include <drm/drm_crtc.h>
#include <drm/drm_edid.h>
#include <drm/drm_of.h>
+#include <drm/drm_panel.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>

@@ -35,6 +36,7 @@ struct simple_bridge {
const struct simple_bridge_info *info;

struct drm_bridge *next_bridge;
+ struct drm_panel *next_panel;
struct regulator *vdd;
struct gpio_desc *enable;

@@ -114,6 +116,10 @@ static int simple_bridge_attach(struct drm_bridge *bridge,
struct simple_bridge *sbridge = drm_bridge_to_simple_bridge(bridge);
int ret;

+ if (sbridge->next_panel)
+ return drm_bridge_attach(bridge->encoder, sbridge->next_bridge,
+ bridge, flags);
+
ret = drm_bridge_attach(bridge->encoder, sbridge->next_bridge, bridge,
DRM_BRIDGE_ATTACH_NO_CONNECTOR);
if (ret < 0)
@@ -247,7 +253,6 @@ static int simple_bridge_get_dpi_color_coding(struct simple_bridge *sbridge,
static int simple_bridge_probe(struct platform_device *pdev)
{
struct simple_bridge *sbridge;
- struct device_node *remote;
int ret;

sbridge = devm_kzalloc(&pdev->dev, sizeof(*sbridge), GFP_KERNEL);
@@ -257,17 +262,20 @@ static int simple_bridge_probe(struct platform_device *pdev)
sbridge->info = of_device_get_match_data(&pdev->dev);

/* Get the next bridge in the pipeline. */
- remote = of_graph_get_remote_node(pdev->dev.of_node, 1, -1);
- if (!remote)
- return -EINVAL;
-
- sbridge->next_bridge = of_drm_find_bridge(remote);
- of_node_put(remote);
-
- if (!sbridge->next_bridge) {
- dev_dbg(&pdev->dev, "Next bridge not found, deferring probe\n");
- return -EPROBE_DEFER;
- }
+ ret = drm_of_find_panel_or_bridge(pdev->dev.of_node, 1, -1,
+ &sbridge->next_panel,
+ &sbridge->next_bridge);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret,
+ "Next panel or bridge not found\n");
+
+ if (sbridge->next_panel)
+ sbridge->next_bridge = devm_drm_panel_bridge_add(&pdev->dev,
+ sbridge->next_panel);
+
+ if (IS_ERR(sbridge->next_bridge))
+ return dev_err_probe(&pdev->dev, PTR_ERR(sbridge->next_bridge),
+ "Next bridge not found\n");

/* Get the regulator and GPIO resources. */
sbridge->vdd = devm_regulator_get_optional(&pdev->dev, "vdd");
--
2.34.1