[PATCH v13 12/17] drm/bridge: analogix_dp: Add new API analogix_dp_finish_probe()

Damon Ding
2026-04-09T06:53:47Z

Since the panel/bridge should logically be positioned behind the
Analogix bridge in the display pipeline, it makes sense to handle
the panel/bridge parsing on the Analogix side. Therefore, we add
a new API analogix_dp_finish_probe(), which combines the panel/bridge
parsing with component addition, to do it.

In order to process component binding right after the probe completes,
the &analogix_dp_plat_data.ops is newly added to pass &component_ops,
for which the &dp_aux_ep_device_with_data.done_probing() of DP AUX bus
only supports passing &drm_dp_aux.

Signed-off-by: Damon Ding <damon.ding@rock-chips.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Heiko Stuebner <heiko@sntech.de> # rk3588

---

Changes in v4:
- Rename the &analogix_dp_plat_data.bridge to
&analogix_dp_plat_data.next_bridge.
- Remame API analogix_dp_find_panel_or_bridge() to
analogix_dp_finish_probe().

Changes in v5:
- Select DRM_DISPLAY_DP_AUX_BUS for DRM_ANALOGIX_DP.

Changes in v9:
- Add Tested-by tag.

Changes in v10:
- Fix to use dev_err_probe() in analogix_dp_finish_probe().
- Expand the commit message.

Changes in v13:
- Modify '(on rk3588)' to '# rk3588' for Tested-by tag.
---
drivers/gpu/drm/bridge/analogix/Kconfig | 1 +
.../drm/bridge/analogix/analogix_dp_core.c | 46 +++++++++++++++++++
include/drm/bridge/analogix_dp.h | 2 +
3 files changed, 49 insertions(+)

diff --git a/drivers/gpu/drm/bridge/analogix/Kconfig b/drivers/gpu/drm/bridge/analogix/Kconfig
index 03dc7ffe824a..8a6136cd675f 100644
--- a/drivers/gpu/drm/bridge/analogix/Kconfig
+++ b/drivers/gpu/drm/bridge/analogix/Kconfig
@@ -29,6 +29,7 @@ config DRM_ANALOGIX_ANX78XX
config DRM_ANALOGIX_DP
tristate
depends on DRM
+ select DRM_DISPLAY_DP_AUX_BUS

config DRM_ANALOGIX_ANX7625
tristate "Analogix Anx7625 MIPI to DP interface support"
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index 4c0192733085..17d078b836e3 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -20,12 +20,14 @@
#include <linux/platform_device.h>

#include <drm/bridge/analogix_dp.h>
+#include <drm/display/drm_dp_aux_bus.h>
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_crtc.h>
#include <drm/drm_device.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>
@@ -1581,6 +1583,50 @@ struct drm_dp_aux *analogix_dp_get_aux(struct analogix_dp_device *dp)
}
EXPORT_SYMBOL_GPL(analogix_dp_get_aux);

+static int analogix_dp_aux_done_probing(struct drm_dp_aux *aux)
+{
+ struct analogix_dp_device *dp = to_dp(aux);
+ struct analogix_dp_plat_data *plat_data = dp->plat_data;
+ int port = plat_data->dev_type == EXYNOS_DP ? 0 : 1;
+ int ret;
+
+ /*
+ * If drm_of_find_panel_or_bridge() returns -ENODEV, there may be no valid panel
+ * or bridge nodes. The driver should go on for the driver-free bridge or the DP
+ * mode applications.
+ */
+ ret = drm_of_find_panel_or_bridge(dp->dev->of_node, port, 0,
+ &plat_data->panel, &plat_data->next_bridge);
+ if (ret && ret != -ENODEV)
+ return ret;
+
+ return component_add(dp->dev, plat_data->ops);
+}
+
+int analogix_dp_finish_probe(struct analogix_dp_device *dp)
+{
+ int ret;
+
+ ret = devm_of_dp_aux_populate_bus(&dp->aux, analogix_dp_aux_done_probing);
+ if (ret) {
+ /*
+ * If devm_of_dp_aux_populate_bus() returns -ENODEV, the done_probing() will
+ * not be called because there are no EP devices. Then the callback function
+ * analogix_dp_aux_done_probing() will be called directly in order to support
+ * the other valid DT configurations.
+ *
+ * NOTE: The devm_of_dp_aux_populate_bus() is allowed to return -EPROBE_DEFER.
+ */
+ if (ret != -ENODEV)
+ return dev_err_probe(dp->dev, ret, "failed to populate aux bus\n");
+
+ return analogix_dp_aux_done_probing(&dp->aux);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(analogix_dp_finish_probe);
+
MODULE_AUTHOR("Jingoo Han <jg1.han@samsung.com>");
MODULE_DESCRIPTION("Analogix DP Core Driver");
MODULE_LICENSE("GPL v2");
diff --git a/include/drm/bridge/analogix_dp.h b/include/drm/bridge/analogix_dp.h
index 3428ffff24c5..bae969dec63a 100644
--- a/include/drm/bridge/analogix_dp.h
+++ b/include/drm/bridge/analogix_dp.h
@@ -30,6 +30,7 @@ struct analogix_dp_plat_data {
struct drm_bridge *next_bridge;
struct drm_encoder *encoder;
struct drm_connector *connector;
+ const struct component_ops *ops;

int (*power_on)(struct analogix_dp_plat_data *);
int (*power_off)(struct analogix_dp_plat_data *);
@@ -49,5 +50,6 @@ int analogix_dp_stop_crc(struct drm_connector *connector);

struct analogix_dp_plat_data *analogix_dp_aux_to_plat_data(struct drm_dp_aux *aux);
struct drm_dp_aux *analogix_dp_get_aux(struct analogix_dp_device *dp);
+int analogix_dp_finish_probe(struct analogix_dp_device *dp);

#endif /* _ANALOGIX_DP_H_ */
--
2.34.1