[PATCH v3 2/3] drm/msm/disp/dpu1: add helper to know if display is builtin

[Kalyan Thota]

Since DRM encoder type for few encoders can be similar
(like eDP and DP) find out if the interface supports HPD
from encoder bridge to differentiate between builtin
and pluggable displays.

Changes in v1:
- add connector type in the disp_info (Dmitry)
- add helper functions to know encoder type
- update commit text reflecting the change

Changes in v2:
- avoid hardcode of connector type for DSI as it may not be true (Dmitry)
- get the HPD information from encoder bridge

Changes in v3:
- use bridge type instead of bridge ops in determining connector (Dmitry)

Signed-off-by: Kalyan Thota <quic_kalyant at quicinc.com>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 27 +++++++++++++++++++++++++++
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h |  6 ++++++
 2 files changed, 33 insertions(+)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index 9c6817b..574f2b0 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -15,6 +15,7 @@
 #include <drm/drm_crtc.h>
 #include <drm/drm_file.h>
 #include <drm/drm_probe_helper.h>
+#include <drm/drm_bridge.h>
 
 #include "msm_drv.h"
 #include "dpu_kms.h"
@@ -217,6 +218,32 @@ static u32 dither_matrix[DITHER_MATRIX_SZ] = {
 	15, 7, 13, 5, 3, 11, 1, 9, 12, 4, 14, 6, 0, 8, 2, 10
 };
 
+bool dpu_encoder_is_builtin(struct drm_encoder *encoder)
+{
+	struct drm_bridge *bridge;
+	int ops = 0;
+
+	if (!encoder)
+		return false;
+
+	/* Get last bridge in the chain to determine connector type */
+	drm_for_each_bridge_in_chain(encoder, bridge)
+		if (!drm_bridge_get_next_bridge(bridge))
+			ops = bridge->type;
+
+	switch (ops) {
+	case DRM_MODE_CONNECTOR_Unknown:
+	case DRM_MODE_CONNECTOR_LVDS:
+	case DRM_MODE_CONNECTOR_eDP:
+	case DRM_MODE_CONNECTOR_DSI:
+	case DRM_MODE_CONNECTOR_DPI:
+	case DRM_MODE_CONNECTOR_WRITEBACK:
+	case DRM_MODE_CONNECTOR_VIRTUAL:
+		return true;
+	default:
+		return false;
+	}
+}
 
 bool dpu_encoder_is_widebus_enabled(const struct drm_encoder *drm_enc)
 {
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
index 9e7236e..7f3d823 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
@@ -224,4 +224,10 @@ void dpu_encoder_cleanup_wb_job(struct drm_encoder *drm_enc,
  */
 bool dpu_encoder_is_valid_for_commit(struct drm_encoder *drm_enc);
 
+/**
+ * dpu_encoder_is_builtin - find if the encoder is of type builtin
+ * @drm_enc:    Pointer to previously created drm encoder structure
+ */
+bool dpu_encoder_is_builtin(struct drm_encoder *drm_enc);
+
 #endif /* __DPU_ENCODER_H__ */
-- 
2.7.4