drm/msm/dpu: revise timing engine programming to support widebus feature

Widebus feature will transmit two pixel data per pixel clock to interface.
Timing engine provides driving force for this purpose. This patch base
on HPG (Hardware Programming Guide) to revise timing engine register
setting to accommodate both widebus and non widebus application. Also
horizontal width parameters need to be reduced by half since two pixel
data are clocked out per pixel clock when widebus feature enabled.

Widebus can be enabled individually at DP. However at DSI, widebus have
to be enabled along with DSC to achieve pixel clock rate be scaled down
with same ratio as compression ratio when 10 bits per source component.
Therefore this patch add no supports of DSI related widebus and compression.

Changes in v2:
-- remove compression related code from timing
-- remove op_info from  struct msm_drm_private
-- remove unnecessary wide_bus_en variables
-- pass wide_bus_en into timing configuration by struct msm_dp

Changes in v3:
-- split patch into 3 patches

Changes in v4:
-- rework timing engine to not interfere with dsi/hdmi
-- cover both widebus and compression

Changes in v5:
-- remove supports of DSI widebus and compression

Changes in v7:
-- split this patch into 3 patches
-- add Tested-by

Changes in v8:
-- move new registers writes under DATA_HCTL_EN features check.

Changes in v10:
-- add const inside dpu_encoder_is_widebus_enabled()
-- drop useless parenthesis please

Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Tested-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/476281/
Link: https://lore.kernel.org/r/1645824192-29670-4-git-send-email-quic_khsieh@quicinc.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index 3940b9c6323b..b9a3940d97a4 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -206,6 +206,8 @@ struct dpu_encoder_virt {
 	struct msm_display_topology topology;
 
 	u32 idle_timeout;
+
+	bool wide_bus_en;
 };
 
 #define to_dpu_encoder_virt(x) container_of(x, struct dpu_encoder_virt, base)
@@ -214,6 +216,14 @@ 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_widebus_enabled(const struct drm_encoder *drm_enc)
+{
+	const struct dpu_encoder_virt *dpu_enc = to_dpu_encoder_virt(drm_enc);
+
+	return dpu_enc->wide_bus_en;
+}
+
 static void _dpu_encoder_setup_dither(struct dpu_hw_pingpong *hw_pp, unsigned bpc)
 {
 	struct dpu_hw_dither_cfg dither_cfg = { 0 };