[PATCH v3 2/3] drm/msm/dp: revise timing engine programming to support compression (DSC)

From: Kuogee Hsieh
Date: Fri Feb 04 2022 - 13:37:12 EST


Divides horizontal width by 3 at timing engine of interface. There are
major part of compression (DSC) programming have to be done at DSC
controller which is not covered by this patch.

Signed-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c | 22 ++++++++++++++++++----
drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h | 3 +++
2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
index 35d4aaa..ee7ca34 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
@@ -128,7 +128,7 @@ static void dpu_hw_intf_setup_timing_engine(struct dpu_hw_intf *ctx,
* video timing. It is recommended to enable it for all cases, except
* if compression is enabled in 1 pixel per clock mode
*/
- if (p->wide_bus_en)
+ if (!p->compression_en || p->wide_bus_en)
intf_cfg2 |= BIT(4);

if (p->wide_bus_en)
@@ -150,10 +150,16 @@ static void dpu_hw_intf_setup_timing_engine(struct dpu_hw_intf *ctx,
*/
data_width = p->width;

- if (!dp_intf && p->wide_bus_en)
+ if (p->compression_en) {
+ data_width = DIV_ROUND_UP(p->dce_bytes_per_line, 3);
+
+ if (p->wide_bus_en)
+ data_width >>= 1;
+ } else if (!dp_intf && p->wide_bus_en) {
data_width = p->width >> 1;
- else
+ } else {
data_width = p->width;
+ }

hsync_data_start_x = hsync_start_x;
hsync_data_end_x = hsync_start_x + data_width - 1;
@@ -178,8 +184,16 @@ static void dpu_hw_intf_setup_timing_engine(struct dpu_hw_intf *ctx,

active_hctl = (active_h_end << 16) | active_h_start;

- if (dp_intf)
+ if (dp_intf) {
display_hctl = active_hctl;
+ if (p->compression_en) {
+ active_data_hctl = (hsync_start_x +
+ p->extra_dto_cycles) << 16;
+ active_data_hctl += hsync_start_x;
+
+ display_data_hctl = active_data_hctl;
+ }
+ }

den_polarity = 0;
if (ctx->cap->type == INTF_HDMI) {
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h
index e4a518a..8fc71ce 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h
@@ -32,6 +32,9 @@ struct intf_timing_params {
u32 hsync_skew;

bool wide_bus_en;
+ bool compression_en;
+ u32 extra_dto_cycles; /* for DP only */
+ u32 dce_bytes_per_line;
};

struct intf_prog_fetch {
--
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