Hi Dmitry,
On 2025/3/2 2:14, Dmitry Baryshkov wrote:
On Sun, Feb 23, 2025 at 07:30:25PM +0800, Andy Yan wrote:
From: Andy Yan <andy.yan@xxxxxxxxxxxxxx>
The DW DP TX Controller is compliant with the DisplayPort Specification
Version 1.4 with the following features:
* DisplayPort 1.4a
* Main Link: 1/2/4 lanes
* Main Link Support 1.62Gbps, 2.7Gbps, 5.4Gbps and 8.1Gbps
* AUX channel 1Mbps
* Single Stream Transport(SST)
* Multistream Transport (MST)
*Type-C support (alternate mode)
* HDCP 2.2, HDCP 1.3
* Supports up to 8/10 bits per color component
* Supports RBG, YCbCr4:4:4, YCbCr4:2:2, YCbCr4:2:0
* Pixel clock up to 594MHz
* I2S, SPDIF audio interface
Add library with common helpers to make it can be shared with
other SoC.
Signed-off-by: Andy Yan <andy.yan@xxxxxxxxxxxxxx>
drm/bridge: cleanup
Stray line?
---
drivers/gpu/drm/bridge/synopsys/Kconfig | 7 +
drivers/gpu/drm/bridge/synopsys/Makefile | 1 +
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 2155 ++++++++++++++++++++++
include/drm/bridge/dw_dp.h | 19 +
4 files changed, 2182 insertions(+)
create mode 100644 drivers/gpu/drm/bridge/synopsys/dw-dp.c
......
+
+static u8 dw_dp_voltage_max(u8 preemph)
+{
+ switch (preemph & DP_TRAIN_PRE_EMPHASIS_MASK) {
+ case DP_TRAIN_PRE_EMPH_LEVEL_0:
+ return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
+ case DP_TRAIN_PRE_EMPH_LEVEL_1:
+ return DP_TRAIN_VOLTAGE_SWING_LEVEL_2;
+ case DP_TRAIN_PRE_EMPH_LEVEL_2:
+ return DP_TRAIN_VOLTAGE_SWING_LEVEL_1;
+ case DP_TRAIN_PRE_EMPH_LEVEL_3:
+ default:
+ return DP_TRAIN_VOLTAGE_SWING_LEVEL_0;
+ }
+}
+
+static void dw_dp_link_get_adjustments(struct dw_dp_link *link,
+ u8 status[DP_LINK_STATUS_SIZE])
+{
+ struct dw_dp_link_train_set *adjust = &link->train.adjust;
+ u8 v = 0;
+ u8 p = 0;
+ unsigned int i;
+
+ for (i = 0; i < link->lanes; i++) {
+ v = drm_dp_get_adjust_request_voltage(status, i);
+ p = drm_dp_get_adjust_request_pre_emphasis(status, i);
+ if (p >= DP_TRAIN_PRE_EMPH_LEVEL_3) {
+ adjust->pre_emphasis[i] = DP_TRAIN_PRE_EMPH_LEVEL_3 >>
+ DP_TRAIN_PRE_EMPHASIS_SHIFT;
+ adjust->pre_max_reached[i] = true;
+ } else {
+ adjust->pre_emphasis[i] = p >> DP_TRAIN_PRE_EMPHASIS_SHIFT;
+ adjust->pre_max_reached[i] = false;
+ }
+ v = min(v, dw_dp_voltage_max(p));
+ if (v >= DP_TRAIN_VOLTAGE_SWING_LEVEL_3) {
+ adjust->voltage_swing[i] = DP_TRAIN_VOLTAGE_SWING_LEVEL_3 >>
+ DP_TRAIN_VOLTAGE_SWING_SHIFT;
+ adjust->voltage_max_reached[i] = true;
+ } else {
+ adjust->voltage_swing[i] = v >> DP_TRAIN_VOLTAGE_SWING_SHIFT;
+ adjust->voltage_max_reached[i] = false;
+ }
+ }
+}
+
+static void dw_dp_link_train_adjust(struct dw_dp_link_train *train)
+{
+ struct dw_dp_link_train_set *request = &train->request;
+ struct dw_dp_link_train_set *adjust = &train->adjust;
+ unsigned int i;
+
+ for (i = 0; i < 4; i++) {
Shouldn't it be a loop up to link->lanes?
+ if (request->voltage_swing[i] != adjust->voltage_swing[i])
+ request->voltage_swing[i] = adjust->voltage_swing[i];
+ if (request->voltage_max_reached[i] != adjust->voltage_max_reached[i])
+ request->voltage_max_reached[i] = adjust->voltage_max_reached[i];
+ }
+
+ for (i = 0; i < 4; i++) {
+ if (request->pre_emphasis[i] != adjust->pre_emphasis[i])
+ request->pre_emphasis[i] = adjust->pre_emphasis[i];
+ if (request->pre_max_reached[i] != adjust->pre_max_reached[i])
+ request->pre_max_reached[i] = adjust->pre_max_reached[i];
Why do you need separate request and adjustment structs?
During link training cr sequence, if dprx keep the LANEx_CR_DONE bit(s)
cleared, the request and adjustment structs are used to check the
old and new valud of ADJUST_REQUEST_LANEx_y register(s) is changed or not
