diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c index a74c855936b2..18e76d1e78e1 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c @@ -1244,6 +1244,73 @@ static const struct drm_bridge_funcs analogix_dp_bridge_funcs = { .detect = analogix_dp_bridge_detect, }; +static int analogix_dp_dt_parse_lanes_map(struct analogix_dp_device *dp) +{ + struct video_info *video_info = &dp->video_info; + struct device_node *endpoint; + u32 lane_idx[LANE_COUNT4]; + u32 map[LANE_COUNT4] = {0, 1, 2, 3}; + bool used[LANE_COUNT4] = {false}; + int num_lanes; + int ret, i; + + memcpy(video_info->lane_map, map, sizeof(map)); + + num_lanes = drm_of_get_data_lanes_count_ep(dp->dev->of_node, 1, 0, 1, + video_info->max_lane_count); + if (num_lanes < 0) + return -EINVAL; + + endpoint = of_graph_get_endpoint_by_regs(dp->dev->of_node, 1, 0); + if (!endpoint) + return -EINVAL; + + ret = of_property_read_u32_array(endpoint, "data-lanes", lane_idx, num_lanes); + of_node_put(endpoint); + if (ret) + return -EINVAL; + + for (i = 0; i < num_lanes; i++) { + if (lane_idx[i] >= LANE_COUNT4) { + dev_dbg(dp->dev, "data-lanes[%d] = %u is out of range\n", i, lane_idx[i]); + return -EINVAL; + } + + if (used[lane_idx[i]]) { + dev_dbg(dp->dev, "data-lanes[%d] = %u is duplicate\n", i, lane_idx[i]); + return -EINVAL; + } + + used[lane_idx[i]] = true; + map[i] = lane_idx[i]; + } + + /* + * Fill the map[] entries not described by 'data-lanes' with the + * lane indices not used so far, e.g. for 'data-lanes = <3 1>': + * + * used[] = {0, 1, 0, 1} // only lanes 1 and 3 are used + * map[] before = {3, 1, x, x} // x = unassigned + * map[] after = {3, 1, 0, 2} + * + * Unused entries have no effect on the current link with fewer + * lanes in use, but filling them with distinct indices keeps the + * LANE_MAP register holding a valid permutation, just like its + * reset value (0xe4), so the mapping remains sane if a sink with + * a different lane count is connected later, e.g. via DP hot-plug. + */ + for (i = 0; i < LANE_COUNT4 && num_lanes < LANE_COUNT4; i++) { + if (!used[i]) + map[num_lanes++] = i; + } + + dev_dbg(dp->dev, "Using parsed lane map: <%u %u %u %u>\n", map[0], map[1], map[2], map[3]); + + memcpy(video_info->lane_map, map, sizeof(map)); + + return 0; +} + static int analogix_dp_dt_parse_pdata(struct analogix_dp_device *dp) { struct device_node *dp_node = dp->dev->of_node; @@ -1282,6 +1349,9 @@ static int analogix_dp_dt_parse_pdata(struct analogix_dp_device *dp) break; } + if (analogix_dp_dt_parse_lanes_map(dp)) + dev_dbg(dp->dev, "No valid data-lanes found, using default lane map\n"); + return 0; } diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h index c7997677a286..4560597604ad 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h @@ -137,6 +137,8 @@ struct video_info { int max_link_rate; enum link_lane_count_type max_lane_count; + + u32 lane_map[LANE_COUNT4]; }; struct link_train { @@ -177,7 +179,7 @@ struct analogix_dp_device { /* analogix_dp_reg.c */ void analogix_dp_enable_video_mute(struct analogix_dp_device *dp, bool enable); void analogix_dp_stop_video(struct analogix_dp_device *dp); -void analogix_dp_lane_swap(struct analogix_dp_device *dp, bool enable); +void analogix_dp_lane_mapping(struct analogix_dp_device *dp); void analogix_dp_init_analog_param(struct analogix_dp_device *dp); void analogix_dp_init_interrupt(struct analogix_dp_device *dp); void analogix_dp_reset(struct analogix_dp_device *dp); diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c index ea8401293a23..c1344a3f013a 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c @@ -48,16 +48,15 @@ void analogix_dp_stop_video(struct analogix_dp_device *dp) writel(reg, dp->reg_base + ANALOGIX_DP_VIDEO_CTL_1); } -void analogix_dp_lane_swap(struct analogix_dp_device *dp, bool enable) +void analogix_dp_lane_mapping(struct analogix_dp_device *dp) { + u32 *lane_map = dp->video_info.lane_map; u32 reg; - if (enable) - reg = LANE3_MAP_LOGIC_LANE_0 | LANE2_MAP_LOGIC_LANE_1 | - LANE1_MAP_LOGIC_LANE_2 | LANE0_MAP_LOGIC_LANE_3; - else - reg = LANE3_MAP_LOGIC_LANE_3 | LANE2_MAP_LOGIC_LANE_2 | - LANE1_MAP_LOGIC_LANE_1 | LANE0_MAP_LOGIC_LANE_0; + reg = lane_map[0] << LANE0_MAP_SHIFT; + reg |= lane_map[1] << LANE1_MAP_SHIFT; + reg |= lane_map[2] << LANE2_MAP_SHIFT; + reg |= lane_map[3] << LANE3_MAP_SHIFT; writel(reg, dp->reg_base + ANALOGIX_DP_LANE_MAP); } @@ -140,7 +139,7 @@ void analogix_dp_reset(struct analogix_dp_device *dp) usleep_range(20, 30); - analogix_dp_lane_swap(dp, 0); + analogix_dp_lane_mapping(dp); writel(0x0, dp->reg_base + ANALOGIX_DP_SYS_CTL_1); writel(0x40, dp->reg_base + ANALOGIX_DP_SYS_CTL_2); diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.h b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.h index 12735139046c..ac914e37089b 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.h +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.h @@ -209,6 +209,10 @@ #define LANE0_MAP_LOGIC_LANE_1 (0x1 << 0) #define LANE0_MAP_LOGIC_LANE_2 (0x2 << 0) #define LANE0_MAP_LOGIC_LANE_3 (0x3 << 0) +#define LANE3_MAP_SHIFT (6) +#define LANE2_MAP_SHIFT (4) +#define LANE1_MAP_SHIFT (2) +#define LANE0_MAP_SHIFT (0) /* ANALOGIX_DP_ANALOG_CTL_1 */ #define TX_TERMINAL_CTRL_50_OHM (0x1 << 4)