diff options
Diffstat (limited to 'drivers/gpu/drm/bridge/ti-sn65dsi86.c')
| -rw-r--r-- | drivers/gpu/drm/bridge/ti-sn65dsi86.c | 71 |
1 files changed, 60 insertions, 11 deletions
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index 47b1948a1dcf..a049e83c9a9a 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -454,7 +454,7 @@ static const unsigned int ti_sn_bridge_dp_rate_lut[] = { 0, 1620, 2160, 2430, 2700, 3240, 4320, 5400 }; -static void ti_sn_bridge_set_dp_rate(struct ti_sn_bridge *pdata) +static int ti_sn_bridge_calc_min_dp_rate_idx(struct ti_sn_bridge *pdata) { unsigned int bit_rate_khz, dp_rate_mhz; unsigned int i; @@ -472,8 +472,42 @@ static void ti_sn_bridge_set_dp_rate(struct ti_sn_bridge *pdata) if (ti_sn_bridge_dp_rate_lut[i] > dp_rate_mhz) break; - regmap_update_bits(pdata->regmap, SN_DATARATE_CONFIG_REG, - DP_DATARATE_MASK, DP_DATARATE(i)); + return i; +} + +static int ti_sn_bridge_get_max_dp_rate_idx(struct ti_sn_bridge *pdata) +{ + u8 data; + int ret; + + ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LINK_RATE, &data); + if (ret != 1) { + DRM_DEV_ERROR(pdata->dev, + "Can't read max rate (%d); assuming 5.4 GHz\n", + ret); + return ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; + } + + /* + * Return an index into ti_sn_bridge_dp_rate_lut. Just hardcode + * these indicies since it's not like the register spec is ever going + * to change and a loop would just be more complicated. Apparently + * the DP sink can only return these few rates as supported even + * though the bridge allows some rates in between. + */ + switch (data) { + case DP_LINK_BW_1_62: + return 1; + case DP_LINK_BW_2_7: + return 4; + case DP_LINK_BW_5_4: + return 7; + } + + DRM_DEV_ERROR(pdata->dev, + "Unexpected max data rate (%#x); assuming 5.4 GHz\n", + (int)data); + return ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; } static void ti_sn_bridge_set_video_timings(struct ti_sn_bridge *pdata) @@ -530,13 +564,15 @@ static unsigned int ti_sn_get_max_lanes(struct ti_sn_bridge *pdata) return data & DP_LANE_COUNT_MASK; } -static int ti_sn_link_training(struct ti_sn_bridge *pdata) +static int ti_sn_link_training(struct ti_sn_bridge *pdata, int dp_rate_idx, + const char **last_err_str) { unsigned int val; int ret; /* set dp clk frequency value */ - ti_sn_bridge_set_dp_rate(pdata); + regmap_update_bits(pdata->regmap, SN_DATARATE_CONFIG_REG, + DP_DATARATE_MASK, DP_DATARATE(dp_rate_idx)); /* enable DP PLL */ regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 1); @@ -545,7 +581,7 @@ static int ti_sn_link_training(struct ti_sn_bridge *pdata) val & DPPLL_SRC_DP_PLL_LOCK, 1000, 50 * 1000); if (ret) { - DRM_ERROR("DP_PLL_LOCK polling failed (%d)\n", ret); + *last_err_str = "DP_PLL_LOCK polling failed"; goto exit; } @@ -556,9 +592,9 @@ static int ti_sn_link_training(struct ti_sn_bridge *pdata) val == ML_TX_NORMAL_MODE, 1000, 500 * 1000); if (ret) { - DRM_ERROR("Training complete polling failed (%d)\n", ret); + *last_err_str = "Training complete polling failed"; } else if (val == ML_TX_MAIN_LINK_OFF) { - DRM_ERROR("Link training failed, link is off\n"); + *last_err_str = "Link training failed, link is off"; ret = -EIO; } @@ -573,8 +609,11 @@ exit: static void ti_sn_bridge_enable(struct drm_bridge *bridge) { struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge); + const char *last_err_str = "No supported DP rate"; + int dp_rate_idx; + int max_dp_rate_idx; unsigned int val; - int ret; + int ret = -EINVAL; /* * Run with the maximum number of lanes that the DP sink supports. @@ -616,9 +655,19 @@ static void ti_sn_bridge_enable(struct drm_bridge *bridge) regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK, val); - ret = ti_sn_link_training(pdata); - if (ret) + /* Train until we run out of rates */ + max_dp_rate_idx = ti_sn_bridge_get_max_dp_rate_idx(pdata); + for (dp_rate_idx = ti_sn_bridge_calc_min_dp_rate_idx(pdata); + dp_rate_idx <= max_dp_rate_idx; + dp_rate_idx++) { + ret = ti_sn_link_training(pdata, dp_rate_idx, &last_err_str); + if (!ret) + break; + } + if (ret) { + DRM_DEV_ERROR(pdata->dev, "%s (%d)\n", last_err_str, ret); return; + } /* config video parameters */ ti_sn_bridge_set_video_timings(pdata); |