From: Laurent Pinchart laurent.pinchart+renesas@ideasonboard.com
Despite the SN65DSI86 being an eDP bridge, on some systems its output is routed to a DisplayPort connector. Enable DisplayPort mode when the next component in the display pipeline is detected as a DisplayPort connector, and disable eDP features in that case.
Signed-off-by: Laurent Pinchart laurent.pinchart+renesas@ideasonboard.com Reworked to set bridge type based on the next bridge/connector. Signed-off-by: Kieran Bingham kieran.bingham+renesas@ideasonboard.com Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Reviewed-by: Douglas Anderson dianders@chromium.org -- Changes since v1/RFC: - Rebased on top of "drm/bridge: ti-sn65dsi86: switch to devm_drm_of_get_bridge" - eDP/DP mode determined from the next bridge connector type.
Changes since v2: - Remove setting of Standard DP Scrambler Seed. (It's read-only). - Prevent setting DP_EDP_CONFIGURATION_SET in ti_sn_bridge_atomic_enable() - Use Doug's suggested text for disabling ASSR on DP mode.
Changes since v3: - Remove ASSR_CONTROL definition
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index c892ecba91c7..c5f020a2d0d3 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -93,6 +93,8 @@ #define SN_DATARATE_CONFIG_REG 0x94 #define DP_DATARATE_MASK GENMASK(7, 5) #define DP_DATARATE(x) ((x) << 5) +#define SN_TRAINING_SETTING_REG 0x95 +#define SCRAMBLE_DISABLE BIT(4) #define SN_ML_TX_MODE_REG 0x96 #define ML_TX_MAIN_LINK_OFF 0 #define ML_TX_NORMAL_MODE BIT(0) @@ -982,6 +984,17 @@ static int ti_sn_link_training(struct ti_sn65dsi86 *pdata, int dp_rate_idx, goto exit; }
+ /* + * eDP panels use an Alternate Scrambler Seed compared to displays + * hooked up via a full DisplayPort connector. SN65DSI86 only supports + * the alternate scrambler seed, not the normal one, so the only way we + * can support full DisplayPort displays is by fully turning off the + * scrambler. + */ + if (pdata->bridge.type == DRM_MODE_CONNECTOR_DisplayPort) + regmap_update_bits(pdata->regmap, SN_TRAINING_SETTING_REG, + SCRAMBLE_DISABLE, SCRAMBLE_DISABLE); + /* * We'll try to link train several times. As part of link training * the bridge chip will write DP_SET_POWER_D0 to DP_SET_POWER. If @@ -1046,12 +1059,13 @@ static void ti_sn_bridge_atomic_enable(struct drm_bridge *bridge,
/* * The SN65DSI86 only supports ASSR Display Authentication method and - * this method is enabled by default. An eDP panel must support this + * this method is enabled for eDP panels. An eDP panel must support this * authentication method. We need to enable this method in the eDP panel * at DisplayPort address 0x0010A prior to link training. */ - drm_dp_dpcd_writeb(&pdata->aux, DP_EDP_CONFIGURATION_SET, - DP_ALTERNATE_SCRAMBLER_RESET_ENABLE); + if (pdata->bridge.type == DRM_MODE_CONNECTOR_eDP) + drm_dp_dpcd_writeb(&pdata->aux, DP_EDP_CONFIGURATION_SET, + DP_ALTERNATE_SCRAMBLER_RESET_ENABLE);
/* Set the DP output format (18 bpp or 24 bpp) */ val = (ti_sn_bridge_get_bpp(old_bridge_state) == 18) ? BPP_18_RGB : 0; @@ -1215,6 +1229,8 @@ static int ti_sn_bridge_probe(struct auxiliary_device *adev,
pdata->bridge.funcs = &ti_sn_bridge_funcs; pdata->bridge.of_node = np; + pdata->bridge.type = pdata->next_bridge->type == DRM_MODE_CONNECTOR_DisplayPort + ? DRM_MODE_CONNECTOR_DisplayPort : DRM_MODE_CONNECTOR_eDP;
drm_bridge_add(&pdata->bridge);