diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c index da3c8521a7fa..c488d160a3c1 100644 --- a/drivers/gpu/drm/display/drm_dp_helper.c +++ b/drivers/gpu/drm/display/drm_dp_helper.c @@ -459,6 +459,64 @@ void drm_dp_lttpr_link_train_channel_eq_delay(const struct drm_dp_aux *aux, } EXPORT_SYMBOL(drm_dp_lttpr_link_train_channel_eq_delay); +/** + * drm_dp_lttpr_wake_timeout_setup() - Grant extended time for sink to wake up + * @aux: The DP AUX channel to use + * @transparent_mode: This is true if lttpr is in transparent mode + * + * This function checks if the sink needs any extended wake time, if it does + * it grants this request. Post this setup the source device can keep trying + * the Aux transaction till the granted wake timeout. + * If this function is not called all Aux transactions are expected to take + * a default of 1ms before they throw an error. + */ +void drm_dp_lttpr_wake_timeout_setup(struct drm_dp_aux *aux, bool transparent_mode) +{ + u8 val = 1; + int ret; + + if (transparent_mode) { + static const u8 timeout_mapping[] = { + [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_1_MS] = 1, + [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_20_MS] = 20, + [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_40_MS] = 40, + [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_60_MS] = 60, + [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_80_MS] = 80, + [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_100_MS] = 100, + }; + + ret = drm_dp_dpcd_readb(aux, DP_EXTENDED_DPRX_SLEEP_WAKE_TIMEOUT_REQUEST, &val); + if (ret != 1) { + drm_dbg_kms(aux->drm_dev, + "Failed to read Extended sleep wake timeout request\n"); + return; + } + + val = (val < sizeof(timeout_mapping) && timeout_mapping[val]) ? + timeout_mapping[val] : 1; + + if (val > 1) + drm_dp_dpcd_writeb(aux, + DP_EXTENDED_DPRX_SLEEP_WAKE_TIMEOUT_GRANT, + DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_GRANTED); + } else { + ret = drm_dp_dpcd_readb(aux, DP_PHY_REPEATER_EXTENDED_WAIT_TIMEOUT, &val); + if (ret != 1) { + drm_dbg_kms(aux->drm_dev, + "Failed to read Extended sleep wake timeout request\n"); + return; + } + + val = (val & DP_EXTENDED_WAKE_TIMEOUT_REQUEST_MASK) ? + (val & DP_EXTENDED_WAKE_TIMEOUT_REQUEST_MASK) * 10 : 1; + + if (val > 1) + drm_dp_dpcd_writeb(aux, DP_PHY_REPEATER_EXTENDED_WAIT_TIMEOUT, + DP_EXTENDED_WAKE_TIMEOUT_GRANT); + } +} +EXPORT_SYMBOL(drm_dp_lttpr_wake_timeout_setup); + u8 drm_dp_link_rate_to_bw_code(int link_rate) { switch (link_rate) { diff --git a/include/drm/display/drm_dp_helper.h b/include/drm/display/drm_dp_helper.h index 8f4054a56039..89a34dff85a4 100644 --- a/include/drm/display/drm_dp_helper.h +++ b/include/drm/display/drm_dp_helper.h @@ -633,6 +633,7 @@ int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]); int drm_dp_lttpr_max_lane_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]); bool drm_dp_lttpr_voltage_swing_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]); bool drm_dp_lttpr_pre_emphasis_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]); +void drm_dp_lttpr_wake_timeout_setup(struct drm_dp_aux *aux, bool transparent_mode); void drm_dp_remote_aux_init(struct drm_dp_aux *aux); void drm_dp_aux_init(struct drm_dp_aux *aux);