diff options
Diffstat (limited to 'drivers/gpu/drm/drm_dp_helper.c')
| -rw-r--r-- | drivers/gpu/drm/drm_dp_helper.c | 232 |
1 files changed, 228 insertions, 4 deletions
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 478dd51f738d..79732402336d 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -150,11 +150,8 @@ void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) } EXPORT_SYMBOL(drm_dp_link_train_clock_recovery_delay); -void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) +static void __drm_dp_link_train_channel_eq_delay(unsigned long rd_interval) { - unsigned long rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] & - DP_TRAINING_AUX_RD_MASK; - if (rd_interval > 4) DRM_DEBUG_KMS("AUX interval %lu, out of range (max 4)\n", rd_interval); @@ -166,8 +163,35 @@ void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) usleep_range(rd_interval, rd_interval * 2); } + +void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) +{ + __drm_dp_link_train_channel_eq_delay(dpcd[DP_TRAINING_AUX_RD_INTERVAL] & + DP_TRAINING_AUX_RD_MASK); +} EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay); +void drm_dp_lttpr_link_train_clock_recovery_delay(void) +{ + usleep_range(100, 200); +} +EXPORT_SYMBOL(drm_dp_lttpr_link_train_clock_recovery_delay); + +static u8 dp_lttpr_phy_cap(const u8 phy_cap[DP_LTTPR_PHY_CAP_SIZE], int r) +{ + return phy_cap[r - DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER1]; +} + +void drm_dp_lttpr_link_train_channel_eq_delay(const u8 phy_cap[DP_LTTPR_PHY_CAP_SIZE]) +{ + u8 interval = dp_lttpr_phy_cap(phy_cap, + DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER1) & + DP_TRAINING_AUX_RD_MASK; + + __drm_dp_link_train_channel_eq_delay(interval); +} +EXPORT_SYMBOL(drm_dp_lttpr_link_train_channel_eq_delay); + u8 drm_dp_link_rate_to_bw_code(int link_rate) { /* Spec says link_bw = link_rate / 0.27Gbps */ @@ -363,6 +387,59 @@ int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux, } EXPORT_SYMBOL(drm_dp_dpcd_read_link_status); +/** + * drm_dp_dpcd_read_phy_link_status - get the link status information for a DP PHY + * @aux: DisplayPort AUX channel + * @dp_phy: the DP PHY to get the link status for + * @link_status: buffer to return the status in + * + * Fetch the AUX DPCD registers for the DPRX or an LTTPR PHY link status. The + * layout of the returned @link_status matches the DPCD register layout of the + * DPRX PHY link status. + * + * Returns 0 if the information was read successfully or a negative error code + * on failure. + */ +int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux, + enum drm_dp_phy dp_phy, + u8 link_status[DP_LINK_STATUS_SIZE]) +{ + int ret; + + if (dp_phy == DP_PHY_DPRX) { + ret = drm_dp_dpcd_read(aux, + DP_LANE0_1_STATUS, + link_status, + DP_LINK_STATUS_SIZE); + + if (ret < 0) + return ret; + + WARN_ON(ret != DP_LINK_STATUS_SIZE); + + return 0; + } + + ret = drm_dp_dpcd_read(aux, + DP_LANE0_1_STATUS_PHY_REPEATER(dp_phy), + link_status, + DP_LINK_STATUS_SIZE - 1); + + if (ret < 0) + return ret; + + WARN_ON(ret != DP_LINK_STATUS_SIZE - 1); + + /* Convert the LTTPR to the sink PHY link status layout */ + memmove(&link_status[DP_SINK_STATUS - DP_LANE0_1_STATUS + 1], + &link_status[DP_SINK_STATUS - DP_LANE0_1_STATUS], + DP_LINK_STATUS_SIZE - (DP_SINK_STATUS - DP_LANE0_1_STATUS) - 1); + link_status[DP_SINK_STATUS - DP_LANE0_1_STATUS] = 0; + + return 0; +} +EXPORT_SYMBOL(drm_dp_dpcd_read_phy_link_status); + static bool is_edid_digital_input_dp(const struct edid *edid) { return edid && edid->revision >= 4 && @@ -2099,6 +2176,153 @@ int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_S EXPORT_SYMBOL(drm_dp_dsc_sink_supported_input_bpcs); /** + * drm_dp_read_lttpr_common_caps - read the LTTPR common capabilities + * @aux: DisplayPort AUX channel + * @caps: buffer to return the capability info in + * + * Read capabilities common to all LTTPRs. + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_read_lttpr_common_caps(struct drm_dp_aux *aux, + u8 caps[DP_LTTPR_COMMON_CAP_SIZE]) +{ + int ret; + + ret = drm_dp_dpcd_read(aux, + DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV, + caps, DP_LTTPR_COMMON_CAP_SIZE); + if (ret < 0) + return ret; + + WARN_ON(ret != DP_LTTPR_COMMON_CAP_SIZE); + + return 0; +} +EXPORT_SYMBOL(drm_dp_read_lttpr_common_caps); + +/** + * drm_dp_read_lttpr_phy_caps - read the capabilities for a given LTTPR PHY + * @aux: DisplayPort AUX channel + * @dp_phy: LTTPR PHY to read the capabilities for + * @caps: buffer to return the capability info in + * + * Read the capabilities for the given LTTPR PHY. + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_read_lttpr_phy_caps(struct drm_dp_aux *aux, + enum drm_dp_phy dp_phy, + u8 caps[DP_LTTPR_PHY_CAP_SIZE]) +{ + int ret; + + ret = drm_dp_dpcd_read(aux, + DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER(dp_phy), + caps, DP_LTTPR_PHY_CAP_SIZE); + if (ret < 0) + return ret; + + WARN_ON(ret != DP_LTTPR_PHY_CAP_SIZE); + + return 0; +} +EXPORT_SYMBOL(drm_dp_read_lttpr_phy_caps); + +static u8 dp_lttpr_common_cap(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE], int r) +{ + return caps[r - DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV]; +} + +/** + * drm_dp_lttpr_count - get the number of detected LTTPRs + * @caps: LTTPR common capabilities + * + * Get the number of detected LTTPRs from the LTTPR common capabilities info. + * + * Returns: + * -ERANGE if more than supported number (8) of LTTPRs are detected + * -EINVAL if the DP_PHY_REPEATER_CNT register contains an invalid value + * otherwise the number of detected LTTPRs + */ +int drm_dp_lttpr_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]) +{ + u8 count = dp_lttpr_common_cap(caps, DP_PHY_REPEATER_CNT); + + switch (hweight8(count)) { + case 0: + return 0; + case 1: + return 8 - ilog2(count); + case 8: + return -ERANGE; + default: + return -EINVAL; + } +} +EXPORT_SYMBOL(drm_dp_lttpr_count); + +/** + * drm_dp_lttpr_max_link_rate - get the maximum link rate supported by all LTTPRs + * @caps: LTTPR common capabilities + * + * Returns the maximum link rate supported by all detected LTTPRs. + */ +int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]) +{ + u8 rate = dp_lttpr_common_cap(caps, DP_MAX_LINK_RATE_PHY_REPEATER); + + return drm_dp_bw_code_to_link_rate(rate); +} +EXPORT_SYMBOL(drm_dp_lttpr_max_link_rate); + +/** + * drm_dp_lttpr_max_lane_count - get the maximum lane count supported by all LTTPRs + * @caps: LTTPR common capabilities + * + * Returns the maximum lane count supported by all detected LTTPRs. + */ +int drm_dp_lttpr_max_lane_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]) +{ + u8 max_lanes = dp_lttpr_common_cap(caps, DP_MAX_LANE_COUNT_PHY_REPEATER); + + return max_lanes & DP_MAX_LANE_COUNT_MASK; +} +EXPORT_SYMBOL(drm_dp_lttpr_max_lane_count); + +/** + * drm_dp_lttpr_voltage_swing_level_3_supported - check for LTTPR vswing3 support + * @caps: LTTPR PHY capabilities + * + * Returns true if the @caps for an LTTPR TX PHY indicate support for + * voltage swing level 3. + */ +bool +drm_dp_lttpr_voltage_swing_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]) +{ + u8 txcap = dp_lttpr_phy_cap(caps, DP_TRANSMITTER_CAPABILITY_PHY_REPEATER1); + + return txcap & DP_VOLTAGE_SWING_LEVEL_3_SUPPORTED; +} +EXPORT_SYMBOL(drm_dp_lttpr_voltage_swing_level_3_supported); + +/** + * drm_dp_lttpr_pre_emphasis_level_3_supported - check for LTTPR preemph3 support + * @caps: LTTPR PHY capabilities + * + * Returns true if the @caps for an LTTPR TX PHY indicate support for + * pre-emphasis level 3. + */ +bool +drm_dp_lttpr_pre_emphasis_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]) +{ + u8 txcap = dp_lttpr_phy_cap(caps, DP_TRANSMITTER_CAPABILITY_PHY_REPEATER1); + + return txcap & DP_PRE_EMPHASIS_LEVEL_3_SUPPORTED; +} +EXPORT_SYMBOL(drm_dp_lttpr_pre_emphasis_level_3_supported); + +/** * drm_dp_get_phy_test_pattern() - get the requested pattern from the sink. * @aux: DisplayPort AUX channel * @data: DP phy compliance test parameters. |