From 9782f52ab5d65a667074beda11b12490935d608b Mon Sep 17 00:00:00 2001 From: Imre Deak Date: Wed, 7 Oct 2020 20:09:15 +0300 Subject: drm/dp: Add LTTPR helpers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add the helpers and register definitions needed to read out the common and per-PHY LTTPR capabilities and perform link training in the LTTPR non-transparent mode. v2: - Add drm_dp_dpcd_read_phy_link_status() and DP_PHY_LTTPR() here instead of adding these to i915. (Ville) v3: - Use memmove() to convert LTTPR to DPRX link status format. (Ville) Cc: dri-devel@lists.freedesktop.org Cc: Ville Syrjälä Reviewed-by: Ville Syrjälä Acked-by: Lyude Paul Acked-by: Daniel Vetter Signed-off-by: Imre Deak Link: https://patchwork.freedesktop.org/patch/msgid/20201007170917.1764556-5-imre.deak@intel.com --- drivers/gpu/drm/drm_dp_helper.c | 232 +++++++++++++++++++++++++++++++++++++++- include/drm/drm_dp_helper.h | 62 +++++++++++ 2 files changed, 290 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 && @@ -2098,6 +2175,153 @@ 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 diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index c9f2851904d0..8dbbfc7a8d83 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -1066,15 +1066,58 @@ struct drm_device; #define DP_MAX_LANE_COUNT_PHY_REPEATER 0xf0004 /* 1.4a */ #define DP_Repeater_FEC_CAPABILITY 0xf0004 /* 1.4 */ #define DP_PHY_REPEATER_EXTENDED_WAIT_TIMEOUT 0xf0005 /* 1.4a */ + +enum drm_dp_phy { + DP_PHY_DPRX, + + DP_PHY_LTTPR1, + DP_PHY_LTTPR2, + DP_PHY_LTTPR3, + DP_PHY_LTTPR4, + DP_PHY_LTTPR5, + DP_PHY_LTTPR6, + DP_PHY_LTTPR7, + DP_PHY_LTTPR8, + + DP_MAX_LTTPR_COUNT = DP_PHY_LTTPR8, +}; + +#define DP_PHY_LTTPR(i) (DP_PHY_LTTPR1 + (i)) + +#define __DP_LTTPR1_BASE 0xf0010 /* 1.3 */ +#define __DP_LTTPR2_BASE 0xf0060 /* 1.3 */ +#define DP_LTTPR_BASE(dp_phy) \ + (__DP_LTTPR1_BASE + (__DP_LTTPR2_BASE - __DP_LTTPR1_BASE) * \ + ((dp_phy) - DP_PHY_LTTPR1)) + +#define DP_LTTPR_REG(dp_phy, lttpr1_reg) \ + (DP_LTTPR_BASE(dp_phy) - DP_LTTPR_BASE(DP_PHY_LTTPR1) + (lttpr1_reg)) + #define DP_TRAINING_PATTERN_SET_PHY_REPEATER1 0xf0010 /* 1.3 */ +#define DP_TRAINING_PATTERN_SET_PHY_REPEATER(dp_phy) \ + DP_LTTPR_REG(dp_phy, DP_TRAINING_PATTERN_SET_PHY_REPEATER1) + #define DP_TRAINING_LANE0_SET_PHY_REPEATER1 0xf0011 /* 1.3 */ +#define DP_TRAINING_LANE0_SET_PHY_REPEATER(dp_phy) \ + DP_LTTPR_REG(dp_phy, DP_TRAINING_LANE0_SET_PHY_REPEATER1) + #define DP_TRAINING_LANE1_SET_PHY_REPEATER1 0xf0012 /* 1.3 */ #define DP_TRAINING_LANE2_SET_PHY_REPEATER1 0xf0013 /* 1.3 */ #define DP_TRAINING_LANE3_SET_PHY_REPEATER1 0xf0014 /* 1.3 */ #define DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER1 0xf0020 /* 1.4a */ +#define DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER(dp_phy) \ + DP_LTTPR_REG(dp_phy, DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER1) + #define DP_TRANSMITTER_CAPABILITY_PHY_REPEATER1 0xf0021 /* 1.4a */ +# define DP_VOLTAGE_SWING_LEVEL_3_SUPPORTED BIT(0) +# define DP_PRE_EMPHASIS_LEVEL_3_SUPPORTED BIT(1) + #define DP_LANE0_1_STATUS_PHY_REPEATER1 0xf0030 /* 1.3 */ +#define DP_LANE0_1_STATUS_PHY_REPEATER(dp_phy) \ + DP_LTTPR_REG(dp_phy, DP_LANE0_1_STATUS_PHY_REPEATER1) + #define DP_LANE2_3_STATUS_PHY_REPEATER1 0xf0031 /* 1.3 */ + #define DP_LANE_ALIGN_STATUS_UPDATED_PHY_REPEATER1 0xf0032 /* 1.3 */ #define DP_ADJUST_REQUEST_LANE0_1_PHY_REPEATER1 0xf0033 /* 1.3 */ #define DP_ADJUST_REQUEST_LANE2_3_PHY_REPEATER1 0xf0034 /* 1.3 */ @@ -1184,9 +1227,13 @@ u8 drm_dp_get_adjust_request_post_cursor(const u8 link_status[DP_LINK_STATUS_SIZ #define DP_DSC_RECEIVER_CAP_SIZE 0xf #define EDP_PSR_RECEIVER_CAP_SIZE 2 #define EDP_DISPLAY_CTL_CAP_SIZE 3 +#define DP_LTTPR_COMMON_CAP_SIZE 8 +#define DP_LTTPR_PHY_CAP_SIZE 3 void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]); +void drm_dp_lttpr_link_train_clock_recovery_delay(void); void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]); +void drm_dp_lttpr_link_train_channel_eq_delay(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]); u8 drm_dp_link_rate_to_bw_code(int link_rate); int drm_dp_bw_code_to_link_rate(u8 link_bw); @@ -1645,6 +1692,10 @@ int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux, int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux, u8 status[DP_LINK_STATUS_SIZE]); +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]); + bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux, u8 real_edid_checksum); @@ -1694,6 +1745,17 @@ bool drm_dp_read_sink_count_cap(struct drm_connector *connector, const struct drm_dp_desc *desc); int drm_dp_read_sink_count(struct drm_dp_aux *aux); +int drm_dp_read_lttpr_common_caps(struct drm_dp_aux *aux, + u8 caps[DP_LTTPR_COMMON_CAP_SIZE]); +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 drm_dp_lttpr_count(const u8 cap[DP_LTTPR_COMMON_CAP_SIZE]); +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_remote_aux_init(struct drm_dp_aux *aux); void drm_dp_aux_init(struct drm_dp_aux *aux); int drm_dp_aux_register(struct drm_dp_aux *aux); -- cgit v1.2.3