On Thu, Sep 24, 2020 at 09:48:03PM +0300, Imre Deak wrote: > 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) > > Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx > Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx> > --- > drivers/gpu/drm/drm_dp_helper.c | 244 +++++++++++++++++++++++++++++++- > include/drm/drm_dp_helper.h | 62 ++++++++ > 2 files changed, 302 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c > index 478dd51f738d..6014c858b06b 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 +387,71 @@ 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]) > +{ > + u8 lttpr_status[DP_LINK_STATUS_SIZE - 1]; > + 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), > + lttpr_status, > + sizeof(lttpr_status)); > + > + if (ret < 0) > + return ret; > + > + WARN_ON(ret != sizeof(lttpr_status)); > + > +#define link_reg(reg) link_status[(reg) - DP_LANE0_1_STATUS] > +#define lttpr_reg(reg) lttpr_status[(reg) - DP_LANE0_1_STATUS_PHY_REPEATER1] > + > + /* Convert the LTTPR to the sink PHY link status layout */ > + link_reg(DP_LANE0_1_STATUS) = lttpr_reg(DP_LANE0_1_STATUS_PHY_REPEATER1); > + link_reg(DP_LANE2_3_STATUS) = lttpr_reg(DP_LANE2_3_STATUS_PHY_REPEATER1); > + link_reg(DP_LANE_ALIGN_STATUS_UPDATED) = > + lttpr_reg(DP_LANE_ALIGN_STATUS_UPDATED_PHY_REPEATER1); > + link_reg(DP_SINK_STATUS) = 0; > + link_reg(DP_ADJUST_REQUEST_LANE0_1) = > + lttpr_reg(DP_ADJUST_REQUEST_LANE0_1_PHY_REPEATER1); > + link_reg(DP_ADJUST_REQUEST_LANE2_3) = > + lttpr_reg(DP_ADJUST_REQUEST_LANE2_3_PHY_REPEATER1); > + > +#undef link_reg > +#undef lttpr_reg Alternative might be to read to the target buffer directly and just memmove() the stuff around a bit. Would avoid having the second buffer on stack. But it's a small buffer so meh. Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > + > + 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 +2187,153 @@ 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 e144b4b9d79a..42b6ab14920a 100644 > --- a/include/drm/drm_dp_helper.h > +++ b/include/drm/drm_dp_helper.h > @@ -1118,15 +1118,58 @@ 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 */ > @@ -1236,9 +1279,13 @@ 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); > @@ -1697,6 +1744,10 @@ 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); > > @@ -1746,6 +1797,17 @@ 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); > -- > 2.25.1 -- Ville Syrjälä Intel _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel