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@xxxxxxxxxxxxxxxxxxxxx
Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
---
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 159191c1ae75..f55a9d1320ca 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 */
@@ -1237,9 +1280,13 @@ 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);
@@ -1698,6 +1745,10 @@ 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);
@@ -1747,6 +1798,17 @@ 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
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