diff options
| -rw-r--r-- | drivers/gpu/drm/drm_dp_helper.c | 127 | ||||
| -rw-r--r-- | include/drm/drm_dp_helper.h | 21 |
2 files changed, 146 insertions, 2 deletions
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 6d0f2c447f3b..c5d15ac62733 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -140,6 +140,133 @@ u8 drm_dp_get_adjust_request_post_cursor(const u8 link_status[DP_LINK_STATUS_SIZ } EXPORT_SYMBOL(drm_dp_get_adjust_request_post_cursor); +static int __8b10b_clock_recovery_delay_us(const struct drm_dp_aux *aux, u8 rd_interval) +{ + if (rd_interval > 4) + drm_dbg_kms(aux->drm_dev, "%s: invalid AUX interval 0x%02x (max 4)\n", + aux->name, rd_interval); + + if (rd_interval == 0) + return 100; + + return rd_interval * 4 * USEC_PER_MSEC; +} + +static int __8b10b_channel_eq_delay_us(const struct drm_dp_aux *aux, u8 rd_interval) +{ + if (rd_interval > 4) + drm_dbg_kms(aux->drm_dev, "%s: invalid AUX interval 0x%02x (max 4)\n", + aux->name, rd_interval); + + if (rd_interval == 0) + return 400; + + return rd_interval * 4 * USEC_PER_MSEC; +} + +static int __128b132b_channel_eq_delay_us(const struct drm_dp_aux *aux, u8 rd_interval) +{ + switch (rd_interval) { + default: + drm_dbg_kms(aux->drm_dev, "%s: invalid AUX interval 0x%02x\n", + aux->name, rd_interval); + fallthrough; + case DP_128B132B_TRAINING_AUX_RD_INTERVAL_400_US: + return 400; + case DP_128B132B_TRAINING_AUX_RD_INTERVAL_4_MS: + return 4000; + case DP_128B132B_TRAINING_AUX_RD_INTERVAL_8_MS: + return 8000; + case DP_128B132B_TRAINING_AUX_RD_INTERVAL_12_MS: + return 12000; + case DP_128B132B_TRAINING_AUX_RD_INTERVAL_16_MS: + return 16000; + case DP_128B132B_TRAINING_AUX_RD_INTERVAL_32_MS: + return 32000; + case DP_128B132B_TRAINING_AUX_RD_INTERVAL_64_MS: + return 64000; + } +} + +/* + * The link training delays are different for: + * + * - Clock recovery vs. channel equalization + * - DPRX vs. LTTPR + * - 128b/132b vs. 8b/10b + * - DPCD rev 1.3 vs. later + * + * Get the correct delay in us, reading DPCD if necessary. + */ +static int __read_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE], + enum drm_dp_phy dp_phy, bool uhbr, bool cr) +{ + int (*parse)(const struct drm_dp_aux *aux, u8 rd_interval); + unsigned int offset; + u8 rd_interval, mask; + + if (dp_phy == DP_PHY_DPRX) { + if (uhbr) { + if (cr) + return 100; + + offset = DP_128B132B_TRAINING_AUX_RD_INTERVAL; + mask = DP_128B132B_TRAINING_AUX_RD_INTERVAL_MASK; + parse = __128b132b_channel_eq_delay_us; + } else { + if (cr && dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14) + return 100; + + offset = DP_TRAINING_AUX_RD_INTERVAL; + mask = DP_TRAINING_AUX_RD_MASK; + if (cr) + parse = __8b10b_clock_recovery_delay_us; + else + parse = __8b10b_channel_eq_delay_us; + } + } else { + if (uhbr) { + offset = DP_128B132B_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER(dp_phy); + mask = DP_128B132B_TRAINING_AUX_RD_INTERVAL_MASK; + parse = __128b132b_channel_eq_delay_us; + } else { + if (cr) + return 100; + + offset = DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER(dp_phy); + mask = DP_TRAINING_AUX_RD_MASK; + parse = __8b10b_channel_eq_delay_us; + } + } + + if (offset < DP_RECEIVER_CAP_SIZE) { + rd_interval = dpcd[offset]; + } else { + if (drm_dp_dpcd_readb(aux, offset, &rd_interval) != 1) { + drm_dbg_kms(aux->drm_dev, "%s: failed rd interval read\n", + aux->name); + /* arbitrary default delay */ + return 400; + } + } + + return parse(aux, rd_interval & mask); +} + +int drm_dp_read_clock_recovery_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE], + enum drm_dp_phy dp_phy, bool uhbr) +{ + return __read_delay(aux, dpcd, dp_phy, uhbr, true); +} +EXPORT_SYMBOL(drm_dp_read_clock_recovery_delay); + +int drm_dp_read_channel_eq_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE], + enum drm_dp_phy dp_phy, bool uhbr) +{ + return __read_delay(aux, dpcd, dp_phy, uhbr, false); +} +EXPORT_SYMBOL(drm_dp_read_channel_eq_delay); + void drm_dp_link_train_clock_recovery_delay(const struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]) { diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index a1df35aa6e68..b653c5da7065 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -1114,8 +1114,15 @@ struct drm_panel; # define DP_UHBR20 (1 << 1) # define DP_UHBR13_5 (1 << 2) -#define DP_128B132B_TRAINING_AUX_RD_INTERVAL 0x2216 /* 2.0 */ -# define DP_128B132B_TRAINING_AUX_RD_INTERVAL_MASK 0x7f +#define DP_128B132B_TRAINING_AUX_RD_INTERVAL 0x2216 /* 2.0 */ +# define DP_128B132B_TRAINING_AUX_RD_INTERVAL_MASK 0x7f +# define DP_128B132B_TRAINING_AUX_RD_INTERVAL_400_US 0x00 +# define DP_128B132B_TRAINING_AUX_RD_INTERVAL_4_MS 0x01 +# define DP_128B132B_TRAINING_AUX_RD_INTERVAL_8_MS 0x02 +# define DP_128B132B_TRAINING_AUX_RD_INTERVAL_12_MS 0x03 +# define DP_128B132B_TRAINING_AUX_RD_INTERVAL_16_MS 0x04 +# define DP_128B132B_TRAINING_AUX_RD_INTERVAL_32_MS 0x05 +# define DP_128B132B_TRAINING_AUX_RD_INTERVAL_64_MS 0x06 #define DP_TEST_264BIT_CUSTOM_PATTERN_7_0 0x2230 #define DP_TEST_264BIT_CUSTOM_PATTERN_263_256 0x2250 @@ -1385,6 +1392,11 @@ enum drm_dp_phy { # define DP_VOLTAGE_SWING_LEVEL_3_SUPPORTED BIT(0) # define DP_PRE_EMPHASIS_LEVEL_3_SUPPORTED BIT(1) +#define DP_128B132B_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER1 0xf0022 /* 2.0 */ +#define DP_128B132B_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER(dp_phy) \ + DP_LTTPR_REG(dp_phy, DP_128B132B_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER1) +/* see DP_128B132B_TRAINING_AUX_RD_INTERVAL for values */ + #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) @@ -1521,6 +1533,11 @@ u8 drm_dp_get_adjust_request_post_cursor(const u8 link_status[DP_LINK_STATUS_SIZ #define DP_LTTPR_COMMON_CAP_SIZE 8 #define DP_LTTPR_PHY_CAP_SIZE 3 +int drm_dp_read_clock_recovery_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE], + enum drm_dp_phy dp_phy, bool uhbr); +int drm_dp_read_channel_eq_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE], + enum drm_dp_phy dp_phy, bool uhbr); + void drm_dp_link_train_clock_recovery_delay(const struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]); void drm_dp_lttpr_link_train_clock_recovery_delay(void); |