Re: [PATCH v6 5/5] drm/rockchip: support dp training outside dp firmware

From: Enric Balletbo Serra
Date: Tue May 22 2018 - 12:13:03 EST

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Lin,

2018-05-22 9:41 GMT+02:00 Enric Balletbo Serra <eballetbo@xxxxxxxxx>:
> Hi Lin
>
> 2018-05-22 3:08 GMT+02:00 hl <hl@xxxxxxxxxxxxxx>:
>> Hi Enric,
>>
>>
>>
>>
>> On Monday, May 21, 2018 11:22 PM, Enric Balletbo Serra wrote:
>>>
>>> Hi Lin,
>>>
>>> 2018-05-21 11:37 GMT+02:00 Lin Huang <hl@xxxxxxxxxxxxxx>:
>>>>
>>>> DP firmware uses fixed phy config values to do training, but some
>>>> boards need to adjust these values to fit for their unique hardware
>>>> design. So get phy config values from dts and use software link training
>>>> instead of relying on firmware, if software training fail, keep firmware
>>>> training as a fallback if sw training fails.
>>>>
>>>> Signed-off-by: Chris Zhong <zyw@xxxxxxxxxxxxxx>
>>>> Signed-off-by: Lin Huang <hl@xxxxxxxxxxxxxx>
>>>> Reviewed-by: Sean Paul <seanpaul@xxxxxxxxxxxx>
>>>> ---
>>>> Changes in v2:
>>>> - update patch following Enric suggest
>>>> Changes in v3:
>>>> - use variable fw_training instead sw_training_success
>>>> - base on DP SPCE, if training fail use lower link rate to retry training
>>>> Changes in v4:
>>>> - improve cdn_dp_get_lower_link_rate() and cdn_dp_software_train_link()
>>>> follow Sean suggest
>>>> Changes in v5:
>>>> - fix some whitespcae issue
>>>> Changes in v6:
>>>> - None
>>>>
>>>> drivers/gpu/drm/rockchip/Makefile | 3 +-
>>>> drivers/gpu/drm/rockchip/cdn-dp-core.c | 24 +-
>>>> drivers/gpu/drm/rockchip/cdn-dp-core.h | 2 +
>>>> drivers/gpu/drm/rockchip/cdn-dp-link-training.c | 420
>>>> ++++++++++++++++++++++++
>>>> drivers/gpu/drm/rockchip/cdn-dp-reg.c | 31 +-
>>>> drivers/gpu/drm/rockchip/cdn-dp-reg.h | 38 ++-
>>>> 6 files changed, 505 insertions(+), 13 deletions(-)
>>>> create mode 100644 drivers/gpu/drm/rockchip/cdn-dp-link-training.c
>>>>
>>>> diff --git a/drivers/gpu/drm/rockchip/Makefile
>>>> b/drivers/gpu/drm/rockchip/Makefile
>>>> index a314e21..b932f62 100644
>>>> --- a/drivers/gpu/drm/rockchip/Makefile
>>>> +++ b/drivers/gpu/drm/rockchip/Makefile
>>>> @@ -9,7 +9,8 @@ rockchipdrm-y := rockchip_drm_drv.o rockchip_drm_fb.o \
>>>> rockchipdrm-$(CONFIG_DRM_FBDEV_EMULATION) += rockchip_drm_fbdev.o
>>>>
>>>> rockchipdrm-$(CONFIG_ROCKCHIP_ANALOGIX_DP) += analogix_dp-rockchip.o
>>>> -rockchipdrm-$(CONFIG_ROCKCHIP_CDN_DP) += cdn-dp-core.o cdn-dp-reg.o
>>>> +rockchipdrm-$(CONFIG_ROCKCHIP_CDN_DP) += cdn-dp-core.o cdn-dp-reg.o \
>>>> + cdn-dp-link-training.o
>>>> rockchipdrm-$(CONFIG_ROCKCHIP_DW_HDMI) += dw_hdmi-rockchip.o
>>>> rockchipdrm-$(CONFIG_ROCKCHIP_DW_MIPI_DSI) += dw-mipi-dsi.o
>>>> rockchipdrm-$(CONFIG_ROCKCHIP_INNO_HDMI) += inno_hdmi.o
>>>> diff --git a/drivers/gpu/drm/rockchip/cdn-dp-core.c
>>>> b/drivers/gpu/drm/rockchip/cdn-dp-core.c
>>>> index cce64c1..d9d0d4d 100644
>>>> --- a/drivers/gpu/drm/rockchip/cdn-dp-core.c
>>>> +++ b/drivers/gpu/drm/rockchip/cdn-dp-core.c
>>>> @@ -629,11 +629,13 @@ static void cdn_dp_encoder_enable(struct
>>>> drm_encoder *encoder)
>>>> goto out;
>>>> }
>>>> }
>>>> -
>>>> - ret = cdn_dp_set_video_status(dp, CONTROL_VIDEO_IDLE);
>>>> - if (ret) {
>>>> - DRM_DEV_ERROR(dp->dev, "Failed to idle video %d\n", ret);
>>>> - goto out;
>>>> + if (dp->use_fw_training == true) {
>>>
>>> You don't need to compare to true. Simply do:
>>>
>>> if (dp->use_fw_training)
>>>
>>>> + ret = cdn_dp_set_video_status(dp, CONTROL_VIDEO_IDLE);
>>>> + if (ret) {
>>>> + DRM_DEV_ERROR(dp->dev,
>>>> + "Failed to idle video %d\n", ret);
>>>> + goto out;
>>>> + }
>>>> }
>>>>
>>>> ret = cdn_dp_config_video(dp);
>>>> @@ -642,11 +644,15 @@ static void cdn_dp_encoder_enable(struct
>>>> drm_encoder *encoder)
>>>> goto out;
>>>> }
>>>>
>>>> - ret = cdn_dp_set_video_status(dp, CONTROL_VIDEO_VALID);
>>>> - if (ret) {
>>>> - DRM_DEV_ERROR(dp->dev, "Failed to valid video %d\n",
>>>> ret);
>>>> - goto out;
>>>> + if (dp->use_fw_training == true) {
>>>
>>> if (dp->use_fw_training)
>>>
>>>> + ret = cdn_dp_set_video_status(dp, CONTROL_VIDEO_VALID);
>>>> + if (ret) {
>>>> + DRM_DEV_ERROR(dp->dev,
>>>> + "Failed to valid video %d\n", ret);
>>>> + goto out;
>>>> + }
>>>> }
>>>> +
>>>> out:
>>>> mutex_unlock(&dp->lock);
>>>> }
>>>> diff --git a/drivers/gpu/drm/rockchip/cdn-dp-core.h
>>>> b/drivers/gpu/drm/rockchip/cdn-dp-core.h
>>>> index 46159b2..77a9793 100644
>>>> --- a/drivers/gpu/drm/rockchip/cdn-dp-core.h
>>>> +++ b/drivers/gpu/drm/rockchip/cdn-dp-core.h
>>>> @@ -84,6 +84,7 @@ struct cdn_dp_device {
>>>> bool connected;
>>>> bool active;
>>>> bool suspended;
>>>> + bool use_fw_training;
>>>>
>>>> const struct firmware *fw; /* cdn dp firmware */
>>>> unsigned int fw_version; /* cdn fw version */
>>>> @@ -106,6 +107,7 @@ struct cdn_dp_device {
>>>> u8 ports;
>>>> u8 lanes;
>>>> int active_port;
>>>> + u8 train_set[4];
>>>>
>>>> u8 dpcd[DP_RECEIVER_CAP_SIZE];
>>>> bool sink_has_audio;
>>>> diff --git a/drivers/gpu/drm/rockchip/cdn-dp-link-training.c
>>>> b/drivers/gpu/drm/rockchip/cdn-dp-link-training.c
>>>> new file mode 100644
>>>> index 0000000..73c3290
>>>> --- /dev/null
>>>> +++ b/drivers/gpu/drm/rockchip/cdn-dp-link-training.c
>>>> @@ -0,0 +1,420 @@
>>>> +// SPDX-License-Identifier: GPL-2.0
>>>> +/*
>>>> + * Copyright (C) Fuzhou Rockchip Electronics Co.Ltd
>>>> + * Author: Chris Zhong <zyw@xxxxxxxxxxxxxx>
>>>> + */

Oh, I just noticed that this is not the preferred format for .c files,
see the discussion here

https://lkml.org/lkml/2017/11/25/133

>>>> +
>>>> +#include <linux/device.h>
>>>> +#include <linux/delay.h>
>>>> +#include <linux/phy/phy.h>
>>>> +#include <soc/rockchip/rockchip_phy_typec.h>
>>>> +
>>>> +#include "cdn-dp-core.h"
>>>> +#include "cdn-dp-reg.h"
>>>> +
>>>> +static void cdn_dp_set_signal_levels(struct cdn_dp_device *dp)
>>>> +{
>>>> + struct cdn_dp_port *port = dp->port[dp->active_port];
>>>> + struct rockchip_typec_phy *tcphy = phy_get_drvdata(port->phy);
>>>> +
>>>> + int rate = drm_dp_bw_code_to_link_rate(dp->link.rate);
>>>> + u8 swing = (dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) >>
>>>> + DP_TRAIN_VOLTAGE_SWING_SHIFT;
>>>> + u8 pre_emphasis = (dp->train_set[0] & DP_TRAIN_PRE_EMPHASIS_MASK)
>>>> + >> DP_TRAIN_PRE_EMPHASIS_SHIFT;
>>>> +
>>>> + tcphy->typec_phy_config(port->phy, rate, dp->link.num_lanes,
>>>> + swing, pre_emphasis);
>>>> +}
>>>> +
>>>> +static int cdn_dp_set_pattern(struct cdn_dp_device *dp, uint8_t
>>>> dp_train_pat)
>>>> +{
>>>> + u32 phy_config, global_config;
>>>> + int ret;
>>>> + uint8_t pattern = dp_train_pat & DP_TRAINING_PATTERN_MASK;
>>>> +
>>>> + global_config = NUM_LANES(dp->link.num_lanes - 1) | SST_MODE |
>>>> + GLOBAL_EN | RG_EN | ENC_RST_DIS | WR_VHSYNC_FALL;
>>>> +
>>>> + phy_config = DP_TX_PHY_ENCODER_BYPASS(0) |
>>>> + DP_TX_PHY_SKEW_BYPASS(0) |
>>>> + DP_TX_PHY_DISPARITY_RST(0) |
>>>> + DP_TX_PHY_LANE0_SKEW(0) |
>>>> + DP_TX_PHY_LANE1_SKEW(1) |
>>>> + DP_TX_PHY_LANE2_SKEW(2) |
>>>> + DP_TX_PHY_LANE3_SKEW(3) |
>>>> + DP_TX_PHY_10BIT_ENABLE(0);
>>>> +
>>>> + if (pattern != DP_TRAINING_PATTERN_DISABLE) {
>>>> + global_config |= NO_VIDEO;
>>>> + phy_config |= DP_TX_PHY_TRAINING_ENABLE(1) |
>>>> + DP_TX_PHY_SCRAMBLER_BYPASS(1) |
>>>> + DP_TX_PHY_TRAINING_PATTERN(pattern);
>>>> + }
>>>> +
>>>> + ret = cdn_dp_reg_write(dp, DP_FRAMER_GLOBAL_CONFIG,
>>>> global_config);
>>>> + if (ret) {
>>>> + DRM_ERROR("fail to set DP_FRAMER_GLOBAL_CONFIG, error:
>>>> %d\n",
>>>> + ret);
>>>> + return ret;
>>>> + }
>>>> +
>>>> + ret = cdn_dp_reg_write(dp, DP_TX_PHY_CONFIG_REG, phy_config);
>>>> + if (ret) {
>>>> + DRM_ERROR("fail to set DP_TX_PHY_CONFIG_REG, error:
>>>> %d\n",
>>>> + ret);
>>>> + return ret;
>>>> + }
>>>> +
>>>> + ret = cdn_dp_reg_write(dp, DPTX_LANE_EN, BIT(dp->link.num_lanes)
>>>> - 1);
>>>> + if (ret) {
>>>> + DRM_ERROR("fail to set DPTX_LANE_EN, error: %d\n", ret);
>>>> + return ret;
>>>> + }
>>>> +
>>>> + if (drm_dp_enhanced_frame_cap(dp->dpcd))
>>>> + ret = cdn_dp_reg_write(dp, DPTX_ENHNCD, 1);
>>>> + else
>>>> + ret = cdn_dp_reg_write(dp, DPTX_ENHNCD, 0);
>>>> + if (ret)
>>>> + DRM_ERROR("failed to set DPTX_ENHNCD, error: %x\n", ret);
>>>> +
>>>> + return ret;
>>>> +}
>>>> +
>>>> +static u8 cdn_dp_pre_emphasis_max(u8 voltage_swing)
>>>> +{
>>>> + switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
>>>> + case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
>>>> + return DP_TRAIN_PRE_EMPH_LEVEL_3;
>>>> + case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
>>>> + return DP_TRAIN_PRE_EMPH_LEVEL_2;
>>>> + case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
>>>> + return DP_TRAIN_PRE_EMPH_LEVEL_1;
>>>> + default:
>>>> + return DP_TRAIN_PRE_EMPH_LEVEL_0;
>>>> + }
>>>> +}
>>>> +
>>>> +static void cdn_dp_get_adjust_train(struct cdn_dp_device *dp,
>>>> + uint8_t
>>>> link_status[DP_LINK_STATUS_SIZE])
>>>> +{
>>>> + int i;
>>>> + uint8_t v = 0, p = 0;
>>>> + uint8_t preemph_max;
>>>> +
>>>> + for (i = 0; i < dp->link.num_lanes; i++) {
>>>> + v = max(v, drm_dp_get_adjust_request_voltage(link_status,
>>>> i));
>>>> + p = max(p,
>>>> drm_dp_get_adjust_request_pre_emphasis(link_status,
>>>> + i));
>>>> + }
>>>> +
>>>> + if (v >= VOLTAGE_LEVEL_2)
>>>> + v = VOLTAGE_LEVEL_2 | DP_TRAIN_MAX_SWING_REACHED;
>>>> +
>>>> + preemph_max = cdn_dp_pre_emphasis_max(v);
>>>> + if (p >= preemph_max)
>>>> + p = preemph_max | DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
>>>> +
>>>> + for (i = 0; i < dp->link.num_lanes; i++)
>>>> + dp->train_set[i] = v | p;
>>>> +}
>>>> +
>>>> +/*
>>>> + * Pick training pattern for channel equalization. Training Pattern 3
>>>> for HBR2
>>>> + * or 1.2 devices that support it, Training Pattern 2 otherwise.
>>>> + */
>>>> +static u32 cdn_dp_select_chaneq_pattern(struct cdn_dp_device *dp)
>>>> +{
>>>> + u32 training_pattern = DP_TRAINING_PATTERN_2;
>>>> +
>>>> + /*
>>>> + * cdn dp support HBR2 also support TPS3. TPS3 support is also
>>>> mandatory
>>>> + * for downstream devices that support HBR2. However, not all
>>>> sinks
>>>> + * follow the spec.
>>>> + */
>>>> + if (drm_dp_tps3_supported(dp->dpcd))
>>>> + training_pattern = DP_TRAINING_PATTERN_3;
>>>> + else
>>>> + DRM_DEBUG_KMS("5.4 Gbps link rate without sink TPS3
>>>> support\n");
>>>> +
>>>> + return training_pattern;
>>>> +}
>>>> +
>>>> +
>>>> +static bool cdn_dp_link_max_vswing_reached(struct cdn_dp_device *dp)
>>>> +{
>>>> + int lane;
>>>> +
>>>> + for (lane = 0; lane < dp->link.num_lanes; lane++)
>>>> + if ((dp->train_set[lane] & DP_TRAIN_MAX_SWING_REACHED) ==
>>>> 0)
>>>> + return false;
>>>> +
>>>> + return true;
>>>> +}
>>>> +
>>>> +static int cdn_dp_update_link_train(struct cdn_dp_device *dp)
>>>> +{
>>>> + int ret;
>>>> +
>>>> + cdn_dp_set_signal_levels(dp);
>>>> +
>>>> + ret = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET,
>>>> + dp->train_set, dp->link.num_lanes);
>>>> + if (ret != dp->link.num_lanes)
>>>> + return -EINVAL;
>>>> +
>>>> + return 0;
>>>> +}
>>>> +
>>>> +static int cdn_dp_set_link_train(struct cdn_dp_device *dp,
>>>> + uint8_t dp_train_pat)
>>>> +{
>>>> + uint8_t buf[sizeof(dp->train_set) + 1];
>>>> + int ret, len;
>>>> +
>>>> + buf[0] = dp_train_pat;
>>>> + if ((dp_train_pat & DP_TRAINING_PATTERN_MASK) ==
>>>> + DP_TRAINING_PATTERN_DISABLE) {
>>>> + /* don't write DP_TRAINING_LANEx_SET on disable */
>>>> + len = 1;
>>>> + } else {
>>>> + /* DP_TRAINING_LANEx_SET follow DP_TRAINING_PATTERN_SET
>>>> */
>>>> + memcpy(buf + 1, dp->train_set, dp->link.num_lanes);
>>>> + len = dp->link.num_lanes + 1;
>>>> + }
>>>> +
>>>> + ret = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_PATTERN_SET,
>>>> + buf, len);
>>>> + if (ret != len)
>>>> + return -EINVAL;
>>>> +
>>>> + return 0;
>>>> +}
>>>> +
>>>> +static int cdn_dp_reset_link_train(struct cdn_dp_device *dp,
>>>> + uint8_t dp_train_pat)
>>>> +{
>>>> + int ret;
>>>> +
>>>> + memset(dp->train_set, 0, sizeof(dp->train_set));
>>>> +
>>>> + cdn_dp_set_signal_levels(dp);
>>>> +
>>>> + ret = cdn_dp_set_pattern(dp, dp_train_pat);
>>>> + if (ret)
>>>> + return ret;
>>>> +
>>>> + return cdn_dp_set_link_train(dp, dp_train_pat);
>>>> +}
>>>> +
>>>> +/* Enable corresponding port and start training pattern 1 */
>>>> +static int cdn_dp_link_training_clock_recovery(struct cdn_dp_device *dp)
>>>> +{
>>>> + u8 voltage;
>>>> + u8 link_status[DP_LINK_STATUS_SIZE];
>>>> + u32 voltage_tries, max_vswing_tries;
>>>> + int ret;
>>>> +
>>>> + /* clock recovery */
>>>> + ret = cdn_dp_reset_link_train(dp, DP_TRAINING_PATTERN_1 |
>>>> + DP_LINK_SCRAMBLING_DISABLE);
>>>> + if (ret) {
>>>> + DRM_ERROR("failed to start link train\n");
>>>> + return ret;
>>>> + }
>>>> +
>>>> + voltage_tries = 1;
>>>> + max_vswing_tries = 0;
>>>> + for (;;) {
>>>> + drm_dp_link_train_clock_recovery_delay(dp->dpcd);
>>>> + if (drm_dp_dpcd_read_link_status(&dp->aux, link_status)
>>>> !=
>>>> + DP_LINK_STATUS_SIZE) {
>>>> + DRM_ERROR("failed to get link status\n");
>>>> + return -EINVAL;
>>>> + }
>>>> +
>>>> + if (drm_dp_clock_recovery_ok(link_status,
>>>> dp->link.num_lanes)) {
>>>> + DRM_DEBUG_KMS("clock recovery OK\n");
>>>> + return 0;
>>>> + }
>>>> +
>>>> + if (voltage_tries >= 5) {
>>>> + DRM_DEBUG_KMS("Same voltage tried 5 times\n");
>>>> + return -EINVAL;
>>>> + }
>>>> +
>>>> + if (max_vswing_tries >= 1) {
>>>> + DRM_DEBUG_KMS("Max Voltage Swing reached\n");
>>>> + return -EINVAL;
>>>> + }
>>>> +
>>>> + voltage = dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
>>>> +
>>>> + /* Update training set as requested by target */
>>>> + cdn_dp_get_adjust_train(dp, link_status);
>>>> + if (cdn_dp_update_link_train(dp)) {
>>>> + DRM_ERROR("failed to update link training\n");
>>>> + return -EINVAL;
>>>> + }
>>>> +
>>>> + if ((dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) ==
>>>> + voltage)
>>>> + ++voltage_tries;
>>>> + else
>>>> + voltage_tries = 1;
>>>> +
>>>> + if (cdn_dp_link_max_vswing_reached(dp))
>>>> + ++max_vswing_tries;
>>>> + }
>>>> +}
>>>> +
>>>> +static int cdn_dp_link_training_channel_equalization(struct
>>>> cdn_dp_device *dp)
>>>> +{
>>>> + int tries, ret;
>>>> + u32 training_pattern;
>>>> + uint8_t link_status[DP_LINK_STATUS_SIZE];
>>>> +
>>>> + training_pattern = cdn_dp_select_chaneq_pattern(dp);
>>>> + training_pattern |= DP_LINK_SCRAMBLING_DISABLE;
>>>> +
>>>> + ret = cdn_dp_set_pattern(dp, training_pattern);
>>>> + if (ret)
>>>> + return ret;
>>>> +
>>>> + ret = cdn_dp_set_link_train(dp, training_pattern);
>>>> + if (ret) {
>>>> + DRM_ERROR("failed to start channel equalization\n");
>>>> + return ret;
>>>> + }
>>>> +
>>>> + for (tries = 0; tries < 5; tries++) {
>>>> + drm_dp_link_train_channel_eq_delay(dp->dpcd);
>>>> + if (drm_dp_dpcd_read_link_status(&dp->aux, link_status)
>>>> !=
>>>> + DP_LINK_STATUS_SIZE) {
>>>> + DRM_ERROR("failed to get link status\n");
>>>> + break;
>>>> + }
>>>> +
>>>> + /* Make sure clock is still ok */
>>>> + if (!drm_dp_clock_recovery_ok(link_status,
>>>> + dp->link.num_lanes)) {
>>>> + DRM_DEBUG_KMS("Clock recovery check failed\n");
>>>> + break;
>>>> + }
>>>> +
>>>> + if (drm_dp_channel_eq_ok(link_status,
>>>> dp->link.num_lanes)) {
>>>> + DRM_DEBUG_KMS("Channel EQ done\n");
>>>> + return 0;
>>>> + }
>>>> +
>>>> + /* Update training set as requested by target */
>>>> + cdn_dp_get_adjust_train(dp, link_status);
>>>> + if (cdn_dp_update_link_train(dp)) {
>>>> + DRM_ERROR("failed to update link training\n");
>>>> + break;
>>>> + }
>>>> + }
>>>> +
>>>> + /* Try 5 times, else fail and try at lower BW */
>>>> + if (tries == 5)
>>>> + DRM_DEBUG_KMS("Channel equalization failed 5 times\n");
>>>> +
>>>> + return -EINVAL;
>>>> +}
>>>> +
>>>> +static int cdn_dp_stop_link_train(struct cdn_dp_device *dp)
>>>> +{
>>>> + int ret = cdn_dp_set_pattern(dp, DP_TRAINING_PATTERN_DISABLE);
>>>> +
>>>> + if (ret)
>>>> + return ret;
>>>> +
>>>> + return cdn_dp_set_link_train(dp, DP_TRAINING_PATTERN_DISABLE);
>>>> +}
>>>> +
>>>> +static int cdn_dp_get_lower_link_rate(struct cdn_dp_device *dp)
>>>> +{
>>>> + switch (dp->link.rate) {
>>>> + case DP_LINK_BW_1_62:
>>>> + return -EINVAL;
>>>> + case DP_LINK_BW_2_7:
>>>> + dp->link.rate = DP_LINK_BW_1_62;
>>>> + break;
>>>> + case DP_LINK_BW_5_4:
>>>> + dp->link.rate = DP_LINK_BW_2_7;
>>>> + break;
>>>> + default:
>>>> + dp->link.rate = DP_LINK_BW_5_4;
>>>> + break;
>>>> + }
>>>> +
>>>> + return 0;
>>>> +}
>>>> +
>>>> +int cdn_dp_software_train_link(struct cdn_dp_device *dp)
>>>> +{
>>>> + int ret, stop_err;
>>>> + u8 link_config[2];
>>>> + u32 rate, sink_max, source_max;
>>>> +
>>>> + ret = drm_dp_dpcd_read(&dp->aux, DP_DPCD_REV, dp->dpcd,
>>>> + sizeof(dp->dpcd));
>>>> + if (ret < 0) {
>>>> + DRM_DEV_ERROR(dp->dev, "Failed to get caps %d\n", ret);
>>>> + return ret;
>>>> + }
>>>> +
>>>> + source_max = dp->lanes;
>>>> + sink_max = drm_dp_max_lane_count(dp->dpcd);
>>>> + dp->link.num_lanes = min(source_max, sink_max);
>>>> +
>>>> + source_max = drm_dp_bw_code_to_link_rate(CDN_DP_MAX_LINK_RATE);
>>>> + sink_max = drm_dp_max_link_rate(dp->dpcd);
>>>> + rate = min(source_max, sink_max);
>>>> + dp->link.rate = drm_dp_link_rate_to_bw_code(rate);
>>>> +
>>>> + link_config[0] = 0;
>>>> + link_config[1] = 0;
>>>> + if (dp->dpcd[DP_MAIN_LINK_CHANNEL_CODING] & 0x01)
>>>> + link_config[1] = DP_SET_ANSI_8B10B;
>>>> + drm_dp_dpcd_write(&dp->aux, DP_DOWNSPREAD_CTRL, link_config, 2);
>>>> +
>>>> + while (true) {
>>>> +
>>>> + /* Write the link configuration data */
>>>> + link_config[0] = dp->link.rate;
>>>> + link_config[1] = dp->link.num_lanes;
>>>> + if (drm_dp_enhanced_frame_cap(dp->dpcd))
>>>> + link_config[1] |=
>>>> DP_LANE_COUNT_ENHANCED_FRAME_EN;
>>>> + drm_dp_dpcd_write(&dp->aux, DP_LINK_BW_SET, link_config,
>>>> 2);
>>>> +
>>>> + ret = cdn_dp_link_training_clock_recovery(dp);
>>>> + if (ret) {
>>>> + if (!cdn_dp_get_lower_link_rate(dp))
>>>> + continue;
>>>> +
>>>> + DRM_ERROR("training clock recovery failed: %d\n",
>>>> ret);
>>>> + break;
>>>> + }
>>>> +
>>>> + ret = cdn_dp_link_training_channel_equalization(dp);
>>>> + if (ret) {
>>>> + if (!cdn_dp_get_lower_link_rate(dp))
>>>> + continue;
>>>> +
>>>> + DRM_ERROR("training channel eq failed: %d\n",
>>>> ret);
>>>> + break;
>>>> + }
>>>> +
>>>> + break;
>>>> + }
>>>> +
>>>> + stop_err = cdn_dp_stop_link_train(dp);
>>>> + if (stop_err) {
>>>> + DRM_ERROR("stop training fail, error: %d\n", stop_err);
>>>> + return stop_err;
>>>> + }
>>>> +
>>>> + return ret;
>>>> +}
>>>> diff --git a/drivers/gpu/drm/rockchip/cdn-dp-reg.c
>>>> b/drivers/gpu/drm/rockchip/cdn-dp-reg.c
>>>> index 979355d..e1273e6 100644
>>>> --- a/drivers/gpu/drm/rockchip/cdn-dp-reg.c
>>>> +++ b/drivers/gpu/drm/rockchip/cdn-dp-reg.c
>>>> @@ -17,7 +17,9 @@
>>>> #include <linux/delay.h>
>>>> #include <linux/io.h>
>>>> #include <linux/iopoll.h>
>>>> +#include <linux/phy/phy.h>
>>>> #include <linux/reset.h>
>>>> +#include <soc/rockchip/rockchip_phy_typec.h>
>>>>
>>>> #include "cdn-dp-core.h"
>>>> #include "cdn-dp-reg.h"
>>>> @@ -189,7 +191,7 @@ static int cdn_dp_mailbox_send(struct cdn_dp_device
>>>> *dp, u8 module_id,
>>>> return 0;
>>>> }
>>>>
>>>> -static int cdn_dp_reg_write(struct cdn_dp_device *dp, u16 addr, u32 val)
>>>> +int cdn_dp_reg_write(struct cdn_dp_device *dp, u16 addr, u32 val)
>>>> {
>>>> u8 msg[6];
>>>>
>>>> @@ -609,6 +611,31 @@ int cdn_dp_train_link(struct cdn_dp_device *dp)
>>>> {
>>>> int ret;
>>>>
>>>> + /*
>>>> + * DP firmware uses fixed phy config values to do training, but
>>>> some
>>>> + * boards need to adjust these values to fit for their unique
>>>> hardware
>>>> + * design. So if the phy is using custom config values, do
>>>> software
>>>> + * link training instead of relying on firmware, if software
>>>> training
>>>> + * fail, keep firmware training as a fallback if sw training
>>>> fails.
>>>> + */
>>>> + ret = cdn_dp_software_train_link(dp);
>>>> + if (ret) {
>>>> + DRM_DEV_ERROR(dp->dev,
>>>> + "Failed to do software training %d\n", ret);
>>>> + goto do_fw_training;
>>>> + }
>>>
>>> If I understand correctly you are changing current behavior. Before
>>> this patch, we use always firmware link training, and after this
>>> patch, we always use software link training. If fails we use the
>>> firmware link training.
>>>
>>> AFAIK my Samsung Chromebook Plus works well with firmware link
>>> training, so there are any benefits of use software link training
>>> instead of firmware link training?
>>>
>>> Looks to me that we should only do software link training on these
>>> platforms that need it, so on those that define the phy-config
>>> property in their DT and use by default firmware link training.
>>
>> Sean and me have discussed about that, and we all agree to use sw training
>> instead the
>> fw training to keep training process consistent, and we do not need add a
>> varialbe in
>> struct rockchip_typec_phy(like use_sw_training before) to distinguish sw and
>> fw training.
>> If training process implement correctly, sw training not different with fw
>> training, and as my
>> test so far, sw training work well on Kevin, ofcourse, we need keep testing
>> it.
>>
>
> Ok, I can also confirm that software training works well on kevin.
> Could you mention this change of behavior in the commit message? I
> think that after these patches the firmware training is unlikely to
> happen.
>
> Thanks,
> Enric
>
>
>>>> + ret = cdn_dp_reg_write(dp, SOURCE_HDTX_CAR, 0xf);
>>>> + if (ret) {
>>>> + DRM_DEV_ERROR(dp->dev,
>>>> + "Failed to write SOURCE_HDTX_CAR register %d\n", ret);
>>>> + goto do_fw_training;
>>>> + }
>>>> + dp->use_fw_training = false;
>>>> + return 0;
>>>> +
>>>> +do_fw_training:
>>>> + dp->use_fw_training = true;
>>>> + DRM_DEV_DEBUG_KMS(dp->dev, "use fw training\n");
>>>> ret = cdn_dp_training_start(dp);
>>>> if (ret) {
>>>> DRM_DEV_ERROR(dp->dev, "Failed to start training %d\n",
>>>> ret);
>>>> @@ -623,7 +650,7 @@ int cdn_dp_train_link(struct cdn_dp_device *dp)
>>>>
>>>> DRM_DEV_DEBUG_KMS(dp->dev, "rate:0x%x, lanes:%d\n",
>>>> dp->link.rate,
>>>> dp->link.num_lanes);
>>>> - return ret;
>>>> + return 0;
>>>> }
>>>>
>>>> int cdn_dp_set_video_status(struct cdn_dp_device *dp, int active)
>>>> diff --git a/drivers/gpu/drm/rockchip/cdn-dp-reg.h
>>>> b/drivers/gpu/drm/rockchip/cdn-dp-reg.h
>>>> index 6580b11..3420771 100644
>>>> --- a/drivers/gpu/drm/rockchip/cdn-dp-reg.h
>>>> +++ b/drivers/gpu/drm/rockchip/cdn-dp-reg.h
>>>> @@ -137,7 +137,7 @@
>>>> #define HPD_EVENT_MASK 0x211c
>>>> #define HPD_EVENT_DET 0x2120
>>>>
>>>> -/* dpyx framer addr */
>>>> +/* dptx framer addr */
>>>> #define DP_FRAMER_GLOBAL_CONFIG 0x2200
>>>> #define DP_SW_RESET 0x2204
>>>> #define DP_FRAMER_TU 0x2208
>>>> @@ -431,6 +431,40 @@
>>>> /* Reference cycles when using lane clock as reference */
>>>> #define LANE_REF_CYC 0x8000
>>>>
>>>> +/* register CM_VID_CTRL */
>>>> +#define LANE_VID_REF_CYC(x) (((x) & (BIT(24) - 1)) <<
>>>> 0)
>>>> +#define NMVID_MEAS_TOLERANCE(x) (((x) & 0xf) <<
>>>> 24)
>>>> +
>>>> +/* register DP_TX_PHY_CONFIG_REG */
>>>> +#define DP_TX_PHY_TRAINING_ENABLE(x) ((x) & 1)
>>>> +#define DP_TX_PHY_TRAINING_TYPE_PRBS7 (0 << 1)
>>>> +#define DP_TX_PHY_TRAINING_TYPE_TPS1 (1 << 1)
>>>> +#define DP_TX_PHY_TRAINING_TYPE_TPS2 (2 << 1)
>>>> +#define DP_TX_PHY_TRAINING_TYPE_TPS3 (3 << 1)
>>>> +#define DP_TX_PHY_TRAINING_TYPE_TPS4 (4 << 1)
>>>> +#define DP_TX_PHY_TRAINING_TYPE_PLTPAT (5 << 1)
>>>> +#define DP_TX_PHY_TRAINING_TYPE_D10_2 (6 << 1)
>>>> +#define DP_TX_PHY_TRAINING_TYPE_HBR2CPAT (8 << 1)
>>>> +#define DP_TX_PHY_TRAINING_PATTERN(x) ((x) << 1)
>>>> +#define DP_TX_PHY_SCRAMBLER_BYPASS(x) (((x) & 1) << 5)
>>>> +#define DP_TX_PHY_ENCODER_BYPASS(x) (((x) & 1) << 6)
>>>> +#define DP_TX_PHY_SKEW_BYPASS(x) (((x) & 1) << 7)
>>>> +#define DP_TX_PHY_DISPARITY_RST(x) (((x) & 1) << 8)
>>>> +#define DP_TX_PHY_LANE0_SKEW(x) (((x) & 7) << 9)
>>>> +#define DP_TX_PHY_LANE1_SKEW(x) (((x) & 7) << 12)
>>>> +#define DP_TX_PHY_LANE2_SKEW(x) (((x) & 7) << 15)
>>>> +#define DP_TX_PHY_LANE3_SKEW(x) (((x) & 7) << 18)
>>>> +#define DP_TX_PHY_10BIT_ENABLE(x) (((x) & 1) << 21)
>>>> +
>>>> +/* register DP_FRAMER_GLOBAL_CONFIG */
>>>> +#define NUM_LANES(x) ((x) & 3)
>>>> +#define SST_MODE (0 << 2)
>>>> +#define RG_EN (0 << 4)
>>>> +#define GLOBAL_EN BIT(3)
>>>> +#define NO_VIDEO BIT(5)
>>>> +#define ENC_RST_DIS BIT(6)
>>>> +#define WR_VHSYNC_FALL BIT(7)
>>>> +
>>>> enum voltage_swing_level {
>>>> VOLTAGE_LEVEL_0,
>>>> VOLTAGE_LEVEL_1,
>>>> @@ -476,6 +510,7 @@ int cdn_dp_set_host_cap(struct cdn_dp_device *dp, u8
>>>> lanes, bool flip);
>>>> int cdn_dp_event_config(struct cdn_dp_device *dp);
>>>> u32 cdn_dp_get_event(struct cdn_dp_device *dp);
>>>> int cdn_dp_get_hpd_status(struct cdn_dp_device *dp);
>>>> +int cdn_dp_reg_write(struct cdn_dp_device *dp, u16 addr, u32 val);
>>>> ssize_t cdn_dp_dpcd_write(struct cdn_dp_device *dp, u32 addr,
>>>> u8 *data, u16 len);
>>>> ssize_t cdn_dp_dpcd_read(struct cdn_dp_device *dp, u32 addr,
>>>> @@ -489,4 +524,5 @@ int cdn_dp_config_video(struct cdn_dp_device *dp);
>>>> int cdn_dp_audio_stop(struct cdn_dp_device *dp, struct audio_info
>>>> *audio);
>>>> int cdn_dp_audio_mute(struct cdn_dp_device *dp, bool enable);
>>>> int cdn_dp_audio_config(struct cdn_dp_device *dp, struct audio_info
>>>> *audio);
>>>> +int cdn_dp_software_train_link(struct cdn_dp_device *dp);
>>>> #endif /* _CDN_DP_REG_H */
>>>> --
>>>> 2.7.4
>>>>
>>>
>>>
>>
>>

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