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Subject: Re: [PATCH 4/4] drm/rockchip: support dp training outside dp firmware
To:     Enric Balletbo Serra <eballetbo@gmail.com>
Cc:     Sean Paul <seanpaul@chromium.org>, David Airlie <airlied@linux.ie>,
        Chris Zhong <zyw@rock-chips.com>,
        Doug Anderson <dianders@chromium.org>,
        Brian Norris <briannorris@chromium.org>,
        "open list:ARM/Rockchip SoC..." <linux-rockchip@lists.infradead.org>,
        =?UTF-8?Q?Heiko_St=c3=bcbner?= <heiko@sntech.de>,
        daniel.vetter@intel.com, jani.nikula@linux.intel.com,
        dri-devel <dri-devel@lists.freedesktop.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        linux-kernel <linux-kernel@vger.kernel.org>
References: <1525421338-1021-1-git-send-email-hl@rock-chips.com>
 <1525421338-1021-4-git-send-email-hl@rock-chips.com>
 <CAFqH_531eY=cnuEsBbXaZRyPYjJJ0nmoqZg_QXcJN0A4tk95YQ@mail.gmail.com>
From:   hl <hl@rock-chips.com>
Message-ID: <d49cc6f2-c8c3-2368-c56e-65e27bd3d6df@rock-chips.com>
Date:   Wed, 9 May 2018 17:47:34 +0800
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On Monday, May 07, 2018 07:29 PM, Enric Balletbo Serra wrote:
> Hi Lin,
>
> Thanks for the patch.
>
> 2018-05-04 10:08 GMT+02:00 Lin Huang <hl@rock-chips.com>:
>> DP firware use fix phy config value to do training, but some
> s/fiware/firmware/
>
>> board need to adjust these value to fit for their hardware design,
>> so we use new phy config to do training outside firmware to meet
>> this situation, if there have new phy config pass from dts, it will
>> use training outside firmware.
>>
> maybe you can rewrite all this in a better way.
>
> ooi, which boards needs this?
>
>
>> Signed-off-by: Chris Zhong <zyw@rock-chips.com>
>> Signed-off-by: Lin Huang <hl@rock-chips.com>
>> ---
>>   drivers/gpu/drm/rockchip/Makefile               |   3 +-
>>   drivers/gpu/drm/rockchip/cdn-dp-core.c          |  23 +-
>>   drivers/gpu/drm/rockchip/cdn-dp-core.h          |   2 +
>>   drivers/gpu/drm/rockchip/cdn-dp-link-training.c | 398 ++++++++++++++++++++++++
>>   drivers/gpu/drm/rockchip/cdn-dp-reg.c           |  33 +-
>>   drivers/gpu/drm/rockchip/cdn-dp-reg.h           |  38 ++-
>>   6 files changed, 480 insertions(+), 17 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 268c190..a2a4208 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->sw_training_success == false) {
>> +               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 +644,14 @@ 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->sw_training_success == false) {
>> +               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..c6050ab 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 sw_training_success;
>>
>>          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..558c945
>> --- /dev/null
>> +++ b/drivers/gpu/drm/rockchip/cdn-dp-link-training.c
>> @@ -0,0 +1,398 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
> For a C source file the format is:
> (https://www.kernel.org/doc/html/latest/process/license-rules.html)
>
> // SPDX-License-Identifier: <SPDX License Expression>
Thanks for pointing it, will fix it.
>> +/*
>> + * Copyright (C) Fuzhou Rockchip Electronics Co.Ltd
>> + * Author: Chris Zhong <zyw@rock-chips.com>
>> + */
>> +
>> +#include <linux/arm-smccc.h>
> Why you need this include?
>
>> +#include <linux/clk.h>
>> +#include <linux/device.h>
>> +#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>
>> +
> In fact, I think that there are other includes that can be removed,
> please review.
>
>> +#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, link_config[2];
>> +       u8 link_status[DP_LINK_STATUS_SIZE];
>> +       u32 voltage_tries, max_vswing_tries;
>> +       u32 rate, sink_max, source_max;
>> +       int 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);
>> +
>> +       /* 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);
>> +
>> +       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);
>> +
>> +       /* 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, cannot "
>> +                                     "continue channel equalization\n");
>> +                       break;
>> +               }
>> +
>> +               if (drm_dp_channel_eq_ok(link_status,  dp->link.num_lanes)) {
>> +                       DRM_DEBUG_KMS("Channel EQ done. DP Training "
>> +                                     "successful\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);
>> +}
>> +
>> +int cdn_dp_software_train_link(struct cdn_dp_device *dp)
>> +{
>> +       int ret, stop_err;
>> +
>> +       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;
>> +       }
>> +
>> +       ret = cdn_dp_link_training_clock_recovery(dp);
>> +       if (ret) {
>> +               DRM_ERROR("training clock recovery fail, error: %d\n", ret);
>> +               goto out;
>> +       }
>> +
>> +       ret = cdn_dp_link_training_channel_equalization(dp);
>> +       if (ret) {
>> +               DRM_ERROR("training channel equalization fail, error: %d\n",
>> +                         ret);
>> +               goto out;
>> +       }
>> +out:
>> +       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 b2f532a..72780f1 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];
>>
>> @@ -605,22 +607,41 @@ static int cdn_dp_get_training_status(struct cdn_dp_device *dp)
>>   int cdn_dp_train_link(struct cdn_dp_device *dp)
>>   {
>>          int ret;
>> +       struct cdn_dp_port *port = dp->port[dp->active_port];
>> +       struct rockchip_typec_phy *tcphy = phy_get_drvdata(port->phy);
>>
>> +       /*
>> +        * 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.
>> +        */
>> +       if (tcphy->need_software_training) {
>> +               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;
>> +               }
>> +               cdn_dp_reg_write(dp, SOURCE_HDTX_CAR, 0xf);
> Check for an error here and act accordingly? Or doesn't matter?
yes, it need, thanks.
>
>> +               dp->sw_training_success = true;
>> +               return 0;
>> +       }
>> +
> nit: Personally I don't like this goto. Maybe you can refactor this.
>
>         if (tcphy->need_software_training) {
>                 ret = cdn_dp_software_train_link(dp);
>                 if (!ret) {
>                         cdn_dp_reg_write(dp, SOURCE_HDTX_CAR, 0xf);
>                         dp->sw_training_success = true;
>                         return 0;
>                 }
>                 DRM_DEV_ERROR(dp->dev, "Failed to do software training
> %d\n", ret);
>         }
if check the cdn_dp_reg_write(dp, SOURCE_HDTX_CAR, 0xf) error, i think 
we still need this goto.
>> +do_fw_training:
> Then remove the goto label.
>
>> +       dp->sw_training_success = false;
>>          ret = cdn_dp_training_start(dp);
>>          if (ret) {
>>                  DRM_DEV_ERROR(dp->dev, "Failed to start training %d\n", ret);
>>                  return ret;
>>          }
>> -
> Do not remove the new line.
>
>>          ret = cdn_dp_get_training_status(dp);
>>          if (ret) {
>>                  DRM_DEV_ERROR(dp->dev, "Failed to get training stat %d\n", ret);
>>                  return ret;
>>          }
>> -
>> -       DRM_DEV_DEBUG_KMS(dp->dev, "rate:0x%x, lanes:%d\n", dp->link.rate,
>> -                         dp->link.num_lanes);
> Why you remove this debug message?
>
>> -       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 aedf2dc..b60a6b2 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 GLOBAL_EN              (1 << 3)
>> +#define RG_EN                  (0 << 4)
>> +#define NO_VIDEO               (1 << 5)
>> +#define ENC_RST_DIS            (1 << 6)
>> +#define WR_VHSYNC_FALL         (1 << 7)
>> +
> Use the BIT() macros for these.
will fix it
>
>>   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
>>
>
>