[PATCH v2 drm-dp 5/7] drm/hisilicon/hibmc: Get link status and dpcd caps
Dmitry Baryshkov
dmitry.baryshkov at linaro.org
Thu Feb 13 00:18:20 UTC 2025
On Mon, Feb 10, 2025 at 10:49:57PM +0800, Yongbang Shi wrote:
> From: Baihan Li <libaihan at huawei.com>
>
> Prepare the hibmc_dp_get_foo() functions for debugfs using in
> next patch. We also add dpcd's if statement in link training process,
> because we have the dpcd.
Unrelated, split to a separate patch.
>
> Signed-off-by: Baihan Li <libaihan at huawei.com>
> Signed-off-by: Yongbang Shi <shiyongbang at huawei.com>
> ---
> drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h | 3 ++
> drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c | 15 ++++++++
> drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h | 3 ++
> drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c | 39 ++++++++++++++++----
> 4 files changed, 52 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h
> index d613da8b544c..8eb1659c7685 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h
> +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h
> @@ -26,6 +26,9 @@ struct hibmc_link_status {
> struct hibmc_link_cap {
> u8 link_rate;
> u8 lanes;
> + int rx_dpcd_revision;
> + bool is_tps3;
> + bool is_tps4;
> };
>
> struct hibmc_dp_link {
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
> index 8adace0befde..5e889c377117 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
> +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
> @@ -227,6 +227,21 @@ int hibmc_dp_mode_set(struct hibmc_dp *dp, struct drm_display_mode *mode)
> return 0;
> }
>
> +u8 hibmc_dp_get_link_rate(struct hibmc_dp *dp)
> +{
> + return dp->dp_dev->link.cap.link_rate;
> +}
> +
> +u8 hibmc_dp_get_lanes(struct hibmc_dp *dp)
> +{
> + return dp->dp_dev->link.cap.lanes;
> +}
> +
> +int hibmc_dp_get_dpcd(struct hibmc_dp *dp)
> +{
> + return dp->dp_dev->link.cap.rx_dpcd_revision;
> +}
> +
> static const struct hibmc_dp_color_raw g_rgb_raw[] = {
> {CBAR_COLOR_BAR, 0x000, 0x000, 0x000},
> {CBAR_WHITE, 0xfff, 0xfff, 0xfff},
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
> index 621a0a1d7eb7..823544b8008b 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
> +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
> @@ -54,6 +54,9 @@ struct hibmc_dp {
> int hibmc_dp_hw_init(struct hibmc_dp *dp);
> int hibmc_dp_mode_set(struct hibmc_dp *dp, struct drm_display_mode *mode);
> void hibmc_dp_display_en(struct hibmc_dp *dp, bool enable);
> +int hibmc_dp_get_dpcd(struct hibmc_dp *dp);
> +u8 hibmc_dp_get_link_rate(struct hibmc_dp *dp);
> +u8 hibmc_dp_get_lanes(struct hibmc_dp *dp);
> void hibmc_dp_set_cbar(struct hibmc_dp *dp, const struct hibmc_dp_cbar_cfg *cfg);
>
> #endif
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c
> index 4a99a9b7e3c4..39345fc78c06 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c
> +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c
> @@ -7,6 +7,7 @@
> #include "dp_comm.h"
> #include "dp_reg.h"
> #include "dp_serdes.h"
> +#include "dp_config.h"
>
> #define HIBMC_EQ_MAX_RETRY 5
>
> @@ -42,11 +43,7 @@ static int hibmc_dp_link_training_configure(struct hibmc_dp_dev *dp)
> return ret >= 0 ? -EIO : ret;
> }
>
> - ret = drm_dp_read_dpcd_caps(dp->aux, dp->dpcd);
> - if (ret)
> - drm_err(dp->dev, "dp aux read dpcd failed, ret: %d\n", ret);
> -
> - return ret;
> + return 0;
> }
>
> static int hibmc_dp_link_set_pattern(struct hibmc_dp_dev *dp, int pattern)
> @@ -189,15 +186,17 @@ static int hibmc_dp_link_training_cr(struct hibmc_dp_dev *dp)
> bool level_changed;
> u32 voltage_tries;
> u32 cr_tries;
> + u32 max_cr;
> int ret;
>
> /*
> * DP 1.4 spec define 10 for maxtries value, for pre DP 1.4 version set a limit of 80
> * (4 voltage levels x 4 preemphasis levels x 5 identical voltage retries)
> */
> + max_cr = dp->link.cap.rx_dpcd_revision >= DP_DPCD_REV_14 ? 10 : 80;
>
> voltage_tries = 1;
> - for (cr_tries = 0; cr_tries < 80; cr_tries++) {
> + for (cr_tries = 0; cr_tries < max_cr; cr_tries++) {
> drm_dp_link_train_clock_recovery_delay(dp->aux, dp->dpcd);
>
> ret = drm_dp_dpcd_read_link_status(dp->aux, lane_status);
> @@ -234,7 +233,7 @@ static int hibmc_dp_link_training_cr(struct hibmc_dp_dev *dp)
> voltage_tries = level_changed ? 1 : voltage_tries + 1;
> }
>
> - drm_err(dp->dev, "dp link training clock recovery 80 times failed\n");
> + drm_err(dp->dev, "dp link training clock recovery %u times failed\n", max_cr);
> dp->link.status.clock_recovered = false;
>
> return 0;
> @@ -244,9 +243,17 @@ static int hibmc_dp_link_training_channel_eq(struct hibmc_dp_dev *dp)
> {
> u8 lane_status[DP_LINK_STATUS_SIZE] = {0};
> u8 eq_tries;
> + int tps;
> int ret;
>
> - ret = hibmc_dp_link_set_pattern(dp, DP_TRAINING_PATTERN_2);
> + if (dp->link.cap.is_tps4)
> + tps = DP_TRAINING_PATTERN_4;
> + else if (dp->link.cap.is_tps3)
> + tps = DP_TRAINING_PATTERN_3;
> + else
> + tps = DP_TRAINING_PATTERN_2;
> +
> + ret = hibmc_dp_link_set_pattern(dp, tps);
> if (ret)
> return ret;
>
> @@ -313,11 +320,27 @@ static int hibmc_dp_link_downgrade_training_eq(struct hibmc_dp_dev *dp)
> return hibmc_dp_link_reduce_rate(dp);
> }
>
> +static void hibmc_dp_update_caps(struct hibmc_dp_dev *dp)
> +{
> + dp->link.cap.rx_dpcd_revision = dp->dpcd[DP_DPCD_REV];
> +
> + dp->link.cap.is_tps3 = (dp->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_13) &&
> + (dp->dpcd[DP_MAX_LANE_COUNT] & DP_TPS3_SUPPORTED);
> + dp->link.cap.is_tps4 = (dp->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14) &&
> + (dp->dpcd[DP_MAX_DOWNSPREAD] & DP_TPS4_SUPPORTED);
> +}
> +
> int hibmc_dp_link_training(struct hibmc_dp_dev *dp)
> {
> struct hibmc_dp_link *link = &dp->link;
> int ret;
>
> + ret = drm_dp_read_dpcd_caps(dp->aux, dp->dpcd);
> + if (ret)
> + drm_err(dp->dev, "dp aux read dpcd failed, ret: %d\n", ret);
> +
> + hibmc_dp_update_caps(dp);
> +
> while (true) {
> ret = hibmc_dp_link_training_cr_pre(dp);
> if (ret)
> --
> 2.33.0
>
--
With best wishes
Dmitry
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