Re: [PATCH v1 06/10] drm/bridge: analogix_dp: Add support for phy configuration.

Damon Ding
2024-12-12T08:55:47Z

Hi Dmitry,

On 2024/11/30 16:53, Dmitry Baryshkov wrote:
> On Wed, Nov 27, 2024 at 03:51:53PM +0800, Damon Ding wrote:
>> Add support to configurate link rate, lane count, voltage swing and
>> pre-emphasis with phy_configure(). It is helpful in application scenarios
>> where analogix controller is mixed with the phy of other vendors.
>>
>> Signed-off-by: Damon Ding <damon.ding@rock-chips.com>
>> ---
>> .../drm/bridge/analogix/analogix_dp_core.c | 4 +-
>> .../drm/bridge/analogix/analogix_dp_core.h | 2 +
>> .../gpu/drm/bridge/analogix/analogix_dp_reg.c | 90 +++++++++++++++++++
>> 3 files changed, 94 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>> index 6f10d88a34c5..7624ed13cdbf 100644
>> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>> @@ -1672,7 +1672,7 @@ EXPORT_SYMBOL_GPL(analogix_dp_probe);
>>
>> int analogix_dp_suspend(struct analogix_dp_device *dp)
>> {
>> - phy_power_off(dp->phy);
>> + analogix_dp_phy_power_off(dp);
>
> Why?
>
>>
>> if (dp->plat_data->power_off)
>> dp->plat_data->power_off(dp->plat_data);
>> @@ -1696,7 +1696,7 @@ int analogix_dp_resume(struct analogix_dp_device *dp)
>> if (dp->plat_data->power_on)
>> dp->plat_data->power_on(dp->plat_data);
>>
>> - phy_power_on(dp->phy);
>> + analogix_dp_phy_power_on(dp);
>
> Why?
>

These changes for phy_power_on()/phy_power_off() may be unnecessary. I
will just put the phy_set_mode() before phy_power_on() in next version.

>>
>> analogix_dp_init_dp(dp);
>>
>> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
>> index 774d11574b09..a76079d61768 100644
>> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
>> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
>> @@ -232,5 +232,7 @@ int analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
>> struct dp_sdp *vsc, bool blocking);
>> ssize_t analogix_dp_transfer(struct analogix_dp_device *dp,
>> struct drm_dp_aux_msg *msg);
>> +void analogix_dp_phy_power_on(struct analogix_dp_device *dp);
>> +void analogix_dp_phy_power_off(struct analogix_dp_device *dp);
>>
>> #endif /* _ANALOGIX_DP_CORE_H */
>> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
>> index 3afc73c858c4..809bb0c72d18 100644
>> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
>> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
>> @@ -11,6 +11,7 @@
>> #include <linux/gpio/consumer.h>
>> #include <linux/io.h>
>> #include <linux/iopoll.h>
>> +#include <linux/phy/phy.h>
>>
>> #include <drm/bridge/analogix_dp.h>
>>
>> @@ -513,10 +514,27 @@ void analogix_dp_enable_sw_function(struct analogix_dp_device *dp)
>> void analogix_dp_set_link_bandwidth(struct analogix_dp_device *dp, u32 bwtype)
>> {
>> u32 reg;
>> + int ret;
>>
>> reg = bwtype;
>> if ((bwtype == DP_LINK_BW_2_7) || (bwtype == DP_LINK_BW_1_62))
>> writel(reg, dp->reg_base + ANALOGIX_DP_LINK_BW_SET);
>> +
>> + if (dp->phy) {
>> + union phy_configure_opts phy_cfg = {0};
>> +
>> + phy_cfg.dp.lanes = dp->link_train.lane_count;
>
> You can drop this, .set_lanes is false.
>
>> + phy_cfg.dp.link_rate =
>> + drm_dp_bw_code_to_link_rate(dp->link_train.link_rate) / 100;
>> + phy_cfg.dp.set_lanes = false;
>> + phy_cfg.dp.set_rate = true;
>> + phy_cfg.dp.set_voltages = false;
>
> You don't need to set those to false, it's cleared by = {0};
>
>> + ret = phy_configure(dp->phy, &phy_cfg);
>> + if (ret && ret != -EOPNOTSUPP) {
>> + dev_err(dp->dev, "%s: phy_configure() failed: %d\n", __func__, ret);
>> + return;
>> + }
>> + }
>> }
>>
>> void analogix_dp_get_link_bandwidth(struct analogix_dp_device *dp, u32 *bwtype)
>> @@ -530,9 +548,24 @@ void analogix_dp_get_link_bandwidth(struct analogix_dp_device *dp, u32 *bwtype)
>> void analogix_dp_set_lane_count(struct analogix_dp_device *dp, u32 count)
>> {
>> u32 reg;
>> + int ret;
>>
>> reg = count;
>> writel(reg, dp->reg_base + ANALOGIX_DP_LANE_COUNT_SET);
>> +
>> + if (dp->phy) {
>> + union phy_configure_opts phy_cfg = {0};
>> +
>> + phy_cfg.dp.lanes = dp->link_train.lane_count;
>> + phy_cfg.dp.set_lanes = true;
>> + phy_cfg.dp.set_rate = false;
>> + phy_cfg.dp.set_voltages = false;
>
> Likewise
>
>> + ret = phy_configure(dp->phy, &phy_cfg);
>> + if (ret && ret != -EOPNOTSUPP) {
>> + dev_err(dp->dev, "%s: phy_configure() failed: %d\n", __func__, ret);
>> + return;
>> + }
>> + }
>> }
>>
>> void analogix_dp_get_lane_count(struct analogix_dp_device *dp, u32 *count)
>> @@ -546,10 +579,39 @@ void analogix_dp_get_lane_count(struct analogix_dp_device *dp, u32 *count)
>> void analogix_dp_set_lane_link_training(struct analogix_dp_device *dp)
>> {
>> u8 lane;
>> + int ret;
>>
>> for (lane = 0; lane < dp->link_train.lane_count; lane++)
>> writel(dp->link_train.training_lane[lane],
>> dp->reg_base + ANALOGIX_DP_LN0_LINK_TRAINING_CTL + 4 * lane);
>> +
>> + if (dp->phy) {
>> + union phy_configure_opts phy_cfg = {0};
>> +
>> + for (lane = 0; lane < dp->link_train.lane_count; lane++) {
>> + u8 training_lane = dp->link_train.training_lane[lane];
>> + u8 vs, pe;
>> +
>> + vs = (training_lane & DP_TRAIN_VOLTAGE_SWING_MASK) >>
>> + DP_TRAIN_VOLTAGE_SWING_SHIFT;
>> + pe = (training_lane & DP_TRAIN_PRE_EMPHASIS_MASK) >>
>> + DP_TRAIN_PRE_EMPHASIS_SHIFT;
>> + phy_cfg.dp.voltage[lane] = vs;
>> + phy_cfg.dp.pre[lane] = pe;
>> + }
>> +
>> + phy_cfg.dp.lanes = dp->link_train.lane_count;
>> + phy_cfg.dp.link_rate =
>> + drm_dp_bw_code_to_link_rate(dp->link_train.link_rate) / 100;
>
> You can drop these two.

Indeed, all the needless assignments for phy_configure() will be deleted
in next version.

>
>> + phy_cfg.dp.set_lanes = false;
>> + phy_cfg.dp.set_rate = false;
>> + phy_cfg.dp.set_voltages = true;
>> + ret = phy_configure(dp->phy, &phy_cfg);
>> + if (ret && ret != -EOPNOTSUPP) {
>> + dev_err(dp->dev, "%s: phy_configure() failed: %d\n", __func__, ret);
>> + return;
>> + }
>> + }
>> }
>>
>> u32 analogix_dp_get_lane_link_training(struct analogix_dp_device *dp, u8 lane)
>> @@ -1053,3 +1115,31 @@ ssize_t analogix_dp_transfer(struct analogix_dp_device *dp,
>>
>> return -EREMOTEIO;
>> }
>> +
>> +void analogix_dp_phy_power_on(struct analogix_dp_device *dp)
>> +{
>> + int ret;
>> +
>> + ret = phy_set_mode(dp->phy, PHY_MODE_DP);
>> + if (ret) {
>> + dev_err(dp->dev, "%s: phy_set_mode() failed: %d\n", __func__, ret);
>> + return;
>> + }
>> +
>> + ret = phy_power_on(dp->phy);
>> + if (ret) {
>> + dev_err(dp->dev, "%s: phy_power_on() failed: %d\n", __func__, ret);
>
> There is already a dev_err() call in phy_power_on().
>
>> + return;
>> + }
>> +}
>> +
>> +void analogix_dp_phy_power_off(struct analogix_dp_device *dp)
>> +{
>> + int ret;
>> +
>> + ret = phy_power_off(dp->phy);
>> + if (ret) {
>> + dev_err(dp->dev, "%s: phy_power_off() failed: %d\n", __func__, ret);
>
> There is already a dev_err() call in phy_power_off().
>
>> + return;
>> + }
>> +}
>> --
>> 2.34.1
>>
>>
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>

Best regards,
Damon