[PATCH v6 07/14] drm/bridge: analogix_dp: Add support to get panel from the DP AUX bus

[Dmitry Baryshkov]

On Thu, Jan 23, 2025 at 06:07:40PM +0800, Damon Ding wrote:
> The main modification is moving the DP AUX initialization from function
> analogix_dp_bind() to analogix_dp_probe(). In order to get the EDID of
> eDP panel during probing, it is also needed to advance PM operaions to
> ensure that eDP controller and phy are prepared for AUX transmission.

This doesn't sound right. Per the documentation of
drm_dp_aux::transfer(), the device should power itself up if transfer()
is called when it is powered off. The caller must only ensure that the
panel is on.

Doug, what's your opinion?

> 
> In addtion, add a new function analogix_dp_remove() to ensure symmetry
> for PM operations.
> 
> Signed-off-by: Damon Ding <damon.ding at rock-chips.com>
> 
> ---
> 
> Changes in v4:
> - Use done_probing() to call drm_of_find_panel_or_bridge() and
>   component_add() when getting panel from the DP AUX bus
> 
> Changes in v5:
> - Advance PM operations to make eDP AUX work well
> 
> Changes in v6:
> - Use devm_pm_runtime_enable() instead of devm_add_action_or_reset()
> - Add a new function analogix_dp_remove() to ensure symmetry for PM
>   operations
> ---
>  .../drm/bridge/analogix/analogix_dp_core.c    | 57 ++++++++++---------
>  .../gpu/drm/rockchip/analogix_dp-rockchip.c   |  4 ++
>  include/drm/bridge/analogix_dp.h              |  1 +
>  3 files changed, 34 insertions(+), 28 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> index 8251adfce2f9..30da8a14361e 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> @@ -1658,14 +1658,42 @@ analogix_dp_probe(struct device *dev, struct analogix_dp_plat_data *plat_data)
>  	}
>  	disable_irq(dp->irq);
>  
> +	dp->aux.name = "DP-AUX";
> +	dp->aux.transfer = analogix_dpaux_transfer;
> +	dp->aux.dev = dp->dev;
> +	drm_dp_aux_init(&dp->aux);
> +
> +	if (IS_ENABLED(CONFIG_PM)) {
> +		pm_runtime_use_autosuspend(dp->dev);
> +		pm_runtime_set_autosuspend_delay(dp->dev, 100);
> +		ret = devm_pm_runtime_enable(dp->dev);
> +		if (ret)
> +			goto err_disable_pm_runtime;
> +	} else {
> +		ret = analogix_dp_resume(dp);
> +		if (ret)
> +			goto err_disable_clk;
> +	}
> +
>  	return dp;
>  
> +err_disable_pm_runtime:
> +	pm_runtime_dont_use_autosuspend(dp->dev);
>  err_disable_clk:
>  	clk_disable_unprepare(dp->clock);
>  	return ERR_PTR(ret);
>  }
>  EXPORT_SYMBOL_GPL(analogix_dp_probe);
>  
> +void analogix_dp_remove(struct analogix_dp_device *dp)
> +{
> +	if (IS_ENABLED(CONFIG_PM))
> +		pm_runtime_dont_use_autosuspend(dp->dev);
> +	else
> +		analogix_dp_suspend(dp);
> +}
> +EXPORT_SYMBOL_GPL(analogix_dp_remove);
> +
>  int analogix_dp_suspend(struct analogix_dp_device *dp)
>  {
>  	phy_power_off(dp->phy);
> @@ -1708,25 +1736,12 @@ int analogix_dp_bind(struct analogix_dp_device *dp, struct drm_device *drm_dev)
>  	dp->drm_dev = drm_dev;
>  	dp->encoder = dp->plat_data->encoder;
>  
> -	if (IS_ENABLED(CONFIG_PM)) {
> -		pm_runtime_use_autosuspend(dp->dev);
> -		pm_runtime_set_autosuspend_delay(dp->dev, 100);
> -		pm_runtime_enable(dp->dev);
> -	} else {
> -		ret = analogix_dp_resume(dp);
> -		if (ret)
> -			return ret;
> -	}
> -
> -	dp->aux.name = "DP-AUX";
> -	dp->aux.transfer = analogix_dpaux_transfer;
> -	dp->aux.dev = dp->dev;
>  	dp->aux.drm_dev = drm_dev;
>  
>  	ret = drm_dp_aux_register(&dp->aux);
>  	if (ret) {
>  		DRM_ERROR("failed to register AUX (%d)\n", ret);
> -		goto err_disable_pm_runtime;
> +		return ret;
>  	}
>  
>  	ret = analogix_dp_create_bridge(drm_dev, dp);
> @@ -1739,13 +1754,6 @@ int analogix_dp_bind(struct analogix_dp_device *dp, struct drm_device *drm_dev)
>  
>  err_unregister_aux:
>  	drm_dp_aux_unregister(&dp->aux);
> -err_disable_pm_runtime:
> -	if (IS_ENABLED(CONFIG_PM)) {
> -		pm_runtime_dont_use_autosuspend(dp->dev);
> -		pm_runtime_disable(dp->dev);
> -	} else {
> -		analogix_dp_suspend(dp);
> -	}
>  
>  	return ret;
>  }
> @@ -1762,13 +1770,6 @@ void analogix_dp_unbind(struct analogix_dp_device *dp)
>  	}
>  
>  	drm_dp_aux_unregister(&dp->aux);
> -
> -	if (IS_ENABLED(CONFIG_PM)) {
> -		pm_runtime_dont_use_autosuspend(dp->dev);
> -		pm_runtime_disable(dp->dev);
> -	} else {
> -		analogix_dp_suspend(dp);
> -	}
>  }
>  EXPORT_SYMBOL_GPL(analogix_dp_unbind);
>  
> diff --git a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
> index a63c2c867059..13f32aeea7ca 100644
> --- a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
> +++ b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
> @@ -459,6 +459,10 @@ static int rockchip_dp_probe(struct platform_device *pdev)
>  
>  static void rockchip_dp_remove(struct platform_device *pdev)
>  {
> +	struct rockchip_dp_device *dp = dev_get_drvdata(&pdev->dev);
> +
> +	analogix_dp_remove(dp->adp);
> +
>  	component_del(&pdev->dev, &rockchip_dp_component_ops);
>  }
>  
> diff --git a/include/drm/bridge/analogix_dp.h b/include/drm/bridge/analogix_dp.h
> index 1b119b547988..d9b721fd7201 100644
> --- a/include/drm/bridge/analogix_dp.h
> +++ b/include/drm/bridge/analogix_dp.h
> @@ -43,6 +43,7 @@ int analogix_dp_suspend(struct analogix_dp_device *dp);
>  
>  struct analogix_dp_device *
>  analogix_dp_probe(struct device *dev, struct analogix_dp_plat_data *plat_data);
> +void analogix_dp_remove(struct analogix_dp_device *dp);
>  int analogix_dp_bind(struct analogix_dp_device *dp, struct drm_device *drm_dev);
>  void analogix_dp_unbind(struct analogix_dp_device *dp);
>  
> -- 
> 2.34.1
> 

-- 
With best wishes
Dmitry