drm/bridge/synopsis: stop clobbering drvdata
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Message ID 20171128010538.119114-1-briannorris@chromium.org
State New, archived
Headers show
Series
  • drm/bridge/synopsis: stop clobbering drvdata
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Commit Message

Brian Norris Nov. 28, 2017, 1:05 a.m. UTC
Bridge drivers/helpers shouldn't be clobbering the drvdata, since a
parent driver might need to own this. Instead, let's return our
'dw_mipi_dsi' object and have callers pass that back to us for removal.

Signed-off-by: Brian Norris <briannorris@chromium.org>
---
 drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 36 ++++++++++-----------------
 drivers/gpu/drm/stm/dw_mipi_dsi-stm.c         | 14 +++++++----
 include/drm/bridge/dw_mipi_dsi.h              | 17 ++++++++-----
 3 files changed, 33 insertions(+), 34 deletions(-)

Comments

Matthias Kaehlcke Nov. 28, 2017, 2:25 a.m. UTC | #1
El Mon, Nov 27, 2017 at 05:05:38PM -0800 Brian Norris ha dit:

> Bridge drivers/helpers shouldn't be clobbering the drvdata, since a
> parent driver might need to own this. Instead, let's return our
> 'dw_mipi_dsi' object and have callers pass that back to us for removal.
> 
> Signed-off-by: Brian Norris <briannorris@chromium.org>
> ---
>  drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 36 ++++++++++-----------------
>  drivers/gpu/drm/stm/dw_mipi_dsi-stm.c         | 14 +++++++----
>  include/drm/bridge/dw_mipi_dsi.h              | 17 ++++++++-----
>  3 files changed, 33 insertions(+), 34 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> index d9cca4fd66ec..c39c7dce20ed 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> @@ -922,8 +922,6 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
>  	dsi->bridge.of_node = pdev->dev.of_node;
>  #endif
>  
> -	dev_set_drvdata(dev, dsi);
> -
>  	return dsi;
>  }
>  
> @@ -935,23 +933,16 @@ static void __dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
>  /*
>   * Probe/remove API, used from platforms based on the DRM bridge API.
>   */
> -int dw_mipi_dsi_probe(struct platform_device *pdev,
> -		      const struct dw_mipi_dsi_plat_data *plat_data)
> +struct dw_mipi_dsi *
> +dw_mipi_dsi_probe(struct platform_device *pdev,
> +		  const struct dw_mipi_dsi_plat_data *plat_data)
>  {
> -	struct dw_mipi_dsi *dsi;
> -
> -	dsi = __dw_mipi_dsi_probe(pdev, plat_data);
> -	if (IS_ERR(dsi))
> -		return PTR_ERR(dsi);
> -
> -	return 0;
> +	return __dw_mipi_dsi_probe(pdev, plat_data);
>  }
>  EXPORT_SYMBOL_GPL(dw_mipi_dsi_probe);
>  
> -void dw_mipi_dsi_remove(struct platform_device *pdev)
> +void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
>  {
> -	struct dw_mipi_dsi *dsi = platform_get_drvdata(pdev);
> -
>  	mipi_dsi_host_unregister(&dsi->dsi_host);
>  
>  	__dw_mipi_dsi_remove(dsi);
> @@ -961,31 +952,30 @@ EXPORT_SYMBOL_GPL(dw_mipi_dsi_remove);
>  /*
>   * Bind/unbind API, used from platforms based on the component framework.
>   */
> -int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
> -		     const struct dw_mipi_dsi_plat_data *plat_data)
> +struct dw_mipi_dsi *
> +dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
> +		 const struct dw_mipi_dsi_plat_data *plat_data)
>  {
>  	struct dw_mipi_dsi *dsi;
>  	int ret;
>  
>  	dsi = __dw_mipi_dsi_probe(pdev, plat_data);
>  	if (IS_ERR(dsi))
> -		return PTR_ERR(dsi);
> +		return dsi;
>  
>  	ret = drm_bridge_attach(encoder, &dsi->bridge, NULL);
>  	if (ret) {
> -		dw_mipi_dsi_remove(pdev);
> +		dw_mipi_dsi_remove(dsi);
>  		DRM_ERROR("Failed to initialize bridge with drm\n");
> -		return ret;
> +		return ERR_PTR(ret);
>  	}
>  
> -	return 0;
> +	return dsi;
>  }
>  EXPORT_SYMBOL_GPL(dw_mipi_dsi_bind);
>  
> -void dw_mipi_dsi_unbind(struct device *dev)
> +void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi)
>  {
> -	struct dw_mipi_dsi *dsi = dev_get_drvdata(dev);
> -
>  	__dw_mipi_dsi_remove(dsi);
>  }
>  EXPORT_SYMBOL_GPL(dw_mipi_dsi_unbind);
> diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> index e5b6310240fe..7ed0ef7f6ec2 100644
> --- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> +++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> @@ -66,6 +66,7 @@ enum dsi_color {
>  struct dw_mipi_dsi_stm {
>  	void __iomem *base;
>  	struct clk *pllref_clk;
> +	struct dw_mipi_dsi *dsi;
>  };
>  
>  static inline void dsi_write(struct dw_mipi_dsi_stm *dsi, u32 reg, u32 val)
> @@ -318,21 +319,24 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
>  	dw_mipi_dsi_stm_plat_data.base = dsi->base;
>  	dw_mipi_dsi_stm_plat_data.priv_data = dsi;
>  
> -	ret = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
> -	if (ret) {
> +	platform_set_drvdata(pdev, dsi);
> +
> +	dsi->dsi = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
> +	if (IS_ERR(dsi->dsi)) {
>  		DRM_ERROR("Failed to initialize mipi dsi host\n");
>  		clk_disable_unprepare(dsi->pllref_clk);
> +		return PTR_ERR(dsi->dsi);
>  	}
>  
> -	return ret;
> +	return 0;
>  }
>  
>  static int dw_mipi_dsi_stm_remove(struct platform_device *pdev)
>  {
> -	struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data;
> +	struct dw_mipi_dsi_stm *dsi = platform_get_drvdata(pdev);
>  
>  	clk_disable_unprepare(dsi->pllref_clk);
> -	dw_mipi_dsi_remove(pdev);
> +	dw_mipi_dsi_remove(dsi->dsi);
>  
>  	return 0;
>  }
> diff --git a/include/drm/bridge/dw_mipi_dsi.h b/include/drm/bridge/dw_mipi_dsi.h
> index 9b30fec302c8..d9c6d549f971 100644
> --- a/include/drm/bridge/dw_mipi_dsi.h
> +++ b/include/drm/bridge/dw_mipi_dsi.h
> @@ -10,6 +10,8 @@
>  #ifndef __DW_MIPI_DSI__
>  #define __DW_MIPI_DSI__
>  
> +struct dw_mipi_dsi;
> +
>  struct dw_mipi_dsi_phy_ops {
>  	int (*init)(void *priv_data);
>  	int (*get_lane_mbps)(void *priv_data, struct drm_display_mode *mode,
> @@ -29,11 +31,14 @@ struct dw_mipi_dsi_plat_data {
>  	void *priv_data;
>  };
>  
> -int dw_mipi_dsi_probe(struct platform_device *pdev,
> -		      const struct dw_mipi_dsi_plat_data *plat_data);
> -void dw_mipi_dsi_remove(struct platform_device *pdev);
> -int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
> -		     const struct dw_mipi_dsi_plat_data *plat_data);
> -void dw_mipi_dsi_unbind(struct device *dev);
> +struct dw_mipi_dsi *dw_mipi_dsi_probe(struct platform_device *pdev,
> +				      const struct dw_mipi_dsi_plat_data
> +				      *plat_data);
> +void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi);
> +struct dw_mipi_dsi *dw_mipi_dsi_bind(struct platform_device *pdev,
> +				     struct drm_encoder *encoder,
> +				     const struct dw_mipi_dsi_plat_data
> +				     *plat_data);
> +void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi);
>  
>  #endif /* __DW_MIPI_DSI__ */

I don't claim to have expertise in this subsystem, but FWIW:

Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Archit Taneja Nov. 28, 2017, 6:27 a.m. UTC | #2
On 11/28/2017 06:35 AM, Brian Norris wrote:
> Bridge drivers/helpers shouldn't be clobbering the drvdata, since a
> parent driver might need to own this. Instead, let's return our
> 'dw_mipi_dsi' object and have callers pass that back to us for removal.
> 

Reviewed-by: Archit Taneja <architt@codeaurora.org>

> Signed-off-by: Brian Norris <briannorris@chromium.org>
> ---
>   drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 36 ++++++++++-----------------
>   drivers/gpu/drm/stm/dw_mipi_dsi-stm.c         | 14 +++++++----
>   include/drm/bridge/dw_mipi_dsi.h              | 17 ++++++++-----
>   3 files changed, 33 insertions(+), 34 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> index d9cca4fd66ec..c39c7dce20ed 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> @@ -922,8 +922,6 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
>   	dsi->bridge.of_node = pdev->dev.of_node;
>   #endif
>   
> -	dev_set_drvdata(dev, dsi);
> -
>   	return dsi;
>   }
>   
> @@ -935,23 +933,16 @@ static void __dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
>   /*
>    * Probe/remove API, used from platforms based on the DRM bridge API.
>    */
> -int dw_mipi_dsi_probe(struct platform_device *pdev,
> -		      const struct dw_mipi_dsi_plat_data *plat_data)
> +struct dw_mipi_dsi *
> +dw_mipi_dsi_probe(struct platform_device *pdev,
> +		  const struct dw_mipi_dsi_plat_data *plat_data)
>   {
> -	struct dw_mipi_dsi *dsi;
> -
> -	dsi = __dw_mipi_dsi_probe(pdev, plat_data);
> -	if (IS_ERR(dsi))
> -		return PTR_ERR(dsi);
> -
> -	return 0;
> +	return __dw_mipi_dsi_probe(pdev, plat_data);
>   }
>   EXPORT_SYMBOL_GPL(dw_mipi_dsi_probe);
>   
> -void dw_mipi_dsi_remove(struct platform_device *pdev)
> +void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
>   {
> -	struct dw_mipi_dsi *dsi = platform_get_drvdata(pdev);
> -
>   	mipi_dsi_host_unregister(&dsi->dsi_host);
>   
>   	__dw_mipi_dsi_remove(dsi);
> @@ -961,31 +952,30 @@ EXPORT_SYMBOL_GPL(dw_mipi_dsi_remove);
>   /*
>    * Bind/unbind API, used from platforms based on the component framework.
>    */
> -int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
> -		     const struct dw_mipi_dsi_plat_data *plat_data)
> +struct dw_mipi_dsi *
> +dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
> +		 const struct dw_mipi_dsi_plat_data *plat_data)
>   {
>   	struct dw_mipi_dsi *dsi;
>   	int ret;
>   
>   	dsi = __dw_mipi_dsi_probe(pdev, plat_data);
>   	if (IS_ERR(dsi))
> -		return PTR_ERR(dsi);
> +		return dsi;
>   
>   	ret = drm_bridge_attach(encoder, &dsi->bridge, NULL);
>   	if (ret) {
> -		dw_mipi_dsi_remove(pdev);
> +		dw_mipi_dsi_remove(dsi);
>   		DRM_ERROR("Failed to initialize bridge with drm\n");
> -		return ret;
> +		return ERR_PTR(ret);
>   	}
>   
> -	return 0;
> +	return dsi;
>   }
>   EXPORT_SYMBOL_GPL(dw_mipi_dsi_bind);
>   
> -void dw_mipi_dsi_unbind(struct device *dev)
> +void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi)
>   {
> -	struct dw_mipi_dsi *dsi = dev_get_drvdata(dev);
> -
>   	__dw_mipi_dsi_remove(dsi);
>   }
>   EXPORT_SYMBOL_GPL(dw_mipi_dsi_unbind);
> diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> index e5b6310240fe..7ed0ef7f6ec2 100644
> --- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> +++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> @@ -66,6 +66,7 @@ enum dsi_color {
>   struct dw_mipi_dsi_stm {
>   	void __iomem *base;
>   	struct clk *pllref_clk;
> +	struct dw_mipi_dsi *dsi;
>   };
>   
>   static inline void dsi_write(struct dw_mipi_dsi_stm *dsi, u32 reg, u32 val)
> @@ -318,21 +319,24 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
>   	dw_mipi_dsi_stm_plat_data.base = dsi->base;
>   	dw_mipi_dsi_stm_plat_data.priv_data = dsi;
>   
> -	ret = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
> -	if (ret) {
> +	platform_set_drvdata(pdev, dsi);
> +
> +	dsi->dsi = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
> +	if (IS_ERR(dsi->dsi)) {
>   		DRM_ERROR("Failed to initialize mipi dsi host\n");
>   		clk_disable_unprepare(dsi->pllref_clk);
> +		return PTR_ERR(dsi->dsi);
>   	}
>   
> -	return ret;
> +	return 0;
>   }
>   
>   static int dw_mipi_dsi_stm_remove(struct platform_device *pdev)
>   {
> -	struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data;
> +	struct dw_mipi_dsi_stm *dsi = platform_get_drvdata(pdev);
>   
>   	clk_disable_unprepare(dsi->pllref_clk);
> -	dw_mipi_dsi_remove(pdev);
> +	dw_mipi_dsi_remove(dsi->dsi);
>   
>   	return 0;
>   }
> diff --git a/include/drm/bridge/dw_mipi_dsi.h b/include/drm/bridge/dw_mipi_dsi.h
> index 9b30fec302c8..d9c6d549f971 100644
> --- a/include/drm/bridge/dw_mipi_dsi.h
> +++ b/include/drm/bridge/dw_mipi_dsi.h
> @@ -10,6 +10,8 @@
>   #ifndef __DW_MIPI_DSI__
>   #define __DW_MIPI_DSI__
>   
> +struct dw_mipi_dsi;
> +
>   struct dw_mipi_dsi_phy_ops {
>   	int (*init)(void *priv_data);
>   	int (*get_lane_mbps)(void *priv_data, struct drm_display_mode *mode,
> @@ -29,11 +31,14 @@ struct dw_mipi_dsi_plat_data {
>   	void *priv_data;
>   };
>   
> -int dw_mipi_dsi_probe(struct platform_device *pdev,
> -		      const struct dw_mipi_dsi_plat_data *plat_data);
> -void dw_mipi_dsi_remove(struct platform_device *pdev);
> -int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
> -		     const struct dw_mipi_dsi_plat_data *plat_data);
> -void dw_mipi_dsi_unbind(struct device *dev);
> +struct dw_mipi_dsi *dw_mipi_dsi_probe(struct platform_device *pdev,
> +				      const struct dw_mipi_dsi_plat_data
> +				      *plat_data);
> +void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi);
> +struct dw_mipi_dsi *dw_mipi_dsi_bind(struct platform_device *pdev,
> +				     struct drm_encoder *encoder,
> +				     const struct dw_mipi_dsi_plat_data
> +				     *plat_data);
> +void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi);
>   
>   #endif /* __DW_MIPI_DSI__ */
>
Philippe CORNU Nov. 28, 2017, 9:34 a.m. UTC | #3
Hi Brian,

On 11/28/2017 02:05 AM, Brian Norris wrote:
> Bridge drivers/helpers shouldn't be clobbering the drvdata, since a
> parent driver might need to own this. Instead, let's return our
> 'dw_mipi_dsi' object and have callers pass that back to us for removal.

And many thanks for this cleanup.
(please update the headline with "synopsys")

Successfully tested on stm.

Acked-by: Philippe Cornu <philippe.cornu@st.com>

Many thanks,
Philippe :-)
> 
> Signed-off-by: Brian Norris <briannorris@chromium.org>
> ---
>   drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 36 ++++++++++-----------------
>   drivers/gpu/drm/stm/dw_mipi_dsi-stm.c         | 14 +++++++----
>   include/drm/bridge/dw_mipi_dsi.h              | 17 ++++++++-----
>   3 files changed, 33 insertions(+), 34 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> index d9cca4fd66ec..c39c7dce20ed 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> @@ -922,8 +922,6 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
>   	dsi->bridge.of_node = pdev->dev.of_node;
>   #endif
>   
> -	dev_set_drvdata(dev, dsi);
> -
>   	return dsi;
>   }
>   
> @@ -935,23 +933,16 @@ static void __dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
>   /*
>    * Probe/remove API, used from platforms based on the DRM bridge API.
>    */
> -int dw_mipi_dsi_probe(struct platform_device *pdev,
> -		      const struct dw_mipi_dsi_plat_data *plat_data)
> +struct dw_mipi_dsi *
> +dw_mipi_dsi_probe(struct platform_device *pdev,
> +		  const struct dw_mipi_dsi_plat_data *plat_data)
>   {
> -	struct dw_mipi_dsi *dsi;
> -
> -	dsi = __dw_mipi_dsi_probe(pdev, plat_data);
> -	if (IS_ERR(dsi))
> -		return PTR_ERR(dsi);
> -
> -	return 0;
> +	return __dw_mipi_dsi_probe(pdev, plat_data);
>   }
>   EXPORT_SYMBOL_GPL(dw_mipi_dsi_probe);
>   
> -void dw_mipi_dsi_remove(struct platform_device *pdev)
> +void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
>   {
> -	struct dw_mipi_dsi *dsi = platform_get_drvdata(pdev);
> -
>   	mipi_dsi_host_unregister(&dsi->dsi_host);
>   
>   	__dw_mipi_dsi_remove(dsi);
> @@ -961,31 +952,30 @@ EXPORT_SYMBOL_GPL(dw_mipi_dsi_remove);
>   /*
>    * Bind/unbind API, used from platforms based on the component framework.
>    */
> -int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
> -		     const struct dw_mipi_dsi_plat_data *plat_data)
> +struct dw_mipi_dsi *
> +dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
> +		 const struct dw_mipi_dsi_plat_data *plat_data)
>   {
>   	struct dw_mipi_dsi *dsi;
>   	int ret;
>   
>   	dsi = __dw_mipi_dsi_probe(pdev, plat_data);
>   	if (IS_ERR(dsi))
> -		return PTR_ERR(dsi);
> +		return dsi;
>   
>   	ret = drm_bridge_attach(encoder, &dsi->bridge, NULL);
>   	if (ret) {
> -		dw_mipi_dsi_remove(pdev);
> +		dw_mipi_dsi_remove(dsi);
>   		DRM_ERROR("Failed to initialize bridge with drm\n");
> -		return ret;
> +		return ERR_PTR(ret);
>   	}
>   
> -	return 0;
> +	return dsi;
>   }
>   EXPORT_SYMBOL_GPL(dw_mipi_dsi_bind);
>   
> -void dw_mipi_dsi_unbind(struct device *dev)
> +void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi)
>   {
> -	struct dw_mipi_dsi *dsi = dev_get_drvdata(dev);
> -
>   	__dw_mipi_dsi_remove(dsi);
>   }
>   EXPORT_SYMBOL_GPL(dw_mipi_dsi_unbind);
> diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> index e5b6310240fe..7ed0ef7f6ec2 100644
> --- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> +++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> @@ -66,6 +66,7 @@ enum dsi_color {
>   struct dw_mipi_dsi_stm {
>   	void __iomem *base;
>   	struct clk *pllref_clk;
> +	struct dw_mipi_dsi *dsi;
>   };
>   
>   static inline void dsi_write(struct dw_mipi_dsi_stm *dsi, u32 reg, u32 val)
> @@ -318,21 +319,24 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
>   	dw_mipi_dsi_stm_plat_data.base = dsi->base;
>   	dw_mipi_dsi_stm_plat_data.priv_data = dsi;
>   
> -	ret = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
> -	if (ret) {
> +	platform_set_drvdata(pdev, dsi);
> +
> +	dsi->dsi = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
> +	if (IS_ERR(dsi->dsi)) {
>   		DRM_ERROR("Failed to initialize mipi dsi host\n");
>   		clk_disable_unprepare(dsi->pllref_clk);
> +		return PTR_ERR(dsi->dsi);
>   	}
>   
> -	return ret;
> +	return 0;
>   }
>   
>   static int dw_mipi_dsi_stm_remove(struct platform_device *pdev)
>   {
> -	struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data;
> +	struct dw_mipi_dsi_stm *dsi = platform_get_drvdata(pdev);
>   
>   	clk_disable_unprepare(dsi->pllref_clk);
> -	dw_mipi_dsi_remove(pdev);
> +	dw_mipi_dsi_remove(dsi->dsi);
>   
>   	return 0;
>   }
> diff --git a/include/drm/bridge/dw_mipi_dsi.h b/include/drm/bridge/dw_mipi_dsi.h
> index 9b30fec302c8..d9c6d549f971 100644
> --- a/include/drm/bridge/dw_mipi_dsi.h
> +++ b/include/drm/bridge/dw_mipi_dsi.h
> @@ -10,6 +10,8 @@
>   #ifndef __DW_MIPI_DSI__
>   #define __DW_MIPI_DSI__
>   
> +struct dw_mipi_dsi;
> +
>   struct dw_mipi_dsi_phy_ops {
>   	int (*init)(void *priv_data);
>   	int (*get_lane_mbps)(void *priv_data, struct drm_display_mode *mode,
> @@ -29,11 +31,14 @@ struct dw_mipi_dsi_plat_data {
>   	void *priv_data;
>   };
>   
> -int dw_mipi_dsi_probe(struct platform_device *pdev,
> -		      const struct dw_mipi_dsi_plat_data *plat_data);
> -void dw_mipi_dsi_remove(struct platform_device *pdev);
> -int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
> -		     const struct dw_mipi_dsi_plat_data *plat_data);
> -void dw_mipi_dsi_unbind(struct device *dev);
> +struct dw_mipi_dsi *dw_mipi_dsi_probe(struct platform_device *pdev,
> +				      const struct dw_mipi_dsi_plat_data
> +				      *plat_data);
> +void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi);
> +struct dw_mipi_dsi *dw_mipi_dsi_bind(struct platform_device *pdev,
> +				     struct drm_encoder *encoder,
> +				     const struct dw_mipi_dsi_plat_data
> +				     *plat_data);
> +void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi);
>   
>   #endif /* __DW_MIPI_DSI__ */
>
Laurent Pinchart Nov. 28, 2017, 12:51 p.m. UTC | #4
Hi Brian,

Thank you for the patch.

I'd mention dw-mipi-dsi in the subject line as the directory contains the dw-
hdmi driver as well that this patch doesn't touch.

On Tuesday, 28 November 2017 03:05:38 EET Brian Norris wrote:
> Bridge drivers/helpers shouldn't be clobbering the drvdata, since a
> parent driver might need to own this.

By parent driver I assume you mean a glue driver that binds to the SoC-
specific compatible string for the DSI transmitter.

> Instead, let's return our
> 'dw_mipi_dsi' object and have callers pass that back to us for removal.
> 
> Signed-off-by: Brian Norris <briannorris@chromium.org>

Wouldn't it be cleaner to embed the dw_mipi_dsi structure in the parent-
specific data structure (struct dw_mipi_dsi_stm and struct 
dw_mipi_dsi_rockchip when the "[PATCH v3 0/5] Update ROCKCHIP DSI driver that 
uses dw-mipi-dsi bridge" patch series will land) instead of allocating it 
dynamically ? We would then have a single object to track.

> ---
>  drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 36 ++++++++++--------------
>  drivers/gpu/drm/stm/dw_mipi_dsi-stm.c         | 14 +++++++----
>  include/drm/bridge/dw_mipi_dsi.h              | 17 ++++++++-----
>  3 files changed, 33 insertions(+), 34 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c index
> d9cca4fd66ec..c39c7dce20ed 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> @@ -922,8 +922,6 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
>  	dsi->bridge.of_node = pdev->dev.of_node;
>  #endif
> 
> -	dev_set_drvdata(dev, dsi);
> -
>  	return dsi;
>  }
> 
> @@ -935,23 +933,16 @@ static void __dw_mipi_dsi_remove(struct dw_mipi_dsi
> *dsi) /*
>   * Probe/remove API, used from platforms based on the DRM bridge API.
>   */
> -int dw_mipi_dsi_probe(struct platform_device *pdev,
> -		      const struct dw_mipi_dsi_plat_data *plat_data)
> +struct dw_mipi_dsi *
> +dw_mipi_dsi_probe(struct platform_device *pdev,
> +		  const struct dw_mipi_dsi_plat_data *plat_data)
>  {
> -	struct dw_mipi_dsi *dsi;
> -
> -	dsi = __dw_mipi_dsi_probe(pdev, plat_data);
> -	if (IS_ERR(dsi))
> -		return PTR_ERR(dsi);
> -
> -	return 0;
> +	return __dw_mipi_dsi_probe(pdev, plat_data);
>  }
>  EXPORT_SYMBOL_GPL(dw_mipi_dsi_probe);
> 
> -void dw_mipi_dsi_remove(struct platform_device *pdev)
> +void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
>  {
> -	struct dw_mipi_dsi *dsi = platform_get_drvdata(pdev);
> -
>  	mipi_dsi_host_unregister(&dsi->dsi_host);
> 
>  	__dw_mipi_dsi_remove(dsi);
> @@ -961,31 +952,30 @@ EXPORT_SYMBOL_GPL(dw_mipi_dsi_remove);
>  /*
>   * Bind/unbind API, used from platforms based on the component framework.
>   */
> -int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder
> *encoder, -		     const struct dw_mipi_dsi_plat_data *plat_data)
> +struct dw_mipi_dsi *
> +dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
> +		 const struct dw_mipi_dsi_plat_data *plat_data)
>  {
>  	struct dw_mipi_dsi *dsi;
>  	int ret;
> 
>  	dsi = __dw_mipi_dsi_probe(pdev, plat_data);
>  	if (IS_ERR(dsi))
> -		return PTR_ERR(dsi);
> +		return dsi;
> 
>  	ret = drm_bridge_attach(encoder, &dsi->bridge, NULL);
>  	if (ret) {
> -		dw_mipi_dsi_remove(pdev);
> +		dw_mipi_dsi_remove(dsi);
>  		DRM_ERROR("Failed to initialize bridge with drm\n");
> -		return ret;
> +		return ERR_PTR(ret);
>  	}
> 
> -	return 0;
> +	return dsi;
>  }
>  EXPORT_SYMBOL_GPL(dw_mipi_dsi_bind);
> 
> -void dw_mipi_dsi_unbind(struct device *dev)
> +void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi)
>  {
> -	struct dw_mipi_dsi *dsi = dev_get_drvdata(dev);
> -
>  	__dw_mipi_dsi_remove(dsi);
>  }
>  EXPORT_SYMBOL_GPL(dw_mipi_dsi_unbind);
> diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c index e5b6310240fe..7ed0ef7f6ec2
> 100644
> --- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> +++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> @@ -66,6 +66,7 @@ enum dsi_color {
>  struct dw_mipi_dsi_stm {
>  	void __iomem *base;
>  	struct clk *pllref_clk;
> +	struct dw_mipi_dsi *dsi;
>  };
> 
>  static inline void dsi_write(struct dw_mipi_dsi_stm *dsi, u32 reg, u32 val)
> @@ -318,21 +319,24 @@ static int dw_mipi_dsi_stm_probe(struct
> platform_device *pdev) dw_mipi_dsi_stm_plat_data.base = dsi->base;
>  	dw_mipi_dsi_stm_plat_data.priv_data = dsi;
> 
> -	ret = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
> -	if (ret) {
> +	platform_set_drvdata(pdev, dsi);
> +
> +	dsi->dsi = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
> +	if (IS_ERR(dsi->dsi)) {
>  		DRM_ERROR("Failed to initialize mipi dsi host\n");
>  		clk_disable_unprepare(dsi->pllref_clk);
> +		return PTR_ERR(dsi->dsi);
>  	}
> 
> -	return ret;
> +	return 0;
>  }
> 
>  static int dw_mipi_dsi_stm_remove(struct platform_device *pdev)
>  {
> -	struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data;
> +	struct dw_mipi_dsi_stm *dsi = platform_get_drvdata(pdev);
> 
>  	clk_disable_unprepare(dsi->pllref_clk);
> -	dw_mipi_dsi_remove(pdev);
> +	dw_mipi_dsi_remove(dsi->dsi);
> 
>  	return 0;
>  }
> diff --git a/include/drm/bridge/dw_mipi_dsi.h
> b/include/drm/bridge/dw_mipi_dsi.h index 9b30fec302c8..d9c6d549f971 100644
> --- a/include/drm/bridge/dw_mipi_dsi.h
> +++ b/include/drm/bridge/dw_mipi_dsi.h
> @@ -10,6 +10,8 @@
>  #ifndef __DW_MIPI_DSI__
>  #define __DW_MIPI_DSI__
> 
> +struct dw_mipi_dsi;
> +
>  struct dw_mipi_dsi_phy_ops {
>  	int (*init)(void *priv_data);
>  	int (*get_lane_mbps)(void *priv_data, struct drm_display_mode *mode,
> @@ -29,11 +31,14 @@ struct dw_mipi_dsi_plat_data {
>  	void *priv_data;
>  };
> 
> -int dw_mipi_dsi_probe(struct platform_device *pdev,
> -		      const struct dw_mipi_dsi_plat_data *plat_data);
> -void dw_mipi_dsi_remove(struct platform_device *pdev);
> -int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder
> *encoder, -		     const struct dw_mipi_dsi_plat_data *plat_data);
> -void dw_mipi_dsi_unbind(struct device *dev);
> +struct dw_mipi_dsi *dw_mipi_dsi_probe(struct platform_device *pdev,
> +				      const struct dw_mipi_dsi_plat_data
> +				      *plat_data);
> +void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi);
> +struct dw_mipi_dsi *dw_mipi_dsi_bind(struct platform_device *pdev,
> +				     struct drm_encoder *encoder,
> +				     const struct dw_mipi_dsi_plat_data
> +				     *plat_data);
> +void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi);
> 
>  #endif /* __DW_MIPI_DSI__ */
Brian Norris Nov. 28, 2017, 6:21 p.m. UTC | #5
Hi Laurent,

On Tue, Nov 28, 2017 at 02:51:46PM +0200, Laurent Pinchart wrote:
> Hi Brian,
> 
> Thank you for the patch.
> 
> I'd mention dw-mipi-dsi in the subject line as the directory contains the dw-
> hdmi driver as well that this patch doesn't touch.

Yep. Does it need another tag in the subject? e.g., '.../dw-mipi-dsi:'?

> On Tuesday, 28 November 2017 03:05:38 EET Brian Norris wrote:
> > Bridge drivers/helpers shouldn't be clobbering the drvdata, since a
> > parent driver might need to own this.
> 
> By parent driver I assume you mean a glue driver that binds to the SoC-
> specific compatible string for the DSI transmitter.

Indeed. Nickey picked this up for his Rockchip driver submission, but
maybe we should reword the commit message a bit.

> > Instead, let's return our
> > 'dw_mipi_dsi' object and have callers pass that back to us for removal.
> > 
> > Signed-off-by: Brian Norris <briannorris@chromium.org>
> 
> Wouldn't it be cleaner to embed the dw_mipi_dsi structure in the parent-
> specific data structure (struct dw_mipi_dsi_stm and struct 
> dw_mipi_dsi_rockchip when the "[PATCH v3 0/5] Update ROCKCHIP DSI driver that 
> uses dw-mipi-dsi bridge" patch series will land) instead of allocating it 
> dynamically ? We would then have a single object to track.

I suppose we could do that too. But that would require exposing the
whole layout of 'struct dw_mipi_dsi' to users. Do we want to sacrifice
the enforced separation for a little bit of nicer object handling?

Also, this was modeled a bit after the similar rework needed to untangle
the drvdata handling in the Rockchip analogix DP driver vs. the analogix
bridge DP code:

[PATCH v6 03/10] drm/bridge: analogix: Do not use device's drvdata
https://patchwork.kernel.org/patch/10015875/

Brian
Philippe CORNU Jan. 9, 2018, 1:01 p.m. UTC | #6
Hi Archit, Andrzej & Laurent,

Regarding this patch from Brian, I think it could be nice to merge it 
(1xAcked-by, 2xReviewed-by).

Could you please have a look?

Only the small "typo" in the headline needs to be changed.

Many thanks,
Philippe :-)

On 11/28/2017 10:34 AM, Philippe CORNU wrote:
> Hi Brian,
> 
> On 11/28/2017 02:05 AM, Brian Norris wrote:
>> Bridge drivers/helpers shouldn't be clobbering the drvdata, since a
>> parent driver might need to own this. Instead, let's return our
>> 'dw_mipi_dsi' object and have callers pass that back to us for removal.
> 
> And many thanks for this cleanup.
> (please update the headline with "synopsys")
> 
> Successfully tested on stm.
> 
> Acked-by: Philippe Cornu <philippe.cornu@st.com>
> 
> Many thanks,
> Philippe :-)
>>
>> Signed-off-by: Brian Norris <briannorris@chromium.org>
>> ---
>>   drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 36 
>> ++++++++++-----------------
>>   drivers/gpu/drm/stm/dw_mipi_dsi-stm.c         | 14 +++++++----
>>   include/drm/bridge/dw_mipi_dsi.h              | 17 ++++++++-----
>>   3 files changed, 33 insertions(+), 34 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c 
>> b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
>> index d9cca4fd66ec..c39c7dce20ed 100644
>> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
>> @@ -922,8 +922,6 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
>>       dsi->bridge.of_node = pdev->dev.of_node;
>>   #endif
>> -    dev_set_drvdata(dev, dsi);
>> -
>>       return dsi;
>>   }
>> @@ -935,23 +933,16 @@ static void __dw_mipi_dsi_remove(struct 
>> dw_mipi_dsi *dsi)
>>   /*
>>    * Probe/remove API, used from platforms based on the DRM bridge API.
>>    */
>> -int dw_mipi_dsi_probe(struct platform_device *pdev,
>> -              const struct dw_mipi_dsi_plat_data *plat_data)
>> +struct dw_mipi_dsi *
>> +dw_mipi_dsi_probe(struct platform_device *pdev,
>> +          const struct dw_mipi_dsi_plat_data *plat_data)
>>   {
>> -    struct dw_mipi_dsi *dsi;
>> -
>> -    dsi = __dw_mipi_dsi_probe(pdev, plat_data);
>> -    if (IS_ERR(dsi))
>> -        return PTR_ERR(dsi);
>> -
>> -    return 0;
>> +    return __dw_mipi_dsi_probe(pdev, plat_data);
>>   }
>>   EXPORT_SYMBOL_GPL(dw_mipi_dsi_probe);
>> -void dw_mipi_dsi_remove(struct platform_device *pdev)
>> +void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
>>   {
>> -    struct dw_mipi_dsi *dsi = platform_get_drvdata(pdev);
>> -
>>       mipi_dsi_host_unregister(&dsi->dsi_host);
>>       __dw_mipi_dsi_remove(dsi);
>> @@ -961,31 +952,30 @@ EXPORT_SYMBOL_GPL(dw_mipi_dsi_remove);
>>   /*
>>    * Bind/unbind API, used from platforms based on the component 
>> framework.
>>    */
>> -int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder 
>> *encoder,
>> -             const struct dw_mipi_dsi_plat_data *plat_data)
>> +struct dw_mipi_dsi *
>> +dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder 
>> *encoder,
>> +         const struct dw_mipi_dsi_plat_data *plat_data)
>>   {
>>       struct dw_mipi_dsi *dsi;
>>       int ret;
>>       dsi = __dw_mipi_dsi_probe(pdev, plat_data);
>>       if (IS_ERR(dsi))
>> -        return PTR_ERR(dsi);
>> +        return dsi;
>>       ret = drm_bridge_attach(encoder, &dsi->bridge, NULL);
>>       if (ret) {
>> -        dw_mipi_dsi_remove(pdev);
>> +        dw_mipi_dsi_remove(dsi);
>>           DRM_ERROR("Failed to initialize bridge with drm\n");
>> -        return ret;
>> +        return ERR_PTR(ret);
>>       }
>> -    return 0;
>> +    return dsi;
>>   }
>>   EXPORT_SYMBOL_GPL(dw_mipi_dsi_bind);
>> -void dw_mipi_dsi_unbind(struct device *dev)
>> +void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi)
>>   {
>> -    struct dw_mipi_dsi *dsi = dev_get_drvdata(dev);
>> -
>>       __dw_mipi_dsi_remove(dsi);
>>   }
>>   EXPORT_SYMBOL_GPL(dw_mipi_dsi_unbind);
>> diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c 
>> b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
>> index e5b6310240fe..7ed0ef7f6ec2 100644
>> --- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
>> +++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
>> @@ -66,6 +66,7 @@ enum dsi_color {
>>   struct dw_mipi_dsi_stm {
>>       void __iomem *base;
>>       struct clk *pllref_clk;
>> +    struct dw_mipi_dsi *dsi;
>>   };
>>   static inline void dsi_write(struct dw_mipi_dsi_stm *dsi, u32 reg, 
>> u32 val)
>> @@ -318,21 +319,24 @@ static int dw_mipi_dsi_stm_probe(struct 
>> platform_device *pdev)
>>       dw_mipi_dsi_stm_plat_data.base = dsi->base;
>>       dw_mipi_dsi_stm_plat_data.priv_data = dsi;
>> -    ret = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
>> -    if (ret) {
>> +    platform_set_drvdata(pdev, dsi);
>> +
>> +    dsi->dsi = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
>> +    if (IS_ERR(dsi->dsi)) {
>>           DRM_ERROR("Failed to initialize mipi dsi host\n");
>>           clk_disable_unprepare(dsi->pllref_clk);
>> +        return PTR_ERR(dsi->dsi);
>>       }
>> -    return ret;
>> +    return 0;
>>   }
>>   static int dw_mipi_dsi_stm_remove(struct platform_device *pdev)
>>   {
>> -    struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data;
>> +    struct dw_mipi_dsi_stm *dsi = platform_get_drvdata(pdev);
>>       clk_disable_unprepare(dsi->pllref_clk);
>> -    dw_mipi_dsi_remove(pdev);
>> +    dw_mipi_dsi_remove(dsi->dsi);
>>       return 0;
>>   }
>> diff --git a/include/drm/bridge/dw_mipi_dsi.h 
>> b/include/drm/bridge/dw_mipi_dsi.h
>> index 9b30fec302c8..d9c6d549f971 100644
>> --- a/include/drm/bridge/dw_mipi_dsi.h
>> +++ b/include/drm/bridge/dw_mipi_dsi.h
>> @@ -10,6 +10,8 @@
>>   #ifndef __DW_MIPI_DSI__
>>   #define __DW_MIPI_DSI__
>> +struct dw_mipi_dsi;
>> +
>>   struct dw_mipi_dsi_phy_ops {
>>       int (*init)(void *priv_data);
>>       int (*get_lane_mbps)(void *priv_data, struct drm_display_mode 
>> *mode,
>> @@ -29,11 +31,14 @@ struct dw_mipi_dsi_plat_data {
>>       void *priv_data;
>>   };
>> -int dw_mipi_dsi_probe(struct platform_device *pdev,
>> -              const struct dw_mipi_dsi_plat_data *plat_data);
>> -void dw_mipi_dsi_remove(struct platform_device *pdev);
>> -int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder 
>> *encoder,
>> -             const struct dw_mipi_dsi_plat_data *plat_data);
>> -void dw_mipi_dsi_unbind(struct device *dev);
>> +struct dw_mipi_dsi *dw_mipi_dsi_probe(struct platform_device *pdev,
>> +                      const struct dw_mipi_dsi_plat_data
>> +                      *plat_data);
>> +void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi);
>> +struct dw_mipi_dsi *dw_mipi_dsi_bind(struct platform_device *pdev,
>> +                     struct drm_encoder *encoder,
>> +                     const struct dw_mipi_dsi_plat_data
>> +                     *plat_data);
>> +void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi);
>>   #endif /* __DW_MIPI_DSI__ */
>>
Laurent Pinchart Jan. 9, 2018, 1:36 p.m. UTC | #7
Hi Brian,

On Tuesday, 28 November 2017 20:21:23 EET Brian Norris wrote:
> On Tue, Nov 28, 2017 at 02:51:46PM +0200, Laurent Pinchart wrote:
> > Hi Brian,
> > 
> > Thank you for the patch.
> > 
> > I'd mention dw-mipi-dsi in the subject line as the directory contains the
> > dw-hdmi driver as well that this patch doesn't touch.
> 
> Yep. Does it need another tag in the subject? e.g., '.../dw-mipi-dsi:'?
> 
> > On Tuesday, 28 November 2017 03:05:38 EET Brian Norris wrote:
> >> Bridge drivers/helpers shouldn't be clobbering the drvdata, since a
> >> parent driver might need to own this.
> > 
> > By parent driver I assume you mean a glue driver that binds to the SoC-
> > specific compatible string for the DSI transmitter.
> 
> Indeed. Nickey picked this up for his Rockchip driver submission, but
> maybe we should reword the commit message a bit.

How about "drm: dw-mipi-dsi: Stop clobbering drvdata" ?

> >> Instead, let's return our
> >> 'dw_mipi_dsi' object and have callers pass that back to us for removal.
> >> 
> >> Signed-off-by: Brian Norris <briannorris@chromium.org>
> > 
> > Wouldn't it be cleaner to embed the dw_mipi_dsi structure in the parent-
> > specific data structure (struct dw_mipi_dsi_stm and struct
> > dw_mipi_dsi_rockchip when the "[PATCH v3 0/5] Update ROCKCHIP DSI driver
> > that uses dw-mipi-dsi bridge" patch series will land) instead of
> > allocating it dynamically ? We would then have a single object to track.
> 
> I suppose we could do that too. But that would require exposing the
> whole layout of 'struct dw_mipi_dsi' to users. Do we want to sacrifice
> the enforced separation for a little bit of nicer object handling?

I certainly don't think we should go for spaghetti code with all objects 
accessing each other :) On the other hand, we're talking about C code, and we 
thus have no way to enforce access restrictions in the compiler, so it's a 
lost battle anyway. I don't see an issue with exposing the object in the sense 
of moving its definition to a header file if it results in cleaner code. I 
think we need to trust developers not to abuse internal APIs, and if they do, 
catch it during review.

> Also, this was modeled a bit after the similar rework needed to untangle
> the drvdata handling in the Rockchip analogix DP driver vs. the analogix
> bridge DP code:
> 
> [PATCH v6 03/10] drm/bridge: analogix: Do not use device's drvdata
> https://patchwork.kernel.org/patch/10015875/
Laurent Pinchart Jan. 9, 2018, 1:37 p.m. UTC | #8
Hi Philippe,

On Tuesday, 9 January 2018 15:01:02 EET Philippe CORNU wrote:
> Hi Archit, Andrzej & Laurent,
> 
> Regarding this patch from Brian, I think it could be nice to merge it 
> (1xAcked-by, 2xReviewed-by).
> 
> Could you please have a look?
> 
> Only the small "typo" in the headline needs to be changed.
> 
> Many thanks,

I've just replied to Brian in this mail thread. Sorry for the delay, it 
slipped through the cracks. Thank you for pinging me.

> On 11/28/2017 10:34 AM, Philippe CORNU wrote:
> 
> > Hi Brian,
> > 
> > On 11/28/2017 02:05 AM, Brian Norris wrote:
> > 
> >> Bridge drivers/helpers shouldn't be clobbering the drvdata, since a
> >> parent driver might need to own this. Instead, let's return our
> >> 'dw_mipi_dsi' object and have callers pass that back to us for removal.
> > 
> > 
> > And many thanks for this cleanup.
> > (please update the headline with "synopsys")
> > 
> > Successfully tested on stm.
> > 
> > Acked-by: Philippe Cornu <philippe.cornu@st.com>
> > 
> > Many thanks,
> > Philippe :-)
> > 
> >>
> >>
> >> Signed-off-by: Brian Norris <briannorris@chromium.org>
> >> ---
> >>   drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 36 
> >> ++++++++++-----------------
> >>   drivers/gpu/drm/stm/dw_mipi_dsi-stm.c         | 14 +++++++----
> >>   include/drm/bridge/dw_mipi_dsi.h              | 17 ++++++++-----
> >>   3 files changed, 33 insertions(+), 34 deletions(-)
> >>
> >>
> >>
> >> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c 
> >> b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> >> index d9cca4fd66ec..c39c7dce20ed 100644
> >> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> >> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> >> @@ -922,8 +922,6 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
> >>       dsi->bridge.of_node = pdev->dev.of_node;
> >>   #endif
> >> -    dev_set_drvdata(dev, dsi);
> >> -
> >>       return dsi;
> >>   }
> >> @@ -935,23 +933,16 @@ static void __dw_mipi_dsi_remove(struct 
> >> dw_mipi_dsi *dsi)
> >>   /*
> >>    * Probe/remove API, used from platforms based on the DRM bridge API.
> >>    */
> >> -int dw_mipi_dsi_probe(struct platform_device *pdev,
> >> -              const struct dw_mipi_dsi_plat_data *plat_data)
> >> +struct dw_mipi_dsi *
> >> +dw_mipi_dsi_probe(struct platform_device *pdev,
> >> +          const struct dw_mipi_dsi_plat_data *plat_data)
> >>   {
> >> -    struct dw_mipi_dsi *dsi;
> >> -
> >> -    dsi = __dw_mipi_dsi_probe(pdev, plat_data);
> >> -    if (IS_ERR(dsi))
> >> -        return PTR_ERR(dsi);
> >> -
> >> -    return 0;
> >> +    return __dw_mipi_dsi_probe(pdev, plat_data);
> >>   }
> >>   EXPORT_SYMBOL_GPL(dw_mipi_dsi_probe);
> >> -void dw_mipi_dsi_remove(struct platform_device *pdev)
> >> +void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
> >>   {
> >> -    struct dw_mipi_dsi *dsi = platform_get_drvdata(pdev);
> >> -
> >>       mipi_dsi_host_unregister(&dsi->dsi_host);
> >>       __dw_mipi_dsi_remove(dsi);
> >> @@ -961,31 +952,30 @@ EXPORT_SYMBOL_GPL(dw_mipi_dsi_remove);
> >>   /*
> >>    * Bind/unbind API, used from platforms based on the component 
> >> framework.
> >>    */
> >> -int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder 
> >> *encoder,
> >> -             const struct dw_mipi_dsi_plat_data *plat_data)
> >> +struct dw_mipi_dsi *
> >> +dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder 
> >> *encoder,
> >> +         const struct dw_mipi_dsi_plat_data *plat_data)
> >>   {
> >>       struct dw_mipi_dsi *dsi;
> >>       int ret;
> >>       dsi = __dw_mipi_dsi_probe(pdev, plat_data);
> >>       if (IS_ERR(dsi))
> >> -        return PTR_ERR(dsi);
> >> +        return dsi;
> >>       ret = drm_bridge_attach(encoder, &dsi->bridge, NULL);
> >>       if (ret) {
> >> -        dw_mipi_dsi_remove(pdev);
> >> +        dw_mipi_dsi_remove(dsi);
> >>           DRM_ERROR("Failed to initialize bridge with drm\n");
> >> -        return ret;
> >> +        return ERR_PTR(ret);
> >>       }
> >> -    return 0;
> >> +    return dsi;
> >>   }
> >>   EXPORT_SYMBOL_GPL(dw_mipi_dsi_bind);
> >> -void dw_mipi_dsi_unbind(struct device *dev)
> >> +void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi)
> >>   {
> >> -    struct dw_mipi_dsi *dsi = dev_get_drvdata(dev);
> >> -
> >>       __dw_mipi_dsi_remove(dsi);
> >>   }
> >>   EXPORT_SYMBOL_GPL(dw_mipi_dsi_unbind);
> >> diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c 
> >> b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> >> index e5b6310240fe..7ed0ef7f6ec2 100644
> >> --- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> >> +++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> >> @@ -66,6 +66,7 @@ enum dsi_color {
> >>   struct dw_mipi_dsi_stm {
> >>       void __iomem *base;
> >>       struct clk *pllref_clk;
> >> +    struct dw_mipi_dsi *dsi;
> >>   };
> >>   static inline void dsi_write(struct dw_mipi_dsi_stm *dsi, u32 reg, 
> >> u32 val)
> >> @@ -318,21 +319,24 @@ static int dw_mipi_dsi_stm_probe(struct 
> >> platform_device *pdev)
> >>       dw_mipi_dsi_stm_plat_data.base = dsi->base;
> >>       dw_mipi_dsi_stm_plat_data.priv_data = dsi;
> >> -    ret = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
> >> -    if (ret) {
> >> +    platform_set_drvdata(pdev, dsi);
> >> +
> >> +    dsi->dsi = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
> >> +    if (IS_ERR(dsi->dsi)) {
> >>           DRM_ERROR("Failed to initialize mipi dsi host\n");
> >>           clk_disable_unprepare(dsi->pllref_clk);
> >> +        return PTR_ERR(dsi->dsi);
> >>       }
> >> -    return ret;
> >> +    return 0;
> >>   }
> >>   static int dw_mipi_dsi_stm_remove(struct platform_device *pdev)
> >>   {
> >> -    struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data;
> >> +    struct dw_mipi_dsi_stm *dsi = platform_get_drvdata(pdev);
> >>       clk_disable_unprepare(dsi->pllref_clk);
> >> -    dw_mipi_dsi_remove(pdev);
> >> +    dw_mipi_dsi_remove(dsi->dsi);
> >>       return 0;
> >>   }
> >> diff --git a/include/drm/bridge/dw_mipi_dsi.h 
> >> b/include/drm/bridge/dw_mipi_dsi.h
> >> index 9b30fec302c8..d9c6d549f971 100644
> >> --- a/include/drm/bridge/dw_mipi_dsi.h
> >> +++ b/include/drm/bridge/dw_mipi_dsi.h
> >> @@ -10,6 +10,8 @@
> >>   #ifndef __DW_MIPI_DSI__
> >>   #define __DW_MIPI_DSI__
> >> +struct dw_mipi_dsi;
> >> +
> >>   struct dw_mipi_dsi_phy_ops {
> >>       int (*init)(void *priv_data);
> >>       int (*get_lane_mbps)(void *priv_data, struct drm_display_mode 
> >> *mode,
> >> @@ -29,11 +31,14 @@ struct dw_mipi_dsi_plat_data {
> >>       void *priv_data;
> >>   };
> >> -int dw_mipi_dsi_probe(struct platform_device *pdev,
> >> -              const struct dw_mipi_dsi_plat_data *plat_data);
> >> -void dw_mipi_dsi_remove(struct platform_device *pdev);
> >> -int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder 
> >> *encoder,
> >> -             const struct dw_mipi_dsi_plat_data *plat_data);
> >> -void dw_mipi_dsi_unbind(struct device *dev);
> >> +struct dw_mipi_dsi *dw_mipi_dsi_probe(struct platform_device *pdev,
> >> +                      const struct dw_mipi_dsi_plat_data
> >> +                      *plat_data);
> >> +void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi);
> >> +struct dw_mipi_dsi *dw_mipi_dsi_bind(struct platform_device *pdev,
> >> +                     struct drm_encoder *encoder,
> >> +                     const struct dw_mipi_dsi_plat_data
> >> +                     *plat_data);
> >> +void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi);
> >>   #endif /* __DW_MIPI_DSI__ */
Andrzej Hajda Jan. 9, 2018, 1:45 p.m. UTC | #9
On 09.01.2018 14:37, Laurent Pinchart wrote:
> Hi Philippe,
>
> On Tuesday, 9 January 2018 15:01:02 EET Philippe CORNU wrote:
>> Hi Archit, Andrzej & Laurent,
>>
>> Regarding this patch from Brian, I think it could be nice to merge it 
>> (1xAcked-by, 2xReviewed-by).
>>
>> Could you please have a look?
>>
>> Only the small "typo" in the headline needs to be changed.
>>
>> Many thanks,
> I've just replied to Brian in this mail thread. Sorry for the delay, it 
> slipped through the cracks. Thank you for pinging me.

I have just pushed the patch to drm-misc-next. I am sorry, if you wanted
to polish it more, from the thread it looked it can be merged as is.

Regards
Andrzej


>> On 11/28/2017 10:34 AM, Philippe CORNU wrote:
>>
>>> Hi Brian,
>>>
>>> On 11/28/2017 02:05 AM, Brian Norris wrote:
>>>
>>>> Bridge drivers/helpers shouldn't be clobbering the drvdata, since a
>>>> parent driver might need to own this. Instead, let's return our
>>>> 'dw_mipi_dsi' object and have callers pass that back to us for removal.
>>>
>>> And many thanks for this cleanup.
>>> (please update the headline with "synopsys")
>>>
>>> Successfully tested on stm.
>>>
>>> Acked-by: Philippe Cornu <philippe.cornu@st.com>
>>>
>>> Many thanks,
>>> Philippe :-)
>>>
>>>>
>>>> Signed-off-by: Brian Norris <briannorris@chromium.org>
>>>> ---
>>>>   drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 36 
>>>> ++++++++++-----------------
>>>>   drivers/gpu/drm/stm/dw_mipi_dsi-stm.c         | 14 +++++++----
>>>>   include/drm/bridge/dw_mipi_dsi.h              | 17 ++++++++-----
>>>>   3 files changed, 33 insertions(+), 34 deletions(-)
>>>>
>>>>
>>>>
>>>> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c 
>>>> b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
>>>> index d9cca4fd66ec..c39c7dce20ed 100644
>>>> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
>>>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
>>>> @@ -922,8 +922,6 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
>>>>       dsi->bridge.of_node = pdev->dev.of_node;
>>>>   #endif
>>>> -    dev_set_drvdata(dev, dsi);
>>>> -
>>>>       return dsi;
>>>>   }
>>>> @@ -935,23 +933,16 @@ static void __dw_mipi_dsi_remove(struct 
>>>> dw_mipi_dsi *dsi)
>>>>   /*
>>>>    * Probe/remove API, used from platforms based on the DRM bridge API.
>>>>    */
>>>> -int dw_mipi_dsi_probe(struct platform_device *pdev,
>>>> -              const struct dw_mipi_dsi_plat_data *plat_data)
>>>> +struct dw_mipi_dsi *
>>>> +dw_mipi_dsi_probe(struct platform_device *pdev,
>>>> +          const struct dw_mipi_dsi_plat_data *plat_data)
>>>>   {
>>>> -    struct dw_mipi_dsi *dsi;
>>>> -
>>>> -    dsi = __dw_mipi_dsi_probe(pdev, plat_data);
>>>> -    if (IS_ERR(dsi))
>>>> -        return PTR_ERR(dsi);
>>>> -
>>>> -    return 0;
>>>> +    return __dw_mipi_dsi_probe(pdev, plat_data);
>>>>   }
>>>>   EXPORT_SYMBOL_GPL(dw_mipi_dsi_probe);
>>>> -void dw_mipi_dsi_remove(struct platform_device *pdev)
>>>> +void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
>>>>   {
>>>> -    struct dw_mipi_dsi *dsi = platform_get_drvdata(pdev);
>>>> -
>>>>       mipi_dsi_host_unregister(&dsi->dsi_host);
>>>>       __dw_mipi_dsi_remove(dsi);
>>>> @@ -961,31 +952,30 @@ EXPORT_SYMBOL_GPL(dw_mipi_dsi_remove);
>>>>   /*
>>>>    * Bind/unbind API, used from platforms based on the component 
>>>> framework.
>>>>    */
>>>> -int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder 
>>>> *encoder,
>>>> -             const struct dw_mipi_dsi_plat_data *plat_data)
>>>> +struct dw_mipi_dsi *
>>>> +dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder 
>>>> *encoder,
>>>> +         const struct dw_mipi_dsi_plat_data *plat_data)
>>>>   {
>>>>       struct dw_mipi_dsi *dsi;
>>>>       int ret;
>>>>       dsi = __dw_mipi_dsi_probe(pdev, plat_data);
>>>>       if (IS_ERR(dsi))
>>>> -        return PTR_ERR(dsi);
>>>> +        return dsi;
>>>>       ret = drm_bridge_attach(encoder, &dsi->bridge, NULL);
>>>>       if (ret) {
>>>> -        dw_mipi_dsi_remove(pdev);
>>>> +        dw_mipi_dsi_remove(dsi);
>>>>           DRM_ERROR("Failed to initialize bridge with drm\n");
>>>> -        return ret;
>>>> +        return ERR_PTR(ret);
>>>>       }
>>>> -    return 0;
>>>> +    return dsi;
>>>>   }
>>>>   EXPORT_SYMBOL_GPL(dw_mipi_dsi_bind);
>>>> -void dw_mipi_dsi_unbind(struct device *dev)
>>>> +void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi)
>>>>   {
>>>> -    struct dw_mipi_dsi *dsi = dev_get_drvdata(dev);
>>>> -
>>>>       __dw_mipi_dsi_remove(dsi);
>>>>   }
>>>>   EXPORT_SYMBOL_GPL(dw_mipi_dsi_unbind);
>>>> diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c 
>>>> b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
>>>> index e5b6310240fe..7ed0ef7f6ec2 100644
>>>> --- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
>>>> +++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
>>>> @@ -66,6 +66,7 @@ enum dsi_color {
>>>>   struct dw_mipi_dsi_stm {
>>>>       void __iomem *base;
>>>>       struct clk *pllref_clk;
>>>> +    struct dw_mipi_dsi *dsi;
>>>>   };
>>>>   static inline void dsi_write(struct dw_mipi_dsi_stm *dsi, u32 reg, 
>>>> u32 val)
>>>> @@ -318,21 +319,24 @@ static int dw_mipi_dsi_stm_probe(struct 
>>>> platform_device *pdev)
>>>>       dw_mipi_dsi_stm_plat_data.base = dsi->base;
>>>>       dw_mipi_dsi_stm_plat_data.priv_data = dsi;
>>>> -    ret = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
>>>> -    if (ret) {
>>>> +    platform_set_drvdata(pdev, dsi);
>>>> +
>>>> +    dsi->dsi = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
>>>> +    if (IS_ERR(dsi->dsi)) {
>>>>           DRM_ERROR("Failed to initialize mipi dsi host\n");
>>>>           clk_disable_unprepare(dsi->pllref_clk);
>>>> +        return PTR_ERR(dsi->dsi);
>>>>       }
>>>> -    return ret;
>>>> +    return 0;
>>>>   }
>>>>   static int dw_mipi_dsi_stm_remove(struct platform_device *pdev)
>>>>   {
>>>> -    struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data;
>>>> +    struct dw_mipi_dsi_stm *dsi = platform_get_drvdata(pdev);
>>>>       clk_disable_unprepare(dsi->pllref_clk);
>>>> -    dw_mipi_dsi_remove(pdev);
>>>> +    dw_mipi_dsi_remove(dsi->dsi);
>>>>       return 0;
>>>>   }
>>>> diff --git a/include/drm/bridge/dw_mipi_dsi.h 
>>>> b/include/drm/bridge/dw_mipi_dsi.h
>>>> index 9b30fec302c8..d9c6d549f971 100644
>>>> --- a/include/drm/bridge/dw_mipi_dsi.h
>>>> +++ b/include/drm/bridge/dw_mipi_dsi.h
>>>> @@ -10,6 +10,8 @@
>>>>   #ifndef __DW_MIPI_DSI__
>>>>   #define __DW_MIPI_DSI__
>>>> +struct dw_mipi_dsi;
>>>> +
>>>>   struct dw_mipi_dsi_phy_ops {
>>>>       int (*init)(void *priv_data);
>>>>       int (*get_lane_mbps)(void *priv_data, struct drm_display_mode 
>>>> *mode,
>>>> @@ -29,11 +31,14 @@ struct dw_mipi_dsi_plat_data {
>>>>       void *priv_data;
>>>>   };
>>>> -int dw_mipi_dsi_probe(struct platform_device *pdev,
>>>> -              const struct dw_mipi_dsi_plat_data *plat_data);
>>>> -void dw_mipi_dsi_remove(struct platform_device *pdev);
>>>> -int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder 
>>>> *encoder,
>>>> -             const struct dw_mipi_dsi_plat_data *plat_data);
>>>> -void dw_mipi_dsi_unbind(struct device *dev);
>>>> +struct dw_mipi_dsi *dw_mipi_dsi_probe(struct platform_device *pdev,
>>>> +                      const struct dw_mipi_dsi_plat_data
>>>> +                      *plat_data);
>>>> +void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi);
>>>> +struct dw_mipi_dsi *dw_mipi_dsi_bind(struct platform_device *pdev,
>>>> +                     struct drm_encoder *encoder,
>>>> +                     const struct dw_mipi_dsi_plat_data
>>>> +                     *plat_data);
>>>> +void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi);
>>>>   #endif /* __DW_MIPI_DSI__ */
>

Patch
diff mbox series

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
index d9cca4fd66ec..c39c7dce20ed 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
@@ -922,8 +922,6 @@  __dw_mipi_dsi_probe(struct platform_device *pdev,
 	dsi->bridge.of_node = pdev->dev.of_node;
 #endif
 
-	dev_set_drvdata(dev, dsi);
-
 	return dsi;
 }
 
@@ -935,23 +933,16 @@  static void __dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
 /*
  * Probe/remove API, used from platforms based on the DRM bridge API.
  */
-int dw_mipi_dsi_probe(struct platform_device *pdev,
-		      const struct dw_mipi_dsi_plat_data *plat_data)
+struct dw_mipi_dsi *
+dw_mipi_dsi_probe(struct platform_device *pdev,
+		  const struct dw_mipi_dsi_plat_data *plat_data)
 {
-	struct dw_mipi_dsi *dsi;
-
-	dsi = __dw_mipi_dsi_probe(pdev, plat_data);
-	if (IS_ERR(dsi))
-		return PTR_ERR(dsi);
-
-	return 0;
+	return __dw_mipi_dsi_probe(pdev, plat_data);
 }
 EXPORT_SYMBOL_GPL(dw_mipi_dsi_probe);
 
-void dw_mipi_dsi_remove(struct platform_device *pdev)
+void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
 {
-	struct dw_mipi_dsi *dsi = platform_get_drvdata(pdev);
-
 	mipi_dsi_host_unregister(&dsi->dsi_host);
 
 	__dw_mipi_dsi_remove(dsi);
@@ -961,31 +952,30 @@  EXPORT_SYMBOL_GPL(dw_mipi_dsi_remove);
 /*
  * Bind/unbind API, used from platforms based on the component framework.
  */
-int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
-		     const struct dw_mipi_dsi_plat_data *plat_data)
+struct dw_mipi_dsi *
+dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
+		 const struct dw_mipi_dsi_plat_data *plat_data)
 {
 	struct dw_mipi_dsi *dsi;
 	int ret;
 
 	dsi = __dw_mipi_dsi_probe(pdev, plat_data);
 	if (IS_ERR(dsi))
-		return PTR_ERR(dsi);
+		return dsi;
 
 	ret = drm_bridge_attach(encoder, &dsi->bridge, NULL);
 	if (ret) {
-		dw_mipi_dsi_remove(pdev);
+		dw_mipi_dsi_remove(dsi);
 		DRM_ERROR("Failed to initialize bridge with drm\n");
-		return ret;
+		return ERR_PTR(ret);
 	}
 
-	return 0;
+	return dsi;
 }
 EXPORT_SYMBOL_GPL(dw_mipi_dsi_bind);
 
-void dw_mipi_dsi_unbind(struct device *dev)
+void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi)
 {
-	struct dw_mipi_dsi *dsi = dev_get_drvdata(dev);
-
 	__dw_mipi_dsi_remove(dsi);
 }
 EXPORT_SYMBOL_GPL(dw_mipi_dsi_unbind);
diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
index e5b6310240fe..7ed0ef7f6ec2 100644
--- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
+++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
@@ -66,6 +66,7 @@  enum dsi_color {
 struct dw_mipi_dsi_stm {
 	void __iomem *base;
 	struct clk *pllref_clk;
+	struct dw_mipi_dsi *dsi;
 };
 
 static inline void dsi_write(struct dw_mipi_dsi_stm *dsi, u32 reg, u32 val)
@@ -318,21 +319,24 @@  static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
 	dw_mipi_dsi_stm_plat_data.base = dsi->base;
 	dw_mipi_dsi_stm_plat_data.priv_data = dsi;
 
-	ret = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
-	if (ret) {
+	platform_set_drvdata(pdev, dsi);
+
+	dsi->dsi = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
+	if (IS_ERR(dsi->dsi)) {
 		DRM_ERROR("Failed to initialize mipi dsi host\n");
 		clk_disable_unprepare(dsi->pllref_clk);
+		return PTR_ERR(dsi->dsi);
 	}
 
-	return ret;
+	return 0;
 }
 
 static int dw_mipi_dsi_stm_remove(struct platform_device *pdev)
 {
-	struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data;
+	struct dw_mipi_dsi_stm *dsi = platform_get_drvdata(pdev);
 
 	clk_disable_unprepare(dsi->pllref_clk);
-	dw_mipi_dsi_remove(pdev);
+	dw_mipi_dsi_remove(dsi->dsi);
 
 	return 0;
 }
diff --git a/include/drm/bridge/dw_mipi_dsi.h b/include/drm/bridge/dw_mipi_dsi.h
index 9b30fec302c8..d9c6d549f971 100644
--- a/include/drm/bridge/dw_mipi_dsi.h
+++ b/include/drm/bridge/dw_mipi_dsi.h
@@ -10,6 +10,8 @@ 
 #ifndef __DW_MIPI_DSI__
 #define __DW_MIPI_DSI__
 
+struct dw_mipi_dsi;
+
 struct dw_mipi_dsi_phy_ops {
 	int (*init)(void *priv_data);
 	int (*get_lane_mbps)(void *priv_data, struct drm_display_mode *mode,
@@ -29,11 +31,14 @@  struct dw_mipi_dsi_plat_data {
 	void *priv_data;
 };
 
-int dw_mipi_dsi_probe(struct platform_device *pdev,
-		      const struct dw_mipi_dsi_plat_data *plat_data);
-void dw_mipi_dsi_remove(struct platform_device *pdev);
-int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
-		     const struct dw_mipi_dsi_plat_data *plat_data);
-void dw_mipi_dsi_unbind(struct device *dev);
+struct dw_mipi_dsi *dw_mipi_dsi_probe(struct platform_device *pdev,
+				      const struct dw_mipi_dsi_plat_data
+				      *plat_data);
+void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi);
+struct dw_mipi_dsi *dw_mipi_dsi_bind(struct platform_device *pdev,
+				     struct drm_encoder *encoder,
+				     const struct dw_mipi_dsi_plat_data
+				     *plat_data);
+void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi);
 
 #endif /* __DW_MIPI_DSI__ */