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[PATCH v5 4/7] usb: dwc3: core: Don't touch resets and clocks

Bjorn Andersson posted 7 patches 9 months ago
There is a newer version of this series
[PATCH v5 4/7] usb: dwc3: core: Don't touch resets and clocks
Posted by Bjorn Andersson 9 months ago 
When the core is integrated with glue, it's reasonable to assume that
the glue driver will have to touch the IP before/after the core takes
the hardware out and into reset. As such the glue must own these
resources and be allowed to turn them on/off outside the core's
handling.

Allow the platform or glue layer to indicate if the core logic for
clocks and resets should be skipped to deal with this.

Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>
---
 drivers/usb/dwc3/core.c | 20 +++++++++++---------
 drivers/usb/dwc3/glue.h |  3 +++
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index b428b6fc3d0a55811e2f75d33d79df4b0c67dcac..77a9848a0ac70fbe563988cecbe489130989aadc 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -2198,15 +2198,17 @@ int dwc3_core_probe(const struct dwc3_probe_data *data)
 	if (IS_ERR(dwc->usb_psy))
 		return dev_err_probe(dev, PTR_ERR(dwc->usb_psy), "couldn't get usb power supply\n");
 
-	dwc->reset = devm_reset_control_array_get_optional_shared(dev);
-	if (IS_ERR(dwc->reset)) {
-		ret = PTR_ERR(dwc->reset);
-		goto err_put_psy;
-	}
+	if (!data->ignore_clocks_and_resets) {
+		dwc->reset = devm_reset_control_array_get_optional_shared(dev);
+		if (IS_ERR(dwc->reset)) {
+			ret = PTR_ERR(dwc->reset);
+			goto err_put_psy;
+		}
 
-	ret = dwc3_get_clocks(dwc);
-	if (ret)
-		goto err_put_psy;
+		ret = dwc3_get_clocks(dwc);
+		if (ret)
+			goto err_put_psy;
+	}
 
 	ret = reset_control_deassert(dwc->reset);
 	if (ret)
@@ -2321,7 +2323,7 @@ EXPORT_SYMBOL_GPL(dwc3_core_probe);
 
 static int dwc3_probe(struct platform_device *pdev)
 {
-	struct dwc3_probe_data probe_data;
+	struct dwc3_probe_data probe_data = {};
 	struct resource *res;
 	struct dwc3 *dwc;
 
diff --git a/drivers/usb/dwc3/glue.h b/drivers/usb/dwc3/glue.h
index e73cfc466012f07214291abe56454934ab014013..703d40c189565b1e28ae28afb8728b78f4cd2fca 100644
--- a/drivers/usb/dwc3/glue.h
+++ b/drivers/usb/dwc3/glue.h
@@ -13,10 +13,13 @@
  * dwc3_probe_data: Initialization parameters passed to dwc3_core_probe()
  * @dwc: Reference to dwc3 context structure
  * @res: resource for the DWC3 core mmio region
+ * @ignore_clocks_and_resets: clocks and resets defined for the device should
+ *		be ignored by the DWC3 core, as they are managed by the glue
  */
 struct dwc3_probe_data {
 	struct dwc3 *dwc;
 	struct resource *res;
+	bool ignore_clocks_and_resets;
 };
 
 int dwc3_core_probe(const struct dwc3_probe_data *data);

-- 
2.48.1
Re: [PATCH v5 4/7] usb: dwc3: core: Don't touch resets and clocks
Posted by Thinh Nguyen 9 months ago 
On Tue, Mar 18, 2025, Bjorn Andersson wrote:
> When the core is integrated with glue, it's reasonable to assume that
> the glue driver will have to touch the IP before/after the core takes
> the hardware out and into reset. As such the glue must own these
> resources and be allowed to turn them on/off outside the core's
> handling.
> 
> Allow the platform or glue layer to indicate if the core logic for
> clocks and resets should be skipped to deal with this.
> 
> Reviewed-by: Frank Li <Frank.Li@nxp.com>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>
> ---
>  drivers/usb/dwc3/core.c | 20 +++++++++++---------
>  drivers/usb/dwc3/glue.h |  3 +++
>  2 files changed, 14 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index b428b6fc3d0a55811e2f75d33d79df4b0c67dcac..77a9848a0ac70fbe563988cecbe489130989aadc 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -2198,15 +2198,17 @@ int dwc3_core_probe(const struct dwc3_probe_data *data)
>  	if (IS_ERR(dwc->usb_psy))
>  		return dev_err_probe(dev, PTR_ERR(dwc->usb_psy), "couldn't get usb power supply\n");
>  
> -	dwc->reset = devm_reset_control_array_get_optional_shared(dev);
> -	if (IS_ERR(dwc->reset)) {
> -		ret = PTR_ERR(dwc->reset);
> -		goto err_put_psy;
> -	}
> +	if (!data->ignore_clocks_and_resets) {
> +		dwc->reset = devm_reset_control_array_get_optional_shared(dev);
> +		if (IS_ERR(dwc->reset)) {
> +			ret = PTR_ERR(dwc->reset);
> +			goto err_put_psy;
> +		}
>  
> -	ret = dwc3_get_clocks(dwc);
> -	if (ret)
> -		goto err_put_psy;
> +		ret = dwc3_get_clocks(dwc);
> +		if (ret)
> +			goto err_put_psy;
> +	}
>  
>  	ret = reset_control_deassert(dwc->reset);
>  	if (ret)
> @@ -2321,7 +2323,7 @@ EXPORT_SYMBOL_GPL(dwc3_core_probe);
>  
>  static int dwc3_probe(struct platform_device *pdev)
>  {
> -	struct dwc3_probe_data probe_data;
> +	struct dwc3_probe_data probe_data = {};
>  	struct resource *res;
>  	struct dwc3 *dwc;
>  
> diff --git a/drivers/usb/dwc3/glue.h b/drivers/usb/dwc3/glue.h
> index e73cfc466012f07214291abe56454934ab014013..703d40c189565b1e28ae28afb8728b78f4cd2fca 100644
> --- a/drivers/usb/dwc3/glue.h
> +++ b/drivers/usb/dwc3/glue.h
> @@ -13,10 +13,13 @@
>   * dwc3_probe_data: Initialization parameters passed to dwc3_core_probe()
>   * @dwc: Reference to dwc3 context structure
>   * @res: resource for the DWC3 core mmio region
> + * @ignore_clocks_and_resets: clocks and resets defined for the device should
> + *		be ignored by the DWC3 core, as they are managed by the glue
>   */
>  struct dwc3_probe_data {
>  	struct dwc3 *dwc;
>  	struct resource *res;
> +	bool ignore_clocks_and_resets;
>  };
>  
>  int dwc3_core_probe(const struct dwc3_probe_data *data);
> 
> -- 
> 2.48.1
> 

Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>

Thanks,
Thinh
Re: [PATCH v5 4/7] usb: dwc3: core: Don't touch resets and clocks
Posted by neil.armstrong@linaro.org 9 months ago 
On 18/03/2025 20:05, Bjorn Andersson wrote:
> When the core is integrated with glue, it's reasonable to assume that
> the glue driver will have to touch the IP before/after the core takes
> the hardware out and into reset. As such the glue must own these
> resources and be allowed to turn them on/off outside the core's
> handling.
> 
> Allow the platform or glue layer to indicate if the core logic for
> clocks and resets should be skipped to deal with this.
> 
> Reviewed-by: Frank Li <Frank.Li@nxp.com>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>
> ---
>   drivers/usb/dwc3/core.c | 20 +++++++++++---------
>   drivers/usb/dwc3/glue.h |  3 +++
>   2 files changed, 14 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index b428b6fc3d0a55811e2f75d33d79df4b0c67dcac..77a9848a0ac70fbe563988cecbe489130989aadc 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -2198,15 +2198,17 @@ int dwc3_core_probe(const struct dwc3_probe_data *data)
>   	if (IS_ERR(dwc->usb_psy))
>   		return dev_err_probe(dev, PTR_ERR(dwc->usb_psy), "couldn't get usb power supply\n");
>   
> -	dwc->reset = devm_reset_control_array_get_optional_shared(dev);
> -	if (IS_ERR(dwc->reset)) {
> -		ret = PTR_ERR(dwc->reset);
> -		goto err_put_psy;
> -	}
> +	if (!data->ignore_clocks_and_resets) {
> +		dwc->reset = devm_reset_control_array_get_optional_shared(dev);
> +		if (IS_ERR(dwc->reset)) {
> +			ret = PTR_ERR(dwc->reset);
> +			goto err_put_psy;
> +		}
>   
> -	ret = dwc3_get_clocks(dwc);
> -	if (ret)
> -		goto err_put_psy;
> +		ret = dwc3_get_clocks(dwc);
> +		if (ret)
> +			goto err_put_psy;
> +	}
>   
>   	ret = reset_control_deassert(dwc->reset);
>   	if (ret)
> @@ -2321,7 +2323,7 @@ EXPORT_SYMBOL_GPL(dwc3_core_probe);
>   
>   static int dwc3_probe(struct platform_device *pdev)
>   {
> -	struct dwc3_probe_data probe_data;
> +	struct dwc3_probe_data probe_data = {};

This should go in the previous patch

Neil

>   	struct resource *res;
>   	struct dwc3 *dwc;
>   
> diff --git a/drivers/usb/dwc3/glue.h b/drivers/usb/dwc3/glue.h
> index e73cfc466012f07214291abe56454934ab014013..703d40c189565b1e28ae28afb8728b78f4cd2fca 100644
> --- a/drivers/usb/dwc3/glue.h
> +++ b/drivers/usb/dwc3/glue.h
> @@ -13,10 +13,13 @@
>    * dwc3_probe_data: Initialization parameters passed to dwc3_core_probe()
>    * @dwc: Reference to dwc3 context structure
>    * @res: resource for the DWC3 core mmio region
> + * @ignore_clocks_and_resets: clocks and resets defined for the device should
> + *		be ignored by the DWC3 core, as they are managed by the glue
>    */
>   struct dwc3_probe_data {
>   	struct dwc3 *dwc;
>   	struct resource *res;
> +	bool ignore_clocks_and_resets;
>   };
>   
>   int dwc3_core_probe(const struct dwc3_probe_data *data);
>
Re: [PATCH v5 4/7] usb: dwc3: core: Don't touch resets and clocks
Posted by Thinh Nguyen 9 months ago 
On Wed, Mar 19, 2025, neil.armstrong@linaro.org wrote:
> On 18/03/2025 20:05, Bjorn Andersson wrote:
> > When the core is integrated with glue, it's reasonable to assume that
> > the glue driver will have to touch the IP before/after the core takes
> > the hardware out and into reset. As such the glue must own these
> > resources and be allowed to turn them on/off outside the core's
> > handling.
> > 
> > Allow the platform or glue layer to indicate if the core logic for
> > clocks and resets should be skipped to deal with this.
> > 
> > Reviewed-by: Frank Li <Frank.Li@nxp.com>
> > Signed-off-by: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>
> > ---
> >   drivers/usb/dwc3/core.c | 20 +++++++++++---------
> >   drivers/usb/dwc3/glue.h |  3 +++
> >   2 files changed, 14 insertions(+), 9 deletions(-)
> > 
> > diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> > index b428b6fc3d0a55811e2f75d33d79df4b0c67dcac..77a9848a0ac70fbe563988cecbe489130989aadc 100644
> > --- a/drivers/usb/dwc3/core.c
> > +++ b/drivers/usb/dwc3/core.c
> > @@ -2198,15 +2198,17 @@ int dwc3_core_probe(const struct dwc3_probe_data *data)
> >   	if (IS_ERR(dwc->usb_psy))
> >   		return dev_err_probe(dev, PTR_ERR(dwc->usb_psy), "couldn't get usb power supply\n");
> > -	dwc->reset = devm_reset_control_array_get_optional_shared(dev);
> > -	if (IS_ERR(dwc->reset)) {
> > -		ret = PTR_ERR(dwc->reset);
> > -		goto err_put_psy;
> > -	}
> > +	if (!data->ignore_clocks_and_resets) {
> > +		dwc->reset = devm_reset_control_array_get_optional_shared(dev);
> > +		if (IS_ERR(dwc->reset)) {
> > +			ret = PTR_ERR(dwc->reset);
> > +			goto err_put_psy;
> > +		}
> > -	ret = dwc3_get_clocks(dwc);
> > -	if (ret)
> > -		goto err_put_psy;
> > +		ret = dwc3_get_clocks(dwc);
> > +		if (ret)
> > +			goto err_put_psy;
> > +	}
> >   	ret = reset_control_deassert(dwc->reset);
> >   	if (ret)
> > @@ -2321,7 +2323,7 @@ EXPORT_SYMBOL_GPL(dwc3_core_probe);
> >   static int dwc3_probe(struct platform_device *pdev)
> >   {
> > -	struct dwc3_probe_data probe_data;
> > +	struct dwc3_probe_data probe_data = {};
> 
> This should go in the previous patch
> 
> Neil
> 

This should be fine to be here since it may not be necessary for the
previous patch.

BR,
Thinh


> >   	struct resource *res;
> >   	struct dwc3 *dwc;
> > diff --git a/drivers/usb/dwc3/glue.h b/drivers/usb/dwc3/glue.h
> > index e73cfc466012f07214291abe56454934ab014013..703d40c189565b1e28ae28afb8728b78f4cd2fca 100644
> > --- a/drivers/usb/dwc3/glue.h
> > +++ b/drivers/usb/dwc3/glue.h
> > @@ -13,10 +13,13 @@
> >    * dwc3_probe_data: Initialization parameters passed to dwc3_core_probe()
> >    * @dwc: Reference to dwc3 context structure
> >    * @res: resource for the DWC3 core mmio region
> > + * @ignore_clocks_and_resets: clocks and resets defined for the device should
> > + *		be ignored by the DWC3 core, as they are managed by the glue
> >    */
> >   struct dwc3_probe_data {
> >   	struct dwc3 *dwc;
> >   	struct resource *res;
> > +	bool ignore_clocks_and_resets;
> >   };
> >   int dwc3_core_probe(const struct dwc3_probe_data *data);
> > 
>

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