[v4] usb: dwc3: qcom: Flatten dwc3 structure

[PATCH v4 3/7] usb: dwc3: core: Don't touch resets and clocks

Posted by Bjorn Andersson 11 months, 2 weeks 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.

Signed-off-by: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>
---
 drivers/usb/dwc3/core.c | 19 +++++++++++--------
 drivers/usb/dwc3/glue.h |  1 +
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index d9f0a6782d36..aecdde8dc999 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -2187,15 +2187,17 @@ 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)
@@ -2328,6 +2330,7 @@ static int dwc3_probe(struct platform_device *pdev)
 
 	probe_data.dwc = dwc;
 	probe_data.res = res;
+	probe_data.ignore_clocks_and_resets = false;
 
 	return dwc3_core_probe(&probe_data);
 }
diff --git a/drivers/usb/dwc3/glue.h b/drivers/usb/dwc3/glue.h
index e73cfc466012..1ddb451bdbd0 100644
--- a/drivers/usb/dwc3/glue.h
+++ b/drivers/usb/dwc3/glue.h
@@ -17,6 +17,7 @@
 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);

-- 
2.45.2

Re: [PATCH v4 3/7] usb: dwc3: core: Don't touch resets and clocks

Posted by Frank Li 11 months, 2 weeks ago

On Wed, Feb 26, 2025 at 04:17:50PM -0800, 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.
>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>
> ---
>  drivers/usb/dwc3/core.c | 19 +++++++++++--------
>  drivers/usb/dwc3/glue.h |  1 +
>  2 files changed, 12 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index d9f0a6782d36..aecdde8dc999 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -2187,15 +2187,17 @@ 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)
> @@ -2328,6 +2330,7 @@ static int dwc3_probe(struct platform_device *pdev)
>
>  	probe_data.dwc = dwc;
>  	probe_data.res = res;
> +	probe_data.ignore_clocks_and_resets = false;
>
>  	return dwc3_core_probe(&probe_data);
>  }
> diff --git a/drivers/usb/dwc3/glue.h b/drivers/usb/dwc3/glue.h
> index e73cfc466012..1ddb451bdbd0 100644
> --- a/drivers/usb/dwc3/glue.h
> +++ b/drivers/usb/dwc3/glue.h
> @@ -17,6 +17,7 @@
>  struct dwc3_probe_data {
>  	struct dwc3 *dwc;
>  	struct resource *res;
> +	bool ignore_clocks_and_resets;

Nit: suggest add kernel doc comments for each fields

Reviewed-by: Frank Li <Frank.Li@nxp.com>

>  };
>
>  int dwc3_core_probe(const struct dwc3_probe_data *data);
>
> --
> 2.45.2
>

Re: [PATCH v4 3/7] usb: dwc3: core: Don't touch resets and clocks

Posted by Dmitry Baryshkov 11 months, 2 weeks ago

On Wed, Feb 26, 2025 at 04:17:50PM -0800, 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.
> 
> Signed-off-by: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>
> ---
>  drivers/usb/dwc3/core.c | 19 +++++++++++--------
>  drivers/usb/dwc3/glue.h |  1 +
>  2 files changed, 12 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index d9f0a6782d36..aecdde8dc999 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -2328,6 +2330,7 @@ static int dwc3_probe(struct platform_device *pdev)
>  
>  	probe_data.dwc = dwc;
>  	probe_data.res = res;
> +	probe_data.ignore_clocks_and_resets = false;

Isn't it a default value?

>  
>  	return dwc3_core_probe(&probe_data);
>  }
> diff --git a/drivers/usb/dwc3/glue.h b/drivers/usb/dwc3/glue.h
> index e73cfc466012..1ddb451bdbd0 100644
> --- a/drivers/usb/dwc3/glue.h
> +++ b/drivers/usb/dwc3/glue.h
> @@ -17,6 +17,7 @@
>  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);
> 
> -- 
> 2.45.2
> 

-- 
With best wishes
Dmitry

Re: [PATCH v4 3/7] usb: dwc3: core: Don't touch resets and clocks

Posted by Bjorn Andersson 11 months, 2 weeks ago

On Thu, Feb 27, 2025 at 06:24:17AM +0200, Dmitry Baryshkov wrote:
> On Wed, Feb 26, 2025 at 04:17:50PM -0800, 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.
> > 
> > Signed-off-by: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>
> > ---
> >  drivers/usb/dwc3/core.c | 19 +++++++++++--------
> >  drivers/usb/dwc3/glue.h |  1 +
> >  2 files changed, 12 insertions(+), 8 deletions(-)
> > 
> > diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> > index d9f0a6782d36..aecdde8dc999 100644
> > --- a/drivers/usb/dwc3/core.c
> > +++ b/drivers/usb/dwc3/core.c
> > @@ -2328,6 +2330,7 @@ static int dwc3_probe(struct platform_device *pdev)
> >  
> >  	probe_data.dwc = dwc;
> >  	probe_data.res = res;
> > +	probe_data.ignore_clocks_and_resets = false;
> 
> Isn't it a default value?
> 

I like the false because it's explicit, but I have no strong attachment
to it.

That said, it's not the default value, because probe_data isn't
zero-initialized. That would however make sense to do, in order to avoid
surprises in the future when probe_data grows.

Regards,
Bjorn

> >  
> >  	return dwc3_core_probe(&probe_data);
> >  }
> > diff --git a/drivers/usb/dwc3/glue.h b/drivers/usb/dwc3/glue.h
> > index e73cfc466012..1ddb451bdbd0 100644
> > --- a/drivers/usb/dwc3/glue.h
> > +++ b/drivers/usb/dwc3/glue.h
> > @@ -17,6 +17,7 @@
> >  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);
> > 
> > -- 
> > 2.45.2
> > 
> 
> -- 
> With best wishes
> Dmitry

Re: [PATCH v4 3/7] usb: dwc3: core: Don't touch resets and clocks

Posted by Dmitry Baryshkov 11 months, 2 weeks ago

On Thu, Feb 27, 2025 at 09:55:29AM -0600, Bjorn Andersson wrote:
> On Thu, Feb 27, 2025 at 06:24:17AM +0200, Dmitry Baryshkov wrote:
> > On Wed, Feb 26, 2025 at 04:17:50PM -0800, 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.
> > > 
> > > Signed-off-by: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>
> > > ---
> > >  drivers/usb/dwc3/core.c | 19 +++++++++++--------
> > >  drivers/usb/dwc3/glue.h |  1 +
> > >  2 files changed, 12 insertions(+), 8 deletions(-)
> > > 
> > > diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> > > index d9f0a6782d36..aecdde8dc999 100644
> > > --- a/drivers/usb/dwc3/core.c
> > > +++ b/drivers/usb/dwc3/core.c
> > > @@ -2328,6 +2330,7 @@ static int dwc3_probe(struct platform_device *pdev)
> > >  
> > >  	probe_data.dwc = dwc;
> > >  	probe_data.res = res;
> > > +	probe_data.ignore_clocks_and_resets = false;
> > 
> > Isn't it a default value?
> > 
> 
> I like the false because it's explicit, but I have no strong attachment
> to it.

I'm more biased to the 'make unusal cases stand out', which means the
defaults can go away to highlight non-default cases.

> 
> That said, it's not the default value, because probe_data isn't
> zero-initialized. That would however make sense to do, in order to avoid
> surprises in the future when probe_data grows.

:-)

> 
> Regards,
> Bjorn
> 
> > >  
> > >  	return dwc3_core_probe(&probe_data);
> > >  }
> > > diff --git a/drivers/usb/dwc3/glue.h b/drivers/usb/dwc3/glue.h
> > > index e73cfc466012..1ddb451bdbd0 100644
> > > --- a/drivers/usb/dwc3/glue.h
> > > +++ b/drivers/usb/dwc3/glue.h
> > > @@ -17,6 +17,7 @@
> > >  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);
> > > 
> > > -- 
> > > 2.45.2
> > > 
> > 
> > -- 
> > With best wishes
> > Dmitry

-- 
With best wishes
Dmitry