[PATCH v2 0/4] drivers: new helper for ioremapping memory resources

[PATCH v2 0/4] drivers: new helper for ioremapping memory resources

[Dejin Zheng]

Since commit "drivers: provide devm_platform_ioremap_resource()",
It was wrap platform_get_resource() and devm_ioremap_resource() as
single helper devm_platform_ioremap_resource(). but now, many drivers
still used platform_get_resource() and devm_ioremap_resource()
together in the kernel tree. The reason can not be replaced is they
still need use the resource variables obtained by platform_get_resource().
so provide this helper.

The first patch in this series adds a wrapper for these two calls and
the other uses it in a driver.

Since V1:
	- add some real users of this function (Thanks for greg k-h's reminder)

Dejin Zheng (4):
  drivers: provide devm_platform_ioremap_and_get_resource()
  usb: host: xhci-plat: convert to
    devm_platform_ioremap_and_get_resource
  usb: host: hisilicon: convert to
    devm_platform_ioremap_and_get_resource
  usb: dwc2: convert to devm_platform_ioremap_and_get_resource

 drivers/base/platform.c         | 18 ++++++++++++++++++
 drivers/usb/dwc2/platform.c     |  3 +--
 drivers/usb/host/xhci-histb.c   |  3 +--
 drivers/usb/host/xhci-plat.c    |  3 +--
 include/linux/platform_device.h |  3 +++
 5 files changed, 24 insertions(+), 6 deletions(-)

-- 
2.25.0

[PATCH v2 1/4] drivers: provide devm_platform_ioremap_and_get_resource()

[Dejin Zheng]

Since commit "drivers: provide devm_platform_ioremap_resource()",
It was wrap platform_get_resource() and devm_ioremap_resource() as
single helper devm_platform_ioremap_resource(). but now, many drivers
still used platform_get_resource() and devm_ioremap_resource()
together in the kernel tree. The reason can not be replaced is they
still need use the resource variables obtained by platform_get_resource().
so provide this helper.

Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
---
 drivers/base/platform.c         | 18 ++++++++++++++++++
 include/linux/platform_device.h |  3 +++
 2 files changed, 21 insertions(+)

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 7fa654f1288b..b3e2409effae 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -62,6 +62,24 @@ struct resource *platform_get_resource(struct platform_device *dev,
 EXPORT_SYMBOL_GPL(platform_get_resource);
 
 #ifdef CONFIG_HAS_IOMEM
+/**
+ * devm_platform_ioremap_and_get_resource - call devm_ioremap_resource() for a
+ *					    platform device and get resource
+ *
+ * @pdev: platform device to use both for memory resource lookup as well as
+ *        resource management
+ * @index: resource index
+ * @res: get the resource
+ */
+void __iomem *
+devm_platform_ioremap_and_get_resource(struct platform_device *pdev,
+				unsigned int index, struct resource **res)
+{
+	*res = platform_get_resource(pdev, IORESOURCE_MEM, index);
+	return devm_ioremap_resource(&pdev->dev, *res);
+}
+EXPORT_SYMBOL_GPL(devm_platform_ioremap_and_get_resource);
+
 /**
  * devm_platform_ioremap_resource - call devm_ioremap_resource() for a platform
  *				    device
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 276a03c24691..5fd1977e3eaf 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -55,6 +55,9 @@ extern struct device *
 platform_find_device_by_driver(struct device *start,
 			       const struct device_driver *drv);
 extern void __iomem *
+devm_platform_ioremap_and_get_resource(struct platform_device *pdev,
+				unsigned int index, struct resource **res);
+extern void __iomem *
 devm_platform_ioremap_resource(struct platform_device *pdev,
 			       unsigned int index);
 extern void __iomem *
-- 
2.25.0

Re: [PATCH v2 1/4] drivers: provide devm_platform_ioremap_and_get_resource()

[Geert Uytterhoeven]

Hi Dejin,

On Sat, Mar 14, 2020 at 6:26 AM Dejin Zheng <zhengdejin5@gmail.com> wrote:
> Since commit "drivers: provide devm_platform_ioremap_resource()",
> It was wrap platform_get_resource() and devm_ioremap_resource() as
> single helper devm_platform_ioremap_resource(). but now, many drivers
> still used platform_get_resource() and devm_ioremap_resource()
> together in the kernel tree. The reason can not be replaced is they
> still need use the resource variables obtained by platform_get_resource().
> so provide this helper.
>
> Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>

Thanks for your patch!

> --- a/drivers/base/platform.c
> +++ b/drivers/base/platform.c
> @@ -62,6 +62,24 @@ struct resource *platform_get_resource(struct platform_device *dev,
>  EXPORT_SYMBOL_GPL(platform_get_resource);
>
>  #ifdef CONFIG_HAS_IOMEM
> +/**
> + * devm_platform_ioremap_and_get_resource - call devm_ioremap_resource() for a
> + *                                         platform device and get resource
> + *
> + * @pdev: platform device to use both for memory resource lookup as well as
> + *        resource management
> + * @index: resource index
> + * @res: get the resource
> + */
> +void __iomem *
> +devm_platform_ioremap_and_get_resource(struct platform_device *pdev,
> +                               unsigned int index, struct resource **res)
> +{
> +       *res = platform_get_resource(pdev, IORESOURCE_MEM, index);
> +       return devm_ioremap_resource(&pdev->dev, *res);
> +}
> +EXPORT_SYMBOL_GPL(devm_platform_ioremap_and_get_resource);

As this duplicates most of the implementation of
devm_platform_ioremap_resource(),
I think it would be better to make res optional:

    void __iomem *
    devm_platform_ioremap_and_get_resource(struct platform_device *pdev,
                                           unsigned int index, struct
resource **resp)
    {
            struct resource **res;

            res = platform_get_resource(pdev, IORESOURCE_MEM, index);
            if (resp)
                    *resp = res;
            return devm_ioremap_resource(&pdev->dev, *res);
    }

And implement devm_platform_ioremap_resource() by calling
devm_platform_ioremap_and_get_resource() with resp = NULL.
Whether the best way to do that is as an exported functions, or as an
inlined function, is to be seen (measure impact on kernel size).

> +
>  /**
>   * devm_platform_ioremap_resource - call devm_ioremap_resource() for a platform
>   *                                 device
> diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
> index 276a03c24691..5fd1977e3eaf 100644
> --- a/include/linux/platform_device.h
> +++ b/include/linux/platform_device.h
> @@ -55,6 +55,9 @@ extern struct device *
>  platform_find_device_by_driver(struct device *start,
>                                const struct device_driver *drv);
>  extern void __iomem *
> +devm_platform_ioremap_and_get_resource(struct platform_device *pdev,
> +                               unsigned int index, struct resource **res);
> +extern void __iomem *
>  devm_platform_ioremap_resource(struct platform_device *pdev,
>                                unsigned int index);
>  extern void __iomem *

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v2 1/4] drivers: provide devm_platform_ioremap_and_get_resource()

[Sergei Shtylyov]

Hello!

On 14.03.2020 8:26, Dejin Zheng wrote:

> Since commit "drivers: provide devm_platform_ioremap_resource()",
> It was wrap platform_get_resource() and devm_ioremap_resource() as
   ^^ it

> single helper devm_platform_ioremap_resource(). but now, many drivers
> still used platform_get_resource() and devm_ioremap_resource()
> together in the kernel tree. The reason can not be replaced is they
> still need use the resource variables obtained by platform_get_resource().
> so provide this helper.

    Not really sure that's worth the effort...

> Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
> ---
>   drivers/base/platform.c         | 18 ++++++++++++++++++
>   include/linux/platform_device.h |  3 +++
>   2 files changed, 21 insertions(+)
> 
> diff --git a/drivers/base/platform.c b/drivers/base/platform.c
> index 7fa654f1288b..b3e2409effae 100644
> --- a/drivers/base/platform.c
> +++ b/drivers/base/platform.c
> @@ -62,6 +62,24 @@ struct resource *platform_get_resource(struct platform_device *dev,
>   EXPORT_SYMBOL_GPL(platform_get_resource);
>   
>   #ifdef CONFIG_HAS_IOMEM
> +/**
> + * devm_platform_ioremap_and_get_resource - call devm_ioremap_resource() for a
> + *					    platform device and get resource
> + *
> + * @pdev: platform device to use both for memory resource lookup as well as
> + *        resource management
> + * @index: resource index
> + * @res: get the resource
> + */
> +void __iomem *
> +devm_platform_ioremap_and_get_resource(struct platform_device *pdev,
> +				unsigned int index, struct resource **res)
> +{
> +	*res = platform_get_resource(pdev, IORESOURCE_MEM, index);
> +	return devm_ioremap_resource(&pdev->dev, *res);
> +}
> +EXPORT_SYMBOL_GPL(devm_platform_ioremap_and_get_resource);

    That looks more like devm_platform_get_and_ioremap_resource().

[...]

MBR, Sergei

Re: [PATCH v2 1/4] drivers: provide devm_platform_ioremap_and_get_resource()

[Dejin Zheng]

On Sun, Mar 15, 2020 at 01:01:14PM +0300, Sergei Shtylyov wrote:
> Hello!
> 
> On 14.03.2020 8:26, Dejin Zheng wrote:
> 
> > Since commit "drivers: provide devm_platform_ioremap_resource()",
> > It was wrap platform_get_resource() and devm_ioremap_resource() as
>   ^^ it
Ok and Thanks!

> 
> > single helper devm_platform_ioremap_resource(). but now, many drivers
> > still used platform_get_resource() and devm_ioremap_resource()
> > together in the kernel tree. The reason can not be replaced is they
> > still need use the resource variables obtained by platform_get_resource().
> > so provide this helper.
> 
>    Not really sure that's worth the effort...
>
Many drivers using platform_get_resource() and devm_ioremap_resource() together
in the kernel tree. if use this helper, have one function call less.

> > Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
> > ---
> >   drivers/base/platform.c         | 18 ++++++++++++++++++
> >   include/linux/platform_device.h |  3 +++
> >   2 files changed, 21 insertions(+)
> > 
> > diff --git a/drivers/base/platform.c b/drivers/base/platform.c
> > index 7fa654f1288b..b3e2409effae 100644
> > --- a/drivers/base/platform.c
> > +++ b/drivers/base/platform.c
> > @@ -62,6 +62,24 @@ struct resource *platform_get_resource(struct platform_device *dev,
> >   EXPORT_SYMBOL_GPL(platform_get_resource);
> >   #ifdef CONFIG_HAS_IOMEM
> > +/**
> > + * devm_platform_ioremap_and_get_resource - call devm_ioremap_resource() for a
> > + *					    platform device and get resource
> > + *
> > + * @pdev: platform device to use both for memory resource lookup as well as
> > + *        resource management
> > + * @index: resource index
> > + * @res: get the resource
> > + */
> > +void __iomem *
> > +devm_platform_ioremap_and_get_resource(struct platform_device *pdev,
> > +				unsigned int index, struct resource **res)
> > +{
> > +	*res = platform_get_resource(pdev, IORESOURCE_MEM, index);
> > +	return devm_ioremap_resource(&pdev->dev, *res);
> > +}
> > +EXPORT_SYMBOL_GPL(devm_platform_ioremap_and_get_resource);
> 
>    That looks more like devm_platform_get_and_ioremap_resource().
> 
Thanks for your suggestions. I will do it.

> [...]
> 
> MBR, Sergei

BR,
Dejin

[PATCH v2 2/4] usb: host: xhci-plat: convert to devm_platform_ioremap_and_get_resource

[Dejin Zheng]

Use devm_platform_ioremap_and_get_resource() to simplify code, which
contains platform_get_resource() and devm_ioremap_resource(), it also
get the resource for use by the following code.

Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
---
 drivers/usb/host/xhci-plat.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index d90cd5ec09cf..2852afa69ee9 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -219,8 +219,7 @@ static int xhci_plat_probe(struct platform_device *pdev)
 		goto disable_runtime;
 	}
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	hcd->regs = devm_ioremap_resource(&pdev->dev, res);
+	hcd->regs = devm_platform_ioremap_and_get_resource(pdev, 0, &res);
 	if (IS_ERR(hcd->regs)) {
 		ret = PTR_ERR(hcd->regs);
 		goto put_hcd;
-- 
2.25.0

[PATCH v2 3/4] usb: host: hisilicon: convert to devm_platform_ioremap_and_get_resource

[Dejin Zheng]

Use devm_platform_ioremap_and_get_resource() to simplify code, which
contains platform_get_resource() and devm_ioremap_resource(), it also
get the resource for use by the following code.

Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
---
 drivers/usb/host/xhci-histb.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci-histb.c b/drivers/usb/host/xhci-histb.c
index 3c4abb5a1c3f..a314139e5343 100644
--- a/drivers/usb/host/xhci-histb.c
+++ b/drivers/usb/host/xhci-histb.c
@@ -219,8 +219,7 @@ static int xhci_histb_probe(struct platform_device *pdev)
 	if (irq < 0)
 		return irq;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	histb->ctrl = devm_ioremap_resource(&pdev->dev, res);
+	histb->ctrl = devm_platform_ioremap_and_get_resource(pdev, 0, &res);
 	if (IS_ERR(histb->ctrl))
 		return PTR_ERR(histb->ctrl);
 
-- 
2.25.0

[PATCH v2 4/4] usb: dwc2: convert to devm_platform_ioremap_and_get_resource

[Dejin Zheng]

Use devm_platform_ioremap_and_get_resource() to simplify code, which
contains platform_get_resource() and devm_ioremap_resource(), it also
get the resource for use by the following code.

Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
---
 drivers/usb/dwc2/platform.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index 3c6ce09a6db5..56eec2b95eaf 100644
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -392,8 +392,7 @@ static int dwc2_driver_probe(struct platform_device *dev)
 		return retval;
 	}
 
-	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
-	hsotg->regs = devm_ioremap_resource(&dev->dev, res);
+	hsotg->regs = devm_platform_ioremap_and_get_resource(dev, 0, &res);
 	if (IS_ERR(hsotg->regs))
 		return PTR_ERR(hsotg->regs);
 
-- 
2.25.0