Hi Greg, On Tue, Mar 17, 2020 at 8:20 PM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > On Sun, Mar 15, 2020 at 10:05:21PM +0800, Dejin Zheng 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. > > > > Suggested-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> > > Suggested-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx> > > Signed-off-by: Dejin Zheng <zhengdejin5@xxxxxxxxx> > > --- > > v2 -> v3: > > - rename the function to > > devm_platform_get_and_ioremap_resource() by Sergei's suggestion. > > - make the last parameter res as optional by Geert's suggestion. > > > > v1 -> v2: > > - No change. > > > > drivers/base/platform.c | 22 ++++++++++++++++++++++ > > include/linux/platform_device.h | 3 +++ > > 2 files changed, 25 insertions(+) > > > > diff --git a/drivers/base/platform.c b/drivers/base/platform.c > > index 7fa654f1288b..9f6a78f79235 100644 > > --- a/drivers/base/platform.c > > +++ b/drivers/base/platform.c > > @@ -62,6 +62,28 @@ struct resource *platform_get_resource(struct platform_device *dev, > > EXPORT_SYMBOL_GPL(platform_get_resource); > > > > #ifdef CONFIG_HAS_IOMEM > > +/** > > + * devm_platform_get_and_ioremap_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_get_and_ioremap_resource(struct platform_device *pdev, > > + unsigned int index, struct resource **res) > > +{ > > + struct resource *r; > > + > > + r = platform_get_resource(pdev, IORESOURCE_MEM, index); > > + if (res) > > + *res = r; > > What happens if that call fails? Shouldn't that be checked? Then devm_ioremap_resource() will print an error message, and return an error. It's designed to be pipelined that way, so you have to check for an error only once. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx 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