Re: [PATCH 01/18] phy: mediatek: add a new helper to update bitfield

[AngeloGioacchino Del Regno]

Il 22/09/22 04:36, Chunfeng Yun ha scritto:
> On Wed, 2022-09-21 at 10:15 +0200, AngeloGioacchino Del Regno wrote:
> > Il 20/09/22 11:00, Chunfeng Yun ha scritto:
> > > Due to FIELD_PREP() macro can be used to prepare a bitfield value,
> > > local ones can be remove; add the new helper to make bitfield
> > > update
> > > easier.
> > >
> > > Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
> > > ---
> > >    drivers/phy/mediatek/phy-mtk-io.h | 7 +++++++
> > >    1 file changed, 7 insertions(+)
> > >
> > > diff --git a/drivers/phy/mediatek/phy-mtk-io.h
> > > b/drivers/phy/mediatek/phy-mtk-io.h
> > > index 500fcdab165d..a723d4afc9b4 100644
> > > --- a/drivers/phy/mediatek/phy-mtk-io.h
> > > +++ b/drivers/phy/mediatek/phy-mtk-io.h
> > > @@ -8,6 +8,7 @@
> > >    #ifndef __PHY_MTK_H__
> > >    #define __PHY_MTK_H__
> > >    
> > > +#include <linux/bitfield.h>
> > >    #include <linux/io.h>
> > >    
> > >    static inline void mtk_phy_clear_bits(void __iomem *reg, u32
> > > bits)
> > > @@ -35,4 +36,10 @@ static inline void mtk_phy_update_bits(void
> > > __iomem *reg, u32 mask, u32 val)
> > >    	writel(tmp, reg);
> > >    }
> > >    
> > > +/* field @mask should be constant and continuous */
> >
> > "Field @mask shall be [...]"
> >                ^^^^^
> Ok, will modify it
>
> > > +static inline void mtk_phy_update_field(void __iomem *reg, u32
> > > mask, u32 val)
> >
> > ...so, (void __iomem *reg, const u32 mask, u32 val)
> Maybe no need const, @mask will be checked it in compile time when
> use FIELD_PREP(), means @mask is a constant value, but not a variable.

Adding const is not *required*, but `mask` is, effectively, a constant, hence
it fully makes sense to add const.

> Thanks
>
> > > +{
> > > +	mtk_phy_update_bits(reg, mask, FIELD_PREP(mask, val));
> > > +}
> > > +
> > >    #endif