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

AngeloGioacchino Del Regno
2022-09-22T07:18:59Z

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@mediatek.com>
>>> ---
>>> 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
>>
>>
>