linux-kernel - Re: [PATCH v2, 14/17] soc: mediatek: mmsys: Use function call for setting mmsys ovl mout register

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Message-ID: <1608687676.18252.11.camel@mhfsdcap03>
Date:   Wed, 23 Dec 2020 09:41:16 +0800
From:   Yongqiang Niu <yongqiang.niu@...iatek.com>
To:     Nicolas Boichat <drinkcat@...omium.org>
CC:     CK Hu <ck.hu@...iatek.com>, Philipp Zabel <p.zabel@...gutronix.de>,
        "Rob Herring" <robh+dt@...nel.org>,
        Matthias Brugger <matthias.bgg@...il.com>,
        Mark Rutland <mark.rutland@....com>,
        Devicetree List <devicetree@...r.kernel.org>,
        David Airlie <airlied@...ux.ie>,
        lkml <linux-kernel@...r.kernel.org>,
        dri-devel <dri-devel@...ts.freedesktop.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@...ts.infradead.org>,
        Daniel Vetter <daniel@...ll.ch>,
        linux-arm Mailing List <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH v2, 14/17] soc: mediatek: mmsys: Use function call for
 setting mmsys ovl mout register

On Tue, 2020-12-15 at 21:42 +0800, Nicolas Boichat wrote:
> On Sat, Dec 12, 2020 at 12:13 PM Yongqiang Niu
> <yongqiang.niu@...iatek.com> wrote:
> >
> > Use function call for setting mmsys ovl mout register
> >
> > Signed-off-by: Yongqiang Niu <yongqiang.niu@...iatek.com>
> > ---
> >  drivers/soc/mediatek/mmsys/mtk-mmsys.c | 18 ++++++++++++++++++
> >  include/linux/soc/mediatek/mtk-mmsys.h |  3 +++
> >  2 files changed, 21 insertions(+)
> >
> > diff --git a/drivers/soc/mediatek/mmsys/mtk-mmsys.c b/drivers/soc/mediatek/mmsys/mtk-mmsys.c
> > index cb76e64..2558b42 100644
> > --- a/drivers/soc/mediatek/mmsys/mtk-mmsys.c
> > +++ b/drivers/soc/mediatek/mmsys/mtk-mmsys.c
> > @@ -78,6 +78,15 @@ void mtk_mmsys_ddp_connect(struct device *dev,
> >                 reg = readl_relaxed(mmsys->regs + addr) | value;
> >                 writel_relaxed(reg, mmsys->regs + addr);
> >         }
> > +
> > +       if (!funcs->ovl_mout_en)
> > +               return;
> > +
> > +       value = funcs->ovl_mout_en(cur, next, &addr);
> > +       if (value) {
> > +               reg = readl_relaxed(mmsys->regs + addr) | value;
> > +               writel_relaxed(reg, mmsys->regs + addr);
> > +       }
> 
> This is technically correct, but I'm afraid this may become and issue
> later if we have another function like ovl_mout_en.
> 
> So maybe it's better to do:
> if (funcs->ovl_mout_en) {
>   value = funcs->ovl_mout_en(cur, next, &addr);
>   ...
> }

will be improved like this in next version
> 
> Or another option: Create a new function
> static unsigned int mtk_mmsys_ovl_mout_en(...) {
>    if (!funcs->ovl_mout_en)
>       return 0;
> }
> 
> and call that, following the same pattern as
> mtk_mmsys_ddp_mout_en/mtk_mmsys_ddp_sel_in?
> 
> >  }
> >  EXPORT_SYMBOL_GPL(mtk_mmsys_ddp_connect);
> >
> > @@ -103,6 +112,15 @@ void mtk_mmsys_ddp_disconnect(struct device *dev,
> >                 reg = readl_relaxed(mmsys->regs + addr) & ~value;
> >                 writel_relaxed(reg, mmsys->regs + addr);
> >         }
> > +
> > +       if (!funcs->ovl_mout_en)
> > +               return;
> > +
> > +       value = funcs->ovl_mout_en(cur, next, &addr);
> > +       if (value) {
> > +               reg = readl_relaxed(mmsys->regs + addr) & ~value;
> > +               writel_relaxed(reg, mmsys->regs + addr);
> > +       }
> >  }
> >  EXPORT_SYMBOL_GPL(mtk_mmsys_ddp_disconnect);
> >
> > diff --git a/include/linux/soc/mediatek/mtk-mmsys.h b/include/linux/soc/mediatek/mtk-mmsys.h
> > index aa4f60e..220203d 100644
> > --- a/include/linux/soc/mediatek/mtk-mmsys.h
> > +++ b/include/linux/soc/mediatek/mtk-mmsys.h
> > @@ -49,6 +49,9 @@ struct mtk_mmsys_conn_funcs {
> >         u32 (*mout_en)(enum mtk_ddp_comp_id cur,
> >                        enum mtk_ddp_comp_id next,
> >                        unsigned int *addr);
> > +       u32 (*ovl_mout_en)(enum mtk_ddp_comp_id cur,
> > +                          enum mtk_ddp_comp_id next,
> > +                          unsigned int *addr);
> >         u32 (*sel_in)(enum mtk_ddp_comp_id cur,
> >                       enum mtk_ddp_comp_id next,
> >                       unsigned int *addr);
> > --
> > 1.8.1.1.dirty
> > _______________________________________________
> > Linux-mediatek mailing list
> > Linux-mediatek@...ts.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-mediatek

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