Re: [PATCH v3 20/21] pmdomain: mediatek: Add bus protect control flow for MT8189

Irving-CH Lin (林建弘)
2025-12-10T10:45:43Z

Hi Angelo,

On Fri, 2025-11-07 at 11:36 +0100, AngeloGioacchino Del Regno wrote:
>
> External email : Please do not click links or open attachments until
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>
> Il 06/11/25 13:42, irving.ch.lin ha scritto:
> > From: Irving-CH Lin <irving-ch.lin@mediatek.com>
> >
> > In MT8189 mminfra power domain, the bus protect policy separates
> > into two parts, one is set before subsys clocks enabled, and
> > another
> > need to enable after subsys clocks enable.
> >
> > Signed-off-by: Irving-CH Lin <irving-ch.lin@mediatek.com>
> > ---
> >   drivers/pmdomain/mediatek/mtk-pm-domains.c | 31
> > ++++++++++++++++++----
> >   drivers/pmdomain/mediatek/mtk-pm-domains.h |  5 ++++
> >   2 files changed, 31 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/pmdomain/mediatek/mtk-pm-domains.c
> > b/drivers/pmdomain/mediatek/mtk-pm-domains.c
> > index 164c6b519af3..222846e52daf 100644
> > --- a/drivers/pmdomain/mediatek/mtk-pm-domains.c
> > +++ b/drivers/pmdomain/mediatek/mtk-pm-domains.c
> > @@ -250,7 +250,7 @@ static int scpsys_bus_protect_set(struct
> > scpsys_domain *pd,
> >                                       MTK_POLL_DELAY_US,
> > MTK_POLL_TIMEOUT);
> >   }
> >
> > -static int scpsys_bus_protect_enable(struct scpsys_domain *pd)
> > +static int scpsys_bus_protect_enable(struct scpsys_domain *pd, u8
> > flags)
> >   {
> >       for (int i = 0; i < SPM_MAX_BUS_PROT_DATA; i++) {
> >               const struct scpsys_bus_prot_data *bpd = &pd->data-
> > >bp_cfg[i];
> > @@ -259,6 +259,10 @@ static int scpsys_bus_protect_enable(struct
> > scpsys_domain *pd)
> >               if (!bpd->bus_prot_set_clr_mask)
> >                       break;
> >
> > +             if ((bpd->flags & BUS_PROT_IGNORE_SUBCLK) !=
> > +                 (flags & BUS_PROT_IGNORE_SUBCLK))
> > +                     continue;
> > +
> >               if (bpd->flags & BUS_PROT_INVERTED)
> >                       ret = scpsys_bus_protect_clear(pd, bpd);
> >               else
> > @@ -270,7 +274,7 @@ static int scpsys_bus_protect_enable(struct
> > scpsys_domain *pd)
> >       return 0;
> >   }
> >
> > -static int scpsys_bus_protect_disable(struct scpsys_domain *pd)
> > +static int scpsys_bus_protect_disable(struct scpsys_domain *pd, u8
> > flags)
> >   {
> >       for (int i = SPM_MAX_BUS_PROT_DATA - 1; i >= 0; i--) {
> >               const struct scpsys_bus_prot_data *bpd = &pd->data-
> > >bp_cfg[i];
> > @@ -279,6 +283,10 @@ static int scpsys_bus_protect_disable(struct
> > scpsys_domain *pd)
> >               if (!bpd->bus_prot_set_clr_mask)
> >                       continue;
> >
> > +             if ((bpd->flags & BUS_PROT_IGNORE_SUBCLK) !=
>
> Is that the right name for this flag?
>
> As far as I understand, you have to set bus protection in two steps,
> right?
> So in the first step you're setting bus protection for the MM_INFRA
> and for
> MM_INFRA_2ND - and in the second step you're setting MM_INFRA_IGN and
> 2_IGN.
>
> So the first step (the prots with BUS_PROT_IGNORE_SUBCLK) unlocks
> SUBSYS clks
> and SRAM ISO access, the second one does the rest.
>
> I think that a better name for this, at this point would be...
>
> if ((bpd->flags & local_flags) & BUS_PROT_SRAM_PROTECTION)
>         continue;
>
> What do you think?
>
> Regards,
> Angelo
>
Yes, the purpose is to set bus with two steps:
In general case, bus protection needs to control after subsys clock
enabled. But on MT8189 MM_INFRA subsys, some bus protection set before
subsys clock enabled.

So here i name bus protection setting w/o subsys clock as
IGNORE_SUBCLK.

thanks

BR,
irving

> > +                 (flags & BUS_PROT_IGNORE_SUBCLK))
> > +                     continue;
> > +
> >               if (bpd->flags & BUS_PROT_INVERTED)
> >                       ret = scpsys_bus_protect_set(pd, bpd);
> >               else
> > @@ -632,6 +640,15 @@ static int scpsys_power_on(struct
> > generic_pm_domain *genpd)
> >       if (ret)
> >               goto err_pwr_ack;
> >
> > +     /*
> > +      * In MT8189 mminfra power domain, the bus protect policy
> > separates
> > +      * into two parts, one is set before subsys clocks enabled,
> > and another
> > +      * need to enable after subsys clocks enable.
> > +      */
> > +     ret = scpsys_bus_protect_disable(pd, BUS_PROT_IGNORE_SUBCLK);
> > +     if (ret < 0)
> > +             goto err_pwr_ack;
> > +
> >       /*
> >        * In few Mediatek platforms(e.g. MT6779), the bus protect
> > policy is
> >        * stricter, which leads to bus protect release must be prior
> > to bus
> > @@ -648,7 +665,7 @@ static int scpsys_power_on(struct
> > generic_pm_domain *genpd)
> >       if (ret < 0)
> >               goto err_disable_subsys_clks;
> >
> > -     ret = scpsys_bus_protect_disable(pd);
> > +     ret = scpsys_bus_protect_disable(pd, 0);
> >       if (ret < 0)
> >               goto err_disable_sram;
> >
> > @@ -662,7 +679,7 @@ static int scpsys_power_on(struct
> > generic_pm_domain *genpd)
> >       return 0;
> >
> >   err_enable_bus_protect:
> > -     scpsys_bus_protect_enable(pd);
> > +     scpsys_bus_protect_enable(pd, 0);
> >   err_disable_sram:
> >       scpsys_sram_disable(pd);
> >   err_disable_subsys_clks:
> > @@ -683,7 +700,7 @@ static int scpsys_power_off(struct
> > generic_pm_domain *genpd)
> >       bool tmp;
> >       int ret;
> >
> > -     ret = scpsys_bus_protect_enable(pd);
> > +     ret = scpsys_bus_protect_enable(pd, 0);
> >       if (ret < 0)
> >               return ret;
> >
> > @@ -697,6 +714,10 @@ static int scpsys_power_off(struct
> > generic_pm_domain *genpd)
> >
> >       clk_bulk_disable_unprepare(pd->num_subsys_clks, pd-
> > >subsys_clks);
> >
> > +     ret = scpsys_bus_protect_enable(pd, BUS_PROT_IGNORE_SUBCLK);
> > +     if (ret < 0)
> > +             return ret;
> > +
> >       if (MTK_SCPD_CAPS(pd, MTK_SCPD_MODEM_PWRSEQ))
> >               scpsys_modem_pwrseq_off(pd);
> >       else
> > diff --git a/drivers/pmdomain/mediatek/mtk-pm-domains.h
> > b/drivers/pmdomain/mediatek/mtk-pm-domains.h
> > index f608e6ec4744..a5dca24cbc2f 100644
> > --- a/drivers/pmdomain/mediatek/mtk-pm-domains.h
> > +++ b/drivers/pmdomain/mediatek/mtk-pm-domains.h
> > @@ -56,6 +56,7 @@ enum scpsys_bus_prot_flags {
> >       BUS_PROT_REG_UPDATE = BIT(1),
> >       BUS_PROT_IGNORE_CLR_ACK = BIT(2),
> >       BUS_PROT_INVERTED = BIT(3),
> > +     BUS_PROT_IGNORE_SUBCLK = BIT(4),
> >   };
> >
> >   enum scpsys_bus_prot_block {
> > @@ -95,6 +96,10 @@ enum scpsys_bus_prot_block {
> >               _BUS_PROT(_hwip, _mask, _set, _clr, _mask,
> > _sta,        \
> >                         BUS_PROT_REG_UPDATE)
> >
> > +#define BUS_PROT_WR_IGN_SUBCLK(_hwip, _mask, _set, _clr,
> > _sta)               \
> > +             _BUS_PROT(_hwip, _mask, _set, _clr, _mask,
> > _sta,        \
> > +                       BUS_PROT_IGNORE_CLR_ACK |
> > BUS_PROT_IGNORE_SUBCLK)
> > +
> >   #define BUS_PROT_INFRA_UPDATE_TOPAXI(_mask)                 \
> >               BUS_PROT_UPDATE(INFRA, _mask,                   \
> >                               INFRA_TOPAXI_PROTECTEN,         \
>
>