Re: [PATCH v15 06/11] soc: mediatek: Add subsys clock control for bus protection

[Weiyi Lu <weiyi.lu@mediatek.com>]

On Thu, 2020-06-04 at 10:29 +0800, Nicolas Boichat wrote:
> On Thu, May 21, 2020 at 5:06 PM Weiyi Lu <weiyi.lu@mediatek.com> wrote:
> >
> > For the bus protection operations, some subsys clocks need to be enabled
> > before releasing the protection, and vice versa.
> > But those subsys clocks could only be controlled once its corresponding
> > power domain is turned on first.
> > In this patch, we add the subsys clock control into its relevant steps.
> >
> > Signed-off-by: Weiyi Lu <weiyi.lu@mediatek.com>
> > ---
> >  drivers/soc/mediatek/mtk-scpsys.c | 62 +++++++++++++++++++++++++++++++++++++--
> >  1 file changed, 60 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/soc/mediatek/mtk-scpsys.c b/drivers/soc/mediatek/mtk-scpsys.c
> > index 59a525a..ef2c668 100644
> > --- a/drivers/soc/mediatek/mtk-scpsys.c
> > +++ b/drivers/soc/mediatek/mtk-scpsys.c
> > [snip]
> >         val |= PWR_ISO_BIT;
> > @@ -498,6 +511,39 @@ static int scpsys_power_off(struct generic_pm_domain *genpd)
> >         return ret;
> >  }
> >
> > +static int init_subsys_clks(struct platform_device *pdev,
> > +               const char *prefix, struct clk **clk)
> > +{
> > +       struct device_node *node = pdev->dev.of_node;
> > +       u32 prefix_len, sub_clk_cnt = 0;
> > +       struct property *prop;
> > +       const char *clk_name;
> > +
> > +       prefix_len = strlen(prefix);
> > +
> > +       of_property_for_each_string(node, "clock-names", prop, clk_name) {
> > +               if (!strncmp(clk_name, prefix, prefix_len) &&
> > +                               (clk_name[prefix_len] == '-')) {
> > +                       if (sub_clk_cnt >= MAX_SUBSYS_CLKS) {
> > +                               dev_err(&pdev->dev,
> > +                                       "subsys clk out of range %d\n",
> > +                                       sub_clk_cnt);
> > +                               return -EINVAL;
> > +                       }
> > +
> > +                       clk[sub_clk_cnt] = devm_clk_get(&pdev->dev,
> > +                                               clk_name);
> > +
> > +                       if (IS_ERR(clk[sub_clk_cnt]))
> > +                               return PTR_ERR(clk[sub_clk_cnt]);
> > +
> > +                       sub_clk_cnt++;
> > +               }
> > +       }
> > +
> > +       return sub_clk_cnt;
> > +}
> > +
> >  static int init_basic_clks(struct platform_device *pdev, struct clk **clk,
> >                         const char * const *name)
> >  {
> > @@ -596,6 +642,18 @@ static struct scp *init_scp(struct platform_device *pdev,
> >                 if (ret)
> >                         return ERR_PTR(ret);
> >
> > +               if (data->subsys_clk_prefix) {
> > +                       ret = init_subsys_clks(pdev,
> > +                                       data->subsys_clk_prefix,
> > +                                       scpd->subsys_clk);
> > +                       if (ret < 0) {
> > +                               dev_err(&pdev->dev,
> > +                                       "%s: subsys clk unavailable\n",
> > +                                       data->name);
> 
> init_subsys_clks should already have printed an error (directly or
> indirectly), so this is not needed.
> 

You're right. I'll remove it in next version v16.

> > +                               return ERR_PTR(ret);
> > +                       }
> > +               }
> > +
> >                 genpd->name = data->name;
> >                 genpd->power_off = scpsys_power_off;
> >                 genpd->power_on = scpsys_power_on;
> > --
> > 1.8.1.1.dirty

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