Date:   Wed, 6 May 2020 15:42:26 +0800
From:   Weiyi Lu <weiyi.lu@...iatek.com>
To:     Enric Balletbo Serra <eballetbo@...il.com>
CC:     Rob Herring <robh@...nel.org>,
        Nicolas Boichat <drinkcat@...omium.org>,
        srv_heupstream <srv_heupstream@...iatek.com>,
        JamesJJ Liao (廖建智) 
        <jamesjj.liao@...iatek.com>,
        linux-kernel <linux-kernel@...r.kernel.org>,
        Fan Chen (陳凡) 
        <fan.chen@...iatek.com>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@...ts.infradead.org>,
        "Sascha Hauer" <kernel@...gutronix.de>,
        Matthias Brugger <matthias.bgg@...il.com>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH v13 06/11] soc: mediatek: Add subsys clock control for
 bus protection


On Fri, 2020-04-24 at 02:19 +0800, Enric Balletbo Serra wrote:
> Hi Weiyi Lu,
> 
> Thank you for the patch.
> 
> Missatge de Weiyi Lu <weiyi.lu@...iatek.com> del dia dv., 20 de març
> 2020 a les 8:33:
> >
> > For the bus protection operations, some subsys clocks need to be enabled
> > before releasing the protection, and vise versa.
> 
> typo s/vise/vice/

Thanks, I'll fix it.

> 
> > 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 relavent steps.
> 
> typo s/relavent/relevant/
> 

Thanks, I'll fix it.

> >
> > Signed-off-by: Weiyi Lu <weiyi.lu@...iatek.com>
> > ---
> >  drivers/soc/mediatek/mtk-scpsys.c | 71 +++++++++++++++++++++++++++++++++++++--
> >  1 file changed, 69 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/soc/mediatek/mtk-scpsys.c b/drivers/soc/mediatek/mtk-scpsys.c
> > index a4fb0b23..2a9478f 100644
> > --- a/drivers/soc/mediatek/mtk-scpsys.c
> > +++ b/drivers/soc/mediatek/mtk-scpsys.c
> > @@ -80,6 +80,7 @@
> >  #define PWR_STATUS_WB                  BIT(27) /* MT7622 */
> >
> >  #define MAX_CLKS       3
> > +#define MAX_SUBSYS_CLKS 10
> >
> >  /**
> >   * struct scp_domain_data - scp domain data for power on/off flow
> > @@ -89,6 +90,8 @@
> >   * @sram_pdn_bits: The mask for sram power control bits.
> >   * @sram_pdn_ack_bits: The mask for sram power control acked bits.
> >   * @basic_clk_name: The basic clocks required by this power domain.
> > + * @subsys_clk_prefix: The prefix name of the clocks need to be enabled
> > + *                     before releasing bus protection.
> >   * @caps: The flag for active wake-up action.
> >   * @bp_table: The mask table for multiple step bus protection.
> >   */
> > @@ -99,6 +102,7 @@ struct scp_domain_data {
> >         u32 sram_pdn_bits;
> >         u32 sram_pdn_ack_bits;
> >         const char *basic_clk_name[MAX_CLKS];
> > +       const char *subsys_clk_prefix;
> >         u8 caps;
> >         struct bus_prot bp_table[MAX_STEPS];
> >  };
> > @@ -109,6 +113,7 @@ struct scp_domain {
> >         struct generic_pm_domain genpd;
> >         struct scp *scp;
> >         struct clk *clk[MAX_CLKS];
> > +       struct clk *subsys_clk[MAX_SUBSYS_CLKS];
> >         const struct scp_domain_data *data;
> >         struct regulator *supply;
> >  };
> > @@ -384,16 +389,22 @@ static int scpsys_power_on(struct generic_pm_domain *genpd)
> >         val |= PWR_RST_B_BIT;
> >         writel(val, ctl_addr);
> >
> > -       ret = scpsys_sram_enable(scpd, ctl_addr);
> > +       ret = scpsys_clk_enable(scpd->subsys_clk, MAX_SUBSYS_CLKS);
> >         if (ret < 0)
> >                 goto err_pwr_ack;
> >
> > +       ret = scpsys_sram_enable(scpd, ctl_addr);
> > +       if (ret < 0)
> > +               goto err_sram;
> > +
> >         ret = scpsys_bus_protect_disable(scpd);
> >         if (ret < 0)
> > -               goto err_pwr_ack;
> > +               goto err_sram;
> >
> >         return 0;
> >
> > +err_sram:
> > +       scpsys_clk_disable(scpd->subsys_clk, MAX_SUBSYS_CLKS);
> >  err_pwr_ack:
> >         scpsys_clk_disable(scpd->clk, MAX_CLKS);
> >  err_clk:
> > @@ -420,6 +431,8 @@ static int scpsys_power_off(struct generic_pm_domain *genpd)
> >         if (ret < 0)
> >                 goto out;
> >
> > +       scpsys_clk_disable(scpd->subsys_clk, MAX_SUBSYS_CLKS);
> > +
> >         /* subsys power off */
> >         val = readl(ctl_addr);
> >         val |= PWR_ISO_BIT;
> > @@ -457,6 +470,48 @@ 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;
> > +
> > +       if (!node) {
> 
> Is this possible? I suspect you can remove this check.
> 

You're right. It never happens, I'll remove it.

> > +               dev_err(&pdev->dev, "Cannot find scpsys node: %ld\n",
> > +                       PTR_ERR(node));
> > +               return PTR_ERR(node);
> > +       }
> > +
> > +       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])) {
> > +                               dev_err(&pdev->dev,
> > +                                       "Subsys clk get fail %ld\n",
> > +                                       PTR_ERR(clk[sub_clk_cnt]));
> 
> This dev_err is redundant, devm_clk_get already prints it if the clock
> is not found.
> 

Got it.

> > +                               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)
> >  {
> > @@ -559,6 +614,18 @@ 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);
> 
> And this print is also redundant.
> 

Got it.
> 
> > +                               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
> > _______________________________________________
> > Linux-mediatek mailing list
> > Linux-mediatek@...ts.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-mediatek
> 
> _______________________________________________
> Linux-mediatek mailing list
> Linux-mediatek@...ts.infradead.org
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