Re: [PATCH v13 06/11] soc: mediatek: Add subsys clock control for bus protection

Weiyi Lu
2020-05-06T07:53:11Z

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@mediatek.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@mediatek.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
> > _______________________________________________
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> > http://lists.infradead.org/mailman/listinfo/linux-mediatek
>
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