Re: [PATCH 1/3] soc: mtk-pm-domains: Fix the clock prepared issue

[Chun-Jie Chen <chun-jie.chen@mediatek.com>]

On Mon, 2021-05-31 at 12:35 +0800, Hsin-Yi Wang wrote:
> From: Weiyi Lu <weiyi.lu@mediatek.com>
> 
> In this new power domain driver, when adding one power domain
> it will prepare the depenedent clocks at the same.
> So we only do clk_bulk_enable/disable control during power ON/OFF.
> When system suspend, the pm runtime framework will forcely power off
> power domains. However, the dependent clocks are disabled but kept
> preapred.
> 
> In MediaTek clock drivers, PLL would be turned ON when we do
> clk_bulk_prepare control.
> 
> Clock hierarchy:
> PLL -->
>        DIV_CK -->
>                  CLK_MUX
>                  (may be dependent clocks)
>                          -->
>                              SUBSYS_CG
>                              (may be dependent clocks)
> 
> It will lead some unexpected clock states during system suspend.
> This patch will fix by doing prepare_enable/disable_unprepare on
> dependent clocks at the same time while we are going to power on/off
> any power domain.
> 
> Signed-off-by: Weiyi Lu <weiyi.lu@mediatek.com>
> Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>

Reviewed-by: chun-jie.chen <chun-jie.chen@mediatek.com>

> ---
>  drivers/soc/mediatek/mtk-pm-domains.c | 31 +++++++----------------
> ----
>  1 file changed, 8 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/soc/mediatek/mtk-pm-domains.c
> b/drivers/soc/mediatek/mtk-pm-domains.c
> index 0af00efa0ef8..536d8c64b2b4 100644
> --- a/drivers/soc/mediatek/mtk-pm-domains.c
> +++ b/drivers/soc/mediatek/mtk-pm-domains.c
> @@ -211,7 +211,7 @@ static int scpsys_power_on(struct
> generic_pm_domain *genpd)
>  	if (ret)
>  		return ret;
>  
> -	ret = clk_bulk_enable(pd->num_clks, pd->clks);
> +	ret = clk_bulk_prepare_enable(pd->num_clks, pd->clks);
>  	if (ret)
>  		goto err_reg;
>  
> @@ -229,7 +229,7 @@ static int scpsys_power_on(struct
> generic_pm_domain *genpd)
>  	regmap_clear_bits(scpsys->base, pd->data->ctl_offs,
> PWR_ISO_BIT);
>  	regmap_set_bits(scpsys->base, pd->data->ctl_offs,
> PWR_RST_B_BIT);
>  
> -	ret = clk_bulk_enable(pd->num_subsys_clks, pd->subsys_clks);
> +	ret = clk_bulk_prepare_enable(pd->num_subsys_clks, pd-
> >subsys_clks);
>  	if (ret)
>  		goto err_pwr_ack;
>  
> @@ -246,9 +246,9 @@ static int scpsys_power_on(struct
> generic_pm_domain *genpd)
>  err_disable_sram:
>  	scpsys_sram_disable(pd);
>  err_disable_subsys_clks:
> -	clk_bulk_disable(pd->num_subsys_clks, pd->subsys_clks);
> +	clk_bulk_disable_unprepare(pd->num_subsys_clks, pd-
> >subsys_clks);
>  err_pwr_ack:
> -	clk_bulk_disable(pd->num_clks, pd->clks);
> +	clk_bulk_disable_unprepare(pd->num_clks, pd->clks);
>  err_reg:
>  	scpsys_regulator_disable(pd->supply);
>  	return ret;
> @@ -269,7 +269,7 @@ static int scpsys_power_off(struct
> generic_pm_domain *genpd)
>  	if (ret < 0)
>  		return ret;
>  
> -	clk_bulk_disable(pd->num_subsys_clks, pd->subsys_clks);
> +	clk_bulk_disable_unprepare(pd->num_subsys_clks, pd-
> >subsys_clks);
>  
>  	/* subsys power off */
>  	regmap_clear_bits(scpsys->base, pd->data->ctl_offs,
> PWR_RST_B_BIT);
> @@ -284,7 +284,7 @@ static int scpsys_power_off(struct
> generic_pm_domain *genpd)
>  	if (ret < 0)
>  		return ret;
>  
> -	clk_bulk_disable(pd->num_clks, pd->clks);
> +	clk_bulk_disable_unprepare(pd->num_clks, pd->clks);
>  
>  	scpsys_regulator_disable(pd->supply);
>  
> @@ -405,14 +405,6 @@ generic_pm_domain *scpsys_add_one_domain(struct
> scpsys *scpsys, struct device_no
>  		pd->subsys_clks[i].clk = clk;
>  	}
>  
> -	ret = clk_bulk_prepare(pd->num_clks, pd->clks);
> -	if (ret)
> -		goto err_put_subsys_clocks;
> -
> -	ret = clk_bulk_prepare(pd->num_subsys_clks, pd->subsys_clks);
> -	if (ret)
> -		goto err_unprepare_clocks;
> -
>  	/*
>  	 * Initially turn on all domains to make the domains usable
>  	 * with !CONFIG_PM and to get the hardware in sync with the
> @@ -427,7 +419,7 @@ generic_pm_domain *scpsys_add_one_domain(struct
> scpsys *scpsys, struct device_no
>  		ret = scpsys_power_on(&pd->genpd);
>  		if (ret < 0) {
>  			dev_err(scpsys->dev, "%pOF: failed to power on
> domain: %d\n", node, ret);
> -			goto err_unprepare_clocks;
> +			goto err_put_subsys_clocks;
>  		}
>  	}
>  
> @@ -435,7 +427,7 @@ generic_pm_domain *scpsys_add_one_domain(struct
> scpsys *scpsys, struct device_no
>  		ret = -EINVAL;
>  		dev_err(scpsys->dev,
>  			"power domain with id %d already exists, check
> your device-tree\n", id);
> -		goto err_unprepare_subsys_clocks;
> +		goto err_put_subsys_clocks;
>  	}
>  
>  	if (!pd->data->name)
> @@ -455,10 +447,6 @@ generic_pm_domain *scpsys_add_one_domain(struct
> scpsys *scpsys, struct device_no
>  
>  	return scpsys->pd_data.domains[id];
>  
> -err_unprepare_subsys_clocks:
> -	clk_bulk_unprepare(pd->num_subsys_clks, pd->subsys_clks);
> -err_unprepare_clocks:
> -	clk_bulk_unprepare(pd->num_clks, pd->clks);
>  err_put_subsys_clocks:
>  	clk_bulk_put(pd->num_subsys_clks, pd->subsys_clks);
>  err_put_clocks:
> @@ -537,10 +525,7 @@ static void scpsys_remove_one_domain(struct
> scpsys_domain *pd)
>  			"failed to remove domain '%s' : %d - state may
> be inconsistent\n",
>  			pd->genpd.name, ret);
>  
> -	clk_bulk_unprepare(pd->num_clks, pd->clks);
>  	clk_bulk_put(pd->num_clks, pd->clks);
> -
> -	clk_bulk_unprepare(pd->num_subsys_clks, pd->subsys_clks);
>  	clk_bulk_put(pd->num_subsys_clks, pd->subsys_clks);
>  }
>