Re: [PATCH 08/12] soc: mediatek: pm-domains: Add subsystem clocks

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

On Thu, 2020-09-10 at 19:28 +0200, Enric Balletbo i Serra wrote:
> From: Matthias Brugger <mbrugger@suse.com>
> 
> For the bus protection operations, some subsystem clocks need to be enabled
> before releasing the protection. This patch identifies the subsystem clocks
> by it's name.
> 
> Suggested-by: Weiyi Lu <weiyi.lu@mediatek.com>
> [Adapted the patch to the mtk-pm-domains driver]
> Signed-off-by: Matthias Brugger <mbrugger@suse.com>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> ---
> 
>  drivers/soc/mediatek/mtk-pm-domains.c | 82 +++++++++++++++++++++++----
>  1 file changed, 70 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/soc/mediatek/mtk-pm-domains.c b/drivers/soc/mediatek/mtk-pm-domains.c
> index 0802eccc3a0b..52a93a87e313 100644
> --- a/drivers/soc/mediatek/mtk-pm-domains.c
> +++ b/drivers/soc/mediatek/mtk-pm-domains.c
> @@ -3,6 +3,7 @@
>   * Copyright (c) 2020 Collabora Ltd.
>   */
>  #include <linux/clk.h>
> +#include <linux/clk-provider.h>
>  #include <linux/init.h>
>  #include <linux/io.h>
>  #include <linux/iopoll.h>
> @@ -81,6 +82,8 @@ struct scpsys_bus_prot_data {
>  	bool bus_prot_reg_update;
>  };
>  
> +#define MAX_SUBSYS_CLKS 10
> +
>  /**
>   * struct scpsys_domain_data - scp domain data for power on/off flow
>   * @sta_mask: The mask for power on/off status bit.
> @@ -107,6 +110,8 @@ struct scpsys_domain {
>  	struct scpsys *scpsys;
>  	int num_clks;
>  	struct clk_bulk_data *clks;
> +	int num_subsys_clks;
> +	struct clk_bulk_data *subsys_clks;
>  	struct regmap *infracfg;
>  	struct regmap *smi;
>  };
> @@ -309,16 +314,22 @@ static int scpsys_power_on(struct generic_pm_domain *genpd)
>  	val |= PWR_RST_B_BIT;
>  	writel(val, ctl_addr);
>  
> +	ret = clk_bulk_enable(pd->num_subsys_clks, pd->subsys_clks);
> +	if (ret)
> +		goto err_pwr_ack;
> +
>  	ret = scpsys_sram_enable(pd, ctl_addr);
>  	if (ret < 0)
> -		goto err_pwr_ack;
> +		goto err_sram;
>  
>  	ret = scpsys_bus_protect_disable(pd);
>  	if (ret < 0)
> -		goto err_pwr_ack;
> +		goto err_sram;
>  
>  	return 0;
>  
> +err_sram:
> +	clk_bulk_disable(pd->num_subsys_clks, pd->subsys_clks);
>  err_pwr_ack:
>  	clk_bulk_disable(pd->num_clks, pd->clks);
>  	dev_err(scpsys->dev, "Failed to power on domain %s\n", genpd->name);
> @@ -342,6 +353,8 @@ 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);
> +
>  	/* subsys power off */
>  	val = readl(ctl_addr);
>  	val |= PWR_ISO_BIT;
> @@ -374,8 +387,11 @@ static int scpsys_add_one_domain(struct scpsys *scpsys, struct device_node *node
>  {
>  	const struct scpsys_domain_data *domain_data;
>  	struct scpsys_domain *pd;
> -	int i, ret;
> +	int i, ret, num_clks;
>  	u32 id;
> +	int clk_ind = 0;
> +	struct property *prop;
> +	const char *clk_name;
>  
>  	ret = of_property_read_u32(node, "reg", &id);
>  	if (ret) {
> @@ -410,28 +426,60 @@ static int scpsys_add_one_domain(struct scpsys *scpsys, struct device_node *node
>  	if (IS_ERR(pd->smi))
>  		pd->smi = NULL;
>  
> -	pd->num_clks = of_clk_get_parent_count(node);
> -	if (pd->num_clks > 0) {
> +	num_clks = of_clk_get_parent_count(node);
> +	if (num_clks > 0) {
> +		/* Calculate number of subsys_clks */
> +		of_property_for_each_string(node, "clock-names", prop, clk_name) {
> +			char *subsys;
> +
> +			subsys = strchr(clk_name, '-');
> +			if (subsys)
> +				pd->num_subsys_clks++;
> +			else
> +				pd->num_clks++;
> +		}
> +

In fact, I don't like the clock naming rules, as Matthias mentioned
before. So in my work v17[1]
I put subsystem clocks under each power domain sub-node without giving
the clock name but put the basic clocks under the power controller node.

[1] https://patchwork.kernel.org/patch/11703191/


>  		pd->clks = devm_kcalloc(scpsys->dev, pd->num_clks, sizeof(*pd->clks), GFP_KERNEL);
>  		if (!pd->clks)
>  			return -ENOMEM;
> -	} else {
> -		pd->num_clks = 0;
> +
> +		pd->subsys_clks = devm_kcalloc(scpsys->dev, pd->num_subsys_clks,
> +					       sizeof(*pd->subsys_clks), GFP_KERNEL);
> +		if (!pd->subsys_clks)
> +			return -ENOMEM;
>  	}
>  
>  	for (i = 0; i < pd->num_clks; i++) {
> -		pd->clks[i].clk = of_clk_get(node, i);
> -		if (IS_ERR(pd->clks[i].clk)) {
> -			ret = PTR_ERR(pd->clks[i].clk);
> +		struct clk *clk = of_clk_get(node, i);
> +		if (IS_ERR(clk)) {
> +			ret = PTR_ERR(clk);
>  			dev_err(scpsys->dev, "%pOFn: failed to get clk at index %d: %d\n", node, i,
>  				ret);
> -			return ret;
> +			goto err_put_clocks;
> +		}
> +
> +		pd->clks[clk_ind++].clk = clk;
> +	}
> +
> +	for (i = 0; i < pd->num_subsys_clks; i++) {
> +		struct clk *clk = of_clk_get(node, i + clk_ind);
> +		if (IS_ERR(clk)) {
> +			ret = PTR_ERR(clk);
> +			dev_err(scpsys->dev, "%pOFn: failed to get clk at index %d: %d\n", node,
> +				i + clk_ind, ret);
> +			goto err_put_subsys_clocks;
>  		}
> +
> +		pd->subsys_clks[i].clk = clk;
>  	}
>  
> +	ret = clk_bulk_prepare(pd->num_subsys_clks, pd->subsys_clks);
> +	if (ret)
> +		goto err_put_subsys_clocks;
> +
>  	ret = clk_bulk_prepare(pd->num_clks, pd->clks);
>  	if (ret)
> -		goto err_put_clocks;
> +		goto err_unprepare_subsys_clocks;
>  
>  	/*
>  	 * Initially turn on all domains to make the domains usable
> @@ -456,6 +504,12 @@ static int scpsys_add_one_domain(struct scpsys *scpsys, struct device_node *node
>  
>  err_unprepare_clocks:
>  	clk_bulk_unprepare(pd->num_clks, pd->clks);
> +err_unprepare_subsys_clocks:
> +	clk_bulk_unprepare(pd->num_subsys_clks, pd->subsys_clks);
> +err_put_subsys_clocks:
> +	clk_bulk_put(pd->num_subsys_clks, pd->subsys_clks);
> +	devm_kfree(scpsys->dev, pd->subsys_clks);
> +	pd->num_subsys_clks = 0;
>  err_put_clocks:
>  	clk_bulk_put(pd->num_clks, pd->clks);
>  	devm_kfree(scpsys->dev, pd->clks);
> @@ -537,6 +591,10 @@ static void scpsys_remove_one_domain(struct scpsys_domain *pd)
>  	clk_bulk_unprepare(pd->num_clks, pd->clks);
>  	clk_bulk_put(pd->num_clks, pd->clks);
>  	pd->num_clks = 0;
> +
> +	clk_bulk_unprepare(pd->num_subsys_clks, pd->subsys_clks);
> +	clk_bulk_put(pd->num_subsys_clks, pd->subsys_clks);
> +	pd->num_subsys_clks = 0;
>  }
>  
>  static void scpsys_domain_cleanup(struct scpsys *scpsys)

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