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

Enric Balletbo Serra
2020-04-23T18:20:12Z

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/

> 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/

>
> 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.

> + 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.

> + 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.

> + 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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