diff mbox series

[v2,3/4] soc: mediatek: add support of MTK_SCPD_STRICT_BUSP cap

Message ID 20220725081853.1636444-4-msp@baylibre.com (mailing list archive)
State New, archived
Headers show
Series soc: mediatek: MT8365 power support | expand

Commit Message

Markus Schneider-Pargmann July 25, 2022, 8:18 a.m. UTC
From: Alexandre Bailon <abailon@baylibre.com>

This adds support for MTK_SCPD_STRICT_BUSP capability. It is a strict
bus protection policy that requires the bus protection to be disabled
before accessing the bus.
This is required by the mt8365, for the MM power domain.

Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
Signed-off-by: Fabien Parent <fparent@baylibre.com>
Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
---

Notes:
    Changes in v2:
    - Fixup error handling path.

 drivers/soc/mediatek/mtk-pm-domains.c | 29 +++++++++++++++++++++++----
 drivers/soc/mediatek/mtk-pm-domains.h |  1 +
 2 files changed, 26 insertions(+), 4 deletions(-)

Comments

AngeloGioacchino Del Regno July 25, 2022, 9:07 a.m. UTC | #1
Il 25/07/22 10:18, Markus Schneider-Pargmann ha scritto:
> From: Alexandre Bailon <abailon@baylibre.com>
> 
> This adds support for MTK_SCPD_STRICT_BUSP capability. It is a strict
> bus protection policy that requires the bus protection to be disabled
> before accessing the bus.
> This is required by the mt8365, for the MM power domain.
> 
> Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
> Signed-off-by: Fabien Parent <fparent@baylibre.com>
> Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
> ---
> 
> Notes:
>      Changes in v2:
>      - Fixup error handling path.
> 
>   drivers/soc/mediatek/mtk-pm-domains.c | 29 +++++++++++++++++++++++----
>   drivers/soc/mediatek/mtk-pm-domains.h |  1 +
>   2 files changed, 26 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/soc/mediatek/mtk-pm-domains.c b/drivers/soc/mediatek/mtk-pm-domains.c
> index d0eae2227813..94ca8981f45e 100644
> --- a/drivers/soc/mediatek/mtk-pm-domains.c
> +++ b/drivers/soc/mediatek/mtk-pm-domains.c
> @@ -240,6 +240,7 @@ static int scpsys_power_on(struct generic_pm_domain *genpd)
>   	struct scpsys *scpsys = pd->scpsys;
>   	bool tmp;
>   	int ret;
> +	bool strict_busprotect;
>   
>   	ret = scpsys_regulator_enable(pd->supply);
>   	if (ret)
> @@ -263,9 +264,18 @@ 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_prepare_enable(pd->num_subsys_clks, pd->subsys_clks);
> -	if (ret)
> -		goto err_pwr_ack;
> +	/*
> +	 * In few Mediatek platforms(e.g. MT6779), the bus protect policy is
> +	 * stricter, which leads to bus protect release must be prior to bus
> +	 * access.
> +	 */
> +	strict_busprotect = MTK_SCPD_CAPS(pd, MTK_SCPD_STRICT_BUSP);
> +	if (!strict_busprotect) {

Please directly check for MTK_SCPD_CAPS, you don't really need that bool variable,
not even for performance... and it fits just fine in one line, even.

	if (!MTK_SCPD_CAPS(pd, MTK_SCPD_STRICT_BUS_PROTECTION)) {

> +		ret = clk_bulk_prepare_enable(pd->num_subsys_clks,
> +					      pd->subsys_clks);
> +		if (ret)
> +			goto err_pwr_ack;
> +	}
>   
>   	ret = scpsys_sram_enable(pd);
>   	if (ret < 0)
> @@ -275,12 +285,23 @@ static int scpsys_power_on(struct generic_pm_domain *genpd)
>   	if (ret < 0)
>   		goto err_disable_sram;
>   
> +	if (strict_busprotect) {

	if (MTK_SCPD_CAPS(pd, MTK_SCPD_STRICT_BUS_PROTECTION)) {

> +		ret = clk_bulk_prepare_enable(pd->num_subsys_clks,
> +					      pd->subsys_clks);
> +		if (ret)
> +			goto err_enable_bus_protect;
> +	}
> +
>   	return 0;
>   
> +err_enable_bus_protect:

For human readability purposes (and paranoidly preventing future mistakes), I'd
add a check for the strict bus protection cap here too.

> +	scpsys_bus_protect_enable(pd);
>   err_disable_sram:
>   	scpsys_sram_disable(pd);
>   err_disable_subsys_clks:
> -	clk_bulk_disable_unprepare(pd->num_subsys_clks, pd->subsys_clks);
> +	if (!strict_busprotect)
> +		clk_bulk_disable_unprepare(pd->num_subsys_clks,
> +					   pd->subsys_clks);
>   err_pwr_ack:
>   	clk_bulk_disable_unprepare(pd->num_clks, pd->clks);
>   err_reg:
> diff --git a/drivers/soc/mediatek/mtk-pm-domains.h b/drivers/soc/mediatek/mtk-pm-domains.h
> index e788d6bdde9d..a50cfb926d22 100644
> --- a/drivers/soc/mediatek/mtk-pm-domains.h
> +++ b/drivers/soc/mediatek/mtk-pm-domains.h
> @@ -8,6 +8,7 @@
>   #define MTK_SCPD_SRAM_ISO		BIT(2)
>   #define MTK_SCPD_KEEP_DEFAULT_OFF	BIT(3)
>   #define MTK_SCPD_DOMAIN_SUPPLY		BIT(4)
> +#define MTK_SCPD_STRICT_BUSP		BIT(5)

MTK_SCPD_STRICT_BUS_PROTECTION is a bit more human readable.

>   #define MTK_SCPD_CAPS(_scpd, _x)	((_scpd)->data->caps & (_x))
>   
>   #define SPM_VDE_PWR_CON			0x0210

Regards,
Angelo
diff mbox series

Patch

diff --git a/drivers/soc/mediatek/mtk-pm-domains.c b/drivers/soc/mediatek/mtk-pm-domains.c
index d0eae2227813..94ca8981f45e 100644
--- a/drivers/soc/mediatek/mtk-pm-domains.c
+++ b/drivers/soc/mediatek/mtk-pm-domains.c
@@ -240,6 +240,7 @@  static int scpsys_power_on(struct generic_pm_domain *genpd)
 	struct scpsys *scpsys = pd->scpsys;
 	bool tmp;
 	int ret;
+	bool strict_busprotect;
 
 	ret = scpsys_regulator_enable(pd->supply);
 	if (ret)
@@ -263,9 +264,18 @@  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_prepare_enable(pd->num_subsys_clks, pd->subsys_clks);
-	if (ret)
-		goto err_pwr_ack;
+	/*
+	 * In few Mediatek platforms(e.g. MT6779), the bus protect policy is
+	 * stricter, which leads to bus protect release must be prior to bus
+	 * access.
+	 */
+	strict_busprotect = MTK_SCPD_CAPS(pd, MTK_SCPD_STRICT_BUSP);
+	if (!strict_busprotect) {
+		ret = clk_bulk_prepare_enable(pd->num_subsys_clks,
+					      pd->subsys_clks);
+		if (ret)
+			goto err_pwr_ack;
+	}
 
 	ret = scpsys_sram_enable(pd);
 	if (ret < 0)
@@ -275,12 +285,23 @@  static int scpsys_power_on(struct generic_pm_domain *genpd)
 	if (ret < 0)
 		goto err_disable_sram;
 
+	if (strict_busprotect) {
+		ret = clk_bulk_prepare_enable(pd->num_subsys_clks,
+					      pd->subsys_clks);
+		if (ret)
+			goto err_enable_bus_protect;
+	}
+
 	return 0;
 
+err_enable_bus_protect:
+	scpsys_bus_protect_enable(pd);
 err_disable_sram:
 	scpsys_sram_disable(pd);
 err_disable_subsys_clks:
-	clk_bulk_disable_unprepare(pd->num_subsys_clks, pd->subsys_clks);
+	if (!strict_busprotect)
+		clk_bulk_disable_unprepare(pd->num_subsys_clks,
+					   pd->subsys_clks);
 err_pwr_ack:
 	clk_bulk_disable_unprepare(pd->num_clks, pd->clks);
 err_reg:
diff --git a/drivers/soc/mediatek/mtk-pm-domains.h b/drivers/soc/mediatek/mtk-pm-domains.h
index e788d6bdde9d..a50cfb926d22 100644
--- a/drivers/soc/mediatek/mtk-pm-domains.h
+++ b/drivers/soc/mediatek/mtk-pm-domains.h
@@ -8,6 +8,7 @@ 
 #define MTK_SCPD_SRAM_ISO		BIT(2)
 #define MTK_SCPD_KEEP_DEFAULT_OFF	BIT(3)
 #define MTK_SCPD_DOMAIN_SUPPLY		BIT(4)
+#define MTK_SCPD_STRICT_BUSP		BIT(5)
 #define MTK_SCPD_CAPS(_scpd, _x)	((_scpd)->data->caps & (_x))
 
 #define SPM_VDE_PWR_CON			0x0210