soc: mediatek: pm-domains: Add domain regulator supply

Some power domains (eg. mfg) needs to turn on power supply before power
on.

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Link: https://lore.kernel.org/r/20210129101208.2625249-3-hsinyi@chromium.org
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>

drivers/soc/mediatek/mt8183-pm-domains.h

@@ -38,6 +38,7 @@ static const struct scpsys_domain_data scpsys_domain_data_mt8183[] = {
 		.ctl_offs = 0x0338,
 		.sram_pdn_bits = GENMASK(8, 8),
 		.sram_pdn_ack_bits = GENMASK(12, 12),
+		.caps = MTK_SCPD_DOMAIN_SUPPLY,
 	},
 	[MT8183_POWER_DOMAIN_MFG_CORE0] = {
 		.sta_mask = BIT(7),

drivers/soc/mediatek/mtk-pm-domains.c

@@ -13,6 +13,7 @@
 #include <linux/platform_device.h>
 #include <linux/pm_domain.h>
 #include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
 #include <linux/soc/mediatek/infracfg.h>
 
 #include "mt8167-pm-domains.h"
@@ -41,6 +42,7 @@ struct scpsys_domain {
 	struct clk_bulk_data *subsys_clks;
 	struct regmap *infracfg;
 	struct regmap *smi;
+	struct regulator *supply;
 };
 
 struct scpsys {
@@ -188,6 +190,16 @@ static int scpsys_bus_protect_disable(struct scpsys_domain *pd)
 	return _scpsys_bus_protect_disable(pd->data->bp_infracfg, pd->infracfg);
 }
 
+static int scpsys_regulator_enable(struct regulator *supply)
+{
+	return supply ? regulator_enable(supply) : 0;
+}
+
+static int scpsys_regulator_disable(struct regulator *supply)
+{
+	return supply ? regulator_disable(supply) : 0;
+}
+
 static int scpsys_power_on(struct generic_pm_domain *genpd)
 {
 	struct scpsys_domain *pd = container_of(genpd, struct scpsys_domain, genpd);
@@ -195,10 +207,14 @@ static int scpsys_power_on(struct generic_pm_domain *genpd)
 	bool tmp;
 	int ret;
 
-	ret = clk_bulk_enable(pd->num_clks, pd->clks);
+	ret = scpsys_regulator_enable(pd->supply);
 	if (ret)
 		return ret;
 
+	ret = clk_bulk_enable(pd->num_clks, pd->clks);
+	if (ret)
+		goto err_reg;
+
 	/* subsys power on */
 	regmap_set_bits(scpsys->base, pd->data->ctl_offs, PWR_ON_BIT);
 	regmap_set_bits(scpsys->base, pd->data->ctl_offs, PWR_ON_2ND_BIT);
@@ -233,6 +249,8 @@ err_disable_subsys_clks:
 	clk_bulk_disable(pd->num_subsys_clks, pd->subsys_clks);
 err_pwr_ack:
 	clk_bulk_disable(pd->num_clks, pd->clks);
+err_reg:
+	scpsys_regulator_disable(pd->supply);
 	return ret;
 }
 
@@ -268,6 +286,8 @@ static int scpsys_power_off(struct generic_pm_domain *genpd)
 
 	clk_bulk_disable(pd->num_clks, pd->clks);
 
+	scpsys_regulator_disable(pd->supply);
+
 	return 0;
 }
 
@@ -276,6 +296,7 @@ generic_pm_domain *scpsys_add_one_domain(struct scpsys *scpsys, struct device_no
 {
 	const struct scpsys_domain_data *domain_data;
 	struct scpsys_domain *pd;
+	struct device_node *root_node = scpsys->dev->of_node;
 	struct property *prop;
 	const char *clk_name;
 	int i, ret, num_clks;
@@ -308,6 +329,25 @@ generic_pm_domain *scpsys_add_one_domain(struct scpsys *scpsys, struct device_no
 	pd->data = domain_data;
 	pd->scpsys = scpsys;
 
+	if (MTK_SCPD_CAPS(pd, MTK_SCPD_DOMAIN_SUPPLY)) {
+		/*
+		 * Find regulator in current power domain node.
+		 * devm_regulator_get() finds regulator in a node and its child
+		 * node, so set of_node to current power domain node then change
+		 * back to original node after regulator is found for current
+		 * power domain node.
+		 */
+		scpsys->dev->of_node = node;
+		pd->supply = devm_regulator_get(scpsys->dev, "domain");
+		scpsys->dev->of_node = root_node;
+		if (IS_ERR(pd->supply)) {
+			dev_err_probe(scpsys->dev, PTR_ERR(pd->supply),
+				      "%pOF: failed to get power supply.\n",
+				      node);
+			return ERR_CAST(pd->supply);
+		}
+	}
+
 	pd->infracfg = syscon_regmap_lookup_by_phandle_optional(node, "mediatek,infracfg");
 	if (IS_ERR(pd->infracfg))
 		return ERR_CAST(pd->infracfg);

drivers/soc/mediatek/mtk-pm-domains.h

@@ -7,6 +7,7 @@
 #define MTK_SCPD_FWAIT_SRAM		BIT(1)
 #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_CAPS(_scpd, _x)	((_scpd)->data->caps & (_x))
 
 #define SPM_VDE_PWR_CON			0x0210