clk: qcom: gdsc: Add support for hierarchical power domains

Some qcom SoCs' can have hierarchical power domains. Let the gdsc structs
specify the parents (if any) and the driver add genpd subdomains for them.
Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

drivers/clk/qcom/common.c

@@ -185,6 +185,7 @@ int qcom_cc_really_probe(struct platform_device *pdev,
 	struct clk **clks;
 	struct qcom_reset_controller *reset;
 	struct qcom_cc *cc;
+	struct gdsc_desc *scd;
 	size_t num_clks = desc->num_clks;
 	struct clk_regmap **rclks = desc->clks;
 
@@ -238,13 +239,22 @@ int qcom_cc_really_probe(struct platform_device *pdev,
 		return ret;
 
 	if (desc->gdscs && desc->num_gdscs) {
-		ret = gdsc_register(dev, desc->gdscs, desc->num_gdscs,
-				    &reset->rcdev, regmap);
+		scd = devm_kzalloc(dev, sizeof(*scd), GFP_KERNEL);
+		if (!scd)
+			return -ENOMEM;
+		scd->dev = dev;
+		scd->scs = desc->gdscs;
+		scd->num = desc->num_gdscs;
+		ret = gdsc_register(scd, &reset->rcdev, regmap);
+		if (ret)
+			return ret;
+		ret = devm_add_action_or_reset(dev, qcom_cc_gdsc_unregister,
+					       scd);
 		if (ret)
 			return ret;
 	}
 
-	return devm_add_action_or_reset(dev, qcom_cc_gdsc_unregister, dev);
+	return 0;
 }
 EXPORT_SYMBOL_GPL(qcom_cc_really_probe);
 

drivers/clk/qcom/gdsc.c

@@ -201,11 +201,14 @@ static int gdsc_init(struct gdsc *sc)
 	return 0;
 }
 
-int gdsc_register(struct device *dev, struct gdsc **scs, size_t num,
+int gdsc_register(struct gdsc_desc *desc,
 		  struct reset_controller_dev *rcdev, struct regmap *regmap)
 {
 	int i, ret;
 	struct genpd_onecell_data *data;
+	struct device *dev = desc->dev;
+	struct gdsc **scs = desc->scs;
+	size_t num = desc->num;
 
 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 	if (!data)
@@ -228,10 +231,30 @@ int gdsc_register(struct device *dev, struct gdsc **scs, size_t num,
 		data->domains[i] = &scs[i]->pd;
 	}
 
+	/* Add subdomains */
+	for (i = 0; i < num; i++) {
+		if (!scs[i])
+			continue;
+		if (scs[i]->parent)
+			pm_genpd_add_subdomain(scs[i]->parent, &scs[i]->pd);
+	}
+
 	return of_genpd_add_provider_onecell(dev->of_node, data);
 }
 
-void gdsc_unregister(struct device *dev)
+void gdsc_unregister(struct gdsc_desc *desc)
 {
+	int i;
+	struct device *dev = desc->dev;
+	struct gdsc **scs = desc->scs;
+	size_t num = desc->num;
+
+	/* Remove subdomains */
+	for (i = 0; i < num; i++) {
+		if (!scs[i])
+			continue;
+		if (scs[i]->parent)
+			pm_genpd_remove_subdomain(scs[i]->parent, &scs[i]->pd);
+	}
 	of_genpd_del_provider(dev->of_node);
 }

drivers/clk/qcom/gdsc.h

@@ -41,6 +41,7 @@ struct reset_controller_dev;
  */
 struct gdsc {
 	struct generic_pm_domain	pd;
+	struct generic_pm_domain	*parent;
 	struct regmap			*regmap;
 	unsigned int			gdscr;
 	unsigned int			*cxcs;
@@ -51,18 +52,24 @@ struct gdsc {
 	unsigned int			reset_count;
 };
 
+struct gdsc_desc {
+	struct device *dev;
+	struct gdsc **scs;
+	size_t num;
+};
+
 #ifdef CONFIG_QCOM_GDSC
-int gdsc_register(struct device *, struct gdsc **, size_t n,
-		  struct reset_controller_dev *, struct regmap *);
-void gdsc_unregister(struct device *);
+int gdsc_register(struct gdsc_desc *desc, struct reset_controller_dev *,
+		  struct regmap *);
+void gdsc_unregister(struct gdsc_desc *desc);
 #else
-static inline int gdsc_register(struct device *d, struct gdsc **g, size_t n,
+static inline int gdsc_register(struct gdsc_desc *desc,
 				struct reset_controller_dev *rcdev,
 				struct regmap *r)
 {
 	return -ENOSYS;
 }
 
-static inline void gdsc_unregister(struct device *d) {};
+static inline void gdsc_unregister(struct gdsc_desc *desc) {};
 #endif /* CONFIG_QCOM_GDSC */
 #endif /* __QCOM_GDSC_H__ */