power domain: Add support for multiple powerdomains per device

There are cases where there are more than one power domain
attached to the device inorder to get the device functional.
So add support for enabling power domain based on the index.
Reviewed-by: NTom Rini <trini@konsulko.com>
Signed-off-by: NLokesh Vutla <lokeshvutla@ti.com>

drivers/power/domain/power-domain-uclass.c

@@ -28,7 +28,8 @@ static int power_domain_of_xlate_default(struct power_domain *power_domain,
 	return 0;
 }
 
-int power_domain_get(struct udevice *dev, struct power_domain *power_domain)
+int power_domain_get_by_index(struct udevice *dev,
+			      struct power_domain *power_domain, int index)
 {
 	struct ofnode_phandle_args args;
 	int ret;
@@ -38,7 +39,8 @@ int power_domain_get(struct udevice *dev, struct power_domain *power_domain)
 	debug("%s(dev=%p, power_domain=%p)\n", __func__, dev, power_domain);
 
 	ret = dev_read_phandle_with_args(dev, "power-domains",
-					 "#power-domain-cells", 0, 0, &args);
+					 "#power-domain-cells", 0, index,
+					 &args);
 	if (ret) {
 		debug("%s: dev_read_phandle_with_args failed: %d\n",
 		      __func__, ret);
@@ -73,6 +75,11 @@ int power_domain_get(struct udevice *dev, struct power_domain *power_domain)
 	return 0;
 }
 
+int power_domain_get(struct udevice *dev, struct power_domain *power_domain)
+{
+	return power_domain_get_by_index(dev, power_domain, 0);
+}
+
 int power_domain_free(struct power_domain *power_domain)
 {
 	struct power_domain_ops *ops = power_domain_dev_ops(power_domain->dev);

include/power-domain.h

@@ -97,6 +97,27 @@ int power_domain_get(struct udevice *dev, struct power_domain *power_domain)
 }
 #endif
 
+/**
+ * power_domain_get_by_index - Get the indexed power domain for a device.
+ *
+ * @dev:		The client device.
+ * @power_domain:	A pointer to a power domain struct to initialize.
+ * @index:		Power domain index to be powered on.
+ *
+ * @return 0 if OK, or a negative error code.
+ */
+#if CONFIG_IS_ENABLED(POWER_DOMAIN)
+int power_domain_get_by_index(struct udevice *dev,
+			      struct power_domain *power_domain, int index);
+#else
+static inline
+int power_domain_get_by_index(struct udevice *dev,
+			      struct power_domain *power_domain, int index)
+{
+	return -ENOSYS;
+}
+#endif
+
 /**
  * power_domain_free - Free a previously requested power domain.
  *