Add input voltage suppliers for PMIC MCP16502

Merge series from Andrei Simion <andrei.simion@microchip.com>:

In this series of patches, support for the *-supply property [1]  is added
(correlated with supply_name [2]) from the core regulator.
Link [1]: https://github.com/torvalds/linux/blob/master/drivers/regulator/core.c#L471
Link [2]: https://github.com/torvalds/linux/blob/master/drivers/regulator/core.c#L2064

I modified the mcp16502.c driver and the dts that use this PMIC.
We added these improvements to provide a complete description of the board power scheme.

Documentation/devicetree/bindings/regulator/microchip,mcp16502.yaml

@@ -28,6 +28,21 @@ properties:
   reg:
     maxItems: 1
 
+  lvin-supply:
+    description: Input supply phandle for LDO1 and LDO2
+
+  pvin1-supply:
+    description: Input supply phandle for VDD_IO (BUCK1)
+
+  pvin2-supply:
+    description: Input supply phandle for VDD_DDR (BUCK2)
+
+  pvin3-supply:
+    description: Input supply phandle for VDD_CORE (BUCK3)
+
+  pvin4-supply:
+    description: Input supply phandle for VDD_OTHER (BUCK4)
+
   regulators:
     type: object
     additionalProperties: false
@@ -68,6 +83,11 @@ examples:
         pmic@5b {
             compatible = "microchip,mcp16502";
             reg = <0x5b>;
+            lvin-supply = <&reg_5v>;
+            pvin1-supply = <&reg_5v>;
+            pvin2-supply = <&reg_5v>;
+            pvin3-supply = <&reg_5v>;
+            pvin4-supply = <&reg_5v>;
 
             regulators {
                 VDD_IO {

drivers/regulator/mcp16502.c

@@ -107,9 +107,10 @@ static unsigned int mcp16502_of_map_mode(unsigned int mode)
 	return REGULATOR_MODE_INVALID;
 }
 
-#define MCP16502_REGULATOR(_name, _id, _ranges, _ops, _ramp_table)	\
+#define MCP16502_REGULATOR(_name, _id, _sn, _ranges, _ops, _ramp_table)	\
 	[_id] = {							\
 		.name			= _name,			\
+		.supply_name		= #_sn,				\
 		.regulators_node	= "regulators",			\
 		.id			= _id,				\
 		.ops			= &(_ops),			\
@@ -467,18 +468,18 @@ static const struct linear_range b234_ranges[] = {
 };
 
 static const struct regulator_desc mcp16502_desc[] = {
-	/* MCP16502_REGULATOR(_name, _id, ranges, regulator_ops, ramp_table) */
-	MCP16502_REGULATOR("VDD_IO", BUCK1, b1l12_ranges, mcp16502_buck_ops,
+	/* MCP16502_REGULATOR(_name, _id, _sn, _ranges, _ops, _ramp_table) */
+	MCP16502_REGULATOR("VDD_IO", BUCK1, pvin1, b1l12_ranges, mcp16502_buck_ops,
 			   mcp16502_ramp_b1l12),
-	MCP16502_REGULATOR("VDD_DDR", BUCK2, b234_ranges, mcp16502_buck_ops,
+	MCP16502_REGULATOR("VDD_DDR", BUCK2, pvin2, b234_ranges, mcp16502_buck_ops,
 			   mcp16502_ramp_b234),
-	MCP16502_REGULATOR("VDD_CORE", BUCK3, b234_ranges, mcp16502_buck_ops,
+	MCP16502_REGULATOR("VDD_CORE", BUCK3, pvin3, b234_ranges, mcp16502_buck_ops,
 			   mcp16502_ramp_b234),
-	MCP16502_REGULATOR("VDD_OTHER", BUCK4, b234_ranges, mcp16502_buck_ops,
+	MCP16502_REGULATOR("VDD_OTHER", BUCK4, pvin4, b234_ranges, mcp16502_buck_ops,
 			   mcp16502_ramp_b234),
-	MCP16502_REGULATOR("LDO1", LDO1, b1l12_ranges, mcp16502_ldo_ops,
+	MCP16502_REGULATOR("LDO1", LDO1, lvin, b1l12_ranges, mcp16502_ldo_ops,
 			   mcp16502_ramp_b1l12),
-	MCP16502_REGULATOR("LDO2", LDO2, b1l12_ranges, mcp16502_ldo_ops,
+	MCP16502_REGULATOR("LDO2", LDO2, lvin, b1l12_ranges, mcp16502_ldo_ops,
 			   mcp16502_ramp_b1l12)
 };