1Regulator Machine Driver Interface
2===================================
3
4The regulator machine driver interface is intended for board/machine specific
5initialisation code to configure the regulator subsystem.
6
7Consider the following machine :-
8
9  Regulator-1 -+-> Regulator-2 --> [Consumer A @ 1.8 - 2.0V]
10               |
11               +-> [Consumer B @ 3.3V]
12
13The drivers for consumers A & B must be mapped to the correct regulator in
14order to control their power supplies. This mapping can be achieved in machine
15initialisation code by creating a struct regulator_consumer_supply for
16each regulator.
17
18struct regulator_consumer_supply {
19	const char *dev_name;	/* consumer dev_name() */
20	const char *supply;	/* consumer supply - e.g. "vcc" */
21};
22
23e.g. for the machine above
24
25static struct regulator_consumer_supply regulator1_consumers[] = {
26	REGULATOR_SUPPLY("Vcc", "consumer B"),
27};
28
29static struct regulator_consumer_supply regulator2_consumers[] = {
30	REGULATOR_SUPPLY("Vcc", "consumer A"),
31};
32
33This maps Regulator-1 to the 'Vcc' supply for Consumer B and maps Regulator-2
34to the 'Vcc' supply for Consumer A.
35
36Constraints can now be registered by defining a struct regulator_init_data
37for each regulator power domain. This structure also maps the consumers
38to their supply regulators :-
39
40static struct regulator_init_data regulator1_data = {
41	.constraints = {
42		.name = "Regulator-1",
43		.min_uV = 3300000,
44		.max_uV = 3300000,
45		.valid_modes_mask = REGULATOR_MODE_NORMAL,
46	},
47	.num_consumer_supplies = ARRAY_SIZE(regulator1_consumers),
48	.consumer_supplies = regulator1_consumers,
49};
50
51The name field should be set to something that is usefully descriptive
52for the board for configuration of supplies for other regulators and
53for use in logging and other diagnostic output.  Normally the name
54used for the supply rail in the schematic is a good choice.  If no
55name is provided then the subsystem will choose one.
56
57Regulator-1 supplies power to Regulator-2. This relationship must be registered
58with the core so that Regulator-1 is also enabled when Consumer A enables its
59supply (Regulator-2). The supply regulator is set by the supply_regulator
60field below and co:-
61
62static struct regulator_init_data regulator2_data = {
63	.supply_regulator = "Regulator-1",
64	.constraints = {
65		.min_uV = 1800000,
66		.max_uV = 2000000,
67		.valid_ops_mask = REGULATOR_CHANGE_VOLTAGE,
68		.valid_modes_mask = REGULATOR_MODE_NORMAL,
69	},
70	.num_consumer_supplies = ARRAY_SIZE(regulator2_consumers),
71	.consumer_supplies = regulator2_consumers,
72};
73
74Finally the regulator devices must be registered in the usual manner.
75
76static struct platform_device regulator_devices[] = {
77	{
78		.name = "regulator",
79		.id = DCDC_1,
80		.dev = {
81			.platform_data = &regulator1_data,
82		},
83	},
84	{
85		.name = "regulator",
86		.id = DCDC_2,
87		.dev = {
88			.platform_data = &regulator2_data,
89		},
90	},
91};
92/* register regulator 1 device */
93platform_device_register(&regulator_devices[0]);
94
95/* register regulator 2 device */
96platform_device_register(&regulator_devices[1]);
97