satip-axe/kernel/Documentation/power/regulator/machine.txt

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Regulator Machine Driver Interface
===================================
The regulator machine driver interface is intended for board/machine specific
initialisation code to configure the regulator subsystem.
Consider the following machine :-
Regulator-1 -+-> Regulator-2 --> [Consumer A @ 1.8 - 2.0V]
|
+-> [Consumer B @ 3.3V]
The drivers for consumers A & B must be mapped to the correct regulator in
order to control their power supply. This mapping can be achieved in machine
initialisation code by creating a struct regulator_consumer_supply for
each regulator.
struct regulator_consumer_supply {
struct device *dev; /* consumer */
const char *supply; /* consumer supply - e.g. "vcc" */
};
e.g. for the machine above
static struct regulator_consumer_supply regulator1_consumers[] = {
{
.dev = &platform_consumerB_device.dev,
.supply = "Vcc",
},};
static struct regulator_consumer_supply regulator2_consumers[] = {
{
.dev = &platform_consumerA_device.dev,
.supply = "Vcc",
},};
This maps Regulator-1 to the 'Vcc' supply for Consumer B and maps Regulator-2
to the 'Vcc' supply for Consumer A.
Constraints can now be registered by defining a struct regulator_init_data
for each regulator power domain. This structure also maps the consumers
to their supply regulator :-
static struct regulator_init_data regulator1_data = {
.constraints = {
.min_uV = 3300000,
.max_uV = 3300000,
.valid_modes_mask = REGULATOR_MODE_NORMAL,
},
.num_consumer_supplies = ARRAY_SIZE(regulator1_consumers),
.consumer_supplies = regulator1_consumers,
};
Regulator-1 supplies power to Regulator-2. This relationship must be registered
with the core so that Regulator-1 is also enabled when Consumer A enables it's
supply (Regulator-2). The supply regulator is set by the supply_regulator_dev
field below:-
static struct regulator_init_data regulator2_data = {
.supply_regulator_dev = &platform_regulator1_device.dev,
.constraints = {
.min_uV = 1800000,
.max_uV = 2000000,
.valid_ops_mask = REGULATOR_CHANGE_VOLTAGE,
.valid_modes_mask = REGULATOR_MODE_NORMAL,
},
.num_consumer_supplies = ARRAY_SIZE(regulator2_consumers),
.consumer_supplies = regulator2_consumers,
};
Finally the regulator devices must be registered in the usual manner.
static struct platform_device regulator_devices[] = {
{
.name = "regulator",
.id = DCDC_1,
.dev = {
.platform_data = &regulator1_data,
},
},
{
.name = "regulator",
.id = DCDC_2,
.dev = {
.platform_data = &regulator2_data,
},
},
};
/* register regulator 1 device */
platform_device_register(&regulator_devices[0]);
/* register regulator 2 device */
platform_device_register(&regulator_devices[1]);