101 lines
3.0 KiB
Plaintext
101 lines
3.0 KiB
Plaintext
Regulator Machine Driver Interface
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===================================
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The regulator machine driver interface is intended for board/machine specific
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initialisation code to configure the regulator subsystem.
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Consider the following machine :-
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Regulator-1 -+-> Regulator-2 --> [Consumer A @ 1.8 - 2.0V]
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+-> [Consumer B @ 3.3V]
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The drivers for consumers A & B must be mapped to the correct regulator in
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order to control their power supply. This mapping can be achieved in machine
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initialisation code by creating a struct regulator_consumer_supply for
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each regulator.
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struct regulator_consumer_supply {
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const char *dev_name; /* consumer dev_name() */
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const char *supply; /* consumer supply - e.g. "vcc" */
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};
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e.g. for the machine above
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static struct regulator_consumer_supply regulator1_consumers[] = {
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{
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.dev_name = "dev_name(consumer B)",
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.supply = "Vcc",
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},};
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static struct regulator_consumer_supply regulator2_consumers[] = {
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{
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.dev = "dev_name(consumer A"),
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.supply = "Vcc",
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},};
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This maps Regulator-1 to the 'Vcc' supply for Consumer B and maps Regulator-2
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to the 'Vcc' supply for Consumer A.
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Constraints can now be registered by defining a struct regulator_init_data
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for each regulator power domain. This structure also maps the consumers
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to their supply regulator :-
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static struct regulator_init_data regulator1_data = {
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.constraints = {
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.name = "Regulator-1",
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.min_uV = 3300000,
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.max_uV = 3300000,
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.valid_modes_mask = REGULATOR_MODE_NORMAL,
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},
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.num_consumer_supplies = ARRAY_SIZE(regulator1_consumers),
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.consumer_supplies = regulator1_consumers,
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};
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The name field should be set to something that is usefully descriptive
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for the board for configuration of supplies for other regulators and
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for use in logging and other diagnostic output. Normally the name
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used for the supply rail in the schematic is a good choice. If no
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name is provided then the subsystem will choose one.
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Regulator-1 supplies power to Regulator-2. This relationship must be registered
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with the core so that Regulator-1 is also enabled when Consumer A enables its
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supply (Regulator-2). The supply regulator is set by the supply_regulator
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field below and co:-
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static struct regulator_init_data regulator2_data = {
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.supply_regulator = "Regulator-1",
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.constraints = {
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.min_uV = 1800000,
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.max_uV = 2000000,
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.valid_ops_mask = REGULATOR_CHANGE_VOLTAGE,
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.valid_modes_mask = REGULATOR_MODE_NORMAL,
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},
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.num_consumer_supplies = ARRAY_SIZE(regulator2_consumers),
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.consumer_supplies = regulator2_consumers,
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};
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Finally the regulator devices must be registered in the usual manner.
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static struct platform_device regulator_devices[] = {
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{
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.name = "regulator",
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.id = DCDC_1,
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.dev = {
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.platform_data = ®ulator1_data,
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},
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},
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{
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.name = "regulator",
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.id = DCDC_2,
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.dev = {
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.platform_data = ®ulator2_data,
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},
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},
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};
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/* register regulator 1 device */
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platform_device_register(®ulator_devices[0]);
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/* register regulator 2 device */
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platform_device_register(®ulator_devices[1]);
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