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Diffstat (limited to 'Documentation/power/regulator/machine.txt')
| -rw-r--r-- | Documentation/power/regulator/machine.txt | 140 |
1 files changed, 66 insertions, 74 deletions
diff --git a/Documentation/power/regulator/machine.txt b/Documentation/power/regulator/machine.txt index c9a35665cf70..ce3487d99abe 100644 --- a/Documentation/power/regulator/machine.txt +++ b/Documentation/power/regulator/machine.txt @@ -2,17 +2,8 @@ Regulator Machine Driver Interface =================================== The regulator machine driver interface is intended for board/machine specific -initialisation code to configure the regulator subsystem. Typical things that -machine drivers would do are :- +initialisation code to configure the regulator subsystem. - 1. Regulator -> Device mapping. - 2. Regulator supply configuration. - 3. Power Domain constraint setting. - - - -1. Regulator -> device mapping -============================== Consider the following machine :- Regulator-1 -+-> Regulator-2 --> [Consumer A @ 1.8 - 2.0V] @@ -21,81 +12,82 @@ Consider the following machine :- 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 calling :- +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" */ +}; -int regulator_set_device_supply(const char *regulator, struct device *dev, - const char *supply); +e.g. for the machine above -and is shown with the following code :- +static struct regulator_consumer_supply regulator1_consumers[] = { +{ + .dev = &platform_consumerB_device.dev, + .supply = "Vcc", +},}; -regulator_set_device_supply("Regulator-1", devB, "Vcc"); -regulator_set_device_supply("Regulator-2", devA, "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. - -2. Regulator supply configuration. -================================== -Consider the following machine (again) :- - - Regulator-1 -+-> Regulator-2 --> [Consumer A @ 1.8 - 2.0V] - | - +-> [Consumer B @ 3.3V] +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). - -This relationship can be register with the core via :- - -int regulator_set_supply(const char *regulator, const char *regulator_supply); - -In this example we would use the following code :- - -regulator_set_supply("Regulator-2", "Regulator-1"); - -Relationships can be queried by calling :- - -const char *regulator_get_supply(const char *regulator); - - -3. Power Domain constraint setting. -=================================== -Each power domain within a system has physical constraints on voltage and -current. This must be defined in software so that the power domain is always -operated within specifications. - -Consider the following machine (again) :- - - Regulator-1 -+-> Regulator-2 --> [Consumer A @ 1.8 - 2.0V] - | - +-> [Consumer B @ 3.3V] - -This gives us two regulators and two power domains: - - Domain 1: Regulator-2, Consumer B. - Domain 2: Consumer A. - -Constraints can be registered by calling :- - -int regulator_set_platform_constraints(const char *regulator, - struct regulation_constraints *constraints); - -The example is defined as follows :- - -struct regulation_constraints domain_1 = { - .min_uV = 3300000, - .max_uV = 3300000, - .valid_modes_mask = REGULATOR_MODE_NORMAL, +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, }; -struct regulation_constraints domain_2 = { - .min_uV = 1800000, - .max_uV = 2000000, - .valid_ops_mask = REGULATOR_CHANGE_VOLTAGE, - .valid_modes_mask = REGULATOR_MODE_NORMAL, +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 = ®ulator1_data, + }, +}, +{ + .name = "regulator", + .id = DCDC_2, + .dev = { + .platform_data = ®ulator2_data, + }, +}, }; +/* register regulator 1 device */ +platform_device_register(&wm8350_regulator_devices[0]); -regulator_set_platform_constraints("Regulator-1", &domain_1); -regulator_set_platform_constraints("Regulator-2", &domain_2); +/* register regulator 2 device */ +platform_device_register(&wm8350_regulator_devices[1]); |