Voltage and current regulator API¶

Author:: Liam Girdwood
Author:: Mark Brown

Introduction¶

This framework is designed to provide a standard kernel interface to control voltage and current regulators.

The intention is to allow systems to dynamically control regulator power output in order to save power and prolong battery life. This applies to both voltage regulators (where voltage output is controllable) and current sinks (where current limit is controllable).

Note that additional (and currently more complete) documentation is available in the Linux kernel source under Documentation/power/regulator.

Glossary¶

The regulator API uses a number of terms which may not be familiar:

Regulator

Electronic device that supplies power to other devices. Most regulators can enable and disable their output and some can also control their output voltage or current.

Consumer

Electronic device which consumes power provided by a regulator. These may either be static, requiring only a fixed supply, or dynamic, requiring active management of the regulator at runtime.

Power Domain

The electronic circuit supplied by a given regulator, including the regulator and all consumer devices. The configuration of the regulator is shared between all the components in the circuit.

Power Management Integrated Circuit (PMIC)

An IC which contains numerous regulators and often also other subsystems. In an embedded system the primary PMIC is often equivalent to a combination of the PSU and southbridge in a desktop system.

Consumer driver interface¶

This offers a similar API to the kernel clock framework. Consumer drivers use get and put operations to acquire and release regulators. Functions are provided to enable and disable the regulator and to get and set the runtime parameters of the regulator.

When requesting regulators consumers use symbolic names for their supplies, such as “Vcc”, which are mapped into actual regulator devices by the machine interface.

A stub version of this API is provided when the regulator framework is not in use in order to minimise the need to use ifdefs.

Enabling and disabling¶

The regulator API provides reference counted enabling and disabling of regulators. Consumer devices use the regulator_enable() and regulator_disable() functions to enable and disable regulators. Calls to the two functions must be balanced.

Note that since multiple consumers may be using a regulator and machine constraints may not allow the regulator to be disabled there is no guarantee that calling regulator_disable() will actually cause the supply provided by the regulator to be disabled. Consumer drivers should assume that the regulator may be enabled at all times.

Configuration¶

Some consumer devices may need to be able to dynamically configure their supplies. For example, MMC drivers may need to select the correct operating voltage for their cards. This may be done while the regulator is enabled or disabled.

The regulator_set_voltage() and regulator_set_current_limit() functions provide the primary interface for this. Both take ranges of voltages and currents, supporting drivers that do not require a specific value (eg, CPU frequency scaling normally permits the CPU to use a wider range of supply voltages at lower frequencies but does not require that the supply voltage be lowered). Where an exact value is required both minimum and maximum values should be identical.

Callbacks¶

Callbacks may also be registered for events such as regulation failures.

Regulator driver interface¶

Drivers for regulator chips register the regulators with the regulator core, providing operations structures to the core. A notifier interface allows error conditions to be reported to the core.

Registration should be triggered by explicit setup done by the platform, supplying a struct regulator_init_data for the regulator containing constraint and supply information.

Machine interface¶

This interface provides a way to define how regulators are connected to consumers on a given system and what the valid operating parameters are for the system.

Supplies¶

Regulator supplies are specified using struct regulator_consumer_supply. This is done at driver registration time as part of the machine constraints.

Constraints¶

As well as defining the connections the machine interface also provides constraints defining the operations that clients are allowed to perform and the parameters that may be set. This is required since generally regulator devices will offer more flexibility than it is safe to use on a given system, for example supporting higher supply voltages than the consumers are rated for.

This is done at driver registration time` by providing a struct regulation_constraints.

The constraints may also specify an initial configuration for the regulator in the constraints, which is particularly useful for use with static consumers.

API reference¶

Due to limitations of the kernel documentation framework and the existing layout of the source code the entire regulator API is documented here.

struct pre_voltage_change_data¶: Data sent with PRE_VOLTAGE_CHANGE event

Definition:

struct pre_voltage_change_data {
    unsigned long old_uV;
    unsigned long min_uV;
    unsigned long max_uV;
};

Members

old_uV: Current voltage before change.
min_uV: Min voltage we’ll change to.
max_uV: Max voltage we’ll change to.

struct regulator_bulk_data¶: Data used for bulk regulator operations.

Definition:

struct regulator_bulk_data {
    const char *supply;
    int init_load_uA;
    struct regulator *consumer;
};

Members

supply: The name of the supply. Initialised by the user before using the bulk regulator APIs.
init_load_uA: After getting the regulator, regulator_set_load() will be called with this load. Initialised by the user before using the bulk regulator APIs.
consumer: The regulator consumer for the supply. This will be managed by the bulk API.

Description

The regulator APIs provide a series of regulator_bulk_() API calls as a convenience to consumers which require multiple supplies. This structure is used to manage data for these calls.

struct regulator_state¶: regulator state during low power system states

Definition:

struct regulator_state {
    int uV;
    int min_uV;
    int max_uV;
    unsigned int mode;
    int enabled;
    bool changeable;
};

Members

uV: Default operating voltage during suspend, it can be adjusted among <min_uV, max_uV>.
min_uV: Minimum suspend voltage may be set.
max_uV: Maximum suspend voltage may be set.
mode: Operating mode during suspend.
enabled: operations during suspend. - DO_NOTHING_IN_SUSPEND - DISABLE_IN_SUSPEND - ENABLE_IN_SUSPEND
changeable: Is this state can be switched between enabled/disabled,

Description

This describes a regulators state during a system wide low power state. One of enabled or disabled must be set for the configuration to be applied.

struct regulation_constraints¶: regulator operating constraints.

Definition:

struct regulation_constraints {
    const char *name;
    int min_uV;
    int max_uV;
    int uV_offset;
    int min_uA;
    int max_uA;
    int ilim_uA;
    int system_load;
    u32 *max_spread;
    int max_uV_step;
    unsigned int valid_modes_mask;
    unsigned int valid_ops_mask;
    int input_uV;
    struct regulator_state state_disk;
    struct regulator_state state_mem;
    struct regulator_state state_standby;
    struct notification_limit over_curr_limits;
    struct notification_limit over_voltage_limits;
    struct notification_limit under_voltage_limits;
    struct notification_limit temp_limits;
    suspend_state_t initial_state;
    unsigned int initial_mode;
    unsigned int ramp_delay;
    unsigned int settling_time;
    unsigned int settling_time_up;
    unsigned int settling_time_down;
    unsigned int enable_time;
    unsigned int uv_less_critical_window_ms;
    unsigned int active_discharge;
    unsigned always_on:1;
    unsigned boot_on:1;
    unsigned apply_uV:1;
    unsigned ramp_disable:1;
    unsigned soft_start:1;
    unsigned pull_down:1;
    unsigned system_critical:1;
    unsigned over_current_protection:1;
    unsigned over_current_detection:1;
    unsigned over_voltage_detection:1;
    unsigned under_voltage_detection:1;
    unsigned over_temp_detection:1;
};

Members

name: Descriptive name for the constraints, used for display purposes.
min_uV: Smallest voltage consumers may set.
max_uV: Largest voltage consumers may set.
uV_offset: Offset applied to voltages from consumer to compensate for voltage drops.
min_uA: Smallest current consumers may set.
max_uA: Largest current consumers may set.
ilim_uA: Maximum input current.
system_load: Load that isn’t captured by any consumer requests.
max_spread: Max possible spread between coupled regulators
max_uV_step: Max possible step change in voltage
valid_modes_mask: Mask of modes which may be configured by consumers.
valid_ops_mask: Operations which may be performed by consumers.
input_uV: Input voltage for regulator when supplied by another regulator.
state_disk: State for regulator when system is suspended in disk mode.
state_mem: State for regulator when system is suspended in mem mode.
state_standby: State for regulator when system is suspended in standby mode.
over_curr_limits: Limits for acting on over current.
over_voltage_limits: Limits for acting on over voltage.
under_voltage_limits: Limits for acting on under voltage.
temp_limits: Limits for acting on over temperature.
initial_state: Suspend state to set by default.
initial_mode: Mode to set at startup.
ramp_delay: Time to settle down after voltage change (unit: uV/us)
settling_time: Time to settle down after voltage change when voltage change is non-linear (unit: microseconds).
settling_time_up: Time to settle down after voltage increase when voltage change is non-linear (unit: microseconds).
settling_time_down: Time to settle down after voltage decrease when voltage change is non-linear (unit: microseconds).
enable_time: Turn-on time of the rails (unit: microseconds)
uv_less_critical_window_ms: Specifies the time window (in milliseconds) following a critical under-voltage (UV) event during which less critical actions can be safely carried out by the system (for example logging). After this time window more critical actions should be done (for example prevent HW damage).
active_discharge: Enable/disable active discharge. The enum regulator_active_discharge values are used for initialisation.
always_on: Set if the regulator should never be disabled.
boot_on: Set if the regulator is enabled when the system is initially started. If the regulator is not enabled by the hardware or bootloader then it will be enabled when the constraints are applied.
apply_uV: Apply the voltage constraint when initialising.
ramp_disable: Disable ramp delay when initialising or when setting voltage.
soft_start: Enable soft start so that voltage ramps slowly.
pull_down: Enable pull down when regulator is disabled.
system_critical: Set if the regulator is critical to system stability or functionality.
over_current_protection: Auto disable on over current event.
over_current_detection: Configure over current limits.
over_voltage_detection: Configure over voltage limits.
under_voltage_detection: Configure under voltage limits.
over_temp_detection: Configure over temperature limits.

Description

This struct describes regulator and board/machine specific constraints.

struct regulator_consumer_supply¶: supply -> device mapping

Definition:

struct regulator_consumer_supply {
    const char *dev_name;
    const char *supply;
};

Members

dev_name: Result of dev_name() for the consumer.
supply: Name for the supply.

Description

This maps a supply name to a device. Use of dev_name allows support for buses which make struct device available late such as I2C.

struct regulator_init_data¶: regulator platform initialisation data.

Definition:

struct regulator_init_data {
    const char *supply_regulator;
    struct regulation_constraints constraints;
    int num_consumer_supplies;
    struct regulator_consumer_supply *consumer_supplies;
    int (*regulator_init)(void *driver_data);
    void *driver_data;
};

Members

supply_regulator: Parent regulator. Specified using the regulator name as it appears in the name field in sysfs, which can be explicitly set using the constraints field ‘name’.
constraints: Constraints. These must be specified for the regulator to be usable.
num_consumer_supplies: Number of consumer device supplies.
consumer_supplies: Consumer device supply configuration.
regulator_init: Callback invoked when the regulator has been registered.
driver_data: Data passed to regulator_init.

Description

Initialisation constraints, our supply and consumers supplies.

struct regulator_ops¶: regulator operations.

Definition:

struct regulator_ops {
    int (*list_voltage) (struct regulator_dev *, unsigned selector);
    int (*set_voltage) (struct regulator_dev *, int min_uV, int max_uV, unsigned *selector);
    int (*map_voltage)(struct regulator_dev *, int min_uV, int max_uV);
    int (*set_voltage_sel) (struct regulator_dev *, unsigned selector);
    int (*get_voltage) (struct regulator_dev *);
    int (*get_voltage_sel) (struct regulator_dev *);
    int (*set_current_limit) (struct regulator_dev *, int min_uA, int max_uA);
    int (*get_current_limit) (struct regulator_dev *);
    int (*set_input_current_limit) (struct regulator_dev *, int lim_uA);
    int (*set_over_current_protection)(struct regulator_dev *, int lim_uA, int severity, bool enable);
    int (*set_over_voltage_protection)(struct regulator_dev *, int lim_uV, int severity, bool enable);
    int (*set_under_voltage_protection)(struct regulator_dev *, int lim_uV, int severity, bool enable);
    int (*set_thermal_protection)(struct regulator_dev *, int lim, int severity, bool enable);
    int (*set_active_discharge)(struct regulator_dev *, bool enable);
    int (*enable) (struct regulator_dev *);
    int (*disable) (struct regulator_dev *);
    int (*is_enabled) (struct regulator_dev *);
    int (*set_mode) (struct regulator_dev *, unsigned int mode);
    unsigned int (*get_mode) (struct regulator_dev *);
    int (*get_error_flags)(struct regulator_dev *, unsigned int *flags);
    int (*enable_time) (struct regulator_dev *);
    int (*set_ramp_delay) (struct regulator_dev *, int ramp_delay);
    int (*set_voltage_time) (struct regulator_dev *, int old_uV, int new_uV);
    int (*set_voltage_time_sel) (struct regulator_dev *,unsigned int old_selector, unsigned int new_selector);
    int (*set_soft_start) (struct regulator_dev *);
    int (*get_status)(struct regulator_dev *);
    unsigned int (*get_optimum_mode) (struct regulator_dev *, int input_uV, int output_uV, int load_uA);
    int (*set_load)(struct regulator_dev *, int load_uA);
    int (*set_bypass)(struct regulator_dev *dev, bool enable);
    int (*get_bypass)(struct regulator_dev *dev, bool *enable);
    int (*set_suspend_voltage) (struct regulator_dev *, int uV);
    int (*set_suspend_enable) (struct regulator_dev *);
    int (*set_suspend_disable) (struct regulator_dev *);
    int (*set_suspend_mode) (struct regulator_dev *, unsigned int mode);
    int (*resume)(struct regulator_dev *rdev);
    int (*set_pull_down) (struct regulator_dev *);
};

Members

list_voltage

Return one of the supported voltages, in microvolts; zero if the selector indicates a voltage that is unusable on this system; or negative errno. Selectors range from zero to one less than regulator_desc.n_voltages. Voltages may be reported in any order.

set_voltage

Set the voltage for the regulator within the range specified. The driver should select the voltage closest to min_uV.

map_voltage

Convert a voltage into a selector

set_voltage_sel

Set the voltage for the regulator using the specified selector.

get_voltage

Return the currently configured voltage for the regulator; return -ENOTRECOVERABLE if regulator can’t be read at bootup and hasn’t been set yet.

get_voltage_sel

Return the currently configured voltage selector for the regulator; return -ENOTRECOVERABLE if regulator can’t be read at bootup and hasn’t been set yet.

set_current_limit

Configure a limit for a current-limited regulator. The driver should select the current closest to max_uA.

get_current_limit

Get the configured limit for a current-limited regulator.

set_input_current_limit

Configure an input limit.

set_over_current_protection

Support enabling of and setting limits for over current situation detection. Detection can be configured for three levels of severity.

REGULATOR_SEVERITY_PROT should automatically shut down the regulator(s).
REGULATOR_SEVERITY_ERR should indicate that over-current situation is
caused by an unrecoverable error but HW does not perform automatic shut down.
REGULATOR_SEVERITY_WARN should indicate situation where hardware is
still believed to not be damaged but that a board sepcific recovery action is needed. If lim_uA is 0 the limit should not be changed but the detection should just be enabled/disabled as is requested.

set_over_voltage_protection

Support enabling of and setting limits for over voltage situation detection. Detection can be configured for same severities as over current protection. Units of uV.

set_under_voltage_protection

Support enabling of and setting limits for under voltage situation detection. Detection can be configured for same severities as over current protection. Units of uV.

set_thermal_protection

Support enabling of and setting limits for over temperature situation detection.Detection can be configured for same severities as over current protection. Units of degree Kelvin.

set_active_discharge

Set active discharge enable/disable of regulators.

enable

Configure the regulator as enabled.

disable

Configure the regulator as disabled.

is_enabled

Return 1 if the regulator is enabled, 0 if not. May also return negative errno.

set_mode

Set the configured operating mode for the regulator.

get_mode

Get the configured operating mode for the regulator.

get_error_flags

Get the current error(s) for the regulator.

enable_time

Time taken for the regulator voltage output voltage to stabilise after being enabled, in microseconds.

set_ramp_delay

Set the ramp delay for the regulator. The driver should select ramp delay equal to or less than(closest) ramp_delay.

set_voltage_time

Time taken for the regulator voltage output voltage to stabilise after being set to a new value, in microseconds. The function receives the from and to voltage as input, it should return the worst case.

set_voltage_time_sel

Time taken for the regulator voltage output voltage to stabilise after being set to a new value, in microseconds. The function receives the from and to voltage selector as input, it should return the worst case.

set_soft_start

Enable soft start for the regulator.

get_status

Return actual (not as-configured) status of regulator, as a REGULATOR_STATUS value (or negative errno)

get_optimum_mode

Get the most efficient operating mode for the regulator when running with the specified parameters.

set_load

Set the load for the regulator.

set_bypass

Set the regulator in bypass mode.

get_bypass

Get the regulator bypass mode state.

set_suspend_voltage

Set the voltage for the regulator when the system is suspended.

set_suspend_enable

Mark the regulator as enabled when the system is suspended.

set_suspend_disable

Mark the regulator as disabled when the system is suspended.

set_suspend_mode

Set the operating mode for the regulator when the system is suspended.

resume

Resume operation of suspended regulator.

set_pull_down

Configure the regulator to pull down when the regulator is disabled.

Description

This struct describes regulator operations which can be implemented by regulator chip drivers.

struct regulator_desc¶: Static regulator descriptor

Definition:

struct regulator_desc {
    const char *name;
    const char *supply_name;
    const char *of_match;
    bool of_match_full_name;
    const char *regulators_node;
    int (*of_parse_cb)(struct device_node *,const struct regulator_desc *, struct regulator_config *);
    int id;
    unsigned int continuous_voltage_range:1;
    unsigned n_voltages;
    unsigned int n_current_limits;
    const struct regulator_ops *ops;
    int irq;
    enum regulator_type type;
    struct module *owner;
    unsigned int min_uV;
    unsigned int uV_step;
    unsigned int linear_min_sel;
    int fixed_uV;
    unsigned int ramp_delay;
    int min_dropout_uV;
    const struct linear_range *linear_ranges;
    const unsigned int *linear_range_selectors_bitfield;
    int n_linear_ranges;
    const unsigned int *volt_table;
    const unsigned int *curr_table;
    unsigned int vsel_range_reg;
    unsigned int vsel_range_mask;
    bool range_applied_by_vsel;
    unsigned int vsel_reg;
    unsigned int vsel_mask;
    unsigned int vsel_step;
    unsigned int csel_reg;
    unsigned int csel_mask;
    unsigned int apply_reg;
    unsigned int apply_bit;
    unsigned int enable_reg;
    unsigned int enable_mask;
    unsigned int enable_val;
    unsigned int disable_val;
    bool enable_is_inverted;
    unsigned int bypass_reg;
    unsigned int bypass_mask;
    unsigned int bypass_val_on;
    unsigned int bypass_val_off;
    unsigned int active_discharge_on;
    unsigned int active_discharge_off;
    unsigned int active_discharge_mask;
    unsigned int active_discharge_reg;
    unsigned int soft_start_reg;
    unsigned int soft_start_mask;
    unsigned int soft_start_val_on;
    unsigned int pull_down_reg;
    unsigned int pull_down_mask;
    unsigned int pull_down_val_on;
    unsigned int ramp_reg;
    unsigned int ramp_mask;
    const unsigned int *ramp_delay_table;
    unsigned int n_ramp_values;
    unsigned int enable_time;
    unsigned int off_on_delay;
    unsigned int poll_enabled_time;
    unsigned int (*of_map_mode)(unsigned int mode);
};

Members

name: Identifying name for the regulator.
supply_name: Identifying the regulator supply
of_match: Name used to identify regulator in DT.
of_match_full_name: A flag to indicate that the of_match string, if present, should be matched against the node full_name.
regulators_node: Name of node containing regulator definitions in DT.
of_parse_cb: Optional callback called only if of_match is present. Will be called for each regulator parsed from DT, during init_data parsing. The regulator_config passed as argument to the callback will be a copy of config passed to regulator_register, valid only for this particular call. Callback may freely change the config but it cannot store it for later usage. Callback should return 0 on success or negative ERRNO indicating failure.
id: Numerical identifier for the regulator.
continuous_voltage_range: Indicates if the regulator can set any voltage within constrains range.
n_voltages: Number of selectors available for ops.list_voltage().
n_current_limits: Number of selectors available for current limits
ops: Regulator operations table.
irq: Interrupt number for the regulator.
type: Indicates if the regulator is a voltage or current regulator.
owner: Module providing the regulator, used for refcounting.
min_uV: Voltage given by the lowest selector (if linear mapping)
uV_step: Voltage increase with each selector (if linear mapping)
linear_min_sel: Minimal selector for starting linear mapping
fixed_uV: Fixed voltage of rails.
ramp_delay: Time to settle down after voltage change (unit: uV/us)
min_dropout_uV: The minimum dropout voltage this regulator can handle
linear_ranges: A constant table of possible voltage ranges.
linear_range_selectors_bitfield: A constant table of voltage range selectors as bitfield values. If pickable ranges are used each range must have corresponding selector here.
n_linear_ranges: Number of entries in the linear_ranges (and in linear_range_selectors_bitfield if used) table(s).
volt_table: Voltage mapping table (if table based mapping)
curr_table: Current limit mapping table (if table based mapping)
vsel_range_reg: Register for range selector when using pickable ranges and regulator_map_*_voltage_*_pickable functions.
vsel_range_mask: Mask for register bitfield used for range selector
range_applied_by_vsel: A flag to indicate that changes to vsel_range_reg are only effective after vsel_reg is written
vsel_reg: Register for selector when using regulator_map_*_voltage_*
vsel_mask: Mask for register bitfield used for selector
vsel_step: Specify the resolution of selector stepping when setting voltage. If 0, then no stepping is done (requested selector is set directly), if >0 then the regulator API will ramp the voltage up/down gradually each time increasing/decreasing the selector by the specified step value.
csel_reg: Register for current limit selector using regmap set_current_limit
csel_mask: Mask for register bitfield used for current limit selector
apply_reg: Register for initiate voltage change on the output when using regulator_set_voltage_sel_regmap
apply_bit: Register bitfield used for initiate voltage change on the output when using regulator_set_voltage_sel_regmap
enable_reg: Register for control when using regmap enable/disable ops
enable_mask: Mask for control when using regmap enable/disable ops
enable_val: Enabling value for control when using regmap enable/disable ops
disable_val: Disabling value for control when using regmap enable/disable ops
enable_is_inverted: A flag to indicate set enable_mask bits to disable when using regulator_enable_regmap and friends APIs.
bypass_reg: Register for control when using regmap set_bypass
bypass_mask: Mask for control when using regmap set_bypass
bypass_val_on: Enabling value for control when using regmap set_bypass
bypass_val_off: Disabling value for control when using regmap set_bypass
active_discharge_on: Disabling value for control when using regmap set_active_discharge
active_discharge_off: Enabling value for control when using regmap set_active_discharge
active_discharge_mask: Mask for control when using regmap set_active_discharge
active_discharge_reg: Register for control when using regmap set_active_discharge
soft_start_reg: Register for control when using regmap set_soft_start
soft_start_mask: Mask for control when using regmap set_soft_start
soft_start_val_on: Enabling value for control when using regmap set_soft_start
pull_down_reg: Register for control when using regmap set_pull_down
pull_down_mask: Mask for control when using regmap set_pull_down
pull_down_val_on: Enabling value for control when using regmap set_pull_down
ramp_reg: Register for controlling the regulator ramp-rate.
ramp_mask: Bitmask for the ramp-rate control register.
ramp_delay_table: Table for mapping the regulator ramp-rate values. Values should be given in units of V/S (uV/uS). See the regulator_set_ramp_delay_regmap().
n_ramp_values: number of elements at ramp_delay_table.
enable_time: Time taken for initial enable of regulator (in uS).
off_on_delay: guard time (in uS), before re-enabling a regulator
poll_enabled_time: The polling interval (in uS) to use while checking that the regulator was actually enabled. Max upto enable_time.
of_map_mode: Maps a hardware mode defined in a DeviceTree to a standard mode

Description

Each regulator registered with the core is described with a structure of this type and a struct regulator_config. This structure contains the non-varying parts of the regulator description.

struct regulator_config¶: Dynamic regulator descriptor

Definition:

struct regulator_config {
    struct device *dev;
    const struct regulator_init_data *init_data;
    void *driver_data;
    struct device_node *of_node;
    struct regmap *regmap;
    struct gpio_desc *ena_gpiod;
};

Members

dev: struct device for the regulator
init_data: platform provided init data, passed through by driver
driver_data: private regulator data
of_node: OpenFirmware node to parse for device tree bindings (may be NULL).
regmap: regmap to use for core regmap helpers if dev_get_regmap() is insufficient.
ena_gpiod: GPIO controlling regulator enable.

Description

Each regulator registered with the core is described with a structure of this type and a struct regulator_desc. This structure contains the runtime variable parts of the regulator description.

struct regulator_err_state¶: regulator error/notification status

Definition:

struct regulator_err_state {
    struct regulator_dev *rdev;
    unsigned long notifs;
    unsigned long errors;
    int possible_errs;
};

Members

rdev: Regulator which status the struct indicates.
notifs: Events which have occurred on the regulator.
errors: Errors which are active on the regulator.
possible_errs: Errors which can be signaled (by given IRQ).

struct regulator_irq_data¶: regulator error/notification status data

Definition:

struct regulator_irq_data {
    struct regulator_err_state *states;
    int num_states;
    void *data;
    long opaque;
};

Members

states: Status structs for each of the associated regulators.
num_states: Amount of associated regulators.
data: Driver data pointer given at regulator_irq_desc.
opaque: Value storage for IC driver. Core does not update this. ICs may want to store status register value here at map_event and compare contents at ‘renable’ callback to see if new problems have been added to status. If that is the case it may be desirable to return REGULATOR_ERROR_CLEARED and not REGULATOR_ERROR_ON to allow IRQ fire again and to generate notifications also for the new issues.

Description

This structure is passed to ‘map_event’ and ‘renable’ callbacks for reporting regulator status to core.

struct regulator_irq_desc¶: notification sender for IRQ based events.

Definition:

struct regulator_irq_desc {
    const char *name;
    int fatal_cnt;
    int reread_ms;
    int irq_off_ms;
    bool skip_off;
    bool high_prio;
    void *data;
    int (*die)(struct regulator_irq_data *rid);
    int (*map_event)(int irq, struct regulator_irq_data *rid, unsigned long *dev_mask);
    int (*renable)(struct regulator_irq_data *rid);
};

Members

name: The visible name for the IRQ
fatal_cnt: If this IRQ is used to signal HW damaging condition it may be best to shut-down regulator(s) or reboot the SOC if error handling is repeatedly failing. If fatal_cnt is given the IRQ handling is aborted if it fails for fatal_cnt times and die() callback (if populated) is called. If die() is not populated poweroff for the system is attempted in order to prevent any further damage.
reread_ms: The time which is waited before attempting to re-read status at the worker if IC reading fails. Immediate re-read is done if time is not specified.
irq_off_ms: The time which IRQ is kept disabled before re-evaluating the status for devices which keep IRQ disabled for duration of the error. If this is not given the IRQ is left enabled and renable is not called.
skip_off: If set to true the IRQ handler will attempt to check if any of the associated regulators are enabled prior to taking other actions. If no regulators are enabled and this is set to true a spurious IRQ is assumed and IRQ_NONE is returned.
high_prio: Boolean to indicate that high priority WQ should be used.
data: Driver private data pointer which will be passed as such to the renable, map_event and die callbacks in regulator_irq_data.
die: Protection callback. If IC status reading or recovery actions fail fatal_cnt times this callback is called or system is powered off. This callback should implement a final protection attempt like disabling the regulator. If protection succeeded die() may return 0. If anything else is returned the core assumes final protection failed and attempts to perform a poweroff as a last resort.
map_event: Driver callback to map IRQ status into regulator devices with events / errors. NOTE: callback MUST initialize both the errors and notifs for all rdevs which it signals having active events as core does not clean the map data. REGULATOR_FAILED_RETRY can be returned to indicate that the status reading from IC failed. If this is repeated for fatal_cnt times the core will call die() callback or power-off the system as a last resort to protect the HW.
renable: Optional callback to check status (if HW supports that) before re-enabling IRQ. If implemented this should clear the error flags so that errors fetched by regulator_get_error_flags() are updated. If callback is not implemented then errors are assumed to be cleared and IRQ is re-enabled. REGULATOR_FAILED_RETRY can be returned to indicate that the status reading from IC failed. If this is repeated for ‘fatal_cnt’ times the core will call die() callback or if die() is not populated then attempt to power-off the system as a last resort to protect the HW. Returning zero indicates that the problem in HW has been solved and IRQ will be re-enabled. Returning REGULATOR_ERROR_ON indicates the error condition is still active and keeps IRQ disabled. Please note that returning REGULATOR_ERROR_ON does not retrigger evaluating what events are active or resending notifications. If this is needed you probably want to return zero and allow IRQ to retrigger causing events to be re-evaluated and re-sent.

Description

This structure is used for registering regulator IRQ notification helper.

struct regulator *regulator_get(struct device *dev, const char *id)¶: lookup and obtain a reference to a regulator.

Parameters

struct device *dev: device for regulator “consumer”
const char *id: Supply name or regulator ID.

Description

Returns a struct regulator corresponding to the regulator producer, or IS_ERR() condition containing errno.

Use of supply names configured via set_consumer_device_supply() is strongly encouraged. It is recommended that the supply name used should match the name used for the supply and/or the relevant device pins in the datasheet.

struct regulator *regulator_get_exclusive(struct device *dev, const char *id)¶: obtain exclusive access to a regulator.

Parameters

struct device *dev: device for regulator “consumer”
const char *id: Supply name or regulator ID.

Description

Returns a struct regulator corresponding to the regulator producer, or IS_ERR() condition containing errno. Other consumers will be unable to obtain this regulator while this reference is held and the use count for the regulator will be initialised to reflect the current state of the regulator.

This is intended for use by consumers which cannot tolerate shared use of the regulator such as those which need to force the regulator off for correct operation of the hardware they are controlling.

Use of supply names configured via set_consumer_device_supply() is strongly encouraged. It is recommended that the supply name used should match the name used for the supply and/or the relevant device pins in the datasheet.

struct regulator *regulator_get_optional(struct device *dev, const char *id)¶: obtain optional access to a regulator.

Parameters

struct device *dev: device for regulator “consumer”
const char *id: Supply name or regulator ID.

Description

Returns a struct regulator corresponding to the regulator producer, or IS_ERR() condition containing errno.

This is intended for use by consumers for devices which can have some supplies unconnected in normal use, such as some MMC devices. It can allow the regulator core to provide stub supplies for other supplies requested using normal regulator_get() calls without disrupting the operation of drivers that can handle absent supplies.

Use of supply names configured via set_consumer_device_supply() is strongly encouraged. It is recommended that the supply name used should match the name used for the supply and/or the relevant device pins in the datasheet.

void regulator_put(struct regulator *regulator)¶: “free” the regulator source

Parameters

struct regulator *regulator: regulator source

Note

drivers must ensure that all regulator_enable calls made on this regulator source are balanced by regulator_disable calls prior to calling this function.

int regulator_register_supply_alias(struct device *dev, const char *id, struct device *alias_dev, const char *alias_id)¶: Provide device alias for supply lookup

Parameters

struct device *dev: device that will be given as the regulator “consumer”
const char *id: Supply name or regulator ID
struct device *alias_dev: device that should be used to lookup the supply
const char *alias_id: Supply name or regulator ID that should be used to lookup the supply

Description

All lookups for id on dev will instead be conducted for alias_id on alias_dev.

void regulator_unregister_supply_alias(struct device *dev, const char *id)¶: Remove device alias

Parameters

struct device *dev: device that will be given as the regulator “consumer”
const char *id: Supply name or regulator ID

Description

Remove a lookup alias if one exists for id on dev.

int regulator_bulk_register_supply_alias(struct device *dev, const char *const *id, struct device *alias_dev, const char *const *alias_id, int num_id)¶: register multiple aliases

Parameters

struct device *dev: device that will be given as the regulator “consumer”
const char *const *id: List of supply names or regulator IDs
struct device *alias_dev: device that should be used to lookup the supply
const char *const *alias_id: List of supply names or regulator IDs that should be used to lookup the supply
int num_id: Number of aliases to register

Description

return 0 on success, an errno on failure.

This helper function allows drivers to register several supply aliases in one operation. If any of the aliases cannot be registered any aliases that were registered will be removed before returning to the caller.

void regulator_bulk_unregister_supply_alias(struct device *dev, const char *const *id, int num_id)¶: unregister multiple aliases

Parameters

struct device *dev: device that will be given as the regulator “consumer”
const char *const *id: List of supply names or regulator IDs
int num_id: Number of aliases to unregister

Description

This helper function allows drivers to unregister several supply aliases in one operation.

int regulator_enable(struct regulator *regulator)¶: enable regulator output

Parameters

struct regulator *regulator: regulator source

Description

Request that the regulator be enabled with the regulator output at the predefined voltage or current value. Calls to regulator_enable() must be balanced with calls to regulator_disable().

NOTE

the output value can be set by other drivers, boot loader or may be hardwired in the regulator.

int regulator_disable(struct regulator *regulator)¶: disable regulator output

Parameters

struct regulator *regulator: regulator source

Description

Disable the regulator output voltage or current. Calls to regulator_enable() must be balanced with calls to regulator_disable().

NOTE

this will only disable the regulator output if no other consumer devices have it enabled, the regulator device supports disabling and machine constraints permit this operation.

int regulator_force_disable(struct regulator *regulator)¶: force disable regulator output

Parameters

struct regulator *regulator: regulator source

Description

Forcibly disable the regulator output voltage or current.

NOTE

this will disable the regulator output even if other consumer devices have it enabled. This should be used for situations when device damage will likely occur if the regulator is not disabled (e.g. over temp).

int regulator_disable_deferred(struct regulator *regulator, int ms)¶: disable regulator output with delay

Parameters

struct regulator *regulator: regulator source
int ms: milliseconds until the regulator is disabled

Description

Execute regulator_disable() on the regulator after a delay. This is intended for use with devices that require some time to quiesce.

NOTE

this will only disable the regulator output if no other consumer devices have it enabled, the regulator device supports disabling and machine constraints permit this operation.

int regulator_is_enabled(struct regulator *regulator)¶: is the regulator output enabled

Parameters

struct regulator *regulator: regulator source

Description

Returns positive if the regulator driver backing the source/client has requested that the device be enabled, zero if it hasn’t, else a negative errno code.

Note that the device backing this regulator handle can have multiple users, so it might be enabled even if regulator_enable() was never called for this particular source.

int regulator_count_voltages(struct regulator *regulator)¶: count regulator_list_voltage() selectors

Parameters

struct regulator *regulator: regulator source

Description

Returns number of selectors, or negative errno. Selectors are numbered starting at zero, and typically correspond to bitfields in hardware registers.

int regulator_list_voltage(struct regulator *regulator, unsigned selector)¶: enumerate supported voltages

Parameters

struct regulator *regulator: regulator source
unsigned selector: identify voltage to list

Context

can sleep

Description

Returns a voltage that can be passed to regulator_set_voltage(), zero if this selector code can’t be used on this system, or a negative errno.

int regulator_get_hardware_vsel_register(struct regulator *regulator, unsigned *vsel_reg, unsigned *vsel_mask)¶: get the HW voltage selector register

Parameters

struct regulator *regulator: regulator source
unsigned *vsel_reg: voltage selector register, output parameter
unsigned *vsel_mask: mask for voltage selector bitfield, output parameter

Description

Returns the hardware register offset and bitmask used for setting the regulator voltage. This might be useful when configuring voltage-scaling hardware or firmware that can make I2C requests behind the kernel’s back, for example.

On success, the output parameters vsel_reg and vsel_mask are filled in and 0 is returned, otherwise a negative errno is returned.

int regulator_list_hardware_vsel(struct regulator *regulator, unsigned selector)¶: get the HW-specific register value for a selector

Parameters

struct regulator *regulator: regulator source
unsigned selector: identify voltage to list

Description

Converts the selector to a hardware-specific voltage selector that can be directly written to the regulator registers. The address of the voltage register can be determined by calling regulator_get_hardware_vsel_register.

On error a negative errno is returned.

unsigned int regulator_get_linear_step(struct regulator *regulator)¶: return the voltage step size between VSEL values

Parameters

struct regulator *regulator: regulator source

Description

Returns the voltage step size between VSEL values for linear regulators, or return 0 if the regulator isn’t a linear regulator.

int regulator_is_supported_voltage(struct regulator *regulator, int min_uV, int max_uV)¶: check if a voltage range can be supported

Parameters

struct regulator *regulator: Regulator to check.
int min_uV: Minimum required voltage in uV.
int max_uV: Maximum required voltage in uV.

Description

Returns a boolean.

int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV)¶: set regulator output voltage

Parameters

struct regulator *regulator: regulator source
int min_uV: Minimum required voltage in uV
int max_uV: Maximum acceptable voltage in uV

Description

Sets a voltage regulator to the desired output voltage. This can be set during any regulator state. IOW, regulator can be disabled or enabled.

If the regulator is enabled then the voltage will change to the new value immediately otherwise if the regulator is disabled the regulator will output at the new voltage when enabled.

NOTE

If the regulator is shared between several devices then the lowest request voltage that meets the system constraints will be used. Regulator system constraints must be set for this regulator before calling this function otherwise this call will fail.

int regulator_set_voltage_time(struct regulator *regulator, int old_uV, int new_uV)¶: get raise/fall time

Parameters

struct regulator *regulator: regulator source
int old_uV: starting voltage in microvolts
int new_uV: target voltage in microvolts

Description

Provided with the starting and ending voltage, this function attempts to calculate the time in microseconds required to rise or fall to this new voltage.

int regulator_set_voltage_time_sel(struct regulator_dev *rdev, unsigned int old_selector, unsigned int new_selector)¶: get raise/fall time

Parameters

struct regulator_dev *rdev: regulator source device
unsigned int old_selector: selector for starting voltage
unsigned int new_selector: selector for target voltage

Description

Provided with the starting and target voltage selectors, this function returns time in microseconds required to rise or fall to this new voltage

Drivers providing ramp_delay in regulation_constraints can use this as their set_voltage_time_sel() operation.

int regulator_sync_voltage(struct regulator *regulator)¶: re-apply last regulator output voltage

Parameters

struct regulator *regulator: regulator source

Description

Re-apply the last configured voltage. This is intended to be used where some external control source the consumer is cooperating with has caused the configured voltage to change.

int regulator_get_voltage(struct regulator *regulator)¶: get regulator output voltage

Parameters

struct regulator *regulator: regulator source

Description

This returns the current regulator voltage in uV.

NOTE

If the regulator is disabled it will return the voltage value. This function should not be used to determine regulator state.

int regulator_set_current_limit(struct regulator *regulator, int min_uA, int max_uA)¶: set regulator output current limit

Parameters

struct regulator *regulator: regulator source
int min_uA: Minimum supported current in uA
int max_uA: Maximum supported current in uA

Description

Sets current sink to the desired output current. This can be set during any regulator state. IOW, regulator can be disabled or enabled.

If the regulator is enabled then the current will change to the new value immediately otherwise if the regulator is disabled the regulator will output at the new current when enabled.

NOTE

Regulator system constraints must be set for this regulator before calling this function otherwise this call will fail.

int regulator_get_current_limit(struct regulator *regulator)¶: get regulator output current

Parameters

struct regulator *regulator: regulator source

Description

This returns the current supplied by the specified current sink in uA.

NOTE

If the regulator is disabled it will return the current value. This function should not be used to determine regulator state.

int regulator_set_mode(struct regulator *regulator, unsigned int mode)¶: set regulator operating mode

Parameters

struct regulator *regulator: regulator source
unsigned int mode: operating mode - one of the REGULATOR_MODE constants

Description

Set regulator operating mode to increase regulator efficiency or improve regulation performance.

NOTE

Regulator system constraints must be set for this regulator before calling this function otherwise this call will fail.

unsigned int regulator_get_mode(struct regulator *regulator)¶: get regulator operating mode

Parameters

struct regulator *regulator: regulator source

Description

Get the current regulator operating mode.

int regulator_get_error_flags(struct regulator *regulator, unsigned int *flags)¶: get regulator error information

Parameters

struct regulator *regulator: regulator source
unsigned int *flags: pointer to store error flags

Description

Get the current regulator error information.

int regulator_set_load(struct regulator *regulator, int uA_load)¶: set regulator load

Parameters

struct regulator *regulator: regulator source
int uA_load: load current

Description

Notifies the regulator core of a new device load. This is then used by DRMS (if enabled by constraints) to set the most efficient regulator operating mode for the new regulator loading.

Consumer devices notify their supply regulator of the maximum power they will require (can be taken from device datasheet in the power consumption tables) when they change operational status and hence power state. Examples of operational state changes that can affect power consumption are :-

o Device is opened / closed. o Device I/O is about to begin or has just finished. o Device is idling in between work.

This information is also exported via sysfs to userspace.

DRMS will sum the total requested load on the regulator and change to the most efficient operating mode if platform constraints allow.

If a regulator is an always-on regulator then an individual consumer’s load will still be removed if that consumer is fully disabled.

On error a negative errno is returned.

NOTE

when a regulator consumer requests to have a regulator disabled then any load that consumer requested no longer counts toward the total requested load. If the regulator is re-enabled then the previously requested load will start counting again.

int regulator_allow_bypass(struct regulator *regulator, bool enable)¶: allow the regulator to go into bypass mode

Parameters

struct regulator *regulator: Regulator to configure
bool enable: enable or disable bypass mode

Description

Allow the regulator to go into bypass mode if all other consumers for the regulator also enable bypass mode and the machine constraints allow this. Bypass mode means that the regulator is simply passing the input directly to the output with no regulation.

int regulator_register_notifier(struct regulator *regulator, struct notifier_block *nb)¶: register regulator event notifier

Parameters

struct regulator *regulator: regulator source
struct notifier_block *nb: notifier block

Description

Register notifier block to receive regulator events.

int regulator_unregister_notifier(struct regulator *regulator, struct notifier_block *nb)¶: unregister regulator event notifier

Parameters

struct regulator *regulator: regulator source
struct notifier_block *nb: notifier block

Description

Unregister regulator event notifier block.

int regulator_bulk_get(struct device *dev, int num_consumers, struct regulator_bulk_data *consumers)¶: get multiple regulator consumers

Parameters

struct device *dev: Device to supply
int num_consumers: Number of consumers to register
struct regulator_bulk_data *consumers: Configuration of consumers; clients are stored here.

Description

return 0 on success, an errno on failure.

This helper function allows drivers to get several regulator consumers in one operation. If any of the regulators cannot be acquired then any regulators that were allocated will be freed before returning to the caller.

int regulator_bulk_enable(int num_consumers, struct regulator_bulk_data *consumers)¶: enable multiple regulator consumers

Parameters

int num_consumers: Number of consumers
struct regulator_bulk_data *consumers: Consumer data; clients are stored here. return 0 on success, an errno on failure

Description

This convenience API allows consumers to enable multiple regulator clients in a single API call. If any consumers cannot be enabled then any others that were enabled will be disabled again prior to return.

int regulator_bulk_disable(int num_consumers, struct regulator_bulk_data *consumers)¶: disable multiple regulator consumers

Parameters

int num_consumers: Number of consumers
struct regulator_bulk_data *consumers: Consumer data; clients are stored here. return 0 on success, an errno on failure

Description

This convenience API allows consumers to disable multiple regulator clients in a single API call. If any consumers cannot be disabled then any others that were disabled will be enabled again prior to return.

int regulator_bulk_force_disable(int num_consumers, struct regulator_bulk_data *consumers)¶: force disable multiple regulator consumers

Parameters

int num_consumers: Number of consumers
struct regulator_bulk_data *consumers: Consumer data; clients are stored here. return 0 on success, an errno on failure

Description

This convenience API allows consumers to forcibly disable multiple regulator clients in a single API call.

NOTE

This should be used for situations when device damage will likely occur if the regulators are not disabled (e.g. over temp). Although regulator_force_disable function call for some consumers can return error numbers, the function is called for all consumers.

void regulator_bulk_free(int num_consumers, struct regulator_bulk_data *consumers)¶: free multiple regulator consumers

Parameters

int num_consumers: Number of consumers
struct regulator_bulk_data *consumers: Consumer data; clients are stored here.

Description

This convenience API allows consumers to free multiple regulator clients in a single API call.

int regulator_notifier_call_chain(struct regulator_dev *rdev, unsigned long event, void *data)¶: call regulator event notifier

Parameters

struct regulator_dev *rdev: regulator source
unsigned long event: notifier block
void *data: callback-specific data.

Description

Called by regulator drivers to notify clients a regulator event has occurred.

int regulator_mode_to_status(unsigned int mode)¶: convert a regulator mode into a status

Parameters

unsigned int mode: Mode to convert

Description

Convert a regulator mode into a status.

struct regulator_dev *regulator_register(struct device *dev, const struct regulator_desc *regulator_desc, const struct regulator_config *cfg)¶: register regulator

Parameters

struct device *dev: the device that drive the regulator
const struct regulator_desc *regulator_desc: regulator to register
const struct regulator_config *cfg: runtime configuration for regulator

Description

Called by regulator drivers to register a regulator. Returns a valid pointer to struct regulator_dev on success or an ERR_PTR() on error.

void regulator_unregister(struct regulator_dev *rdev)¶: unregister regulator

Parameters

struct regulator_dev *rdev: regulator to unregister

Description

Called by regulator drivers to unregister a regulator.

void regulator_has_full_constraints(void)¶: the system has fully specified constraints

Parameters

void: no arguments

Description

Calling this function will cause the regulator API to disable all regulators which have a zero use count and don’t have an always_on constraint in a late_initcall.

The intention is that this will become the default behaviour in a future kernel release so users are encouraged to use this facility now.

void *rdev_get_drvdata(struct regulator_dev *rdev)¶: get rdev regulator driver data

Parameters

struct regulator_dev *rdev: regulator

Description

Get rdev regulator driver private data. This call can be used in the regulator driver context.

void *regulator_get_drvdata(struct regulator *regulator)¶: get regulator driver data

Parameters

struct regulator *regulator: regulator

Description

Get regulator driver private data. This call can be used in the consumer driver context when non API regulator specific functions need to be called.

void regulator_set_drvdata(struct regulator *regulator, void *data)¶: set regulator driver data

Parameters

struct regulator *regulator: regulator
void *data: data

int rdev_get_id(struct regulator_dev *rdev)¶: get regulator ID

Parameters

struct regulator_dev *rdev: regulator

The Linux Kernel

Contents

This Page

Voltage and current regulator API¶

Introduction¶

Glossary¶

Consumer driver interface¶

Enabling and disabling¶

Configuration¶

Callbacks¶

Regulator driver interface¶

Machine interface¶

Supplies¶

Constraints¶

API reference¶