Liam Girdwood

lrg@slimlogic.co.uk

Mark Brown Wolfson Microelectronics

broonie@opensource.wolfsonmicro.com

2007-2008 Wolfson Microelectronics 2008 Liam Girdwood This documentation is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License version 2 as published by the Free Software Foundation. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA For more details see the file COPYING in the source distribution of Linux. 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. 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. 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. 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. 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 may also be registered for events such as regulation failures. 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. 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. Regulator supplies are specified using struct regulator_consumer_supply. This is done at driver registration time as part of the machine 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. Due to limitations of the kernel documentation framework and the existing layout of the source code the entire regulator API is documented here. Kernel Hackers Manual July 2017 struct pre_voltage_change_data 9 4.1.27 struct pre_voltage_change_data Data sent with PRE_VOLTAGE_CHANGE event struct pre_voltage_change_data { unsigned long old_uV; unsigned long min_uV; unsigned long max_uV; }; old_uV Current voltage before change. min_uV Min voltage we'll change to. max_uV Max voltage we'll change to. Kernel Hackers Manual July 2017 struct regulator_bulk_data 9 4.1.27 struct regulator_bulk_data Data used for bulk regulator operations. struct regulator_bulk_data { const char * supply; struct regulator * consumer; }; supply The name of the supply. 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. 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. Kernel Hackers Manual July 2017 struct regulator_state 9 4.1.27 struct regulator_state regulator state during low power system states struct regulator_state { int uV; unsigned int mode; int enabled; int disabled; }; uV Operating voltage during suspend. mode Operating mode during suspend. enabled Enabled during suspend. disabled Disabled during suspend. 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. Kernel Hackers Manual July 2017 struct regulation_constraints 9 4.1.27 struct regulation_constraints regulator operating constraints. struct regulation_constraints { const char * name; int min_uV; int max_uV; int uV_offset; int min_uA; int max_uA; 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; suspend_state_t initial_state; unsigned int initial_mode; unsigned int ramp_delay; unsigned int enable_time; unsigned always_on:1; unsigned boot_on:1; unsigned apply_uV:1; unsigned ramp_disable:1; }; 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. 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. 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) enable_time Turn-on time of the rails (unit: microseconds) 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. This struct describes regulator and board/machine specific constraints. Kernel Hackers Manual July 2017 struct regulator_consumer_supply 9 4.1.27 struct regulator_consumer_supply supply -> device mapping struct regulator_consumer_supply { const char * dev_name; const char * supply; }; dev_name Result of dev_name for the consumer. supply Name for the supply. 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. Kernel Hackers Manual July 2017 struct regulator_init_data 9 4.1.27 struct regulator_init_data regulator platform initialisation data. 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; }; 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. Initialisation constraints, our supply and consumers supplies. Kernel Hackers Manual July 2017 struct regulator_linear_range 9 4.1.27 struct regulator_linear_range specify linear voltage ranges struct regulator_linear_range { unsigned int min_uV; unsigned int min_sel; unsigned int max_sel; unsigned int uV_step; }; min_uV Lowest voltage in range min_sel Lowest selector for range max_sel Highest selector for range uV_step Step size Specify a range of voltages for regulator_map_linar_range and regulator_list_linear_range. Kernel Hackers Manual July 2017 struct regulator_ops 9 4.1.27 struct regulator_ops regulator operations. 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 (* 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 (* enable_time) (struct regulator_dev *); int (* set_ramp_delay) (struct regulator_dev *, int ramp_delay); int (* set_voltage_time_sel) (struct regulator_dev *,unsigned int old_selector,unsigned int new_selector); 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); }; 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. get_voltage_sel Return the currently configured voltage selector for the regulator. 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. 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. 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_sel Time taken for the regulator voltage output voltage to stabilise after being set to a new value, in microseconds. The function provides the from and to voltage selector, the function should return the worst case. 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. This struct describes regulator operations which can be implemented by regulator chip drivers. Kernel Hackers Manual July 2017 struct regulator_desc 9 4.1.27 struct regulator_desc Static regulator descriptor struct regulator_desc { const char * name; const char * supply_name; const char * of_match; const char * regulators_node; int (* of_parse_cb) (struct device_node *,const struct regulator_desc *,struct regulator_config *); int id; bool continuous_voltage_range; unsigned n_voltages; 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; const struct regulator_linear_range * linear_ranges; int n_linear_ranges; const unsigned int * volt_table; unsigned int vsel_reg; unsigned int vsel_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 enable_time; unsigned int off_on_delay; unsigned int (* of_map_mode) (unsigned int mode); }; name Identifying name for the regulator. supply_name Identifying the regulator supply of_match Name used to identify regulator in DT. 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. 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) linear_ranges A constant table of possible voltage ranges. n_linear_ranges Number of entries in the linear_ranges table. volt_table Voltage mapping table (if table based mapping) vsel_reg Register for selector when using regulator_regmap_X_voltage_ vsel_mask Mask for register bitfield used for 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 enable_time Time taken for initial enable of regulator (in uS). off_on_delay guard time (in uS), before re-enabling a regulator of_map_mode Maps a hardware mode defined in a DeviceTree to a standard mode 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. Kernel Hackers Manual July 2017 struct regulator_config 9 4.1.27 struct regulator_config Dynamic regulator descriptor struct regulator_config { struct device * dev; const struct regulator_init_data * init_data; void * driver_data; struct device_node * of_node; struct regmap * regmap; bool ena_gpio_initialized; int ena_gpio; unsigned int ena_gpio_invert:1; unsigned int ena_gpio_flags; }; 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_gpio_initialized GPIO controlling regulator enable was properly initialized, meaning that >= 0 is a valid gpio identifier and < 0 is a non existent gpio. ena_gpio GPIO controlling regulator enable. ena_gpio_invert Sense for GPIO enable control. ena_gpio_flags Flags to use when calling gpio_request_one 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. Kernel Hackers Manual July 2017 regulator_get 9 4.1.27 regulator_get lookup and obtain a reference to a regulator. struct regulator * regulator_get struct device * dev const char * id dev device for regulator consumer id Supply name or regulator ID. Returns a struct regulator corresponding to the regulator producer, or IS_ERR condition containing errno. Use of supply names configured via regulator_set_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. Kernel Hackers Manual July 2017 regulator_get_exclusive 9 4.1.27 regulator_get_exclusive obtain exclusive access to a regulator. struct regulator * regulator_get_exclusive struct device * dev const char * id dev device for regulator consumer id Supply name or regulator ID. 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 regulator_set_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. Kernel Hackers Manual July 2017 regulator_get_optional 9 4.1.27 regulator_get_optional obtain optional access to a regulator. struct regulator * regulator_get_optional struct device * dev const char * id dev device for regulator consumer id Supply name or regulator ID. 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 regulator_set_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. Kernel Hackers Manual July 2017 regulator_put 9 4.1.27 regulator_put "free" the regulator source void regulator_put struct regulator * regulator regulator regulator source drivers must ensure that all regulator_enable calls made on this regulator source are balanced by regulator_disable calls prior to calling this function. Kernel Hackers Manual July 2017 regulator_register_supply_alias 9 4.1.27 regulator_register_supply_alias Provide device alias for supply lookup int regulator_register_supply_alias struct device * dev const char * id struct device * alias_dev const char * alias_id dev device that will be given as the regulator consumer id Supply name or regulator ID alias_dev device that should be used to lookup the supply alias_id Supply name or regulator ID that should be used to lookup the supply All lookups for id on dev will instead be conducted for alias_id on alias_dev. Kernel Hackers Manual July 2017 regulator_unregister_supply_alias 9 4.1.27 regulator_unregister_supply_alias Remove device alias void regulator_unregister_supply_alias struct device * dev const char * id dev device that will be given as the regulator consumer id Supply name or regulator ID Remove a lookup alias if one exists for id on dev. Kernel Hackers Manual July 2017 regulator_bulk_register_supply_alias 9 4.1.27 regulator_bulk_register_supply_alias register multiple aliases 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 dev device that will be given as the regulator consumer id List of supply names or regulator IDs alias_dev device that should be used to lookup the supply alias_id List of supply names or regulator IDs that should be used to lookup the supply num_id Number of aliases to register 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. Kernel Hackers Manual July 2017 regulator_bulk_unregister_supply_alias 9 4.1.27 regulator_bulk_unregister_supply_alias unregister multiple aliases void regulator_bulk_unregister_supply_alias struct device * dev const char *const * id int num_id dev device that will be given as the regulator consumer id List of supply names or regulator IDs num_id Number of aliases to unregister This helper function allows drivers to unregister several supply aliases in one operation. Kernel Hackers Manual July 2017 regulator_enable 9 4.1.27 regulator_enable enable regulator output int regulator_enable struct regulator * regulator regulator regulator source 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. the output value can be set by other drivers, boot loader or may be hardwired in the regulator. Kernel Hackers Manual July 2017 regulator_disable 9 4.1.27 regulator_disable disable regulator output int regulator_disable struct regulator * regulator regulator regulator source Disable the regulator output voltage or current. Calls to regulator_enable must be balanced with calls to regulator_disable. 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. Kernel Hackers Manual July 2017 regulator_force_disable 9 4.1.27 regulator_force_disable force disable regulator output int regulator_force_disable struct regulator * regulator regulator regulator source Forcibly disable the regulator output voltage or current. 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). Kernel Hackers Manual July 2017 regulator_disable_deferred 9 4.1.27 regulator_disable_deferred disable regulator output with delay int regulator_disable_deferred struct regulator * regulator int ms regulator regulator source ms miliseconds until the regulator is disabled Execute regulator_disable on the regulator after a delay. This is intended for use with devices that require some time to quiesce. 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. Kernel Hackers Manual July 2017 regulator_is_enabled 9 4.1.27 regulator_is_enabled is the regulator output enabled int regulator_is_enabled struct regulator * regulator regulator regulator source 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. Kernel Hackers Manual July 2017 regulator_can_change_voltage 9 4.1.27 regulator_can_change_voltage check if regulator can change voltage int regulator_can_change_voltage struct regulator * regulator regulator regulator source Returns positive if the regulator driver backing the source/client can change its voltage, false otherwise. Useful for detecting fixed or dummy regulators and disabling voltage change logic in the client driver. Kernel Hackers Manual July 2017 regulator_count_voltages 9 4.1.27 regulator_count_voltages count regulator_list_voltage selectors int regulator_count_voltages struct regulator * regulator regulator regulator source Returns number of selectors, or negative errno. Selectors are numbered starting at zero, and typically correspond to bitfields in hardware registers. Kernel Hackers Manual July 2017 regulator_list_voltage 9 4.1.27 regulator_list_voltage enumerate supported voltages int regulator_list_voltage struct regulator * regulator unsigned selector regulator regulator source selector identify voltage to list can sleep 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. Kernel Hackers Manual July 2017 regulator_get_hardware_vsel_register 9 4.1.27 regulator_get_hardware_vsel_register get the HW voltage selector register int regulator_get_hardware_vsel_register struct regulator * regulator unsigned * vsel_reg unsigned * vsel_mask regulator regulator source vsel_reg voltage selector register, output parameter vsel_mask mask for voltage selector bitfield, output parameter 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. Kernel Hackers Manual July 2017 regulator_list_hardware_vsel 9 4.1.27 regulator_list_hardware_vsel get the HW-specific register value for a selector int regulator_list_hardware_vsel struct regulator * regulator unsigned selector regulator regulator source selector identify voltage to list 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. Kernel Hackers Manual July 2017 regulator_get_linear_step 9 4.1.27 regulator_get_linear_step return the voltage step size between VSEL values unsigned int regulator_get_linear_step struct regulator * regulator regulator regulator source Returns the voltage step size between VSEL values for linear regulators, or return 0 if the regulator isn't a linear regulator. Kernel Hackers Manual July 2017 regulator_is_supported_voltage 9 4.1.27 regulator_is_supported_voltage check if a voltage range can be supported int regulator_is_supported_voltage struct regulator * regulator int min_uV int max_uV regulator Regulator to check. min_uV Minimum required voltage in uV. max_uV Maximum required voltage in uV. Returns a boolean or a negative error code. Kernel Hackers Manual July 2017 regulator_set_voltage 9 4.1.27 regulator_set_voltage set regulator output voltage int regulator_set_voltage struct regulator * regulator int min_uV int max_uV regulator regulator source min_uV Minimum required voltage in uV max_uV Maximum acceptable voltage in uV 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. 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. Kernel Hackers Manual July 2017 regulator_set_voltage_time 9 4.1.27 regulator_set_voltage_time get raise/fall time int regulator_set_voltage_time struct regulator * regulator int old_uV int new_uV regulator regulator source old_uV starting voltage in microvolts new_uV target voltage in microvolts 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. Kernel Hackers Manual July 2017 regulator_set_voltage_time_sel 9 4.1.27 regulator_set_voltage_time_sel get raise/fall time int regulator_set_voltage_time_sel struct regulator_dev * rdev unsigned int old_selector unsigned int new_selector rdev regulator source device old_selector selector for starting voltage new_selector selector for target voltage 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. Kernel Hackers Manual July 2017 regulator_sync_voltage 9 4.1.27 regulator_sync_voltage re-apply last regulator output voltage int regulator_sync_voltage struct regulator * regulator regulator regulator source 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. Kernel Hackers Manual July 2017 regulator_get_voltage 9 4.1.27 regulator_get_voltage get regulator output voltage int regulator_get_voltage struct regulator * regulator regulator regulator source This returns the current regulator voltage in uV. If the regulator is disabled it will return the voltage value. This function should not be used to determine regulator state. Kernel Hackers Manual July 2017 regulator_set_current_limit 9 4.1.27 regulator_set_current_limit set regulator output current limit int regulator_set_current_limit struct regulator * regulator int min_uA int max_uA regulator regulator source min_uA Minimum supported current in uA max_uA Maximum supported current in uA 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. Regulator system constraints must be set for this regulator before calling this function otherwise this call will fail. Kernel Hackers Manual July 2017 regulator_get_current_limit 9 4.1.27 regulator_get_current_limit get regulator output current int regulator_get_current_limit struct regulator * regulator regulator regulator source This returns the current supplied by the specified current sink in uA. If the regulator is disabled it will return the current value. This function should not be used to determine regulator state. Kernel Hackers Manual July 2017 regulator_set_mode 9 4.1.27 regulator_set_mode set regulator operating mode int regulator_set_mode struct regulator * regulator unsigned int mode regulator regulator source mode operating mode - one of the REGULATOR_MODE constants Set regulator operating mode to increase regulator efficiency or improve regulation performance. Regulator system constraints must be set for this regulator before calling this function otherwise this call will fail. Kernel Hackers Manual July 2017 regulator_get_mode 9 4.1.27 regulator_get_mode get regulator operating mode unsigned int regulator_get_mode struct regulator * regulator regulator regulator source Get the current regulator operating mode. Kernel Hackers Manual July 2017 regulator_set_load 9 4.1.27 regulator_set_load set regulator load int regulator_set_load struct regulator * regulator int uA_load regulator regulator source uA_load load current 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 - 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. On error a negative errno is returned. Kernel Hackers Manual July 2017 regulator_allow_bypass 9 4.1.27 regulator_allow_bypass allow the regulator to go into bypass mode int regulator_allow_bypass struct regulator * regulator bool enable regulator Regulator to configure enable enable or disable bypass mode 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. Kernel Hackers Manual July 2017 regulator_register_notifier 9 4.1.27 regulator_register_notifier register regulator event notifier int regulator_register_notifier struct regulator * regulator struct notifier_block * nb regulator regulator source nb notifier block Register notifier block to receive regulator events. Kernel Hackers Manual July 2017 regulator_unregister_notifier 9 4.1.27 regulator_unregister_notifier unregister regulator event notifier int regulator_unregister_notifier struct regulator * regulator struct notifier_block * nb regulator regulator source nb notifier block Unregister regulator event notifier block. Kernel Hackers Manual July 2017 regulator_bulk_get 9 4.1.27 regulator_bulk_get get multiple regulator consumers int regulator_bulk_get struct device * dev int num_consumers struct regulator_bulk_data * consumers dev Device to supply num_consumers Number of consumers to register consumers Configuration of consumers; clients are stored here. 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. Kernel Hackers Manual July 2017 regulator_bulk_enable 9 4.1.27 regulator_bulk_enable enable multiple regulator consumers int regulator_bulk_enable int num_consumers struct regulator_bulk_data * consumers num_consumers Number of consumers consumers Consumer data; clients are stored here. return 0 on success, an errno on failure 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. Kernel Hackers Manual July 2017 regulator_bulk_disable 9 4.1.27 regulator_bulk_disable disable multiple regulator consumers int regulator_bulk_disable int num_consumers struct regulator_bulk_data * consumers num_consumers Number of consumers consumers Consumer data; clients are stored here. return 0 on success, an errno on failure 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. Kernel Hackers Manual July 2017 regulator_bulk_force_disable 9 4.1.27 regulator_bulk_force_disable force disable multiple regulator consumers int regulator_bulk_force_disable int num_consumers struct regulator_bulk_data * consumers num_consumers Number of consumers consumers Consumer data; clients are stored here. return 0 on success, an errno on failure This convenience API allows consumers to forcibly disable multiple regulator clients in a single API call. 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. Kernel Hackers Manual July 2017 regulator_bulk_free 9 4.1.27 regulator_bulk_free free multiple regulator consumers void regulator_bulk_free int num_consumers struct regulator_bulk_data * consumers num_consumers Number of consumers consumers Consumer data; clients are stored here. This convenience API allows consumers to free multiple regulator clients in a single API call. Kernel Hackers Manual July 2017 regulator_notifier_call_chain 9 4.1.27 regulator_notifier_call_chain call regulator event notifier int regulator_notifier_call_chain struct regulator_dev * rdev unsigned long event void * data rdev regulator source event notifier block data callback-specific data. Called by regulator drivers to notify clients a regulator event has occurred. We also notify regulator clients downstream. Note lock must be held by caller. Kernel Hackers Manual July 2017 regulator_mode_to_status 9 4.1.27 regulator_mode_to_status convert a regulator mode into a status int regulator_mode_to_status unsigned int mode mode Mode to convert Convert a regulator mode into a status. Kernel Hackers Manual July 2017 regulator_register 9 4.1.27 regulator_register register regulator struct regulator_dev * regulator_register const struct regulator_desc * regulator_desc const struct regulator_config * cfg regulator_desc regulator to register cfg runtime configuration for regulator Called by regulator drivers to register a regulator. Returns a valid pointer to struct regulator_dev on success or an ERR_PTR on error. Kernel Hackers Manual July 2017 regulator_unregister 9 4.1.27 regulator_unregister unregister regulator void regulator_unregister struct regulator_dev * rdev rdev regulator to unregister Called by regulator drivers to unregister a regulator. Kernel Hackers Manual July 2017 regulator_suspend_prepare 9 4.1.27 regulator_suspend_prepare prepare regulators for system wide suspend int regulator_suspend_prepare suspend_state_t state state system suspend state Configure each regulator with it's suspend operating parameters for state. This will usually be called by machine suspend code prior to supending. Kernel Hackers Manual July 2017 regulator_suspend_finish 9 4.1.27 regulator_suspend_finish resume regulators from system wide suspend int regulator_suspend_finish void void no arguments Turn on regulators that might be turned off by regulator_suspend_prepare and that should be turned on according to the regulators properties. Kernel Hackers Manual July 2017 regulator_has_full_constraints 9 4.1.27 regulator_has_full_constraints the system has fully specified constraints void regulator_has_full_constraints void void no arguments 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. Kernel Hackers Manual July 2017 rdev_get_drvdata 9 4.1.27 rdev_get_drvdata get rdev regulator driver data void * rdev_get_drvdata struct regulator_dev * rdev rdev regulator Get rdev regulator driver private data. This call can be used in the regulator driver context. Kernel Hackers Manual July 2017 regulator_get_drvdata 9 4.1.27 regulator_get_drvdata get regulator driver data void * regulator_get_drvdata struct regulator * regulator regulator regulator 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. Kernel Hackers Manual July 2017 regulator_set_drvdata 9 4.1.27 regulator_set_drvdata set regulator driver data void regulator_set_drvdata struct regulator * regulator void * data regulator regulator data data Kernel Hackers Manual July 2017 rdev_get_id 9 4.1.27 rdev_get_id get regulator ID int rdev_get_id struct regulator_dev * rdev rdev regulator