Power

Power management detection of active power source, and approximate battery state. More...

Collaboration diagram for Power:

Typedefs
typedef void(*	hw_power_callback_t) (hw_power_t *power, hw_power_flag_t flags, uint32_t value, void *user_data)
	Power status callback prototype. More...

Enumerations
enum	hw_power_flag_t { HW_POWER_UNKNOWN = 0, HW_POWER_USB = (1 << 0), HW_POWER_BATTERY = (1 << 1), HW_POWER_RESET = (1 << 2) }
	Power source capability / status flags. More...

Functions
hw_power_t *	hw_power_init (uint8_t gpio_vsys, uint8_t gpio_vbus, hw_power_callback_t callback, void *user_data)
	Initialize power management. More...
bool	hw_power_valid (hw_power_t *power)
	Determine if the power handle is initialized and usable. More...
void	hw_power_finalize (hw_power_t *power)
	Finalize and release any resources. More...
uint8_t	hw_power_battery_percent (hw_power_t *power)
	Approximate battery state of charge. More...
hw_power_flag_t	hw_power_source (hw_power_t *power)
	Current detected power source(s). More...

Detailed Description

Power management detection of active power source, and approximate battery state.

The power management interface provides battery state of charge reporting (0–100%) when supported, and optional asynchronous callback notification on power changes.

In order to be notified of power changes, the user must provide a callback function when initializing the power management interface, and in the main event loop, call hw_poll().

In order to be notified of reset events, the watchdog must be initialized and the user must call hw_watchdog_reset() to initiate a reset event.

Typedef Documentation

hw_power_callback_t

typedef void(* hw_power_callback_t) (hw_power_t *power, hw_power_flag_t flags, uint32_t value, void *user_data)

Power status callback prototype.

Parameters

power	Pointer to the associated power handle
flags	Bitmask of power flags that changed since the last callback. If HW_POWER_BATTERY flag is set, the callback may be invoked on battery level changes. If HW_POWER_RESET is set, the callback was invoked on a reset event.
value	If flags includes HW_POWER_BATTERY then the value is a battery percentage (1-100) or zero if unknown. If HW_POWER_RESET is set, the value is the reset delay in milliseconds.
user_data	Optional user data pointer passed to the callback.

Definition at line 64 of file power.h.

Enumeration Type Documentation

hw_power_flag_t

enum hw_power_flag_t

Power source capability / status flags.

Bitmask describing which power sources are currently present / can be detected. Implementations may return a combination (e.g. USB + BATTERY) if simultaneous presence is detectable; otherwise a single dominant source may be reported. When no information is available, HW_POWER_UNKNOWN is returned.

Enumerator
HW_POWER_UNKNOWN	Unknown power source.
HW_POWER_USB	USB (VBUS) power.
HW_POWER_BATTERY	Battery power.
HW_POWER_RESET	Hardware will reset.

Definition at line 44 of file power.h.

             {
  HW_POWER_UNKNOWN = 0,        
  HW_POWER_USB = (1 << 0),     
  HW_POWER_BATTERY = (1 << 1), 
  HW_POWER_RESET = (1 << 2),   
} hw_power_flag_t;

Function Documentation

hw_power_battery_percent()

uint8_t hw_power_battery_percent

(

hw_power_t *

power

)

Approximate battery state of charge.

Parameters

power

Power handle

Returns

Integer percentage 0–100 inclusive.

If unsupported or indeterminable, returns 100

hw_power_finalize()

void hw_power_finalize

(

hw_power_t *

power

)

Finalize and release any resources.

Parameters

power

Power handle

Safe to call on an already finalized or never‑initialized handle; in that case it is a no‑op. After finalization, hw_power_valid() returns false.

hw_power_init()

hw_power_t* hw_power_init	(	uint8_t	gpio_vsys,
		uint8_t	gpio_vbus,
		hw_power_callback_t	callback,
		void *	user_data
	)

Initialize power management.

Parameters

gpio_vsys	GPIO (or 0xFF for default) used for VSYS / battery sense (platform specific)
gpio_vbus	GPIO (or 0xFF for default) used for VBUS / USB present detect
callback	Optional callback for asynchronous updates (may be NULL)

Returns

Pointer to a hw_power_t handle, or NULL

GPIO arguments are platform dependent; pass 0xFF to use default signals, or if unavailable. The returned handle is valid if hw_power_valid() subsequently reports true. Supplying a callback enables event driven notification when supported.

hw_power_source()

hw_power_flag_t hw_power_source

(

hw_power_t *

power

)

Current detected power source(s).

Parameters

power

Power handle

Returns

Bitmask of hw_power_flag_t flags; HW_POWER_UNKNOWN if unknown.

hw_power_valid()

bool hw_power_valid

(

hw_power_t *

power

)

Determine if the power handle is initialized and usable.

Parameters

power

Power handle

Returns

True if initialized and not finalized; false otherwise.