Documentation/power/charger-manager.rst

7 Charger Manager provides in-kernel battery charger management that
8 requires temperature monitoring during suspend-to-RAM state
9 and where each battery may have multiple chargers attached and the userland
12 Charger Manager is a platform_driver with power-supply-class entries.
13 An instance of Charger Manager (a platform-device created with Charger-Manager)
14 represents an independent battery with chargers. If there are multiple
26 	own power-supply-class and each power-supply-class can provide
27 	different information about the battery status. This framework
28 	aggregates charger-related information from multiple sources and
29 	shows combined information as a single power-supply-class.
31 * Support for in suspend-to-RAM polling (with suspend_again callback)
32 	While the battery is being charged and the system is in suspend-to-RAM,
33 	we may need to monitor the battery health by looking at the ambient or
34 	battery temperature. We can accomplish this by waking up the system
36 	monitoring the battery health and tasks, and user processes that are
41 	only affects the charging time, but the lifespan of the battery.
50 * Support for premature full-battery event handling
51 	If the battery voltage drops by "fullbatt_vchkdrop_uV" after
52 	"fullbatt_vchkdrop_ms" from the full-battery event, the framework
56 * Support for uevent-notify
57 	With the charger-related events, the device sends
60 2. Global Charger-Manager Data related with suspend_again
62 In order to setup Charger Manager with suspend-again feature
63 (in-suspend monitoring), the user should provide charger_global_desc
65 This charger_global_desc data for in-suspend monitoring is global
69 and it will manage in-suspend monitoring for all instances of Charger Manager.
72 properly in order to activate in-suspend monitoring:
78 	saves and restores the alarm value and use the previously-defined
80 	Charger Manager does not interfere with previously-defined alarms.
84 	the wakeup-from-suspend is caused only by the alarm of "rtc" in the
92 	assumes that the suspend-duration is same as the alarm length.
98 When cm_suspend_again is called, it monitors every battery. The suspend_ops
107 (in-suspend monitoring) results in "normal".
109 4. Charger-Manager Data (struct charger_desc)
111 For each battery charged independently from other batteries (if a series of
113 battery), an instance of Charger Manager is attached to it. The following
118 	The power-supply-class name of the battery. Default is
119 	"battery" if psy_name is NULL. Users can access the psy entries
124 		do not poll this battery.
126 		always poll this battery.
128 		poll this battery if and only if an external power
131 		poll this battery if and only if the battery is being charged.
134 	If both have non-zero values, Charger Manager will check the
135 	battery voltage drop fullbatt_vchkdrop_ms after the battery is fully
137 	Manager will try to recharge the battery by disabling and enabling
143 	If specified with a non-zero value, Charger Manager assumes
144 	that the battery is full (capacity = 100) if the battery is not being
145 	charged and the battery voltage is equal to or greater than
150 	this battery every polling_interval_ms or more frequently.
154 		assume that the battery exists.
156 		assume that the battery does not exists.
158 		get battery presence information from fuel gauge.
160 		get battery presence from chargers.
163 	An array ending with NULL that has power-supply-class names of
164 	chargers. Each power-supply-class should provide "PRESENT" (if
167 	the battery is {"FULL" or not FULL} or {"FULL", "Charging",
175 	Power-supply-class name of the fuel gauge.
178 	This callback returns 0 if the temperature is safe for charging,
181 	the temperature in 1/1000 of centigrade.
182 	The source of temperature can be battery or ambient one according to
186 5. Notify Charger-Manager of charger events: cm_notify_event()
192 associated with Charger-Manager. The parameter "type"
199 At the charger/battery-related events such as battery-pulled-out,
200 charger-pulled-out, charger-inserted, DCIN-over/under-voltage, charger-stopped,
203 a) charger-on/off b) external-power-in/out c) battery-in/out (while charging)