xref: /openbmc/linux/include/linux/power_supply.h (revision d2a3b501)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  *  Universal power supply monitor class
4  *
5  *  Copyright © 2007  Anton Vorontsov <cbou@mail.ru>
6  *  Copyright © 2004  Szabolcs Gyurko
7  *  Copyright © 2003  Ian Molton <spyro@f2s.com>
8  *
9  *  Modified: 2004, Oct     Szabolcs Gyurko
10  */
11 
12 #ifndef __LINUX_POWER_SUPPLY_H__
13 #define __LINUX_POWER_SUPPLY_H__
14 
15 #include <linux/device.h>
16 #include <linux/workqueue.h>
17 #include <linux/leds.h>
18 #include <linux/spinlock.h>
19 #include <linux/notifier.h>
20 
21 /*
22  * All voltages, currents, charges, energies, time and temperatures in uV,
23  * µA, µAh, µWh, seconds and tenths of degree Celsius unless otherwise
24  * stated. It's driver's job to convert its raw values to units in which
25  * this class operates.
26  */
27 
28 /*
29  * For systems where the charger determines the maximum battery capacity
30  * the min and max fields should be used to present these values to user
31  * space. Unused/unknown fields will not appear in sysfs.
32  */
33 
34 enum {
35 	POWER_SUPPLY_STATUS_UNKNOWN = 0,
36 	POWER_SUPPLY_STATUS_CHARGING,
37 	POWER_SUPPLY_STATUS_DISCHARGING,
38 	POWER_SUPPLY_STATUS_NOT_CHARGING,
39 	POWER_SUPPLY_STATUS_FULL,
40 };
41 
42 /* What algorithm is the charger using? */
43 enum {
44 	POWER_SUPPLY_CHARGE_TYPE_UNKNOWN = 0,
45 	POWER_SUPPLY_CHARGE_TYPE_NONE,
46 	POWER_SUPPLY_CHARGE_TYPE_TRICKLE,	/* slow speed */
47 	POWER_SUPPLY_CHARGE_TYPE_FAST,		/* fast speed */
48 	POWER_SUPPLY_CHARGE_TYPE_STANDARD,	/* normal speed */
49 	POWER_SUPPLY_CHARGE_TYPE_ADAPTIVE,	/* dynamically adjusted speed */
50 	POWER_SUPPLY_CHARGE_TYPE_CUSTOM,	/* use CHARGE_CONTROL_* props */
51 	POWER_SUPPLY_CHARGE_TYPE_LONGLIFE,	/* slow speed, longer life */
52 	POWER_SUPPLY_CHARGE_TYPE_BYPASS,	/* bypassing the charger */
53 };
54 
55 enum {
56 	POWER_SUPPLY_HEALTH_UNKNOWN = 0,
57 	POWER_SUPPLY_HEALTH_GOOD,
58 	POWER_SUPPLY_HEALTH_OVERHEAT,
59 	POWER_SUPPLY_HEALTH_DEAD,
60 	POWER_SUPPLY_HEALTH_OVERVOLTAGE,
61 	POWER_SUPPLY_HEALTH_UNSPEC_FAILURE,
62 	POWER_SUPPLY_HEALTH_COLD,
63 	POWER_SUPPLY_HEALTH_WATCHDOG_TIMER_EXPIRE,
64 	POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE,
65 	POWER_SUPPLY_HEALTH_OVERCURRENT,
66 	POWER_SUPPLY_HEALTH_CALIBRATION_REQUIRED,
67 	POWER_SUPPLY_HEALTH_WARM,
68 	POWER_SUPPLY_HEALTH_COOL,
69 	POWER_SUPPLY_HEALTH_HOT,
70 	POWER_SUPPLY_HEALTH_NO_BATTERY,
71 };
72 
73 enum {
74 	POWER_SUPPLY_TECHNOLOGY_UNKNOWN = 0,
75 	POWER_SUPPLY_TECHNOLOGY_NiMH,
76 	POWER_SUPPLY_TECHNOLOGY_LION,
77 	POWER_SUPPLY_TECHNOLOGY_LIPO,
78 	POWER_SUPPLY_TECHNOLOGY_LiFe,
79 	POWER_SUPPLY_TECHNOLOGY_NiCd,
80 	POWER_SUPPLY_TECHNOLOGY_LiMn,
81 };
82 
83 enum {
84 	POWER_SUPPLY_CAPACITY_LEVEL_UNKNOWN = 0,
85 	POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL,
86 	POWER_SUPPLY_CAPACITY_LEVEL_LOW,
87 	POWER_SUPPLY_CAPACITY_LEVEL_NORMAL,
88 	POWER_SUPPLY_CAPACITY_LEVEL_HIGH,
89 	POWER_SUPPLY_CAPACITY_LEVEL_FULL,
90 };
91 
92 enum {
93 	POWER_SUPPLY_SCOPE_UNKNOWN = 0,
94 	POWER_SUPPLY_SCOPE_SYSTEM,
95 	POWER_SUPPLY_SCOPE_DEVICE,
96 };
97 
98 enum power_supply_property {
99 	/* Properties of type `int' */
100 	POWER_SUPPLY_PROP_STATUS = 0,
101 	POWER_SUPPLY_PROP_CHARGE_TYPE,
102 	POWER_SUPPLY_PROP_HEALTH,
103 	POWER_SUPPLY_PROP_PRESENT,
104 	POWER_SUPPLY_PROP_ONLINE,
105 	POWER_SUPPLY_PROP_AUTHENTIC,
106 	POWER_SUPPLY_PROP_TECHNOLOGY,
107 	POWER_SUPPLY_PROP_CYCLE_COUNT,
108 	POWER_SUPPLY_PROP_VOLTAGE_MAX,
109 	POWER_SUPPLY_PROP_VOLTAGE_MIN,
110 	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
111 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
112 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
113 	POWER_SUPPLY_PROP_VOLTAGE_AVG,
114 	POWER_SUPPLY_PROP_VOLTAGE_OCV,
115 	POWER_SUPPLY_PROP_VOLTAGE_BOOT,
116 	POWER_SUPPLY_PROP_CURRENT_MAX,
117 	POWER_SUPPLY_PROP_CURRENT_NOW,
118 	POWER_SUPPLY_PROP_CURRENT_AVG,
119 	POWER_SUPPLY_PROP_CURRENT_BOOT,
120 	POWER_SUPPLY_PROP_POWER_NOW,
121 	POWER_SUPPLY_PROP_POWER_AVG,
122 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
123 	POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN,
124 	POWER_SUPPLY_PROP_CHARGE_FULL,
125 	POWER_SUPPLY_PROP_CHARGE_EMPTY,
126 	POWER_SUPPLY_PROP_CHARGE_NOW,
127 	POWER_SUPPLY_PROP_CHARGE_AVG,
128 	POWER_SUPPLY_PROP_CHARGE_COUNTER,
129 	POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT,
130 	POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX,
131 	POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE,
132 	POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX,
133 	POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT,
134 	POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX,
135 	POWER_SUPPLY_PROP_CHARGE_CONTROL_START_THRESHOLD, /* in percents! */
136 	POWER_SUPPLY_PROP_CHARGE_CONTROL_END_THRESHOLD, /* in percents! */
137 	POWER_SUPPLY_PROP_CHARGE_BEHAVIOUR,
138 	POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
139 	POWER_SUPPLY_PROP_INPUT_VOLTAGE_LIMIT,
140 	POWER_SUPPLY_PROP_INPUT_POWER_LIMIT,
141 	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
142 	POWER_SUPPLY_PROP_ENERGY_EMPTY_DESIGN,
143 	POWER_SUPPLY_PROP_ENERGY_FULL,
144 	POWER_SUPPLY_PROP_ENERGY_EMPTY,
145 	POWER_SUPPLY_PROP_ENERGY_NOW,
146 	POWER_SUPPLY_PROP_ENERGY_AVG,
147 	POWER_SUPPLY_PROP_CAPACITY, /* in percents! */
148 	POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN, /* in percents! */
149 	POWER_SUPPLY_PROP_CAPACITY_ALERT_MAX, /* in percents! */
150 	POWER_SUPPLY_PROP_CAPACITY_ERROR_MARGIN, /* in percents! */
151 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
152 	POWER_SUPPLY_PROP_TEMP,
153 	POWER_SUPPLY_PROP_TEMP_MAX,
154 	POWER_SUPPLY_PROP_TEMP_MIN,
155 	POWER_SUPPLY_PROP_TEMP_ALERT_MIN,
156 	POWER_SUPPLY_PROP_TEMP_ALERT_MAX,
157 	POWER_SUPPLY_PROP_TEMP_AMBIENT,
158 	POWER_SUPPLY_PROP_TEMP_AMBIENT_ALERT_MIN,
159 	POWER_SUPPLY_PROP_TEMP_AMBIENT_ALERT_MAX,
160 	POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
161 	POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
162 	POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,
163 	POWER_SUPPLY_PROP_TIME_TO_FULL_AVG,
164 	POWER_SUPPLY_PROP_TYPE, /* use power_supply.type instead */
165 	POWER_SUPPLY_PROP_USB_TYPE,
166 	POWER_SUPPLY_PROP_SCOPE,
167 	POWER_SUPPLY_PROP_PRECHARGE_CURRENT,
168 	POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT,
169 	POWER_SUPPLY_PROP_CALIBRATE,
170 	POWER_SUPPLY_PROP_MANUFACTURE_YEAR,
171 	POWER_SUPPLY_PROP_MANUFACTURE_MONTH,
172 	POWER_SUPPLY_PROP_MANUFACTURE_DAY,
173 	/* Properties of type `const char *' */
174 	POWER_SUPPLY_PROP_MODEL_NAME,
175 	POWER_SUPPLY_PROP_MANUFACTURER,
176 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
177 };
178 
179 enum power_supply_type {
180 	POWER_SUPPLY_TYPE_UNKNOWN = 0,
181 	POWER_SUPPLY_TYPE_BATTERY,
182 	POWER_SUPPLY_TYPE_UPS,
183 	POWER_SUPPLY_TYPE_MAINS,
184 	POWER_SUPPLY_TYPE_USB,			/* Standard Downstream Port */
185 	POWER_SUPPLY_TYPE_USB_DCP,		/* Dedicated Charging Port */
186 	POWER_SUPPLY_TYPE_USB_CDP,		/* Charging Downstream Port */
187 	POWER_SUPPLY_TYPE_USB_ACA,		/* Accessory Charger Adapters */
188 	POWER_SUPPLY_TYPE_USB_TYPE_C,		/* Type C Port */
189 	POWER_SUPPLY_TYPE_USB_PD,		/* Power Delivery Port */
190 	POWER_SUPPLY_TYPE_USB_PD_DRP,		/* PD Dual Role Port */
191 	POWER_SUPPLY_TYPE_APPLE_BRICK_ID,	/* Apple Charging Method */
192 	POWER_SUPPLY_TYPE_WIRELESS,		/* Wireless */
193 };
194 
195 enum power_supply_usb_type {
196 	POWER_SUPPLY_USB_TYPE_UNKNOWN = 0,
197 	POWER_SUPPLY_USB_TYPE_SDP,		/* Standard Downstream Port */
198 	POWER_SUPPLY_USB_TYPE_DCP,		/* Dedicated Charging Port */
199 	POWER_SUPPLY_USB_TYPE_CDP,		/* Charging Downstream Port */
200 	POWER_SUPPLY_USB_TYPE_ACA,		/* Accessory Charger Adapters */
201 	POWER_SUPPLY_USB_TYPE_C,		/* Type C Port */
202 	POWER_SUPPLY_USB_TYPE_PD,		/* Power Delivery Port */
203 	POWER_SUPPLY_USB_TYPE_PD_DRP,		/* PD Dual Role Port */
204 	POWER_SUPPLY_USB_TYPE_PD_PPS,		/* PD Programmable Power Supply */
205 	POWER_SUPPLY_USB_TYPE_APPLE_BRICK_ID,	/* Apple Charging Method */
206 };
207 
208 enum power_supply_charge_behaviour {
209 	POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO = 0,
210 	POWER_SUPPLY_CHARGE_BEHAVIOUR_INHIBIT_CHARGE,
211 	POWER_SUPPLY_CHARGE_BEHAVIOUR_FORCE_DISCHARGE,
212 };
213 
214 enum power_supply_notifier_events {
215 	PSY_EVENT_PROP_CHANGED,
216 };
217 
218 union power_supply_propval {
219 	int intval;
220 	const char *strval;
221 };
222 
223 struct device_node;
224 struct power_supply;
225 
226 /* Run-time specific power supply configuration */
227 struct power_supply_config {
228 	struct device_node *of_node;
229 	struct fwnode_handle *fwnode;
230 
231 	/* Driver private data */
232 	void *drv_data;
233 
234 	/* Device specific sysfs attributes */
235 	const struct attribute_group **attr_grp;
236 
237 	char **supplied_to;
238 	size_t num_supplicants;
239 };
240 
241 /* Description of power supply */
242 struct power_supply_desc {
243 	const char *name;
244 	enum power_supply_type type;
245 	const enum power_supply_usb_type *usb_types;
246 	size_t num_usb_types;
247 	const enum power_supply_property *properties;
248 	size_t num_properties;
249 
250 	/*
251 	 * Functions for drivers implementing power supply class.
252 	 * These shouldn't be called directly by other drivers for accessing
253 	 * this power supply. Instead use power_supply_*() functions (for
254 	 * example power_supply_get_property()).
255 	 */
256 	int (*get_property)(struct power_supply *psy,
257 			    enum power_supply_property psp,
258 			    union power_supply_propval *val);
259 	int (*set_property)(struct power_supply *psy,
260 			    enum power_supply_property psp,
261 			    const union power_supply_propval *val);
262 	/*
263 	 * property_is_writeable() will be called during registration
264 	 * of power supply. If this happens during device probe then it must
265 	 * not access internal data of device (because probe did not end).
266 	 */
267 	int (*property_is_writeable)(struct power_supply *psy,
268 				     enum power_supply_property psp);
269 	void (*external_power_changed)(struct power_supply *psy);
270 	void (*set_charged)(struct power_supply *psy);
271 
272 	/*
273 	 * Set if thermal zone should not be created for this power supply.
274 	 * For example for virtual supplies forwarding calls to actual
275 	 * sensors or other supplies.
276 	 */
277 	bool no_thermal;
278 	/* For APM emulation, think legacy userspace. */
279 	int use_for_apm;
280 };
281 
282 struct power_supply {
283 	const struct power_supply_desc *desc;
284 
285 	char **supplied_to;
286 	size_t num_supplicants;
287 
288 	char **supplied_from;
289 	size_t num_supplies;
290 	struct device_node *of_node;
291 
292 	/* Driver private data */
293 	void *drv_data;
294 
295 	/* private */
296 	struct device dev;
297 	struct work_struct changed_work;
298 	struct delayed_work deferred_register_work;
299 	spinlock_t changed_lock;
300 	bool changed;
301 	bool initialized;
302 	bool removing;
303 	atomic_t use_cnt;
304 	struct power_supply_battery_info *battery_info;
305 #ifdef CONFIG_THERMAL
306 	struct thermal_zone_device *tzd;
307 	struct thermal_cooling_device *tcd;
308 #endif
309 
310 #ifdef CONFIG_LEDS_TRIGGERS
311 	struct led_trigger *charging_full_trig;
312 	char *charging_full_trig_name;
313 	struct led_trigger *charging_trig;
314 	char *charging_trig_name;
315 	struct led_trigger *full_trig;
316 	char *full_trig_name;
317 	struct led_trigger *online_trig;
318 	char *online_trig_name;
319 	struct led_trigger *charging_blink_full_solid_trig;
320 	char *charging_blink_full_solid_trig_name;
321 #endif
322 };
323 
324 /*
325  * This is recommended structure to specify static power supply parameters.
326  * Generic one, parametrizable for different power supplies. Power supply
327  * class itself does not use it, but that's what implementing most platform
328  * drivers, should try reuse for consistency.
329  */
330 
331 struct power_supply_info {
332 	const char *name;
333 	int technology;
334 	int voltage_max_design;
335 	int voltage_min_design;
336 	int charge_full_design;
337 	int charge_empty_design;
338 	int energy_full_design;
339 	int energy_empty_design;
340 	int use_for_apm;
341 };
342 
343 struct power_supply_battery_ocv_table {
344 	int ocv;	/* microVolts */
345 	int capacity;	/* percent */
346 };
347 
348 struct power_supply_resistance_temp_table {
349 	int temp;	/* celsius */
350 	int resistance;	/* internal resistance percent */
351 };
352 
353 struct power_supply_vbat_ri_table {
354 	int vbat_uv;	/* Battery voltage in microvolt */
355 	int ri_uohm;	/* Internal resistance in microohm */
356 };
357 
358 /**
359  * struct power_supply_maintenance_charge_table - setting for maintenace charging
360  * @charge_current_max_ua: maintenance charging current that is used to keep
361  *   the charge of the battery full as current is consumed after full charging.
362  *   The corresponding charge_voltage_max_uv is used as a safeguard: when we
363  *   reach this voltage the maintenance charging current is turned off. It is
364  *   turned back on if we fall below this voltage.
365  * @charge_voltage_max_uv: maintenance charging voltage that is usually a bit
366  *   lower than the constant_charge_voltage_max_uv. We can apply this settings
367  *   charge_current_max_ua until we get back up to this voltage.
368  * @safety_timer_minutes: maintenance charging safety timer, with an expiry
369  *   time in minutes. We will only use maintenance charging in this setting
370  *   for a certain amount of time, then we will first move to the next
371  *   maintenance charge current and voltage pair in respective array and wait
372  *   for the next safety timer timeout, or, if we reached the last maintencance
373  *   charging setting, disable charging until we reach
374  *   charge_restart_voltage_uv and restart ordinary CC/CV charging from there.
375  *   These timers should be chosen to align with the typical discharge curve
376  *   for the battery.
377  *
378  * Ordinary CC/CV charging will stop charging when the charge current goes
379  * below charge_term_current_ua, and then restart it (if the device is still
380  * plugged into the charger) at charge_restart_voltage_uv. This happens in most
381  * consumer products because the power usage while connected to a charger is
382  * not zero, and devices are not manufactured to draw power directly from the
383  * charger: instead they will at all times dissipate the battery a little, like
384  * the power used in standby mode. This will over time give a charge graph
385  * such as this:
386  *
387  * Energy
388  *  ^      ...        ...      ...      ...      ...      ...      ...
389  *  |    .   .       .  .     .  .     .  .     .  .     .  .     .
390  *  |  ..     .   ..     .  ..    .  ..    .  ..    .  ..    .  ..
391  *  |.          ..        ..       ..       ..       ..       ..
392  *  +-------------------------------------------------------------------> t
393  *
394  * Practically this means that the Li-ions are wandering back and forth in the
395  * battery and this causes degeneration of the battery anode and cathode.
396  * To prolong the life of the battery, maintenance charging is applied after
397  * reaching charge_term_current_ua to hold up the charge in the battery while
398  * consuming power, thus lowering the wear on the battery:
399  *
400  * Energy
401  *  ^      .......................................
402  *  |    .                                        ......................
403  *  |  ..
404  *  |.
405  *  +-------------------------------------------------------------------> t
406  *
407  * Maintenance charging uses the voltages from this table: a table of settings
408  * is traversed using a slightly lower current and voltage than what is used for
409  * CC/CV charging. The maintenance charging will for safety reasons not go on
410  * indefinately: we lower the current and voltage with successive maintenance
411  * settings, then disable charging completely after we reach the last one,
412  * and after that we do not restart charging until we reach
413  * charge_restart_voltage_uv (see struct power_supply_battery_info) and restart
414  * ordinary CC/CV charging from there.
415  *
416  * As an example, a Samsung EB425161LA Lithium-Ion battery is CC/CV charged
417  * at 900mA to 4340mV, then maintenance charged at 600mA and 4150mV for up to
418  * 60 hours, then maintenance charged at 600mA and 4100mV for up to 200 hours.
419  * After this the charge cycle is restarted waiting for
420  * charge_restart_voltage_uv.
421  *
422  * For most mobile electronics this type of maintenance charging is enough for
423  * the user to disconnect the device and make use of it before both maintenance
424  * charging cycles are complete, if the current and voltage has been chosen
425  * appropriately. These need to be determined from battery discharge curves
426  * and expected standby current.
427  *
428  * If the voltage anyway drops to charge_restart_voltage_uv during maintenance
429  * charging, ordinary CC/CV charging is restarted. This can happen if the
430  * device is e.g. actively used during charging, so more current is drawn than
431  * the expected stand-by current. Also overvoltage protection will be applied
432  * as usual.
433  */
434 struct power_supply_maintenance_charge_table {
435 	int charge_current_max_ua;
436 	int charge_voltage_max_uv;
437 	int charge_safety_timer_minutes;
438 };
439 
440 #define POWER_SUPPLY_OCV_TEMP_MAX 20
441 
442 /**
443  * struct power_supply_battery_info - information about batteries
444  * @technology: from the POWER_SUPPLY_TECHNOLOGY_* enum
445  * @energy_full_design_uwh: energy content when fully charged in microwatt
446  *   hours
447  * @charge_full_design_uah: charge content when fully charged in microampere
448  *   hours
449  * @voltage_min_design_uv: minimum voltage across the poles when the battery
450  *   is at minimum voltage level in microvolts. If the voltage drops below this
451  *   level the battery will need precharging when using CC/CV charging.
452  * @voltage_max_design_uv: voltage across the poles when the battery is fully
453  *   charged in microvolts. This is the "nominal voltage" i.e. the voltage
454  *   printed on the label of the battery.
455  * @tricklecharge_current_ua: the tricklecharge current used when trickle
456  *   charging the battery in microamperes. This is the charging phase when the
457  *   battery is completely empty and we need to carefully trickle in some
458  *   charge until we reach the precharging voltage.
459  * @precharge_current_ua: current to use in the precharge phase in microamperes,
460  *   the precharge rate is limited by limiting the current to this value.
461  * @precharge_voltage_max_uv: the maximum voltage allowed when precharging in
462  *   microvolts. When we pass this voltage we will nominally switch over to the
463  *   CC (constant current) charging phase defined by constant_charge_current_ua
464  *   and constant_charge_voltage_max_uv.
465  * @charge_term_current_ua: when the current in the CV (constant voltage)
466  *   charging phase drops below this value in microamperes the charging will
467  *   terminate completely and not restart until the voltage over the battery
468  *   poles reach charge_restart_voltage_uv unless we use maintenance charging.
469  * @charge_restart_voltage_uv: when the battery has been fully charged by
470  *   CC/CV charging and charging has been disabled, and the voltage subsequently
471  *   drops below this value in microvolts, the charging will be restarted
472  *   (typically using CV charging).
473  * @overvoltage_limit_uv: If the voltage exceeds the nominal voltage
474  *   voltage_max_design_uv and we reach this voltage level, all charging must
475  *   stop and emergency procedures take place, such as shutting down the system
476  *   in some cases.
477  * @constant_charge_current_max_ua: current in microamperes to use in the CC
478  *   (constant current) charging phase. The charging rate is limited
479  *   by this current. This is the main charging phase and as the current is
480  *   constant into the battery the voltage slowly ascends to
481  *   constant_charge_voltage_max_uv.
482  * @constant_charge_voltage_max_uv: voltage in microvolts signifying the end of
483  *   the CC (constant current) charging phase and the beginning of the CV
484  *   (constant voltage) charging phase.
485  * @maintenance_charge: an array of maintenance charging settings to be used
486  *   after the main CC/CV charging phase is complete.
487  * @maintenance_charge_size: the number of maintenance charging settings in
488  *   maintenance_charge.
489  * @alert_low_temp_charge_current_ua: The charging current to use if the battery
490  *   enters low alert temperature, i.e. if the internal temperature is between
491  *   temp_alert_min and temp_min. No matter the charging phase, this
492  *   and alert_high_temp_charge_voltage_uv will be applied.
493  * @alert_low_temp_charge_voltage_uv: Same as alert_low_temp_charge_current_ua,
494  *   but for the charging voltage.
495  * @alert_high_temp_charge_current_ua: The charging current to use if the
496  *   battery enters high alert temperature, i.e. if the internal temperature is
497  *   between temp_alert_max and temp_max. No matter the charging phase, this
498  *   and alert_high_temp_charge_voltage_uv will be applied, usually lowering
499  *   the charging current as an evasive manouver.
500  * @alert_high_temp_charge_voltage_uv: Same as
501  *   alert_high_temp_charge_current_ua, but for the charging voltage.
502  * @factory_internal_resistance_uohm: the internal resistance of the battery
503  *   at fabrication time, expressed in microohms. This resistance will vary
504  *   depending on the lifetime and charge of the battery, so this is just a
505  *   nominal ballpark figure. This internal resistance is given for the state
506  *   when the battery is discharging.
507  * @factory_internal_resistance_charging_uohm: the internal resistance of the
508  *   battery at fabrication time while charging, expressed in microohms.
509  *   The charging process will affect the internal resistance of the battery
510  *   so this value provides a better resistance under these circumstances.
511  *   This resistance will vary depending on the lifetime and charge of the
512  *   battery, so this is just a nominal ballpark figure.
513  * @ocv_temp: array indicating the open circuit voltage (OCV) capacity
514  *   temperature indices. This is an array of temperatures in degrees Celsius
515  *   indicating which capacity table to use for a certain temperature, since
516  *   the capacity for reasons of chemistry will be different at different
517  *   temperatures. Determining capacity is a multivariate problem and the
518  *   temperature is the first variable we determine.
519  * @temp_ambient_alert_min: the battery will go outside of operating conditions
520  *   when the ambient temperature goes below this temperature in degrees
521  *   Celsius.
522  * @temp_ambient_alert_max: the battery will go outside of operating conditions
523  *   when the ambient temperature goes above this temperature in degrees
524  *   Celsius.
525  * @temp_alert_min: the battery should issue an alert if the internal
526  *   temperature goes below this temperature in degrees Celsius.
527  * @temp_alert_max: the battery should issue an alert if the internal
528  *   temperature goes above this temperature in degrees Celsius.
529  * @temp_min: the battery will go outside of operating conditions when
530  *   the internal temperature goes below this temperature in degrees Celsius.
531  *   Normally this means the system should shut down.
532  * @temp_max: the battery will go outside of operating conditions when
533  *   the internal temperature goes above this temperature in degrees Celsius.
534  *   Normally this means the system should shut down.
535  * @ocv_table: for each entry in ocv_temp there is a corresponding entry in
536  *   ocv_table and a size for each entry in ocv_table_size. These arrays
537  *   determine the capacity in percent in relation to the voltage in microvolts
538  *   at the indexed temperature.
539  * @ocv_table_size: for each entry in ocv_temp this array is giving the size of
540  *   each entry in the array of capacity arrays in ocv_table.
541  * @resist_table: this is a table that correlates a battery temperature to the
542  *   expected internal resistance at this temperature. The resistance is given
543  *   as a percentage of factory_internal_resistance_uohm. Knowing the
544  *   resistance of the battery is usually necessary for calculating the open
545  *   circuit voltage (OCV) that is then used with the ocv_table to calculate
546  *   the capacity of the battery. The resist_table must be ordered descending
547  *   by temperature: highest temperature with lowest resistance first, lowest
548  *   temperature with highest resistance last.
549  * @resist_table_size: the number of items in the resist_table.
550  * @vbat2ri_discharging: this is a table that correlates Battery voltage (VBAT)
551  *   to internal resistance (Ri). The resistance is given in microohm for the
552  *   corresponding voltage in microvolts. The internal resistance is used to
553  *   determine the open circuit voltage so that we can determine the capacity
554  *   of the battery. These voltages to resistance tables apply when the battery
555  *   is discharging. The table must be ordered descending by voltage: highest
556  *   voltage first.
557  * @vbat2ri_discharging_size: the number of items in the vbat2ri_discharging
558  *   table.
559  * @vbat2ri_charging: same function as vbat2ri_discharging but for the state
560  *   when the battery is charging. Being under charge changes the battery's
561  *   internal resistance characteristics so a separate table is needed.*
562  *   The table must be ordered descending by voltage: highest voltage first.
563  * @vbat2ri_charging_size: the number of items in the vbat2ri_charging
564  *   table.
565  * @bti_resistance_ohm: The Battery Type Indicator (BIT) nominal resistance
566  *   in ohms for this battery, if an identification resistor is mounted
567  *   between a third battery terminal and ground. This scheme is used by a lot
568  *   of mobile device batteries.
569  * @bti_resistance_tolerance: The tolerance in percent of the BTI resistance,
570  *   for example 10 for +/- 10%, if the bti_resistance is set to 7000 and the
571  *   tolerance is 10% we will detect a proper battery if the BTI resistance
572  *   is between 6300 and 7700 Ohm.
573  *
574  * This is the recommended struct to manage static battery parameters,
575  * populated by power_supply_get_battery_info(). Most platform drivers should
576  * use these for consistency.
577  *
578  * Its field names must correspond to elements in enum power_supply_property.
579  * The default field value is -EINVAL or NULL for pointers.
580  *
581  * CC/CV CHARGING:
582  *
583  * The charging parameters here assume a CC/CV charging scheme. This method
584  * is most common with Lithium Ion batteries (other methods are possible) and
585  * looks as follows:
586  *
587  * ^ Battery voltage
588  * |                                               --- overvoltage_limit_uv
589  * |
590  * |                    ...................................................
591  * |                 .. constant_charge_voltage_max_uv
592  * |              ..
593  * |             .
594  * |            .
595  * |           .
596  * |          .
597  * |         .
598  * |     .. precharge_voltage_max_uv
599  * |  ..
600  * |. (trickle charging)
601  * +------------------------------------------------------------------> time
602  *
603  * ^ Current into the battery
604  * |
605  * |      ............. constant_charge_current_max_ua
606  * |      .            .
607  * |      .             .
608  * |      .              .
609  * |      .               .
610  * |      .                ..
611  * |      .                  ....
612  * |      .                       .....
613  * |    ... precharge_current_ua       .......  charge_term_current_ua
614  * |    .                                    .
615  * |    .                                    .
616  * |.... tricklecharge_current_ua            .
617  * |                                         .
618  * +-----------------------------------------------------------------> time
619  *
620  * These diagrams are synchronized on time and the voltage and current
621  * follow each other.
622  *
623  * With CC/CV charging commence over time like this for an empty battery:
624  *
625  * 1. When the battery is completely empty it may need to be charged with
626  *    an especially small current so that electrons just "trickle in",
627  *    this is the tricklecharge_current_ua.
628  *
629  * 2. Next a small initial pre-charge current (precharge_current_ua)
630  *    is applied if the voltage is below precharge_voltage_max_uv until we
631  *    reach precharge_voltage_max_uv. CAUTION: in some texts this is referred
632  *    to as "trickle charging" but the use in the Linux kernel is different
633  *    see below!
634  *
635  * 3. Then the main charging current is applied, which is called the constant
636  *    current (CC) phase. A current regulator is set up to allow
637  *    constant_charge_current_max_ua of current to flow into the battery.
638  *    The chemical reaction in the battery will make the voltage go up as
639  *    charge goes into the battery. This current is applied until we reach
640  *    the constant_charge_voltage_max_uv voltage.
641  *
642  * 4. At this voltage we switch over to the constant voltage (CV) phase. This
643  *    means we allow current to go into the battery, but we keep the voltage
644  *    fixed. This current will continue to charge the battery while keeping
645  *    the voltage the same. A chemical reaction in the battery goes on
646  *    storing energy without affecting the voltage. Over time the current
647  *    will slowly drop and when we reach charge_term_current_ua we will
648  *    end the constant voltage phase.
649  *
650  * After this the battery is fully charged, and if we do not support maintenance
651  * charging, the charging will not restart until power dissipation makes the
652  * voltage fall so that we reach charge_restart_voltage_uv and at this point
653  * we restart charging at the appropriate phase, usually this will be inside
654  * the CV phase.
655  *
656  * If we support maintenance charging the voltage is however kept high after
657  * the CV phase with a very low current. This is meant to let the same charge
658  * go in for usage while the charger is still connected, mainly for
659  * dissipation for the power consuming entity while connected to the
660  * charger.
661  *
662  * All charging MUST terminate if the overvoltage_limit_uv is ever reached.
663  * Overcharging Lithium Ion cells can be DANGEROUS and lead to fire or
664  * explosions.
665  *
666  * DETERMINING BATTERY CAPACITY:
667  *
668  * Several members of the struct deal with trying to determine the remaining
669  * capacity in the battery, usually as a percentage of charge. In practice
670  * many chargers uses a so-called fuel gauge or coloumb counter that measure
671  * how much charge goes into the battery and how much goes out (+/- leak
672  * consumption). This does not help if we do not know how much capacity the
673  * battery has to begin with, such as when it is first used or was taken out
674  * and charged in a separate charger. Therefore many capacity algorithms use
675  * the open circuit voltage with a look-up table to determine the rough
676  * capacity of the battery. The open circuit voltage can be conceptualized
677  * with an ideal voltage source (V) in series with an internal resistance (Ri)
678  * like this:
679  *
680  *      +-------> IBAT >----------------+
681  *      |                    ^          |
682  *     [ ] Ri                |          |
683  *      |                    | VBAT     |
684  *      o <----------        |          |
685  *     +|           ^        |         [ ] Rload
686  *    .---.         |        |          |
687  *    | V |         | OCV    |          |
688  *    '---'         |        |          |
689  *      |           |        |          |
690  *  GND +-------------------------------+
691  *
692  * If we disconnect the load (here simplified as a fixed resistance Rload)
693  * and measure VBAT with a infinite impedance voltage meter we will get
694  * VBAT = OCV and this assumption is sometimes made even under load, assuming
695  * Rload is insignificant. However this will be of dubious quality because the
696  * load is rarely that small and Ri is strongly nonlinear depending on
697  * temperature and how much capacity is left in the battery due to the
698  * chemistry involved.
699  *
700  * In many practical applications we cannot just disconnect the battery from
701  * the load, so instead we often try to measure the instantaneous IBAT (the
702  * current out from the battery), estimate the Ri and thus calculate the
703  * voltage drop over Ri and compensate like this:
704  *
705  *   OCV = VBAT - (IBAT * Ri)
706  *
707  * The tables vbat2ri_discharging and vbat2ri_charging are used to determine
708  * (by interpolation) the Ri from the VBAT under load. These curves are highly
709  * nonlinear and may need many datapoints but can be found in datasheets for
710  * some batteries. This gives the compensated open circuit voltage (OCV) for
711  * the battery even under load. Using this method will also compensate for
712  * temperature changes in the environment: this will also make the internal
713  * resistance change, and it will affect the VBAT under load, so correlating
714  * VBAT to Ri takes both remaining capacity and temperature into consideration.
715  *
716  * Alternatively a manufacturer can specify how the capacity of the battery
717  * is dependent on the battery temperature which is the main factor affecting
718  * Ri. As we know all checmical reactions are faster when it is warm and slower
719  * when it is cold. You can put in 1500mAh and only get 800mAh out before the
720  * voltage drops too low for example. This effect is also highly nonlinear and
721  * the purpose of the table resist_table: this will take a temperature and
722  * tell us how big percentage of Ri the specified temperature correlates to.
723  * Usually we have 100% of the factory_internal_resistance_uohm at 25 degrees
724  * Celsius.
725  *
726  * The power supply class itself doesn't use this struct as of now.
727  */
728 
729 struct power_supply_battery_info {
730 	unsigned int technology;
731 	int energy_full_design_uwh;
732 	int charge_full_design_uah;
733 	int voltage_min_design_uv;
734 	int voltage_max_design_uv;
735 	int tricklecharge_current_ua;
736 	int precharge_current_ua;
737 	int precharge_voltage_max_uv;
738 	int charge_term_current_ua;
739 	int charge_restart_voltage_uv;
740 	int overvoltage_limit_uv;
741 	int constant_charge_current_max_ua;
742 	int constant_charge_voltage_max_uv;
743 	struct power_supply_maintenance_charge_table *maintenance_charge;
744 	int maintenance_charge_size;
745 	int alert_low_temp_charge_current_ua;
746 	int alert_low_temp_charge_voltage_uv;
747 	int alert_high_temp_charge_current_ua;
748 	int alert_high_temp_charge_voltage_uv;
749 	int factory_internal_resistance_uohm;
750 	int factory_internal_resistance_charging_uohm;
751 	int ocv_temp[POWER_SUPPLY_OCV_TEMP_MAX];
752 	int temp_ambient_alert_min;
753 	int temp_ambient_alert_max;
754 	int temp_alert_min;
755 	int temp_alert_max;
756 	int temp_min;
757 	int temp_max;
758 	struct power_supply_battery_ocv_table *ocv_table[POWER_SUPPLY_OCV_TEMP_MAX];
759 	int ocv_table_size[POWER_SUPPLY_OCV_TEMP_MAX];
760 	struct power_supply_resistance_temp_table *resist_table;
761 	int resist_table_size;
762 	struct power_supply_vbat_ri_table *vbat2ri_discharging;
763 	int vbat2ri_discharging_size;
764 	struct power_supply_vbat_ri_table *vbat2ri_charging;
765 	int vbat2ri_charging_size;
766 	int bti_resistance_ohm;
767 	int bti_resistance_tolerance;
768 };
769 
770 extern struct blocking_notifier_head power_supply_notifier;
771 extern int power_supply_reg_notifier(struct notifier_block *nb);
772 extern void power_supply_unreg_notifier(struct notifier_block *nb);
773 #if IS_ENABLED(CONFIG_POWER_SUPPLY)
774 extern struct power_supply *power_supply_get_by_name(const char *name);
775 extern void power_supply_put(struct power_supply *psy);
776 #else
777 static inline void power_supply_put(struct power_supply *psy) {}
778 static inline struct power_supply *power_supply_get_by_name(const char *name)
779 { return NULL; }
780 #endif
781 #ifdef CONFIG_OF
782 extern struct power_supply *power_supply_get_by_phandle(struct device_node *np,
783 							const char *property);
784 extern struct power_supply *devm_power_supply_get_by_phandle(
785 				    struct device *dev, const char *property);
786 #else /* !CONFIG_OF */
787 static inline struct power_supply *
788 power_supply_get_by_phandle(struct device_node *np, const char *property)
789 { return NULL; }
790 static inline struct power_supply *
791 devm_power_supply_get_by_phandle(struct device *dev, const char *property)
792 { return NULL; }
793 #endif /* CONFIG_OF */
794 
795 extern const enum power_supply_property power_supply_battery_info_properties[];
796 extern const size_t power_supply_battery_info_properties_size;
797 extern int power_supply_get_battery_info(struct power_supply *psy,
798 					 struct power_supply_battery_info **info_out);
799 extern void power_supply_put_battery_info(struct power_supply *psy,
800 					  struct power_supply_battery_info *info);
801 extern bool power_supply_battery_info_has_prop(struct power_supply_battery_info *info,
802 					       enum power_supply_property psp);
803 extern int power_supply_battery_info_get_prop(struct power_supply_battery_info *info,
804 					      enum power_supply_property psp,
805 					      union power_supply_propval *val);
806 extern int power_supply_ocv2cap_simple(struct power_supply_battery_ocv_table *table,
807 				       int table_len, int ocv);
808 extern struct power_supply_battery_ocv_table *
809 power_supply_find_ocv2cap_table(struct power_supply_battery_info *info,
810 				int temp, int *table_len);
811 extern int power_supply_batinfo_ocv2cap(struct power_supply_battery_info *info,
812 					int ocv, int temp);
813 extern int
814 power_supply_temp2resist_simple(struct power_supply_resistance_temp_table *table,
815 				int table_len, int temp);
816 extern int power_supply_vbat2ri(struct power_supply_battery_info *info,
817 				int vbat_uv, bool charging);
818 extern struct power_supply_maintenance_charge_table *
819 power_supply_get_maintenance_charging_setting(struct power_supply_battery_info *info, int index);
820 extern bool power_supply_battery_bti_in_range(struct power_supply_battery_info *info,
821 					      int resistance);
822 extern void power_supply_changed(struct power_supply *psy);
823 extern int power_supply_am_i_supplied(struct power_supply *psy);
824 int power_supply_get_property_from_supplier(struct power_supply *psy,
825 					    enum power_supply_property psp,
826 					    union power_supply_propval *val);
827 extern int power_supply_set_battery_charged(struct power_supply *psy);
828 
829 static inline bool
830 power_supply_supports_maintenance_charging(struct power_supply_battery_info *info)
831 {
832 	struct power_supply_maintenance_charge_table *mt;
833 
834 	mt = power_supply_get_maintenance_charging_setting(info, 0);
835 
836 	return (mt != NULL);
837 }
838 
839 static inline bool
840 power_supply_supports_vbat2ri(struct power_supply_battery_info *info)
841 {
842 	return ((info->vbat2ri_discharging != NULL) &&
843 		info->vbat2ri_discharging_size > 0);
844 }
845 
846 static inline bool
847 power_supply_supports_temp2ri(struct power_supply_battery_info *info)
848 {
849 	return ((info->resist_table != NULL) &&
850 		info->resist_table_size > 0);
851 }
852 
853 #ifdef CONFIG_POWER_SUPPLY
854 extern int power_supply_is_system_supplied(void);
855 #else
856 static inline int power_supply_is_system_supplied(void) { return -ENOSYS; }
857 #endif
858 
859 extern int power_supply_get_property(struct power_supply *psy,
860 			    enum power_supply_property psp,
861 			    union power_supply_propval *val);
862 #if IS_ENABLED(CONFIG_POWER_SUPPLY)
863 extern int power_supply_set_property(struct power_supply *psy,
864 			    enum power_supply_property psp,
865 			    const union power_supply_propval *val);
866 #else
867 static inline int power_supply_set_property(struct power_supply *psy,
868 			    enum power_supply_property psp,
869 			    const union power_supply_propval *val)
870 { return 0; }
871 #endif
872 extern int power_supply_property_is_writeable(struct power_supply *psy,
873 					enum power_supply_property psp);
874 extern void power_supply_external_power_changed(struct power_supply *psy);
875 
876 extern struct power_supply *__must_check
877 power_supply_register(struct device *parent,
878 				 const struct power_supply_desc *desc,
879 				 const struct power_supply_config *cfg);
880 extern struct power_supply *__must_check
881 power_supply_register_no_ws(struct device *parent,
882 				 const struct power_supply_desc *desc,
883 				 const struct power_supply_config *cfg);
884 extern struct power_supply *__must_check
885 devm_power_supply_register(struct device *parent,
886 				 const struct power_supply_desc *desc,
887 				 const struct power_supply_config *cfg);
888 extern struct power_supply *__must_check
889 devm_power_supply_register_no_ws(struct device *parent,
890 				 const struct power_supply_desc *desc,
891 				 const struct power_supply_config *cfg);
892 extern void power_supply_unregister(struct power_supply *psy);
893 extern int power_supply_powers(struct power_supply *psy, struct device *dev);
894 
895 #define to_power_supply(device) container_of(device, struct power_supply, dev)
896 
897 extern void *power_supply_get_drvdata(struct power_supply *psy);
898 /* For APM emulation, think legacy userspace. */
899 extern struct class *power_supply_class;
900 
901 static inline bool power_supply_is_amp_property(enum power_supply_property psp)
902 {
903 	switch (psp) {
904 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
905 	case POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN:
906 	case POWER_SUPPLY_PROP_CHARGE_FULL:
907 	case POWER_SUPPLY_PROP_CHARGE_EMPTY:
908 	case POWER_SUPPLY_PROP_CHARGE_NOW:
909 	case POWER_SUPPLY_PROP_CHARGE_AVG:
910 	case POWER_SUPPLY_PROP_CHARGE_COUNTER:
911 	case POWER_SUPPLY_PROP_PRECHARGE_CURRENT:
912 	case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
913 	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
914 	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
915 	case POWER_SUPPLY_PROP_CURRENT_MAX:
916 	case POWER_SUPPLY_PROP_CURRENT_NOW:
917 	case POWER_SUPPLY_PROP_CURRENT_AVG:
918 	case POWER_SUPPLY_PROP_CURRENT_BOOT:
919 		return true;
920 	default:
921 		break;
922 	}
923 
924 	return false;
925 }
926 
927 static inline bool power_supply_is_watt_property(enum power_supply_property psp)
928 {
929 	switch (psp) {
930 	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
931 	case POWER_SUPPLY_PROP_ENERGY_EMPTY_DESIGN:
932 	case POWER_SUPPLY_PROP_ENERGY_FULL:
933 	case POWER_SUPPLY_PROP_ENERGY_EMPTY:
934 	case POWER_SUPPLY_PROP_ENERGY_NOW:
935 	case POWER_SUPPLY_PROP_ENERGY_AVG:
936 	case POWER_SUPPLY_PROP_VOLTAGE_MAX:
937 	case POWER_SUPPLY_PROP_VOLTAGE_MIN:
938 	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
939 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
940 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
941 	case POWER_SUPPLY_PROP_VOLTAGE_AVG:
942 	case POWER_SUPPLY_PROP_VOLTAGE_OCV:
943 	case POWER_SUPPLY_PROP_VOLTAGE_BOOT:
944 	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
945 	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
946 	case POWER_SUPPLY_PROP_POWER_NOW:
947 		return true;
948 	default:
949 		break;
950 	}
951 
952 	return false;
953 }
954 
955 #ifdef CONFIG_POWER_SUPPLY_HWMON
956 int power_supply_add_hwmon_sysfs(struct power_supply *psy);
957 void power_supply_remove_hwmon_sysfs(struct power_supply *psy);
958 #else
959 static inline int power_supply_add_hwmon_sysfs(struct power_supply *psy)
960 {
961 	return 0;
962 }
963 
964 static inline
965 void power_supply_remove_hwmon_sysfs(struct power_supply *psy) {}
966 #endif
967 
968 #ifdef CONFIG_SYSFS
969 ssize_t power_supply_charge_behaviour_show(struct device *dev,
970 					   unsigned int available_behaviours,
971 					   enum power_supply_charge_behaviour behaviour,
972 					   char *buf);
973 
974 int power_supply_charge_behaviour_parse(unsigned int available_behaviours, const char *buf);
975 #else
976 static inline
977 ssize_t power_supply_charge_behaviour_show(struct device *dev,
978 					   unsigned int available_behaviours,
979 					   enum power_supply_charge_behaviour behaviour,
980 					   char *buf)
981 {
982 	return -EOPNOTSUPP;
983 }
984 
985 static inline int power_supply_charge_behaviour_parse(unsigned int available_behaviours,
986 						      const char *buf)
987 {
988 	return -EOPNOTSUPP;
989 }
990 #endif
991 
992 #endif /* __LINUX_POWER_SUPPLY_H__ */
993