1/*
2 * Copyright © 2007 Anton Vorontsov <cbou@mail.ru>
3 * Copyright © 2007 Eugeny Boger <eugenyboger@dgap.mipt.ru>
4 *
5 * Author: Eugeny Boger <eugenyboger@dgap.mipt.ru>
6 *
7 * Use consistent with the GNU GPL is permitted,
8 * provided that this copyright notice is
9 * preserved in its entirety in all copies and derived works.
10 */
11
12#include <linux/module.h>
13#include <linux/device.h>
14#include <linux/power_supply.h>
15#include <linux/apm-emulation.h>
16
17
18#define PSY_PROP(psy, prop, val) (psy->get_property(psy, \
19			 POWER_SUPPLY_PROP_##prop, val))
20
21#define _MPSY_PROP(prop, val) (main_battery->get_property(main_battery, \
22							 prop, val))
23
24#define MPSY_PROP(prop, val) _MPSY_PROP(POWER_SUPPLY_PROP_##prop, val)
25
26static DEFINE_MUTEX(apm_mutex);
27static struct power_supply *main_battery;
28
29enum apm_source {
30	SOURCE_ENERGY,
31	SOURCE_CHARGE,
32	SOURCE_VOLTAGE,
33};
34
35struct find_bat_param {
36	struct power_supply *main;
37	struct power_supply *bat;
38	struct power_supply *max_charge_bat;
39	struct power_supply *max_energy_bat;
40	union power_supply_propval full;
41	int max_charge;
42	int max_energy;
43};
44
45static int __find_main_battery(struct device *dev, void *data)
46{
47	struct find_bat_param *bp = (struct find_bat_param *)data;
48
49	bp->bat = dev_get_drvdata(dev);
50
51	if (bp->bat->use_for_apm) {
52		/* nice, we explicitly asked to report this battery. */
53		bp->main = bp->bat;
54		return 1;
55	}
56
57	if (!PSY_PROP(bp->bat, CHARGE_FULL_DESIGN, &bp->full) ||
58			!PSY_PROP(bp->bat, CHARGE_FULL, &bp->full)) {
59		if (bp->full.intval > bp->max_charge) {
60			bp->max_charge_bat = bp->bat;
61			bp->max_charge = bp->full.intval;
62		}
63	} else if (!PSY_PROP(bp->bat, ENERGY_FULL_DESIGN, &bp->full) ||
64			!PSY_PROP(bp->bat, ENERGY_FULL, &bp->full)) {
65		if (bp->full.intval > bp->max_energy) {
66			bp->max_energy_bat = bp->bat;
67			bp->max_energy = bp->full.intval;
68		}
69	}
70	return 0;
71}
72
73static void find_main_battery(void)
74{
75	struct find_bat_param bp;
76	int error;
77
78	memset(&bp, 0, sizeof(struct find_bat_param));
79	main_battery = NULL;
80	bp.main = main_battery;
81
82	error = class_for_each_device(power_supply_class, NULL, &bp,
83				      __find_main_battery);
84	if (error) {
85		main_battery = bp.main;
86		return;
87	}
88
89	if ((bp.max_energy_bat && bp.max_charge_bat) &&
90			(bp.max_energy_bat != bp.max_charge_bat)) {
91		/* try guess battery with more capacity */
92		if (!PSY_PROP(bp.max_charge_bat, VOLTAGE_MAX_DESIGN,
93			      &bp.full)) {
94			if (bp.max_energy > bp.max_charge * bp.full.intval)
95				main_battery = bp.max_energy_bat;
96			else
97				main_battery = bp.max_charge_bat;
98		} else if (!PSY_PROP(bp.max_energy_bat, VOLTAGE_MAX_DESIGN,
99								  &bp.full)) {
100			if (bp.max_charge > bp.max_energy / bp.full.intval)
101				main_battery = bp.max_charge_bat;
102			else
103				main_battery = bp.max_energy_bat;
104		} else {
105			/* give up, choice any */
106			main_battery = bp.max_energy_bat;
107		}
108	} else if (bp.max_charge_bat) {
109		main_battery = bp.max_charge_bat;
110	} else if (bp.max_energy_bat) {
111		main_battery = bp.max_energy_bat;
112	} else {
113		/* give up, try the last if any */
114		main_battery = bp.bat;
115	}
116}
117
118static int do_calculate_time(int status, enum apm_source source)
119{
120	union power_supply_propval full;
121	union power_supply_propval empty;
122	union power_supply_propval cur;
123	union power_supply_propval I;
124	enum power_supply_property full_prop;
125	enum power_supply_property full_design_prop;
126	enum power_supply_property empty_prop;
127	enum power_supply_property empty_design_prop;
128	enum power_supply_property cur_avg_prop;
129	enum power_supply_property cur_now_prop;
130
131	if (MPSY_PROP(CURRENT_AVG, &I)) {
132		/* if battery can't report average value, use momentary */
133		if (MPSY_PROP(CURRENT_NOW, &I))
134			return -1;
135	}
136
137	if (!I.intval)
138		return 0;
139
140	switch (source) {
141	case SOURCE_CHARGE:
142		full_prop = POWER_SUPPLY_PROP_CHARGE_FULL;
143		full_design_prop = POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN;
144		empty_prop = POWER_SUPPLY_PROP_CHARGE_EMPTY;
145		empty_design_prop = POWER_SUPPLY_PROP_CHARGE_EMPTY;
146		cur_avg_prop = POWER_SUPPLY_PROP_CHARGE_AVG;
147		cur_now_prop = POWER_SUPPLY_PROP_CHARGE_NOW;
148		break;
149	case SOURCE_ENERGY:
150		full_prop = POWER_SUPPLY_PROP_ENERGY_FULL;
151		full_design_prop = POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN;
152		empty_prop = POWER_SUPPLY_PROP_ENERGY_EMPTY;
153		empty_design_prop = POWER_SUPPLY_PROP_CHARGE_EMPTY;
154		cur_avg_prop = POWER_SUPPLY_PROP_ENERGY_AVG;
155		cur_now_prop = POWER_SUPPLY_PROP_ENERGY_NOW;
156		break;
157	case SOURCE_VOLTAGE:
158		full_prop = POWER_SUPPLY_PROP_VOLTAGE_MAX;
159		full_design_prop = POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN;
160		empty_prop = POWER_SUPPLY_PROP_VOLTAGE_MIN;
161		empty_design_prop = POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN;
162		cur_avg_prop = POWER_SUPPLY_PROP_VOLTAGE_AVG;
163		cur_now_prop = POWER_SUPPLY_PROP_VOLTAGE_NOW;
164		break;
165	default:
166		printk(KERN_ERR "Unsupported source: %d\n", source);
167		return -1;
168	}
169
170	if (_MPSY_PROP(full_prop, &full)) {
171		/* if battery can't report this property, use design value */
172		if (_MPSY_PROP(full_design_prop, &full))
173			return -1;
174	}
175
176	if (_MPSY_PROP(empty_prop, &empty)) {
177		/* if battery can't report this property, use design value */
178		if (_MPSY_PROP(empty_design_prop, &empty))
179			empty.intval = 0;
180	}
181
182	if (_MPSY_PROP(cur_avg_prop, &cur)) {
183		/* if battery can't report average value, use momentary */
184		if (_MPSY_PROP(cur_now_prop, &cur))
185			return -1;
186	}
187
188	if (status == POWER_SUPPLY_STATUS_CHARGING)
189		return ((cur.intval - full.intval) * 60L) / I.intval;
190	else
191		return -((cur.intval - empty.intval) * 60L) / I.intval;
192}
193
194static int calculate_time(int status)
195{
196	int time;
197
198	time = do_calculate_time(status, SOURCE_ENERGY);
199	if (time != -1)
200		return time;
201
202	time = do_calculate_time(status, SOURCE_CHARGE);
203	if (time != -1)
204		return time;
205
206	time = do_calculate_time(status, SOURCE_VOLTAGE);
207	if (time != -1)
208		return time;
209
210	return -1;
211}
212
213static int calculate_capacity(enum apm_source source)
214{
215	enum power_supply_property full_prop, empty_prop;
216	enum power_supply_property full_design_prop, empty_design_prop;
217	enum power_supply_property now_prop, avg_prop;
218	union power_supply_propval empty, full, cur;
219	int ret;
220
221	switch (source) {
222	case SOURCE_CHARGE:
223		full_prop = POWER_SUPPLY_PROP_CHARGE_FULL;
224		empty_prop = POWER_SUPPLY_PROP_CHARGE_EMPTY;
225		full_design_prop = POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN;
226		empty_design_prop = POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN;
227		now_prop = POWER_SUPPLY_PROP_CHARGE_NOW;
228		avg_prop = POWER_SUPPLY_PROP_CHARGE_AVG;
229		break;
230	case SOURCE_ENERGY:
231		full_prop = POWER_SUPPLY_PROP_ENERGY_FULL;
232		empty_prop = POWER_SUPPLY_PROP_ENERGY_EMPTY;
233		full_design_prop = POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN;
234		empty_design_prop = POWER_SUPPLY_PROP_ENERGY_EMPTY_DESIGN;
235		now_prop = POWER_SUPPLY_PROP_ENERGY_NOW;
236		avg_prop = POWER_SUPPLY_PROP_ENERGY_AVG;
237		break;
238	case SOURCE_VOLTAGE:
239		full_prop = POWER_SUPPLY_PROP_VOLTAGE_MAX;
240		empty_prop = POWER_SUPPLY_PROP_VOLTAGE_MIN;
241		full_design_prop = POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN;
242		empty_design_prop = POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN;
243		now_prop = POWER_SUPPLY_PROP_VOLTAGE_NOW;
244		avg_prop = POWER_SUPPLY_PROP_VOLTAGE_AVG;
245		break;
246	default:
247		printk(KERN_ERR "Unsupported source: %d\n", source);
248		return -1;
249	}
250
251	if (_MPSY_PROP(full_prop, &full)) {
252		/* if battery can't report this property, use design value */
253		if (_MPSY_PROP(full_design_prop, &full))
254			return -1;
255	}
256
257	if (_MPSY_PROP(avg_prop, &cur)) {
258		/* if battery can't report average value, use momentary */
259		if (_MPSY_PROP(now_prop, &cur))
260			return -1;
261	}
262
263	if (_MPSY_PROP(empty_prop, &empty)) {
264		/* if battery can't report this property, use design value */
265		if (_MPSY_PROP(empty_design_prop, &empty))
266			empty.intval = 0;
267	}
268
269	if (full.intval - empty.intval)
270		ret =  ((cur.intval - empty.intval) * 100L) /
271		       (full.intval - empty.intval);
272	else
273		return -1;
274
275	if (ret > 100)
276		return 100;
277	else if (ret < 0)
278		return 0;
279
280	return ret;
281}
282
283static void apm_battery_apm_get_power_status(struct apm_power_info *info)
284{
285	union power_supply_propval status;
286	union power_supply_propval capacity, time_to_full, time_to_empty;
287
288	mutex_lock(&apm_mutex);
289	find_main_battery();
290	if (!main_battery) {
291		mutex_unlock(&apm_mutex);
292		return;
293	}
294
295	/* status */
296
297	if (MPSY_PROP(STATUS, &status))
298		status.intval = POWER_SUPPLY_STATUS_UNKNOWN;
299
300	/* ac line status */
301
302	if ((status.intval == POWER_SUPPLY_STATUS_CHARGING) ||
303	    (status.intval == POWER_SUPPLY_STATUS_NOT_CHARGING) ||
304	    (status.intval == POWER_SUPPLY_STATUS_FULL))
305		info->ac_line_status = APM_AC_ONLINE;
306	else
307		info->ac_line_status = APM_AC_OFFLINE;
308
309	/* battery life (i.e. capacity, in percents) */
310
311	if (MPSY_PROP(CAPACITY, &capacity) == 0) {
312		info->battery_life = capacity.intval;
313	} else {
314		/* try calculate using energy */
315		info->battery_life = calculate_capacity(SOURCE_ENERGY);
316		/* if failed try calculate using charge instead */
317		if (info->battery_life == -1)
318			info->battery_life = calculate_capacity(SOURCE_CHARGE);
319		if (info->battery_life == -1)
320			info->battery_life = calculate_capacity(SOURCE_VOLTAGE);
321	}
322
323	/* charging status */
324
325	if (status.intval == POWER_SUPPLY_STATUS_CHARGING) {
326		info->battery_status = APM_BATTERY_STATUS_CHARGING;
327	} else {
328		if (info->battery_life > 50)
329			info->battery_status = APM_BATTERY_STATUS_HIGH;
330		else if (info->battery_life > 5)
331			info->battery_status = APM_BATTERY_STATUS_LOW;
332		else
333			info->battery_status = APM_BATTERY_STATUS_CRITICAL;
334	}
335	info->battery_flag = info->battery_status;
336
337	/* time */
338
339	info->units = APM_UNITS_MINS;
340
341	if (status.intval == POWER_SUPPLY_STATUS_CHARGING) {
342		if (!MPSY_PROP(TIME_TO_FULL_AVG, &time_to_full) ||
343				!MPSY_PROP(TIME_TO_FULL_NOW, &time_to_full))
344			info->time = time_to_full.intval / 60;
345		else
346			info->time = calculate_time(status.intval);
347	} else {
348		if (!MPSY_PROP(TIME_TO_EMPTY_AVG, &time_to_empty) ||
349			      !MPSY_PROP(TIME_TO_EMPTY_NOW, &time_to_empty))
350			info->time = time_to_empty.intval / 60;
351		else
352			info->time = calculate_time(status.intval);
353	}
354
355	mutex_unlock(&apm_mutex);
356}
357
358static int __init apm_battery_init(void)
359{
360	printk(KERN_INFO "APM Battery Driver\n");
361
362	apm_get_power_status = apm_battery_apm_get_power_status;
363	return 0;
364}
365
366static void __exit apm_battery_exit(void)
367{
368	apm_get_power_status = NULL;
369}
370
371module_init(apm_battery_init);
372module_exit(apm_battery_exit);
373
374MODULE_AUTHOR("Eugeny Boger <eugenyboger@dgap.mipt.ru>");
375MODULE_DESCRIPTION("APM emulation driver for battery monitoring class");
376MODULE_LICENSE("GPL");
377