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