olpc_battery.c revision 1ca5b9d2183f11bb8b69e04b19a7faf7f600a840 
1/*
2 * Battery driver for One Laptop Per Child board.
3 *
4 *	Copyright © 2006  David Woodhouse <dwmw2@infradead.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include <linux/module.h>
12#include <linux/err.h>
13#include <linux/platform_device.h>
14#include <linux/power_supply.h>
15#include <linux/jiffies.h>
16#include <linux/sched.h>
17#include <asm/olpc.h>
18
19
20#define EC_BAT_VOLTAGE	0x10	/* uint16_t,	*9.76/32,    mV   */
21#define EC_BAT_CURRENT	0x11	/* int16_t,	*15.625/120, mA   */
22#define EC_BAT_ACR	0x12
23#define EC_BAT_TEMP	0x13	/* uint16_t,	*100/256,   °C  */
24#define EC_AMB_TEMP	0x14	/* uint16_t,	*100/256,   °C  */
25#define EC_BAT_STATUS	0x15	/* uint8_t,	bitmask */
26#define EC_BAT_SOC	0x16	/* uint8_t,	percentage */
27#define EC_BAT_SERIAL	0x17	/* uint8_t[6] */
28#define EC_BAT_EEPROM	0x18	/* uint8_t adr as input, uint8_t output */
29#define EC_BAT_ERRCODE	0x1f	/* uint8_t,	bitmask */
30
31#define BAT_STAT_PRESENT	0x01
32#define BAT_STAT_FULL		0x02
33#define BAT_STAT_LOW		0x04
34#define BAT_STAT_DESTROY	0x08
35#define BAT_STAT_AC		0x10
36#define BAT_STAT_CHARGING	0x20
37#define BAT_STAT_DISCHARGING	0x40
38
39#define BAT_ERR_INFOFAIL	0x02
40#define BAT_ERR_OVERVOLTAGE	0x04
41#define BAT_ERR_OVERTEMP	0x05
42#define BAT_ERR_GAUGESTOP	0x06
43#define BAT_ERR_OUT_OF_CONTROL	0x07
44#define BAT_ERR_ID_FAIL		0x09
45#define BAT_ERR_ACR_FAIL	0x10
46
47#define BAT_ADDR_MFR_TYPE	0x5F
48
49/*********************************************************************
50 *		Power
51 *********************************************************************/
52
53static int olpc_ac_get_prop(struct power_supply *psy,
54			    enum power_supply_property psp,
55			    union power_supply_propval *val)
56{
57	int ret = 0;
58	uint8_t status;
59
60	switch (psp) {
61	case POWER_SUPPLY_PROP_ONLINE:
62		ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1);
63		if (ret)
64			return ret;
65
66		val->intval = !!(status & BAT_STAT_AC);
67		break;
68	default:
69		ret = -EINVAL;
70		break;
71	}
72	return ret;
73}
74
75static enum power_supply_property olpc_ac_props[] = {
76	POWER_SUPPLY_PROP_ONLINE,
77};
78
79static struct power_supply olpc_ac = {
80	.name = "olpc-ac",
81	.type = POWER_SUPPLY_TYPE_MAINS,
82	.properties = olpc_ac_props,
83	.num_properties = ARRAY_SIZE(olpc_ac_props),
84	.get_property = olpc_ac_get_prop,
85};
86
87static char bat_serial[17]; /* Ick */
88
89/*********************************************************************
90 *		Battery properties
91 *********************************************************************/
92static int olpc_bat_get_property(struct power_supply *psy,
93				 enum power_supply_property psp,
94				 union power_supply_propval *val)
95{
96	int ret = 0;
97	int16_t ec_word;
98	uint8_t ec_byte;
99	uint64_t ser_buf;
100
101	ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &ec_byte, 1);
102	if (ret)
103		return ret;
104
105	/* Theoretically there's a race here -- the battery could be
106	   removed immediately after we check whether it's present, and
107	   then we query for some other property of the now-absent battery.
108	   It doesn't matter though -- the EC will return the last-known
109	   information, and it's as if we just ran that _little_ bit faster
110	   and managed to read it out before the battery went away. */
111	if (!(ec_byte & BAT_STAT_PRESENT) && psp != POWER_SUPPLY_PROP_PRESENT)
112		return -ENODEV;
113
114	switch (psp) {
115	case POWER_SUPPLY_PROP_STATUS:
116		if (olpc_platform_info.ecver > 0x44) {
117			if (ec_byte & BAT_STAT_CHARGING)
118				val->intval = POWER_SUPPLY_STATUS_CHARGING;
119			else if (ec_byte & BAT_STAT_DISCHARGING)
120				val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
121			else if (ec_byte & BAT_STAT_FULL)
122				val->intval = POWER_SUPPLY_STATUS_FULL;
123			else /* er,... */
124				val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
125		} else {
126			/* Older EC didn't report charge/discharge bits */
127			if (!(ec_byte & BAT_STAT_AC)) /* No AC means discharging */
128				val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
129			else if (ec_byte & BAT_STAT_FULL)
130				val->intval = POWER_SUPPLY_STATUS_FULL;
131			else /* Not _necessarily_ true but EC doesn't tell all yet */
132				val->intval = POWER_SUPPLY_STATUS_CHARGING;
133			break;
134		}
135	case POWER_SUPPLY_PROP_PRESENT:
136		val->intval = !!(ec_byte & BAT_STAT_PRESENT);
137		break;
138
139	case POWER_SUPPLY_PROP_HEALTH:
140		if (ec_byte & BAT_STAT_DESTROY)
141			val->intval = POWER_SUPPLY_HEALTH_DEAD;
142		else {
143			ret = olpc_ec_cmd(EC_BAT_ERRCODE, NULL, 0, &ec_byte, 1);
144			if (ret)
145				return ret;
146
147			switch (ec_byte) {
148			case 0:
149				val->intval = POWER_SUPPLY_HEALTH_GOOD;
150				break;
151
152			case BAT_ERR_OVERTEMP:
153				val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
154				break;
155
156			case BAT_ERR_OVERVOLTAGE:
157				val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
158				break;
159
160			case BAT_ERR_INFOFAIL:
161			case BAT_ERR_OUT_OF_CONTROL:
162			case BAT_ERR_ID_FAIL:
163			case BAT_ERR_ACR_FAIL:
164				val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
165				break;
166
167			default:
168				/* Eep. We don't know this failure code */
169				return -EIO;
170			}
171		}
172		break;
173
174	case POWER_SUPPLY_PROP_MANUFACTURER:
175		ec_byte = BAT_ADDR_MFR_TYPE;
176		ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
177		if (ret)
178			return ret;
179
180		switch (ec_byte >> 4) {
181		case 1:
182			val->strval = "Gold Peak";
183			break;
184		case 2:
185			val->strval = "BYD";
186			break;
187		default:
188			val->strval = "Unknown";
189			break;
190		}
191		break;
192	case POWER_SUPPLY_PROP_TECHNOLOGY:
193		ec_byte = BAT_ADDR_MFR_TYPE;
194		ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
195		if (ret)
196			return ret;
197
198		switch (ec_byte & 0xf) {
199		case 1:
200			val->intval = POWER_SUPPLY_TECHNOLOGY_NiMH;
201			break;
202		case 2:
203			val->intval = POWER_SUPPLY_TECHNOLOGY_LiFe;
204			break;
205		default:
206			val->intval = POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
207			break;
208		}
209		break;
210	case POWER_SUPPLY_PROP_VOLTAGE_AVG:
211		ret = olpc_ec_cmd(EC_BAT_VOLTAGE, NULL, 0, (void *)&ec_word, 2);
212		if (ret)
213			return ret;
214
215		ec_word = be16_to_cpu(ec_word);
216		val->intval = ec_word * 9760L / 32;
217		break;
218	case POWER_SUPPLY_PROP_CURRENT_AVG:
219		ret = olpc_ec_cmd(EC_BAT_CURRENT, NULL, 0, (void *)&ec_word, 2);
220		if (ret)
221			return ret;
222
223		ec_word = be16_to_cpu(ec_word);
224		val->intval = ec_word * 15625L / 120;
225		break;
226	case POWER_SUPPLY_PROP_CAPACITY:
227		ret = olpc_ec_cmd(EC_BAT_SOC, NULL, 0, &ec_byte, 1);
228		if (ret)
229			return ret;
230		val->intval = ec_byte;
231		break;
232	case POWER_SUPPLY_PROP_TEMP:
233		ret = olpc_ec_cmd(EC_BAT_TEMP, NULL, 0, (void *)&ec_word, 2);
234		if (ret)
235			return ret;
236		ec_word = be16_to_cpu(ec_word);
237		val->intval = ec_word * 100 / 256;
238		break;
239	case POWER_SUPPLY_PROP_TEMP_AMBIENT:
240		ret = olpc_ec_cmd(EC_AMB_TEMP, NULL, 0, (void *)&ec_word, 2);
241		if (ret)
242			return ret;
243
244		ec_word = be16_to_cpu(ec_word);
245		val->intval = ec_word * 100 / 256;
246		break;
247	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
248		ret = olpc_ec_cmd(EC_BAT_SERIAL, NULL, 0, (void *)&ser_buf, 8);
249		if (ret)
250			return ret;
251
252		sprintf(bat_serial, "%016llx", (long long)be64_to_cpu(ser_buf));
253		val->strval = bat_serial;
254		break;
255	default:
256		ret = -EINVAL;
257		break;
258	}
259
260	return ret;
261}
262
263static enum power_supply_property olpc_bat_props[] = {
264	POWER_SUPPLY_PROP_STATUS,
265	POWER_SUPPLY_PROP_PRESENT,
266	POWER_SUPPLY_PROP_HEALTH,
267	POWER_SUPPLY_PROP_TECHNOLOGY,
268	POWER_SUPPLY_PROP_VOLTAGE_AVG,
269	POWER_SUPPLY_PROP_CURRENT_AVG,
270	POWER_SUPPLY_PROP_CAPACITY,
271	POWER_SUPPLY_PROP_TEMP,
272	POWER_SUPPLY_PROP_TEMP_AMBIENT,
273	POWER_SUPPLY_PROP_MANUFACTURER,
274	POWER_SUPPLY_PROP_SERIAL_NUMBER,
275};
276
277/*********************************************************************
278 *		Initialisation
279 *********************************************************************/
280
281static struct platform_device *bat_pdev;
282
283static struct power_supply olpc_bat = {
284	.properties = olpc_bat_props,
285	.num_properties = ARRAY_SIZE(olpc_bat_props),
286	.get_property = olpc_bat_get_property,
287	.use_for_apm = 1,
288};
289
290void olpc_battery_trigger_uevent(unsigned long cause)
291{
292	if (cause & EC_SCI_SRC_ACPWR)
293		kobject_uevent(&olpc_ac.dev->kobj, KOBJ_CHANGE);
294	if (cause & (EC_SCI_SRC_BATERR|EC_SCI_SRC_BATSOC|EC_SCI_SRC_BATTERY))
295		kobject_uevent(&olpc_bat.dev->kobj, KOBJ_CHANGE);
296}
297
298static int __init olpc_bat_init(void)
299{
300	int ret = 0;
301	uint8_t status;
302
303	if (!olpc_platform_info.ecver)
304		return -ENXIO;
305	if (olpc_platform_info.ecver < 0x43) {
306		printk(KERN_NOTICE "OLPC EC version 0x%02x too old for battery driver.\n", olpc_platform_info.ecver);
307		return -ENXIO;
308	}
309
310	ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1);
311	if (ret)
312		return ret;
313
314	/* Ignore the status. It doesn't actually matter */
315
316	bat_pdev = platform_device_register_simple("olpc-battery", 0, NULL, 0);
317	if (IS_ERR(bat_pdev))
318		return PTR_ERR(bat_pdev);
319
320	ret = power_supply_register(&bat_pdev->dev, &olpc_ac);
321	if (ret)
322		goto ac_failed;
323
324	olpc_bat.name = bat_pdev->name;
325
326	ret = power_supply_register(&bat_pdev->dev, &olpc_bat);
327	if (ret)
328		goto battery_failed;
329
330	goto success;
331
332battery_failed:
333	power_supply_unregister(&olpc_ac);
334ac_failed:
335	platform_device_unregister(bat_pdev);
336success:
337	return ret;
338}
339
340static void __exit olpc_bat_exit(void)
341{
342	power_supply_unregister(&olpc_bat);
343	power_supply_unregister(&olpc_ac);
344	platform_device_unregister(bat_pdev);
345}
346
347module_init(olpc_bat_init);
348module_exit(olpc_bat_exit);
349
350MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
351MODULE_LICENSE("GPL");
352MODULE_DESCRIPTION("Battery driver for One Laptop Per Child 'XO' machine");
353