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 /* int16_t, *6250/15, µAh */
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
olpc_ac_get_prop(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)53 static 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
75 static enum power_supply_property olpc_ac_props[] = {
76 POWER_SUPPLY_PROP_ONLINE,
77 };
78
79 static 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
87 static char bat_serial[17]; /* Ick */
88
olpc_bat_get_status(union power_supply_propval * val,uint8_t ec_byte)89 static int olpc_bat_get_status(union power_supply_propval *val, uint8_t ec_byte)
90 {
91 if (olpc_platform_info.ecver > 0x44) {
92 if (ec_byte & BAT_STAT_CHARGING)
93 val->intval = POWER_SUPPLY_STATUS_CHARGING;
94 else if (ec_byte & BAT_STAT_DISCHARGING)
95 val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
96 else if (ec_byte & BAT_STAT_FULL)
97 val->intval = POWER_SUPPLY_STATUS_FULL;
98 else /* er,... */
99 val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
100 } else {
101 /* Older EC didn't report charge/discharge bits */
102 if (!(ec_byte & BAT_STAT_AC)) /* No AC means discharging */
103 val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
104 else if (ec_byte & BAT_STAT_FULL)
105 val->intval = POWER_SUPPLY_STATUS_FULL;
106 else /* Not _necessarily_ true but EC doesn't tell all yet */
107 val->intval = POWER_SUPPLY_STATUS_CHARGING;
108 }
109
110 return 0;
111 }
112
olpc_bat_get_health(union power_supply_propval * val)113 static int olpc_bat_get_health(union power_supply_propval *val)
114 {
115 uint8_t ec_byte;
116 int ret;
117
118 ret = olpc_ec_cmd(EC_BAT_ERRCODE, NULL, 0, &ec_byte, 1);
119 if (ret)
120 return ret;
121
122 switch (ec_byte) {
123 case 0:
124 val->intval = POWER_SUPPLY_HEALTH_GOOD;
125 break;
126
127 case BAT_ERR_OVERTEMP:
128 val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
129 break;
130
131 case BAT_ERR_OVERVOLTAGE:
132 val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
133 break;
134
135 case BAT_ERR_INFOFAIL:
136 case BAT_ERR_OUT_OF_CONTROL:
137 case BAT_ERR_ID_FAIL:
138 case BAT_ERR_ACR_FAIL:
139 val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
140 break;
141
142 default:
143 /* Eep. We don't know this failure code */
144 ret = -EIO;
145 }
146
147 return ret;
148 }
149
olpc_bat_get_mfr(union power_supply_propval * val)150 static int olpc_bat_get_mfr(union power_supply_propval *val)
151 {
152 uint8_t ec_byte;
153 int ret;
154
155 ec_byte = BAT_ADDR_MFR_TYPE;
156 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
157 if (ret)
158 return ret;
159
160 switch (ec_byte >> 4) {
161 case 1:
162 val->strval = "Gold Peak";
163 break;
164 case 2:
165 val->strval = "BYD";
166 break;
167 default:
168 val->strval = "Unknown";
169 break;
170 }
171
172 return ret;
173 }
174
olpc_bat_get_tech(union power_supply_propval * val)175 static int olpc_bat_get_tech(union power_supply_propval *val)
176 {
177 uint8_t ec_byte;
178 int ret;
179
180 ec_byte = BAT_ADDR_MFR_TYPE;
181 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
182 if (ret)
183 return ret;
184
185 switch (ec_byte & 0xf) {
186 case 1:
187 val->intval = POWER_SUPPLY_TECHNOLOGY_NiMH;
188 break;
189 case 2:
190 val->intval = POWER_SUPPLY_TECHNOLOGY_LiFe;
191 break;
192 default:
193 val->intval = POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
194 break;
195 }
196
197 return ret;
198 }
199
200 /*********************************************************************
201 * Battery properties
202 *********************************************************************/
olpc_bat_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)203 static int olpc_bat_get_property(struct power_supply *psy,
204 enum power_supply_property psp,
205 union power_supply_propval *val)
206 {
207 int ret = 0;
208 __be16 ec_word;
209 uint8_t ec_byte;
210 __be64 ser_buf;
211
212 ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &ec_byte, 1);
213 if (ret)
214 return ret;
215
216 /* Theoretically there's a race here -- the battery could be
217 removed immediately after we check whether it's present, and
218 then we query for some other property of the now-absent battery.
219 It doesn't matter though -- the EC will return the last-known
220 information, and it's as if we just ran that _little_ bit faster
221 and managed to read it out before the battery went away. */
222 if (!(ec_byte & BAT_STAT_PRESENT) && psp != POWER_SUPPLY_PROP_PRESENT)
223 return -ENODEV;
224
225 switch (psp) {
226 case POWER_SUPPLY_PROP_STATUS:
227 ret = olpc_bat_get_status(val, ec_byte);
228 if (ret)
229 return ret;
230 break;
231 case POWER_SUPPLY_PROP_PRESENT:
232 val->intval = !!(ec_byte & BAT_STAT_PRESENT);
233 break;
234
235 case POWER_SUPPLY_PROP_HEALTH:
236 if (ec_byte & BAT_STAT_DESTROY)
237 val->intval = POWER_SUPPLY_HEALTH_DEAD;
238 else {
239 ret = olpc_bat_get_health(val);
240 if (ret)
241 return ret;
242 }
243 break;
244
245 case POWER_SUPPLY_PROP_MANUFACTURER:
246 ret = olpc_bat_get_mfr(val);
247 if (ret)
248 return ret;
249 break;
250 case POWER_SUPPLY_PROP_TECHNOLOGY:
251 ret = olpc_bat_get_tech(val);
252 if (ret)
253 return ret;
254 break;
255 case POWER_SUPPLY_PROP_VOLTAGE_AVG:
256 ret = olpc_ec_cmd(EC_BAT_VOLTAGE, NULL, 0, (void *)&ec_word, 2);
257 if (ret)
258 return ret;
259
260 val->intval = (int)be16_to_cpu(ec_word) * 9760L / 32;
261 break;
262 case POWER_SUPPLY_PROP_CURRENT_AVG:
263 ret = olpc_ec_cmd(EC_BAT_CURRENT, NULL, 0, (void *)&ec_word, 2);
264 if (ret)
265 return ret;
266
267 val->intval = (int)be16_to_cpu(ec_word) * 15625L / 120;
268 break;
269 case POWER_SUPPLY_PROP_CAPACITY:
270 ret = olpc_ec_cmd(EC_BAT_SOC, NULL, 0, &ec_byte, 1);
271 if (ret)
272 return ret;
273 val->intval = ec_byte;
274 break;
275 case POWER_SUPPLY_PROP_TEMP:
276 ret = olpc_ec_cmd(EC_BAT_TEMP, NULL, 0, (void *)&ec_word, 2);
277 if (ret)
278 return ret;
279
280 val->intval = (int)be16_to_cpu(ec_word) * 100 / 256;
281 break;
282 case POWER_SUPPLY_PROP_TEMP_AMBIENT:
283 ret = olpc_ec_cmd(EC_AMB_TEMP, NULL, 0, (void *)&ec_word, 2);
284 if (ret)
285 return ret;
286
287 val->intval = (int)be16_to_cpu(ec_word) * 100 / 256;
288 break;
289 case POWER_SUPPLY_PROP_CHARGE_COUNTER:
290 ret = olpc_ec_cmd(EC_BAT_ACR, NULL, 0, (void *)&ec_word, 2);
291 if (ret)
292 return ret;
293
294 val->intval = (int)be16_to_cpu(ec_word) * 6250 / 15;
295 break;
296 case POWER_SUPPLY_PROP_SERIAL_NUMBER:
297 ret = olpc_ec_cmd(EC_BAT_SERIAL, NULL, 0, (void *)&ser_buf, 8);
298 if (ret)
299 return ret;
300
301 sprintf(bat_serial, "%016llx", (long long)be64_to_cpu(ser_buf));
302 val->strval = bat_serial;
303 break;
304 default:
305 ret = -EINVAL;
306 break;
307 }
308
309 return ret;
310 }
311
312 static enum power_supply_property olpc_bat_props[] = {
313 POWER_SUPPLY_PROP_STATUS,
314 POWER_SUPPLY_PROP_PRESENT,
315 POWER_SUPPLY_PROP_HEALTH,
316 POWER_SUPPLY_PROP_TECHNOLOGY,
317 POWER_SUPPLY_PROP_VOLTAGE_AVG,
318 POWER_SUPPLY_PROP_CURRENT_AVG,
319 POWER_SUPPLY_PROP_CAPACITY,
320 POWER_SUPPLY_PROP_TEMP,
321 POWER_SUPPLY_PROP_TEMP_AMBIENT,
322 POWER_SUPPLY_PROP_MANUFACTURER,
323 POWER_SUPPLY_PROP_SERIAL_NUMBER,
324 POWER_SUPPLY_PROP_CHARGE_COUNTER,
325 };
326
327 /* EEPROM reading goes completely around the power_supply API, sadly */
328
329 #define EEPROM_START 0x20
330 #define EEPROM_END 0x80
331 #define EEPROM_SIZE (EEPROM_END - EEPROM_START)
332
olpc_bat_eeprom_read(struct kobject * kobj,struct bin_attribute * attr,char * buf,loff_t off,size_t count)333 static ssize_t olpc_bat_eeprom_read(struct kobject *kobj,
334 struct bin_attribute *attr, char *buf, loff_t off, size_t count)
335 {
336 uint8_t ec_byte;
337 int ret, end;
338
339 if (off >= EEPROM_SIZE)
340 return 0;
341 if (off + count > EEPROM_SIZE)
342 count = EEPROM_SIZE - off;
343
344 end = EEPROM_START + off + count;
345 for (ec_byte = EEPROM_START + off; ec_byte < end; ec_byte++) {
346 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1,
347 &buf[ec_byte - EEPROM_START], 1);
348 if (ret) {
349 printk(KERN_ERR "olpc-battery: EC command "
350 "EC_BAT_EEPROM @ 0x%x failed -"
351 " %d!\n", ec_byte, ret);
352 return -EIO;
353 }
354 }
355
356 return count;
357 }
358
359 static struct bin_attribute olpc_bat_eeprom = {
360 .attr = {
361 .name = "eeprom",
362 .mode = S_IRUGO,
363 .owner = THIS_MODULE,
364 },
365 .size = 0,
366 .read = olpc_bat_eeprom_read,
367 };
368
369 /*********************************************************************
370 * Initialisation
371 *********************************************************************/
372
373 static struct platform_device *bat_pdev;
374
375 static struct power_supply olpc_bat = {
376 .properties = olpc_bat_props,
377 .num_properties = ARRAY_SIZE(olpc_bat_props),
378 .get_property = olpc_bat_get_property,
379 .use_for_apm = 1,
380 };
381
olpc_battery_trigger_uevent(unsigned long cause)382 void olpc_battery_trigger_uevent(unsigned long cause)
383 {
384 if (cause & EC_SCI_SRC_ACPWR)
385 kobject_uevent(&olpc_ac.dev->kobj, KOBJ_CHANGE);
386 if (cause & (EC_SCI_SRC_BATERR|EC_SCI_SRC_BATSOC|EC_SCI_SRC_BATTERY))
387 kobject_uevent(&olpc_bat.dev->kobj, KOBJ_CHANGE);
388 }
389
olpc_bat_init(void)390 static int __init olpc_bat_init(void)
391 {
392 int ret = 0;
393 uint8_t status;
394
395 if (!olpc_platform_info.ecver)
396 return -ENXIO;
397
398 /*
399 * We've seen a number of EC protocol changes; this driver requires
400 * the latest EC protocol, supported by 0x44 and above.
401 */
402 if (olpc_platform_info.ecver < 0x44) {
403 printk(KERN_NOTICE "OLPC EC version 0x%02x too old for "
404 "battery driver.\n", olpc_platform_info.ecver);
405 return -ENXIO;
406 }
407
408 ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1);
409 if (ret)
410 return ret;
411
412 /* Ignore the status. It doesn't actually matter */
413
414 bat_pdev = platform_device_register_simple("olpc-battery", 0, NULL, 0);
415 if (IS_ERR(bat_pdev))
416 return PTR_ERR(bat_pdev);
417
418 ret = power_supply_register(&bat_pdev->dev, &olpc_ac);
419 if (ret)
420 goto ac_failed;
421
422 olpc_bat.name = bat_pdev->name;
423
424 ret = power_supply_register(&bat_pdev->dev, &olpc_bat);
425 if (ret)
426 goto battery_failed;
427
428 ret = device_create_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
429 if (ret)
430 goto eeprom_failed;
431
432 goto success;
433
434 eeprom_failed:
435 power_supply_unregister(&olpc_bat);
436 battery_failed:
437 power_supply_unregister(&olpc_ac);
438 ac_failed:
439 platform_device_unregister(bat_pdev);
440 success:
441 return ret;
442 }
443
olpc_bat_exit(void)444 static void __exit olpc_bat_exit(void)
445 {
446 device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
447 power_supply_unregister(&olpc_bat);
448 power_supply_unregister(&olpc_ac);
449 platform_device_unregister(bat_pdev);
450 }
451
452 module_init(olpc_bat_init);
453 module_exit(olpc_bat_exit);
454
455 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
456 MODULE_LICENSE("GPL");
457 MODULE_DESCRIPTION("Battery driver for One Laptop Per Child 'XO' machine");
458