878684df76671b41befb25ab30593b0d00ed6f42
[linux-2.6.git] / drivers / power / olpc_battery.c
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
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 /*********************************************************************
88  *              Battery properties
89  *********************************************************************/
90 static int olpc_bat_get_property(struct power_supply *psy,
91                                  enum power_supply_property psp,
92                                  union power_supply_propval *val)
93 {
94         int ret = 0;
95         int16_t ec_word;
96         uint8_t ec_byte;
97
98         ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &ec_byte, 1);
99         if (ret)
100                 return ret;
101
102         /* Theoretically there's a race here -- the battery could be
103            removed immediately after we check whether it's present, and
104            then we query for some other property of the now-absent battery.
105            It doesn't matter though -- the EC will return the last-known
106            information, and it's as if we just ran that _little_ bit faster
107            and managed to read it out before the battery went away. */
108         if (!(ec_byte & BAT_STAT_PRESENT) && psp != POWER_SUPPLY_PROP_PRESENT)
109                 return -ENODEV;
110
111         switch (psp) {
112         case POWER_SUPPLY_PROP_STATUS:
113                 if (olpc_platform_info.ecver > 0x44) {
114                         if (ec_byte & BAT_STAT_CHARGING)
115                                 val->intval = POWER_SUPPLY_STATUS_CHARGING;
116                         else if (ec_byte & BAT_STAT_DISCHARGING)
117                                 val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
118                         else if (ec_byte & BAT_STAT_FULL)
119                                 val->intval = POWER_SUPPLY_STATUS_FULL;
120                         else /* er,... */
121                                 val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
122                 } else {
123                         /* Older EC didn't report charge/discharge bits */
124                         if (!(ec_byte & BAT_STAT_AC)) /* No AC means discharging */
125                                 val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
126                         else if (ec_byte & BAT_STAT_FULL)
127                                 val->intval = POWER_SUPPLY_STATUS_FULL;
128                         else /* Not _necessarily_ true but EC doesn't tell all yet */
129                                 val->intval = POWER_SUPPLY_STATUS_CHARGING;
130                         break;
131                 }
132         case POWER_SUPPLY_PROP_PRESENT:
133                 val->intval = !!(ec_byte & BAT_STAT_PRESENT);
134                 break;
135
136         case POWER_SUPPLY_PROP_HEALTH:
137                 if (ec_byte & BAT_STAT_DESTROY)
138                         val->intval = POWER_SUPPLY_HEALTH_DEAD;
139                 else {
140                         ret = olpc_ec_cmd(EC_BAT_ERRCODE, NULL, 0, &ec_byte, 1);
141                         if (ret)
142                                 return ret;
143
144                         switch (ec_byte) {
145                         case 0:
146                                 val->intval = POWER_SUPPLY_HEALTH_GOOD;
147                                 break;
148
149                         case BAT_ERR_OVERTEMP:
150                                 val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
151                                 break;
152
153                         case BAT_ERR_OVERVOLTAGE:
154                                 val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
155                                 break;
156
157                         case BAT_ERR_INFOFAIL:
158                         case BAT_ERR_OUT_OF_CONTROL:
159                         case BAT_ERR_ID_FAIL:
160                         case BAT_ERR_ACR_FAIL:
161                                 val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
162                                 break;
163
164                         default:
165                                 /* Eep. We don't know this failure code */
166                                 return -EIO;
167                         }
168                 }
169                 break;
170
171         case POWER_SUPPLY_PROP_MANUFACTURER:
172                 ec_byte = BAT_ADDR_MFR_TYPE;
173                 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
174                 if (ret)
175                         return ret;
176
177                 switch (ec_byte >> 4) {
178                 case 1:
179                         val->strval = "Gold Peak";
180                         break;
181                 case 2:
182                         val->strval = "BYD";
183                         break;
184                 default:
185                         val->strval = "Unknown";
186                         break;
187                 }
188                 break;
189         case POWER_SUPPLY_PROP_TECHNOLOGY:
190                 ec_byte = BAT_ADDR_MFR_TYPE;
191                 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
192                 if (ret)
193                         return ret;
194
195                 switch (ec_byte & 0xf) {
196                 case 1:
197                         val->intval = POWER_SUPPLY_TECHNOLOGY_NiMH;
198                         break;
199                 case 2:
200                         val->intval = POWER_SUPPLY_TECHNOLOGY_LiFe;
201                         break;
202                 default:
203                         val->intval = POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
204                         break;
205                 }
206                 break;
207         case POWER_SUPPLY_PROP_VOLTAGE_AVG:
208                 ret = olpc_ec_cmd(EC_BAT_VOLTAGE, NULL, 0, (void *)&ec_word, 2);
209                 if (ret)
210                         return ret;
211
212                 ec_word = be16_to_cpu(ec_word);
213                 val->intval = ec_word * 9760L / 32;
214                 break;
215         case POWER_SUPPLY_PROP_CURRENT_AVG:
216                 ret = olpc_ec_cmd(EC_BAT_CURRENT, NULL, 0, (void *)&ec_word, 2);
217                 if (ret)
218                         return ret;
219
220                 ec_word = be16_to_cpu(ec_word);
221                 val->intval = ec_word * 15625L / 120;
222                 break;
223         case POWER_SUPPLY_PROP_CAPACITY:
224                 ret = olpc_ec_cmd(EC_BAT_SOC, NULL, 0, &ec_byte, 1);
225                 if (ret)
226                         return ret;
227                 val->intval = ec_byte;
228                 break;
229         case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
230                 if (ec_byte & BAT_STAT_FULL)
231                         val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
232                 else if (ec_byte & BAT_STAT_LOW)
233                         val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
234                 else
235                         val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
236                 break;
237         case POWER_SUPPLY_PROP_TEMP:
238                 ret = olpc_ec_cmd(EC_BAT_TEMP, NULL, 0, (void *)&ec_word, 2);
239                 if (ret)
240                         return ret;
241                 ec_word = be16_to_cpu(ec_word);
242                 val->intval = ec_word * 100 / 256;
243                 break;
244         case POWER_SUPPLY_PROP_TEMP_AMBIENT:
245                 ret = olpc_ec_cmd(EC_AMB_TEMP, NULL, 0, (void *)&ec_word, 2);
246                 if (ret)
247                         return ret;
248
249                 ec_word = be16_to_cpu(ec_word);
250                 val->intval = ec_word * 100 / 256;
251                 break;
252         default:
253                 ret = -EINVAL;
254                 break;
255         }
256
257         return ret;
258 }
259
260 static enum power_supply_property olpc_bat_props[] = {
261         POWER_SUPPLY_PROP_STATUS,
262         POWER_SUPPLY_PROP_PRESENT,
263         POWER_SUPPLY_PROP_HEALTH,
264         POWER_SUPPLY_PROP_TECHNOLOGY,
265         POWER_SUPPLY_PROP_VOLTAGE_AVG,
266         POWER_SUPPLY_PROP_CURRENT_AVG,
267         POWER_SUPPLY_PROP_CAPACITY,
268         POWER_SUPPLY_PROP_CAPACITY_LEVEL,
269         POWER_SUPPLY_PROP_TEMP,
270         POWER_SUPPLY_PROP_TEMP_AMBIENT,
271         POWER_SUPPLY_PROP_MANUFACTURER,
272 };
273
274 /*********************************************************************
275  *              Initialisation
276  *********************************************************************/
277
278 static struct platform_device *bat_pdev;
279
280 static struct power_supply olpc_bat = {
281         .properties = olpc_bat_props,
282         .num_properties = ARRAY_SIZE(olpc_bat_props),
283         .get_property = olpc_bat_get_property,
284         .use_for_apm = 1,
285 };
286
287 void olpc_battery_trigger_uevent(unsigned long cause)
288 {
289         if (cause & EC_SCI_SRC_ACPWR)
290                 kobject_uevent(&olpc_ac.dev->kobj, KOBJ_CHANGE);
291         if (cause & (EC_SCI_SRC_BATERR|EC_SCI_SRC_BATSOC|EC_SCI_SRC_BATTERY))
292                 kobject_uevent(&olpc_bat.dev->kobj, KOBJ_CHANGE);
293 }
294
295 static int __init olpc_bat_init(void)
296 {
297         int ret = 0;
298         uint8_t status;
299
300         if (!olpc_platform_info.ecver)
301                 return -ENXIO;
302         if (olpc_platform_info.ecver < 0x43) {
303                 printk(KERN_NOTICE "OLPC EC version 0x%02x too old for battery driver.\n", olpc_platform_info.ecver);
304                 return -ENXIO;
305         }
306
307         ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1);
308         if (ret)
309                 return ret;
310
311         /* Ignore the status. It doesn't actually matter */
312
313         bat_pdev = platform_device_register_simple("olpc-battery", 0, NULL, 0);
314         if (IS_ERR(bat_pdev))
315                 return PTR_ERR(bat_pdev);
316
317         ret = power_supply_register(&bat_pdev->dev, &olpc_ac);
318         if (ret)
319                 goto ac_failed;
320
321         olpc_bat.name = bat_pdev->name;
322
323         ret = power_supply_register(&bat_pdev->dev, &olpc_bat);
324         if (ret)
325                 goto battery_failed;
326
327         olpc_register_battery_callback(&olpc_battery_trigger_uevent);
328         goto success;
329
330 battery_failed:
331         power_supply_unregister(&olpc_ac);
332 ac_failed:
333         platform_device_unregister(bat_pdev);
334 success:
335         return ret;
336 }
337
338 static void __exit olpc_bat_exit(void)
339 {
340         olpc_deregister_battery_callback();
341         power_supply_unregister(&olpc_bat);
342         power_supply_unregister(&olpc_ac);
343         platform_device_unregister(bat_pdev);
344         return;
345 }
346
347 module_init(olpc_bat_init);
348 module_exit(olpc_bat_exit);
349
350 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
351 MODULE_LICENSE("GPL");
352 MODULE_DESCRIPTION("Battery driver for One Laptop Per Child 'XO' machine");