Commit | Line | Data |
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b996ad0e RG |
1 | /* |
2 | * BQ27x00 battery driver | |
3 | * | |
4 | * Copyright (C) 2008 Rodolfo Giometti <giometti@linux.it> | |
5 | * Copyright (C) 2008 Eurotech S.p.A. <info@eurotech.it> | |
6 | * | |
7 | * Based on a previous work by Copyright (C) 2008 Texas Instruments, Inc. | |
8 | * | |
9 | * This package is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License version 2 as | |
11 | * published by the Free Software Foundation. | |
12 | * | |
13 | * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR | |
14 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED | |
15 | * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. | |
16 | * | |
17 | */ | |
18 | #include <linux/module.h> | |
19 | #include <linux/param.h> | |
20 | #include <linux/jiffies.h> | |
21 | #include <linux/workqueue.h> | |
22 | #include <linux/delay.h> | |
23 | #include <linux/platform_device.h> | |
24 | #include <linux/power_supply.h> | |
25 | #include <linux/idr.h> | |
b996ad0e | 26 | #include <linux/i2c.h> |
5a0e3ad6 | 27 | #include <linux/slab.h> |
8aef7e8f | 28 | #include <asm/unaligned.h> |
b996ad0e | 29 | |
e20908d9 | 30 | #define DRIVER_VERSION "1.1.0" |
b996ad0e RG |
31 | |
32 | #define BQ27x00_REG_TEMP 0x06 | |
33 | #define BQ27x00_REG_VOLT 0x08 | |
b996ad0e RG |
34 | #define BQ27x00_REG_AI 0x14 |
35 | #define BQ27x00_REG_FLAGS 0x0A | |
4e924a81 GI |
36 | #define BQ27x00_REG_TTE 0x16 |
37 | #define BQ27x00_REG_TTF 0x18 | |
38 | #define BQ27x00_REG_TTECP 0x26 | |
b996ad0e | 39 | |
e20908d9 | 40 | #define BQ27000_REG_RSOC 0x0B /* Relative State-of-Charge */ |
4e924a81 | 41 | #define BQ27000_FLAG_CHGS BIT(7) |
e20908d9 GI |
42 | |
43 | #define BQ27500_REG_SOC 0x2c | |
4e924a81 GI |
44 | #define BQ27500_FLAG_DSC BIT(0) |
45 | #define BQ27500_FLAG_FC BIT(9) | |
e20908d9 | 46 | |
b996ad0e RG |
47 | /* If the system has several batteries we need a different name for each |
48 | * of them... | |
49 | */ | |
50 | static DEFINE_IDR(battery_id); | |
51 | static DEFINE_MUTEX(battery_mutex); | |
52 | ||
53 | struct bq27x00_device_info; | |
54 | struct bq27x00_access_methods { | |
55 | int (*read)(u8 reg, int *rt_value, int b_single, | |
56 | struct bq27x00_device_info *di); | |
57 | }; | |
58 | ||
e20908d9 GI |
59 | enum bq27x00_chip { BQ27000, BQ27500 }; |
60 | ||
b996ad0e RG |
61 | struct bq27x00_device_info { |
62 | struct device *dev; | |
63 | int id; | |
b996ad0e RG |
64 | struct bq27x00_access_methods *bus; |
65 | struct power_supply bat; | |
e20908d9 | 66 | enum bq27x00_chip chip; |
b996ad0e RG |
67 | |
68 | struct i2c_client *client; | |
69 | }; | |
70 | ||
71 | static enum power_supply_property bq27x00_battery_props[] = { | |
4e924a81 | 72 | POWER_SUPPLY_PROP_STATUS, |
b996ad0e RG |
73 | POWER_SUPPLY_PROP_PRESENT, |
74 | POWER_SUPPLY_PROP_VOLTAGE_NOW, | |
75 | POWER_SUPPLY_PROP_CURRENT_NOW, | |
76 | POWER_SUPPLY_PROP_CAPACITY, | |
77 | POWER_SUPPLY_PROP_TEMP, | |
4e924a81 GI |
78 | POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW, |
79 | POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG, | |
80 | POWER_SUPPLY_PROP_TIME_TO_FULL_NOW, | |
b996ad0e RG |
81 | }; |
82 | ||
83 | /* | |
84 | * Common code for BQ27x00 devices | |
85 | */ | |
86 | ||
87 | static int bq27x00_read(u8 reg, int *rt_value, int b_single, | |
88 | struct bq27x00_device_info *di) | |
89 | { | |
97f70c23 | 90 | return di->bus->read(reg, rt_value, b_single, di); |
b996ad0e RG |
91 | } |
92 | ||
93 | /* | |
b4de3608 | 94 | * Return the battery temperature in tenths of degree Celsius |
b996ad0e RG |
95 | * Or < 0 if something fails. |
96 | */ | |
97 | static int bq27x00_battery_temperature(struct bq27x00_device_info *di) | |
98 | { | |
99 | int ret; | |
100 | int temp = 0; | |
101 | ||
102 | ret = bq27x00_read(BQ27x00_REG_TEMP, &temp, 0, di); | |
103 | if (ret) { | |
104 | dev_err(di->dev, "error reading temperature\n"); | |
105 | return ret; | |
106 | } | |
107 | ||
e20908d9 GI |
108 | if (di->chip == BQ27500) |
109 | return temp - 2731; | |
110 | else | |
111 | return ((temp >> 2) - 273) * 10; | |
b996ad0e RG |
112 | } |
113 | ||
114 | /* | |
115 | * Return the battery Voltage in milivolts | |
116 | * Or < 0 if something fails. | |
117 | */ | |
118 | static int bq27x00_battery_voltage(struct bq27x00_device_info *di) | |
119 | { | |
120 | int ret; | |
121 | int volt = 0; | |
122 | ||
123 | ret = bq27x00_read(BQ27x00_REG_VOLT, &volt, 0, di); | |
124 | if (ret) { | |
125 | dev_err(di->dev, "error reading voltage\n"); | |
126 | return ret; | |
127 | } | |
128 | ||
afbc74fd | 129 | return volt * 1000; |
b996ad0e RG |
130 | } |
131 | ||
132 | /* | |
133 | * Return the battery average current | |
134 | * Note that current can be negative signed as well | |
135 | * Or 0 if something fails. | |
136 | */ | |
137 | static int bq27x00_battery_current(struct bq27x00_device_info *di) | |
138 | { | |
139 | int ret; | |
140 | int curr = 0; | |
141 | int flags = 0; | |
142 | ||
143 | ret = bq27x00_read(BQ27x00_REG_AI, &curr, 0, di); | |
144 | if (ret) { | |
145 | dev_err(di->dev, "error reading current\n"); | |
146 | return 0; | |
147 | } | |
e20908d9 GI |
148 | |
149 | if (di->chip == BQ27500) { | |
150 | /* bq27500 returns signed value */ | |
151 | curr = (int)(s16)curr; | |
152 | } else { | |
153 | ret = bq27x00_read(BQ27x00_REG_FLAGS, &flags, 0, di); | |
154 | if (ret < 0) { | |
155 | dev_err(di->dev, "error reading flags\n"); | |
156 | return 0; | |
157 | } | |
4e924a81 | 158 | if (flags & BQ27000_FLAG_CHGS) { |
e20908d9 | 159 | dev_dbg(di->dev, "negative current!\n"); |
afbc74fd | 160 | curr = -curr; |
e20908d9 | 161 | } |
b996ad0e | 162 | } |
e20908d9 | 163 | |
afbc74fd | 164 | return curr * 1000; |
b996ad0e RG |
165 | } |
166 | ||
167 | /* | |
168 | * Return the battery Relative State-of-Charge | |
169 | * Or < 0 if something fails. | |
170 | */ | |
171 | static int bq27x00_battery_rsoc(struct bq27x00_device_info *di) | |
172 | { | |
173 | int ret; | |
174 | int rsoc = 0; | |
175 | ||
e20908d9 GI |
176 | if (di->chip == BQ27500) |
177 | ret = bq27x00_read(BQ27500_REG_SOC, &rsoc, 0, di); | |
178 | else | |
179 | ret = bq27x00_read(BQ27000_REG_RSOC, &rsoc, 1, di); | |
b996ad0e RG |
180 | if (ret) { |
181 | dev_err(di->dev, "error reading relative State-of-Charge\n"); | |
182 | return ret; | |
183 | } | |
184 | ||
97f70c23 | 185 | return rsoc; |
b996ad0e RG |
186 | } |
187 | ||
4e924a81 GI |
188 | static int bq27x00_battery_status(struct bq27x00_device_info *di, |
189 | union power_supply_propval *val) | |
190 | { | |
191 | int flags = 0; | |
192 | int status; | |
193 | int ret; | |
194 | ||
195 | ret = bq27x00_read(BQ27x00_REG_FLAGS, &flags, 0, di); | |
196 | if (ret < 0) { | |
197 | dev_err(di->dev, "error reading flags\n"); | |
198 | return ret; | |
199 | } | |
200 | ||
201 | if (di->chip == BQ27500) { | |
202 | if (flags & BQ27500_FLAG_FC) | |
203 | status = POWER_SUPPLY_STATUS_FULL; | |
204 | else if (flags & BQ27500_FLAG_DSC) | |
205 | status = POWER_SUPPLY_STATUS_DISCHARGING; | |
206 | else | |
207 | status = POWER_SUPPLY_STATUS_CHARGING; | |
208 | } else { | |
209 | if (flags & BQ27000_FLAG_CHGS) | |
210 | status = POWER_SUPPLY_STATUS_CHARGING; | |
211 | else | |
212 | status = POWER_SUPPLY_STATUS_DISCHARGING; | |
213 | } | |
214 | ||
215 | val->intval = status; | |
216 | return 0; | |
217 | } | |
218 | ||
219 | /* | |
220 | * Read a time register. | |
221 | * Return < 0 if something fails. | |
222 | */ | |
223 | static int bq27x00_battery_time(struct bq27x00_device_info *di, int reg, | |
224 | union power_supply_propval *val) | |
225 | { | |
226 | int tval = 0; | |
227 | int ret; | |
228 | ||
229 | ret = bq27x00_read(reg, &tval, 0, di); | |
230 | if (ret) { | |
231 | dev_err(di->dev, "error reading register %02x\n", reg); | |
232 | return ret; | |
233 | } | |
234 | ||
235 | if (tval == 65535) | |
236 | return -ENODATA; | |
237 | ||
238 | val->intval = tval * 60; | |
239 | return 0; | |
240 | } | |
241 | ||
b996ad0e RG |
242 | #define to_bq27x00_device_info(x) container_of((x), \ |
243 | struct bq27x00_device_info, bat); | |
244 | ||
245 | static int bq27x00_battery_get_property(struct power_supply *psy, | |
246 | enum power_supply_property psp, | |
247 | union power_supply_propval *val) | |
248 | { | |
4e924a81 | 249 | int ret = 0; |
b996ad0e RG |
250 | struct bq27x00_device_info *di = to_bq27x00_device_info(psy); |
251 | ||
252 | switch (psp) { | |
4e924a81 GI |
253 | case POWER_SUPPLY_PROP_STATUS: |
254 | ret = bq27x00_battery_status(di, val); | |
255 | break; | |
b996ad0e RG |
256 | case POWER_SUPPLY_PROP_VOLTAGE_NOW: |
257 | case POWER_SUPPLY_PROP_PRESENT: | |
258 | val->intval = bq27x00_battery_voltage(di); | |
259 | if (psp == POWER_SUPPLY_PROP_PRESENT) | |
260 | val->intval = val->intval <= 0 ? 0 : 1; | |
261 | break; | |
262 | case POWER_SUPPLY_PROP_CURRENT_NOW: | |
263 | val->intval = bq27x00_battery_current(di); | |
264 | break; | |
265 | case POWER_SUPPLY_PROP_CAPACITY: | |
266 | val->intval = bq27x00_battery_rsoc(di); | |
267 | break; | |
268 | case POWER_SUPPLY_PROP_TEMP: | |
269 | val->intval = bq27x00_battery_temperature(di); | |
270 | break; | |
4e924a81 GI |
271 | case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW: |
272 | ret = bq27x00_battery_time(di, BQ27x00_REG_TTE, val); | |
273 | break; | |
274 | case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG: | |
275 | ret = bq27x00_battery_time(di, BQ27x00_REG_TTECP, val); | |
276 | break; | |
277 | case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW: | |
278 | ret = bq27x00_battery_time(di, BQ27x00_REG_TTF, val); | |
279 | break; | |
b996ad0e RG |
280 | default: |
281 | return -EINVAL; | |
282 | } | |
283 | ||
4e924a81 | 284 | return ret; |
b996ad0e RG |
285 | } |
286 | ||
287 | static void bq27x00_powersupply_init(struct bq27x00_device_info *di) | |
288 | { | |
289 | di->bat.type = POWER_SUPPLY_TYPE_BATTERY; | |
290 | di->bat.properties = bq27x00_battery_props; | |
291 | di->bat.num_properties = ARRAY_SIZE(bq27x00_battery_props); | |
292 | di->bat.get_property = bq27x00_battery_get_property; | |
293 | di->bat.external_power_changed = NULL; | |
294 | } | |
295 | ||
296 | /* | |
e20908d9 | 297 | * i2c specific code |
b996ad0e RG |
298 | */ |
299 | ||
e20908d9 | 300 | static int bq27x00_read_i2c(u8 reg, int *rt_value, int b_single, |
b996ad0e RG |
301 | struct bq27x00_device_info *di) |
302 | { | |
303 | struct i2c_client *client = di->client; | |
304 | struct i2c_msg msg[1]; | |
305 | unsigned char data[2]; | |
306 | int err; | |
307 | ||
308 | if (!client->adapter) | |
309 | return -ENODEV; | |
310 | ||
311 | msg->addr = client->addr; | |
312 | msg->flags = 0; | |
313 | msg->len = 1; | |
314 | msg->buf = data; | |
315 | ||
316 | data[0] = reg; | |
317 | err = i2c_transfer(client->adapter, msg, 1); | |
318 | ||
319 | if (err >= 0) { | |
320 | if (!b_single) | |
321 | msg->len = 2; | |
322 | else | |
323 | msg->len = 1; | |
324 | ||
325 | msg->flags = I2C_M_RD; | |
326 | err = i2c_transfer(client->adapter, msg, 1); | |
327 | if (err >= 0) { | |
328 | if (!b_single) | |
97f70c23 | 329 | *rt_value = get_unaligned_le16(data); |
b996ad0e RG |
330 | else |
331 | *rt_value = data[0]; | |
332 | ||
333 | return 0; | |
334 | } | |
335 | } | |
336 | return err; | |
337 | } | |
338 | ||
e20908d9 | 339 | static int bq27x00_battery_probe(struct i2c_client *client, |
b996ad0e RG |
340 | const struct i2c_device_id *id) |
341 | { | |
342 | char *name; | |
343 | struct bq27x00_device_info *di; | |
344 | struct bq27x00_access_methods *bus; | |
345 | int num; | |
346 | int retval = 0; | |
347 | ||
348 | /* Get new ID for the new battery device */ | |
349 | retval = idr_pre_get(&battery_id, GFP_KERNEL); | |
350 | if (retval == 0) | |
351 | return -ENOMEM; | |
352 | mutex_lock(&battery_mutex); | |
353 | retval = idr_get_new(&battery_id, client, &num); | |
354 | mutex_unlock(&battery_mutex); | |
355 | if (retval < 0) | |
356 | return retval; | |
357 | ||
e20908d9 | 358 | name = kasprintf(GFP_KERNEL, "%s-%d", id->name, num); |
b996ad0e RG |
359 | if (!name) { |
360 | dev_err(&client->dev, "failed to allocate device name\n"); | |
361 | retval = -ENOMEM; | |
362 | goto batt_failed_1; | |
363 | } | |
364 | ||
365 | di = kzalloc(sizeof(*di), GFP_KERNEL); | |
366 | if (!di) { | |
367 | dev_err(&client->dev, "failed to allocate device info data\n"); | |
368 | retval = -ENOMEM; | |
369 | goto batt_failed_2; | |
370 | } | |
371 | di->id = num; | |
e20908d9 | 372 | di->chip = id->driver_data; |
b996ad0e RG |
373 | |
374 | bus = kzalloc(sizeof(*bus), GFP_KERNEL); | |
375 | if (!bus) { | |
376 | dev_err(&client->dev, "failed to allocate access method " | |
377 | "data\n"); | |
378 | retval = -ENOMEM; | |
379 | goto batt_failed_3; | |
380 | } | |
381 | ||
382 | i2c_set_clientdata(client, di); | |
383 | di->dev = &client->dev; | |
384 | di->bat.name = name; | |
e20908d9 | 385 | bus->read = &bq27x00_read_i2c; |
b996ad0e RG |
386 | di->bus = bus; |
387 | di->client = client; | |
388 | ||
389 | bq27x00_powersupply_init(di); | |
390 | ||
391 | retval = power_supply_register(&client->dev, &di->bat); | |
392 | if (retval) { | |
393 | dev_err(&client->dev, "failed to register battery\n"); | |
394 | goto batt_failed_4; | |
395 | } | |
396 | ||
397 | dev_info(&client->dev, "support ver. %s enabled\n", DRIVER_VERSION); | |
398 | ||
399 | return 0; | |
400 | ||
401 | batt_failed_4: | |
402 | kfree(bus); | |
403 | batt_failed_3: | |
404 | kfree(di); | |
405 | batt_failed_2: | |
406 | kfree(name); | |
407 | batt_failed_1: | |
408 | mutex_lock(&battery_mutex); | |
409 | idr_remove(&battery_id, num); | |
410 | mutex_unlock(&battery_mutex); | |
411 | ||
412 | return retval; | |
413 | } | |
414 | ||
e20908d9 | 415 | static int bq27x00_battery_remove(struct i2c_client *client) |
b996ad0e RG |
416 | { |
417 | struct bq27x00_device_info *di = i2c_get_clientdata(client); | |
418 | ||
419 | power_supply_unregister(&di->bat); | |
420 | ||
9292585c | 421 | kfree(di->bus); |
b996ad0e RG |
422 | kfree(di->bat.name); |
423 | ||
424 | mutex_lock(&battery_mutex); | |
425 | idr_remove(&battery_id, di->id); | |
426 | mutex_unlock(&battery_mutex); | |
427 | ||
428 | kfree(di); | |
429 | ||
430 | return 0; | |
431 | } | |
432 | ||
433 | /* | |
434 | * Module stuff | |
435 | */ | |
436 | ||
e20908d9 GI |
437 | static const struct i2c_device_id bq27x00_id[] = { |
438 | { "bq27200", BQ27000 }, /* bq27200 is same as bq27000, but with i2c */ | |
439 | { "bq27500", BQ27500 }, | |
b996ad0e RG |
440 | {}, |
441 | }; | |
442 | ||
e20908d9 | 443 | static struct i2c_driver bq27x00_battery_driver = { |
b996ad0e | 444 | .driver = { |
e20908d9 | 445 | .name = "bq27x00-battery", |
b996ad0e | 446 | }, |
e20908d9 GI |
447 | .probe = bq27x00_battery_probe, |
448 | .remove = bq27x00_battery_remove, | |
449 | .id_table = bq27x00_id, | |
b996ad0e RG |
450 | }; |
451 | ||
452 | static int __init bq27x00_battery_init(void) | |
453 | { | |
454 | int ret; | |
455 | ||
e20908d9 | 456 | ret = i2c_add_driver(&bq27x00_battery_driver); |
b996ad0e | 457 | if (ret) |
e20908d9 | 458 | printk(KERN_ERR "Unable to register BQ27x00 driver\n"); |
b996ad0e RG |
459 | |
460 | return ret; | |
461 | } | |
462 | module_init(bq27x00_battery_init); | |
463 | ||
464 | static void __exit bq27x00_battery_exit(void) | |
465 | { | |
e20908d9 | 466 | i2c_del_driver(&bq27x00_battery_driver); |
b996ad0e RG |
467 | } |
468 | module_exit(bq27x00_battery_exit); | |
469 | ||
470 | MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>"); | |
471 | MODULE_DESCRIPTION("BQ27x00 battery monitor driver"); | |
472 | MODULE_LICENSE("GPL"); |