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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> |
26 | #include <linux/i2c.h> |
27 | #include <linux/slab.h> |
28 | #include <asm/unaligned.h> |
29 | |
30 | #define DRIVER_VERSION "1.1.0" |
31 | |
32 | #define BQ27x00_REG_TEMP 0x06 |
33 | #define BQ27x00_REG_VOLT 0x08 |
34 | #define BQ27x00_REG_AI 0x14 |
35 | #define BQ27x00_REG_FLAGS 0x0A |
36 | #define BQ27x00_REG_TTE 0x16 |
37 | #define BQ27x00_REG_TTF 0x18 |
38 | #define BQ27x00_REG_TTECP 0x26 |
39 | |
40 | #define BQ27000_REG_RSOC 0x0B /* Relative State-of-Charge */ |
41 | #define BQ27000_FLAG_CHGS BIT(7) |
42 | |
43 | #define BQ27500_REG_SOC 0x2c |
44 | #define BQ27500_FLAG_DSC BIT(0) |
45 | #define BQ27500_FLAG_FC BIT(9) |
46 | |
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 | |
59 | enum bq27x00_chip { BQ27000, BQ27500 }; |
60 | |
61 | struct bq27x00_device_info { |
62 | struct device *dev; |
63 | int id; |
64 | struct bq27x00_access_methods *bus; |
65 | struct power_supply bat; |
66 | enum bq27x00_chip chip; |
67 | |
68 | struct i2c_client *client; |
69 | }; |
70 | |
71 | static enum power_supply_property bq27x00_battery_props[] = { |
72 | POWER_SUPPLY_PROP_STATUS, |
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, |
78 | POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW, |
79 | POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG, |
80 | POWER_SUPPLY_PROP_TIME_TO_FULL_NOW, |
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 | { |
90 | return di->bus->read(reg, rt_value, b_single, di); |
91 | } |
92 | |
93 | /* |
94 | * Return the battery temperature in tenths of degree Celsius |
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 | |
108 | if (di->chip == BQ27500) |
109 | return temp - 2731; |
110 | else |
111 | return ((temp >> 2) - 273) * 10; |
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 | |
129 | return volt * 1000; |
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 | } |
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 | } |
158 | if (flags & BQ27000_FLAG_CHGS) { |
159 | dev_dbg(di->dev, "negative current!\n"); |
160 | curr = -curr; |
161 | } |
162 | } |
163 | |
164 | return curr * 1000; |
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 | |
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); |
180 | if (ret) { |
181 | dev_err(di->dev, "error reading relative State-of-Charge\n"); |
182 | return ret; |
183 | } |
184 | |
185 | return rsoc; |
186 | } |
187 | |
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 | |
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 | { |
249 | int ret = 0; |
250 | struct bq27x00_device_info *di = to_bq27x00_device_info(psy); |
251 | |
252 | switch (psp) { |
253 | case POWER_SUPPLY_PROP_STATUS: |
254 | ret = bq27x00_battery_status(di, val); |
255 | break; |
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; |
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; |
280 | default: |
281 | return -EINVAL; |
282 | } |
283 | |
284 | return ret; |
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 | /* |
297 | * i2c specific code |
298 | */ |
299 | |
300 | static int bq27x00_read_i2c(u8 reg, int *rt_value, int b_single, |
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) |
329 | *rt_value = get_unaligned_le16(data); |
330 | else |
331 | *rt_value = data[0]; |
332 | |
333 | return 0; |
334 | } |
335 | } |
336 | return err; |
337 | } |
338 | |
339 | static int bq27x00_battery_probe(struct i2c_client *client, |
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 | |
358 | name = kasprintf(GFP_KERNEL, "%s-%d", id->name, num); |
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; |
372 | di->chip = id->driver_data; |
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; |
385 | bus->read = &bq27x00_read_i2c; |
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 | |
415 | static int bq27x00_battery_remove(struct i2c_client *client) |
416 | { |
417 | struct bq27x00_device_info *di = i2c_get_clientdata(client); |
418 | |
419 | power_supply_unregister(&di->bat); |
420 | |
421 | kfree(di->bat.name); |
422 | |
423 | mutex_lock(&battery_mutex); |
424 | idr_remove(&battery_id, di->id); |
425 | mutex_unlock(&battery_mutex); |
426 | |
427 | kfree(di); |
428 | |
429 | return 0; |
430 | } |
431 | |
432 | /* |
433 | * Module stuff |
434 | */ |
435 | |
436 | static const struct i2c_device_id bq27x00_id[] = { |
437 | { "bq27200", BQ27000 }, /* bq27200 is same as bq27000, but with i2c */ |
438 | { "bq27500", BQ27500 }, |
439 | {}, |
440 | }; |
441 | |
442 | static struct i2c_driver bq27x00_battery_driver = { |
443 | .driver = { |
444 | .name = "bq27x00-battery", |
445 | }, |
446 | .probe = bq27x00_battery_probe, |
447 | .remove = bq27x00_battery_remove, |
448 | .id_table = bq27x00_id, |
449 | }; |
450 | |
451 | static int __init bq27x00_battery_init(void) |
452 | { |
453 | int ret; |
454 | |
455 | ret = i2c_add_driver(&bq27x00_battery_driver); |
456 | if (ret) |
457 | printk(KERN_ERR "Unable to register BQ27x00 driver\n"); |
458 | |
459 | return ret; |
460 | } |
461 | module_init(bq27x00_battery_init); |
462 | |
463 | static void __exit bq27x00_battery_exit(void) |
464 | { |
465 | i2c_del_driver(&bq27x00_battery_driver); |
466 | } |
467 | module_exit(bq27x00_battery_exit); |
468 | |
469 | MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>"); |
470 | MODULE_DESCRIPTION("BQ27x00 battery monitor driver"); |
471 | MODULE_LICENSE("GPL"); |
472 |
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