Commit | Line | Data |
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bfdb46ce RM |
1 | /* |
2 | * I2C client/driver for the Maxim/Dallas DS2782 Stand-Alone Fuel Gauge IC | |
3 | * | |
4 | * Copyright (C) 2009 Bluewater Systems Ltd | |
5 | * | |
1c5454ee | 6 | * Author: Ryan Mallon |
bfdb46ce | 7 | * |
9b9ade6b YV |
8 | * DS2786 added by Yulia Vilensky <vilensky@compulab.co.il> |
9 | * | |
7cee9aef ER |
10 | * UEvent sending added by Evgeny Romanov <romanov@neurosoft.ru> |
11 | * | |
bfdb46ce RM |
12 | * This program is free software; you can redistribute it and/or modify |
13 | * it under the terms of the GNU General Public License version 2 as | |
14 | * published by the Free Software Foundation. | |
15 | * | |
16 | */ | |
17 | ||
18 | #include <linux/kernel.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/types.h> | |
21 | #include <linux/errno.h> | |
22 | #include <linux/swab.h> | |
23 | #include <linux/i2c.h> | |
7cee9aef | 24 | #include <linux/delay.h> |
bfdb46ce RM |
25 | #include <linux/idr.h> |
26 | #include <linux/power_supply.h> | |
5a0e3ad6 | 27 | #include <linux/slab.h> |
9b9ade6b | 28 | #include <linux/ds2782_battery.h> |
bfdb46ce RM |
29 | |
30 | #define DS2782_REG_RARC 0x06 /* Remaining active relative capacity */ | |
31 | ||
9b9ade6b YV |
32 | #define DS278x_REG_VOLT_MSB 0x0c |
33 | #define DS278x_REG_TEMP_MSB 0x0a | |
34 | #define DS278x_REG_CURRENT_MSB 0x0e | |
bfdb46ce RM |
35 | |
36 | /* EEPROM Block */ | |
37 | #define DS2782_REG_RSNSP 0x69 /* Sense resistor value */ | |
38 | ||
39 | /* Current unit measurement in uA for a 1 milli-ohm sense resistor */ | |
40 | #define DS2782_CURRENT_UNITS 1563 | |
41 | ||
9b9ade6b YV |
42 | #define DS2786_REG_RARC 0x02 /* Remaining active relative capacity */ |
43 | ||
44 | #define DS2786_CURRENT_UNITS 25 | |
45 | ||
7cee9aef ER |
46 | #define DS278x_DELAY 1000 |
47 | ||
9b9ade6b YV |
48 | struct ds278x_info; |
49 | ||
50 | struct ds278x_battery_ops { | |
eb9650d6 | 51 | int (*get_battery_current)(struct ds278x_info *info, int *current_uA); |
353f867b RM |
52 | int (*get_battery_voltage)(struct ds278x_info *info, int *voltage_uV); |
53 | int (*get_battery_capacity)(struct ds278x_info *info, int *capacity); | |
9b9ade6b YV |
54 | }; |
55 | ||
56 | #define to_ds278x_info(x) container_of(x, struct ds278x_info, battery) | |
bfdb46ce | 57 | |
9b9ade6b | 58 | struct ds278x_info { |
bfdb46ce RM |
59 | struct i2c_client *client; |
60 | struct power_supply battery; | |
9b9ade6b | 61 | struct ds278x_battery_ops *ops; |
7cee9aef | 62 | struct delayed_work bat_work; |
bfdb46ce | 63 | int id; |
9b9ade6b | 64 | int rsns; |
7cee9aef ER |
65 | int capacity; |
66 | int status; /* State Of Charge */ | |
bfdb46ce RM |
67 | }; |
68 | ||
69 | static DEFINE_IDR(battery_id); | |
70 | static DEFINE_MUTEX(battery_lock); | |
71 | ||
9b9ade6b | 72 | static inline int ds278x_read_reg(struct ds278x_info *info, int reg, u8 *val) |
bfdb46ce RM |
73 | { |
74 | int ret; | |
75 | ||
76 | ret = i2c_smbus_read_byte_data(info->client, reg); | |
77 | if (ret < 0) { | |
78 | dev_err(&info->client->dev, "register read failed\n"); | |
79 | return ret; | |
80 | } | |
81 | ||
82 | *val = ret; | |
83 | return 0; | |
84 | } | |
85 | ||
9b9ade6b | 86 | static inline int ds278x_read_reg16(struct ds278x_info *info, int reg_msb, |
bfdb46ce RM |
87 | s16 *val) |
88 | { | |
89 | int ret; | |
90 | ||
8511748b | 91 | ret = i2c_smbus_read_word_data(info->client, reg_msb); |
bfdb46ce RM |
92 | if (ret < 0) { |
93 | dev_err(&info->client->dev, "register read failed\n"); | |
94 | return ret; | |
95 | } | |
96 | ||
8511748b | 97 | *val = swab16(ret); |
bfdb46ce RM |
98 | return 0; |
99 | } | |
100 | ||
9b9ade6b | 101 | static int ds278x_get_temp(struct ds278x_info *info, int *temp) |
bfdb46ce RM |
102 | { |
103 | s16 raw; | |
104 | int err; | |
105 | ||
106 | /* | |
107 | * Temperature is measured in units of 0.125 degrees celcius, the | |
108 | * power_supply class measures temperature in tenths of degrees | |
109 | * celsius. The temperature value is stored as a 10 bit number, plus | |
110 | * sign in the upper bits of a 16 bit register. | |
111 | */ | |
9b9ade6b | 112 | err = ds278x_read_reg16(info, DS278x_REG_TEMP_MSB, &raw); |
bfdb46ce RM |
113 | if (err) |
114 | return err; | |
115 | *temp = ((raw / 32) * 125) / 100; | |
116 | return 0; | |
117 | } | |
118 | ||
9b9ade6b | 119 | static int ds2782_get_current(struct ds278x_info *info, int *current_uA) |
bfdb46ce RM |
120 | { |
121 | int sense_res; | |
122 | int err; | |
123 | u8 sense_res_raw; | |
124 | s16 raw; | |
125 | ||
126 | /* | |
127 | * The units of measurement for current are dependent on the value of | |
128 | * the sense resistor. | |
129 | */ | |
9b9ade6b | 130 | err = ds278x_read_reg(info, DS2782_REG_RSNSP, &sense_res_raw); |
bfdb46ce RM |
131 | if (err) |
132 | return err; | |
133 | if (sense_res_raw == 0) { | |
134 | dev_err(&info->client->dev, "sense resistor value is 0\n"); | |
135 | return -ENXIO; | |
136 | } | |
137 | sense_res = 1000 / sense_res_raw; | |
138 | ||
139 | dev_dbg(&info->client->dev, "sense resistor = %d milli-ohms\n", | |
140 | sense_res); | |
9b9ade6b | 141 | err = ds278x_read_reg16(info, DS278x_REG_CURRENT_MSB, &raw); |
bfdb46ce RM |
142 | if (err) |
143 | return err; | |
144 | *current_uA = raw * (DS2782_CURRENT_UNITS / sense_res); | |
145 | return 0; | |
146 | } | |
147 | ||
353f867b | 148 | static int ds2782_get_voltage(struct ds278x_info *info, int *voltage_uV) |
bfdb46ce RM |
149 | { |
150 | s16 raw; | |
151 | int err; | |
152 | ||
153 | /* | |
154 | * Voltage is measured in units of 4.88mV. The voltage is stored as | |
155 | * a 10-bit number plus sign, in the upper bits of a 16-bit register | |
156 | */ | |
9b9ade6b | 157 | err = ds278x_read_reg16(info, DS278x_REG_VOLT_MSB, &raw); |
bfdb46ce RM |
158 | if (err) |
159 | return err; | |
353f867b | 160 | *voltage_uV = (raw / 32) * 4800; |
bfdb46ce RM |
161 | return 0; |
162 | } | |
163 | ||
9b9ade6b | 164 | static int ds2782_get_capacity(struct ds278x_info *info, int *capacity) |
bfdb46ce RM |
165 | { |
166 | int err; | |
167 | u8 raw; | |
168 | ||
9b9ade6b | 169 | err = ds278x_read_reg(info, DS2782_REG_RARC, &raw); |
bfdb46ce RM |
170 | if (err) |
171 | return err; | |
172 | *capacity = raw; | |
2d31757c | 173 | return 0; |
bfdb46ce RM |
174 | } |
175 | ||
9b9ade6b YV |
176 | static int ds2786_get_current(struct ds278x_info *info, int *current_uA) |
177 | { | |
178 | int err; | |
179 | s16 raw; | |
180 | ||
181 | err = ds278x_read_reg16(info, DS278x_REG_CURRENT_MSB, &raw); | |
182 | if (err) | |
183 | return err; | |
184 | *current_uA = (raw / 16) * (DS2786_CURRENT_UNITS / info->rsns); | |
185 | return 0; | |
186 | } | |
187 | ||
353f867b | 188 | static int ds2786_get_voltage(struct ds278x_info *info, int *voltage_uV) |
9b9ade6b YV |
189 | { |
190 | s16 raw; | |
191 | int err; | |
192 | ||
193 | /* | |
194 | * Voltage is measured in units of 1.22mV. The voltage is stored as | |
1b5e1c6e | 195 | * a 12-bit number plus sign, in the upper bits of a 16-bit register |
9b9ade6b YV |
196 | */ |
197 | err = ds278x_read_reg16(info, DS278x_REG_VOLT_MSB, &raw); | |
198 | if (err) | |
199 | return err; | |
353f867b | 200 | *voltage_uV = (raw / 8) * 1220; |
9b9ade6b YV |
201 | return 0; |
202 | } | |
203 | ||
204 | static int ds2786_get_capacity(struct ds278x_info *info, int *capacity) | |
205 | { | |
206 | int err; | |
207 | u8 raw; | |
208 | ||
209 | err = ds278x_read_reg(info, DS2786_REG_RARC, &raw); | |
210 | if (err) | |
211 | return err; | |
212 | /* Relative capacity is displayed with resolution 0.5 % */ | |
213 | *capacity = raw/2 ; | |
214 | return 0; | |
215 | } | |
216 | ||
217 | static int ds278x_get_status(struct ds278x_info *info, int *status) | |
bfdb46ce RM |
218 | { |
219 | int err; | |
220 | int current_uA; | |
221 | int capacity; | |
222 | ||
eb9650d6 | 223 | err = info->ops->get_battery_current(info, ¤t_uA); |
bfdb46ce RM |
224 | if (err) |
225 | return err; | |
226 | ||
eb9650d6 | 227 | err = info->ops->get_battery_capacity(info, &capacity); |
bfdb46ce RM |
228 | if (err) |
229 | return err; | |
230 | ||
7cee9aef ER |
231 | info->capacity = capacity; |
232 | ||
bfdb46ce RM |
233 | if (capacity == 100) |
234 | *status = POWER_SUPPLY_STATUS_FULL; | |
235 | else if (current_uA == 0) | |
236 | *status = POWER_SUPPLY_STATUS_NOT_CHARGING; | |
237 | else if (current_uA < 0) | |
238 | *status = POWER_SUPPLY_STATUS_DISCHARGING; | |
239 | else | |
240 | *status = POWER_SUPPLY_STATUS_CHARGING; | |
241 | ||
242 | return 0; | |
243 | } | |
244 | ||
9b9ade6b | 245 | static int ds278x_battery_get_property(struct power_supply *psy, |
bfdb46ce RM |
246 | enum power_supply_property prop, |
247 | union power_supply_propval *val) | |
248 | { | |
9b9ade6b | 249 | struct ds278x_info *info = to_ds278x_info(psy); |
bfdb46ce RM |
250 | int ret; |
251 | ||
252 | switch (prop) { | |
253 | case POWER_SUPPLY_PROP_STATUS: | |
9b9ade6b | 254 | ret = ds278x_get_status(info, &val->intval); |
bfdb46ce RM |
255 | break; |
256 | ||
257 | case POWER_SUPPLY_PROP_CAPACITY: | |
eb9650d6 | 258 | ret = info->ops->get_battery_capacity(info, &val->intval); |
bfdb46ce RM |
259 | break; |
260 | ||
261 | case POWER_SUPPLY_PROP_VOLTAGE_NOW: | |
eb9650d6 | 262 | ret = info->ops->get_battery_voltage(info, &val->intval); |
bfdb46ce RM |
263 | break; |
264 | ||
265 | case POWER_SUPPLY_PROP_CURRENT_NOW: | |
eb9650d6 | 266 | ret = info->ops->get_battery_current(info, &val->intval); |
bfdb46ce RM |
267 | break; |
268 | ||
269 | case POWER_SUPPLY_PROP_TEMP: | |
9b9ade6b | 270 | ret = ds278x_get_temp(info, &val->intval); |
bfdb46ce RM |
271 | break; |
272 | ||
273 | default: | |
274 | ret = -EINVAL; | |
275 | } | |
276 | ||
277 | return ret; | |
278 | } | |
279 | ||
7cee9aef ER |
280 | static void ds278x_bat_update(struct ds278x_info *info) |
281 | { | |
282 | int old_status = info->status; | |
283 | int old_capacity = info->capacity; | |
284 | ||
285 | ds278x_get_status(info, &info->status); | |
286 | ||
287 | if ((old_status != info->status) || (old_capacity != info->capacity)) | |
288 | power_supply_changed(&info->battery); | |
289 | } | |
290 | ||
291 | static void ds278x_bat_work(struct work_struct *work) | |
292 | { | |
293 | struct ds278x_info *info; | |
294 | ||
295 | info = container_of(work, struct ds278x_info, bat_work.work); | |
296 | ds278x_bat_update(info); | |
297 | ||
298 | schedule_delayed_work(&info->bat_work, DS278x_DELAY); | |
299 | } | |
300 | ||
9b9ade6b | 301 | static enum power_supply_property ds278x_battery_props[] = { |
bfdb46ce RM |
302 | POWER_SUPPLY_PROP_STATUS, |
303 | POWER_SUPPLY_PROP_CAPACITY, | |
304 | POWER_SUPPLY_PROP_VOLTAGE_NOW, | |
305 | POWER_SUPPLY_PROP_CURRENT_NOW, | |
306 | POWER_SUPPLY_PROP_TEMP, | |
307 | }; | |
308 | ||
9b9ade6b | 309 | static void ds278x_power_supply_init(struct power_supply *battery) |
bfdb46ce RM |
310 | { |
311 | battery->type = POWER_SUPPLY_TYPE_BATTERY; | |
9b9ade6b YV |
312 | battery->properties = ds278x_battery_props; |
313 | battery->num_properties = ARRAY_SIZE(ds278x_battery_props); | |
314 | battery->get_property = ds278x_battery_get_property; | |
bfdb46ce RM |
315 | battery->external_power_changed = NULL; |
316 | } | |
317 | ||
9b9ade6b | 318 | static int ds278x_battery_remove(struct i2c_client *client) |
bfdb46ce | 319 | { |
9b9ade6b | 320 | struct ds278x_info *info = i2c_get_clientdata(client); |
bfdb46ce RM |
321 | |
322 | power_supply_unregister(&info->battery); | |
323 | kfree(info->battery.name); | |
324 | ||
325 | mutex_lock(&battery_lock); | |
326 | idr_remove(&battery_id, info->id); | |
327 | mutex_unlock(&battery_lock); | |
328 | ||
7cee9aef ER |
329 | cancel_delayed_work(&info->bat_work); |
330 | ||
bfdb46ce RM |
331 | kfree(info); |
332 | return 0; | |
333 | } | |
334 | ||
cc6616f6 | 335 | #ifdef CONFIG_PM_SLEEP |
7cee9aef | 336 | |
cc6616f6 | 337 | static int ds278x_suspend(struct device *dev) |
7cee9aef | 338 | { |
cc6616f6 | 339 | struct i2c_client *client = to_i2c_client(dev); |
7cee9aef ER |
340 | struct ds278x_info *info = i2c_get_clientdata(client); |
341 | ||
342 | cancel_delayed_work(&info->bat_work); | |
343 | return 0; | |
344 | } | |
345 | ||
cc6616f6 | 346 | static int ds278x_resume(struct device *dev) |
7cee9aef | 347 | { |
cc6616f6 | 348 | struct i2c_client *client = to_i2c_client(dev); |
7cee9aef ER |
349 | struct ds278x_info *info = i2c_get_clientdata(client); |
350 | ||
351 | schedule_delayed_work(&info->bat_work, DS278x_DELAY); | |
352 | return 0; | |
353 | } | |
354 | ||
cc6616f6 LPC |
355 | static SIMPLE_DEV_PM_OPS(ds278x_battery_pm_ops, ds278x_suspend, ds278x_resume); |
356 | #define DS278X_BATTERY_PM_OPS (&ds278x_battery_pm_ops) | |
7cee9aef | 357 | |
cc6616f6 LPC |
358 | #else |
359 | #define DS278X_BATTERY_PM_OPS NULL | |
360 | #endif /* CONFIG_PM_SLEEP */ | |
7cee9aef | 361 | |
ab6cc8f9 AV |
362 | enum ds278x_num_id { |
363 | DS2782 = 0, | |
364 | DS2786, | |
365 | }; | |
366 | ||
9b9ade6b | 367 | static struct ds278x_battery_ops ds278x_ops[] = { |
ab6cc8f9 | 368 | [DS2782] = { |
eb9650d6 PH |
369 | .get_battery_current = ds2782_get_current, |
370 | .get_battery_voltage = ds2782_get_voltage, | |
371 | .get_battery_capacity = ds2782_get_capacity, | |
9b9ade6b | 372 | }, |
ab6cc8f9 | 373 | [DS2786] = { |
eb9650d6 PH |
374 | .get_battery_current = ds2786_get_current, |
375 | .get_battery_voltage = ds2786_get_voltage, | |
376 | .get_battery_capacity = ds2786_get_capacity, | |
9b9ade6b YV |
377 | } |
378 | }; | |
379 | ||
380 | static int ds278x_battery_probe(struct i2c_client *client, | |
bfdb46ce RM |
381 | const struct i2c_device_id *id) |
382 | { | |
9b9ade6b YV |
383 | struct ds278x_platform_data *pdata = client->dev.platform_data; |
384 | struct ds278x_info *info; | |
bfdb46ce RM |
385 | int ret; |
386 | int num; | |
387 | ||
9b9ade6b YV |
388 | /* |
389 | * ds2786 should have the sense resistor value set | |
390 | * in the platform data | |
391 | */ | |
ab6cc8f9 | 392 | if (id->driver_data == DS2786 && !pdata) { |
9b9ade6b YV |
393 | dev_err(&client->dev, "missing platform data for ds2786\n"); |
394 | return -EINVAL; | |
395 | } | |
396 | ||
bfdb46ce | 397 | /* Get an ID for this battery */ |
bfdb46ce | 398 | mutex_lock(&battery_lock); |
05e2cefa | 399 | ret = idr_alloc(&battery_id, client, 0, 0, GFP_KERNEL); |
bfdb46ce RM |
400 | mutex_unlock(&battery_lock); |
401 | if (ret < 0) | |
402 | goto fail_id; | |
05e2cefa | 403 | num = ret; |
bfdb46ce RM |
404 | |
405 | info = kzalloc(sizeof(*info), GFP_KERNEL); | |
406 | if (!info) { | |
407 | ret = -ENOMEM; | |
408 | goto fail_info; | |
409 | } | |
410 | ||
9b9ade6b | 411 | info->battery.name = kasprintf(GFP_KERNEL, "%s-%d", client->name, num); |
bfdb46ce RM |
412 | if (!info->battery.name) { |
413 | ret = -ENOMEM; | |
414 | goto fail_name; | |
415 | } | |
416 | ||
ab6cc8f9 | 417 | if (id->driver_data == DS2786) |
9b9ade6b YV |
418 | info->rsns = pdata->rsns; |
419 | ||
bfdb46ce RM |
420 | i2c_set_clientdata(client, info); |
421 | info->client = client; | |
9b9ade6b YV |
422 | info->id = num; |
423 | info->ops = &ds278x_ops[id->driver_data]; | |
424 | ds278x_power_supply_init(&info->battery); | |
bfdb46ce | 425 | |
7cee9aef ER |
426 | info->capacity = 100; |
427 | info->status = POWER_SUPPLY_STATUS_FULL; | |
428 | ||
429 | INIT_DELAYED_WORK(&info->bat_work, ds278x_bat_work); | |
430 | ||
bfdb46ce RM |
431 | ret = power_supply_register(&client->dev, &info->battery); |
432 | if (ret) { | |
433 | dev_err(&client->dev, "failed to register battery\n"); | |
434 | goto fail_register; | |
7cee9aef ER |
435 | } else { |
436 | schedule_delayed_work(&info->bat_work, DS278x_DELAY); | |
bfdb46ce RM |
437 | } |
438 | ||
439 | return 0; | |
440 | ||
441 | fail_register: | |
442 | kfree(info->battery.name); | |
443 | fail_name: | |
bfdb46ce RM |
444 | kfree(info); |
445 | fail_info: | |
446 | mutex_lock(&battery_lock); | |
447 | idr_remove(&battery_id, num); | |
448 | mutex_unlock(&battery_lock); | |
449 | fail_id: | |
450 | return ret; | |
451 | } | |
452 | ||
9b9ade6b | 453 | static const struct i2c_device_id ds278x_id[] = { |
ab6cc8f9 AV |
454 | {"ds2782", DS2782}, |
455 | {"ds2786", DS2786}, | |
bfdb46ce RM |
456 | {}, |
457 | }; | |
84ab16f5 | 458 | MODULE_DEVICE_TABLE(i2c, ds278x_id); |
bfdb46ce | 459 | |
9b9ade6b | 460 | static struct i2c_driver ds278x_battery_driver = { |
bfdb46ce RM |
461 | .driver = { |
462 | .name = "ds2782-battery", | |
cc6616f6 | 463 | .pm = DS278X_BATTERY_PM_OPS, |
bfdb46ce | 464 | }, |
9b9ade6b YV |
465 | .probe = ds278x_battery_probe, |
466 | .remove = ds278x_battery_remove, | |
467 | .id_table = ds278x_id, | |
bfdb46ce | 468 | }; |
5ff92e7a | 469 | module_i2c_driver(ds278x_battery_driver); |
bfdb46ce | 470 | |
1c5454ee | 471 | MODULE_AUTHOR("Ryan Mallon"); |
bfdb46ce RM |
472 | MODULE_DESCRIPTION("Maxim/Dallas DS2782 Stand-Alone Fuel Gauage IC driver"); |
473 | MODULE_LICENSE("GPL"); |