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