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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
31
32#define DS278x_REG_VOLT_MSB 0x0c
33#define DS278x_REG_TEMP_MSB 0x0a
34#define DS278x_REG_CURRENT_MSB 0x0e
35
36
37#define DS2782_REG_RSNSP 0x69
38
39
40#define DS2782_CURRENT_UNITS 1563
41
42#define DS2786_REG_RARC 0x02
43
44#define DS2786_CURRENT_UNITS 25
45
46#define DS278x_DELAY 1000
47
48struct ds278x_info;
49
50struct 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
58struct 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;
68};
69
70static DEFINE_IDR(battery_id);
71static DEFINE_MUTEX(battery_lock);
72
73static 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
87static 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
102static int ds278x_get_temp(struct ds278x_info *info, int *temp)
103{
104 s16 raw;
105 int err;
106
107
108
109
110
111
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
120static 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
129
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
149static int ds2782_get_voltage(struct ds278x_info *info, int *voltage_uV)
150{
151 s16 raw;
152 int err;
153
154
155
156
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
165static 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
177static 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
189static int ds2786_get_voltage(struct ds278x_info *info, int *voltage_uV)
190{
191 s16 raw;
192 int err;
193
194
195
196
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
205static 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
214 *capacity = raw/2 ;
215 return 0;
216}
217
218static 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, ¤t_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
246static 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
281static 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
292static 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
302static 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
310static 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
319static 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
338static 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
347static 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
356
357static SIMPLE_DEV_PM_OPS(ds278x_battery_pm_ops, ds278x_suspend, ds278x_resume);
358
359enum ds278x_num_id {
360 DS2782 = 0,
361 DS2786,
362};
363
364static 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
377static 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
388
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
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
443fail_register:
444 kfree(info->battery_desc.name);
445fail_name:
446 kfree(info);
447fail_info:
448 mutex_lock(&battery_lock);
449 idr_remove(&battery_id, num);
450 mutex_unlock(&battery_lock);
451fail_id:
452 return ret;
453}
454
455static const struct i2c_device_id ds278x_id[] = {
456 {"ds2782", DS2782},
457 {"ds2786", DS2786},
458 {},
459};
460MODULE_DEVICE_TABLE(i2c, ds278x_id);
461
462static 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};
471module_i2c_driver(ds278x_battery_driver);
472
473MODULE_AUTHOR("Ryan Mallon");
474MODULE_DESCRIPTION("Maxim/Dallas DS2782 Stand-Alone Fuel Gauage IC driver");
475MODULE_LICENSE("GPL");
476
