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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 <asm/unaligned.h>
28
29#define DRIVER_VERSION "1.0.0"
30
31#define BQ27x00_REG_TEMP 0x06
32#define BQ27x00_REG_VOLT 0x08
33#define BQ27x00_REG_RSOC 0x0B
34#define BQ27x00_REG_AI 0x14
35#define BQ27x00_REG_FLAGS 0x0A
36
37
38
39
40static DEFINE_IDR(battery_id);
41static DEFINE_MUTEX(battery_mutex);
42
43struct bq27x00_device_info;
44struct bq27x00_access_methods {
45 int (*read)(u8 reg, int *rt_value, int b_single,
46 struct bq27x00_device_info *di);
47};
48
49struct bq27x00_device_info {
50 struct device *dev;
51 int id;
52 int voltage_uV;
53 int current_uA;
54 int temp_C;
55 int charge_rsoc;
56 struct bq27x00_access_methods *bus;
57 struct power_supply bat;
58
59 struct i2c_client *client;
60};
61
62static enum power_supply_property bq27x00_battery_props[] = {
63 POWER_SUPPLY_PROP_PRESENT,
64 POWER_SUPPLY_PROP_VOLTAGE_NOW,
65 POWER_SUPPLY_PROP_CURRENT_NOW,
66 POWER_SUPPLY_PROP_CAPACITY,
67 POWER_SUPPLY_PROP_TEMP,
68};
69
70
71
72
73
74static int bq27x00_read(u8 reg, int *rt_value, int b_single,
75 struct bq27x00_device_info *di)
76{
77 int ret;
78
79 ret = di->bus->read(reg, rt_value, b_single, di);
80 *rt_value = be16_to_cpu(*rt_value);
81
82 return ret;
83}
84
85
86
87
88
89static int bq27x00_battery_temperature(struct bq27x00_device_info *di)
90{
91 int ret;
92 int temp = 0;
93
94 ret = bq27x00_read(BQ27x00_REG_TEMP, &temp, 0, di);
95 if (ret) {
96 dev_err(di->dev, "error reading temperature\n");
97 return ret;
98 }
99
100 return (temp >> 2) - 273;
101}
102
103
104
105
106
107static int bq27x00_battery_voltage(struct bq27x00_device_info *di)
108{
109 int ret;
110 int volt = 0;
111
112 ret = bq27x00_read(BQ27x00_REG_VOLT, &volt, 0, di);
113 if (ret) {
114 dev_err(di->dev, "error reading voltage\n");
115 return ret;
116 }
117
118 return volt;
119}
120
121
122
123
124
125
126static int bq27x00_battery_current(struct bq27x00_device_info *di)
127{
128 int ret;
129 int curr = 0;
130 int flags = 0;
131
132 ret = bq27x00_read(BQ27x00_REG_AI, &curr, 0, di);
133 if (ret) {
134 dev_err(di->dev, "error reading current\n");
135 return 0;
136 }
137 ret = bq27x00_read(BQ27x00_REG_FLAGS, &flags, 0, di);
138 if (ret < 0) {
139 dev_err(di->dev, "error reading flags\n");
140 return 0;
141 }
142 if ((flags & (1 << 7)) != 0) {
143 dev_dbg(di->dev, "negative current!\n");
144 return -curr;
145 }
146 return curr;
147}
148
149
150
151
152
153static int bq27x00_battery_rsoc(struct bq27x00_device_info *di)
154{
155 int ret;
156 int rsoc = 0;
157
158 ret = bq27x00_read(BQ27x00_REG_RSOC, &rsoc, 1, di);
159 if (ret) {
160 dev_err(di->dev, "error reading relative State-of-Charge\n");
161 return ret;
162 }
163
164 return rsoc >> 8;
165}
166
167#define to_bq27x00_device_info(x) container_of((x), \
168 struct bq27x00_device_info, bat);
169
170static int bq27x00_battery_get_property(struct power_supply *psy,
171 enum power_supply_property psp,
172 union power_supply_propval *val)
173{
174 struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
175
176 switch (psp) {
177 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
178 case POWER_SUPPLY_PROP_PRESENT:
179 val->intval = bq27x00_battery_voltage(di);
180 if (psp == POWER_SUPPLY_PROP_PRESENT)
181 val->intval = val->intval <= 0 ? 0 : 1;
182 break;
183 case POWER_SUPPLY_PROP_CURRENT_NOW:
184 val->intval = bq27x00_battery_current(di);
185 break;
186 case POWER_SUPPLY_PROP_CAPACITY:
187 val->intval = bq27x00_battery_rsoc(di);
188 break;
189 case POWER_SUPPLY_PROP_TEMP:
190 val->intval = bq27x00_battery_temperature(di);
191 break;
192 default:
193 return -EINVAL;
194 }
195
196 return 0;
197}
198
199static void bq27x00_powersupply_init(struct bq27x00_device_info *di)
200{
201 di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
202 di->bat.properties = bq27x00_battery_props;
203 di->bat.num_properties = ARRAY_SIZE(bq27x00_battery_props);
204 di->bat.get_property = bq27x00_battery_get_property;
205 di->bat.external_power_changed = NULL;
206}
207
208
209
210
211
212static int bq27200_read(u8 reg, int *rt_value, int b_single,
213 struct bq27x00_device_info *di)
214{
215 struct i2c_client *client = di->client;
216 struct i2c_msg msg[1];
217 unsigned char data[2];
218 int err;
219
220 if (!client->adapter)
221 return -ENODEV;
222
223 msg->addr = client->addr;
224 msg->flags = 0;
225 msg->len = 1;
226 msg->buf = data;
227
228 data[0] = reg;
229 err = i2c_transfer(client->adapter, msg, 1);
230
231 if (err >= 0) {
232 if (!b_single)
233 msg->len = 2;
234 else
235 msg->len = 1;
236
237 msg->flags = I2C_M_RD;
238 err = i2c_transfer(client->adapter, msg, 1);
239 if (err >= 0) {
240 if (!b_single)
241 *rt_value = get_unaligned_be16(data);
242 else
243 *rt_value = data[0];
244
245 return 0;
246 }
247 }
248 return err;
249}
250
251static int bq27200_battery_probe(struct i2c_client *client,
252 const struct i2c_device_id *id)
253{
254 char *name;
255 struct bq27x00_device_info *di;
256 struct bq27x00_access_methods *bus;
257 int num;
258 int retval = 0;
259
260
261 retval = idr_pre_get(&battery_id, GFP_KERNEL);
262 if (retval == 0)
263 return -ENOMEM;
264 mutex_lock(&battery_mutex);
265 retval = idr_get_new(&battery_id, client, &num);
266 mutex_unlock(&battery_mutex);
267 if (retval < 0)
268 return retval;
269
270 name = kasprintf(GFP_KERNEL, "bq27200-%d", num);
271 if (!name) {
272 dev_err(&client->dev, "failed to allocate device name\n");
273 retval = -ENOMEM;
274 goto batt_failed_1;
275 }
276
277 di = kzalloc(sizeof(*di), GFP_KERNEL);
278 if (!di) {
279 dev_err(&client->dev, "failed to allocate device info data\n");
280 retval = -ENOMEM;
281 goto batt_failed_2;
282 }
283 di->id = num;
284
285 bus = kzalloc(sizeof(*bus), GFP_KERNEL);
286 if (!bus) {
287 dev_err(&client->dev, "failed to allocate access method "
288 "data\n");
289 retval = -ENOMEM;
290 goto batt_failed_3;
291 }
292
293 i2c_set_clientdata(client, di);
294 di->dev = &client->dev;
295 di->bat.name = name;
296 bus->read = &bq27200_read;
297 di->bus = bus;
298 di->client = client;
299
300 bq27x00_powersupply_init(di);
301
302 retval = power_supply_register(&client->dev, &di->bat);
303 if (retval) {
304 dev_err(&client->dev, "failed to register battery\n");
305 goto batt_failed_4;
306 }
307
308 dev_info(&client->dev, "support ver. %s enabled\n", DRIVER_VERSION);
309
310 return 0;
311
312batt_failed_4:
313 kfree(bus);
314batt_failed_3:
315 kfree(di);
316batt_failed_2:
317 kfree(name);
318batt_failed_1:
319 mutex_lock(&battery_mutex);
320 idr_remove(&battery_id, num);
321 mutex_unlock(&battery_mutex);
322
323 return retval;
324}
325
326static int bq27200_battery_remove(struct i2c_client *client)
327{
328 struct bq27x00_device_info *di = i2c_get_clientdata(client);
329
330 power_supply_unregister(&di->bat);
331
332 kfree(di->bat.name);
333
334 mutex_lock(&battery_mutex);
335 idr_remove(&battery_id, di->id);
336 mutex_unlock(&battery_mutex);
337
338 kfree(di);
339
340 return 0;
341}
342
343
344
345
346
347static const struct i2c_device_id bq27200_id[] = {
348 { "bq27200", 0 },
349 {},
350};
351
352static struct i2c_driver bq27200_battery_driver = {
353 .driver = {
354 .name = "bq27200-battery",
355 },
356 .probe = bq27200_battery_probe,
357 .remove = bq27200_battery_remove,
358 .id_table = bq27200_id,
359};
360
361static int __init bq27x00_battery_init(void)
362{
363 int ret;
364
365 ret = i2c_add_driver(&bq27200_battery_driver);
366 if (ret)
367 printk(KERN_ERR "Unable to register BQ27200 driver\n");
368
369 return ret;
370}
371module_init(bq27x00_battery_init);
372
373static void __exit bq27x00_battery_exit(void)
374{
375 i2c_del_driver(&bq27200_battery_driver);
376}
377module_exit(bq27x00_battery_exit);
378
379MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
380MODULE_DESCRIPTION("BQ27x00 battery monitor driver");
381MODULE_LICENSE("GPL");
382
