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b996ad0e RG |
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 | ||
27 | #include <linux/i2c.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 /* Relative State-of-Charge */ | |
34 | #define BQ27x00_REG_AI 0x14 | |
35 | #define BQ27x00_REG_FLAGS 0x0A | |
36 | #define HIGH_BYTE(A) ((A) << 8) | |
37 | ||
38 | /* If the system has several batteries we need a different name for each | |
39 | * of them... | |
40 | */ | |
41 | static DEFINE_IDR(battery_id); | |
42 | static DEFINE_MUTEX(battery_mutex); | |
43 | ||
44 | struct bq27x00_device_info; | |
45 | struct bq27x00_access_methods { | |
46 | int (*read)(u8 reg, int *rt_value, int b_single, | |
47 | struct bq27x00_device_info *di); | |
48 | }; | |
49 | ||
50 | struct bq27x00_device_info { | |
51 | struct device *dev; | |
52 | int id; | |
53 | int voltage_uV; | |
54 | int current_uA; | |
55 | int temp_C; | |
56 | int charge_rsoc; | |
57 | struct bq27x00_access_methods *bus; | |
58 | struct power_supply bat; | |
59 | ||
60 | struct i2c_client *client; | |
61 | }; | |
62 | ||
63 | static enum power_supply_property bq27x00_battery_props[] = { | |
64 | POWER_SUPPLY_PROP_PRESENT, | |
65 | POWER_SUPPLY_PROP_VOLTAGE_NOW, | |
66 | POWER_SUPPLY_PROP_CURRENT_NOW, | |
67 | POWER_SUPPLY_PROP_CAPACITY, | |
68 | POWER_SUPPLY_PROP_TEMP, | |
69 | }; | |
70 | ||
71 | /* | |
72 | * Common code for BQ27x00 devices | |
73 | */ | |
74 | ||
75 | static int bq27x00_read(u8 reg, int *rt_value, int b_single, | |
76 | struct bq27x00_device_info *di) | |
77 | { | |
78 | int ret; | |
79 | ||
80 | ret = di->bus->read(reg, rt_value, b_single, di); | |
81 | *rt_value = be16_to_cpu(*rt_value); | |
82 | ||
83 | return ret; | |
84 | } | |
85 | ||
86 | /* | |
87 | * Return the battery temperature in Celcius degrees | |
88 | * Or < 0 if something fails. | |
89 | */ | |
90 | static int bq27x00_battery_temperature(struct bq27x00_device_info *di) | |
91 | { | |
92 | int ret; | |
93 | int temp = 0; | |
94 | ||
95 | ret = bq27x00_read(BQ27x00_REG_TEMP, &temp, 0, di); | |
96 | if (ret) { | |
97 | dev_err(di->dev, "error reading temperature\n"); | |
98 | return ret; | |
99 | } | |
100 | ||
101 | return (temp >> 2) - 273; | |
102 | } | |
103 | ||
104 | /* | |
105 | * Return the battery Voltage in milivolts | |
106 | * Or < 0 if something fails. | |
107 | */ | |
108 | static int bq27x00_battery_voltage(struct bq27x00_device_info *di) | |
109 | { | |
110 | int ret; | |
111 | int volt = 0; | |
112 | ||
113 | ret = bq27x00_read(BQ27x00_REG_VOLT, &volt, 0, di); | |
114 | if (ret) { | |
115 | dev_err(di->dev, "error reading voltage\n"); | |
116 | return ret; | |
117 | } | |
118 | ||
119 | return volt; | |
120 | } | |
121 | ||
122 | /* | |
123 | * Return the battery average current | |
124 | * Note that current can be negative signed as well | |
125 | * Or 0 if something fails. | |
126 | */ | |
127 | static int bq27x00_battery_current(struct bq27x00_device_info *di) | |
128 | { | |
129 | int ret; | |
130 | int curr = 0; | |
131 | int flags = 0; | |
132 | ||
133 | ret = bq27x00_read(BQ27x00_REG_AI, &curr, 0, di); | |
134 | if (ret) { | |
135 | dev_err(di->dev, "error reading current\n"); | |
136 | return 0; | |
137 | } | |
138 | ret = bq27x00_read(BQ27x00_REG_FLAGS, &flags, 0, di); | |
139 | if (ret < 0) { | |
140 | dev_err(di->dev, "error reading flags\n"); | |
141 | return 0; | |
142 | } | |
143 | if ((flags & (1 << 7)) != 0) { | |
144 | dev_dbg(di->dev, "negative current!\n"); | |
145 | return -curr; | |
146 | } | |
147 | return curr; | |
148 | } | |
149 | ||
150 | /* | |
151 | * Return the battery Relative State-of-Charge | |
152 | * Or < 0 if something fails. | |
153 | */ | |
154 | static int bq27x00_battery_rsoc(struct bq27x00_device_info *di) | |
155 | { | |
156 | int ret; | |
157 | int rsoc = 0; | |
158 | ||
159 | ret = bq27x00_read(BQ27x00_REG_RSOC, &rsoc, 1, di); | |
160 | if (ret) { | |
161 | dev_err(di->dev, "error reading relative State-of-Charge\n"); | |
162 | return ret; | |
163 | } | |
164 | ||
165 | return rsoc >> 8; | |
166 | } | |
167 | ||
168 | #define to_bq27x00_device_info(x) container_of((x), \ | |
169 | struct bq27x00_device_info, bat); | |
170 | ||
171 | static int bq27x00_battery_get_property(struct power_supply *psy, | |
172 | enum power_supply_property psp, | |
173 | union power_supply_propval *val) | |
174 | { | |
175 | struct bq27x00_device_info *di = to_bq27x00_device_info(psy); | |
176 | ||
177 | switch (psp) { | |
178 | case POWER_SUPPLY_PROP_VOLTAGE_NOW: | |
179 | case POWER_SUPPLY_PROP_PRESENT: | |
180 | val->intval = bq27x00_battery_voltage(di); | |
181 | if (psp == POWER_SUPPLY_PROP_PRESENT) | |
182 | val->intval = val->intval <= 0 ? 0 : 1; | |
183 | break; | |
184 | case POWER_SUPPLY_PROP_CURRENT_NOW: | |
185 | val->intval = bq27x00_battery_current(di); | |
186 | break; | |
187 | case POWER_SUPPLY_PROP_CAPACITY: | |
188 | val->intval = bq27x00_battery_rsoc(di); | |
189 | break; | |
190 | case POWER_SUPPLY_PROP_TEMP: | |
191 | val->intval = bq27x00_battery_temperature(di); | |
192 | break; | |
193 | default: | |
194 | return -EINVAL; | |
195 | } | |
196 | ||
197 | return 0; | |
198 | } | |
199 | ||
200 | static void bq27x00_powersupply_init(struct bq27x00_device_info *di) | |
201 | { | |
202 | di->bat.type = POWER_SUPPLY_TYPE_BATTERY; | |
203 | di->bat.properties = bq27x00_battery_props; | |
204 | di->bat.num_properties = ARRAY_SIZE(bq27x00_battery_props); | |
205 | di->bat.get_property = bq27x00_battery_get_property; | |
206 | di->bat.external_power_changed = NULL; | |
207 | } | |
208 | ||
209 | /* | |
210 | * BQ27200 specific code | |
211 | */ | |
212 | ||
213 | static int bq27200_read(u8 reg, int *rt_value, int b_single, | |
214 | struct bq27x00_device_info *di) | |
215 | { | |
216 | struct i2c_client *client = di->client; | |
217 | struct i2c_msg msg[1]; | |
218 | unsigned char data[2]; | |
219 | int err; | |
220 | ||
221 | if (!client->adapter) | |
222 | return -ENODEV; | |
223 | ||
224 | msg->addr = client->addr; | |
225 | msg->flags = 0; | |
226 | msg->len = 1; | |
227 | msg->buf = data; | |
228 | ||
229 | data[0] = reg; | |
230 | err = i2c_transfer(client->adapter, msg, 1); | |
231 | ||
232 | if (err >= 0) { | |
233 | if (!b_single) | |
234 | msg->len = 2; | |
235 | else | |
236 | msg->len = 1; | |
237 | ||
238 | msg->flags = I2C_M_RD; | |
239 | err = i2c_transfer(client->adapter, msg, 1); | |
240 | if (err >= 0) { | |
241 | if (!b_single) | |
242 | *rt_value = data[1] | HIGH_BYTE(data[0]); | |
243 | else | |
244 | *rt_value = data[0]; | |
245 | ||
246 | return 0; | |
247 | } | |
248 | } | |
249 | return err; | |
250 | } | |
251 | ||
252 | static int bq27200_battery_probe(struct i2c_client *client, | |
253 | const struct i2c_device_id *id) | |
254 | { | |
255 | char *name; | |
256 | struct bq27x00_device_info *di; | |
257 | struct bq27x00_access_methods *bus; | |
258 | int num; | |
259 | int retval = 0; | |
260 | ||
261 | /* Get new ID for the new battery device */ | |
262 | retval = idr_pre_get(&battery_id, GFP_KERNEL); | |
263 | if (retval == 0) | |
264 | return -ENOMEM; | |
265 | mutex_lock(&battery_mutex); | |
266 | retval = idr_get_new(&battery_id, client, &num); | |
267 | mutex_unlock(&battery_mutex); | |
268 | if (retval < 0) | |
269 | return retval; | |
270 | ||
271 | name = kasprintf(GFP_KERNEL, "bq27200-%d", num); | |
272 | if (!name) { | |
273 | dev_err(&client->dev, "failed to allocate device name\n"); | |
274 | retval = -ENOMEM; | |
275 | goto batt_failed_1; | |
276 | } | |
277 | ||
278 | di = kzalloc(sizeof(*di), GFP_KERNEL); | |
279 | if (!di) { | |
280 | dev_err(&client->dev, "failed to allocate device info data\n"); | |
281 | retval = -ENOMEM; | |
282 | goto batt_failed_2; | |
283 | } | |
284 | di->id = num; | |
285 | ||
286 | bus = kzalloc(sizeof(*bus), GFP_KERNEL); | |
287 | if (!bus) { | |
288 | dev_err(&client->dev, "failed to allocate access method " | |
289 | "data\n"); | |
290 | retval = -ENOMEM; | |
291 | goto batt_failed_3; | |
292 | } | |
293 | ||
294 | i2c_set_clientdata(client, di); | |
295 | di->dev = &client->dev; | |
296 | di->bat.name = name; | |
297 | bus->read = &bq27200_read; | |
298 | di->bus = bus; | |
299 | di->client = client; | |
300 | ||
301 | bq27x00_powersupply_init(di); | |
302 | ||
303 | retval = power_supply_register(&client->dev, &di->bat); | |
304 | if (retval) { | |
305 | dev_err(&client->dev, "failed to register battery\n"); | |
306 | goto batt_failed_4; | |
307 | } | |
308 | ||
309 | dev_info(&client->dev, "support ver. %s enabled\n", DRIVER_VERSION); | |
310 | ||
311 | return 0; | |
312 | ||
313 | batt_failed_4: | |
314 | kfree(bus); | |
315 | batt_failed_3: | |
316 | kfree(di); | |
317 | batt_failed_2: | |
318 | kfree(name); | |
319 | batt_failed_1: | |
320 | mutex_lock(&battery_mutex); | |
321 | idr_remove(&battery_id, num); | |
322 | mutex_unlock(&battery_mutex); | |
323 | ||
324 | return retval; | |
325 | } | |
326 | ||
327 | static int bq27200_battery_remove(struct i2c_client *client) | |
328 | { | |
329 | struct bq27x00_device_info *di = i2c_get_clientdata(client); | |
330 | ||
331 | power_supply_unregister(&di->bat); | |
332 | ||
333 | kfree(di->bat.name); | |
334 | ||
335 | mutex_lock(&battery_mutex); | |
336 | idr_remove(&battery_id, di->id); | |
337 | mutex_unlock(&battery_mutex); | |
338 | ||
339 | kfree(di); | |
340 | ||
341 | return 0; | |
342 | } | |
343 | ||
344 | /* | |
345 | * Module stuff | |
346 | */ | |
347 | ||
348 | static const struct i2c_device_id bq27200_id[] = { | |
349 | { "bq27200", 0 }, | |
350 | {}, | |
351 | }; | |
352 | ||
353 | static struct i2c_driver bq27200_battery_driver = { | |
354 | .driver = { | |
355 | .name = "bq27200-battery", | |
356 | }, | |
357 | .probe = bq27200_battery_probe, | |
358 | .remove = bq27200_battery_remove, | |
359 | .id_table = bq27200_id, | |
360 | }; | |
361 | ||
362 | static int __init bq27x00_battery_init(void) | |
363 | { | |
364 | int ret; | |
365 | ||
366 | ret = i2c_add_driver(&bq27200_battery_driver); | |
367 | if (ret) | |
368 | printk(KERN_ERR "Unable to register BQ27200 driver\n"); | |
369 | ||
370 | return ret; | |
371 | } | |
372 | module_init(bq27x00_battery_init); | |
373 | ||
374 | static void __exit bq27x00_battery_exit(void) | |
375 | { | |
376 | i2c_del_driver(&bq27200_battery_driver); | |
377 | } | |
378 | module_exit(bq27x00_battery_exit); | |
379 | ||
380 | MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>"); | |
381 | MODULE_DESCRIPTION("BQ27x00 battery monitor driver"); | |
382 | MODULE_LICENSE("GPL"); |