2 * BQ27x00 battery driver
4 * Copyright (C) 2008 Rodolfo Giometti <giometti@linux.it>
5 * Copyright (C) 2008 Eurotech S.p.A. <info@eurotech.it>
7 * Based on a previous work by Copyright (C) 2008 Texas Instruments, Inc.
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.
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.
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>
29 #define DRIVER_VERSION "1.1.0"
31 #define BQ27x00_REG_TEMP 0x06
32 #define BQ27x00_REG_VOLT 0x08
33 #define BQ27x00_REG_AI 0x14
34 #define BQ27x00_REG_FLAGS 0x0A
35 #define BQ27x00_REG_TTE 0x16
36 #define BQ27x00_REG_TTF 0x18
37 #define BQ27x00_REG_TTECP 0x26
39 #define BQ27000_REG_RSOC 0x0B /* Relative State-of-Charge */
40 #define BQ27000_FLAG_CHGS BIT(7)
42 #define BQ27500_REG_SOC 0x2c
43 #define BQ27500_FLAG_DSC BIT(0)
44 #define BQ27500_FLAG_FC BIT(9)
46 /* If the system has several batteries we need a different name for each
49 static DEFINE_IDR(battery_id
);
50 static DEFINE_MUTEX(battery_mutex
);
52 struct bq27x00_device_info
;
53 struct bq27x00_access_methods
{
54 int (*read
)(u8 reg
, int *rt_value
, int b_single
,
55 struct bq27x00_device_info
*di
);
58 enum bq27x00_chip
{ BQ27000
, BQ27500
};
60 struct bq27x00_device_info
{
63 struct bq27x00_access_methods
*bus
;
64 struct power_supply bat
;
65 enum bq27x00_chip chip
;
67 struct i2c_client
*client
;
70 static enum power_supply_property bq27x00_battery_props
[] = {
71 POWER_SUPPLY_PROP_STATUS
,
72 POWER_SUPPLY_PROP_PRESENT
,
73 POWER_SUPPLY_PROP_VOLTAGE_NOW
,
74 POWER_SUPPLY_PROP_CURRENT_NOW
,
75 POWER_SUPPLY_PROP_CAPACITY
,
76 POWER_SUPPLY_PROP_TEMP
,
77 POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW
,
78 POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG
,
79 POWER_SUPPLY_PROP_TIME_TO_FULL_NOW
,
83 * Common code for BQ27x00 devices
86 static int bq27x00_read(u8 reg
, int *rt_value
, int b_single
,
87 struct bq27x00_device_info
*di
)
89 return di
->bus
->read(reg
, rt_value
, b_single
, di
);
93 * Return the battery temperature in tenths of degree Celsius
94 * Or < 0 if something fails.
96 static int bq27x00_battery_temperature(struct bq27x00_device_info
*di
)
101 ret
= bq27x00_read(BQ27x00_REG_TEMP
, &temp
, 0, di
);
103 dev_err(di
->dev
, "error reading temperature\n");
107 if (di
->chip
== BQ27500
)
110 return ((temp
>> 2) - 273) * 10;
114 * Return the battery Voltage in milivolts
115 * Or < 0 if something fails.
117 static int bq27x00_battery_voltage(struct bq27x00_device_info
*di
)
122 ret
= bq27x00_read(BQ27x00_REG_VOLT
, &volt
, 0, di
);
124 dev_err(di
->dev
, "error reading voltage\n");
132 * Return the battery average current
133 * Note that current can be negative signed as well
134 * Or 0 if something fails.
136 static int bq27x00_battery_current(struct bq27x00_device_info
*di
)
142 ret
= bq27x00_read(BQ27x00_REG_AI
, &curr
, 0, di
);
144 dev_err(di
->dev
, "error reading current\n");
148 if (di
->chip
== BQ27500
) {
149 /* bq27500 returns signed value */
150 curr
= (int)(s16
)curr
;
152 ret
= bq27x00_read(BQ27x00_REG_FLAGS
, &flags
, 0, di
);
154 dev_err(di
->dev
, "error reading flags\n");
157 if (flags
& BQ27000_FLAG_CHGS
) {
158 dev_dbg(di
->dev
, "negative current!\n");
167 * Return the battery Relative State-of-Charge
168 * Or < 0 if something fails.
170 static int bq27x00_battery_rsoc(struct bq27x00_device_info
*di
)
175 if (di
->chip
== BQ27500
)
176 ret
= bq27x00_read(BQ27500_REG_SOC
, &rsoc
, 0, di
);
178 ret
= bq27x00_read(BQ27000_REG_RSOC
, &rsoc
, 1, di
);
180 dev_err(di
->dev
, "error reading relative State-of-Charge\n");
187 static int bq27x00_battery_status(struct bq27x00_device_info
*di
,
188 union power_supply_propval
*val
)
194 ret
= bq27x00_read(BQ27x00_REG_FLAGS
, &flags
, 0, di
);
196 dev_err(di
->dev
, "error reading flags\n");
200 if (di
->chip
== BQ27500
) {
201 if (flags
& BQ27500_FLAG_FC
)
202 status
= POWER_SUPPLY_STATUS_FULL
;
203 else if (flags
& BQ27500_FLAG_DSC
)
204 status
= POWER_SUPPLY_STATUS_DISCHARGING
;
206 status
= POWER_SUPPLY_STATUS_CHARGING
;
208 if (flags
& BQ27000_FLAG_CHGS
)
209 status
= POWER_SUPPLY_STATUS_CHARGING
;
211 status
= POWER_SUPPLY_STATUS_DISCHARGING
;
214 val
->intval
= status
;
219 * Read a time register.
220 * Return < 0 if something fails.
222 static int bq27x00_battery_time(struct bq27x00_device_info
*di
, int reg
,
223 union power_supply_propval
*val
)
228 ret
= bq27x00_read(reg
, &tval
, 0, di
);
230 dev_err(di
->dev
, "error reading register %02x\n", reg
);
237 val
->intval
= tval
* 60;
241 #define to_bq27x00_device_info(x) container_of((x), \
242 struct bq27x00_device_info, bat);
244 static int bq27x00_battery_get_property(struct power_supply
*psy
,
245 enum power_supply_property psp
,
246 union power_supply_propval
*val
)
249 struct bq27x00_device_info
*di
= to_bq27x00_device_info(psy
);
252 case POWER_SUPPLY_PROP_STATUS
:
253 ret
= bq27x00_battery_status(di
, val
);
255 case POWER_SUPPLY_PROP_VOLTAGE_NOW
:
256 case POWER_SUPPLY_PROP_PRESENT
:
257 val
->intval
= bq27x00_battery_voltage(di
);
258 if (psp
== POWER_SUPPLY_PROP_PRESENT
)
259 val
->intval
= val
->intval
<= 0 ? 0 : 1;
261 case POWER_SUPPLY_PROP_CURRENT_NOW
:
262 val
->intval
= bq27x00_battery_current(di
);
264 case POWER_SUPPLY_PROP_CAPACITY
:
265 val
->intval
= bq27x00_battery_rsoc(di
);
267 case POWER_SUPPLY_PROP_TEMP
:
268 val
->intval
= bq27x00_battery_temperature(di
);
270 case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW
:
271 ret
= bq27x00_battery_time(di
, BQ27x00_REG_TTE
, val
);
273 case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG
:
274 ret
= bq27x00_battery_time(di
, BQ27x00_REG_TTECP
, val
);
276 case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW
:
277 ret
= bq27x00_battery_time(di
, BQ27x00_REG_TTF
, val
);
286 static void bq27x00_powersupply_init(struct bq27x00_device_info
*di
)
288 di
->bat
.type
= POWER_SUPPLY_TYPE_BATTERY
;
289 di
->bat
.properties
= bq27x00_battery_props
;
290 di
->bat
.num_properties
= ARRAY_SIZE(bq27x00_battery_props
);
291 di
->bat
.get_property
= bq27x00_battery_get_property
;
292 di
->bat
.external_power_changed
= NULL
;
299 static int bq27x00_read_i2c(u8 reg
, int *rt_value
, int b_single
,
300 struct bq27x00_device_info
*di
)
302 struct i2c_client
*client
= di
->client
;
303 struct i2c_msg msg
[1];
304 unsigned char data
[2];
307 if (!client
->adapter
)
310 msg
->addr
= client
->addr
;
316 err
= i2c_transfer(client
->adapter
, msg
, 1);
324 msg
->flags
= I2C_M_RD
;
325 err
= i2c_transfer(client
->adapter
, msg
, 1);
328 *rt_value
= get_unaligned_le16(data
);
338 static int bq27x00_battery_probe(struct i2c_client
*client
,
339 const struct i2c_device_id
*id
)
342 struct bq27x00_device_info
*di
;
343 struct bq27x00_access_methods
*bus
;
347 /* Get new ID for the new battery device */
348 retval
= idr_pre_get(&battery_id
, GFP_KERNEL
);
351 mutex_lock(&battery_mutex
);
352 retval
= idr_get_new(&battery_id
, client
, &num
);
353 mutex_unlock(&battery_mutex
);
357 name
= kasprintf(GFP_KERNEL
, "%s-%d", id
->name
, num
);
359 dev_err(&client
->dev
, "failed to allocate device name\n");
364 di
= kzalloc(sizeof(*di
), GFP_KERNEL
);
366 dev_err(&client
->dev
, "failed to allocate device info data\n");
371 di
->chip
= id
->driver_data
;
373 bus
= kzalloc(sizeof(*bus
), GFP_KERNEL
);
375 dev_err(&client
->dev
, "failed to allocate access method "
381 i2c_set_clientdata(client
, di
);
382 di
->dev
= &client
->dev
;
384 bus
->read
= &bq27x00_read_i2c
;
388 bq27x00_powersupply_init(di
);
390 retval
= power_supply_register(&client
->dev
, &di
->bat
);
392 dev_err(&client
->dev
, "failed to register battery\n");
396 dev_info(&client
->dev
, "support ver. %s enabled\n", DRIVER_VERSION
);
407 mutex_lock(&battery_mutex
);
408 idr_remove(&battery_id
, num
);
409 mutex_unlock(&battery_mutex
);
414 static int bq27x00_battery_remove(struct i2c_client
*client
)
416 struct bq27x00_device_info
*di
= i2c_get_clientdata(client
);
418 power_supply_unregister(&di
->bat
);
422 mutex_lock(&battery_mutex
);
423 idr_remove(&battery_id
, di
->id
);
424 mutex_unlock(&battery_mutex
);
435 static const struct i2c_device_id bq27x00_id
[] = {
436 { "bq27200", BQ27000
}, /* bq27200 is same as bq27000, but with i2c */
437 { "bq27500", BQ27500
},
441 static struct i2c_driver bq27x00_battery_driver
= {
443 .name
= "bq27x00-battery",
445 .probe
= bq27x00_battery_probe
,
446 .remove
= bq27x00_battery_remove
,
447 .id_table
= bq27x00_id
,
450 static int __init
bq27x00_battery_init(void)
454 ret
= i2c_add_driver(&bq27x00_battery_driver
);
456 printk(KERN_ERR
"Unable to register BQ27x00 driver\n");
460 module_init(bq27x00_battery_init
);
462 static void __exit
bq27x00_battery_exit(void)
464 i2c_del_driver(&bq27x00_battery_driver
);
466 module_exit(bq27x00_battery_exit
);
468 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
469 MODULE_DESCRIPTION("BQ27x00 battery monitor driver");
470 MODULE_LICENSE("GPL");