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 <linux/slab.h>
28 #include <asm/unaligned.h>
30 #define DRIVER_VERSION "1.1.0"
32 #define BQ27x00_REG_TEMP 0x06
33 #define BQ27x00_REG_VOLT 0x08
34 #define BQ27x00_REG_AI 0x14
35 #define BQ27x00_REG_FLAGS 0x0A
36 #define BQ27x00_REG_TTE 0x16
37 #define BQ27x00_REG_TTF 0x18
38 #define BQ27x00_REG_TTECP 0x26
40 #define BQ27000_REG_RSOC 0x0B /* Relative State-of-Charge */
41 #define BQ27000_FLAG_CHGS BIT(7)
43 #define BQ27500_REG_SOC 0x2c
44 #define BQ27500_FLAG_DSC BIT(0)
45 #define BQ27500_FLAG_FC BIT(9)
47 #define BQ27000_RS 20 /* Resistor sense */
49 /* If the system has several batteries we need a different name for each
52 static DEFINE_IDR(battery_id
);
53 static DEFINE_MUTEX(battery_mutex
);
55 struct bq27x00_device_info
;
56 struct bq27x00_access_methods
{
57 int (*read
)(u8 reg
, int *rt_value
, int b_single
,
58 struct bq27x00_device_info
*di
);
61 enum bq27x00_chip
{ BQ27000
, BQ27500
};
63 struct bq27x00_device_info
{
66 struct bq27x00_access_methods
*bus
;
67 struct power_supply bat
;
68 enum bq27x00_chip chip
;
70 struct i2c_client
*client
;
73 static enum power_supply_property bq27x00_battery_props
[] = {
74 POWER_SUPPLY_PROP_STATUS
,
75 POWER_SUPPLY_PROP_PRESENT
,
76 POWER_SUPPLY_PROP_VOLTAGE_NOW
,
77 POWER_SUPPLY_PROP_CURRENT_NOW
,
78 POWER_SUPPLY_PROP_CAPACITY
,
79 POWER_SUPPLY_PROP_TEMP
,
80 POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW
,
81 POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG
,
82 POWER_SUPPLY_PROP_TIME_TO_FULL_NOW
,
83 POWER_SUPPLY_PROP_TECHNOLOGY
,
87 * Common code for BQ27x00 devices
90 static int bq27x00_read(u8 reg
, int *rt_value
, int b_single
,
91 struct bq27x00_device_info
*di
)
93 return di
->bus
->read(reg
, rt_value
, b_single
, di
);
97 * Return the battery temperature in tenths of degree Celsius
98 * Or < 0 if something fails.
100 static int bq27x00_battery_temperature(struct bq27x00_device_info
*di
)
105 ret
= bq27x00_read(BQ27x00_REG_TEMP
, &temp
, 0, di
);
107 dev_err(di
->dev
, "error reading temperature\n");
111 if (di
->chip
== BQ27500
)
114 return ((temp
* 5) - 5463) / 2;
118 * Return the battery Voltage in milivolts
119 * Or < 0 if something fails.
121 static int bq27x00_battery_voltage(struct bq27x00_device_info
*di
)
126 ret
= bq27x00_read(BQ27x00_REG_VOLT
, &volt
, 0, di
);
128 dev_err(di
->dev
, "error reading voltage\n");
136 * Return the battery average current
137 * Note that current can be negative signed as well
138 * Or 0 if something fails.
140 static int bq27x00_battery_current(struct bq27x00_device_info
*di
)
146 ret
= bq27x00_read(BQ27x00_REG_AI
, &curr
, 0, di
);
148 dev_err(di
->dev
, "error reading current\n");
152 if (di
->chip
== BQ27500
) {
153 /* bq27500 returns signed value */
154 curr
= (int)((s16
)curr
) * 1000;
156 ret
= bq27x00_read(BQ27x00_REG_FLAGS
, &flags
, 0, di
);
158 dev_err(di
->dev
, "error reading flags\n");
161 if (flags
& BQ27000_FLAG_CHGS
) {
162 dev_dbg(di
->dev
, "negative current!\n");
165 curr
= curr
* 3570 / BQ27000_RS
;
172 * Return the battery Relative State-of-Charge
173 * Or < 0 if something fails.
175 static int bq27x00_battery_rsoc(struct bq27x00_device_info
*di
)
180 if (di
->chip
== BQ27500
)
181 ret
= bq27x00_read(BQ27500_REG_SOC
, &rsoc
, 0, di
);
183 ret
= bq27x00_read(BQ27000_REG_RSOC
, &rsoc
, 1, di
);
185 dev_err(di
->dev
, "error reading relative State-of-Charge\n");
192 static int bq27x00_battery_status(struct bq27x00_device_info
*di
,
193 union power_supply_propval
*val
)
199 ret
= bq27x00_read(BQ27x00_REG_FLAGS
, &flags
, 0, di
);
201 dev_err(di
->dev
, "error reading flags\n");
205 if (di
->chip
== BQ27500
) {
206 if (flags
& BQ27500_FLAG_FC
)
207 status
= POWER_SUPPLY_STATUS_FULL
;
208 else if (flags
& BQ27500_FLAG_DSC
)
209 status
= POWER_SUPPLY_STATUS_DISCHARGING
;
211 status
= POWER_SUPPLY_STATUS_CHARGING
;
213 if (flags
& BQ27000_FLAG_CHGS
)
214 status
= POWER_SUPPLY_STATUS_CHARGING
;
216 status
= POWER_SUPPLY_STATUS_DISCHARGING
;
219 val
->intval
= status
;
224 * Read a time register.
225 * Return < 0 if something fails.
227 static int bq27x00_battery_time(struct bq27x00_device_info
*di
, int reg
,
228 union power_supply_propval
*val
)
233 ret
= bq27x00_read(reg
, &tval
, 0, di
);
235 dev_err(di
->dev
, "error reading register %02x\n", reg
);
242 val
->intval
= tval
* 60;
246 #define to_bq27x00_device_info(x) container_of((x), \
247 struct bq27x00_device_info, bat);
249 static int bq27x00_battery_get_property(struct power_supply
*psy
,
250 enum power_supply_property psp
,
251 union power_supply_propval
*val
)
254 struct bq27x00_device_info
*di
= to_bq27x00_device_info(psy
);
257 case POWER_SUPPLY_PROP_STATUS
:
258 ret
= bq27x00_battery_status(di
, val
);
260 case POWER_SUPPLY_PROP_VOLTAGE_NOW
:
261 case POWER_SUPPLY_PROP_PRESENT
:
262 val
->intval
= bq27x00_battery_voltage(di
);
263 if (psp
== POWER_SUPPLY_PROP_PRESENT
)
264 val
->intval
= val
->intval
<= 0 ? 0 : 1;
266 case POWER_SUPPLY_PROP_CURRENT_NOW
:
267 val
->intval
= bq27x00_battery_current(di
);
269 case POWER_SUPPLY_PROP_CAPACITY
:
270 val
->intval
= bq27x00_battery_rsoc(di
);
272 case POWER_SUPPLY_PROP_TEMP
:
273 val
->intval
= bq27x00_battery_temperature(di
);
275 case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW
:
276 ret
= bq27x00_battery_time(di
, BQ27x00_REG_TTE
, val
);
278 case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG
:
279 ret
= bq27x00_battery_time(di
, BQ27x00_REG_TTECP
, val
);
281 case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW
:
282 ret
= bq27x00_battery_time(di
, BQ27x00_REG_TTF
, val
);
284 case POWER_SUPPLY_PROP_TECHNOLOGY
:
285 val
->intval
= POWER_SUPPLY_TECHNOLOGY_LION
;
294 static void bq27x00_powersupply_init(struct bq27x00_device_info
*di
)
296 di
->bat
.type
= POWER_SUPPLY_TYPE_BATTERY
;
297 di
->bat
.properties
= bq27x00_battery_props
;
298 di
->bat
.num_properties
= ARRAY_SIZE(bq27x00_battery_props
);
299 di
->bat
.get_property
= bq27x00_battery_get_property
;
300 di
->bat
.external_power_changed
= NULL
;
307 static int bq27x00_read_i2c(u8 reg
, int *rt_value
, int b_single
,
308 struct bq27x00_device_info
*di
)
310 struct i2c_client
*client
= di
->client
;
311 struct i2c_msg msg
[1];
312 unsigned char data
[2];
315 if (!client
->adapter
)
318 msg
->addr
= client
->addr
;
324 err
= i2c_transfer(client
->adapter
, msg
, 1);
332 msg
->flags
= I2C_M_RD
;
333 err
= i2c_transfer(client
->adapter
, msg
, 1);
336 *rt_value
= get_unaligned_le16(data
);
346 static int bq27x00_battery_probe(struct i2c_client
*client
,
347 const struct i2c_device_id
*id
)
350 struct bq27x00_device_info
*di
;
351 struct bq27x00_access_methods
*bus
;
355 /* Get new ID for the new battery device */
356 retval
= idr_pre_get(&battery_id
, GFP_KERNEL
);
359 mutex_lock(&battery_mutex
);
360 retval
= idr_get_new(&battery_id
, client
, &num
);
361 mutex_unlock(&battery_mutex
);
365 name
= kasprintf(GFP_KERNEL
, "%s-%d", id
->name
, num
);
367 dev_err(&client
->dev
, "failed to allocate device name\n");
372 di
= kzalloc(sizeof(*di
), GFP_KERNEL
);
374 dev_err(&client
->dev
, "failed to allocate device info data\n");
379 di
->chip
= id
->driver_data
;
381 bus
= kzalloc(sizeof(*bus
), GFP_KERNEL
);
383 dev_err(&client
->dev
, "failed to allocate access method "
389 i2c_set_clientdata(client
, di
);
390 di
->dev
= &client
->dev
;
392 bus
->read
= &bq27x00_read_i2c
;
396 bq27x00_powersupply_init(di
);
398 retval
= power_supply_register(&client
->dev
, &di
->bat
);
400 dev_err(&client
->dev
, "failed to register battery\n");
404 dev_info(&client
->dev
, "support ver. %s enabled\n", DRIVER_VERSION
);
415 mutex_lock(&battery_mutex
);
416 idr_remove(&battery_id
, num
);
417 mutex_unlock(&battery_mutex
);
422 static int bq27x00_battery_remove(struct i2c_client
*client
)
424 struct bq27x00_device_info
*di
= i2c_get_clientdata(client
);
426 power_supply_unregister(&di
->bat
);
431 mutex_lock(&battery_mutex
);
432 idr_remove(&battery_id
, di
->id
);
433 mutex_unlock(&battery_mutex
);
444 static const struct i2c_device_id bq27x00_id
[] = {
445 { "bq27200", BQ27000
}, /* bq27200 is same as bq27000, but with i2c */
446 { "bq27500", BQ27500
},
450 static struct i2c_driver bq27x00_battery_driver
= {
452 .name
= "bq27x00-battery",
454 .probe
= bq27x00_battery_probe
,
455 .remove
= bq27x00_battery_remove
,
456 .id_table
= bq27x00_id
,
459 static int __init
bq27x00_battery_init(void)
463 ret
= i2c_add_driver(&bq27x00_battery_driver
);
465 printk(KERN_ERR
"Unable to register BQ27x00 driver\n");
469 module_init(bq27x00_battery_init
);
471 static void __exit
bq27x00_battery_exit(void)
473 i2c_del_driver(&bq27x00_battery_driver
);
475 module_exit(bq27x00_battery_exit
);
477 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
478 MODULE_DESCRIPTION("BQ27x00 battery monitor driver");
479 MODULE_LICENSE("GPL");