2 * BQ27x00 battery driver
4 * Copyright (C) 2008 Rodolfo Giometti <giometti@linux.it>
5 * Copyright (C) 2008 Eurotech S.p.A. <info@eurotech.it>
6 * Copyright (C) 2010-2011 Lars-Peter Clausen <lars@metafoo.de>
8 * Based on a previous work by Copyright (C) 2008 Texas Instruments, Inc.
10 * This package is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
14 * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
16 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
22 * http://focus.ti.com/docs/prod/folders/print/bq27000.html
23 * http://focus.ti.com/docs/prod/folders/print/bq27500.html
26 #include <linux/module.h>
27 #include <linux/param.h>
28 #include <linux/jiffies.h>
29 #include <linux/workqueue.h>
30 #include <linux/delay.h>
31 #include <linux/platform_device.h>
32 #include <linux/power_supply.h>
33 #include <linux/idr.h>
34 #include <linux/i2c.h>
35 #include <linux/slab.h>
36 #include <asm/unaligned.h>
38 #include <linux/power/bq27x00_battery.h>
40 #define DRIVER_VERSION "1.2.0"
42 #define BQ27x00_REG_TEMP 0x06
43 #define BQ27x00_REG_VOLT 0x08
44 #define BQ27x00_REG_AI 0x14
45 #define BQ27x00_REG_FLAGS 0x0A
46 #define BQ27x00_REG_TTE 0x16
47 #define BQ27x00_REG_TTF 0x18
48 #define BQ27x00_REG_TTECP 0x26
49 #define BQ27x00_REG_NAC 0x0C /* Nominal available capaciy */
50 #define BQ27x00_REG_LMD 0x12 /* Last measured discharge */
51 #define BQ27x00_REG_CYCT 0x2A /* Cycle count total */
52 #define BQ27x00_REG_AE 0x22 /* Available enery */
54 #define BQ27000_REG_RSOC 0x0B /* Relative State-of-Charge */
55 #define BQ27000_REG_ILMD 0x76 /* Initial last measured discharge */
56 #define BQ27000_FLAG_CHGS BIT(7)
58 #define BQ27500_REG_SOC 0x2c
59 #define BQ27500_REG_DCAP 0x3C /* Design capacity */
60 #define BQ27500_FLAG_DSC BIT(0)
61 #define BQ27500_FLAG_FC BIT(9)
63 #define BQ27000_RS 20 /* Resistor sense */
65 struct bq27x00_device_info
;
66 struct bq27x00_access_methods
{
67 int (*read
)(struct bq27x00_device_info
*di
, u8 reg
, bool single
);
70 enum bq27x00_chip
{ BQ27000
, BQ27500
};
72 struct bq27x00_reg_cache
{
75 int time_to_empty_avg
;
85 struct bq27x00_device_info
{
88 enum bq27x00_chip chip
;
90 struct bq27x00_reg_cache cache
;
91 int charge_design_full
;
93 unsigned long last_update
;
94 struct delayed_work work
;
96 struct power_supply bat
;
98 struct bq27x00_access_methods bus
;
103 static enum power_supply_property bq27x00_battery_props
[] = {
104 POWER_SUPPLY_PROP_STATUS
,
105 POWER_SUPPLY_PROP_PRESENT
,
106 POWER_SUPPLY_PROP_VOLTAGE_NOW
,
107 POWER_SUPPLY_PROP_CURRENT_NOW
,
108 POWER_SUPPLY_PROP_CAPACITY
,
109 POWER_SUPPLY_PROP_TEMP
,
110 POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW
,
111 POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG
,
112 POWER_SUPPLY_PROP_TIME_TO_FULL_NOW
,
113 POWER_SUPPLY_PROP_TECHNOLOGY
,
114 POWER_SUPPLY_PROP_CHARGE_FULL
,
115 POWER_SUPPLY_PROP_CHARGE_NOW
,
116 POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN
,
117 POWER_SUPPLY_PROP_CHARGE_COUNTER
,
118 POWER_SUPPLY_PROP_ENERGY_NOW
,
121 static unsigned int poll_interval
= 360;
122 module_param(poll_interval
, uint
, 0644);
123 MODULE_PARM_DESC(poll_interval
, "battery poll interval in seconds - " \
124 "0 disables polling");
127 * Common code for BQ27x00 devices
130 static inline int bq27x00_read(struct bq27x00_device_info
*di
, u8 reg
,
133 return di
->bus
.read(di
, reg
, single
);
137 * Return the battery Relative State-of-Charge
138 * Or < 0 if something fails.
140 static int bq27x00_battery_read_rsoc(struct bq27x00_device_info
*di
)
144 if (di
->chip
== BQ27500
)
145 rsoc
= bq27x00_read(di
, BQ27500_REG_SOC
, false);
147 rsoc
= bq27x00_read(di
, BQ27000_REG_RSOC
, true);
150 dev_err(di
->dev
, "error reading relative State-of-Charge\n");
156 * Return a battery charge value in µAh
157 * Or < 0 if something fails.
159 static int bq27x00_battery_read_charge(struct bq27x00_device_info
*di
, u8 reg
)
163 charge
= bq27x00_read(di
, reg
, false);
165 dev_err(di
->dev
, "error reading nominal available capacity\n");
169 if (di
->chip
== BQ27500
)
172 charge
= charge
* 3570 / BQ27000_RS
;
178 * Return the battery Nominal available capaciy in µAh
179 * Or < 0 if something fails.
181 static inline int bq27x00_battery_read_nac(struct bq27x00_device_info
*di
)
183 return bq27x00_battery_read_charge(di
, BQ27x00_REG_NAC
);
187 * Return the battery Last measured discharge in µAh
188 * Or < 0 if something fails.
190 static inline int bq27x00_battery_read_lmd(struct bq27x00_device_info
*di
)
192 return bq27x00_battery_read_charge(di
, BQ27x00_REG_LMD
);
196 * Return the battery Initial last measured discharge in µAh
197 * Or < 0 if something fails.
199 static int bq27x00_battery_read_ilmd(struct bq27x00_device_info
*di
)
203 if (di
->chip
== BQ27500
)
204 ilmd
= bq27x00_read(di
, BQ27500_REG_DCAP
, false);
206 ilmd
= bq27x00_read(di
, BQ27000_REG_ILMD
, true);
209 dev_err(di
->dev
, "error reading initial last measured discharge\n");
213 if (di
->chip
== BQ27500
)
216 ilmd
= ilmd
* 256 * 3570 / BQ27000_RS
;
222 * Return the battery Cycle count total
223 * Or < 0 if something fails.
225 static int bq27x00_battery_read_cyct(struct bq27x00_device_info
*di
)
229 cyct
= bq27x00_read(di
, BQ27x00_REG_CYCT
, false);
231 dev_err(di
->dev
, "error reading cycle count total\n");
237 * Read a time register.
238 * Return < 0 if something fails.
240 static int bq27x00_battery_read_time(struct bq27x00_device_info
*di
, u8 reg
)
244 tval
= bq27x00_read(di
, reg
, false);
246 dev_err(di
->dev
, "error reading register %02x: %d\n", reg
, tval
);
256 static void bq27x00_update(struct bq27x00_device_info
*di
)
258 struct bq27x00_reg_cache cache
= {0, };
259 bool is_bq27500
= di
->chip
== BQ27500
;
261 cache
.flags
= bq27x00_read(di
, BQ27x00_REG_FLAGS
, is_bq27500
);
262 if (cache
.flags
>= 0) {
263 cache
.capacity
= bq27x00_battery_read_rsoc(di
);
264 cache
.temperature
= bq27x00_read(di
, BQ27x00_REG_TEMP
, false);
265 cache
.time_to_empty
= bq27x00_battery_read_time(di
, BQ27x00_REG_TTE
);
266 cache
.time_to_empty_avg
= bq27x00_battery_read_time(di
, BQ27x00_REG_TTECP
);
267 cache
.time_to_full
= bq27x00_battery_read_time(di
, BQ27x00_REG_TTF
);
268 cache
.charge_full
= bq27x00_battery_read_lmd(di
);
269 cache
.charge_counter
= bq27x00_battery_read_cyct(di
);
272 cache
.current_now
= bq27x00_read(di
, BQ27x00_REG_AI
, false);
274 /* We only have to read charge design full once */
275 if (di
->charge_design_full
<= 0)
276 di
->charge_design_full
= bq27x00_battery_read_ilmd(di
);
279 /* Ignore current_now which is a snapshot of the current battery state
280 * and is likely to be different even between two consecutive reads */
281 if (memcmp(&di
->cache
, &cache
, sizeof(cache
) - sizeof(int)) != 0) {
283 power_supply_changed(&di
->bat
);
286 di
->last_update
= jiffies
;
289 static void bq27x00_battery_poll(struct work_struct
*work
)
291 struct bq27x00_device_info
*di
=
292 container_of(work
, struct bq27x00_device_info
, work
.work
);
296 if (poll_interval
> 0) {
297 /* The timer does not have to be accurate. */
298 set_timer_slack(&di
->work
.timer
, poll_interval
* HZ
/ 4);
299 schedule_delayed_work(&di
->work
, poll_interval
* HZ
);
305 * Return the battery temperature in tenths of degree Celsius
306 * Or < 0 if something fails.
308 static int bq27x00_battery_temperature(struct bq27x00_device_info
*di
,
309 union power_supply_propval
*val
)
311 if (di
->cache
.temperature
< 0)
312 return di
->cache
.temperature
;
314 if (di
->chip
== BQ27500
)
315 val
->intval
= di
->cache
.temperature
- 2731;
317 val
->intval
= ((di
->cache
.temperature
* 5) - 5463) / 2;
323 * Return the battery average current
324 * Note that current can be negative signed as well
325 * Or 0 if something fails.
327 static int bq27x00_battery_current(struct bq27x00_device_info
*di
,
328 union power_supply_propval
*val
)
332 if (di
->chip
== BQ27500
)
333 curr
= bq27x00_read(di
, BQ27x00_REG_AI
, false);
335 curr
= di
->cache
.current_now
;
340 if (di
->chip
== BQ27500
) {
341 /* bq27500 returns signed value */
342 val
->intval
= (int)((s16
)curr
) * 1000;
344 if (di
->cache
.flags
& BQ27000_FLAG_CHGS
) {
345 dev_dbg(di
->dev
, "negative current!\n");
349 val
->intval
= curr
* 3570 / BQ27000_RS
;
355 static int bq27x00_battery_status(struct bq27x00_device_info
*di
,
356 union power_supply_propval
*val
)
360 if (di
->chip
== BQ27500
) {
361 if (di
->cache
.flags
& BQ27500_FLAG_FC
)
362 status
= POWER_SUPPLY_STATUS_FULL
;
363 else if (di
->cache
.flags
& BQ27500_FLAG_DSC
)
364 status
= POWER_SUPPLY_STATUS_DISCHARGING
;
366 status
= POWER_SUPPLY_STATUS_CHARGING
;
368 if (di
->cache
.flags
& BQ27000_FLAG_CHGS
)
369 status
= POWER_SUPPLY_STATUS_CHARGING
;
371 status
= POWER_SUPPLY_STATUS_DISCHARGING
;
374 val
->intval
= status
;
380 * Return the battery Voltage in milivolts
381 * Or < 0 if something fails.
383 static int bq27x00_battery_voltage(struct bq27x00_device_info
*di
,
384 union power_supply_propval
*val
)
388 volt
= bq27x00_read(di
, BQ27x00_REG_VOLT
, false);
392 val
->intval
= volt
* 1000;
398 * Return the battery Available energy in µWh
399 * Or < 0 if something fails.
401 static int bq27x00_battery_energy(struct bq27x00_device_info
*di
,
402 union power_supply_propval
*val
)
406 ae
= bq27x00_read(di
, BQ27x00_REG_AE
, false);
408 dev_err(di
->dev
, "error reading available energy\n");
412 if (di
->chip
== BQ27500
)
415 ae
= ae
* 29200 / BQ27000_RS
;
423 static int bq27x00_simple_value(int value
,
424 union power_supply_propval
*val
)
434 #define to_bq27x00_device_info(x) container_of((x), \
435 struct bq27x00_device_info, bat);
437 static int bq27x00_battery_get_property(struct power_supply
*psy
,
438 enum power_supply_property psp
,
439 union power_supply_propval
*val
)
442 struct bq27x00_device_info
*di
= to_bq27x00_device_info(psy
);
444 mutex_lock(&di
->lock
);
445 if (time_is_before_jiffies(di
->last_update
+ 5 * HZ
)) {
446 cancel_delayed_work_sync(&di
->work
);
447 bq27x00_battery_poll(&di
->work
.work
);
449 mutex_unlock(&di
->lock
);
451 if (psp
!= POWER_SUPPLY_PROP_PRESENT
&& di
->cache
.flags
< 0)
455 case POWER_SUPPLY_PROP_STATUS
:
456 ret
= bq27x00_battery_status(di
, val
);
458 case POWER_SUPPLY_PROP_VOLTAGE_NOW
:
459 ret
= bq27x00_battery_voltage(di
, val
);
461 case POWER_SUPPLY_PROP_PRESENT
:
462 val
->intval
= di
->cache
.flags
< 0 ? 0 : 1;
464 case POWER_SUPPLY_PROP_CURRENT_NOW
:
465 ret
= bq27x00_battery_current(di
, val
);
467 case POWER_SUPPLY_PROP_CAPACITY
:
468 ret
= bq27x00_simple_value(di
->cache
.capacity
, val
);
470 case POWER_SUPPLY_PROP_TEMP
:
471 ret
= bq27x00_battery_temperature(di
, val
);
473 case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW
:
474 ret
= bq27x00_simple_value(di
->cache
.time_to_empty
, val
);
476 case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG
:
477 ret
= bq27x00_simple_value(di
->cache
.time_to_empty_avg
, val
);
479 case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW
:
480 ret
= bq27x00_simple_value(di
->cache
.time_to_full
, val
);
482 case POWER_SUPPLY_PROP_TECHNOLOGY
:
483 val
->intval
= POWER_SUPPLY_TECHNOLOGY_LION
;
485 case POWER_SUPPLY_PROP_CHARGE_NOW
:
486 ret
= bq27x00_simple_value(bq27x00_battery_read_nac(di
), val
);
488 case POWER_SUPPLY_PROP_CHARGE_FULL
:
489 ret
= bq27x00_simple_value(di
->cache
.charge_full
, val
);
491 case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN
:
492 ret
= bq27x00_simple_value(di
->charge_design_full
, val
);
494 case POWER_SUPPLY_PROP_CHARGE_COUNTER
:
495 ret
= bq27x00_simple_value(di
->cache
.charge_counter
, val
);
497 case POWER_SUPPLY_PROP_ENERGY_NOW
:
498 ret
= bq27x00_battery_energy(di
, val
);
507 static void bq27x00_external_power_changed(struct power_supply
*psy
)
509 struct bq27x00_device_info
*di
= to_bq27x00_device_info(psy
);
511 cancel_delayed_work_sync(&di
->work
);
512 schedule_delayed_work(&di
->work
, 0);
515 static int bq27x00_powersupply_init(struct bq27x00_device_info
*di
)
519 di
->bat
.type
= POWER_SUPPLY_TYPE_BATTERY
;
520 di
->bat
.properties
= bq27x00_battery_props
;
521 di
->bat
.num_properties
= ARRAY_SIZE(bq27x00_battery_props
);
522 di
->bat
.get_property
= bq27x00_battery_get_property
;
523 di
->bat
.external_power_changed
= bq27x00_external_power_changed
;
525 INIT_DELAYED_WORK(&di
->work
, bq27x00_battery_poll
);
526 mutex_init(&di
->lock
);
528 ret
= power_supply_register(di
->dev
, &di
->bat
);
530 dev_err(di
->dev
, "failed to register battery: %d\n", ret
);
534 dev_info(di
->dev
, "support ver. %s enabled\n", DRIVER_VERSION
);
541 static void bq27x00_powersupply_unregister(struct bq27x00_device_info
*di
)
543 cancel_delayed_work_sync(&di
->work
);
545 power_supply_unregister(&di
->bat
);
547 mutex_destroy(&di
->lock
);
551 /* i2c specific code */
552 #ifdef CONFIG_BATTERY_BQ27X00_I2C
554 /* If the system has several batteries we need a different name for each
557 static DEFINE_IDR(battery_id
);
558 static DEFINE_MUTEX(battery_mutex
);
560 static int bq27x00_read_i2c(struct bq27x00_device_info
*di
, u8 reg
, bool single
)
562 struct i2c_client
*client
= to_i2c_client(di
->dev
);
563 struct i2c_msg msg
[1];
564 unsigned char data
[2];
567 if (!client
->adapter
)
570 msg
->addr
= client
->addr
;
576 ret
= i2c_transfer(client
->adapter
, msg
, 1);
584 msg
->flags
= I2C_M_RD
;
585 ret
= i2c_transfer(client
->adapter
, msg
, 1);
588 ret
= get_unaligned_le16(data
);
596 static int bq27x00_battery_probe(struct i2c_client
*client
,
597 const struct i2c_device_id
*id
)
600 struct bq27x00_device_info
*di
;
604 /* Get new ID for the new battery device */
605 retval
= idr_pre_get(&battery_id
, GFP_KERNEL
);
608 mutex_lock(&battery_mutex
);
609 retval
= idr_get_new(&battery_id
, client
, &num
);
610 mutex_unlock(&battery_mutex
);
614 name
= kasprintf(GFP_KERNEL
, "%s-%d", id
->name
, num
);
616 dev_err(&client
->dev
, "failed to allocate device name\n");
621 di
= kzalloc(sizeof(*di
), GFP_KERNEL
);
623 dev_err(&client
->dev
, "failed to allocate device info data\n");
629 di
->dev
= &client
->dev
;
630 di
->chip
= id
->driver_data
;
632 di
->bus
.read
= &bq27x00_read_i2c
;
634 if (bq27x00_powersupply_init(di
))
637 i2c_set_clientdata(client
, di
);
646 mutex_lock(&battery_mutex
);
647 idr_remove(&battery_id
, num
);
648 mutex_unlock(&battery_mutex
);
653 static int bq27x00_battery_remove(struct i2c_client
*client
)
655 struct bq27x00_device_info
*di
= i2c_get_clientdata(client
);
657 bq27x00_powersupply_unregister(di
);
661 mutex_lock(&battery_mutex
);
662 idr_remove(&battery_id
, di
->id
);
663 mutex_unlock(&battery_mutex
);
670 static const struct i2c_device_id bq27x00_id
[] = {
671 { "bq27200", BQ27000
}, /* bq27200 is same as bq27000, but with i2c */
672 { "bq27500", BQ27500
},
675 MODULE_DEVICE_TABLE(i2c
, bq27x00_id
);
677 static struct i2c_driver bq27x00_battery_driver
= {
679 .name
= "bq27x00-battery",
681 .probe
= bq27x00_battery_probe
,
682 .remove
= bq27x00_battery_remove
,
683 .id_table
= bq27x00_id
,
686 static inline int bq27x00_battery_i2c_init(void)
688 int ret
= i2c_add_driver(&bq27x00_battery_driver
);
690 printk(KERN_ERR
"Unable to register BQ27x00 i2c driver\n");
695 static inline void bq27x00_battery_i2c_exit(void)
697 i2c_del_driver(&bq27x00_battery_driver
);
702 static inline int bq27x00_battery_i2c_init(void) { return 0; }
703 static inline void bq27x00_battery_i2c_exit(void) {};
707 /* platform specific code */
708 #ifdef CONFIG_BATTERY_BQ27X00_PLATFORM
710 static int bq27000_read_platform(struct bq27x00_device_info
*di
, u8 reg
,
713 struct device
*dev
= di
->dev
;
714 struct bq27000_platform_data
*pdata
= dev
->platform_data
;
715 unsigned int timeout
= 3;
720 /* Make sure the value has not changed in between reading the
721 * lower and the upper part */
722 upper
= pdata
->read(dev
, reg
+ 1);
728 lower
= pdata
->read(dev
, reg
);
732 upper
= pdata
->read(dev
, reg
+ 1);
733 } while (temp
!= upper
&& --timeout
);
738 return (upper
<< 8) | lower
;
741 return pdata
->read(dev
, reg
);
744 static int __devinit
bq27000_battery_probe(struct platform_device
*pdev
)
746 struct bq27x00_device_info
*di
;
747 struct bq27000_platform_data
*pdata
= pdev
->dev
.platform_data
;
751 dev_err(&pdev
->dev
, "no platform_data supplied\n");
756 dev_err(&pdev
->dev
, "no hdq read callback supplied\n");
760 di
= kzalloc(sizeof(*di
), GFP_KERNEL
);
762 dev_err(&pdev
->dev
, "failed to allocate device info data\n");
766 platform_set_drvdata(pdev
, di
);
768 di
->dev
= &pdev
->dev
;
771 di
->bat
.name
= pdata
->name
?: dev_name(&pdev
->dev
);
772 di
->bus
.read
= &bq27000_read_platform
;
774 ret
= bq27x00_powersupply_init(di
);
781 platform_set_drvdata(pdev
, NULL
);
787 static int __devexit
bq27000_battery_remove(struct platform_device
*pdev
)
789 struct bq27x00_device_info
*di
= platform_get_drvdata(pdev
);
791 bq27x00_powersupply_unregister(di
);
793 platform_set_drvdata(pdev
, NULL
);
799 static struct platform_driver bq27000_battery_driver
= {
800 .probe
= bq27000_battery_probe
,
801 .remove
= __devexit_p(bq27000_battery_remove
),
803 .name
= "bq27000-battery",
804 .owner
= THIS_MODULE
,
808 static inline int bq27x00_battery_platform_init(void)
810 int ret
= platform_driver_register(&bq27000_battery_driver
);
812 printk(KERN_ERR
"Unable to register BQ27000 platform driver\n");
817 static inline void bq27x00_battery_platform_exit(void)
819 platform_driver_unregister(&bq27000_battery_driver
);
824 static inline int bq27x00_battery_platform_init(void) { return 0; }
825 static inline void bq27x00_battery_platform_exit(void) {};
833 static int __init
bq27x00_battery_init(void)
837 ret
= bq27x00_battery_i2c_init();
841 ret
= bq27x00_battery_platform_init();
843 bq27x00_battery_i2c_exit();
847 module_init(bq27x00_battery_init
);
849 static void __exit
bq27x00_battery_exit(void)
851 bq27x00_battery_platform_exit();
852 bq27x00_battery_i2c_exit();
854 module_exit(bq27x00_battery_exit
);
856 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
857 MODULE_DESCRIPTION("BQ27x00 battery monitor driver");
858 MODULE_LICENSE("GPL");