1 // SPDX-License-Identifier: GPL-2.0-only
3 * 1-wire client/driver for the Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC
5 * Copyright (C) 2010 Indesign, LLC
7 * Author: Clifton Barnes <cabarnes@indesign-llc.com>
9 * Based on ds2760_battery and ds2782_battery drivers
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/param.h>
16 #include <linux/platform_device.h>
17 #include <linux/power_supply.h>
18 #include <linux/idr.h>
21 #include "../../w1/slaves/w1_ds2780.h"
23 /* Current unit measurement in uA for a 1 milli-ohm sense resistor */
24 #define DS2780_CURRENT_UNITS 1563
25 /* Charge unit measurement in uAh for a 1 milli-ohm sense resistor */
26 #define DS2780_CHARGE_UNITS 6250
27 /* Number of bytes in user EEPROM space */
28 #define DS2780_USER_EEPROM_SIZE (DS2780_EEPROM_BLOCK0_END - \
29 DS2780_EEPROM_BLOCK0_START + 1)
30 /* Number of bytes in parameter EEPROM space */
31 #define DS2780_PARAM_EEPROM_SIZE (DS2780_EEPROM_BLOCK1_END - \
32 DS2780_EEPROM_BLOCK1_START + 1)
34 struct ds2780_device_info
{
36 struct power_supply
*bat
;
37 struct power_supply_desc bat_desc
;
38 struct device
*w1_dev
;
46 static const char model
[] = "DS2780";
47 static const char manufacturer
[] = "Maxim/Dallas";
49 static inline struct ds2780_device_info
*
50 to_ds2780_device_info(struct power_supply
*psy
)
52 return power_supply_get_drvdata(psy
);
55 static inline int ds2780_battery_io(struct ds2780_device_info
*dev_info
,
56 char *buf
, int addr
, size_t count
, int io
)
58 return w1_ds2780_io(dev_info
->w1_dev
, buf
, addr
, count
, io
);
61 static inline int ds2780_read8(struct ds2780_device_info
*dev_info
, u8
*val
,
64 return ds2780_battery_io(dev_info
, val
, addr
, sizeof(u8
), 0);
67 static int ds2780_read16(struct ds2780_device_info
*dev_info
, s16
*val
,
73 ret
= ds2780_battery_io(dev_info
, raw
, addr
, sizeof(raw
), 0);
77 *val
= (raw
[0] << 8) | raw
[1];
82 static inline int ds2780_read_block(struct ds2780_device_info
*dev_info
,
83 u8
*val
, int addr
, size_t count
)
85 return ds2780_battery_io(dev_info
, val
, addr
, count
, 0);
88 static inline int ds2780_write(struct ds2780_device_info
*dev_info
, u8
*val
,
89 int addr
, size_t count
)
91 return ds2780_battery_io(dev_info
, val
, addr
, count
, 1);
94 static inline int ds2780_store_eeprom(struct device
*dev
, int addr
)
96 return w1_ds2780_eeprom_cmd(dev
, addr
, W1_DS2780_COPY_DATA
);
99 static inline int ds2780_recall_eeprom(struct device
*dev
, int addr
)
101 return w1_ds2780_eeprom_cmd(dev
, addr
, W1_DS2780_RECALL_DATA
);
104 static int ds2780_save_eeprom(struct ds2780_device_info
*dev_info
, int reg
)
108 ret
= ds2780_store_eeprom(dev_info
->w1_dev
, reg
);
112 ret
= ds2780_recall_eeprom(dev_info
->w1_dev
, reg
);
119 /* Set sense resistor value in mhos */
120 static int ds2780_set_sense_register(struct ds2780_device_info
*dev_info
,
125 ret
= ds2780_write(dev_info
, &conductance
,
126 DS2780_RSNSP_REG
, sizeof(u8
));
130 return ds2780_save_eeprom(dev_info
, DS2780_RSNSP_REG
);
133 /* Get RSGAIN value from 0 to 1.999 in steps of 0.001 */
134 static int ds2780_get_rsgain_register(struct ds2780_device_info
*dev_info
,
137 return ds2780_read16(dev_info
, rsgain
, DS2780_RSGAIN_MSB_REG
);
140 /* Set RSGAIN value from 0 to 1.999 in steps of 0.001 */
141 static int ds2780_set_rsgain_register(struct ds2780_device_info
*dev_info
,
145 u8 raw
[] = {rsgain
>> 8, rsgain
& 0xFF};
147 ret
= ds2780_write(dev_info
, raw
,
148 DS2780_RSGAIN_MSB_REG
, sizeof(raw
));
152 return ds2780_save_eeprom(dev_info
, DS2780_RSGAIN_MSB_REG
);
155 static int ds2780_get_voltage(struct ds2780_device_info
*dev_info
,
162 * The voltage value is located in 10 bits across the voltage MSB
163 * and LSB registers in two's compliment form
164 * Sign bit of the voltage value is in bit 7 of the voltage MSB register
165 * Bits 9 - 3 of the voltage value are in bits 6 - 0 of the
166 * voltage MSB register
167 * Bits 2 - 0 of the voltage value are in bits 7 - 5 of the
168 * voltage LSB register
170 ret
= ds2780_read16(dev_info
, &voltage_raw
,
171 DS2780_VOLT_MSB_REG
);
176 * DS2780 reports voltage in units of 4.88mV, but the battery class
177 * reports in units of uV, so convert by multiplying by 4880.
179 *voltage_uV
= (voltage_raw
/ 32) * 4880;
183 static int ds2780_get_temperature(struct ds2780_device_info
*dev_info
,
190 * The temperature value is located in 10 bits across the temperature
191 * MSB and LSB registers in two's compliment form
192 * Sign bit of the temperature value is in bit 7 of the temperature
194 * Bits 9 - 3 of the temperature value are in bits 6 - 0 of the
195 * temperature MSB register
196 * Bits 2 - 0 of the temperature value are in bits 7 - 5 of the
197 * temperature LSB register
199 ret
= ds2780_read16(dev_info
, &temperature_raw
,
200 DS2780_TEMP_MSB_REG
);
205 * Temperature is measured in units of 0.125 degrees celcius, the
206 * power_supply class measures temperature in tenths of degrees
207 * celsius. The temperature value is stored as a 10 bit number, plus
208 * sign in the upper bits of a 16 bit register.
210 *temperature
= ((temperature_raw
/ 32) * 125) / 100;
214 static int ds2780_get_current(struct ds2780_device_info
*dev_info
,
215 enum current_types type
, int *current_uA
)
219 u8 sense_res_raw
, reg_msb
;
222 * The units of measurement for current are dependent on the value of
223 * the sense resistor.
225 ret
= ds2780_read8(dev_info
, &sense_res_raw
, DS2780_RSNSP_REG
);
229 if (sense_res_raw
== 0) {
230 dev_err(dev_info
->dev
, "sense resistor value is 0\n");
233 sense_res
= 1000 / sense_res_raw
;
235 if (type
== CURRENT_NOW
)
236 reg_msb
= DS2780_CURRENT_MSB_REG
;
237 else if (type
== CURRENT_AVG
)
238 reg_msb
= DS2780_IAVG_MSB_REG
;
243 * The current value is located in 16 bits across the current MSB
244 * and LSB registers in two's compliment form
245 * Sign bit of the current value is in bit 7 of the current MSB register
246 * Bits 14 - 8 of the current value are in bits 6 - 0 of the current
248 * Bits 7 - 0 of the current value are in bits 7 - 0 of the current
251 ret
= ds2780_read16(dev_info
, ¤t_raw
, reg_msb
);
255 *current_uA
= current_raw
* (DS2780_CURRENT_UNITS
/ sense_res
);
259 static int ds2780_get_accumulated_current(struct ds2780_device_info
*dev_info
,
260 int *accumulated_current
)
267 * The units of measurement for accumulated current are dependent on
268 * the value of the sense resistor.
270 ret
= ds2780_read8(dev_info
, &sense_res_raw
, DS2780_RSNSP_REG
);
274 if (sense_res_raw
== 0) {
275 dev_err(dev_info
->dev
, "sense resistor value is 0\n");
278 sense_res
= 1000 / sense_res_raw
;
281 * The ACR value is located in 16 bits across the ACR MSB and
283 * Bits 15 - 8 of the ACR value are in bits 7 - 0 of the ACR
285 * Bits 7 - 0 of the ACR value are in bits 7 - 0 of the ACR
288 ret
= ds2780_read16(dev_info
, ¤t_raw
, DS2780_ACR_MSB_REG
);
292 *accumulated_current
= current_raw
* (DS2780_CHARGE_UNITS
/ sense_res
);
296 static int ds2780_get_capacity(struct ds2780_device_info
*dev_info
,
302 ret
= ds2780_read8(dev_info
, &raw
, DS2780_RARC_REG
);
310 static int ds2780_get_status(struct ds2780_device_info
*dev_info
, int *status
)
312 int ret
, current_uA
, capacity
;
314 ret
= ds2780_get_current(dev_info
, CURRENT_NOW
, ¤t_uA
);
318 ret
= ds2780_get_capacity(dev_info
, &capacity
);
323 *status
= POWER_SUPPLY_STATUS_FULL
;
324 else if (current_uA
== 0)
325 *status
= POWER_SUPPLY_STATUS_NOT_CHARGING
;
326 else if (current_uA
< 0)
327 *status
= POWER_SUPPLY_STATUS_DISCHARGING
;
329 *status
= POWER_SUPPLY_STATUS_CHARGING
;
334 static int ds2780_get_charge_now(struct ds2780_device_info
*dev_info
,
341 * The RAAC value is located in 16 bits across the RAAC MSB and
343 * Bits 15 - 8 of the RAAC value are in bits 7 - 0 of the RAAC
345 * Bits 7 - 0 of the RAAC value are in bits 7 - 0 of the RAAC
348 ret
= ds2780_read16(dev_info
, &charge_raw
, DS2780_RAAC_MSB_REG
);
352 *charge_now
= charge_raw
* 1600;
356 static int ds2780_get_control_register(struct ds2780_device_info
*dev_info
,
359 return ds2780_read8(dev_info
, control_reg
, DS2780_CONTROL_REG
);
362 static int ds2780_set_control_register(struct ds2780_device_info
*dev_info
,
367 ret
= ds2780_write(dev_info
, &control_reg
,
368 DS2780_CONTROL_REG
, sizeof(u8
));
372 return ds2780_save_eeprom(dev_info
, DS2780_CONTROL_REG
);
375 static int ds2780_battery_get_property(struct power_supply
*psy
,
376 enum power_supply_property psp
,
377 union power_supply_propval
*val
)
380 struct ds2780_device_info
*dev_info
= to_ds2780_device_info(psy
);
383 case POWER_SUPPLY_PROP_VOLTAGE_NOW
:
384 ret
= ds2780_get_voltage(dev_info
, &val
->intval
);
387 case POWER_SUPPLY_PROP_TEMP
:
388 ret
= ds2780_get_temperature(dev_info
, &val
->intval
);
391 case POWER_SUPPLY_PROP_MODEL_NAME
:
395 case POWER_SUPPLY_PROP_MANUFACTURER
:
396 val
->strval
= manufacturer
;
399 case POWER_SUPPLY_PROP_CURRENT_NOW
:
400 ret
= ds2780_get_current(dev_info
, CURRENT_NOW
, &val
->intval
);
403 case POWER_SUPPLY_PROP_CURRENT_AVG
:
404 ret
= ds2780_get_current(dev_info
, CURRENT_AVG
, &val
->intval
);
407 case POWER_SUPPLY_PROP_STATUS
:
408 ret
= ds2780_get_status(dev_info
, &val
->intval
);
411 case POWER_SUPPLY_PROP_CAPACITY
:
412 ret
= ds2780_get_capacity(dev_info
, &val
->intval
);
415 case POWER_SUPPLY_PROP_CHARGE_COUNTER
:
416 ret
= ds2780_get_accumulated_current(dev_info
, &val
->intval
);
419 case POWER_SUPPLY_PROP_CHARGE_NOW
:
420 ret
= ds2780_get_charge_now(dev_info
, &val
->intval
);
430 static enum power_supply_property ds2780_battery_props
[] = {
431 POWER_SUPPLY_PROP_STATUS
,
432 POWER_SUPPLY_PROP_VOLTAGE_NOW
,
433 POWER_SUPPLY_PROP_TEMP
,
434 POWER_SUPPLY_PROP_MODEL_NAME
,
435 POWER_SUPPLY_PROP_MANUFACTURER
,
436 POWER_SUPPLY_PROP_CURRENT_NOW
,
437 POWER_SUPPLY_PROP_CURRENT_AVG
,
438 POWER_SUPPLY_PROP_CAPACITY
,
439 POWER_SUPPLY_PROP_CHARGE_COUNTER
,
440 POWER_SUPPLY_PROP_CHARGE_NOW
,
443 static ssize_t
ds2780_get_pmod_enabled(struct device
*dev
,
444 struct device_attribute
*attr
,
449 struct power_supply
*psy
= to_power_supply(dev
);
450 struct ds2780_device_info
*dev_info
= to_ds2780_device_info(psy
);
453 ret
= ds2780_get_control_register(dev_info
, &control_reg
);
457 return sprintf(buf
, "%d\n",
458 !!(control_reg
& DS2780_CONTROL_REG_PMOD
));
461 static ssize_t
ds2780_set_pmod_enabled(struct device
*dev
,
462 struct device_attribute
*attr
,
467 u8 control_reg
, new_setting
;
468 struct power_supply
*psy
= to_power_supply(dev
);
469 struct ds2780_device_info
*dev_info
= to_ds2780_device_info(psy
);
472 ret
= ds2780_get_control_register(dev_info
, &control_reg
);
476 ret
= kstrtou8(buf
, 0, &new_setting
);
480 if ((new_setting
!= 0) && (new_setting
!= 1)) {
481 dev_err(dev_info
->dev
, "Invalid pmod setting (0 or 1)\n");
486 control_reg
|= DS2780_CONTROL_REG_PMOD
;
488 control_reg
&= ~DS2780_CONTROL_REG_PMOD
;
490 ret
= ds2780_set_control_register(dev_info
, control_reg
);
497 static ssize_t
ds2780_get_sense_resistor_value(struct device
*dev
,
498 struct device_attribute
*attr
,
503 struct power_supply
*psy
= to_power_supply(dev
);
504 struct ds2780_device_info
*dev_info
= to_ds2780_device_info(psy
);
506 ret
= ds2780_read8(dev_info
, &sense_resistor
, DS2780_RSNSP_REG
);
510 ret
= sprintf(buf
, "%d\n", sense_resistor
);
514 static ssize_t
ds2780_set_sense_resistor_value(struct device
*dev
,
515 struct device_attribute
*attr
,
521 struct power_supply
*psy
= to_power_supply(dev
);
522 struct ds2780_device_info
*dev_info
= to_ds2780_device_info(psy
);
524 ret
= kstrtou8(buf
, 0, &new_setting
);
528 ret
= ds2780_set_sense_register(dev_info
, new_setting
);
535 static ssize_t
ds2780_get_rsgain_setting(struct device
*dev
,
536 struct device_attribute
*attr
,
541 struct power_supply
*psy
= to_power_supply(dev
);
542 struct ds2780_device_info
*dev_info
= to_ds2780_device_info(psy
);
544 ret
= ds2780_get_rsgain_register(dev_info
, &rsgain
);
548 return sprintf(buf
, "%d\n", rsgain
);
551 static ssize_t
ds2780_set_rsgain_setting(struct device
*dev
,
552 struct device_attribute
*attr
,
558 struct power_supply
*psy
= to_power_supply(dev
);
559 struct ds2780_device_info
*dev_info
= to_ds2780_device_info(psy
);
561 ret
= kstrtou16(buf
, 0, &new_setting
);
565 /* Gain can only be from 0 to 1.999 in steps of .001 */
566 if (new_setting
> 1999) {
567 dev_err(dev_info
->dev
, "Invalid rsgain setting (0 - 1999)\n");
571 ret
= ds2780_set_rsgain_register(dev_info
, new_setting
);
578 static ssize_t
ds2780_get_pio_pin(struct device
*dev
,
579 struct device_attribute
*attr
,
584 struct power_supply
*psy
= to_power_supply(dev
);
585 struct ds2780_device_info
*dev_info
= to_ds2780_device_info(psy
);
587 ret
= ds2780_read8(dev_info
, &sfr
, DS2780_SFR_REG
);
591 ret
= sprintf(buf
, "%d\n", sfr
& DS2780_SFR_REG_PIOSC
);
595 static ssize_t
ds2780_set_pio_pin(struct device
*dev
,
596 struct device_attribute
*attr
,
602 struct power_supply
*psy
= to_power_supply(dev
);
603 struct ds2780_device_info
*dev_info
= to_ds2780_device_info(psy
);
605 ret
= kstrtou8(buf
, 0, &new_setting
);
609 if ((new_setting
!= 0) && (new_setting
!= 1)) {
610 dev_err(dev_info
->dev
, "Invalid pio_pin setting (0 or 1)\n");
614 ret
= ds2780_write(dev_info
, &new_setting
,
615 DS2780_SFR_REG
, sizeof(u8
));
622 static ssize_t
ds2780_read_param_eeprom_bin(struct file
*filp
,
623 struct kobject
*kobj
,
624 struct bin_attribute
*bin_attr
,
625 char *buf
, loff_t off
, size_t count
)
627 struct device
*dev
= container_of(kobj
, struct device
, kobj
);
628 struct power_supply
*psy
= to_power_supply(dev
);
629 struct ds2780_device_info
*dev_info
= to_ds2780_device_info(psy
);
631 return ds2780_read_block(dev_info
, buf
,
632 DS2780_EEPROM_BLOCK1_START
+ off
, count
);
635 static ssize_t
ds2780_write_param_eeprom_bin(struct file
*filp
,
636 struct kobject
*kobj
,
637 struct bin_attribute
*bin_attr
,
638 char *buf
, loff_t off
, size_t count
)
640 struct device
*dev
= container_of(kobj
, struct device
, kobj
);
641 struct power_supply
*psy
= to_power_supply(dev
);
642 struct ds2780_device_info
*dev_info
= to_ds2780_device_info(psy
);
645 ret
= ds2780_write(dev_info
, buf
,
646 DS2780_EEPROM_BLOCK1_START
+ off
, count
);
650 ret
= ds2780_save_eeprom(dev_info
, DS2780_EEPROM_BLOCK1_START
);
657 static struct bin_attribute ds2780_param_eeprom_bin_attr
= {
659 .name
= "param_eeprom",
660 .mode
= S_IRUGO
| S_IWUSR
,
662 .size
= DS2780_PARAM_EEPROM_SIZE
,
663 .read
= ds2780_read_param_eeprom_bin
,
664 .write
= ds2780_write_param_eeprom_bin
,
667 static ssize_t
ds2780_read_user_eeprom_bin(struct file
*filp
,
668 struct kobject
*kobj
,
669 struct bin_attribute
*bin_attr
,
670 char *buf
, loff_t off
, size_t count
)
672 struct device
*dev
= container_of(kobj
, struct device
, kobj
);
673 struct power_supply
*psy
= to_power_supply(dev
);
674 struct ds2780_device_info
*dev_info
= to_ds2780_device_info(psy
);
676 return ds2780_read_block(dev_info
, buf
,
677 DS2780_EEPROM_BLOCK0_START
+ off
, count
);
680 static ssize_t
ds2780_write_user_eeprom_bin(struct file
*filp
,
681 struct kobject
*kobj
,
682 struct bin_attribute
*bin_attr
,
683 char *buf
, loff_t off
, size_t count
)
685 struct device
*dev
= container_of(kobj
, struct device
, kobj
);
686 struct power_supply
*psy
= to_power_supply(dev
);
687 struct ds2780_device_info
*dev_info
= to_ds2780_device_info(psy
);
690 ret
= ds2780_write(dev_info
, buf
,
691 DS2780_EEPROM_BLOCK0_START
+ off
, count
);
695 ret
= ds2780_save_eeprom(dev_info
, DS2780_EEPROM_BLOCK0_START
);
702 static struct bin_attribute ds2780_user_eeprom_bin_attr
= {
704 .name
= "user_eeprom",
705 .mode
= S_IRUGO
| S_IWUSR
,
707 .size
= DS2780_USER_EEPROM_SIZE
,
708 .read
= ds2780_read_user_eeprom_bin
,
709 .write
= ds2780_write_user_eeprom_bin
,
712 static DEVICE_ATTR(pmod_enabled
, S_IRUGO
| S_IWUSR
, ds2780_get_pmod_enabled
,
713 ds2780_set_pmod_enabled
);
714 static DEVICE_ATTR(sense_resistor_value
, S_IRUGO
| S_IWUSR
,
715 ds2780_get_sense_resistor_value
, ds2780_set_sense_resistor_value
);
716 static DEVICE_ATTR(rsgain_setting
, S_IRUGO
| S_IWUSR
, ds2780_get_rsgain_setting
,
717 ds2780_set_rsgain_setting
);
718 static DEVICE_ATTR(pio_pin
, S_IRUGO
| S_IWUSR
, ds2780_get_pio_pin
,
721 static struct attribute
*ds2780_sysfs_attrs
[] = {
722 &dev_attr_pmod_enabled
.attr
,
723 &dev_attr_sense_resistor_value
.attr
,
724 &dev_attr_rsgain_setting
.attr
,
725 &dev_attr_pio_pin
.attr
,
729 static struct bin_attribute
*ds2780_sysfs_bin_attrs
[] = {
730 &ds2780_param_eeprom_bin_attr
,
731 &ds2780_user_eeprom_bin_attr
,
735 static const struct attribute_group ds2780_sysfs_group
= {
736 .attrs
= ds2780_sysfs_attrs
,
737 .bin_attrs
= ds2780_sysfs_bin_attrs
,
740 static const struct attribute_group
*ds2780_sysfs_groups
[] = {
745 static int ds2780_battery_probe(struct platform_device
*pdev
)
747 struct power_supply_config psy_cfg
= {};
748 struct ds2780_device_info
*dev_info
;
750 dev_info
= devm_kzalloc(&pdev
->dev
, sizeof(*dev_info
), GFP_KERNEL
);
754 platform_set_drvdata(pdev
, dev_info
);
756 dev_info
->dev
= &pdev
->dev
;
757 dev_info
->w1_dev
= pdev
->dev
.parent
;
758 dev_info
->bat_desc
.name
= dev_name(&pdev
->dev
);
759 dev_info
->bat_desc
.type
= POWER_SUPPLY_TYPE_BATTERY
;
760 dev_info
->bat_desc
.properties
= ds2780_battery_props
;
761 dev_info
->bat_desc
.num_properties
= ARRAY_SIZE(ds2780_battery_props
);
762 dev_info
->bat_desc
.get_property
= ds2780_battery_get_property
;
764 psy_cfg
.drv_data
= dev_info
;
765 psy_cfg
.attr_grp
= ds2780_sysfs_groups
;
767 dev_info
->bat
= devm_power_supply_register(&pdev
->dev
,
770 if (IS_ERR(dev_info
->bat
)) {
771 dev_err(dev_info
->dev
, "failed to register battery\n");
772 return PTR_ERR(dev_info
->bat
);
778 static struct platform_driver ds2780_battery_driver
= {
780 .name
= "ds2780-battery",
782 .probe
= ds2780_battery_probe
,
785 module_platform_driver(ds2780_battery_driver
);
787 MODULE_LICENSE("GPL");
788 MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>");
789 MODULE_DESCRIPTION("Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC driver");
790 MODULE_ALIAS("platform:ds2780-battery");