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 complement 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 complement 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 complement 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 sysfs_emit(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 = sysfs_emit(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 sysfs_emit(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 = sysfs_emit(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 = kobj_to_dev(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 = kobj_to_dev(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 = kobj_to_dev(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 = kobj_to_dev(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");