/* * 1-wire client/driver for the Maxim/Dallas DS2781 Stand-Alone Fuel Gauge IC * * Author: Renata Sayakhova <renata@oktetlabs.ru> * * Based on ds2780_battery drivers * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * */ #include <linux/module.h> #include <linux/slab.h> #include <linux/param.h> #include <linux/pm.h> #include <linux/platform_device.h> #include <linux/power_supply.h> #include <linux/idr.h> #include <linux/w1.h> #include "../../w1/slaves/w1_ds2781.h" /* Current unit measurement in uA for a 1 milli-ohm sense resistor */ #define DS2781_CURRENT_UNITS 1563 /* Charge unit measurement in uAh for a 1 milli-ohm sense resistor */ #define DS2781_CHARGE_UNITS 6250 /* Number of bytes in user EEPROM space */ #define DS2781_USER_EEPROM_SIZE (DS2781_EEPROM_BLOCK0_END - \ DS2781_EEPROM_BLOCK0_START + 1) /* Number of bytes in parameter EEPROM space */ #define DS2781_PARAM_EEPROM_SIZE (DS2781_EEPROM_BLOCK1_END - \ DS2781_EEPROM_BLOCK1_START + 1) struct ds2781_device_info { struct device *dev; struct power_supply *bat; struct power_supply_desc bat_desc; struct device *w1_dev; }; enum current_types { CURRENT_NOW, CURRENT_AVG, }; static const char model[] = "DS2781"; static const char manufacturer[] = "Maxim/Dallas"; static inline struct ds2781_device_info * to_ds2781_device_info(struct power_supply *psy) { return power_supply_get_drvdata(psy); } static inline struct power_supply *to_power_supply(struct device *dev) { return dev_get_drvdata(dev); } static inline int ds2781_battery_io(struct ds2781_device_info *dev_info, char *buf, int addr, size_t count, int io) { return w1_ds2781_io(dev_info->w1_dev, buf, addr, count, io); } static int w1_ds2781_read(struct ds2781_device_info *dev_info, char *buf, int addr, size_t count) { return ds2781_battery_io(dev_info, buf, addr, count, 0); } static inline int ds2781_read8(struct ds2781_device_info *dev_info, u8 *val, int addr) { return ds2781_battery_io(dev_info, val, addr, sizeof(u8), 0); } static int ds2781_read16(struct ds2781_device_info *dev_info, s16 *val, int addr) { int ret; u8 raw[2]; ret = ds2781_battery_io(dev_info, raw, addr, sizeof(raw), 0); if (ret < 0) return ret; *val = (raw[0] << 8) | raw[1]; return 0; } static inline int ds2781_read_block(struct ds2781_device_info *dev_info, u8 *val, int addr, size_t count) { return ds2781_battery_io(dev_info, val, addr, count, 0); } static inline int ds2781_write(struct ds2781_device_info *dev_info, u8 *val, int addr, size_t count) { return ds2781_battery_io(dev_info, val, addr, count, 1); } static inline int ds2781_store_eeprom(struct device *dev, int addr) { return w1_ds2781_eeprom_cmd(dev, addr, W1_DS2781_COPY_DATA); } static inline int ds2781_recall_eeprom(struct device *dev, int addr) { return w1_ds2781_eeprom_cmd(dev, addr, W1_DS2781_RECALL_DATA); } static int ds2781_save_eeprom(struct ds2781_device_info *dev_info, int reg) { int ret; ret = ds2781_store_eeprom(dev_info->w1_dev, reg); if (ret < 0) return ret; ret = ds2781_recall_eeprom(dev_info->w1_dev, reg); if (ret < 0) return ret; return 0; } /* Set sense resistor value in mhos */ static int ds2781_set_sense_register(struct ds2781_device_info *dev_info, u8 conductance) { int ret; ret = ds2781_write(dev_info, &conductance, DS2781_RSNSP, sizeof(u8)); if (ret < 0) return ret; return ds2781_save_eeprom(dev_info, DS2781_RSNSP); } /* Get RSGAIN value from 0 to 1.999 in steps of 0.001 */ static int ds2781_get_rsgain_register(struct ds2781_device_info *dev_info, u16 *rsgain) { return ds2781_read16(dev_info, rsgain, DS2781_RSGAIN_MSB); } /* Set RSGAIN value from 0 to 1.999 in steps of 0.001 */ static int ds2781_set_rsgain_register(struct ds2781_device_info *dev_info, u16 rsgain) { int ret; u8 raw[] = {rsgain >> 8, rsgain & 0xFF}; ret = ds2781_write(dev_info, raw, DS2781_RSGAIN_MSB, sizeof(raw)); if (ret < 0) return ret; return ds2781_save_eeprom(dev_info, DS2781_RSGAIN_MSB); } static int ds2781_get_voltage(struct ds2781_device_info *dev_info, int *voltage_uV) { int ret; char val[2]; int voltage_raw; ret = w1_ds2781_read(dev_info, val, DS2781_VOLT_MSB, 2 * sizeof(u8)); if (ret < 0) return ret; /* * The voltage value is located in 10 bits across the voltage MSB * and LSB registers in two's compliment form * Sign bit of the voltage value is in bit 7 of the voltage MSB register * Bits 9 - 3 of the voltage value are in bits 6 - 0 of the * voltage MSB register * Bits 2 - 0 of the voltage value are in bits 7 - 5 of the * voltage LSB register */ voltage_raw = (val[0] << 3) | (val[1] >> 5); /* DS2781 reports voltage in units of 9.76mV, but the battery class * reports in units of uV, so convert by multiplying by 9760. */ *voltage_uV = voltage_raw * 9760; return 0; } static int ds2781_get_temperature(struct ds2781_device_info *dev_info, int *temp) { int ret; char val[2]; int temp_raw; ret = w1_ds2781_read(dev_info, val, DS2781_TEMP_MSB, 2 * sizeof(u8)); if (ret < 0) return ret; /* * The temperature value is located in 10 bits across the temperature * MSB and LSB registers in two's compliment form * Sign bit of the temperature value is in bit 7 of the temperature * MSB register * Bits 9 - 3 of the temperature value are in bits 6 - 0 of the * temperature MSB register * Bits 2 - 0 of the temperature value are in bits 7 - 5 of the * temperature LSB register */ temp_raw = ((val[0]) << 3) | (val[1] >> 5); *temp = temp_raw + (temp_raw / 4); return 0; } static int ds2781_get_current(struct ds2781_device_info *dev_info, enum current_types type, int *current_uA) { int ret, sense_res; s16 current_raw; u8 sense_res_raw, reg_msb; /* * The units of measurement for current are dependent on the value of * the sense resistor. */ ret = ds2781_read8(dev_info, &sense_res_raw, DS2781_RSNSP); if (ret < 0) return ret; if (sense_res_raw == 0) { dev_err(dev_info->dev, "sense resistor value is 0\n"); return -EINVAL; } sense_res = 1000 / sense_res_raw; if (type == CURRENT_NOW) reg_msb = DS2781_CURRENT_MSB; else if (type == CURRENT_AVG) reg_msb = DS2781_IAVG_MSB; else return -EINVAL; /* * The current value is located in 16 bits across the current MSB * and LSB registers in two's compliment form * Sign bit of the current value is in bit 7 of the current MSB register * Bits 14 - 8 of the current value are in bits 6 - 0 of the current * MSB register * Bits 7 - 0 of the current value are in bits 7 - 0 of the current * LSB register */ ret = ds2781_read16(dev_info, ¤t_raw, reg_msb); if (ret < 0) return ret; *current_uA = current_raw * (DS2781_CURRENT_UNITS / sense_res); return 0; } static int ds2781_get_accumulated_current(struct ds2781_device_info *dev_info, int *accumulated_current) { int ret, sense_res; s16 current_raw; u8 sense_res_raw; /* * The units of measurement for accumulated current are dependent on * the value of the sense resistor. */ ret = ds2781_read8(dev_info, &sense_res_raw, DS2781_RSNSP); if (ret < 0) return ret; if (sense_res_raw == 0) { dev_err(dev_info->dev, "sense resistor value is 0\n"); return -EINVAL; } sense_res = 1000 / sense_res_raw; /* * The ACR value is located in 16 bits across the ACR MSB and * LSB registers * Bits 15 - 8 of the ACR value are in bits 7 - 0 of the ACR * MSB register * Bits 7 - 0 of the ACR value are in bits 7 - 0 of the ACR * LSB register */ ret = ds2781_read16(dev_info, ¤t_raw, DS2781_ACR_MSB); if (ret < 0) return ret; *accumulated_current = current_raw * (DS2781_CHARGE_UNITS / sense_res); return 0; } static int ds2781_get_capacity(struct ds2781_device_info *dev_info, int *capacity) { int ret; u8 raw; ret = ds2781_read8(dev_info, &raw, DS2781_RARC); if (ret < 0) return ret; *capacity = raw; return 0; } static int ds2781_get_status(struct ds2781_device_info *dev_info, int *status) { int ret, current_uA, capacity; ret = ds2781_get_current(dev_info, CURRENT_NOW, ¤t_uA); if (ret < 0) return ret; ret = ds2781_get_capacity(dev_info, &capacity); if (ret < 0) return ret; if (power_supply_am_i_supplied(dev_info->bat)) { if (capacity == 100) *status = POWER_SUPPLY_STATUS_FULL; else if (current_uA > 50000) *status = POWER_SUPPLY_STATUS_CHARGING; else *status = POWER_SUPPLY_STATUS_NOT_CHARGING; } else { *status = POWER_SUPPLY_STATUS_DISCHARGING; } return 0; } static int ds2781_get_charge_now(struct ds2781_device_info *dev_info, int *charge_now) { int ret; u16 charge_raw; /* * The RAAC value is located in 16 bits across the RAAC MSB and * LSB registers * Bits 15 - 8 of the RAAC value are in bits 7 - 0 of the RAAC * MSB register * Bits 7 - 0 of the RAAC value are in bits 7 - 0 of the RAAC * LSB register */ ret = ds2781_read16(dev_info, &charge_raw, DS2781_RAAC_MSB); if (ret < 0) return ret; *charge_now = charge_raw * 1600; return 0; } static int ds2781_get_control_register(struct ds2781_device_info *dev_info, u8 *control_reg) { return ds2781_read8(dev_info, control_reg, DS2781_CONTROL); } static int ds2781_set_control_register(struct ds2781_device_info *dev_info, u8 control_reg) { int ret; ret = ds2781_write(dev_info, &control_reg, DS2781_CONTROL, sizeof(u8)); if (ret < 0) return ret; return ds2781_save_eeprom(dev_info, DS2781_CONTROL); } static int ds2781_battery_get_property(struct power_supply *psy, enum power_supply_property psp, union power_supply_propval *val) { int ret = 0; struct ds2781_device_info *dev_info = to_ds2781_device_info(psy); switch (psp) { case POWER_SUPPLY_PROP_VOLTAGE_NOW: ret = ds2781_get_voltage(dev_info, &val->intval); break; case POWER_SUPPLY_PROP_TEMP: ret = ds2781_get_temperature(dev_info, &val->intval); break; case POWER_SUPPLY_PROP_MODEL_NAME: val->strval = model; break; case POWER_SUPPLY_PROP_MANUFACTURER: val->strval = manufacturer; break; case POWER_SUPPLY_PROP_CURRENT_NOW: ret = ds2781_get_current(dev_info, CURRENT_NOW, &val->intval); break; case POWER_SUPPLY_PROP_CURRENT_AVG: ret = ds2781_get_current(dev_info, CURRENT_AVG, &val->intval); break; case POWER_SUPPLY_PROP_STATUS: ret = ds2781_get_status(dev_info, &val->intval); break; case POWER_SUPPLY_PROP_CAPACITY: ret = ds2781_get_capacity(dev_info, &val->intval); break; case POWER_SUPPLY_PROP_CHARGE_COUNTER: ret = ds2781_get_accumulated_current(dev_info, &val->intval); break; case POWER_SUPPLY_PROP_CHARGE_NOW: ret = ds2781_get_charge_now(dev_info, &val->intval); break; default: ret = -EINVAL; } return ret; } static enum power_supply_property ds2781_battery_props[] = { POWER_SUPPLY_PROP_STATUS, POWER_SUPPLY_PROP_VOLTAGE_NOW, POWER_SUPPLY_PROP_TEMP, POWER_SUPPLY_PROP_MODEL_NAME, POWER_SUPPLY_PROP_MANUFACTURER, POWER_SUPPLY_PROP_CURRENT_NOW, POWER_SUPPLY_PROP_CURRENT_AVG, POWER_SUPPLY_PROP_CAPACITY, POWER_SUPPLY_PROP_CHARGE_COUNTER, POWER_SUPPLY_PROP_CHARGE_NOW, }; static ssize_t ds2781_get_pmod_enabled(struct device *dev, struct device_attribute *attr, char *buf) { int ret; u8 control_reg; struct power_supply *psy = to_power_supply(dev); struct ds2781_device_info *dev_info = to_ds2781_device_info(psy); /* Get power mode */ ret = ds2781_get_control_register(dev_info, &control_reg); if (ret < 0) return ret; return sprintf(buf, "%d\n", !!(control_reg & DS2781_CONTROL_PMOD)); } static ssize_t ds2781_set_pmod_enabled(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { int ret; u8 control_reg, new_setting; struct power_supply *psy = to_power_supply(dev); struct ds2781_device_info *dev_info = to_ds2781_device_info(psy); /* Set power mode */ ret = ds2781_get_control_register(dev_info, &control_reg); if (ret < 0) return ret; ret = kstrtou8(buf, 0, &new_setting); if (ret < 0) return ret; if ((new_setting != 0) && (new_setting != 1)) { dev_err(dev_info->dev, "Invalid pmod setting (0 or 1)\n"); return -EINVAL; } if (new_setting) control_reg |= DS2781_CONTROL_PMOD; else control_reg &= ~DS2781_CONTROL_PMOD; ret = ds2781_set_control_register(dev_info, control_reg); if (ret < 0) return ret; return count; } static ssize_t ds2781_get_sense_resistor_value(struct device *dev, struct device_attribute *attr, char *buf) { int ret; u8 sense_resistor; struct power_supply *psy = to_power_supply(dev); struct ds2781_device_info *dev_info = to_ds2781_device_info(psy); ret = ds2781_read8(dev_info, &sense_resistor, DS2781_RSNSP); if (ret < 0) return ret; ret = sprintf(buf, "%d\n", sense_resistor); return ret; } static ssize_t ds2781_set_sense_resistor_value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { int ret; u8 new_setting; struct power_supply *psy = to_power_supply(dev); struct ds2781_device_info *dev_info = to_ds2781_device_info(psy); ret = kstrtou8(buf, 0, &new_setting); if (ret < 0) return ret; ret = ds2781_set_sense_register(dev_info, new_setting); if (ret < 0) return ret; return count; } static ssize_t ds2781_get_rsgain_setting(struct device *dev, struct device_attribute *attr, char *buf) { int ret; u16 rsgain; struct power_supply *psy = to_power_supply(dev); struct ds2781_device_info *dev_info = to_ds2781_device_info(psy); ret = ds2781_get_rsgain_register(dev_info, &rsgain); if (ret < 0) return ret; return sprintf(buf, "%d\n", rsgain); } static ssize_t ds2781_set_rsgain_setting(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { int ret; u16 new_setting; struct power_supply *psy = to_power_supply(dev); struct ds2781_device_info *dev_info = to_ds2781_device_info(psy); ret = kstrtou16(buf, 0, &new_setting); if (ret < 0) return ret; /* Gain can only be from 0 to 1.999 in steps of .001 */ if (new_setting > 1999) { dev_err(dev_info->dev, "Invalid rsgain setting (0 - 1999)\n"); return -EINVAL; } ret = ds2781_set_rsgain_register(dev_info, new_setting); if (ret < 0) return ret; return count; } static ssize_t ds2781_get_pio_pin(struct device *dev, struct device_attribute *attr, char *buf) { int ret; u8 sfr; struct power_supply *psy = to_power_supply(dev); struct ds2781_device_info *dev_info = to_ds2781_device_info(psy); ret = ds2781_read8(dev_info, &sfr, DS2781_SFR); if (ret < 0) return ret; ret = sprintf(buf, "%d\n", sfr & DS2781_SFR_PIOSC); return ret; } static ssize_t ds2781_set_pio_pin(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { int ret; u8 new_setting; struct power_supply *psy = to_power_supply(dev); struct ds2781_device_info *dev_info = to_ds2781_device_info(psy); ret = kstrtou8(buf, 0, &new_setting); if (ret < 0) return ret; if ((new_setting != 0) && (new_setting != 1)) { dev_err(dev_info->dev, "Invalid pio_pin setting (0 or 1)\n"); return -EINVAL; } ret = ds2781_write(dev_info, &new_setting, DS2781_SFR, sizeof(u8)); if (ret < 0) return ret; return count; } static ssize_t ds2781_read_param_eeprom_bin(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) { struct device *dev = container_of(kobj, struct device, kobj); struct power_supply *psy = to_power_supply(dev); struct ds2781_device_info *dev_info = to_ds2781_device_info(psy); return ds2781_read_block(dev_info, buf, DS2781_EEPROM_BLOCK1_START + off, count); } static ssize_t ds2781_write_param_eeprom_bin(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) { struct device *dev = container_of(kobj, struct device, kobj); struct power_supply *psy = to_power_supply(dev); struct ds2781_device_info *dev_info = to_ds2781_device_info(psy); int ret; ret = ds2781_write(dev_info, buf, DS2781_EEPROM_BLOCK1_START + off, count); if (ret < 0) return ret; ret = ds2781_save_eeprom(dev_info, DS2781_EEPROM_BLOCK1_START); if (ret < 0) return ret; return count; } static const struct bin_attribute ds2781_param_eeprom_bin_attr = { .attr = { .name = "param_eeprom", .mode = S_IRUGO | S_IWUSR, }, .size = DS2781_PARAM_EEPROM_SIZE, .read = ds2781_read_param_eeprom_bin, .write = ds2781_write_param_eeprom_bin, }; static ssize_t ds2781_read_user_eeprom_bin(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) { struct device *dev = container_of(kobj, struct device, kobj); struct power_supply *psy = to_power_supply(dev); struct ds2781_device_info *dev_info = to_ds2781_device_info(psy); return ds2781_read_block(dev_info, buf, DS2781_EEPROM_BLOCK0_START + off, count); } static ssize_t ds2781_write_user_eeprom_bin(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) { struct device *dev = container_of(kobj, struct device, kobj); struct power_supply *psy = to_power_supply(dev); struct ds2781_device_info *dev_info = to_ds2781_device_info(psy); int ret; ret = ds2781_write(dev_info, buf, DS2781_EEPROM_BLOCK0_START + off, count); if (ret < 0) return ret; ret = ds2781_save_eeprom(dev_info, DS2781_EEPROM_BLOCK0_START); if (ret < 0) return ret; return count; } static const struct bin_attribute ds2781_user_eeprom_bin_attr = { .attr = { .name = "user_eeprom", .mode = S_IRUGO | S_IWUSR, }, .size = DS2781_USER_EEPROM_SIZE, .read = ds2781_read_user_eeprom_bin, .write = ds2781_write_user_eeprom_bin, }; static DEVICE_ATTR(pmod_enabled, S_IRUGO | S_IWUSR, ds2781_get_pmod_enabled, ds2781_set_pmod_enabled); static DEVICE_ATTR(sense_resistor_value, S_IRUGO | S_IWUSR, ds2781_get_sense_resistor_value, ds2781_set_sense_resistor_value); static DEVICE_ATTR(rsgain_setting, S_IRUGO | S_IWUSR, ds2781_get_rsgain_setting, ds2781_set_rsgain_setting); static DEVICE_ATTR(pio_pin, S_IRUGO | S_IWUSR, ds2781_get_pio_pin, ds2781_set_pio_pin); static struct attribute *ds2781_attributes[] = { &dev_attr_pmod_enabled.attr, &dev_attr_sense_resistor_value.attr, &dev_attr_rsgain_setting.attr, &dev_attr_pio_pin.attr, NULL }; static const struct attribute_group ds2781_attr_group = { .attrs = ds2781_attributes, }; static int ds2781_battery_probe(struct platform_device *pdev) { struct power_supply_config psy_cfg = {}; int ret = 0; struct ds2781_device_info *dev_info; dev_info = devm_kzalloc(&pdev->dev, sizeof(*dev_info), GFP_KERNEL); if (!dev_info) return -ENOMEM; platform_set_drvdata(pdev, dev_info); dev_info->dev = &pdev->dev; dev_info->w1_dev = pdev->dev.parent; dev_info->bat_desc.name = dev_name(&pdev->dev); dev_info->bat_desc.type = POWER_SUPPLY_TYPE_BATTERY; dev_info->bat_desc.properties = ds2781_battery_props; dev_info->bat_desc.num_properties = ARRAY_SIZE(ds2781_battery_props); dev_info->bat_desc.get_property = ds2781_battery_get_property; psy_cfg.drv_data = dev_info; dev_info->bat = power_supply_register(&pdev->dev, &dev_info->bat_desc, &psy_cfg); if (IS_ERR(dev_info->bat)) { dev_err(dev_info->dev, "failed to register battery\n"); ret = PTR_ERR(dev_info->bat); goto fail; } ret = sysfs_create_group(&dev_info->bat->dev.kobj, &ds2781_attr_group); if (ret) { dev_err(dev_info->dev, "failed to create sysfs group\n"); goto fail_unregister; } ret = sysfs_create_bin_file(&dev_info->bat->dev.kobj, &ds2781_param_eeprom_bin_attr); if (ret) { dev_err(dev_info->dev, "failed to create param eeprom bin file"); goto fail_remove_group; } ret = sysfs_create_bin_file(&dev_info->bat->dev.kobj, &ds2781_user_eeprom_bin_attr); if (ret) { dev_err(dev_info->dev, "failed to create user eeprom bin file"); goto fail_remove_bin_file; } return 0; fail_remove_bin_file: sysfs_remove_bin_file(&dev_info->bat->dev.kobj, &ds2781_param_eeprom_bin_attr); fail_remove_group: sysfs_remove_group(&dev_info->bat->dev.kobj, &ds2781_attr_group); fail_unregister: power_supply_unregister(dev_info->bat); fail: return ret; } static int ds2781_battery_remove(struct platform_device *pdev) { struct ds2781_device_info *dev_info = platform_get_drvdata(pdev); /* * Remove attributes before unregistering power supply * because 'bat' will be freed on power_supply_unregister() call. */ sysfs_remove_group(&dev_info->bat->dev.kobj, &ds2781_attr_group); power_supply_unregister(dev_info->bat); return 0; } static struct platform_driver ds2781_battery_driver = { .driver = { .name = "ds2781-battery", }, .probe = ds2781_battery_probe, .remove = ds2781_battery_remove, }; module_platform_driver(ds2781_battery_driver); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Renata Sayakhova <renata@oktetlabs.ru>"); MODULE_DESCRIPTION("Maxim/Dallas DS2781 Stand-Alone Fuel Gauage IC driver"); MODULE_ALIAS("platform:ds2781-battery");