diff options
Diffstat (limited to 'drivers/power/supply/max1721x_battery.c')
| -rw-r--r-- | drivers/power/supply/max1721x_battery.c | 448 |
1 files changed, 448 insertions, 0 deletions
diff --git a/drivers/power/supply/max1721x_battery.c b/drivers/power/supply/max1721x_battery.c new file mode 100644 index 0000000000..bac43ab9e9 --- /dev/null +++ b/drivers/power/supply/max1721x_battery.c @@ -0,0 +1,448 @@ +/* + * 1-Wire implementation for Maxim Semiconductor + * MAX7211/MAX17215 standalone fuel gauge chip + * + * Copyright (C) 2017 Radioavionica Corporation + * Author: Alex A. Mihaylov <minimumlaw@rambler.ru> + * + * Use consistent with the GNU GPL is permitted, + * provided that this copyright notice is + * preserved in its entirety in all copies and derived works. + * + */ + +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/w1.h> +#include <linux/regmap.h> +#include <linux/power_supply.h> + +#define W1_MAX1721X_FAMILY_ID 0x26 +#define DEF_DEV_NAME_MAX17211 "MAX17211" +#define DEF_DEV_NAME_MAX17215 "MAX17215" +#define DEF_DEV_NAME_UNKNOWN "UNKNOWN" +#define DEF_MFG_NAME "MAXIM" + +#define PSY_MAX_NAME_LEN 32 + +/* Number of valid register addresses in W1 mode */ +#define MAX1721X_MAX_REG_NR 0x1EF + +/* Factory settings (nonvolatile registers) (W1 specific) */ +#define MAX1721X_REG_NRSENSE 0x1CF /* RSense in 10^-5 Ohm */ +/* Strings */ +#define MAX1721X_REG_MFG_STR 0x1CC +#define MAX1721X_REG_MFG_NUMB 3 +#define MAX1721X_REG_DEV_STR 0x1DB +#define MAX1721X_REG_DEV_NUMB 5 +/* HEX Strings */ +#define MAX1721X_REG_SER_HEX 0x1D8 + +/* MAX172XX Output Registers for W1 chips */ +#define MAX172XX_REG_STATUS 0x000 /* status reg */ +#define MAX172XX_BAT_PRESENT (1<<4) /* battery connected bit */ +#define MAX172XX_REG_DEVNAME 0x021 /* chip config */ +#define MAX172XX_DEV_MASK 0x000F /* chip type mask */ +#define MAX172X1_DEV 0x0001 +#define MAX172X5_DEV 0x0005 +#define MAX172XX_REG_TEMP 0x008 /* Temperature */ +#define MAX172XX_REG_BATT 0x0DA /* Battery voltage */ +#define MAX172XX_REG_CURRENT 0x00A /* Actual current */ +#define MAX172XX_REG_AVGCURRENT 0x00B /* Average current */ +#define MAX172XX_REG_REPSOC 0x006 /* Percentage of charge */ +#define MAX172XX_REG_DESIGNCAP 0x018 /* Design capacity */ +#define MAX172XX_REG_REPCAP 0x005 /* Average capacity */ +#define MAX172XX_REG_TTE 0x011 /* Time to empty */ +#define MAX172XX_REG_TTF 0x020 /* Time to full */ + +struct max17211_device_info { + char name[PSY_MAX_NAME_LEN]; + struct power_supply *bat; + struct power_supply_desc bat_desc; + struct device *w1_dev; + struct regmap *regmap; + /* battery design format */ + unsigned int rsense; /* in tenths uOhm */ + char DeviceName[2 * MAX1721X_REG_DEV_NUMB + 1]; + char ManufacturerName[2 * MAX1721X_REG_MFG_NUMB + 1]; + char SerialNumber[13]; /* see get_sn_str() later for comment */ +}; + +/* Convert regs value to power_supply units */ + +static inline int max172xx_time_to_ps(unsigned int reg) +{ + return reg * 5625 / 1000; /* in sec. */ +} + +static inline int max172xx_percent_to_ps(unsigned int reg) +{ + return reg / 256; /* in percent from 0 to 100 */ +} + +static inline int max172xx_voltage_to_ps(unsigned int reg) +{ + return reg * 1250; /* in uV */ +} + +static inline int max172xx_capacity_to_ps(unsigned int reg) +{ + return reg * 500; /* in uAh */ +} + +/* + * Current and temperature is signed values, so unsigned regs + * value must be converted to signed type + */ + +static inline int max172xx_temperature_to_ps(unsigned int reg) +{ + int val = (int16_t)(reg); + + return val * 10 / 256; /* in tenths of deg. C */ +} + +/* + * Calculating current registers resolution: + * + * RSense stored in 10^-5 Ohm, so measurement voltage must be + * in 10^-11 Volts for get current in uA. + * 16 bit current reg fullscale +/-51.2mV is 102400 uV. + * So: 102400 / 65535 * 10^5 = 156252 + */ +static inline int max172xx_current_to_voltage(unsigned int reg) +{ + int val = (int16_t)(reg); + + return val * 156252; +} + + +static inline struct max17211_device_info * +to_device_info(struct power_supply *psy) +{ + return power_supply_get_drvdata(psy); +} + +static int max1721x_battery_get_property(struct power_supply *psy, + enum power_supply_property psp, + union power_supply_propval *val) +{ + struct max17211_device_info *info = to_device_info(psy); + unsigned int reg = 0; + int ret = 0; + + switch (psp) { + case POWER_SUPPLY_PROP_PRESENT: + /* + * POWER_SUPPLY_PROP_PRESENT will always readable via + * sysfs interface. Value return 0 if battery not + * present or unaccessible via W1. + */ + val->intval = + regmap_read(info->regmap, MAX172XX_REG_STATUS, + ®) ? 0 : !(reg & MAX172XX_BAT_PRESENT); + break; + case POWER_SUPPLY_PROP_CAPACITY: + ret = regmap_read(info->regmap, MAX172XX_REG_REPSOC, ®); + val->intval = max172xx_percent_to_ps(reg); + break; + case POWER_SUPPLY_PROP_VOLTAGE_NOW: + ret = regmap_read(info->regmap, MAX172XX_REG_BATT, ®); + val->intval = max172xx_voltage_to_ps(reg); + break; + case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN: + ret = regmap_read(info->regmap, MAX172XX_REG_DESIGNCAP, ®); + val->intval = max172xx_capacity_to_ps(reg); + break; + case POWER_SUPPLY_PROP_CHARGE_AVG: + ret = regmap_read(info->regmap, MAX172XX_REG_REPCAP, ®); + val->intval = max172xx_capacity_to_ps(reg); + break; + case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG: + ret = regmap_read(info->regmap, MAX172XX_REG_TTE, ®); + val->intval = max172xx_time_to_ps(reg); + break; + case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG: + ret = regmap_read(info->regmap, MAX172XX_REG_TTF, ®); + val->intval = max172xx_time_to_ps(reg); + break; + case POWER_SUPPLY_PROP_TEMP: + ret = regmap_read(info->regmap, MAX172XX_REG_TEMP, ®); + val->intval = max172xx_temperature_to_ps(reg); + break; + /* We need signed current, so must cast info->rsense to signed type */ + case POWER_SUPPLY_PROP_CURRENT_NOW: + ret = regmap_read(info->regmap, MAX172XX_REG_CURRENT, ®); + val->intval = + max172xx_current_to_voltage(reg) / (int)info->rsense; + break; + case POWER_SUPPLY_PROP_CURRENT_AVG: + ret = regmap_read(info->regmap, MAX172XX_REG_AVGCURRENT, ®); + val->intval = + max172xx_current_to_voltage(reg) / (int)info->rsense; + break; + /* + * Strings already received and inited by probe. + * We do dummy read for check battery still available. + */ + case POWER_SUPPLY_PROP_MODEL_NAME: + ret = regmap_read(info->regmap, MAX1721X_REG_DEV_STR, ®); + val->strval = info->DeviceName; + break; + case POWER_SUPPLY_PROP_MANUFACTURER: + ret = regmap_read(info->regmap, MAX1721X_REG_MFG_STR, ®); + val->strval = info->ManufacturerName; + break; + case POWER_SUPPLY_PROP_SERIAL_NUMBER: + ret = regmap_read(info->regmap, MAX1721X_REG_SER_HEX, ®); + val->strval = info->SerialNumber; + break; + default: + ret = -EINVAL; + } + + return ret; +} + +static enum power_supply_property max1721x_battery_props[] = { + /* int */ + POWER_SUPPLY_PROP_PRESENT, + POWER_SUPPLY_PROP_CAPACITY, + POWER_SUPPLY_PROP_VOLTAGE_NOW, + POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN, + POWER_SUPPLY_PROP_CHARGE_AVG, + POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG, + POWER_SUPPLY_PROP_TIME_TO_FULL_AVG, + POWER_SUPPLY_PROP_TEMP, + POWER_SUPPLY_PROP_CURRENT_NOW, + POWER_SUPPLY_PROP_CURRENT_AVG, + /* strings */ + POWER_SUPPLY_PROP_MODEL_NAME, + POWER_SUPPLY_PROP_MANUFACTURER, + POWER_SUPPLY_PROP_SERIAL_NUMBER, +}; + +static int get_string(struct max17211_device_info *info, + uint16_t reg, uint8_t nr, char *str) +{ + unsigned int val; + + if (!str || !(reg == MAX1721X_REG_MFG_STR || + reg == MAX1721X_REG_DEV_STR)) + return -EFAULT; + + while (nr--) { + if (regmap_read(info->regmap, reg++, &val)) + return -EFAULT; + *str++ = val>>8 & 0x00FF; + *str++ = val & 0x00FF; + } + return 0; +} + +/* Maxim say: Serial number is a hex string up to 12 hex characters */ +static int get_sn_string(struct max17211_device_info *info, char *str) +{ + unsigned int val[3]; + + if (!str) + return -EFAULT; + + if (regmap_read(info->regmap, MAX1721X_REG_SER_HEX, &val[0])) + return -EFAULT; + if (regmap_read(info->regmap, MAX1721X_REG_SER_HEX + 1, &val[1])) + return -EFAULT; + if (regmap_read(info->regmap, MAX1721X_REG_SER_HEX + 2, &val[2])) + return -EFAULT; + + snprintf(str, 13, "%04X%04X%04X", val[0], val[1], val[2]); + return 0; +} + +/* + * MAX1721x registers description for w1-regmap + */ +static const struct regmap_range max1721x_allow_range[] = { + regmap_reg_range(0, 0xDF), /* volatile data */ + regmap_reg_range(0x180, 0x1DF), /* non-volatile memory */ + regmap_reg_range(0x1E0, 0x1EF), /* non-volatile history (unused) */ +}; + +static const struct regmap_range max1721x_deny_range[] = { + /* volatile data unused registers */ + regmap_reg_range(0x24, 0x26), + regmap_reg_range(0x30, 0x31), + regmap_reg_range(0x33, 0x34), + regmap_reg_range(0x37, 0x37), + regmap_reg_range(0x3B, 0x3C), + regmap_reg_range(0x40, 0x41), + regmap_reg_range(0x43, 0x44), + regmap_reg_range(0x47, 0x49), + regmap_reg_range(0x4B, 0x4C), + regmap_reg_range(0x4E, 0xAF), + regmap_reg_range(0xB1, 0xB3), + regmap_reg_range(0xB5, 0xB7), + regmap_reg_range(0xBF, 0xD0), + regmap_reg_range(0xDB, 0xDB), + /* hole between volatile and non-volatile registers */ + regmap_reg_range(0xE0, 0x17F), +}; + +static const struct regmap_access_table max1721x_regs = { + .yes_ranges = max1721x_allow_range, + .n_yes_ranges = ARRAY_SIZE(max1721x_allow_range), + .no_ranges = max1721x_deny_range, + .n_no_ranges = ARRAY_SIZE(max1721x_deny_range), +}; + +/* + * Model Gauge M5 Algorithm output register + * Volatile data (must not be cached) + */ +static const struct regmap_range max1721x_volatile_allow[] = { + regmap_reg_range(0, 0xDF), +}; + +static const struct regmap_access_table max1721x_volatile_regs = { + .yes_ranges = max1721x_volatile_allow, + .n_yes_ranges = ARRAY_SIZE(max1721x_volatile_allow), +}; + +/* + * W1-regmap config + */ +static const struct regmap_config max1721x_regmap_w1_config = { + .reg_bits = 16, + .val_bits = 16, + .rd_table = &max1721x_regs, + .volatile_table = &max1721x_volatile_regs, + .max_register = MAX1721X_MAX_REG_NR, +}; + +static int devm_w1_max1721x_add_device(struct w1_slave *sl) +{ + struct power_supply_config psy_cfg = {}; + struct max17211_device_info *info; + + info = devm_kzalloc(&sl->dev, sizeof(*info), GFP_KERNEL); + if (!info) + return -ENOMEM; + + sl->family_data = (void *)info; + info->w1_dev = &sl->dev; + + /* + * power_supply class battery name translated from W1 slave device + * unique ID (look like 26-0123456789AB) to "max1721x-0123456789AB\0" + * so, 26 (device family) correspond to max1721x devices. + * Device name still unique for any number of connected devices. + */ + snprintf(info->name, sizeof(info->name), + "max1721x-%012X", (unsigned int)sl->reg_num.id); + info->bat_desc.name = info->name; + + /* + * FixMe: battery device name exceed max len for thermal_zone device + * name and translation to thermal_zone must be disabled. + */ + info->bat_desc.no_thermal = true; + info->bat_desc.type = POWER_SUPPLY_TYPE_BATTERY; + info->bat_desc.properties = max1721x_battery_props; + info->bat_desc.num_properties = ARRAY_SIZE(max1721x_battery_props); + info->bat_desc.get_property = max1721x_battery_get_property; + psy_cfg.drv_data = info; + + /* regmap init */ + info->regmap = devm_regmap_init_w1(info->w1_dev, + &max1721x_regmap_w1_config); + if (IS_ERR(info->regmap)) { + int err = PTR_ERR(info->regmap); + + dev_err(info->w1_dev, "Failed to allocate register map: %d\n", + err); + return err; + } + + /* rsense init */ + info->rsense = 0; + if (regmap_read(info->regmap, MAX1721X_REG_NRSENSE, &info->rsense)) { + dev_err(info->w1_dev, "Can't read RSense. Hardware error.\n"); + return -ENODEV; + } + + if (!info->rsense) { + dev_warn(info->w1_dev, "RSense not calibrated, set 10 mOhms!\n"); + info->rsense = 1000; /* in regs in 10^-5 */ + } + dev_info(info->w1_dev, "RSense: %d mOhms.\n", info->rsense / 100); + + if (get_string(info, MAX1721X_REG_MFG_STR, + MAX1721X_REG_MFG_NUMB, info->ManufacturerName)) { + dev_err(info->w1_dev, "Can't read manufacturer. Hardware error.\n"); + return -ENODEV; + } + + if (!info->ManufacturerName[0]) + strscpy(info->ManufacturerName, DEF_MFG_NAME, + 2 * MAX1721X_REG_MFG_NUMB); + + if (get_string(info, MAX1721X_REG_DEV_STR, + MAX1721X_REG_DEV_NUMB, info->DeviceName)) { + dev_err(info->w1_dev, "Can't read device. Hardware error.\n"); + return -ENODEV; + } + if (!info->DeviceName[0]) { + unsigned int dev_name; + + if (regmap_read(info->regmap, + MAX172XX_REG_DEVNAME, &dev_name)) { + dev_err(info->w1_dev, "Can't read device name reg.\n"); + return -ENODEV; + } + + switch (dev_name & MAX172XX_DEV_MASK) { + case MAX172X1_DEV: + strscpy(info->DeviceName, DEF_DEV_NAME_MAX17211, + 2 * MAX1721X_REG_DEV_NUMB); + break; + case MAX172X5_DEV: + strscpy(info->DeviceName, DEF_DEV_NAME_MAX17215, + 2 * MAX1721X_REG_DEV_NUMB); + break; + default: + strscpy(info->DeviceName, DEF_DEV_NAME_UNKNOWN, + 2 * MAX1721X_REG_DEV_NUMB); + } + } + + if (get_sn_string(info, info->SerialNumber)) { + dev_err(info->w1_dev, "Can't read serial. Hardware error.\n"); + return -ENODEV; + } + + info->bat = devm_power_supply_register(&sl->dev, &info->bat_desc, + &psy_cfg); + if (IS_ERR(info->bat)) { + dev_err(info->w1_dev, "failed to register battery\n"); + return PTR_ERR(info->bat); + } + + return 0; +} + +static const struct w1_family_ops w1_max1721x_fops = { + .add_slave = devm_w1_max1721x_add_device, +}; + +static struct w1_family w1_max1721x_family = { + .fid = W1_MAX1721X_FAMILY_ID, + .fops = &w1_max1721x_fops, +}; + +module_w1_family(w1_max1721x_family); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Alex A. Mihaylov <minimumlaw@rambler.ru>"); +MODULE_DESCRIPTION("Maxim MAX17211/MAX17215 Fuel Gauge IC driver"); +MODULE_ALIAS("w1-family-" __stringify(W1_MAX1721X_FAMILY_ID)); |