/*
* 1-Wire implementation for Maxim Semiconductor
* MAX7211/MAX17215 standalone fuel gauge chip
*
* Copyright (C) 2017 Radioavionica Corporation
* Author: Alex A. Mihaylov <[email protected]>
*
* 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 <[email protected]>");
MODULE_DESCRIPTION("Maxim MAX17211/MAX17215 Fuel Gauge IC driver");
MODULE_ALIAS("w1-family-" __stringify(W1_MAX1721X_FAMILY_ID));
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