// SPDX-License-Identifier: GPL-2.0
/*
* Fuel gauge driver for CellWise 2013 / 2015
*
* Copyright (C) 2012, RockChip
* Copyright (C) 2020, Tobias Schramm
*
* Authors: xuhuicong <xhc@rock-chips.com>
* Authors: Tobias Schramm <t.schramm@manjaro.org>
*/
#include <linux/bits.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/gfp.h>
#include <linux/gpio/consumer.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/power_supply.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/time.h>
#include <linux/workqueue.h>
#define CW2015_SIZE_BATINFO 64
#define CW2015_RESET_TRIES 5
#define CW2015_REG_VERSION 0x00
#define CW2015_REG_VCELL 0x02
#define CW2015_REG_SOC 0x04
#define CW2015_REG_RRT_ALERT 0x06
#define CW2015_REG_CONFIG 0x08
#define CW2015_REG_MODE 0x0A
#define CW2015_REG_BATINFO 0x10
#define CW2015_MODE_SLEEP_MASK GENMASK(7, 6)
#define CW2015_MODE_SLEEP (0x03 << 6)
#define CW2015_MODE_NORMAL (0x00 << 6)
#define CW2015_MODE_QUICK_START (0x03 << 4)
#define CW2015_MODE_RESTART (0x0f << 0)
#define CW2015_CONFIG_UPDATE_FLG (0x01 << 1)
#define CW2015_ATHD(x) ((x) << 3)
#define CW2015_MASK_ATHD GENMASK(7, 3)
#define CW2015_MASK_SOC GENMASK(12, 0)
/* reset gauge of no valid state of charge could be polled for 40s */
#define CW2015_BAT_SOC_ERROR_MS (40 * MSEC_PER_SEC)
/* reset gauge if state of charge stuck for half an hour during charging */
#define CW2015_BAT_CHARGING_STUCK_MS (1800 * MSEC_PER_SEC)
/* poll interval from CellWise GPL Android driver example */
#define CW2015_DEFAULT_POLL_INTERVAL_MS 8000
#define CW2015_AVERAGING_SAMPLES 3
struct cw_battery {
struct device *dev;
struct workqueue_struct *battery_workqueue;
struct delayed_work battery_delay_work;
struct regmap *regmap;
struct power_supply *rk_bat;
struct power_supply_battery_info battery;
u8 *bat_profile;
bool charger_attached;
bool battery_changed;
int soc;
int voltage_mv;
int status;
int time_to_empty;
int charge_count;
u32 poll_interval_ms;
u8 alert_level;
unsigned int read_errors;
unsigned int charge_stuck_cnt;
};
static int cw_read_word(struct cw_battery *cw_bat, u8 reg, u16 *val)
{
__be16 value;
int ret;
ret = regmap_bulk_read(cw_bat->regmap, reg, &value, sizeof(value));
if (ret)
return ret;
*val = be16_to_cpu(value);
return 0;
}
static int cw_update_profile(struct cw_battery *cw_bat)
{
int ret;
unsigned int reg_val;
u8 reset_val;
/* make sure gauge is not in sleep mode */
ret = regmap_read(cw_bat->regmap, CW2015_REG_MODE, ®_val);
if (ret)
return ret;
reset_val = reg_val;
if ((reg_val & CW2015_MODE_SLEEP_MASK) == CW2015_MODE_SLEEP) {
dev_err(cw_bat->dev,
"Gauge is in sleep mode, can't update battery info\n");
return -EINVAL;
}
/* write new battery info */
ret = regmap_raw_write(cw_bat->regmap, CW2015_REG_BATINFO,
cw_bat->bat_profile,
CW2015_SIZE_BATINFO);
if (ret)
return ret;
/* set config update flag */
reg_val |= CW2015_CONFIG_UPDATE_FLG;
reg_val &= ~CW2015_MASK_ATHD;
reg_val |= CW2015_ATHD(cw_bat->alert_level);
ret = regmap_write(cw_bat->regmap, CW2015_REG_CONFIG, reg_val);
if (ret)
return ret;
/* reset gauge to apply new battery profile */
reset_val &= ~CW2015_MODE_RESTART;
reg_val = reset_val | CW2015_MODE_RESTART;
ret = regmap_write(cw_bat->regmap, CW2015_REG_MODE, reg_val);
if (ret)
return ret;
/* wait for gauge to reset */
msleep(20);
/* clear reset flag */
ret = regmap_write(cw_bat->regmap, CW2015_REG_MODE, reset_val);
if (ret)
return ret;
/* wait for gauge to become ready */
ret = regmap_read_poll_timeout(cw_bat->regmap, CW2015_REG_SOC,
reg_val, reg_val <= 100,
10 * USEC_PER_MSEC, 10 * USEC_PER_SEC);
if (ret)
dev_err(cw_bat->dev,
"Gauge did not become ready after profile upload\n");
else
dev_dbg(cw_bat->dev, "Battery profile updated\n");
return ret;
}
static int cw_init(struct cw_battery *cw_bat)
{
int ret;
unsigned int reg_val = CW2015_MODE_SLEEP;
if ((reg_val & CW2015_MODE_SLEEP_MASK) == CW2015_MODE_SLEEP) {
reg_val = CW2015_MODE_NORMAL;
ret = regmap_write(cw_bat->regmap, CW2015_REG_MODE, reg_val);
if (ret)
return ret;
}
ret = regmap_read(cw_bat->regmap, CW2015_REG_CONFIG, ®_val);
if (ret)
return ret;
if ((reg_val & CW2015_MASK_ATHD) != CW2015_ATHD(cw_bat->alert_level)) {
dev_dbg(cw_bat->dev, "Setting new alert level\n");
reg_val &= ~CW2015_MASK_ATHD;
reg_val |= ~CW2015_ATHD(cw_bat->alert_level);
ret = regmap_write(cw_bat->regmap, CW2015_REG_CONFIG, reg_val);
if (ret)
return ret;
}
ret = regmap_read(cw_bat->regmap, CW2015_REG_CONFIG, ®_val);
if (ret)
return ret;
if (!(reg_val & CW2015_CONFIG_UPDATE_FLG)) {
dev_dbg(cw_bat->dev,
"Battery profile not present, uploading battery profile\n");
if (cw_bat->bat_profile) {
ret = cw_update_profile(cw_bat);
if (ret) {
dev_err(cw_bat->dev,
"Failed to upload battery profile\n");
return ret;
}
} else {
dev_warn(cw_bat->dev,
"No profile specified, continuing without profile\n");
}
} else if (cw_bat->bat_profile) {
u8 bat_info[CW2015_SIZE_BATINFO];
ret = regmap_raw_read(cw_bat->regmap, CW2015_REG_BATINFO,
bat_info, CW2015_SIZE_BATINFO);
if (ret) {
dev_err(cw_bat->dev,
"Failed to read stored battery profile\n");
return ret;
}
if (memcmp(bat_info, cw_bat->bat_profile, CW2015_SIZE_BATINFO)) {
dev_warn(cw_bat->dev, "Replacing stored battery profile\n");
ret = cw_update_profile(cw_bat);
if (ret)
return ret;
}
} else {
dev_warn(cw_bat->dev,
"Can't check current battery profile, no profile provided\n");
}
dev_dbg(cw_bat->dev, "Battery profile configured\n");
return 0;
}
static int cw_power_on_reset(struct cw_battery *cw_bat)
{
int ret;
unsigned char reset_val;
reset_val = CW2015_MODE_SLEEP;
ret = regmap_write(cw_bat->regmap, CW2015_REG_MODE, reset_val);
if (ret)
return ret;
/* wait for gauge to enter sleep */
msleep(20);
reset_val = CW2015_MODE_NORMAL;
ret = regmap_write(cw_bat->regmap, CW2015_REG_MODE, reset_val);
if (ret)
return ret;
ret = cw_init(cw_bat);
if (ret)
return ret;
return 0;
}
#define HYSTERESIS(current, previous, up, down) \
(((current) < (previous) + (up)) && ((current) > (previous) - (down)))
static int cw_get_soc(struct cw_battery *cw_bat)
{
unsigned int soc;
int ret;
ret = regmap_read(cw_bat->regmap, CW2015_REG_SOC, &soc);
if (ret)
return ret;
if (soc > 100) {
int max_error_cycles =
CW2015_BAT_SOC_ERROR_MS / cw_bat->poll_interval_ms;
dev_err(cw_bat->dev, "Invalid SoC %d%%\n", soc);
cw_bat->read_errors++;
if (cw_bat->read_errors > max_error_cycles) {
dev_warn(cw_bat->dev,
"Too many invalid SoC reports, resetting gauge\n");
cw_power_on_reset(cw_bat);
cw_bat->read_errors = 0;
}
return cw_bat->soc;
}
cw_bat->read_errors = 0;
/* Reset gauge if stuck while charging */
if (cw_bat->status == POWER_SUPPLY_STATUS_CHARGING && soc == cw_bat->soc) {
int max_stuck_cycles =
CW2015_BAT_CHARGING_STUCK_MS / cw_bat->poll_interval_ms;
cw_bat->charge_stuck_cnt++;
if (cw_bat->charge_stuck_cnt > max_stuck_cycles) {
dev_warn(cw_bat->dev,
"SoC stuck @%u%%, resetting gauge\n", soc);
cw_power_on_reset(cw_bat);
cw_bat->charge_stuck_cnt = 0;
}
} else {
cw_bat->charge_stuck_cnt = 0;
}
/* Ignore voltage dips during charge */
if (cw_bat->charger_attached && HYSTERESIS(soc, cw_bat->soc, 0, 3))
soc = cw_bat->soc;
/* Ignore voltage spikes during discharge */
if (!cw_bat->charger_attached && HYSTERESIS(soc, cw_bat->soc, 3, 0))
soc = cw_bat->soc;
return soc;
}
static int cw_get_voltage(struct cw_battery *cw_bat)
{
int ret, i, voltage_mv;
u16 reg_val;
u32 avg = 0;
for (i = 0; i < CW2015_AVERAGING_SAMPLES; i++) {
ret = cw_read_word(cw_bat, CW2015_REG_VCELL, ®_val);
if (ret)
return ret;
avg += reg_val;
}
avg /= CW2015_AVERAGING_SAMPLES;
/*
* 305 uV per ADC step
* Use 312 / 1024 as efficient approximation of 305 / 1000
* Negligible error of 0.1%
*/
voltage_mv = avg * 312 / 1024;
dev_dbg(cw_bat->dev, "Read voltage: %d mV, raw=0x%04x\n",
voltage_mv, reg_val);
return voltage_mv;
}
static int cw_get_time_to_empty(struct cw_battery *cw_bat)
{
int ret;
u16 value16;
ret = cw_read_word(cw_bat, CW2015_REG_RRT_ALERT, &value16);
if (ret)
return ret;
return value16 & CW2015_MASK_SOC;
}
static void cw_update_charge_status(struct cw_battery *cw_bat)
{
int ret;
ret = power_supply_am_i_supplied(cw_bat->rk_bat);
if (ret < 0) {
dev_warn(cw_bat->dev, "Failed to get supply state: %d\n", ret);
} else {
bool charger_attached;
charger_attached = !!ret;
if (cw_bat->charger_attached != charger_attached) {
cw_bat->battery_changed = true;
if (charger_attached)
cw_bat->charge_count++;
}
cw_bat->charger_attached = charger_attached;
}
}
static void cw_update_soc(struct cw_battery *cw_bat)
{
int soc;
soc = cw_get_soc(cw_bat);
if (soc < 0)
dev_err(cw_bat->dev, "Failed to get SoC from gauge: %d\n", soc);
else if (cw_bat->soc != soc) {
cw_bat->soc = soc;
cw_bat->battery_changed = true;
}
}
static void cw_update_voltage(struct cw_battery *cw_bat)
{
int voltage_mv;
voltage_mv = cw_get_voltage(cw_bat);
if (voltage_mv < 0)
dev_err(cw_bat->dev, "Failed to get voltage from gauge: %d\n",
voltage_mv);
else
cw_bat->voltage_mv = voltage_mv;
}
static void cw_update_status(struct cw_battery *cw_bat)
{
int status = POWER_SUPPLY_STATUS_DISCHARGING;
if (cw_bat->charger_attached) {
if (cw_bat->soc >= 100)
status = POWER_SUPPLY_STATUS_FULL;
else
status = POWER_SUPPLY_STATUS_CHARGING;
}
if (cw_bat->status != status)
cw_bat->battery_changed = true;
cw_bat->status = status;
}
static void cw_update_time_to_empty(struct cw_battery *cw_bat)
{
int time_to_empty;
time_to_empty = cw_get_time_to_empty(cw_bat);
if (time_to_empty < 0)
dev_err(cw_bat->dev, "Failed to get time to empty from gauge: %d\n",
time_to_empty);
else if (cw_bat->time_to_empty != time_to_empty) {
cw_bat->time_to_empty = time_to_empty;
cw_bat->battery_changed = true;
}
}
static void cw_bat_work(struct work_struct *work)
{
struct delayed_work *delay_work;
struct cw_battery *cw_bat;
int ret;
unsigned int reg_val;
delay_work = to_delayed_work(work);
cw_bat = container_of(delay_work, struct cw_battery, battery_delay_work);
ret = regmap_read(cw_bat->regmap, CW2015_REG_MODE, ®_val);
if (ret) {
dev_err(cw_bat->dev, "Failed to read mode from gauge: %d\n", ret);
} else {
if ((reg_val & CW2015_MODE_SLEEP_MASK) == CW2015_MODE_SLEEP) {
int i;
for (i = 0; i < CW2015_RESET_TRIES; i++) {
if (!cw_power_on_reset(cw_bat))
break;
}
}
cw_update_soc(cw_bat);
cw_update_voltage(cw_bat);
cw_update_charge_status(cw_bat);
cw_update_status(cw_bat);
cw_update_time_to_empty(cw_bat);
}
dev_dbg(cw_bat->dev, "charger_attached = %d\n", cw_bat->charger_attached);
dev_dbg(cw_bat->dev, "status = %d\n", cw_bat->status);
dev_dbg(cw_bat->dev, "soc = %d%%\n", cw_bat->soc);
dev_dbg(cw_bat->dev, "voltage = %dmV\n", cw_bat->voltage_mv);
if (cw_bat->battery_changed)
power_supply_changed(cw_bat->rk_bat);
cw_bat->battery_changed = false;
queue_delayed_work(cw_bat->battery_workqueue,
&cw_bat->battery_delay_work,
msecs_to_jiffies(cw_bat->poll_interval_ms));
}
static bool cw_battery_valid_time_to_empty(struct cw_battery *cw_bat)
{
return cw_bat->time_to_empty > 0 &&
cw_bat->time_to_empty < CW2015_MASK_SOC &&
cw_bat->status == POWER_SUPPLY_STATUS_DISCHARGING;
}
static int cw_battery_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct cw_battery *cw_bat;
cw_bat = power_supply_get_drvdata(psy);
switch (psp) {
case POWER_SUPPLY_PROP_CAPACITY:
val->intval = cw_bat->soc;
break;
case POWER_SUPPLY_PROP_STATUS:
val->intval = cw_bat->status;
break;
case POWER_SUPPLY_PROP_PRESENT:
val->intval = !!cw_bat->voltage_mv;
break;
case POWER_SUPPLY_PROP_VOLTAGE_NOW:
val->intval = cw_bat->voltage_mv * 1000;
break;
case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
if (cw_battery_valid_time_to_empty(cw_bat))
val->intval = cw_bat->time_to_empty;
else
val->intval = 0;
break;
case POWER_SUPPLY_PROP_TECHNOLOGY:
val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
break;
case POWER_SUPPLY_PROP_CHARGE_COUNTER:
val->intval = cw_bat->charge_count;
break;
case POWER_SUPPLY_PROP_CHARGE_FULL:
case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
if (cw_bat->battery.charge_full_design_uah > 0)
val->intval = cw_bat->battery.charge_full_design_uah;
else
val->intval = 0;
break;
case POWER_SUPPLY_PROP_CURRENT_NOW:
if (cw_battery_valid_time_to_empty(cw_bat) &&
cw_bat->battery.charge_full_design_uah > 0) {
/* calculate remaining capacity */
val->intval = cw_bat->battery.charge_full_design_uah;
val->intval = val->intval * cw_bat->soc / 100;
/* estimate current based on time to empty */
val->intval = 60 * val->intval / cw_bat->time_to_empty;
} else {
val->intval = 0;
}
break;
default:
break;
}
return 0;
}
static enum power_supply_property cw_battery_properties[] = {
POWER_SUPPLY_PROP_CAPACITY,
POWER_SUPPLY_PROP_STATUS,
POWER_SUPPLY_PROP_PRESENT,
POWER_SUPPLY_PROP_VOLTAGE_NOW,
POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
POWER_SUPPLY_PROP_TECHNOLOGY,
POWER_SUPPLY_PROP_CHARGE_COUNTER,
POWER_SUPPLY_PROP_CHARGE_FULL,
POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
POWER_SUPPLY_PROP_CURRENT_NOW,
};
static const struct power_supply_desc cw2015_bat_desc = {
.name = "cw2015-battery",
.type = POWER_SUPPLY_TYPE_BATTERY,
.properties = cw_battery_properties,
.num_properties = ARRAY_SIZE(cw_battery_properties),
.get_property = cw_battery_get_property,
};
static int cw2015_parse_properties(struct cw_battery *cw_bat)
{
struct device *dev = cw_bat->dev;
int length;
int ret;
length = device_property_count_u8(dev, "cellwise,battery-profile");
if (length < 0) {
dev_warn(cw_bat->dev,
"No battery-profile found, using current flash contents\n");
} else if (length != CW2015_SIZE_BATINFO) {
dev_err(cw_bat->dev, "battery-profile must be %d bytes\n",
CW2015_SIZE_BATINFO);
return -EINVAL;
} else {
cw_bat->bat_profile = devm_kzalloc(dev, length, GFP_KERNEL);
if (!cw_bat->bat_profile)
return -ENOMEM;
ret = device_property_read_u8_array(dev,
"cellwise,battery-profile",
cw_bat->bat_profile,
length);
if (ret)
return ret;
}
ret = device_property_read_u32(dev, "cellwise,monitor-interval-ms",
&cw_bat->poll_interval_ms);
if (ret) {
dev_dbg(cw_bat->dev, "Using default poll interval\n");
cw_bat->poll_interval_ms = CW2015_DEFAULT_POLL_INTERVAL_MS;
}
return 0;
}
static const struct regmap_range regmap_ranges_rd_yes[] = {
regmap_reg_range(CW2015_REG_VERSION, CW2015_REG_VERSION),
regmap_reg_range(CW2015_REG_VCELL, CW2015_REG_CONFIG),
regmap_reg_range(CW2015_REG_MODE, CW2015_REG_MODE),
regmap_reg_range(CW2015_REG_BATINFO,
CW2015_REG_BATINFO + CW2015_SIZE_BATINFO - 1),
};
static const struct regmap_access_table regmap_rd_table = {
.yes_ranges = regmap_ranges_rd_yes,
.n_yes_ranges = 4,
};
static const struct regmap_range regmap_ranges_wr_yes[] = {
regmap_reg_range(CW2015_REG_RRT_ALERT, CW2015_REG_CONFIG),
regmap_reg_range(CW2015_REG_MODE, CW2015_REG_MODE),
regmap_reg_range(CW2015_REG_BATINFO,
CW2015_REG_BATINFO + CW2015_SIZE_BATINFO - 1),
};
static const struct regmap_access_table regmap_wr_table = {
.yes_ranges = regmap_ranges_wr_yes,
.n_yes_ranges = 3,
};
static const struct regmap_range regmap_ranges_vol_yes[] = {
regmap_reg_range(CW2015_REG_VCELL, CW2015_REG_SOC + 1),
};
static const struct regmap_access_table regmap_vol_table = {
.yes_ranges = regmap_ranges_vol_yes,
.n_yes_ranges = 1,
};
static const struct regmap_config cw2015_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.rd_table = ®map_rd_table,
.wr_table = ®map_wr_table,
.volatile_table = ®map_vol_table,
.max_register = CW2015_REG_BATINFO + CW2015_SIZE_BATINFO - 1,
};
static int cw_bat_probe(struct i2c_client *client)
{
int ret;
struct cw_battery *cw_bat;
struct power_supply_config psy_cfg = { 0 };
cw_bat = devm_kzalloc(&client->dev, sizeof(*cw_bat), GFP_KERNEL);
if (!cw_bat)
return -ENOMEM;
i2c_set_clientdata(client, cw_bat);
cw_bat->dev = &client->dev;
cw_bat->soc = 1;
ret = cw2015_parse_properties(cw_bat);
if (ret) {
dev_err(cw_bat->dev, "Failed to parse cw2015 properties\n");
return ret;
}
cw_bat->regmap = devm_regmap_init_i2c(client, &cw2015_regmap_config);
if (IS_ERR(cw_bat->regmap)) {
dev_err(cw_bat->dev, "Failed to allocate regmap: %ld\n",
PTR_ERR(cw_bat->regmap));
return PTR_ERR(cw_bat->regmap);
}
ret = cw_init(cw_bat);
if (ret) {
dev_err(cw_bat->dev, "Init failed: %d\n", ret);
return ret;
}
psy_cfg.drv_data = cw_bat;
psy_cfg.fwnode = dev_fwnode(cw_bat->dev);
cw_bat->rk_bat = devm_power_supply_register(&client->dev,
&cw2015_bat_desc,
&psy_cfg);
if (IS_ERR(cw_bat->rk_bat)) {
dev_err(cw_bat->dev, "Failed to register power supply\n");
return PTR_ERR(cw_bat->rk_bat);
}
ret = power_supply_get_battery_info(cw_bat->rk_bat, &cw_bat->battery);
if (ret) {
dev_warn(cw_bat->dev,
"No monitored battery, some properties will be missing\n");
}
cw_bat->battery_workqueue = create_singlethread_workqueue("rk_battery");
INIT_DELAYED_WORK(&cw_bat->battery_delay_work, cw_bat_work);
queue_delayed_work(cw_bat->battery_workqueue,
&cw_bat->battery_delay_work, msecs_to_jiffies(10));
return 0;
}
static int __maybe_unused cw_bat_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct cw_battery *cw_bat = i2c_get_clientdata(client);
cancel_delayed_work_sync(&cw_bat->battery_delay_work);
return 0;
}
static int __maybe_unused cw_bat_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct cw_battery *cw_bat = i2c_get_clientdata(client);
queue_delayed_work(cw_bat->battery_workqueue,
&cw_bat->battery_delay_work, 0);
return 0;
}
static SIMPLE_DEV_PM_OPS(cw_bat_pm_ops, cw_bat_suspend, cw_bat_resume);
static int cw_bat_remove(struct i2c_client *client)
{
struct cw_battery *cw_bat = i2c_get_clientdata(client);
cancel_delayed_work_sync(&cw_bat->battery_delay_work);
power_supply_put_battery_info(cw_bat->rk_bat, &cw_bat->battery);
return 0;
}
static const struct i2c_device_id cw_bat_id_table[] = {
{ "cw2015", 0 },
{ }
};
static const struct of_device_id cw2015_of_match[] = {
{ .compatible = "cellwise,cw2015" },
{ }
};
MODULE_DEVICE_TABLE(of, cw2015_of_match);
static struct i2c_driver cw_bat_driver = {
.driver = {
.name = "cw2015",
.of_match_table = cw2015_of_match,
.pm = &cw_bat_pm_ops,
},
.probe_new = cw_bat_probe,
.remove = cw_bat_remove,
.id_table = cw_bat_id_table,
};
module_i2c_driver(cw_bat_driver);
MODULE_AUTHOR("xhc<xhc@rock-chips.com>");
MODULE_AUTHOR("Tobias Schramm <t.schramm@manjaro.org>");
MODULE_DESCRIPTION("cw2015/cw2013 battery driver");
MODULE_LICENSE("GPL");