linux/drivers/power/supply/ltc2941-battery-gauge.c
Rob Herring 2ce8284c31 power: Explicitly include correct DT includes
The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Acked-by: David Lechner <david@lechnology.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
2023-07-19 22:47:03 +02:00

648 lines
16 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* I2C client/driver for the Linear Technology LTC2941, LTC2942, LTC2943
* and LTC2944 Battery Gas Gauge IC
*
* Copyright (C) 2014 Topic Embedded Systems
*
* Author: Auryn Verwegen
* Author: Mike Looijmans
*/
#include <linux/devm-helpers.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/swab.h>
#include <linux/i2c.h>
#include <linux/delay.h>
#include <linux/power_supply.h>
#include <linux/slab.h>
#define I16_MSB(x) ((x >> 8) & 0xFF)
#define I16_LSB(x) (x & 0xFF)
#define LTC294X_WORK_DELAY 10 /* Update delay in seconds */
#define LTC294X_MAX_VALUE 0xFFFF
#define LTC294X_MID_SUPPLY 0x7FFF
#define LTC2941_MAX_PRESCALER_EXP 7
#define LTC2943_MAX_PRESCALER_EXP 6
enum ltc294x_reg {
LTC294X_REG_STATUS = 0x00,
LTC294X_REG_CONTROL = 0x01,
LTC294X_REG_ACC_CHARGE_MSB = 0x02,
LTC294X_REG_ACC_CHARGE_LSB = 0x03,
LTC294X_REG_CHARGE_THR_HIGH_MSB = 0x04,
LTC294X_REG_CHARGE_THR_HIGH_LSB = 0x05,
LTC294X_REG_CHARGE_THR_LOW_MSB = 0x06,
LTC294X_REG_CHARGE_THR_LOW_LSB = 0x07,
LTC294X_REG_VOLTAGE_MSB = 0x08,
LTC294X_REG_VOLTAGE_LSB = 0x09,
LTC2942_REG_TEMPERATURE_MSB = 0x0C,
LTC2942_REG_TEMPERATURE_LSB = 0x0D,
LTC2943_REG_CURRENT_MSB = 0x0E,
LTC2943_REG_CURRENT_LSB = 0x0F,
LTC2943_REG_TEMPERATURE_MSB = 0x14,
LTC2943_REG_TEMPERATURE_LSB = 0x15,
};
enum ltc294x_id {
LTC2941_ID,
LTC2942_ID,
LTC2943_ID,
LTC2944_ID,
};
#define LTC2941_REG_STATUS_CHIP_ID BIT(7)
#define LTC2942_REG_CONTROL_MODE_SCAN (BIT(7) | BIT(6))
#define LTC2943_REG_CONTROL_MODE_SCAN BIT(7)
#define LTC294X_REG_CONTROL_PRESCALER_MASK (BIT(5) | BIT(4) | BIT(3))
#define LTC294X_REG_CONTROL_SHUTDOWN_MASK (BIT(0))
#define LTC294X_REG_CONTROL_PRESCALER_SET(x) \
((x << 3) & LTC294X_REG_CONTROL_PRESCALER_MASK)
#define LTC294X_REG_CONTROL_ALCC_CONFIG_DISABLED 0
#define LTC294X_REG_CONTROL_ADC_DISABLE(x) ((x) & ~(BIT(7) | BIT(6)))
struct ltc294x_info {
struct i2c_client *client; /* I2C Client pointer */
struct power_supply *supply; /* Supply pointer */
struct power_supply_desc supply_desc; /* Supply description */
struct delayed_work work; /* Work scheduler */
enum ltc294x_id id; /* Chip type */
int charge; /* Last charge register content */
int r_sense; /* mOhm */
int Qlsb; /* nAh */
};
static inline int convert_bin_to_uAh(
const struct ltc294x_info *info, int Q)
{
return ((Q * (info->Qlsb / 10))) / 100;
}
static inline int convert_uAh_to_bin(
const struct ltc294x_info *info, int uAh)
{
int Q;
Q = (uAh * 100) / (info->Qlsb/10);
return (Q < LTC294X_MAX_VALUE) ? Q : LTC294X_MAX_VALUE;
}
static int ltc294x_read_regs(struct i2c_client *client,
enum ltc294x_reg reg, u8 *buf, int num_regs)
{
int ret;
struct i2c_msg msgs[2] = { };
u8 reg_start = reg;
msgs[0].addr = client->addr;
msgs[0].len = 1;
msgs[0].buf = &reg_start;
msgs[1].addr = client->addr;
msgs[1].len = num_regs;
msgs[1].buf = buf;
msgs[1].flags = I2C_M_RD;
ret = i2c_transfer(client->adapter, &msgs[0], 2);
if (ret < 0) {
dev_err(&client->dev, "ltc2941 read_reg(0x%x[%d]) failed: %pe\n",
reg, num_regs, ERR_PTR(ret));
return ret;
}
dev_dbg(&client->dev, "%s (%#x, %d) -> %#x\n",
__func__, reg, num_regs, *buf);
return 0;
}
static int ltc294x_write_regs(struct i2c_client *client,
enum ltc294x_reg reg, const u8 *buf, int num_regs)
{
int ret;
u8 reg_start = reg;
ret = i2c_smbus_write_i2c_block_data(client, reg_start, num_regs, buf);
if (ret < 0) {
dev_err(&client->dev, "ltc2941 write_reg(0x%x[%d]) failed: %pe\n",
reg, num_regs, ERR_PTR(ret));
return ret;
}
dev_dbg(&client->dev, "%s (%#x, %d) -> %#x\n",
__func__, reg, num_regs, *buf);
return 0;
}
static int ltc294x_reset(const struct ltc294x_info *info, int prescaler_exp)
{
int ret;
u8 value;
u8 control;
/* Read status and control registers */
ret = ltc294x_read_regs(info->client, LTC294X_REG_CONTROL, &value, 1);
if (ret < 0)
return ret;
control = LTC294X_REG_CONTROL_PRESCALER_SET(prescaler_exp) |
LTC294X_REG_CONTROL_ALCC_CONFIG_DISABLED;
/* Put device into "monitor" mode */
switch (info->id) {
case LTC2942_ID: /* 2942 measures every 2 sec */
control |= LTC2942_REG_CONTROL_MODE_SCAN;
break;
case LTC2943_ID:
case LTC2944_ID: /* 2943 and 2944 measure every 10 sec */
control |= LTC2943_REG_CONTROL_MODE_SCAN;
break;
default:
break;
}
if (value != control) {
ret = ltc294x_write_regs(info->client,
LTC294X_REG_CONTROL, &control, 1);
if (ret < 0)
return ret;
}
return 0;
}
static int ltc294x_read_charge_register(const struct ltc294x_info *info,
enum ltc294x_reg reg)
{
int ret;
u8 datar[2];
ret = ltc294x_read_regs(info->client, reg, &datar[0], 2);
if (ret < 0)
return ret;
return (datar[0] << 8) + datar[1];
}
static int ltc294x_get_charge(const struct ltc294x_info *info,
enum ltc294x_reg reg, int *val)
{
int value = ltc294x_read_charge_register(info, reg);
if (value < 0)
return value;
/* When r_sense < 0, this counts up when the battery discharges */
if (info->Qlsb < 0)
value -= 0xFFFF;
*val = convert_bin_to_uAh(info, value);
return 0;
}
static int ltc294x_set_charge_now(const struct ltc294x_info *info, int val)
{
int ret;
u8 dataw[2];
u8 ctrl_reg;
s32 value;
value = convert_uAh_to_bin(info, val);
/* Direction depends on how sense+/- were connected */
if (info->Qlsb < 0)
value += 0xFFFF;
if ((value < 0) || (value > 0xFFFF)) /* input validation */
return -EINVAL;
/* Read control register */
ret = ltc294x_read_regs(info->client,
LTC294X_REG_CONTROL, &ctrl_reg, 1);
if (ret < 0)
return ret;
/* Disable analog section */
ctrl_reg |= LTC294X_REG_CONTROL_SHUTDOWN_MASK;
ret = ltc294x_write_regs(info->client,
LTC294X_REG_CONTROL, &ctrl_reg, 1);
if (ret < 0)
return ret;
/* Set new charge value */
dataw[0] = I16_MSB(value);
dataw[1] = I16_LSB(value);
ret = ltc294x_write_regs(info->client,
LTC294X_REG_ACC_CHARGE_MSB, &dataw[0], 2);
if (ret < 0)
goto error_exit;
/* Enable analog section */
error_exit:
ctrl_reg &= ~LTC294X_REG_CONTROL_SHUTDOWN_MASK;
ret = ltc294x_write_regs(info->client,
LTC294X_REG_CONTROL, &ctrl_reg, 1);
return ret < 0 ? ret : 0;
}
static int ltc294x_set_charge_thr(const struct ltc294x_info *info,
enum ltc294x_reg reg, int val)
{
u8 dataw[2];
s32 value;
value = convert_uAh_to_bin(info, val);
/* Direction depends on how sense+/- were connected */
if (info->Qlsb < 0)
value += 0xFFFF;
if ((value < 0) || (value > 0xFFFF)) /* input validation */
return -EINVAL;
/* Set new charge value */
dataw[0] = I16_MSB(value);
dataw[1] = I16_LSB(value);
return ltc294x_write_regs(info->client, reg, &dataw[0], 2);
}
static int ltc294x_get_charge_counter(
const struct ltc294x_info *info, int *val)
{
int value = ltc294x_read_charge_register(info, LTC294X_REG_ACC_CHARGE_MSB);
if (value < 0)
return value;
value -= LTC294X_MID_SUPPLY;
*val = convert_bin_to_uAh(info, value);
return 0;
}
static int ltc294x_get_voltage(const struct ltc294x_info *info, int *val)
{
int ret;
u8 datar[2];
u32 value;
ret = ltc294x_read_regs(info->client,
LTC294X_REG_VOLTAGE_MSB, &datar[0], 2);
value = (datar[0] << 8) | datar[1];
switch (info->id) {
case LTC2943_ID:
value *= 23600 * 2;
value /= 0xFFFF;
value *= 1000 / 2;
break;
case LTC2944_ID:
value *= 70800 / 5*4;
value /= 0xFFFF;
value *= 1000 * 5/4;
break;
default:
value *= 6000 * 10;
value /= 0xFFFF;
value *= 1000 / 10;
break;
}
*val = value;
return ret;
}
static int ltc294x_get_current(const struct ltc294x_info *info, int *val)
{
int ret;
u8 datar[2];
s32 value;
ret = ltc294x_read_regs(info->client,
LTC2943_REG_CURRENT_MSB, &datar[0], 2);
value = (datar[0] << 8) | datar[1];
value -= 0x7FFF;
if (info->id == LTC2944_ID)
value *= 64000;
else
value *= 60000;
/* Value is in range -32k..+32k, r_sense is usually 10..50 mOhm,
* the formula below keeps everything in s32 range while preserving
* enough digits */
*val = 1000 * (value / (info->r_sense * 0x7FFF)); /* in uA */
return ret;
}
static int ltc294x_get_temperature(const struct ltc294x_info *info, int *val)
{
enum ltc294x_reg reg;
int ret;
u8 datar[2];
u32 value;
if (info->id == LTC2942_ID) {
reg = LTC2942_REG_TEMPERATURE_MSB;
value = 6000; /* Full-scale is 600 Kelvin */
} else {
reg = LTC2943_REG_TEMPERATURE_MSB;
value = 5100; /* Full-scale is 510 Kelvin */
}
ret = ltc294x_read_regs(info->client, reg, &datar[0], 2);
value *= (datar[0] << 8) | datar[1];
/* Convert to tenths of degree Celsius */
*val = value / 0xFFFF - 2722;
return ret;
}
static int ltc294x_get_property(struct power_supply *psy,
enum power_supply_property prop,
union power_supply_propval *val)
{
struct ltc294x_info *info = power_supply_get_drvdata(psy);
switch (prop) {
case POWER_SUPPLY_PROP_CHARGE_FULL:
return ltc294x_get_charge(info, LTC294X_REG_CHARGE_THR_HIGH_MSB,
&val->intval);
case POWER_SUPPLY_PROP_CHARGE_EMPTY:
return ltc294x_get_charge(info, LTC294X_REG_CHARGE_THR_LOW_MSB,
&val->intval);
case POWER_SUPPLY_PROP_CHARGE_NOW:
return ltc294x_get_charge(info, LTC294X_REG_ACC_CHARGE_MSB,
&val->intval);
case POWER_SUPPLY_PROP_CHARGE_COUNTER:
return ltc294x_get_charge_counter(info, &val->intval);
case POWER_SUPPLY_PROP_VOLTAGE_NOW:
return ltc294x_get_voltage(info, &val->intval);
case POWER_SUPPLY_PROP_CURRENT_NOW:
return ltc294x_get_current(info, &val->intval);
case POWER_SUPPLY_PROP_TEMP:
return ltc294x_get_temperature(info, &val->intval);
default:
return -EINVAL;
}
}
static int ltc294x_set_property(struct power_supply *psy,
enum power_supply_property psp,
const union power_supply_propval *val)
{
struct ltc294x_info *info = power_supply_get_drvdata(psy);
switch (psp) {
case POWER_SUPPLY_PROP_CHARGE_FULL:
return ltc294x_set_charge_thr(info,
LTC294X_REG_CHARGE_THR_HIGH_MSB, val->intval);
case POWER_SUPPLY_PROP_CHARGE_EMPTY:
return ltc294x_set_charge_thr(info,
LTC294X_REG_CHARGE_THR_LOW_MSB, val->intval);
case POWER_SUPPLY_PROP_CHARGE_NOW:
return ltc294x_set_charge_now(info, val->intval);
default:
return -EPERM;
}
}
static int ltc294x_property_is_writeable(
struct power_supply *psy, enum power_supply_property psp)
{
switch (psp) {
case POWER_SUPPLY_PROP_CHARGE_FULL:
case POWER_SUPPLY_PROP_CHARGE_EMPTY:
case POWER_SUPPLY_PROP_CHARGE_NOW:
return 1;
default:
return 0;
}
}
static void ltc294x_update(struct ltc294x_info *info)
{
int charge = ltc294x_read_charge_register(info, LTC294X_REG_ACC_CHARGE_MSB);
if (charge != info->charge) {
info->charge = charge;
power_supply_changed(info->supply);
}
}
static void ltc294x_work(struct work_struct *work)
{
struct ltc294x_info *info;
info = container_of(work, struct ltc294x_info, work.work);
ltc294x_update(info);
schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
}
static enum power_supply_property ltc294x_properties[] = {
POWER_SUPPLY_PROP_CHARGE_COUNTER,
POWER_SUPPLY_PROP_CHARGE_FULL,
POWER_SUPPLY_PROP_CHARGE_EMPTY,
POWER_SUPPLY_PROP_CHARGE_NOW,
POWER_SUPPLY_PROP_VOLTAGE_NOW,
POWER_SUPPLY_PROP_TEMP,
POWER_SUPPLY_PROP_CURRENT_NOW,
};
static int ltc294x_i2c_probe(struct i2c_client *client)
{
struct power_supply_config psy_cfg = {};
struct ltc294x_info *info;
struct device_node *np;
int ret;
u32 prescaler_exp;
s32 r_sense;
u8 status;
info = devm_kzalloc(&client->dev, sizeof(*info), GFP_KERNEL);
if (info == NULL)
return -ENOMEM;
i2c_set_clientdata(client, info);
np = of_node_get(client->dev.of_node);
info->id = (enum ltc294x_id) (uintptr_t) of_device_get_match_data(
&client->dev);
info->supply_desc.name = np->name;
/* r_sense can be negative, when sense+ is connected to the battery
* instead of the sense-. This results in reversed measurements. */
ret = of_property_read_u32(np, "lltc,resistor-sense", &r_sense);
if (ret < 0)
return dev_err_probe(&client->dev, ret,
"Could not find lltc,resistor-sense in devicetree\n");
info->r_sense = r_sense;
ret = of_property_read_u32(np, "lltc,prescaler-exponent",
&prescaler_exp);
if (ret < 0) {
dev_warn(&client->dev,
"lltc,prescaler-exponent not in devicetree\n");
prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
}
if (info->id == LTC2943_ID) {
if (prescaler_exp > LTC2943_MAX_PRESCALER_EXP)
prescaler_exp = LTC2943_MAX_PRESCALER_EXP;
info->Qlsb = ((340 * 50000) / r_sense) >>
(12 - 2*prescaler_exp);
} else {
if (prescaler_exp > LTC2941_MAX_PRESCALER_EXP)
prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
info->Qlsb = ((85 * 50000) / r_sense) >>
(7 - prescaler_exp);
}
/* Read status register to check for LTC2942 */
if (info->id == LTC2941_ID || info->id == LTC2942_ID) {
ret = ltc294x_read_regs(client, LTC294X_REG_STATUS, &status, 1);
if (ret < 0)
return dev_err_probe(&client->dev, ret,
"Could not read status register\n");
if (status & LTC2941_REG_STATUS_CHIP_ID)
info->id = LTC2941_ID;
else
info->id = LTC2942_ID;
}
info->client = client;
info->supply_desc.type = POWER_SUPPLY_TYPE_BATTERY;
info->supply_desc.properties = ltc294x_properties;
switch (info->id) {
case LTC2944_ID:
case LTC2943_ID:
info->supply_desc.num_properties =
ARRAY_SIZE(ltc294x_properties);
break;
case LTC2942_ID:
info->supply_desc.num_properties =
ARRAY_SIZE(ltc294x_properties) - 1;
break;
case LTC2941_ID:
default:
info->supply_desc.num_properties =
ARRAY_SIZE(ltc294x_properties) - 3;
break;
}
info->supply_desc.get_property = ltc294x_get_property;
info->supply_desc.set_property = ltc294x_set_property;
info->supply_desc.property_is_writeable = ltc294x_property_is_writeable;
info->supply_desc.external_power_changed = NULL;
psy_cfg.drv_data = info;
ret = devm_delayed_work_autocancel(&client->dev, &info->work,
ltc294x_work);
if (ret)
return ret;
ret = ltc294x_reset(info, prescaler_exp);
if (ret < 0)
return dev_err_probe(&client->dev, ret,
"Communication with chip failed\n");
info->supply = devm_power_supply_register(&client->dev,
&info->supply_desc, &psy_cfg);
if (IS_ERR(info->supply))
return dev_err_probe(&client->dev, PTR_ERR(info->supply),
"failed to register ltc2941\n");
schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
return 0;
}
static void ltc294x_i2c_shutdown(struct i2c_client *client)
{
struct ltc294x_info *info = i2c_get_clientdata(client);
int ret;
u8 value;
u8 control;
/* The LTC2941 does not need any special handling */
if (info->id == LTC2941_ID)
return;
/* Read control register */
ret = ltc294x_read_regs(info->client, LTC294X_REG_CONTROL, &value, 1);
if (ret < 0)
return;
/* Disable continuous ADC conversion as this drains the battery */
control = LTC294X_REG_CONTROL_ADC_DISABLE(value);
if (control != value)
ltc294x_write_regs(info->client, LTC294X_REG_CONTROL,
&control, 1);
}
#ifdef CONFIG_PM_SLEEP
static int ltc294x_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct ltc294x_info *info = i2c_get_clientdata(client);
cancel_delayed_work(&info->work);
return 0;
}
static int ltc294x_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct ltc294x_info *info = i2c_get_clientdata(client);
schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
return 0;
}
static SIMPLE_DEV_PM_OPS(ltc294x_pm_ops, ltc294x_suspend, ltc294x_resume);
#define LTC294X_PM_OPS (&ltc294x_pm_ops)
#else
#define LTC294X_PM_OPS NULL
#endif /* CONFIG_PM_SLEEP */
static const struct i2c_device_id ltc294x_i2c_id[] = {
{ "ltc2941", LTC2941_ID, },
{ "ltc2942", LTC2942_ID, },
{ "ltc2943", LTC2943_ID, },
{ "ltc2944", LTC2944_ID, },
{ },
};
MODULE_DEVICE_TABLE(i2c, ltc294x_i2c_id);
static const struct of_device_id ltc294x_i2c_of_match[] = {
{
.compatible = "lltc,ltc2941",
.data = (void *)LTC2941_ID,
},
{
.compatible = "lltc,ltc2942",
.data = (void *)LTC2942_ID,
},
{
.compatible = "lltc,ltc2943",
.data = (void *)LTC2943_ID,
},
{
.compatible = "lltc,ltc2944",
.data = (void *)LTC2944_ID,
},
{ },
};
MODULE_DEVICE_TABLE(of, ltc294x_i2c_of_match);
static struct i2c_driver ltc294x_driver = {
.driver = {
.name = "LTC2941",
.of_match_table = ltc294x_i2c_of_match,
.pm = LTC294X_PM_OPS,
},
.probe = ltc294x_i2c_probe,
.shutdown = ltc294x_i2c_shutdown,
.id_table = ltc294x_i2c_id,
};
module_i2c_driver(ltc294x_driver);
MODULE_AUTHOR("Auryn Verwegen, Topic Embedded Systems");
MODULE_AUTHOR("Mike Looijmans, Topic Embedded Products");
MODULE_DESCRIPTION("LTC2941/LTC2942/LTC2943/LTC2944 Battery Gas Gauge IC driver");
MODULE_LICENSE("GPL");