linux/drivers/power/supply/wilco-charger.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Charging control driver for the Wilco EC
*
* Copyright 2019 Google LLC
*
* See Documentation/ABI/testing/sysfs-class-power and
* Documentation/ABI/testing/sysfs-class-power-wilco for userspace interface
* and other info.
*/
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/platform_data/wilco-ec.h>
#include <linux/power_supply.h>
#define DRV_NAME "wilco-charger"
/* Property IDs and related EC constants */
#define PID_CHARGE_MODE 0x0710
#define PID_CHARGE_LOWER_LIMIT 0x0711
#define PID_CHARGE_UPPER_LIMIT 0x0712
enum charge_mode {
CHARGE_MODE_STD = 1, /* Used for Standard */
CHARGE_MODE_EXP = 2, /* Express Charge, used for Fast */
CHARGE_MODE_AC = 3, /* Mostly AC use, used for Trickle */
CHARGE_MODE_AUTO = 4, /* Used for Adaptive */
CHARGE_MODE_CUSTOM = 5, /* Used for Custom */
CHARGE_MODE_LONGLIFE = 6, /* Used for Long Life */
};
#define CHARGE_LOWER_LIMIT_MIN 50
#define CHARGE_LOWER_LIMIT_MAX 95
#define CHARGE_UPPER_LIMIT_MIN 55
#define CHARGE_UPPER_LIMIT_MAX 100
/* Convert from POWER_SUPPLY_PROP_CHARGE_TYPE value to the EC's charge mode */
static int psp_val_to_charge_mode(int psp_val)
{
switch (psp_val) {
case POWER_SUPPLY_CHARGE_TYPE_TRICKLE:
return CHARGE_MODE_AC;
case POWER_SUPPLY_CHARGE_TYPE_FAST:
return CHARGE_MODE_EXP;
case POWER_SUPPLY_CHARGE_TYPE_STANDARD:
return CHARGE_MODE_STD;
case POWER_SUPPLY_CHARGE_TYPE_ADAPTIVE:
return CHARGE_MODE_AUTO;
case POWER_SUPPLY_CHARGE_TYPE_CUSTOM:
return CHARGE_MODE_CUSTOM;
case POWER_SUPPLY_CHARGE_TYPE_LONGLIFE:
return CHARGE_MODE_LONGLIFE;
default:
return -EINVAL;
}
}
/* Convert from EC's charge mode to POWER_SUPPLY_PROP_CHARGE_TYPE value */
static int charge_mode_to_psp_val(enum charge_mode mode)
{
switch (mode) {
case CHARGE_MODE_AC:
return POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
case CHARGE_MODE_EXP:
return POWER_SUPPLY_CHARGE_TYPE_FAST;
case CHARGE_MODE_STD:
return POWER_SUPPLY_CHARGE_TYPE_STANDARD;
case CHARGE_MODE_AUTO:
return POWER_SUPPLY_CHARGE_TYPE_ADAPTIVE;
case CHARGE_MODE_CUSTOM:
return POWER_SUPPLY_CHARGE_TYPE_CUSTOM;
case CHARGE_MODE_LONGLIFE:
return POWER_SUPPLY_CHARGE_TYPE_LONGLIFE;
default:
return -EINVAL;
}
}
static enum power_supply_property wilco_charge_props[] = {
POWER_SUPPLY_PROP_CHARGE_TYPE,
POWER_SUPPLY_PROP_CHARGE_CONTROL_START_THRESHOLD,
POWER_SUPPLY_PROP_CHARGE_CONTROL_END_THRESHOLD,
};
static int wilco_charge_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct wilco_ec_device *ec = power_supply_get_drvdata(psy);
u32 property_id;
int ret;
u8 raw;
switch (psp) {
case POWER_SUPPLY_PROP_CHARGE_TYPE:
property_id = PID_CHARGE_MODE;
break;
case POWER_SUPPLY_PROP_CHARGE_CONTROL_START_THRESHOLD:
property_id = PID_CHARGE_LOWER_LIMIT;
break;
case POWER_SUPPLY_PROP_CHARGE_CONTROL_END_THRESHOLD:
property_id = PID_CHARGE_UPPER_LIMIT;
break;
default:
return -EINVAL;
}
ret = wilco_ec_get_byte_property(ec, property_id, &raw);
if (ret < 0)
return ret;
if (property_id == PID_CHARGE_MODE) {
ret = charge_mode_to_psp_val(raw);
if (ret < 0)
return -EBADMSG;
raw = ret;
}
val->intval = raw;
return 0;
}
static int wilco_charge_set_property(struct power_supply *psy,
enum power_supply_property psp,
const union power_supply_propval *val)
{
struct wilco_ec_device *ec = power_supply_get_drvdata(psy);
int mode;
switch (psp) {
case POWER_SUPPLY_PROP_CHARGE_TYPE:
mode = psp_val_to_charge_mode(val->intval);
if (mode < 0)
return -EINVAL;
return wilco_ec_set_byte_property(ec, PID_CHARGE_MODE, mode);
case POWER_SUPPLY_PROP_CHARGE_CONTROL_START_THRESHOLD:
if (val->intval < CHARGE_LOWER_LIMIT_MIN ||
val->intval > CHARGE_LOWER_LIMIT_MAX)
return -EINVAL;
return wilco_ec_set_byte_property(ec, PID_CHARGE_LOWER_LIMIT,
val->intval);
case POWER_SUPPLY_PROP_CHARGE_CONTROL_END_THRESHOLD:
if (val->intval < CHARGE_UPPER_LIMIT_MIN ||
val->intval > CHARGE_UPPER_LIMIT_MAX)
return -EINVAL;
return wilco_ec_set_byte_property(ec, PID_CHARGE_UPPER_LIMIT,
val->intval);
default:
return -EINVAL;
}
}
static int wilco_charge_property_is_writeable(struct power_supply *psy,
enum power_supply_property psp)
{
return 1;
}
static const struct power_supply_desc wilco_ps_desc = {
.properties = wilco_charge_props,
.num_properties = ARRAY_SIZE(wilco_charge_props),
.get_property = wilco_charge_get_property,
.set_property = wilco_charge_set_property,
.property_is_writeable = wilco_charge_property_is_writeable,
.name = DRV_NAME,
.type = POWER_SUPPLY_TYPE_MAINS,
};
static int wilco_charge_probe(struct platform_device *pdev)
{
struct wilco_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
struct power_supply_config psy_cfg = {};
struct power_supply *psy;
psy_cfg.drv_data = ec;
psy = devm_power_supply_register(&pdev->dev, &wilco_ps_desc, &psy_cfg);
return PTR_ERR_OR_ZERO(psy);
}
static struct platform_driver wilco_charge_driver = {
.probe = wilco_charge_probe,
.driver = {
.name = DRV_NAME,
}
};
module_platform_driver(wilco_charge_driver);
MODULE_ALIAS("platform:" DRV_NAME);
MODULE_AUTHOR("Nick Crews <ncrews@chromium.org>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Wilco EC charge control driver");