// SPDX-License-Identifier: GPL-2.0-or-later
/*
* ChromeOS EC driver for charge control
*
* Copyright (C) 2024 Thomas Weißschuh <[email protected]>
*/
#include <acpi/battery.h>
#include <linux/container_of.h>
#include <linux/dmi.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/platform_data/cros_ec_commands.h>
#include <linux/platform_data/cros_ec_proto.h>
#include <linux/platform_device.h>
#include <linux/types.h>
#define EC_CHARGE_CONTROL_BEHAVIOURS (BIT(POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO) | \
BIT(POWER_SUPPLY_CHARGE_BEHAVIOUR_INHIBIT_CHARGE) | \
BIT(POWER_SUPPLY_CHARGE_BEHAVIOUR_FORCE_DISCHARGE))
enum CROS_CHCTL_ATTR {
CROS_CHCTL_ATTR_START_THRESHOLD,
CROS_CHCTL_ATTR_END_THRESHOLD,
CROS_CHCTL_ATTR_CHARGE_BEHAVIOUR,
_CROS_CHCTL_ATTR_COUNT
};
/*
* Semantics of data *returned* from the EC API and Linux sysfs differ
* slightly, also the v1 API can not return any data.
* To match the expected sysfs API, data is never read back from the EC but
* cached in the driver.
*
* Changes to the EC bypassing the driver will not be reflected in sysfs.
* Any change to "charge_behaviour" will synchronize the EC with the driver state.
*/
struct cros_chctl_priv {
struct cros_ec_device *cros_ec;
struct acpi_battery_hook battery_hook;
struct power_supply *hooked_battery;
u8 cmd_version;
/* The callbacks need to access this priv structure.
* As neither the struct device nor power_supply are under the drivers
* control, embed the attributes within priv to use with container_of().
*/
struct device_attribute device_attrs[_CROS_CHCTL_ATTR_COUNT];
struct attribute *attributes[_CROS_CHCTL_ATTR_COUNT];
struct attribute_group group;
enum power_supply_charge_behaviour current_behaviour;
u8 current_start_threshold, current_end_threshold;
};
static int cros_chctl_send_charge_control_cmd(struct cros_ec_device *cros_ec,
u8 cmd_version, struct ec_params_charge_control *req)
{
static const u8 outsizes[] = {
[1] = offsetof(struct ec_params_charge_control, cmd),
[2] = sizeof(struct ec_params_charge_control),
[3] = sizeof(struct ec_params_charge_control),
};
struct {
struct cros_ec_command msg;
union {
struct ec_params_charge_control req;
struct ec_response_charge_control resp;
} __packed data;
} __packed buf = {
.msg = {
.command = EC_CMD_CHARGE_CONTROL,
.version = cmd_version,
.insize = 0,
.outsize = outsizes[cmd_version],
},
.data.req = *req,
};
return cros_ec_cmd_xfer_status(cros_ec, &buf.msg);
}
static int cros_chctl_configure_ec(struct cros_chctl_priv *priv)
{
struct ec_params_charge_control req = {};
req.cmd = EC_CHARGE_CONTROL_CMD_SET;
switch (priv->current_behaviour) {
case POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO:
req.mode = CHARGE_CONTROL_NORMAL;
break;
case POWER_SUPPLY_CHARGE_BEHAVIOUR_INHIBIT_CHARGE:
req.mode = CHARGE_CONTROL_IDLE;
break;
case POWER_SUPPLY_CHARGE_BEHAVIOUR_FORCE_DISCHARGE:
req.mode = CHARGE_CONTROL_DISCHARGE;
break;
default:
return -EINVAL;
}
if (priv->current_behaviour == POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO &&
!(priv->current_start_threshold == 0 && priv->current_end_threshold == 100)) {
req.sustain_soc.lower = priv->current_start_threshold;
req.sustain_soc.upper = priv->current_end_threshold;
} else {
/* Disable charging limits */
req.sustain_soc.lower = -1;
req.sustain_soc.upper = -1;
}
return cros_chctl_send_charge_control_cmd(priv->cros_ec, priv->cmd_version, &req);
}
static struct cros_chctl_priv *cros_chctl_attr_to_priv(struct attribute *attr,
enum CROS_CHCTL_ATTR idx)
{
struct device_attribute *dev_attr = container_of(attr, struct device_attribute, attr);
return container_of(dev_attr, struct cros_chctl_priv, device_attrs[idx]);
}
static ssize_t cros_chctl_store_threshold(struct device *dev, struct cros_chctl_priv *priv,
int is_end_threshold, const char *buf, size_t count)
{
int ret, val;
ret = kstrtoint(buf, 10, &val);
if (ret < 0)
return ret;
if (val < 0 || val > 100)
return -EINVAL;
if (is_end_threshold) {
if (val <= priv->current_start_threshold)
return -EINVAL;
priv->current_end_threshold = val;
} else {
if (val >= priv->current_end_threshold)
return -EINVAL;
priv->current_start_threshold = val;
}
if (priv->current_behaviour == POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO) {
ret = cros_chctl_configure_ec(priv);
if (ret < 0)
return ret;
}
return count;
}
static ssize_t charge_control_start_threshold_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct cros_chctl_priv *priv = cros_chctl_attr_to_priv(&attr->attr,
CROS_CHCTL_ATTR_START_THRESHOLD);
return sysfs_emit(buf, "%u\n", (unsigned int)priv->current_start_threshold);
}
static ssize_t charge_control_start_threshold_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct cros_chctl_priv *priv = cros_chctl_attr_to_priv(&attr->attr,
CROS_CHCTL_ATTR_START_THRESHOLD);
return cros_chctl_store_threshold(dev, priv, 0, buf, count);
}
static ssize_t charge_control_end_threshold_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct cros_chctl_priv *priv = cros_chctl_attr_to_priv(&attr->attr,
CROS_CHCTL_ATTR_END_THRESHOLD);
return sysfs_emit(buf, "%u\n", (unsigned int)priv->current_end_threshold);
}
static ssize_t charge_control_end_threshold_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct cros_chctl_priv *priv = cros_chctl_attr_to_priv(&attr->attr,
CROS_CHCTL_ATTR_END_THRESHOLD);
return cros_chctl_store_threshold(dev, priv, 1, buf, count);
}
static ssize_t charge_behaviour_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct cros_chctl_priv *priv = cros_chctl_attr_to_priv(&attr->attr,
CROS_CHCTL_ATTR_CHARGE_BEHAVIOUR);
return power_supply_charge_behaviour_show(dev, EC_CHARGE_CONTROL_BEHAVIOURS,
priv->current_behaviour, buf);
}
static ssize_t charge_behaviour_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct cros_chctl_priv *priv = cros_chctl_attr_to_priv(&attr->attr,
CROS_CHCTL_ATTR_CHARGE_BEHAVIOUR);
int ret;
ret = power_supply_charge_behaviour_parse(EC_CHARGE_CONTROL_BEHAVIOURS, buf);
if (ret < 0)
return ret;
priv->current_behaviour = ret;
ret = cros_chctl_configure_ec(priv);
if (ret < 0)
return ret;
return count;
}
static umode_t cros_chtl_attr_is_visible(struct kobject *kobj, struct attribute *attr, int n)
{
struct cros_chctl_priv *priv = cros_chctl_attr_to_priv(attr, n);
if (priv->cmd_version < 2) {
if (n == CROS_CHCTL_ATTR_START_THRESHOLD)
return 0;
if (n == CROS_CHCTL_ATTR_END_THRESHOLD)
return 0;
}
return attr->mode;
}
static int cros_chctl_add_battery(struct power_supply *battery, struct acpi_battery_hook *hook)
{
struct cros_chctl_priv *priv = container_of(hook, struct cros_chctl_priv, battery_hook);
if (priv->hooked_battery)
return 0;
priv->hooked_battery = battery;
return device_add_group(&battery->dev, &priv->group);
}
static int cros_chctl_remove_battery(struct power_supply *battery, struct acpi_battery_hook *hook)
{
struct cros_chctl_priv *priv = container_of(hook, struct cros_chctl_priv, battery_hook);
if (priv->hooked_battery == battery) {
device_remove_group(&battery->dev, &priv->group);
priv->hooked_battery = NULL;
}
return 0;
}
static bool probe_with_fwk_charge_control;
module_param(probe_with_fwk_charge_control, bool, 0644);
MODULE_PARM_DESC(probe_with_fwk_charge_control,
"Probe the driver in the presence of the custom Framework EC charge control");
static int cros_chctl_fwk_charge_control_versions(struct cros_ec_device *cros_ec)
{
if (!dmi_match(DMI_SYS_VENDOR, "Framework"))
return 0;
return cros_ec_get_cmd_versions(cros_ec, 0x3E03 /* FW_EC_CMD_CHARGE_LIMIT */);
}
static int cros_chctl_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
struct cros_ec_device *cros_ec = ec_dev->ec_dev;
struct cros_chctl_priv *priv;
size_t i;
int ret;
ret = cros_chctl_fwk_charge_control_versions(cros_ec);
if (ret < 0)
return ret;
if (ret > 0 && !probe_with_fwk_charge_control) {
dev_info(dev, "Framework charge control detected, preventing load\n");
return -ENODEV;
}
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
ret = cros_ec_get_cmd_versions(cros_ec, EC_CMD_CHARGE_CONTROL);
if (ret < 0)
return ret;
else if (ret & EC_VER_MASK(3))
priv->cmd_version = 3;
else if (ret & EC_VER_MASK(2))
priv->cmd_version = 2;
else if (ret & EC_VER_MASK(1))
priv->cmd_version = 1;
else
return -ENODEV;
dev_dbg(dev, "Command version: %u\n", (unsigned int)priv->cmd_version);
priv->cros_ec = cros_ec;
priv->device_attrs[CROS_CHCTL_ATTR_START_THRESHOLD] =
(struct device_attribute)__ATTR_RW(charge_control_start_threshold);
priv->device_attrs[CROS_CHCTL_ATTR_END_THRESHOLD] =
(struct device_attribute)__ATTR_RW(charge_control_end_threshold);
priv->device_attrs[CROS_CHCTL_ATTR_CHARGE_BEHAVIOUR] =
(struct device_attribute)__ATTR_RW(charge_behaviour);
for (i = 0; i < _CROS_CHCTL_ATTR_COUNT; i++) {
sysfs_attr_init(&priv->device_attrs[i].attr);
priv->attributes[i] = &priv->device_attrs[i].attr;
}
priv->group.is_visible = cros_chtl_attr_is_visible;
priv->group.attrs = priv->attributes;
priv->battery_hook.name = dev_name(dev);
priv->battery_hook.add_battery = cros_chctl_add_battery;
priv->battery_hook.remove_battery = cros_chctl_remove_battery;
priv->current_behaviour = POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO;
priv->current_start_threshold = 0;
priv->current_end_threshold = 100;
/* Bring EC into well-known state */
ret = cros_chctl_configure_ec(priv);
if (ret < 0)
return ret;
return devm_battery_hook_register(dev, &priv->battery_hook);
}
static const struct platform_device_id cros_chctl_id[] = {
{ "cros-charge-control", 0 },
{}
};
static struct platform_driver cros_chctl_driver = {
.driver.name = "cros-charge-control",
.probe = cros_chctl_probe,
.id_table = cros_chctl_id,
};
module_platform_driver(cros_chctl_driver);
MODULE_DEVICE_TABLE(platform, cros_chctl_id);
MODULE_DESCRIPTION("ChromeOS EC charge control");
MODULE_AUTHOR("Thomas Weißschuh <[email protected]>");
MODULE_LICENSE("GPL");
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