diff options
Diffstat (limited to 'drivers/power/supply/cros_charge-control.c')
| -rw-r--r-- | drivers/power/supply/cros_charge-control.c | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/drivers/power/supply/cros_charge-control.c b/drivers/power/supply/cros_charge-control.c new file mode 100644 index 000000000000..17c53591ce19 --- /dev/null +++ b/drivers/power/supply/cros_charge-control.c @@ -0,0 +1,352 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * ChromeOS EC driver for charge control + * + * Copyright (C) 2024 Thomas Weißschuh <linux@weissschuh.net> + */ +#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 <linux@weissschuh.net>"); +MODULE_LICENSE("GPL"); |