| Message ID | 20240616-cros_ec-charge-control-v4-4-74d649a9117d@weissschuh.net (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | ChromeOS Embedded Controller charge control driver | expand |
Hi, On Sun, Jun 16, 2024 at 09:03:32PM GMT, Thomas Weißschuh wrote: > The ChromeOS Embedded Controller implements a command to control charge > thresholds and behaviour. > > Use it to implement the standard Linux charge_control_start_threshold, > charge_control_end_threshold and charge_behaviour sysfs UAPIs. > > The driver is designed to be probed via the cros_ec mfd device. > > Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> > --- Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> -- Sebastian > MAINTAINERS | 6 + > drivers/power/supply/Kconfig | 12 ++ > drivers/power/supply/Makefile | 1 + > drivers/power/supply/cros_charge-control.c | 335 +++++++++++++++++++++++++++++ > 4 files changed, 354 insertions(+) > > diff --git a/MAINTAINERS b/MAINTAINERS > index e4e6aad46668..8101cd0df305 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -5135,6 +5135,11 @@ S: Maintained > F: Documentation/devicetree/bindings/sound/google,cros-ec-codec.yaml > F: sound/soc/codecs/cros_ec_codec.* > > +CHROMEOS EC CHARGE CONTROL > +M: Thomas Weißschuh <thomas@weissschuh.net> > +S: Maintained > +F: drivers/power/supply/cros_charge-control.c > + > CHROMEOS EC HARDWARE MONITORING > M: Thomas Weißschuh <thomas@weissschuh.net> > L: chrome-platform@lists.linux.dev > @@ -5148,6 +5153,7 @@ M: Benson Leung <bleung@chromium.org> > R: Guenter Roeck <groeck@chromium.org> > L: chrome-platform@lists.linux.dev > S: Maintained > +F: drivers/power/supply/cros_charge-control.c > F: drivers/power/supply/cros_usbpd-charger.c > N: cros_ec > N: cros-ec > diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig > index 3e31375491d5..f6321a42aa53 100644 > --- a/drivers/power/supply/Kconfig > +++ b/drivers/power/supply/Kconfig > @@ -860,6 +860,18 @@ config CHARGER_CROS_PCHG > the peripheral charge ports from the EC and converts that into > power_supply properties. > > +config CHARGER_CROS_CONTROL > + tristate "ChromeOS EC based charge control" > + depends on MFD_CROS_EC_DEV > + depends on ACPI_BATTERY > + default MFD_CROS_EC_DEV > + help > + Say Y here to enable ChromeOS EC based battery charge control. > + This driver can manage charge thresholds and behaviour. > + > + This driver can also be built as a module. If so, the module will be > + called cros_charge-control. > + > config CHARGER_SC2731 > tristate "Spreadtrum SC2731 charger driver" > depends on MFD_SC27XX_PMIC || COMPILE_TEST > diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile > index 58b567278034..31ca6653a564 100644 > --- a/drivers/power/supply/Makefile > +++ b/drivers/power/supply/Makefile > @@ -100,6 +100,7 @@ obj-$(CONFIG_CHARGER_TPS65090) += tps65090-charger.o > obj-$(CONFIG_CHARGER_TPS65217) += tps65217_charger.o > obj-$(CONFIG_AXP288_FUEL_GAUGE) += axp288_fuel_gauge.o > obj-$(CONFIG_AXP288_CHARGER) += axp288_charger.o > +obj-$(CONFIG_CHARGER_CROS_CONTROL) += cros_charge-control.o > obj-$(CONFIG_CHARGER_CROS_USBPD) += cros_usbpd-charger.o > obj-$(CONFIG_CHARGER_CROS_PCHG) += cros_peripheral_charger.o > obj-$(CONFIG_CHARGER_SC2731) += sc2731_charger.o > diff --git a/drivers/power/supply/cros_charge-control.c b/drivers/power/supply/cros_charge-control.c > new file mode 100644 > index 000000000000..e1317a6f23ca > --- /dev/null > +++ b/drivers/power/supply/cros_charge-control.c > @@ -0,0 +1,335 @@ > +// 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/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 DRV_NAME "cros-charge-control" > + > +#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); > + enum power_supply_charge_behaviour behaviour; > + int ret; > + > + behaviour = power_supply_charge_behaviour_parse(EC_CHARGE_CONTROL_BEHAVIOURS, buf); > + if (behaviour < 0) > + return behaviour; > + > + priv->current_behaviour = behaviour; > + > + 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 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; > + > + 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->attributes[_CROS_CHCTL_ATTR_COUNT] = NULL; > + 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[] = { > + { DRV_NAME, 0 }, > + { } > +}; > + > +static struct platform_driver cros_chctl_driver = { > + .driver.name = DRV_NAME, > + .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"); > > -- > 2.45.2 >
Hi Sebastian, On 2024-06-20 00:24:23+0000, Sebastian Reichel wrote: > On Sun, Jun 16, 2024 at 09:03:32PM GMT, Thomas Weißschuh wrote: > > The ChromeOS Embedded Controller implements a command to control charge > > thresholds and behaviour. > > > > Use it to implement the standard Linux charge_control_start_threshold, > > charge_control_end_threshold and charge_behaviour sysfs UAPIs. > > > > The driver is designed to be probed via the cros_ec mfd device. > > > > Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> > > --- > > Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> Thanks! <snip> Would you also take a look at patch 5, "power: supply: cros_charge-control: don't load if Framework control is present"? I'm still wondering what the best solution for the two different EC APIs would be. Maybe you have an idea? In short: Framework laptops have a downstream charge control API in their EC. This drivers binds to the upstream CrOS EC APIs, which does work on Framework laptops. If the downstream API is used, it overrides the functionality of the upstream API. Choices I see: * Ignore the incompatibility and just load the driver (maybe log something) * Detect if the downstream API is actively used during probing (If enabled by UEFI) and either * don't load the driver * disable the current downstream API configuration, so the driver works * disable the downstream API and take over its configuration into the upstream driver * Detect if the downstream API is present at all and don't load the driver (currently implemented) The problem is that the downstream API is still usable and its usage would break this driver. On the other hand, disabling the driver forces users to manually specify a kernel commandline, preventing most users from actually making use of it. (For the future I plan on adapting the Framework EC firmware to avoid this issue, but there is no telling how long it will take and if it is accepted at all) Thanks for any ideas, Thomas
diff --git a/MAINTAINERS b/MAINTAINERS index e4e6aad46668..8101cd0df305 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5135,6 +5135,11 @@ S: Maintained F: Documentation/devicetree/bindings/sound/google,cros-ec-codec.yaml F: sound/soc/codecs/cros_ec_codec.* +CHROMEOS EC CHARGE CONTROL +M: Thomas Weißschuh <thomas@weissschuh.net> +S: Maintained +F: drivers/power/supply/cros_charge-control.c + CHROMEOS EC HARDWARE MONITORING M: Thomas Weißschuh <thomas@weissschuh.net> L: chrome-platform@lists.linux.dev @@ -5148,6 +5153,7 @@ M: Benson Leung <bleung@chromium.org> R: Guenter Roeck <groeck@chromium.org> L: chrome-platform@lists.linux.dev S: Maintained +F: drivers/power/supply/cros_charge-control.c F: drivers/power/supply/cros_usbpd-charger.c N: cros_ec N: cros-ec diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig index 3e31375491d5..f6321a42aa53 100644 --- a/drivers/power/supply/Kconfig +++ b/drivers/power/supply/Kconfig @@ -860,6 +860,18 @@ config CHARGER_CROS_PCHG the peripheral charge ports from the EC and converts that into power_supply properties. +config CHARGER_CROS_CONTROL + tristate "ChromeOS EC based charge control" + depends on MFD_CROS_EC_DEV + depends on ACPI_BATTERY + default MFD_CROS_EC_DEV + help + Say Y here to enable ChromeOS EC based battery charge control. + This driver can manage charge thresholds and behaviour. + + This driver can also be built as a module. If so, the module will be + called cros_charge-control. + config CHARGER_SC2731 tristate "Spreadtrum SC2731 charger driver" depends on MFD_SC27XX_PMIC || COMPILE_TEST diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile index 58b567278034..31ca6653a564 100644 --- a/drivers/power/supply/Makefile +++ b/drivers/power/supply/Makefile @@ -100,6 +100,7 @@ obj-$(CONFIG_CHARGER_TPS65090) += tps65090-charger.o obj-$(CONFIG_CHARGER_TPS65217) += tps65217_charger.o obj-$(CONFIG_AXP288_FUEL_GAUGE) += axp288_fuel_gauge.o obj-$(CONFIG_AXP288_CHARGER) += axp288_charger.o +obj-$(CONFIG_CHARGER_CROS_CONTROL) += cros_charge-control.o obj-$(CONFIG_CHARGER_CROS_USBPD) += cros_usbpd-charger.o obj-$(CONFIG_CHARGER_CROS_PCHG) += cros_peripheral_charger.o obj-$(CONFIG_CHARGER_SC2731) += sc2731_charger.o diff --git a/drivers/power/supply/cros_charge-control.c b/drivers/power/supply/cros_charge-control.c new file mode 100644 index 000000000000..e1317a6f23ca --- /dev/null +++ b/drivers/power/supply/cros_charge-control.c @@ -0,0 +1,335 @@ +// 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/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 DRV_NAME "cros-charge-control" + +#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); + enum power_supply_charge_behaviour behaviour; + int ret; + + behaviour = power_supply_charge_behaviour_parse(EC_CHARGE_CONTROL_BEHAVIOURS, buf); + if (behaviour < 0) + return behaviour; + + priv->current_behaviour = behaviour; + + 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 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; + + 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->attributes[_CROS_CHCTL_ATTR_COUNT] = NULL; + 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[] = { + { DRV_NAME, 0 }, + { } +}; + +static struct platform_driver cros_chctl_driver = { + .driver.name = DRV_NAME, + .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");
The ChromeOS Embedded Controller implements a command to control charge thresholds and behaviour. Use it to implement the standard Linux charge_control_start_threshold, charge_control_end_threshold and charge_behaviour sysfs UAPIs. The driver is designed to be probed via the cros_ec mfd device. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> --- MAINTAINERS | 6 + drivers/power/supply/Kconfig | 12 ++ drivers/power/supply/Makefile | 1 + drivers/power/supply/cros_charge-control.c | 335 +++++++++++++++++++++++++++++ 4 files changed, 354 insertions(+)