Add control of the charging algorithm used on Wilco devices. See Documentation/ABI/testing/sysfs-class-power-wilco for the userspace interface and other info.
v5 changes: -Remove OP_SYNC, it has no immediate use case. -Merge properties.h into wilco-ec.h -Remove enum get_set_sync_op from the public interface, since without OP_SYNC they are irrelevant. -Fix Kconfigs and Makefiles so they actually work with the v4 changes -Tweak some formatting, spacing, and comments -Fix validation of charge_type so illegal values can't be set. Before negative error codes were accidentally getting casted to positive numbers -Remove more unneeded parentheses. v4 changes: -Use put_unaligned_le32() to store PID in request. -Move implementation from drivers/platform/chrome/wilco_ec/charge_config.c to drivers/power/supply/wilco_charger.c -Move drivers/platform/chrome/wilco_ec/properties.h to include/linux/platform_data/wilco-ec-properties.h -Remove parentheses in switch statement in psp_val_to_charge_mode() -Check for any negatvie return code from psp_val_to_charge_mode() instead of just -EINVAL so its less brittle -Tweak comments in wilco-ec-properties.h v3 changes: -Add this changelog -Fix commit message tags v2 changes: -Update Documentation to say KernelVersion 5.2 -Update Documentation to explain Trickle mode better. -rename things from using *PCC* to *CHARGE* -Split up conversions between POWER_SUPPLY_PROP_CHARGE_TYPE values and Wilco EC codes -Use devm_ flavor of power_supply_register(), which simplifies things -Add extra error checking on property messages received from the EC -Fix bug in memcpy() calls in properties.c -Refactor fill_property_id() -Add valid input checks to charge_type -Properly convert charge_type when get()ting Signed-off-by: Nick Crews <[email protected]> --- .../ABI/testing/sysfs-class-power-wilco | 30 +++ drivers/platform/chrome/wilco_ec/Kconfig | 9 + drivers/platform/chrome/wilco_ec/Makefile | 2 +- drivers/platform/chrome/wilco_ec/core.c | 13 ++ drivers/platform/chrome/wilco_ec/properties.c | 134 ++++++++++++ drivers/power/supply/Makefile | 1 + drivers/power/supply/wilco-charger.c | 190 ++++++++++++++++++ include/linux/platform_data/wilco-ec.h | 73 +++++++ 8 files changed, 451 insertions(+), 1 deletion(-) create mode 100644 Documentation/ABI/testing/sysfs-class-power-wilco create mode 100644 drivers/platform/chrome/wilco_ec/properties.c create mode 100644 drivers/power/supply/wilco-charger.c diff --git a/Documentation/ABI/testing/sysfs-class-power-wilco b/Documentation/ABI/testing/sysfs-class-power-wilco new file mode 100644 index 000000000000..7f3b01310476 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-power-wilco @@ -0,0 +1,30 @@ +What: /sys/class/power_supply/wilco_charger/charge_type +Date: April 2019 +KernelVersion: 5.2 +Description: + What charging algorithm to use: + + Standard: Fully charges battery at a standard rate. + Adaptive: Battery settings adaptively optimized based on + typical battery usage pattern. + Fast: Battery charges over a shorter period. + Trickle: Extends battery lifespan, intended for users who + primarily use their Chromebook while connected to AC. + Custom: A low and high threshold percentage is specified. + Charging begins when level drops below + charge_control_start_threshold, and ceases when + level is above charge_control_end_threshold. + +What: /sys/class/power_supply/wilco_charger/charge_control_start_threshold +Date: April 2019 +KernelVersion: 5.2 +Description: + Used when charge_type="Custom", as described above. Measured in + percentages. The valid range is [50, 95]. + +What: /sys/class/power_supply/wilco_charger/charge_control_end_threshold +Date: April 2019 +KernelVersion: 5.2 +Description: + Used when charge_type="Custom", as described above. Measured in + percentages. The valid range is [55, 100]. diff --git a/drivers/platform/chrome/wilco_ec/Kconfig b/drivers/platform/chrome/wilco_ec/Kconfig index e09e4cebe9b4..ec0db8dd14c2 100644 --- a/drivers/platform/chrome/wilco_ec/Kconfig +++ b/drivers/platform/chrome/wilco_ec/Kconfig @@ -18,3 +18,12 @@ config WILCO_EC_DEBUGFS manipulation and allow for testing arbitrary commands. This interface is intended for debug only and will not be present on production devices. + +config CHARGER_WILCO + tristate "Enable charger control" + depends on WILCO_EC + help + If you say Y here, you get support to control the charging + routines performed by the Wilco Embedded Controller. + Further information can be found in + Documentation/ABI/testing/sysfs-class-power-wilco) diff --git a/drivers/platform/chrome/wilco_ec/Makefile b/drivers/platform/chrome/wilco_ec/Makefile index 063e7fb4ea17..29b734137786 100644 --- a/drivers/platform/chrome/wilco_ec/Makefile +++ b/drivers/platform/chrome/wilco_ec/Makefile @@ -1,6 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 -wilco_ec-objs := core.o mailbox.o +wilco_ec-objs := core.o mailbox.o properties.o obj-$(CONFIG_WILCO_EC) += wilco_ec.o wilco_ec_debugfs-objs := debugfs.o obj-$(CONFIG_WILCO_EC_DEBUGFS) += wilco_ec_debugfs.o diff --git a/drivers/platform/chrome/wilco_ec/core.c b/drivers/platform/chrome/wilco_ec/core.c index 05e1e2be1c91..a8e3ef59f4ea 100644 --- a/drivers/platform/chrome/wilco_ec/core.c +++ b/drivers/platform/chrome/wilco_ec/core.c @@ -89,8 +89,20 @@ static int wilco_ec_probe(struct platform_device *pdev) goto unregister_debugfs; } + /* Register child device to be found by charger config driver. */ + ec->charger_pdev = platform_device_register_data(dev, "wilco-charger", + PLATFORM_DEVID_AUTO, + NULL, 0); + if (IS_ERR(ec->charger_pdev)) { + dev_err(dev, "Failed to create charger platform device\n"); + ret = PTR_ERR(ec->charger_pdev); + goto unregister_rtc; + } + return 0; +unregister_rtc: + platform_device_unregister(ec->rtc_pdev); unregister_debugfs: if (ec->debugfs_pdev) platform_device_unregister(ec->debugfs_pdev); @@ -102,6 +114,7 @@ static int wilco_ec_remove(struct platform_device *pdev) { struct wilco_ec_device *ec = platform_get_drvdata(pdev); + platform_device_unregister(ec->charger_pdev); platform_device_unregister(ec->rtc_pdev); if (ec->debugfs_pdev) platform_device_unregister(ec->debugfs_pdev); diff --git a/drivers/platform/chrome/wilco_ec/properties.c b/drivers/platform/chrome/wilco_ec/properties.c new file mode 100644 index 000000000000..307619554da8 --- /dev/null +++ b/drivers/platform/chrome/wilco_ec/properties.c @@ -0,0 +1,134 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2019 Google LLC + */ + +#include <linux/platform_data/wilco-ec.h> +#include <linux/string.h> +#include <linux/unaligned/le_memmove.h> + +/* Operation code; what the EC should do with the property */ +enum property_op { + OP_GET = 0, + OP_SET = 1, +}; + +struct ec_property_request { + u8 op; /* One of enum property_op */ + u8 property_id[4]; /* The 32 bit PID is stored Little Endian */ + u8 length; + u8 data[WILCO_EC_PROPERTY_MAX_SIZE]; +} __packed; + +struct ec_property_response { + u8 reserved[2]; + u8 op; /* One of enum property_op */ + u8 property_id[4]; /* The 32 bit PID is stored Little Endian */ + u8 length; + u8 data[WILCO_EC_PROPERTY_MAX_SIZE]; +} __packed; + +static int send_property_msg(struct wilco_ec_device *ec, + struct ec_property_request *rq, + struct ec_property_response *rs) +{ + struct wilco_ec_message ec_msg; + int ret; + + memset(&ec_msg, 0, sizeof(ec_msg)); + ec_msg.type = WILCO_EC_MSG_PROPERTY; + ec_msg.request_data = rq; + ec_msg.request_size = sizeof(*rq); + ec_msg.response_data = rs; + ec_msg.response_size = sizeof(*rs); + + ret = wilco_ec_mailbox(ec, &ec_msg); + if (ret < 0) + return ret; + if (rs->op != rq->op) + return -EBADMSG; + if (memcmp(rq->property_id, rs->property_id, sizeof(rs->property_id))) + return -EBADMSG; + if (rs->length > sizeof(rs->data)) + return -EMSGSIZE; + + return 0; +} + +int wilco_ec_get_property(struct wilco_ec_device *ec, + struct wilco_ec_property_msg *prop_msg) +{ + struct ec_property_request rq; + struct ec_property_response rs; + int ret; + + memset(&rq, 0, sizeof(rq)); + rq.op = OP_GET; + put_unaligned_le32(prop_msg->property_id, rq.property_id); + + ret = send_property_msg(ec, &rq, &rs); + if (ret < 0) + return ret; + + prop_msg->length = rs.length; + memcpy(prop_msg->data, rs.data, rs.length); + + return 0; +} +EXPORT_SYMBOL_GPL(wilco_ec_get_property); + +int wilco_ec_set_property(struct wilco_ec_device *ec, + struct wilco_ec_property_msg *prop_msg) +{ + struct ec_property_request rq; + struct ec_property_response rs; + int ret; + + memset(&rq, 0, sizeof(rq)); + rq.op = OP_SET; + put_unaligned_le32(prop_msg->property_id, rq.property_id); + rq.length = prop_msg->length; + memcpy(rq.data, prop_msg->data, prop_msg->length); + + ret = send_property_msg(ec, &rq, &rs); + if (ret < 0) + return ret; + if (rs.length != prop_msg->length) + return -EBADMSG; + + return 0; +} +EXPORT_SYMBOL_GPL(wilco_ec_set_property); + +int wilco_ec_get_byte_property(struct wilco_ec_device *ec, u32 property_id, + u8 *val) +{ + struct wilco_ec_property_msg msg; + int ret; + + msg.property_id = property_id; + + ret = wilco_ec_get_property(ec, &msg); + if (ret < 0) + return ret; + if (msg.length != 1) + return -EBADMSG; + + *val = msg.data[0]; + + return 0; +} +EXPORT_SYMBOL_GPL(wilco_ec_get_byte_property); + +int wilco_ec_set_byte_property(struct wilco_ec_device *ec, u32 property_id, + u8 val) +{ + struct wilco_ec_property_msg msg; + + msg.property_id = property_id; + msg.data[0] = val; + msg.length = 1; + + return wilco_ec_set_property(ec, &msg); +} +EXPORT_SYMBOL_GPL(wilco_ec_set_byte_property); diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile index b731c2a9b695..2b603a142701 100644 --- a/drivers/power/supply/Makefile +++ b/drivers/power/supply/Makefile @@ -87,3 +87,4 @@ obj-$(CONFIG_AXP288_CHARGER) += axp288_charger.o obj-$(CONFIG_CHARGER_CROS_USBPD) += cros_usbpd-charger.o obj-$(CONFIG_CHARGER_SC2731) += sc2731_charger.o obj-$(CONFIG_FUEL_GAUGE_SC27XX) += sc27xx_fuel_gauge.o +obj-$(CONFIG_CHARGER_WILCO) += wilco-charger.o diff --git a/drivers/power/supply/wilco-charger.c b/drivers/power/supply/wilco-charger.c new file mode 100644 index 000000000000..96544c25bb80 --- /dev/null +++ b/drivers/power/supply/wilco-charger.c @@ -0,0 +1,190 @@ +// 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_ILLEGAL = -1, + 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 */ +}; + +#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 enum charge_mode 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; + default: + return CHARGE_MODE_ILLEGAL; + } +} + +/* 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; + 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); + enum charge_mode mode; + + switch (psp) { + case POWER_SUPPLY_PROP_CHARGE_TYPE: + mode = psp_val_to_charge_mode(val->intval); + if (mode == CHARGE_MODE_ILLEGAL) + 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 = "wilco-charger", + .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); + if (IS_ERR(psy)) + return PTR_ERR(psy); + + return 0; +} + +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 <[email protected]>"); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Wilco EC charge control driver"); diff --git a/include/linux/platform_data/wilco-ec.h b/include/linux/platform_data/wilco-ec.h index 1ff224793c99..66d9f177bec2 100644 --- a/include/linux/platform_data/wilco-ec.h +++ b/include/linux/platform_data/wilco-ec.h @@ -32,6 +32,7 @@ * @data_size: Size of the data buffer used for EC communication. * @debugfs_pdev: The child platform_device used by the debugfs sub-driver. * @rtc_pdev: The child platform_device used by the RTC sub-driver. + * @charger_pdev: Child platform_device used by the charger config sub-driver. */ struct wilco_ec_device { struct device *dev; @@ -43,6 +44,7 @@ struct wilco_ec_device { size_t data_size; struct platform_device *debugfs_pdev; struct platform_device *rtc_pdev; + struct platform_device *charger_pdev; }; /** @@ -123,4 +125,75 @@ struct wilco_ec_message { */ int wilco_ec_mailbox(struct wilco_ec_device *ec, struct wilco_ec_message *msg); +/* + * A Property is typically a data item that is stored to NVRAM + * by the EC. Each of these data items has an index associated + * with it, known as the Property ID (PID). Properties may have + * variable lengths, up to a max of WILCO_EC_PROPERTY_MAX_SIZE + * bytes. Properties can be simple integers, or they may be more + * complex binary data. + */ + +#define WILCO_EC_PROPERTY_MAX_SIZE 4 + +/** + * struct ec_property_set_msg - Message to get or set a property. + * @property_id: Which property to get or set. + * @length: Number of bytes of |data| that are used. + * @data: Actual property data. + */ +struct wilco_ec_property_msg { + u32 property_id; + int length; + u8 data[WILCO_EC_PROPERTY_MAX_SIZE]; +}; + +/** + * wilco_ec_get_property() - Retrieve a property from the EC. + * @ec: Embedded Controller device. + * @prop_msg: Message for request and response. + * + * The property_id field of |prop_msg| should be filled before calling this + * function. The result will be stored in the data and length fields. + * + * Return: 0 on success, negative error code on failure. + */ +int wilco_ec_get_property(struct wilco_ec_device *ec, + struct wilco_ec_property_msg *prop_msg); + +/** + * wilco_ec_set_property() - Store a property on the EC. + * @ec: Embedded Controller device. + * @prop_msg: Message for request and response. + * + * The property_id, length, and data fields of |prop_msg| should be + * filled before calling this function. + * + * Return: 0 on success, negative error code on failure. + */ +int wilco_ec_set_property(struct wilco_ec_device *ec, + struct wilco_ec_property_msg *prop_msg); + +/** + * wilco_ec_get_byte_property() - Retrieve a byte-size property from the EC. + * @ec: Embedded Controller device. + * @property_id: Which property to retrieve. + * @val: The result value, will be filled by this function. + * + * Return: 0 on success, negative error code on failure. + */ +int wilco_ec_get_byte_property(struct wilco_ec_device *ec, u32 property_id, + u8 *val); + +/** + * wilco_ec_get_byte_property() - Store a byte-size property on the EC. + * @ec: Embedded Controller device. + * @property_id: Which property to store. + * @val: Value to store. + * + * Return: 0 on success, negative error code on failure. + */ +int wilco_ec_set_byte_property(struct wilco_ec_device *ec, u32 property_id, + u8 val); + #endif /* WILCO_EC_H */ -- 2.20.1
