// SPDX-License-Identifier: GPL-2.0-only /* * huawei-gaokun-ec - An EC driver for HUAWEI Matebook E Go * * Copyright (C) 2024-2025 Pengyu Luo */ #include #include #include #include #include #include #include #include #include #include #include #include #define EC_EVENT 0x06 /* Also can be found in ACPI specification 12.3 */ #define EC_READ 0x80 #define EC_WRITE 0x81 #define EC_BURST 0x82 #define EC_QUERY 0x84 #define EC_FN_LOCK_ON 0x5A #define EC_FN_LOCK_OFF 0x55 #define EC_FN_LOCK_READ 0x6B #define EC_FN_LOCK_WRITE 0x6C #define EC_EVENT_LID 0x81 #define EC_LID_STATE 0x80 #define EC_LID_OPEN BIT(1) #define EC_TEMP_REG 0x61 #define EC_STANDBY_REG 0xB2 #define EC_STANDBY_ENTER 0xDB #define EC_STANDBY_EXIT 0xEB enum gaokun_ec_smart_charge_cmd { SMART_CHARGE_DATA_WRITE = 0xE3, SMART_CHARGE_DATA_READ, SMART_CHARGE_ENABLE_WRITE, SMART_CHARGE_ENABLE_READ, }; enum gaokun_ec_ucsi_cmd { UCSI_REG_WRITE = 0xD2, UCSI_REG_READ, UCSI_DATA_WRITE, UCSI_DATA_READ, }; #define UCSI_REG_SIZE 7 /* * For tx, command sequences are arranged as * {master_cmd, slave_cmd, data_len, data_seq} */ #define REQ_HDR_SIZE 3 #define INPUT_SIZE_OFFSET 2 #define REQ_LEN(req) (REQ_HDR_SIZE + (req)[INPUT_SIZE_OFFSET]) /* * For rx, data sequences are arranged as * {status, data_len(unreliable), data_seq} */ #define RESP_HDR_SIZE 2 #define MKREQ(REG0, REG1, SIZE, ...) \ { \ REG0, REG1, SIZE, \ /* ## will remove comma when SIZE is 0 */ \ ## __VA_ARGS__, \ /* make sure len(pkt[3:]) >= SIZE */ \ [3 + (SIZE)] = 0, \ } #define MKRESP(SIZE) \ { \ [RESP_HDR_SIZE + (SIZE) - 1] = 0, \ } /* Possible size 1, 4, 20, 24. Most of the time, the size is 1. */ static inline void refill_req(u8 *dest, const u8 *src, size_t size) { memcpy(dest + REQ_HDR_SIZE, src, size); } static inline void refill_req_byte(u8 *dest, const u8 *src) { dest[REQ_HDR_SIZE] = *src; } /* Possible size 1, 2, 4, 7, 20. Most of the time, the size is 1. */ static inline void extr_resp(u8 *dest, const u8 *src, size_t size) { memcpy(dest, src + RESP_HDR_SIZE, size); } static inline void extr_resp_byte(u8 *dest, const u8 *src) { *dest = src[RESP_HDR_SIZE]; } static inline void *extr_resp_shallow(const u8 *src) { return (void *)(src + RESP_HDR_SIZE); } struct gaokun_ec { struct i2c_client *client; struct mutex lock; /* EC transaction lock */ struct blocking_notifier_head notifier_list; struct device *hwmon_dev; struct input_dev *idev; bool suspended; }; static int gaokun_ec_request(struct gaokun_ec *ec, const u8 *req, size_t resp_len, u8 *resp) { struct i2c_client *client = ec->client; struct i2c_msg msgs[] = { { .addr = client->addr, .flags = client->flags, .len = REQ_LEN(req), .buf = (void *)req, }, { .addr = client->addr, .flags = client->flags | I2C_M_RD, .len = resp_len, .buf = resp, }, }; int ret; guard(mutex)(&ec->lock); ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); if (ret != ARRAY_SIZE(msgs)) { dev_err(&client->dev, "I2C transfer error %d\n", ret); goto out_after_break; } ret = *resp; if (ret) dev_err(&client->dev, "EC transaction error %d\n", ret); out_after_break: usleep_range(2000, 2500); /* have a break, ACPI did this */ return ret; } /* -------------------------------------------------------------------------- */ /* Common API */ /** * gaokun_ec_read - Read from EC * @ec: The gaokun_ec structure * @req: The sequence to request * @resp_len: The size to read * @resp: The buffer to store response sequence * * This function is used to read data after writing a magic sequence to EC. * All EC operations depend on this function. * * Huawei uses magic sequences everywhere to complete various functions, all * these sequences are passed to ECCD(a ACPI method which is quiet similar * to gaokun_ec_request), there is no good abstraction to generalize these * sequences, so just wrap it for now. Almost all magic sequences are kept * in this file. * * Return: 0 on success or negative error code. */ int gaokun_ec_read(struct gaokun_ec *ec, const u8 *req, size_t resp_len, u8 *resp) { return gaokun_ec_request(ec, req, resp_len, resp); } EXPORT_SYMBOL_GPL(gaokun_ec_read); /** * gaokun_ec_write - Write to EC * @ec: The gaokun_ec structure * @req: The sequence to request * * This function has no big difference from gaokun_ec_read. When caller care * only write status and no actual data are returned, then use it. * * Return: 0 on success or negative error code. */ int gaokun_ec_write(struct gaokun_ec *ec, const u8 *req) { u8 ec_resp[] = MKRESP(0); return gaokun_ec_request(ec, req, sizeof(ec_resp), ec_resp); } EXPORT_SYMBOL_GPL(gaokun_ec_write); int gaokun_ec_read_byte(struct gaokun_ec *ec, const u8 *req, u8 *byte) { int ret; u8 ec_resp[] = MKRESP(sizeof(*byte)); ret = gaokun_ec_read(ec, req, sizeof(ec_resp), ec_resp); extr_resp_byte(byte, ec_resp); return ret; } EXPORT_SYMBOL_GPL(gaokun_ec_read_byte); /** * gaokun_ec_register_notify - Register a notifier callback for EC events. * @ec: The gaokun_ec structure * @nb: Notifier block pointer to register * * Return: 0 on success or negative error code. */ int gaokun_ec_register_notify(struct gaokun_ec *ec, struct notifier_block *nb) { return blocking_notifier_chain_register(&ec->notifier_list, nb); } EXPORT_SYMBOL_GPL(gaokun_ec_register_notify); /** * gaokun_ec_unregister_notify - Unregister notifier callback for EC events. * @ec: The gaokun_ec structure * @nb: Notifier block pointer to unregister * * Unregister a notifier callback that was previously registered with * gaokun_ec_register_notify(). */ void gaokun_ec_unregister_notify(struct gaokun_ec *ec, struct notifier_block *nb) { blocking_notifier_chain_unregister(&ec->notifier_list, nb); } EXPORT_SYMBOL_GPL(gaokun_ec_unregister_notify); /* -------------------------------------------------------------------------- */ /* API for PSY */ /** * gaokun_ec_psy_multi_read - Read contiguous registers * @ec: The gaokun_ec structure * @reg: The start register * @resp_len: The number of registers to be read * @resp: The buffer to store response sequence * * Return: 0 on success or negative error code. */ int gaokun_ec_psy_multi_read(struct gaokun_ec *ec, u8 reg, size_t resp_len, u8 *resp) { u8 ec_req[] = MKREQ(0x02, EC_READ, 1, 0); u8 ec_resp[] = MKRESP(1); int i, ret; for (i = 0; i < resp_len; ++i, reg++) { refill_req_byte(ec_req, ®); ret = gaokun_ec_read(ec, ec_req, sizeof(ec_resp), ec_resp); if (ret) return ret; extr_resp_byte(&resp[i], ec_resp); } return 0; } EXPORT_SYMBOL_GPL(gaokun_ec_psy_multi_read); /* Smart charge */ /** * gaokun_ec_psy_get_smart_charge - Get smart charge data from EC * @ec: The gaokun_ec structure * @resp: The buffer to store response sequence (mode, delay, start, end) * * Return: 0 on success or negative error code. */ int gaokun_ec_psy_get_smart_charge(struct gaokun_ec *ec, u8 resp[GAOKUN_SMART_CHARGE_DATA_SIZE]) { /* GBCM */ u8 ec_req[] = MKREQ(0x02, SMART_CHARGE_DATA_READ, 0); u8 ec_resp[] = MKRESP(GAOKUN_SMART_CHARGE_DATA_SIZE); int ret; ret = gaokun_ec_read(ec, ec_req, sizeof(ec_resp), ec_resp); if (ret) return ret; extr_resp(resp, ec_resp, GAOKUN_SMART_CHARGE_DATA_SIZE); return 0; } EXPORT_SYMBOL_GPL(gaokun_ec_psy_get_smart_charge); static inline bool validate_battery_threshold_range(u8 start, u8 end) { return end != 0 && start <= end && end <= 100; } /** * gaokun_ec_psy_set_smart_charge - Set smart charge data * @ec: The gaokun_ec structure * @req: The sequence to request (mode, delay, start, end) * * Return: 0 on success or negative error code. */ int gaokun_ec_psy_set_smart_charge(struct gaokun_ec *ec, const u8 req[GAOKUN_SMART_CHARGE_DATA_SIZE]) { /* SBCM */ u8 ec_req[] = MKREQ(0x02, SMART_CHARGE_DATA_WRITE, GAOKUN_SMART_CHARGE_DATA_SIZE); if (!validate_battery_threshold_range(req[2], req[3])) return -EINVAL; refill_req(ec_req, req, GAOKUN_SMART_CHARGE_DATA_SIZE); return gaokun_ec_write(ec, ec_req); } EXPORT_SYMBOL_GPL(gaokun_ec_psy_set_smart_charge); /* Smart charge enable */ /** * gaokun_ec_psy_get_smart_charge_enable - Get smart charge state * @ec: The gaokun_ec structure * @on: The state * * Return: 0 on success or negative error code. */ int gaokun_ec_psy_get_smart_charge_enable(struct gaokun_ec *ec, bool *on) { /* GBAC */ u8 ec_req[] = MKREQ(0x02, SMART_CHARGE_ENABLE_READ, 0); u8 state; int ret; ret = gaokun_ec_read_byte(ec, ec_req, &state); if (ret) return ret; *on = !!state; return 0; } EXPORT_SYMBOL_GPL(gaokun_ec_psy_get_smart_charge_enable); /** * gaokun_ec_psy_set_smart_charge_enable - Set smart charge state * @ec: The gaokun_ec structure * @on: The state * * Return: 0 on success or negative error code. */ int gaokun_ec_psy_set_smart_charge_enable(struct gaokun_ec *ec, bool on) { /* SBAC */ u8 ec_req[] = MKREQ(0x02, SMART_CHARGE_ENABLE_WRITE, 1, on); return gaokun_ec_write(ec, ec_req); } EXPORT_SYMBOL_GPL(gaokun_ec_psy_set_smart_charge_enable); /* -------------------------------------------------------------------------- */ /* API for UCSI */ /** * gaokun_ec_ucsi_read - Read UCSI data from EC * @ec: The gaokun_ec structure * @resp: The buffer to store response sequence * * Read CCI and MSGI (used by UCSI subdriver). * * Return: 0 on success or negative error code. */ int gaokun_ec_ucsi_read(struct gaokun_ec *ec, u8 resp[GAOKUN_UCSI_READ_SIZE]) { u8 ec_req[] = MKREQ(0x03, UCSI_DATA_READ, 0); u8 ec_resp[] = MKRESP(GAOKUN_UCSI_READ_SIZE); int ret; ret = gaokun_ec_read(ec, ec_req, sizeof(ec_resp), ec_resp); if (ret) return ret; extr_resp(resp, ec_resp, GAOKUN_UCSI_READ_SIZE); return 0; } EXPORT_SYMBOL_GPL(gaokun_ec_ucsi_read); /** * gaokun_ec_ucsi_write - Write UCSI data to EC * @ec: The gaokun_ec structure * @req: The sequence to request * * Write CTRL and MSGO (used by UCSI subdriver). * * Return: 0 on success or negative error code. */ int gaokun_ec_ucsi_write(struct gaokun_ec *ec, const u8 req[GAOKUN_UCSI_WRITE_SIZE]) { u8 ec_req[] = MKREQ(0x03, UCSI_DATA_WRITE, GAOKUN_UCSI_WRITE_SIZE); refill_req(ec_req, req, GAOKUN_UCSI_WRITE_SIZE); return gaokun_ec_write(ec, ec_req); } EXPORT_SYMBOL_GPL(gaokun_ec_ucsi_write); /** * gaokun_ec_ucsi_get_reg - Get UCSI register from EC * @ec: The gaokun_ec structure * @ureg: The gaokun ucsi register * * Get UCSI register data (used by UCSI subdriver). * * Return: 0 on success or negative error code. */ int gaokun_ec_ucsi_get_reg(struct gaokun_ec *ec, struct gaokun_ucsi_reg *ureg) { u8 ec_req[] = MKREQ(0x03, UCSI_REG_READ, 0); u8 ec_resp[] = MKRESP(UCSI_REG_SIZE); int ret; ret = gaokun_ec_read(ec, ec_req, sizeof(ec_resp), ec_resp); if (ret) return ret; extr_resp((u8 *)ureg, ec_resp, UCSI_REG_SIZE); return 0; } EXPORT_SYMBOL_GPL(gaokun_ec_ucsi_get_reg); /** * gaokun_ec_ucsi_pan_ack - Ack pin assignment notifications from EC * @ec: The gaokun_ec structure * @port_id: The port id receiving and handling the notifications * * Ack pin assignment notifications (used by UCSI subdriver). * * Return: 0 on success or negative error code. */ int gaokun_ec_ucsi_pan_ack(struct gaokun_ec *ec, int port_id) { u8 ec_req[] = MKREQ(0x03, UCSI_REG_WRITE, 1); u8 data = 1 << port_id; if (port_id == GAOKUN_UCSI_NO_PORT_UPDATE) data = 0; refill_req_byte(ec_req, &data); return gaokun_ec_write(ec, ec_req); } EXPORT_SYMBOL_GPL(gaokun_ec_ucsi_pan_ack); /* -------------------------------------------------------------------------- */ /* EC Sysfs */ /* Fn lock */ static int gaokun_ec_get_fn_lock(struct gaokun_ec *ec, bool *on) { /* GFRS */ u8 ec_req[] = MKREQ(0x02, EC_FN_LOCK_READ, 0); int ret; u8 state; ret = gaokun_ec_read_byte(ec, ec_req, &state); if (ret) return ret; if (state == EC_FN_LOCK_ON) *on = true; else if (state == EC_FN_LOCK_OFF) *on = false; else return -EIO; return 0; } static int gaokun_ec_set_fn_lock(struct gaokun_ec *ec, bool on) { /* SFRS */ u8 ec_req[] = MKREQ(0x02, EC_FN_LOCK_WRITE, 1, on ? EC_FN_LOCK_ON : EC_FN_LOCK_OFF); return gaokun_ec_write(ec, ec_req); } static ssize_t fn_lock_show(struct device *dev, struct device_attribute *attr, char *buf) { struct gaokun_ec *ec = dev_get_drvdata(dev); bool on; int ret; ret = gaokun_ec_get_fn_lock(ec, &on); if (ret) return ret; return sysfs_emit(buf, "%d\n", on); } static ssize_t fn_lock_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t size) { struct gaokun_ec *ec = dev_get_drvdata(dev); bool on; int ret; if (kstrtobool(buf, &on)) return -EINVAL; ret = gaokun_ec_set_fn_lock(ec, on); if (ret) return ret; return size; } static DEVICE_ATTR_RW(fn_lock); static struct attribute *gaokun_ec_attrs[] = { &dev_attr_fn_lock.attr, NULL, }; ATTRIBUTE_GROUPS(gaokun_ec); /* -------------------------------------------------------------------------- */ /* Thermal Zone HwMon */ /* Range from 0 to 0x2C, partially valid */ static const u8 temp_reg[] = { 0x05, 0x07, 0x08, 0x0E, 0x0F, 0x12, 0x15, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A }; static int gaokun_ec_get_temp(struct gaokun_ec *ec, u8 idx, long *temp) { /* GTMP */ u8 ec_req[] = MKREQ(0x02, EC_TEMP_REG, 1, temp_reg[idx]); u8 ec_resp[] = MKRESP(sizeof(__le16)); __le16 *tmp; int ret; ret = gaokun_ec_read(ec, ec_req, sizeof(ec_resp), ec_resp); if (ret) return ret; tmp = (__le16 *)extr_resp_shallow(ec_resp); *temp = le16_to_cpu(*tmp) * 100; /* convert to HwMon's unit */ return 0; } static umode_t gaokun_ec_hwmon_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr, int channel) { return type == hwmon_temp ? 0444 : 0; } static int gaokun_ec_hwmon_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long *val) { struct gaokun_ec *ec = dev_get_drvdata(dev); if (type == hwmon_temp) return gaokun_ec_get_temp(ec, channel, val); return -EINVAL; } static const struct hwmon_ops gaokun_ec_hwmon_ops = { .is_visible = gaokun_ec_hwmon_is_visible, .read = gaokun_ec_hwmon_read, }; static u32 gaokun_ec_temp_config[] = { [0 ... ARRAY_SIZE(temp_reg) - 1] = HWMON_T_INPUT, 0 }; static const struct hwmon_channel_info gaokun_ec_temp = { .type = hwmon_temp, .config = gaokun_ec_temp_config, }; static const struct hwmon_channel_info * const gaokun_ec_hwmon_info[] = { &gaokun_ec_temp, NULL }; static const struct hwmon_chip_info gaokun_ec_hwmon_chip_info = { .ops = &gaokun_ec_hwmon_ops, .info = gaokun_ec_hwmon_info, }; /* -------------------------------------------------------------------------- */ /* Modern Standby */ static int gaokun_ec_suspend(struct device *dev) { struct gaokun_ec *ec = dev_get_drvdata(dev); u8 ec_req[] = MKREQ(0x02, EC_STANDBY_REG, 1, EC_STANDBY_ENTER); int ret; if (ec->suspended) return 0; ret = gaokun_ec_write(ec, ec_req); if (ret) return ret; ec->suspended = true; return 0; } static int gaokun_ec_resume(struct device *dev) { struct gaokun_ec *ec = dev_get_drvdata(dev); u8 ec_req[] = MKREQ(0x02, EC_STANDBY_REG, 1, EC_STANDBY_EXIT); int ret; int i; if (!ec->suspended) return 0; for (i = 0; i < 3; ++i) { ret = gaokun_ec_write(ec, ec_req); if (ret == 0) break; msleep(100); /* EC need time to resume */ }; ec->suspended = false; return 0; } static void gaokun_aux_release(struct device *dev) { struct auxiliary_device *adev = to_auxiliary_dev(dev); kfree(adev); } static void gaokun_aux_remove(void *data) { struct auxiliary_device *adev = data; auxiliary_device_delete(adev); auxiliary_device_uninit(adev); } static int gaokun_aux_init(struct device *parent, const char *name, struct gaokun_ec *ec) { struct auxiliary_device *adev; int ret; adev = kzalloc(sizeof(*adev), GFP_KERNEL); if (!adev) return -ENOMEM; adev->name = name; adev->id = 0; adev->dev.parent = parent; adev->dev.release = gaokun_aux_release; adev->dev.platform_data = ec; /* Allow aux devices to access parent's DT nodes directly */ device_set_of_node_from_dev(&adev->dev, parent); ret = auxiliary_device_init(adev); if (ret) { kfree(adev); return ret; } ret = auxiliary_device_add(adev); if (ret) { auxiliary_device_uninit(adev); return ret; } return devm_add_action_or_reset(parent, gaokun_aux_remove, adev); } /* -------------------------------------------------------------------------- */ /* EC */ static irqreturn_t gaokun_ec_irq_handler(int irq, void *data) { struct gaokun_ec *ec = data; u8 ec_req[] = MKREQ(EC_EVENT, EC_QUERY, 0); u8 status, id; int ret; ret = gaokun_ec_read_byte(ec, ec_req, &id); if (ret) return IRQ_HANDLED; switch (id) { case 0x0: /* No event */ break; case EC_EVENT_LID: gaokun_ec_psy_read_byte(ec, EC_LID_STATE, &status); status &= EC_LID_OPEN; input_report_switch(ec->idev, SW_LID, !status); input_sync(ec->idev); break; default: blocking_notifier_call_chain(&ec->notifier_list, id, ec); } return IRQ_HANDLED; } static int gaokun_ec_probe(struct i2c_client *client) { struct device *dev = &client->dev; struct gaokun_ec *ec; int ret; ec = devm_kzalloc(dev, sizeof(*ec), GFP_KERNEL); if (!ec) return -ENOMEM; ret = devm_mutex_init(dev, &ec->lock); if (ret) return ret; ec->client = client; i2c_set_clientdata(client, ec); BLOCKING_INIT_NOTIFIER_HEAD(&ec->notifier_list); /* Lid switch */ ec->idev = devm_input_allocate_device(dev); if (!ec->idev) return -ENOMEM; ec->idev->name = "LID"; ec->idev->phys = "gaokun-ec/input0"; input_set_capability(ec->idev, EV_SW, SW_LID); ret = input_register_device(ec->idev); if (ret) return dev_err_probe(dev, ret, "Failed to register input device\n"); ret = gaokun_aux_init(dev, GAOKUN_DEV_PSY, ec); if (ret) return ret; ret = gaokun_aux_init(dev, GAOKUN_DEV_UCSI, ec); if (ret) return ret; ret = devm_request_threaded_irq(dev, client->irq, NULL, gaokun_ec_irq_handler, IRQF_ONESHOT, dev_name(dev), ec); if (ret) return dev_err_probe(dev, ret, "Failed to request IRQ\n"); ec->hwmon_dev = devm_hwmon_device_register_with_info(dev, "gaokun_ec_hwmon", ec, &gaokun_ec_hwmon_chip_info, NULL); if (IS_ERR(ec->hwmon_dev)) return dev_err_probe(dev, PTR_ERR(ec->hwmon_dev), "Failed to register hwmon device\n"); return 0; } static const struct i2c_device_id gaokun_ec_id[] = { { "gaokun-ec", }, { } }; MODULE_DEVICE_TABLE(i2c, gaokun_ec_id); static const struct of_device_id gaokun_ec_of_match[] = { { .compatible = "huawei,gaokun3-ec", }, { } }; MODULE_DEVICE_TABLE(of, gaokun_ec_of_match); static const struct dev_pm_ops gaokun_ec_pm_ops = { NOIRQ_SYSTEM_SLEEP_PM_OPS(gaokun_ec_suspend, gaokun_ec_resume) }; static struct i2c_driver gaokun_ec_driver = { .driver = { .name = "gaokun-ec", .of_match_table = gaokun_ec_of_match, .pm = &gaokun_ec_pm_ops, .dev_groups = gaokun_ec_groups, }, .probe = gaokun_ec_probe, .id_table = gaokun_ec_id, }; module_i2c_driver(gaokun_ec_driver); MODULE_DESCRIPTION("HUAWEI Matebook E Go EC driver"); MODULE_AUTHOR("Pengyu Luo "); MODULE_LICENSE("GPL");