]> git.ipfire.org Git - thirdparty/linux.git/commitdiff
platform: arm64: add Huawei Matebook E Go EC driver
authorPengyu Luo <mitltlatltl@gmail.com>
Fri, 14 Feb 2025 18:06:55 +0000 (02:06 +0800)
committerIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Mon, 3 Mar 2025 08:55:36 +0000 (10:55 +0200)
There are three variants of which Huawei released the first two
simultaneously.

Huawei Matebook E Go LTE(sc8180x), codename seems to be gaokun2.
Huawei Matebook E Go(sc8280xp@3.0GHz), codename must be gaokun3. (see [1])
Huawei Matebook E Go 2023(sc8280xp@2.69GHz), codename should be also gaokun3.

Adding support for the latter two variants for now, this driver should
also work for the sc8180x variant according to acpi table files, but I
don't have the device to test yet.

Different from other Qualcomm Snapdragon sc8280xp based machines, the
Huawei Matebook E Go uses an embedded controller while others use
a system called PMIC GLink. This embedded controller can be used to
perform a set of various functions, including, but not limited to:

- Battery and charger monitoring;
- Charge control and smart charge;
- Fn_lock settings;
- Tablet lid status;
- Temperature sensors;
- USB Type-C notifications (ports orientation,  DP alt mode HPD);
- USB Type-C PD (according to observation, up to 48w).

Add a driver for the EC which creates devices for UCSI and power supply
devices.

This driver is inspired by the following drivers:
        drivers/platform/arm64/acer-aspire1-ec.c
        drivers/platform/arm64/lenovo-yoga-c630.c
        drivers/platform/x86/huawei-wmi.c

Also thanks for reviewers' working. They have made this patch improve
a lot.

[1] https://bugzilla.kernel.org/show_bug.cgi?id=219645

Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20250214180656.28599-3-mitltlatltl@gmail.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
MAINTAINERS
drivers/platform/arm64/Kconfig
drivers/platform/arm64/Makefile
drivers/platform/arm64/huawei-gaokun-ec.c [new file with mode: 0644]
include/linux/platform_data/huawei-gaokun-ec.h [new file with mode: 0644]

index f71fec78e1cf097e3ea9b71105893548537f70c4..0669b6433b1a68bf4af913ab1095422730a255d1 100644 (file)
@@ -10698,6 +10698,13 @@ S:     Maintained
 F:     Documentation/networking/device_drivers/ethernet/huawei/hinic.rst
 F:     drivers/net/ethernet/huawei/hinic/
 
+HUAWEI MATEBOOK E GO EMBEDDED CONTROLLER DRIVER
+M:     Pengyu Luo <mitltlatltl@gmail.com>
+S:     Maintained
+F:     Documentation/devicetree/bindings/platform/huawei,gaokun-ec.yaml
+F:     drivers/platform/arm64/huawei-gaokun-ec.c
+F:     include/linux/platform_data/huawei-gaokun-ec.h
+
 HUGETLB SUBSYSTEM
 M:     Muchun Song <muchun.song@linux.dev>
 L:     linux-mm@kvack.org
index f88395ea337616dafa81c911c782663277959fc4..0abe5377891b5a4ab9e72fc96cbc070ac021513a 100644 (file)
@@ -33,6 +33,27 @@ config EC_ACER_ASPIRE1
          laptop where this information is not properly exposed via the
          standard ACPI devices.
 
+config EC_HUAWEI_GAOKUN
+       tristate "Huawei Matebook E Go Embedded Controller driver"
+       depends on ARCH_QCOM || COMPILE_TEST
+       depends on I2C
+       depends on INPUT
+       depends on HWMON
+       select AUXILIARY_BUS
+
+       help
+         Say Y here to enable the EC driver for the Huawei Matebook E Go
+         which is a sc8280xp-based 2-in-1 tablet. The driver handles battery
+         (information, charge control) and USB Type-C DP HPD events as well
+         as some misc functions like the lid sensor and temperature sensors,
+         etc.
+
+         This driver provides battery and AC status support for the mentioned
+         laptop where this information is not properly exposed via the
+         standard ACPI devices.
+
+         Say M or Y here to include this support.
+
 config EC_LENOVO_YOGA_C630
        tristate "Lenovo Yoga C630 Embedded Controller driver"
        depends on ARCH_QCOM || COMPILE_TEST
index b2ae9114fdd89f2fa4e5f09267002a6eb729a0be..46a99eba3264cc40e812567d1533bb86031a6af3 100644 (file)
@@ -6,4 +6,5 @@
 #
 
 obj-$(CONFIG_EC_ACER_ASPIRE1)  += acer-aspire1-ec.o
+obj-$(CONFIG_EC_HUAWEI_GAOKUN) += huawei-gaokun-ec.o
 obj-$(CONFIG_EC_LENOVO_YOGA_C630) += lenovo-yoga-c630.o
diff --git a/drivers/platform/arm64/huawei-gaokun-ec.c b/drivers/platform/arm64/huawei-gaokun-ec.c
new file mode 100644 (file)
index 0000000..97c2607
--- /dev/null
@@ -0,0 +1,825 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * huawei-gaokun-ec - An EC driver for HUAWEI Matebook E Go
+ *
+ * Copyright (C) 2024-2025 Pengyu Luo <mitltlatltl@gmail.com>
+ */
+
+#include <linux/auxiliary_bus.h>
+#include <linux/cleanup.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/notifier.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_data/huawei-gaokun-ec.h>
+
+#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, &reg);
+               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 <mitltlatltl@gmail.com>");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/platform_data/huawei-gaokun-ec.h b/include/linux/platform_data/huawei-gaokun-ec.h
new file mode 100644 (file)
index 0000000..faa15d3
--- /dev/null
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Huawei Matebook E Go Embedded Controller
+ *
+ * Copyright (C) 2024-2025 Pengyu Luo <mitltlatltl@gmail.com>
+ */
+
+#ifndef __HUAWEI_GAOKUN_EC_H__
+#define __HUAWEI_GAOKUN_EC_H__
+
+#define GAOKUN_UCSI_CCI_SIZE   4
+#define GAOKUN_UCSI_MSGI_SIZE  16
+#define GAOKUN_UCSI_READ_SIZE  (GAOKUN_UCSI_CCI_SIZE + GAOKUN_UCSI_MSGI_SIZE)
+#define GAOKUN_UCSI_WRITE_SIZE 24 /* 8B CTRL, 16B MSGO */
+
+#define GAOKUN_UCSI_NO_PORT_UPDATE     (-1)
+
+#define GAOKUN_SMART_CHARGE_DATA_SIZE  4 /* mode, delay, start, end */
+
+/* -------------------------------------------------------------------------- */
+
+struct gaokun_ec;
+struct gaokun_ucsi_reg;
+struct notifier_block;
+
+#define GAOKUN_MOD_NAME                        "huawei_gaokun_ec"
+#define GAOKUN_DEV_PSY                 "psy"
+#define GAOKUN_DEV_UCSI                        "ucsi"
+
+/* -------------------------------------------------------------------------- */
+/* Common API */
+
+int gaokun_ec_register_notify(struct gaokun_ec *ec,
+                             struct notifier_block *nb);
+void gaokun_ec_unregister_notify(struct gaokun_ec *ec,
+                                struct notifier_block *nb);
+
+int gaokun_ec_read(struct gaokun_ec *ec, const u8 *req,
+                  size_t resp_len, u8 *resp);
+int gaokun_ec_write(struct gaokun_ec *ec, const u8 *req);
+int gaokun_ec_read_byte(struct gaokun_ec *ec, const u8 *req, u8 *byte);
+
+/* -------------------------------------------------------------------------- */
+/* API for PSY */
+
+int gaokun_ec_psy_multi_read(struct gaokun_ec *ec, u8 reg,
+                            size_t resp_len, u8 *resp);
+
+static inline int gaokun_ec_psy_read_byte(struct gaokun_ec *ec,
+                                         u8 reg, u8 *byte)
+{
+       return gaokun_ec_psy_multi_read(ec, reg, sizeof(*byte), byte);
+}
+
+static inline int gaokun_ec_psy_read_word(struct gaokun_ec *ec,
+                                         u8 reg, u16 *word)
+{
+       return gaokun_ec_psy_multi_read(ec, reg, sizeof(*word), (u8 *)word);
+}
+
+int gaokun_ec_psy_get_smart_charge(struct gaokun_ec *ec,
+                                  u8 resp[GAOKUN_SMART_CHARGE_DATA_SIZE]);
+int gaokun_ec_psy_set_smart_charge(struct gaokun_ec *ec,
+                                  const u8 req[GAOKUN_SMART_CHARGE_DATA_SIZE]);
+
+int gaokun_ec_psy_get_smart_charge_enable(struct gaokun_ec *ec, bool *on);
+int gaokun_ec_psy_set_smart_charge_enable(struct gaokun_ec *ec, bool on);
+
+/* -------------------------------------------------------------------------- */
+/* API for UCSI */
+
+int gaokun_ec_ucsi_read(struct gaokun_ec *ec, u8 resp[GAOKUN_UCSI_READ_SIZE]);
+int gaokun_ec_ucsi_write(struct gaokun_ec *ec,
+                        const u8 req[GAOKUN_UCSI_WRITE_SIZE]);
+
+int gaokun_ec_ucsi_get_reg(struct gaokun_ec *ec, struct gaokun_ucsi_reg *ureg);
+int gaokun_ec_ucsi_pan_ack(struct gaokun_ec *ec, int port_id);
+
+#endif /* __HUAWEI_GAOKUN_EC_H__ */