[PATCH RESEND v5 0/3] platform: arm64: Huawei Matebook E Go embedded controller

[PATCH RESEND v5 0/3] platform: arm64: Huawei Matebook E Go embedded controller

[Pengyu Luo]

This adds binding, drivers and the DT support for the Huawei Matebook E Go
(sc8280xp-based) Embedded Controller which is also found in Huawei Matebook
E Go LTE (sc8180x-based), but I don't have the sc8180x one to perform
tests, so this series enable support for sc8280xp variant only, this series
provides the following features:

- battery and charger information report
- charging thresholds control
- FN lock (An alternative method)
- LID switch detection
- Temperature sensors
- USB Type-C altmode
- USB Type-C PD(high power)

Thanks to the work of Bjorn and Dmitry([1]), the work of Nikita([2]),
writing a EC driver won't be suffering. This work refers a lot to their
work, also, many other works. I mentioned them in commit messages.

Depends: https://lore.kernel.org/linux-arm-msm/20241220160530.444864-1-mitltlatltl@gmail.com

[1] https://lore.kernel.org/all/20240614-yoga-ec-driver-v7-0-9f0b9b40ae76@linaro.org/
[2] https://lore.kernel.org/all/20240315-aspire1-ec-v5-0-f93381deff39@trvn.ru/

base-commit: 1573c8d4cb206a2d1454ff711e79f8df2353290b

Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
---
Changes in v5 RESEND:
- Rebased on tag next-20250120
- Link to v5: https://lore.kernel.org/linux-arm-msm/20250117140348.180681-1-mitltlatltl@gmail.com

Changes in v5:
- handle return code of i2c_transfer() (Bryan)
- rename threshold validatition function (Bryan)
- add enumerates and defines for registers (Bryan)
- drop extra line in header (Heikki)
- Link to v4: https://lore.kernel.org/linux-arm-msm/20250116111559.83641-1-mitltlatltl@gmail.com

Changes in v4:
- use new API to register hwmon device instead of the deprecated one. (Guenter)
- add Reviewed-by tag for dt-binding (Krzysztof)
- drop unnecessary header (Ilpo)
- use guard mutex (Ilpo)
- improve comments and naming (Ilpo)
- add a shallow copy version of extr_resp() (Ilpo)
- add functions to handle resp and req whose size is 1
- drop PSY and UCSI subdrivers, commit them once the base driver is upstreamed
- Link to v3: https://lore.kernel.org/linux-arm-msm/20250113175049.590511-1-mitltlatltl@gmail.com

Changes in v3:
- Link to v2: https://lore.kernel.org/linux-arm-msm/20250105174159.227831-1-mitltlatltl@gmail.com

dt-binding:
- drop generic compatibles. (Krzysztof)
- remove '+' to use literal block style. (Krzysztof)

ec:
- take struct gaokun_ucsi_reg as parameter (Heikki)
- add almost all kernel doc comments (Krzysztof, Heikki)

ucsi:
- drop unnecessary ucsi quirks (Dmitry)
- add UCSI v1.0 to ucsi.h (Heikki)
- use gaokun_ucsi_read_cci() to read cci directly (Heikki)
- drop unnecessary gaokun_ucsi_get_port_num (Heikki)
- rename member port_num => num_ports (Heikki)
- fix completion, forgot to signal threads in previous version

dt:
- fix indentation (Konrad)
- add a link between role switch and connector

Changes in v2:
- Link to v1: https://lore.kernel.org/linux-arm-msm/20241227171353.404432-1-mitltlatltl@gmail.com

global:
- drop qcom's products(i.e. sc8180x, sx8280xp) everywhere, use 'product'-based instead(Krzysztof, Bryan)
- drop Cc Nikita Travkin, we had discussed the device in PM.
- add myself to MAINTAINERS

dt-binding:
- fix building (Rob Herring (Arm))
- remove unnecessary code (Krzysztof)
- add bugzilla documentation, insights of gaokun(see [1] or patch[1/5]) (Krzysztof, Aiqun(Maria))
- explain the difference between PMIC GLink and gaokun EC (Aiqun(Maria))

ec:
- use Linux style comments (Krzysztof)
- add a comment for mutex lock (Krzysztof)
- add more kerneldoc for exported functions (Krzysztof)
- eliminate unnecessary conditions (Bryan)
- add a macro for check thresholds (Bryan)
- improve English (Bryan)
- use existing sysfs interface(hwmon, psy) whenever possible (Krzysztof)
- use __le16 and related endianess conversion function for temp data (Ilpo)
- drop alias for packet headers (Ilpo)
- avoid hardcoding i2c msgs size (Aiqun(Maria))
- add a comment for the sleep in critial region (Bryan, Aiqun(Maria))
- use macro to construct packet (Bryan, Aiqun(Maria))

wmi:
- dropped

ucsi:
- reorder headers (Bryan)
- a comment for the orientation map macro (Bryan)
- make mux mode map more explicit(minus six is very clear now) (Bryan, Dmitry)
- handle port update exceptions return (Bryan)
- a comment for the UCSI quirks (Dmitry)
- use the inline hint for the short register function (Dmitry)
- use the API with delay to handle register instead of a direct sleep (Bryan)
- handle unfinished initialization early

psy:
- add charging related sysfs to here (Krzysztof, Dmitry)
- document ABI for power_supply sysfs (Krzysztof)
- drop charging threshold, use smart charging instead

dts:
- correct indentation, properties' order. (Konrad)

Pengyu Luo (3):
  dt-bindings: platform: Add Huawei Matebook E Go EC
  platform: arm64: add Huawei Matebook E Go EC driver
  arm64: dts: qcom: gaokun3: Add Embedded Controller node

 .../bindings/platform/huawei,gaokun-ec.yaml   | 124 +++
 MAINTAINERS                                   |   7 +
 .../boot/dts/qcom/sc8280xp-huawei-gaokun3.dts | 163 ++++
 drivers/platform/arm64/Kconfig                |  21 +
 drivers/platform/arm64/Makefile               |   1 +
 drivers/platform/arm64/huawei-gaokun-ec.c     | 822 ++++++++++++++++++
 .../linux/platform_data/huawei-gaokun-ec.h    |  79 ++
 7 files changed, 1217 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/platform/huawei,gaokun-ec.yaml
 create mode 100644 drivers/platform/arm64/huawei-gaokun-ec.c
 create mode 100644 include/linux/platform_data/huawei-gaokun-ec.h

-- 
2.48.1

[PATCH RESEND v5 1/3] dt-bindings: platform: Add Huawei Matebook E Go EC

[Pengyu Luo]

Add binding for the EC found in the Huawei Matebook E Go and
Huawei Matebook E Go LTE 2-in-1 tablets, the former one is a QS sc8280xp
based tablet, the latter one is a QS sc8180x based tablet.

This series has a codename, gaokun. More information about gaokun, please
check https://bugzilla.kernel.org/show_bug.cgi?id=219645

Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 .../bindings/platform/huawei,gaokun-ec.yaml   | 124 ++++++++++++++++++
 1 file changed, 124 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/platform/huawei,gaokun-ec.yaml

diff --git a/Documentation/devicetree/bindings/platform/huawei,gaokun-ec.yaml b/Documentation/devicetree/bindings/platform/huawei,gaokun-ec.yaml
new file mode 100644
index 000000000..4a03b0ee3
--- /dev/null
+++ b/Documentation/devicetree/bindings/platform/huawei,gaokun-ec.yaml
@@ -0,0 +1,124 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/platform/huawei,gaokun-ec.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Huawei Matebook E Go Embedded Controller
+
+maintainers:
+  - Pengyu Luo <mitltlatltl@gmail.com>
+
+description:
+  Different from other Qualcomm Snapdragon sc8180x and sc8280xp-based
+  machines, the Huawei Matebook E Go tablets use embedded controllers
+  while others use a system called PMIC GLink which handles battery,
+  UCSI, USB Type-C DP Alt Mode. In addition, Huawei's implementation
+  also handles additional features, such as charging thresholds, FN
+  lock, smart charging, tablet lid status, thermal sensors, and more.
+
+properties:
+  compatible:
+    enum:
+      - huawei,gaokun3-ec
+
+  reg:
+    const: 0x38
+
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+  interrupts:
+    maxItems: 1
+
+patternProperties:
+  '^connector@[01]$':
+    $ref: /schemas/connector/usb-connector.yaml#
+
+    properties:
+      reg:
+        maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        embedded-controller@38 {
+            compatible = "huawei,gaokun3-ec";
+            reg = <0x38>;
+
+            interrupts-extended = <&tlmm 107 IRQ_TYPE_LEVEL_LOW>;
+
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            connector@0 {
+                compatible = "usb-c-connector";
+                reg = <0>;
+                power-role = "dual";
+                data-role = "dual";
+
+                ports {
+                    #address-cells = <1>;
+                    #size-cells = <0>;
+
+                    port@0 {
+                        reg = <0>;
+
+                        ucsi0_ss_in: endpoint {
+                            remote-endpoint = <&usb_0_qmpphy_out>;
+                        };
+                    };
+
+                    port@1 {
+                        reg = <1>;
+
+                        ucsi0_sbu: endpoint {
+                            remote-endpoint = <&usb0_sbu_mux>;
+                        };
+                    };
+                };
+            };
+
+            connector@1 {
+                compatible = "usb-c-connector";
+                reg = <1>;
+                power-role = "dual";
+                data-role = "dual";
+
+                ports {
+                    #address-cells = <1>;
+                    #size-cells = <0>;
+
+                    port@0 {
+                        reg = <0>;
+
+                        ucsi1_ss_in: endpoint {
+                            remote-endpoint = <&usb_1_qmpphy_out>;
+                        };
+                    };
+
+                    port@1 {
+                        reg = <1>;
+
+                        ucsi1_sbu: endpoint {
+                            remote-endpoint = <&usb1_sbu_mux>;
+                        };
+                    };
+                };
+            };
+        };
+    };
-- 
2.47.1

[PATCH RESEND v5 2/3] platform: arm64: add Huawei Matebook E Go EC driver

[Pengyu Luo]

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

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

Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
---
 MAINTAINERS                                   |   7 +
 drivers/platform/arm64/Kconfig                |  21 +
 drivers/platform/arm64/Makefile               |   1 +
 drivers/platform/arm64/huawei-gaokun-ec.c     | 822 ++++++++++++++++++
 .../linux/platform_data/huawei-gaokun-ec.h    |  79 ++
 5 files changed, 930 insertions(+)
 create mode 100644 drivers/platform/arm64/huawei-gaokun-ec.c
 create mode 100644 include/linux/platform_data/huawei-gaokun-ec.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 790fa54b8..5a2e53c92 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10695,6 +10695,13 @@ 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
diff --git a/drivers/platform/arm64/Kconfig b/drivers/platform/arm64/Kconfig
index f88395ea3..6ceee3c16 100644
--- a/drivers/platform/arm64/Kconfig
+++ b/drivers/platform/arm64/Kconfig
@@ -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
+	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
diff --git a/drivers/platform/arm64/Makefile b/drivers/platform/arm64/Makefile
index b2ae9114f..46a99eba3 100644
--- a/drivers/platform/arm64/Makefile
+++ b/drivers/platform/arm64/Makefile
@@ -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
index 000000000..ff42efad9
--- /dev/null
+++ b/drivers/platform/arm64/huawei-gaokun-ec.c
@@ -0,0 +1,822 @@
+// 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 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 = 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 & status;
+		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;
+
+	mutex_init(&ec->lock);
+	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
index 000000000..faa15d315
--- /dev/null
+++ b/include/linux/platform_data/huawei-gaokun-ec.h
@@ -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__ */
-- 
2.47.1

Re: [PATCH RESEND v5 2/3] platform: arm64: add Huawei Matebook E Go EC driver

[Ilpo Järvinen]

On Tue, 21 Jan 2025, Pengyu Luo wrote:

> 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
> 
> [1] https://bugzilla.kernel.org/show_bug.cgi?id=219645
> 
> Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
> ---
>  MAINTAINERS                                   |   7 +
>  drivers/platform/arm64/Kconfig                |  21 +
>  drivers/platform/arm64/Makefile               |   1 +
>  drivers/platform/arm64/huawei-gaokun-ec.c     | 822 ++++++++++++++++++
>  .../linux/platform_data/huawei-gaokun-ec.h    |  79 ++
>  5 files changed, 930 insertions(+)
>  create mode 100644 drivers/platform/arm64/huawei-gaokun-ec.c
>  create mode 100644 include/linux/platform_data/huawei-gaokun-ec.h
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 790fa54b8..5a2e53c92 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -10695,6 +10695,13 @@ 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
> diff --git a/drivers/platform/arm64/Kconfig b/drivers/platform/arm64/Kconfig
> index f88395ea3..6ceee3c16 100644
> --- a/drivers/platform/arm64/Kconfig
> +++ b/drivers/platform/arm64/Kconfig
> @@ -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
> +	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
> diff --git a/drivers/platform/arm64/Makefile b/drivers/platform/arm64/Makefile
> index b2ae9114f..46a99eba3 100644
> --- a/drivers/platform/arm64/Makefile
> +++ b/drivers/platform/arm64/Makefile
> @@ -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
> index 000000000..ff42efad9
> --- /dev/null
> +++ b/drivers/platform/arm64/huawei-gaokun-ec.c
> @@ -0,0 +1,822 @@
> +// 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 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 = 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);

Please put also "on ?" to the second line to have it entirely on the same 
line.

> +
> +	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 & 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;
> +
> +	mutex_init(&ec->lock);

Use devm_mutex_init() so you don't need to add the missing deinit for it. 

Also remember to add the error handling for devm_mutex_init() (forgetting 
the error handling is a typical pitfall when doing that conversion).


My general feel is that this patch has improved a lot, good work! :-)

-- 
 i.


> +	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
> index 000000000..faa15d315
> --- /dev/null
> +++ b/include/linux/platform_data/huawei-gaokun-ec.h
> @@ -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__ */
> 

[PATCH RESEND v5 3/3] arm64: dts: qcom: gaokun3: Add Embedded Controller node

[Pengyu Luo]

The Embedded Controller in the Huawei Matebook E Go is accessible on &i2c15
and provides battery and adapter status, port orientation status, as well
as HPD event notifications for two USB Type-C port, etc.

Add the EC to the device tree and describe the relationship among
the type-c connectors, role switches, orientation switches and the QMP
combo PHY.

Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 .../boot/dts/qcom/sc8280xp-huawei-gaokun3.dts | 163 ++++++++++++++++++
 1 file changed, 163 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/sc8280xp-huawei-gaokun3.dts b/arch/arm64/boot/dts/qcom/sc8280xp-huawei-gaokun3.dts
index 09b95f89e..1667c7157 100644
--- a/arch/arm64/boot/dts/qcom/sc8280xp-huawei-gaokun3.dts
+++ b/arch/arm64/boot/dts/qcom/sc8280xp-huawei-gaokun3.dts
@@ -28,6 +28,7 @@ / {
 
 	aliases {
 		i2c4 = &i2c4;
+		i2c15 = &i2c15;
 		serial1 = &uart2;
 	};
 
@@ -216,6 +217,40 @@ map1 {
 		};
 	};
 
+	usb0-sbu-mux {
+		compatible = "pericom,pi3usb102", "gpio-sbu-mux";
+
+		select-gpios = <&tlmm 164 GPIO_ACTIVE_HIGH>;
+
+		pinctrl-0 = <&usb0_sbu_default>;
+		pinctrl-names = "default";
+
+		orientation-switch;
+
+		port {
+			usb0_sbu_mux: endpoint {
+				remote-endpoint = <&ucsi0_sbu>;
+			};
+		};
+	};
+
+	usb1-sbu-mux {
+		compatible = "pericom,pi3usb102", "gpio-sbu-mux";
+
+		select-gpios = <&tlmm 47 GPIO_ACTIVE_HIGH>;
+
+		pinctrl-0 = <&usb1_sbu_default>;
+		pinctrl-names = "default";
+
+		orientation-switch;
+
+		port {
+			usb1_sbu_mux: endpoint {
+				remote-endpoint = <&ucsi1_sbu>;
+			};
+		};
+	};
+
 	wcn6855-pmu {
 		compatible = "qcom,wcn6855-pmu";
 
@@ -584,6 +619,97 @@ touchscreen@4f {
 
 };
 
+&i2c15 {
+	clock-frequency = <400000>;
+
+	pinctrl-0 = <&i2c15_default>;
+	pinctrl-names = "default";
+
+	status = "okay";
+
+	embedded-controller@38 {
+		compatible = "huawei,gaokun3-ec";
+		reg = <0x38>;
+
+		interrupts-extended = <&tlmm 107 IRQ_TYPE_LEVEL_LOW>;
+
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		connector@0 {
+			compatible = "usb-c-connector";
+			reg = <0>;
+			power-role = "dual";
+			data-role = "dual";
+
+			ports {
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				port@0 {
+					reg = <0>;
+
+					ucsi0_hs_in: endpoint {
+						remote-endpoint = <&usb_0_dwc3_hs>;
+					};
+				};
+
+				port@1 {
+					reg = <1>;
+
+					ucsi0_ss_in: endpoint {
+						remote-endpoint = <&usb_0_qmpphy_out>;
+					};
+				};
+
+				port@2 {
+					reg = <2>;
+
+					ucsi0_sbu: endpoint {
+						remote-endpoint = <&usb0_sbu_mux>;
+					};
+				};
+			};
+		};
+
+		connector@1 {
+			compatible = "usb-c-connector";
+			reg = <1>;
+			power-role = "dual";
+			data-role = "dual";
+
+			ports {
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				port@0 {
+					reg = <0>;
+
+					ucsi1_hs_in: endpoint {
+						remote-endpoint = <&usb_1_dwc3_hs>;
+					};
+				};
+
+				port@1 {
+					reg = <1>;
+
+					ucsi1_ss_in: endpoint {
+						remote-endpoint = <&usb_1_qmpphy_out>;
+					};
+				};
+
+				port@2 {
+					reg = <2>;
+
+					ucsi1_sbu: endpoint {
+						remote-endpoint = <&usb1_sbu_mux>;
+					};
+				};
+			};
+		};
+	};
+};
+
 &mdss0 {
 	status = "okay";
 };
@@ -1004,6 +1130,10 @@ &usb_0_dwc3 {
 	dr_mode = "host";
 };
 
+&usb_0_dwc3_hs {
+	remote-endpoint = <&ucsi0_hs_in>;
+};
+
 &usb_0_hsphy {
 	vdda-pll-supply = <&vreg_l9d>;
 	vdda18-supply = <&vreg_l1c>;
@@ -1025,6 +1155,10 @@ &usb_0_qmpphy_dp_in {
 	remote-endpoint = <&mdss0_dp0_out>;
 };
 
+&usb_0_qmpphy_out {
+	remote-endpoint = <&ucsi0_ss_in>;
+};
+
 &usb_1 {
 	status = "okay";
 };
@@ -1033,6 +1167,10 @@ &usb_1_dwc3 {
 	dr_mode = "host";
 };
 
+&usb_1_dwc3_hs {
+	remote-endpoint = <&ucsi1_hs_in>;
+};
+
 &usb_1_hsphy {
 	vdda-pll-supply = <&vreg_l4b>;
 	vdda18-supply = <&vreg_l1c>;
@@ -1054,6 +1192,10 @@ &usb_1_qmpphy_dp_in {
 	remote-endpoint = <&mdss0_dp1_out>;
 };
 
+&usb_1_qmpphy_out {
+	remote-endpoint = <&ucsi1_ss_in>;
+};
+
 &usb_2 {
 	status = "okay";
 };
@@ -1177,6 +1319,13 @@ i2c4_default: i2c4-default-state {
 		bias-disable;
 	};
 
+	i2c15_default: i2c15-default-state {
+		pins = "gpio36", "gpio37";
+		function = "qup15";
+		drive-strength = <2>;
+		bias-pull-up;
+	};
+
 	mode_pin_active: mode-pin-state {
 		pins = "gpio26";
 		function = "gpio";
@@ -1301,6 +1450,20 @@ tx-pins {
 		};
 	};
 
+	usb0_sbu_default: usb0-sbu-state {
+		pins = "gpio164";
+		function = "gpio";
+		drive-strength = <16>;
+		bias-disable;
+	};
+
+	usb1_sbu_default: usb1-sbu-state {
+		pins = "gpio47";
+		function = "gpio";
+		drive-strength = <16>;
+		bias-disable;
+	};
+
 	wcd_default: wcd-default-state {
 		reset-pins {
 			pins = "gpio106";
-- 
2.47.1

Re: [PATCH RESEND v5 3/3] arm64: dts: qcom: gaokun3: Add Embedded Controller node

[Konrad Dybcio]

On 20.01.2025 5:47 PM, Pengyu Luo wrote:
> The Embedded Controller in the Huawei Matebook E Go is accessible on &i2c15
> and provides battery and adapter status, port orientation status, as well
> as HPD event notifications for two USB Type-C port, etc.
> 
> Add the EC to the device tree and describe the relationship among
> the type-c connectors, role switches, orientation switches and the QMP
> combo PHY.
> 
> Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> ---

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>

Konrad