[PATCH v6 10/19] HID: hid-lenovo-go-s: Add Lenovo Legion Go S Series HID Driver

["Derek J. Clark" <derekjohn.clark@gmail.com>]

Adds initial framework for a new HID driver, hid-lenovo-go-s, along with
a uevent to report the firmware version for the MCU.

This driver primarily provides access to the configurable settings of the
Lenovo Legion Go S controller. It will attach if the controller is in
xinput or dinput mode. Non-configuration raw reports are forwarded to
ensure the other endpoints continue to function as normal.

Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Co-developed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Co-developed-by: Ethan Tidmore <ethantidmore06@gmail.com>
Signed-off-by: Ethan Tidmore <ethantidmore06@gmail.com>
Signed-off-by: Derek J. Clark <derekjohn.clark@gmail.com>
---
v6:
  - Include signdedness bug fix by Ethan Tidmore.
  - Make local attributes static.
  - Use NULL instead of 0 in mcu_propery_out when there is no data.
v4:
  - Use dmabuf per request instead of devm allocated static buffer.
    Resolves bug with side effects during suspend.
  - Remove unnecessary HID quirks and return to HID_CONNECT_HIDRAW.
  - Adjust delayed work time to 5ms to fix some side effects during
    resume when the MCU disconnects in some circumstances.
  - Cleaner formatting on multiple debug messages.
v3:
  - Include Mario's SOB tag
---
 MAINTAINERS                   |   1 +
 drivers/hid/Kconfig           |  12 ++
 drivers/hid/Makefile          |   1 +
 drivers/hid/hid-ids.h         |   4 +
 drivers/hid/hid-lenovo-go-s.c | 278 ++++++++++++++++++++++++++++++++++
 5 files changed, 296 insertions(+)
 create mode 100644 drivers/hid/hid-lenovo-go-s.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 75d89590f3d2..c81f10292ff7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14420,6 +14420,7 @@ M:	Derek J. Clark <derekjohn.clark@gmail.com>
 M:	Mark Pearson <mpearson-lenovo@squebb.ca>
 L:	linux-input@vger.kernel.org
 S:	Maintained
+F:	drivers/hid/hid-lenovo-go-s.c
 F:	drivers/hid/hid-lenovo-go.c
 F:	drivers/hid/hid-lenovo.c
 
diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 2925dba429f5..10c12d8e6557 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -635,6 +635,18 @@ config HID_LENOVO_GO
 	and Legion Go 2 Handheld Console Controllers. Say M here to compile this
 	driver as a module. The module will be called hid-lenovo-go.
 
+config HID_LENOVO_GO_S
+	tristate "HID Driver for Lenovo Legion Go S Controller"
+	depends on USB_HID
+	select LEDS_CLASS
+	select LEDS_CLASS_MULTICOLOR
+	help
+	Support for Lenovo Legion Go S Handheld Console Controller.
+
+	Say Y here to include configuration interface support for the Lenovo Legion Go
+	S. Say M here to compile this driver as a module. The module will be called
+	hid-lenovo-go-s.
+
 config HID_LETSKETCH
 	tristate "Letsketch WP9620N tablets"
 	depends on USB_HID
diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index 79fbe4e3e2f4..07dfdb6a49c5 100644
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -77,6 +77,7 @@ obj-$(CONFIG_HID_KYSONA)	+= hid-kysona.o
 obj-$(CONFIG_HID_LCPOWER)	+= hid-lcpower.o
 obj-$(CONFIG_HID_LENOVO)	+= hid-lenovo.o
 obj-$(CONFIG_HID_LENOVO_GO)	+= hid-lenovo-go.o
+obj-$(CONFIG_HID_LENOVO_GO_S)	+= hid-lenovo-go-s.o
 obj-$(CONFIG_HID_LETSKETCH)	+= hid-letsketch.o
 obj-$(CONFIG_HID_LOGITECH)	+= hid-logitech.o
 obj-$(CONFIG_HID_LOGITECH)	+= hid-lg-g15.o
diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 093ee86ebf90..145eb9921fee 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -739,6 +739,10 @@
 #define USB_DEVICE_ID_ITE8595		0x8595
 #define USB_DEVICE_ID_ITE_MEDION_E1239T	0xce50
 
+#define USB_VENDOR_ID_QHE		0x1a86
+#define USB_DEVICE_ID_LENOVO_LEGION_GO_S_XINPUT 0xe310
+#define USB_DEVICE_ID_LENOVO_LEGION_GO_S_DINPUT 0xe311
+
 #define USB_VENDOR_ID_JABRA		0x0b0e
 #define USB_DEVICE_ID_JABRA_SPEAK_410	0x0412
 #define USB_DEVICE_ID_JABRA_SPEAK_510	0x0420
diff --git a/drivers/hid/hid-lenovo-go-s.c b/drivers/hid/hid-lenovo-go-s.c
new file mode 100644
index 000000000000..c9f57dfa145a
--- /dev/null
+++ b/drivers/hid/hid-lenovo-go-s.c
@@ -0,0 +1,278 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  HID driver for Lenovo Legion Go S devices.
+ *
+ *  Copyright (c) 2026 Derek J. Clark <derekjohn.clark@gmail.com>
+ *  Copyright (c) 2026 Valve Corporation
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/array_size.h>
+#include <linux/cleanup.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/dev_printk.h>
+#include <linux/device.h>
+#include <linux/hid.h>
+#include <linux/jiffies.h>
+#include <linux/mutex.h>
+#include <linux/printk.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/unaligned.h>
+#include <linux/usb.h>
+#include <linux/workqueue.h>
+#include <linux/workqueue_types.h>
+
+#include "hid-ids.h"
+
+#define GO_S_CFG_INTF_IN	0x84
+#define GO_S_PACKET_SIZE	64
+
+static struct hid_gos_cfg {
+	struct delayed_work gos_cfg_setup;
+	struct completion send_cmd_complete;
+	struct hid_device *hdev;
+	struct mutex cfg_mutex; /*ensure single synchronous output report*/
+} drvdata;
+
+struct command_report {
+	u8 cmd;
+	u8 sub_cmd;
+	u8 data[63];
+} __packed;
+
+struct version_report {
+	u8 cmd;
+	u32 version;
+	u8 reserved[59];
+} __packed;
+
+enum mcu_command_index {
+	GET_VERSION = 0x01,
+	GET_MCU_ID,
+	GET_GAMEPAD_CFG,
+	SET_GAMEPAD_CFG,
+	GET_TP_PARAM,
+	SET_TP_PARAM,
+	GET_RGB_CFG = 0x0f,
+	SET_RGB_CFG,
+	GET_PL_TEST = 0xdf,
+};
+
+#define FEATURE_NONE 0x00
+
+static int hid_gos_version_event(u8 *data)
+{
+	struct version_report *ver_rep = (struct version_report *)data;
+
+	drvdata.hdev->firmware_version = get_unaligned_le32(&ver_rep->version);
+	return 0;
+}
+
+static int get_endpoint_address(struct hid_device *hdev)
+{
+	struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
+	struct usb_host_endpoint *ep;
+
+	if (intf) {
+		ep = intf->cur_altsetting->endpoint;
+		if (ep)
+			return ep->desc.bEndpointAddress;
+	}
+
+	return -ENODEV;
+}
+
+static int hid_gos_raw_event(struct hid_device *hdev, struct hid_report *report,
+			     u8 *data, int size)
+{
+	struct command_report *cmd_rep;
+	int ep, ret;
+
+	ep = get_endpoint_address(hdev);
+	if (ep != GO_S_CFG_INTF_IN)
+		return 0;
+
+	if (size != GO_S_PACKET_SIZE)
+		return -EINVAL;
+
+	cmd_rep = (struct command_report *)data;
+
+	switch (cmd_rep->cmd) {
+	case GET_VERSION:
+		ret = hid_gos_version_event(data);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+	dev_dbg(&hdev->dev, "Rx data as raw input report: [%*ph]\n",
+		GO_S_PACKET_SIZE, data);
+
+	complete(&drvdata.send_cmd_complete);
+	return ret;
+}
+
+static int mcu_property_out(struct hid_device *hdev, u8 command, u8 index,
+			    u8 *data, size_t len)
+{
+	unsigned char *dmabuf __free(kfree) = NULL;
+	u8 header[] = { command, index };
+	size_t header_size = ARRAY_SIZE(header);
+	int timeout, ret;
+
+	if (header_size + len > GO_S_PACKET_SIZE)
+		return -EINVAL;
+
+	guard(mutex)(&drvdata.cfg_mutex);
+	/* We can't use a devm_alloc reusable buffer without side effects during suspend */
+	dmabuf = kzalloc(GO_S_PACKET_SIZE, GFP_KERNEL);
+	if (!dmabuf)
+		return -ENOMEM;
+
+	memcpy(dmabuf, header, header_size);
+	memcpy(dmabuf + header_size, data, len);
+
+	dev_dbg(&hdev->dev, "Send data as raw output report: [%*ph]\n",
+		GO_S_PACKET_SIZE, dmabuf);
+
+	ret = hid_hw_output_report(hdev, dmabuf, GO_S_PACKET_SIZE);
+	if (ret < 0)
+		return ret;
+
+	ret = ret == GO_S_PACKET_SIZE ? 0 : -EINVAL;
+	if (ret)
+		return ret;
+
+	/* PL_TEST commands can take longer because they go out to another device */
+	timeout = (command == GET_PL_TEST) ? 200 : 5;
+	ret = wait_for_completion_interruptible_timeout(&drvdata.send_cmd_complete,
+							msecs_to_jiffies(timeout));
+
+	if (ret == 0) /* timeout occurred */
+		ret = -EBUSY;
+
+	reinit_completion(&drvdata.send_cmd_complete);
+	return 0;
+}
+
+static void cfg_setup(struct work_struct *work)
+{
+	int ret;
+
+	ret = mcu_property_out(drvdata.hdev, GET_VERSION, FEATURE_NONE, NULL, 0);
+	if (ret) {
+		dev_err(&drvdata.hdev->dev, "Failed to retrieve MCU Version: %i\n", ret);
+		return;
+	}
+}
+
+static int hid_gos_cfg_probe(struct hid_device *hdev,
+			     const struct hid_device_id *_id)
+{
+	int ret;
+
+	hid_set_drvdata(hdev, &drvdata);
+	drvdata.hdev = hdev;
+	mutex_init(&drvdata.cfg_mutex);
+
+	init_completion(&drvdata.send_cmd_complete);
+
+	/* Executing calls prior to returning from probe will lock the MCU. Schedule
+	 * initial data call after probe has completed and MCU can accept calls.
+	 */
+	INIT_DELAYED_WORK(&drvdata.gos_cfg_setup, &cfg_setup);
+	ret = schedule_delayed_work(&drvdata.gos_cfg_setup, msecs_to_jiffies(2));
+	if (!ret) {
+		dev_err(&hdev->dev, "Failed to schedule startup delayed work\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static void hid_gos_cfg_remove(struct hid_device *hdev)
+{
+	guard(mutex)(&drvdata.cfg_mutex);
+	cancel_delayed_work_sync(&drvdata.gos_cfg_setup);
+	hid_hw_close(hdev);
+	hid_hw_stop(hdev);
+	hid_set_drvdata(hdev, NULL);
+}
+
+static int hid_gos_probe(struct hid_device *hdev,
+			 const struct hid_device_id *id)
+{
+	int ret, ep;
+
+	ret = hid_parse(hdev);
+	if (ret) {
+		hid_err(hdev, "Parse failed\n");
+		return ret;
+	}
+
+	ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
+	if (ret) {
+		hid_err(hdev, "Failed to start HID device\n");
+		return ret;
+	}
+
+	ret = hid_hw_open(hdev);
+	if (ret) {
+		hid_err(hdev, "Failed to open HID device\n");
+		hid_hw_stop(hdev);
+		return ret;
+	}
+
+	ep = get_endpoint_address(hdev);
+	if (ep != GO_S_CFG_INTF_IN) {
+		dev_dbg(&hdev->dev, "Started interface %x as generic HID device.\n", ep);
+		return 0;
+	}
+
+	ret = hid_gos_cfg_probe(hdev, id);
+	if (ret)
+		dev_err_probe(&hdev->dev, ret, "Failed to start configuration interface");
+
+	dev_dbg(&hdev->dev, "Started interface %x as Go S configuration interface\n", ep);
+	return ret;
+}
+
+static void hid_gos_remove(struct hid_device *hdev)
+{
+	int ep = get_endpoint_address(hdev);
+
+	switch (ep) {
+	case GO_S_CFG_INTF_IN:
+		hid_gos_cfg_remove(hdev);
+		break;
+	default:
+		hid_hw_close(hdev);
+		hid_hw_stop(hdev);
+
+		break;
+	}
+}
+
+static const struct hid_device_id hid_gos_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_QHE,
+			 USB_DEVICE_ID_LENOVO_LEGION_GO_S_XINPUT) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_QHE,
+			 USB_DEVICE_ID_LENOVO_LEGION_GO_S_DINPUT) },
+	{}
+};
+
+MODULE_DEVICE_TABLE(hid, hid_gos_devices);
+static struct hid_driver hid_lenovo_go_s = {
+	.name = "hid-lenovo-go-s",
+	.id_table = hid_gos_devices,
+	.probe = hid_gos_probe,
+	.remove = hid_gos_remove,
+	.raw_event = hid_gos_raw_event,
+};
+module_hid_driver(hid_lenovo_go_s);
+
+MODULE_AUTHOR("Derek J. Clark");
+MODULE_DESCRIPTION("HID Driver for Lenovo Legion Go S Series gamepad.");
+MODULE_LICENSE("GPL");
-- 
2.53.0