[PATCH v9 0/3] HID: nintendo: Add preliminary Switch 2 controller driver

[PATCH v9 0/3] HID: nintendo: Add preliminary Switch 2 controller driver

[Vicki Pfau]

This series adds preliminary support for Switch 2 controllers using the
same split-driver model as previous versions. This is a minor iteration on
v7, fixing errors pointed out by sashiko.

At this point I'm pretty sure that what's left are imagined errors. It has
a lot of ideas of what can be run concurrently that I'm no longer convinced
of. If nothing obvious stands out, I'd like a review from a human before
fixing more nothings from sashiko.

Vicki Pfau (3):
  HID: nintendo: Add preliminary Switch 2 controller driver
  HID: nintendo: Add rumble support for Switch 2 controllers
  HID: nintendo: Add unified report format support

 MAINTAINERS                                   |    1 +
 drivers/hid/Kconfig                           |   19 +-
 drivers/hid/hid-ids.h                         |    4 +
 drivers/hid/hid-nintendo.c                    | 1670 ++++++++++++++++-
 drivers/hid/hid-nintendo.h                    |   72 +
 drivers/input/joystick/Kconfig                |   11 +
 drivers/input/joystick/Makefile               |    1 +
 drivers/input/joystick/nintendo-switch2-usb.c |  464 +++++
 8 files changed, 2201 insertions(+), 41 deletions(-)
 create mode 100644 drivers/hid/hid-nintendo.h
 create mode 100644 drivers/input/joystick/nintendo-switch2-usb.c

-- 
2.54.0

[PATCH v9 1/3] HID: nintendo: Add preliminary Switch 2 controller driver

[Vicki Pfau]

This adds a new driver for the Switch 2 controllers. The Switch 2 uses an
unusual split-interface design such that input and rumble occur on the main
HID interface, but all other communication occurs over a "configuration"
interface. This is the case on both USB and Bluetooth, so this new driver
uses a split-driver design with the HID interface being the "main" driver
and the configuration interface is a secondary driver that looks up to the
HID interface, sharing resources on a common struct.

Due to using a non-standard pairing interface as well as Bluetooth
communications being extremely limited in the kernel, a custom interface
between userspace and the kernel will need to be designed, along with
bringup in BlueZ. That is beyond the scope of this initial patch, which
only contains the generic HID and USB configuration interface drivers.

This initial work supports general input for the Joy-Con 2, Pro Controller
2, and GameCube NSO controllers. IMU, rumble and battery support is not yet
present.

Signed-off-by: Vicki Pfau <vi@endrift.com>
---
 MAINTAINERS                                   |    1 +
 drivers/hid/Kconfig                           |   11 +-
 drivers/hid/hid-ids.h                         |    4 +
 drivers/hid/hid-nintendo.c                    | 1264 ++++++++++++++++-
 drivers/hid/hid-nintendo.h                    |   72 +
 drivers/input/joystick/Kconfig                |   11 +
 drivers/input/joystick/Makefile               |    1 +
 drivers/input/joystick/nintendo-switch2-usb.c |  464 ++++++
 8 files changed, 1818 insertions(+), 10 deletions(-)
 create mode 100644 drivers/hid/hid-nintendo.h
 create mode 100644 drivers/input/joystick/nintendo-switch2-usb.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 4ecd282f8f52..778982ab298e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19051,6 +19051,7 @@ F:	drivers/scsi/nsp32*
 
 NINTENDO HID DRIVER
 M:	Daniel J. Ogorchock <djogorchock@gmail.com>
+M:	Vicki Pfau <vi@endrift.com>
 L:	linux-input@vger.kernel.org
 S:	Maintained
 F:	drivers/hid/hid-nintendo*
diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index f9bcaeb66385..19c77c323ec9 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -843,10 +843,13 @@ config HID_NINTENDO
 	depends on LEDS_CLASS
 	select POWER_SUPPLY
 	help
-	Adds support for the Nintendo Switch Joy-Cons, NSO, Pro Controller.
-	All controllers support bluetooth, and the Pro Controller also supports
-	its USB mode. This also includes support for the Nintendo Switch Online
-	Controllers which include the NES, Genesis, SNES, and N64 controllers.
+	Adds support for the Nintendo Switch Joy-Cons, NSO, Pro Controller, as
+	well as Nintendo Switch 2 Joy-Cons, Pro Controller, and NSO GameCube
+	controllers. All Switch controllers support bluetooth, and the Pro
+	Controller also supports its USB mode. This also includes support for
+	the Nintendo Switch Online Controllers which include the NES, Genesis,
+	SNES, and N64 controllers. Switch 2 controllers currently only support
+	USB mode.
 
 	To compile this driver as a module, choose M here: the
 	module will be called hid-nintendo.
diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 1059922baaac..9ba62b8fb894 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -1103,6 +1103,10 @@
 #define USB_DEVICE_ID_NINTENDO_SNESCON	0x2017
 #define USB_DEVICE_ID_NINTENDO_GENCON	0x201e
 #define USB_DEVICE_ID_NINTENDO_N64CON	0x2019
+#define USB_DEVICE_ID_NINTENDO_NS2_JOYCONR	0x2066
+#define USB_DEVICE_ID_NINTENDO_NS2_JOYCONL	0x2067
+#define USB_DEVICE_ID_NINTENDO_NS2_PROCON	0x2069
+#define USB_DEVICE_ID_NINTENDO_NS2_GCCON	0x2073
 
 #define USB_VENDOR_ID_NOVATEK		0x0603
 #define USB_DEVICE_ID_NOVATEK_PCT	0x0600
diff --git a/drivers/hid/hid-nintendo.c b/drivers/hid/hid-nintendo.c
index e7302ec01ff1..5aacb8e88b70 100644
--- a/drivers/hid/hid-nintendo.c
+++ b/drivers/hid/hid-nintendo.c
@@ -1,11 +1,13 @@
 // SPDX-License-Identifier: GPL-2.0+
 /*
- * HID driver for Nintendo Switch Joy-Cons and Pro Controllers
+ * HID driver for Nintendo Switch Joy-Cons and Pro Controllers, as well as
+ * Nintendo Switch 2 Joy-Cons, Pro Controller, and GameCube Controller
  *
  * Copyright (c) 2019-2021 Daniel J. Ogorchock <djogorchock@gmail.com>
  * Portions Copyright (c) 2020 Nadia Holmquist Pedersen <nadia@nhp.sh>
  * Copyright (c) 2022 Emily Strickland <linux@emily.st>
  * Copyright (c) 2023 Ryan McClelland <rymcclel@gmail.com>
+ * Copyright (c) 2026 Valve Software
  *
  * The following resources/projects were referenced for this driver:
  *   https://github.com/dekuNukem/Nintendo_Switch_Reverse_Engineering
@@ -13,6 +15,8 @@
  *   https://github.com/FrotBot/SwitchProConLinuxUSB
  *   https://github.com/MTCKC/ProconXInput
  *   https://github.com/Davidobot/BetterJoyForCemu
+ *   https://gist.github.com/shinyquagsire23/66f006b46c56216acbaac6c1e2279b64
+ *   https://github.com/ndeadly/switch2_controller_research
  *   hid-wiimote kernel hid driver
  *   hid-logitech-hidpp driver
  *   hid-sony driver
@@ -29,6 +33,7 @@
  */
 
 #include "hid-ids.h"
+#include "hid-nintendo.h"
 #include <linux/unaligned.h>
 #include <linux/delay.h>
 #include <linux/device.h>
@@ -41,6 +46,8 @@
 #include <linux/module.h>
 #include <linux/power_supply.h>
 #include <linux/spinlock.h>
+#include <linux/usb.h>
+#include "usbhid/usbhid.h"
 
 /*
  * Reference the url below for the following HID report defines:
@@ -2662,7 +2669,7 @@ static int joycon_ctlr_handle_event(struct joycon_ctlr *ctlr, u8 *data,
 	return ret;
 }
 
-static int nintendo_hid_event(struct hid_device *hdev,
+static int joycon_event(struct hid_device *hdev,
 			      struct hid_report *report, u8 *raw_data, int size)
 {
 	struct joycon_ctlr *ctlr = hid_get_drvdata(hdev);
@@ -2673,7 +2680,7 @@ static int nintendo_hid_event(struct hid_device *hdev,
 	return joycon_ctlr_handle_event(ctlr, raw_data, size);
 }
 
-static int nintendo_hid_probe(struct hid_device *hdev,
+static int joycon_probe(struct hid_device *hdev,
 			    const struct hid_device_id *id)
 {
 	int ret;
@@ -2777,7 +2784,7 @@ static int nintendo_hid_probe(struct hid_device *hdev,
 	return ret;
 }
 
-static void nintendo_hid_remove(struct hid_device *hdev)
+static void joycon_remove(struct hid_device *hdev)
 {
 	struct joycon_ctlr *ctlr = hid_get_drvdata(hdev);
 	unsigned long flags;
@@ -2796,7 +2803,7 @@ static void nintendo_hid_remove(struct hid_device *hdev)
 	hid_hw_stop(hdev);
 }
 
-static int nintendo_hid_resume(struct hid_device *hdev)
+static int joycon_resume(struct hid_device *hdev)
 {
 	struct joycon_ctlr *ctlr = hid_get_drvdata(hdev);
 	int ret;
@@ -2819,7 +2826,7 @@ static int nintendo_hid_resume(struct hid_device *hdev)
 	return ret;
 }
 
-static int nintendo_hid_suspend(struct hid_device *hdev, pm_message_t message)
+static int joycon_suspend(struct hid_device *hdev, pm_message_t message)
 {
 	struct joycon_ctlr *ctlr = hid_get_drvdata(hdev);
 
@@ -2838,7 +2845,1194 @@ static int nintendo_hid_suspend(struct hid_device *hdev, pm_message_t message)
 	return 0;
 }
 
+/*
+ * =============================================================================
+ * Switch 2 support
+ * =============================================================================
+ */
+#define NS2_BTNR_B	BIT(0)
+#define NS2_BTNR_A	BIT(1)
+#define NS2_BTNR_Y	BIT(2)
+#define NS2_BTNR_X	BIT(3)
+#define NS2_BTNR_R	BIT(4)
+#define NS2_BTNR_ZR	BIT(5)
+#define NS2_BTNR_PLUS	BIT(6)
+#define NS2_BTNR_RS	BIT(7)
+
+#define NS2_BTNL_DOWN	BIT(0)
+#define NS2_BTNL_RIGHT	BIT(1)
+#define NS2_BTNL_LEFT	BIT(2)
+#define NS2_BTNL_UP	BIT(3)
+#define NS2_BTNL_L	BIT(4)
+#define NS2_BTNL_ZL	BIT(5)
+#define NS2_BTNL_MINUS	BIT(6)
+#define NS2_BTNL_LS	BIT(7)
+
+#define NS2_BTN3_C	BIT(4)
+#define NS2_BTN3_SR	BIT(6)
+#define NS2_BTN3_SL	BIT(7)
+
+#define NS2_BTN_JCR_HOME	BIT(0)
+#define NS2_BTN_JCR_GR		BIT(2)
+#define NS2_BTN_JCR_C		NS2_BTN3_C
+#define NS2_BTN_JCR_SR		NS2_BTN3_SR
+#define NS2_BTN_JCR_SL		NS2_BTN3_SL
+
+#define NS2_BTN_JCL_CAPTURE	BIT(0)
+#define NS2_BTN_JCL_GL		BIT(2)
+#define NS2_BTN_JCL_SR		NS2_BTN3_SR
+#define NS2_BTN_JCL_SL		NS2_BTN3_SL
+
+#define NS2_BTN_PRO_HOME	BIT(0)
+#define NS2_BTN_PRO_CAPTURE	BIT(1)
+#define NS2_BTN_PRO_GR		BIT(2)
+#define NS2_BTN_PRO_GL		BIT(3)
+#define NS2_BTN_PRO_C		NS2_BTN3_C
+
+#define NS2_BTN_GC_HOME		BIT(0)
+#define NS2_BTN_GC_CAPTURE	BIT(1)
+#define NS2_BTN_GC_C		NS2_BTN3_C
+
+#define NS2_TRIGGER_RANGE	4095
+#define NS2_AXIS_MIN		-32768
+#define NS2_AXIS_MAX		32767
+
+#define NS2_MAX_PLAYER_ID	8
+
+#define NS2_MAX_INIT_RETRIES	4
+
+#define NS2_FLASH_ADDR_SERIAL			0x13002
+#define NS2_FLASH_ADDR_FACTORY_PRIMARY_CALIB	0x130a8
+#define NS2_FLASH_ADDR_FACTORY_SECONDARY_CALIB	0x130e8
+#define NS2_FLASH_ADDR_FACTORY_TRIGGER_CALIB	0x13140
+#define NS2_FLASH_ADDR_USER_PRIMARY_CALIB	0x1fc040
+#define NS2_FLASH_ADDR_USER_SECONDARY_CALIB	0x1fc080
+
+#define NS2_FLASH_SIZE_SERIAL 0x10
+#define NS2_FLASH_SIZE_FACTORY_AXIS_CALIB 9
+#define NS2_FLASH_SIZE_FACTORY_TRIGGER_CALIB 2
+#define NS2_FLASH_SIZE_USER_AXIS_CALIB 11
+
+#define NS2_USER_CALIB_MAGIC 0xa1b2
+
+#define NS2_FEATURE_BUTTONS	BIT(0)
+#define NS2_FEATURE_ANALOG	BIT(1)
+#define NS2_FEATURE_IMU		BIT(2)
+#define NS2_FEATURE_MOUSE	BIT(4)
+#define NS2_FEATURE_RUMBLE	BIT(5)
+#define NS2_FEATURE_MAGNETO	BIT(7)
+
+enum switch2_subcmd_flash {
+	NS2_SUBCMD_FLASH_READ_BLOCK = 0x01,
+	NS2_SUBCMD_FLASH_WRITE_BLOCK = 0x02,
+	NS2_SUBCMD_FLASH_ERASE_BLOCK = 0x03,
+	NS2_SUBCMD_FLASH_READ = 0x04,
+	NS2_SUBCMD_FLASH_WRITE = 0x05,
+};
+
+enum switch2_subcmd_init {
+	NS2_SUBCMD_INIT_SELECT_REPORT = 0xa,
+	NS2_SUBCMD_INIT_USB = 0xd,
+};
+
+enum switch2_subcmd_feature_select {
+	NS2_SUBCMD_FEATSEL_GET_INFO = 0x1,
+	NS2_SUBCMD_FEATSEL_SET_MASK = 0x2,
+	NS2_SUBCMD_FEATSEL_CLEAR_MASK = 0x3,
+	NS2_SUBCMD_FEATSEL_ENABLE = 0x4,
+	NS2_SUBCMD_FEATSEL_DISABLE = 0x5,
+};
+
+enum switch2_subcmd_grip {
+	NS2_SUBCMD_GRIP_GET_INFO = 0x1,
+	NS2_SUBCMD_GRIP_ENABLE_BUTTONS = 0x2,
+	NS2_SUBCMD_GRIP_GET_INFO_EXT = 0x3,
+};
+
+enum switch2_subcmd_led {
+	NS2_SUBCMD_LED_P1 = 0x1,
+	NS2_SUBCMD_LED_P2 = 0x2,
+	NS2_SUBCMD_LED_P3 = 0x3,
+	NS2_SUBCMD_LED_P4 = 0x4,
+	NS2_SUBCMD_LED_ALL_ON = 0x5,
+	NS2_SUBCMD_LED_ALL_OFF = 0x6,
+	NS2_SUBCMD_LED_PATTERN = 0x7,
+	NS2_SUBCMD_LED_BLINK = 0x8,
+};
+
+enum switch2_subcmd_fw_info {
+	NS2_SUBCMD_FW_INFO_GET = 0x1,
+};
+
+enum switch2_ctlr_type {
+	NS2_CTLR_TYPE_JCL = 0x00,
+	NS2_CTLR_TYPE_JCR = 0x01,
+	NS2_CTLR_TYPE_PRO = 0x02,
+	NS2_CTLR_TYPE_GC = 0x03,
+};
+
+enum switch2_report_id {
+	NS2_REPORT_UNIFIED = 0x05,
+	NS2_REPORT_JCL = 0x07,
+	NS2_REPORT_JCR = 0x08,
+	NS2_REPORT_PRO = 0x09,
+	NS2_REPORT_GC = 0x0a,
+};
+
+enum switch2_init_step {
+	NS2_INIT_READ_SERIAL,
+	NS2_INIT_GET_FIRMWARE_INFO,
+	NS2_INIT_READ_FACTORY_PRIMARY_CALIB,
+	NS2_INIT_READ_FACTORY_SECONDARY_CALIB,
+	NS2_INIT_READ_FACTORY_TRIGGER_CALIB,
+	NS2_INIT_READ_USER_PRIMARY_CALIB,
+	NS2_INIT_READ_USER_SECONDARY_CALIB,
+	NS2_INIT_SET_FEATURE_MASK,
+	NS2_INIT_ENABLE_FEATURES,
+	NS2_INIT_GRIP_BUTTONS,
+	NS2_INIT_REPORT_FORMAT,
+	NS2_INIT_SET_PLAYER_LEDS,
+	NS2_INIT_INPUT,
+	NS2_INIT_FINISH,
+	NS2_INIT_DONE,
+};
+
+struct switch2_version_info {
+	uint8_t major;
+	uint8_t minor;
+	uint8_t patch;
+	uint8_t ctlr_type;
+	__le32 unk;
+	int8_t dsp_major;
+	int8_t dsp_minor;
+	int8_t dsp_patch;
+	int8_t dsp_type;
+};
+
+struct switch2_axis_calibration {
+	uint16_t neutral;
+	uint16_t negative;
+	uint16_t positive;
+};
+
+struct switch2_stick_calibration {
+	struct switch2_axis_calibration x;
+	struct switch2_axis_calibration y;
+};
+
+struct switch2_controller {
+	struct hid_device *hdev;
+	struct switch2_cfg_intf *cfg;
+	struct kref refcount;
+
+	char name[64];
+	char phys[64];
+	struct list_head entry;
+	struct mutex lock;
+
+	enum switch2_ctlr_type ctlr_type;
+	enum switch2_init_step init_step;
+	int init_retries;
+	struct input_dev __rcu *input;
+	char serial[NS2_FLASH_SIZE_SERIAL + 1];
+	struct switch2_version_info version;
+
+	struct switch2_stick_calibration stick_calib[2];
+	uint8_t lt_zero;
+	uint8_t rt_zero;
+
+	uint32_t player_id;
+	struct led_classdev leds[4];
+};
+
+static DEFINE_MUTEX(switch2_controllers_lock);
+static LIST_HEAD(switch2_controllers);
+
+struct switch2_ctlr_button_mapping {
+	uint32_t code;
+	int byte;
+	uint32_t bit;
+};
+
+static const struct switch2_ctlr_button_mapping ns2_left_joycon_button_mappings[] = {
+	{ BTN_DPAD_LEFT,	0, NS2_BTNL_LEFT,	},
+	{ BTN_DPAD_UP,		0, NS2_BTNL_UP,		},
+	{ BTN_DPAD_DOWN,	0, NS2_BTNL_DOWN,	},
+	{ BTN_DPAD_RIGHT,	0, NS2_BTNL_RIGHT,	},
+	{ BTN_TL,		0, NS2_BTNL_L,		},
+	{ BTN_TL2,		0, NS2_BTNL_ZL,		},
+	{ BTN_SELECT,		0, NS2_BTNL_MINUS,	},
+	{ BTN_THUMBL,		0, NS2_BTNL_LS,		},
+	{ KEY_RECORD,		1, NS2_BTN_JCL_CAPTURE,	},
+	{ BTN_GRIPR,		1, NS2_BTN_JCL_SL,	},
+	{ BTN_GRIPR2,		1, NS2_BTN_JCL_SR,	},
+	{ BTN_GRIPL,		1, NS2_BTN_JCL_GL,	},
+	{ /* sentinel */ },
+};
+
+static const struct switch2_ctlr_button_mapping ns2_right_joycon_button_mappings[] = {
+	{ BTN_SOUTH,	0, NS2_BTNR_A,		},
+	{ BTN_EAST,	0, NS2_BTNR_B,		},
+	{ BTN_NORTH,	0, NS2_BTNR_X,		},
+	{ BTN_WEST,	0, NS2_BTNR_Y,		},
+	{ BTN_TR,	0, NS2_BTNR_R,		},
+	{ BTN_TR2,	0, NS2_BTNR_ZR,		},
+	{ BTN_START,	0, NS2_BTNR_PLUS,	},
+	{ BTN_THUMBR,	0, NS2_BTNR_RS,		},
+	{ BTN_C,	1, NS2_BTN_JCR_C,	},
+	{ BTN_MODE,	1, NS2_BTN_JCR_HOME,	},
+	{ BTN_GRIPL2,	1, NS2_BTN_JCR_SL,	},
+	{ BTN_GRIPL,	1, NS2_BTN_JCR_SR,	},
+	{ BTN_GRIPR,	1, NS2_BTN_JCR_GR,	},
+	{ /* sentinel */ },
+};
+
+static const struct switch2_ctlr_button_mapping ns2_procon_mappings[] = {
+	{ BTN_SOUTH,	0, NS2_BTNR_A,		},
+	{ BTN_EAST,	0, NS2_BTNR_B,		},
+	{ BTN_NORTH,	0, NS2_BTNR_X,		},
+	{ BTN_WEST,	0, NS2_BTNR_Y,		},
+	{ BTN_TL,	1, NS2_BTNL_L,		},
+	{ BTN_TR,	0, NS2_BTNR_R,		},
+	{ BTN_TL2,	1, NS2_BTNL_ZL,		},
+	{ BTN_TR2,	0, NS2_BTNR_ZR,		},
+	{ BTN_SELECT,	1, NS2_BTNL_MINUS,	},
+	{ BTN_START,	0, NS2_BTNR_PLUS,	},
+	{ BTN_THUMBL,	1, NS2_BTNL_LS,		},
+	{ BTN_THUMBR,	0, NS2_BTNR_RS,		},
+	{ BTN_MODE,	2, NS2_BTN_PRO_HOME	},
+	{ KEY_RECORD,	2, NS2_BTN_PRO_CAPTURE	},
+	{ BTN_GRIPR,	2, NS2_BTN_PRO_GR	},
+	{ BTN_GRIPL,	2, NS2_BTN_PRO_GL	},
+	{ BTN_C,	2, NS2_BTN_PRO_C	},
+	{ /* sentinel */ },
+};
+
+static const struct switch2_ctlr_button_mapping ns2_gccon_mappings[] = {
+	{ BTN_SOUTH,	0, NS2_BTNR_A,		},
+	{ BTN_EAST,	0, NS2_BTNR_B,		},
+	{ BTN_NORTH,	0, NS2_BTNR_X,		},
+	{ BTN_WEST,	0, NS2_BTNR_Y,		},
+	{ BTN_TL2,	1, NS2_BTNL_L,		},
+	{ BTN_TR2,	0, NS2_BTNR_R,		},
+	{ BTN_TL,	1, NS2_BTNL_ZL,		},
+	{ BTN_TR,	0, NS2_BTNR_ZR,		},
+	{ BTN_SELECT,	1, NS2_BTNL_MINUS,	},
+	{ BTN_START,	0, NS2_BTNR_PLUS,	},
+	{ BTN_MODE,	2, NS2_BTN_GC_HOME	},
+	{ KEY_RECORD,	2, NS2_BTN_GC_CAPTURE	},
+	{ BTN_C,	2, NS2_BTN_GC_C		},
+	{ /* sentinel */ },
+};
+
+static const uint8_t switch2_init_cmd_data[] = {
+	/*
+	 * The last 6 bytes of this packet are the MAC address of
+	 * the console, but we don't need that for USB
+	 */
+	0x01, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF
+};
+
+static const uint8_t switch2_one_data[] = { 0x01, 0x00, 0x00, 0x00 };
+
+static const uint8_t switch2_feature_mask[] = {
+	NS2_FEATURE_BUTTONS | NS2_FEATURE_ANALOG | NS2_FEATURE_IMU,
+	0x00, 0x00, 0x00
+};
+
+static void switch2_init_step_done(struct switch2_controller *ns2, enum switch2_init_step step)
+{
+	if (ns2->init_step != step)
+		return;
+
+	ns2->init_retries = 0;
+	ns2->init_step++;
+}
+
+static inline bool switch2_ctlr_is_joycon(enum switch2_ctlr_type type)
+{
+	return type == NS2_CTLR_TYPE_JCL || type == NS2_CTLR_TYPE_JCR;
+}
+
+static struct switch2_controller *switch2_get_controller(const char *phys)
+{
+	struct switch2_controller *ns2;
+
+	guard(mutex)(&switch2_controllers_lock);
+	list_for_each_entry(ns2, &switch2_controllers, entry) {
+		if (strncmp(ns2->phys, phys, sizeof(ns2->phys)) == 0) {
+			if (kref_get_unless_zero(&ns2->refcount))
+				return ns2;
+		}
+	}
+	ns2 = kzalloc(sizeof(*ns2), GFP_KERNEL);
+	if (!ns2)
+		return ERR_PTR(-ENOMEM);
+
+	kref_init(&ns2->refcount);
+	mutex_init(&ns2->lock);
+	INIT_LIST_HEAD(&ns2->entry);
+	list_add(&ns2->entry, &switch2_controllers);
+	strscpy(ns2->phys, phys, sizeof(ns2->phys));
+	return ns2;
+}
+
+static void switch2_controller_put(struct switch2_controller *ns2)
+{
+	struct input_dev *input;
+
+	rcu_read_lock();
+	input = rcu_dereference(ns2->input);
+	rcu_read_unlock();
+
+	rcu_assign_pointer(ns2->input, NULL);
+	synchronize_rcu();
+
+	ns2->init_step = 0;
+
+	if (input)
+		input_unregister_device(input);
+}
+
+static void switch2_kref_put(struct kref *refcount)
+{
+	struct switch2_controller *ns2 = container_of(refcount,
+		struct switch2_controller, refcount);
+
+	guard(mutex)(&switch2_controllers_lock);
+	list_del_init(&ns2->entry);
+	mutex_destroy(&ns2->lock);
+	kfree(ns2);
+}
+
+static int switch2_set_leds(struct switch2_controller *ns2)
+{
+	int i;
+	uint8_t message[8] = { 0 };
+
+	for (i = 0; i < JC_NUM_LEDS; i++)
+		message[0] |= (!!ns2->leds[i].brightness) << i;
+
+	if (!ns2->cfg)
+		return -ENOTCONN;
+	return ns2->cfg->send_command(NS2_CMD_LED, NS2_SUBCMD_LED_PATTERN,
+		&message, sizeof(message),
+		ns2->cfg);
+}
+
+static int switch2_player_led_brightness_set(struct led_classdev *led,
+					    enum led_brightness brightness)
+{
+	struct device *dev = led->dev->parent;
+	struct input_dev *input = to_input_dev(dev);
+	struct switch2_controller *ns2 = input_get_drvdata(input);
+
+	if (!ns2)
+		return -ENODEV;
+
+	guard(mutex)(&ns2->lock);
+	return switch2_set_leds(ns2);
+}
+
+static void switch2_leds_create(struct switch2_controller *ns2)
+{
+	struct hid_device *hdev = ns2->hdev;
+	struct led_classdev *led;
+	int i;
+	int player_led_pattern;
+
+	player_led_pattern = ns2->player_id % JC_NUM_LED_PATTERNS;
+	hid_dbg(hdev, "assigned player %d led pattern", player_led_pattern + 1);
+
+	for (i = 0; i < JC_NUM_LEDS; i++) {
+		led = &ns2->leds[i];
+		led->brightness = joycon_player_led_patterns[player_led_pattern][i];
+		led->max_brightness = 1;
+		led->brightness_set_blocking = switch2_player_led_brightness_set;
+		led->flags = LED_CORE_SUSPENDRESUME | LED_HW_PLUGGABLE | LED_RETAIN_AT_SHUTDOWN;
+	}
+}
+
+static void switch2_config_buttons(struct input_dev *idev,
+	const struct switch2_ctlr_button_mapping button_mappings[])
+{
+	const struct switch2_ctlr_button_mapping *button;
+
+	for (button = button_mappings; button->code; button++)
+		input_set_capability(idev, EV_KEY, button->code);
+}
+
+static int switch2_input_ref(struct input_dev *input)
+{
+	struct switch2_controller *ns2 = input_get_drvdata(input);
+
+	kref_get(&ns2->refcount);
+
+	return 0;
+}
+
+static void switch2_input_deref(struct input_dev *input)
+{
+	struct switch2_controller *ns2 = input_get_drvdata(input);
+
+	kref_put(&ns2->refcount, switch2_kref_put);
+}
+
+static int switch2_init_input(struct switch2_controller *ns2)
+{
+	struct input_dev *input;
+	struct hid_device *hdev = ns2->hdev;
+	int i;
+	int ret;
+
+	switch2_init_step_done(ns2, NS2_INIT_FINISH);
+
+	rcu_read_lock();
+	input = rcu_dereference(ns2->input);
+	rcu_read_unlock();
+
+	if (input)
+		return 0;
+
+	input = input_allocate_device();
+	if (!input)
+		return -ENOMEM;
+
+	input_set_drvdata(input, ns2);
+	input->open = switch2_input_ref;
+	input->close = switch2_input_deref;
+	input->dev.parent = &hdev->dev;
+	input->id.bustype = hdev->bus;
+	input->id.vendor = hdev->vendor;
+	input->id.product = hdev->product;
+	input->id.version = hdev->version;
+	input->uniq = ns2->serial;
+	input->name = ns2->name;
+	input->phys = hdev->phys;
+
+	switch (ns2->ctlr_type) {
+	case NS2_CTLR_TYPE_JCL:
+		input_set_abs_params(input, ABS_X, NS2_AXIS_MIN, NS2_AXIS_MAX, 32, 128);
+		input_set_abs_params(input, ABS_Y, NS2_AXIS_MIN, NS2_AXIS_MAX, 32, 128);
+		switch2_config_buttons(input, ns2_left_joycon_button_mappings);
+		break;
+	case NS2_CTLR_TYPE_JCR:
+		input_set_abs_params(input, ABS_X, NS2_AXIS_MIN, NS2_AXIS_MAX, 32, 128);
+		input_set_abs_params(input, ABS_Y, NS2_AXIS_MIN, NS2_AXIS_MAX, 32, 128);
+		switch2_config_buttons(input, ns2_right_joycon_button_mappings);
+		break;
+	case NS2_CTLR_TYPE_GC:
+		input_set_abs_params(input, ABS_X, NS2_AXIS_MIN, NS2_AXIS_MAX, 32, 128);
+		input_set_abs_params(input, ABS_Y, NS2_AXIS_MIN, NS2_AXIS_MAX, 32, 128);
+		input_set_abs_params(input, ABS_RX, NS2_AXIS_MIN, NS2_AXIS_MAX, 32, 128);
+		input_set_abs_params(input, ABS_RY, NS2_AXIS_MIN, NS2_AXIS_MAX, 32, 128);
+		input_set_abs_params(input, ABS_Z, 0, NS2_TRIGGER_RANGE, 32, 128);
+		input_set_abs_params(input, ABS_RZ, 0, NS2_TRIGGER_RANGE, 32, 128);
+		input_set_abs_params(input, ABS_HAT0X, -1, 1, 0, 0);
+		input_set_abs_params(input, ABS_HAT0Y, -1, 1, 0, 0);
+		switch2_config_buttons(input, ns2_gccon_mappings);
+		break;
+	case NS2_CTLR_TYPE_PRO:
+		input_set_abs_params(input, ABS_X, NS2_AXIS_MIN, NS2_AXIS_MAX, 32, 128);
+		input_set_abs_params(input, ABS_Y, NS2_AXIS_MIN, NS2_AXIS_MAX, 32, 128);
+		input_set_abs_params(input, ABS_RX, NS2_AXIS_MIN, NS2_AXIS_MAX, 32, 128);
+		input_set_abs_params(input, ABS_RY, NS2_AXIS_MIN, NS2_AXIS_MAX, 32, 128);
+		input_set_abs_params(input, ABS_HAT0X, -1, 1, 0, 0);
+		input_set_abs_params(input, ABS_HAT0Y, -1, 1, 0, 0);
+		switch2_config_buttons(input, ns2_procon_mappings);
+		break;
+	default:
+		input_free_device(input);
+		return -EINVAL;
+	}
+
+	hid_info(ns2->hdev, "Firmware version %u.%u.%u (type %i)\n", ns2->version.major,
+		ns2->version.minor, ns2->version.patch, ns2->version.ctlr_type);
+	if (ns2->version.dsp_type >= 0)
+		hid_info(ns2->hdev, "DSP version %u.%u.%u\n", ns2->version.dsp_major,
+			ns2->version.dsp_minor, ns2->version.dsp_patch);
+
+	ret = input_register_device(input);
+	if (ret < 0) {
+		hid_err(ns2->hdev, "Failed to register input; ret=%d\n", ret);
+		input_free_device(input);
+		return ret;
+	}
+
+	for (i = 0; i < JC_NUM_LEDS; i++) {
+		struct led_classdev *led = &ns2->leds[i];
+		char *name = devm_kasprintf(&input->dev, GFP_KERNEL, "%s:%s:%s",
+				      dev_name(&input->dev),
+				      "green",
+				      joycon_player_led_names[i]);
+
+		if (!name) {
+			dev_err(&input->dev, "Failed to allocate name for player %d LED; ret=%d\n",
+				i + 1, ret);
+			break;
+		}
+
+		led->name = name;
+		ret = devm_led_classdev_register(&input->dev, led);
+		if (ret < 0) {
+			dev_err(&input->dev, "Failed to register player %d LED; ret=%d\n",
+				i + 1, ret);
+			break;
+		}
+	}
+
+	rcu_assign_pointer(ns2->input, input);
+	synchronize_rcu();
+	return 0;
+}
+
+static bool switch2_parse_stick_calibration(struct switch2_stick_calibration *calib,
+	const uint8_t *data)
+{
+	static const uint8_t UNCALIBRATED[9] = {
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF
+	};
+	if (memcmp(UNCALIBRATED, data, sizeof(UNCALIBRATED)) == 0)
+		return false;
+
+	calib->x.neutral = data[0];
+	calib->x.neutral |= (data[1] & 0x0F) << 8;
+
+	calib->y.neutral = data[1] >> 4;
+	calib->y.neutral |= data[2] << 4;
+
+	calib->x.positive = data[3];
+	calib->x.positive |= (data[4] & 0x0F) << 8;
+
+	calib->y.positive = data[4] >> 4;
+	calib->y.positive |= data[5] << 4;
+
+	calib->x.negative = data[6];
+	calib->x.negative |= (data[7] & 0x0F) << 8;
+
+	calib->y.negative = data[7] >> 4;
+	calib->y.negative |= data[8] << 4;
+
+	return true;
+}
+
+static void switch2_handle_flash_read(struct switch2_controller *ns2, uint8_t size,
+	uint32_t address, const uint8_t *data)
+{
+	bool ok;
+
+	switch (address) {
+	case NS2_FLASH_ADDR_SERIAL:
+		if (size != NS2_FLASH_SIZE_SERIAL)
+			return;
+		memcpy(ns2->serial, data, size);
+		switch2_init_step_done(ns2, NS2_INIT_READ_SERIAL);
+		break;
+	case NS2_FLASH_ADDR_FACTORY_PRIMARY_CALIB:
+		if (size != NS2_FLASH_SIZE_FACTORY_AXIS_CALIB)
+			return;
+		switch2_init_step_done(ns2, NS2_INIT_READ_FACTORY_PRIMARY_CALIB);
+		ok = switch2_parse_stick_calibration(&ns2->stick_calib[0], data);
+		if (ok) {
+			hid_dbg(ns2->hdev, "Got factory primary stick calibration:\n");
+			hid_dbg(ns2->hdev, "Left max: %i, neutral: %i, right max: %i\n",
+				ns2->stick_calib[0].x.negative,
+				ns2->stick_calib[0].x.neutral,
+				ns2->stick_calib[0].x.positive);
+			hid_dbg(ns2->hdev, "Down max: %i, neutral: %i, up max: %i\n",
+				ns2->stick_calib[0].y.negative,
+				ns2->stick_calib[0].y.neutral,
+				ns2->stick_calib[0].y.positive);
+		} else {
+			hid_dbg(ns2->hdev, "Factory primary stick calibration not present\n");
+		}
+		break;
+	case NS2_FLASH_ADDR_FACTORY_SECONDARY_CALIB:
+		if (size != NS2_FLASH_SIZE_FACTORY_AXIS_CALIB)
+			return;
+		switch2_init_step_done(ns2, NS2_INIT_READ_FACTORY_SECONDARY_CALIB);
+		ok = switch2_parse_stick_calibration(&ns2->stick_calib[1], data);
+		if (ok) {
+			hid_dbg(ns2->hdev, "Got factory secondary stick calibration:\n");
+			hid_dbg(ns2->hdev, "Left max: %i, neutral: %i, right max: %i\n",
+				ns2->stick_calib[1].x.negative,
+				ns2->stick_calib[1].x.neutral,
+				ns2->stick_calib[1].x.positive);
+			hid_dbg(ns2->hdev, "Down max: %i, neutral: %i, up max: %i\n",
+				ns2->stick_calib[1].y.negative,
+				ns2->stick_calib[1].y.neutral,
+				ns2->stick_calib[1].y.positive);
+		} else {
+			hid_dbg(ns2->hdev, "Factory secondary stick calibration not present\n");
+		}
+		break;
+	case NS2_FLASH_ADDR_FACTORY_TRIGGER_CALIB:
+		if (size != NS2_FLASH_SIZE_FACTORY_TRIGGER_CALIB)
+			return;
+		switch2_init_step_done(ns2, NS2_INIT_READ_FACTORY_TRIGGER_CALIB);
+		if (data[0] != 0xFF && data[1] != 0xFF) {
+			ns2->lt_zero = data[0];
+			ns2->rt_zero = data[1];
+
+			hid_dbg(ns2->hdev, "Got factory trigger calibration:\n");
+			hid_dbg(ns2->hdev, "Left zero point: %i\n", ns2->lt_zero);
+			hid_dbg(ns2->hdev, "Right zero point: %i\n", ns2->rt_zero);
+		} else {
+			hid_dbg(ns2->hdev, "Factory trigger calibration not present\n");
+		}
+		break;
+	case NS2_FLASH_ADDR_USER_PRIMARY_CALIB:
+		if (size != NS2_FLASH_SIZE_USER_AXIS_CALIB)
+			return;
+		switch2_init_step_done(ns2, NS2_INIT_READ_USER_PRIMARY_CALIB);
+		if (__le16_to_cpu(*(__le16 *)data) != NS2_USER_CALIB_MAGIC) {
+			hid_dbg(ns2->hdev, "No user primary stick calibration present\n");
+			break;
+		}
+
+		ok = switch2_parse_stick_calibration(&ns2->stick_calib[0], &data[2]);
+		if (ok) {
+			hid_dbg(ns2->hdev, "Got user primary stick calibration:\n");
+			hid_dbg(ns2->hdev, "Left max: %i, neutral: %i, right max: %i\n",
+				ns2->stick_calib[0].x.negative,
+				ns2->stick_calib[0].x.neutral,
+				ns2->stick_calib[0].x.positive);
+			hid_dbg(ns2->hdev, "Down max: %i, neutral: %i, up max: %i\n",
+				ns2->stick_calib[0].y.negative,
+				ns2->stick_calib[0].y.neutral,
+				ns2->stick_calib[0].y.positive);
+		} else {
+			hid_dbg(ns2->hdev, "No user primary stick calibration present\n");
+		}
+		break;
+	case NS2_FLASH_ADDR_USER_SECONDARY_CALIB:
+		if (size != NS2_FLASH_SIZE_USER_AXIS_CALIB)
+			return;
+		switch2_init_step_done(ns2, NS2_INIT_READ_USER_SECONDARY_CALIB);
+		if (__le16_to_cpu(*(__le16 *)data) != NS2_USER_CALIB_MAGIC) {
+			hid_dbg(ns2->hdev, "No user secondary stick calibration present\n");
+			break;
+		}
+
+		ok = switch2_parse_stick_calibration(&ns2->stick_calib[1], &data[2]);
+		if (ok) {
+			hid_dbg(ns2->hdev, "Got user secondary stick calibration:\n");
+			hid_dbg(ns2->hdev, "Left max: %i, neutral: %i, right max: %i\n",
+				ns2->stick_calib[1].x.negative,
+				ns2->stick_calib[1].x.neutral,
+				ns2->stick_calib[1].x.positive);
+			hid_dbg(ns2->hdev, "Down max: %i, neutral: %i, up max: %i\n",
+				ns2->stick_calib[1].y.negative,
+				ns2->stick_calib[1].y.neutral,
+				ns2->stick_calib[1].y.positive);
+		} else {
+			hid_dbg(ns2->hdev, "No user secondary stick calibration present\n");
+		}
+		break;
+	}
+}
+
+static void switch2_report_buttons(struct input_dev *input, const uint8_t *bytes,
+	const struct switch2_ctlr_button_mapping button_mappings[])
+{
+	const struct switch2_ctlr_button_mapping *button;
+
+	for (button = button_mappings; button->code; button++)
+		input_report_key(input, button->code, bytes[button->byte] & button->bit);
+}
+
+static void switch2_report_axis(struct input_dev *input, struct switch2_axis_calibration *calib,
+	int axis, bool invert, int value)
+{
+	if (calib && calib->neutral && calib->negative && calib->positive) {
+		value -= calib->neutral;
+		value *= NS2_AXIS_MAX + 1;
+		if (value < 0)
+			value /= calib->negative;
+		else
+			value /= calib->positive;
+	} else {
+		value = (value - 2048) * 16;
+	}
+
+	if (invert)
+		value = -value;
+	input_report_abs(input, axis,
+		clamp(value, NS2_AXIS_MIN, NS2_AXIS_MAX));
+}
+
+static void switch2_report_stick(struct input_dev *input, struct switch2_stick_calibration *calib,
+	int x, bool invert_x, int y, bool invert_y, const uint8_t *data)
+{
+	switch2_report_axis(input, &calib->x, x, invert_x, data[0] | ((data[1] & 0x0F) << 8));
+	switch2_report_axis(input, &calib->y, y, invert_y, (data[1] >> 4) | (data[2] << 4));
+}
+
+static void switch2_report_trigger(struct input_dev *input, uint8_t zero, int abs, uint8_t data)
+{
+	int value = (NS2_TRIGGER_RANGE + 1) * (data - zero);
+
+	if (zero != 232)
+		value /= (232 - zero);
+	input_report_abs(input, abs, clamp(value, 0, NS2_TRIGGER_RANGE));
+}
+
+static int switch2_event(struct hid_device *hdev, struct hid_report *report, uint8_t *raw_data,
+	int size)
+{
+	struct switch2_controller *ns2 = hid_get_drvdata(hdev);
+	struct input_dev *input;
+
+	if (report->type != HID_INPUT_REPORT)
+		return 0;
+
+	if (size < 15)
+		return -EINVAL;
+
+	guard(rcu)();
+	input = rcu_dereference(ns2->input);
+
+	if (!input)
+		return 0;
+
+	switch (report->id) {
+	case NS2_REPORT_UNIFIED:
+		/*
+		 * TODO
+		 * This won't be sent unless the report type gets changed via command
+		 * 03-0A, but we should support it at some point regardless.
+		 */
+		break;
+	case NS2_REPORT_JCL:
+		switch2_report_stick(input, &ns2->stick_calib[0], ABS_X, false,
+			ABS_Y, true, &raw_data[6]);
+		switch2_report_buttons(input, &raw_data[3], ns2_left_joycon_button_mappings);
+		break;
+	case NS2_REPORT_JCR:
+		switch2_report_stick(input, &ns2->stick_calib[0], ABS_X, false,
+			ABS_Y, true, &raw_data[6]);
+		switch2_report_buttons(input, &raw_data[3], ns2_right_joycon_button_mappings);
+		break;
+	case NS2_REPORT_GC:
+		input_report_abs(input, ABS_HAT0X,
+			!!(raw_data[4] & NS2_BTNL_RIGHT) -
+			!!(raw_data[4] & NS2_BTNL_LEFT));
+		input_report_abs(input, ABS_HAT0Y,
+			!!(raw_data[4] & NS2_BTNL_DOWN) -
+			!!(raw_data[4] & NS2_BTNL_UP));
+		switch2_report_buttons(input, &raw_data[3], ns2_gccon_mappings);
+		switch2_report_stick(input, &ns2->stick_calib[0], ABS_X, false,
+			ABS_Y, true, &raw_data[6]);
+		switch2_report_stick(input, &ns2->stick_calib[1], ABS_RX, false,
+			ABS_RY, true, &raw_data[9]);
+		switch2_report_trigger(input, ns2->lt_zero, ABS_Z, raw_data[13]);
+		switch2_report_trigger(input, ns2->rt_zero, ABS_RZ, raw_data[14]);
+		break;
+	case NS2_REPORT_PRO:
+		input_report_abs(input, ABS_HAT0X,
+			!!(raw_data[4] & NS2_BTNL_RIGHT) -
+			!!(raw_data[4] & NS2_BTNL_LEFT));
+		input_report_abs(input, ABS_HAT0Y,
+			!!(raw_data[4] & NS2_BTNL_DOWN) -
+			!!(raw_data[4] & NS2_BTNL_UP));
+		switch2_report_buttons(input, &raw_data[3], ns2_procon_mappings);
+		switch2_report_stick(input, &ns2->stick_calib[0], ABS_X, false,
+			ABS_Y, true, &raw_data[6]);
+		switch2_report_stick(input, &ns2->stick_calib[1], ABS_RX, false,
+			ABS_RY, true, &raw_data[9]);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	input_sync(input);
+	return 0;
+}
+
+static int switch2_features_enable(struct switch2_controller *ns2, int features)
+{
+	__le32 feature_bits = __cpu_to_le32(features);
+
+	if (!ns2->cfg)
+		return -ENOTCONN;
+	return ns2->cfg->send_command(NS2_CMD_FEATSEL, NS2_SUBCMD_FEATSEL_ENABLE,
+		&feature_bits, sizeof(feature_bits),
+		ns2->cfg);
+}
+
+static int switch2_read_flash(struct switch2_controller *ns2, uint32_t address,
+	uint8_t size)
+{
+	uint8_t message[8] = { size, 0x7e };
+
+	if (!ns2->cfg)
+		return -ENOTCONN;
+	put_unaligned_le32(address, &message[4]);
+	return ns2->cfg->send_command(NS2_CMD_FLASH, NS2_SUBCMD_FLASH_READ, message,
+		sizeof(message), ns2->cfg);
+}
+
+static int switch2_set_player_id(struct switch2_controller *ns2, uint32_t player_id)
+{
+	int i;
+	int player_led_pattern = player_id % JC_NUM_LED_PATTERNS;
+
+	for (i = 0; i < JC_NUM_LEDS; i++)
+		ns2->leds[i].brightness = joycon_player_led_patterns[player_led_pattern][i];
+
+	return switch2_set_leds(ns2);
+}
+
+static int switch2_set_report_format(struct switch2_controller *ns2, enum switch2_report_id fmt)
+{
+	__le32 format_id = __cpu_to_le32(fmt);
+
+	if (!ns2->cfg)
+		return -ENOTCONN;
+	return ns2->cfg->send_command(NS2_CMD_INIT, NS2_SUBCMD_INIT_SELECT_REPORT,
+		&format_id, sizeof(format_id),
+		ns2->cfg);
+}
+
+static int switch2_init_controller(struct switch2_controller *ns2)
+{
+	if (ns2->init_step == NS2_INIT_DONE)
+		return 0;
+
+	if (!ns2->cfg)
+		return -ENOTCONN;
+
+	if (ns2->init_retries > NS2_MAX_INIT_RETRIES) {
+		if (ns2->init_retries == NS2_MAX_INIT_RETRIES + 1) {
+			dev_err(ns2->cfg->dev, "Failed to configure controller\n");
+			ns2->init_retries++;
+		}
+		return -EIO;
+	}
+
+	ns2->init_retries++;
+	switch (ns2->init_step) {
+	case NS2_INIT_READ_SERIAL:
+		return switch2_read_flash(ns2, NS2_FLASH_ADDR_SERIAL,
+			NS2_FLASH_SIZE_SERIAL);
+	case NS2_INIT_GET_FIRMWARE_INFO:
+		return ns2->cfg->send_command(NS2_CMD_FW_INFO, NS2_SUBCMD_FW_INFO_GET,
+			NULL, 0, ns2->cfg);
+	case NS2_INIT_READ_FACTORY_PRIMARY_CALIB:
+		return switch2_read_flash(ns2, NS2_FLASH_ADDR_FACTORY_PRIMARY_CALIB,
+			NS2_FLASH_SIZE_FACTORY_AXIS_CALIB);
+	case NS2_INIT_READ_FACTORY_SECONDARY_CALIB:
+		if (switch2_ctlr_is_joycon(ns2->ctlr_type)) {
+			switch2_init_step_done(ns2, ns2->init_step);
+			return switch2_init_controller(ns2);
+		}
+		return switch2_read_flash(ns2, NS2_FLASH_ADDR_FACTORY_SECONDARY_CALIB,
+			NS2_FLASH_SIZE_FACTORY_AXIS_CALIB);
+	case NS2_INIT_READ_FACTORY_TRIGGER_CALIB:
+		if (ns2->ctlr_type != NS2_CTLR_TYPE_GC) {
+			switch2_init_step_done(ns2, ns2->init_step);
+			return switch2_init_controller(ns2);
+		}
+		return switch2_read_flash(ns2, NS2_FLASH_ADDR_FACTORY_TRIGGER_CALIB,
+			NS2_FLASH_SIZE_FACTORY_TRIGGER_CALIB);
+	case NS2_INIT_READ_USER_PRIMARY_CALIB:
+		return switch2_read_flash(ns2, NS2_FLASH_ADDR_USER_PRIMARY_CALIB,
+			NS2_FLASH_SIZE_USER_AXIS_CALIB);
+	case NS2_INIT_READ_USER_SECONDARY_CALIB:
+		if (switch2_ctlr_is_joycon(ns2->ctlr_type)) {
+			switch2_init_step_done(ns2, ns2->init_step);
+			return switch2_init_controller(ns2);
+		}
+		return switch2_read_flash(ns2, NS2_FLASH_ADDR_USER_SECONDARY_CALIB,
+			NS2_FLASH_SIZE_USER_AXIS_CALIB);
+	case NS2_INIT_SET_FEATURE_MASK:
+		return ns2->cfg->send_command(NS2_CMD_FEATSEL, NS2_SUBCMD_FEATSEL_SET_MASK,
+			switch2_feature_mask, sizeof(switch2_feature_mask), ns2->cfg);
+	case NS2_INIT_ENABLE_FEATURES:
+		return switch2_features_enable(ns2, NS2_FEATURE_BUTTONS | NS2_FEATURE_ANALOG);
+	case NS2_INIT_GRIP_BUTTONS:
+		if (!switch2_ctlr_is_joycon(ns2->ctlr_type)) {
+			switch2_init_step_done(ns2, ns2->init_step);
+			return switch2_init_controller(ns2);
+		}
+		return ns2->cfg->send_command(NS2_CMD_GRIP, NS2_SUBCMD_GRIP_ENABLE_BUTTONS,
+			switch2_one_data, sizeof(switch2_one_data),
+			ns2->cfg);
+	case NS2_INIT_REPORT_FORMAT:
+		switch (ns2->ctlr_type) {
+		case NS2_CTLR_TYPE_JCL:
+			return switch2_set_report_format(ns2, NS2_REPORT_JCL);
+		case NS2_CTLR_TYPE_JCR:
+			return switch2_set_report_format(ns2, NS2_REPORT_JCR);
+		case NS2_CTLR_TYPE_PRO:
+			return switch2_set_report_format(ns2, NS2_REPORT_PRO);
+		case NS2_CTLR_TYPE_GC:
+			return switch2_set_report_format(ns2, NS2_REPORT_GC);
+		default:
+			switch2_init_step_done(ns2, ns2->init_step);
+			return switch2_init_controller(ns2);
+		}
+	case NS2_INIT_SET_PLAYER_LEDS:
+		return switch2_set_player_id(ns2, ns2->player_id);
+	case NS2_INIT_INPUT:
+		return ns2->cfg->send_command(NS2_CMD_INIT, NS2_SUBCMD_INIT_USB,
+			switch2_init_cmd_data, sizeof(switch2_init_cmd_data), ns2->cfg);
+	case NS2_INIT_FINISH:
+		if (ns2->hdev)
+			return switch2_init_input(ns2);
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		break;
+	}
+	return 0;
+}
+
+int switch2_receive_command(struct switch2_controller *ns2,
+	const uint8_t *message, size_t length)
+{
+	const struct switch2_cmd_header *header;
+	int ret = 0;
+
+	if (length < 8)
+		return -EINVAL;
+
+	print_hex_dump_debug("got cmd: ", DUMP_PREFIX_OFFSET, 16, 1, message, length, false);
+
+	mutex_lock(&ns2->lock);
+
+	header = (const struct switch2_cmd_header *)message;
+	if (!(header->flags & NS2_FLAG_OK)) {
+		dev_warn(ns2->cfg->dev, "Packet error %02x replying to command %x:%x",
+			header->flags, header->command, header->subcommand);
+		ret = -EIO;
+		goto exit;
+	}
+	message = &message[8];
+	length -= 8;
+
+	switch (header->command) {
+	case NS2_CMD_FLASH:
+		if (header->subcommand == NS2_SUBCMD_FLASH_READ) {
+			uint8_t read_size;
+			uint32_t read_address;
+
+			if (length < 8) {
+				ret = -EINVAL;
+				goto exit;
+			}
+			read_size = message[0];
+			read_address = get_unaligned_le32(&message[4]);
+			if (length < read_size + 8) {
+				ret = -EINVAL;
+				goto exit;
+			}
+			switch2_handle_flash_read(ns2, read_size, read_address, &message[8]);
+		}
+		break;
+	case NS2_CMD_INIT:
+		if (header->subcommand == NS2_SUBCMD_INIT_USB)
+			switch2_init_step_done(ns2, NS2_INIT_INPUT);
+		else if (header->subcommand == NS2_SUBCMD_INIT_SELECT_REPORT)
+			switch2_init_step_done(ns2, NS2_INIT_REPORT_FORMAT);
+		break;
+	case NS2_CMD_GRIP:
+		if (header->subcommand == NS2_SUBCMD_GRIP_ENABLE_BUTTONS)
+			switch2_init_step_done(ns2, NS2_INIT_GRIP_BUTTONS);
+		break;
+	case NS2_CMD_LED:
+		if (header->subcommand == NS2_SUBCMD_LED_PATTERN)
+			switch2_init_step_done(ns2, NS2_INIT_SET_PLAYER_LEDS);
+		break;
+	case NS2_CMD_FEATSEL:
+		if (header->subcommand == NS2_SUBCMD_FEATSEL_SET_MASK)
+			switch2_init_step_done(ns2, NS2_INIT_SET_FEATURE_MASK);
+		else if (header->subcommand == NS2_SUBCMD_FEATSEL_ENABLE)
+			switch2_init_step_done(ns2, NS2_INIT_ENABLE_FEATURES);
+		break;
+	case NS2_CMD_FW_INFO:
+		if (header->subcommand == NS2_SUBCMD_FW_INFO_GET) {
+			if (length < sizeof(ns2->version)) {
+				ret = -EINVAL;
+				goto exit;
+			}
+			memcpy(&ns2->version, message, sizeof(ns2->version));
+			ns2->ctlr_type = ns2->version.ctlr_type;
+			switch2_init_step_done(ns2, NS2_INIT_GET_FIRMWARE_INFO);
+		}
+		break;
+	default:
+		break;
+	}
+
+exit:
+	if (ns2->init_step < NS2_INIT_DONE)
+		switch2_init_controller(ns2);
+
+	mutex_unlock(&ns2->lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(switch2_receive_command);
+
+int switch2_controller_attach_cfg(const char *phys, struct switch2_cfg_intf *cfg)
+{
+	struct switch2_controller *ns2 = switch2_get_controller(phys);
+	int ret = 0;
+
+	if (IS_ERR(ns2))
+		return PTR_ERR(ns2);
+
+	mutex_lock(&ns2->lock);
+	if (ns2->cfg) {
+		ret = -EBUSY;
+		goto out;
+	}
+	cfg->parent = ns2;
+	ns2->cfg = cfg;
+
+	if (ns2->hdev)
+		ret = switch2_init_controller(ns2);
+
+	if (ret < 0) {
+		cfg->parent = NULL;
+		ns2->cfg = NULL;
+	}
+
+out:
+	mutex_unlock(&ns2->lock);
+
+	if (ret < 0)
+		kref_put(&ns2->refcount, switch2_kref_put);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(switch2_controller_attach_cfg);
+
+void switch2_controller_detach_cfg(struct switch2_controller *ns2)
+{
+	mutex_lock(&ns2->lock);
+	if (!ns2->cfg || WARN_ON(ns2 != ns2->cfg->parent)) {
+		mutex_unlock(&ns2->lock);
+		return;
+	}
+	ns2->cfg->parent = NULL;
+	ns2->cfg = NULL;
+	switch2_controller_put(ns2);
+	mutex_unlock(&ns2->lock);
+	kref_put(&ns2->refcount, switch2_kref_put);
+}
+EXPORT_SYMBOL_GPL(switch2_controller_detach_cfg);
+
+static int switch2_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+	struct switch2_controller *ns2;
+	struct usb_device *udev;
+	char phys[64];
+	int ret;
+
+	if (!hid_is_usb(hdev))
+		return -ENODEV;
+
+	udev = hid_to_usb_dev(hdev);
+	if (usb_make_path(udev, phys, sizeof(phys)) < 0)
+		return -EINVAL;
+
+	ret = hid_parse(hdev);
+	if (ret) {
+		hid_err(hdev, "parse failed %d\n", ret);
+		return ret;
+	}
+
+	ns2 = switch2_get_controller(phys);
+	if (IS_ERR(ns2))
+		return PTR_ERR(ns2);
+
+	mutex_lock(&ns2->lock);
+	if (ns2->hdev) {
+		ret = -EBUSY;
+		hid_err(hdev,
+			"Second hdevs tried to claim same controller, first=%p vs second=%p\n",
+			ns2->hdev, hdev);
+		goto err_put;
+	}
+	ns2->hdev = hdev;
+	hid_set_drvdata(hdev, ns2);
+
+	switch (hdev->product | (hdev->vendor << 16)) {
+	default:
+		strscpy(ns2->name, hdev->name, sizeof(ns2->name));
+		break;
+	/* Some controllers have slightly wrong names so we override them */
+	case USB_DEVICE_ID_NINTENDO_NS2_JOYCONR | (USB_VENDOR_ID_NINTENDO << 16):
+		/* Missing the "2" in the name */
+		strscpy(ns2->name, "Nintendo Joy-Con 2 (R)", sizeof(ns2->name));
+		break;
+	case USB_DEVICE_ID_NINTENDO_NS2_GCCON | (USB_VENDOR_ID_NINTENDO << 16):
+		/* Has "Nintendo" in the name twice */
+		strscpy(ns2->name, "Nintendo GameCube Controller", sizeof(ns2->name));
+		break;
+	}
+
+	ns2->player_id = U32_MAX;
+	ret = ida_alloc(&nintendo_player_id_allocator, GFP_KERNEL);
+	if (ret < 0)
+		hid_warn(hdev, "Failed to allocate player ID, skipping; ret=%d\n", ret);
+	else
+		ns2->player_id = ret;
+
+	switch2_leds_create(ns2);
+
+	ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
+	if (ret) {
+		hid_err(hdev, "hw_start failed %d\n", ret);
+		goto err_cleanup;
+	}
+
+	ret = hid_hw_open(hdev);
+	if (ret) {
+		hid_err(hdev, "hw_open failed %d\n", ret);
+		goto err_stop;
+	}
+
+	ret = 0;
+	if (ns2->cfg)
+		ret = switch2_init_controller(ns2);
+
+	if (!ret) {
+		mutex_unlock(&ns2->lock);
+		return 0;
+	}
+
+	hid_hw_close(hdev);
+err_stop:
+	hid_hw_stop(hdev);
+err_cleanup:
+	ida_free(&nintendo_player_id_allocator, ns2->player_id);
+	ns2->hdev = NULL;
+err_put:
+	switch2_controller_put(ns2);
+	mutex_unlock(&ns2->lock);
+	kref_put(&ns2->refcount, switch2_kref_put);
+
+	return ret;
+}
+
+static void switch2_remove(struct hid_device *hdev)
+{
+	struct switch2_controller *ns2 = hid_get_drvdata(hdev);
+
+	mutex_lock(&ns2->lock);
+	switch2_controller_put(ns2);
+	ns2->hdev = NULL;
+	hid_set_drvdata(hdev, NULL);
+	ida_free(&nintendo_player_id_allocator, ns2->player_id);
+	mutex_unlock(&ns2->lock);
+	kref_put(&ns2->refcount, switch2_kref_put);
+	hid_hw_close(hdev);
+	hid_hw_stop(hdev);
+}
+
 static const struct hid_device_id nintendo_hid_devices[] = {
+	/* Switch devices */
 	{ HID_USB_DEVICE(USB_VENDOR_ID_NINTENDO,
 			 USB_DEVICE_ID_NINTENDO_PROCON) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_NINTENDO,
@@ -2863,10 +4057,67 @@ static const struct hid_device_id nintendo_hid_devices[] = {
 			 USB_DEVICE_ID_NINTENDO_N64CON) },
 	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_HORI,
 			 USB_DEVICE_ID_HORI_WIRELESS_SWITCH_PAD) },
+	/* Switch 2 devices */
+	{ HID_USB_DEVICE(USB_VENDOR_ID_NINTENDO,
+			 USB_DEVICE_ID_NINTENDO_NS2_JOYCONL) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_NINTENDO,
+			 USB_DEVICE_ID_NINTENDO_NS2_JOYCONR) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_NINTENDO,
+			 USB_DEVICE_ID_NINTENDO_NS2_PROCON) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_NINTENDO,
+			 USB_DEVICE_ID_NINTENDO_NS2_GCCON) },
 	{ }
 };
 MODULE_DEVICE_TABLE(hid, nintendo_hid_devices);
 
+static bool nintendo_is_switch2(struct hid_device *hdev)
+{
+	return hdev->vendor == USB_VENDOR_ID_NINTENDO &&
+		hdev->product >= USB_DEVICE_ID_NINTENDO_NS2_JOYCONR;
+}
+
+static void nintendo_hid_remove(struct hid_device *hdev)
+{
+	if (nintendo_is_switch2(hdev))
+		switch2_remove(hdev);
+	else
+		joycon_remove(hdev);
+}
+
+static int nintendo_hid_event(struct hid_device *hdev,
+			      struct hid_report *report, u8 *raw_data, int size)
+{
+	if (nintendo_is_switch2(hdev))
+		return switch2_event(hdev, report, raw_data, size);
+	else
+		return joycon_event(hdev, report, raw_data, size);
+}
+
+static int nintendo_hid_probe(struct hid_device *hdev,
+			    const struct hid_device_id *id)
+{
+	if (nintendo_is_switch2(hdev))
+		return switch2_probe(hdev, id);
+	else
+		return joycon_probe(hdev, id);
+}
+
+static int nintendo_hid_resume(struct hid_device *hdev)
+{
+	if (nintendo_is_switch2(hdev))
+		return 0;
+	else
+		return joycon_resume(hdev);
+}
+
+static int nintendo_hid_suspend(struct hid_device *hdev, pm_message_t message)
+{
+	if (nintendo_is_switch2(hdev))
+		return 0;
+	else
+		return joycon_suspend(hdev, message);
+}
+
 static struct hid_driver nintendo_hid_driver = {
 	.name		= "nintendo",
 	.id_table	= nintendo_hid_devices,
@@ -2894,4 +4145,5 @@ MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Ryan McClelland <rymcclel@gmail.com>");
 MODULE_AUTHOR("Emily Strickland <linux@emily.st>");
 MODULE_AUTHOR("Daniel J. Ogorchock <djogorchock@gmail.com>");
+MODULE_AUTHOR("Vicki Pfau <vi@endrift.com>");
 MODULE_DESCRIPTION("Driver for Nintendo Switch Controllers");
diff --git a/drivers/hid/hid-nintendo.h b/drivers/hid/hid-nintendo.h
new file mode 100644
index 000000000000..7aff22f30266
--- /dev/null
+++ b/drivers/hid/hid-nintendo.h
@@ -0,0 +1,72 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * HID driver for Nintendo Switch 2 controllers
+ *
+ * Copyright (c) 2025 Valve Software
+ *
+ * This driver is based on the following work:
+ *   https://gist.github.com/shinyquagsire23/66f006b46c56216acbaac6c1e2279b64
+ *   https://github.com/ndeadly/switch2_controller_research
+ */
+
+#ifndef __HID_NINTENDO_H
+#define __HID_NINTENDO_H
+
+#include <linux/bits.h>
+
+#define NS2_FLAG_OK	BIT(0)
+#define NS2_FLAG_NACK	BIT(2)
+
+enum switch2_cmd {
+	NS2_CMD_NFC = 0x01,
+	NS2_CMD_FLASH = 0x02,
+	NS2_CMD_INIT = 0x03,
+	NS2_CMD_GRIP = 0x08,
+	NS2_CMD_LED = 0x09,
+	NS2_CMD_VIBRATE = 0x0a,
+	NS2_CMD_BATTERY = 0x0b,
+	NS2_CMD_FEATSEL = 0x0c,
+	NS2_CMD_FW_UPD = 0x0d,
+	NS2_CMD_FW_INFO = 0x10,
+	NS2_CMD_BT_PAIR = 0x15,
+};
+
+enum switch2_direction {
+	NS2_DIR_IN = 0x00,
+	NS2_DIR_OUT = 0x90,
+};
+
+enum switch2_transport {
+	NS2_TRANS_USB = 0x00,
+	NS2_TRANS_BT = 0x01,
+};
+
+struct switch2_cmd_header {
+	uint8_t command;
+	uint8_t flags;
+	uint8_t transport;
+	uint8_t subcommand;
+	uint8_t unk1;
+	uint8_t length;
+	uint16_t unk2;
+};
+static_assert(sizeof(struct switch2_cmd_header) == 8);
+
+struct device;
+struct switch2_controller;
+struct switch2_cfg_intf {
+	struct switch2_controller *parent;
+	struct device *dev;
+
+	int (*send_command)(enum switch2_cmd command, uint8_t subcommand,
+		const void *message, size_t length,
+		struct switch2_cfg_intf *intf);
+};
+
+int switch2_controller_attach_cfg(const char *phys, struct switch2_cfg_intf *cfg);
+void switch2_controller_detach_cfg(struct switch2_controller *controller);
+
+int switch2_receive_command(struct switch2_controller *controller,
+	const uint8_t *message, size_t length);
+
+#endif
diff --git a/drivers/input/joystick/Kconfig b/drivers/input/joystick/Kconfig
index 7755e5b454d2..868262c6ccd9 100644
--- a/drivers/input/joystick/Kconfig
+++ b/drivers/input/joystick/Kconfig
@@ -422,4 +422,15 @@ config JOYSTICK_SEESAW
 	  To compile this driver as a module, choose M here: the module will be
 	  called adafruit-seesaw.
 
+config JOYSTICK_NINTENDO_SWITCH2_USB
+	tristate "Wired Nintendo Switch 2 controller support"
+	depends on HID_NINTENDO
+	depends on USB
+	help
+	  Say Y here if you want to enable support for wired Nintendo Switch 2
+	  controllers.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called nintendo-switch2-usb.
+
 endif
diff --git a/drivers/input/joystick/Makefile b/drivers/input/joystick/Makefile
index 9976f596a920..8f92900ae885 100644
--- a/drivers/input/joystick/Makefile
+++ b/drivers/input/joystick/Makefile
@@ -34,6 +34,7 @@ obj-$(CONFIG_JOYSTICK_SIDEWINDER)	+= sidewinder.o
 obj-$(CONFIG_JOYSTICK_SPACEBALL)	+= spaceball.o
 obj-$(CONFIG_JOYSTICK_SPACEORB)		+= spaceorb.o
 obj-$(CONFIG_JOYSTICK_STINGER)		+= stinger.o
+obj-$(CONFIG_JOYSTICK_NINTENDO_SWITCH2_USB)	+= nintendo-switch2-usb.o
 obj-$(CONFIG_JOYSTICK_TMDC)		+= tmdc.o
 obj-$(CONFIG_JOYSTICK_TURBOGRAFX)	+= turbografx.o
 obj-$(CONFIG_JOYSTICK_TWIDJOY)		+= twidjoy.o
diff --git a/drivers/input/joystick/nintendo-switch2-usb.c b/drivers/input/joystick/nintendo-switch2-usb.c
new file mode 100644
index 000000000000..0a004918c1f1
--- /dev/null
+++ b/drivers/input/joystick/nintendo-switch2-usb.c
@@ -0,0 +1,464 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * USB driver for Nintendo Switch 2 controllers configuration interface
+ *
+ * Copyright (c) 2025 Valve Software
+ *
+ * This driver is based on the following work:
+ *   https://gist.github.com/shinyquagsire23/66f006b46c56216acbaac6c1e2279b64
+ *   https://github.com/ndeadly/switch2_controller_research
+ */
+
+#include "../../hid/hid-ids.h"
+#include "../../hid/hid-nintendo.h"
+#include <linux/module.h>
+#include <linux/usb/input.h>
+
+#define NS2_BULK_SIZE 64
+#define NS2_IN_URBS 2
+#define NS2_OUT_URBS 4
+
+static struct usb_driver switch2_usb;
+
+enum switch2_urb_state {
+	NS2_URB_FREE,
+	NS2_URB_OUT,
+	NS2_URB_IN,
+};
+
+struct switch2_urb {
+	struct urb *urb;
+	uint8_t *data;
+	enum switch2_urb_state state;
+};
+
+struct switch2_usb {
+	struct switch2_cfg_intf cfg;
+	struct usb_device *udev;
+
+	struct switch2_urb bulk_in[NS2_IN_URBS];
+	struct usb_anchor bulk_in_anchor;
+	bool shutdown;
+	spinlock_t bulk_in_lock;
+
+	struct switch2_urb bulk_out[NS2_OUT_URBS];
+	struct usb_anchor bulk_out_anchor;
+	spinlock_t bulk_out_lock;
+
+	struct work_struct message_in_work;
+};
+
+static void switch2_bulk_in(struct urb *urb)
+{
+	struct switch2_usb *ns2_usb = urb->context;
+	int i;
+	bool schedule = false;
+	unsigned long flags;
+
+	switch (urb->status) {
+	case 0:
+		schedule = true;
+		break;
+	case -ECONNRESET:
+	case -ENOENT:
+	case -ESHUTDOWN:
+		dev_dbg(&ns2_usb->udev->dev, "shutting down input urb: %d\n", urb->status);
+		return;
+	default:
+		dev_dbg(&ns2_usb->udev->dev, "unknown input urb status: %d\n", urb->status);
+		break;
+	}
+
+	spin_lock_irqsave(&ns2_usb->bulk_in_lock, flags);
+	for (i = 0; i < NS2_IN_URBS; i++) {
+		int err;
+		struct switch2_urb *ns2_urb;
+
+		if (ns2_usb->bulk_in[i].urb == urb) {
+			ns2_usb->bulk_in[i].state = NS2_URB_IN;
+			continue;
+		}
+
+		if (ns2_usb->bulk_in[i].state != NS2_URB_FREE)
+			continue;
+
+		/*
+		 * We want exactly one bulk in URB scheduled at a time, so only
+		 * reschedule this immediately if nothing else is scheduled
+		 * currently.
+		 */
+		if (!usb_anchor_empty(&ns2_usb->bulk_in_anchor) || ns2_usb->shutdown)
+			continue;
+
+		ns2_urb = &ns2_usb->bulk_in[i];
+		if (!ns2_urb)
+			continue;
+
+		usb_anchor_urb(ns2_urb->urb, &ns2_usb->bulk_in_anchor);
+		err = usb_submit_urb(ns2_urb->urb, GFP_ATOMIC);
+		if (err) {
+			usb_unanchor_urb(ns2_urb->urb);
+			dev_dbg(&ns2_usb->udev->dev, "failed to queue input urb: %d\n", err);
+		} else {
+			ns2_urb->state = NS2_URB_OUT;
+		}
+	}
+	spin_unlock_irqrestore(&ns2_usb->bulk_in_lock, flags);
+
+	if (schedule)
+		schedule_work(&ns2_usb->message_in_work);
+}
+
+static void switch2_bulk_out(struct urb *urb)
+{
+	struct switch2_usb *ns2_usb = urb->context;
+	int i;
+
+	guard(spinlock_irqsave)(&ns2_usb->bulk_out_lock);
+
+	switch (urb->status) {
+	case 0:
+		break;
+	case -ECONNRESET:
+	case -ENOENT:
+	case -ESHUTDOWN:
+		dev_dbg(&ns2_usb->udev->dev, "shutting down output urb: %d\n", urb->status);
+		break;
+	default:
+		dev_dbg(&ns2_usb->udev->dev, "unknown output urb status: %d\n", urb->status);
+		break;
+	}
+
+	for (i = 0; i < NS2_OUT_URBS; i++) {
+		if (ns2_usb->bulk_out[i].urb != urb)
+			continue;
+
+		ns2_usb->bulk_out[i].state = NS2_URB_FREE;
+		break;
+	}
+}
+
+static int switch2_usb_send_cmd(enum switch2_cmd command, uint8_t subcommand,
+	const void *message, size_t size, struct switch2_cfg_intf *cfg)
+{
+	struct switch2_usb *ns2_usb = (struct switch2_usb *)cfg;
+	struct switch2_urb *urb = NULL;
+	int i;
+	int ret;
+	unsigned long flags;
+
+	struct switch2_cmd_header header = {
+		command, NS2_DIR_OUT | NS2_FLAG_OK, NS2_TRANS_USB, subcommand, 0, size
+	};
+
+	if (WARN_ON(size > 56))
+		return -EINVAL;
+
+	spin_lock_irqsave(&ns2_usb->bulk_out_lock, flags);
+	for (i = 0; i < NS2_OUT_URBS; i++) {
+		if (ns2_usb->bulk_out[i].state != NS2_URB_FREE)
+			continue;
+
+		urb = &ns2_usb->bulk_out[i];
+		urb->state = NS2_URB_OUT;
+		break;
+	}
+	spin_unlock_irqrestore(&ns2_usb->bulk_out_lock, flags);
+
+	if (!urb) {
+		dev_warn(&ns2_usb->udev->dev, "output queue full, dropping message\n");
+		return -ENOBUFS;
+	}
+
+	memcpy(urb->data, &header, sizeof(header));
+	if (message && size)
+		memcpy(&urb->data[8], message, size);
+	urb->urb->transfer_buffer_length = size + sizeof(header);
+
+	print_hex_dump_debug("sending cmd: ", DUMP_PREFIX_OFFSET, 16, 1, urb->data,
+		size + sizeof(header), false);
+
+	usb_anchor_urb(urb->urb, &ns2_usb->bulk_out_anchor);
+	ret = usb_submit_urb(urb->urb, GFP_KERNEL);
+	if (ret) {
+		if (ret != -ENODEV)
+			dev_warn(&ns2_usb->udev->dev, "failed to submit output urb: %i", ret);
+		spin_lock_irqsave(&ns2_usb->bulk_out_lock, flags);
+		urb->state = NS2_URB_FREE;
+		spin_unlock_irqrestore(&ns2_usb->bulk_out_lock, flags);
+		usb_unanchor_urb(urb->urb);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void switch2_usb_message_in_work(struct work_struct *work)
+{
+	struct switch2_usb *ns2_usb = container_of(work, struct switch2_usb, message_in_work);
+	struct switch2_urb *urb;
+	int err;
+	int i;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ns2_usb->bulk_in_lock, flags);
+	for (i = 0; i < NS2_IN_URBS; i++) {
+		urb = &ns2_usb->bulk_in[i];
+		if (urb->state != NS2_URB_IN)
+			continue;
+		spin_unlock_irqrestore(&ns2_usb->bulk_in_lock, flags);
+
+		if (ns2_usb->cfg.parent) {
+			err = switch2_receive_command(ns2_usb->cfg.parent,
+				urb->urb->transfer_buffer, urb->urb->actual_length);
+			if (err)
+				dev_dbg(&ns2_usb->udev->dev, "receive command failed: %d\n", err);
+		} else {
+			dev_err(&ns2_usb->udev->dev,
+				"Got message before controller is fully set up; discarding\n");
+		}
+
+		spin_lock_irqsave(&ns2_usb->bulk_in_lock, flags);
+		urb->state = NS2_URB_FREE;
+		/*
+		 * We want exactly one bulk in URB scheduled at a time, so only
+		 * reschedule this immediately if nothing else is scheduled
+		 * currently.
+		 */
+		if (!usb_anchor_empty(&ns2_usb->bulk_in_anchor) || ns2_usb->shutdown)
+			continue;
+
+		usb_anchor_urb(urb->urb, &ns2_usb->bulk_in_anchor);
+		err = usb_submit_urb(urb->urb, GFP_ATOMIC);
+		if (err) {
+			usb_unanchor_urb(urb->urb);
+			dev_dbg(&ns2_usb->udev->dev,
+				"failed to queue input urb: %d\n", err);
+		} else {
+			urb->state = NS2_URB_OUT;
+		}
+	}
+	spin_unlock_irqrestore(&ns2_usb->bulk_in_lock, flags);
+}
+
+static int switch2_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
+{
+	struct switch2_usb *ns2_usb;
+	struct usb_device *udev;
+	struct usb_endpoint_descriptor *bulk_in, *bulk_out;
+	struct urb *urb;
+	uint8_t *data;
+	char phys[64];
+	int ret;
+	int i;
+	unsigned long flags;
+
+	udev = interface_to_usbdev(intf);
+	if (usb_make_path(udev, phys, sizeof(phys)) < 0)
+		return -EINVAL;
+
+	ret = usb_find_common_endpoints(intf->cur_altsetting, &bulk_in, &bulk_out, NULL, NULL);
+	if (ret) {
+		dev_err(&intf->dev, "failed to find bulk EPs\n");
+		return ret;
+	}
+
+	ns2_usb = devm_kzalloc(&intf->dev, sizeof(*ns2_usb), GFP_KERNEL);
+	if (!ns2_usb)
+		return -ENOMEM;
+
+	init_usb_anchor(&ns2_usb->bulk_out_anchor);
+	spin_lock_init(&ns2_usb->bulk_out_lock);
+	init_usb_anchor(&ns2_usb->bulk_in_anchor);
+	spin_lock_init(&ns2_usb->bulk_in_lock);
+	INIT_WORK(&ns2_usb->message_in_work, switch2_usb_message_in_work);
+
+	ns2_usb->udev = udev;
+	for (i = 0; i < NS2_IN_URBS; i++) {
+		urb = usb_alloc_urb(0, GFP_KERNEL);
+		if (!urb) {
+			ret = -ENOMEM;
+			goto err_free_in;
+		}
+
+		data = usb_alloc_coherent(udev, NS2_BULK_SIZE, GFP_KERNEL,
+			&urb->transfer_dma);
+		if (!data) {
+			usb_free_urb(urb);
+			ret = -ENOMEM;
+			goto err_free_in;
+		}
+
+		spin_lock_irqsave(&ns2_usb->bulk_in_lock, flags);
+		usb_fill_bulk_urb(urb, udev,
+			usb_rcvbulkpipe(udev, bulk_in->bEndpointAddress),
+			data, NS2_BULK_SIZE, switch2_bulk_in, ns2_usb);
+		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+
+		ns2_usb->bulk_in[i].urb = urb;
+		ns2_usb->bulk_in[i].data = data;
+		spin_unlock_irqrestore(&ns2_usb->bulk_in_lock, flags);
+	}
+
+	for (i = 0; i < NS2_OUT_URBS; i++) {
+		urb = usb_alloc_urb(0, GFP_KERNEL);
+		if (!urb) {
+			ret = -ENOMEM;
+			goto err_free_out;
+		}
+
+		data = usb_alloc_coherent(udev, NS2_BULK_SIZE, GFP_KERNEL,
+			&urb->transfer_dma);
+		if (!data) {
+			usb_free_urb(urb);
+			ret = -ENOMEM;
+			goto err_free_out;
+		}
+
+		spin_lock_irqsave(&ns2_usb->bulk_out_lock, flags);
+		usb_fill_bulk_urb(urb, udev,
+			usb_sndbulkpipe(udev, bulk_out->bEndpointAddress),
+			data, NS2_BULK_SIZE, switch2_bulk_out, ns2_usb);
+		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+
+		ns2_usb->bulk_out[i].urb = urb;
+		ns2_usb->bulk_out[i].data = data;
+		spin_unlock_irqrestore(&ns2_usb->bulk_out_lock, flags);
+	}
+
+	usb_set_intfdata(intf, ns2_usb);
+
+	ns2_usb->cfg.dev = &ns2_usb->udev->dev;
+	ns2_usb->cfg.send_command = switch2_usb_send_cmd;
+
+	spin_lock_irqsave(&ns2_usb->bulk_in_lock, flags);
+	ns2_usb->bulk_in[0].state = NS2_URB_OUT;
+	usb_anchor_urb(ns2_usb->bulk_in[0].urb, &ns2_usb->bulk_in_anchor);
+	ret = usb_submit_urb(ns2_usb->bulk_in[0].urb, GFP_ATOMIC);
+	spin_unlock_irqrestore(&ns2_usb->bulk_in_lock, flags);
+
+	if (ret < 0)
+		goto err_free_out;
+
+	ret = switch2_controller_attach_cfg(phys, &ns2_usb->cfg);
+	if (ret < 0)
+		goto err_free_out;
+
+	return 0;
+
+err_free_out:
+	usb_kill_anchored_urbs(&ns2_usb->bulk_out_anchor);
+	for (i = 0; i < NS2_OUT_URBS; i++) {
+		spin_lock_irqsave(&ns2_usb->bulk_out_lock, flags);
+		urb = ns2_usb->bulk_out[i].urb;
+		data = ns2_usb->bulk_out[i].data;
+		if (!urb) {
+			spin_unlock_irqrestore(&ns2_usb->bulk_out_lock, flags);
+			continue;
+		}
+
+		ns2_usb->bulk_out[i].urb = NULL;
+		ns2_usb->bulk_out[i].data = NULL;
+		spin_unlock_irqrestore(&ns2_usb->bulk_out_lock, flags);
+
+		usb_free_coherent(ns2_usb->udev, NS2_BULK_SIZE, data, urb->transfer_dma);
+		usb_free_urb(urb);
+	}
+err_free_in:
+	spin_lock_irqsave(&ns2_usb->bulk_in_lock, flags);
+	ns2_usb->shutdown = true;
+	spin_unlock_irqrestore(&ns2_usb->bulk_in_lock, flags);
+
+	usb_kill_anchored_urbs(&ns2_usb->bulk_in_anchor);
+	cancel_work_sync(&ns2_usb->message_in_work);
+	for (i = 0; i < NS2_IN_URBS; i++) {
+		spin_lock_irqsave(&ns2_usb->bulk_in_lock, flags);
+		urb = ns2_usb->bulk_in[i].urb;
+		data = ns2_usb->bulk_in[i].data;
+		if (!urb) {
+			spin_unlock_irqrestore(&ns2_usb->bulk_in_lock, flags);
+			continue;
+		}
+
+		ns2_usb->bulk_in[i].urb = NULL;
+		ns2_usb->bulk_in[i].data = NULL;
+		spin_unlock_irqrestore(&ns2_usb->bulk_in_lock, flags);
+
+		usb_free_coherent(ns2_usb->udev, NS2_BULK_SIZE, data, urb->transfer_dma);
+		usb_free_urb(urb);
+	}
+	devm_kfree(&intf->dev, ns2_usb);
+
+	return ret;
+}
+
+static void switch2_usb_disconnect(struct usb_interface *intf)
+{
+	struct switch2_usb *ns2_usb = usb_get_intfdata(intf);
+	unsigned long flags;
+	struct urb *urb;
+	uint8_t *data;
+	int i;
+
+	/* Prevent any further IN URBs from being scheduled */
+	spin_lock_irqsave(&ns2_usb->bulk_in_lock, flags);
+	ns2_usb->shutdown = true;
+	spin_unlock_irqrestore(&ns2_usb->bulk_in_lock, flags);
+
+	usb_kill_anchored_urbs(&ns2_usb->bulk_in_anchor);
+	cancel_work_sync(&ns2_usb->message_in_work);
+	for (i = 0; i < NS2_IN_URBS; i++) {
+		spin_lock_irqsave(&ns2_usb->bulk_in_lock, flags);
+		urb = ns2_usb->bulk_in[i].urb;
+		data = ns2_usb->bulk_in[i].data;
+		ns2_usb->bulk_in[i].urb = NULL;
+		ns2_usb->bulk_in[i].data = NULL;
+		spin_unlock_irqrestore(&ns2_usb->bulk_in_lock, flags);
+
+		usb_free_coherent(ns2_usb->udev, NS2_BULK_SIZE, data, urb->transfer_dma);
+		usb_free_urb(urb);
+	}
+
+	/*
+	 * We need to detach *before* we kill the out URBs to make sure no
+	 * further URBs get scheduled by the HID endpoint in the meantime.
+	 */
+	switch2_controller_detach_cfg(ns2_usb->cfg.parent);
+
+	usb_kill_anchored_urbs(&ns2_usb->bulk_out_anchor);
+	for (i = 0; i < NS2_OUT_URBS; i++) {
+		spin_lock_irqsave(&ns2_usb->bulk_out_lock, flags);
+		urb = ns2_usb->bulk_out[i].urb;
+		data = ns2_usb->bulk_out[i].data;
+		ns2_usb->bulk_out[i].urb = NULL;
+		ns2_usb->bulk_out[i].data = NULL;
+		spin_unlock_irqrestore(&ns2_usb->bulk_out_lock, flags);
+
+		usb_free_coherent(ns2_usb->udev, NS2_BULK_SIZE, data, urb->transfer_dma);
+		usb_free_urb(urb);
+	}
+}
+
+#define SWITCH2_CONTROLLER(vend, prod) \
+	USB_DEVICE_AND_INTERFACE_INFO(vend, prod, USB_CLASS_VENDOR_SPEC, 0, 0)
+
+static const struct usb_device_id switch2_usb_devices[] = {
+	{ SWITCH2_CONTROLLER(USB_VENDOR_ID_NINTENDO, USB_DEVICE_ID_NINTENDO_NS2_JOYCONL) },
+	{ SWITCH2_CONTROLLER(USB_VENDOR_ID_NINTENDO, USB_DEVICE_ID_NINTENDO_NS2_JOYCONR) },
+	{ SWITCH2_CONTROLLER(USB_VENDOR_ID_NINTENDO, USB_DEVICE_ID_NINTENDO_NS2_PROCON) },
+	{ SWITCH2_CONTROLLER(USB_VENDOR_ID_NINTENDO, USB_DEVICE_ID_NINTENDO_NS2_GCCON) },
+	{ }
+};
+MODULE_DEVICE_TABLE(usb, switch2_usb_devices);
+
+static struct usb_driver switch2_usb = {
+	.name		= "nintendo-switch2",
+	.id_table	= switch2_usb_devices,
+	.probe		= switch2_usb_probe,
+	.disconnect	= switch2_usb_disconnect,
+};
+module_usb_driver(switch2_usb);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Vicki Pfau <vi@endrift.com>");
+MODULE_DESCRIPTION("Driver for Nintendo Switch 2 Controllers");
-- 
2.54.0

Re: [PATCH v9 1/3] HID: nintendo: Add preliminary Switch 2 controller driver

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 7 potential issue(s) to consider:
- [High] Potential NULL pointer dereference in `switch2_handle_flash_read()` when receiving spontaneous or delayed USB messages.
- [High] Race condition in `switch2_remove()` clearing drvdata before hardware stop causes NULL pointer dereference.
- [High] Unconditional `ida_free()` with `U32_MAX` triggers a `BUG_ON` panic on probe failure or device removal.
- [High] Using `devm_led_classdev_register` with `&input->dev` causes a devres circular reference, leaking devices and causing a Use-After-Free.
- [High] The `-EBUSY` error path in `switch2_probe` erroneously destroys the active input device of the existing interface.
- [High] TOCTOU race condition in `switch2_usb_disconnect` causes UAF due to missing `usb_kill_urb`.
- [Medium] URB slot leak and stuck polling on transient USB errors, plus processing of invalid data.
--

commit ef162798bccd0977cafe2dea531f9e56194e0992
Author: Vicki Pfau <vi@endrift.com>
Subject: HID: nintendo: Add preliminary Switch 2 controller driver

This patch adds a new driver for Nintendo Switch 2 controllers, using a
split-driver design for HID and USB configuration interfaces. It brings
support for Joy-Con 2, Pro Controller 2, and GameCube NSO controllers via USB.

I found a few regressions while reviewing this patch.

> diff --git a/drivers/hid/hid-nintendo.c b/drivers/hid/hid-nintendo.c
> index e7302ec01ff1f..5aacb8e88b704 100644
> --- a/drivers/hid/hid-nintendo.c
> +++ b/drivers/hid/hid-nintendo.c
> @@ -2838,7 +2845,1194 @@ static int nintendo_hid_suspend(struct hid_device *hdev, pm_message_t message)
> [ ... ]
> +static void switch2_handle_flash_read(struct switch2_controller *ns2, uint8_t size,
> +	uint32_t address, const uint8_t *data)
> +{
> +	bool ok;
> +
> +	switch (address) {
> [ ... ]
> +	case NS2_FLASH_ADDR_FACTORY_PRIMARY_CALIB:
> +		if (size != NS2_FLASH_SIZE_FACTORY_AXIS_CALIB)
> +			return;
> +		switch2_init_step_done(ns2, NS2_INIT_READ_FACTORY_PRIMARY_CALIB);
> +		ok = switch2_parse_stick_calibration(&ns2->stick_calib[0], data);
> +		if (ok) {

[Severity: High]
Can this cause a NULL pointer dereference? If the USB configuration
interface receives a flash read reply before the HID interface finishes
probing, or if a delayed response arrives from a previous session,
ns2->hdev will be NULL when hid_dbg is called.

> +			hid_dbg(ns2->hdev, "Got factory primary stick calibration:\n");
> +			hid_dbg(ns2->hdev, "Left max: %i, neutral: %i, right max: %i\n",
> [ ... ]
> +static int switch2_init_input(struct switch2_controller *ns2)
> +{
> [ ... ]
> +	for (i = 0; i < JC_NUM_LEDS; i++) {
> +		struct led_classdev *led = &ns2->leds[i];
> +		char *name = devm_kasprintf(&input->dev, GFP_KERNEL, "%s:%s:%s",
> +				      dev_name(&input->dev),
> +				      "green",
> +				      joycon_player_led_names[i]);
> +
> +		if (!name) {
> +			dev_err(&input->dev, "Failed to allocate name for player %d LED; ret=%d\n",
> +				i + 1, ret);
> +			break;
> +		}
> +
> +		led->name = name;

[Severity: High]
Could this create a circular devres reference? The LED class devices hold
references to their parent (the input device). When the controller is
removed, the input device's devres cleanup won't run until its refcount
hits 0, which cannot happen because the LED devices still exist.

Since the led_classdev structures are embedded in ns2 (which is freed on
removal), might this cause a use-after-free when the leaked LED sysfs
nodes are later accessed?

> +		ret = devm_led_classdev_register(&input->dev, led);
> +		if (ret < 0) {
> +			dev_err(&input->dev, "Failed to register player %d LED; ret=%d\n",
> [ ... ]
> +static int switch2_probe(struct hid_device *hdev, const struct hid_device_id *id)
> +{
> [ ... ]
> +	ns2->player_id = U32_MAX;
> +	ret = ida_alloc(&nintendo_player_id_allocator, GFP_KERNEL);
> +	if (ret < 0)
> +		hid_warn(hdev, "Failed to allocate player ID, skipping; ret=%d\n", ret);
> +	else
> +		ns2->player_id = ret;
> [ ... ]
> +	hid_hw_close(hdev);
> +err_stop:
> +	hid_hw_stop(hdev);
> +err_cleanup:
> +	ida_free(&nintendo_player_id_allocator, ns2->player_id);
> +	ns2->hdev = NULL;

[Severity: High]
Does this error path break the already active controller? If a second HID
interface for the same physical controller probes and detects a conflict,
it returns -EBUSY and jumps to err_put.

However, unconditionally calling switch2_controller_put(ns2) here tears
down the input device for the existing, bound interface.

> +err_put:
> +	switch2_controller_put(ns2);
> +	mutex_unlock(&ns2->lock);
> +	kref_put(&ns2->refcount, switch2_kref_put);
> +
> +	return ret;
> +}
> +
> +static void switch2_remove(struct hid_device *hdev)
> +{
> +	struct switch2_controller *ns2 = hid_get_drvdata(hdev);
> +
> +	mutex_lock(&ns2->lock);
> +	switch2_controller_put(ns2);
> +	ns2->hdev = NULL;

[Severity: High]
Can this cause a race condition leading to a NULL pointer dereference?
The drvdata is set to NULL before hid_hw_stop() halts the hardware.

If an input interrupt triggers switch2_event() in this window, it will
retrieve a NULL pointer from hid_get_drvdata() and immediately dereference
it when calling rcu_dereference(ns2->input).

> +	hid_set_drvdata(hdev, NULL);

[Severity: High]
Does this trigger a panic if ida_alloc() failed during probe? If the probe
fails to allocate the ID, ns2->player_id remains U32_MAX.

Unconditionally calling ida_free() during removal passes this value, which
casts to -1 and will trigger the BUG_ON((int)id < 0) inside the ida_free()
implementation.

> +	ida_free(&nintendo_player_id_allocator, ns2->player_id);
> +	mutex_unlock(&ns2->lock);
> +	kref_put(&ns2->refcount, switch2_kref_put);
> +	hid_hw_close(hdev);
> +	hid_hw_stop(hdev);
> +}

> diff --git a/drivers/input/joystick/nintendo-switch2-usb.c b/drivers/input/joystick/nintendo-switch2-usb.c
> new file mode 100644
> index 0000000000000..0a004918c1f10
> --- /dev/null
> +++ b/drivers/input/joystick/nintendo-switch2-usb.c
> @@ -0,0 +1,464 @@
> [ ... ]
> +static void switch2_bulk_in(struct urb *urb)
> +{
> [ ... ]
> +	switch (urb->status) {
> +	case 0:
> +		schedule = true;
> +		break;
> +	case -ECONNRESET:
> +	case -ENOENT:
> +	case -ESHUTDOWN:
> +		dev_dbg(&ns2_usb->udev->dev, "shutting down input urb: %d\n", urb->status);
> +		return;
> +	default:
> +		dev_dbg(&ns2_usb->udev->dev, "unknown input urb status: %d\n", urb->status);
> +		break;
> +	}
> +
> +	spin_lock_irqsave(&ns2_usb->bulk_in_lock, flags);
> +	for (i = 0; i < NS2_IN_URBS; i++) {
> +		int err;
> +		struct switch2_urb *ns2_urb;
> +

[Severity: Medium]
Does this leak the URB slot and process invalid data? If an URB completes
with an error, the schedule flag remains false, but the state is set to
NS2_URB_IN. If both IN URBs fail, the workqueue is never scheduled again.

If the workqueue is scheduled by the other URB, switch2_usb_message_in_work()
will process this failed URB without validating urb->status, passing
potentially garbage data to switch2_receive_command().

> +		if (ns2_usb->bulk_in[i].urb == urb) {
> +			ns2_usb->bulk_in[i].state = NS2_URB_IN;
> +			continue;
> +		}
> [ ... ]
> +static void switch2_usb_disconnect(struct usb_interface *intf)
> +{
> [ ... ]
> +	/* Prevent any further IN URBs from being scheduled */
> +	spin_lock_irqsave(&ns2_usb->bulk_in_lock, flags);
> +	ns2_usb->shutdown = true;
> +	spin_unlock_irqrestore(&ns2_usb->bulk_in_lock, flags);
> +

[Severity: High]
Is there a TOCTOU race condition here during disconnect? The USB core
unanchors URBs before invoking their completion handler.

If switch2_bulk_in() is running concurrently, usb_kill_anchored_urbs()
won't wait for it. cancel_work_sync() might return immediately if the
handler hasn't yet called schedule_work().

Could the handler then schedule work on the freed ns2_usb structure,
leading to a use-after-free?

> +	usb_kill_anchored_urbs(&ns2_usb->bulk_in_anchor);
> +	cancel_work_sync(&ns2_usb->message_in_work);
> +	for (i = 0; i < NS2_IN_URBS; i++) {
> +		spin_lock_irqsave(&ns2_usb->bulk_in_lock, flags);

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260701065606.4169999-1-vi@endrift.com?part=1

[PATCH v9 2/3] HID: nintendo: Add rumble support for Switch 2 controllers

[Vicki Pfau]

This adds rumble support for both the "HD Rumble" linear resonant actuator
type as used in the Joy-Cons and Pro Controller, as well as the eccentric
rotating mass type used in the GameCube controller. Note that since there's
currently no API for exposing full control of LRAs with evdev, it only
simulates a basic rumble for now.

Signed-off-by: Vicki Pfau <vi@endrift.com>
---
 drivers/hid/Kconfig        |   8 +-
 drivers/hid/hid-nintendo.c | 217 ++++++++++++++++++++++++++++++++++++-
 2 files changed, 218 insertions(+), 7 deletions(-)

diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 19c77c323ec9..851eed76c236 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -859,10 +859,10 @@ config NINTENDO_FF
 	depends on HID_NINTENDO
 	select INPUT_FF_MEMLESS
 	help
-	Say Y here if you have a Nintendo Switch controller and want to enable
-	force feedback support for it. This works for both joy-cons, the pro
-	controller, and the NSO N64 controller. For the pro controller, both
-	rumble motors can be controlled individually.
+	Say Y here if you have a Nintendo Switch or Switch 2 controller and want
+	to enable force feedback support for it. This works for Joy-Cons, the Pro
+	Controllers, and the NSO N64 and GameCube controller. For the Pro
+	Controller, both rumble motors can be controlled individually.
 
 config HID_NTI
 	tristate "NTI keyboard adapters"
diff --git a/drivers/hid/hid-nintendo.c b/drivers/hid/hid-nintendo.c
index 5aacb8e88b70..96463e1586bb 100644
--- a/drivers/hid/hid-nintendo.c
+++ b/drivers/hid/hid-nintendo.c
@@ -2989,6 +2989,7 @@ enum switch2_init_step {
 	NS2_INIT_READ_USER_SECONDARY_CALIB,
 	NS2_INIT_SET_FEATURE_MASK,
 	NS2_INIT_ENABLE_FEATURES,
+	NS2_INIT_ENABLE_RUMBLE,
 	NS2_INIT_GRIP_BUTTONS,
 	NS2_INIT_REPORT_FORMAT,
 	NS2_INIT_SET_PLAYER_LEDS,
@@ -3020,6 +3021,18 @@ struct switch2_stick_calibration {
 	struct switch2_axis_calibration y;
 };
 
+struct switch2_hd_rumble {
+	uint16_t hi_freq : 10;
+	uint16_t hi_amp : 10;
+	uint16_t lo_freq : 10;
+	uint16_t lo_amp : 10;
+} __packed;
+
+struct switch2_erm_rumble {
+	uint16_t error;
+	uint16_t amplitude;
+};
+
 struct switch2_controller {
 	struct hid_device *hdev;
 	struct switch2_cfg_intf *cfg;
@@ -3043,8 +3056,45 @@ struct switch2_controller {
 
 	uint32_t player_id;
 	struct led_classdev leds[4];
+
+#if IS_ENABLED(CONFIG_NINTENDO_FF)
+	spinlock_t rumble_lock;
+	uint8_t rumble_seq;
+	union {
+		struct switch2_hd_rumble hd;
+		struct switch2_erm_rumble sd;
+	} rumble;
+	uint64_t last_rumble_work;
+	struct delayed_work rumble_work;
+	uint8_t *rumble_buffer;
+#endif
 };
 
+enum gc_rumble {
+	GC_RUMBLE_OFF = 0,
+	GC_RUMBLE_ON = 1,
+	GC_RUMBLE_STOP = 2,
+};
+
+/*
+ * The highest rumble level for "HD Rumble" is strong enough to potentially damage the controller,
+ * and also leaves your hands feeling like melted jelly, so we set a semi-arbitrary scaling factor
+ * to artificially limit the maximum for safety and comfort. It is currently unknown if the Switch
+ * 2 itself does something similar, but it's quite likely.
+ *
+ * This value must be between 0 and 1024, otherwise the math below will overflow.
+ */
+#define RUMBLE_MAX 450u
+
+/*
+ * Semi-arbitrary values used to simulate the "rumble" sensation of an eccentric rotating
+ * mass type haptic motor on the Switch 2 controllers' linear resonant actuator type haptics.
+ *
+ * The units used are unknown, but the values must be between 0 and 1023.
+ */
+#define RUMBLE_HI_FREQ 0x187
+#define RUMBLE_LO_FREQ 0x112
+
 static DEFINE_MUTEX(switch2_controllers_lock);
 static LIST_HEAD(switch2_controllers);
 
@@ -3136,7 +3186,7 @@ static const uint8_t switch2_init_cmd_data[] = {
 static const uint8_t switch2_one_data[] = { 0x01, 0x00, 0x00, 0x00 };
 
 static const uint8_t switch2_feature_mask[] = {
-	NS2_FEATURE_BUTTONS | NS2_FEATURE_ANALOG | NS2_FEATURE_IMU,
+	NS2_FEATURE_BUTTONS | NS2_FEATURE_ANALOG | NS2_FEATURE_IMU | NS2_FEATURE_RUMBLE,
 	0x00, 0x00, 0x00
 };
 
@@ -3197,7 +3247,11 @@ static void switch2_controller_put(struct switch2_controller *ns2)
 static void switch2_kref_put(struct kref *refcount)
 {
 	struct switch2_controller *ns2 = container_of(refcount,
-		struct switch2_controller, refcount);
+					struct switch2_controller, refcount);
+
+#if IS_ENABLED(CONFIG_NINTENDO_FF)
+	cancel_delayed_work_sync(&ns2->rumble_work);
+#endif
 
 	guard(mutex)(&switch2_controllers_lock);
 	list_del_init(&ns2->entry);
@@ -3205,6 +3259,125 @@ static void switch2_kref_put(struct kref *refcount)
 	kfree(ns2);
 }
 
+#if IS_ENABLED(CONFIG_NINTENDO_FF)
+static void switch2_encode_rumble(struct switch2_hd_rumble *rumble, uint8_t buffer[5])
+{
+	buffer[0] = rumble->hi_freq;
+	buffer[1] = (rumble->hi_freq >> 8) | (rumble->hi_amp << 2);
+	buffer[2] = (rumble->hi_amp >> 6) | (rumble->lo_freq << 4);
+	buffer[3] = (rumble->lo_freq >> 4) | (rumble->lo_amp << 6);
+	buffer[4] = rumble->lo_amp >> 2;
+}
+
+static int switch2_play_effect(struct input_dev *dev, void *data, struct ff_effect *effect)
+{
+	struct switch2_controller *ns2 = input_get_drvdata(dev);
+	unsigned long flags;
+
+	if (effect->type != FF_RUMBLE)
+		return 0;
+
+	spin_lock_irqsave(&ns2->rumble_lock, flags);
+	if (ns2->ctlr_type == NS2_CTLR_TYPE_GC) {
+		ns2->rumble.sd.amplitude = max(effect->u.rumble.strong_magnitude,
+			(uint16_t) (effect->u.rumble.weak_magnitude >> 1));
+	} else {
+		ns2->rumble.hd.hi_freq = RUMBLE_HI_FREQ;
+		ns2->rumble.hd.lo_freq = RUMBLE_LO_FREQ;
+		ns2->rumble.hd.hi_amp = effect->u.rumble.weak_magnitude * RUMBLE_MAX >> 16;
+		ns2->rumble.hd.lo_amp = effect->u.rumble.strong_magnitude * RUMBLE_MAX >> 16;
+	}
+	spin_unlock_irqrestore(&ns2->rumble_lock, flags);
+
+	schedule_delayed_work(&ns2->rumble_work, 0);
+
+	return 0;
+}
+
+static void switch2_rumble_work(struct work_struct *work)
+{
+	struct switch2_controller *ns2 = container_of(to_delayed_work(work),
+						      struct switch2_controller, rumble_work);
+	unsigned long flags;
+	bool active;
+	int ret = 0;
+
+	spin_lock_irqsave(&ns2->rumble_lock, flags);
+	ns2->rumble_buffer[0x1] = 0x50 | ns2->rumble_seq;
+	if (ns2->ctlr_type == NS2_CTLR_TYPE_GC) {
+		ns2->rumble_buffer[0] = 3;
+		if (ns2->rumble.sd.amplitude == 0) {
+			ns2->rumble_buffer[2] = GC_RUMBLE_STOP;
+			ns2->rumble.sd.error = 0;
+			active = false;
+		} else {
+			if (ns2->rumble.sd.error < ns2->rumble.sd.amplitude) {
+				ns2->rumble_buffer[2] = GC_RUMBLE_ON;
+				ns2->rumble.sd.error += U16_MAX - ns2->rumble.sd.amplitude;
+			} else {
+				ns2->rumble_buffer[2] = GC_RUMBLE_OFF;
+				ns2->rumble.sd.error -= ns2->rumble.sd.amplitude;
+			}
+			active = true;
+		}
+	} else {
+		ns2->rumble_buffer[0] = 1;
+		switch2_encode_rumble(&ns2->rumble.hd, &ns2->rumble_buffer[0x2]);
+		active = ns2->rumble.hd.hi_amp || ns2->rumble.hd.lo_amp;
+		if (ns2->ctlr_type == NS2_CTLR_TYPE_PRO) {
+			/*
+			 * The Pro Controller contains separate LRAs on each
+			 * side that can be controlled individually.
+			 */
+			ns2->rumble_buffer[0] = 2;
+			ns2->rumble_buffer[0x11] = 0x50 | ns2->rumble_seq;
+			switch2_encode_rumble(&ns2->rumble.hd, &ns2->rumble_buffer[0x12]);
+		}
+	}
+	ns2->rumble_seq = (ns2->rumble_seq + 1) & 0xF;
+	spin_unlock_irqrestore(&ns2->rumble_lock, flags);
+
+	if (active) {
+		unsigned long interval = msecs_to_jiffies(4);
+		uint64_t current_jiffies = get_jiffies_64();
+
+		if (!ns2->last_rumble_work)
+			ns2->last_rumble_work = current_jiffies;
+		else
+			ns2->last_rumble_work += interval;
+
+		/* Reschedule a little early to make sure the buffer never underruns */
+		interval += msecs_to_jiffies(2);
+		if (ns2->last_rumble_work + interval >= current_jiffies)
+			schedule_delayed_work(&ns2->rumble_work,
+				ns2->last_rumble_work + interval - current_jiffies);
+		else
+			schedule_delayed_work(&ns2->rumble_work, 0);
+	} else {
+		ns2->last_rumble_work = 0;
+	}
+
+	mutex_lock(&ns2->lock);
+	if (!ns2->hdev) {
+		cancel_delayed_work(&ns2->rumble_work);
+	} else {
+		ret = hid_hw_output_report(ns2->hdev, ns2->rumble_buffer, 64);
+		/*
+		 * Don't log on ENODEV, ESHUTDOWN, or EPROTO, which can happen
+		 * mid-hotplug. Also cancel any further work on ENODEV or
+		 * ESHUTDOWN as they're clear indications that the endpoint
+		 * is dead.
+		 */
+		if (ret == -ENODEV || ret == -ESHUTDOWN)
+			cancel_delayed_work(&ns2->rumble_work);
+		else if (ret < 0 && ret != -EPROTO)
+			hid_warn_ratelimited(ns2->hdev,
+				"Failed to send output report ret=%d\n", ret);
+	}
+	mutex_unlock(&ns2->lock);
+}
+#endif
+
 static int switch2_set_leds(struct switch2_controller *ns2)
 {
 	int i;
@@ -3275,6 +3448,9 @@ static void switch2_input_deref(struct input_dev *input)
 {
 	struct switch2_controller *ns2 = input_get_drvdata(input);
 
+#if IS_ENABLED(CONFIG_NINTENDO_FF)
+	cancel_delayed_work(&ns2->rumble_work);
+#endif
 	kref_put(&ns2->refcount, switch2_kref_put);
 }
 
@@ -3346,6 +3522,20 @@ static int switch2_init_input(struct switch2_controller *ns2)
 		return -EINVAL;
 	}
 
+#if IS_ENABLED(CONFIG_NINTENDO_FF)
+	ns2->rumble_buffer = devm_kzalloc(&input->dev, 64, GFP_KERNEL);
+	if (!ns2->rumble_buffer) {
+		input_free_device(input);
+		return -ENOMEM;
+	}
+	input_set_capability(input, EV_FF, FF_RUMBLE);
+	ret = input_ff_create_memless(input, NULL, switch2_play_effect);
+	if (ret) {
+		input_free_device(input);
+		return ret;
+	}
+#endif
+
 	hid_info(ns2->hdev, "Firmware version %u.%u.%u (type %i)\n", ns2->version.major,
 		ns2->version.minor, ns2->version.patch, ns2->version.ctlr_type);
 	if (ns2->version.dsp_type >= 0)
@@ -3749,7 +3939,16 @@ static int switch2_init_controller(struct switch2_controller *ns2)
 		return ns2->cfg->send_command(NS2_CMD_FEATSEL, NS2_SUBCMD_FEATSEL_SET_MASK,
 			switch2_feature_mask, sizeof(switch2_feature_mask), ns2->cfg);
 	case NS2_INIT_ENABLE_FEATURES:
-		return switch2_features_enable(ns2, NS2_FEATURE_BUTTONS | NS2_FEATURE_ANALOG);
+		return switch2_features_enable(ns2, NS2_FEATURE_BUTTONS |
+			NS2_FEATURE_ANALOG | NS2_FEATURE_RUMBLE);
+	case NS2_INIT_ENABLE_RUMBLE:
+		/*
+		 * It is unclear what this packet is supposed to be for, but it
+		 * appears to be needed for rumble to work reliably. The reply
+		 * data indicates it might be a query of some sort, but we
+		 * ignore the reply so long as it doesn't return an error.
+		 */
+		return ns2->cfg->send_command(0x11, 1, NULL, 0, ns2->cfg);
 	case NS2_INIT_GRIP_BUTTONS:
 		if (!switch2_ctlr_is_joycon(ns2->ctlr_type)) {
 			switch2_init_step_done(ns2, ns2->init_step);
@@ -3861,6 +4060,10 @@ int switch2_receive_command(struct switch2_controller *ns2,
 			switch2_init_step_done(ns2, NS2_INIT_GET_FIRMWARE_INFO);
 		}
 		break;
+	case 0x11:
+		if (header->subcommand == 1)
+			switch2_init_step_done(ns2, NS2_INIT_ENABLE_RUMBLE);
+		break;
 	default:
 		break;
 	}
@@ -3981,6 +4184,11 @@ static int switch2_probe(struct hid_device *hdev, const struct hid_device_id *id
 
 	switch2_leds_create(ns2);
 
+#if IS_ENABLED(CONFIG_NINTENDO_FF)
+	spin_lock_init(&ns2->rumble_lock);
+	INIT_DELAYED_WORK(&ns2->rumble_work, switch2_rumble_work);
+#endif
+
 	ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
 	if (ret) {
 		hid_err(hdev, "hw_start failed %d\n", ret);
@@ -4026,6 +4234,9 @@ static void switch2_remove(struct hid_device *hdev)
 	hid_set_drvdata(hdev, NULL);
 	ida_free(&nintendo_player_id_allocator, ns2->player_id);
 	mutex_unlock(&ns2->lock);
+#if IS_ENABLED(CONFIG_NINTENDO_FF)
+	cancel_delayed_work_sync(&ns2->rumble_work);
+#endif
 	kref_put(&ns2->refcount, switch2_kref_put);
 	hid_hw_close(hdev);
 	hid_hw_stop(hdev);
-- 
2.54.0

Re: [PATCH v9 2/3] HID: nintendo: Add rumble support for Switch 2 controllers

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:
- [High] Use-After-Free on `ns2->rumble_buffer` during device teardown due to devres lifecycle mismatch.
- [Medium] Rumble work scheduling math error adds 2ms instead of subtracting, causing it to run late and risk buffer underruns.
- [Medium] Pro Controller rumble motors receive identical signals, failing to control them individually as claimed.
--

commit 0899ea0ef032bf60e7abf4c07b73da1a806a6406
Author: Vicki Pfau <vi@endrift.com>
Date:   Wed Jul 1 06:56:03 2026 +0000

    HID: nintendo: Add rumble support for Switch 2 controllers
    
    This adds rumble support for both the "HD Rumble" linear resonant actuator
    type as used in the Joy-Cons and Pro Controller, as well as the eccentric
    rotating mass type used in the GameCube controller. Note that since there's
    currently no API for exposing full control of LRAs with evdev, it only
    simulates a basic rumble for now.

> diff --git a/drivers/hid/hid-nintendo.c b/drivers/hid/hid-nintendo.c
> index 5aacb8e88b704..96463e1586bbd 100644
> --- a/drivers/hid/hid-nintendo.c
> +++ b/drivers/hid/hid-nintendo.c
> @@ -3205,6 +3259,125 @@ static void switch2_kref_put(struct kref *refcount)
[ ... ]
> +static int switch2_play_effect(struct input_dev *dev, void *data, struct ff_effect *effect)
> +{
[ ... ]
> +	if (ns2->ctlr_type == NS2_CTLR_TYPE_GC) {
> +		ns2->rumble.sd.amplitude = max(effect->u.rumble.strong_magnitude,
> +			(uint16_t) (effect->u.rumble.weak_magnitude >> 1));
> +	} else {
> +		ns2->rumble.hd.hi_freq = RUMBLE_HI_FREQ;
> +		ns2->rumble.hd.lo_freq = RUMBLE_LO_FREQ;
> +		ns2->rumble.hd.hi_amp = effect->u.rumble.weak_magnitude * RUMBLE_MAX >> 16;
> +		ns2->rumble.hd.lo_amp = effect->u.rumble.strong_magnitude * RUMBLE_MAX >> 16;
> +	}
> +	spin_unlock_irqrestore(&ns2->rumble_lock, flags);
> +
> +	schedule_delayed_work(&ns2->rumble_work, 0);
> +
> +	return 0;
> +}
> +
> +static void switch2_rumble_work(struct work_struct *work)
> +{
[ ... ]
> +	} else {
> +		ns2->rumble_buffer[0] = 1;
> +		switch2_encode_rumble(&ns2->rumble.hd, &ns2->rumble_buffer[0x2]);
> +		active = ns2->rumble.hd.hi_amp || ns2->rumble.hd.lo_amp;
> +		if (ns2->ctlr_type == NS2_CTLR_TYPE_PRO) {
> +			/*
> +			 * The Pro Controller contains separate LRAs on each
> +			 * side that can be controlled individually.
> +			 */
> +			ns2->rumble_buffer[0] = 2;
> +			ns2->rumble_buffer[0x11] = 0x50 | ns2->rumble_seq;
> +			switch2_encode_rumble(&ns2->rumble.hd, &ns2->rumble_buffer[0x12]);
> +		}
> +	}

[Severity: Medium]
Does this code accurately provide independent control of the two rumble motors?

The commit message and the comment above mention that the Pro Controller's left
and right rumble motors can be controlled individually.

However, in switch2_play_effect(), the strong and weak magnitudes are mixed
into a single switch2_hd_rumble structure (ns2->rumble.hd). 

Then in switch2_rumble_work(), this exact same structure is encoded into both
the left (offset 0x2) and right (offset 0x12) rumble buffers. 

Since both physical motors receive the exact same mixed signal (both high and 
low frequencies simultaneously), doesn't this result in identical rumble on 
both sides rather than individual control?

> +	ns2->rumble_seq = (ns2->rumble_seq + 1) & 0xF;
> +	spin_unlock_irqrestore(&ns2->rumble_lock, flags);
> +
> +	if (active) {
> +		unsigned long interval = msecs_to_jiffies(4);
> +		uint64_t current_jiffies = get_jiffies_64();
> +
> +		if (!ns2->last_rumble_work)
> +			ns2->last_rumble_work = current_jiffies;
> +		else
> +			ns2->last_rumble_work += interval;
> +
> +		/* Reschedule a little early to make sure the buffer never underruns */
> +		interval += msecs_to_jiffies(2);
> +		if (ns2->last_rumble_work + interval >= current_jiffies)
> +			schedule_delayed_work(&ns2->rumble_work,
> +				ns2->last_rumble_work + interval - current_jiffies);

[Severity: Medium]
Does this schedule the work early or late?

The comment mentions rescheduling slightly early to prevent buffer underruns.

Since interval starts at 4ms, adding 2ms to it with
interval += msecs_to_jiffies(2) makes the new interval 6ms. 

When scheduling for ns2->last_rumble_work + interval, this appears to target
a time 6ms after the last theoretical tick instead of the intended earlier
target (which would be 2ms after, or interval - 2ms).

Could this delay cause the work to run later than intended and lead to the 
buffer underruns the comment warns about?

[ ... ]
> @@ -3346,6 +3522,20 @@ static int switch2_init_input(struct switch2_controller *ns2)
[ ... ]
> +#if IS_ENABLED(CONFIG_NINTENDO_FF)
> +	ns2->rumble_buffer = devm_kzalloc(&input->dev, 64, GFP_KERNEL);
> +	if (!ns2->rumble_buffer) {
> +		input_free_device(input);
> +		return -ENOMEM;
> +	}

[Severity: High]
Can this lead to a use-after-free during device removal?

The rumble_buffer is allocated with devm_kzalloc() tied to the input device, 
so it gets freed when the input device is unregistered and its final reference
is dropped.

However, looking at the teardown sequence, if the input device is unregistered
(for example via switch2_controller_put() calling input_unregister_device())
before the delayed work is completely synced and canceled, the worker could run
and access the freed rumble_buffer.

Would it be safer to allocate this buffer without devm, or ensure the delayed
work is fully canceled prior to unregistering the input device?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260701065606.4169999-1-vi@endrift.com?part=2

[PATCH v9 3/3] HID: nintendo: Add unified report format support

[Vicki Pfau]

This adds support for the "unified" report format that all controllers also
support, which has overlapping fields for like buttons and axes between
them.

Signed-off-by: Vicki Pfau <vi@endrift.com>
---
 drivers/hid/hid-nintendo.c | 151 +++++++++++++++++++++++++++++++++++--
 1 file changed, 146 insertions(+), 5 deletions(-)

diff --git a/drivers/hid/hid-nintendo.c b/drivers/hid/hid-nintendo.c
index 96463e1586bb..b406e6cfd221 100644
--- a/drivers/hid/hid-nintendo.c
+++ b/drivers/hid/hid-nintendo.c
@@ -2872,6 +2872,36 @@ static int joycon_suspend(struct hid_device *hdev, pm_message_t message)
 #define NS2_BTN3_SR	BIT(6)
 #define NS2_BTN3_SL	BIT(7)
 
+#define NS2_BTN_U1_Y	BIT(0)
+#define NS2_BTN_U1_X	BIT(1)
+#define NS2_BTN_U1_B	BIT(2)
+#define NS2_BTN_U1_A	BIT(3)
+#define NS2_BTN_U1_SR	BIT(4)
+#define NS2_BTN_U1_SL	BIT(5)
+#define NS2_BTN_U1_R	BIT(6)
+#define NS2_BTN_U1_ZR	BIT(7)
+
+#define NS2_BTN_U2_MINUS	BIT(0)
+#define NS2_BTN_U2_PLUS		BIT(1)
+#define NS2_BTN_U2_RS		BIT(2)
+#define NS2_BTN_U2_LS		BIT(3)
+#define NS2_BTN_U2_HOME		BIT(4)
+#define NS2_BTN_U2_CAPTURE	BIT(5)
+#define NS2_BTN_U2_C		BIT(6)
+
+#define NS2_BTN_U3_DOWN		BIT(0)
+#define NS2_BTN_U3_UP		BIT(1)
+#define NS2_BTN_U3_RIGHT	BIT(2)
+#define NS2_BTN_U3_LEFT		BIT(3)
+#define NS2_BTN_U3_SR		BIT(4)
+#define NS2_BTN_U3_SL		BIT(5)
+#define NS2_BTN_U3_L		BIT(6)
+#define NS2_BTN_U3_ZL		BIT(7)
+
+#define NS2_BTN_U4_GR		BIT(0)
+#define NS2_BTN_U4_GL		BIT(1)
+#define NS2_BTN_U4_HEADSET	BIT(5)
+
 #define NS2_BTN_JCR_HOME	BIT(0)
 #define NS2_BTN_JCR_GR		BIT(2)
 #define NS2_BTN_JCR_C		NS2_BTN3_C
@@ -3120,6 +3150,22 @@ static const struct switch2_ctlr_button_mapping ns2_left_joycon_button_mappings[
 	{ /* sentinel */ },
 };
 
+static const struct switch2_ctlr_button_mapping ns2_left_joycon_button_unified_mappings[] = {
+	{ BTN_DPAD_LEFT,	2, NS2_BTN_U3_LEFT,	},
+	{ BTN_DPAD_UP,		2, NS2_BTN_U3_UP,	},
+	{ BTN_DPAD_DOWN,	2, NS2_BTN_U3_DOWN,	},
+	{ BTN_DPAD_RIGHT,	2, NS2_BTN_U3_RIGHT,	},
+	{ BTN_TL,		2, NS2_BTN_U3_L,	},
+	{ BTN_TL2,		2, NS2_BTN_U3_ZL,	},
+	{ BTN_SELECT,		1, NS2_BTN_U2_MINUS,	},
+	{ BTN_THUMBL,		1, NS2_BTN_U2_LS,	},
+	{ KEY_RECORD,		1, NS2_BTN_U2_CAPTURE,	},
+	{ BTN_GRIPR,		2, NS2_BTN_U3_SL,	},
+	{ BTN_GRIPR2,		2, NS2_BTN_U3_SR,	},
+	{ BTN_GRIPL,		3, NS2_BTN_U4_GL,	},
+	{ /* sentinel */ },
+};
+
 static const struct switch2_ctlr_button_mapping ns2_right_joycon_button_mappings[] = {
 	{ BTN_SOUTH,	0, NS2_BTNR_A,		},
 	{ BTN_EAST,	0, NS2_BTNR_B,		},
@@ -3137,6 +3183,23 @@ static const struct switch2_ctlr_button_mapping ns2_right_joycon_button_mappings
 	{ /* sentinel */ },
 };
 
+static const struct switch2_ctlr_button_mapping ns2_right_joycon_button_unified_mappings[] = {
+	{ BTN_SOUTH,	0, NS2_BTN_U1_A,	},
+	{ BTN_EAST,	0, NS2_BTN_U1_B,	},
+	{ BTN_NORTH,	0, NS2_BTN_U1_X,	},
+	{ BTN_WEST,	0, NS2_BTN_U1_Y,	},
+	{ BTN_TR,	0, NS2_BTN_U1_R,	},
+	{ BTN_TR2,	0, NS2_BTN_U1_ZR	},
+	{ BTN_START,	1, NS2_BTN_U2_PLUS,	},
+	{ BTN_THUMBR,	1, NS2_BTN_U2_RS,	},
+	{ BTN_C,	1, NS2_BTN_U2_C,	},
+	{ BTN_MODE,	1, NS2_BTN_U2_HOME,	},
+	{ BTN_GRIPL2,	0, NS2_BTN_U1_SL,	},
+	{ BTN_GRIPL,	0, NS2_BTN_U1_SR,	},
+	{ BTN_GRIPR,	3, NS2_BTN_U4_GR,	},
+	{ /* sentinel */ },
+};
+
 static const struct switch2_ctlr_button_mapping ns2_procon_mappings[] = {
 	{ BTN_SOUTH,	0, NS2_BTNR_A,		},
 	{ BTN_EAST,	0, NS2_BTNR_B,		},
@@ -3158,6 +3221,27 @@ static const struct switch2_ctlr_button_mapping ns2_procon_mappings[] = {
 	{ /* sentinel */ },
 };
 
+static const struct switch2_ctlr_button_mapping ns2_procon_unified_mappings[] = {
+	{ BTN_SOUTH,	0, NS2_BTN_U1_A,	},
+	{ BTN_EAST,	0, NS2_BTN_U1_B,	},
+	{ BTN_NORTH,	0, NS2_BTN_U1_X,	},
+	{ BTN_WEST,	0, NS2_BTN_U1_Y,	},
+	{ BTN_TL,	2, NS2_BTN_U3_L,	},
+	{ BTN_TR,	0, NS2_BTN_U1_R,	},
+	{ BTN_TL2,	2, NS2_BTN_U3_ZL,	},
+	{ BTN_TR2,	0, NS2_BTN_U1_ZR,	},
+	{ BTN_SELECT,	1, NS2_BTN_U2_MINUS,	},
+	{ BTN_START,	1, NS2_BTN_U2_PLUS,	},
+	{ BTN_THUMBL,	1, NS2_BTN_U2_LS,	},
+	{ BTN_THUMBR,	1, NS2_BTN_U2_RS,	},
+	{ BTN_MODE,	1, NS2_BTN_U2_HOME	},
+	{ KEY_RECORD,	1, NS2_BTN_U2_CAPTURE	},
+	{ BTN_GRIPR,	3, NS2_BTN_U4_GR	},
+	{ BTN_GRIPL,	3, NS2_BTN_U4_GL	},
+	{ BTN_C,	1, NS2_BTN_U2_C		},
+	{ /* sentinel */ },
+};
+
 static const struct switch2_ctlr_button_mapping ns2_gccon_mappings[] = {
 	{ BTN_SOUTH,	0, NS2_BTNR_A,		},
 	{ BTN_EAST,	0, NS2_BTNR_B,		},
@@ -3175,6 +3259,23 @@ static const struct switch2_ctlr_button_mapping ns2_gccon_mappings[] = {
 	{ /* sentinel */ },
 };
 
+static const struct switch2_ctlr_button_mapping ns2_gccon_unified_mappings[] = {
+	{ BTN_SOUTH,	0, NS2_BTN_U1_A,	},
+	{ BTN_EAST,	0, NS2_BTN_U1_B,	},
+	{ BTN_NORTH,	0, NS2_BTN_U1_X,	},
+	{ BTN_WEST,	0, NS2_BTN_U1_Y,	},
+	{ BTN_TL2,	2, NS2_BTN_U3_L,	},
+	{ BTN_TR2,	0, NS2_BTN_U1_R,	},
+	{ BTN_TL,	2, NS2_BTN_U3_ZL	},
+	{ BTN_TR,	0, NS2_BTN_U1_ZR	},
+	{ BTN_SELECT,	1, NS2_BTN_U2_MINUS,	},
+	{ BTN_START,	1, NS2_BTN_U2_PLUS,	},
+	{ BTN_MODE,	1, NS2_BTN_U2_HOME	},
+	{ KEY_RECORD,	1, NS2_BTN_U2_CAPTURE	},
+	{ BTN_C,	1, NS2_BTN_U2_C		},
+	{ /* sentinel */ },
+};
+
 static const uint8_t switch2_init_cmd_data[] = {
 	/*
 	 * The last 6 bytes of this packet are the MAC address of
@@ -3787,11 +3888,51 @@ static int switch2_event(struct hid_device *hdev, struct hid_report *report, uin
 
 	switch (report->id) {
 	case NS2_REPORT_UNIFIED:
-		/*
-		 * TODO
-		 * This won't be sent unless the report type gets changed via command
-		 * 03-0A, but we should support it at some point regardless.
-		 */
+		if (size < 0x3f)
+			return -EINVAL;
+
+		switch (ns2->ctlr_type) {
+		case NS2_CTLR_TYPE_JCL:
+			switch2_report_stick(input, &ns2->stick_calib[0],
+				ABS_X, false, ABS_Y, true, &raw_data[11]);
+			switch2_report_buttons(input, &raw_data[5],
+				ns2_left_joycon_button_unified_mappings);
+			break;
+		case NS2_CTLR_TYPE_JCR:
+			switch2_report_stick(input, &ns2->stick_calib[0],
+				ABS_X, false, ABS_Y, true, &raw_data[14]);
+			switch2_report_buttons(input, &raw_data[5],
+				ns2_right_joycon_button_unified_mappings);
+			break;
+		case NS2_CTLR_TYPE_GC:
+			input_report_abs(input, ABS_HAT0X,
+				!!(raw_data[7] & NS2_BTN_U3_RIGHT) -
+				!!(raw_data[7] & NS2_BTN_U3_LEFT));
+			input_report_abs(input, ABS_HAT0Y,
+				!!(raw_data[7] & NS2_BTN_U3_DOWN) -
+				!!(raw_data[7] & NS2_BTN_U3_UP));
+			switch2_report_buttons(input, &raw_data[5], ns2_gccon_unified_mappings);
+			switch2_report_stick(input, &ns2->stick_calib[0],
+				ABS_X, false, ABS_Y, true, &raw_data[11]);
+			switch2_report_stick(input, &ns2->stick_calib[1],
+				ABS_RX, false, ABS_RY, true, &raw_data[14]);
+			switch2_report_trigger(input, ns2->lt_zero, ABS_Z, raw_data[0x3d]);
+			switch2_report_trigger(input, ns2->rt_zero, ABS_RZ, raw_data[0x3e]);
+			break;
+		case NS2_CTLR_TYPE_PRO:
+			input_report_abs(input, ABS_HAT0X,
+				!!(raw_data[7] & NS2_BTN_U3_RIGHT) -
+				!!(raw_data[7] & NS2_BTN_U3_LEFT));
+			input_report_abs(input, ABS_HAT0Y,
+				!!(raw_data[7] & NS2_BTN_U3_DOWN) -
+				!!(raw_data[7] & NS2_BTN_U3_UP));
+			switch2_report_buttons(input, &raw_data[5], ns2_procon_unified_mappings);
+			switch2_report_stick(input, &ns2->stick_calib[0],
+				ABS_X, false, ABS_Y, true, &raw_data[11]);
+			switch2_report_stick(input, &ns2->stick_calib[1],
+				ABS_RX, false, ABS_RY, true, &raw_data[14]);
+			break;
+		}
 		break;
 	case NS2_REPORT_JCL:
 		switch2_report_stick(input, &ns2->stick_calib[0], ABS_X, false,
-- 
2.54.0

Re: [PATCH v9 3/3] HID: nintendo: Add unified report format support

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [Critical] LED class devices registered with devm_led_classdev_register() outlive their containing switch2_controller structure, leading to a UAF if accessed via sysfs after the device is unplugged.
--

commit 84beb320490de870df51e881a9a77c861e3838ca
Author: Vicki Pfau <vi@endrift.com>

HID: nintendo: Add unified report format support

This adds support for the "unified" report format that all controllers also
support, which has overlapping fields for like buttons and axes between
them.

> diff --git a/drivers/hid/hid-nintendo.c b/drivers/hid/hid-nintendo.c
> index 96463e1586bbd..b406e6cfd221f 100644
> --- a/drivers/hid/hid-nintendo.c
> +++ b/drivers/hid/hid-nintendo.c

[ ... ]

[Severity: Critical]
This is a pre-existing issue, but can this lead to a use-after-free when the
device is unplugged?

Looking at switch2_init_input(), LEDs are registered with a devm action tied to
input->dev:

drivers/hid/hid-nintendo.c:switch2_init_input() {
    ...
    ret = devm_led_classdev_register(&input->dev, led);
    ...
}

This means their teardown action is delayed until the input device's kobject is
released.

However, the ns2 structure containing the leds array is freed manually in
switch2_kref_put() upon device removal:

drivers/hid/hid-nintendo.c:switch2_kref_put() {
    ...
    kfree(ns2);
    ...
}

Because the LED sysfs device is a child of input->dev, it prevents input->dev
from being released until it is unregistered. This creates a circular dependency
where the devm cleanup is never triggered.

If a process keeps the LED sysfs file open, input->dev remains alive, but ns2
is freed. Does this leave the LED sysfs endpoints pointing to freed memory,
potentially executing function pointers from the freed ns2 structure when
writing to the LED sysfs brightness file?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260701065606.4169999-1-vi@endrift.com?part=3