[PATCH v11 0/3] HID: nintendo: Add preliminary Switch 2 controller

[PATCH v11 0/3] HID: nintendo: Add preliminary Switch 2 controller

[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
v10, fixing some small errors pointed out by sashiko. The remaining issues
sashiko found in v10 appear to be purely imagined. Hopefully it doesn't
come up with new things this time.

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                    | 1680 ++++++++++++++++-
 drivers/hid/hid-nintendo.h                    |   72 +
 drivers/input/joystick/Kconfig                |   11 +
 drivers/input/joystick/Makefile               |    1 +
 drivers/input/joystick/nintendo-switch2-usb.c |  468 +++++
 8 files changed, 2215 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 v11 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                    | 1278 ++++++++++++++++-
 drivers/hid/hid-nintendo.h                    |   72 +
 drivers/input/joystick/Kconfig                |   11 +
 drivers/input/joystick/Makefile               |    1 +
 drivers/input/joystick/nintendo-switch2-usb.c |  468 ++++++
 8 files changed, 1836 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..e21c36921832 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 +2845,1208 @@ 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_INPUT,
+	NS2_INIT_SET_PLAYER_LEDS,
+	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;
+};
+
+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 int switch2_init_controller(struct switch2_controller *ns2);
+
+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;
+
+	mutex_lock(&ns2->lock);
+	rcu_read_lock();
+	input = rcu_dereference(ns2->input);
+	rcu_read_unlock();
+
+	rcu_assign_pointer(ns2->input, NULL);
+	synchronize_rcu();
+
+	ns2->init_step = 0;
+	mutex_unlock(&ns2->lock);
+
+	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_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 player_led_pattern;
+	int i;
+	int ret;
+
+	rcu_read_lock();
+	input = rcu_dereference(ns2->input);
+	rcu_read_unlock();
+
+	if (input) {
+		switch2_init_step_done(ns2, NS2_INIT_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;
+	}
+
+	player_led_pattern = ns2->player_id % JC_NUM_LED_PATTERNS;
+	hid_dbg(hdev, "assigned player %d led pattern", player_led_pattern + 1);
+
+	ns2->leds = devm_kcalloc(&input->dev, JC_NUM_LEDS, sizeof(*ns2->leds), GFP_KERNEL);
+	if (!ns2->leds) {
+		hid_err(ns2->hdev, "Failed to allocate LEDs\n");
+		input_unregister_device(input);
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < JC_NUM_LEDS; i++) {
+		struct led_classdev *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;
+		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();
+
+	switch2_init_step_done(ns2, NS2_INIT_INPUT);
+	return switch2_init_controller(ns2);
+}
+
+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 (ns2->hdev) {
+			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 (ns2->hdev) {
+			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];
+
+			if (ns2->hdev) {
+				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 if (ns2->hdev) {
+			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 (get_unaligned_le16((__le16 *)data) != NS2_USER_CALIB_MAGIC) {
+			if (ns2->hdev)
+				hid_dbg(ns2->hdev, "No user primary stick calibration present\n");
+			break;
+		}
+
+		ok = switch2_parse_stick_calibration(&ns2->stick_calib[0], &data[2]);
+		if (ns2->hdev) {
+			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 (get_unaligned_le16((__le16 *)data) != NS2_USER_CALIB_MAGIC) {
+			if (ns2->hdev)
+				hid_dbg(ns2->hdev, "No user secondary stick calibration present\n");
+			break;
+		}
+
+		ok = switch2_parse_stick_calibration(&ns2->stick_calib[1], &data[2]);
+		if (ns2->hdev) {
+			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);
+}
+
+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) {
+			if (ns2->cfg)
+				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_INPUT:
+		if (ns2->hdev)
+			return switch2_init_input(ns2);
+		break;
+	case NS2_INIT_SET_PLAYER_LEDS:
+		return switch2_set_player_id(ns2, ns2->player_id);
+	case NS2_INIT_FINISH:
+		return ns2->cfg->send_command(NS2_CMD_INIT, NS2_SUBCMD_INIT_USB,
+			switch2_init_cmd_data, sizeof(switch2_init_cmd_data), ns2->cfg);
+	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)) {
+		if (ns2->cfg)
+			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_FINISH);
+		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;
+	mutex_unlock(&ns2->lock);
+	switch2_controller_put(ns2);
+	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) {
+		mutex_unlock(&ns2->lock);
+		hid_err(hdev,
+			"Second hdev tried to claim same controller, first=%p vs second=%p\n",
+			ns2->hdev, hdev);
+		kref_put(&ns2->refcount, switch2_kref_put);
+		return -EBUSY;
+	}
+	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;
+
+	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;
+	mutex_unlock(&ns2->lock);
+	switch2_controller_put(ns2);
+	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);
+
+	switch2_controller_put(ns2);
+	mutex_lock(&ns2->lock);
+	ns2->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 +4071,67 @@ 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 +4159,5 @@ 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..a6999a0a26ae
--- /dev/null
+++ b/drivers/input/joystick/nintendo-switch2-usb.c
@@ -0,0 +1,468 @@
+// 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:
+	case -EPIPE:
+		break;
+	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) {
+			if (schedule) {
+				ns2_usb->bulk_in[i].state = NS2_URB_IN;
+				continue;
+			} else {
+				ns2_usb->bulk_in[i].state = NS2_URB_FREE;
+			}
+		}
+
+		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:
+	case -EPIPE:
+		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 v11 1/3] HID: nintendo: Add preliminary Switch 2 controller driver

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [High] Concurrent URB completion and device disconnect paths cause a Use-After-Free due to missing synchronization.
- [High] Immediate resubmission of failed bulk IN URBs causes an interrupt storm.
--

Note: The format of this review has been altered to use a free-form summary of findings rather than inline patch quoting due to recitation restrictions.

commit 77b4d4df4f2d3eefe6970b5429bc05e1a86ecc7e
Author: Vicki Pfau <vi@endrift.com>

HID: nintendo: Add preliminary Switch 2 controller driver

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.

[Severity: High]
In switch2_bulk_in(), could this cause a use-after-free during device
disconnect?

When switch2_usb_disconnect() executes concurrently with an URB completion,
it calls usb_kill_anchored_urbs() to cancel in-flight URBs. However, the USB
core unanchors the URB just before invoking the completion handler. Thus,
usb_kill_anchored_urbs() misses the URB being processed:

switch2_usb_disconnect()
    usb_kill_anchored_urbs(&ns2_usb->bulk_in_anchor);
    cancel_work_sync(&ns2_usb->message_in_work);

If switch2_bulk_in() is preempted before it schedules work:

switch2_bulk_in()
    ...
    if (schedule)
        schedule_work(&ns2_usb->message_in_work);

the disconnect path will complete and free ns2_usb via devres. When the
completion handler resumes, it attempts to access the freed context. Does
this missing synchronization need to be addressed?

[Severity: High]
Can an interrupt storm occur if a bulk IN URB fails persistently?

In switch2_bulk_in(), if an URB completes with an error like -EPIPE or
-EPROTO, the schedule boolean is false, but the URB state is set to
NS2_URB_FREE. The driver then immediately evaluates it for resubmission:

switch2_bulk_in()
    ...
    usb_anchor_urb(ns2_urb->urb, &ns2_usb->bulk_in_anchor);
    err = usb_submit_urb(ns2_urb->urb, GFP_ATOMIC);

Since the device isn't shutting down and the anchor is empty, the exact same
failing URB is resubmitted instantly. This will likely fail again right
away, re-invoking the handler and creating an infinite loop. Should the
resubmission logic be delayed or halted upon encountering persistent
errors?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260702214704.1859350-1-vi@endrift.com?part=1

[PATCH v11 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 | 211 ++++++++++++++++++++++++++++++++++++-
 2 files changed, 213 insertions(+), 6 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 e21c36921832..a36f4fd9a1da 100644
--- a/drivers/hid/hid-nintendo.c
+++ b/drivers/hid/hid-nintendo.c
@@ -37,6 +37,7 @@
 #include <linux/unaligned.h>
 #include <linux/delay.h>
 #include <linux/device.h>
+#include <linux/devm-helpers.h>
 #include <linux/kernel.h>
 #include <linux/hid.h>
 #include <linux/idr.h>
@@ -2989,6 +2990,7 @@ 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_INPUT,
@@ -3020,6 +3022,18 @@ 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 +3057,45 @@ struct switch2_controller {
 
 	uint32_t player_id;
 	struct led_classdev *leds;
+
+#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 +3187,7 @@ 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
 };
 
@@ -3209,6 +3260,125 @@ 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;
@@ -3332,6 +3502,26 @@ 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;
+	}
+	ret = devm_delayed_work_autocancel(&input->dev, &ns2->rumble_work, switch2_rumble_work);
+	if (ret < 0) {
+		input_free_device(input);
+		return ret;
+	}
+
+	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)
@@ -3765,7 +3955,16 @@ 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);
@@ -3878,6 +4077,10 @@ 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;
 	}
@@ -3997,6 +4200,10 @@ static int switch2_probe(struct hid_device *hdev, const struct hid_device_id *id
 	else
 		ns2->player_id = ret;
 
+#if IS_ENABLED(CONFIG_NINTENDO_FF)
+	spin_lock_init(&ns2->rumble_lock);
+#endif
+
 	ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
 	if (ret) {
 		hid_err(hdev, "hw_start failed %d\n", ret);
-- 
2.54.0

Re: [PATCH v11 2/3] HID: nintendo: Add rumble support for Switch 2 controllers

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:

New issues:
- [High] Use-After-Free of rumble_work and controller state due to devm lifecycle mismatch

Pre-existing issues:
- [High] Circular reference in LED devm registration causes permanent memory leak and Use-After-Free
--

commit 24b9a46372beedd9b4a7b187b2ec2e8fa3058997
Author: Vicki Pfau <vi@endrift.com>

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.

> diff --git a/drivers/hid/hid-nintendo.c b/drivers/hid/hid-nintendo.c
> index e21c369218325..a36f4fd9a1da5 100644
> --- a/drivers/hid/hid-nintendo.c
> +++ b/drivers/hid/hid-nintendo.c
[ ... ]
> @@ -3209,6 +3260,125 @@ static void switch2_kref_put(struct kref *refcount)
>  	kfree(ns2);
>  }
>  
> +#if IS_ENABLED(CONFIG_NINTENDO_FF)
[ ... ]
> +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);

[Severity: High]
If the device is unplugged and `ns2` is manually freed, can this work
function execute concurrently and attempt to acquire `ns2->rumble_lock`
on freed memory?

> +	ns2->rumble_buffer[0x1] = 0x50 | ns2->rumble_seq;
[ ... ]
> @@ -3332,6 +3502,26 @@ static int switch2_init_input(struct switch2_controller *ns2)
>  		return -EINVAL;
>  	}
>  

[Severity: High]
This is a pre-existing issue, but does registering the LED devices with
devm create a circular reference by binding the LED devres to the input
device while simultaneously setting it as the parent?

The driver core's device_add() function automatically takes a reference to
the parent device (&input->dev). Since devres is attached to the same
parent, it waits for the parent's refcount to drop to 0 before unregistering
the LEDs, which means neither can be released. 

Does this permanently leak the input device, LED devices, and devm
allocations? 

Furthermore, because `ns2` is freed manually upon device removal, could
lingering LED sysfs attributes trigger a use-after-free crash if a user
writes to them, causing switch2_player_led_brightness_set() to dereference
the freed `ns2` pointer?

> +#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;
> +	}
> +	ret = devm_delayed_work_autocancel(&input->dev, &ns2->rumble_work, switch2_rumble_work);

[Severity: High]
Does binding the rumble work lifecycle to &input->dev cause a
use-after-free when `ns2` is manually freed?

If a user unplugs the controller while holding the input device open,
`ns2` is freed in the removal path, but the devres cleanup for the input
device will run later. 

Will this result in the devres cleanup unconditionally calling
cancel_delayed_work_sync(&ns2->rumble_work) on the already-freed
`ns2` pointer?

> +	if (ret < 0) {
> +		input_free_device(input);
> +		return ret;
> +	}
> +
> +	input_set_capability(input, EV_FF, FF_RUMBLE);
> +	ret = input_ff_create_memless(input, NULL, switch2_play_effect);
[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260702214704.1859350-1-vi@endrift.com?part=2

[PATCH v11 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 a36f4fd9a1da..ca2126f85bb3 100644
--- a/drivers/hid/hid-nintendo.c
+++ b/drivers/hid/hid-nintendo.c
@@ -2873,6 +2873,36 @@ 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
@@ -3121,6 +3151,22 @@ 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,		},
@@ -3138,6 +3184,23 @@ 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,		},
@@ -3159,6 +3222,27 @@ 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,		},
@@ -3176,6 +3260,23 @@ 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
@@ -3802,11 +3903,51 @@ 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