Introduce a driver for the Corsair Void family of headsets, supporting:
 - Battery reporting (power_supply)
 - Sidetone setting support
 - Physical microphone location reporting
 - Headset and receiver firmware version reporting
 - Built-in alert triggering
 - USB wireless_status

Tested with a Void Pro Wireless, Void Elite Wireless and a Void Elite Wired

Signed-off-by: Stuart Hayhurst <stuart.a.hayhurst@gmail.com>
---

v4 -> v5:
 - Changed kernel version in sysfs docs to 6.13
 - Use CONFIG_HID_CORSAIR instead of CONFIG_HID_CORSAIR_VOID

v3 -> v4:
 - Added missing <linux/device.h> include
 - Added missing newline, fix indent
 - Use hid_hw_raw_request return code directly for wireless sidetone
 - Use battery status enum for remaining values
 - Use of devm_kasprintf() to create battery string
 - Moved corsair_void_request_status error reporting to callers
 - Simplified corsair_void_request_status
 - Removed battery_struct_size, use sizeof(*battery_data) instead
 - Removed unnecessary curly brackets in send_alert_store

v2 -> v3:
 - Use __free(kfree) helper to free allocations
 - Combined similar condition checks
 - Check power_supply was created successfully before saving it
 - Removed explicit initialisation of return value in corsair_void_probe
 - Use preferred syntax for drvdata's struct allocation size
 - Removed named success exit point from driver probe
 - Removed unused driver probe exit point

v1 -> v2:
 - Added a module author email address
 - Removed unused variable (psy_cfg)
 - Corrected status request buffer size from 12 bytes to 2 bytes
 - Use enums for battery status
 - Use kmalloc instead of kzalloc where applicable
 - Use __le16 type for cpu_to_le16
 - Use DEVICE_ATTR_RO and DEVICE_ATTR_WO to create attributes
 - Simplified corsair_void_set_sidetone_wired
 - Cleaned up patch description

 .../ABI/testing/sysfs-driver-hid-corsair-void |  38 +
 drivers/hid/Kconfig                           |   3 +
 drivers/hid/Makefile                          |   2 +-
 drivers/hid/hid-corsair-void.c                | 829 ++++++++++++++++++
 4 files changed, 871 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/ABI/testing/sysfs-driver-hid-corsair-void
 create mode 100644 drivers/hid/hid-corsair-void.c

diff --git a/Documentation/ABI/testing/sysfs-driver-hid-corsair-void b/Documentation/ABI/testing/sysfs-driver-hid-corsair-void
new file mode 100644
index 000000000000..83fa625c0025
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-hid-corsair-void
@@ -0,0 +1,38 @@
+What:		/sys/bus/hid/drivers/hid-corsair-void/<dev>/fw_version_headset
+Date:		January 2024
+KernelVersion:	6.13
+Contact:	Stuart Hayhurst <stuart.a.hayhurst@gmail.com>
+Description:	(R) The firmware version of the headset
+			* Returns -ENODATA if no version was reported
+
+What:		/sys/bus/hid/drivers/hid-corsair-void/<dev>/fw_version_receiver
+Date:		January 2024
+KernelVersion:	6.13
+Contact:	Stuart Hayhurst <stuart.a.hayhurst@gmail.com>
+Description:	(R) The firmware version of the receiver
+
+What:		/sys/bus/hid/drivers/hid-corsair-void/<dev>/microphone_up
+Date:		July 2023
+KernelVersion:	6.13
+Contact:	Stuart Hayhurst <stuart.a.hayhurst@gmail.com>
+Description:	(R) Get the physical position of the microphone
+			* 1 -> Microphone up
+			* 0 -> Microphone down
+
+What:		/sys/bus/hid/drivers/hid-corsair-void/<dev>/send_alert
+Date:		July 2023
+KernelVersion:	6.13
+Contact:	Stuart Hayhurst <stuart.a.hayhurst@gmail.com>
+Description:	(W) Play a built-in notification from the headset (0 / 1)
+
+What:		/sys/bus/hid/drivers/hid-corsair-void/<dev>/set_sidetone
+Date:		December 2023
+KernelVersion:	6.13
+Contact:	Stuart Hayhurst <stuart.a.hayhurst@gmail.com>
+Description:	(W) Set the sidetone volume (0 - sidetone_max)
+
+What:		/sys/bus/hid/drivers/hid-corsair-void/<dev>/sidetone_max
+Date:		July 2024
+KernelVersion:	6.13
+Contact:	Stuart Hayhurst <stuart.a.hayhurst@gmail.com>
+Description:	(R) Report the maximum sidetone volume
diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index f8a56d631242..5a90523146f7 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -213,13 +213,16 @@ config HID_CHICONY
 config HID_CORSAIR
 	tristate "Corsair devices"
 	depends on USB_HID && LEDS_CLASS
+	select POWER_SUPPLY
 	help
 	Support for Corsair devices that are not fully compliant with the
 	HID standard.
+	Support for Corsair Void headsets.
 
 	Supported devices:
 	- Vengeance K90
 	- Scimitar PRO RGB
+	- Corsair Void headsets
 
 config HID_COUGAR
 	tristate "Cougar devices"
diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index 496dab54c73a..ea2ed38d7e31 100644
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -38,7 +38,7 @@ obj-$(CONFIG_HID_BIGBEN_FF)	+= hid-bigbenff.o
 obj-$(CONFIG_HID_CHERRY)	+= hid-cherry.o
 obj-$(CONFIG_HID_CHICONY)	+= hid-chicony.o
 obj-$(CONFIG_HID_CMEDIA)	+= hid-cmedia.o
-obj-$(CONFIG_HID_CORSAIR)	+= hid-corsair.o
+obj-$(CONFIG_HID_CORSAIR)	+= hid-corsair.o hid-corsair-void.o
 obj-$(CONFIG_HID_COUGAR)	+= hid-cougar.o
 obj-$(CONFIG_HID_CP2112)	+= hid-cp2112.o
 obj-$(CONFIG_HID_CYPRESS)	+= hid-cypress.o
diff --git a/drivers/hid/hid-corsair-void.c b/drivers/hid/hid-corsair-void.c
new file mode 100644
index 000000000000..6ece56b850fc
--- /dev/null
+++ b/drivers/hid/hid-corsair-void.c
@@ -0,0 +1,829 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  HID driver for Corsair Void headsets
+ *
+ *  Copyright (C) 2023-2024 Stuart Hayhurst
+ */
+
+/* -------------------------------------------------------------------------- */
+/* Receiver report information: (ID 100)                                      */
+/* -------------------------------------------------------------------------- */
+/*
+ * When queried, the receiver reponds with 5 bytes to describe the battery
+ *   The power button, mute button and moving the mic also trigger this report
+ * This includes power button + mic + connection + battery status and capacity
+ * The information below may not be perfect, it's been gathered through guesses
+ *
+ * 0: REPORT ID
+ *  100 for the battery packet
+ *
+ * 1: POWER BUTTON + (?)
+ *  Largest bit is 1 when power button pressed
+ *
+ * 2: BATTERY CAPACITY + MIC STATUS
+ *  Battery capacity:
+ *    Seems to report ~54 higher than reality when charging
+ *    Capped at 100, charging or not
+ *  Microphone status:
+ *    Largest bit is set to 1 when the mic is physically up
+ *    No bits change when the mic is muted, only when physically moved
+ *    This report is sent every time the mic is moved, no polling required
+ *
+ * 3: CONNECTION STATUS
+ *  16: Wired headset
+ *  38: Initialising
+ *  49: Lost connection
+ *  51: Disconnected, searching
+ *  52: Disconnected, not searching
+ *  177: Normal
+ *
+ * 4: BATTERY STATUS
+ *  0: Disconnected
+ *  1: Normal
+ *  2: Low
+ *  3: Critical - sent during shutdown
+ *  4: Fully charged
+ *  5: Charging
+ */
+/* -------------------------------------------------------------------------- */
+
+/* -------------------------------------------------------------------------- */
+/* Receiver report information: (ID 102)                                      */
+/* -------------------------------------------------------------------------- */
+/*
+ * When queried, the recevier responds with 4 bytes to describe the firmware
+ * The first 2 bytes are for the receiver, the second 2 are the headset
+ * The headset firmware version will be 0 if no headset is connected
+ *
+ * 0: Recevier firmware major version
+ *  Major version of the receiver's firmware
+ *
+ * 1: Recevier firmware minor version
+ *  Minor version of the receiver's firmware
+ *
+ * 2: Headset firmware major version
+ *  Major version of the headset's firmware
+ *
+ * 3: Headset firmware minor version
+ *  Minor version of the headset's firmware
+ */
+/* -------------------------------------------------------------------------- */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/cleanup.h>
+#include <linux/device.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/power_supply.h>
+#include <linux/usb.h>
+#include <linux/workqueue.h>
+#include <asm/byteorder.h>
+
+#include "hid-ids.h"
+
+#define CORSAIR_VOID_DEVICE(id, type)		{ HID_USB_DEVICE(USB_VENDOR_ID_CORSAIR, (id)), \
+						.driver_data = (type) }
+#define CORSAIR_VOID_WIRELESS_DEVICE(id)	CORSAIR_VOID_DEVICE((id), CORSAIR_VOID_WIRELESS)
+#define CORSAIR_VOID_WIRED_DEVICE(id)		CORSAIR_VOID_DEVICE((id), CORSAIR_VOID_WIRED)
+
+#define CORSAIR_VOID_STATUS_REQUEST_ID		0xC9
+#define CORSAIR_VOID_NOTIF_REQUEST_ID		0xCA
+#define CORSAIR_VOID_SIDETONE_REQUEST_ID	0xFF
+#define CORSAIR_VOID_STATUS_REPORT_ID		0x64
+#define CORSAIR_VOID_FIRMWARE_REPORT_ID		0x66
+
+#define CORSAIR_VOID_USB_SIDETONE_REQUEST	0x1
+#define CORSAIR_VOID_USB_SIDETONE_REQUEST_TYPE	0x21
+#define CORSAIR_VOID_USB_SIDETONE_VALUE		0x200
+#define CORSAIR_VOID_USB_SIDETONE_INDEX		0xB00
+
+#define CORSAIR_VOID_MIC_MASK			GENMASK(7, 7)
+#define CORSAIR_VOID_CAPACITY_MASK		GENMASK(6, 0)
+
+#define CORSAIR_VOID_WIRELESS_CONNECTED		177
+
+#define CORSAIR_VOID_SIDETONE_MAX_WIRELESS	55
+#define CORSAIR_VOID_SIDETONE_MAX_WIRED		4096
+
+enum {
+	CORSAIR_VOID_WIRELESS,
+	CORSAIR_VOID_WIRED,
+};
+
+enum {
+	CORSAIR_VOID_BATTERY_NORMAL	= 1,
+	CORSAIR_VOID_BATTERY_LOW	= 2,
+	CORSAIR_VOID_BATTERY_CRITICAL	= 3,
+	CORSAIR_VOID_BATTERY_CHARGED	= 4,
+	CORSAIR_VOID_BATTERY_CHARGING	= 5,
+};
+
+static enum power_supply_property corsair_void_battery_props[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_CAPACITY,
+	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
+	POWER_SUPPLY_PROP_SCOPE,
+	POWER_SUPPLY_PROP_MODEL_NAME,
+	POWER_SUPPLY_PROP_MANUFACTURER,
+};
+
+struct corsair_void_battery_data {
+	int status;
+	bool present;
+	int capacity;
+	int capacity_level;
+};
+
+struct corsair_void_drvdata {
+	struct hid_device *hid_dev;
+	struct device *dev;
+
+	char *name;
+	bool is_wired;
+	unsigned int sidetone_max;
+
+	struct corsair_void_battery_data battery_data;
+	bool mic_up;
+	bool connected;
+	int fw_receiver_major;
+	int fw_receiver_minor;
+	int fw_headset_major;
+	int fw_headset_minor;
+
+	struct power_supply *battery;
+	struct power_supply_desc battery_desc;
+	struct mutex battery_mutex;
+
+	struct delayed_work delayed_status_work;
+	struct delayed_work delayed_firmware_work;
+	struct work_struct battery_remove_work;
+	struct work_struct battery_add_work;
+};
+
+/*
+ * Functions to process receiver data
+*/
+
+static void corsair_void_set_wireless_status(struct corsair_void_drvdata *drvdata)
+{
+	struct usb_interface *usb_if = to_usb_interface(drvdata->dev->parent);
+
+	if (drvdata->is_wired)
+		return;
+
+	usb_set_wireless_status(usb_if, drvdata->connected ?
+					USB_WIRELESS_STATUS_CONNECTED :
+					USB_WIRELESS_STATUS_DISCONNECTED);
+}
+
+static void corsair_void_set_unknown_batt(struct corsair_void_drvdata *drvdata)
+{
+	struct corsair_void_battery_data *battery_data = &drvdata->battery_data;
+
+	battery_data->status = POWER_SUPPLY_STATUS_UNKNOWN;
+	battery_data->present = false;
+	battery_data->capacity = 0;
+	battery_data->capacity_level = POWER_SUPPLY_CAPACITY_LEVEL_UNKNOWN;
+}
+
+/* Reset data that may change between wireless connections */
+static void corsair_void_set_unknown_wireless_data(struct corsair_void_drvdata *drvdata)
+{
+	/* Only 0 out headset, receiver is always known if relevant */
+	drvdata->fw_headset_major = 0;
+	drvdata->fw_headset_minor = 0;
+
+	drvdata->connected = false;
+	drvdata->mic_up = false;
+
+	corsair_void_set_wireless_status(drvdata);
+}
+
+static void corsair_void_process_receiver(struct corsair_void_drvdata *drvdata,
+					  int raw_battery_capacity,
+					  int raw_connection_status,
+					  int raw_battery_status)
+{
+	struct corsair_void_battery_data *battery_data = &drvdata->battery_data;
+	struct corsair_void_battery_data orig_battery_data;
+
+	/* Save initial battery data, to compare later */
+	orig_battery_data = *battery_data;
+
+	/* Headset not connected, or it's wired */
+	if (raw_connection_status != CORSAIR_VOID_WIRELESS_CONNECTED)
+		goto unknown_battery;
+
+	/* Battery information unavailable */
+	if (raw_battery_status == 0)
+		goto unknown_battery;
+
+	/* Battery must be connected then */
+	battery_data->present = true;
+	battery_data->capacity_level = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
+
+	/* Set battery status */
+	switch (raw_battery_status) {
+	case CORSAIR_VOID_BATTERY_NORMAL:
+	case CORSAIR_VOID_BATTERY_LOW:
+	case CORSAIR_VOID_BATTERY_CRITICAL:
+		battery_data->status = POWER_SUPPLY_STATUS_DISCHARGING;
+		if (raw_battery_status == CORSAIR_VOID_BATTERY_LOW)
+			battery_data->capacity_level = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
+		else if (raw_battery_status == CORSAIR_VOID_BATTERY_CRITICAL)
+			battery_data->capacity_level = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
+
+		break;
+	case CORSAIR_VOID_BATTERY_CHARGED:
+		battery_data->status = POWER_SUPPLY_STATUS_FULL;
+		break;
+	case CORSAIR_VOID_BATTERY_CHARGING:
+		battery_data->status = POWER_SUPPLY_STATUS_CHARGING;
+		break;
+	default:
+		hid_warn(drvdata->hid_dev, "unknown battery status '%d'",
+			 raw_battery_status);
+		goto unknown_battery;
+		break;
+	}
+
+	battery_data->capacity = raw_battery_capacity;
+	corsair_void_set_wireless_status(drvdata);
+
+	goto success;
+unknown_battery:
+	corsair_void_set_unknown_batt(drvdata);
+success:
+
+	/* Inform power supply if battery values changed */
+	if (memcmp(&orig_battery_data, battery_data, sizeof(*battery_data))) {
+		scoped_guard(mutex, &drvdata->battery_mutex) {
+			if (drvdata->battery) {
+				power_supply_changed(drvdata->battery);
+			}
+		}
+	}
+}
+
+/*
+ * Functions to report stored data
+*/
+
+static int corsair_void_battery_get_property(struct power_supply *psy,
+					     enum power_supply_property prop,
+					     union power_supply_propval *val)
+{
+	struct corsair_void_drvdata *drvdata = power_supply_get_drvdata(psy);
+
+	switch (prop) {
+		case POWER_SUPPLY_PROP_SCOPE:
+			val->intval = POWER_SUPPLY_SCOPE_DEVICE;
+			break;
+		case POWER_SUPPLY_PROP_MODEL_NAME:
+			if (!strncmp(drvdata->hid_dev->name, "Corsair ", 8))
+				val->strval = drvdata->hid_dev->name + 8;
+			else
+				val->strval = drvdata->hid_dev->name;
+			break;
+		case POWER_SUPPLY_PROP_MANUFACTURER:
+			val->strval = "Corsair";
+			break;
+		case POWER_SUPPLY_PROP_STATUS:
+			val->intval = drvdata->battery_data.status;
+			break;
+		case POWER_SUPPLY_PROP_PRESENT:
+			val->intval = drvdata->battery_data.present;
+			break;
+		case POWER_SUPPLY_PROP_CAPACITY:
+			val->intval = drvdata->battery_data.capacity;
+			break;
+		case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
+			val->intval = drvdata->battery_data.capacity_level;
+			break;
+		default:
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+static ssize_t microphone_up_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct corsair_void_drvdata *drvdata = dev_get_drvdata(dev);
+
+	if (!drvdata->connected)
+		return -ENODEV;
+
+	return sysfs_emit(buf, "%d\n", drvdata->mic_up);
+}
+
+static ssize_t fw_version_receiver_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct corsair_void_drvdata *drvdata = dev_get_drvdata(dev);
+
+	if (drvdata->fw_receiver_major == 0 && drvdata->fw_receiver_minor == 0)
+		return -ENODATA;
+
+	return sysfs_emit(buf, "%d.%02d\n", drvdata->fw_receiver_major,
+			  drvdata->fw_receiver_minor);
+}
+
+
+static ssize_t fw_version_headset_show(struct device *dev,
+				       struct device_attribute *attr,
+				       char *buf)
+{
+	struct corsair_void_drvdata *drvdata = dev_get_drvdata(dev);
+
+	if (drvdata->fw_headset_major == 0 && drvdata->fw_headset_minor == 0)
+		return -ENODATA;
+
+	return sysfs_emit(buf, "%d.%02d\n", drvdata->fw_headset_major,
+			  drvdata->fw_headset_minor);
+}
+
+static ssize_t sidetone_max_show(struct device *dev,
+				 struct device_attribute *attr,
+				 char *buf)
+{
+	struct corsair_void_drvdata *drvdata = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%d\n", drvdata->sidetone_max);
+}
+
+/*
+ * Functions to send data to headset
+*/
+
+static ssize_t send_alert_store(struct device *dev,
+				struct device_attribute *attr,
+				const char *buf, size_t count)
+{
+	struct corsair_void_drvdata *drvdata = dev_get_drvdata(dev);
+	struct hid_device *hid_dev = drvdata->hid_dev;
+	unsigned char alert_id;
+	unsigned char *send_buf __free(kfree) = NULL;
+	int ret;
+
+	if (!drvdata->connected || drvdata->is_wired)
+		return -ENODEV;
+
+	/* Only accept 0 or 1 for alert ID */
+	if (kstrtou8(buf, 10, &alert_id) || alert_id >= 2)
+		return -EINVAL;
+
+	send_buf = kmalloc(3, GFP_KERNEL);
+	if (!send_buf)
+		return -ENOMEM;
+
+	/* Packet format to send alert with ID alert_id */
+	send_buf[0] = CORSAIR_VOID_NOTIF_REQUEST_ID;
+	send_buf[1] = 0x02;
+	send_buf[2] = alert_id;
+
+	ret = hid_hw_raw_request(hid_dev, CORSAIR_VOID_NOTIF_REQUEST_ID,
+				 send_buf, 3, HID_OUTPUT_REPORT,
+				 HID_REQ_SET_REPORT);
+	if (ret < 0)
+		hid_warn(hid_dev, "failed to send alert request (reason: %d)",
+			 ret);
+	else
+		ret = count;
+
+	return ret;
+}
+
+static int corsair_void_set_sidetone_wired(struct device *dev, const char *buf,
+					   unsigned int sidetone)
+{
+	struct usb_interface *usb_if = to_usb_interface(dev->parent);
+	struct usb_device *usb_dev = interface_to_usbdev(usb_if);
+
+	/* Packet format to set sidetone for wired headsets */
+	__le16 sidetone_le = cpu_to_le16(sidetone);
+
+	return usb_control_msg_send(usb_dev, 0,
+				   CORSAIR_VOID_USB_SIDETONE_REQUEST,
+				   CORSAIR_VOID_USB_SIDETONE_REQUEST_TYPE,
+				   CORSAIR_VOID_USB_SIDETONE_VALUE,
+				   CORSAIR_VOID_USB_SIDETONE_INDEX,
+				   &sidetone_le, 2, USB_CTRL_SET_TIMEOUT,
+				   GFP_KERNEL);
+}
+
+static int corsair_void_set_sidetone_wireless(struct device *dev,
+					      const char *buf,
+					      unsigned char sidetone)
+{
+	struct corsair_void_drvdata *drvdata = dev_get_drvdata(dev);
+	struct hid_device *hid_dev = drvdata->hid_dev;
+	unsigned char *send_buf __free(kfree) = NULL;
+
+	send_buf = kmalloc(12, GFP_KERNEL);
+	if (!send_buf)
+		return -ENOMEM;
+
+	/* Packet format to set sidetone for wireless headsets */
+	send_buf[0] = CORSAIR_VOID_SIDETONE_REQUEST_ID;
+	send_buf[1] = 0x0B;
+	send_buf[2] = 0x00;
+	send_buf[3] = 0xFF;
+	send_buf[4] = 0x04;
+	send_buf[5] = 0x0E;
+	send_buf[6] = 0xFF;
+	send_buf[7] = 0x05;
+	send_buf[8] = 0x01;
+	send_buf[9] = 0x04;
+	send_buf[10] = 0x00;
+	send_buf[11] = sidetone + 200;
+
+	return hid_hw_raw_request(hid_dev, CORSAIR_VOID_SIDETONE_REQUEST_ID,
+				  send_buf, 12, HID_FEATURE_REPORT,
+				  HID_REQ_SET_REPORT);
+}
+
+static ssize_t set_sidetone_store(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf, size_t count)
+{
+	struct corsair_void_drvdata *drvdata = dev_get_drvdata(dev);
+	struct hid_device *hid_dev = drvdata->hid_dev;
+	unsigned int sidetone;
+	int ret;
+
+	if (!drvdata->connected)
+		return -ENODEV;
+
+	/* sidetone must be between 0 and drvdata->sidetone_max inclusive */
+	if (kstrtouint(buf, 10, &sidetone) || sidetone > drvdata->sidetone_max)
+		return -EINVAL;
+
+	if (drvdata->is_wired)
+		ret = corsair_void_set_sidetone_wired(dev, buf, sidetone);
+	else
+		ret = corsair_void_set_sidetone_wireless(dev, buf, sidetone);
+
+	if (ret < 0)
+		hid_warn(hid_dev, "failed to send sidetone (reason: %d)", ret);
+	else
+		ret = count;
+
+	return ret;
+}
+
+static int corsair_void_request_status(struct hid_device *hid_dev, int id)
+{
+	unsigned char *send_buf __free(kfree) = NULL;
+
+	send_buf = kmalloc(2, GFP_KERNEL);
+	if (!send_buf)
+		return -ENOMEM;
+
+	/* Packet format to request data item (status / firmware) refresh */
+	send_buf[0] = CORSAIR_VOID_STATUS_REQUEST_ID;
+	send_buf[1] = id;
+
+	/* Send request for data refresh */
+	return hid_hw_raw_request(hid_dev, CORSAIR_VOID_STATUS_REQUEST_ID,
+				  send_buf, 2, HID_OUTPUT_REPORT,
+				  HID_REQ_SET_REPORT);
+}
+
+/*
+ * Headset connect / disconnect handlers and work handlers
+*/
+
+static void corsair_void_status_work_handler(struct work_struct *work)
+{
+	struct corsair_void_drvdata *drvdata;
+	struct delayed_work *delayed_work;
+	int battery_ret;
+
+	delayed_work = container_of(work, struct delayed_work, work);
+	drvdata = container_of(delayed_work, struct corsair_void_drvdata,
+			       delayed_status_work);
+
+	battery_ret = corsair_void_request_status(drvdata->hid_dev,
+						  CORSAIR_VOID_STATUS_REPORT_ID);
+	if (battery_ret < 0) {
+		hid_warn(drvdata->hid_dev,
+			 "failed to request battery (reason: %d)", battery_ret);
+	}
+}
+
+static void corsair_void_firmware_work_handler(struct work_struct *work)
+{
+	struct corsair_void_drvdata *drvdata;
+	struct delayed_work *delayed_work;
+	int firmware_ret;
+
+	delayed_work = container_of(work, struct delayed_work, work);
+	drvdata = container_of(delayed_work, struct corsair_void_drvdata,
+			       delayed_firmware_work);
+
+	firmware_ret = corsair_void_request_status(drvdata->hid_dev,
+						   CORSAIR_VOID_FIRMWARE_REPORT_ID);
+	if (firmware_ret < 0) {
+		hid_warn(drvdata->hid_dev,
+			 "failed to request firmware (reason: %d)", firmware_ret);
+	}
+
+}
+
+static void corsair_void_battery_remove_work_handler(struct work_struct *work)
+{
+	struct corsair_void_drvdata *drvdata;
+
+	drvdata = container_of(work, struct corsair_void_drvdata,
+			       battery_remove_work);
+	scoped_guard(mutex, &drvdata->battery_mutex) {
+		if (drvdata->battery) {
+			power_supply_unregister(drvdata->battery);
+			drvdata->battery = NULL;
+		}
+	}
+}
+
+static void corsair_void_battery_add_work_handler(struct work_struct *work)
+{
+	struct corsair_void_drvdata *drvdata;
+	struct power_supply_config psy_cfg;
+	struct power_supply *new_supply;
+
+	drvdata = container_of(work, struct corsair_void_drvdata,
+			       battery_add_work);
+	guard(mutex)(&drvdata->battery_mutex);
+	if (drvdata->battery)
+		return;
+
+	psy_cfg.drv_data = drvdata;
+	new_supply = power_supply_register(drvdata->dev,
+					   &drvdata->battery_desc,
+					   &psy_cfg);
+
+	if (IS_ERR(new_supply)) {
+		hid_err(drvdata->hid_dev,
+			"failed to register battery '%s' (reason: %ld)\n",
+			drvdata->battery_desc.name,
+			PTR_ERR(new_supply));
+		return;
+	}
+
+	if (power_supply_powers(new_supply, drvdata->dev)) {
+		power_supply_unregister(new_supply);
+		return;
+	}
+
+	drvdata->battery = new_supply;
+}
+
+static void corsair_void_headset_connected(struct corsair_void_drvdata *drvdata)
+{
+	schedule_work(&drvdata->battery_add_work);
+	schedule_delayed_work(&drvdata->delayed_firmware_work,
+			      msecs_to_jiffies(100));
+}
+
+static void corsair_void_headset_disconnected(struct corsair_void_drvdata *drvdata)
+{
+	schedule_work(&drvdata->battery_remove_work);
+
+	corsair_void_set_unknown_wireless_data(drvdata);
+	corsair_void_set_unknown_batt(drvdata);
+}
+
+/*
+ * Driver setup, probing and HID event handling
+*/
+
+static DEVICE_ATTR_RO(fw_version_receiver);
+static DEVICE_ATTR_RO(fw_version_headset);
+static DEVICE_ATTR_RO(microphone_up);
+static DEVICE_ATTR_RO(sidetone_max);
+
+static DEVICE_ATTR_WO(send_alert);
+static DEVICE_ATTR_WO(set_sidetone);
+
+static struct attribute *corsair_void_attrs[] = {
+	&dev_attr_fw_version_receiver.attr,
+	&dev_attr_fw_version_headset.attr,
+	&dev_attr_microphone_up.attr,
+	&dev_attr_send_alert.attr,
+	&dev_attr_set_sidetone.attr,
+	&dev_attr_sidetone_max.attr,
+	NULL,
+};
+
+static const struct attribute_group corsair_void_attr_group = {
+	.attrs = corsair_void_attrs,
+};
+
+static int corsair_void_probe(struct hid_device *hid_dev,
+			      const struct hid_device_id *hid_id)
+{
+	int ret;
+	struct corsair_void_drvdata *drvdata;
+	char *name;
+
+	if (!hid_is_usb(hid_dev))
+		return -EINVAL;
+
+	drvdata = devm_kzalloc(&hid_dev->dev, sizeof(*drvdata),
+			       GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	hid_set_drvdata(hid_dev, drvdata);
+	dev_set_drvdata(&hid_dev->dev, drvdata);
+
+	drvdata->dev = &hid_dev->dev;
+	drvdata->hid_dev = hid_dev;
+	drvdata->is_wired = hid_id->driver_data == CORSAIR_VOID_WIRED;
+
+	drvdata->sidetone_max = CORSAIR_VOID_SIDETONE_MAX_WIRELESS;
+	if (drvdata->is_wired)
+		drvdata->sidetone_max = CORSAIR_VOID_SIDETONE_MAX_WIRED;
+
+	/* Set initial values for no wireless headset attached */
+	/* If a headset is attached, it'll be prompted later */
+	corsair_void_set_unknown_wireless_data(drvdata);
+	corsair_void_set_unknown_batt(drvdata);
+
+	/* Receiver version won't be reset after init */
+	/* Headset version already set via set_unknown_wireless_data */
+	drvdata->fw_receiver_major = 0;
+	drvdata->fw_receiver_minor = 0;
+
+	ret = hid_parse(hid_dev);
+	if (ret) {
+		hid_err(hid_dev, "parse failed (reason: %d)\n", ret);
+		return ret;
+	}
+
+	name = devm_kasprintf(drvdata->dev, GFP_KERNEL,
+			      "corsair-void-%d-battery", hid_dev->id);
+	if (!name)
+		return -ENOMEM;
+
+	drvdata->battery_desc.name = name;
+	drvdata->battery_desc.type = POWER_SUPPLY_TYPE_BATTERY;
+	drvdata->battery_desc.properties = corsair_void_battery_props;
+	drvdata->battery_desc.num_properties = ARRAY_SIZE(corsair_void_battery_props);
+	drvdata->battery_desc.get_property = corsair_void_battery_get_property;
+
+	drvdata->battery = NULL;
+	INIT_WORK(&drvdata->battery_remove_work,
+		  corsair_void_battery_remove_work_handler);
+	INIT_WORK(&drvdata->battery_add_work,
+		  corsair_void_battery_add_work_handler);
+	ret = devm_mutex_init(drvdata->dev, &drvdata->battery_mutex);
+	if (ret)
+		return ret;
+
+	ret = sysfs_create_group(&hid_dev->dev.kobj, &corsair_void_attr_group);
+	if (ret)
+		return ret;
+
+	/* Any failures after here will need to call hid_hw_stop */
+	ret = hid_hw_start(hid_dev, HID_CONNECT_DEFAULT);
+	if (ret) {
+		hid_err(hid_dev, "hid_hw_start failed (reason: %d)\n", ret);
+		goto failed_after_sysfs;
+	}
+
+	/* Refresh battery data, in case wireless headset is already connected */
+	INIT_DELAYED_WORK(&drvdata->delayed_status_work,
+			  corsair_void_status_work_handler);
+	schedule_delayed_work(&drvdata->delayed_status_work,
+			      msecs_to_jiffies(100));
+
+	/* Refresh firmware versions */
+	INIT_DELAYED_WORK(&drvdata->delayed_firmware_work,
+			  corsair_void_firmware_work_handler);
+	schedule_delayed_work(&drvdata->delayed_firmware_work,
+			      msecs_to_jiffies(100));
+
+	return 0;
+
+failed_after_sysfs:
+	sysfs_remove_group(&hid_dev->dev.kobj, &corsair_void_attr_group);
+	return ret;
+}
+
+static void corsair_void_remove(struct hid_device *hid_dev)
+{
+	struct corsair_void_drvdata *drvdata = hid_get_drvdata(hid_dev);
+
+	hid_hw_stop(hid_dev);
+	cancel_work_sync(&drvdata->battery_remove_work);
+	cancel_work_sync(&drvdata->battery_add_work);
+	if (drvdata->battery)
+		power_supply_unregister(drvdata->battery);
+
+	cancel_delayed_work_sync(&drvdata->delayed_firmware_work);
+	sysfs_remove_group(&hid_dev->dev.kobj, &corsair_void_attr_group);
+}
+
+static int corsair_void_raw_event(struct hid_device *hid_dev,
+				  struct hid_report *hid_report,
+				  u8 *data, int size)
+{
+	struct corsair_void_drvdata *drvdata = hid_get_drvdata(hid_dev);
+	bool was_connected = drvdata->connected;
+
+	/* Description of packets are documented at the top of this file */
+	if (hid_report->id == CORSAIR_VOID_STATUS_REPORT_ID) {
+		drvdata->mic_up = FIELD_GET(CORSAIR_VOID_MIC_MASK, data[2]);
+		drvdata->connected = (data[3] == CORSAIR_VOID_WIRELESS_CONNECTED) ||
+				     drvdata->is_wired;
+
+		corsair_void_process_receiver(drvdata,
+					      FIELD_GET(CORSAIR_VOID_CAPACITY_MASK, data[2]),
+					      data[3], data[4]);
+	} else if (hid_report->id == CORSAIR_VOID_FIRMWARE_REPORT_ID) {
+		drvdata->fw_receiver_major = data[1];
+		drvdata->fw_receiver_minor = data[2];
+		drvdata->fw_headset_major = data[3];
+		drvdata->fw_headset_minor = data[4];
+	}
+
+	/* Handle wireless headset connect / disconnect */
+	if ((was_connected != drvdata->connected) && !drvdata->is_wired) {
+		if (drvdata->connected)
+			corsair_void_headset_connected(drvdata);
+		else
+			corsair_void_headset_disconnected(drvdata);
+	}
+
+	return 0;
+}
+
+static const struct hid_device_id corsair_void_devices[] = {
+	/* Corsair Void Wireless */
+	CORSAIR_VOID_WIRELESS_DEVICE(0x0a0c),
+	CORSAIR_VOID_WIRELESS_DEVICE(0x0a2b),
+	CORSAIR_VOID_WIRELESS_DEVICE(0x1b23),
+	CORSAIR_VOID_WIRELESS_DEVICE(0x1b25),
+	CORSAIR_VOID_WIRELESS_DEVICE(0x1b27),
+
+	/* Corsair Void USB */
+	CORSAIR_VOID_WIRED_DEVICE(0x0a0f),
+	CORSAIR_VOID_WIRED_DEVICE(0x1b1c),
+	CORSAIR_VOID_WIRED_DEVICE(0x1b29),
+	CORSAIR_VOID_WIRED_DEVICE(0x1b2a),
+
+	/* Corsair Void Surround */
+	CORSAIR_VOID_WIRED_DEVICE(0x0a30),
+	CORSAIR_VOID_WIRED_DEVICE(0x0a31),
+
+	/* Corsair Void Pro Wireless */
+	CORSAIR_VOID_WIRELESS_DEVICE(0x0a14),
+	CORSAIR_VOID_WIRELESS_DEVICE(0x0a16),
+	CORSAIR_VOID_WIRELESS_DEVICE(0x0a1a),
+
+	/* Corsair Void Pro USB */
+	CORSAIR_VOID_WIRED_DEVICE(0x0a17),
+	CORSAIR_VOID_WIRED_DEVICE(0x0a1d),
+
+	/* Corsair Void Pro Surround */
+	CORSAIR_VOID_WIRED_DEVICE(0x0a18),
+	CORSAIR_VOID_WIRED_DEVICE(0x0a1e),
+	CORSAIR_VOID_WIRED_DEVICE(0x0a1f),
+
+	/* Corsair Void Elite Wireless */
+	CORSAIR_VOID_WIRELESS_DEVICE(0x0a51),
+	CORSAIR_VOID_WIRELESS_DEVICE(0x0a55),
+	CORSAIR_VOID_WIRELESS_DEVICE(0x0a75),
+
+	/* Corsair Void Elite USB */
+	CORSAIR_VOID_WIRED_DEVICE(0x0a52),
+	CORSAIR_VOID_WIRED_DEVICE(0x0a56),
+
+	/* Corsair Void Elite Surround */
+	CORSAIR_VOID_WIRED_DEVICE(0x0a53),
+	CORSAIR_VOID_WIRED_DEVICE(0x0a57),
+
+	{}
+};
+
+MODULE_DEVICE_TABLE(hid, corsair_void_devices);
+
+static struct hid_driver corsair_void_driver = {
+	.name = "hid-corsair-void",
+	.id_table = corsair_void_devices,
+	.probe = corsair_void_probe,
+	.remove = corsair_void_remove,
+	.raw_event = corsair_void_raw_event,
+};
+
+module_hid_driver(corsair_void_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Stuart Hayhurst <stuart.a.hayhurst@gmail.com>");
+MODULE_DESCRIPTION("HID driver for Corsair Void headsets");
-- 
2.45.2

On Wed, 9 Oct 2024, Stuart Hayhurst wrote:

> Introduce a driver for the Corsair Void family of headsets, supporting:
>  - Battery reporting (power_supply)
>  - Sidetone setting support
>  - Physical microphone location reporting
>  - Headset and receiver firmware version reporting
>  - Built-in alert triggering
>  - USB wireless_status
> 
> Tested with a Void Pro Wireless, Void Elite Wireless and a Void Elite Wired
> 
> Signed-off-by: Stuart Hayhurst <stuart.a.hayhurst@gmail.com>
> ---
> 
> v4 -> v5:
>  - Changed kernel version in sysfs docs to 6.13
>  - Use CONFIG_HID_CORSAIR instead of CONFIG_HID_CORSAIR_VOID
> 
> v3 -> v4:
>  - Added missing <linux/device.h> include
>  - Added missing newline, fix indent
>  - Use hid_hw_raw_request return code directly for wireless sidetone
>  - Use battery status enum for remaining values
>  - Use of devm_kasprintf() to create battery string
>  - Moved corsair_void_request_status error reporting to callers
>  - Simplified corsair_void_request_status
>  - Removed battery_struct_size, use sizeof(*battery_data) instead
>  - Removed unnecessary curly brackets in send_alert_store
> 
> v2 -> v3:
>  - Use __free(kfree) helper to free allocations
>  - Combined similar condition checks
>  - Check power_supply was created successfully before saving it
>  - Removed explicit initialisation of return value in corsair_void_probe
>  - Use preferred syntax for drvdata's struct allocation size
>  - Removed named success exit point from driver probe
>  - Removed unused driver probe exit point
> 
> v1 -> v2:
>  - Added a module author email address
>  - Removed unused variable (psy_cfg)
>  - Corrected status request buffer size from 12 bytes to 2 bytes
>  - Use enums for battery status
>  - Use kmalloc instead of kzalloc where applicable
>  - Use __le16 type for cpu_to_le16
>  - Use DEVICE_ATTR_RO and DEVICE_ATTR_WO to create attributes
>  - Simplified corsair_void_set_sidetone_wired
>  - Cleaned up patch description
> 
>  .../ABI/testing/sysfs-driver-hid-corsair-void |  38 +
>  drivers/hid/Kconfig                           |   3 +
>  drivers/hid/Makefile                          |   2 +-
>  drivers/hid/hid-corsair-void.c                | 829 ++++++++++++++++++
>  4 files changed, 871 insertions(+), 1 deletion(-)
>  create mode 100644 Documentation/ABI/testing/sysfs-driver-hid-corsair-void
>  create mode 100644 drivers/hid/hid-corsair-void.c

Applied to hid.git#for-6.13/corsair. Thanks,

-- 
Jiri Kosina
SUSE Labs