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From:   Aleksa Savic <savicaleksa83@gmail.com>
To:     linux-hwmon@vger.kernel.org
Cc:     Jean Delvare <jdelvare@suse.com>,
        Guenter Roeck <linux@roeck-us.net>,
        Jonathan Corbet <corbet@lwn.net>, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] hwmon: (aquacomputer_d5next) Add support for Aquacomputer Octo
Date:   Tue,  8 Mar 2022 11:52:25 +0100
Message-Id: <20220308105225.24178-1-savicaleksa83@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Extend aquacomputer_d5next driver to expose hardware temperature sensors
and fans of the Aquacomputer Octo fan controller, which communicates
through a proprietary USB HID protocol.

Four temperature sensors and eight PWM controllable fans are available.
Additionally, serial number, firmware version and power-on count are
exposed through debugfs.

This driver has been tested on x86_64.

Signed-off-by: Aleksa Savic <savicaleksa83@gmail.com>
---
Lindent works much better than VS Code, so there should be some
formatting fixes. Also, update Kbuild to reflect new features of
the driver.
---
 Documentation/hwmon/aquacomputer_d5next.rst |   4 +
 drivers/hwmon/Kconfig                       |   7 +-
 drivers/hwmon/aquacomputer_d5next.c         | 402 +++++++++++++++++++-
 3 files changed, 396 insertions(+), 17 deletions(-)

diff --git a/Documentation/hwmon/aquacomputer_d5next.rst b/Documentation/hwmon/aquacomputer_d5next.rst
index 3373e27b707d..e69f718caf5b 100644
--- a/Documentation/hwmon/aquacomputer_d5next.rst
+++ b/Documentation/hwmon/aquacomputer_d5next.rst
@@ -7,6 +7,7 @@ Supported devices:
 
 * Aquacomputer D5 Next watercooling pump
 * Aquacomputer Farbwerk 360 RGB controller
+* Aquacomputer Octo fan controller
 
 Author: Aleksa Savic
 
@@ -28,6 +29,9 @@ seems to require sending it a complete configuration. That includes addressable
 RGB LEDs, for which there is no standard sysfs interface. Thus, that task is
 better suited for userspace tools.
 
+The Octo exposes four temperature sensors and eight PWM controllable fans, along
+with their speed (in RPM), power, voltage and current.
+
 The Farbwerk 360 exposes four temperature sensors. Depending on the device,
 not all sysfs and debugfs entries will be available.
 
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index d3986310ec21..0b6a84af1353 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -256,11 +256,12 @@ config SENSORS_AHT10
 	  will be called aht10.
 
 config SENSORS_AQUACOMPUTER_D5NEXT
-	tristate "Aquacomputer D5 Next watercooling pump"
+	tristate "Aquacomputer D5 Next, Octo and Farbwerk 360"
 	depends on USB_HID
 	help
-	  If you say yes here you get support for the Aquacomputer D5 Next
-	  watercooling pump sensors.
+	  If you say yes here you get support for sensors and fans of
+	  the Aquacomputer D5 Next watercooling pump, Octo fan
+	  controller and Farbwerk 360 RGB controller, where available.
 
 	  This driver can also be built as a module. If so, the module
 	  will be called aquacomputer_d5next.
diff --git a/drivers/hwmon/aquacomputer_d5next.c b/drivers/hwmon/aquacomputer_d5next.c
index 525809cf7c95..f45f8afc2b15 100644
--- a/drivers/hwmon/aquacomputer_d5next.c
+++ b/drivers/hwmon/aquacomputer_d5next.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0+
 /*
- * hwmon driver for Aquacomputer devices (D5 Next, Farbwerk 360)
+ * hwmon driver for Aquacomputer devices (D5 Next, Farbwerk 360, Octo)
  *
  * Aquacomputer devices send HID reports (with ID 0x01) every second to report
  * sensor values.
@@ -8,23 +8,27 @@
  * Copyright 2021 Aleksa Savic <savicaleksa83@gmail.com>
  */
 
+#include <linux/crc16.h>
 #include <linux/debugfs.h>
 #include <linux/hid.h>
 #include <linux/hwmon.h>
 #include <linux/jiffies.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/seq_file.h>
 #include <asm/unaligned.h>
 
 #define USB_VENDOR_ID_AQUACOMPUTER	0x0c70
 #define USB_PRODUCT_ID_D5NEXT		0xf00e
 #define USB_PRODUCT_ID_FARBWERK360	0xf010
+#define USB_PRODUCT_ID_OCTO		0xf011
 
-enum kinds { d5next, farbwerk360 };
+enum kinds { d5next, farbwerk360, octo };
 
 static const char *const aqc_device_names[] = {
 	[d5next] = "d5next",
-	[farbwerk360] = "farbwerk360"
+	[farbwerk360] = "farbwerk360",
+	[octo] = "octo"
 };
 
 #define DRIVER_NAME			"aquacomputer_d5next"
@@ -35,6 +39,18 @@ static const char *const aqc_device_names[] = {
 #define SERIAL_SECOND_PART		5
 #define FIRMWARE_VERSION		13
 
+#define CTRL_REPORT_ID			0x03
+
+/* The HID report that the official software always sends
+ * after writing values, currently same for all devices
+ */
+#define SECONDARY_CTRL_REPORT_ID	0x02
+#define SECONDARY_CTRL_REPORT_SIZE	0x0B
+
+static u8 secondary_ctrl_report[] = {
+	0x02, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x34, 0xC6
+};
+
 /* Register offsets for the D5 Next pump */
 #define D5NEXT_POWER_CYCLES		24
 
@@ -55,10 +71,34 @@ static const char *const aqc_device_names[] = {
 
 /* Register offsets for the Farbwerk 360 RGB controller */
 #define FARBWERK360_NUM_SENSORS		4
-#define FARBWERK360_SENSOR_START		0x32
+#define FARBWERK360_SENSOR_START	0x32
 #define FARBWERK360_SENSOR_SIZE		0x02
 #define FARBWERK360_SENSOR_DISCONNECTED	0x7FFF
 
+/* Register offsets for the Octo fan controller */
+#define OCTO_POWER_CYCLES		0x18
+#define OCTO_NUM_FANS			8
+#define OCTO_FAN_PERCENT_OFFSET		0x00
+#define OCTO_FAN_VOLTAGE_OFFSET		0x02
+#define OCTO_FAN_CURRENT_OFFSET		0x04
+#define OCTO_FAN_POWER_OFFSET		0x06
+#define OCTO_FAN_SPEED_OFFSET		0x08
+
+static u8 octo_sensor_fan_offsets[] = { 0x7D, 0x8A, 0x97, 0xA4, 0xB1, 0xBE, 0xCB, 0xD8 };
+
+#define OCTO_NUM_SENSORS		4
+#define OCTO_SENSOR_START		0x3D
+#define OCTO_SENSOR_SIZE		0x02
+#define OCTO_SENSOR_DISCONNECTED	0x7FFF
+
+#define OCTO_CTRL_REPORT_SIZE			0x65F
+#define OCTO_CTRL_REPORT_CHECKSUM_OFFSET	0x65D
+#define OCTO_CTRL_REPORT_CHECKSUM_START		0x01
+#define OCTO_CTRL_REPORT_CHECKSUM_LENGTH	0x65C
+
+/* Fan speed registers in Octo control report (from 0-100%) */
+static u16 octo_ctrl_fan_offsets[] = { 0x5B, 0xB0, 0x105, 0x15A, 0x1AF, 0x204, 0x259, 0x2AE };
+
 /* Labels for D5 Next */
 #define L_D5NEXT_COOLANT_TEMP		"Coolant temp"
 
@@ -83,7 +123,7 @@ static const char *const label_d5next_current[] = {
 	"Fan current"
 };
 
-/* Labels for Farbwerk 360 temperature sensors */
+/* Labels for Farbwerk 360 and Octo temperature sensors */
 static const char *const label_temp_sensors[] = {
 	"Sensor 1",
 	"Sensor 2",
@@ -91,30 +131,192 @@ static const char *const label_temp_sensors[] = {
 	"Sensor 4"
 };
 
+/* Labels for Octo */
+static const char *const label_fan_speed[] = {
+	"Fan 1 speed",
+	"Fan 2 speed",
+	"Fan 3 speed",
+	"Fan 4 speed",
+	"Fan 5 speed",
+	"Fan 6 speed",
+	"Fan 7 speed",
+	"Fan 8 speed"
+};
+
+static const char *const label_fan_power[] = {
+	"Fan 1 power",
+	"Fan 2 power",
+	"Fan 3 power",
+	"Fan 4 power",
+	"Fan 5 power",
+	"Fan 6 power",
+	"Fan 7 power",
+	"Fan 8 power"
+};
+
+static const char *const label_fan_voltage[] = {
+	"Fan 1 voltage",
+	"Fan 2 voltage",
+	"Fan 3 voltage",
+	"Fan 4 voltage",
+	"Fan 5 voltage",
+	"Fan 6 voltage",
+	"Fan 7 voltage",
+	"Fan 8 voltage"
+};
+
+static const char *const label_fan_current[] = {
+	"Fan 1 current",
+	"Fan 2 current",
+	"Fan 3 current",
+	"Fan 4 current",
+	"Fan 5 current",
+	"Fan 6 current",
+	"Fan 7 current",
+	"Fan 8 current"
+};
+
 struct aqc_data {
 	struct hid_device *hdev;
 	struct device *hwmon_dev;
 	struct dentry *debugfs;
+	struct mutex mutex; /* Used for locking access when reading and writing PWM values */
 	enum kinds kind;
 	const char *name;
 
+	int buffer_size;
+	u8 *buffer; /* Stores the control report */
+	int checksum_start; /* Where the checksummed region starts */
+	int checksum_length; /* And where it ends */
+	int checksum_offset; /* Position of checksum, usually at the very end */
+
 	/* General info, same across all devices */
 	u32 serial_number[2];
 	u16 firmware_version;
 
-	/* D5 Next specific - how many times the device was powered on */
+	/* How many times the device was powered on, if available */
 	u32 power_cycles;
 
 	/* Sensor values */
 	s32 temp_input[4];
-	u16 speed_input[2];
-	u32 power_input[2];
-	u16 voltage_input[3];
-	u16 current_input[2];
+	u16 speed_input[8];
+	u32 power_input[8];
+	u16 voltage_input[8];
+	u16 current_input[8];
 
 	unsigned long updated;
 };
 
+static int aqc_be_percent_to_pwm(u16 val)
+{
+	return DIV_ROUND_CLOSEST(ntohs(val) * 255, 100 * 100);
+}
+
+static u16 aqc_pwm_to_percent(u8 val)
+{
+	return DIV_ROUND_CLOSEST(val * 100 * 100, 255);
+}
+
+/* Expects the mutex to be locked */
+static int aqc_get_ctrl_data(struct aqc_data *priv)
+{
+	int ret;
+
+	memset(priv->buffer, 0x00, priv->buffer_size);
+	ret = hid_hw_raw_request(priv->hdev, CTRL_REPORT_ID, priv->buffer,
+				 priv->buffer_size, HID_FEATURE_REPORT, HID_REQ_GET_REPORT);
+	if (ret < 0)
+		ret = -ENODATA;
+
+	return ret;
+}
+
+/* Expects the mutex to be locked */
+static int aqc_send_ctrl_data(struct aqc_data *priv)
+{
+	int ret;
+	u16 checksum = 0xffff;	/* Init value for CRC-16/USB */
+
+	checksum = crc16(checksum, priv->buffer + priv->checksum_start, priv->checksum_length);
+	checksum ^= 0xffff;	/* Xorout value for CRC-16/USB */
+
+	/* Place the new checksum at the end of the report */
+	put_unaligned_be16(checksum, priv->buffer + priv->checksum_offset);
+
+	/* Send the patched up report back to the device - all other settings stay the same */
+	ret = hid_hw_raw_request(priv->hdev, CTRL_REPORT_ID, priv->buffer, priv->buffer_size,
+				 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
+	if (ret < 0)
+		goto exit;
+
+	/* The official software sends this report after every change, so do it here as well */
+	ret =
+	    hid_hw_raw_request(priv->hdev, SECONDARY_CTRL_REPORT_ID, secondary_ctrl_report,
+			       SECONDARY_CTRL_REPORT_SIZE, HID_FEATURE_REPORT,
+			       HID_REQ_SET_REPORT);
+exit:
+	return ret;
+}
+
+/* Refreshes the control buffer and returns value at offset in big endian */
+static int aqc_get_ctrl_val(struct aqc_data *priv, int offset, void *val, size_t size)
+{
+	int ret;
+
+	mutex_lock(&priv->mutex);
+
+	if (size < 1 || size > 4) {
+		ret = -EINVAL;
+		goto unlock_and_return;
+	}
+
+	ret = aqc_get_ctrl_data(priv);
+	if (ret < 0)
+		goto unlock_and_return;
+
+	memcpy(val, priv->buffer + offset, size);
+
+unlock_and_return:
+	mutex_unlock(&priv->mutex);
+	return ret;
+}
+
+static int aqc_set_ctrl_val(struct aqc_data *priv, int offset, long val, size_t size)
+{
+	int ret;
+
+	mutex_lock(&priv->mutex);
+
+	if (size < 1 || size > 4) {
+		ret = -EINVAL;
+		goto unlock_and_return;
+	}
+
+	ret = aqc_get_ctrl_data(priv);
+	if (ret < 0)
+		goto unlock_and_return;
+
+	switch (size) {
+	case 4:
+		put_unaligned_be32(val, priv->buffer + offset);
+		break;
+	case 2:
+		put_unaligned_be16((u16)val, priv->buffer + offset);
+		break;
+	case 1:
+		priv->buffer[offset] = val;
+		break;
+	default:
+		break;
+	}
+
+	ret = aqc_send_ctrl_data(priv);
+
+unlock_and_return:
+	mutex_unlock(&priv->mutex);
+	return ret;
+}
+
 static umode_t aqc_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr,
 			      int channel)
 {
@@ -128,17 +330,47 @@ static umode_t aqc_is_visible(const void *data, enum hwmon_sensor_types type, u3
 				return 0444;
 			break;
 		case farbwerk360:
+		case octo:
 			return 0444;
 		default:
 			break;
 		}
 		break;
+	case hwmon_pwm:
+		switch (priv->kind) {
+		case octo:
+			switch (attr) {
+			case hwmon_pwm_input:
+				return 0644;
+			default:
+				break;
+			}
+			break;
+		default:
+			break;
+		}
+		break;
 	case hwmon_fan:
 	case hwmon_power:
-	case hwmon_in:
 	case hwmon_curr:
 		switch (priv->kind) {
 		case d5next:
+			if (channel < 2)
+				return 0444;
+			break;
+		case octo:
+			return 0444;
+		default:
+			break;
+		}
+		break;
+	case hwmon_in:
+		switch (priv->kind) {
+		case d5next:
+			if (channel < 3)
+				return 0444;
+			break;
+		case octo:
 			return 0444;
 		default:
 			break;
@@ -154,6 +386,7 @@ static umode_t aqc_is_visible(const void *data, enum hwmon_sensor_types type, u3
 static int aqc_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 		    int channel, long *val)
 {
+	int ret;
 	struct aqc_data *priv = dev_get_drvdata(dev);
 
 	if (time_after(jiffies, priv->updated + STATUS_UPDATE_INTERVAL))
@@ -172,6 +405,19 @@ static int aqc_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 	case hwmon_power:
 		*val = priv->power_input[channel];
 		break;
+	case hwmon_pwm:
+		switch (priv->kind) {
+		case octo:
+			ret = aqc_get_ctrl_val(priv, octo_ctrl_fan_offsets[channel], val, 2);
+			if (ret < 0)
+				return ret;
+
+			*val = aqc_be_percent_to_pwm(*val);
+			break;
+		default:
+			break;
+		}
+		break;
 	case hwmon_in:
 		*val = priv->voltage_input[channel];
 		break;
@@ -197,6 +443,7 @@ static int aqc_read_string(struct device *dev, enum hwmon_sensor_types type, u32
 			*str = L_D5NEXT_COOLANT_TEMP;
 			break;
 		case farbwerk360:
+		case octo:
 			*str = label_temp_sensors[channel];
 			break;
 		default:
@@ -208,6 +455,9 @@ static int aqc_read_string(struct device *dev, enum hwmon_sensor_types type, u32
 		case d5next:
 			*str = label_d5next_speeds[channel];
 			break;
+		case octo:
+			*str = label_fan_speed[channel];
+			break;
 		default:
 			break;
 		}
@@ -217,6 +467,9 @@ static int aqc_read_string(struct device *dev, enum hwmon_sensor_types type, u32
 		case d5next:
 			*str = label_d5next_power[channel];
 			break;
+		case octo:
+			*str = label_fan_power[channel];
+			break;
 		default:
 			break;
 		}
@@ -226,6 +479,9 @@ static int aqc_read_string(struct device *dev, enum hwmon_sensor_types type, u32
 		case d5next:
 			*str = label_d5next_voltages[channel];
 			break;
+		case octo:
+			*str = label_fan_voltage[channel];
+			break;
 		default:
 			break;
 		}
@@ -235,6 +491,41 @@ static int aqc_read_string(struct device *dev, enum hwmon_sensor_types type, u32
 		case d5next:
 			*str = label_d5next_current[channel];
 			break;
+		case octo:
+			*str = label_fan_current[channel];
+			break;
+		default:
+			break;
+		}
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int aqc_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
+		     int channel, long val)
+{
+	int ret;
+	struct aqc_data *priv = dev_get_drvdata(dev);
+
+	switch (type) {
+	case hwmon_pwm:
+		switch (attr) {
+		case hwmon_pwm_input:
+			switch (priv->kind) {
+			case octo:
+				ret =
+				    aqc_set_ctrl_val(priv, octo_ctrl_fan_offsets[channel],
+						     aqc_pwm_to_percent(val), 2);
+				if (ret < 0)
+					return ret;
+				break;
+			default:
+				break;
+			}
 		default:
 			break;
 		}
@@ -250,6 +541,7 @@ static const struct hwmon_ops aqc_hwmon_ops = {
 	.is_visible = aqc_is_visible,
 	.read = aqc_read,
 	.read_string = aqc_read_string,
+	.write = aqc_write
 };
 
 static const struct hwmon_channel_info *aqc_info[] = {
@@ -259,16 +551,48 @@ static const struct hwmon_channel_info *aqc_info[] = {
 			   HWMON_T_INPUT | HWMON_T_LABEL,
 			   HWMON_T_INPUT | HWMON_T_LABEL),
 	HWMON_CHANNEL_INFO(fan,
+			   HWMON_F_INPUT | HWMON_F_LABEL,
+			   HWMON_F_INPUT | HWMON_F_LABEL,
+			   HWMON_F_INPUT | HWMON_F_LABEL,
+			   HWMON_F_INPUT | HWMON_F_LABEL,
+			   HWMON_F_INPUT | HWMON_F_LABEL,
+			   HWMON_F_INPUT | HWMON_F_LABEL,
 			   HWMON_F_INPUT | HWMON_F_LABEL,
 			   HWMON_F_INPUT | HWMON_F_LABEL),
 	HWMON_CHANNEL_INFO(power,
+			   HWMON_P_INPUT | HWMON_P_LABEL,
+			   HWMON_P_INPUT | HWMON_P_LABEL,
+			   HWMON_P_INPUT | HWMON_P_LABEL,
+			   HWMON_P_INPUT | HWMON_P_LABEL,
+			   HWMON_P_INPUT | HWMON_P_LABEL,
+			   HWMON_P_INPUT | HWMON_P_LABEL,
 			   HWMON_P_INPUT | HWMON_P_LABEL,
 			   HWMON_P_INPUT | HWMON_P_LABEL),
+	HWMON_CHANNEL_INFO(pwm,
+			   HWMON_PWM_INPUT,
+			   HWMON_PWM_INPUT,
+			   HWMON_PWM_INPUT,
+			   HWMON_PWM_INPUT,
+			   HWMON_PWM_INPUT,
+			   HWMON_PWM_INPUT,
+			   HWMON_PWM_INPUT,
+			   HWMON_PWM_INPUT),
 	HWMON_CHANNEL_INFO(in,
+			   HWMON_I_INPUT | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LABEL,
 			   HWMON_I_INPUT | HWMON_I_LABEL,
 			   HWMON_I_INPUT | HWMON_I_LABEL,
 			   HWMON_I_INPUT | HWMON_I_LABEL),
 	HWMON_CHANNEL_INFO(curr,
+			   HWMON_C_INPUT | HWMON_C_LABEL,
+			   HWMON_C_INPUT | HWMON_C_LABEL,
+			   HWMON_C_INPUT | HWMON_C_LABEL,
+			   HWMON_C_INPUT | HWMON_C_LABEL,
+			   HWMON_C_INPUT | HWMON_C_LABEL,
+			   HWMON_C_INPUT | HWMON_C_LABEL,
 			   HWMON_C_INPUT | HWMON_C_LABEL,
 			   HWMON_C_INPUT | HWMON_C_LABEL),
 	NULL
@@ -326,6 +650,35 @@ static int aqc_raw_event(struct hid_device *hdev, struct hid_report *report, u8
 				priv->temp_input[i] = sensor_value * 10;
 		}
 		break;
+	case octo:
+		priv->power_cycles = get_unaligned_be32(data + OCTO_POWER_CYCLES);
+
+		/* Fan speed and related readings */
+		for (i = 0; i < OCTO_NUM_FANS; i++) {
+			priv->speed_input[i] =
+			    get_unaligned_be16(data + octo_sensor_fan_offsets[i] +
+					       OCTO_FAN_SPEED_OFFSET);
+			priv->power_input[i] =
+			    get_unaligned_be16(data + octo_sensor_fan_offsets[i] +
+					       OCTO_FAN_POWER_OFFSET) * 10000;
+			priv->voltage_input[i] =
+			    get_unaligned_be16(data + octo_sensor_fan_offsets[i] +
+					       OCTO_FAN_VOLTAGE_OFFSET) * 10;
+			priv->current_input[i] =
+			    get_unaligned_be16(data + octo_sensor_fan_offsets[i] +
+					       OCTO_FAN_CURRENT_OFFSET);
+		}
+
+		/* Temperature sensor readings */
+		for (i = 0; i < OCTO_NUM_SENSORS; i++) {
+			sensor_value = get_unaligned_be16(data + OCTO_SENSOR_START +
+							  i * OCTO_SENSOR_SIZE);
+			if (sensor_value == OCTO_SENSOR_DISCONNECTED)
+				priv->temp_input[i] = -ENODATA;
+			else
+				priv->temp_input[i] = sensor_value * 10;
+		}
+		break;
 	default:
 		break;
 	}
@@ -376,10 +729,17 @@ static void aqc_debugfs_init(struct aqc_data *priv)
 
 	priv->debugfs = debugfs_create_dir(name, NULL);
 	debugfs_create_file("serial_number", 0444, priv->debugfs, priv, &serial_number_fops);
-	debugfs_create_file("firmware_version", 0444, priv->debugfs, priv, &firmware_version_fops);
+	debugfs_create_file("firmware_version", 0444, priv->debugfs, priv,
+			    &firmware_version_fops);
 
-	if (priv->kind == d5next)
-		debugfs_create_file("power_cycles", 0444, priv->debugfs, priv, &power_cycles_fops);
+	switch (priv->kind) {
+	case d5next:
+	case octo:
+		debugfs_create_file("power_cycles", 0444, priv->debugfs, priv,
+				    &power_cycles_fops);
+	default:
+		break;
+	}
 }
 
 #else
@@ -423,12 +783,25 @@ static int aqc_probe(struct hid_device *hdev, const struct hid_device_id *id)
 	case USB_PRODUCT_ID_FARBWERK360:
 		priv->kind = farbwerk360;
 		break;
+	case USB_PRODUCT_ID_OCTO:
+		priv->kind = octo;
+		priv->buffer_size = OCTO_CTRL_REPORT_SIZE;
+		priv->checksum_start = OCTO_CTRL_REPORT_CHECKSUM_START;
+		priv->checksum_length = OCTO_CTRL_REPORT_CHECKSUM_LENGTH;
+		priv->checksum_offset = OCTO_CTRL_REPORT_CHECKSUM_OFFSET;
+		break;
 	default:
 		break;
 	}
 
 	priv->name = aqc_device_names[priv->kind];
 
+	priv->buffer = devm_kzalloc(&hdev->dev, priv->buffer_size, GFP_KERNEL);
+	if (!priv->buffer)
+		return -ENOMEM;
+
+	mutex_init(&priv->mutex);
+
 	priv->hwmon_dev = hwmon_device_register_with_info(&hdev->dev, priv->name, priv,
 							  &aqc_chip_info, NULL);
 
@@ -462,6 +835,7 @@ static void aqc_remove(struct hid_device *hdev)
 static const struct hid_device_id aqc_table[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_AQUACOMPUTER, USB_PRODUCT_ID_D5NEXT) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_AQUACOMPUTER, USB_PRODUCT_ID_FARBWERK360) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_AQUACOMPUTER, USB_PRODUCT_ID_OCTO) },
 	{ }
 };
 
-- 
2.35.1