235 lines · c
1// SPDX-License-Identifier: GPL-2.0+2/*3 * nzxt-kraken2.c - hwmon driver for NZXT Kraken X42/X52/X62/X72 coolers4 *5 * The device asynchronously sends HID reports (with id 0x04) twice a second to6 * communicate current fan speed, pump speed and coolant temperature. The7 * device does not respond to Get_Report requests for this status report.8 *9 * Copyright 2019-2021 Jonas Malaco <jonas@protocubo.io>10 */11 12#include <linux/unaligned.h>13#include <linux/hid.h>14#include <linux/hwmon.h>15#include <linux/jiffies.h>16#include <linux/module.h>17 18#define STATUS_REPORT_ID 0x0419#define STATUS_VALIDITY 2 /* seconds; equivalent to 4 missed updates */20 21static const char *const kraken2_temp_label[] = {22 "Coolant",23};24 25static const char *const kraken2_fan_label[] = {26 "Fan",27 "Pump",28};29 30struct kraken2_priv_data {31 struct hid_device *hid_dev;32 struct device *hwmon_dev;33 s32 temp_input[1];34 u16 fan_input[2];35 unsigned long updated; /* jiffies */36};37 38static umode_t kraken2_is_visible(const void *data,39 enum hwmon_sensor_types type,40 u32 attr, int channel)41{42 return 0444;43}44 45static int kraken2_read(struct device *dev, enum hwmon_sensor_types type,46 u32 attr, int channel, long *val)47{48 struct kraken2_priv_data *priv = dev_get_drvdata(dev);49 50 if (time_after(jiffies, priv->updated + STATUS_VALIDITY * HZ))51 return -ENODATA;52 53 switch (type) {54 case hwmon_temp:55 *val = priv->temp_input[channel];56 break;57 case hwmon_fan:58 *val = priv->fan_input[channel];59 break;60 default:61 return -EOPNOTSUPP; /* unreachable */62 }63 64 return 0;65}66 67static int kraken2_read_string(struct device *dev, enum hwmon_sensor_types type,68 u32 attr, int channel, const char **str)69{70 switch (type) {71 case hwmon_temp:72 *str = kraken2_temp_label[channel];73 break;74 case hwmon_fan:75 *str = kraken2_fan_label[channel];76 break;77 default:78 return -EOPNOTSUPP; /* unreachable */79 }80 return 0;81}82 83static const struct hwmon_ops kraken2_hwmon_ops = {84 .is_visible = kraken2_is_visible,85 .read = kraken2_read,86 .read_string = kraken2_read_string,87};88 89static const struct hwmon_channel_info * const kraken2_info[] = {90 HWMON_CHANNEL_INFO(temp,91 HWMON_T_INPUT | HWMON_T_LABEL),92 HWMON_CHANNEL_INFO(fan,93 HWMON_F_INPUT | HWMON_F_LABEL,94 HWMON_F_INPUT | HWMON_F_LABEL),95 NULL96};97 98static const struct hwmon_chip_info kraken2_chip_info = {99 .ops = &kraken2_hwmon_ops,100 .info = kraken2_info,101};102 103static int kraken2_raw_event(struct hid_device *hdev,104 struct hid_report *report, u8 *data, int size)105{106 struct kraken2_priv_data *priv;107 108 if (size < 7 || report->id != STATUS_REPORT_ID)109 return 0;110 111 priv = hid_get_drvdata(hdev);112 113 /*114 * The fractional byte of the coolant temperature has been observed to115 * be in the interval [1,9], but some of these steps are also116 * consistently skipped for certain integer parts.117 *118 * For the lack of a better idea, assume that the resolution is 0.1°C,119 * and that the missing steps are artifacts of how the firmware120 * processes the raw sensor data.121 */122 priv->temp_input[0] = data[1] * 1000 + data[2] * 100;123 124 priv->fan_input[0] = get_unaligned_be16(data + 3);125 priv->fan_input[1] = get_unaligned_be16(data + 5);126 127 priv->updated = jiffies;128 129 return 0;130}131 132static int kraken2_probe(struct hid_device *hdev,133 const struct hid_device_id *id)134{135 struct kraken2_priv_data *priv;136 int ret;137 138 priv = devm_kzalloc(&hdev->dev, sizeof(*priv), GFP_KERNEL);139 if (!priv)140 return -ENOMEM;141 142 priv->hid_dev = hdev;143 hid_set_drvdata(hdev, priv);144 145 /*146 * Initialize ->updated to STATUS_VALIDITY seconds in the past, making147 * the initial empty data invalid for kraken2_read without the need for148 * a special case there.149 */150 priv->updated = jiffies - STATUS_VALIDITY * HZ;151 152 ret = hid_parse(hdev);153 if (ret) {154 hid_err(hdev, "hid parse failed with %d\n", ret);155 return ret;156 }157 158 /*159 * Enable hidraw so existing user-space tools can continue to work.160 */161 ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);162 if (ret) {163 hid_err(hdev, "hid hw start failed with %d\n", ret);164 return ret;165 }166 167 ret = hid_hw_open(hdev);168 if (ret) {169 hid_err(hdev, "hid hw open failed with %d\n", ret);170 goto fail_and_stop;171 }172 173 priv->hwmon_dev = hwmon_device_register_with_info(&hdev->dev, "kraken2",174 priv, &kraken2_chip_info,175 NULL);176 if (IS_ERR(priv->hwmon_dev)) {177 ret = PTR_ERR(priv->hwmon_dev);178 hid_err(hdev, "hwmon registration failed with %d\n", ret);179 goto fail_and_close;180 }181 182 return 0;183 184fail_and_close:185 hid_hw_close(hdev);186fail_and_stop:187 hid_hw_stop(hdev);188 return ret;189}190 191static void kraken2_remove(struct hid_device *hdev)192{193 struct kraken2_priv_data *priv = hid_get_drvdata(hdev);194 195 hwmon_device_unregister(priv->hwmon_dev);196 197 hid_hw_close(hdev);198 hid_hw_stop(hdev);199}200 201static const struct hid_device_id kraken2_table[] = {202 { HID_USB_DEVICE(0x1e71, 0x170e) }, /* NZXT Kraken X42/X52/X62/X72 */203 { }204};205 206MODULE_DEVICE_TABLE(hid, kraken2_table);207 208static struct hid_driver kraken2_driver = {209 .name = "nzxt-kraken2",210 .id_table = kraken2_table,211 .probe = kraken2_probe,212 .remove = kraken2_remove,213 .raw_event = kraken2_raw_event,214};215 216static int __init kraken2_init(void)217{218 return hid_register_driver(&kraken2_driver);219}220 221static void __exit kraken2_exit(void)222{223 hid_unregister_driver(&kraken2_driver);224}225 226/*227 * When compiled into the kernel, initialize after the hid bus.228 */229late_initcall(kraken2_init);230module_exit(kraken2_exit);231 232MODULE_LICENSE("GPL");233MODULE_AUTHOR("Jonas Malaco <jonas@protocubo.io>");234MODULE_DESCRIPTION("Hwmon driver for NZXT Kraken X42/X52/X62/X72 coolers");235