1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* |
3 | * nzxt-kraken2.c - hwmon driver for NZXT Kraken X42/X52/X62/X72 coolers |
4 | * |
5 | * The device asynchronously sends HID reports (with id 0x04) twice a second to |
6 | * communicate current fan speed, pump speed and coolant temperature. The |
7 | * 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 <asm/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 0x04 |
19 | #define STATUS_VALIDITY 2 /* seconds; equivalent to 4 missed updates */ |
20 | |
21 | static const char *const kraken2_temp_label[] = { |
22 | "Coolant" , |
23 | }; |
24 | |
25 | static const char *const kraken2_fan_label[] = { |
26 | "Fan" , |
27 | "Pump" , |
28 | }; |
29 | |
30 | struct 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 | |
38 | static 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 | |
45 | static 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 | |
67 | static 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 | |
83 | static 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 | |
89 | static 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 | NULL |
96 | }; |
97 | |
98 | static const struct hwmon_chip_info kraken2_chip_info = { |
99 | .ops = &kraken2_hwmon_ops, |
100 | .info = kraken2_info, |
101 | }; |
102 | |
103 | static 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 to |
115 | * be in the interval [1,9], but some of these steps are also |
116 | * 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 firmware |
120 | * 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(p: data + 3); |
125 | priv->fan_input[1] = get_unaligned_be16(p: data + 5); |
126 | |
127 | priv->updated = jiffies; |
128 | |
129 | return 0; |
130 | } |
131 | |
132 | static 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(dev: &hdev->dev, size: sizeof(*priv), GFP_KERNEL); |
139 | if (!priv) |
140 | return -ENOMEM; |
141 | |
142 | priv->hid_dev = hdev; |
143 | hid_set_drvdata(hdev, data: priv); |
144 | |
145 | /* |
146 | * Initialize ->updated to STATUS_VALIDITY seconds in the past, making |
147 | * the initial empty data invalid for kraken2_read without the need for |
148 | * 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(dev: &hdev->dev, name: "kraken2" , |
174 | drvdata: priv, info: &kraken2_chip_info, |
175 | NULL); |
176 | if (IS_ERR(ptr: priv->hwmon_dev)) { |
177 | ret = PTR_ERR(ptr: 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 | |
184 | fail_and_close: |
185 | hid_hw_close(hdev); |
186 | fail_and_stop: |
187 | hid_hw_stop(hdev); |
188 | return ret; |
189 | } |
190 | |
191 | static void kraken2_remove(struct hid_device *hdev) |
192 | { |
193 | struct kraken2_priv_data *priv = hid_get_drvdata(hdev); |
194 | |
195 | hwmon_device_unregister(dev: priv->hwmon_dev); |
196 | |
197 | hid_hw_close(hdev); |
198 | hid_hw_stop(hdev); |
199 | } |
200 | |
201 | static const struct hid_device_id kraken2_table[] = { |
202 | { HID_USB_DEVICE(0x1e71, 0x170e) }, /* NZXT Kraken X42/X52/X62/X72 */ |
203 | { } |
204 | }; |
205 | |
206 | MODULE_DEVICE_TABLE(hid, kraken2_table); |
207 | |
208 | static 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 | |
216 | static int __init kraken2_init(void) |
217 | { |
218 | return hid_register_driver(&kraken2_driver); |
219 | } |
220 | |
221 | static 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 | */ |
229 | late_initcall(kraken2_init); |
230 | module_exit(kraken2_exit); |
231 | |
232 | MODULE_LICENSE("GPL" ); |
233 | MODULE_AUTHOR("Jonas Malaco <jonas@protocubo.io>" ); |
234 | MODULE_DESCRIPTION("Hwmon driver for NZXT Kraken X42/X52/X62/X72 coolers" ); |
235 | |