1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * hwmon interface for the ACPI Fan driver.
4 *
5 * Copyright (C) 2024 Armin Wolf <W_Armin@gmx.de>
6 */
7
8 #include <linux/acpi.h>
9 #include <linux/device.h>
10 #include <linux/err.h>
11 #include <linux/hwmon.h>
12 #include <linux/limits.h>
13 #include <linux/types.h>
14 #include <linux/units.h>
15
16 #include "fan.h"
17
acpi_fan_get_current_fps(struct acpi_fan * fan,u64 control)18 static struct acpi_fan_fps *acpi_fan_get_current_fps(struct acpi_fan *fan, u64 control)
19 {
20 unsigned int i;
21
22 for (i = 0; i < fan->fps_count; i++) {
23 if (fan->fps[i].control == control)
24 return &fan->fps[i];
25 }
26
27 return NULL;
28 }
29
acpi_fan_hwmon_is_visible(const void * drvdata,enum hwmon_sensor_types type,u32 attr,int channel)30 static umode_t acpi_fan_hwmon_is_visible(const void *drvdata, enum hwmon_sensor_types type,
31 u32 attr, int channel)
32 {
33 const struct acpi_fan *fan = drvdata;
34 unsigned int i;
35
36 switch (type) {
37 case hwmon_fan:
38 switch (attr) {
39 case hwmon_fan_input:
40 return 0444;
41 case hwmon_fan_target:
42 /* Only acpi4 fans support fan control. */
43 if (!fan->acpi4)
44 return 0;
45
46 /*
47 * When in fine grain control mode, not every fan control value
48 * has an associated fan performance state.
49 */
50 if (fan->fif.fine_grain_ctrl)
51 return 0;
52
53 return 0444;
54 default:
55 return 0;
56 }
57 case hwmon_power:
58 switch (attr) {
59 case hwmon_power_input:
60 /* Only acpi4 fans support fan control. */
61 if (!fan->acpi4)
62 return 0;
63
64 /*
65 * When in fine grain control mode, not every fan control value
66 * has an associated fan performance state.
67 */
68 if (fan->fif.fine_grain_ctrl)
69 return 0;
70
71 /*
72 * When all fan performance states contain no valid power data,
73 * when the associated attribute should not be created.
74 */
75 for (i = 0; i < fan->fps_count; i++) {
76 if (acpi_fan_power_valid(fan->fps[i].power))
77 return 0444;
78 }
79
80 return 0;
81 default:
82 return 0;
83 }
84 default:
85 return 0;
86 }
87 }
88
acpi_fan_hwmon_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)89 static int acpi_fan_hwmon_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
90 int channel, long *val)
91 {
92 struct acpi_fan *fan = dev_get_drvdata(dev);
93 struct acpi_fan_fps *fps;
94 struct acpi_fan_fst fst;
95 int ret;
96
97 ret = acpi_fan_get_fst(fan->handle, &fst);
98 if (ret < 0)
99 return ret;
100
101 switch (type) {
102 case hwmon_fan:
103 switch (attr) {
104 case hwmon_fan_input:
105 if (!acpi_fan_speed_valid(fst.speed))
106 return -ENODEV;
107
108 if (fst.speed > LONG_MAX)
109 return -EOVERFLOW;
110
111 *val = fst.speed;
112 return 0;
113 case hwmon_fan_target:
114 fps = acpi_fan_get_current_fps(fan, fst.control);
115 if (!fps)
116 return -EIO;
117
118 if (fps->speed > LONG_MAX)
119 return -EOVERFLOW;
120
121 *val = fps->speed;
122 return 0;
123 default:
124 return -EOPNOTSUPP;
125 }
126 case hwmon_power:
127 switch (attr) {
128 case hwmon_power_input:
129 fps = acpi_fan_get_current_fps(fan, fst.control);
130 if (!fps)
131 return -EIO;
132
133 if (!acpi_fan_power_valid(fps->power))
134 return -ENODEV;
135
136 if (fps->power > LONG_MAX / MICROWATT_PER_MILLIWATT)
137 return -EOVERFLOW;
138
139 *val = fps->power * MICROWATT_PER_MILLIWATT;
140 return 0;
141 default:
142 return -EOPNOTSUPP;
143 }
144 default:
145 return -EOPNOTSUPP;
146 }
147 }
148
149 static const struct hwmon_ops acpi_fan_hwmon_ops = {
150 .is_visible = acpi_fan_hwmon_is_visible,
151 .read = acpi_fan_hwmon_read,
152 };
153
154 static const struct hwmon_channel_info * const acpi_fan_hwmon_info[] = {
155 HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT | HWMON_F_TARGET),
156 HWMON_CHANNEL_INFO(power, HWMON_P_INPUT),
157 NULL
158 };
159
160 static const struct hwmon_chip_info acpi_fan_hwmon_chip_info = {
161 .ops = &acpi_fan_hwmon_ops,
162 .info = acpi_fan_hwmon_info,
163 };
164
acpi_fan_notify_hwmon(struct device * dev)165 void acpi_fan_notify_hwmon(struct device *dev)
166 {
167 struct acpi_fan *fan = dev_get_drvdata(dev);
168
169 hwmon_notify_event(fan->hdev, hwmon_fan, hwmon_fan_input, 0);
170 }
171
devm_acpi_fan_create_hwmon(struct device * dev)172 int devm_acpi_fan_create_hwmon(struct device *dev)
173 {
174 struct acpi_fan *fan = dev_get_drvdata(dev);
175
176 fan->hdev = devm_hwmon_device_register_with_info(dev, "acpi_fan", fan,
177 &acpi_fan_hwmon_chip_info, NULL);
178
179 return PTR_ERR_OR_ZERO(fan->hdev);
180 }
181