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 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 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 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 }; 164 165 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 } 171 172 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