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1// SPDX-License-Identifier: GPL-2.0-or-later2/*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/* Returned when the ACPI fan does not support speed reporting */19#define FAN_SPEED_UNAVAILABLE U32_MAX20#define FAN_POWER_UNAVAILABLE U32_MAX21 22static struct acpi_fan_fps *acpi_fan_get_current_fps(struct acpi_fan *fan, u64 control)23{24 unsigned int i;25 26 for (i = 0; i < fan->fps_count; i++) {27 if (fan->fps[i].control == control)28 return &fan->fps[i];29 }30 31 return NULL;32}33 34static umode_t acpi_fan_hwmon_is_visible(const void *drvdata, enum hwmon_sensor_types type,35 u32 attr, int channel)36{37 const struct acpi_fan *fan = drvdata;38 unsigned int i;39 40 switch (type) {41 case hwmon_fan:42 switch (attr) {43 case hwmon_fan_input:44 return 0444;45 case hwmon_fan_target:46 /*47 * When in fine grain control mode, not every fan control value48 * 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 /*61 * When in fine grain control mode, not every fan control value62 * has an associated fan performance state.63 */64 if (fan->fif.fine_grain_ctrl)65 return 0;66 67 /*68 * When all fan performance states contain no valid power data,69 * when the associated attribute should not be created.70 */71 for (i = 0; i < fan->fps_count; i++) {72 if (fan->fps[i].power != FAN_POWER_UNAVAILABLE)73 return 0444;74 }75 76 return 0;77 default:78 return 0;79 }80 default:81 return 0;82 }83}84 85static int acpi_fan_hwmon_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,86 int channel, long *val)87{88 struct acpi_device *adev = to_acpi_device(dev->parent);89 struct acpi_fan *fan = dev_get_drvdata(dev);90 struct acpi_fan_fps *fps;91 struct acpi_fan_fst fst;92 int ret;93 94 ret = acpi_fan_get_fst(adev, &fst);95 if (ret < 0)96 return ret;97 98 switch (type) {99 case hwmon_fan:100 switch (attr) {101 case hwmon_fan_input:102 if (fst.speed == FAN_SPEED_UNAVAILABLE)103 return -ENODEV;104 105 if (fst.speed > LONG_MAX)106 return -EOVERFLOW;107 108 *val = fst.speed;109 return 0;110 case hwmon_fan_target:111 fps = acpi_fan_get_current_fps(fan, fst.control);112 if (!fps)113 return -EIO;114 115 if (fps->speed > LONG_MAX)116 return -EOVERFLOW;117 118 *val = fps->speed;119 return 0;120 default:121 return -EOPNOTSUPP;122 }123 case hwmon_power:124 switch (attr) {125 case hwmon_power_input:126 fps = acpi_fan_get_current_fps(fan, fst.control);127 if (!fps)128 return -EIO;129 130 if (fps->power == FAN_POWER_UNAVAILABLE)131 return -ENODEV;132 133 if (fps->power > LONG_MAX / MICROWATT_PER_MILLIWATT)134 return -EOVERFLOW;135 136 *val = fps->power * MICROWATT_PER_MILLIWATT;137 return 0;138 default:139 return -EOPNOTSUPP;140 }141 default:142 return -EOPNOTSUPP;143 }144}145 146static const struct hwmon_ops acpi_fan_hwmon_ops = {147 .is_visible = acpi_fan_hwmon_is_visible,148 .read = acpi_fan_hwmon_read,149};150 151static const struct hwmon_channel_info * const acpi_fan_hwmon_info[] = {152 HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT | HWMON_F_TARGET),153 HWMON_CHANNEL_INFO(power, HWMON_P_INPUT),154 NULL155};156 157static const struct hwmon_chip_info acpi_fan_hwmon_chip_info = {158 .ops = &acpi_fan_hwmon_ops,159 .info = acpi_fan_hwmon_info,160};161 162int devm_acpi_fan_create_hwmon(struct acpi_device *device)163{164 struct acpi_fan *fan = acpi_driver_data(device);165 struct device *hdev;166 167 hdev = devm_hwmon_device_register_with_info(&device->dev, "acpi_fan", fan,168 &acpi_fan_hwmon_chip_info, NULL);169 return PTR_ERR_OR_ZERO(hdev);170}171