diff options
Diffstat (limited to 'drivers/acpi/fan_hwmon.c')
| -rw-r--r-- | drivers/acpi/fan_hwmon.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/drivers/acpi/fan_hwmon.c b/drivers/acpi/fan_hwmon.c new file mode 100644 index 000000000000..bd0d31a398fa --- /dev/null +++ b/drivers/acpi/fan_hwmon.c @@ -0,0 +1,170 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * hwmon interface for the ACPI Fan driver. + * + * Copyright (C) 2024 Armin Wolf <W_Armin@gmx.de> + */ + +#include <linux/acpi.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/hwmon.h> +#include <linux/limits.h> +#include <linux/types.h> +#include <linux/units.h> + +#include "fan.h" + +/* Returned when the ACPI fan does not support speed reporting */ +#define FAN_SPEED_UNAVAILABLE U32_MAX +#define FAN_POWER_UNAVAILABLE U32_MAX + +static struct acpi_fan_fps *acpi_fan_get_current_fps(struct acpi_fan *fan, u64 control) +{ + unsigned int i; + + for (i = 0; i < fan->fps_count; i++) { + if (fan->fps[i].control == control) + return &fan->fps[i]; + } + + return NULL; +} + +static umode_t acpi_fan_hwmon_is_visible(const void *drvdata, enum hwmon_sensor_types type, + u32 attr, int channel) +{ + const struct acpi_fan *fan = drvdata; + unsigned int i; + + switch (type) { + case hwmon_fan: + switch (attr) { + case hwmon_fan_input: + return 0444; + case hwmon_fan_target: + /* + * When in fine grain control mode, not every fan control value + * has an associated fan performance state. + */ + if (fan->fif.fine_grain_ctrl) + return 0; + + return 0444; + default: + return 0; + } + case hwmon_power: + switch (attr) { + case hwmon_power_input: + /* + * When in fine grain control mode, not every fan control value + * has an associated fan performance state. + */ + if (fan->fif.fine_grain_ctrl) + return 0; + + /* + * When all fan performance states contain no valid power data, + * when the associated attribute should not be created. + */ + for (i = 0; i < fan->fps_count; i++) { + if (fan->fps[i].power != FAN_POWER_UNAVAILABLE) + return 0444; + } + + return 0; + default: + return 0; + } + default: + return 0; + } +} + +static int acpi_fan_hwmon_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, + int channel, long *val) +{ + struct acpi_device *adev = to_acpi_device(dev->parent); + struct acpi_fan *fan = dev_get_drvdata(dev); + struct acpi_fan_fps *fps; + struct acpi_fan_fst fst; + int ret; + + ret = acpi_fan_get_fst(adev, &fst); + if (ret < 0) + return ret; + + switch (type) { + case hwmon_fan: + switch (attr) { + case hwmon_fan_input: + if (fst.speed == FAN_SPEED_UNAVAILABLE) + return -ENODEV; + + if (fst.speed > LONG_MAX) + return -EOVERFLOW; + + *val = fst.speed; + return 0; + case hwmon_fan_target: + fps = acpi_fan_get_current_fps(fan, fst.control); + if (!fps) + return -EIO; + + if (fps->speed > LONG_MAX) + return -EOVERFLOW; + + *val = fps->speed; + return 0; + default: + return -EOPNOTSUPP; + } + case hwmon_power: + switch (attr) { + case hwmon_power_input: + fps = acpi_fan_get_current_fps(fan, fst.control); + if (!fps) + return -EIO; + + if (fps->power == FAN_POWER_UNAVAILABLE) + return -ENODEV; + + if (fps->power > LONG_MAX / MICROWATT_PER_MILLIWATT) + return -EOVERFLOW; + + *val = fps->power * MICROWATT_PER_MILLIWATT; + return 0; + default: + return -EOPNOTSUPP; + } + default: + return -EOPNOTSUPP; + } +} + +static const struct hwmon_ops acpi_fan_hwmon_ops = { + .is_visible = acpi_fan_hwmon_is_visible, + .read = acpi_fan_hwmon_read, +}; + +static const struct hwmon_channel_info * const acpi_fan_hwmon_info[] = { + HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT | HWMON_F_TARGET), + HWMON_CHANNEL_INFO(power, HWMON_P_INPUT), + NULL +}; + +static const struct hwmon_chip_info acpi_fan_hwmon_chip_info = { + .ops = &acpi_fan_hwmon_ops, + .info = acpi_fan_hwmon_info, +}; + +int devm_acpi_fan_create_hwmon(struct acpi_device *device) +{ + struct acpi_fan *fan = acpi_driver_data(device); + struct device *hdev; + + hdev = devm_hwmon_device_register_with_info(&device->dev, "acpi_fan", fan, + &acpi_fan_hwmon_chip_info, NULL); + return PTR_ERR_OR_ZERO(hdev); +} |