diff options
Diffstat (limited to 'drivers/acpi/fan.h')
| -rw-r--r-- | drivers/acpi/fan.h | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/drivers/acpi/fan.h b/drivers/acpi/fan.h index bedbab0e8e4e..0d73433c3889 100644 --- a/drivers/acpi/fan.h +++ b/drivers/acpi/fan.h @@ -11,6 +11,7 @@ #define _ACPI_FAN_H_ #include <linux/kconfig.h> +#include <linux/limits.h> #define ACPI_FAN_DEVICE_IDS \ {"INT3404", }, /* Fan */ \ @@ -60,6 +61,38 @@ struct acpi_fan { struct device_attribute fine_grain_control; }; +/** + * acpi_fan_speed_valid - Check if fan speed value is valid + * @speeed: Speed value returned by the ACPI firmware + * + * Check if the fan speed value returned by the ACPI firmware is valid. This function is + * necessary as ACPI firmware implementations can return 0xFFFFFFFF to signal that the + * ACPI fan does not support speed reporting. Additionally, some buggy ACPI firmware + * implementations return a value larger than the 32-bit integer value defined by + * the ACPI specification when using placeholder values. Such invalid values are also + * detected by this function. + * + * Returns: True if the fan speed value is valid, false otherwise. + */ +static inline bool acpi_fan_speed_valid(u64 speed) +{ + return speed < U32_MAX; +} + +/** + * acpi_fan_power_valid - Check if fan power value is valid + * @power: Power value returned by the ACPI firmware + * + * Check if the fan power value returned by the ACPI firmware is valid. + * See acpi_fan_speed_valid() for details. + * + * Returns: True if the fan power value is valid, false otherwise. + */ +static inline bool acpi_fan_power_valid(u64 power) +{ + return power < U32_MAX; +} + int acpi_fan_get_fst(acpi_handle handle, struct acpi_fan_fst *fst); int acpi_fan_create_attributes(struct acpi_device *device); void acpi_fan_delete_attributes(struct acpi_device *device); |