STRUCT EMC2305_CDEV_DATA(9)

🎀 NAME 🎀

okay so this is the Kernel API Manual page for struct emc2305_cdev_data — literally the device-specific cooling device state, bestie. The whole name vibe is: struct emc2305_cdev_data - device-specific cooling device state. no cap.

✨ SYNOPSIS ✨

Here’s the struct in all its main-character glory:

struct emc2305_cdev_data {
    struct thermal_cooling_device *cdev;
    unsigned int cur_state;
    unsigned long last_hwmon_state;
    unsigned long last_thermal_state;
};

🧚 Members 🧚

• cdev — cooling device. iconic.
• cur_state — cooling current state. lowkey exactly what it says.
• last_hwmon_state — last cooling state updated by the hwmon subsystem.
• last_thermal_state — last cooling state updated by the thermal subsystem.

💅 Description 💅

The last_hwmon_state and last_thermal_state fields are here to support the fan low limit speed feature. Bestie, the purpose of this feature is to provide the ability to limit fan speed according to some system-wise considerations — like absence of some replaceable units (PSU or line cards), high system ambient temperature, unreliable transceivers temperature sensing, or some other factors which indirectly impact the system’s airflow. it’s giving airflow damage control, fr fr.

Fan low limit feature is supported through the hwmon interface: the hwmon pwm attribute is used for setting the low limit for fan speed in case the thermal subsystem is configured in the kernel. In this case, setting fan speed through hwmon will never let the thermal subsystem select a lower duty cycle than the duty cycle selected with the pwm attribute. From the other side, fan speed is to be updated in hardware through pwm only in case the requested fan speed is above the last speed set by the thermal subsystem; otherwise, the requested fan speed will be just stored with no PWM update.

🌈 SEE ALSO 🌈

• Kernel file ./drivers/hwmon/emc2305.c
• struct emc2305_data(9)

mwah 💋 this page lives under ./drivers/hwmon and is dated October 2026 — that’s the footer, bestie, and yes it ate. 🫶✨