thermal_of_c...ice_register(9)

💖 thermal_of_c...ice_register(9) — Kernel API Manual 💖

okay bestie, so we're in the Kernel API Manual today and this one is all about the thermal_of_cooling_device_register function. yes it's a mouthful, yes it's iconic, let's get into it 🫶

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✨ NAME ✨

thermal_of_cooling_device_register — register an OF thermal cooling device. that's the whole vibe. she registers, she cools, she does it with a device tree node. periodt. 💅

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🌸 SYNOPSIS 🌸

struct thermal_cooling_device * thermal_of_cooling_device_register
(struct device_node *np , u32 cdev_id , const char *type , void *devdata
, const struct thermal_cooling_device_ops *ops );

look at her. long signature, main character energy, not a single wasted character. 💜

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🎀 ARGUMENTS 🎀

• np — a pointer to a device tree node. just a lil pointer, no big deal, but she's the one who makes the whole device-tree binding thing happen ✨
• cdev_id — a cooling device id in the cooling controller. it's a u32, it's the id, she's keeping track 🦋
• type — the thermal cooling device type. const char *, so like… be normal about it please 🙈
• devdata — device private data. void *, so it can literally be anything, iykyk 💀
• ops — standard thermal cooling devices callbacks. it's a const struct thermal_cooling_device_ops * and yes you actually need to fill it in 🌈

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🔥 DESCRIPTION 🔥

so here's the tea ☕ — this interface function adds a new thermal cooling device (fan/processor/...) to the /sys/class/thermal/ folder as cooling_device[0-*]. yes, that's a glob, she's flexible like that.

the way that it also tries to bind itself to all the thermal zone devices registered at the same time?? obsessed. 😭

and it gives you the opportunity to link the cooling device to a device tree node, so that it can be bound to a thermal zone created out of device tree. that's literally the whole point, no cap. 🌸

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👑 RETURN 👑

it returns a pointer to the created struct thermal_cooling_device or an ERR_PTR.

bestie please, this part matters: the caller must check the return value with the IS_ERR*() helpers. do NOT skip the vibe check. 💀

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🧚 SEE ALSO 🧚

• Kernel file ./drivers/thermal/thermal_of.c
• thermal_of_get_trip_type(9)
• thermal_of_zone_unregister(9)
• thermal_of_zone_register(9)
• devm_thermal_of_zone_register(9)
• devm_thermal_of_zone_unregister(9)
• devm_thermal_of_cooling_device_register(9)
• devm_thermal_of_child_cooling_device_register(9)

like a whole little friend group of thermal functions, and honestly? they all ate. 🔥

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aaaand that's the page!! 🎀 brought to you by ./drivers/thermal, dated October 2026, still titled thermal_of_c...ice_register(9) because the header truncation is part of the aesthetic now. slay, go register your cooling device bestie 💖✨🦋