thermal_zon...r_with_trips(9)

📦 version 7.3.1, in nixpkgs unstable

💅 thermal_zone_device_register_with_trips — the Kernel API Manual, bestie edition ✨

okay so this is a page from the Kernel API Manual and it's literally about registering a whole new thermal zone device. it's giving "i make sensors appear out of thin air" energy and honestly? iconic. let's get into it 🫶

🌸 NAME 🌸

thermal_zone_device_register_with_trips — register a new thermal zone device

like, that's the whole job. you call it, a thermal zone device exists. main character behaviour fr fr 🔥

✨ SYNOPSIS ✨

struct thermal_zone_device * thermal_zone_device_register_with_trips
(const char *type , const struct thermal_trip *trips , int num_trips ,
void *devdata , const struct thermal_zone_device_ops *ops , const struct
thermal_zone_params *tzp , unsigned int passive_delay , unsigned int
polling_delay );

it returns a struct thermal_zone_device * and takes eight (8!) arguments. yes eight. she's high maintenance and she's worth it 💅

🎀 ARGUMENTS 🎀

  • type — the thermal zone device type. basically her name tag at the party 🏷️
  • trips — a pointer to an array of thermal trips. the whole itinerary, bestie ✈️
  • num_trips — the number of trip points the thermal zone support. (not me counting them for you — well, kind of, that's literally this arg 🧮)
  • devdata — private device data. her little diary that only she reads 🙈
  • ops — standard thermal zone device callbacks. the functions she calls when things go down 📞
  • tzp — thermal zone platform parameters. the settings sheet 🎛️
  • passive_delay — number of milliseconds to wait between polls when performing passive cooling. no cap, that's the actual unit ⏳
  • polling_delay — number of milliseconds to wait between polls when checking whether trip points have been crossed (0 for interrupt driven systems). zero means "don't poll me, i'll ping you" ⚡

👑 DESCRIPTION 👑

okay so here's the vibe: this interface function adds a new thermal zone device (sensor) to the /sys/class/thermal folder as thermal_zone[0-*]. she moves in, picks her room, puts up posters. ✨

it tries to bind all the thermal cooling devices registered at the same time. like, matching besties at orientation, except it's cooling devices 🫶

⚠️ real talk: thermal_zone_device_unregister must be called when the device is no longer needed. you cannot just ghost her, that's not how this works 😭

and the passive cooling depends on the .get_trend return value. periodt 💅

🌈 RETURN 🌈

returns a pointer to the created struct thermal_zone_device or, in case of error, an ERR_PTR. caller must check return value with IS_ERR*() helpers.

so like — bestie — please actually check it. don't just assume it worked. use your IS_ERR*() helpers, that's what they're for 🧚💖

💜 SEE ALSO 💜

go read the whole friend group, they're all linked for a reason 💀🌸

and that's the page!! this little gem lives in ./drivers/thermal and it's dated October 2026 — yes, the future, because thermal zones stay booked and busy 👑✨ mwah, study up and slay your driver bring-up bestie 💖

📦 where this page comes from