dtpm_register(9)

📦 version 7.3.1, in nixpkgs unstable

💖 dtpm_register — NAME, bestie edition 💖

okay so this page is from the Kernel API Manual, and it's literally all about dtpm_register — which registers a dtpm node in the hierarchy tree 🌳✨ yes, that's the whole vibe.

✨ SYNOPSIS ✨

int dtpm_register (const char *name , struct dtpm *dtpm , struct dtpm
*parent );

like, three args, one int back, no cap 🫶

🎀 ARGUMENTS 🎀

  • name — a string specifying the name of the node 💅
  • dtpm — a pointer to a dtpm structure corresponding to the new node 🦋
  • parent — a pointer to a dtpm structure corresponding to the parent node 🌸

🌈 DESCRIPTION 🌈

So the whole point: you're creating a dtpm node in the tree 🌳

If no parent is specified, then the node is the root node of the hierarchy — main character energy, queen of the tree 👑. But heads up: if the root node already exists, then the registration will fail. no takebacks, no duplicates 🙈

Also, the powercap controller must be initialized before calling this function — like, do that first, fr fr ⚠️

And the dtpm structure must be initialized with the power numbers before calling this function. don't skip that step bestie 😭

🔥 RETURN 🔥

zero on success 🎉 — and a negative value in case of error:

  • -EAGAIN — the function is called before the framework is initialized 💀
  • -EBUSY — the root node is already inserted 🚫
  • -EINVAL —
    • there is no root node yet and parent is specified
    • no all ops are defined
    • parent have ops which are reserved for leaves

Other negative values are reported back from the powercap framework 🫶

ngl that -EINVAL list is giving "read it twice" energy — check your ops and your parent before you come crying to the kernel 💅

🦋 SEE ALSO 🦋

Kernel file ./drivers/powercap/dtpm.c

go read those next, iykyk 📚✨

and that's the page!! 🎀 this one lives under ./drivers/powercap, dated October 2026 — mwah, go register some nodes responsibly bestie 💖🌳🫶

📦 where this page comes from