cpc_write_ffh(9)

📦 version 7.3.1, in nixpkgs unstable

💖 cpc_write_ffh — Write FFH register 💖

okay bestie, welcome to cpc_write_ffh(9), a lil kernel API page from the cpc_write_ffh part of the manual (section 9, kernel API, iykyk). this one's short and sweet, so let's get into it 🎀

✨ SYNOPSIS ✨

int cpc_write_ffh (int cpunum , struct cpc_reg *reg , u64 val );

like, that's the whole vibe: you give it a CPU number, a register, and a value, and it hands you back an int. slay 💅

🌸 ARGUMENTS 🌸

  • cpunum — the CPU number you're writing to, periodt. that's the one. 👑
  • reg — the cppc register information, aka the deets about which register we're messing with.
  • val — the value to write. literally just the value. no cap. ✨

🦋 DESCRIPTION 🦋

so what does it actually do? it writes a value of bit_width bits to a specified address and bit_offset. that's it, that's the whole thing — you point it at an address, you give it an offset, and it drops bit_width bits of your value in there. it's giving surgical precision 💖

⭐ RETURN ⭐

0 for success, and an error code if it's not. so yeah, check your return value, bestie, don't just ghost it 😭

🎀 SEE ALSO 🎀

the kernel file lives at ./drivers/acpi/cppc_acpi.c — iconic. and here's the whole friend group, all of them (9):

💀 real talk: there's a cpc_read_ffh(9) too, so if you're the reading type, go say hi. this page is the writing one. don't mix 'em up 🫶

and that's the page, bestie! it lives under ./drivers/acpi, dated October 2026, from the cpc_write_ffh(9) manual. go forth and write those FFH registers 💜✨🍓

📦 where this page comes from