dfll_request_rate(9)

📦 version 7.3.1, in nixpkgs unstable

💅 dfll_request_rate — ok so this is the glow-up page for setting the DFLL's next rate 💅

Welcome to the Kernel API Manual, bestie 🎀 — this little page is all about dfll_request_rate, and honestly? It's giving "tell the clock what vibe we're going for next." Let's go ✨

🌸 NAME 🌸

dfll_request_rate — set the next rate for the DFLL to tune to 🎯

✨ SYNOPSIS ✨

int dfll_request_rate (struct tegra_dfll *td , unsigned long rate );

🫶 ARGUMENTS 🫶

  • td — the DFLL instance, like, the specific one you're talking to 💖
  • rate — the clock rate you want to target, iykyk 🌈

🔥 DESCRIPTION 🔥

So what this does is take the requested clock rate rate and convert it into the DFLL control logic settings. Literally translating your dreams into registers 💅

Here's the tea on the two modes:

  • If you're in closed-loop mode, it'll update the new settings immediately so the DFLL output rate adjusts accordingly — instant main character energy ✨
  • Otherwise, it just saves them and chills until the next switch to closed loop 💤

Return values, no cap:

  • 0 upon success — slay 🎉
  • -EPERM if the DFLL driver has not yet been initialized — rude, but okay 😭
  • -EINVAL if rate is outside the DFLL's tunable range — bestie that rate is not it 🙈

👑 SEE ALSO 👑

Kernel file ./drivers/clk/tegra/clk-dfll.c plus this whole friend group:

💀 Friendly reminder bestie: -EINVAL means your rate was out of range, and -EPERM means the driver wasn't initialized yet. Check those before you spiral 🫶

And that's the whole page, periodt 🧚 This one lives down in ./drivers/clk/tegra, dated October 2026 — go drink some water and go touch a clock tree 💜💖✨

📦 where this page comes from