devm_clk_bulk_get_optional(9)

📦 version 7.3.1, in nixpkgs unstable

💅 devm_clk_bulk_get_optional — from the Kernel API Manual, bestie ✨

okay so picture this: you're in the kernel, you've got a whole squad of clocks to grab, and some of them might literally not exist yet. that's the vibe this function was made for 🫶

🌸 NAME 🌸

devm_clk_bulk_get_optional — the managed way to get multiple optional consumer clocks. that's it, that's the whole name, periodt 💅

✨ SYNOPSIS ✨

int devm_clk_bulk_get_optional (struct device *dev , int num_clks ,
       struct clk_bulk_data *clks );

like, that's the whole signature. no cap. 🎀

🎯 ARGUMENTS 🎯

  • dev — the device that's acting as the clock "consumer". it's the one doing the consuming, main character energy 👑
  • num_clks — the number of clk_bulk_data. yes, it's a count. yes, it matters. don't skip it 🙈
  • clks — pointer to the clk_bulk_data table that belongs to the consumer. this is the whole squad of clocks, right here 🦋

💖 DESCRIPTION 💖

so it behaves exactly the same as devm_clk_bulk_get... except for the one iconic little twist: when there's no clock producer at all 🔥 in that exact case, instead of hitting you with -ENOENT, the function just returns NULL for the given clk. that's it, no drama, no error code, just NULL. the assumption baked in here is that all the clocks in clk_bulk_data are optional — every single one, so don't come at it with a required clock, that's not the assignment 💀

It returns 0 if all the clocks specified in the clk_bulk_data table are obtained successfully, or if for any clk there was no clk provider available at all. otherwise it returns a valid IS_ERR condition containing errno. so like, 0 = we're so back, IS_ERR = it's over 😭

the implementation uses dev and clk_bulk_data.id to determine the clock consumer, and thereby the clock producer. iykyk. and the clock that comes back is stored in each clk_bulk_data.clk field ⭐

🚨 Drivers must assume that the clock source is not enabled. like, do not assume it's already up and running. it is NOT. assume nothing, bestie.
🚨 Also: clk_bulk_get should not be called from within interrupt context. hard no. don't do it. 🙅‍♀️

🌈 SEE ALSO 🌈

Kernel file ./include/linux/clk.h — and honestly the whole clock extended family showed up for this one, so let's give them their moment:

and that's the page!! 🎀 this little beauty lives in ./include/linux, and it's stamped October 2026 — so like, future-dated and thriving ✨ mwah, go get those optional clocks bestie 💜

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