component_add_typed(9)

📦 version 7.3.1, in nixpkgs unstable

💅 component_add_typed(9) 💅

okay so this is a page straight out of the Kernel API Manual — component_add_typed(9), bestie. yes it's a mouthful, no we're not skipping it, it's actually kind of iconic once you get it. 🎀

✨ NAME ✨

component_add_typed — register a component. that's it, that's the whole vibe check. 🦋

✨ SYNOPSIS ✨

int component_add_typed (struct device *dev , const struct component_ops
*ops , int subcomponent );

like, look at that signature. three args, one int coming back at you. we love a return value that tells us how it went. 💜

✨ ARGUMENTS ✨

  • dev — the component device. the whole main character of this call, honestly. 👑
  • ops — the component callbacks. this is where all the little functions live, and they are not going to run yet (more on that below, keep reading, i promise it's good). 🫶
  • subcomponent — a nonzero identifier for subcomponents. nonzero!! do not pass zero, i'm so serious. 🙈

✨ DESCRIPTION ✨

okay so what this does is register a shiny new component for dev. and here's the tea: the functions sitting inside ops do not get called right away. nope. they get called later, when the aggregate driver is ready to bind the overall driver by calling component_bind_all. so think of it as dropping your callback functions off and being like "okay call me when it's time". also, see also struct component_ops. 📞

now about subcomponent — it must be nonzero, periodt. and the reason is kind of slay actually: it's how the kernel tells apart multiple components that are all registered on the same device dev. and these components are match using component_match_add_typed. that's the matching half of the equation, iykyk. 🧚

⚠️ important warning bestie: the component needs to be unregistered at driver unload/disconnect by calling component_del. do not leave it hanging. that's how you get leaks and sadness and a very grumpy kernel. no cap. 💀

also, see also component_add — the un-typed cousin of this function. family reunion. 🌈

✨ SEE ALSO ✨

and that's the whole page, bestie — you ate that. 💅✨🦋🌸💜

sign-off time: this little slice of kernel knowledge lives in ./drivers/base, and it's stamped October 2026, filed under component_add_typed(9). go register a component responsibly. mwah. 🎀⭐👑

📦 where this page comes from