comedi_alloc_subdevices(9)

✨ NAME ✨

comedi_alloc_subdevices — this is the Kernel API Manual page for it, and it's literally the function that allocates subdevices for a COMEDI device 🎀

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🌸 SYNOPSIS 🌸

int comedi_alloc_subdevices (struct comedi_device *dev , int num_subdevices );

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💅 ARGUMENTS 💅

• dev — your COMEDI device. like, the actual device struct you're handing over, bestie 🫶
• num_subdevices — how many subdevices you want to allocate. that's the number. that's the whole vibe ✨

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👑 DESCRIPTION 👑

Okay so picture this: comedi_alloc_subdevices allocates and initializes an array of struct comedi_subdevice for the COMEDI device. Both. It's an overachiever, we love that for it 💖

If it works, it sets dev->subdevices to point to the first one in the array, and it sets dev->n_subdevices to the number. Chef's kiss, everything wired up 🔥

Now the return values, because we must discuss:

• Returns 0 on success — slay, no notes 👑
• Returns -EINVAL if num_subdevices is < 1 — like, bestie, you can't ask for zero or negative subdevices, that's not a thing 🙈
• Returns -ENOMEM if it failed to allocate the memory — the allocation simply did not eat 💀

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🦋 SEE ALSO 🦋

Kernel file ./drivers/comedi/drivers.c — that's where the actual source lives, iykyk 📁

And the whole friend group, fr fr:

• comedi_set_hw_dev(9)
• comedi_alloc_devpriv(9)
• comedi_alloc_subdev_readback(9)
• comedi_readback_insn_read(9)
• comedi_timeout(9)
• comedi_dio_insn_config(9)
• comedi_dio_update_state(9)
• comedi_bytes_per_scan_cmd(9)
• comedi_bytes_per_scan(9)
• comedi_nscans_left(9)
• comedi_nsamples_left(9)
• comedi_inc_scan_progress(9)
• comedi_handle_events(9)
• comedi_load_firmware(9)
• __comedi_check_request_region(9)
• comedi_check_request_region(9)
• comedi_legacy_detach(9)
• comedi_auto_config(9)
• comedi_auto_unconfig(9)
• comedi_driver_register(9)
• comedi_driver_unregister(9)

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and that's the page, bestie!! 🌈 it comes to you from ./drivers/comedi and it's dated October 2026 — go forth and allocate your subdevices responsibly ✨🧚💜