i3c_i2c_driver_register(9)

💜 i3c_i2c_driver_register(9) — Kernel API Manual ✨

okay so bestie, we're in the Linux kernel API manual and this one is literally the "get both of your drivers registered at once" function. no cap. 🫶

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🌸 NAME 🌸

i3c_i2c_driver_register — register an i2c and an i3c driver, together, like a little duo 💅

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✨ SYNOPSIS ✨

int i3c_i2c_driver_register (struct i3c_driver *i3cdrv , struct
       i2c_driver *i2cdrv );

two pointers, one function call, both drivers signed up. iconic behavior honestly.

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🎀 ARGUMENTS 🎀

• i3cdrv — the I3C driver to register. this is the I3C side of the situation 🦋
• i2cdrv — the I2C driver to register. and this is the I2C side 🌸

both of them, bestie. you don't get to pick just one.

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🌈 DESCRIPTION 🌈

so what this does is it registers both i2cdev and i3cdev in one go — and (this is the important part, don't skip it 👀) it fails if one of these registrations fails. so if one of them goes off the rails, the whole call is like nope, we're not doing this 💀

it's mainly useful for devices that support both I2C and I3C modes. you know, the dual-mode girlies. main character energy, both modes, one function 🎀

also!! quick caveat, don't miss this: when CONFIG_I3C is not enabled, this function only registers the I2C driver. that's just how it is, fr fr 🧚

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⭐ RETURN ⭐

0 if both registrations succeed — slay, we love a clean zero 🥳

a negative error code otherwise. yeah. iconique of the error handling.

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💖 SEE ALSO 💖

kicking off with the kernel file ./include/linux/i3c/device.h, and then the whole friend group:

• enum i3c_error_code(9)
• enum i3c_xfer_mode(9)
• struct i3c_xfer(9)
• enum i3c_dcr(9)
• struct i3c_device_info(9)
• struct i3c_driver(9)
• dev_to_i3cdev(9)
• module_i3c_driver(9)
• i3c_i2c_driver_unregister(9)
• module_i3c_i2c_driver(9)
• struct i3c_ibi_setup(9)

go read them, iykyk 📚🦋

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💡 and if you register, you better also know about i3c_i2c_driver_unregister(9) — cleanup is self care, periodt 🌸

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okay that's the whole page bestie, no notes 💅

signing off from ./include/linux/i3c, dated October 2026 — that's the source and the date, and i3c_i2c_driver_register(9) is the whole vibe 🫶✨🎀