i2c_find_device_by_fwnode(9)

💜 i2c_find_device_by_fwnode ✨

okay bestie, so this is a page from the Kernel API Manual (yes, the Kernel API Manual, we're in the big leagues now 🫶), and it's all about one very specific little lookup function. it's short, it's sweet, and it's lowkey important. let's get into it 💅

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🌸 NAME 🌸

i2c_find_device_by_fwnode — find an i2c_client for the fwnode. that's it. that's the whole vibe. 🎀

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⭐ SYNOPSIS ⭐

struct i2c_client * i2c_find_device_by_fwnode (struct fwnode_handle
*fwnode );

like, you hand it a fwnode, it hands you back a struct i2c_client *. classic trade, no cap 🤝

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🦋 ARGUMENTS 🦋

• fwnode — the struct fwnode_handle that corresponds to the struct i2c_client you're chasing. this is your little "hey, this firmware node right here, that's the one" receipt 🧾✨

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💖 DESCRIPTION 💖

so what does it do? it looks up the struct i2c_client that corresponds to fwnode, and returns it. that's the main character move 🌟

and here's the fine print, because of course there's fine print:

• if no client can be found, it returns NULL 🫠
• if fwnode is NULL, it also returns NULL — so yeah, null in, null out, no drama, no crash 🙈

⚠️ important bestie!! the user must call put_device(client->dev) once you're done with the i2c client. this is not optional, this is not a suggestion, this is the rules. forget it and you're leaking, and not in the cute way 😭 please release your device. periodt 💅

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👑 SEE ALSO 👑

the kernel file lives at ./drivers/i2c/i2c-core-base.c — that's home base 🏠

and here's the whole friend group, enjoy the roll call 🎉:

• i2c_verify_client(9)
• i2c_adapter_lock_bus(9)
• i2c_adapter_trylock_bus(9)
• i2c_adapter_unlock_bus(9)
• i2c_new_client_device(9)
• i2c_unregister_device(9)
• i2c_new_dummy_device(9)
• devm_i2c_new_dummy_device(9)
• i2c_new_ancillary_device(9)
• i2c_verify_adapter(9)
• i2c_handle_smbus_host_notify(9)
• i2c_add_adapter(9)
• i2c_add_numbered_adapter(9)
• i2c_del_adapter(9)
• devm_i2c_add_adapter(9)
• i2c_find_adapter_by_fwnode(9)
• i2c_get_adapter_by_fwnode(9)
• i2c_parse_fw_timings(9)
• i2c_del_driver(9)
• __i2c_transfer(9)
• i2c_transfer(9)
• i2c_transfer_buffer_flags(9)
• i2c_get_device_id(9)
• i2c_client_get_device_id(9)
• i2c_get_dma_safe_msg_buf(9)
• i2c_put_dma_safe_msg_buf(9)

like, the whole i2c extended universe, fr fr 🌈

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aaaand that's the page!! 💜 this one came from ./drivers/i2c, dated October 2026, and it's filed under i2c_find_device_by_fwnode(9). go forth and remember your put_device() bestie, i'm rooting for you 🫶🎀✨