i2c_smbus_read_byte_data(9)

✨ i2c_smbus_read_byte_data ✨

okay bestie, this one's from the Kernel API Manual, section 9 — pull up a chair 🫶

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🌸 NAME 🌸

i2c_smbus_read_byte_data — the SMBus "read byte" protocol, and honestly? it's giving minimal icon energy 👑

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🦋 SYNOPSIS 🦋

s32 i2c_smbus_read_byte_data (const struct i2c_client *client , u8
command );

like, that's the whole vibe. two args, one function, zero drama ✨

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🎀 ARGUMENTS 🎀

• client — handle to the slave device 💅 this is your little connection to the thing you're talking to
• command — a byte that gets interpreted by the slave, iykyk 🔥 the device decides what it means

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💖 DESCRIPTION 💖

so what does it do? it executes the SMBus "read byte" protocol. that's it, that's the whole thing 🌈

it returns a negative errno — or, if you're lucky and everything slayed, a data byte received from the device 💫

no cap: if it comes back negative, that's an error, not a value. do not confuse them bestie 😭

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👑 SEE ALSO 👑

the kernel file lives at ./drivers/i2c/i2c-core-smbus.c — and here's the whole friend group 🧚:

• i2c_smbus_pec(9)
• i2c_smbus_read_byte(9)
• i2c_smbus_write_byte(9)
• i2c_smbus_write_byte_data(9)
• i2c_smbus_read_word_data(9)
• i2c_smbus_write_word_data(9)
• i2c_smbus_read_block_data(9)
• i2c_smbus_write_block_data(9)
• i2c_smbus_xfer(9)
• i2c_smbus_read_i2c_block_data_or_emulated(9)
• i2c_new_smbus_alert_device(9)

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okay that's the page!! source path ./drivers/i2c, dated October 2026, manual section 9 — mwah, go read some bytes bestie 💜🍓