i2c_smbus_read_block_data(9)

💖 i2c_smbus_read_block_data(9) 💖

okay bestie, welcome to the Kernel API Manual page for i2c_smbus_read_block_data(9) — this is the SMBus “block read” protocol and it is lowkey iconic 💅✨

🌸 NAME 🌸

i2c_smbus_read_block_data — SMBus “block read” protocol 🎀

✨ SYNOPSIS ✨

s32 i2c_smbus_read_block_data (const struct i2c_client *client , u8
command , u8 *values );

🦋 ARGUMENTS 🦋

• client — handle to the slave device 🫶
• command — the byte that gets interpreted by the slave 💌
• values — byte array into which data will be read; it needs to be big enough to hold the data returned by the slave. SMBus allows at most 32 bytes, no cap 🧚

👑 DESCRIPTION 👑

This executes the SMBus “block read” protocol, returning negative errno else the number of data bytes in the slave’s response. literally that’s the whole vibe ✨

⚠️ caveat bestie: using this function requires that the client’s adapter support the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers support this; its emulation through I2C messaging relies on a specific mechanism (I2C_M_RECV_LEN) which may not be implemented. so yeah, check before you ship it 💀

🌈 SEE ALSO 🌈

• Kernel file ./drivers/i2c/i2c-core-smbus.c
• i2c_smbus_pec(9)
• i2c_smbus_read_byte(9)
• i2c_smbus_write_byte(9)
• i2c_smbus_read_byte_data(9)
• i2c_smbus_write_byte_data(9)
• i2c_smbus_read_word_data(9)
• i2c_smbus_write_word_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)

mwah 💋 this cutie came from ./drivers/i2c, dated October 2026 🎀