i2c_master_send_dmasafe(9)

💖 NAME 💖

okay so bestie, welcome to the Kernel API Manual glow-up of i2c_master_send_dmasafe — this function issues a single I2C message in master transmit mode using a DMA safe buffer. iconic behavior, no cap. 🦋

✨ SYNOPSIS ✨

int i2c_master_send_dmasafe (const struct i2c_client *client , const char *buf , int count );

🎀 ARGUMENTS 🎀

• client — handle to slave device — the whole point, your fave connection 💅
• buf — data that will be written to the slave, must be safe to use with DMA. yes, DMA safe, not just vibes safe 🫶
• count — how many bytes to write, must be less than 64k since msg.len is u16. keep it under 64k, periodt.

🌸 DESCRIPTION 🌸

it returns a negative errno, or else the number of bytes written. that's the whole tea: negative errno = error path, otherwise you get the byte count. 💖

🌈 SEE ALSO 🌈

the Kernel file is ./include/linux/i2c.h, and the whole bestie squad is:

• i2c_master_recv(9)
• i2c_master_recv_dmasafe(9)
• i2c_master_send(9)
• struct i2c_device_identity(9)
• enum i2c_driver_flags(9)
• struct i2c_driver(9)
• struct i2c_client(9)
• struct i2c_board_info(9)
• I2C_BOARD_INFO(9)
• struct i2c_algorithm(9)
• struct i2c_lock_operations(9)
• struct i2c_timings(9)
• struct i2c_bus_recovery_info(9)
• struct i2c_adapter_quirks(9)
• i2c_lock_bus(9)
• i2c_trylock_bus(9)
• i2c_unlock_bus(9)
• i2c_mark_adapter_suspended(9)
• i2c_mark_adapter_resumed(9)
• i2c_check_quirks(9)
• module_i2c_driver(9)
• builtin_i2c_driver(9)

k bye bestie 💅 this page's source/version is ./include/linux and the date is October 2026 — go slay your I2C DMA safe sends 🎀