STRUCT I2C_BOARD_INFO(9)

🌸 NAME 🌸

okay so this is the struct i2c_board_info(9) page from the Kernel API Manual — and it’s literally the template for device creation, bestie. 🫶

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✨ SYNOPSIS ✨

here’s the struct in all its main-character glory:

       struct i2c_board_info {
           char type[I2C_NAME_SIZE];
           unsigned short  flags;
           unsigned short  addr;
           const char      *dev_name;
           void *platform_data;
           struct fwnode_handle *fwnode;
           const struct software_node *swnode;
           const struct resource *resources;
           unsigned int    num_resources;
           int irq;
        };

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🫶 Members 🫶

• type — chip type, to initialize i2c_client.name
• flags — to initialize i2c_client.flags
• addr — stored in i2c_client.addr
• dev_name — overrides the default <busnr>-<addr> dev_name if it’s set
• platform_data — stored in i2c_client.dev.platform_data
• fwnode — device node supplied by the platform firmware
• swnode — software node for the device
• resources — resources associated with the device
• num_resources — number of resources in the resources array
• irq — stored in i2c_client.irq

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💅 Description 💅

no cap, I2C doesn't actually support hardware probing, although controllers and devices may be able to use I2C_SMBUS_QUICK to tell whether or not there’s a device at a given address. 😭 Drivers commonly need more information than that, such as chip type, configuration, associated IRQ, and so on.

i2c_board_info is used to build tables of information listing I2C devices that are present. This information is used to grow the driver model tree. 🌱

For mainboards this is done statically using i2c_register_board_info; bus numbers identify adapters that aren't yet available. For add-on boards, i2c_new_client_device does this dynamically with the adapter already known. slay. 👑

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🌈 SEE ALSO 🌈

• Kernel file ./include/linux/i2c.h
• i2c_master_recv(9)
• i2c_master_recv_dmasafe(9)
• i2c_master_send(9)
• i2c_master_send_dmasafe(9)
• struct i2c_device_identity(9)
• enum i2c_driver_flags(9)
• struct i2c_driver(9)
• struct i2c_client(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)

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mwah 💋 — this cutie came from ./include/linux, dated October 2026, and the footer still whispers struct i2c_board_info(9). periodt. 🎀