path: root/drivers/i2c/i2c-core.h
AgeCommit message (Collapse)Author
2009-06-19i2c: Use rwsem instead of mutex for board infoRodolfo Giometti
By using rwsem we can easily manage recursive calls of i2c_scan_static_board_info() function without breaking the locking. Signed-off-by: Rodolfo Giometti <giometti@linux.it> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01i2c: Add i2c_board_info and i2c_new_device()David Brownell
This provides partial support for new-style I2C driver binding. It builds on "struct i2c_board_info" declarations that identify I2C devices on a given board. This is needed on systems with I2C devices that can't be fully probed and/or autoconfigured, such as many embedded Linux configurations where the way a given I2C device is wired may affect how it must be used. There are two models for declaring such devices: * LATE -- using a public function i2c_new_device(). This lets modules declare I2C devices found *AFTER* a given I2C adapter becomes available. For example, a PCI card could create adapters giving access to utility chips on that card, and this would be used to associate those chips with those adapters. * EARLY -- from arch_initcall() level code, using a non-exported function i2c_register_board_info(). This copies the declarations *BEFORE* such an i2c_adapter becomes available, arranging that i2c_new_device() will be called later when i2c-core registers the relevant i2c_adapter. For example, arch/.../.../board-*.c files would declare the I2C devices along with their platform data, and I2C devices would behave much like PNPACPI devices. (That is, both enumerate from board-specific tables.) To match the exported i2c_new_device(), the previously-private function i2c_unregister_device() is now exported. Pending later patches using these new APIs, this is effectively a NOP. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Jean Delvare <khali@linux-fr.org>