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| -rw-r--r-- | Documentation/i2c/writing-clients | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/Documentation/i2c/writing-clients b/Documentation/i2c/writing-clients index 54255fd68ec..e62fbfa1282 100644 --- a/Documentation/i2c/writing-clients +++ b/Documentation/i2c/writing-clients @@ -200,6 +200,44 @@ device typing support in the hardware. The driver and module name should match, so hotplug/coldplug mechanisms will modprobe the driver. +Device Creation (Standard driver model) +--------------------------------------- + +If you know for a fact that an I2C device is connected to a given I2C bus, +you can instantiate that device by simply filling an i2c_board_info +structure with the device address and driver name, and calling +i2c_new_device(). This will create the device, then the driver core will +take care of finding the right driver and will call its probe() method. +If a driver supports different device types, you can specify the type you +want using the type field. You can also specify an IRQ and platform data +if needed. + +Sometimes you know that a device is connected to a given I2C bus, but you +don't know the exact address it uses. This happens on TV adapters for +example, where the same driver supports dozens of slightly different +models, and I2C device addresses change from one model to the next. In +that case, you can use the i2c_new_probed_device() variant, which is +similar to i2c_new_device(), except that it takes an additional list of +possible I2C addresses to probe. A device is created for the first +responsive address in the list. If you expect more than one device to be +present in the address range, simply call i2c_new_probed_device() that +many times. + +The call to i2c_new_device() or i2c_new_probed_device() typically happens +in the I2C bus driver. You may want to save the returned i2c_client +reference for later use. + + +Device Deletion (Standard driver model) +--------------------------------------- + +Each I2C device which has been created using i2c_new_device() or +i2c_new_probed_device() can be unregistered by calling +i2c_unregister_device(). If you don't call it explicitly, it will be +called automatically before the underlying I2C bus itself is removed, as a +device can't survive its parent in the device driver model. + + Legacy Driver Binding Model --------------------------- |