On Wed, Feb 16, 2011 at 03:13:07AM -0500, Peter Korsgaard wrote: > >>>>> "Guenter" == Guenter Roeck <guenter.roeck@xxxxxxxxxxxx> writes: > > Guenter> Hi all, > > Guenter> I am trying to use the new GPIO based I2C > Guenter> multiplexer. Unfortunately, I have an initialization problem > Guenter> with it. > > Guenter> Some time after registering the multiplexer as platform driver, its > Guenter> probe function is called. Unfortunately, that does not happen in sync > Guenter> with I2C adapter initialization. The GPIO mux probe function is called > Guenter> before the parent's (ie the multiplexed I2C adapter) probe function is > Guenter> called. As a result, the GPIO mux driver does not find its parent i2c > Guenter> adapter, and the probe function aborts with an error. > > Guenter> Any idea how I I can fix the problem, ie how I can ensure that > Guenter> the GPIO mux probe function is only called after its parent > Guenter> I2C adapter is initialized ? > > What i2c bus controller are you using? Are you registering it's platform > data very late (E.G. after you register the platform data for gpiomux)? > > If you do register the platform data in the correct order, things SHOULD > work correctly as busses are listed in drivers/i2c/Makefile before > muxes, but alternatively you could play with the init order (E.G. use > subsys_initcall instead of module_init in the bus driver, see > b8680784875 for an example). > Turns out bus_register_notifier(&i2c_bus_type, &my_bus_notifier); is my friend here. Wait for the i2c adapter to be registered, which results in a notifier call. Then register the mux driver from the notifier function. Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
