On Fri, Jul 30, 2010 at 12:44 PM, Marek Vasut wrote: > Dne Čt 29. července 2010 12:00:41 Wookey napsal(a): >> +++ Marek Vasut [2010-07-29 05:16 +0200]: >> > Add supported for PCF8574A GPIO expander and LEDs attached to it. >> >> This IO board is an add-on used in some ballon configurations, not >> part of the core board. There needs to be some way of selecting this >> support when the loon is used in this configuration. We have the >> balloon_has() macro which is used for dealing with the different >> builds of the board itself. Perhaps it should be extended to deal with >> add-on board functionality too? >> >> More obvious is using the CONFIG system to just enable this if >> CUED_IO_BOARD is configured. > > You can just disable the PCF driver if you want to save space. In case you won't > have the CUED board connected, the driver will just fail to probe so it's ok I > believe. > > The macro could be extended, but do we want such a weird stuff in kernel? > (especially if the driver can simply fail to probe). Are we able to detect this expansion board at run-time and registers i2c/led-gpio if present. The thing I'm worried more on space is the gpio_leds will be registered there even without the expansion board, but what if someone tries to read/write to those LED controls? >> >> Wookey > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >