On 11/19/07, Timur Tabi <[EMAIL PROTECTED]> wrote: > Jon Smirl wrote: > > > In the ALSA SOC model the i2s, codec and ac97 drivers are all generic. > > A fabric driver tells specifically how a generic codec is wired into > > the board. What I haven't been able figure out is how to load the > > right fabric driver. > > Do not use the device tree to load the fabric driver!
Heh, technically you can't use the device tree to load any device drivers, it's just a data structure. :-) You probably mean "don't use the of_platform bus to load the fabric driver". He still needs to use the data in the device tree to decide what fabric drivers to use. of_platform_bus would be awkward to use for this because the node describing the fabric doesn't cleanly sit on any particular bus (ie. it describes the board; it does not describe the device). In this case; it probably is appropriate to have the platform code instantiate a platform_device for the fabric (instead of an of_platform device) which the fabric driver can bind against. Another option is to explicitly call of_platform_device_create in the platform code on the fabric node (which should be a child of the root node) so that you can have an of_platform_bus fabric driver. Cheers, g. > > The layout of the hardware and the relationship between the I2S, I2C, codec, > and whatever device is determined by *both* the fabric driver and the device > tree. The information about the devices itself, and *some* information about > their relationship is stored in the device tree. Everything else is in the > fabric driver. > > The design of the device tree is already locked in stone, so to speak. The DT > can only store what it is allowed to store. If there's something more that > you need, you'll have to put it in the fabric driver. > > If I weren't on vacation this week, I'd email you my code. It's almost done > and it demonstrates what I'm thinking. > > -- > Timur Tabi > Linux Kernel Developer @ Freescale > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@ozlabs.org > https://ozlabs.org/mailman/listinfo/linuxppc-dev > -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd. [EMAIL PROTECTED] (403) 399-0195 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
