On 2/8/07, Juergen Beisert <[EMAIL PROTECTED]> wrote: > Hi all, > > currently I am writing an SPI driver for a PSC unit.
Cool; that would be useful! :) I look forward to seeing it. > To calculate the baudrate > this unit should use I need the fsystem frequence (fsystem is the used name > in the datasheet). Is there a generic way (API) to read back this clock? > > For the IPB clock I found mpc52xx_find_ipb_freq() from the open firmware > framework. Is there something similar for the fsystem clock? Hmmm, yeah... Sylvain brought this up a while ago. We currently don't have that information in the device tree definition; but it is needed. I need to add a new device tree property; probably 'system-frequency' in the soc node. It is also possible to derive fsystem from the /soc5200/bus-frequency by interpreting the registers; but i think that's rather ugly. I'm working on the device tree bindings at the moment. I'll add in a property for the system frequency and post the patch for comments. Once that's defined, it's trivial to add a function to return the system frequency. Cheers, g. -- Grant Likely, B.Sc. P.Eng. Secret Lab Technologies Ltd. [EMAIL PROTECTED] (403) 399-0195 _______________________________________________ Linuxppc-embedded mailing list [email protected] https://ozlabs.org/mailman/listinfo/linuxppc-embedded
