Benjamin, On Mittwoch, 24. September 2008, Benjamin Herrenschmidt wrote: > On Wed, 2008-09-24 at 12:15 -0600, Grant Likely wrote: > > On Wed, Sep 24, 2008 at 05:16:34PM +0200, Juergen Beisert wrote: > > > On Dienstag, 23. September 2008, Juergen Beisert wrote: > > > > What Kernel do you run on your target? On my hardware a 2.6.23 still > > > > work as expected, but a 2.6.26 fails all the time. > > > > > > One should enable the internal USB clock. If done, it works... In > > > 2.6.23 is was done in mpc52xx_common.c. It was removed in 2.6.24. > > > > It was removed because some 5200 platform do not use USB and should not > > enable the internal clock. In general, it is not the kernel's job to > > configure clocking and pin usage on the chip. Instead, it should be set > > correctly at power up by U-Boot. > > Or by the USB host driver :-)
But how to deal with platform specific things like (in this case) unknown external clock or usage of the internal clock generator (= how to setup the frequency divider)? > > However, if firmware *cannot* be changed, there is a workaround. > > You can create a new platform specific board support file in > > arch/powerpc/platforms/52xx/ that matches against your specific board > > and performs the needed fixups. An example of this is lite5200.c. Many > > lite5200 boards have older versions of U-Boot installed which does not > > correctly configure clocks or port-config. So, lite5200.c matches to > > the board instead of mpc5200_simple.c so that the board specific fixups > > can be performed easily. You should do the same for your board. > > I tend to thing that drivers should deal with their own clocks. ACK. But only to switch them on and off. Not to configure them. > In fact it would be nice if one could stop the clocks while the host port is > in suspend no ? ACK. Juergen -- Dipl.-Ing. Juergen Beisert | http://www.pengutronix.de Pengutronix - Linux Solutions for Science and Industry Handelsregister: Amtsgericht Hildesheim, HRA 2686 Vertretung Sued/Muenchen, Germany Phone: +49-8766-939 228 | Fax: +49-5121-206917-9 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
