On Friday 16 of August 2013 10:56:32 Sascha Hauer wrote: > On Fri, Aug 16, 2013 at 04:01:25PM +0800, Nicolin Chen wrote: > > Hi Sascha, > > > > Thank you for the detailed comments. > > > > On Fri, Aug 16, 2013 at 09:08:18AM +0200, Sascha Hauer wrote: > > > Which of them the driver should use is configuration and thus > > > normally > > > should *not* be described in the devicetree. However, there may be > > > no > > > good way for the driver to know which clock to use in which case. > > > There > > > may be additional board requirements which are unknown to the > > > driver. So in this case it might be valid to put the information > > > which clock to use into the devicetree. But be aware that from the > > > moment you put this information into the devicetree the driver is > > > no longer free to chose the best clock, even if in future we find a > > > good way to automatically guess the best clock. Do you have some > > > insights in which case I would use which input clock? Is this only > > > about which clock has the best suitable input frequency or is this > > > also about synchronization of the audio signal with some other > > > unit? > > > > I understand. What I'm thinking now is to let the driver find the best > > clock source for tx clock and a correspond divisor like this: > > > > "tx<0-8>" Optional Tx clock source for spdif playback. > > > > If absent, will use core clock. > > The index from 0 to 8 is identical > > to the clock source list described > > in TxClk_Source bit of register STC. > > Multiple clock source are allowed > > for this tx clock source. The driver > > will select one source from them for > > each supported sample rate according > > to the clock rates of these provided > > clock sources. > > You mean tx<0-7>. > > Also I would make this option required. Use a dummy clock for mux inputs > that are grounded for a specific SoC.
Why do you need a dummy clock? The driver can simply try to grab all the possible clocks and discard those that failed, so you can just keep those grounded clocks unspecified. Best regards, Tomasz _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
