[PATCH 2/8] clk: bcm2835: add missing PLL clock divider

Martin Sperl kernel at martin.sperl.org
Thu Mar 17 10:38:51 PDT 2016


> On 17.03.2016, at 17:57, Eric Anholt <eric at anholt.net> wrote:
> 
> 
> These don't exist on the hardware as far as I've been able to find.  "I
> found it in a header file somewhere" is not sufficient justification to
> expose it.
> 
> I'm working on getting a series of all of these reviewed and ready, so
> I'm just dropping these PLLB hunks.

Fine with that - my test shows that these are not configured by the firmware.

As for headers: my experience is that these are the better resource
compared to all the public available documentation…

If you remember the “frac” bit discussion where you said:

  Once again, trusting the docs turns out to be a bad idea.  You're right,
  the non-MASH clocks *do* have a bit 9 to enable fractional mode.  Sigh.

Also my understanding is that those headers are still used by the firmware
developers, so I guess that these are pretty stable and well maintained
(even if the ones available are by now a bit dated).

They even contain ifdefs for some earlier versions of the chip - 
see the dma-channels and their interrupts…
I.e: BCM2708A0 which does not have the DMA channels 9 to 15

So I would not discount all those pieces of information as totally
irrelevant.




More information about the linux-arm-kernel mailing list