On Fri, Mar 02, 2012 at 10:15:11AM +0100, Simon Guinot wrote: > Hi Jason, > > On Thu, Mar 01, 2012 at 06:20:55PM +0000, Jason Cooper wrote: > > Converted register address to a variable so that it could be set from > > fdt. Also, pull clock frequency from fdt and clean up failure logic a > > bit. > > > > Same as rtc-mv, this device is used in all kirkwood boards. So, it is > > placed in kirkwood.dtsi. > > > > Signed-off-by: Jason Cooper <ja...@lakedaemon.net> > > --- > > arch/arm/boot/dts/kirkwood.dtsi | 6 +++++ > > arch/arm/mach-kirkwood/board-dt.c | 1 - > > arch/arm/mach-kirkwood/common.c | 2 +- > > arch/arm/mach-kirkwood/common.h | 1 - > > drivers/watchdog/orion_wdt.c | 44 > > ++++++++++++++++++++++++++---------- > > 5 files changed, 39 insertions(+), 15 deletions(-) > > > > diff --git a/arch/arm/boot/dts/kirkwood.dtsi > > b/arch/arm/boot/dts/kirkwood.dtsi > > index 5fb185c..bf28424 100644 > > --- a/arch/arm/boot/dts/kirkwood.dtsi > > +++ b/arch/arm/boot/dts/kirkwood.dtsi > > @@ -8,5 +8,11 @@ > > reg = <0xf1010300 0x1f>; > > interrupts = <53>; > > }; > > + > > + wdt@fed20300 { > > + compatible = "marvell,orion-wdt"; > > + reg = <0xfed20300 0x28>; > > + clock-frequency = <200000000>; > > + }; > > How this will work for boards using a different clock frequency (TCLK) ? > Here, we could have 166MHz for example. > > Can this node be updated during the board initialization with a detected > TCLK value ? > > Or maybe this clock-frequency can reference a TCLK frequency defined in > a board specific dts (I don't know if the DT format allow such things) ?
Grr... good catch. I originally had this in kirkwood-dreamplug.dts, which is always 200000000. That's not the case in kirkwood.dtsi. What I would like to do, and I haven't had time to look into it (I thought I would tackle it later as a refinement :-( ), is a reference of some sort, eg: in kirkwood.dtsi: / { compatible = "marvell,kirkwood"; tclk:clock-frequency = <200000000>; wdt@fed20300 { compatible = "marvell,orion-wdt"; reg = <0xfed20300 0x28>; clock-frequency = &tclk; }; }; then, in kirkwood-foobar.dts /include/ "kirkwood.dtsi" / { model = "foobar"; compatible = "..."; tclk:clock-frequency = <166000000>; }; but I'm not sure if that would work. In any case, the simplest answer is to set clock-frequency in kirkwood-dreamplug.dts as a root node property, and then each driver that needs tclk, requests the clock-frequency from the root node. Hopefully, Grant can chime in on this one. Thanks for the review, Jason. _______________________________________________ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss