On 03/22/2013 04:41 PM, Sören Brinkmann wrote: > Hi Lars, > > On Thu, Mar 21, 2013 at 07:32:52PM +0100, Lars-Peter Clausen wrote: >> On 03/21/2013 12:56 AM, Sören Brinkmann wrote: >>> Hi, >>> >>> I spent some time working on this and incorporating feedback. Here's an >>> updated proposal for a clock controller for Zynq: >>> >>> Required properties: >>> - #clock-cells : Must be 1 >>> - compatible : "xlnx,ps7-clkc" (this may become 'xlnx,zynq-clkc' >>> terminology differs a bit between Xilinx internal and mainline) >>> - ps-clk-frequency : Frequency of the oscillator providing ps_clk in HZ >>> (usually 33 MHz oscillators are used for Zynq >>> platforms) >>> - clock-output-names : List of strings used to name the clock outputs. >>> Shall be a list of the outputs given below. >>> >>> Optional properties: >>> - clocks : as described in the clock bindings >>> - clock-names : as described in the clock bindings >>> >>> Clock inputs: >>> The following strings are optional parameters to the 'clock-names' property >>> in >>> order to provide optional (E)MIO clock sources. >>> - swdt_ext_clk >>> - gem0_emio_clk >>> - gem1_emio_clk >>> - mio_clk_XX # with XX = 00..53 >>> >>> Example: >>> clkc: clkc { >>> #clock-cells = <1>; >>> compatible = "xlnx,ps7-clkc"; >>> ps-clk-frequency = <33333333>; >> >> The input frequency should be a clock as well. > > Again, monolithic vs split. I don't see a reason not to just internally > call clk_register_fixed_rate(). That way its children do not have to > cope with a variable name for the xtal. > Also, with my proposal 'clocks' and 'clock-names' would be purely > optional properties, only required if optional external inputs are > present. Having the xtal defined externally would add mandatory entries for > those props.
But isn't the clock source board-specific? It's a completely separate object from Zynq's own clock controller HW, and as such should be represented by a separate DT node, right? The issue with parent clock names is simply a red herring. A solution is needed to registered clock with a parent clock object, rather than a parent clock name. Then, the parent names are completely irrelevant. _______________________________________________ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss