Question about fixed-clock

Fabio Estevam
2013-02-19T01:33:48Z

Hi Daniel,

On Mon, Feb 18, 2013 at 8:55 PM, Daniel Mack <zonque@gmail.com> wrote:
> Hi,
>
> This might be a stupid question, but I'm somehow stuck here. I'm using a
> driver with the following DTS sub-node:
>
> ref25: ref25M {
> compatible = "fixed-clock";
> #clock-cells = <0>;
> clock-frequency = <25000000>;
> };
>
> clock-generator at 0 {
> /* ... */
> #clock-cells = <1>;
> clocks = <&ref25>;
> }
>
> The device driver for clock-generator uses something like the following
> call to get its clock:
>
> clk = of_clk_get(np, 0);
>
> but the return value is ERR_PTR(-ENOENT) and I also can't find this
> clock in the clk debugfs tree.
>
> This is on a OMAP/AM33xx device with kernel 3.8-rc7 plus the -next tips
> of arm-soc and omap, but with no other special clock options selected in
> the config. Is there anything I'm missing to correctly instantiate the
> dummy clock?

Have you registered it with clk_register_fixed_rate() ?

In imx we use imx_clk_fixed, which in turns call clk_register_fixed_rate().

Take a look at arch/arm/mach-imx/clk-imx51-imx53.c for a reference.