On 11/12/19 7:42 PM, Drew Fustini wrote:
> On Tue, Nov 12, 2019 at 12:44 AM Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> wrote:
>> Can you send the output of
>>
>> cat /sys/kernel/debug/clk/clk_summary
>>
>> Once before loading the module and once after loading it.
>
> I moved the target for the mcp2515 clock from 'target-path = "/";' to
> 'target = <&scm_clocks>;' and 'clk_get_rate(clk) now returns 16MHz:
\o/ yeay \o/
> fragment@4 {
> target = <&scm_clocks>;
> __overlay__ {
> mcp2515_clock: mcp2515_clock {
> compatible = "fixed-clock";
> #clock-cells = <0>;
> clock-frequency = <16000000>;
> };
> };
> };
>
> Here is the current overlay:
> https://gist.github.com/pdp7/56174646bb9d075b041f24de2bb01973
>
> dmesg shows it is working correctly:
> [ 60.089957] mcp251x_can_probe: clk_get_rate(clk)=16000000
>
> I guess the issue was I targeting the wrong node for the clock to be
> found with clk_get_rate().
I should definitely learn something about DT overlays. I just used
ready-to-use raspi mcp2515 overlay.
> Here is the clk_summary with it working correctly:
>
> debian@beaglebone:/opt/source/bb.org-overlays$ cat
> /sys/kernel/debug/clk/clk_summary
> clock enable_cnt prepare_cnt rate
> accuracy phase
> ----------------------------------------------------------------------------------------
> mcp2515_clock 1 1 16000000
> 0 0
This is after module loading?
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
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