Re: [PATCH v4 8/9] mips: ralink: get cpu rate from new driver code

From: Sergio Paracuellos
Date: Sat Jun 17 2023 - 11:35:44 EST


On Sat, Jun 17, 2023 at 4:48 PM Krzysztof Kozlowski
<krzysztof.kozlowski@xxxxxxxxxx> wrote:
>
> On 17/06/2023 07:24, Sergio Paracuellos wrote:
> > At very early stage on boot, there is a need to set 'mips_hpt_frequency'.
> > This timer frequency is a half of the CPU frequency. To get clocks properly
> > set we need to call to 'of_clk_init()' and properly get cpu clock frequency
> > afterwards. Depending on the SoC, CPU clock index in the clock provider is
> > different being two for MT7620 SoC and one for the rest. Hence, adapt code
> > to be aligned with new clock driver.
>
>
> > void __init plat_time_init(void)
> > {
> > + struct of_phandle_args clkspec;
> > struct clk *clk;
> > + int cpu_clk_idx;
> >
> > ralink_of_remap();
> >
> > - ralink_clk_init();
> > - clk = clk_get_sys("cpu", NULL);
> > + cpu_clk_idx = clk_cpu_index();
> > + if (cpu_clk_idx == -1)
> > + panic("unable to get CPU clock index");
> > +
> > + of_clk_init(NULL);
> > + clkspec.np = of_find_node_by_name(NULL, "sysc");
> > + clkspec.args_count = 1;
> > + clkspec.args[0] = cpu_clk_idx;
> > + clk = of_clk_get_from_provider(&clkspec);
>
> This is very obfuscated way of getting clock. Why can't you get it from
> "clocks" property of "cpu", like every other recent platform?

I did not find any other approach that works for me. So I ended up in this one.
Can you point me out in a sample of code doing the same so I can check
if it works for me then?

>
> Anyway, NAK for of_find_node_by_name(), because you now create ABI for
> node name. It's broken approach.

I will change whatever is needed to provide a valid approach. Please,
point me out in the right direction.

>
> Best regards,
> Krzysztof
>

Thanks in advance for your time.

Best regards,
Sergio Paracuellos