On 17/06/2023 17:35, Sergio Paracuellos wrote:
> 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?
You mean bindings?
git grep cpus.yaml
Driver?
git grep clk_get_rate
clk_get
eventually of_clk_get
It all depends on the context.
Anyway, it is very easy to find existing solutions not using
of_find_node_by_name for your platform:
git grep mips_hpt_frequency
First result.
Best regards,
Krzysztof
