Re: [PATCH RESEND V2 1/3] clocksource/drivers/sysctr: Add optional clock-frequency property

From: Daniel Lezcano
Date: Thu Jun 27 2019 - 04:07:17 EST


On 27/06/2019 02:43, Anson Huang wrote:
> Hi, Daniel
>
>> On 26/06/2019 03:42, Anson Huang wrote:
>>> Hi, Daniel
>>>
>>>> On 23/06/2019 14:38, Anson.Huang@xxxxxxx wrote:
>>>>> From: Anson Huang <Anson.Huang@xxxxxxx>
>>>>>
>>>>> Systems which use platform driver model for clock driver require the
>>>>> clock frequency to be supplied via device tree when system counter
>>>>> driver is enabled.
>>>>>
>>>>> This is necessary as in the platform driver model the of_clk
>>>>> operations do not work correctly because system counter driver is
>>>>> initialized in early phase of system boot up, and clock driver using
>>>>> platform driver model is NOT ready at that time, it will cause
>>>>> system counter driver initialization failed.
>>>>>
>>>>> Add the optinal clock-frequency to the device tree bindings of the
>>>>> NXP system counter, so the frequency can be handed in and the of_clk
>>>>> operations can be skipped.
>>>>
>>>> Isn't it possible to create a fixed-clock and refer to it? So no need
>>>> to create a specific action before calling timer_of_init() ?
>>>>
>>>
>>> As the clock must be ready before the TIMER_OF_DECLARE, so adding a
>>> CLK_OF_DECLARE_DRIVER in clock driver to ONLY register a fixed-clock?
>>> The system counter's frequency are different on different platforms,
>>> so adding fixed clock in system counter driver is NOT a good idea,
>>> ONLY the DT node or the clock driver can create this fixed clock according to
>> platforms, can you advise where to create this fixed clock is better?
>>
>> Can you point me to a DT with the "nxp,sysctr-timer" ?
>
> The DT node of system counter is new added in 3/3 of this patch series, also can be found
> from below link:
> https://patchwork.kernel.org/patch/11011703/

Sorry, I was unclear. I meant a patch with the timer defined using a
clock as defined currently in the binding (no clock-frequency).


--
<http://www.linaro.org/> Linaro.org â Open source software for ARM SoCs

Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog