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SubjectRe: [PATCH] clk: stm32h7: Add stm32h743 clock driver
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Hi Stephen

Sorry for delay i was on sick live

On 04/07/2017 09:51 PM, Stephen Boyd wrote:
> On 04/06, Gabriel Fernandez wrote:
>> On 04/06/2017 12:32 AM, Stephen Boyd wrote:
>>> On 03/15, gabriel.fernandez@st.com wrote:
>>>> diff --git a/Documentation/devicetree/bindings/clock/st,stm32h7-rcc.txt b/Documentation/devicetree/bindings/clock/st,stm32h7-rcc.txt
>>>> new file mode 100644
>>>> index 0000000..9d4b587
>>>> --- /dev/null
>>>> +++ b/Documentation/devicetree/bindings/clock/st,stm32h7-rcc.txt
>>>> @@ -0,0 +1,152 @@
>>>> +
>>>> + rcc: rcc@58024400 {
>>>> + #reset-cells = <1>;
>>>> + #clock-cells = <2>
>>>> + compatible = "st,stm32h743-rcc", "st,stm32-rcc";
>>>> + reg = <0x58024400 0x400>;
>>>> + clocks = <&clk_hse>, <&clk_lse>, <&clk_i2s_ckin>;
>>>> +
>>>> + st,syscfg = <&pwrcfg>;
>>>> +
>>>> + #address-cells = <1>;
>>>> + #size-cells = <0>;
>>>> +
>>>> + vco1@58024430 {
>>>> + #clock-cells = <0>;
>>>> + compatible = "stm32,pll";
>>>> + reg = <0>;
>>> reg is super confusing and doesn't match unit address.
>> ok i fixed it in the v2
>>
>>>> + };
>>> Why? Shouldn't we know this from the compatible string how many
>>> PLLs there are and where they're located? Export the PLLs through
>>> rcc node's clock-cells?
>>>
>> Because i need to offer the possibility to change the PLL VCO
>> frequencies at the start-up of this driver clock.
>> The VCO algorithm needs a division factor, a multiplication factor
>> and a fractional factor.
>> Lot's of solution are possible for one frequency and it's nightmare
>> to satisfy the 3 output dividers of the PLL.
> Sure, but do we need to configure that on a per-board basis or a
> per-SoC basis? If it's just some configuration, I wonder why we
> don't put that into the driver and base it off some compatible
> string that includes the SoC the device is for.
>
I prefer to let in first, the responsibility of the boot loader to
change VCO parameters.
Then i propose a new version without DT configuration of PLL's
are you ok for that ?

best regards

Gabriel



To simply


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