[PATCH v2 1/5] dt-bindings: clock: add exynos8890 SoC
Ivaylo Ivanov Ivanov
ivo.ivanov.ivanov1 at gmail.com
Mon Jan 19 02:43:50 PST 2026
On 22.10.25 10:44, Krzysztof Kozlowski wrote:
> On Fri, Oct 17, 2025 at 07:13:29PM +0300, Ivaylo Ivanov wrote:
>> + - if:
>> + properties:
>> + compatible:
>> + contains:
>> + const: samsung,exynos8890-cmu-aud
>> +
>> + then:
>> + properties:
>> + clocks:
>> + items:
>> + - description: External reference clock (76.8 MHz)
>> + - description: CMU_AUD PLL clock (from CMU_TOP)
>> +
>> + clock-names:
>> + items:
>> + - const: oscclk
>> + - const: pll
>> +
>> + - if:
>> + properties:
>> + compatible:
>> + contains:
>> + const: samsung,exynos8890-cmu-bus0
>> +
>> + then:
>> + properties:
>> + clocks:
>> + items:
>> + - description: External reference clock (76.8 MHz)
>> + - description: CMU_BUS0 ACLK 528MHz clock (from CMU_TOP)
>> + - description: CMU_BUS0 ACLK 200MHz clock (from CMU_TOP)
>> + - description: CMU_BUS0 PCLK 132MHz clock (from CMU_TOP)
>> +
>> + clock-names:
>> + items:
>> + - const: oscclk
>> + - const: "528"
>> + - const: "200"
>> + - const: "132"
>
> We do not want the frequency here, for sure not frequency alone. There
> is no such code/syntax. Really. Please do not invent your own style.
> That's just pclk. You describe here the logical name of this clock
> input.
>
> ACLK is AXI bus clock, so if this block receives only one ACLK, then
> this is just "axi" or "bus". Recently we were calling this "bus".
>
> Same in other places. If two AXI bus clocks come in, they could be named
> bus0 and bus1, or in this case - because these are sources for
> generating further ACLKs - bus_528 and bus_200, to indicate that one
> will be for AXI bus clocked 528 MHz and other for 200 MHz.
>
> Please wait for some other opinions, because same rule I would like to
> apply to ExynosAuto, Artpec and Google GS.
>
> @Raghav Sharma, @Alim Akhtar, @Sam Protsenko, @Peter Griffin, @André
> Draszik - share your thoughs please?
>
> And to clarify in simple terms for others or for the future:
> 1. HCLK would be the AHB bus, so also bus. Both ACLK and HCLK are for
> memory accesses.
> 2. PCLK is APB bus, for registers.
> 3. SCLK is for main operation of the block (called special clock, but no
> clue what is so special about it).
>
So the consensus is to do something like this..
- const: oscclk
- const: bus_528
- const: bus_200
- const: pclk
.., right?
Mentioned people haven't replied. I'm asking because I think it'd be more
straightforward to go with just aclk_528 pclk_132 sclk_... or axi_528 apb_132.
What do you think?
Best regards,
Ivaylo
>> +
>> + - if:
>> + properties:
>> + compatible:
>> + contains:
>> + const: samsung,exynos8890-cmu-bus1
>> +
...
> Best regards,
> Krzysztof
>
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