Re: [PATCH v2 24/25] arm64: dts: renesas: rzg3s-smarc: Enable SSI3

[Claudiu Beznea <claudiu.beznea@tuxon.dev>]

On 12.11.2024 11:03, Biju Das wrote:
> Hi Claudiu,
> 
>> -----Original Message-----
>> From: Claudiu Beznea <claudiu.beznea@tuxon.dev>
>> Sent: 12 November 2024 08:31
>> Subject: Re: [PATCH v2 24/25] arm64: dts: renesas: rzg3s-smarc: Enable SSI3
>>
>> Hi, Biju,
>>
>> On 11.11.2024 13:30, Biju Das wrote:
>>> Hi Claudiu,
>>>
>>>> -----Original Message-----
>>>> From: Claudiu Beznea <claudiu.beznea@tuxon.dev>
>>>> Sent: 11 November 2024 11:20
>>>> Subject: Re: [PATCH v2 24/25] arm64: dts: renesas: rzg3s-smarc:
>>>> Enable SSI3
>>>>
>>>> Hi, Biju,
>>>>
>>>> On 10.11.2024 10:54, Biju Das wrote:
>>>>> Hi Claudiu,
>>>>>
>>>>> Thanks for the patch.
>>>>>
>>>>>
>>>>>> -----Original Message-----
>>>>>> From: Claudiu <claudiu.beznea@tuxon.dev>
>>>>>> Sent: 08 November 2024 10:50
>>>>>> Subject: [PATCH v2 24/25] arm64: dts: renesas: rzg3s-smarc: Enable
>>>>>> SSI3
>>>>>>
>>>>>> From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
>>>>>>
>>>>>> Enable SSI3.
>>>>>>
>>>>>> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
>>>>>> ---
>>>>>>
>>>>>> Changes in v2:
>>>>>> - none
>>>>>>
>>>>>>  arch/arm64/boot/dts/renesas/rzg3s-smarc.dtsi | 26
>>>>>> ++++++++++++++++++++
>>>>>>  1 file changed, 26 insertions(+)
>>>>>>
>>>>>> diff --git a/arch/arm64/boot/dts/renesas/rzg3s-smarc.dtsi
>>>>>> b/arch/arm64/boot/dts/renesas/rzg3s-
>>>>>> smarc.dtsi
>>>>>> index 4aa99814b808..6dd439e68bd4 100644
>>>>>> --- a/arch/arm64/boot/dts/renesas/rzg3s-smarc.dtsi
>>>>>> +++ b/arch/arm64/boot/dts/renesas/rzg3s-smarc.dtsi
>>>>>> @@ -64,6 +64,11 @@ vccq_sdhi1: regulator-vccq-sdhi1 {
>>>>>>  	};
>>>>>>  };
>>>>>>
>>>>>
>>>>> &audio_clk1 {
>>>>>        assigned-clocks = <&versa3 xx>;
>>>>>        clock-frequency = <11289600>; };
>>>>
>>>> audio_clk1 node is in the RZ/G3S dtsi to keep the compilation happy.
>>>>
>>>> For this board the audio clock1 for the SSI 3 is from <&versa3 2>.
>>>>
>>>> If we fill in the audio_clk1 here it will be useless, there will be
>>>> no consumers for it and it is not available on board.
>>>
>>> As per SSI IP needs external clks AUDIO_CLK1 and AUDIO_CLK2.
>>>
>>> AUDIO_CLK1 is provided by versa3 generator and
>>> AUDIO_CLK2 is provided by Crystal.
>>>
>>> Currently AUDIO_CLK2 it reports a frequency of 12288000 which is a
>>> multiple of 48kHz whereas for AUDIO_CLK1, it reports a frequency of 0.
>>
>> Why? You mentioned above that "AUDIO_CLK1 is provided by versa3 generator".
> 
> Output from versa3 generator is connector to AUDIO_CLK1 

According to schematics this is true.


> that you described in
> SoC dtsi node with the entries
> 
> +	audio_clk1: audio-clk1 {
> +		compatible = "fixed-clock";
> +		#clock-cells = <0>;
> +		/* This value must be overridden by boards that provide it. */
> +		clock-frequency = <0>;
> +		status = "disabled";
> +	};

That is a clock node, placeholder in the DTSI, to make compilation happy.

> 
> This needs to be overridden by board dts,

Only if used, otherwise is an useless node.

> where versa3 is providing this clk.
> Currently there is no relation between this SoC device node and versa3 clk output for audio clk1.

I may be wrong or I many not understand what you are trying to say, but
isn't what this patch does? See this diff from this patch:

+&ssi3 {
+	clocks = <&cpg CPG_MOD R9A08G045_SSI3_PCLK2>,
+		 <&cpg CPG_MOD R9A08G045_SSI3_PCLK_SFR>,
+		 <&versa3 2>, <&audio_clk2>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&ssi3_pins>, <&audio_clock_pins>;
+	status = "okay";
+};