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[PATCH v1 2/4] ARM: dts: rockchip: remove unlikly-to-exist DAC from elgin-r1

Conor Dooley posted 4 patches 1 year, 5 months ago
[PATCH v1 2/4] ARM: dts: rockchip: remove unlikly-to-exist DAC from elgin-r1
Posted by Conor Dooley 1 year, 5 months ago 
From: Conor Dooley <conor.dooley@microchip.com>

The Rohm dh2228fv (really the bh2228fv, the compatible in the kernel has
a typo) does not support frequencies above 10 MHz, nor per the
datasheet appear to use either CPOL or CPHA. I suspect that this
devicetree is abusing the compatible in order to bind the spidev driver
in Linux. Pretending to have devices on a board for this purpose is not
acceptable, so remove it.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
---
I could not find any documentation for this board online, and it does
not blatantly say that the device is a "spidev" like other [ab]users, so
it is possible there's actually a DAC here - but I doubt it is a
bh2228fv given the other incompatibilities.
---
 arch/arm/boot/dts/rockchip/rv1108-elgin-r1.dts | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/arch/arm/boot/dts/rockchip/rv1108-elgin-r1.dts b/arch/arm/boot/dts/rockchip/rv1108-elgin-r1.dts
index 2d9994379eb2..9df1cef406c5 100644
--- a/arch/arm/boot/dts/rockchip/rv1108-elgin-r1.dts
+++ b/arch/arm/boot/dts/rockchip/rv1108-elgin-r1.dts
@@ -167,14 +167,6 @@ &spi {
 	pinctrl-names = "default";
 	pinctrl-0 = <&spim1_clk &spim1_cs0 &spim1_tx &spim1_rx>;
 	status = "okay";
-
-	dh2228fv: dac@0 {
-		compatible = "rohm,dh2228fv";
-		reg = <0>;
-		spi-max-frequency = <24000000>;
-		spi-cpha;
-		spi-cpol;
-	};
 };
 
 &u2phy {
-- 
2.43.0
Re: [PATCH v1 2/4] ARM: dts: rockchip: remove unlikly-to-exist DAC from elgin-r1
Posted by Dragan Simic 1 year, 5 months ago 
Hello Conor,

On 2024-07-17 11:37, Conor Dooley wrote:
> From: Conor Dooley <conor.dooley@microchip.com>
> 
> The Rohm dh2228fv (really the bh2228fv, the compatible in the kernel 
> has
> a typo) does not support frequencies above 10 MHz, nor per the
> datasheet appear to use either CPOL or CPHA. I suspect that this
> devicetree is abusing the compatible in order to bind the spidev driver
> in Linux. Pretending to have devices on a board for this purpose is not
> acceptable, so remove it.
> 
> Signed-off-by: Conor Dooley <conor.dooley@microchip.com>

There's a small typo in the patch subject:
s/unlikly/unlikely/

> ---
> I could not find any documentation for this board online, and it does
> not blatantly say that the device is a "spidev" like other [ab]users, 
> so
> it is possible there's actually a DAC here - but I doubt it is a
> bh2228fv given the other incompatibilities.
> ---
>  arch/arm/boot/dts/rockchip/rv1108-elgin-r1.dts | 8 --------
>  1 file changed, 8 deletions(-)
> 
> diff --git a/arch/arm/boot/dts/rockchip/rv1108-elgin-r1.dts
> b/arch/arm/boot/dts/rockchip/rv1108-elgin-r1.dts
> index 2d9994379eb2..9df1cef406c5 100644
> --- a/arch/arm/boot/dts/rockchip/rv1108-elgin-r1.dts
> +++ b/arch/arm/boot/dts/rockchip/rv1108-elgin-r1.dts
> @@ -167,14 +167,6 @@ &spi {
>  	pinctrl-names = "default";
>  	pinctrl-0 = <&spim1_clk &spim1_cs0 &spim1_tx &spim1_rx>;
>  	status = "okay";
> -
> -	dh2228fv: dac@0 {
> -		compatible = "rohm,dh2228fv";
> -		reg = <0>;
> -		spi-max-frequency = <24000000>;
> -		spi-cpha;
> -		spi-cpol;
> -	};
>  };
> 
>  &u2phy {
Re: [PATCH v1 2/4] ARM: dts: rockchip: remove unlikly-to-exist DAC from elgin-r1
Posted by Dragan Simic 1 year, 5 months ago 
On 2024-07-18 06:20, Dragan Simic wrote:
> Hello Conor,
> 
> On 2024-07-17 11:37, Conor Dooley wrote:
>> From: Conor Dooley <conor.dooley@microchip.com>
>> 
>> The Rohm dh2228fv (really the bh2228fv, the compatible in the kernel 
>> has
>> a typo) does not support frequencies above 10 MHz, nor per the
>> datasheet appear to use either CPOL or CPHA. I suspect that this
>> devicetree is abusing the compatible in order to bind the spidev 
>> driver
>> in Linux. Pretending to have devices on a board for this purpose is 
>> not
>> acceptable, so remove it.
>> 
>> Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
> 
> There's a small typo in the patch subject:
> s/unlikly/unlikely/

Ah, sorry for the noise, I see now it's been pointed out already.

>> ---
>> I could not find any documentation for this board online, and it does
>> not blatantly say that the device is a "spidev" like other [ab]users, 
>> so
>> it is possible there's actually a DAC here - but I doubt it is a
>> bh2228fv given the other incompatibilities.
>> ---
>>  arch/arm/boot/dts/rockchip/rv1108-elgin-r1.dts | 8 --------
>>  1 file changed, 8 deletions(-)
>> 
>> diff --git a/arch/arm/boot/dts/rockchip/rv1108-elgin-r1.dts
>> b/arch/arm/boot/dts/rockchip/rv1108-elgin-r1.dts
>> index 2d9994379eb2..9df1cef406c5 100644
>> --- a/arch/arm/boot/dts/rockchip/rv1108-elgin-r1.dts
>> +++ b/arch/arm/boot/dts/rockchip/rv1108-elgin-r1.dts
>> @@ -167,14 +167,6 @@ &spi {
>>  	pinctrl-names = "default";
>>  	pinctrl-0 = <&spim1_clk &spim1_cs0 &spim1_tx &spim1_rx>;
>>  	status = "okay";
>> -
>> -	dh2228fv: dac@0 {
>> -		compatible = "rohm,dh2228fv";
>> -		reg = <0>;
>> -		spi-max-frequency = <24000000>;
>> -		spi-cpha;
>> -		spi-cpol;
>> -	};
>>  };
>> 
>>  &u2phy {
> 
> _______________________________________________
> Linux-rockchip mailing list
> Linux-rockchip@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-rockchip
Re: [PATCH v1 2/4] ARM: dts: rockchip: remove unlikly-to-exist DAC from elgin-r1
Posted by Fabio Estevam 1 year, 5 months ago 
On Wed, Jul 17, 2024 at 6:38 AM Conor Dooley <conor@kernel.org> wrote:
>
> From: Conor Dooley <conor.dooley@microchip.com>
>
> The Rohm dh2228fv (really the bh2228fv, the compatible in the kernel has
> a typo) does not support frequencies above 10 MHz, nor per the
> datasheet appear to use either CPOL or CPHA. I suspect that this
> devicetree is abusing the compatible in order to bind the spidev driver
> in Linux. Pretending to have devices on a board for this purpose is not
> acceptable, so remove it.

In the Subject: s/unlikly/unlikely

Reviewed-by: Fabio Estevam <festevam@gmail.com>
Re: [PATCH v1 2/4] ARM: dts: rockchip: remove unlikly-to-exist DAC from elgin-r1
Posted by Krzysztof Kozlowski 1 year, 5 months ago 
On 17/07/2024 11:37, Conor Dooley wrote:
> From: Conor Dooley <conor.dooley@microchip.com>
> 
> The Rohm dh2228fv (really the bh2228fv, the compatible in the kernel has
> a typo) does not support frequencies above 10 MHz, nor per the
> datasheet appear to use either CPOL or CPHA. I suspect that this
> devicetree is abusing the compatible in order to bind the spidev driver
> in Linux. Pretending to have devices on a board for this purpose is not
> acceptable, so remove it.
> 
> Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
> ---
> I could not find any documentation for this board online, and it does
> not blatantly say that the device is a "spidev" like other [ab]users, so
> it is possible there's actually a DAC here - but I doubt it is a
> bh2228fv given the other incompatibilities.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof
Re: [PATCH v1 2/4] ARM: dts: rockchip: remove unlikly-to-exist DAC from elgin-r1
Posted by Heiko Stübner 1 year, 5 months ago 
adding Otavio,

Am Mittwoch, 17. Juli 2024, 11:37:54 CEST schrieb Conor Dooley:
> From: Conor Dooley <conor.dooley@microchip.com>
> 
> The Rohm dh2228fv (really the bh2228fv, the compatible in the kernel has
> a typo) does not support frequencies above 10 MHz, nor per the
> datasheet appear to use either CPOL or CPHA. I suspect that this
> devicetree is abusing the compatible in order to bind the spidev driver
> in Linux. Pretending to have devices on a board for this purpose is not
> acceptable, so remove it.

Reasoning is sound, so I'll pick this up after the merge window.


> Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
> ---
> I could not find any documentation for this board online, and it does
> not blatantly say that the device is a "spidev" like other [ab]users, so
> it is possible there's actually a DAC here - but I doubt it is a
> bh2228fv given the other incompatibilities.

Otavio, as the original submitter of the Elgin R1 [0], do you happen
to know what type of device this is? Especially as there really do not
seem to be any schematics around for that board.


Heiko



[0] https://patchwork.kernel.org/project/linux-rockchip/patch/20190104014023.17973-4-otavio@ossystems.com.br/

> ---
>  arch/arm/boot/dts/rockchip/rv1108-elgin-r1.dts | 8 --------
>  1 file changed, 8 deletions(-)
> 
> diff --git a/arch/arm/boot/dts/rockchip/rv1108-elgin-r1.dts b/arch/arm/boot/dts/rockchip/rv1108-elgin-r1.dts
> index 2d9994379eb2..9df1cef406c5 100644
> --- a/arch/arm/boot/dts/rockchip/rv1108-elgin-r1.dts
> +++ b/arch/arm/boot/dts/rockchip/rv1108-elgin-r1.dts
> @@ -167,14 +167,6 @@ &spi {
>  	pinctrl-names = "default";
>  	pinctrl-0 = <&spim1_clk &spim1_cs0 &spim1_tx &spim1_rx>;
>  	status = "okay";
> -
> -	dh2228fv: dac@0 {
> -		compatible = "rohm,dh2228fv";
> -		reg = <0>;
> -		spi-max-frequency = <24000000>;
> -		spi-cpha;
> -		spi-cpol;
> -	};
>  };
>  
>  &u2phy {
>

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