Re: [PATCH v4 2/2] dt-bindings: media: imx-jpeg: Assign slot for imx jpeg encoder/decoder

From: Conor Dooley
Date: Tue Sep 26 2023 - 09:25:56 EST


Hi,

On Tue, Sep 26, 2023 at 06:10:00PM +0800, Ming Qian wrote:
> There are total 4 slots available in the IP, and we only need to use one
> slot in one os, assign a single slot, configure interrupt and power
> domain only for 1 slot, not for the all 4 slots.
>
> Signed-off-by: Ming Qian <ming.qian@xxxxxxx>
> ---
> v4
> - improve commit message

> - don't make an ABI break

What does this mean? Can you please try to explain things a bit more
clearly in your changelogs?

Also, where is the code that actually makes use of these properties?

> v3
> - add vender prefix, change property slot to nxp,slot
> - add type for property slot
>
> .../bindings/media/nxp,imx8-jpeg.yaml | 45 +++++++++----------
> 1 file changed, 21 insertions(+), 24 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/media/nxp,imx8-jpeg.yaml b/Documentation/devicetree/bindings/media/nxp,imx8-jpeg.yaml
> index 3d9d1db37040..4bcfc815c894 100644
> --- a/Documentation/devicetree/bindings/media/nxp,imx8-jpeg.yaml
> +++ b/Documentation/devicetree/bindings/media/nxp,imx8-jpeg.yaml
> @@ -32,19 +32,26 @@ properties:
> maxItems: 1
>
> interrupts:
> - description: |
> - There are 4 slots available in the IP, which the driver may use
> - If a certain slot is used, it should have an associated interrupt
> - The interrupt with index i is assumed to be for slot i
> - minItems: 1 # At least one slot is needed by the driver
> - maxItems: 4 # The IP has 4 slots available for use
> + description:
> + Interrupt number for slot
> + maxItems: 1

So, what happens to users that already exist that have 2, 3 or 4
interrupts? Your commit message says:
> There are total 4 slots available in the IP, and we only need to use one
> slot in one os, assign a single slot, configure interrupt and power
> domain only for 1 slot, not for the all 4 slots.

Note that "only need to use one" doesn't mean that a user might not
want to use more than one. Is it possible to use more than one slot?

Also, if the interrupt numbers map 1:1 to slots, as the previous binding
states, why do you even need this new "nxp,slot" property?

Thanks,
Conor.

>
> power-domains:
> description:
> List of phandle and PM domain specifier as documented in
> Documentation/devicetree/bindings/power/power_domain.txt
> - minItems: 2 # Wrapper and 1 slot
> - maxItems: 5 # Wrapper and 4 slots
> + minItems: 1 # VPUMIX
> + maxItems: 2 # Wrapper and 1 slot
> +
> + nxp,slot:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description:
> + Integer number of slot index used. There are 4 slots available in the IP,
> + and driver can use a certain slot, it should have an associated interrupt
> + and power-domain. In theory, it supports 4 os or vm. If not specified, 0
> + is used by default.
> + minimum: 0
> + maximum: 3
>
> required:
> - compatible
> @@ -62,28 +69,18 @@ examples:
> jpegdec: jpegdec@58400000 {
> compatible = "nxp,imx8qxp-jpgdec";
> reg = <0x58400000 0x00050000 >;
> - interrupts = <GIC_SPI 309 IRQ_TYPE_LEVEL_HIGH>,
> - <GIC_SPI 310 IRQ_TYPE_LEVEL_HIGH>,
> - <GIC_SPI 311 IRQ_TYPE_LEVEL_HIGH>,
> - <GIC_SPI 312 IRQ_TYPE_LEVEL_HIGH>;
> + interrupts = <GIC_SPI 309 IRQ_TYPE_LEVEL_HIGH>;
> power-domains = <&pd IMX_SC_R_MJPEG_DEC_MP>,
> - <&pd IMX_SC_R_MJPEG_DEC_S0>,
> - <&pd IMX_SC_R_MJPEG_DEC_S1>,
> - <&pd IMX_SC_R_MJPEG_DEC_S2>,
> - <&pd IMX_SC_R_MJPEG_DEC_S3>;
> + <&pd IMX_SC_R_MJPEG_DEC_S0>;
> + nxp,slot = <0>;
> };
>
> jpegenc: jpegenc@58450000 {
> compatible = "nxp,imx8qm-jpgenc", "nxp,imx8qxp-jpgenc";
> reg = <0x58450000 0x00050000 >;
> - interrupts = <GIC_SPI 305 IRQ_TYPE_LEVEL_HIGH>,
> - <GIC_SPI 306 IRQ_TYPE_LEVEL_HIGH>,
> - <GIC_SPI 307 IRQ_TYPE_LEVEL_HIGH>,
> - <GIC_SPI 308 IRQ_TYPE_LEVEL_HIGH>;
> + interrupts = <GIC_SPI 305 IRQ_TYPE_LEVEL_HIGH>;
> power-domains = <&pd IMX_SC_R_MJPEG_ENC_MP>,
> - <&pd IMX_SC_R_MJPEG_ENC_S0>,
> - <&pd IMX_SC_R_MJPEG_ENC_S1>,
> - <&pd IMX_SC_R_MJPEG_ENC_S2>,
> - <&pd IMX_SC_R_MJPEG_ENC_S3>;
> + <&pd IMX_SC_R_MJPEG_ENC_S0>;
> + nxp,slot = <0>;
> };
> ...
> --
> 2.38.1
>

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