[v2,3/6] dt-bindings: mmc: fsl-imx-esdhc: add fsl,broken-auto-tuning binding

From: Haibo Chen <haibo.chen@nxp.com>

Add a new fsl,broken-auto-tuning binding for sdio devices. When sdio
device support sdio interrupt, need to use this property to disable
auto-tuning. Auto-tuning circuit is conflict with sdio interrupt.

Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
---
 Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.yaml | 9 +++++++++
 1 file changed, 9 insertions(+)

On Wed, Aug 18, 2021 at 07:16:52PM +0800, haibo.chen@nxp.com wrote:
> From: Haibo Chen <haibo.chen@nxp.com>
> 
> Add a new fsl,broken-auto-tuning binding for sdio devices. When sdio
> device support sdio interrupt, need to use this property to disable
> auto-tuning. Auto-tuning circuit is conflict with sdio interrupt.
> 
> Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
> ---
>  Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.yaml | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.yaml b/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.yaml
> index b5baf439fbac..d7c8e5880473 100644
> --- a/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.yaml
> +++ b/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.yaml
> @@ -93,6 +93,15 @@ properties:
>        tuning step can't find the proper delay window within limited tuning retries.
>      default: 0
>  
> +  fsl,broken-auto-tuning:
> +    description: |
> +      Recommend for SDIO cards that enables SDIO interrupt for SDR104 and SDR50 mode.
> +      SDIO interrupt uses DAT[1] to signal the card's interrupt. Auto-tuning circuit
> +      will detect this interrupt on DAT[1] when in 4Bit bus mode, and take it just
> +      as normal data, wrongly adjust the delay cell. This property is used to disable
> +      the auto-tuning function.
> +    type: boolean

Seems like something that could be broken on a variety of hosts and 
should be common?

If auto tuning is broken, shouldn't that speed be disabled?

Rob

Hi Haibo,

Am Mittwoch, dem 18.08.2021 um 19:16 +0800 schrieb haibo.chen@nxp.com:
> From: Haibo Chen <haibo.chen@nxp.com>
> 
> Add a new fsl,broken-auto-tuning binding for sdio devices. When sdio
> device support sdio interrupt, need to use this property to disable
> auto-tuning. Auto-tuning circuit is conflict with sdio interrupt.
> 
Wouldn't it be possible to do this automatically by the driver without
a DT property when a SDIO card is detected?

Regards,
Lucas

> Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
> ---
>  Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.yaml | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.yaml b/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.yaml
> index b5baf439fbac..d7c8e5880473 100644
> --- a/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.yaml
> +++ b/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.yaml
> @@ -93,6 +93,15 @@ properties:
>        tuning step can't find the proper delay window within limited tuning retries.
>      default: 0
>  
> +  fsl,broken-auto-tuning:
> +    description: |
> +      Recommend for SDIO cards that enables SDIO interrupt for SDR104 and SDR50 mode.
> +      SDIO interrupt uses DAT[1] to signal the card's interrupt. Auto-tuning circuit
> +      will detect this interrupt on DAT[1] when in 4Bit bus mode, and take it just
> +      as normal data, wrongly adjust the delay cell. This property is used to disable
> +      the auto-tuning function.
> +    type: boolean
> +
>    fsl,strobe-dll-delay-target:
>      $ref: /schemas/types.yaml#/definitions/uint32
>      description: |