Re: [PATCH v2 3/6] dt-bindings: mmc: fsl-imx-esdhc: add fsl,broken-auto-tuning binding
From: Rob Herring <robh@kernel.org>
Date: 2021-08-18 18:49:04
Also in:
linux-arm-kernel, linux-mmc
On Wed, Aug 18, 2021 at 07:16:52PM +0800, haibo.chen@nxp.com wrote:
quoted hunk ↗ jump to hunk
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