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From: Lucas Stach <dev@lynxeye.de>
To: Rob Herring <robh+dt@kernel.org>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	Adrian Hunter <adrian.hunter@intel.com>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>,
	Fabio Estevam <festevam@gmail.com>,
	linux-mmc@vger.kernel.org, devicetree@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/2] dt-bindings: mmc: add no-mmc-hs400 flag
Date: Sat,  8 May 2021 22:56:57 +0200	[thread overview]
Message-ID: <20210508205658.91105-1-dev@lynxeye.de> (raw)

HS400 requires a data strobe line in addition to the other MMC signal
lines, so if a board design neglects to wire up this signal, HS400 mode
is no available, even if both the controller and the eMMC are claiming
to support this mode. Add a DT flag to allow boards to disable the
HS400 support in this case.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
---
 Documentation/devicetree/bindings/mmc/mmc-controller.yaml | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/mmc-controller.yaml b/Documentation/devicetree/bindings/mmc/mmc-controller.yaml
index e141330c1114..ac80d09df3a9 100644
--- a/Documentation/devicetree/bindings/mmc/mmc-controller.yaml
+++ b/Documentation/devicetree/bindings/mmc/mmc-controller.yaml
@@ -220,6 +220,11 @@ properties:
     description:
       eMMC HS400 enhanced strobe mode is supported
 
+  no-mmc-hs400:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description:
+      All eMMC HS400 modes are not supported.
+
   dsr:
     description:
       Value the card Driver Stage Register (DSR) should be programmed
-- 
2.31.1


WARNING: multiple messages have this Message-ID (diff)
From: Lucas Stach <dev@lynxeye.de>
To: Rob Herring <robh+dt@kernel.org>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	Adrian Hunter <adrian.hunter@intel.com>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>,
	Fabio Estevam <festevam@gmail.com>,
	linux-mmc@vger.kernel.org, devicetree@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/2] dt-bindings: mmc: add no-mmc-hs400 flag
Date: Sat,  8 May 2021 22:56:57 +0200	[thread overview]
Message-ID: <20210508205658.91105-1-dev@lynxeye.de> (raw)

HS400 requires a data strobe line in addition to the other MMC signal
lines, so if a board design neglects to wire up this signal, HS400 mode
is no available, even if both the controller and the eMMC are claiming
to support this mode. Add a DT flag to allow boards to disable the
HS400 support in this case.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
---
 Documentation/devicetree/bindings/mmc/mmc-controller.yaml | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/mmc-controller.yaml b/Documentation/devicetree/bindings/mmc/mmc-controller.yaml
index e141330c1114..ac80d09df3a9 100644
--- a/Documentation/devicetree/bindings/mmc/mmc-controller.yaml
+++ b/Documentation/devicetree/bindings/mmc/mmc-controller.yaml
@@ -220,6 +220,11 @@ properties:
     description:
       eMMC HS400 enhanced strobe mode is supported
 
+  no-mmc-hs400:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description:
+      All eMMC HS400 modes are not supported.
+
   dsr:
     description:
       Value the card Driver Stage Register (DSR) should be programmed
-- 
2.31.1


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             reply	other threads:[~2021-05-08 21:06 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-08 20:56 Lucas Stach [this message]
2021-05-08 20:56 ` [PATCH 1/2] dt-bindings: mmc: add no-mmc-hs400 flag Lucas Stach
2021-05-08 20:56 ` [PATCH 2/2] mmc: sdhci-esdhc-imx: add support for disabling HS400 mode via DT Lucas Stach
2021-05-08 20:56   ` Lucas Stach
2021-05-10  6:29   ` Bough Chen
2021-05-10  6:29     ` Bough Chen
2021-05-10 16:16 ` [PATCH 1/2] dt-bindings: mmc: add no-mmc-hs400 flag Rob Herring
2021-05-10 16:16   ` Rob Herring

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