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* [PATCH 1/2] dt-bindings: mmc: add no-mmc-hs400 flag
@ 2021-05-08 20:56 ` Lucas Stach
  0 siblings, 0 replies; 8+ messages in thread
From: Lucas Stach @ 2021-05-08 20:56 UTC (permalink / raw
  To: Rob Herring, Ulf Hansson, Adrian Hunter
  Cc: Pengutronix Kernel Team, Fabio Estevam, linux-mmc, devicetree,
	linux-arm-kernel

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


^ permalink raw reply related	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2021-05-10 16:18 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2021-05-08 20:56 [PATCH 1/2] dt-bindings: mmc: add no-mmc-hs400 flag Lucas Stach
2021-05-08 20:56 ` 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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