[PATCH] dt-bindings: mmc: Set maximum documented operating frequency as 384MHz

From: Bhupesh Sharma
Date: Mon Jul 25 2022 - 14:09:39 EST


As Ulf noted in [1], the maximum operating frequency
documented in the mmc-controller device-tree bindings
should be updated to the maximum frequency supported
by the mmc controller(s).

Without this fix in place, the 'make dtbs_check' reports
issues with 'max-frequency' value for ipq8074 sdhci node:

arch/arm64/boot/dts/qcom/ipq8074-hk01.dtb: mmc@7824900:
max-frequency:0:0: 384000000 is greater than the maximum of 200000000

[1]. https://www.spinics.net/lists/kernel/msg4442049.html

Cc: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Cc: Rob Herring <robh@xxxxxxxxxx>
Signed-off-by: Bhupesh Sharma <bhupesh.sharma@xxxxxxxxxx>
---
- Rebased on linux-next/master

.../devicetree/bindings/mmc/mmc-controller.yaml | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/mmc/mmc-controller.yaml b/Documentation/devicetree/bindings/mmc/mmc-controller.yaml
index ff5ce89e5111..c49f3060c24a 100644
--- a/Documentation/devicetree/bindings/mmc/mmc-controller.yaml
+++ b/Documentation/devicetree/bindings/mmc/mmc-controller.yaml
@@ -87,12 +87,19 @@ properties:
enum: [1, 4, 8]
default: 1

+ # Maximum operating frequency:
+ # - for eMMC, the maximum supported frequency is 200MHz,
+ # - for SD/SDIO cards the SDR104 mode has a max supported
+ # frequency of 208MHz,
+ # - some mmc host controllers do support a max frequency
+ # upto 384MHz,
+ # so lets keep the maximum supported value here.
max-frequency:
description:
Maximum operating frequency of the bus.
$ref: /schemas/types.yaml#/definitions/uint32
minimum: 400000
- maximum: 200000000
+ maximum: 384000000

disable-wp:
$ref: /schemas/types.yaml#/definitions/flag
--
2.35.3