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

[Bhupesh Sharma <bhupesh.sharma@linaro.org>]

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@linaro.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>
---
- 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