Some platforms may require limiting the maximum frequency used in SD
High-Speed (HS) mode due to board-level hardware constraints. For
example, certain boards may include level shifters or other components
that cannot reliably operate at the default 50 MHz HS frequency.
Introduce a new optional device tree property max-sd-hs-frequency to
limit the maximum frequency (in Hz) used for SD cards operating in
High-Speed (HS) mode.
Signed-off-by: Sarthak Garg <quic_sartgarg@xxxxxxxxxxx>
---
.../devicetree/bindings/mmc/mmc-controller-common.yaml | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/Documentation/devicetree/bindings/mmc/mmc-controller-common.yaml b/Documentation/devicetree/bindings/mmc/mmc-controller-common.yaml
index 9a7235439759..6c2529b976d1 100644
--- a/Documentation/devicetree/bindings/mmc/mmc-controller-common.yaml
+++ b/Documentation/devicetree/bindings/mmc/mmc-controller-common.yaml
@@ -93,6 +93,16 @@ properties:
minimum: 400000
maximum: 384000000
+ max-sd-hs-frequency:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ Maximum frequency (in Hz) to be used for SD cards operating in
+ High-Speed (HS) mode. This is useful for board-specific limitations,
+ such as level shifters or others where the card cannot reliably
+ operate at the default 50 MHz HS frequency.
+ minimum: 400000
+ maximum: 50000000
+
disable-wp:
$ref: /schemas/types.yaml#/definitions/flag
description:
--
2.34.1
