[PATCH 1/2] dt-bindings: mtd: spi-nor: Add output-driver-strength property

From: Alexander Stein
Date: Mon Oct 04 2021 - 07:15:44 EST


From: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxx>

This property is for optimizing output voltage impedance and is
specific to each board.

Signed-off-by: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxx>
---
I checked Micron and Macronix datasheets. Both have similar but not
identical supported values. Also the register locations are different.
For those reasons I decided to specify the Ohms value directly and let
the device specfic driver figure out if it is supported where to write
it to.
BTW: Are the Ohm values and the corresponding register bits standardized
somewhere?

Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml b/Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml
index ed590d7c6e37..7d7f20a741b5 100644
--- a/Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml
+++ b/Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml
@@ -72,6 +72,12 @@ properties:
be used on such systems, to denote the absence of a reliable reset
mechanism.

+ output-driver-strength:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ Output driver strength in Ohms which optimizes the impedance at Vcc/2
+ output voltage.
+
label: true

partitions:
--
2.25.1