Not all FRAM chips have a device ID and implement the corresponding read
command. Thus the memory size, which is contained in the device ID,
cannot be detected and has to be set manually as it is done for EEPROMs.

Link: https://lore.kernel.org/all/20250401133148.38330-1-m.heidelberg@cab.de/
Signed-off-by: Markus Heidelberg <m.heidelberg@cab.de>
---
 Documentation/devicetree/bindings/eeprom/at25.yaml | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/eeprom/at25.yaml b/Documentation/devicetree/bindings/eeprom/at25.yaml
index c31e5e719525..00e0f07b44f8 100644
--- a/Documentation/devicetree/bindings/eeprom/at25.yaml
+++ b/Documentation/devicetree/bindings/eeprom/at25.yaml
@@ -56,6 +56,7 @@ properties:
     $ref: /schemas/types.yaml#/definitions/uint32
     description:
       Total eeprom size in bytes.
+      Also used for FRAMs without device ID where the size cannot be detected.
 
   address-width:
     $ref: /schemas/types.yaml#/definitions/uint32
@@ -146,4 +147,11 @@ examples:
             reg = <1>;
             spi-max-frequency = <40000000>;
         };
+
+        fram@2 {
+            compatible = "cypress,fm25", "atmel,at25";
+            reg = <2>;
+            spi-max-frequency = <20000000>;
+            size = <2048>;
+        };
     };
-- 
2.43.0

On Fri, 15 Aug 2025 11:58:36 +0200, Markus Heidelberg wrote:
> Not all FRAM chips have a device ID and implement the corresponding read
> command. Thus the memory size, which is contained in the device ID,
> cannot be detected and has to be set manually as it is done for EEPROMs.
> 
> Link: https://lore.kernel.org/all/20250401133148.38330-1-m.heidelberg@cab.de/
> Signed-off-by: Markus Heidelberg <m.heidelberg@cab.de>
> ---
>  Documentation/devicetree/bindings/eeprom/at25.yaml | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>