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| author | Jiri Prchal <jiri.prchal@aksignal.cz> | 2021-06-11 11:45:58 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-06-11 12:23:10 +0200 |
| commit | fd307a4ad332ef50be5569c92490219e7cd84ce5 (patch) | |
| tree | 6683353455acad103535cdbceb9af084ff50531a /Documentation | |
| parent | 989f77e3fdee2e8f414dd1da9b6397d8763d414e (diff) | |
| download | linux-fd307a4ad332ef50be5569c92490219e7cd84ce5.tar.bz2 | |
nvmem: prepare basics for FRAM support
Added enum and string for FRAM (ferroelectric RAM) to expose it as file
named "fram".
Added documentation of sysfs file.
Signed-off-by: Jiri Prchal <jiri.prchal@aksignal.cz>
Link: https://lore.kernel.org/r/20210611094601.95131-2-jiri.prchal@aksignal.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-spi-eeprom | 19 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/eeprom/at25.yaml | 31 |
2 files changed, 44 insertions, 6 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-spi-eeprom b/Documentation/ABI/testing/sysfs-class-spi-eeprom new file mode 100644 index 000000000000..1ff757982079 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-spi-eeprom @@ -0,0 +1,19 @@ +What: /sys/class/spi_master/spi<bus>/spi<bus>.<dev>/fram +Date: June 2021 +KernelVersion: 5.14 +Contact: Jiri Prchal <jiri.prchal@aksignal.cz> +Description: + Contains the FRAM binary data. Same as EEPROM, just another file + name to indicate that it employs ferroelectric process. + It performs write operations at bus speed - no write delays. + +What: /sys/class/spi_master/spi<bus>/spi<bus>.<dev>/sernum +Date: May 2021 +KernelVersion: 5.14 +Contact: Jiri Prchal <jiri.prchal@aksignal.cz> +Description: + Contains the serial number of the Cypress FRAM (FM25VN) if it is + present. It will be displayed as a 8 byte hex string, as read + from the device. + + This is a read-only attribute. diff --git a/Documentation/devicetree/bindings/eeprom/at25.yaml b/Documentation/devicetree/bindings/eeprom/at25.yaml index 6a2dc8b3ed14..fbf99e346966 100644 --- a/Documentation/devicetree/bindings/eeprom/at25.yaml +++ b/Documentation/devicetree/bindings/eeprom/at25.yaml @@ -4,14 +4,16 @@ $id: "http://devicetree.org/schemas/eeprom/at25.yaml#" $schema: "http://devicetree.org/meta-schemas/core.yaml#" -title: SPI EEPROMs compatible with Atmel's AT25 +title: SPI EEPROMs or FRAMs compatible with Atmel's AT25 maintainers: - Christian Eggers <ceggers@arri.de> properties: $nodename: - pattern: "^eeprom@[0-9a-f]{1,2}$" + anyOf: + - pattern: "^eeprom@[0-9a-f]{1,2}$" + - pattern: "^fram@[0-9a-f]{1,2}$" # There are multiple known vendors who manufacture EEPROM chips compatible # with Atmel's AT25. The compatible string requires two items where the @@ -31,6 +33,7 @@ properties: - microchip,25lc040 - st,m95m02 - st,m95256 + - cypress,fm25 - const: atmel,at25 @@ -47,7 +50,7 @@ properties: $ref: /schemas/types.yaml#/definitions/uint32 enum: [1, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072] description: - Size of the eeprom page. + Size of the eeprom page. FRAMs don't have pages. size: $ref: /schemas/types.yaml#/definitions/uint32 @@ -100,9 +103,19 @@ required: - compatible - reg - spi-max-frequency - - pagesize - - size - - address-width + +allOf: + - if: + properties: + compatible: + not: + contains: + const: cypress,fm25 + then: + required: + - pagesize + - size + - address-width additionalProperties: false @@ -125,4 +138,10 @@ examples: size = <32768>; address-width = <16>; }; + + fram@1 { + compatible = "cypress,fm25", "atmel,at25"; + reg = <1>; + spi-max-frequency = <40000000>; + }; }; |