From d6ae0d578d24303941c1424b049d2cae28277666 Mon Sep 17 00:00:00 2001 From: David Daney Date: Wed, 22 Aug 2012 12:03:57 -0700 Subject: misc/at25, dt: Improve at25 SPI eeprom device tree bindings. Commit 002176db (misc: at25: Parse dt settings) added device tree bindings the differ significantly in style from the I2C EEPROM bindings and don't seem well vetted. Here I deprecate (but still support) the "at25,*" properties, and add what I hope is a better alternative. These new bindings also happen to be deployed in the field and were previously submitted for consideration here: https://lists.ozlabs.org/pipermail/devicetree-discuss/2012-May/015556.html The advantages of the new bindings are that they are similar to the I2C EEPROMs and they don't conflate read-only and the address width modes in a binary encoded blob. Signed-off-by: David Daney Cc: Alexandre Pereira da Silva Cc: Greg Kroah-Hartman Cc: Michael Hennerich Cc: Axel Lin Signed-off-by: Greg Kroah-Hartman --- Documentation/devicetree/bindings/misc/at25.txt | 34 +++++++++++++++++-------- 1 file changed, 24 insertions(+), 10 deletions(-) (limited to 'Documentation/devicetree/bindings/misc') diff --git a/Documentation/devicetree/bindings/misc/at25.txt b/Documentation/devicetree/bindings/misc/at25.txt index ab3c327929d..1d3447165c3 100644 --- a/Documentation/devicetree/bindings/misc/at25.txt +++ b/Documentation/devicetree/bindings/misc/at25.txt @@ -1,21 +1,35 @@ -Atmel AT25 eeprom +EEPROMs (SPI) compatible with Atmel at25. Required properties: - compatible : "atmel,at25". - reg : chip select number - spi-max-frequency : max spi frequency to use +- pagesize : size of the eeprom page +- size : total eeprom size in bytes +- address-width : number of address bits (one of 8, 16, or 24) +Optional properties: +- spi-cpha : SPI shifted clock phase, as per spi-bus bindings. +- spi-cpol : SPI inverse clock polarity, as per spi-bus bindings. +- read-only : this parameter-less property disables writes to the eeprom + +Obsolete legacy properties are can be used in place of "size", "pagesize", +"address-width", and "read-only": - at25,byte-len : total eeprom size in bytes - at25,addr-mode : addr-mode flags, as defined in include/linux/spi/eeprom.h - at25,page-size : size of the eeprom page -Examples: -at25@0 { - compatible = "atmel,at25"; - reg = <0> - spi-max-frequency = <5000000>; +Additional compatible properties are also allowed. + +Example: + at25@0 { + compatible = "atmel,at25", "st,m95256"; + reg = <0> + spi-max-frequency = <5000000>; + spi-cpha; + spi-cpol; - at25,byte-len = <0x8000>; - at25,addr-mode = <2>; - at25,page-size = <64>; -}; + pagesize = <64>; + size = <32768>; + address-width = <16>; + }; -- cgit v1.2.3-70-g09d2