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| author | David Daney <david.daney@cavium.com> | 2012-08-22 23:03:57 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-09-06 01:10:29 +0400 |
| commit | d6ae0d578d24303941c1424b049d2cae28277666 (patch) | |
| tree | 408e4d6d19acc44353761517731c5ce486e4882e /Documentation | |
| parent | 9af514232e9e74cbcd24700fc321b7c71a536568 (diff) | |
| download | linux-d6ae0d578d24303941c1424b049d2cae28277666.tar.xz | |
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 <david.daney@cavium.com>
Cc: Alexandre Pereira da Silva <aletes.xgr@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michael Hennerich <michael.hennerich@analog.com>
Cc: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/devicetree/bindings/misc/at25.txt | 34 |
1 files changed, 24 insertions, 10 deletions
diff --git a/Documentation/devicetree/bindings/misc/at25.txt b/Documentation/devicetree/bindings/misc/at25.txt index ab3c327929dd..1d3447165c37 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>; + }; |