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authorDavid Daney <david.daney@cavium.com>2012-08-22 23:03:57 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-09-06 01:10:29 +0400
commitd6ae0d578d24303941c1424b049d2cae28277666 (patch)
tree408e4d6d19acc44353761517731c5ce486e4882e /Documentation/devicetree/bindings/misc
parent9af514232e9e74cbcd24700fc321b7c71a536568 (diff)
downloadlinux-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/devicetree/bindings/misc')
-rw-r--r--Documentation/devicetree/bindings/misc/at25.txt34
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>;
+ };