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authorBartosz Golaszewski <brgl@bgdev.pl>2017-12-19 12:09:23 +0100
committerBartosz Golaszewski <brgl@bgdev.pl>2018-01-01 19:40:50 +0100
commit3f3d8ef7f4eff5909b0cc996718de81de99af1e6 (patch)
treefdce99b54088b5ea308b28dd822f323dae705301
parentef542e59d7a11d343149b60609f422effede9d80 (diff)
dt-bindings: at24: new optional property - wp-gpios
AT24 EEPROMs have a write-protect pin, which - when pulled high - inhibits writes to the upper quadrant of memory (although it has been observed that on some chips it disables writing to the entire memory range). On some boards, this pin is connected to a GPIO and pulled high by default, which forces the user to manually change its state before writing. On linux this means that we either need to hog the line all the time, or set the GPIO value before writing from outside of the at24 driver. Add a new optional property to the device tree binding document, which allows to specify the GPIO line to which the write-protect pin is connected. Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Rob Herring <robh@kernel.org>
-rw-r--r--Documentation/devicetree/bindings/eeprom/at24.txt3
1 files changed, 3 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/eeprom/at24.txt b/Documentation/devicetree/bindings/eeprom/at24.txt
index a0415b8471bb..cbc80e194ac6 100644
--- a/Documentation/devicetree/bindings/eeprom/at24.txt
+++ b/Documentation/devicetree/bindings/eeprom/at24.txt
@@ -43,10 +43,13 @@ Optional properties:
eeprom does not automatically roll over reads to the next
slave address. Please consult the manual of your device.
+ - wp-gpios: GPIO to which the write-protect pin of the chip is connected.
+
Example:
eeprom@52 {
compatible = "atmel,24c32";
reg = <0x52>;
pagesize = <32>;
+ wp-gpios = <&gpio1 3 0>;
};

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