Commit 14f49573 authored by Khouloud Touil's avatar Khouloud Touil Committed by Bartosz Golaszewski

dt-bindings: nvmem: new optional property wp-gpios

Several memories have a write-protect pin, that when pulled high, it
blocks the write operation.

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.

Instead of modifying all the memory drivers to check this pin, make
the NVMEM subsystem check if the write-protect GPIO being passed
through the nvmem_config or defined in the device tree and pull it
low whenever writing to the memory.

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: default avatarKhouloud Touil <ktouil@baylibre.com>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarBartosz Golaszewski <bgolaszewski@baylibre.com>
parent 69afc4b6
...@@ -34,6 +34,14 @@ properties: ...@@ -34,6 +34,14 @@ properties:
description: description:
Mark the provider as read only. Mark the provider as read only.
wp-gpios:
description:
GPIO to which the write-protect pin of the chip is connected.
The write-protect GPIO is asserted, when it's driven high
(logical '1') to block the write operation. It's deasserted,
when it's driven low (logical '0') to allow writing.
maxItems: 1
patternProperties: patternProperties:
"^.*@[0-9a-f]+$": "^.*@[0-9a-f]+$":
type: object type: object
...@@ -63,9 +71,12 @@ patternProperties: ...@@ -63,9 +71,12 @@ patternProperties:
examples: examples:
- | - |
#include <dt-bindings/gpio/gpio.h>
qfprom: eeprom@700000 { qfprom: eeprom@700000 {
#address-cells = <1>; #address-cells = <1>;
#size-cells = <1>; #size-cells = <1>;
wp-gpios = <&gpio1 3 GPIO_ACTIVE_HIGH>;
/* ... */ /* ... */
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment