[PATCH v2 1/2] dt-binding: hwmon: add gpio-brownout bindings

Marco Felsch
2018-10-29T23:24:27Z

Add dt-bindings for gpio-brownout detection devices. Such a device
determines the voltage good/bad state by the gpio line level.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
.../bindings/hwmon/gpio-brownout.txt | 32 +++++++++++++++++++
1 file changed, 32 insertions(+)
create mode 100644 Documentation/devicetree/bindings/hwmon/gpio-brownout.txt

diff --git a/Documentation/devicetree/bindings/hwmon/gpio-brownout.txt b/Documentation/devicetree/bindings/hwmon/gpio-brownout.txt
new file mode 100644
index 000000000000..f3272befc8f8
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/gpio-brownout.txt
@@ -0,0 +1,32 @@
+Device-Tree bindings for GPIO line brownout detection
+
+Required properties:
+- compatible: Must be "gpio-brownout"
+- gpio-brownout,sense-gpios: This gpio is used to detect a brownout. The gpio
+ must support interrupts.
+
+Optional properties:
+- gpio-brownout,dev-list: A list of i2c or spi device phandles. All
+ listed devices will be released from their drivers in the order they listed
+ upon a brownout detection. This can be helpful to avoid a interrupt flood,
+ because some system designs power off all external devices immediately and
+ keep the host on for a certain time.
+
+Example:
+
+i2c3 {
+ temp_core: lm75@48 { };
+ temp_chassis: lm75@49 { };
+};
+
+spi1 {
+ ts: ad7879@1 { };
+};
+
+/ {
+ gpio_brownout {
+ compatible = "gpio-brownout";
+ gpio-brownout,sense-gpios = <&gpio3 3 GPIO_ACTIVE_LOW>;
+ gpio-brownout,dev-list = <&temp_core &ts>;
+ };
+};
--
2.19.1