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Diffstat (limited to 'Documentation/devicetree/bindings/i2c/i2c-gpio.txt')
-rw-r--r--Documentation/devicetree/bindings/i2c/i2c-gpio.txt32
1 files changed, 23 insertions, 9 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c-gpio.txt b/Documentation/devicetree/bindings/i2c/i2c-gpio.txt
index 4f8ec947c6bd..38a05562d1d2 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-gpio.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-gpio.txt
@@ -2,25 +2,39 @@ Device-Tree bindings for i2c gpio driver
Required properties:
- compatible = "i2c-gpio";
- - gpios: sda and scl gpio
-
+ - sda-gpios: gpio used for the sda signal, this should be flagged as
+ active high using open drain with (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)
+ from <dt-bindings/gpio/gpio.h> since the signal is by definition
+ open drain.
+ - scl-gpios: gpio used for the scl signal, this should be flagged as
+ active high using open drain with (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)
+ from <dt-bindings/gpio/gpio.h> since the signal is by definition
+ open drain.
Optional properties:
- - i2c-gpio,sda-open-drain: sda as open drain
- - i2c-gpio,scl-open-drain: scl as open drain
- i2c-gpio,scl-output-only: scl as output only
- i2c-gpio,delay-us: delay between GPIO operations (may depend on each platform)
- i2c-gpio,timeout-ms: timeout to get data
+Deprecated properties, do not use in new device tree sources:
+ - gpios: sda and scl gpio, alternative for {sda,scl}-gpios
+ - i2c-gpio,sda-open-drain: this means that something outside of our
+ control has put the GPIO line used for SDA into open drain mode, and
+ that something is not the GPIO chip. It is essentially an
+ inconsistency flag.
+ - i2c-gpio,scl-open-drain: this means that something outside of our
+ control has put the GPIO line used for SCL into open drain mode, and
+ that something is not the GPIO chip. It is essentially an
+ inconsistency flag.
+
Example nodes:
+#include <dt-bindings/gpio/gpio.h>
+
i2c@0 {
compatible = "i2c-gpio";
- gpios = <&pioA 23 0 /* sda */
- &pioA 24 0 /* scl */
- >;
- i2c-gpio,sda-open-drain;
- i2c-gpio,scl-open-drain;
+ sda-gpios = <&pioA 23 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>;
+ scl-gpios = <&pioA 24 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>;
i2c-gpio,delay-us = <2>; /* ~100 kHz */
#address-cells = <1>;
#size-cells = <0>;