diff options
Diffstat (limited to 'Documentation/devicetree/bindings/i2c/i2c-gpio.txt')
| -rw-r--r-- | Documentation/devicetree/bindings/i2c/i2c-gpio.txt | 32 |
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>; |