DM: I2C: Introduce 'u-boot, i2c-transaction-bytes' property

[oweals/u-boot.git] / doc / device-tree-bindings / i2c / i2c.txt

diff --git a/doc/device-tree-bindings/i2c/i2c.txt b/doc/device-tree-bindings/i2c/i2c.txt
index de818d4713f0c6f77f6a63ed0eb315ec5e66e746..9698e4899b54c8135a863e78ef1cdca74a2bb9b5 100644 (file)
--- a/doc/device-tree-bindings/i2c/i2c.txt
+++ b/doc/device-tree-bindings/i2c/i2c.txt
@@ -12,6 +12,10 @@ property which allows the chip offset length to be selected.
 Optional properties:
 - u-boot,i2c-offset-len - length of chip offset in bytes. If omitted the
     default value of 1 is used.
+- u-boot,i2c-transaction-bytes - the length of single I2C transaction on
+    the bus. Some devices require more than single byte transmission
+    (e.g. mc34708 mfd). This information is necessary to correctly
+     initialize (put into idle state) I2C bus after soft reset.
 - gpios = <sda ...>, <scl ...>;
   pinctrl-names = "default", "gpio";
   pinctrl-0 = <&i2c_xfer>;
@@ -28,6 +32,7 @@ i2c4: i2c@12ca0000 {
                compatible = "google,cros-ec";
                i2c-max-frequency = <100000>;
                u-boot,i2c-offset-len = <0>;
+               u-boot,i2c-transaction-bytes = <3>;
                ec-interrupt = <&gpx1 6 GPIO_ACTIVE_LOW>;
        };
 };