There are slave devices that understand I2C but have read-only SDA and
SCL. Examples are FD650 7-segment LED controller and its derivatives.
Typical board designs don't even have a pull-up for both pins.
Therefore add properties for not using open-drain. For write-only SCL
we have a property already, add one for write-only SDA.
Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
---
v4:
- add no-pullup properties
v5:
- add checking mutually-exclusive properties to schema
---
.../devicetree/bindings/i2c/i2c-gpio.yaml | 26 +++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/Documentation/devicetree/bindings/i2c/i2c-gpio.yaml b/Documentation/devicetree/bindings/i2c/i2c-gpio.yaml
index e0d76d5eb..afd4925c2 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-gpio.yaml
+++ b/Documentation/devicetree/bindings/i2c/i2c-gpio.yaml
@@ -33,6 +33,10 @@ properties:
open drain.
maxItems: 1
+ i2c-gpio,sda-output-only:
+ description: sda as output only
+ type: boolean
+
i2c-gpio,scl-output-only:
description: scl as output only
type: boolean
@@ -63,6 +67,28 @@ properties:
GPIO line used for SCL into open drain mode, and that something is not
the GPIO chip. It is essentially an inconsistency flag.
+ i2c-gpio,sda-has-no-pullup:
+ type: boolean
+ description: sda is used in a non-compliant way and has no pull-up.
+ Therefore disable open-drain. This property is mutually-exclusive
+ with i2c-gpio,sda-open-drain.
+
+ i2c-gpio,scl-has-no-pullup:
+ type: boolean
+ description: scl is used in a non-compliant way and has no pull-up.
+ Therefore disable open-drain. This property is mutually-exclusive
+ with i2c-gpio,scl-open-drain.
+
+dependencies:
+ i2c-gpio,sda-has-no-pullup:
+ not:
+ required:
+ - i2c-gpio,sda-open-drain
+ i2c-gpio,scl-has-no-pullup:
+ not:
+ required:
+ - i2c-gpio,scl-open-drain
+
required:
- compatible
- sda-gpios
--
2.39.0
