dt-bindings: slave-device: add current-speed property

This adds a new DT property to define the current baud rate of the
slave device.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/Documentation/devicetree/bindings/serial/slave-device.txt b/Documentation/devicetree/bindings/serial/slave-device.txt
index f660379..40110e0 100644 (file)
--- a/Documentation/devicetree/bindings/serial/slave-device.txt
+++ b/Documentation/devicetree/bindings/serial/slave-device.txt
@@ -21,6 +21,15 @@ Optional Properties:
                  can support. For example, a particular board has some signal
                  quality issue or the host processor can't support higher
                  baud rates.
+- current-speed        : The current baud rate the device operates at. This should
+                 only be present in case a driver has no chance to know
+                 the baud rate of the slave device.
+                 Examples:
+                   * device supports auto-baud
+                   * the rate is setup by a bootloader and there is no
+                     way to reset the device
+                   * device baud rate is configured by its firmware but
+                     there is no way to request the actual settings
 
 Example: