summaryrefslogtreecommitdiffstats
path: root/Documentation/devicetree/bindings/ptp/timestamper.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/devicetree/bindings/ptp/timestamper.txt')
-rw-r--r--Documentation/devicetree/bindings/ptp/timestamper.txt42
1 files changed, 42 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/ptp/timestamper.txt b/Documentation/devicetree/bindings/ptp/timestamper.txt
new file mode 100644
index 000000000000..fc550ce4d4ea
--- /dev/null
+++ b/Documentation/devicetree/bindings/ptp/timestamper.txt
@@ -0,0 +1,42 @@
+Time stamps from MII bus snooping devices
+
+This binding supports non-PHY devices that snoop the MII bus and
+provide time stamps. In contrast to PHY time stamping drivers (which
+can simply attach their interface directly to the PHY instance), stand
+alone MII time stamping drivers use this binding to specify the
+connection between the snooping device and a given network interface.
+
+Non-PHY MII time stamping drivers typically talk to the control
+interface over another bus like I2C, SPI, UART, or via a memory mapped
+peripheral. This controller device is associated with one or more
+time stamping channels, each of which snoops on a MII bus.
+
+The "timestamper" property lives in a phy node and links a time
+stamping channel from the controller device to that phy's MII bus.
+
+Example:
+
+ tstamper: timestamper@10000000 {
+ compatible = "ines,ptp-ctrl";
+ reg = <0x10000000 0x80>;
+ };
+
+ ethernet@20000000 {
+ mdio {
+ ethernet-phy@1 {
+ timestamper = <&tstamper 0>;
+ };
+ };
+ };
+
+ ethernet@30000000 {
+ mdio {
+ ethernet-phy@2 {
+ timestamper = <&tstamper 1>;
+ };
+ };
+ };
+
+In this example, time stamps from the MII bus attached to phy@1 will
+appear on time stamp channel 0 (zero), and those from phy@2 appear on
+channel 1.