1 Time stamps from MII bus snooping devices 1 Time stamps from MII bus snooping devices
2 2
3 This binding supports non-PHY devices that sno 3 This binding supports non-PHY devices that snoop the MII bus and
4 provide time stamps. In contrast to PHY time 4 provide time stamps. In contrast to PHY time stamping drivers (which
5 can simply attach their interface directly to 5 can simply attach their interface directly to the PHY instance), stand
6 alone MII time stamping drivers use this bindi 6 alone MII time stamping drivers use this binding to specify the
7 connection between the snooping device and a g 7 connection between the snooping device and a given network interface.
8 8
9 Non-PHY MII time stamping drivers typically ta 9 Non-PHY MII time stamping drivers typically talk to the control
10 interface over another bus like I2C, SPI, UART 10 interface over another bus like I2C, SPI, UART, or via a memory mapped
11 peripheral. This controller device is associa 11 peripheral. This controller device is associated with one or more
12 time stamping channels, each of which snoops o 12 time stamping channels, each of which snoops on a MII bus.
13 13
14 The "timestamper" property lives in a phy node 14 The "timestamper" property lives in a phy node and links a time
15 stamping channel from the controller device to 15 stamping channel from the controller device to that phy's MII bus.
16 16
17 Example: 17 Example:
18 18
19 tstamper: timestamper@10000000 { 19 tstamper: timestamper@10000000 {
20 compatible = "ines,ptp-ctrl"; 20 compatible = "ines,ptp-ctrl";
21 reg = <0x10000000 0x80>; 21 reg = <0x10000000 0x80>;
22 }; 22 };
23 23
24 ethernet@20000000 { 24 ethernet@20000000 {
25 mdio { 25 mdio {
26 ethernet-phy@1 { 26 ethernet-phy@1 {
27 timestamper = 27 timestamper = <&tstamper 0>;
28 }; 28 };
29 }; 29 };
30 }; 30 };
31 31
32 ethernet@30000000 { 32 ethernet@30000000 {
33 mdio { 33 mdio {
34 ethernet-phy@2 { 34 ethernet-phy@2 {
35 timestamper = 35 timestamper = <&tstamper 1>;
36 }; 36 };
37 }; 37 };
38 }; 38 };
39 39
40 In this example, time stamps from the MII bus 40 In this example, time stamps from the MII bus attached to phy@1 will
41 appear on time stamp channel 0 (zero), and tho 41 appear on time stamp channel 0 (zero), and those from phy@2 appear on
42 channel 1. 42 channel 1.
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