Changes for supporting some PHY Diagnostics

[harshitgulati18]

This change includes support for reading the following PHY layer diagnostics in SAI -

1. Per PMD Lane Rx Signal Detect
2. Per PMD Lane Rx Lock Status (aka CDR status)
3. PCS Rx Link Status
4. Per FEC Lane Alignment Marker Lock

These are some useful diagnostics for debugging a link down or a link flap issue.

All of these diagnostics support a 'current' status and a 'changed' flag and therefore common helper types have been added that are shared by these 4 diagnostics. The current status indicates the status at the time of the read by NOS. The 'changed' flag indicates if the status changed at least once since the last read by NOS.

Following is an example sequence that demonstrates what a NOS will receive when it tries to read the rx signal detect with hardware state changes happening in the background. 'read_rx_signal_detect' is used to depict a read by the NOS.

1. Initial Hardware State : RX_SIGNAL_DETECT = false
2. read_rx_signal_detect -> {current=false, changed=false}
3. Hardware State : RX_SIGNAL_DETECT = true
4. read_rx_signal_detect -> {current=true, changed=true}
5. read_rx_signal_detect -> {current=true, changed=false} // Changed flag resets because no hardware state changes since last read
6. Hardware State : RX_SIGNAL_DETECT = false
7. read_rx_signal_detect -> {current=false, changed=true}
8. Hardware State : RX_SIGNAL_DETECT = true
9. Hardware State : RX_SIGNAL_DETECT = false
10. read_rx_signal_detect -> {current=false, changed=true} // Changed is true because the hardware state changed to at least once since the last read

Following is an example code for how a NOS can read these diagnostics

sai_attribute_t rx_signal_detect_attr;
rx_signal_detect_attr.id = SAI_PORT_ATTR_RX_SIGNAL_DETECT;
sai_port_api_t* port_api;
port_api->get_port_attribute(port_id, 1, &rx_signal_detect_attr);
// Assuming just one PMD lane
sai_current_and_changed_status_t signal_detect_lane1 = rx_signal_detect_attr.value. portboolcurrentandchangedstatuslist.list[0].value;
printf("{current=%d, changed=%d}", signal_detect_lane1.current, signal_detect_lane1.changed);

[kcudnik]

should this struct have more meaningful name rather than names and types of fields?

[harshitgulati18]

I changed the name of the struct. Please check the new revision

[kcudnik]

should this struct have more meaningful name rather than names and types of fields?

[harshitgulati18]

I changed the name of the struct. Please check the new revision

[kcudnik]

please address comments