Copyright (c) 2019, Juniper Networks, Inc.
All rights reserved.

Front panel LEDs
================
There are 4 system LEDs in the front panel. Master, System, Alarm, & Beacon.
LED controls can be found under /sys/class/leds. The sysfs interface & 
colour mappings are as follows:

For master LED: /sys/class/leds/master/brightness
  0 => off
  1 => green

For system LED: /sys/class/leds/system/brightness
  0 => off
  1 => green

For alarm LED: /sys/class/leds/alarm/brightness
  0 => off
  1 => amber
  2 => red

For beacon LED: /sys/class/leds/beacon/brightness
  0 => off
  1 => blue
  
For any of the above LEDs, max_brightness file can tell the maximum value 
accepted.

System FANs
===========
There are 4 fans and each of the fan has 2 fan modules. Overall there are 
8 fans in the system. 

Fan controls can be found in /sys/bus/i2c/devices/17-0068. All the fans 
are controlled by one duty cycle value, ranges from 0 to 100

Fan duty cycle can be controlled through /sys/bus/i2c/devices/17-0068/pwm1

Fan module presence is given by /sys/bus/i2c/devices/17-0068/fan[1-4]_present 
file. A value of '1' indicate that fan is present & a value of '0' otherwise.

Fan rotation direction is given by /sys/bus/i2c/devices/17-0068/fan[1-4]_direction.
A value of '0' indicate the direction is AFO (Front to back airflow) or Airflow 
out. A value of '1' indicate that direction is AFI (Back to front airflow) or 
Airflow in.

Fan speed is given by fan[1-4]_input

Temperature sensors
===================
There are 6 temperature sensors. The readings are available in 
/sys/bus/i2c/devices/{0}-00{1}/hwmon/hwmon*/temp1_input

System PSUs
===========
There are two independent PSUs. These are controlled by a dedicated CPLD. 
The status registers are mapped under /sys/bus/i2c/devices/9-0050 and 
/sys/bus/i2c/devices/10-0053.

SFPs
====
There are 64 QSFP+ modules supported in qfx5210 platform. EEPORMs will be 
mapped under /sys/bus/i2c/devices/[25-88]-0050/ sysfs directory.

FEC should be turned on for 100G SR optics and should be turned off for
100G LR optics. If the optic is changed, please update the entry and
reload the configuration. If the FEC mode is not set as per the optic
type the port may not link up or work properly.

As an example, see this configuration for FEC for 100G SR4 optics in
/etc/sonic/config_db.json
                           
"Ethernet4": {
            "admin_status": "up",
            "alias": "Ethernet4",
            "fec": "rs",
            "index": "1",
            "lanes": "65,66,67,68",
            "mtu": "9100",
            "speed": "100000"
        }

Sensor details
==============
LM75 supported sensor modules will be available under 'sensors' command. 
If you want to get all the sensor data including the SFPs & LEDs, you can 
invoke 'sudo juniper_qfx5210_util.py show'

Platform poweroff
=================
Linux poweroff commands such as 'poweroff', 'shutdown', 'halt', etc. will not
power off qfx5210 platform as there are custom CPLDs control the power off 
sequences. So acpi poweroff hooks are added for powering off the qfx5210. The 
following messages are displayed in the console towards end of poweroff
sequence:

    [   52.500807] System halt/power_off
    [   52.866331] reboot: Power down
    [   52.903257] pm_power_off: qfx5210_cpld_power_off

Once the above messages are seen, you can safely remove the power to the system.

Similarly platform reboot sequences are in place for system reboot. The following
messages are displayed in the console when the system is rebooted:

    [ 6053.163363] System restart: qfx5210_cpld_soft_reset

Platform monitoring daemon
==========================
“juniper_qfx5210_monitor.py” is the platform monitoring script. 
It implements the qfx5210 EM policy. This script will run as system service 
and monitor the temperature sensors in every 20 seconds. Based on the EM 
policy thresholds, it controls the fan rpm, manage alarm leds, and 
shutdown the box.