[Mellanox] Add support for set/get system led status (#4829)

System health feature needs to set/get system led status

- Add a led object in chassis class and initialize it when the API is called on host side
- Read/write system led system fs to get/set the status

platform/mellanox/mlnx-platform-api/sonic_platform/chassis.py

@@ -56,6 +56,9 @@ port_position_tuple_list = [(0, 0, 31, 32, 1), (0, 0, 15, 16, 1), (0, 48, 55, 56
 class Chassis(ChassisBase):
     """Platform-specific Chassis class"""
 
+    # System status LED
+    _led = None
+
     def __init__(self):
         super(Chassis, self).__init__()
 
@@ -156,6 +159,10 @@ class Chassis(ChassisBase):
         self._component_list.append(ComponentBIOS())
         self._component_list.extend(ComponentCPLD.get_component_list())
 
+    def initizalize_system_led(self):
+        from .led import SystemLed
+        Chassis._led = SystemLed()
+
 
     def get_name(self):
         """
@@ -467,3 +474,25 @@ class Chassis(ChassisBase):
         from .thermal_manager import ThermalManager
         return ThermalManager
 
+    def set_status_led(self, color):
+        """
+        Sets the state of the system LED
+
+        Args:
+            color: A string representing the color with which to set the
+                   system LED
+
+        Returns:
+            bool: True if system LED state is set successfully, False if not
+        """
+        return False if not Chassis._led else Chassis._led.set_status(color)
+
+    def get_status_led(self):
+        """
+        Gets the state of the system LED
+
+        Returns:
+            A string, one of the valid LED color strings which could be vendor
+            specified.
+        """
+        return None if not Chassis._led else Chassis._led.get_status()

platform/mellanox/mlnx-platform-api/sonic_platform/led.py

@@ -3,12 +3,16 @@ import os
 
 class Led(object):
     STATUS_LED_COLOR_GREEN = 'green'
+    STATUS_LED_COLOR_GREEN_BLINK = 'green_blink'
     STATUS_LED_COLOR_RED = 'red'
+    STATUS_LED_COLOR_RED_BLINK = 'red_blink'
     STATUS_LED_COLOR_ORANGE = 'orange'
+    STATUS_LED_COLOR_ORANGE_BLINK = 'orange_blink'
     STATUS_LED_COLOR_OFF = 'off'
 
     LED_ON = '1'
     LED_OFF = '0'
+    LED_BLINK = '50'
 
     LED_PATH = "/var/run/hw-management/led/"
 
@@ -19,6 +23,11 @@ class Led(object):
 
         status = False
         try:
+            self._stop_blink(led_cap_list)
+            blink_pos = color.find('blink')
+            if blink_pos != -1:
+                return self._set_status_blink(color, blink_pos, led_cap_list)
+
             if color == Led.STATUS_LED_COLOR_GREEN:
                 with open(self.get_green_led_path(), 'w') as led:
                     led.write(Led.LED_ON)
@@ -54,12 +63,53 @@ class Led(object):
 
         return status
 
+    def _set_status_blink(self, color, blink_pos, led_cap_list):
+        if color not in led_cap_list:
+            if color == Led.STATUS_LED_COLOR_RED_BLINK and Led.STATUS_LED_COLOR_ORANGE_BLINK in led_cap_list:
+                color = Led.STATUS_LED_COLOR_ORANGE_BLINK
+            elif color == Led.STATUS_LED_COLOR_ORANGE_BLINK and Led.STATUS_LED_COLOR_RED_BLINK in led_cap_list:
+                color = Led.STATUS_LED_COLOR_RED_BLINK
+            else:
+                return False
+
+        if Led.STATUS_LED_COLOR_GREEN_BLINK == color:
+            self._set_led_blink_status(self.get_green_led_delay_on_path(), self.get_green_led_delay_off_path(), Led.LED_BLINK)
+        elif Led.STATUS_LED_COLOR_RED_BLINK == color:
+            self._set_led_blink_status(self.get_red_led_delay_on_path(), self.get_red_led_delay_off_path(), Led.LED_BLINK)
+        elif Led.STATUS_LED_COLOR_ORANGE_BLINK == color:
+            self._set_led_blink_status(self.get_orange_led_delay_on_path(), self.get_orange_led_delay_off_path(), Led.LED_BLINK)
+        else:
+            return False
+
+        return True
+
+    def _stop_blink(self, led_cap_list):
+        try:
+            if Led.STATUS_LED_COLOR_GREEN_BLINK in led_cap_list:
+                self._set_led_blink_status(self.get_green_led_delay_on_path(), self.get_green_led_delay_off_path(), Led.LED_OFF)
+            if Led.STATUS_LED_COLOR_RED_BLINK in led_cap_list:
+                self._set_led_blink_status(self.get_red_led_delay_on_path(), self.get_red_led_delay_off_path(), Led.LED_OFF)
+            if Led.STATUS_LED_COLOR_ORANGE_BLINK in led_cap_list:
+                self._set_led_blink_status(self.get_orange_led_delay_on_path(), self.get_orange_led_delay_off_path(), Led.LED_OFF)
+        except Exception as e:
+            return
+
+    def _set_led_blink_status(self, delay_on_file, delay_off_file, value):
+        with open(delay_on_file, 'w') as led:
+            led.write(value)
+        with open(delay_off_file, 'w') as led:
+            led.write(value)
+
     def get_status(self):
         led_cap_list = self.get_capability()
         if led_cap_list is None:
             return Led.STATUS_LED_COLOR_OFF
 
         try:
+            blink_status = self._get_blink_status(led_cap_list)
+            if blink_status is not None:
+                return blink_status
+
             with open(self.get_green_led_path(), 'r') as led:
                 if Led.LED_OFF != led.read().rstrip('\n'):
                     return Led.STATUS_LED_COLOR_GREEN
@@ -77,12 +127,35 @@ class Led(object):
 
         return Led.STATUS_LED_COLOR_OFF
 
+    def _get_blink_status(self, led_cap_list):
+        try:
+            if Led.STATUS_LED_COLOR_GREEN_BLINK in led_cap_list:
+                if self._is_led_blinking(self.get_green_led_delay_on_path(), self.get_green_led_delay_off_path()):
+                    return Led.STATUS_LED_COLOR_GREEN_BLINK
+            if Led.STATUS_LED_COLOR_RED_BLINK in led_cap_list:
+                if self._is_led_blinking(self.get_red_led_delay_on_path(), self.get_red_led_delay_off_path()):
+                    return Led.STATUS_LED_COLOR_RED_BLINK
+            if Led.STATUS_LED_COLOR_ORANGE_BLINK in led_cap_list:
+                if self._is_led_blinking(self.get_orange_led_delay_on_path(), self.get_orange_led_delay_off_path()):
+                    return Led.STATUS_LED_COLOR_ORANGE_BLINK
+        except Exception as e:
+            return None
+
+        return None
+
+    def _is_led_blinking(self, delay_on_file, delay_off_file):
+        with open(delay_on_file, 'r') as led:
+            delay_on = led.read().rstrip('\n')
+        with open(delay_off_file, 'r') as led:
+            delay_off = led.read().rstrip('\n')
+        return delay_on != Led.LED_OFF and delay_off != Led.LED_OFF
+
     def get_capability(self):
         cap_list = None
         try:
             with open(self.get_led_cap_path(), 'r') as led_cap:
                 caps = led_cap.read()
-                cap_list = caps.split()
+                cap_list = set(caps.split())
         except (ValueError, IOError):
             pass
         
@@ -91,12 +164,30 @@ class Led(object):
     def get_green_led_path(self):
         pass
 
+    def get_green_led_delay_off_path(self):
+        return '{}_delay_off'.format(self.get_green_led_path())
+
+    def get_green_led_delay_on_path(self):
+        return '{}_delay_on'.format(self.get_green_led_path())
+
     def get_red_led_path(self):
         pass
 
+    def get_red_led_delay_off_path(self):
+        return '{}_delay_off'.format(self.get_red_led_path())
+
+    def get_red_led_delay_on_path(self):
+        return '{}_delay_on'.format(self.get_red_led_path())
+
     def get_orange_led_path(self):
         pass
 
+    def get_orange_led_delay_off_path(self):
+        return '{}_delay_off'.format(self.get_orange_led_path())
+
+    def get_orange_led_delay_on_path(self):
+        return '{}_delay_on'.format(self.get_orange_led_path())
+
     def get_led_cap_path(self):
         pass
 
@@ -159,6 +250,26 @@ class PsuLed(Led):
         return self._led_cap_path
 
 
+class SystemLed(Led):
+    def __init__(self):
+        self._green_led_path = os.path.join(Led.LED_PATH, "led_status_green")
+        self._red_led_path = os.path.join(Led.LED_PATH, "led_status_red")
+        self._orange_led_path = os.path.join(Led.LED_PATH, "led_status_orange")
+        self._led_cap_path = os.path.join(Led.LED_PATH, "led_status_capability")
+
+    def get_green_led_path(self):
+        return self._green_led_path
+
+    def get_red_led_path(self):
+        return self._red_led_path
+
+    def get_orange_led_path(self):
+        return self._orange_led_path
+
+    def get_led_cap_path(self):
+        return self._led_cap_path
+
+
 class SharedLed(object):
     LED_PRIORITY = {
         Led.STATUS_LED_COLOR_RED: 0,

platform/mellanox/mlnx-platform-api/sonic_platform/platform.py

@@ -19,6 +19,7 @@ class Platform(PlatformBase):
         if self._is_host():
             self._chassis = Chassis()
             self._chassis.initialize_components()
+            self._chassis.initizalize_system_led()
         else:
             self._chassis = Chassis()
             self._chassis.initialize_psu()