[Mellanox]Implement plugins for PSU, fan and thermal (sonic-net#4041)

* [plugins]add fan functions, add voltage, current, power for psu
* [plugins]link fanutil.py and psuutil.py to those in 2700
* [plugin]add thermal
* [plugin]add symbol links for thermalutil for all SKUs

Conflicts:
	device/mellanox/x86_64-mlnx_msn2410-r0/plugins/psuutil.py
	device/mellanox/x86_64-mlnx_msn2700-r0/plugins/psuutil.py
	device/mellanox/x86_64-mlnx_msn2740-r0/plugins/psuutil.py

device/mellanox/x86_64-mlnx_msn2010-r0/plugins/fanutil.py

@@ -0,0 +1 @@
+../../x86_64-mlnx_msn2700-r0/plugins/fanutil.py

device/mellanox/x86_64-mlnx_msn2010-r0/plugins/thermalutil.py

@@ -0,0 +1 @@
+../../x86_64-mlnx_msn2700-r0/plugins/thermalutil.py

device/mellanox/x86_64-mlnx_msn2100-r0/plugins/fanutil.py

@@ -0,0 +1 @@
+../../x86_64-mlnx_msn2700-r0/plugins/fanutil.py

device/mellanox/x86_64-mlnx_msn2100-r0/plugins/thermalutil.py

@@ -0,0 +1 @@
+../../x86_64-mlnx_msn2700-r0/plugins/thermalutil.py

device/mellanox/x86_64-mlnx_msn2410-r0/plugins/fanutil.py

@@ -0,0 +1 @@
+../../x86_64-mlnx_msn2700-r0/plugins/fanutil.py

device/mellanox/x86_64-mlnx_msn2410-r0/plugins/psuutil.py

@@ -0,0 +1 @@
+../../x86_64-mlnx_msn2700-r0/plugins/psuutil.py

device/mellanox/x86_64-mlnx_msn2410-r0/plugins/thermalutil.py

@@ -0,0 +1 @@
+../../x86_64-mlnx_msn2700-r0/plugins/thermalutil.py

device/mellanox/x86_64-mlnx_msn2700-r0/plugins/fanutil.py

@@ -0,0 +1,168 @@
+#!/usr/bin/env python
+
+#############################################################################
+# Mellanox
+#
+# Module contains an implementation of SONiC PSU Base API and
+# provides the PSUs status which are available in the platform
+#
+#############################################################################
+
+
+try:
+    import os.path
+    import syslog
+    import subprocess
+    from glob import glob
+    from sonic_fan.fan_base import FanBase
+except ImportError as e:
+    raise ImportError (str(e) + "- required module not found")
+
+def log_err(msg):
+    syslog.openlog("fanutil")
+    syslog.syslog(syslog.LOG_ERR, msg)
+    syslog.closelog()
+
+class FanUtil(FanBase):
+    """Platform-specific FanUtil class"""
+
+    PWM_MAX = 255
+    MAX_FAN_PER_DRAWER = 2
+    GET_HWSKU_CMD = "sonic-cfggen -d -v DEVICE_METADATA.localhost.hwsku"
+    sku_with_unpluggable_fan = ['ACS-MSN2010', 'ACS-MSN2100']
+    FAN_BASE_DIR_PATTERN = "/sys/devices/platform/mlxplat/i2c_mlxcpld.1/i2c-1/i2c-2/2-0048/hwmon/hwmon*"
+    FAN_HOTPLUG_STATUS_BASE_DIR_PATTERN = "/sys/devices/platform/mlxplat/mlxreg-hotplug/hwmon/hwmon*"
+
+    def __init__(self):
+        FanBase.__init__(self)
+
+        self.sku_name = self._get_sku_name()
+
+        if self.sku_name in self.sku_with_unpluggable_fan:
+            self.fan_status = None
+            self.unpluggable_fan = True
+        else:
+            fan_hotplug_status_base_list = glob(self.FAN_HOTPLUG_STATUS_BASE_DIR_PATTERN)
+            if len(fan_hotplug_status_base_list) != 1:
+                raise RuntimeError("Can't find hotplug hwmon path for fan info from {}".format(self.FAN_HOTPLUG_STATUS_BASE_DIR_PATTERN))
+            self.fan_status = os.path.join(fan_hotplug_status_base_list[0], "fan{}")
+            self.unpluggable_fan = False
+        fan_base_dir_list = glob(self.FAN_BASE_DIR_PATTERN)
+        if len(fan_base_dir_list) != 1:
+            raise RuntimeError("Can't find hwmon path for fan info from {}".format(self.FAN_BASE_DIR_PATTERN))
+
+        self.fan_get_speed = os.path.join(fan_base_dir_list[0], "fan{}_input")
+        self.fan_set_speed = os.path.join(fan_base_dir_list[0], "pwm1")
+
+        self.num_of_fan, self.num_of_drawer = self._extract_num_of_fans_and_fan_drawers()
+
+    def _get_sku_name(self):
+        p = subprocess.Popen(self.GET_HWSKU_CMD, shell=True, stdout=subprocess.PIPE)
+        out, err = p.communicate()
+        return out.rstrip('\n')
+
+    def _extract_num_of_fans_and_fan_drawers(self):
+        # So far we don't have files representing the number of fans and drawers
+        # The only way to retrieve the number is to count files.
+        # for number of fans, we get it via couting the speed files.
+        # for number of draws, we get it via couting the status files.
+        list_of_fan_speed = glob(self.fan_get_speed.format("*"))
+        num_of_fan = len(list_of_fan_speed)
+        list_of_fan_status = glob(self.fan_status)
+        num_of_drawer = len(list_of_fan_status)
+
+        return num_of_fan, num_of_drawer
+
+    def _convert_fan_index_to_drawer_index(self, index):
+        return (index + self.MAX_FAN_PER_DRAWER - 1) / self.MAX_FAN_PER_DRAWER
+
+    def _read_file(self, file_pattern, index = None):
+        """
+        Reads the file of the fan
+
+        :param file_pattern: The filename convention
+        :param index: An integer, 1-based index of the fan of which to query status
+        :return: int
+        """
+        return_value = 0
+        try:
+            with open(os.path.join(file_pattern.format(index)), 'r') as file_to_read:
+                return_value = int(file_to_read.read())
+        except IOError:
+            log_err("Read file {} failed".format(file_pattern.format(index)))
+            return return_value
+
+        return return_value
+
+    def get_num_fans(self):
+        """
+        Retrieves the number of FANs supported on the device
+
+        :return: An integer, the number of FANs supported on the device
+        """
+        return self.num_of_fan
+
+    def get_status(self, index):
+        """
+        Retrieves the operational status of FAN defined
+                by index 1-based <index>
+
+        :param index: An integer, 1-based index of the PSU of which to query status
+        :return: Boolean,
+            - True if FAN is running with some speed 
+            - False if FAN has stopped running
+        """
+        if not self.get_presence(index):
+            return False
+
+        return self.get_speed(index) != 0
+
+    def get_presence(self, index):
+        """
+        Retrieves the presence status of a FAN defined
+                by 1-based index <index>
+
+        :param index: An integer, 1-based index of the FAN of which to query status
+        :return: Boolean, True if FAN is plugged, False if not
+        """
+        if index > self.num_of_fan:
+            raise RuntimeError("index ({}) shouldn't be greater than number of fans ({})".format(index, self.num_of_fan))
+
+        if self.unpluggable_fan:
+            return True
+
+        draw_index = self._convert_fan_index_to_drawer_index(index)
+        presence = self._read_file(self.fan_status, draw_index)
+
+        return presence != 0
+
+    def get_speed(self, index):
+        """
+        Retrieves the speed of a Front FAN in the tray in revolutions per minute defined
+                by 1-based index <index>
+
+        :param index: An integer, 1-based index of the FAN of which to query speed
+        :return: integer, denoting front FAN speed
+        """
+        speed = self._read_file(self.fan_get_speed, self.num_of_fan - index + 1)
+
+        return speed
+
+    def set_speed(self, val):
+        """
+        Sets the speed of all the FANs to a value denoted by the duty-cycle percentage val
+
+        :param val: An integer, <0-100> denoting FAN duty cycle percentage 
+        :return: Boolean, True if operation is successful, False if not
+        """
+        status = True
+        pwm = int(round(self.PWM_MAX*val/100.0))
+
+        try:
+            with open(os.path.join(self.fan_set_speed), 'w') as fan_pwm:
+                fan_pwm.write(str(pwm))
+        except (ValueError, IOError):
+            log_err("Read file {} failed".format(self.fan_set_speed))
+            status = False
+
+        return status