[device] Add PSU utility for platform ly1200 of MiTAC (#1673)

[platform/broadcom/sonic-platform-modules-mitac] Install acpi package for daemon and adjust i2c sequence

Signed-off-by: Eddy Weng <eddy.weng@mic.com.tw>

device/mitac/x86_64-mitac_ly1200_b32h0_c3-r0/plugins/psuutil.py

@@ -0,0 +1,72 @@
+#!/usr/bin/env python
+
+#############################################################################
+# MiTAC
+#
+# Module contains an implementation of SONiC PSU Base API and
+# provides the PSUs status which are available in the platform
+#
+#############################################################################
+
+import os.path
+
+try:
+    from sonic_psu.psu_base import PsuBase
+except ImportError as e:
+    raise ImportError (str(e) + "- required module not found")
+
+class PsuUtil(PsuBase):
+    """Platform-specific PSUutil class"""
+
+    def __init__(self):
+        PsuBase.__init__(self)
+
+        self.psu_nums = 2
+        self.psu_path = "/sys/bus/i2c/devices/1-0032/"
+        self.psu_presence = "ps{}_ps"
+        self.psu_oper_status = "ps{}_pg"
+
+    def get_num_psus(self):
+        """
+        Retrieves the number of PSUs available on the device
+        :return: An integer, the number of PSUs available on the device
+        """
+        return self.psu_nums
+
+    def get_psu_status(self, index):
+        """
+        Retrieves the oprational status of power supply unit (PSU) defined
+                by 1-based index <index>
+        :param index: An integer, 1-based index of the PSU of which to query status
+        :return: Boolean, True if PSU is operating properly, False if PSU is faulty
+        """
+        if index is None:
+            return False
+
+        status = 1
+        try:
+            with open(self.psu_path + self.psu_oper_status.format(index), 'r') as power_status:
+                status = int(power_status.read(), 0)
+        except IOError:
+            return False
+
+        return status == 0
+
+    def get_psu_presence(self, index):
+        """
+        Retrieves the presence status of power supply unit (PSU) defined
+                by 1-based index <index>
+        :param index: An integer, 1-based index of the PSU of which to query status
+        :return: Boolean, True if PSU is plugged, False if not
+        """
+        if index is None:
+            return False
+
+        status = 1
+        try:
+            with open(self.psu_path + self.psu_presence.format(index), 'r') as presence_status:
+                status = int(presence_status.read(), 0)
+        except IOError:
+            return False
+
+        return status == 0