From c183ce8c6fef0179cb4c1ae4ff2baa62ebf24822 Mon Sep 17 00:00:00 2001
From: Stephen Sun <stephens@mellanox.com>
Date: Sun, 14 Jul 2019 10:04:51 +0300
Subject: [PATCH 1/8] install new platform api on host

---
 files/build_templates/sonic_debian_extension.j2 | 6 ++++++
 platform/mellanox/mlnx-platform-api.mk          | 1 +
 2 files changed, 7 insertions(+)

diff --git a/files/build_templates/sonic_debian_extension.j2 b/files/build_templates/sonic_debian_extension.j2
index 7dfd6dadb673..98f0d0c5bbe3 100644
--- a/files/build_templates/sonic_debian_extension.j2
+++ b/files/build_templates/sonic_debian_extension.j2
@@ -343,6 +343,12 @@ sudo cp $files_path/$ISSU_VERSION_FILE $FILESYSTEM_ROOT/etc/mlnx/issu-version
 sudo cp $files_path/$MLNX_FFB_SCRIPT $FILESYSTEM_ROOT/usr/bin/mlnx-ffb.sh
 j2 platform/mellanox/mlnx-fw-upgrade.j2 | sudo tee $FILESYSTEM_ROOT/usr/bin/mlnx-fw-upgrade.sh
 sudo chmod 755 $FILESYSTEM_ROOT/usr/bin/mlnx-fw-upgrade.sh
+
+# Install mlnx-sonic-platform-common Python 2 package
+MLNX_PLATFORM_COMMON_PY2_WHEEL_NAME=$(basename {{mlnx_platform_api_py2_wheel_path}})
+sudo cp {{mlnx_platform_api_py2_wheel_path}} $FILESYSTEM_ROOT/$MLNX_PLATFORM_COMMON_PY2_WHEEL_NAME
+sudo https_proxy=$https_proxy LANG=C chroot $FILESYSTEM_ROOT pip install $MLNX_PLATFORM_COMMON_PY2_WHEEL_NAME
+sudo rm -rf $FILESYSTEM_ROOT/$MLNX_PLATFORM_COMMON_PY2_WHEEL_NAME
 {% endif %}
 
 {%- if SONIC_ROUTING_STACK == "frr" %}
diff --git a/platform/mellanox/mlnx-platform-api.mk b/platform/mellanox/mlnx-platform-api.mk
index 98a57d0090ed..4b70e59debc1 100644
--- a/platform/mellanox/mlnx-platform-api.mk
+++ b/platform/mellanox/mlnx-platform-api.mk
@@ -5,3 +5,4 @@ $(SONIC_PLATFORM_API_PY2)_SRC_PATH = $(PLATFORM_PATH)/mlnx-platform-api
 $(SONIC_PLATFORM_API_PY2)_PYTHON_VERSION = 2
 SONIC_PYTHON_WHEELS += $(SONIC_PLATFORM_API_PY2)
 
+export mlnx_platform_api_py2_wheel_path="$(addprefix $(PYTHON_WHEELS_PATH)/,$(SONIC_PLATFORM_API_PY2))"

From 235e7922641016f206acee31047e9c3f480fdb02 Mon Sep 17 00:00:00 2001
From: Stephen Sun <stephens@mellanox.com>
Date: Mon, 15 Jul 2019 13:35:02 +0300
Subject: [PATCH 2/8] 1. install necessary dependencys of chassis api on host,
 like sonic-daemon-base 2. remove dependency on the modules not feasible to
 install on host, like swsscomm, sdk, etc.

---
 .../build_templates/sonic_debian_extension.j2 |   6 ++
 .../sonic_platform/chassis_host.py            | 100 ++++++++++++++++++
 .../sonic_platform/platform.py                |  23 ++++
 rules/sonic-daemon-base.mk                    |   1 +
 .../sonic_daemon_base/daemon_base.py          |   7 +-
 5 files changed, 136 insertions(+), 1 deletion(-)
 create mode 100644 platform/mellanox/mlnx-platform-api/sonic_platform/chassis_host.py
 create mode 100644 platform/mellanox/mlnx-platform-api/sonic_platform/platform.py

diff --git a/files/build_templates/sonic_debian_extension.j2 b/files/build_templates/sonic_debian_extension.j2
index 98f0d0c5bbe3..ef9721346708 100644
--- a/files/build_templates/sonic_debian_extension.j2
+++ b/files/build_templates/sonic_debian_extension.j2
@@ -102,6 +102,12 @@ sudo cp {{platform_common_py2_wheel_path}} $FILESYSTEM_ROOT/$PLATFORM_COMMON_PY2
 sudo https_proxy=$https_proxy LANG=C chroot $FILESYSTEM_ROOT pip install $PLATFORM_COMMON_PY2_WHEEL_NAME
 sudo rm -rf $FILESYSTEM_ROOT/$PLATFORM_COMMON_PY2_WHEEL_NAME
 
+# Install sonic-daemon-base Python 2 package
+DAEMON_BASE_PY2_WHEEL_NAME=$(basename {{daemon_base_py2_wheel_path}})
+sudo cp {{daemon_base_py2_wheel_path}} $FILESYSTEM_ROOT/$DAEMON_BASE_PY2_WHEEL_NAME
+sudo https_proxy=$https_proxy LANG=C chroot $FILESYSTEM_ROOT pip install $DAEMON_BASE_PY2_WHEEL_NAME
+sudo rm -rf $FILESYSTEM_ROOT/$DAEMON_BASE_PY2_WHEEL_NAME
+
 # Install built Python Click package (and its dependencies via 'apt-get -y install -f')
 # Do this before installing sonic-utilities so that it doesn't attempt to install
 # an older version as part of its dependencies
diff --git a/platform/mellanox/mlnx-platform-api/sonic_platform/chassis_host.py b/platform/mellanox/mlnx-platform-api/sonic_platform/chassis_host.py
new file mode 100644
index 000000000000..9e6c62935364
--- /dev/null
+++ b/platform/mellanox/mlnx-platform-api/sonic_platform/chassis_host.py
@@ -0,0 +1,100 @@
+#!/usr/bin/env python
+
+#############################################################################
+# Mellanox
+#
+# Module contains an implementation of SONiC Platform Base API and
+# provides the Chassis information which are available in the platform
+#
+#############################################################################
+
+import sys
+
+try:
+    from sonic_platform_base.chassis_base import ChassisBase
+    from sonic_platform.watchdog import get_watchdog
+    from sonic_daemon_base.daemon_base import Logger
+    from os import listdir
+    from os.path import isfile, join
+    import io
+    import syslog
+except ImportError as e:
+    raise ImportError (str(e) + "- required module not found")
+
+HWMGMT_SYSTEM_ROOT = '/var/run/hw-management/system/'
+
+#reboot cause related definitions
+REBOOT_CAUSE_ROOT = HWMGMT_SYSTEM_ROOT
+
+REBOOT_CAUSE_POWER_LOSS_FILE = 'reset_main_pwr_fail'
+REBOOT_CAUSE_AUX_POWER_LOSS_FILE = 'reset_aux_pwr_or_ref'
+REBOOT_CAUSE_THERMAL_OVERLOAD_ASIC_FILE = 'reset_asic_thermal'
+REBOOT_CAUSE_WATCHDOG_FILE = 'reset_hotswap_or_wd'
+REBOOT_CAUSE_MLNX_FIRMWARE_RESET = 'reset_fw_reset'
+
+REBOOT_CAUSE_FILE_LENGTH = 1
+
+# Global logger class instance
+SYSLOG_IDENTIFIER = "mlnx-chassis"
+logger = Logger(SYSLOG_IDENTIFIER)
+
+class Chassis(ChassisBase):
+    """Platform-specific Chassis class"""
+
+    def __init__(self):
+        super(Chassis, self).__init__()
+
+        # Initialize watchdog
+        self._watchdog = get_watchdog()
+
+    def _read_generic_file(self, filename, len):
+        """
+        Read a generic file, returns the contents of the file
+        """
+        result = ''
+        try:
+            fileobj = io.open(filename)
+            result = fileobj.read(len)
+            fileobj.close()
+            return result
+        except:
+            logger.log_warning("Fail to read file {}, maybe it doesn't exist".format(filename))
+            return ''
+
+    def _verify_reboot_cause(self, filename):
+        '''
+        Open and read the reboot cause file in 
+        /var/run/hwmanagement/system (which is defined as REBOOT_CAUSE_ROOT)
+        If a reboot cause file doesn't exists, returns '0'.
+        '''
+        return bool(int(self._read_generic_file(join(REBOOT_CAUSE_ROOT, filename), REBOOT_CAUSE_FILE_LENGTH).rstrip('\n')))
+
+    def get_reboot_cause(self):
+        """
+        Retrieves the cause of the previous reboot
+
+        Returns:
+            A tuple (string, string) where the first element is a string
+            containing the cause of the previous reboot. This string must be
+            one of the predefined strings in this class. If the first string
+            is "REBOOT_CAUSE_HARDWARE_OTHER", the second string can be used
+            to pass a description of the reboot cause.
+        """
+        # read reboot causes files in the following order
+        minor_cause = ''
+        if self._verify_reboot_cause(REBOOT_CAUSE_POWER_LOSS_FILE):
+            major_cause = self.REBOOT_CAUSE_POWER_LOSS
+        elif self._verify_reboot_cause(REBOOT_CAUSE_AUX_POWER_LOSS_FILE):
+            major_cause = self.REBOOT_CAUSE_POWER_LOSS
+        elif self._verify_reboot_cause(REBOOT_CAUSE_THERMAL_OVERLOAD_ASIC_FILE):
+            major_cause = self.REBOOT_CAUSE_THERMAL_OVERLOAD_ASIC
+        elif self._verify_reboot_cause(REBOOT_CAUSE_WATCHDOG_FILE):
+            major_cause = self.REBOOT_CAUSE_WATCHDOG
+        else:
+            major_cause = self.REBOOT_CAUSE_HARDWARE_OTHER
+            if self._verify_reboot_cause(REBOOT_CAUSE_MLNX_FIRMWARE_RESET):
+                minor_cause = "Reset by ASIC firmware"
+            else:
+                major_cause = self.REBOOT_CAUSE_NON_HARDWARE
+
+        return major_cause, minor_cause
diff --git a/platform/mellanox/mlnx-platform-api/sonic_platform/platform.py b/platform/mellanox/mlnx-platform-api/sonic_platform/platform.py
new file mode 100644
index 000000000000..2ef67907e02a
--- /dev/null
+++ b/platform/mellanox/mlnx-platform-api/sonic_platform/platform.py
@@ -0,0 +1,23 @@
+#!/usr/bin/env python
+
+#############################################################################
+# Mellanox
+#
+# implementation of new platform api
+#############################################################################
+
+try:
+    from sonic_platform_base.platform_base import PlatformBase
+#    from sonic_platform.chassis import Chassis
+except ImportError as e:
+    raise ImportError(str(e) + "- required module not found")
+
+class Platform(PlatformBase):
+    def __init__(self, daemon = None):
+        PlatformBase.__init__(self)
+        if daemon is None:
+            from sonic_platform.chassis_host import Chassis
+            self._chassis = Chassis()
+        else:
+            from sonic_platform.chassis import Chassis
+            self._chassis = Chassis()
diff --git a/rules/sonic-daemon-base.mk b/rules/sonic-daemon-base.mk
index dad0900e75ca..5385c18f1f12 100644
--- a/rules/sonic-daemon-base.mk
+++ b/rules/sonic-daemon-base.mk
@@ -5,3 +5,4 @@ $(SONIC_DAEMON_BASE_PY2)_SRC_PATH = $(SRC_PATH)/sonic-daemon-base
 $(SONIC_DAEMON_BASE_PY2)_PYTHON_VERSION = 2
 SONIC_PYTHON_WHEELS += $(SONIC_DAEMON_BASE_PY2)
 
+export daemon_base_py2_wheel_path="$(addprefix $(PYTHON_WHEELS_PATH)/,$(SONIC_DAEMON_BASE_PY2))"
diff --git a/src/sonic-daemon-base/sonic_daemon_base/daemon_base.py b/src/sonic-daemon-base/sonic_daemon_base/daemon_base.py
index 4f26806f4f11..443303882acf 100644
--- a/src/sonic-daemon-base/sonic_daemon_base/daemon_base.py
+++ b/src/sonic-daemon-base/sonic_daemon_base/daemon_base.py
@@ -7,7 +7,6 @@
     import os
     import sys
     import syslog
-    from swsscommon import swsscommon
 except ImportError, e:
     raise ImportError (str(e) + " - required module not found")
 
@@ -38,6 +37,7 @@
 #
 
 def db_connect(db):
+    from swsscommon import swsscommon
     return swsscommon.DBConnector(db,
                                   REDIS_HOSTNAME,
                                   REDIS_PORT,
@@ -89,6 +89,11 @@ def log_debug(self, msg, also_print_to_console=False):
 #
 
 class DaemonBase(object):
+
+    DAEMON_WATCHDOG = "watch-dog"
+    DAEMON_SYSEEPROM = "syseepromd"
+    DAEMON_XCVRD = "xcvrd"
+    DAEMON_PSUD = "psud"
     def __init__(self):
         # Register our signal handlers
         signal.signal(signal.SIGHUP, self.signal_handler)

From 69168ca4c61e6f4864723445043001000d1de7ad Mon Sep 17 00:00:00 2001
From: Stephen Sun <stephens@mellanox.com>
Date: Wed, 17 Jul 2019 01:39:15 +0300
Subject: [PATCH 3/8] add dependency on SONIC_PLATFORM_API_PY2 for
 SONIC_INSTALLERS

---
 slave.mk | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/slave.mk b/slave.mk
index 925cad3b3236..b8a5ce711c29 100644
--- a/slave.mk
+++ b/slave.mk
@@ -598,7 +598,8 @@ $(addprefix $(TARGET_PATH)/, $(SONIC_INSTALLERS)) : $(TARGET_PATH)/% : \
         $(addprefix $(PYTHON_DEBS_PATH)/,$(SONIC_UTILS)) \
         $(addprefix $(PYTHON_WHEELS_PATH)/,$(SONIC_CONFIG_ENGINE)) \
         $(addprefix $(PYTHON_WHEELS_PATH)/,$(SONIC_PLATFORM_COMMON_PY2)) \
-        $(addprefix $(PYTHON_WHEELS_PATH)/,$(REDIS_DUMP_LOAD_PY2))
+        $(addprefix $(PYTHON_WHEELS_PATH)/,$(REDIS_DUMP_LOAD_PY2)) \
+        $(addprefix $(PYTHON_WHEELS_PATH)/,$(SONIC_PLATFORM_API_PY2))
 	$(HEADER)
 	# Pass initramfs and linux kernel explicitly. They are used for all platforms
 	export debs_path="$(STRETCH_DEBS_PATH)"

From 0e46276bcdaf032a2d5d21edfe8e9f4ec3d5d5b0 Mon Sep 17 00:00:00 2001
From: Stephen Sun <stephens@mellanox.com>
Date: Wed, 17 Jul 2019 10:17:42 +0300
Subject: [PATCH 4/8] fix type in process-reboot-cause

---
 files/image_config/process-reboot-cause/process-reboot-cause | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/files/image_config/process-reboot-cause/process-reboot-cause b/files/image_config/process-reboot-cause/process-reboot-cause
index 0d5ae78137fa..2e152c699ce7 100755
--- a/files/image_config/process-reboot-cause/process-reboot-cause
+++ b/files/image_config/process-reboot-cause/process-reboot-cause
@@ -70,7 +70,7 @@ def main():
     # if there is no sonic_platform package installed, we only provide
     # software-related reboot causes.
     try:
-        import sonic_platform
+        import sonic_platform.platform
 
         # Check if the previous reboot was caused by hardware
         platform = sonic_platform.platform.Platform()

From a45d957600f59150a2c328a34c376fbebc520e34 Mon Sep 17 00:00:00 2001
From: Stephen Sun <stephens@mellanox.com>
Date: Wed, 17 Jul 2019 10:19:26 +0300
Subject: [PATCH 5/8] fix the issue "'NoneType' object has no attribute
 'closelog'" which results from referencing an already destroyed global
 variable when destructuring daemon_base.Logger by introducing a class member
 to represent the global

---
 .../sonic_daemon_base/daemon_base.py          | 25 ++++++++++---------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/src/sonic-daemon-base/sonic_daemon_base/daemon_base.py b/src/sonic-daemon-base/sonic_daemon_base/daemon_base.py
index 443303882acf..b762c1b02fe4 100644
--- a/src/sonic-daemon-base/sonic_daemon_base/daemon_base.py
+++ b/src/sonic-daemon-base/sonic_daemon_base/daemon_base.py
@@ -6,7 +6,6 @@
     import subprocess
     import os
     import sys
-    import syslog
 except ImportError, e:
     raise ImportError (str(e) + " - required module not found")
 
@@ -49,37 +48,39 @@ def db_connect(db):
 
 class Logger(object):
     def __init__(self, syslog_identifier):
-        syslog.openlog(ident=syslog_identifier, logoption=syslog.LOG_NDELAY, facility=syslog.LOG_DAEMON)
+        import syslog
+        self.syslog = syslog
+        self.syslog.openlog(ident=syslog_identifier, logoption=self.syslog.LOG_NDELAY, facility=self.syslog.LOG_DAEMON)
 
     def __del__(self):
-        syslog.closelog()
+        self.syslog.closelog()
 
     def log_error(self, msg, also_print_to_console=False):
-        syslog.syslog(syslog.LOG_ERR, msg)
+        self.syslog.syslog(self.syslog.LOG_ERR, msg)
 
         if also_print_to_console:
             print msg
 
     def log_warning(self, msg, also_print_to_console=False):
-        syslog.syslog(syslog.LOG_WARNING, msg)
+        self.syslog.syslog(self.syslog.LOG_WARNING, msg)
 
         if also_print_to_console:
             print msg
 
     def log_notice(self, msg, also_print_to_console=False):
-        syslog.syslog(syslog.LOG_NOTICE, msg)
+        self.syslog.syslog(self.syslog.LOG_NOTICE, msg)
 
         if also_print_to_console:
             print msg
 
     def log_info(self, msg, also_print_to_console=False):
-        syslog.syslog(syslog.LOG_INFO, msg)
+        self.syslog.syslog(self.syslog.LOG_INFO, msg)
 
         if also_print_to_console:
             print msg
 
     def log_debug(self, msg, also_print_to_console=False):
-        syslog.syslog(syslog.LOG_DEBUG, msg)
+        self.syslog.syslog(self.syslog.LOG_DEBUG, msg)
 
         if also_print_to_console:
             print msg
@@ -103,15 +104,15 @@ def __init__(self):
     # Signal handler
     def signal_handler(self, sig, frame):
         if sig == signal.SIGHUP:
-            syslog.syslog(syslog.LOG_INFO, "Caught SIGHUP - ignoring...")
+            self.syslog.syslog(self.syslog.LOG_INFO, "Caught SIGHUP - ignoring...")
         elif sig == signal.SIGINT:
-            syslog.syslog(syslog.LOG_INFO, "Caught SIGINT - exiting...")
+            self.syslog.syslog(self.syslog.LOG_INFO, "Caught SIGINT - exiting...")
             sys.exit(128 + sig)
         elif sig == signal.SIGTERM:
-            syslog.syslog(syslog.LOG_INFO, "Caught SIGTERM - exiting...")
+            self.syslog.syslog(self.syslog.LOG_INFO, "Caught SIGTERM - exiting...")
             sys.exit(128 + sig)
         else:
-            syslog.syslog(syslog.LOG_WARNING, "Caught unhandled signal '" + sig + "'")
+            self.syslog.syslog(self.syslog.LOG_WARNING, "Caught unhandled signal '" + sig + "'")
 
     # Returns platform and hwsku
     def get_platform_and_hwsku(self):

From ca90b7a24109d9497409e4961c789603c1501ebd Mon Sep 17 00:00:00 2001
From: Stephen Sun <stephens@mellanox.com>
Date: Thu, 18 Jul 2019 03:24:59 +0300
Subject: [PATCH 6/8] enhance the reboot cause by supporting aux power failure,
 long/short push on power button

---
 .../mlnx-platform-api/sonic_platform/chassis.py   | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/platform/mellanox/mlnx-platform-api/sonic_platform/chassis.py b/platform/mellanox/mlnx-platform-api/sonic_platform/chassis.py
index f9875a296d35..7c0b81c4a7d4 100644
--- a/platform/mellanox/mlnx-platform-api/sonic_platform/chassis.py
+++ b/platform/mellanox/mlnx-platform-api/sonic_platform/chassis.py
@@ -41,9 +41,12 @@
 REBOOT_CAUSE_ROOT = HWMGMT_SYSTEM_ROOT
 
 REBOOT_CAUSE_POWER_LOSS_FILE = 'reset_main_pwr_fail'
+REBOOT_CAUSE_AUX_POWER_LOSS_FILE = 'reset_aux_pwr_or_ref'
 REBOOT_CAUSE_THERMAL_OVERLOAD_ASIC_FILE = 'reset_asic_thermal'
 REBOOT_CAUSE_WATCHDOG_FILE = 'reset_hotswap_or_wd'
 REBOOT_CAUSE_MLNX_FIRMWARE_RESET = 'reset_fw_reset'
+REBOOT_CAUSE_LONG_PB = 'reset_long_pb'
+REBOOT_CAUSE_SHORT_PB = 'reset_short_pb'
 
 REBOOT_CAUSE_FILE_LENGTH = 1
 
@@ -193,7 +196,10 @@ def _verify_reboot_cause(self, filename):
         /var/run/hwmanagement/system (which is defined as REBOOT_CAUSE_ROOT)
         If a reboot cause file doesn't exists, returns '0'.
         '''
-        return bool(int(self._read_generic_file(join(REBOOT_CAUSE_ROOT, filename), REBOOT_CAUSE_FILE_LENGTH).rstrip('\n')))
+        try:
+            return bool(int(self._read_generic_file(join(REBOOT_CAUSE_ROOT, filename), REBOOT_CAUSE_FILE_LENGTH).rstrip('\n')))
+        except:
+            return False
 
     def get_reboot_cause(self):
         """
@@ -210,6 +216,8 @@ def get_reboot_cause(self):
         minor_cause = ''
         if self._verify_reboot_cause(REBOOT_CAUSE_POWER_LOSS_FILE):
             major_cause = self.REBOOT_CAUSE_POWER_LOSS
+        elif self._verify_reboot_cause(REBOOT_CAUSE_AUX_POWER_LOSS_FILE):
+            major_cause = self.REBOOT_CAUSE_POWER_LOSS
         elif self._verify_reboot_cause(REBOOT_CAUSE_THERMAL_OVERLOAD_ASIC_FILE):
             major_cause = self.REBOOT_CAUSE_THERMAL_OVERLOAD_ASIC
         elif self._verify_reboot_cause(REBOOT_CAUSE_WATCHDOG_FILE):
@@ -218,9 +226,12 @@ def get_reboot_cause(self):
             major_cause = self.REBOOT_CAUSE_HARDWARE_OTHER
             if self._verify_reboot_cause(REBOOT_CAUSE_MLNX_FIRMWARE_RESET):
                 minor_cause = "Reset by ASIC firmware"
+            elif self._verify_reboot_cause(REBOOT_CAUSE_LONG_PB):
+                minor_cause = "Reset by long press on power button"
+            elif self._verify_reboot_cause(REBOOT_CAUSE_SHORT_PB):
+                minor_cause = "Reset by short press on power button"
             else:
                 major_cause = self.REBOOT_CAUSE_NON_HARDWARE
-
         return major_cause, minor_cause
 
     def _get_cpld_version(self, version_file):

From 18e271769ad96baa59dcec13596b90de7b3dfa6b Mon Sep 17 00:00:00 2001
From: Stephen Sun <stephens@mellanox.com>
Date: Thu, 18 Jul 2019 06:30:26 +0300
Subject: [PATCH 7/8] optimize chassis's initialization by 1. removing
 iniaializations of varient components out from constructor and providing one
 initializer for each. 2. only import other modules when initializing it. by
 doing so, initializing time is reduced and unnecessary dependencies of
 chassis is removed for daemons who don't need them.

---
 .../sonic_platform/chassis.py                 |  29 +++--
 .../sonic_platform/chassis_host.py            | 100 ------------------
 .../sonic_platform/platform.py                |  10 +-
 3 files changed, 28 insertions(+), 111 deletions(-)
 delete mode 100644 platform/mellanox/mlnx-platform-api/sonic_platform/chassis_host.py

diff --git a/platform/mellanox/mlnx-platform-api/sonic_platform/chassis.py b/platform/mellanox/mlnx-platform-api/sonic_platform/chassis.py
index 7c0b81c4a7d4..9e50c9347bc8 100644
--- a/platform/mellanox/mlnx-platform-api/sonic_platform/chassis.py
+++ b/platform/mellanox/mlnx-platform-api/sonic_platform/chassis.py
@@ -12,13 +12,7 @@
 
 try:
     from sonic_platform_base.chassis_base import ChassisBase
-    from sonic_platform.psu import Psu
-    from sonic_platform.fan import Fan
-    from sonic_platform.fan import FAN_PATH
-    from sonic_platform.sfp import SFP
-    from sonic_platform.watchdog import get_watchdog
     from sonic_daemon_base.daemon_base import Logger
-    from eeprom import Eeprom
     from os import listdir
     from os.path import isfile, join
     import io
@@ -81,14 +75,27 @@ class Chassis(ChassisBase):
     def __init__(self):
         super(Chassis, self).__init__()
 
+        # move the initialization of each components to their dedicated initializer
+        # which will be called from platform
+
+    def initialize_psu(self):
+        from sonic_platform.psu import Psu
         # Initialize PSU list
+        self.psu_module = Psu
         for index in range(MLNX_NUM_PSU):
             psu = Psu(index)
             self._psu_list.append(psu)
 
+    def initialize_watchdog(self):
+        from sonic_platform.watchdog import get_watchdog
         # Initialize watchdog
         self._watchdog = get_watchdog()
 
+    def initialize_fan(self):
+        from sonic_platform.fan import Fan
+        from sonic_platform.fan import FAN_PATH
+        self.fan_module = Fan
+        self.fan_path = FAN_PATH
         # Initialize FAN list
         multi_rotor_in_drawer = False
         num_of_fan, num_of_drawer = self._extract_num_of_fans_and_fan_drawers()
@@ -101,6 +108,9 @@ def __init__(self):
                 fan = Fan(index, index)
             self._fan_list.append(fan)
 
+    def initialize_sfp(self):
+        from sonic_platform.sfp import SFP
+        self.sfp_module = SFP
         # Initialize SFP list
         port_position_tuple = self._get_port_position_tuple_by_sku_name()
         self.PORT_START = port_position_tuple[0]
@@ -115,9 +125,12 @@ def __init__(self):
                 sfp_module = SFP(index, 'SFP')
             self._sfp_list.append(sfp_module)
 
+    def initialize_eeprom(self):
+        from eeprom import Eeprom
         # Initialize EEPROM
         self.eeprom = Eeprom()
 
+    def initialize_components_list(self):
         # Initialize component list
         self._component_name_list.append(COMPONENT_BIOS)
         self._component_name_list.append(COMPONENT_FIRMWARE)
@@ -127,8 +140,8 @@ def __init__(self):
     def _extract_num_of_fans_and_fan_drawers(self):
         num_of_fan = 0
         num_of_drawer = 0
-        for f in listdir(FAN_PATH):
-            if isfile(join(FAN_PATH, f)):
+        for f in listdir(self.fan_path):
+            if isfile(join(self.fan_path, f)):
                 match_obj = re.match('fan(\d+)_speed_get', f)
                 if match_obj != None:
                     if int(match_obj.group(1)) > num_of_fan:
diff --git a/platform/mellanox/mlnx-platform-api/sonic_platform/chassis_host.py b/platform/mellanox/mlnx-platform-api/sonic_platform/chassis_host.py
deleted file mode 100644
index 9e6c62935364..000000000000
--- a/platform/mellanox/mlnx-platform-api/sonic_platform/chassis_host.py
+++ /dev/null
@@ -1,100 +0,0 @@
-#!/usr/bin/env python
-
-#############################################################################
-# Mellanox
-#
-# Module contains an implementation of SONiC Platform Base API and
-# provides the Chassis information which are available in the platform
-#
-#############################################################################
-
-import sys
-
-try:
-    from sonic_platform_base.chassis_base import ChassisBase
-    from sonic_platform.watchdog import get_watchdog
-    from sonic_daemon_base.daemon_base import Logger
-    from os import listdir
-    from os.path import isfile, join
-    import io
-    import syslog
-except ImportError as e:
-    raise ImportError (str(e) + "- required module not found")
-
-HWMGMT_SYSTEM_ROOT = '/var/run/hw-management/system/'
-
-#reboot cause related definitions
-REBOOT_CAUSE_ROOT = HWMGMT_SYSTEM_ROOT
-
-REBOOT_CAUSE_POWER_LOSS_FILE = 'reset_main_pwr_fail'
-REBOOT_CAUSE_AUX_POWER_LOSS_FILE = 'reset_aux_pwr_or_ref'
-REBOOT_CAUSE_THERMAL_OVERLOAD_ASIC_FILE = 'reset_asic_thermal'
-REBOOT_CAUSE_WATCHDOG_FILE = 'reset_hotswap_or_wd'
-REBOOT_CAUSE_MLNX_FIRMWARE_RESET = 'reset_fw_reset'
-
-REBOOT_CAUSE_FILE_LENGTH = 1
-
-# Global logger class instance
-SYSLOG_IDENTIFIER = "mlnx-chassis"
-logger = Logger(SYSLOG_IDENTIFIER)
-
-class Chassis(ChassisBase):
-    """Platform-specific Chassis class"""
-
-    def __init__(self):
-        super(Chassis, self).__init__()
-
-        # Initialize watchdog
-        self._watchdog = get_watchdog()
-
-    def _read_generic_file(self, filename, len):
-        """
-        Read a generic file, returns the contents of the file
-        """
-        result = ''
-        try:
-            fileobj = io.open(filename)
-            result = fileobj.read(len)
-            fileobj.close()
-            return result
-        except:
-            logger.log_warning("Fail to read file {}, maybe it doesn't exist".format(filename))
-            return ''
-
-    def _verify_reboot_cause(self, filename):
-        '''
-        Open and read the reboot cause file in 
-        /var/run/hwmanagement/system (which is defined as REBOOT_CAUSE_ROOT)
-        If a reboot cause file doesn't exists, returns '0'.
-        '''
-        return bool(int(self._read_generic_file(join(REBOOT_CAUSE_ROOT, filename), REBOOT_CAUSE_FILE_LENGTH).rstrip('\n')))
-
-    def get_reboot_cause(self):
-        """
-        Retrieves the cause of the previous reboot
-
-        Returns:
-            A tuple (string, string) where the first element is a string
-            containing the cause of the previous reboot. This string must be
-            one of the predefined strings in this class. If the first string
-            is "REBOOT_CAUSE_HARDWARE_OTHER", the second string can be used
-            to pass a description of the reboot cause.
-        """
-        # read reboot causes files in the following order
-        minor_cause = ''
-        if self._verify_reboot_cause(REBOOT_CAUSE_POWER_LOSS_FILE):
-            major_cause = self.REBOOT_CAUSE_POWER_LOSS
-        elif self._verify_reboot_cause(REBOOT_CAUSE_AUX_POWER_LOSS_FILE):
-            major_cause = self.REBOOT_CAUSE_POWER_LOSS
-        elif self._verify_reboot_cause(REBOOT_CAUSE_THERMAL_OVERLOAD_ASIC_FILE):
-            major_cause = self.REBOOT_CAUSE_THERMAL_OVERLOAD_ASIC
-        elif self._verify_reboot_cause(REBOOT_CAUSE_WATCHDOG_FILE):
-            major_cause = self.REBOOT_CAUSE_WATCHDOG
-        else:
-            major_cause = self.REBOOT_CAUSE_HARDWARE_OTHER
-            if self._verify_reboot_cause(REBOOT_CAUSE_MLNX_FIRMWARE_RESET):
-                minor_cause = "Reset by ASIC firmware"
-            else:
-                major_cause = self.REBOOT_CAUSE_NON_HARDWARE
-
-        return major_cause, minor_cause
diff --git a/platform/mellanox/mlnx-platform-api/sonic_platform/platform.py b/platform/mellanox/mlnx-platform-api/sonic_platform/platform.py
index 2ef67907e02a..a95bc9b9098f 100644
--- a/platform/mellanox/mlnx-platform-api/sonic_platform/platform.py
+++ b/platform/mellanox/mlnx-platform-api/sonic_platform/platform.py
@@ -8,7 +8,7 @@
 
 try:
     from sonic_platform_base.platform_base import PlatformBase
-#    from sonic_platform.chassis import Chassis
+    from sonic_platform.chassis import Chassis
 except ImportError as e:
     raise ImportError(str(e) + "- required module not found")
 
@@ -16,8 +16,12 @@ class Platform(PlatformBase):
     def __init__(self, daemon = None):
         PlatformBase.__init__(self)
         if daemon is None:
-            from sonic_platform.chassis_host import Chassis
             self._chassis = Chassis()
+            self._chassis.initialize_watchdog()
         else:
-            from sonic_platform.chassis import Chassis
             self._chassis = Chassis()
+            self._chassis.initialize_psu()
+            self._chassis.initialize_fan()
+            self._chassis.initialize_sfp()
+            self._chassis.initialize_eeprom()
+            self._chassis.initialize_components_list()

From e2fe79d7839477b6e8eaab2cb5d08302ef89d843 Mon Sep 17 00:00:00 2001
From: Stephen Sun <stephens@mellanox.com>
Date: Thu, 25 Jul 2019 17:26:15 +0300
Subject: [PATCH 8/8] [sonic_platform] we decide to split chassis in a
 host/daemon basis rather than a per-daemon bases. adjust the argument of
 Platform() accordingly as well as all code that calls Platform.

---
 files/image_config/process-reboot-cause/process-reboot-cause  | 2 +-
 .../mellanox/mlnx-platform-api/sonic_platform/platform.py     | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/files/image_config/process-reboot-cause/process-reboot-cause b/files/image_config/process-reboot-cause/process-reboot-cause
index 2e152c699ce7..4d64b87402ce 100755
--- a/files/image_config/process-reboot-cause/process-reboot-cause
+++ b/files/image_config/process-reboot-cause/process-reboot-cause
@@ -73,7 +73,7 @@ def main():
         import sonic_platform.platform
 
         # Check if the previous reboot was caused by hardware
-        platform = sonic_platform.platform.Platform()
+        platform = sonic_platform.platform.Platform(True)
 
         chassis = platform.get_chassis()
 
diff --git a/platform/mellanox/mlnx-platform-api/sonic_platform/platform.py b/platform/mellanox/mlnx-platform-api/sonic_platform/platform.py
index a95bc9b9098f..fee01d2f8add 100644
--- a/platform/mellanox/mlnx-platform-api/sonic_platform/platform.py
+++ b/platform/mellanox/mlnx-platform-api/sonic_platform/platform.py
@@ -13,9 +13,9 @@
     raise ImportError(str(e) + "- required module not found")
 
 class Platform(PlatformBase):
-    def __init__(self, daemon = None):
+    def __init__(self, is_host = False):
         PlatformBase.__init__(self)
-        if daemon is None:
+        if is_host:
             self._chassis = Chassis()
             self._chassis.initialize_watchdog()
         else: