diff --git a/meta-lanyang/recipes-phosphor/chassis/avsbus-control.bb b/meta-lanyang/recipes-phosphor/chassis/avsbus-control.bb
new file mode 100644
index 0000000..ff68f39
--- /dev/null
+++ b/meta-lanyang/recipes-phosphor/chassis/avsbus-control.bb
@@ -0,0 +1,28 @@
+SUMMARY = "Lanyang AVSBus control"
+DESCRIPTION = "Voltage regulator module (VRM) AVSBus control for Lanyang"
+PR = "r0"
+
+inherit obmc-phosphor-systemd
+inherit obmc-phosphor-license
+
+TMPL_OFF = "avsbus-disable@.service"
+TMPL_ON = "avsbus-enable@.service"
+INSTFMT_OFF = "avsbus-disable@{0}.service"
+INSTFMT_ON = "avsbus-enable@{0}.service"
+TGTFMT_OFF = "obmc-host-stop@{0}.target"
+TGTFMT_ON = "obmc-chassis-poweron@{0}.target"
+FMT_OFF = "../${TMPL_OFF}:${TGTFMT_OFF}.wants/${INSTFMT_OFF}"
+FMT_ON = "../${TMPL_ON}:${TGTFMT_ON}.requires/${INSTFMT_ON}"
+
+SYSTEMD_SERVICE_${PN} += "${TMPL_OFF}"
+SYSTEMD_LINK_${PN} += "${@compose_list(d, 'FMT_OFF', 'OBMC_CHASSIS_INSTANCES')}"
+SYSTEMD_SERVICE_${PN} += "${TMPL_ON}"
+SYSTEMD_LINK_${PN} += "${@compose_list(d, 'FMT_ON', 'OBMC_CHASSIS_INSTANCES')}"
+
+SRC_URI += "file://lanyang_avsbus.sh"
+RDEPENDS_${PN} += "i2c-tools"
+
+do_install() {
+        install -d ${D}${bindir}
+        install -m 0755 ${WORKDIR}/lanyang_avsbus.sh ${D}${bindir}/lanyang_avsbus.sh
+}
diff --git a/meta-lanyang/recipes-phosphor/chassis/avsbus-control/avsbus-disable@.service b/meta-lanyang/recipes-phosphor/chassis/avsbus-control/avsbus-disable@.service
new file mode 100644
index 0000000..add5f22
--- /dev/null
+++ b/meta-lanyang/recipes-phosphor/chassis/avsbus-control/avsbus-disable@.service
@@ -0,0 +1,15 @@
+[Unit]
+Description=Disable AVSBus on VRMs
+Wants=obmc-power-stop-pre@%i.target
+Before=obmc-power-stop-pre@%i.target
+Conflicts=obmc-host-startmin@%i.target
+ConditionPathExists=!/run/openbmc/chassis@%i-on
+
+[Service]
+ExecStart=/usr/bin/env lanyang_avsbus.sh disable
+SyslogIdentifier=lanyang_avsbus.sh
+Type=oneshot
+RemainAfterExit=yes
+
+[Install]
+WantedBy=obmc-host-stop@%i.target
diff --git a/meta-lanyang/recipes-phosphor/chassis/avsbus-control/avsbus-enable@.service b/meta-lanyang/recipes-phosphor/chassis/avsbus-control/avsbus-enable@.service
new file mode 100644
index 0000000..787ec4c
--- /dev/null
+++ b/meta-lanyang/recipes-phosphor/chassis/avsbus-control/avsbus-enable@.service
@@ -0,0 +1,16 @@
+[Unit]
+Description=Enable AVSBus on VRMs
+Wants=obmc-host-start-pre@%i.target
+Before=obmc-host-start-pre@%i.target
+Conflicts=obmc-host-stop@%i.target
+ConditionPathExists=!/run/openbmc/chassis@%i-on
+
+[Service]
+ExecStart=/usr/bin/env lanyang_avsbus.sh vdn_max
+ExecStart=/usr/bin/env lanyang_avsbus.sh enable
+SyslogIdentifier=lanyang_avsbus.sh
+Type=oneshot
+RemainAfterExit=yes
+
+[Install]
+RequiredBy=obmc-chassis-poweron@%i.target
diff --git a/meta-lanyang/recipes-phosphor/chassis/avsbus-control/lanyang_avsbus.sh b/meta-lanyang/recipes-phosphor/chassis/avsbus-control/lanyang_avsbus.sh
new file mode 100755
index 0000000..bf58def
--- /dev/null
+++ b/meta-lanyang/recipes-phosphor/chassis/avsbus-control/lanyang_avsbus.sh
@@ -0,0 +1,98 @@
+#!/bin/sh -e
+# AVSBus control for PMBUS voltage regulator modules (VRMs)
+# Switches output voltage target between
+# - VOUT_COMMAND register (AVSBus disabled, default on Zaius)
+# - AVSBus target output (AVSBus enabled, voltage set by host)
+
+cpu0_i2c_bus="5"
+cpu1_i2c_bus="6"
+busses="$cpu0_i2c_bus $cpu1_i2c_bus"
+vdd_i2c_addr_page="0x60:0x01"
+vdn_i2c_addr_page="0x64:0x01"
+vcs_i2c_addr_page="0x64:0x00"
+addrs_pages="$vdd_i2c_addr_page $vdn_i2c_addr_page $vcs_i2c_addr_page"
+
+# Usage: vrm_set_page <bus> <i2c_address> <page>
+vrm_set_page()
+{
+    i2cset -y $1 $2 0x00 $3 b
+}
+
+# Usage: vrm_avs_enable <bus> <i2c_address> <page>
+# Initializes the AVSBus VOUT setpoint to the value in PMBus VOUT_COMMAND
+# Sets OPERATION PMBUS register to
+# - Enable/Disable: On
+# - VOUT Source: AVSBus Target Rail Voltage
+# - AVSBus Copy: VOUT_COMMAND remains unchanged
+# Writes to VOUT setpoint over AVSBus will persist after the VRM is switched to
+# PMBus control. Switching back to AVSBus control restores this persisted
+# setpoint rather than re-initializing to PMBus VOUT_COMMAND. This behavior is
+# known to Intersil and writing VOUT_COMMAND over PMBus is the only workaround.
+vrm_avs_enable()
+{
+    vrm_set_page "$@"
+    echo Enabling AVSBus on bus $1 VRM @$2 rail $3...
+    local vout_command=`i2cget -y $1 $2 0x21 w`
+    i2cset -y $1 $2 0x21 $vout_command w
+    i2cset -y $1 $2 0x01 0xb0 b
+}
+
+# Usage: vrm_avs_disable <bus> <i2c_address> <page>
+# Sets OPERATION PMBUS register to
+# - Enable/Disable: On
+# - VOUT Source: VOUT_COMMAND
+# - AVSBus Copy: VOUT_COMMAND remains unchanged
+vrm_avs_disable()
+{
+    vrm_set_page "$@"
+    echo Disabling AVSBus on bus $1 VRM @$2 rail $3...
+    i2cset -y $1 $2 0x01 0x80 b
+}
+
+# Usage: vrm_vout_max_1v1 <bus> <i2c_address> <page>
+# Sets VOUT_MAX to 1.1V
+vrm_vout_max_1v1()
+{
+    vrm_set_page "$@"
+    echo Setting VOUT_MAX=[1.1V] on bus $1 VRM @$2 rail $3...
+    i2cset -y $1 $2 0x24 0x44c w
+}
+
+# Usage: vrm_print <bus> <i2c_address> <page>
+vrm_print()
+{
+    vrm_set_page "$@"
+    local operation=`i2cget -y $1 $2 0x01 b`
+    local vout=`i2cget -y $1 $2 0x8b w`
+    local iout=`i2cget -y $1 $2 0x8c w`
+    echo VRM on bus $1 @$2 rail $3: OPERATION=$operation VOUT=$vout IOUT=$iout
+}
+
+# Usage: for_each_rail <command>
+# <command> will be invoked with <bus> <i2c_address> <page>
+for_each_rail()
+{
+    for bus in $busses
+    do
+        for addr_page in $addrs_pages
+        do
+            $1 $bus `echo $addr_page | tr : " "`
+        done
+    done
+}
+
+if [ "$1" == "enable" ]
+then
+    for_each_rail vrm_avs_enable
+elif [ "$1" == "disable" ]
+then
+    for_each_rail vrm_avs_disable
+elif [ "$1" == "vdn_max" ]
+then
+    addrs_pages="$vdn_i2c_addr_page"
+    for_each_rail vrm_vout_max_1v1
+else
+    for_each_rail vrm_print
+    echo "\"$0 <enable|disable>\" to control whether VRMs use AVSBus"
+    echo "\"$0 <vdn_max>\" to set VDN rails VOUT_MAX to 1.1V"
+fi