1 files changed, 99 insertions, 0 deletions
diff --git a/meta-facebook/meta-wedge/recipes-wedge/fbutils/files/setup_rov.sh b/meta-facebook/meta-wedge/recipes-wedge/fbutils/files/setup_rov.sh
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@@ -0,0 +1,99 @@
+#!/bin/bash
+#
+# Copyright 2014-present Facebook. All Rights Reserved.
+#
+# This program file is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation; version 2 of the License.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+# for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program in a file named COPYING; if not, write to the
+# Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor,
+# Boston, MA 02110-1301 USA
+#
+
+# The T2 chip can prefer different input voltages, depending, presumably
+# of manufacturing variations.  We need to determine whether it wants
+# 0.95V or 1.025V, reset the T2 to reduce total power usage, set the
+# outgoing voltage on the first buck converter, and bring T2 up out of
+# reset.
+
+. /usr/local/fbpackages/utils/ast-functions
+
+# read the T2 ROV after the GPIOs are enabled
+t2_rov() {
+    local val0 val1 val2
+    # Note that the values are *not* read in order.
+    val0=$(cat /sys/class/gpio/gpio58/value 2>/dev/null)
+    val1=$(cat /sys/class/gpio/gpio56/value 2>/dev/null)
+    val2=$(cat /sys/class/gpio/gpio57/value 2>/dev/null)
+    echo $((val0 | (val1 << 1) | (val2 << 2)))
+}
+
+rov=$(t2_rov)
+
+# target_volts come from the data sheet and 18mV of loss and
+# some fudging based on actual measurements to get either 1.025V
+# or 0.95V at T2
+if [ $rov -eq 1 ]; then
+    target_volts=0x5a
+elif [ $rov -eq 2 ]; then
+    target_volts=0x65
+else
+    echo "Unrecognized T2 ROV value $rov, setting failed."
+    exit 1
+fi
+target_volts=$(( $target_volts * 1 ))  # normalize to decimal
+
+# We shouldn't have to rmmod pmbus, because it hasn't been loaded yet,
+# but if the script is rerun after the system is up, it may be necessary.
+rmmod pmbus
+reload=$?
+
+# Get current voltage value
+cur_volts=$(i2cget -y 1 0x60 0x8b w)
+cur_volts=$(( $cur_volts * 1 ))  # normalize to decimal
+
+# Only bounce the T2 if we actually need to modify the voltage
+if [ $cur_volts -ne $target_volts ]; then 
+    # Set values before turning out output;  we're using "PCIE, then MCS"
+    echo 1 > /sys/class/gpio/gpio42/value
+    echo 1 > /sys/class/gpio/gpio43/value
+    echo out > /sys/class/gpio/gpio42/direction
+    echo out > /sys/class/gpio/gpio43/direction
+    echo 0 > /sys/class/gpio/gpio16/value
+    echo out > /sys/class/gpio/gpio16/direction
+    # T2 is in reset;  note that this may cause NMI messages on the uServer,
+    # which shouldn't be up anyway when this is first run.
+    
+    # Set the requested value to the current value to avoid rapid shifts
+    i2cset -y 1 0x60 0x21 $cur_volts w
+    # Enable the requested voltage
+    i2cset -y 1 0x60 0xd2 0x5a
+    i2cset -y 1 0x60 0xd3 0x5a
+    sleep 1
+
+    # Set the target voltage
+    i2cset -y 1 0x60 0x21 $target_volts w
+    
+    sleep 1
+
+    # Let T2 come out of reset
+    echo 1 > /sys/class/gpio/gpio16/value
+    echo "T2 ROV value set based on $rov."
+    sleep 2
+    echo 0 > /sys/class/gpio/gpio42/value
+    echo 0 > /sys/class/gpio/gpio43/value
+else
+    echo "T2 ROV already correctly set."
+fi
+# Bring back pmbus if necessary
+if [ $reload -eq 0 ]; then
+    modprobe pmbus
+fi