meta-facebook: santabarbara: detect SSC vendor before disabling SSC

Add 2nd source TI SSC support.
Read the vendor id register to tell Renesas and TI SSC chips apart, then
apply the matching disable sequence for each.

Change-Id: I019bd9d2d4c46877676e7695cc46186fa4c8975f
Signed-off-by: Fred Chen <Fred.Chen@quantatw.com>

meta-facebook/meta-santabarbara/recipes-phosphor/state/phosphor-state-manager/phosphor-state-manager-init

diff --git a/meta-facebook/meta-santabarbara/recipes-phosphor/state/phosphor-state-manager/phosphor-state-manager-init b/meta-facebook/meta-santabarbara/recipes-phosphor/state/phosphor-state-manager/phosphor-state-manager-init
index 3005614..4f3a29f 100644
--- a/meta-facebook/meta-santabarbara/recipes-phosphor/state/phosphor-state-manager/phosphor-state-manager-init
+++ b/meta-facebook/meta-santabarbara/recipes-phosphor/state/phosphor-state-manager/phosphor-state-manager-init
@@ -4,8 +4,27 @@
 source /usr/libexec/fb-common-functions
 
 # Disable SSC
-i2ctransfer -fy 17 w2@0x09 0xfd 0x03
-i2ctransfer -fy 17 w2@0x09 0x07 0x00
+SSC_BUS=17
+SSC_ADDR=0x09
+
+# Set page 0 to read vendor id
+if ! i2ctransfer -fy "$SSC_BUS" w2@"$SSC_ADDR" 0xfd 0x00 2>/dev/null; then
+    echo "SSC device not found, skip disabling SSC" >&2
+else
+    read -r SSC_VENDOR_ID0 SSC_VENDOR_ID1 <<< "$(i2ctransfer -fy "$SSC_BUS" w1@"$SSC_ADDR" 0x00 r2)"
+
+    if [ "$SSC_VENDOR_ID0" = "0x33" ] && [ "$SSC_VENDOR_ID1" = "0x10" ]; then
+        # Renesas
+        i2ctransfer -fy "$SSC_BUS" w2@"$SSC_ADDR" 0xfd 0x03
+        i2ctransfer -fy "$SSC_BUS" w2@"$SSC_ADDR" 0x07 0x00
+    elif [ "$SSC_VENDOR_ID0" = "0x8b" ] && [ "$SSC_VENDOR_ID1" = "0x03" ]; then
+        # TI
+        i2ctransfer -fy "$SSC_BUS" w2@"$SSC_ADDR" 0xfd 0x00
+        i2ctransfer -fy "$SSC_BUS" w2@"$SSC_ADDR" 0x3c 0x20
+    else
+        echo "unknown SSC vendor id ($SSC_VENDOR_ID0/$SSC_VENDOR_ID1), skip disabling SSC" >&2
+    fi
+fi
 
 # Create /dev/mem
 if [ ! -c /dev/mem ]; then