bthelper: Add the ability to set the Pi BDADDR

If Bluetooth is being enabled via the kernel, hciattach isn't run and
we lose the ability to set the BDADDR. Extend bthelper to use the
bdaddr utility on Pis that haven't had the BT section of the OTP
programmed.

Also ensure that btuart doesn't do anything unless necessary.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

usr/bin/bthelper

@@ -1,21 +1,38 @@
 #!/bin/sh
-# For on-board BT, route SCO packets to the HCI interface (enables HFP/HSP)
+# For on-board BT, configure the BDADDR if necessary and route SCO packets
+# to the HCI interface (enables HFP/HSP)
 
 set -e
 
 if [ "$#" -ne 1 ]; then
-   echo "Usage: $0 <bluetooth hci device>"
-   exit 0
+    echo "Usage: $0 <bluetooth hci device>"
+    exit 0
+fi
+
+dev=$1
+
+# Need to bring hci up before looking at MAC as it can be all zeros during init
+/bin/hciconfig $dev up
+/bin/hciconfig $dev | grep -q "Bus: UART" ||
+    (echo Not a UART-attached BT Modem; exit 0)
+
+if ( /usr/bin/bdaddr -i "$dev" | grep -q -E '\s(B8:27:EB:|DC:A6:32:)' ); then
+    echo Raspberry Pi BDADDR already set
+else
+    SERIAL=`cat /proc/device-tree/serial-number | cut -c9-`
+    B1=`echo $SERIAL | cut -c3-4`
+    B2=`echo $SERIAL | cut -c5-6`
+    B3=`echo $SERIAL | cut -c7-8`
+    BDADDR=`printf b8:27:eb:%02x:%02x:%02x $((0x$B1 ^ 0xaa)) $((0x$B2 ^ 0xaa)) $((0x$B3 ^ 0xaa))`
+
+    /usr/bin/bdaddr -i "$dev" $BDADDR
+    /bin/hciconfig $dev reset
 fi
 
 # Force reinitialisation to allow extra features such as Secure Simple Pairing
 # to be enabled
 /usr/bin/bluetoothctl power off
 /usr/bin/bluetoothctl power on
 
-dev="$1"
-# Need to bring hci up before looking at MAC as it can be all zeros during init
-/bin/hciconfig "$dev" up
-/bin/hciconfig "$dev" | grep -qE "BD Address: (B8:27:EB|DC:A6:32):" || exit 0
+# Route SCO packets to the HCI interface (enables HFP/HSP)
 /usr/bin/hcitool -i "$dev" cmd 0x3f 0x1c 0x01 0x02 0x00 0x01 0x01 > /dev/null
-

usr/bin/btuart

@@ -11,6 +11,11 @@ else
   BDADDR=`printf b8:27:eb:%02x:%02x:%02x $((0x$B1 ^ 0xaa)) $((0x$B2 ^ 0xaa)) $((0x$B3 ^ 0xaa))`
 fi
 
+if [ -e /sys/class/bluetooth/hci0 ]; then
+  # Bluetooth is already enabled
+  exit 0
+fi
+
 uart0="`cat /proc/device-tree/aliases/uart0`"
 serial1="`cat /proc/device-tree/aliases/serial1`"