import companion controller tools

Most Theobroma Systems SoMs feature a Cortex-M0 companion controller.
This commit includes:

 * a shell script for resetting and flashing the MCU
 * a OpenOCD config file for onboard debugging

3 files changed, 184 insertions, 0 deletions

diff --git a/companion-controller/README.md b/companion-controller/README.md
new file mode 100644
index 0000000..226e8cb
--- /dev/null
+++ b/companion-controller/README.md
@@ -0,0 +1,30 @@
+# cortex-m0.sh
+
+`cortex-m0.sh` is a helper script to control the on-module companion controller.
+
+Parameters:
+
+    --reset              - resets the Cortex M0
+    --dfu                - enables DFU loader
+    --disable            - keep Cortex M0 in reset
+    --flash [<firmware>] - flash the given firmware
+
+# openocd.cfg
+
+On some modules GPIO based SWD support is available. A config file is
+provided in the tools directory.
+
+    openocd -f tools/openocd.cfg
+
+To select a specific board set the q7_module variable
+
+    openocd -c "set q7_module a64" -f tools/openocd.cfg
+
+OpenOCD in Debian Stretch and Ubuntu Xenial are missing the sysfsgpio
+interface and you have to rebuild it from source∵
+
+    git clone git://repo.or.cz/openocd.git openocd-code
+    cd openocd-code
+    ./bootstrap
+    ./configure --exec-prefix=~/openocd --prefix=~/openocd --enable-sysfsgpio
+    make && make install
diff --git a/companion-controller/cortex-m0.sh b/companion-controller/cortex-m0.sh
new file mode 100755
index 0000000..7f259b0
--- /dev/null
+++ b/companion-controller/cortex-m0.sh
@@ -0,0 +1,124 @@
+#!/bin/bash
+
+SYSFSPATH=/sys/class/gpio
+
+# defaults
+RESET_INVERT=0
+BOOT0_INVERT=0
+FIRMWARE=/usr/local/share/cortex-m0/cortex-m0.dfu
+
+die() {
+	echo "$*" 1>&2
+	exit 1
+}
+
+usage() {
+	echo "Usage: $0 [--reset|--dfu|--disable|--flash [<firmwarea>]]"
+	echo "  --reset              - resets the Cortex M0"
+	echo "  --dfu                - enables DFU loader"
+	echo "  --disable            - keep Cortex M0 in reset"
+	echo "  --flash [<firmware>] - flash the given firmware"
+
+	exit 1
+}
+
+gpiosetup() {
+	for PIN in ${RESET_PIN},${RESET_INVERT} ${BOOT0_PIN},${BOOT0_INVERT}
+	do
+		IFS=',' read PINNUM INVERT <<< "${PIN}"
+		if [ ! -d ${SYSFSPATH}/gpio${PINNUM} ] ; then
+			echo ${PINNUM} > ${SYSFSPATH}/export
+		fi
+		echo out > ${SYSFSPATH}/gpio${PINNUM}/direction
+		echo ${INVERT} > ${SYSFSPATH}/gpio${PINNUM}/active_low
+	done
+}
+
+reset_stm32() {
+	echo 0 >  ${SYSFSPATH}/gpio${RESET_PIN}/value
+	echo 0 >  ${SYSFSPATH}/gpio${BOOT0_PIN}/value
+	sleep 0.1
+	echo 1 >  ${SYSFSPATH}/gpio${RESET_PIN}/value
+}
+
+enable_dfu() {
+	gpiosetup
+	echo 0 >  ${SYSFSPATH}/gpio${RESET_PIN}/value
+	echo 1 >  ${SYSFSPATH}/gpio${BOOT0_PIN}/value
+	sleep 0.1
+	echo 1 >  ${SYSFSPATH}/gpio${RESET_PIN}/value
+}
+
+[ -f /proc/device-tree/model ] || die "can't determine hardware version"
+
+MODEL=$(cat /proc/device-tree/model | tr -d '\000')
+
+case "$MODEL" in
+	"Theobroma Systems A31 Pangolin")
+		RESET_PIN=90
+		BOOT0_PIN=67
+	  ;;
+	"Theobroma Systems A80 Armadillo")
+		RESET_PIN=128
+		BOOT0_PIN=129
+	  ;;
+	"Theobroma Systems A64-uQ7 SoM")
+		RESET_PIN=195
+		BOOT0_PIN=197
+	  ;;
+	"Theobroma Systems RK3399-Q7 SoM")
+		RESET_PIN=56
+		BOOT0_PIN=76
+		RESET_INVERT=1
+		BOOT0_INVERT=1
+	  ;;
+	*)
+		die "${MODEL} not supported"
+		;;
+esac
+
+case "$1" in
+--reset) echo "reseting Cortex M0"
+	gpiosetup
+	reset_stm32
+    ;;
+--dfu) echo "enabling DFU loader"
+	gpiosetup
+	enable_dfu
+    ;;
+--disable) echo "disabling Cortex M0"
+	gpiosetup
+	echo 0 >  ${SYSFSPATH}/gpio${RESET_PIN}/value
+    ;;
+--flash)
+	if [ $# -eq 2 ] ; then
+		[ -f "$2" ] || die "flash file ${2} does not exist"
+		FIRMWARE=$2
+	elif [ $# -gt 2 ] ; then
+		usage
+	fi
+	command -v dfu-util >/dev/null 2>&1 || die "dfu-util needed but not found"
+	echo "flashing Cortex M0"
+	gpiosetup
+	enable_dfu
+	echo waiting for DFU loader
+	if command -v lsusb >/dev/null 2>&1; then
+		while ! lsusb -d 0483:df11 > /dev/null
+		do
+			sleep .1
+			echo -n .
+		done
+		echo -e "\nfound"
+	else
+		sleep 5
+	fi
+	dfu-util -a 0 -D ${FIRMWARE}
+	reset_stm32
+    ;;
+--*) usage
+    ;;
+*) usage
+    ;;
+esac
+
+exit 0
diff --git a/companion-controller/openocd.cfg b/companion-controller/openocd.cfg
new file mode 100644
index 0000000..71a1297
--- /dev/null
+++ b/companion-controller/openocd.cfg
@@ -0,0 +1,30 @@
+interface sysfsgpio
+
+if { ! [ info exists q7_module ] } {
+# set default module here
+  set q7_module rk3399
+}
+
+switch $q7_module {
+  rk3399 {
+     sysfsgpio_swdio_num     106
+     sysfsgpio_swclk_num     111
+     sysfsgpio_srst_num      45
+     echo "INFO: If reset isn't working set SRST to active low"
+     echo "INFO: echo 1 > /sys/class/gpio/gpio45/active_low"
+   }
+
+  a64 {
+     sysfsgpio_swdio_num     131
+     sysfsgpio_swclk_num     130
+     sysfsgpio_srst_num      195
+   }
+
+   default {
+     echo "Error: Unkown module $q7_module"
+     shutdown
+   }
+}
+
+transport select swd
+source [find target/stm32f0x.cfg]