em357: added target files for em357 and em358

This patch adds support for Silicon Labs (formerly Ember) EM357
and EM358 chips and derivatives.

Change-Id: Ie63aed95a2f4ef1a6b955e301a51b4de1b3a5462
Signed-off-by: Ed Beroset <beroset@ieee.org>
Reviewed-on: http://openocd.zylin.com/2470
Tested-by: jenkins
Reviewed-by: Paul Fertser <fercerpav@gmail.com>

tcl/target/em357.cfg

@@ -0,0 +1,67 @@
+#
+# Target configuration for the Silicon Labs EM357 chips
+#
+
+#
+# em357 family supports JTAG and SWD transports
+#
+source [find target/swj-dp.tcl]
+
+if { [info exists CHIPNAME] } {
+   set _CHIPNAME $CHIPNAME
+} else {
+   set _CHIPNAME em357
+}
+
+# Work-area is a space in RAM used for flash programming
+# By default use 4kB
+if { [info exists WORKAREASIZE] } {
+   set _WORKAREASIZE $WORKAREASIZE
+} else {
+   set _WORKAREASIZE 0x1000
+}
+
+if { [info exists CPUTAPID] } {
+   set _CPUTAPID $CPUTAPID
+} else {
+   if { [using_jtag] } {
+      set _CPUTAPID 0x3ba00477
+   } else {
+      set _CPUTAPID 0x1ba00477
+   }
+}
+
+if { [info exists BSTAPID] } {
+   set _BSTAPID $BSTAPID
+} else {
+  set _BSTAPID 0x069aa62b
+}
+
+if { [info exists CHIPNAME] } {
+   set _CHIPNAME $CHIPNAME
+} else {
+   set _CHIPNAME em358
+}
+
+if { [info exists FLASHSIZE] } {
+    set _FLASHSIZE $FLASHSIZE
+} else {
+    set _FLASHSIZE 0x30000
+}
+
+swj_newdap $_CHIPNAME cpu -irlen 4 -expected-id $_CPUTAPID
+if { [using_jtag] } {
+    swj_newdap $_CHIPNAME bs -irlen 4 -expected-id $_BSTAPID -ircapture 0xe -irmask 0xf
+}
+
+set _TARGETNAME $_CHIPNAME.cpu
+target create $_TARGETNAME cortex_m -endian little -chain-position $_TARGETNAME
+
+$_TARGETNAME configure -work-area-phys 0x20000000 -work-area-size $_WORKAREASIZE -work-area-backup 0
+
+set _FLASHNAME $_CHIPNAME.flash
+flash bank $_FLASHNAME em357 0x08000000 $_FLASHSIZE 0 0 $_TARGETNAME
+
+if { ![using_hla]} {
+    cortex_m reset_config sysresetreq
+}

tcl/target/em358.cfg

@@ -0,0 +1,14 @@
+#
+# Target configuration for the Silicon Labs EM358 chips
+
+#
+# em357 family supports JTAG and SWD transports
+#
+
+if { ![info exists CHIPNAME] } {
+   set CHIPNAME em358
+}
+
+# 512K of flash in the em358 chips
+set FLASHSIZE 0x80000
+source [find target/em357.cfg]