flash/nor: Add Infineon XMC1000 flash driver

The XMC1000 family uses a very different flash interface from XMC4000.

Tested on XMC 2Go and XMC1100 Boot Kit.

Change-Id: I3edaed420ef1c0fb89fdf221022c8b04163d41b3
Signed-off-by: Andreas Färber <afaerber@suse.de>
Reviewed-on: http://openocd.zylin.com/3418
Reviewed-by: Freddie Chopin <freddie.chopin@gmail.com>
Tested-by: jenkins

contrib/loaders/flash/xmc1xxx/erase_check.S

@@ -0,0 +1,67 @@
+/*
+ * Infineon XMC1000 flash sector erase check
+ *
+ * Copyright (c) 2016 Andreas Färber
+ *
+ * Based on XMC1100 AA-Step Reference Manual
+ *
+ * License: GPL-2.0+
+ */
+
+#include "xmc1xxx.S"
+
+	.macro verify_block, nvmbase, addr, tmp, tmp2
+
+	movs	\tmp, #0x00
+	mvns	\tmp, \tmp
+	str	\tmp, [\addr, #0x0]
+	str	\tmp, [\addr, #0x4]
+	str	\tmp, [\addr, #0x8]
+	str	\tmp, [\addr, #0xC]
+
+	busy_wait \nvmbase, \tmp, \tmp2
+
+	.endm
+
+
+	.macro erase_check, nvmbase, addr, end, tmp, tmp2
+
+	ldrh	\tmp, [\nvmbase, #NVMCONF]
+	movs	\tmp2, #NVMCONF_HRLEV_MASK
+	mvns	\tmp2, \tmp2
+	ands	\tmp, \tmp, \tmp2
+	movs	\tmp2, #NVMCONF_HRLEV_HRE
+	orrs	\tmp, \tmp, \tmp2
+	strh	\tmp, [\nvmbase, #NVMCONF]
+
+	movs	\tmp, #NVMPROG_ACTION_VERIFY_CONTINUOUS
+	strh	\tmp, [\nvmbase, #NVMPROG]
+2001:
+	verify_block \nvmbase, \addr, \tmp, \tmp2
+
+	ldrh	\tmp, [\nvmbase, #NVMSTATUS]
+	movs	\tmp2, #NVMSTATUS_VERR_MASK
+	ands	\tmp, \tmp, \tmp2
+	cmp	\tmp, #NVMSTATUS_VERR_NOFAIL
+	bne	2010f
+
+	adds	\addr, \addr, #NVM_BLOCK_SIZE
+	cmp	\addr, \end
+	blt	2001b
+2010:
+	movs	\tmp, #NVMPROG_ACTION_IDLE
+	strh	\tmp, [\nvmbase, #NVMPROG]
+
+	.endm
+
+
+	/*
+	 * r0 = 0x40050000
+	 * r1 = e.g. 0x10001000
+	 * r2 = e.g. 0x10002000
+	 * NVMPROG.ACTION = 0x00
+	 */
+erase_check:
+	erase_check r0, r1, r2, r3, r4
+
+	bkpt	#0