flash: New Spansion FM4 flash driver

The Spansion FM4 family of microcontrollers does not offer a way to
identify the chip model nor the flash size, except for Dual Flash vs.
regular layout. Therefore the family is passed as argument and
wildcard-matched - MB9BFx6x and S6E2CC families are supported.

Iterations showed that ...
1) Just doing the flash command sequence from SRAM loader code for each
half-word took 20 minutes for an 8 KB block.
2) Doing the busy-wait in the loader merely reduced the time to 19 minutes.
3) Significant performance gains were achieved by looping in loader code
rather than in OpenOCD and by maximizing the batch size across sectors,
getting us down to ~2 seconds for 8 KB and ~2.5 minutes for 1.1 MB.
(Tested with SK-FM4-176L-S6E2CC-ETH v11, CMSIS-DAP v23.)

gcc, objcopy -Obinary and bin2char.sh are used for automating the
integration of hand-written assembler snippets.

Change-Id: I092c81074662534f50b71b91d54eb8e0098fec76
Signed-off-by: Andreas Färber <afaerber@suse.de>
Reviewed-on: http://openocd.zylin.com/2190
Tested-by: jenkins
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>

6 files changed, 225 insertions, 0 deletions

diff --git a/contrib/loaders/flash/fm4/Makefile b/contrib/loaders/flash/fm4/Makefile
new file mode 100644
index 0000000..eb4cbd0
--- /dev/null
+++ b/contrib/loaders/flash/fm4/Makefile
@@ -0,0 +1,30 @@
+BIN2C = ../../../../src/helper/bin2char.sh
+
+CROSS_COMPILE ?= arm-none-eabi-
+
+CC=$(CROSS_COMPILE)gcc
+OBJCOPY=$(CROSS_COMPILE)objcopy
+OBJDUMP=$(CROSS_COMPILE)objdump
+
+all: erase.inc write.inc
+
+.PHONY: clean
+
+.INTERMEDIATE: erase.elf write.elf
+
+erase.elf write.elf: fm4.h
+
+%.elf: %.S
+	$(CC) -static -nostartfiles $< -o $@
+
+%.lst: %.elf
+	$(OBJDUMP) -S $< > $@
+
+%.bin: %.elf
+	$(OBJCOPY) -Obinary $< $@
+
+%.inc: %.bin
+	$(BIN2C) < $< > $@
+
+clean:
+	-rm -f *.elf *.lst *.bin *.inc
diff --git a/contrib/loaders/flash/fm4/erase.S b/contrib/loaders/flash/fm4/erase.S
new file mode 100644
index 0000000..6fdf81d
--- /dev/null
+++ b/contrib/loaders/flash/fm4/erase.S
@@ -0,0 +1,77 @@
+/*
+ * Spansion FM4 flash sector erase algorithm
+ *
+ * Copyright (c) 2015 Andreas Färber
+ *
+ * Based on S6E2CC_MN709-00007 for S6E2CC/C5/C4/C3/C2/C1 series
+ */
+
+#include "fm4.h"
+
+#define RESULT_OKAY	0
+#define RESULT_NONE	1
+#define RESULT_TIMEOUT	2
+
+	.macro busy_wait, res, addr, tmp1, tmp2, tmp3
+
+	ldrb	\tmp1, [\addr] /* ignore */
+1001:
+	ldrb	\tmp1, [\addr]
+	ldrb	\tmp2, [\addr]
+
+	and	\tmp3, \tmp1, #FLASH_TOGG
+	and	\tmp2, \tmp2, #FLASH_TOGG
+	cmp	\tmp3, \tmp2
+	beq	1010f
+
+	and	\tmp2, \tmp1, #FLASH_TLOV
+	cmp	\tmp2, #0
+	beq	1001b
+
+	ldrb	\tmp1, [\addr]
+	ldrb	\tmp2, [\addr]
+
+	and	\tmp3, \tmp1, #FLASH_TOGG
+	and	\tmp2, \tmp2, #FLASH_TOGG
+	cmp	\tmp3, \tmp2
+	beq	1010f
+
+	mov	\res, #RESULT_TIMEOUT
+	bkpt	#0
+1010:
+	mov	\res, #RESULT_OKAY
+
+	.endm
+
+
+	.macro erase, cmdseqaddr1, cmdseqaddr2, sa, res, tmp1, tmp2, tmp3
+
+	mov	\res, #RESULT_NONE
+
+	mov	\tmp1, #0xAA
+	strh	\tmp1, [\cmdseqaddr1]
+	mov	\tmp2, #0x55
+	strh	\tmp2, [\cmdseqaddr2]
+	mov	\tmp3, #0x80
+	strh	\tmp3, [\cmdseqaddr1]
+	strh	\tmp1, [\cmdseqaddr1]
+	strh	\tmp2, [\cmdseqaddr2]
+	mov	\tmp3, #0x30
+	strh	\tmp3, [\sa]
+
+	busy_wait \res, \sa, \tmp1, \tmp2, \tmp3
+
+	.endm
+
+
+	/* r0 = 0xAA8
+	 * r1 = 0x554
+	 * r2 = SA
+	 * r3 = result
+	 */
+erase:
+	erase r0, r1, r2, r3, r4, r5, r6
+
+	bkpt	#0
+
+data:
diff --git a/contrib/loaders/flash/fm4/erase.inc b/contrib/loaders/flash/fm4/erase.inc
new file mode 100644
index 0000000..9f38067
--- /dev/null
+++ b/contrib/loaders/flash/fm4/erase.inc
@@ -0,0 +1,7 @@
+/* Autogenerated with ../../../../src/helper/bin2char.sh */
+0x4f,0xf0,0x01,0x03,0x4f,0xf0,0xaa,0x04,0x04,0x80,0x4f,0xf0,0x55,0x05,0x0d,0x80,
+0x4f,0xf0,0x80,0x06,0x06,0x80,0x04,0x80,0x0d,0x80,0x4f,0xf0,0x30,0x06,0x16,0x80,
+0x14,0x78,0x14,0x78,0x15,0x78,0x04,0xf0,0x40,0x06,0x05,0xf0,0x40,0x05,0xae,0x42,
+0x0e,0xd0,0x04,0xf0,0x20,0x05,0x00,0x2d,0xf3,0xd0,0x14,0x78,0x15,0x78,0x04,0xf0,
+0x40,0x06,0x05,0xf0,0x40,0x05,0xae,0x42,0x02,0xd0,0x4f,0xf0,0x02,0x03,0x00,0xbe,
+0x4f,0xf0,0x00,0x03,0x00,0xbe,
diff --git a/contrib/loaders/flash/fm4/fm4.h b/contrib/loaders/flash/fm4/fm4.h
new file mode 100644
index 0000000..603aac8
--- /dev/null
+++ b/contrib/loaders/flash/fm4/fm4.h
@@ -0,0 +1,19 @@
+/*
+ * Spansion FM4 flash macros
+ *
+ * Copyright (c) 2015 Andreas Färber
+ *
+ * Based on S6E2CC_MN709-00007 for S6E2CC/C5/C4/C3/C2/C1 series
+ */
+
+	.text
+	.syntax unified
+	.cpu cortex-m4
+	.thumb
+	.thumb_func
+
+
+#define FLASH_DPOL	(1 << 7)
+#define FLASH_TOGG	(1 << 6)
+#define FLASH_TLOV	(1 << 5)
+#define FLASH_TOGG2	(1 << 2)
diff --git a/contrib/loaders/flash/fm4/write.S b/contrib/loaders/flash/fm4/write.S
new file mode 100644
index 0000000..a8d01cd
--- /dev/null
+++ b/contrib/loaders/flash/fm4/write.S
@@ -0,0 +1,85 @@
+/*
+ * Spansion FM4 flash write algorithm
+ *
+ * Copyright (c) 2015 Andreas Färber
+ *
+ * Based on S6E2CC_MN709-00007 for S6E2CC/C5/C4/C3/C2/C1 series
+ */
+
+#include "fm4.h"
+
+#define RESULT_OKAY	0
+#define RESULT_NONE	1
+#define RESULT_TIMEOUT	2
+
+	.macro busy_wait, res, addr, data, tmp1, tmp2, tmp3
+
+	ldrb	\tmp1, [\addr] /* ignore */
+	and	\tmp2, \data, #FLASH_DPOL
+1001:
+	ldrb	\tmp1, [\addr]
+	and	\tmp3, \tmp1, #FLASH_DPOL
+	cmp	\tmp3, \tmp2
+	beq	1010f
+
+	and	\tmp3, \tmp1, #FLASH_TLOV
+	cmp	\tmp3, #0
+	beq	1001b
+
+	ldrb	\tmp1, [\addr]
+	and	\tmp3, \tmp1, #FLASH_DPOL
+	cmp	\tmp3, \tmp2
+	beq	1010f
+
+	mov	\res, #RESULT_TIMEOUT
+	bkpt	#0
+1010:
+	.endm
+
+
+	.macro write_one, res, cmdseqaddr1, cmdseqaddr2, pa, pd, tmp1, tmp2, tmp3
+
+	mov	\tmp1, #0xAA
+	strh	\tmp1, [\cmdseqaddr1]
+	mov	\tmp1, #0x55
+	strh	\tmp1, [\cmdseqaddr2]
+	mov	\tmp1, #0xA0
+	strh	\tmp1, [\cmdseqaddr1]
+	strh	\pd, [\pa]
+
+	busy_wait \res, \pa, \pd, \tmp1, \tmp2, \tmp3
+
+	.endm
+
+
+	.macro write, cmdseqaddr1, cmdseqaddr2, dest, src, cnt, res, tmp1, tmp2, tmp3, tmp4
+
+	mov	\res, #RESULT_NONE
+2001:
+	cbz	\cnt, 2010f
+
+	ldrh	\tmp1, [\src]
+	write_one \res, \cmdseqaddr1, \cmdseqaddr2, \dest, \tmp1, \tmp2, \tmp3, \tmp4
+
+	sub	\cnt, \cnt, #1
+	add	\dest, \dest, #2
+	add	\src, \src, #2
+	b	2001b
+2010:
+	mov	\res, #RESULT_OKAY
+	.endm
+
+
+	/* r0 = 0xAA8
+	 * r1 = 0x554
+	 * r2 = dest
+	 * r3 = src
+	 * r4 = cnt
+	 * r5 = result
+	 */
+write:
+	write r0, r1, r2, r3, r4, r5, r6, r7, r8, r9
+
+	bkpt	#0
+
+data:
diff --git a/contrib/loaders/flash/fm4/write.inc b/contrib/loaders/flash/fm4/write.inc
new file mode 100644
index 0000000..3d8472b
--- /dev/null
+++ b/contrib/loaders/flash/fm4/write.inc
@@ -0,0 +1,7 @@
+/* Autogenerated with ../../../../src/helper/bin2char.sh */
+0x4f,0xf0,0x01,0x05,0x34,0xb3,0x1e,0x88,0x4f,0xf0,0xaa,0x07,0x07,0x80,0x4f,0xf0,
+0x55,0x07,0x0f,0x80,0x4f,0xf0,0xa0,0x07,0x07,0x80,0x16,0x80,0x17,0x78,0x06,0xf0,
+0x80,0x08,0x17,0x78,0x07,0xf0,0x80,0x09,0xc1,0x45,0x0c,0xd0,0x07,0xf0,0x20,0x09,
+0xb9,0xf1,0x00,0x0f,0xf5,0xd0,0x17,0x78,0x07,0xf0,0x80,0x09,0xc1,0x45,0x02,0xd0,
+0x4f,0xf0,0x02,0x05,0x00,0xbe,0xa4,0xf1,0x01,0x04,0x02,0xf1,0x02,0x02,0x03,0xf1,
+0x02,0x03,0xd7,0xe7,0x4f,0xf0,0x00,0x05,0x00,0xbe,