flash: erase_address now has an unlock option

Quite useful to be able to unlock the flash, just like in
the flash write_image cmd.

Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>

doc/openocd.texi

@@ -21,7 +21,7 @@ of the Open On-Chip Debugger (OpenOCD).
 @itemize @bullet
 @item Copyright @copyright{} 2008 The OpenOCD Project
 @item Copyright @copyright{} 2007-2008 Spencer Oliver @email{spen@@spen-soft.co.uk}
-@item Copyright @copyright{} 2008 Oyvind Harboe @email{oyvind.harboe@@zylin.com}
+@item Copyright @copyright{} 2008-2010 Oyvind Harboe @email{oyvind.harboe@@zylin.com}
 @item Copyright @copyright{} 2008 Duane Ellis @email{openocd@@duaneellis.com}
 @item Copyright @copyright{} 2009-2010 David Brownell
 @end itemize
@@ -4043,7 +4043,7 @@ specifies "to the end of the flash bank".
 The @var{num} parameter is a value shown by @command{flash banks}.
 @end deffn
 
-@deffn Command {flash erase_address} [@option{pad}] address length
+@deffn Command {flash erase_address} [@option{pad}] [@option{unlock}] address length
 Erase sectors starting at @var{address} for @var{length} bytes.
 Unless @option{pad} is specified, @math{address} must begin a
 flash sector, and @math{address + length - 1} must end a sector.
@@ -4053,6 +4053,8 @@ The flash bank to use is inferred from the @var{address}, and
 the specified length must stay within that bank.
 As a special case, when @var{length} is zero and @var{address} is
 the start of the bank, the whole flash is erased.
+If @option{unlock} is specified, then the flash is unprotected
+before erase starts. 
 @end deffn
 
 @deffn Command {flash fillw} address word length

src/flash/nor/core.c

@@ -502,7 +502,7 @@ static int flash_driver_unprotect(struct flash_bank *bank, int first, int last)
 	return flash_driver_protect(bank, 0, first, last);
 }
 
-static int flash_unlock_address_range(struct target *target, uint32_t addr, uint32_t length)
+int flash_unlock_address_range(struct target *target, uint32_t addr, uint32_t length)
 {
 	/* By default, pad to sector boundaries ... the real issue here
 	 * is that our (only) caller *permanently* removes protection,

src/flash/nor/core.h

@@ -108,6 +108,9 @@ int flash_register_commands(struct command_context *cmd_ctx);
 int flash_erase_address_range(struct target *target,
 		bool pad, uint32_t addr, uint32_t length);
 
+int flash_unlock_address_range(struct target *target, uint32_t addr,
+		uint32_t length);
+
 /**
  * Writes @a image into the @a target flash.  The @a written parameter
  * will contain the

src/flash/nor/tcl.c

@@ -194,32 +194,40 @@ COMMAND_HANDLER(handle_flash_erase_check_command)
 COMMAND_HANDLER(handle_flash_erase_address_command)
 {
 	struct flash_bank *p;
-	int retval;
+	int retval = ERROR_OK;
 	int address;
 	int length;
 	bool do_pad = false;
+	bool do_unlock = false;
 	struct target *target = get_current_target(CMD_CTX);
 
-	switch (CMD_ARGC) {
-	case 3:
+	while (CMD_ARGC >= 3)
+	{
 		/* Optionally pad out the address range to block/sector
 		 * boundaries.  We can't know if there's data in that part
 		 * of the flash; only do padding if we're told to.
 		 */
-		if (strcmp("pad", CMD_ARGV[0]) != 0)
+		if (strcmp("pad", CMD_ARGV[0]) == 0)
+		{
+			do_pad = true;
+		} else if (strcmp("unlock", CMD_ARGV[0]) == 0)
+		{
+			do_unlock = true;
+		} else
+		{
 			return ERROR_COMMAND_SYNTAX_ERROR;
-		do_pad = true;
+		}
 		CMD_ARGC--;
 		CMD_ARGV++;
-		/* FALL THROUGH */
-	case 2:
-		COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], address);
-		COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], length);
-		break;
-	default:
+	}
+	if (CMD_ARGC != 2)
+	{
 		return ERROR_COMMAND_SYNTAX_ERROR;
 	}
 
+	COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], address);
+	COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], length);
+
 	if (length <= 0)
 	{
 		command_print(CMD_CTX, "Length must be >0");
@@ -238,7 +246,15 @@ COMMAND_HANDLER(handle_flash_erase_address_command)
 	struct duration bench;
 	duration_start(&bench);
 
-	retval = flash_erase_address_range(target, do_pad, address, length);
+	if (do_unlock)
+	{
+		retval = flash_unlock_address_range(target, address, length);
+	}
+
+	if (retval == ERROR_OK)
+	{
+		retval = flash_erase_address_range(target, do_pad, address, length);
+	}
 
 	if ((ERROR_OK == retval) && (duration_measure(&bench) == ERROR_OK))
 	{
@@ -709,12 +725,15 @@ static const struct command_registration flash_exec_command_handlers[] = {
 		.name = "erase_address",
 		.handler = handle_flash_erase_address_command,
 		.mode = COMMAND_EXEC,
-		.usage = "['pad'] address length",
+		.usage = "['pad'] ['unlock'] address length",
 		.help = "Erase flash sectors starting at address and "
 			"continuing for length bytes.  If 'pad' is specified, "
 			"data outside that range may also be erased: the start "
 			"address may be decreased, and length increased, so "
-			"that all of the first and last sectors are erased.",
+			"that all of the first and last sectors are erased. "
+			"If 'unlock' is specified, then the flash is unprotected "
+			"before erasing.",
+
 	},
 	{
 		.name = "fillw",