mtd-utils: Add flash_otp_erase

On some SPI NOR flashes you can actually erase the OTP region until its
fully locked. Add a small utility for that.

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 64 insertions, 0 deletions

diff --git a/misc-utils/flash_otp_erase.c b/misc-utils/flash_otp_erase.c
new file mode 100644
index 0000000..771e230
--- /dev/null
+++ b/misc-utils/flash_otp_erase.c
@@ -0,0 +1,64 @@
+/*
+ * flash_otp_erase.c -- erase area of One-Time-Program data
+ */
+
+#define PROGRAM_NAME "flash_otp_erase"
+
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <sys/ioctl.h>
+
+#include <mtd/mtd-user.h>
+#include "common.h"
+
+int main(int argc,char *argv[])
+{
+	int fd, val, ret, offset, size;
+	struct otp_info info;
+	char *p;
+
+	if (argc != 5 || strcmp(argv[1], "-u")) {
+		fprintf(stderr, "Usage: %s -u <device> <offset> <size>\n", PROGRAM_NAME);
+		fprintf(stderr, "offset and size must match on OTP region boundaries\n");
+		return EINVAL;
+	}
+
+	fd = open(argv[2], O_WRONLY);
+	if (fd < 0) {
+		perror(argv[2]);
+		return errno;
+	}
+
+	val = MTD_OTP_USER;
+	ret = ioctl(fd, OTPSELECT, &val);
+	if (ret < 0) {
+		perror("OTPSELECT");
+		return errno;
+	}
+
+	offset = strtoul(argv[3], &p, 0);
+	if (argv[3][0] == 0 || *p != 0) {
+		fprintf(stderr, "%s: bad offset value\n", PROGRAM_NAME);
+		return ERANGE;
+	}
+
+	size = strtoul(argv[4], &p, 0);
+	if (argv[4][0] == 0 || *p != 0) {
+		fprintf(stderr, "%s: bad size value\n", PROGRAM_NAME);
+		return ERANGE;
+	}
+
+	info.start = offset;
+	info.length = size;
+	ret = ioctl(fd, OTPERASE, &info);
+	if (ret	< 0) {
+		perror("OTPERASE");
+		return errno;
+	}
+
+	return 0;
+}