cmd: mtd: OTP access support

Add access to OTP region. It supports info, dump, write and lock
operations. Usage example:

'mtd otpread nand0 u 0 1024' - dump 1024 bytes of user area starting
 from offset 0 of device 'nand0'.

'mtd otpwrite nand0 10 11223344' - write binary data 0x11, 0x22, 0x33,
 0x44 to offset 10 to user area of device 'nand0'.

'mtd otplock nand0 0 1024' - lock 1024 bytes of user area starting
 from offset 0 of device 'nand0'.

'mtd otpinfo nand0 f' - show info about factory area of device 'nand0'.

Link: https://lore.kernel.org/all/20240326223919.3781-1-avkrasnov@salutedevices.com
Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>

2 files changed, 241 insertions, 0 deletions

diff --git a/cmd/Kconfig b/cmd/Kconfig
index f9f271616d..8eeb99eea5 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -1361,6 +1361,13 @@ config CMD_MTD
 	help
 	  MTD commands support.
 
+config CMD_MTD_OTP
+	bool "mtd otp"
+	depends on CMD_MTD
+	select HEXDUMP
+	help
+	  MTD commands for OTP access.
+
 config CMD_MUX
 	bool "mux"
 	depends on MULTIPLEXER
diff --git a/cmd/mtd.c b/cmd/mtd.c
index 9083a6840a..9189f45cab 100644
--- a/cmd/mtd.c
+++ b/cmd/mtd.c
@@ -11,6 +11,9 @@
 #include <command.h>
 #include <common.h>
 #include <console.h>
+#if CONFIG_IS_ENABLED(CMD_MTD_OTP)
+#include <hexdump.h>
+#endif
 #include <malloc.h>
 #include <mapmem.h>
 #include <mtd.h>
@@ -202,6 +205,221 @@ static bool mtd_oob_write_is_empty(struct mtd_oob_ops *op)
 	return true;
 }
 
+#if CONFIG_IS_ENABLED(CMD_MTD_OTP)
+static int do_mtd_otp_read(struct cmd_tbl *cmdtp, int flag, int argc,
+			   char *const argv[])
+{
+	struct mtd_info *mtd;
+	size_t retlen;
+	off_t from;
+	size_t len;
+	bool user;
+	int ret;
+	u8 *buf;
+
+	if (argc != 5)
+		return CMD_RET_USAGE;
+
+	if (!strcmp(argv[2], "u"))
+		user = true;
+	else if (!strcmp(argv[2], "f"))
+		user = false;
+	else
+		return CMD_RET_USAGE;
+
+	mtd = get_mtd_by_name(argv[1]);
+	if (IS_ERR_OR_NULL(mtd))
+		return CMD_RET_FAILURE;
+
+	from = simple_strtoul(argv[3], NULL, 0);
+	len = simple_strtoul(argv[4], NULL, 0);
+
+	ret = CMD_RET_FAILURE;
+
+	buf = malloc(len);
+	if (!buf)
+		goto put_mtd;
+
+	printf("Reading %s OTP from 0x%lx, %zu bytes\n",
+	       user ? "user" : "factory", from, len);
+
+	if (user)
+		ret = mtd_read_user_prot_reg(mtd, from, len, &retlen, buf);
+	else
+		ret = mtd_read_fact_prot_reg(mtd, from, len, &retlen, buf);
+	if (ret) {
+		free(buf);
+		pr_err("OTP read failed: %d\n", ret);
+		ret = CMD_RET_FAILURE;
+		goto put_mtd;
+	}
+
+	if (retlen != len)
+		pr_err("OTP read returns %zu, but %zu expected\n",
+		       retlen, len);
+
+	print_hex_dump("", 0, 16, 1, buf, retlen, true);
+
+	free(buf);
+
+	ret = CMD_RET_SUCCESS;
+
+put_mtd:
+	put_mtd_device(mtd);
+
+	return ret;
+}
+
+static int do_mtd_otp_lock(struct cmd_tbl *cmdtp, int flag, int argc,
+			   char *const argv[])
+{
+	struct mtd_info *mtd;
+	off_t from;
+	size_t len;
+	int ret;
+
+	if (argc != 4)
+		return CMD_RET_USAGE;
+
+	mtd = get_mtd_by_name(argv[1]);
+	if (IS_ERR_OR_NULL(mtd))
+		return CMD_RET_FAILURE;
+
+	from = simple_strtoul(argv[2], NULL, 0);
+	len = simple_strtoul(argv[3], NULL, 0);
+
+	ret = mtd_lock_user_prot_reg(mtd, from, len);
+	if (ret) {
+		pr_err("OTP lock failed: %d\n", ret);
+		ret = CMD_RET_FAILURE;
+		goto put_mtd;
+	}
+
+	ret = CMD_RET_SUCCESS;
+
+put_mtd:
+	put_mtd_device(mtd);
+
+	return ret;
+}
+
+static int do_mtd_otp_write(struct cmd_tbl *cmdtp, int flag, int argc,
+			    char *const argv[])
+{
+	struct mtd_info *mtd;
+	size_t retlen;
+	size_t binlen;
+	u8 *binbuf;
+	off_t from;
+	int ret;
+
+	if (argc != 4)
+		return CMD_RET_USAGE;
+
+	mtd = get_mtd_by_name(argv[1]);
+	if (IS_ERR_OR_NULL(mtd))
+		return CMD_RET_FAILURE;
+
+	from = simple_strtoul(argv[2], NULL, 0);
+	binlen = strlen(argv[3]) / 2;
+
+	ret = CMD_RET_FAILURE;
+	binbuf = malloc(binlen);
+	if (!binbuf)
+		goto put_mtd;
+
+	hex2bin(binbuf, argv[3], binlen);
+
+	printf("Will write:\n");
+
+	print_hex_dump("", 0, 16, 1, binbuf, binlen, true);
+
+	printf("to 0x%lx\n", from);
+
+	printf("Continue (y/n)?\n");
+
+	if (confirm_yesno() != 1) {
+		pr_err("OTP write canceled\n");
+		ret = CMD_RET_SUCCESS;
+		goto put_mtd;
+	}
+
+	ret = mtd_write_user_prot_reg(mtd, from, binlen, &retlen, binbuf);
+	if (ret) {
+		pr_err("OTP write failed: %d\n", ret);
+		ret = CMD_RET_FAILURE;
+		goto put_mtd;
+	}
+
+	if (retlen != binlen)
+		pr_err("OTP write returns %zu, but %zu expected\n",
+		       retlen, binlen);
+
+	ret = CMD_RET_SUCCESS;
+
+put_mtd:
+	free(binbuf);
+	put_mtd_device(mtd);
+
+	return ret;
+}
+
+static int do_mtd_otp_info(struct cmd_tbl *cmdtp, int flag, int argc,
+			   char *const argv[])
+{
+	struct otp_info otp_info;
+	struct mtd_info *mtd;
+	size_t retlen;
+	bool user;
+	int ret;
+
+	if (argc != 3)
+		return CMD_RET_USAGE;
+
+	if (!strcmp(argv[2], "u"))
+		user = true;
+	else if (!strcmp(argv[2], "f"))
+		user = false;
+	else
+		return CMD_RET_USAGE;
+
+	mtd = get_mtd_by_name(argv[1]);
+	if (IS_ERR_OR_NULL(mtd))
+		return CMD_RET_FAILURE;
+
+	if (user)
+		ret = mtd_get_user_prot_info(mtd, sizeof(otp_info), &retlen,
+					     &otp_info);
+	else
+		ret = mtd_get_fact_prot_info(mtd, sizeof(otp_info), &retlen,
+					     &otp_info);
+	if (ret) {
+		pr_err("OTP info failed: %d\n", ret);
+		ret = CMD_RET_FAILURE;
+		goto put_mtd;
+	}
+
+	if (retlen != sizeof(otp_info)) {
+		pr_err("OTP info returns %zu, but %zu expected\n",
+		       retlen, sizeof(otp_info));
+		ret = CMD_RET_FAILURE;
+		goto put_mtd;
+	}
+
+	printf("%s OTP region info:\n", user ? "User" : "Factory");
+	printf("\tstart: %u\n", otp_info.start);
+	printf("\tlength: %u\n", otp_info.length);
+	printf("\tlocked: %u\n", otp_info.locked);
+
+	ret = CMD_RET_SUCCESS;
+
+put_mtd:
+	put_mtd_device(mtd);
+
+	return ret;
+}
+#endif
+
 static int do_mtd_list(struct cmd_tbl *cmdtp, int flag, int argc,
 		       char *const argv[])
 {
@@ -551,6 +769,12 @@ U_BOOT_LONGHELP(mtd,
 	"\n"
 	"Specific functions:\n"
 	"mtd bad                               <name>\n"
+#if CONFIG_IS_ENABLED(CMD_MTD_OTP)
+	"mtd otpread                           <name> [u|f] <off> <size>\n"
+	"mtd otpwrite                          <name> <off> <hex string>\n"
+	"mtd otplock                           <name> <off> <size>\n"
+	"mtd otpinfo                           <name> [u|f]\n"
+#endif
 	"\n"
 	"With:\n"
 	"\t<name>: NAND partition/chip name (or corresponding DM device name or OF path)\n"
@@ -561,10 +785,20 @@ U_BOOT_LONGHELP(mtd,
 	"\t<size>: length of the operation in bytes (default: the entire device)\n"
 	"\t\t* must be a multiple of a block for erase\n"
 	"\t\t* must be a multiple of a page otherwise (special case: default is a page with dump)\n"
+#if CONFIG_IS_ENABLED(CMD_MTD_OTP)
+	"\t<hex string>: hex string without '0x' and spaces. Example: ABCD1234\n"
+	"\t[u|f]: user or factory OTP region\n"
+#endif
 	"\n"
 	"The .dontskipff option forces writing empty pages, don't use it if unsure.\n");
 
 U_BOOT_CMD_WITH_SUBCMDS(mtd, "MTD utils", mtd_help_text,
+#if CONFIG_IS_ENABLED(CMD_MTD_OTP)
+		U_BOOT_SUBCMD_MKENT(otpread, 5, 1, do_mtd_otp_read),
+		U_BOOT_SUBCMD_MKENT(otpwrite, 4, 1, do_mtd_otp_write),
+		U_BOOT_SUBCMD_MKENT(otplock, 4, 1, do_mtd_otp_lock),
+		U_BOOT_SUBCMD_MKENT(otpinfo, 3, 1, do_mtd_otp_info),
+#endif
 		U_BOOT_SUBCMD_MKENT(list, 1, 1, do_mtd_list),
 		U_BOOT_SUBCMD_MKENT_COMPLETE(read, 5, 0, do_mtd_io,
 					     mtd_name_complete),