xref: /rk3399_rockchip-uboot/drivers/misc/misc_otp.c (revision 8f805b784698251c605c161a3d9099f355f51087)
1 // SPDX-License-Identifier:     GPL-2.0+
2 /*
3  * Copyright (C) 2020 Rockchip Electronics Co., Ltd
4  */
5 
6 #include <common.h>
7 #include <dm.h>
8 #include <dm/uclass.h>
9 #include <misc.h>
10 
11 struct udevice *misc_otp_get_device(u32 capability)
12 {
13 	return misc_get_device_by_capability(capability);
14 }
15 
16 int misc_otp_read(struct udevice *dev, int offset, void *buf, int size)
17 {
18 	return misc_read(dev, offset, buf, size);
19 }
20 
21 int misc_otp_write(struct udevice *dev, int offset, const void *buf, int size)
22 {
23 	return misc_write(dev, offset, (void *)buf, size);
24 }
25 
26 int misc_otp_ioctl(struct udevice *dev, unsigned long request, void *buf)
27 {
28 	return misc_ioctl(dev, request, buf);
29 }
30 
31 int misc_otp_write_verify(struct udevice *dev, int offset, const uint8_t *write_buf, int size)
32 {
33 	uint8_t verify_buf[size];
34 	uint8_t read_buf[size];
35 	int i, written_size = 0, ret = 0;
36 
37 	memset(verify_buf, 0, sizeof(verify_buf));
38 	memset(read_buf, 0, sizeof(read_buf));
39 
40 	ret = misc_otp_read(dev, offset, &read_buf, size);
41 	if (ret) {
42 		printf("OTP: misc_otp_read fail, ret=%d\n", ret);
43 		goto out;
44 	}
45 
46 	for (i = 0; i < size; i++) {
47 		/* Already 1 value in otp can't be written to 0. */
48 		if (read_buf[i] & ~write_buf[i]) {
49 			printf("OTP: The zone is partly written.\n");
50 			ret = -EACCES;
51 			goto out;
52 		}
53 		if ((read_buf[i] == write_buf[i]) && write_buf[i])
54 			written_size++;
55 		else
56 			break;
57 	}
58 
59 	if (size == written_size) {
60 		printf("OTP: The secure region has been written.\n");
61 		ret = -EIO;
62 		goto out;
63 	}
64 
65 	ret = misc_otp_write(dev, (offset + written_size), &write_buf[written_size],
66 			     (size - written_size));
67 	if (ret) {
68 		printf("OTP: misc_otp_write fail, ret=%d\n", ret);
69 		goto out;
70 	}
71 
72 	ret = misc_otp_read(dev, (offset + written_size), verify_buf, (size - written_size));
73 	if (ret) {
74 		printf("OTP: misc_otp_read(verify) fail, ret=%d\n", ret);
75 		goto out;
76 	}
77 
78 	for (i = 0; i < (size - written_size); i++) {
79 		if ((write_buf[i + written_size] | read_buf[i + written_size]) != verify_buf[i]) {
80 			ret = -EIO;
81 			printf("OTP: Actual value(%u) is different from expected value(%u).\n",
82 			       verify_buf[i], (write_buf[i + written_size] | read_buf[i + written_size]));
83 			goto out;
84 		}
85 	}
86 
87 out:
88 	return ret;
89 }
90