xref: /openbmc/u-boot/cmd/otp.c (revision ba10b852)
1 /*
2  * cmd_otp.c - interface to Blackfin on-chip One-Time-Programmable memory
3  *
4  * Copyright (c) 2007-2008 Analog Devices Inc.
5  *
6  * Licensed under the GPL-2 or later.
7  */
8 
9 /* There are 512 128-bit "pages" (0x000 through 0x1FF).
10  * The pages are accessable as 64-bit "halfpages" (an upper and lower half).
11  * The pages are not part of the memory map.  There is an OTP controller which
12  * handles scanning in/out of bits.  While access is done through OTP MMRs,
13  * the bootrom provides C-callable helper functions to handle the interaction.
14  */
15 
16 #include <config.h>
17 #include <common.h>
18 #include <command.h>
19 #include <console.h>
20 
21 #include <asm/blackfin.h>
22 #include <asm/clock.h>
23 #include <asm/mach-common/bits/otp.h>
24 
25 static const char *otp_strerror(uint32_t err)
26 {
27 	switch (err) {
28 	case 0:                   return "no error";
29 	case OTP_WRITE_ERROR:     return "OTP fuse write error";
30 	case OTP_READ_ERROR:      return "OTP fuse read error";
31 	case OTP_ACC_VIO_ERROR:   return "invalid OTP address";
32 	case OTP_DATA_MULT_ERROR: return "multiple bad bits detected";
33 	case OTP_ECC_MULT_ERROR:  return "error in ECC bits";
34 	case OTP_PREV_WR_ERROR:   return "space already written";
35 	case OTP_DATA_SB_WARN:    return "single bad bit in half page";
36 	case OTP_ECC_SB_WARN:     return "single bad bit in ECC";
37 	default:                  return "unknown error";
38 	}
39 }
40 
41 #define lowup(x) ((x) % 2 ? "upper" : "lower")
42 
43 static int check_voltage(void)
44 {
45 	/* Make sure voltage limits are within datasheet spec */
46 	uint16_t vr_ctl = bfin_read_VR_CTL();
47 
48 #ifdef __ADSPBF54x__
49 	/* 0.9V <= VDDINT <= 1.1V */
50 	if ((vr_ctl & 0xc) && (vr_ctl & 0xc0) == 0xc0)
51 		return 1;
52 #else
53 	/* for the parts w/out qualification yet */
54 	(void)vr_ctl;
55 #endif
56 
57 	return 0;
58 }
59 
60 static void set_otp_timing(bool write)
61 {
62 	static uint32_t timing;
63 	if (!timing) {
64 		uint32_t tp1, tp2, tp3;
65 		/* OTP_TP1 = 1000 / sclk_period (in nanoseconds)
66 		 * OTP_TP1 = 1000 / (1 / get_sclk() * 10^9)
67 		 * OTP_TP1 = (1000 * get_sclk()) / 10^9
68 		 * OTP_TP1 = get_sclk() / 10^6
69 		 */
70 		tp1 = get_sclk() / 1000000;
71 		/* OTP_TP2 = 400 / (2 * sclk_period)
72 		 * OTP_TP2 = 400 / (2 * 1 / get_sclk() * 10^9)
73 		 * OTP_TP2 = (400 * get_sclk()) / (2 * 10^9)
74 		 * OTP_TP2 = (2 * get_sclk()) / 10^7
75 		 */
76 		tp2 = (2 * get_sclk() / 10000000) << 8;
77 		/* OTP_TP3 = magic constant */
78 		tp3 = (0x1401) << 15;
79 		timing = tp1 | tp2 | tp3;
80 	}
81 
82 	bfrom_OtpCommand(OTP_INIT, write ? timing : timing & ~(-1 << 15));
83 }
84 
85 int do_otp(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
86 {
87 	char *cmd;
88 	uint32_t ret, base_flags;
89 	bool prompt_user, force_read;
90 	uint32_t (*otp_func)(uint32_t page, uint32_t flags, uint64_t *page_content);
91 
92 	if (argc < 4) {
93  usage:
94 		return CMD_RET_USAGE;
95 	}
96 
97 	prompt_user = false;
98 	base_flags = 0;
99 	cmd = argv[1];
100 	if (!strcmp(cmd, "read"))
101 		otp_func = bfrom_OtpRead;
102 	else if (!strcmp(cmd, "dump")) {
103 		otp_func = bfrom_OtpRead;
104 		force_read = true;
105 	} else if (!strcmp(cmd, "write")) {
106 		otp_func = bfrom_OtpWrite;
107 		base_flags = OTP_CHECK_FOR_PREV_WRITE;
108 		if (!strcmp(argv[2], "--force")) {
109 			argv++;
110 			--argc;
111 		} else
112 			prompt_user = false;
113 	} else if (!strcmp(cmd, "lock")) {
114 		if (argc != 4)
115 			goto usage;
116 		otp_func = bfrom_OtpWrite;
117 		base_flags = OTP_LOCK;
118 	} else
119 		goto usage;
120 
121 	uint64_t *addr = (uint64_t *)simple_strtoul(argv[2], NULL, 16);
122 	uint32_t page = simple_strtoul(argv[3], NULL, 16);
123 	uint32_t flags;
124 	size_t i, count;
125 	ulong half;
126 
127 	if (argc > 4)
128 		count = simple_strtoul(argv[4], NULL, 16);
129 	else
130 		count = 2;
131 
132 	if (argc > 5) {
133 		half = simple_strtoul(argv[5], NULL, 16);
134 		if (half != 0 && half != 1) {
135 			puts("Error: 'half' can only be '0' or '1'\n");
136 			goto usage;
137 		}
138 	} else
139 		half = 0;
140 
141 	/* "otp lock" has slightly different semantics */
142 	if (base_flags & OTP_LOCK) {
143 		count = page;
144 		page = (uint32_t)addr;
145 		addr = NULL;
146 	}
147 
148 	/* do to the nature of OTP, make sure users are sure */
149 	if (prompt_user) {
150 		printf(
151 			"Writing one time programmable memory\n"
152 			"Make sure your operating voltages and temperature are within spec\n"
153 			"   source address:  0x%p\n"
154 			"   OTP destination: %s page 0x%03X - %s page 0x%03lX\n"
155 			"   number to write: %lu halfpages\n"
156 			" type \"YES\" (no quotes) to confirm: ",
157 			addr,
158 			lowup(half), page,
159 			lowup(half + count - 1), page + (half + count - 1) / 2,
160 			half + count
161 		);
162 		if (!confirm_yesno()) {
163 			printf(" Aborting\n");
164 			return 1;
165 		}
166 	}
167 
168 	printf("OTP memory %s: addr 0x%p  page 0x%03X  count %zu ... ",
169 		cmd, addr, page, count);
170 
171 	set_otp_timing(otp_func == bfrom_OtpWrite);
172 	if (otp_func == bfrom_OtpWrite && check_voltage()) {
173 		puts("ERROR: VDDINT voltage is out of spec for writing\n");
174 		return -1;
175 	}
176 
177 	/* Do the actual reading/writing stuff */
178 	ret = 0;
179 	for (i = half; i < count + half; ++i) {
180 		flags = base_flags | (i % 2 ? OTP_UPPER_HALF : OTP_LOWER_HALF);
181  try_again:
182 		ret = otp_func(page, flags, addr);
183 		if (ret & OTP_MASTER_ERROR) {
184 			if (force_read) {
185 				if (flags & OTP_NO_ECC)
186 					break;
187 				else
188 					flags |= OTP_NO_ECC;
189 				puts("E");
190 				goto try_again;
191 			} else
192 				break;
193 		} else if (ret)
194 			puts("W");
195 		else
196 			puts(".");
197 		if (!(base_flags & OTP_LOCK)) {
198 			++addr;
199 			if (i % 2)
200 				++page;
201 		} else
202 			++page;
203 	}
204 	if (ret & 0x1)
205 		printf("\nERROR at page 0x%03X (%s-halfpage): 0x%03X: %s\n",
206 			page, lowup(i), ret, otp_strerror(ret));
207 	else
208 		puts(" done\n");
209 
210 	/* Make sure we disable writing */
211 	set_otp_timing(false);
212 	bfrom_OtpCommand(OTP_CLOSE, 0);
213 
214 	return ret;
215 }
216 
217 U_BOOT_CMD(
218 	otp, 7, 0, do_otp,
219 	"One-Time-Programmable sub-system",
220 	"read <addr> <page> [count] [half]\n"
221 	" - read 'count' half-pages starting at 'page' (offset 'half') to 'addr'\n"
222 	"otp dump <addr> <page> [count] [half]\n"
223 	" - like 'otp read', but skip read errors\n"
224 	"otp write [--force] <addr> <page> [count] [half]\n"
225 	" - write 'count' half-pages starting at 'page' (offset 'half') from 'addr'\n"
226 	"otp lock <page> <count>\n"
227 	" - lock 'count' pages starting at 'page'"
228 );
229