1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Based on board/freescale/common/sys_eeprom.c
4  * Copyright 2006, 2008-2009, 2011 Freescale Semiconductor
5  *
6  * This defines the API for storing board information in the
7  * eeprom. It has been adapted from an earlier version of the
8  * Freescale API, but has a number of key differences. Because
9  * the two APIs are independent and may diverge further, the
10  * Varisys version of the API is implemented separately here.
11  */
12 
13 #include <common.h>
14 #include <command.h>
15 #include <i2c.h>
16 #include <linux/ctype.h>
17 
18 #include "eeprom.h"
19 
20 #ifdef CONFIG_SYS_I2C_EEPROM_NXID_MAC
21 #define MAX_NUM_PORTS	CONFIG_SYS_I2C_EEPROM_NXID_MAC
22 #else
23 #define MAX_NUM_PORTS	8
24 #endif
25 #define NXID_VERSION	0
26 
27 /**
28  * static eeprom: EEPROM layout for NXID formats
29  *
30  * See Freescale application note AN3638 for details.
31  */
32 static struct __attribute__ ((__packed__)) eeprom {
33 	u8 id[4];         /* 0x00 - 0x03 EEPROM Tag 'NXID' */
34 	u8 sn[12];        /* 0x04 - 0x0F Serial Number */
35 	u8 errata[5];     /* 0x10 - 0x14 Errata Level */
36 	u8 date[6];       /* 0x15 - 0x1a Build Date */
37 	u8 res_0;         /* 0x1b        Reserved */
38 	u32 version;      /* 0x1c - 0x1f NXID Version */
39 	u8 tempcal[8];    /* 0x20 - 0x27 Temperature Calibration Factors */
40 	u8 tempcalsys[2]; /* 0x28 - 0x29 System Temperature Calibration Factors */
41 	u8 tempcalflags;  /* 0x2a        Temperature Calibration Flags */
42 	u8 res_1[21];     /* 0x2b - 0x3f Reserved */
43 	u8 mac_count;     /* 0x40        Number of MAC addresses */
44 	u8 mac_flag;      /* 0x41        MAC table flags */
45 	u8 mac[MAX_NUM_PORTS][6];     /* 0x42 - x MAC addresses */
46 	u32 crc;          /* x+1         CRC32 checksum */
47 } e;
48 
49 /* Set to 1 if we've read EEPROM into memory */
50 static int has_been_read;
51 
52 /* Is this a valid NXID EEPROM? */
53 #define is_valid ((e.id[0] == 'N') || (e.id[1] == 'X') || \
54 		  (e.id[2] == 'I') || (e.id[3] == 'D'))
55 
56 /** Fixed ID field in EEPROM */
57 static unsigned char uid[16];
58 
59 static int eeprom_bus_num = -1;
60 static int eeprom_addr;
61 static int eeprom_addr_len;
62 
63 /**
64  * This must be called before any eeprom access.
65  */
66 void init_eeprom(int bus_num, int addr, int addr_len)
67 {
68 	eeprom_bus_num = bus_num;
69 	eeprom_addr = addr;
70 	eeprom_addr_len = addr_len;
71 }
72 
73 /**
74  * show_eeprom - display the contents of the EEPROM
75  */
76 void show_eeprom(void)
77 {
78 	int i;
79 	unsigned int crc;
80 
81 	/* EEPROM tag ID, either CCID or NXID */
82 	printf("ID: %c%c%c%c v%u\n", e.id[0], e.id[1], e.id[2], e.id[3],
83 		be32_to_cpu(e.version));
84 
85 	/* Serial number */
86 	printf("SN: %s\n", e.sn);
87 
88 	printf("UID: ");
89 	for (i = 0; i < 16; i++)
90 		printf("%02x", uid[i]);
91 	printf("\n");
92 
93 	/* Errata level. */
94 	printf("Errata: %s\n", e.errata);
95 
96 	/* Build date, BCD date values, as YYMMDDhhmmss */
97 	printf("Build date: 20%02x/%02x/%02x %02x:%02x:%02x %s\n",
98 		e.date[0], e.date[1], e.date[2],
99 		e.date[3] & 0x7F, e.date[4], e.date[5],
100 		e.date[3] & 0x80 ? "PM" : "");
101 
102 	/* Show MAC addresses  */
103 	for (i = 0; i < min(e.mac_count, (u8)MAX_NUM_PORTS); i++) {
104 		u8 *p = e.mac[i];
105 
106 		printf("Eth%u: %02x:%02x:%02x:%02x:%02x:%02x\n", i,
107 		       p[0], p[1], p[2], p[3], p[4], p[5]);
108 	}
109 
110 	crc = crc32(0, (void *)&e, sizeof(e) - 4);
111 
112 	if (crc == be32_to_cpu(e.crc))
113 		printf("CRC: %08x\n", be32_to_cpu(e.crc));
114 	else
115 		printf("CRC: %08x (should be %08x)\n",
116 		       be32_to_cpu(e.crc), crc);
117 
118 #ifdef DEBUG
119 	printf("EEPROM dump: (0x%x bytes)\n", sizeof(e));
120 	for (i = 0; i < sizeof(e); i++) {
121 		if ((i % 16) == 0)
122 			printf("%02X: ", i);
123 		printf("%02X ", ((u8 *)&e)[i]);
124 		if (((i % 16) == 15) || (i == sizeof(e) - 1))
125 			printf("\n");
126 	}
127 #endif
128 }
129 
130 /**
131  * read_eeprom - read the EEPROM into memory
132  */
133 int read_eeprom(void)
134 {
135 	int ret;
136 	unsigned int bus;
137 
138 	if (eeprom_bus_num < 0) {
139 		printf("EEPROM not configured\n");
140 		return -1;
141 	}
142 
143 	if (has_been_read)
144 		return 0;
145 
146 	bus = i2c_get_bus_num();
147 	i2c_set_bus_num(eeprom_bus_num);
148 
149 	ret = i2c_read(eeprom_addr, 0, eeprom_addr_len,
150 		(void *)&e, sizeof(e));
151 
152 
153 	/* Fixed address of ID field */
154 	i2c_read(0x5f, 0x80, 1, uid, 16);
155 
156 	i2c_set_bus_num(bus);
157 
158 #ifdef DEBUG
159 	show_eeprom();
160 #endif
161 
162 	has_been_read = (ret == 0) ? 1 : 0;
163 
164 	return ret;
165 }
166 
167 /**
168  *  update_crc - update the CRC
169  *
170  *  This function should be called after each update to the EEPROM structure,
171  *  to make sure the CRC is always correct.
172  */
173 static void update_crc(void)
174 {
175 	u32 crc, crc_offset = offsetof(struct eeprom, crc);
176 
177 	crc = crc32(0, (void *)&e, crc_offset);
178 	e.crc = cpu_to_be32(crc);
179 }
180 
181 /**
182  * prog_eeprom - write the EEPROM from memory
183  */
184 static int prog_eeprom(void)
185 {
186 	int ret = 0;
187 	int i;
188 	void *p;
189 	unsigned int bus;
190 
191 	if (eeprom_bus_num < 0) {
192 		printf("EEPROM not configured\n");
193 		return -1;
194 	}
195 
196 	/* Set the reserved values to 0xFF   */
197 	e.res_0 = 0xFF;
198 	memset(e.res_1, 0xFF, sizeof(e.res_1));
199 	update_crc();
200 
201 	bus = i2c_get_bus_num();
202 	i2c_set_bus_num(eeprom_bus_num);
203 
204 	/*
205 	 * The AT24C02 datasheet says that data can only be written in page
206 	 * mode, which means 8 bytes at a time, and it takes up to 5ms to
207 	 * complete a given write.
208 	 */
209 	for (i = 0, p = &e; i < sizeof(e); i += 8, p += 8) {
210 		ret = i2c_write(eeprom_addr, i, eeprom_addr_len,
211 			p, min((int)(sizeof(e) - i), 8));
212 		if (ret)
213 			break;
214 		udelay(5000);	/* 5ms write cycle timing */
215 	}
216 
217 	if (!ret) {
218 		/* Verify the write by reading back the EEPROM and comparing */
219 		struct eeprom e2;
220 
221 		ret = i2c_read(eeprom_addr, 0,
222 			eeprom_addr_len, (void *)&e2, sizeof(e2));
223 		if (!ret && memcmp(&e, &e2, sizeof(e)))
224 			ret = -1;
225 	}
226 
227 	i2c_set_bus_num(bus);
228 
229 	if (ret) {
230 		printf("Programming failed.\n");
231 		has_been_read = 0;
232 		return -1;
233 	}
234 
235 	printf("Programming passed.\n");
236 	return 0;
237 }
238 
239 /**
240  * h2i - converts hex character into a number
241  *
242  * This function takes a hexadecimal character (e.g. '7' or 'C') and returns
243  * the integer equivalent.
244  */
245 static inline u8 h2i(char p)
246 {
247 	if ((p >= '0') && (p <= '9'))
248 		return p - '0';
249 
250 	if ((p >= 'A') && (p <= 'F'))
251 		return (p - 'A') + 10;
252 
253 	if ((p >= 'a') && (p <= 'f'))
254 		return (p - 'a') + 10;
255 
256 	return 0;
257 }
258 
259 /**
260  * set_date - stores the build date into the EEPROM
261  *
262  * This function takes a pointer to a string in the format "YYMMDDhhmmss"
263  * (2-digit year, 2-digit month, etc), converts it to a 6-byte BCD string,
264  * and stores it in the build date field of the EEPROM local copy.
265  */
266 static void set_date(const char *string)
267 {
268 	unsigned int i;
269 
270 	if (strlen(string) != 12) {
271 		printf("Usage: mac date YYMMDDhhmmss\n");
272 		return;
273 	}
274 
275 	for (i = 0; i < 6; i++)
276 		e.date[i] = h2i(string[2 * i]) << 4 | h2i(string[2 * i + 1]);
277 
278 	update_crc();
279 }
280 
281 /**
282  * set_mac_address - stores a MAC address into the EEPROM
283  *
284  * This function takes a pointer to MAC address string
285  * (i.e."XX:XX:XX:XX:XX:XX", where "XX" is a two-digit hex number) and
286  * stores it in one of the MAC address fields of the EEPROM local copy.
287  */
288 static void set_mac_address(unsigned int index, const char *string)
289 {
290 	char *p = (char *)string;
291 	unsigned int i;
292 
293 	if ((index >= MAX_NUM_PORTS) || !string) {
294 		printf("Usage: mac <n> XX:XX:XX:XX:XX:XX\n");
295 		return;
296 	}
297 
298 	for (i = 0; *p && (i < 6); i++) {
299 		e.mac[index][i] = simple_strtoul(p, &p, 16);
300 		if (*p == ':')
301 			p++;
302 	}
303 
304 	update_crc();
305 }
306 
307 int do_mac(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
308 {
309 	char cmd;
310 
311 	if (argc == 1) {
312 		show_eeprom();
313 		return 0;
314 	}
315 
316 	cmd = argv[1][0];
317 
318 	if (cmd == 'r') {
319 		read_eeprom();
320 		return 0;
321 	}
322 
323 	if (cmd == 'i') {
324 		memcpy(e.id, "NXID", sizeof(e.id));
325 		e.version = NXID_VERSION;
326 		update_crc();
327 		return 0;
328 	}
329 
330 	if (!is_valid) {
331 		printf("Please read the EEPROM ('r') and/or set the ID ('i') first.\n");
332 		return 0;
333 	}
334 
335 	if (argc == 2) {
336 		switch (cmd) {
337 		case 's':	/* save */
338 			prog_eeprom();
339 			break;
340 		default:
341 			return cmd_usage(cmdtp);
342 		}
343 
344 		return 0;
345 	}
346 
347 	/* We know we have at least one parameter  */
348 
349 	switch (cmd) {
350 	case 'n':	/* serial number */
351 		memset(e.sn, 0, sizeof(e.sn));
352 		strncpy((char *)e.sn, argv[2], sizeof(e.sn) - 1);
353 		update_crc();
354 		break;
355 	case 'e':	/* errata */
356 		memset(e.errata, 0, 5);
357 		strncpy((char *)e.errata, argv[2], 4);
358 		update_crc();
359 		break;
360 	case 'd':	/* date BCD format YYMMDDhhmmss */
361 		set_date(argv[2]);
362 		break;
363 	case 'p':	/* MAC table size */
364 		e.mac_count = simple_strtoul(argv[2], NULL, 16);
365 		update_crc();
366 		break;
367 	case '0' ... '9':	/* "mac 0" through "mac 22" */
368 		set_mac_address(simple_strtoul(argv[1], NULL, 10), argv[2]);
369 		break;
370 	case 'h':	/* help */
371 	default:
372 		return cmd_usage(cmdtp);
373 	}
374 
375 	return 0;
376 }
377 
378 int mac_read_from_generic_eeprom(const char *envvar, int chip,
379 	int address, int mac_bus)
380 {
381 	int ret;
382 	unsigned int bus;
383 	unsigned char mac[6];
384 	char ethaddr[18];
385 
386 	bus = i2c_get_bus_num();
387 	i2c_set_bus_num(mac_bus);
388 
389 	ret = i2c_read(chip, address, 1, mac, 6);
390 
391 	i2c_set_bus_num(bus);
392 
393 	if (!ret) {
394 		sprintf(ethaddr, "%02X:%02X:%02X:%02X:%02X:%02X",
395 			mac[0],
396 			mac[1],
397 			mac[2],
398 			mac[3],
399 			mac[4],
400 			mac[5]);
401 
402 		printf("MAC: %s\n", ethaddr);
403 		env_set(envvar, ethaddr);
404 	}
405 
406 	return ret;
407 }
408 
409 void mac_read_from_fixed_id(void)
410 {
411 #ifdef CONFIG_SYS_I2C_MAC1_CHIP_ADDR
412 	mac_read_from_generic_eeprom("ethaddr", CONFIG_SYS_I2C_MAC1_CHIP_ADDR,
413 		CONFIG_SYS_I2C_MAC1_DATA_ADDR, CONFIG_SYS_I2C_MAC1_BUS);
414 #endif
415 #ifdef CONFIG_SYS_I2C_MAC2_CHIP_ADDR
416 	mac_read_from_generic_eeprom("eth1addr", CONFIG_SYS_I2C_MAC2_CHIP_ADDR,
417 		CONFIG_SYS_I2C_MAC2_DATA_ADDR, CONFIG_SYS_I2C_MAC2_BUS);
418 #endif
419 }
420 
421 /**
422  * mac_read_from_eeprom - read the MAC addresses from EEPROM
423  *
424  * This function reads the MAC addresses from EEPROM and sets the
425  * appropriate environment variables for each one read.
426  *
427  * The environment variables are only set if they haven't been set already.
428  * This ensures that any user-saved variables are never overwritten.
429  *
430  * This function must be called after relocation.
431  *
432  * For NXID v1 EEPROMs, we support loading and up-converting the older NXID v0
433  * format.  In a v0 EEPROM, there are only eight MAC addresses and the CRC is
434  * located at a different offset.
435  */
436 int mac_read_from_eeprom_common(void)
437 {
438 	unsigned int i;
439 	u32 crc, crc_offset = offsetof(struct eeprom, crc);
440 	u32 *crcp; /* Pointer to the CRC in the data read from the EEPROM */
441 
442 	puts("EEPROM: ");
443 
444 	if (read_eeprom()) {
445 		printf("Read failed.\n");
446 		return 0;
447 	}
448 
449 	if (!is_valid) {
450 		printf("Invalid ID (%02x %02x %02x %02x)\n",
451 		       e.id[0], e.id[1], e.id[2], e.id[3]);
452 		return 0;
453 	}
454 
455 	crc = crc32(0, (void *)&e, crc_offset);
456 	crcp = (void *)&e + crc_offset;
457 	if (crc != be32_to_cpu(*crcp)) {
458 		printf("CRC mismatch (%08x != %08x)\n", crc,
459 			be32_to_cpu(e.crc));
460 		return 0;
461 	}
462 
463 	/*
464 	 * MAC address #9 in v1 occupies the same position as the CRC in v0.
465 	 * Erase it so that it's not mistaken for a MAC address.  We'll
466 	 * update the CRC later.
467 	 */
468 	if (e.version == 0)
469 		memset(e.mac[8], 0xff, 6);
470 
471 	for (i = 0; i < min(e.mac_count, (u8)MAX_NUM_PORTS); i++) {
472 		if (memcmp(&e.mac[i], "\0\0\0\0\0\0", 6) &&
473 		    memcmp(&e.mac[i], "\xFF\xFF\xFF\xFF\xFF\xFF", 6)) {
474 			char ethaddr[18];
475 			char enetvar[9];
476 
477 			sprintf(ethaddr, "%02X:%02X:%02X:%02X:%02X:%02X",
478 				e.mac[i][0],
479 				e.mac[i][1],
480 				e.mac[i][2],
481 				e.mac[i][3],
482 				e.mac[i][4],
483 				e.mac[i][5]);
484 			sprintf(enetvar, i ? "eth%daddr" : "ethaddr", i);
485 			/* Only initialize environment variables that are blank
486 			 * (i.e. have not yet been set)
487 			 */
488 			if (!env_get(enetvar))
489 				env_set(enetvar, ethaddr);
490 		}
491 	}
492 
493 	printf("%c%c%c%c v%u\n", e.id[0], e.id[1], e.id[2], e.id[3],
494 		be32_to_cpu(e.version));
495 
496 	return 0;
497 }
498