1 /*
2  * Based on board/freescale/common/sys_eeprom.c
3  * Copyright 2006, 2008-2009, 2011 Freescale Semiconductor
4  *
5  * This defines the API for storing board information in the
6  * eeprom. It has been adapted from an earlier version of the
7  * Freescale API, but has a number of key differences. Because
8  * the two APIs are independent and may diverge further, the
9  * Varisys version of the API is implemented separately here.
10  *
11  * SPDX-License-Identifier:    GPL-2.0+
12  */
13 
14 #include <common.h>
15 #include <command.h>
16 #include <i2c.h>
17 #include <linux/ctype.h>
18 
19 #include "eeprom.h"
20 
21 #ifdef CONFIG_SYS_I2C_EEPROM_NXID_MAC
22 #define MAX_NUM_PORTS	CONFIG_SYS_I2C_EEPROM_NXID_MAC
23 #else
24 #define MAX_NUM_PORTS	8
25 #endif
26 #define NXID_VERSION	0
27 
28 /**
29  * static eeprom: EEPROM layout for NXID formats
30  *
31  * See Freescale application note AN3638 for details.
32  */
33 static struct __attribute__ ((__packed__)) eeprom {
34 	u8 id[4];         /* 0x00 - 0x03 EEPROM Tag 'NXID' */
35 	u8 sn[12];        /* 0x04 - 0x0F Serial Number */
36 	u8 errata[5];     /* 0x10 - 0x14 Errata Level */
37 	u8 date[6];       /* 0x15 - 0x1a Build Date */
38 	u8 res_0;         /* 0x1b        Reserved */
39 	u32 version;      /* 0x1c - 0x1f NXID Version */
40 	u8 tempcal[8];    /* 0x20 - 0x27 Temperature Calibration Factors */
41 	u8 tempcalsys[2]; /* 0x28 - 0x29 System Temperature Calibration Factors */
42 	u8 tempcalflags;  /* 0x2a        Temperature Calibration Flags */
43 	u8 res_1[21];     /* 0x2b - 0x3f Reserved */
44 	u8 mac_count;     /* 0x40        Number of MAC addresses */
45 	u8 mac_flag;      /* 0x41        MAC table flags */
46 	u8 mac[MAX_NUM_PORTS][6];     /* 0x42 - x MAC addresses */
47 	u32 crc;          /* x+1         CRC32 checksum */
48 } e;
49 
50 /* Set to 1 if we've read EEPROM into memory */
51 static int has_been_read;
52 
53 /* Is this a valid NXID EEPROM? */
54 #define is_valid ((e.id[0] == 'N') || (e.id[1] == 'X') || \
55 		  (e.id[2] == 'I') || (e.id[3] == 'D'))
56 
57 /** Fixed ID field in EEPROM */
58 static unsigned char uid[16];
59 
60 static int eeprom_bus_num = -1;
61 static int eeprom_addr;
62 static int eeprom_addr_len;
63 
64 /**
65  * This must be called before any eeprom access.
66  */
67 void init_eeprom(int bus_num, int addr, int addr_len)
68 {
69 	eeprom_bus_num = bus_num;
70 	eeprom_addr = addr;
71 	eeprom_addr_len = addr_len;
72 }
73 
74 /**
75  * show_eeprom - display the contents of the EEPROM
76  */
77 void show_eeprom(void)
78 {
79 	int i;
80 	unsigned int crc;
81 
82 	/* EEPROM tag ID, either CCID or NXID */
83 	printf("ID: %c%c%c%c v%u\n", e.id[0], e.id[1], e.id[2], e.id[3],
84 		be32_to_cpu(e.version));
85 
86 	/* Serial number */
87 	printf("SN: %s\n", e.sn);
88 
89 	printf("UID: ");
90 	for (i = 0; i < 16; i++)
91 		printf("%02x", uid[i]);
92 	printf("\n");
93 
94 	/* Errata level. */
95 	printf("Errata: %s\n", e.errata);
96 
97 	/* Build date, BCD date values, as YYMMDDhhmmss */
98 	printf("Build date: 20%02x/%02x/%02x %02x:%02x:%02x %s\n",
99 		e.date[0], e.date[1], e.date[2],
100 		e.date[3] & 0x7F, e.date[4], e.date[5],
101 		e.date[3] & 0x80 ? "PM" : "");
102 
103 	/* Show MAC addresses  */
104 	for (i = 0; i < min(e.mac_count, (u8)MAX_NUM_PORTS); i++) {
105 		u8 *p = e.mac[i];
106 
107 		printf("Eth%u: %02x:%02x:%02x:%02x:%02x:%02x\n", i,
108 		       p[0], p[1], p[2], p[3], p[4], p[5]);
109 	}
110 
111 	crc = crc32(0, (void *)&e, sizeof(e) - 4);
112 
113 	if (crc == be32_to_cpu(e.crc))
114 		printf("CRC: %08x\n", be32_to_cpu(e.crc));
115 	else
116 		printf("CRC: %08x (should be %08x)\n",
117 		       be32_to_cpu(e.crc), crc);
118 
119 #ifdef DEBUG
120 	printf("EEPROM dump: (0x%x bytes)\n", sizeof(e));
121 	for (i = 0; i < sizeof(e); i++) {
122 		if ((i % 16) == 0)
123 			printf("%02X: ", i);
124 		printf("%02X ", ((u8 *)&e)[i]);
125 		if (((i % 16) == 15) || (i == sizeof(e) - 1))
126 			printf("\n");
127 	}
128 #endif
129 }
130 
131 /**
132  * read_eeprom - read the EEPROM into memory
133  */
134 int read_eeprom(void)
135 {
136 	int ret;
137 	unsigned int bus;
138 
139 	if (eeprom_bus_num < 0) {
140 		printf("EEPROM not configured\n");
141 		return -1;
142 	}
143 
144 	if (has_been_read)
145 		return 0;
146 
147 	bus = i2c_get_bus_num();
148 	i2c_set_bus_num(eeprom_bus_num);
149 
150 	ret = i2c_read(eeprom_addr, 0, eeprom_addr_len,
151 		(void *)&e, sizeof(e));
152 
153 
154 	/* Fixed address of ID field */
155 	i2c_read(0x5f, 0x80, 1, uid, 16);
156 
157 	i2c_set_bus_num(bus);
158 
159 #ifdef DEBUG
160 	show_eeprom();
161 #endif
162 
163 	has_been_read = (ret == 0) ? 1 : 0;
164 
165 	return ret;
166 }
167 
168 /**
169  *  update_crc - update the CRC
170  *
171  *  This function should be called after each update to the EEPROM structure,
172  *  to make sure the CRC is always correct.
173  */
174 static void update_crc(void)
175 {
176 	u32 crc, crc_offset = offsetof(struct eeprom, crc);
177 
178 	crc = crc32(0, (void *)&e, crc_offset);
179 	e.crc = cpu_to_be32(crc);
180 }
181 
182 /**
183  * prog_eeprom - write the EEPROM from memory
184  */
185 static int prog_eeprom(void)
186 {
187 	int ret = 0;
188 	int i;
189 	void *p;
190 	unsigned int bus;
191 
192 	if (eeprom_bus_num < 0) {
193 		printf("EEPROM not configured\n");
194 		return -1;
195 	}
196 
197 	/* Set the reserved values to 0xFF   */
198 	e.res_0 = 0xFF;
199 	memset(e.res_1, 0xFF, sizeof(e.res_1));
200 	update_crc();
201 
202 	bus = i2c_get_bus_num();
203 	i2c_set_bus_num(eeprom_bus_num);
204 
205 	/*
206 	 * The AT24C02 datasheet says that data can only be written in page
207 	 * mode, which means 8 bytes at a time, and it takes up to 5ms to
208 	 * complete a given write.
209 	 */
210 	for (i = 0, p = &e; i < sizeof(e); i += 8, p += 8) {
211 		ret = i2c_write(eeprom_addr, i, eeprom_addr_len,
212 			p, min((int)(sizeof(e) - i), 8));
213 		if (ret)
214 			break;
215 		udelay(5000);	/* 5ms write cycle timing */
216 	}
217 
218 	if (!ret) {
219 		/* Verify the write by reading back the EEPROM and comparing */
220 		struct eeprom e2;
221 
222 		ret = i2c_read(eeprom_addr, 0,
223 			eeprom_addr_len, (void *)&e2, sizeof(e2));
224 		if (!ret && memcmp(&e, &e2, sizeof(e)))
225 			ret = -1;
226 	}
227 
228 	i2c_set_bus_num(bus);
229 
230 	if (ret) {
231 		printf("Programming failed.\n");
232 		has_been_read = 0;
233 		return -1;
234 	}
235 
236 	printf("Programming passed.\n");
237 	return 0;
238 }
239 
240 /**
241  * h2i - converts hex character into a number
242  *
243  * This function takes a hexadecimal character (e.g. '7' or 'C') and returns
244  * the integer equivalent.
245  */
246 static inline u8 h2i(char p)
247 {
248 	if ((p >= '0') && (p <= '9'))
249 		return p - '0';
250 
251 	if ((p >= 'A') && (p <= 'F'))
252 		return (p - 'A') + 10;
253 
254 	if ((p >= 'a') && (p <= 'f'))
255 		return (p - 'a') + 10;
256 
257 	return 0;
258 }
259 
260 /**
261  * set_date - stores the build date into the EEPROM
262  *
263  * This function takes a pointer to a string in the format "YYMMDDhhmmss"
264  * (2-digit year, 2-digit month, etc), converts it to a 6-byte BCD string,
265  * and stores it in the build date field of the EEPROM local copy.
266  */
267 static void set_date(const char *string)
268 {
269 	unsigned int i;
270 
271 	if (strlen(string) != 12) {
272 		printf("Usage: mac date YYMMDDhhmmss\n");
273 		return;
274 	}
275 
276 	for (i = 0; i < 6; i++)
277 		e.date[i] = h2i(string[2 * i]) << 4 | h2i(string[2 * i + 1]);
278 
279 	update_crc();
280 }
281 
282 /**
283  * set_mac_address - stores a MAC address into the EEPROM
284  *
285  * This function takes a pointer to MAC address string
286  * (i.e."XX:XX:XX:XX:XX:XX", where "XX" is a two-digit hex number) and
287  * stores it in one of the MAC address fields of the EEPROM local copy.
288  */
289 static void set_mac_address(unsigned int index, const char *string)
290 {
291 	char *p = (char *)string;
292 	unsigned int i;
293 
294 	if ((index >= MAX_NUM_PORTS) || !string) {
295 		printf("Usage: mac <n> XX:XX:XX:XX:XX:XX\n");
296 		return;
297 	}
298 
299 	for (i = 0; *p && (i < 6); i++) {
300 		e.mac[index][i] = simple_strtoul(p, &p, 16);
301 		if (*p == ':')
302 			p++;
303 	}
304 
305 	update_crc();
306 }
307 
308 int do_mac(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
309 {
310 	char cmd;
311 
312 	if (argc == 1) {
313 		show_eeprom();
314 		return 0;
315 	}
316 
317 	cmd = argv[1][0];
318 
319 	if (cmd == 'r') {
320 		read_eeprom();
321 		return 0;
322 	}
323 
324 	if (cmd == 'i') {
325 		memcpy(e.id, "NXID", sizeof(e.id));
326 		e.version = NXID_VERSION;
327 		update_crc();
328 		return 0;
329 	}
330 
331 	if (!is_valid) {
332 		printf("Please read the EEPROM ('r') and/or set the ID ('i') first.\n");
333 		return 0;
334 	}
335 
336 	if (argc == 2) {
337 		switch (cmd) {
338 		case 's':	/* save */
339 			prog_eeprom();
340 			break;
341 		default:
342 			return cmd_usage(cmdtp);
343 		}
344 
345 		return 0;
346 	}
347 
348 	/* We know we have at least one parameter  */
349 
350 	switch (cmd) {
351 	case 'n':	/* serial number */
352 		memset(e.sn, 0, sizeof(e.sn));
353 		strncpy((char *)e.sn, argv[2], sizeof(e.sn) - 1);
354 		update_crc();
355 		break;
356 	case 'e':	/* errata */
357 		memset(e.errata, 0, 5);
358 		strncpy((char *)e.errata, argv[2], 4);
359 		update_crc();
360 		break;
361 	case 'd':	/* date BCD format YYMMDDhhmmss */
362 		set_date(argv[2]);
363 		break;
364 	case 'p':	/* MAC table size */
365 		e.mac_count = simple_strtoul(argv[2], NULL, 16);
366 		update_crc();
367 		break;
368 	case '0' ... '9':	/* "mac 0" through "mac 22" */
369 		set_mac_address(simple_strtoul(argv[1], NULL, 10), argv[2]);
370 		break;
371 	case 'h':	/* help */
372 	default:
373 		return cmd_usage(cmdtp);
374 	}
375 
376 	return 0;
377 }
378 
379 int mac_read_from_generic_eeprom(const char *envvar, int chip,
380 	int address, int mac_bus)
381 {
382 	int ret;
383 	unsigned int bus;
384 	unsigned char mac[6];
385 	char ethaddr[18];
386 
387 	bus = i2c_get_bus_num();
388 	i2c_set_bus_num(mac_bus);
389 
390 	ret = i2c_read(chip, address, 1, mac, 6);
391 
392 	i2c_set_bus_num(bus);
393 
394 	if (!ret) {
395 		sprintf(ethaddr, "%02X:%02X:%02X:%02X:%02X:%02X",
396 			mac[0],
397 			mac[1],
398 			mac[2],
399 			mac[3],
400 			mac[4],
401 			mac[5]);
402 
403 		printf("MAC: %s\n", ethaddr);
404 		env_set(envvar, ethaddr);
405 	}
406 
407 	return ret;
408 }
409 
410 void mac_read_from_fixed_id(void)
411 {
412 #ifdef CONFIG_SYS_I2C_MAC1_CHIP_ADDR
413 	mac_read_from_generic_eeprom("ethaddr", CONFIG_SYS_I2C_MAC1_CHIP_ADDR,
414 		CONFIG_SYS_I2C_MAC1_DATA_ADDR, CONFIG_SYS_I2C_MAC1_BUS);
415 #endif
416 #ifdef CONFIG_SYS_I2C_MAC2_CHIP_ADDR
417 	mac_read_from_generic_eeprom("eth1addr", CONFIG_SYS_I2C_MAC2_CHIP_ADDR,
418 		CONFIG_SYS_I2C_MAC2_DATA_ADDR, CONFIG_SYS_I2C_MAC2_BUS);
419 #endif
420 }
421 
422 /**
423  * mac_read_from_eeprom - read the MAC addresses from EEPROM
424  *
425  * This function reads the MAC addresses from EEPROM and sets the
426  * appropriate environment variables for each one read.
427  *
428  * The environment variables are only set if they haven't been set already.
429  * This ensures that any user-saved variables are never overwritten.
430  *
431  * This function must be called after relocation.
432  *
433  * For NXID v1 EEPROMs, we support loading and up-converting the older NXID v0
434  * format.  In a v0 EEPROM, there are only eight MAC addresses and the CRC is
435  * located at a different offset.
436  */
437 int mac_read_from_eeprom_common(void)
438 {
439 	unsigned int i;
440 	u32 crc, crc_offset = offsetof(struct eeprom, crc);
441 	u32 *crcp; /* Pointer to the CRC in the data read from the EEPROM */
442 
443 	puts("EEPROM: ");
444 
445 	if (read_eeprom()) {
446 		printf("Read failed.\n");
447 		return 0;
448 	}
449 
450 	if (!is_valid) {
451 		printf("Invalid ID (%02x %02x %02x %02x)\n",
452 		       e.id[0], e.id[1], e.id[2], e.id[3]);
453 		return 0;
454 	}
455 
456 	crc = crc32(0, (void *)&e, crc_offset);
457 	crcp = (void *)&e + crc_offset;
458 	if (crc != be32_to_cpu(*crcp)) {
459 		printf("CRC mismatch (%08x != %08x)\n", crc,
460 			be32_to_cpu(e.crc));
461 		return 0;
462 	}
463 
464 	/*
465 	 * MAC address #9 in v1 occupies the same position as the CRC in v0.
466 	 * Erase it so that it's not mistaken for a MAC address.  We'll
467 	 * update the CRC later.
468 	 */
469 	if (e.version == 0)
470 		memset(e.mac[8], 0xff, 6);
471 
472 	for (i = 0; i < min(e.mac_count, (u8)MAX_NUM_PORTS); i++) {
473 		if (memcmp(&e.mac[i], "\0\0\0\0\0\0", 6) &&
474 		    memcmp(&e.mac[i], "\xFF\xFF\xFF\xFF\xFF\xFF", 6)) {
475 			char ethaddr[18];
476 			char enetvar[9];
477 
478 			sprintf(ethaddr, "%02X:%02X:%02X:%02X:%02X:%02X",
479 				e.mac[i][0],
480 				e.mac[i][1],
481 				e.mac[i][2],
482 				e.mac[i][3],
483 				e.mac[i][4],
484 				e.mac[i][5]);
485 			sprintf(enetvar, i ? "eth%daddr" : "ethaddr", i);
486 			/* Only initialize environment variables that are blank
487 			 * (i.e. have not yet been set)
488 			 */
489 			if (!env_get(enetvar))
490 				env_set(enetvar, ethaddr);
491 		}
492 	}
493 
494 	printf("%c%c%c%c v%u\n", e.id[0], e.id[1], e.id[2], e.id[3],
495 		be32_to_cpu(e.version));
496 
497 	return 0;
498 }
499