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1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2000, 2001
4  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5  */
6 
7 /*
8  * Support for read and write access to EEPROM like memory devices. This
9  * includes regular EEPROM as well as  FRAM (ferroelectic nonvolaile RAM).
10  * FRAM devices read and write data at bus speed. In particular, there is no
11  * write delay. Also, there is no limit imposed on the number of bytes that can
12  * be transferred with a single read or write.
13  *
14  * Use the following configuration options to ensure no unneeded performance
15  * degradation (typical for EEPROM) is incured for FRAM memory:
16  *
17  * #define CONFIG_SYS_I2C_FRAM
18  * #undef CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS
19  *
20  */
21 
22 #include <common.h>
23 #include <config.h>
24 #include <command.h>
25 #include <eeprom.h>
26 #include <i2c.h>
27 #include <eeprom_layout.h>
28 
29 #ifndef	CONFIG_SYS_I2C_SPEED
30 #define	CONFIG_SYS_I2C_SPEED	50000
31 #endif
32 
33 #ifndef CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS
34 #define CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS	0
35 #endif
36 
37 #ifndef CONFIG_SYS_EEPROM_PAGE_WRITE_BITS
38 #define CONFIG_SYS_EEPROM_PAGE_WRITE_BITS	8
39 #endif
40 
41 #ifndef	I2C_RXTX_LEN
42 #define I2C_RXTX_LEN	128
43 #endif
44 
45 #define	EEPROM_PAGE_SIZE	(1 << CONFIG_SYS_EEPROM_PAGE_WRITE_BITS)
46 #define	EEPROM_PAGE_OFFSET(x)	((x) & (EEPROM_PAGE_SIZE - 1))
47 
48 /*
49  * for CONFIG_SYS_I2C_EEPROM_ADDR_LEN == 2 (16-bit EEPROM address) offset is
50  *   0x000nxxxx for EEPROM address selectors at n, offset xxxx in EEPROM.
51  *
52  * for CONFIG_SYS_I2C_EEPROM_ADDR_LEN == 1 (8-bit EEPROM page address) offset is
53  *   0x00000nxx for EEPROM address selectors and page number at n.
54  */
55 #if !defined(CONFIG_SPI) || defined(CONFIG_ENV_EEPROM_IS_ON_I2C)
56 #if !defined(CONFIG_SYS_I2C_EEPROM_ADDR_LEN) || \
57 	(CONFIG_SYS_I2C_EEPROM_ADDR_LEN < 1) || \
58 	(CONFIG_SYS_I2C_EEPROM_ADDR_LEN > 2)
59 #error CONFIG_SYS_I2C_EEPROM_ADDR_LEN must be 1 or 2
60 #endif
61 #endif
62 
63 #if defined(CONFIG_DM_I2C)
64 int eeprom_i2c_bus;
65 #endif
66 
eeprom_write_enable(unsigned dev_addr,int state)67 __weak int eeprom_write_enable(unsigned dev_addr, int state)
68 {
69 	return 0;
70 }
71 
eeprom_init(int bus)72 void eeprom_init(int bus)
73 {
74 	/* I2C EEPROM */
75 #if defined(CONFIG_DM_I2C)
76 	eeprom_i2c_bus = bus;
77 #elif defined(CONFIG_SYS_I2C)
78 	if (bus >= 0)
79 		i2c_set_bus_num(bus);
80 	i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
81 #endif
82 }
83 
eeprom_addr(unsigned dev_addr,unsigned offset,uchar * addr)84 static int eeprom_addr(unsigned dev_addr, unsigned offset, uchar *addr)
85 {
86 	unsigned blk_off;
87 	int alen;
88 
89 	blk_off = offset & 0xff;	/* block offset */
90 #if CONFIG_SYS_I2C_EEPROM_ADDR_LEN == 1
91 	addr[0] = offset >> 8;		/* block number */
92 	addr[1] = blk_off;		/* block offset */
93 	alen = 2;
94 #else
95 	addr[0] = offset >> 16;		/* block number */
96 	addr[1] = offset >>  8;		/* upper address octet */
97 	addr[2] = blk_off;		/* lower address octet */
98 	alen = 3;
99 #endif	/* CONFIG_SYS_I2C_EEPROM_ADDR_LEN */
100 
101 	addr[0] |= dev_addr;		/* insert device address */
102 
103 	return alen;
104 }
105 
eeprom_len(unsigned offset,unsigned end)106 static int eeprom_len(unsigned offset, unsigned end)
107 {
108 	unsigned len = end - offset;
109 
110 	/*
111 	 * For a FRAM device there is no limit on the number of the
112 	 * bytes that can be accessed with the single read or write
113 	 * operation.
114 	 */
115 #if !defined(CONFIG_SYS_I2C_FRAM)
116 	unsigned blk_off = offset & 0xff;
117 	unsigned maxlen = EEPROM_PAGE_SIZE - EEPROM_PAGE_OFFSET(blk_off);
118 
119 	if (maxlen > I2C_RXTX_LEN)
120 		maxlen = I2C_RXTX_LEN;
121 
122 	if (len > maxlen)
123 		len = maxlen;
124 #endif
125 
126 	return len;
127 }
128 
eeprom_rw_block(unsigned offset,uchar * addr,unsigned alen,uchar * buffer,unsigned len,bool read)129 static int eeprom_rw_block(unsigned offset, uchar *addr, unsigned alen,
130 			   uchar *buffer, unsigned len, bool read)
131 {
132 	int ret = 0;
133 
134 #if defined(CONFIG_DM_I2C)
135 	struct udevice *dev;
136 
137 	ret = i2c_get_chip_for_busnum(eeprom_i2c_bus, addr[0],
138 				      alen - 1, &dev);
139 	if (ret) {
140 		printf("%s: Cannot find udev for a bus %d\n", __func__,
141 		       eeprom_i2c_bus);
142 		return CMD_RET_FAILURE;
143 	}
144 
145 	if (read)
146 		ret = dm_i2c_read(dev, offset, buffer, len);
147 	else
148 		ret = dm_i2c_write(dev, offset, buffer, len);
149 
150 #else /* Non DM I2C support - will be removed */
151 
152 	if (read)
153 		ret = i2c_read(addr[0], offset, alen - 1, buffer, len);
154 	else
155 		ret = i2c_write(addr[0], offset, alen - 1, buffer, len);
156 #endif /* CONFIG_DM_I2C */
157 	if (ret)
158 		ret = CMD_RET_FAILURE;
159 
160 	return ret;
161 }
162 
eeprom_rw(unsigned dev_addr,unsigned offset,uchar * buffer,unsigned cnt,bool read)163 static int eeprom_rw(unsigned dev_addr, unsigned offset, uchar *buffer,
164 		     unsigned cnt, bool read)
165 {
166 	unsigned end = offset + cnt;
167 	unsigned alen, len;
168 	int rcode = 0;
169 	uchar addr[3];
170 
171 #if defined(CONFIG_SYS_I2C_EEPROM_BUS)
172 	eeprom_init(CONFIG_SYS_I2C_EEPROM_BUS);
173 #endif
174 
175 	while (offset < end) {
176 		alen = eeprom_addr(dev_addr, offset, addr);
177 
178 		len = eeprom_len(offset, end);
179 
180 		rcode = eeprom_rw_block(offset, addr, alen, buffer, len, read);
181 
182 		buffer += len;
183 		offset += len;
184 
185 		if (!read)
186 			udelay(CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS * 1000);
187 	}
188 
189 	return rcode;
190 }
191 
eeprom_read(unsigned dev_addr,unsigned offset,uchar * buffer,unsigned cnt)192 int eeprom_read(unsigned dev_addr, unsigned offset, uchar *buffer, unsigned cnt)
193 {
194 	/*
195 	 * Read data until done or would cross a page boundary.
196 	 * We must write the address again when changing pages
197 	 * because the next page may be in a different device.
198 	 */
199 	return eeprom_rw(dev_addr, offset, buffer, cnt, 1);
200 }
201 
eeprom_write(unsigned dev_addr,unsigned offset,uchar * buffer,unsigned cnt)202 int eeprom_write(unsigned dev_addr, unsigned offset,
203 		 uchar *buffer, unsigned cnt)
204 {
205 	int ret;
206 
207 	eeprom_write_enable(dev_addr, 1);
208 
209 	/*
210 	 * Write data until done or would cross a write page boundary.
211 	 * We must write the address again when changing pages
212 	 * because the address counter only increments within a page.
213 	 */
214 	ret = eeprom_rw(dev_addr, offset, buffer, cnt, 0);
215 
216 	eeprom_write_enable(dev_addr, 0);
217 	return ret;
218 }
219 
parse_numeric_param(char * str)220 static int parse_numeric_param(char *str)
221 {
222 	char *endptr;
223 	int value = simple_strtol(str, &endptr, 16);
224 
225 	return (*endptr != '\0') ? -1 : value;
226 }
227 
228 /**
229  * parse_i2c_bus_addr - parse the i2c bus and i2c devaddr parameters
230  *
231  * @i2c_bus:	address to store the i2c bus
232  * @i2c_addr:	address to store the device i2c address
233  * @argc:	count of command line arguments left to parse
234  * @argv:	command line arguments left to parse
235  * @argc_no_bus_addr:	argc value we expect to see when bus & addr aren't given
236  *
237  * @returns:	number of arguments parsed or CMD_RET_USAGE if error
238  */
parse_i2c_bus_addr(int * i2c_bus,ulong * i2c_addr,int argc,char * const argv[],int argc_no_bus_addr)239 static int parse_i2c_bus_addr(int *i2c_bus, ulong *i2c_addr, int argc,
240 			      char * const argv[], int argc_no_bus_addr)
241 {
242 	int argc_no_bus = argc_no_bus_addr + 1;
243 	int argc_bus_addr = argc_no_bus_addr + 2;
244 
245 #ifdef CONFIG_SYS_DEF_EEPROM_ADDR
246 	if (argc == argc_no_bus_addr) {
247 		*i2c_bus = -1;
248 		*i2c_addr = CONFIG_SYS_DEF_EEPROM_ADDR;
249 
250 		return 0;
251 	}
252 #endif
253 	if (argc == argc_no_bus) {
254 		*i2c_bus = -1;
255 		*i2c_addr = parse_numeric_param(argv[0]);
256 
257 		return 1;
258 	}
259 
260 	if (argc == argc_bus_addr) {
261 		*i2c_bus = parse_numeric_param(argv[0]);
262 		*i2c_addr = parse_numeric_param(argv[1]);
263 
264 		return 2;
265 	}
266 
267 	return CMD_RET_USAGE;
268 }
269 
270 #ifdef CONFIG_CMD_EEPROM_LAYOUT
271 
eeprom_parse_layout_version(char * str)272 __weak int eeprom_parse_layout_version(char *str)
273 {
274 	return LAYOUT_VERSION_UNRECOGNIZED;
275 }
276 
277 static unsigned char eeprom_buf[CONFIG_SYS_EEPROM_SIZE];
278 
279 #endif
280 
281 enum eeprom_action {
282 	EEPROM_READ,
283 	EEPROM_WRITE,
284 	EEPROM_PRINT,
285 	EEPROM_UPDATE,
286 	EEPROM_ACTION_INVALID,
287 };
288 
parse_action(char * cmd)289 static enum eeprom_action parse_action(char *cmd)
290 {
291 	if (!strncmp(cmd, "read", 4))
292 		return EEPROM_READ;
293 	if (!strncmp(cmd, "write", 5))
294 		return EEPROM_WRITE;
295 #ifdef CONFIG_CMD_EEPROM_LAYOUT
296 	if (!strncmp(cmd, "print", 5))
297 		return EEPROM_PRINT;
298 	if (!strncmp(cmd, "update", 6))
299 		return EEPROM_UPDATE;
300 #endif
301 
302 	return EEPROM_ACTION_INVALID;
303 }
304 
eeprom_execute_command(enum eeprom_action action,int i2c_bus,ulong i2c_addr,int layout_ver,char * key,char * value,ulong addr,ulong off,ulong cnt)305 static int eeprom_execute_command(enum eeprom_action action, int i2c_bus,
306 				  ulong i2c_addr, int layout_ver, char *key,
307 				  char *value, ulong addr, ulong off, ulong cnt)
308 {
309 	int rcode = 0;
310 	const char *const fmt =
311 		"\nEEPROM @0x%lX %s: addr %08lx  off %04lx  count %ld ... ";
312 #ifdef CONFIG_CMD_EEPROM_LAYOUT
313 	struct eeprom_layout layout;
314 #endif
315 
316 	if (action == EEPROM_ACTION_INVALID)
317 		return CMD_RET_USAGE;
318 
319 	eeprom_init(i2c_bus);
320 	if (action == EEPROM_READ) {
321 		printf(fmt, i2c_addr, "read", addr, off, cnt);
322 
323 		rcode = eeprom_read(i2c_addr, off, (uchar *)addr, cnt);
324 
325 		puts("done\n");
326 		return rcode;
327 	} else if (action == EEPROM_WRITE) {
328 		printf(fmt, i2c_addr, "write", addr, off, cnt);
329 
330 		rcode = eeprom_write(i2c_addr, off, (uchar *)addr, cnt);
331 
332 		puts("done\n");
333 		return rcode;
334 	}
335 
336 #ifdef CONFIG_CMD_EEPROM_LAYOUT
337 	rcode = eeprom_read(i2c_addr, 0, eeprom_buf, CONFIG_SYS_EEPROM_SIZE);
338 	if (rcode < 0)
339 		return rcode;
340 
341 	eeprom_layout_setup(&layout, eeprom_buf, CONFIG_SYS_EEPROM_SIZE,
342 			    layout_ver);
343 
344 	if (action == EEPROM_PRINT) {
345 		layout.print(&layout);
346 		return 0;
347 	}
348 
349 	layout.update(&layout, key, value);
350 
351 	rcode = eeprom_write(i2c_addr, 0, layout.data, CONFIG_SYS_EEPROM_SIZE);
352 #endif
353 
354 	return rcode;
355 }
356 
357 #define NEXT_PARAM(argc, index)	{ (argc)--; (index)++; }
do_eeprom(cmd_tbl_t * cmdtp,int flag,int argc,char * const argv[])358 int do_eeprom(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
359 {
360 	int layout_ver = LAYOUT_VERSION_AUTODETECT;
361 	enum eeprom_action action = EEPROM_ACTION_INVALID;
362 	int i2c_bus = -1, index = 0;
363 	ulong i2c_addr = -1, addr = 0, cnt = 0, off = 0;
364 	int ret;
365 	char *field_name = "";
366 	char *field_value = "";
367 
368 	if (argc <= 1)
369 		return CMD_RET_USAGE;
370 
371 	NEXT_PARAM(argc, index); /* Skip program name */
372 
373 	action = parse_action(argv[index]);
374 	NEXT_PARAM(argc, index);
375 
376 	if (action == EEPROM_ACTION_INVALID)
377 		return CMD_RET_USAGE;
378 
379 #ifdef CONFIG_CMD_EEPROM_LAYOUT
380 	if (action == EEPROM_PRINT || action == EEPROM_UPDATE) {
381 		if (!strcmp(argv[index], "-l")) {
382 			NEXT_PARAM(argc, index);
383 			layout_ver = eeprom_parse_layout_version(argv[index]);
384 			NEXT_PARAM(argc, index);
385 		}
386 	}
387 #endif
388 
389 	switch (action) {
390 	case EEPROM_READ:
391 	case EEPROM_WRITE:
392 		ret = parse_i2c_bus_addr(&i2c_bus, &i2c_addr, argc,
393 					 argv + index, 3);
394 		break;
395 	case EEPROM_PRINT:
396 		ret = parse_i2c_bus_addr(&i2c_bus, &i2c_addr, argc,
397 					 argv + index, 0);
398 		break;
399 	case EEPROM_UPDATE:
400 		ret = parse_i2c_bus_addr(&i2c_bus, &i2c_addr, argc,
401 					 argv + index, 2);
402 		break;
403 	default:
404 		/* Get compiler to stop whining */
405 		return CMD_RET_USAGE;
406 	}
407 
408 	if (ret == CMD_RET_USAGE)
409 		return ret;
410 
411 	while (ret--)
412 		NEXT_PARAM(argc, index);
413 
414 	if (action == EEPROM_READ || action == EEPROM_WRITE) {
415 		addr = parse_numeric_param(argv[index]);
416 		NEXT_PARAM(argc, index);
417 		off = parse_numeric_param(argv[index]);
418 		NEXT_PARAM(argc, index);
419 		cnt = parse_numeric_param(argv[index]);
420 	}
421 
422 #ifdef CONFIG_CMD_EEPROM_LAYOUT
423 	if (action == EEPROM_UPDATE) {
424 		field_name = argv[index];
425 		NEXT_PARAM(argc, index);
426 		field_value = argv[index];
427 		NEXT_PARAM(argc, index);
428 	}
429 #endif
430 
431 	return eeprom_execute_command(action, i2c_bus, i2c_addr, layout_ver,
432 				      field_name, field_value, addr, off, cnt);
433 }
434 
435 U_BOOT_CMD(
436 	eeprom,	8,	1,	do_eeprom,
437 	"EEPROM sub-system",
438 	"read  <bus> <devaddr> addr off cnt\n"
439 	"eeprom write <bus> <devaddr> addr off cnt\n"
440 	"       - read/write `cnt' bytes from `devaddr` EEPROM at offset `off'"
441 #ifdef CONFIG_CMD_EEPROM_LAYOUT
442 	"\n"
443 	"eeprom print [-l <layout_version>] <bus> <devaddr>\n"
444 	"       - Print layout fields and their data in human readable format\n"
445 	"eeprom update [-l <layout_version>] <bus> <devaddr> field_name field_value\n"
446 	"       - Update a specific eeprom field with new data.\n"
447 	"         The new data must be written in the same human readable format as shown by the print command.\n"
448 	"\n"
449 	"LAYOUT VERSIONS\n"
450 	"The -l option can be used to force the command to interpret the EEPROM data using the chosen layout.\n"
451 	"If the -l option is omitted, the command will auto detect the layout based on the data in the EEPROM.\n"
452 	"The values which can be provided with the -l option are:\n"
453 	CONFIG_EEPROM_LAYOUT_HELP_STRING"\n"
454 #endif
455 )
456