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2b7a5056 WS |
1 | /* |
2 | * at24.c - handle most I2C EEPROMs | |
3 | * | |
4 | * Copyright (C) 2005-2007 David Brownell | |
5 | * Copyright (C) 2008 Wolfram Sang, Pengutronix | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
11 | */ | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/init.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/delay.h> | |
17 | #include <linux/mutex.h> | |
18 | #include <linux/sysfs.h> | |
19 | #include <linux/mod_devicetable.h> | |
20 | #include <linux/log2.h> | |
21 | #include <linux/bitops.h> | |
22 | #include <linux/jiffies.h> | |
23 | #include <linux/i2c.h> | |
24 | #include <linux/i2c/at24.h> | |
25 | ||
26 | /* | |
27 | * I2C EEPROMs from most vendors are inexpensive and mostly interchangeable. | |
28 | * Differences between different vendor product lines (like Atmel AT24C or | |
29 | * MicroChip 24LC, etc) won't much matter for typical read/write access. | |
30 | * There are also I2C RAM chips, likewise interchangeable. One example | |
31 | * would be the PCF8570, which acts like a 24c02 EEPROM (256 bytes). | |
32 | * | |
33 | * However, misconfiguration can lose data. "Set 16-bit memory address" | |
34 | * to a part with 8-bit addressing will overwrite data. Writing with too | |
35 | * big a page size also loses data. And it's not safe to assume that the | |
36 | * conventional addresses 0x50..0x57 only hold eeproms; a PCF8563 RTC | |
37 | * uses 0x51, for just one example. | |
38 | * | |
39 | * Accordingly, explicit board-specific configuration data should be used | |
40 | * in almost all cases. (One partial exception is an SMBus used to access | |
41 | * "SPD" data for DRAM sticks. Those only use 24c02 EEPROMs.) | |
42 | * | |
43 | * So this driver uses "new style" I2C driver binding, expecting to be | |
44 | * told what devices exist. That may be in arch/X/mach-Y/board-Z.c or | |
45 | * similar kernel-resident tables; or, configuration data coming from | |
46 | * a bootloader. | |
47 | * | |
48 | * Other than binding model, current differences from "eeprom" driver are | |
49 | * that this one handles write access and isn't restricted to 24c02 devices. | |
50 | * It also handles larger devices (32 kbit and up) with two-byte addresses, | |
51 | * which won't work on pure SMBus systems. | |
52 | */ | |
53 | ||
54 | struct at24_data { | |
55 | struct at24_platform_data chip; | |
7274ec8b | 56 | struct memory_accessor macc; |
2b7a5056 WS |
57 | bool use_smbus; |
58 | ||
59 | /* | |
60 | * Lock protects against activities from other Linux tasks, | |
61 | * but not from changes by other I2C masters. | |
62 | */ | |
63 | struct mutex lock; | |
64 | struct bin_attribute bin; | |
65 | ||
66 | u8 *writebuf; | |
67 | unsigned write_max; | |
68 | unsigned num_addresses; | |
69 | ||
70 | /* | |
71 | * Some chips tie up multiple I2C addresses; dummy devices reserve | |
72 | * them for us, and we'll use them with SMBus calls. | |
73 | */ | |
74 | struct i2c_client *client[]; | |
75 | }; | |
76 | ||
77 | /* | |
78 | * This parameter is to help this driver avoid blocking other drivers out | |
79 | * of I2C for potentially troublesome amounts of time. With a 100 kHz I2C | |
80 | * clock, one 256 byte read takes about 1/43 second which is excessive; | |
81 | * but the 1/170 second it takes at 400 kHz may be quite reasonable; and | |
82 | * at 1 MHz (Fm+) a 1/430 second delay could easily be invisible. | |
83 | * | |
84 | * This value is forced to be a power of two so that writes align on pages. | |
85 | */ | |
86 | static unsigned io_limit = 128; | |
87 | module_param(io_limit, uint, 0); | |
88 | MODULE_PARM_DESC(io_limit, "Maximum bytes per I/O (default 128)"); | |
89 | ||
90 | /* | |
91 | * Specs often allow 5 msec for a page write, sometimes 20 msec; | |
92 | * it's important to recover from write timeouts. | |
93 | */ | |
94 | static unsigned write_timeout = 25; | |
95 | module_param(write_timeout, uint, 0); | |
96 | MODULE_PARM_DESC(write_timeout, "Time (in ms) to try writes (default 25)"); | |
97 | ||
98 | #define AT24_SIZE_BYTELEN 5 | |
99 | #define AT24_SIZE_FLAGS 8 | |
100 | ||
101 | #define AT24_BITMASK(x) (BIT(x) - 1) | |
102 | ||
103 | /* create non-zero magic value for given eeprom parameters */ | |
104 | #define AT24_DEVICE_MAGIC(_len, _flags) \ | |
105 | ((1 << AT24_SIZE_FLAGS | (_flags)) \ | |
106 | << AT24_SIZE_BYTELEN | ilog2(_len)) | |
107 | ||
108 | static const struct i2c_device_id at24_ids[] = { | |
109 | /* needs 8 addresses as A0-A2 are ignored */ | |
110 | { "24c00", AT24_DEVICE_MAGIC(128 / 8, AT24_FLAG_TAKE8ADDR) }, | |
111 | /* old variants can't be handled with this generic entry! */ | |
112 | { "24c01", AT24_DEVICE_MAGIC(1024 / 8, 0) }, | |
113 | { "24c02", AT24_DEVICE_MAGIC(2048 / 8, 0) }, | |
114 | /* spd is a 24c02 in memory DIMMs */ | |
115 | { "spd", AT24_DEVICE_MAGIC(2048 / 8, | |
116 | AT24_FLAG_READONLY | AT24_FLAG_IRUGO) }, | |
117 | { "24c04", AT24_DEVICE_MAGIC(4096 / 8, 0) }, | |
118 | /* 24rf08 quirk is handled at i2c-core */ | |
119 | { "24c08", AT24_DEVICE_MAGIC(8192 / 8, 0) }, | |
120 | { "24c16", AT24_DEVICE_MAGIC(16384 / 8, 0) }, | |
121 | { "24c32", AT24_DEVICE_MAGIC(32768 / 8, AT24_FLAG_ADDR16) }, | |
122 | { "24c64", AT24_DEVICE_MAGIC(65536 / 8, AT24_FLAG_ADDR16) }, | |
123 | { "24c128", AT24_DEVICE_MAGIC(131072 / 8, AT24_FLAG_ADDR16) }, | |
124 | { "24c256", AT24_DEVICE_MAGIC(262144 / 8, AT24_FLAG_ADDR16) }, | |
125 | { "24c512", AT24_DEVICE_MAGIC(524288 / 8, AT24_FLAG_ADDR16) }, | |
126 | { "24c1024", AT24_DEVICE_MAGIC(1048576 / 8, AT24_FLAG_ADDR16) }, | |
127 | { "at24", 0 }, | |
128 | { /* END OF LIST */ } | |
129 | }; | |
130 | MODULE_DEVICE_TABLE(i2c, at24_ids); | |
131 | ||
132 | /*-------------------------------------------------------------------------*/ | |
133 | ||
134 | /* | |
135 | * This routine supports chips which consume multiple I2C addresses. It | |
136 | * computes the addressing information to be used for a given r/w request. | |
137 | * Assumes that sanity checks for offset happened at sysfs-layer. | |
138 | */ | |
139 | static struct i2c_client *at24_translate_offset(struct at24_data *at24, | |
140 | unsigned *offset) | |
141 | { | |
142 | unsigned i; | |
143 | ||
144 | if (at24->chip.flags & AT24_FLAG_ADDR16) { | |
145 | i = *offset >> 16; | |
146 | *offset &= 0xffff; | |
147 | } else { | |
148 | i = *offset >> 8; | |
149 | *offset &= 0xff; | |
150 | } | |
151 | ||
152 | return at24->client[i]; | |
153 | } | |
154 | ||
155 | static ssize_t at24_eeprom_read(struct at24_data *at24, char *buf, | |
156 | unsigned offset, size_t count) | |
157 | { | |
158 | struct i2c_msg msg[2]; | |
159 | u8 msgbuf[2]; | |
160 | struct i2c_client *client; | |
161 | int status, i; | |
162 | ||
163 | memset(msg, 0, sizeof(msg)); | |
164 | ||
165 | /* | |
166 | * REVISIT some multi-address chips don't rollover page reads to | |
167 | * the next slave address, so we may need to truncate the count. | |
168 | * Those chips might need another quirk flag. | |
169 | * | |
170 | * If the real hardware used four adjacent 24c02 chips and that | |
171 | * were misconfigured as one 24c08, that would be a similar effect: | |
172 | * one "eeprom" file not four, but larger reads would fail when | |
173 | * they crossed certain pages. | |
174 | */ | |
175 | ||
176 | /* | |
177 | * Slave address and byte offset derive from the offset. Always | |
178 | * set the byte address; on a multi-master board, another master | |
179 | * may have changed the chip's "current" address pointer. | |
180 | */ | |
181 | client = at24_translate_offset(at24, &offset); | |
182 | ||
183 | if (count > io_limit) | |
184 | count = io_limit; | |
185 | ||
186 | /* Smaller eeproms can work given some SMBus extension calls */ | |
187 | if (at24->use_smbus) { | |
188 | if (count > I2C_SMBUS_BLOCK_MAX) | |
189 | count = I2C_SMBUS_BLOCK_MAX; | |
190 | status = i2c_smbus_read_i2c_block_data(client, offset, | |
191 | count, buf); | |
2ce5b34f | 192 | dev_dbg(&client->dev, "smbus read %zu@%d --> %d\n", |
2b7a5056 WS |
193 | count, offset, status); |
194 | return (status < 0) ? -EIO : status; | |
195 | } | |
196 | ||
197 | /* | |
198 | * When we have a better choice than SMBus calls, use a combined | |
199 | * I2C message. Write address; then read up to io_limit data bytes. | |
200 | * Note that read page rollover helps us here (unlike writes). | |
201 | * msgbuf is u8 and will cast to our needs. | |
202 | */ | |
203 | i = 0; | |
204 | if (at24->chip.flags & AT24_FLAG_ADDR16) | |
205 | msgbuf[i++] = offset >> 8; | |
206 | msgbuf[i++] = offset; | |
207 | ||
208 | msg[0].addr = client->addr; | |
209 | msg[0].buf = msgbuf; | |
210 | msg[0].len = i; | |
211 | ||
212 | msg[1].addr = client->addr; | |
213 | msg[1].flags = I2C_M_RD; | |
214 | msg[1].buf = buf; | |
215 | msg[1].len = count; | |
216 | ||
217 | status = i2c_transfer(client->adapter, msg, 2); | |
2ce5b34f | 218 | dev_dbg(&client->dev, "i2c read %zu@%d --> %d\n", |
2b7a5056 WS |
219 | count, offset, status); |
220 | ||
221 | if (status == 2) | |
222 | return count; | |
223 | else if (status >= 0) | |
224 | return -EIO; | |
225 | else | |
226 | return status; | |
227 | } | |
228 | ||
7274ec8b | 229 | static ssize_t at24_read(struct at24_data *at24, |
2b7a5056 WS |
230 | char *buf, loff_t off, size_t count) |
231 | { | |
2b7a5056 WS |
232 | ssize_t retval = 0; |
233 | ||
2b7a5056 WS |
234 | if (unlikely(!count)) |
235 | return count; | |
236 | ||
237 | /* | |
238 | * Read data from chip, protecting against concurrent updates | |
239 | * from this host, but not from other I2C masters. | |
240 | */ | |
241 | mutex_lock(&at24->lock); | |
242 | ||
243 | while (count) { | |
244 | ssize_t status; | |
245 | ||
246 | status = at24_eeprom_read(at24, buf, off, count); | |
247 | if (status <= 0) { | |
248 | if (retval == 0) | |
249 | retval = status; | |
250 | break; | |
251 | } | |
252 | buf += status; | |
253 | off += status; | |
254 | count -= status; | |
255 | retval += status; | |
256 | } | |
257 | ||
258 | mutex_unlock(&at24->lock); | |
259 | ||
260 | return retval; | |
261 | } | |
262 | ||
7274ec8b KH |
263 | static ssize_t at24_bin_read(struct kobject *kobj, struct bin_attribute *attr, |
264 | char *buf, loff_t off, size_t count) | |
265 | { | |
266 | struct at24_data *at24; | |
2b7a5056 | 267 | |
7274ec8b KH |
268 | at24 = dev_get_drvdata(container_of(kobj, struct device, kobj)); |
269 | return at24_read(at24, buf, off, count); | |
270 | } | |
2b7a5056 WS |
271 | |
272 | ||
273 | /* | |
274 | * Note that if the hardware write-protect pin is pulled high, the whole | |
275 | * chip is normally write protected. But there are plenty of product | |
276 | * variants here, including OTP fuses and partial chip protect. | |
277 | * | |
278 | * We only use page mode writes; the alternative is sloooow. This routine | |
279 | * writes at most one page. | |
280 | */ | |
280ca299 | 281 | static ssize_t at24_eeprom_write(struct at24_data *at24, const char *buf, |
2b7a5056 WS |
282 | unsigned offset, size_t count) |
283 | { | |
284 | struct i2c_client *client; | |
285 | struct i2c_msg msg; | |
286 | ssize_t status; | |
287 | unsigned long timeout, write_time; | |
288 | unsigned next_page; | |
289 | ||
290 | /* Get corresponding I2C address and adjust offset */ | |
291 | client = at24_translate_offset(at24, &offset); | |
292 | ||
293 | /* write_max is at most a page */ | |
294 | if (count > at24->write_max) | |
295 | count = at24->write_max; | |
296 | ||
297 | /* Never roll over backwards, to the start of this page */ | |
298 | next_page = roundup(offset + 1, at24->chip.page_size); | |
299 | if (offset + count > next_page) | |
300 | count = next_page - offset; | |
301 | ||
302 | /* If we'll use I2C calls for I/O, set up the message */ | |
303 | if (!at24->use_smbus) { | |
304 | int i = 0; | |
305 | ||
306 | msg.addr = client->addr; | |
307 | msg.flags = 0; | |
308 | ||
309 | /* msg.buf is u8 and casts will mask the values */ | |
310 | msg.buf = at24->writebuf; | |
311 | if (at24->chip.flags & AT24_FLAG_ADDR16) | |
312 | msg.buf[i++] = offset >> 8; | |
313 | ||
314 | msg.buf[i++] = offset; | |
315 | memcpy(&msg.buf[i], buf, count); | |
316 | msg.len = i + count; | |
317 | } | |
318 | ||
319 | /* | |
320 | * Writes fail if the previous one didn't complete yet. We may | |
321 | * loop a few times until this one succeeds, waiting at least | |
322 | * long enough for one entire page write to work. | |
323 | */ | |
324 | timeout = jiffies + msecs_to_jiffies(write_timeout); | |
325 | do { | |
326 | write_time = jiffies; | |
327 | if (at24->use_smbus) { | |
328 | status = i2c_smbus_write_i2c_block_data(client, | |
329 | offset, count, buf); | |
330 | if (status == 0) | |
331 | status = count; | |
332 | } else { | |
333 | status = i2c_transfer(client->adapter, &msg, 1); | |
334 | if (status == 1) | |
335 | status = count; | |
336 | } | |
2ce5b34f | 337 | dev_dbg(&client->dev, "write %zu@%d --> %zd (%ld)\n", |
2b7a5056 WS |
338 | count, offset, status, jiffies); |
339 | ||
340 | if (status == count) | |
341 | return count; | |
342 | ||
343 | /* REVISIT: at HZ=100, this is sloooow */ | |
344 | msleep(1); | |
345 | } while (time_before(write_time, timeout)); | |
346 | ||
347 | return -ETIMEDOUT; | |
348 | } | |
349 | ||
280ca299 GU |
350 | static ssize_t at24_write(struct at24_data *at24, const char *buf, loff_t off, |
351 | size_t count) | |
2b7a5056 | 352 | { |
2b7a5056 WS |
353 | ssize_t retval = 0; |
354 | ||
2b7a5056 WS |
355 | if (unlikely(!count)) |
356 | return count; | |
357 | ||
358 | /* | |
359 | * Write data to chip, protecting against concurrent updates | |
360 | * from this host, but not from other I2C masters. | |
361 | */ | |
362 | mutex_lock(&at24->lock); | |
363 | ||
364 | while (count) { | |
365 | ssize_t status; | |
366 | ||
367 | status = at24_eeprom_write(at24, buf, off, count); | |
368 | if (status <= 0) { | |
369 | if (retval == 0) | |
370 | retval = status; | |
371 | break; | |
372 | } | |
373 | buf += status; | |
374 | off += status; | |
375 | count -= status; | |
376 | retval += status; | |
377 | } | |
378 | ||
379 | mutex_unlock(&at24->lock); | |
380 | ||
381 | return retval; | |
382 | } | |
383 | ||
7274ec8b KH |
384 | static ssize_t at24_bin_write(struct kobject *kobj, struct bin_attribute *attr, |
385 | char *buf, loff_t off, size_t count) | |
386 | { | |
387 | struct at24_data *at24; | |
388 | ||
389 | at24 = dev_get_drvdata(container_of(kobj, struct device, kobj)); | |
390 | return at24_write(at24, buf, off, count); | |
391 | } | |
392 | ||
393 | /*-------------------------------------------------------------------------*/ | |
394 | ||
395 | /* | |
396 | * This lets other kernel code access the eeprom data. For example, it | |
397 | * might hold a board's Ethernet address, or board-specific calibration | |
398 | * data generated on the manufacturing floor. | |
399 | */ | |
400 | ||
401 | static ssize_t at24_macc_read(struct memory_accessor *macc, char *buf, | |
402 | off_t offset, size_t count) | |
403 | { | |
404 | struct at24_data *at24 = container_of(macc, struct at24_data, macc); | |
405 | ||
406 | return at24_read(at24, buf, offset, count); | |
407 | } | |
408 | ||
280ca299 | 409 | static ssize_t at24_macc_write(struct memory_accessor *macc, const char *buf, |
7274ec8b KH |
410 | off_t offset, size_t count) |
411 | { | |
412 | struct at24_data *at24 = container_of(macc, struct at24_data, macc); | |
413 | ||
414 | return at24_write(at24, buf, offset, count); | |
415 | } | |
416 | ||
2b7a5056 WS |
417 | /*-------------------------------------------------------------------------*/ |
418 | ||
419 | static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) | |
420 | { | |
421 | struct at24_platform_data chip; | |
422 | bool writable; | |
423 | bool use_smbus = false; | |
424 | struct at24_data *at24; | |
425 | int err; | |
426 | unsigned i, num_addresses; | |
427 | kernel_ulong_t magic; | |
428 | ||
429 | if (client->dev.platform_data) { | |
430 | chip = *(struct at24_platform_data *)client->dev.platform_data; | |
431 | } else { | |
432 | if (!id->driver_data) { | |
433 | err = -ENODEV; | |
434 | goto err_out; | |
435 | } | |
436 | magic = id->driver_data; | |
437 | chip.byte_len = BIT(magic & AT24_BITMASK(AT24_SIZE_BYTELEN)); | |
438 | magic >>= AT24_SIZE_BYTELEN; | |
439 | chip.flags = magic & AT24_BITMASK(AT24_SIZE_FLAGS); | |
440 | /* | |
441 | * This is slow, but we can't know all eeproms, so we better | |
442 | * play safe. Specifying custom eeprom-types via platform_data | |
443 | * is recommended anyhow. | |
444 | */ | |
445 | chip.page_size = 1; | |
7274ec8b KH |
446 | |
447 | chip.setup = NULL; | |
448 | chip.context = NULL; | |
2b7a5056 WS |
449 | } |
450 | ||
451 | if (!is_power_of_2(chip.byte_len)) | |
452 | dev_warn(&client->dev, | |
453 | "byte_len looks suspicious (no power of 2)!\n"); | |
454 | if (!is_power_of_2(chip.page_size)) | |
455 | dev_warn(&client->dev, | |
456 | "page_size looks suspicious (no power of 2)!\n"); | |
457 | ||
458 | /* Use I2C operations unless we're stuck with SMBus extensions. */ | |
459 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { | |
460 | if (chip.flags & AT24_FLAG_ADDR16) { | |
461 | err = -EPFNOSUPPORT; | |
462 | goto err_out; | |
463 | } | |
464 | if (!i2c_check_functionality(client->adapter, | |
465 | I2C_FUNC_SMBUS_READ_I2C_BLOCK)) { | |
466 | err = -EPFNOSUPPORT; | |
467 | goto err_out; | |
468 | } | |
469 | use_smbus = true; | |
470 | } | |
471 | ||
472 | if (chip.flags & AT24_FLAG_TAKE8ADDR) | |
473 | num_addresses = 8; | |
474 | else | |
475 | num_addresses = DIV_ROUND_UP(chip.byte_len, | |
476 | (chip.flags & AT24_FLAG_ADDR16) ? 65536 : 256); | |
477 | ||
478 | at24 = kzalloc(sizeof(struct at24_data) + | |
479 | num_addresses * sizeof(struct i2c_client *), GFP_KERNEL); | |
480 | if (!at24) { | |
481 | err = -ENOMEM; | |
482 | goto err_out; | |
483 | } | |
484 | ||
485 | mutex_init(&at24->lock); | |
486 | at24->use_smbus = use_smbus; | |
487 | at24->chip = chip; | |
488 | at24->num_addresses = num_addresses; | |
489 | ||
490 | /* | |
491 | * Export the EEPROM bytes through sysfs, since that's convenient. | |
492 | * By default, only root should see the data (maybe passwords etc) | |
493 | */ | |
494 | at24->bin.attr.name = "eeprom"; | |
495 | at24->bin.attr.mode = chip.flags & AT24_FLAG_IRUGO ? S_IRUGO : S_IRUSR; | |
2b7a5056 WS |
496 | at24->bin.read = at24_bin_read; |
497 | at24->bin.size = chip.byte_len; | |
498 | ||
7274ec8b KH |
499 | at24->macc.read = at24_macc_read; |
500 | ||
2b7a5056 WS |
501 | writable = !(chip.flags & AT24_FLAG_READONLY); |
502 | if (writable) { | |
503 | if (!use_smbus || i2c_check_functionality(client->adapter, | |
504 | I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)) { | |
505 | ||
506 | unsigned write_max = chip.page_size; | |
507 | ||
7274ec8b KH |
508 | at24->macc.write = at24_macc_write; |
509 | ||
2b7a5056 WS |
510 | at24->bin.write = at24_bin_write; |
511 | at24->bin.attr.mode |= S_IWUSR; | |
512 | ||
513 | if (write_max > io_limit) | |
514 | write_max = io_limit; | |
515 | if (use_smbus && write_max > I2C_SMBUS_BLOCK_MAX) | |
516 | write_max = I2C_SMBUS_BLOCK_MAX; | |
517 | at24->write_max = write_max; | |
518 | ||
519 | /* buffer (data + address at the beginning) */ | |
520 | at24->writebuf = kmalloc(write_max + 2, GFP_KERNEL); | |
521 | if (!at24->writebuf) { | |
522 | err = -ENOMEM; | |
523 | goto err_struct; | |
524 | } | |
525 | } else { | |
526 | dev_warn(&client->dev, | |
527 | "cannot write due to controller restrictions."); | |
528 | } | |
529 | } | |
530 | ||
531 | at24->client[0] = client; | |
532 | ||
533 | /* use dummy devices for multiple-address chips */ | |
534 | for (i = 1; i < num_addresses; i++) { | |
535 | at24->client[i] = i2c_new_dummy(client->adapter, | |
536 | client->addr + i); | |
537 | if (!at24->client[i]) { | |
538 | dev_err(&client->dev, "address 0x%02x unavailable\n", | |
539 | client->addr + i); | |
540 | err = -EADDRINUSE; | |
541 | goto err_clients; | |
542 | } | |
543 | } | |
544 | ||
545 | err = sysfs_create_bin_file(&client->dev.kobj, &at24->bin); | |
546 | if (err) | |
547 | goto err_clients; | |
548 | ||
549 | i2c_set_clientdata(client, at24); | |
550 | ||
2ce5b34f | 551 | dev_info(&client->dev, "%zu byte %s EEPROM %s\n", |
2b7a5056 WS |
552 | at24->bin.size, client->name, |
553 | writable ? "(writable)" : "(read-only)"); | |
554 | dev_dbg(&client->dev, | |
555 | "page_size %d, num_addresses %d, write_max %d%s\n", | |
556 | chip.page_size, num_addresses, | |
557 | at24->write_max, | |
558 | use_smbus ? ", use_smbus" : ""); | |
559 | ||
7274ec8b KH |
560 | /* export data to kernel code */ |
561 | if (chip.setup) | |
562 | chip.setup(&at24->macc, chip.context); | |
563 | ||
2b7a5056 WS |
564 | return 0; |
565 | ||
566 | err_clients: | |
567 | for (i = 1; i < num_addresses; i++) | |
568 | if (at24->client[i]) | |
569 | i2c_unregister_device(at24->client[i]); | |
570 | ||
571 | kfree(at24->writebuf); | |
572 | err_struct: | |
573 | kfree(at24); | |
574 | err_out: | |
575 | dev_dbg(&client->dev, "probe error %d\n", err); | |
576 | return err; | |
577 | } | |
578 | ||
579 | static int __devexit at24_remove(struct i2c_client *client) | |
580 | { | |
581 | struct at24_data *at24; | |
582 | int i; | |
583 | ||
584 | at24 = i2c_get_clientdata(client); | |
585 | sysfs_remove_bin_file(&client->dev.kobj, &at24->bin); | |
586 | ||
587 | for (i = 1; i < at24->num_addresses; i++) | |
588 | i2c_unregister_device(at24->client[i]); | |
589 | ||
590 | kfree(at24->writebuf); | |
591 | kfree(at24); | |
592 | i2c_set_clientdata(client, NULL); | |
593 | return 0; | |
594 | } | |
595 | ||
596 | /*-------------------------------------------------------------------------*/ | |
597 | ||
598 | static struct i2c_driver at24_driver = { | |
599 | .driver = { | |
600 | .name = "at24", | |
601 | .owner = THIS_MODULE, | |
602 | }, | |
603 | .probe = at24_probe, | |
604 | .remove = __devexit_p(at24_remove), | |
605 | .id_table = at24_ids, | |
606 | }; | |
607 | ||
608 | static int __init at24_init(void) | |
609 | { | |
610 | io_limit = rounddown_pow_of_two(io_limit); | |
611 | return i2c_add_driver(&at24_driver); | |
612 | } | |
613 | module_init(at24_init); | |
614 | ||
615 | static void __exit at24_exit(void) | |
616 | { | |
617 | i2c_del_driver(&at24_driver); | |
618 | } | |
619 | module_exit(at24_exit); | |
620 | ||
621 | MODULE_DESCRIPTION("Driver for most I2C EEPROMs"); | |
622 | MODULE_AUTHOR("David Brownell and Wolfram Sang"); | |
623 | MODULE_LICENSE("GPL"); |