Commit | Line | Data |
---|---|---|
06b4501e AG |
1 | /* |
2 | * Driver for 93xx46 EEPROMs | |
3 | * | |
4 | * (C) 2011 DENX Software Engineering, Anatolij Gustschin <agust@denx.de> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | */ | |
10 | ||
11 | #include <linux/delay.h> | |
12 | #include <linux/device.h> | |
3ca9b1ac | 13 | #include <linux/gpio/consumer.h> |
06b4501e | 14 | #include <linux/kernel.h> |
06b4501e AG |
15 | #include <linux/module.h> |
16 | #include <linux/mutex.h> | |
c074abe0 CT |
17 | #include <linux/of.h> |
18 | #include <linux/of_device.h> | |
3ca9b1ac | 19 | #include <linux/of_gpio.h> |
06b4501e AG |
20 | #include <linux/slab.h> |
21 | #include <linux/spi/spi.h> | |
22 | #include <linux/sysfs.h> | |
23 | #include <linux/eeprom_93xx46.h> | |
24 | ||
25 | #define OP_START 0x4 | |
26 | #define OP_WRITE (OP_START | 0x1) | |
27 | #define OP_READ (OP_START | 0x2) | |
28 | #define ADDR_EWDS 0x00 | |
29 | #define ADDR_ERAL 0x20 | |
30 | #define ADDR_EWEN 0x30 | |
31 | ||
e1379b56 CT |
32 | struct eeprom_93xx46_devtype_data { |
33 | unsigned int quirks; | |
34 | }; | |
35 | ||
36 | static const struct eeprom_93xx46_devtype_data atmel_at93c46d_data = { | |
37 | .quirks = EEPROM_93XX46_QUIRK_SINGLE_WORD_READ | | |
38 | EEPROM_93XX46_QUIRK_INSTRUCTION_LENGTH, | |
39 | }; | |
40 | ||
06b4501e AG |
41 | struct eeprom_93xx46_dev { |
42 | struct spi_device *spi; | |
43 | struct eeprom_93xx46_platform_data *pdata; | |
44 | struct bin_attribute bin; | |
45 | struct mutex lock; | |
46 | int addrlen; | |
47 | }; | |
48 | ||
e1379b56 CT |
49 | static inline bool has_quirk_single_word_read(struct eeprom_93xx46_dev *edev) |
50 | { | |
51 | return edev->pdata->quirks & EEPROM_93XX46_QUIRK_SINGLE_WORD_READ; | |
52 | } | |
53 | ||
54 | static inline bool has_quirk_instruction_length(struct eeprom_93xx46_dev *edev) | |
55 | { | |
56 | return edev->pdata->quirks & EEPROM_93XX46_QUIRK_INSTRUCTION_LENGTH; | |
57 | } | |
58 | ||
06b4501e AG |
59 | static ssize_t |
60 | eeprom_93xx46_bin_read(struct file *filp, struct kobject *kobj, | |
61 | struct bin_attribute *bin_attr, | |
62 | char *buf, loff_t off, size_t count) | |
63 | { | |
64 | struct eeprom_93xx46_dev *edev; | |
65 | struct device *dev; | |
e1379b56 | 66 | ssize_t ret = 0; |
06b4501e | 67 | |
092462c2 | 68 | dev = kobj_to_dev(kobj); |
06b4501e AG |
69 | edev = dev_get_drvdata(dev); |
70 | ||
e1379b56 | 71 | mutex_lock(&edev->lock); |
06b4501e | 72 | |
e1379b56 CT |
73 | if (edev->pdata->prepare) |
74 | edev->pdata->prepare(edev); | |
06b4501e | 75 | |
e1379b56 CT |
76 | while (count) { |
77 | struct spi_message m; | |
78 | struct spi_transfer t[2] = { { 0 } }; | |
79 | u16 cmd_addr = OP_READ << edev->addrlen; | |
80 | size_t nbytes = count; | |
81 | int bits; | |
82 | int err; | |
83 | ||
84 | if (edev->addrlen == 7) { | |
85 | cmd_addr |= off & 0x7f; | |
86 | bits = 10; | |
87 | if (has_quirk_single_word_read(edev)) | |
88 | nbytes = 1; | |
89 | } else { | |
90 | cmd_addr |= (off >> 1) & 0x3f; | |
91 | bits = 9; | |
92 | if (has_quirk_single_word_read(edev)) | |
93 | nbytes = 2; | |
94 | } | |
06b4501e | 95 | |
e1379b56 CT |
96 | dev_dbg(&edev->spi->dev, "read cmd 0x%x, %d Hz\n", |
97 | cmd_addr, edev->spi->max_speed_hz); | |
06b4501e | 98 | |
e1379b56 | 99 | spi_message_init(&m); |
06b4501e | 100 | |
e1379b56 CT |
101 | t[0].tx_buf = (char *)&cmd_addr; |
102 | t[0].len = 2; | |
103 | t[0].bits_per_word = bits; | |
104 | spi_message_add_tail(&t[0], &m); | |
06b4501e | 105 | |
e1379b56 CT |
106 | t[1].rx_buf = buf; |
107 | t[1].len = count; | |
108 | t[1].bits_per_word = 8; | |
109 | spi_message_add_tail(&t[1], &m); | |
06b4501e | 110 | |
e1379b56 CT |
111 | err = spi_sync(edev->spi, &m); |
112 | /* have to wait at least Tcsl ns */ | |
113 | ndelay(250); | |
06b4501e | 114 | |
e1379b56 CT |
115 | if (err) { |
116 | dev_err(&edev->spi->dev, "read %zu bytes at %d: err. %d\n", | |
117 | nbytes, (int)off, err); | |
118 | ret = err; | |
119 | break; | |
120 | } | |
121 | ||
122 | buf += nbytes; | |
123 | off += nbytes; | |
124 | count -= nbytes; | |
125 | ret += nbytes; | |
06b4501e AG |
126 | } |
127 | ||
128 | if (edev->pdata->finish) | |
129 | edev->pdata->finish(edev); | |
130 | ||
131 | mutex_unlock(&edev->lock); | |
e1379b56 | 132 | return ret; |
06b4501e AG |
133 | } |
134 | ||
135 | static int eeprom_93xx46_ew(struct eeprom_93xx46_dev *edev, int is_on) | |
136 | { | |
137 | struct spi_message m; | |
138 | struct spi_transfer t; | |
139 | int bits, ret; | |
140 | u16 cmd_addr; | |
141 | ||
142 | cmd_addr = OP_START << edev->addrlen; | |
143 | if (edev->addrlen == 7) { | |
144 | cmd_addr |= (is_on ? ADDR_EWEN : ADDR_EWDS) << 1; | |
145 | bits = 10; | |
146 | } else { | |
147 | cmd_addr |= (is_on ? ADDR_EWEN : ADDR_EWDS); | |
148 | bits = 9; | |
149 | } | |
150 | ||
e1379b56 CT |
151 | if (has_quirk_instruction_length(edev)) { |
152 | cmd_addr <<= 2; | |
153 | bits += 2; | |
154 | } | |
155 | ||
156 | dev_dbg(&edev->spi->dev, "ew%s cmd 0x%04x, %d bits\n", | |
157 | is_on ? "en" : "ds", cmd_addr, bits); | |
06b4501e AG |
158 | |
159 | spi_message_init(&m); | |
160 | memset(&t, 0, sizeof(t)); | |
161 | ||
162 | t.tx_buf = &cmd_addr; | |
163 | t.len = 2; | |
164 | t.bits_per_word = bits; | |
165 | spi_message_add_tail(&t, &m); | |
166 | ||
167 | mutex_lock(&edev->lock); | |
168 | ||
169 | if (edev->pdata->prepare) | |
170 | edev->pdata->prepare(edev); | |
171 | ||
172 | ret = spi_sync(edev->spi, &m); | |
173 | /* have to wait at least Tcsl ns */ | |
174 | ndelay(250); | |
175 | if (ret) | |
176 | dev_err(&edev->spi->dev, "erase/write %sable error %d\n", | |
177 | is_on ? "en" : "dis", ret); | |
178 | ||
179 | if (edev->pdata->finish) | |
180 | edev->pdata->finish(edev); | |
181 | ||
182 | mutex_unlock(&edev->lock); | |
183 | return ret; | |
184 | } | |
185 | ||
186 | static ssize_t | |
187 | eeprom_93xx46_write_word(struct eeprom_93xx46_dev *edev, | |
188 | const char *buf, unsigned off) | |
189 | { | |
190 | struct spi_message m; | |
191 | struct spi_transfer t[2]; | |
192 | int bits, data_len, ret; | |
193 | u16 cmd_addr; | |
194 | ||
195 | cmd_addr = OP_WRITE << edev->addrlen; | |
196 | ||
197 | if (edev->addrlen == 7) { | |
198 | cmd_addr |= off & 0x7f; | |
199 | bits = 10; | |
200 | data_len = 1; | |
201 | } else { | |
cb54ad6c | 202 | cmd_addr |= (off >> 1) & 0x3f; |
06b4501e AG |
203 | bits = 9; |
204 | data_len = 2; | |
205 | } | |
206 | ||
207 | dev_dbg(&edev->spi->dev, "write cmd 0x%x\n", cmd_addr); | |
208 | ||
209 | spi_message_init(&m); | |
210 | memset(t, 0, sizeof(t)); | |
211 | ||
212 | t[0].tx_buf = (char *)&cmd_addr; | |
213 | t[0].len = 2; | |
214 | t[0].bits_per_word = bits; | |
215 | spi_message_add_tail(&t[0], &m); | |
216 | ||
217 | t[1].tx_buf = buf; | |
218 | t[1].len = data_len; | |
219 | t[1].bits_per_word = 8; | |
220 | spi_message_add_tail(&t[1], &m); | |
221 | ||
222 | ret = spi_sync(edev->spi, &m); | |
223 | /* have to wait program cycle time Twc ms */ | |
224 | mdelay(6); | |
225 | return ret; | |
226 | } | |
227 | ||
228 | static ssize_t | |
229 | eeprom_93xx46_bin_write(struct file *filp, struct kobject *kobj, | |
230 | struct bin_attribute *bin_attr, | |
231 | char *buf, loff_t off, size_t count) | |
232 | { | |
233 | struct eeprom_93xx46_dev *edev; | |
234 | struct device *dev; | |
235 | int i, ret, step = 1; | |
236 | ||
092462c2 | 237 | dev = kobj_to_dev(kobj); |
06b4501e AG |
238 | edev = dev_get_drvdata(dev); |
239 | ||
06b4501e AG |
240 | /* only write even number of bytes on 16-bit devices */ |
241 | if (edev->addrlen == 6) { | |
242 | step = 2; | |
243 | count &= ~1; | |
244 | } | |
245 | ||
246 | /* erase/write enable */ | |
247 | ret = eeprom_93xx46_ew(edev, 1); | |
248 | if (ret) | |
249 | return ret; | |
250 | ||
251 | mutex_lock(&edev->lock); | |
252 | ||
253 | if (edev->pdata->prepare) | |
254 | edev->pdata->prepare(edev); | |
255 | ||
256 | for (i = 0; i < count; i += step) { | |
257 | ret = eeprom_93xx46_write_word(edev, &buf[i], off + i); | |
258 | if (ret) { | |
259 | dev_err(&edev->spi->dev, "write failed at %d: %d\n", | |
260 | (int)off + i, ret); | |
261 | break; | |
262 | } | |
263 | } | |
264 | ||
265 | if (edev->pdata->finish) | |
266 | edev->pdata->finish(edev); | |
267 | ||
268 | mutex_unlock(&edev->lock); | |
269 | ||
270 | /* erase/write disable */ | |
271 | eeprom_93xx46_ew(edev, 0); | |
272 | return ret ? : count; | |
273 | } | |
274 | ||
275 | static int eeprom_93xx46_eral(struct eeprom_93xx46_dev *edev) | |
276 | { | |
277 | struct eeprom_93xx46_platform_data *pd = edev->pdata; | |
278 | struct spi_message m; | |
279 | struct spi_transfer t; | |
280 | int bits, ret; | |
281 | u16 cmd_addr; | |
282 | ||
283 | cmd_addr = OP_START << edev->addrlen; | |
284 | if (edev->addrlen == 7) { | |
285 | cmd_addr |= ADDR_ERAL << 1; | |
286 | bits = 10; | |
287 | } else { | |
288 | cmd_addr |= ADDR_ERAL; | |
289 | bits = 9; | |
290 | } | |
291 | ||
e1379b56 CT |
292 | if (has_quirk_instruction_length(edev)) { |
293 | cmd_addr <<= 2; | |
294 | bits += 2; | |
295 | } | |
296 | ||
297 | dev_dbg(&edev->spi->dev, "eral cmd 0x%04x, %d bits\n", cmd_addr, bits); | |
298 | ||
06b4501e AG |
299 | spi_message_init(&m); |
300 | memset(&t, 0, sizeof(t)); | |
301 | ||
302 | t.tx_buf = &cmd_addr; | |
303 | t.len = 2; | |
304 | t.bits_per_word = bits; | |
305 | spi_message_add_tail(&t, &m); | |
306 | ||
307 | mutex_lock(&edev->lock); | |
308 | ||
309 | if (edev->pdata->prepare) | |
310 | edev->pdata->prepare(edev); | |
311 | ||
312 | ret = spi_sync(edev->spi, &m); | |
313 | if (ret) | |
314 | dev_err(&edev->spi->dev, "erase error %d\n", ret); | |
315 | /* have to wait erase cycle time Tec ms */ | |
316 | mdelay(6); | |
317 | ||
318 | if (pd->finish) | |
319 | pd->finish(edev); | |
320 | ||
321 | mutex_unlock(&edev->lock); | |
322 | return ret; | |
323 | } | |
324 | ||
325 | static ssize_t eeprom_93xx46_store_erase(struct device *dev, | |
326 | struct device_attribute *attr, | |
327 | const char *buf, size_t count) | |
328 | { | |
329 | struct eeprom_93xx46_dev *edev = dev_get_drvdata(dev); | |
330 | int erase = 0, ret; | |
331 | ||
332 | sscanf(buf, "%d", &erase); | |
333 | if (erase) { | |
334 | ret = eeprom_93xx46_ew(edev, 1); | |
335 | if (ret) | |
336 | return ret; | |
337 | ret = eeprom_93xx46_eral(edev); | |
338 | if (ret) | |
339 | return ret; | |
340 | ret = eeprom_93xx46_ew(edev, 0); | |
341 | if (ret) | |
342 | return ret; | |
343 | } | |
344 | return count; | |
345 | } | |
346 | static DEVICE_ATTR(erase, S_IWUSR, NULL, eeprom_93xx46_store_erase); | |
347 | ||
3ca9b1ac CT |
348 | static void select_assert(void *context) |
349 | { | |
350 | struct eeprom_93xx46_dev *edev = context; | |
351 | ||
352 | gpiod_set_value_cansleep(edev->pdata->select, 1); | |
353 | } | |
354 | ||
355 | static void select_deassert(void *context) | |
356 | { | |
357 | struct eeprom_93xx46_dev *edev = context; | |
358 | ||
359 | gpiod_set_value_cansleep(edev->pdata->select, 0); | |
360 | } | |
361 | ||
c074abe0 CT |
362 | static const struct of_device_id eeprom_93xx46_of_table[] = { |
363 | { .compatible = "eeprom-93xx46", }, | |
e1379b56 | 364 | { .compatible = "atmel,at93c46d", .data = &atmel_at93c46d_data, }, |
c074abe0 CT |
365 | {} |
366 | }; | |
367 | MODULE_DEVICE_TABLE(of, eeprom_93xx46_of_table); | |
368 | ||
369 | static int eeprom_93xx46_probe_dt(struct spi_device *spi) | |
370 | { | |
e1379b56 CT |
371 | const struct of_device_id *of_id = |
372 | of_match_device(eeprom_93xx46_of_table, &spi->dev); | |
c074abe0 CT |
373 | struct device_node *np = spi->dev.of_node; |
374 | struct eeprom_93xx46_platform_data *pd; | |
375 | u32 tmp; | |
3ca9b1ac CT |
376 | int gpio; |
377 | enum of_gpio_flags of_flags; | |
c074abe0 CT |
378 | int ret; |
379 | ||
380 | pd = devm_kzalloc(&spi->dev, sizeof(*pd), GFP_KERNEL); | |
381 | if (!pd) | |
382 | return -ENOMEM; | |
383 | ||
384 | ret = of_property_read_u32(np, "data-size", &tmp); | |
385 | if (ret < 0) { | |
386 | dev_err(&spi->dev, "data-size property not found\n"); | |
387 | return ret; | |
388 | } | |
389 | ||
390 | if (tmp == 8) { | |
391 | pd->flags |= EE_ADDR8; | |
392 | } else if (tmp == 16) { | |
393 | pd->flags |= EE_ADDR16; | |
394 | } else { | |
395 | dev_err(&spi->dev, "invalid data-size (%d)\n", tmp); | |
396 | return -EINVAL; | |
397 | } | |
398 | ||
399 | if (of_property_read_bool(np, "read-only")) | |
400 | pd->flags |= EE_READONLY; | |
401 | ||
3ca9b1ac CT |
402 | gpio = of_get_named_gpio_flags(np, "select-gpios", 0, &of_flags); |
403 | if (gpio_is_valid(gpio)) { | |
404 | unsigned long flags = | |
405 | of_flags == OF_GPIO_ACTIVE_LOW ? GPIOF_ACTIVE_LOW : 0; | |
406 | ||
407 | ret = devm_gpio_request_one(&spi->dev, gpio, flags, | |
408 | "eeprom_93xx46_select"); | |
409 | if (ret) | |
410 | return ret; | |
411 | ||
412 | pd->select = gpio_to_desc(gpio); | |
413 | pd->prepare = select_assert; | |
414 | pd->finish = select_deassert; | |
415 | ||
416 | gpiod_direction_output(pd->select, 0); | |
417 | } | |
418 | ||
e1379b56 CT |
419 | if (of_id->data) { |
420 | const struct eeprom_93xx46_devtype_data *data = of_id->data; | |
421 | ||
422 | pd->quirks = data->quirks; | |
423 | } | |
424 | ||
c074abe0 CT |
425 | spi->dev.platform_data = pd; |
426 | ||
427 | return 0; | |
428 | } | |
429 | ||
80c8ae28 | 430 | static int eeprom_93xx46_probe(struct spi_device *spi) |
06b4501e AG |
431 | { |
432 | struct eeprom_93xx46_platform_data *pd; | |
433 | struct eeprom_93xx46_dev *edev; | |
434 | int err; | |
435 | ||
c074abe0 CT |
436 | if (spi->dev.of_node) { |
437 | err = eeprom_93xx46_probe_dt(spi); | |
438 | if (err < 0) | |
439 | return err; | |
440 | } | |
441 | ||
06b4501e AG |
442 | pd = spi->dev.platform_data; |
443 | if (!pd) { | |
444 | dev_err(&spi->dev, "missing platform data\n"); | |
445 | return -ENODEV; | |
446 | } | |
447 | ||
448 | edev = kzalloc(sizeof(*edev), GFP_KERNEL); | |
449 | if (!edev) | |
450 | return -ENOMEM; | |
451 | ||
452 | if (pd->flags & EE_ADDR8) | |
453 | edev->addrlen = 7; | |
454 | else if (pd->flags & EE_ADDR16) | |
455 | edev->addrlen = 6; | |
456 | else { | |
457 | dev_err(&spi->dev, "unspecified address type\n"); | |
458 | err = -EINVAL; | |
459 | goto fail; | |
460 | } | |
461 | ||
462 | mutex_init(&edev->lock); | |
463 | ||
464 | edev->spi = spi_dev_get(spi); | |
465 | edev->pdata = pd; | |
466 | ||
467 | sysfs_bin_attr_init(&edev->bin); | |
468 | edev->bin.attr.name = "eeprom"; | |
469 | edev->bin.attr.mode = S_IRUSR; | |
470 | edev->bin.read = eeprom_93xx46_bin_read; | |
471 | edev->bin.size = 128; | |
472 | if (!(pd->flags & EE_READONLY)) { | |
473 | edev->bin.write = eeprom_93xx46_bin_write; | |
474 | edev->bin.attr.mode |= S_IWUSR; | |
475 | } | |
476 | ||
477 | err = sysfs_create_bin_file(&spi->dev.kobj, &edev->bin); | |
478 | if (err) | |
479 | goto fail; | |
480 | ||
481 | dev_info(&spi->dev, "%d-bit eeprom %s\n", | |
482 | (pd->flags & EE_ADDR8) ? 8 : 16, | |
483 | (pd->flags & EE_READONLY) ? "(readonly)" : ""); | |
484 | ||
485 | if (!(pd->flags & EE_READONLY)) { | |
486 | if (device_create_file(&spi->dev, &dev_attr_erase)) | |
487 | dev_err(&spi->dev, "can't create erase interface\n"); | |
488 | } | |
489 | ||
5ba75b55 | 490 | spi_set_drvdata(spi, edev); |
06b4501e AG |
491 | return 0; |
492 | fail: | |
493 | kfree(edev); | |
494 | return err; | |
495 | } | |
496 | ||
486a5c28 | 497 | static int eeprom_93xx46_remove(struct spi_device *spi) |
06b4501e | 498 | { |
5ba75b55 | 499 | struct eeprom_93xx46_dev *edev = spi_get_drvdata(spi); |
06b4501e AG |
500 | |
501 | if (!(edev->pdata->flags & EE_READONLY)) | |
502 | device_remove_file(&spi->dev, &dev_attr_erase); | |
503 | ||
504 | sysfs_remove_bin_file(&spi->dev.kobj, &edev->bin); | |
06b4501e AG |
505 | kfree(edev); |
506 | return 0; | |
507 | } | |
508 | ||
509 | static struct spi_driver eeprom_93xx46_driver = { | |
510 | .driver = { | |
511 | .name = "93xx46", | |
c074abe0 | 512 | .of_match_table = of_match_ptr(eeprom_93xx46_of_table), |
06b4501e AG |
513 | }, |
514 | .probe = eeprom_93xx46_probe, | |
2d6bed9c | 515 | .remove = eeprom_93xx46_remove, |
06b4501e AG |
516 | }; |
517 | ||
a3dc3c9e | 518 | module_spi_driver(eeprom_93xx46_driver); |
06b4501e AG |
519 | |
520 | MODULE_LICENSE("GPL"); | |
521 | MODULE_DESCRIPTION("Driver for 93xx46 EEPROMs"); | |
522 | MODULE_AUTHOR("Anatolij Gustschin <agust@denx.de>"); | |
523 | MODULE_ALIAS("spi:93xx46"); |