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eace75cf SK |
1 | /* |
2 | * nvmem framework core. | |
3 | * | |
4 | * Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla@linaro.org> | |
5 | * Copyright (C) 2013 Maxime Ripard <maxime.ripard@free-electrons.com> | |
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 version 2 and | |
9 | * only version 2 as published by the Free Software Foundation. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | */ | |
16 | ||
17 | #include <linux/device.h> | |
18 | #include <linux/export.h> | |
19 | #include <linux/fs.h> | |
20 | #include <linux/idr.h> | |
21 | #include <linux/init.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/nvmem-consumer.h> | |
24 | #include <linux/nvmem-provider.h> | |
25 | #include <linux/of.h> | |
26 | #include <linux/regmap.h> | |
27 | #include <linux/slab.h> | |
28 | ||
29 | struct nvmem_device { | |
30 | const char *name; | |
31 | struct regmap *regmap; | |
32 | struct module *owner; | |
33 | struct device dev; | |
34 | int stride; | |
35 | int word_size; | |
36 | int ncells; | |
37 | int id; | |
38 | int users; | |
39 | size_t size; | |
40 | bool read_only; | |
b6c217ab AL |
41 | int flags; |
42 | struct bin_attribute eeprom; | |
43 | struct device *base_dev; | |
eace75cf SK |
44 | }; |
45 | ||
b6c217ab AL |
46 | #define FLAG_COMPAT BIT(0) |
47 | ||
eace75cf SK |
48 | struct nvmem_cell { |
49 | const char *name; | |
50 | int offset; | |
51 | int bytes; | |
52 | int bit_offset; | |
53 | int nbits; | |
54 | struct nvmem_device *nvmem; | |
55 | struct list_head node; | |
56 | }; | |
57 | ||
58 | static DEFINE_MUTEX(nvmem_mutex); | |
59 | static DEFINE_IDA(nvmem_ida); | |
60 | ||
61 | static LIST_HEAD(nvmem_cells); | |
62 | static DEFINE_MUTEX(nvmem_cells_mutex); | |
63 | ||
b6c217ab AL |
64 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
65 | static struct lock_class_key eeprom_lock_key; | |
66 | #endif | |
67 | ||
eace75cf SK |
68 | #define to_nvmem_device(d) container_of(d, struct nvmem_device, dev) |
69 | ||
70 | static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj, | |
71 | struct bin_attribute *attr, | |
72 | char *buf, loff_t pos, size_t count) | |
73 | { | |
b6c217ab AL |
74 | struct device *dev; |
75 | struct nvmem_device *nvmem; | |
eace75cf SK |
76 | int rc; |
77 | ||
b6c217ab AL |
78 | if (attr->private) |
79 | dev = attr->private; | |
80 | else | |
81 | dev = container_of(kobj, struct device, kobj); | |
82 | nvmem = to_nvmem_device(dev); | |
83 | ||
eace75cf | 84 | /* Stop the user from reading */ |
7c806883 | 85 | if (pos >= nvmem->size) |
eace75cf SK |
86 | return 0; |
87 | ||
313a72ff SK |
88 | if (count < nvmem->word_size) |
89 | return -EINVAL; | |
90 | ||
eace75cf SK |
91 | if (pos + count > nvmem->size) |
92 | count = nvmem->size - pos; | |
93 | ||
94 | count = round_down(count, nvmem->word_size); | |
95 | ||
96 | rc = regmap_raw_read(nvmem->regmap, pos, buf, count); | |
97 | ||
98 | if (IS_ERR_VALUE(rc)) | |
99 | return rc; | |
100 | ||
101 | return count; | |
102 | } | |
103 | ||
104 | static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj, | |
105 | struct bin_attribute *attr, | |
106 | char *buf, loff_t pos, size_t count) | |
107 | { | |
b6c217ab AL |
108 | struct device *dev; |
109 | struct nvmem_device *nvmem; | |
eace75cf SK |
110 | int rc; |
111 | ||
b6c217ab AL |
112 | if (attr->private) |
113 | dev = attr->private; | |
114 | else | |
115 | dev = container_of(kobj, struct device, kobj); | |
116 | nvmem = to_nvmem_device(dev); | |
117 | ||
eace75cf | 118 | /* Stop the user from writing */ |
7c806883 | 119 | if (pos >= nvmem->size) |
eace75cf SK |
120 | return 0; |
121 | ||
313a72ff SK |
122 | if (count < nvmem->word_size) |
123 | return -EINVAL; | |
124 | ||
eace75cf SK |
125 | if (pos + count > nvmem->size) |
126 | count = nvmem->size - pos; | |
127 | ||
128 | count = round_down(count, nvmem->word_size); | |
129 | ||
130 | rc = regmap_raw_write(nvmem->regmap, pos, buf, count); | |
131 | ||
132 | if (IS_ERR_VALUE(rc)) | |
133 | return rc; | |
134 | ||
135 | return count; | |
136 | } | |
137 | ||
138 | /* default read/write permissions */ | |
139 | static struct bin_attribute bin_attr_rw_nvmem = { | |
140 | .attr = { | |
141 | .name = "nvmem", | |
142 | .mode = S_IWUSR | S_IRUGO, | |
143 | }, | |
144 | .read = bin_attr_nvmem_read, | |
145 | .write = bin_attr_nvmem_write, | |
146 | }; | |
147 | ||
148 | static struct bin_attribute *nvmem_bin_rw_attributes[] = { | |
149 | &bin_attr_rw_nvmem, | |
150 | NULL, | |
151 | }; | |
152 | ||
153 | static const struct attribute_group nvmem_bin_rw_group = { | |
154 | .bin_attrs = nvmem_bin_rw_attributes, | |
155 | }; | |
156 | ||
157 | static const struct attribute_group *nvmem_rw_dev_groups[] = { | |
158 | &nvmem_bin_rw_group, | |
159 | NULL, | |
160 | }; | |
161 | ||
162 | /* read only permission */ | |
163 | static struct bin_attribute bin_attr_ro_nvmem = { | |
164 | .attr = { | |
165 | .name = "nvmem", | |
166 | .mode = S_IRUGO, | |
167 | }, | |
168 | .read = bin_attr_nvmem_read, | |
169 | }; | |
170 | ||
171 | static struct bin_attribute *nvmem_bin_ro_attributes[] = { | |
172 | &bin_attr_ro_nvmem, | |
173 | NULL, | |
174 | }; | |
175 | ||
176 | static const struct attribute_group nvmem_bin_ro_group = { | |
177 | .bin_attrs = nvmem_bin_ro_attributes, | |
178 | }; | |
179 | ||
180 | static const struct attribute_group *nvmem_ro_dev_groups[] = { | |
181 | &nvmem_bin_ro_group, | |
182 | NULL, | |
183 | }; | |
184 | ||
811b0d65 AL |
185 | /* default read/write permissions, root only */ |
186 | static struct bin_attribute bin_attr_rw_root_nvmem = { | |
187 | .attr = { | |
188 | .name = "nvmem", | |
189 | .mode = S_IWUSR | S_IRUSR, | |
190 | }, | |
191 | .read = bin_attr_nvmem_read, | |
192 | .write = bin_attr_nvmem_write, | |
193 | }; | |
194 | ||
195 | static struct bin_attribute *nvmem_bin_rw_root_attributes[] = { | |
196 | &bin_attr_rw_root_nvmem, | |
197 | NULL, | |
198 | }; | |
199 | ||
200 | static const struct attribute_group nvmem_bin_rw_root_group = { | |
201 | .bin_attrs = nvmem_bin_rw_root_attributes, | |
202 | }; | |
203 | ||
204 | static const struct attribute_group *nvmem_rw_root_dev_groups[] = { | |
205 | &nvmem_bin_rw_root_group, | |
206 | NULL, | |
207 | }; | |
208 | ||
209 | /* read only permission, root only */ | |
210 | static struct bin_attribute bin_attr_ro_root_nvmem = { | |
211 | .attr = { | |
212 | .name = "nvmem", | |
213 | .mode = S_IRUSR, | |
214 | }, | |
215 | .read = bin_attr_nvmem_read, | |
216 | }; | |
217 | ||
218 | static struct bin_attribute *nvmem_bin_ro_root_attributes[] = { | |
219 | &bin_attr_ro_root_nvmem, | |
220 | NULL, | |
221 | }; | |
222 | ||
223 | static const struct attribute_group nvmem_bin_ro_root_group = { | |
224 | .bin_attrs = nvmem_bin_ro_root_attributes, | |
225 | }; | |
226 | ||
227 | static const struct attribute_group *nvmem_ro_root_dev_groups[] = { | |
228 | &nvmem_bin_ro_root_group, | |
229 | NULL, | |
230 | }; | |
231 | ||
eace75cf SK |
232 | static void nvmem_release(struct device *dev) |
233 | { | |
234 | struct nvmem_device *nvmem = to_nvmem_device(dev); | |
235 | ||
236 | ida_simple_remove(&nvmem_ida, nvmem->id); | |
237 | kfree(nvmem); | |
238 | } | |
239 | ||
240 | static const struct device_type nvmem_provider_type = { | |
241 | .release = nvmem_release, | |
242 | }; | |
243 | ||
244 | static struct bus_type nvmem_bus_type = { | |
245 | .name = "nvmem", | |
246 | }; | |
247 | ||
248 | static int of_nvmem_match(struct device *dev, void *nvmem_np) | |
249 | { | |
250 | return dev->of_node == nvmem_np; | |
251 | } | |
252 | ||
253 | static struct nvmem_device *of_nvmem_find(struct device_node *nvmem_np) | |
254 | { | |
255 | struct device *d; | |
256 | ||
257 | if (!nvmem_np) | |
258 | return NULL; | |
259 | ||
260 | d = bus_find_device(&nvmem_bus_type, NULL, nvmem_np, of_nvmem_match); | |
261 | ||
262 | if (!d) | |
263 | return NULL; | |
264 | ||
265 | return to_nvmem_device(d); | |
266 | } | |
267 | ||
268 | static struct nvmem_cell *nvmem_find_cell(const char *cell_id) | |
269 | { | |
270 | struct nvmem_cell *p; | |
271 | ||
272 | list_for_each_entry(p, &nvmem_cells, node) | |
273 | if (p && !strcmp(p->name, cell_id)) | |
274 | return p; | |
275 | ||
276 | return NULL; | |
277 | } | |
278 | ||
279 | static void nvmem_cell_drop(struct nvmem_cell *cell) | |
280 | { | |
281 | mutex_lock(&nvmem_cells_mutex); | |
282 | list_del(&cell->node); | |
283 | mutex_unlock(&nvmem_cells_mutex); | |
284 | kfree(cell); | |
285 | } | |
286 | ||
287 | static void nvmem_device_remove_all_cells(const struct nvmem_device *nvmem) | |
288 | { | |
289 | struct nvmem_cell *cell; | |
290 | struct list_head *p, *n; | |
291 | ||
292 | list_for_each_safe(p, n, &nvmem_cells) { | |
293 | cell = list_entry(p, struct nvmem_cell, node); | |
294 | if (cell->nvmem == nvmem) | |
295 | nvmem_cell_drop(cell); | |
296 | } | |
297 | } | |
298 | ||
299 | static void nvmem_cell_add(struct nvmem_cell *cell) | |
300 | { | |
301 | mutex_lock(&nvmem_cells_mutex); | |
302 | list_add_tail(&cell->node, &nvmem_cells); | |
303 | mutex_unlock(&nvmem_cells_mutex); | |
304 | } | |
305 | ||
306 | static int nvmem_cell_info_to_nvmem_cell(struct nvmem_device *nvmem, | |
307 | const struct nvmem_cell_info *info, | |
308 | struct nvmem_cell *cell) | |
309 | { | |
310 | cell->nvmem = nvmem; | |
311 | cell->offset = info->offset; | |
312 | cell->bytes = info->bytes; | |
313 | cell->name = info->name; | |
314 | ||
315 | cell->bit_offset = info->bit_offset; | |
316 | cell->nbits = info->nbits; | |
317 | ||
318 | if (cell->nbits) | |
319 | cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset, | |
320 | BITS_PER_BYTE); | |
321 | ||
322 | if (!IS_ALIGNED(cell->offset, nvmem->stride)) { | |
323 | dev_err(&nvmem->dev, | |
324 | "cell %s unaligned to nvmem stride %d\n", | |
325 | cell->name, nvmem->stride); | |
326 | return -EINVAL; | |
327 | } | |
328 | ||
329 | return 0; | |
330 | } | |
331 | ||
332 | static int nvmem_add_cells(struct nvmem_device *nvmem, | |
333 | const struct nvmem_config *cfg) | |
334 | { | |
335 | struct nvmem_cell **cells; | |
336 | const struct nvmem_cell_info *info = cfg->cells; | |
337 | int i, rval; | |
338 | ||
339 | cells = kcalloc(cfg->ncells, sizeof(*cells), GFP_KERNEL); | |
340 | if (!cells) | |
341 | return -ENOMEM; | |
342 | ||
343 | for (i = 0; i < cfg->ncells; i++) { | |
344 | cells[i] = kzalloc(sizeof(**cells), GFP_KERNEL); | |
345 | if (!cells[i]) { | |
346 | rval = -ENOMEM; | |
347 | goto err; | |
348 | } | |
349 | ||
350 | rval = nvmem_cell_info_to_nvmem_cell(nvmem, &info[i], cells[i]); | |
351 | if (IS_ERR_VALUE(rval)) { | |
352 | kfree(cells[i]); | |
353 | goto err; | |
354 | } | |
355 | ||
356 | nvmem_cell_add(cells[i]); | |
357 | } | |
358 | ||
359 | nvmem->ncells = cfg->ncells; | |
360 | /* remove tmp array */ | |
361 | kfree(cells); | |
362 | ||
363 | return 0; | |
364 | err: | |
dfdf1414 | 365 | while (i--) |
eace75cf SK |
366 | nvmem_cell_drop(cells[i]); |
367 | ||
dfdf1414 RV |
368 | kfree(cells); |
369 | ||
eace75cf SK |
370 | return rval; |
371 | } | |
372 | ||
b6c217ab AL |
373 | /* |
374 | * nvmem_setup_compat() - Create an additional binary entry in | |
375 | * drivers sys directory, to be backwards compatible with the older | |
376 | * drivers/misc/eeprom drivers. | |
377 | */ | |
378 | static int nvmem_setup_compat(struct nvmem_device *nvmem, | |
379 | const struct nvmem_config *config) | |
380 | { | |
381 | int rval; | |
382 | ||
383 | if (!config->base_dev) | |
384 | return -EINVAL; | |
385 | ||
386 | if (nvmem->read_only) | |
387 | nvmem->eeprom = bin_attr_ro_root_nvmem; | |
388 | else | |
389 | nvmem->eeprom = bin_attr_rw_root_nvmem; | |
390 | nvmem->eeprom.attr.name = "eeprom"; | |
391 | nvmem->eeprom.size = nvmem->size; | |
392 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
393 | nvmem->eeprom.attr.key = &eeprom_lock_key; | |
394 | #endif | |
395 | nvmem->eeprom.private = &nvmem->dev; | |
396 | nvmem->base_dev = config->base_dev; | |
397 | ||
398 | rval = device_create_bin_file(nvmem->base_dev, &nvmem->eeprom); | |
399 | if (rval) { | |
400 | dev_err(&nvmem->dev, | |
401 | "Failed to create eeprom binary file %d\n", rval); | |
402 | return rval; | |
403 | } | |
404 | ||
405 | nvmem->flags |= FLAG_COMPAT; | |
406 | ||
407 | return 0; | |
408 | } | |
409 | ||
eace75cf SK |
410 | /** |
411 | * nvmem_register() - Register a nvmem device for given nvmem_config. | |
412 | * Also creates an binary entry in /sys/bus/nvmem/devices/dev-name/nvmem | |
413 | * | |
414 | * @config: nvmem device configuration with which nvmem device is created. | |
415 | * | |
416 | * Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device | |
417 | * on success. | |
418 | */ | |
419 | ||
420 | struct nvmem_device *nvmem_register(const struct nvmem_config *config) | |
421 | { | |
422 | struct nvmem_device *nvmem; | |
423 | struct device_node *np; | |
424 | struct regmap *rm; | |
425 | int rval; | |
426 | ||
427 | if (!config->dev) | |
428 | return ERR_PTR(-EINVAL); | |
429 | ||
430 | rm = dev_get_regmap(config->dev, NULL); | |
431 | if (!rm) { | |
432 | dev_err(config->dev, "Regmap not found\n"); | |
433 | return ERR_PTR(-EINVAL); | |
434 | } | |
435 | ||
436 | nvmem = kzalloc(sizeof(*nvmem), GFP_KERNEL); | |
437 | if (!nvmem) | |
438 | return ERR_PTR(-ENOMEM); | |
439 | ||
440 | rval = ida_simple_get(&nvmem_ida, 0, 0, GFP_KERNEL); | |
441 | if (rval < 0) { | |
442 | kfree(nvmem); | |
443 | return ERR_PTR(rval); | |
444 | } | |
445 | ||
446 | nvmem->id = rval; | |
447 | nvmem->regmap = rm; | |
448 | nvmem->owner = config->owner; | |
449 | nvmem->stride = regmap_get_reg_stride(rm); | |
450 | nvmem->word_size = regmap_get_val_bytes(rm); | |
451 | nvmem->size = regmap_get_max_register(rm) + nvmem->stride; | |
452 | nvmem->dev.type = &nvmem_provider_type; | |
453 | nvmem->dev.bus = &nvmem_bus_type; | |
454 | nvmem->dev.parent = config->dev; | |
455 | np = config->dev->of_node; | |
456 | nvmem->dev.of_node = np; | |
457 | dev_set_name(&nvmem->dev, "%s%d", | |
458 | config->name ? : "nvmem", config->id); | |
459 | ||
460 | nvmem->read_only = of_property_read_bool(np, "read-only") | | |
461 | config->read_only; | |
462 | ||
811b0d65 AL |
463 | if (config->root_only) |
464 | nvmem->dev.groups = nvmem->read_only ? | |
465 | nvmem_ro_root_dev_groups : | |
466 | nvmem_rw_root_dev_groups; | |
467 | else | |
468 | nvmem->dev.groups = nvmem->read_only ? | |
469 | nvmem_ro_dev_groups : | |
470 | nvmem_rw_dev_groups; | |
eace75cf SK |
471 | |
472 | device_initialize(&nvmem->dev); | |
473 | ||
474 | dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name); | |
475 | ||
476 | rval = device_add(&nvmem->dev); | |
b6c217ab AL |
477 | if (rval) |
478 | goto out; | |
479 | ||
480 | if (config->compat) { | |
481 | rval = nvmem_setup_compat(nvmem, config); | |
482 | if (rval) | |
483 | goto out; | |
eace75cf SK |
484 | } |
485 | ||
486 | if (config->cells) | |
487 | nvmem_add_cells(nvmem, config); | |
488 | ||
489 | return nvmem; | |
b6c217ab AL |
490 | out: |
491 | ida_simple_remove(&nvmem_ida, nvmem->id); | |
492 | kfree(nvmem); | |
493 | return ERR_PTR(rval); | |
eace75cf SK |
494 | } |
495 | EXPORT_SYMBOL_GPL(nvmem_register); | |
496 | ||
497 | /** | |
498 | * nvmem_unregister() - Unregister previously registered nvmem device | |
499 | * | |
500 | * @nvmem: Pointer to previously registered nvmem device. | |
501 | * | |
502 | * Return: Will be an negative on error or a zero on success. | |
503 | */ | |
504 | int nvmem_unregister(struct nvmem_device *nvmem) | |
505 | { | |
69aba794 SK |
506 | mutex_lock(&nvmem_mutex); |
507 | if (nvmem->users) { | |
508 | mutex_unlock(&nvmem_mutex); | |
eace75cf | 509 | return -EBUSY; |
69aba794 SK |
510 | } |
511 | mutex_unlock(&nvmem_mutex); | |
eace75cf | 512 | |
b6c217ab AL |
513 | if (nvmem->flags & FLAG_COMPAT) |
514 | device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom); | |
515 | ||
eace75cf SK |
516 | nvmem_device_remove_all_cells(nvmem); |
517 | device_del(&nvmem->dev); | |
518 | ||
519 | return 0; | |
520 | } | |
521 | EXPORT_SYMBOL_GPL(nvmem_unregister); | |
522 | ||
69aba794 SK |
523 | static struct nvmem_device *__nvmem_device_get(struct device_node *np, |
524 | struct nvmem_cell **cellp, | |
525 | const char *cell_id) | |
526 | { | |
527 | struct nvmem_device *nvmem = NULL; | |
528 | ||
529 | mutex_lock(&nvmem_mutex); | |
530 | ||
531 | if (np) { | |
532 | nvmem = of_nvmem_find(np); | |
533 | if (!nvmem) { | |
534 | mutex_unlock(&nvmem_mutex); | |
535 | return ERR_PTR(-EPROBE_DEFER); | |
536 | } | |
537 | } else { | |
538 | struct nvmem_cell *cell = nvmem_find_cell(cell_id); | |
539 | ||
540 | if (cell) { | |
541 | nvmem = cell->nvmem; | |
542 | *cellp = cell; | |
543 | } | |
544 | ||
545 | if (!nvmem) { | |
546 | mutex_unlock(&nvmem_mutex); | |
547 | return ERR_PTR(-ENOENT); | |
548 | } | |
549 | } | |
550 | ||
551 | nvmem->users++; | |
552 | mutex_unlock(&nvmem_mutex); | |
553 | ||
554 | if (!try_module_get(nvmem->owner)) { | |
555 | dev_err(&nvmem->dev, | |
556 | "could not increase module refcount for cell %s\n", | |
557 | nvmem->name); | |
558 | ||
559 | mutex_lock(&nvmem_mutex); | |
560 | nvmem->users--; | |
561 | mutex_unlock(&nvmem_mutex); | |
562 | ||
563 | return ERR_PTR(-EINVAL); | |
564 | } | |
565 | ||
566 | return nvmem; | |
567 | } | |
568 | ||
569 | static void __nvmem_device_put(struct nvmem_device *nvmem) | |
570 | { | |
571 | module_put(nvmem->owner); | |
572 | mutex_lock(&nvmem_mutex); | |
573 | nvmem->users--; | |
574 | mutex_unlock(&nvmem_mutex); | |
575 | } | |
576 | ||
e2a5402e SK |
577 | static int nvmem_match(struct device *dev, void *data) |
578 | { | |
579 | return !strcmp(dev_name(dev), data); | |
580 | } | |
581 | ||
582 | static struct nvmem_device *nvmem_find(const char *name) | |
583 | { | |
584 | struct device *d; | |
585 | ||
586 | d = bus_find_device(&nvmem_bus_type, NULL, (void *)name, nvmem_match); | |
587 | ||
588 | if (!d) | |
589 | return NULL; | |
590 | ||
591 | return to_nvmem_device(d); | |
592 | } | |
593 | ||
594 | #if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OF) | |
595 | /** | |
596 | * of_nvmem_device_get() - Get nvmem device from a given id | |
597 | * | |
598 | * @dev node: Device tree node that uses the nvmem device | |
599 | * @id: nvmem name from nvmem-names property. | |
600 | * | |
601 | * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device | |
602 | * on success. | |
603 | */ | |
604 | struct nvmem_device *of_nvmem_device_get(struct device_node *np, const char *id) | |
605 | { | |
606 | ||
607 | struct device_node *nvmem_np; | |
608 | int index; | |
609 | ||
610 | index = of_property_match_string(np, "nvmem-names", id); | |
611 | ||
612 | nvmem_np = of_parse_phandle(np, "nvmem", index); | |
613 | if (!nvmem_np) | |
614 | return ERR_PTR(-EINVAL); | |
615 | ||
616 | return __nvmem_device_get(nvmem_np, NULL, NULL); | |
617 | } | |
618 | EXPORT_SYMBOL_GPL(of_nvmem_device_get); | |
619 | #endif | |
620 | ||
621 | /** | |
622 | * nvmem_device_get() - Get nvmem device from a given id | |
623 | * | |
624 | * @dev : Device that uses the nvmem device | |
625 | * @id: nvmem name from nvmem-names property. | |
626 | * | |
627 | * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device | |
628 | * on success. | |
629 | */ | |
630 | struct nvmem_device *nvmem_device_get(struct device *dev, const char *dev_name) | |
631 | { | |
632 | if (dev->of_node) { /* try dt first */ | |
633 | struct nvmem_device *nvmem; | |
634 | ||
635 | nvmem = of_nvmem_device_get(dev->of_node, dev_name); | |
636 | ||
637 | if (!IS_ERR(nvmem) || PTR_ERR(nvmem) == -EPROBE_DEFER) | |
638 | return nvmem; | |
639 | ||
640 | } | |
641 | ||
642 | return nvmem_find(dev_name); | |
643 | } | |
644 | EXPORT_SYMBOL_GPL(nvmem_device_get); | |
645 | ||
646 | static int devm_nvmem_device_match(struct device *dev, void *res, void *data) | |
647 | { | |
648 | struct nvmem_device **nvmem = res; | |
649 | ||
650 | if (WARN_ON(!nvmem || !*nvmem)) | |
651 | return 0; | |
652 | ||
653 | return *nvmem == data; | |
654 | } | |
655 | ||
656 | static void devm_nvmem_device_release(struct device *dev, void *res) | |
657 | { | |
658 | nvmem_device_put(*(struct nvmem_device **)res); | |
659 | } | |
660 | ||
661 | /** | |
662 | * devm_nvmem_device_put() - put alredy got nvmem device | |
663 | * | |
664 | * @nvmem: pointer to nvmem device allocated by devm_nvmem_cell_get(), | |
665 | * that needs to be released. | |
666 | */ | |
667 | void devm_nvmem_device_put(struct device *dev, struct nvmem_device *nvmem) | |
668 | { | |
669 | int ret; | |
670 | ||
671 | ret = devres_release(dev, devm_nvmem_device_release, | |
672 | devm_nvmem_device_match, nvmem); | |
673 | ||
674 | WARN_ON(ret); | |
675 | } | |
676 | EXPORT_SYMBOL_GPL(devm_nvmem_device_put); | |
677 | ||
678 | /** | |
679 | * nvmem_device_put() - put alredy got nvmem device | |
680 | * | |
681 | * @nvmem: pointer to nvmem device that needs to be released. | |
682 | */ | |
683 | void nvmem_device_put(struct nvmem_device *nvmem) | |
684 | { | |
685 | __nvmem_device_put(nvmem); | |
686 | } | |
687 | EXPORT_SYMBOL_GPL(nvmem_device_put); | |
688 | ||
689 | /** | |
690 | * devm_nvmem_device_get() - Get nvmem cell of device form a given id | |
691 | * | |
692 | * @dev node: Device tree node that uses the nvmem cell | |
693 | * @id: nvmem name in nvmems property. | |
694 | * | |
695 | * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_cell | |
696 | * on success. The nvmem_cell will be freed by the automatically once the | |
697 | * device is freed. | |
698 | */ | |
699 | struct nvmem_device *devm_nvmem_device_get(struct device *dev, const char *id) | |
700 | { | |
701 | struct nvmem_device **ptr, *nvmem; | |
702 | ||
703 | ptr = devres_alloc(devm_nvmem_device_release, sizeof(*ptr), GFP_KERNEL); | |
704 | if (!ptr) | |
705 | return ERR_PTR(-ENOMEM); | |
706 | ||
707 | nvmem = nvmem_device_get(dev, id); | |
708 | if (!IS_ERR(nvmem)) { | |
709 | *ptr = nvmem; | |
710 | devres_add(dev, ptr); | |
711 | } else { | |
712 | devres_free(ptr); | |
713 | } | |
714 | ||
715 | return nvmem; | |
716 | } | |
717 | EXPORT_SYMBOL_GPL(devm_nvmem_device_get); | |
718 | ||
69aba794 SK |
719 | static struct nvmem_cell *nvmem_cell_get_from_list(const char *cell_id) |
720 | { | |
721 | struct nvmem_cell *cell = NULL; | |
722 | struct nvmem_device *nvmem; | |
723 | ||
724 | nvmem = __nvmem_device_get(NULL, &cell, cell_id); | |
725 | if (IS_ERR(nvmem)) | |
726 | return ERR_CAST(nvmem); | |
727 | ||
728 | return cell; | |
729 | } | |
730 | ||
731 | #if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OF) | |
732 | /** | |
733 | * of_nvmem_cell_get() - Get a nvmem cell from given device node and cell id | |
734 | * | |
735 | * @dev node: Device tree node that uses the nvmem cell | |
736 | * @id: nvmem cell name from nvmem-cell-names property. | |
737 | * | |
738 | * Return: Will be an ERR_PTR() on error or a valid pointer | |
739 | * to a struct nvmem_cell. The nvmem_cell will be freed by the | |
740 | * nvmem_cell_put(). | |
741 | */ | |
742 | struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, | |
743 | const char *name) | |
744 | { | |
745 | struct device_node *cell_np, *nvmem_np; | |
746 | struct nvmem_cell *cell; | |
747 | struct nvmem_device *nvmem; | |
748 | const __be32 *addr; | |
749 | int rval, len, index; | |
750 | ||
751 | index = of_property_match_string(np, "nvmem-cell-names", name); | |
752 | ||
753 | cell_np = of_parse_phandle(np, "nvmem-cells", index); | |
754 | if (!cell_np) | |
755 | return ERR_PTR(-EINVAL); | |
756 | ||
757 | nvmem_np = of_get_next_parent(cell_np); | |
758 | if (!nvmem_np) | |
759 | return ERR_PTR(-EINVAL); | |
760 | ||
761 | nvmem = __nvmem_device_get(nvmem_np, NULL, NULL); | |
762 | if (IS_ERR(nvmem)) | |
763 | return ERR_CAST(nvmem); | |
764 | ||
765 | addr = of_get_property(cell_np, "reg", &len); | |
766 | if (!addr || (len < 2 * sizeof(u32))) { | |
767 | dev_err(&nvmem->dev, "nvmem: invalid reg on %s\n", | |
768 | cell_np->full_name); | |
769 | rval = -EINVAL; | |
770 | goto err_mem; | |
771 | } | |
772 | ||
773 | cell = kzalloc(sizeof(*cell), GFP_KERNEL); | |
774 | if (!cell) { | |
775 | rval = -ENOMEM; | |
776 | goto err_mem; | |
777 | } | |
778 | ||
779 | cell->nvmem = nvmem; | |
780 | cell->offset = be32_to_cpup(addr++); | |
781 | cell->bytes = be32_to_cpup(addr); | |
782 | cell->name = cell_np->name; | |
783 | ||
784 | addr = of_get_property(cell_np, "bits", &len); | |
785 | if (addr && len == (2 * sizeof(u32))) { | |
786 | cell->bit_offset = be32_to_cpup(addr++); | |
787 | cell->nbits = be32_to_cpup(addr); | |
788 | } | |
789 | ||
790 | if (cell->nbits) | |
791 | cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset, | |
792 | BITS_PER_BYTE); | |
793 | ||
794 | if (!IS_ALIGNED(cell->offset, nvmem->stride)) { | |
795 | dev_err(&nvmem->dev, | |
796 | "cell %s unaligned to nvmem stride %d\n", | |
797 | cell->name, nvmem->stride); | |
798 | rval = -EINVAL; | |
799 | goto err_sanity; | |
800 | } | |
801 | ||
802 | nvmem_cell_add(cell); | |
803 | ||
804 | return cell; | |
805 | ||
806 | err_sanity: | |
807 | kfree(cell); | |
808 | ||
809 | err_mem: | |
810 | __nvmem_device_put(nvmem); | |
811 | ||
812 | return ERR_PTR(rval); | |
813 | } | |
814 | EXPORT_SYMBOL_GPL(of_nvmem_cell_get); | |
815 | #endif | |
816 | ||
817 | /** | |
818 | * nvmem_cell_get() - Get nvmem cell of device form a given cell name | |
819 | * | |
820 | * @dev node: Device tree node that uses the nvmem cell | |
821 | * @id: nvmem cell name to get. | |
822 | * | |
823 | * Return: Will be an ERR_PTR() on error or a valid pointer | |
824 | * to a struct nvmem_cell. The nvmem_cell will be freed by the | |
825 | * nvmem_cell_put(). | |
826 | */ | |
827 | struct nvmem_cell *nvmem_cell_get(struct device *dev, const char *cell_id) | |
828 | { | |
829 | struct nvmem_cell *cell; | |
830 | ||
831 | if (dev->of_node) { /* try dt first */ | |
832 | cell = of_nvmem_cell_get(dev->of_node, cell_id); | |
833 | if (!IS_ERR(cell) || PTR_ERR(cell) == -EPROBE_DEFER) | |
834 | return cell; | |
835 | } | |
836 | ||
837 | return nvmem_cell_get_from_list(cell_id); | |
838 | } | |
839 | EXPORT_SYMBOL_GPL(nvmem_cell_get); | |
840 | ||
841 | static void devm_nvmem_cell_release(struct device *dev, void *res) | |
842 | { | |
843 | nvmem_cell_put(*(struct nvmem_cell **)res); | |
844 | } | |
845 | ||
846 | /** | |
847 | * devm_nvmem_cell_get() - Get nvmem cell of device form a given id | |
848 | * | |
849 | * @dev node: Device tree node that uses the nvmem cell | |
850 | * @id: nvmem id in nvmem-names property. | |
851 | * | |
852 | * Return: Will be an ERR_PTR() on error or a valid pointer | |
853 | * to a struct nvmem_cell. The nvmem_cell will be freed by the | |
854 | * automatically once the device is freed. | |
855 | */ | |
856 | struct nvmem_cell *devm_nvmem_cell_get(struct device *dev, const char *id) | |
857 | { | |
858 | struct nvmem_cell **ptr, *cell; | |
859 | ||
860 | ptr = devres_alloc(devm_nvmem_cell_release, sizeof(*ptr), GFP_KERNEL); | |
861 | if (!ptr) | |
862 | return ERR_PTR(-ENOMEM); | |
863 | ||
864 | cell = nvmem_cell_get(dev, id); | |
865 | if (!IS_ERR(cell)) { | |
866 | *ptr = cell; | |
867 | devres_add(dev, ptr); | |
868 | } else { | |
869 | devres_free(ptr); | |
870 | } | |
871 | ||
872 | return cell; | |
873 | } | |
874 | EXPORT_SYMBOL_GPL(devm_nvmem_cell_get); | |
875 | ||
876 | static int devm_nvmem_cell_match(struct device *dev, void *res, void *data) | |
877 | { | |
878 | struct nvmem_cell **c = res; | |
879 | ||
880 | if (WARN_ON(!c || !*c)) | |
881 | return 0; | |
882 | ||
883 | return *c == data; | |
884 | } | |
885 | ||
886 | /** | |
887 | * devm_nvmem_cell_put() - Release previously allocated nvmem cell | |
888 | * from devm_nvmem_cell_get. | |
889 | * | |
890 | * @cell: Previously allocated nvmem cell by devm_nvmem_cell_get() | |
891 | */ | |
892 | void devm_nvmem_cell_put(struct device *dev, struct nvmem_cell *cell) | |
893 | { | |
894 | int ret; | |
895 | ||
896 | ret = devres_release(dev, devm_nvmem_cell_release, | |
897 | devm_nvmem_cell_match, cell); | |
898 | ||
899 | WARN_ON(ret); | |
900 | } | |
901 | EXPORT_SYMBOL(devm_nvmem_cell_put); | |
902 | ||
903 | /** | |
904 | * nvmem_cell_put() - Release previously allocated nvmem cell. | |
905 | * | |
906 | * @cell: Previously allocated nvmem cell by nvmem_cell_get() | |
907 | */ | |
908 | void nvmem_cell_put(struct nvmem_cell *cell) | |
909 | { | |
910 | struct nvmem_device *nvmem = cell->nvmem; | |
911 | ||
912 | __nvmem_device_put(nvmem); | |
913 | nvmem_cell_drop(cell); | |
914 | } | |
915 | EXPORT_SYMBOL_GPL(nvmem_cell_put); | |
916 | ||
917 | static inline void nvmem_shift_read_buffer_in_place(struct nvmem_cell *cell, | |
918 | void *buf) | |
919 | { | |
920 | u8 *p, *b; | |
921 | int i, bit_offset = cell->bit_offset; | |
922 | ||
923 | p = b = buf; | |
924 | if (bit_offset) { | |
925 | /* First shift */ | |
926 | *b++ >>= bit_offset; | |
927 | ||
928 | /* setup rest of the bytes if any */ | |
929 | for (i = 1; i < cell->bytes; i++) { | |
930 | /* Get bits from next byte and shift them towards msb */ | |
931 | *p |= *b << (BITS_PER_BYTE - bit_offset); | |
932 | ||
933 | p = b; | |
934 | *b++ >>= bit_offset; | |
935 | } | |
936 | ||
937 | /* result fits in less bytes */ | |
938 | if (cell->bytes != DIV_ROUND_UP(cell->nbits, BITS_PER_BYTE)) | |
939 | *p-- = 0; | |
940 | } | |
941 | /* clear msb bits if any leftover in the last byte */ | |
942 | *p &= GENMASK((cell->nbits%BITS_PER_BYTE) - 1, 0); | |
943 | } | |
944 | ||
945 | static int __nvmem_cell_read(struct nvmem_device *nvmem, | |
946 | struct nvmem_cell *cell, | |
947 | void *buf, size_t *len) | |
948 | { | |
949 | int rc; | |
950 | ||
951 | rc = regmap_raw_read(nvmem->regmap, cell->offset, buf, cell->bytes); | |
952 | ||
953 | if (IS_ERR_VALUE(rc)) | |
954 | return rc; | |
955 | ||
956 | /* shift bits in-place */ | |
cbf854ab | 957 | if (cell->bit_offset || cell->nbits) |
69aba794 SK |
958 | nvmem_shift_read_buffer_in_place(cell, buf); |
959 | ||
960 | *len = cell->bytes; | |
961 | ||
962 | return 0; | |
963 | } | |
964 | ||
965 | /** | |
966 | * nvmem_cell_read() - Read a given nvmem cell | |
967 | * | |
968 | * @cell: nvmem cell to be read. | |
969 | * @len: pointer to length of cell which will be populated on successful read. | |
970 | * | |
971 | * Return: ERR_PTR() on error or a valid pointer to a char * buffer on success. | |
972 | * The buffer should be freed by the consumer with a kfree(). | |
973 | */ | |
974 | void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len) | |
975 | { | |
976 | struct nvmem_device *nvmem = cell->nvmem; | |
977 | u8 *buf; | |
978 | int rc; | |
979 | ||
980 | if (!nvmem || !nvmem->regmap) | |
981 | return ERR_PTR(-EINVAL); | |
982 | ||
983 | buf = kzalloc(cell->bytes, GFP_KERNEL); | |
984 | if (!buf) | |
985 | return ERR_PTR(-ENOMEM); | |
986 | ||
987 | rc = __nvmem_cell_read(nvmem, cell, buf, len); | |
988 | if (IS_ERR_VALUE(rc)) { | |
989 | kfree(buf); | |
990 | return ERR_PTR(rc); | |
991 | } | |
992 | ||
993 | return buf; | |
994 | } | |
995 | EXPORT_SYMBOL_GPL(nvmem_cell_read); | |
996 | ||
997 | static inline void *nvmem_cell_prepare_write_buffer(struct nvmem_cell *cell, | |
998 | u8 *_buf, int len) | |
999 | { | |
1000 | struct nvmem_device *nvmem = cell->nvmem; | |
1001 | int i, rc, nbits, bit_offset = cell->bit_offset; | |
1002 | u8 v, *p, *buf, *b, pbyte, pbits; | |
1003 | ||
1004 | nbits = cell->nbits; | |
1005 | buf = kzalloc(cell->bytes, GFP_KERNEL); | |
1006 | if (!buf) | |
1007 | return ERR_PTR(-ENOMEM); | |
1008 | ||
1009 | memcpy(buf, _buf, len); | |
1010 | p = b = buf; | |
1011 | ||
1012 | if (bit_offset) { | |
1013 | pbyte = *b; | |
1014 | *b <<= bit_offset; | |
1015 | ||
1016 | /* setup the first byte with lsb bits from nvmem */ | |
1017 | rc = regmap_raw_read(nvmem->regmap, cell->offset, &v, 1); | |
1018 | *b++ |= GENMASK(bit_offset - 1, 0) & v; | |
1019 | ||
1020 | /* setup rest of the byte if any */ | |
1021 | for (i = 1; i < cell->bytes; i++) { | |
1022 | /* Get last byte bits and shift them towards lsb */ | |
1023 | pbits = pbyte >> (BITS_PER_BYTE - 1 - bit_offset); | |
1024 | pbyte = *b; | |
1025 | p = b; | |
1026 | *b <<= bit_offset; | |
1027 | *b++ |= pbits; | |
1028 | } | |
1029 | } | |
1030 | ||
1031 | /* if it's not end on byte boundary */ | |
1032 | if ((nbits + bit_offset) % BITS_PER_BYTE) { | |
1033 | /* setup the last byte with msb bits from nvmem */ | |
1034 | rc = regmap_raw_read(nvmem->regmap, | |
1035 | cell->offset + cell->bytes - 1, &v, 1); | |
1036 | *p |= GENMASK(7, (nbits + bit_offset) % BITS_PER_BYTE) & v; | |
1037 | ||
1038 | } | |
1039 | ||
1040 | return buf; | |
1041 | } | |
1042 | ||
1043 | /** | |
1044 | * nvmem_cell_write() - Write to a given nvmem cell | |
1045 | * | |
1046 | * @cell: nvmem cell to be written. | |
1047 | * @buf: Buffer to be written. | |
1048 | * @len: length of buffer to be written to nvmem cell. | |
1049 | * | |
1050 | * Return: length of bytes written or negative on failure. | |
1051 | */ | |
1052 | int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len) | |
1053 | { | |
1054 | struct nvmem_device *nvmem = cell->nvmem; | |
1055 | int rc; | |
1056 | ||
1057 | if (!nvmem || !nvmem->regmap || nvmem->read_only || | |
1058 | (cell->bit_offset == 0 && len != cell->bytes)) | |
1059 | return -EINVAL; | |
1060 | ||
1061 | if (cell->bit_offset || cell->nbits) { | |
1062 | buf = nvmem_cell_prepare_write_buffer(cell, buf, len); | |
1063 | if (IS_ERR(buf)) | |
1064 | return PTR_ERR(buf); | |
1065 | } | |
1066 | ||
1067 | rc = regmap_raw_write(nvmem->regmap, cell->offset, buf, cell->bytes); | |
1068 | ||
1069 | /* free the tmp buffer */ | |
ace22170 | 1070 | if (cell->bit_offset || cell->nbits) |
69aba794 SK |
1071 | kfree(buf); |
1072 | ||
1073 | if (IS_ERR_VALUE(rc)) | |
1074 | return rc; | |
1075 | ||
1076 | return len; | |
1077 | } | |
1078 | EXPORT_SYMBOL_GPL(nvmem_cell_write); | |
1079 | ||
e2a5402e SK |
1080 | /** |
1081 | * nvmem_device_cell_read() - Read a given nvmem device and cell | |
1082 | * | |
1083 | * @nvmem: nvmem device to read from. | |
1084 | * @info: nvmem cell info to be read. | |
1085 | * @buf: buffer pointer which will be populated on successful read. | |
1086 | * | |
1087 | * Return: length of successful bytes read on success and negative | |
1088 | * error code on error. | |
1089 | */ | |
1090 | ssize_t nvmem_device_cell_read(struct nvmem_device *nvmem, | |
1091 | struct nvmem_cell_info *info, void *buf) | |
1092 | { | |
1093 | struct nvmem_cell cell; | |
1094 | int rc; | |
1095 | ssize_t len; | |
1096 | ||
1097 | if (!nvmem || !nvmem->regmap) | |
1098 | return -EINVAL; | |
1099 | ||
1100 | rc = nvmem_cell_info_to_nvmem_cell(nvmem, info, &cell); | |
1101 | if (IS_ERR_VALUE(rc)) | |
1102 | return rc; | |
1103 | ||
1104 | rc = __nvmem_cell_read(nvmem, &cell, buf, &len); | |
1105 | if (IS_ERR_VALUE(rc)) | |
1106 | return rc; | |
1107 | ||
1108 | return len; | |
1109 | } | |
1110 | EXPORT_SYMBOL_GPL(nvmem_device_cell_read); | |
1111 | ||
1112 | /** | |
1113 | * nvmem_device_cell_write() - Write cell to a given nvmem device | |
1114 | * | |
1115 | * @nvmem: nvmem device to be written to. | |
1116 | * @info: nvmem cell info to be written | |
1117 | * @buf: buffer to be written to cell. | |
1118 | * | |
1119 | * Return: length of bytes written or negative error code on failure. | |
1120 | * */ | |
1121 | int nvmem_device_cell_write(struct nvmem_device *nvmem, | |
1122 | struct nvmem_cell_info *info, void *buf) | |
1123 | { | |
1124 | struct nvmem_cell cell; | |
1125 | int rc; | |
1126 | ||
1127 | if (!nvmem || !nvmem->regmap) | |
1128 | return -EINVAL; | |
1129 | ||
1130 | rc = nvmem_cell_info_to_nvmem_cell(nvmem, info, &cell); | |
1131 | if (IS_ERR_VALUE(rc)) | |
1132 | return rc; | |
1133 | ||
1134 | return nvmem_cell_write(&cell, buf, cell.bytes); | |
1135 | } | |
1136 | EXPORT_SYMBOL_GPL(nvmem_device_cell_write); | |
1137 | ||
1138 | /** | |
1139 | * nvmem_device_read() - Read from a given nvmem device | |
1140 | * | |
1141 | * @nvmem: nvmem device to read from. | |
1142 | * @offset: offset in nvmem device. | |
1143 | * @bytes: number of bytes to read. | |
1144 | * @buf: buffer pointer which will be populated on successful read. | |
1145 | * | |
1146 | * Return: length of successful bytes read on success and negative | |
1147 | * error code on error. | |
1148 | */ | |
1149 | int nvmem_device_read(struct nvmem_device *nvmem, | |
1150 | unsigned int offset, | |
1151 | size_t bytes, void *buf) | |
1152 | { | |
1153 | int rc; | |
1154 | ||
1155 | if (!nvmem || !nvmem->regmap) | |
1156 | return -EINVAL; | |
1157 | ||
1158 | rc = regmap_raw_read(nvmem->regmap, offset, buf, bytes); | |
1159 | ||
1160 | if (IS_ERR_VALUE(rc)) | |
1161 | return rc; | |
1162 | ||
1163 | return bytes; | |
1164 | } | |
1165 | EXPORT_SYMBOL_GPL(nvmem_device_read); | |
1166 | ||
1167 | /** | |
1168 | * nvmem_device_write() - Write cell to a given nvmem device | |
1169 | * | |
1170 | * @nvmem: nvmem device to be written to. | |
1171 | * @offset: offset in nvmem device. | |
1172 | * @bytes: number of bytes to write. | |
1173 | * @buf: buffer to be written. | |
1174 | * | |
1175 | * Return: length of bytes written or negative error code on failure. | |
1176 | * */ | |
1177 | int nvmem_device_write(struct nvmem_device *nvmem, | |
1178 | unsigned int offset, | |
1179 | size_t bytes, void *buf) | |
1180 | { | |
1181 | int rc; | |
1182 | ||
1183 | if (!nvmem || !nvmem->regmap) | |
1184 | return -EINVAL; | |
1185 | ||
1186 | rc = regmap_raw_write(nvmem->regmap, offset, buf, bytes); | |
1187 | ||
1188 | if (IS_ERR_VALUE(rc)) | |
1189 | return rc; | |
1190 | ||
1191 | ||
1192 | return bytes; | |
1193 | } | |
1194 | EXPORT_SYMBOL_GPL(nvmem_device_write); | |
1195 | ||
eace75cf SK |
1196 | static int __init nvmem_init(void) |
1197 | { | |
1198 | return bus_register(&nvmem_bus_type); | |
1199 | } | |
1200 | ||
1201 | static void __exit nvmem_exit(void) | |
1202 | { | |
1203 | bus_unregister(&nvmem_bus_type); | |
1204 | } | |
1205 | ||
1206 | subsys_initcall(nvmem_init); | |
1207 | module_exit(nvmem_exit); | |
1208 | ||
1209 | MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org"); | |
1210 | MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com"); | |
1211 | MODULE_DESCRIPTION("nvmem Driver Core"); | |
1212 | MODULE_LICENSE("GPL v2"); |