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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> | |
eace75cf SK |
26 | #include <linux/slab.h> |
27 | ||
28 | struct nvmem_device { | |
29 | const char *name; | |
eace75cf SK |
30 | struct module *owner; |
31 | struct device dev; | |
32 | int stride; | |
33 | int word_size; | |
34 | int ncells; | |
35 | int id; | |
36 | int users; | |
37 | size_t size; | |
38 | bool read_only; | |
b6c217ab AL |
39 | int flags; |
40 | struct bin_attribute eeprom; | |
41 | struct device *base_dev; | |
795ddd18 SK |
42 | nvmem_reg_read_t reg_read; |
43 | nvmem_reg_write_t reg_write; | |
44 | void *priv; | |
eace75cf SK |
45 | }; |
46 | ||
b6c217ab AL |
47 | #define FLAG_COMPAT BIT(0) |
48 | ||
eace75cf SK |
49 | struct nvmem_cell { |
50 | const char *name; | |
51 | int offset; | |
52 | int bytes; | |
53 | int bit_offset; | |
54 | int nbits; | |
55 | struct nvmem_device *nvmem; | |
56 | struct list_head node; | |
57 | }; | |
58 | ||
59 | static DEFINE_MUTEX(nvmem_mutex); | |
60 | static DEFINE_IDA(nvmem_ida); | |
61 | ||
62 | static LIST_HEAD(nvmem_cells); | |
63 | static DEFINE_MUTEX(nvmem_cells_mutex); | |
64 | ||
b6c217ab AL |
65 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
66 | static struct lock_class_key eeprom_lock_key; | |
67 | #endif | |
68 | ||
eace75cf | 69 | #define to_nvmem_device(d) container_of(d, struct nvmem_device, dev) |
795ddd18 SK |
70 | static int nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset, |
71 | void *val, size_t bytes) | |
72 | { | |
73 | if (nvmem->reg_read) | |
74 | return nvmem->reg_read(nvmem->priv, offset, val, bytes); | |
75 | ||
76 | return -EINVAL; | |
77 | } | |
78 | ||
79 | static int nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset, | |
80 | void *val, size_t bytes) | |
81 | { | |
82 | if (nvmem->reg_write) | |
83 | return nvmem->reg_write(nvmem->priv, offset, val, bytes); | |
84 | ||
85 | return -EINVAL; | |
86 | } | |
eace75cf SK |
87 | |
88 | static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj, | |
89 | struct bin_attribute *attr, | |
90 | char *buf, loff_t pos, size_t count) | |
91 | { | |
b6c217ab AL |
92 | struct device *dev; |
93 | struct nvmem_device *nvmem; | |
eace75cf SK |
94 | int rc; |
95 | ||
b6c217ab AL |
96 | if (attr->private) |
97 | dev = attr->private; | |
98 | else | |
99 | dev = container_of(kobj, struct device, kobj); | |
100 | nvmem = to_nvmem_device(dev); | |
101 | ||
eace75cf | 102 | /* Stop the user from reading */ |
7c806883 | 103 | if (pos >= nvmem->size) |
eace75cf SK |
104 | return 0; |
105 | ||
313a72ff SK |
106 | if (count < nvmem->word_size) |
107 | return -EINVAL; | |
108 | ||
eace75cf SK |
109 | if (pos + count > nvmem->size) |
110 | count = nvmem->size - pos; | |
111 | ||
112 | count = round_down(count, nvmem->word_size); | |
113 | ||
795ddd18 | 114 | rc = nvmem_reg_read(nvmem, pos, buf, count); |
eace75cf | 115 | |
287980e4 | 116 | if (rc) |
eace75cf SK |
117 | return rc; |
118 | ||
119 | return count; | |
120 | } | |
121 | ||
122 | static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj, | |
123 | struct bin_attribute *attr, | |
124 | char *buf, loff_t pos, size_t count) | |
125 | { | |
b6c217ab AL |
126 | struct device *dev; |
127 | struct nvmem_device *nvmem; | |
eace75cf SK |
128 | int rc; |
129 | ||
b6c217ab AL |
130 | if (attr->private) |
131 | dev = attr->private; | |
132 | else | |
133 | dev = container_of(kobj, struct device, kobj); | |
134 | nvmem = to_nvmem_device(dev); | |
135 | ||
eace75cf | 136 | /* Stop the user from writing */ |
7c806883 | 137 | if (pos >= nvmem->size) |
eace75cf SK |
138 | return 0; |
139 | ||
313a72ff SK |
140 | if (count < nvmem->word_size) |
141 | return -EINVAL; | |
142 | ||
eace75cf SK |
143 | if (pos + count > nvmem->size) |
144 | count = nvmem->size - pos; | |
145 | ||
146 | count = round_down(count, nvmem->word_size); | |
147 | ||
795ddd18 | 148 | rc = nvmem_reg_write(nvmem, pos, buf, count); |
eace75cf | 149 | |
287980e4 | 150 | if (rc) |
eace75cf SK |
151 | return rc; |
152 | ||
153 | return count; | |
154 | } | |
155 | ||
156 | /* default read/write permissions */ | |
157 | static struct bin_attribute bin_attr_rw_nvmem = { | |
158 | .attr = { | |
159 | .name = "nvmem", | |
160 | .mode = S_IWUSR | S_IRUGO, | |
161 | }, | |
162 | .read = bin_attr_nvmem_read, | |
163 | .write = bin_attr_nvmem_write, | |
164 | }; | |
165 | ||
166 | static struct bin_attribute *nvmem_bin_rw_attributes[] = { | |
167 | &bin_attr_rw_nvmem, | |
168 | NULL, | |
169 | }; | |
170 | ||
171 | static const struct attribute_group nvmem_bin_rw_group = { | |
172 | .bin_attrs = nvmem_bin_rw_attributes, | |
173 | }; | |
174 | ||
175 | static const struct attribute_group *nvmem_rw_dev_groups[] = { | |
176 | &nvmem_bin_rw_group, | |
177 | NULL, | |
178 | }; | |
179 | ||
180 | /* read only permission */ | |
181 | static struct bin_attribute bin_attr_ro_nvmem = { | |
182 | .attr = { | |
183 | .name = "nvmem", | |
184 | .mode = S_IRUGO, | |
185 | }, | |
186 | .read = bin_attr_nvmem_read, | |
187 | }; | |
188 | ||
189 | static struct bin_attribute *nvmem_bin_ro_attributes[] = { | |
190 | &bin_attr_ro_nvmem, | |
191 | NULL, | |
192 | }; | |
193 | ||
194 | static const struct attribute_group nvmem_bin_ro_group = { | |
195 | .bin_attrs = nvmem_bin_ro_attributes, | |
196 | }; | |
197 | ||
198 | static const struct attribute_group *nvmem_ro_dev_groups[] = { | |
199 | &nvmem_bin_ro_group, | |
200 | NULL, | |
201 | }; | |
202 | ||
811b0d65 AL |
203 | /* default read/write permissions, root only */ |
204 | static struct bin_attribute bin_attr_rw_root_nvmem = { | |
205 | .attr = { | |
206 | .name = "nvmem", | |
207 | .mode = S_IWUSR | S_IRUSR, | |
208 | }, | |
209 | .read = bin_attr_nvmem_read, | |
210 | .write = bin_attr_nvmem_write, | |
211 | }; | |
212 | ||
213 | static struct bin_attribute *nvmem_bin_rw_root_attributes[] = { | |
214 | &bin_attr_rw_root_nvmem, | |
215 | NULL, | |
216 | }; | |
217 | ||
218 | static const struct attribute_group nvmem_bin_rw_root_group = { | |
219 | .bin_attrs = nvmem_bin_rw_root_attributes, | |
220 | }; | |
221 | ||
222 | static const struct attribute_group *nvmem_rw_root_dev_groups[] = { | |
223 | &nvmem_bin_rw_root_group, | |
224 | NULL, | |
225 | }; | |
226 | ||
227 | /* read only permission, root only */ | |
228 | static struct bin_attribute bin_attr_ro_root_nvmem = { | |
229 | .attr = { | |
230 | .name = "nvmem", | |
231 | .mode = S_IRUSR, | |
232 | }, | |
233 | .read = bin_attr_nvmem_read, | |
234 | }; | |
235 | ||
236 | static struct bin_attribute *nvmem_bin_ro_root_attributes[] = { | |
237 | &bin_attr_ro_root_nvmem, | |
238 | NULL, | |
239 | }; | |
240 | ||
241 | static const struct attribute_group nvmem_bin_ro_root_group = { | |
242 | .bin_attrs = nvmem_bin_ro_root_attributes, | |
243 | }; | |
244 | ||
245 | static const struct attribute_group *nvmem_ro_root_dev_groups[] = { | |
246 | &nvmem_bin_ro_root_group, | |
247 | NULL, | |
248 | }; | |
249 | ||
eace75cf SK |
250 | static void nvmem_release(struct device *dev) |
251 | { | |
252 | struct nvmem_device *nvmem = to_nvmem_device(dev); | |
253 | ||
254 | ida_simple_remove(&nvmem_ida, nvmem->id); | |
255 | kfree(nvmem); | |
256 | } | |
257 | ||
258 | static const struct device_type nvmem_provider_type = { | |
259 | .release = nvmem_release, | |
260 | }; | |
261 | ||
262 | static struct bus_type nvmem_bus_type = { | |
263 | .name = "nvmem", | |
264 | }; | |
265 | ||
266 | static int of_nvmem_match(struct device *dev, void *nvmem_np) | |
267 | { | |
268 | return dev->of_node == nvmem_np; | |
269 | } | |
270 | ||
271 | static struct nvmem_device *of_nvmem_find(struct device_node *nvmem_np) | |
272 | { | |
273 | struct device *d; | |
274 | ||
275 | if (!nvmem_np) | |
276 | return NULL; | |
277 | ||
278 | d = bus_find_device(&nvmem_bus_type, NULL, nvmem_np, of_nvmem_match); | |
279 | ||
280 | if (!d) | |
281 | return NULL; | |
282 | ||
283 | return to_nvmem_device(d); | |
284 | } | |
285 | ||
286 | static struct nvmem_cell *nvmem_find_cell(const char *cell_id) | |
287 | { | |
288 | struct nvmem_cell *p; | |
289 | ||
666d6a36 HK |
290 | mutex_lock(&nvmem_cells_mutex); |
291 | ||
eace75cf | 292 | list_for_each_entry(p, &nvmem_cells, node) |
666d6a36 HK |
293 | if (p && !strcmp(p->name, cell_id)) { |
294 | mutex_unlock(&nvmem_cells_mutex); | |
eace75cf | 295 | return p; |
666d6a36 HK |
296 | } |
297 | ||
298 | mutex_unlock(&nvmem_cells_mutex); | |
eace75cf SK |
299 | |
300 | return NULL; | |
301 | } | |
302 | ||
303 | static void nvmem_cell_drop(struct nvmem_cell *cell) | |
304 | { | |
305 | mutex_lock(&nvmem_cells_mutex); | |
306 | list_del(&cell->node); | |
307 | mutex_unlock(&nvmem_cells_mutex); | |
308 | kfree(cell); | |
309 | } | |
310 | ||
311 | static void nvmem_device_remove_all_cells(const struct nvmem_device *nvmem) | |
312 | { | |
313 | struct nvmem_cell *cell; | |
314 | struct list_head *p, *n; | |
315 | ||
316 | list_for_each_safe(p, n, &nvmem_cells) { | |
317 | cell = list_entry(p, struct nvmem_cell, node); | |
318 | if (cell->nvmem == nvmem) | |
319 | nvmem_cell_drop(cell); | |
320 | } | |
321 | } | |
322 | ||
323 | static void nvmem_cell_add(struct nvmem_cell *cell) | |
324 | { | |
325 | mutex_lock(&nvmem_cells_mutex); | |
326 | list_add_tail(&cell->node, &nvmem_cells); | |
327 | mutex_unlock(&nvmem_cells_mutex); | |
328 | } | |
329 | ||
330 | static int nvmem_cell_info_to_nvmem_cell(struct nvmem_device *nvmem, | |
331 | const struct nvmem_cell_info *info, | |
332 | struct nvmem_cell *cell) | |
333 | { | |
334 | cell->nvmem = nvmem; | |
335 | cell->offset = info->offset; | |
336 | cell->bytes = info->bytes; | |
337 | cell->name = info->name; | |
338 | ||
339 | cell->bit_offset = info->bit_offset; | |
340 | cell->nbits = info->nbits; | |
341 | ||
342 | if (cell->nbits) | |
343 | cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset, | |
344 | BITS_PER_BYTE); | |
345 | ||
346 | if (!IS_ALIGNED(cell->offset, nvmem->stride)) { | |
347 | dev_err(&nvmem->dev, | |
348 | "cell %s unaligned to nvmem stride %d\n", | |
349 | cell->name, nvmem->stride); | |
350 | return -EINVAL; | |
351 | } | |
352 | ||
353 | return 0; | |
354 | } | |
355 | ||
356 | static int nvmem_add_cells(struct nvmem_device *nvmem, | |
357 | const struct nvmem_config *cfg) | |
358 | { | |
359 | struct nvmem_cell **cells; | |
360 | const struct nvmem_cell_info *info = cfg->cells; | |
361 | int i, rval; | |
362 | ||
363 | cells = kcalloc(cfg->ncells, sizeof(*cells), GFP_KERNEL); | |
364 | if (!cells) | |
365 | return -ENOMEM; | |
366 | ||
367 | for (i = 0; i < cfg->ncells; i++) { | |
368 | cells[i] = kzalloc(sizeof(**cells), GFP_KERNEL); | |
369 | if (!cells[i]) { | |
370 | rval = -ENOMEM; | |
371 | goto err; | |
372 | } | |
373 | ||
374 | rval = nvmem_cell_info_to_nvmem_cell(nvmem, &info[i], cells[i]); | |
287980e4 | 375 | if (rval) { |
eace75cf SK |
376 | kfree(cells[i]); |
377 | goto err; | |
378 | } | |
379 | ||
380 | nvmem_cell_add(cells[i]); | |
381 | } | |
382 | ||
383 | nvmem->ncells = cfg->ncells; | |
384 | /* remove tmp array */ | |
385 | kfree(cells); | |
386 | ||
387 | return 0; | |
388 | err: | |
dfdf1414 | 389 | while (i--) |
eace75cf SK |
390 | nvmem_cell_drop(cells[i]); |
391 | ||
dfdf1414 RV |
392 | kfree(cells); |
393 | ||
eace75cf SK |
394 | return rval; |
395 | } | |
396 | ||
b6c217ab AL |
397 | /* |
398 | * nvmem_setup_compat() - Create an additional binary entry in | |
399 | * drivers sys directory, to be backwards compatible with the older | |
400 | * drivers/misc/eeprom drivers. | |
401 | */ | |
402 | static int nvmem_setup_compat(struct nvmem_device *nvmem, | |
403 | const struct nvmem_config *config) | |
404 | { | |
405 | int rval; | |
406 | ||
407 | if (!config->base_dev) | |
408 | return -EINVAL; | |
409 | ||
410 | if (nvmem->read_only) | |
411 | nvmem->eeprom = bin_attr_ro_root_nvmem; | |
412 | else | |
413 | nvmem->eeprom = bin_attr_rw_root_nvmem; | |
414 | nvmem->eeprom.attr.name = "eeprom"; | |
415 | nvmem->eeprom.size = nvmem->size; | |
416 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
417 | nvmem->eeprom.attr.key = &eeprom_lock_key; | |
418 | #endif | |
419 | nvmem->eeprom.private = &nvmem->dev; | |
420 | nvmem->base_dev = config->base_dev; | |
421 | ||
422 | rval = device_create_bin_file(nvmem->base_dev, &nvmem->eeprom); | |
423 | if (rval) { | |
424 | dev_err(&nvmem->dev, | |
425 | "Failed to create eeprom binary file %d\n", rval); | |
426 | return rval; | |
427 | } | |
428 | ||
429 | nvmem->flags |= FLAG_COMPAT; | |
430 | ||
431 | return 0; | |
432 | } | |
433 | ||
eace75cf SK |
434 | /** |
435 | * nvmem_register() - Register a nvmem device for given nvmem_config. | |
436 | * Also creates an binary entry in /sys/bus/nvmem/devices/dev-name/nvmem | |
437 | * | |
438 | * @config: nvmem device configuration with which nvmem device is created. | |
439 | * | |
440 | * Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device | |
441 | * on success. | |
442 | */ | |
443 | ||
444 | struct nvmem_device *nvmem_register(const struct nvmem_config *config) | |
445 | { | |
446 | struct nvmem_device *nvmem; | |
447 | struct device_node *np; | |
eace75cf SK |
448 | int rval; |
449 | ||
450 | if (!config->dev) | |
451 | return ERR_PTR(-EINVAL); | |
452 | ||
eace75cf SK |
453 | nvmem = kzalloc(sizeof(*nvmem), GFP_KERNEL); |
454 | if (!nvmem) | |
455 | return ERR_PTR(-ENOMEM); | |
456 | ||
457 | rval = ida_simple_get(&nvmem_ida, 0, 0, GFP_KERNEL); | |
458 | if (rval < 0) { | |
459 | kfree(nvmem); | |
460 | return ERR_PTR(rval); | |
461 | } | |
462 | ||
463 | nvmem->id = rval; | |
eace75cf | 464 | nvmem->owner = config->owner; |
795ddd18 SK |
465 | nvmem->stride = config->stride; |
466 | nvmem->word_size = config->word_size; | |
467 | nvmem->size = config->size; | |
eace75cf SK |
468 | nvmem->dev.type = &nvmem_provider_type; |
469 | nvmem->dev.bus = &nvmem_bus_type; | |
470 | nvmem->dev.parent = config->dev; | |
795ddd18 SK |
471 | nvmem->priv = config->priv; |
472 | nvmem->reg_read = config->reg_read; | |
473 | nvmem->reg_write = config->reg_write; | |
eace75cf SK |
474 | np = config->dev->of_node; |
475 | nvmem->dev.of_node = np; | |
476 | dev_set_name(&nvmem->dev, "%s%d", | |
5253193d AB |
477 | config->name ? : "nvmem", |
478 | config->name ? config->id : nvmem->id); | |
eace75cf SK |
479 | |
480 | nvmem->read_only = of_property_read_bool(np, "read-only") | | |
481 | config->read_only; | |
482 | ||
811b0d65 AL |
483 | if (config->root_only) |
484 | nvmem->dev.groups = nvmem->read_only ? | |
485 | nvmem_ro_root_dev_groups : | |
486 | nvmem_rw_root_dev_groups; | |
487 | else | |
488 | nvmem->dev.groups = nvmem->read_only ? | |
489 | nvmem_ro_dev_groups : | |
490 | nvmem_rw_dev_groups; | |
eace75cf SK |
491 | |
492 | device_initialize(&nvmem->dev); | |
493 | ||
494 | dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name); | |
495 | ||
496 | rval = device_add(&nvmem->dev); | |
b6c217ab | 497 | if (rval) |
3360acdf | 498 | goto err_put_device; |
b6c217ab AL |
499 | |
500 | if (config->compat) { | |
501 | rval = nvmem_setup_compat(nvmem, config); | |
502 | if (rval) | |
3360acdf | 503 | goto err_device_del; |
eace75cf SK |
504 | } |
505 | ||
506 | if (config->cells) | |
507 | nvmem_add_cells(nvmem, config); | |
508 | ||
509 | return nvmem; | |
3360acdf JH |
510 | |
511 | err_device_del: | |
512 | device_del(&nvmem->dev); | |
513 | err_put_device: | |
514 | put_device(&nvmem->dev); | |
515 | ||
b6c217ab | 516 | return ERR_PTR(rval); |
eace75cf SK |
517 | } |
518 | EXPORT_SYMBOL_GPL(nvmem_register); | |
519 | ||
520 | /** | |
521 | * nvmem_unregister() - Unregister previously registered nvmem device | |
522 | * | |
523 | * @nvmem: Pointer to previously registered nvmem device. | |
524 | * | |
525 | * Return: Will be an negative on error or a zero on success. | |
526 | */ | |
527 | int nvmem_unregister(struct nvmem_device *nvmem) | |
528 | { | |
69aba794 SK |
529 | mutex_lock(&nvmem_mutex); |
530 | if (nvmem->users) { | |
531 | mutex_unlock(&nvmem_mutex); | |
eace75cf | 532 | return -EBUSY; |
69aba794 SK |
533 | } |
534 | mutex_unlock(&nvmem_mutex); | |
eace75cf | 535 | |
b6c217ab AL |
536 | if (nvmem->flags & FLAG_COMPAT) |
537 | device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom); | |
538 | ||
eace75cf SK |
539 | nvmem_device_remove_all_cells(nvmem); |
540 | device_del(&nvmem->dev); | |
79fbf046 | 541 | put_device(&nvmem->dev); |
eace75cf SK |
542 | |
543 | return 0; | |
544 | } | |
545 | EXPORT_SYMBOL_GPL(nvmem_unregister); | |
546 | ||
69aba794 SK |
547 | static struct nvmem_device *__nvmem_device_get(struct device_node *np, |
548 | struct nvmem_cell **cellp, | |
549 | const char *cell_id) | |
550 | { | |
551 | struct nvmem_device *nvmem = NULL; | |
552 | ||
553 | mutex_lock(&nvmem_mutex); | |
554 | ||
555 | if (np) { | |
556 | nvmem = of_nvmem_find(np); | |
557 | if (!nvmem) { | |
558 | mutex_unlock(&nvmem_mutex); | |
559 | return ERR_PTR(-EPROBE_DEFER); | |
560 | } | |
561 | } else { | |
562 | struct nvmem_cell *cell = nvmem_find_cell(cell_id); | |
563 | ||
564 | if (cell) { | |
565 | nvmem = cell->nvmem; | |
566 | *cellp = cell; | |
567 | } | |
568 | ||
569 | if (!nvmem) { | |
570 | mutex_unlock(&nvmem_mutex); | |
571 | return ERR_PTR(-ENOENT); | |
572 | } | |
573 | } | |
574 | ||
575 | nvmem->users++; | |
576 | mutex_unlock(&nvmem_mutex); | |
577 | ||
578 | if (!try_module_get(nvmem->owner)) { | |
579 | dev_err(&nvmem->dev, | |
580 | "could not increase module refcount for cell %s\n", | |
581 | nvmem->name); | |
582 | ||
583 | mutex_lock(&nvmem_mutex); | |
584 | nvmem->users--; | |
585 | mutex_unlock(&nvmem_mutex); | |
586 | ||
587 | return ERR_PTR(-EINVAL); | |
588 | } | |
589 | ||
590 | return nvmem; | |
591 | } | |
592 | ||
593 | static void __nvmem_device_put(struct nvmem_device *nvmem) | |
594 | { | |
595 | module_put(nvmem->owner); | |
596 | mutex_lock(&nvmem_mutex); | |
597 | nvmem->users--; | |
598 | mutex_unlock(&nvmem_mutex); | |
599 | } | |
600 | ||
e2a5402e SK |
601 | static int nvmem_match(struct device *dev, void *data) |
602 | { | |
603 | return !strcmp(dev_name(dev), data); | |
604 | } | |
605 | ||
606 | static struct nvmem_device *nvmem_find(const char *name) | |
607 | { | |
608 | struct device *d; | |
609 | ||
610 | d = bus_find_device(&nvmem_bus_type, NULL, (void *)name, nvmem_match); | |
611 | ||
612 | if (!d) | |
613 | return NULL; | |
614 | ||
615 | return to_nvmem_device(d); | |
616 | } | |
617 | ||
618 | #if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OF) | |
619 | /** | |
620 | * of_nvmem_device_get() - Get nvmem device from a given id | |
621 | * | |
29143268 | 622 | * @np: Device tree node that uses the nvmem device. |
e2a5402e SK |
623 | * @id: nvmem name from nvmem-names property. |
624 | * | |
625 | * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device | |
626 | * on success. | |
627 | */ | |
628 | struct nvmem_device *of_nvmem_device_get(struct device_node *np, const char *id) | |
629 | { | |
630 | ||
631 | struct device_node *nvmem_np; | |
632 | int index; | |
633 | ||
634 | index = of_property_match_string(np, "nvmem-names", id); | |
635 | ||
636 | nvmem_np = of_parse_phandle(np, "nvmem", index); | |
637 | if (!nvmem_np) | |
638 | return ERR_PTR(-EINVAL); | |
639 | ||
640 | return __nvmem_device_get(nvmem_np, NULL, NULL); | |
641 | } | |
642 | EXPORT_SYMBOL_GPL(of_nvmem_device_get); | |
643 | #endif | |
644 | ||
645 | /** | |
646 | * nvmem_device_get() - Get nvmem device from a given id | |
647 | * | |
29143268 VG |
648 | * @dev: Device that uses the nvmem device. |
649 | * @dev_name: name of the requested nvmem device. | |
e2a5402e SK |
650 | * |
651 | * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device | |
652 | * on success. | |
653 | */ | |
654 | struct nvmem_device *nvmem_device_get(struct device *dev, const char *dev_name) | |
655 | { | |
656 | if (dev->of_node) { /* try dt first */ | |
657 | struct nvmem_device *nvmem; | |
658 | ||
659 | nvmem = of_nvmem_device_get(dev->of_node, dev_name); | |
660 | ||
661 | if (!IS_ERR(nvmem) || PTR_ERR(nvmem) == -EPROBE_DEFER) | |
662 | return nvmem; | |
663 | ||
664 | } | |
665 | ||
666 | return nvmem_find(dev_name); | |
667 | } | |
668 | EXPORT_SYMBOL_GPL(nvmem_device_get); | |
669 | ||
670 | static int devm_nvmem_device_match(struct device *dev, void *res, void *data) | |
671 | { | |
672 | struct nvmem_device **nvmem = res; | |
673 | ||
674 | if (WARN_ON(!nvmem || !*nvmem)) | |
675 | return 0; | |
676 | ||
677 | return *nvmem == data; | |
678 | } | |
679 | ||
680 | static void devm_nvmem_device_release(struct device *dev, void *res) | |
681 | { | |
682 | nvmem_device_put(*(struct nvmem_device **)res); | |
683 | } | |
684 | ||
685 | /** | |
686 | * devm_nvmem_device_put() - put alredy got nvmem device | |
687 | * | |
29143268 | 688 | * @dev: Device that uses the nvmem device. |
e2a5402e SK |
689 | * @nvmem: pointer to nvmem device allocated by devm_nvmem_cell_get(), |
690 | * that needs to be released. | |
691 | */ | |
692 | void devm_nvmem_device_put(struct device *dev, struct nvmem_device *nvmem) | |
693 | { | |
694 | int ret; | |
695 | ||
696 | ret = devres_release(dev, devm_nvmem_device_release, | |
697 | devm_nvmem_device_match, nvmem); | |
698 | ||
699 | WARN_ON(ret); | |
700 | } | |
701 | EXPORT_SYMBOL_GPL(devm_nvmem_device_put); | |
702 | ||
703 | /** | |
704 | * nvmem_device_put() - put alredy got nvmem device | |
705 | * | |
706 | * @nvmem: pointer to nvmem device that needs to be released. | |
707 | */ | |
708 | void nvmem_device_put(struct nvmem_device *nvmem) | |
709 | { | |
710 | __nvmem_device_put(nvmem); | |
711 | } | |
712 | EXPORT_SYMBOL_GPL(nvmem_device_put); | |
713 | ||
714 | /** | |
715 | * devm_nvmem_device_get() - Get nvmem cell of device form a given id | |
716 | * | |
29143268 VG |
717 | * @dev: Device that requests the nvmem device. |
718 | * @id: name id for the requested nvmem device. | |
e2a5402e SK |
719 | * |
720 | * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_cell | |
721 | * on success. The nvmem_cell will be freed by the automatically once the | |
722 | * device is freed. | |
723 | */ | |
724 | struct nvmem_device *devm_nvmem_device_get(struct device *dev, const char *id) | |
725 | { | |
726 | struct nvmem_device **ptr, *nvmem; | |
727 | ||
728 | ptr = devres_alloc(devm_nvmem_device_release, sizeof(*ptr), GFP_KERNEL); | |
729 | if (!ptr) | |
730 | return ERR_PTR(-ENOMEM); | |
731 | ||
732 | nvmem = nvmem_device_get(dev, id); | |
733 | if (!IS_ERR(nvmem)) { | |
734 | *ptr = nvmem; | |
735 | devres_add(dev, ptr); | |
736 | } else { | |
737 | devres_free(ptr); | |
738 | } | |
739 | ||
740 | return nvmem; | |
741 | } | |
742 | EXPORT_SYMBOL_GPL(devm_nvmem_device_get); | |
743 | ||
69aba794 SK |
744 | static struct nvmem_cell *nvmem_cell_get_from_list(const char *cell_id) |
745 | { | |
746 | struct nvmem_cell *cell = NULL; | |
747 | struct nvmem_device *nvmem; | |
748 | ||
749 | nvmem = __nvmem_device_get(NULL, &cell, cell_id); | |
750 | if (IS_ERR(nvmem)) | |
751 | return ERR_CAST(nvmem); | |
752 | ||
753 | return cell; | |
754 | } | |
755 | ||
756 | #if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OF) | |
757 | /** | |
758 | * of_nvmem_cell_get() - Get a nvmem cell from given device node and cell id | |
759 | * | |
29143268 | 760 | * @np: Device tree node that uses the nvmem cell. |
fd0c478c VG |
761 | * @name: nvmem cell name from nvmem-cell-names property, or NULL |
762 | * for the cell at index 0 (the lone cell with no accompanying | |
763 | * nvmem-cell-names property). | |
69aba794 SK |
764 | * |
765 | * Return: Will be an ERR_PTR() on error or a valid pointer | |
766 | * to a struct nvmem_cell. The nvmem_cell will be freed by the | |
767 | * nvmem_cell_put(). | |
768 | */ | |
769 | struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, | |
770 | const char *name) | |
771 | { | |
772 | struct device_node *cell_np, *nvmem_np; | |
773 | struct nvmem_cell *cell; | |
774 | struct nvmem_device *nvmem; | |
775 | const __be32 *addr; | |
fd0c478c VG |
776 | int rval, len; |
777 | int index = 0; | |
69aba794 | 778 | |
fd0c478c VG |
779 | /* if cell name exists, find index to the name */ |
780 | if (name) | |
781 | index = of_property_match_string(np, "nvmem-cell-names", name); | |
69aba794 SK |
782 | |
783 | cell_np = of_parse_phandle(np, "nvmem-cells", index); | |
784 | if (!cell_np) | |
785 | return ERR_PTR(-EINVAL); | |
786 | ||
787 | nvmem_np = of_get_next_parent(cell_np); | |
788 | if (!nvmem_np) | |
789 | return ERR_PTR(-EINVAL); | |
790 | ||
791 | nvmem = __nvmem_device_get(nvmem_np, NULL, NULL); | |
792 | if (IS_ERR(nvmem)) | |
793 | return ERR_CAST(nvmem); | |
794 | ||
795 | addr = of_get_property(cell_np, "reg", &len); | |
796 | if (!addr || (len < 2 * sizeof(u32))) { | |
797 | dev_err(&nvmem->dev, "nvmem: invalid reg on %s\n", | |
798 | cell_np->full_name); | |
799 | rval = -EINVAL; | |
800 | goto err_mem; | |
801 | } | |
802 | ||
803 | cell = kzalloc(sizeof(*cell), GFP_KERNEL); | |
804 | if (!cell) { | |
805 | rval = -ENOMEM; | |
806 | goto err_mem; | |
807 | } | |
808 | ||
809 | cell->nvmem = nvmem; | |
810 | cell->offset = be32_to_cpup(addr++); | |
811 | cell->bytes = be32_to_cpup(addr); | |
812 | cell->name = cell_np->name; | |
813 | ||
814 | addr = of_get_property(cell_np, "bits", &len); | |
815 | if (addr && len == (2 * sizeof(u32))) { | |
816 | cell->bit_offset = be32_to_cpup(addr++); | |
817 | cell->nbits = be32_to_cpup(addr); | |
818 | } | |
819 | ||
820 | if (cell->nbits) | |
821 | cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset, | |
822 | BITS_PER_BYTE); | |
823 | ||
824 | if (!IS_ALIGNED(cell->offset, nvmem->stride)) { | |
825 | dev_err(&nvmem->dev, | |
826 | "cell %s unaligned to nvmem stride %d\n", | |
827 | cell->name, nvmem->stride); | |
828 | rval = -EINVAL; | |
829 | goto err_sanity; | |
830 | } | |
831 | ||
832 | nvmem_cell_add(cell); | |
833 | ||
834 | return cell; | |
835 | ||
836 | err_sanity: | |
837 | kfree(cell); | |
838 | ||
839 | err_mem: | |
840 | __nvmem_device_put(nvmem); | |
841 | ||
842 | return ERR_PTR(rval); | |
843 | } | |
844 | EXPORT_SYMBOL_GPL(of_nvmem_cell_get); | |
845 | #endif | |
846 | ||
847 | /** | |
848 | * nvmem_cell_get() - Get nvmem cell of device form a given cell name | |
849 | * | |
29143268 VG |
850 | * @dev: Device that requests the nvmem cell. |
851 | * @cell_id: nvmem cell name to get. | |
69aba794 SK |
852 | * |
853 | * Return: Will be an ERR_PTR() on error or a valid pointer | |
854 | * to a struct nvmem_cell. The nvmem_cell will be freed by the | |
855 | * nvmem_cell_put(). | |
856 | */ | |
857 | struct nvmem_cell *nvmem_cell_get(struct device *dev, const char *cell_id) | |
858 | { | |
859 | struct nvmem_cell *cell; | |
860 | ||
861 | if (dev->of_node) { /* try dt first */ | |
862 | cell = of_nvmem_cell_get(dev->of_node, cell_id); | |
863 | if (!IS_ERR(cell) || PTR_ERR(cell) == -EPROBE_DEFER) | |
864 | return cell; | |
865 | } | |
866 | ||
867 | return nvmem_cell_get_from_list(cell_id); | |
868 | } | |
869 | EXPORT_SYMBOL_GPL(nvmem_cell_get); | |
870 | ||
871 | static void devm_nvmem_cell_release(struct device *dev, void *res) | |
872 | { | |
873 | nvmem_cell_put(*(struct nvmem_cell **)res); | |
874 | } | |
875 | ||
876 | /** | |
877 | * devm_nvmem_cell_get() - Get nvmem cell of device form a given id | |
878 | * | |
29143268 VG |
879 | * @dev: Device that requests the nvmem cell. |
880 | * @id: nvmem cell name id to get. | |
69aba794 SK |
881 | * |
882 | * Return: Will be an ERR_PTR() on error or a valid pointer | |
883 | * to a struct nvmem_cell. The nvmem_cell will be freed by the | |
884 | * automatically once the device is freed. | |
885 | */ | |
886 | struct nvmem_cell *devm_nvmem_cell_get(struct device *dev, const char *id) | |
887 | { | |
888 | struct nvmem_cell **ptr, *cell; | |
889 | ||
890 | ptr = devres_alloc(devm_nvmem_cell_release, sizeof(*ptr), GFP_KERNEL); | |
891 | if (!ptr) | |
892 | return ERR_PTR(-ENOMEM); | |
893 | ||
894 | cell = nvmem_cell_get(dev, id); | |
895 | if (!IS_ERR(cell)) { | |
896 | *ptr = cell; | |
897 | devres_add(dev, ptr); | |
898 | } else { | |
899 | devres_free(ptr); | |
900 | } | |
901 | ||
902 | return cell; | |
903 | } | |
904 | EXPORT_SYMBOL_GPL(devm_nvmem_cell_get); | |
905 | ||
906 | static int devm_nvmem_cell_match(struct device *dev, void *res, void *data) | |
907 | { | |
908 | struct nvmem_cell **c = res; | |
909 | ||
910 | if (WARN_ON(!c || !*c)) | |
911 | return 0; | |
912 | ||
913 | return *c == data; | |
914 | } | |
915 | ||
916 | /** | |
917 | * devm_nvmem_cell_put() - Release previously allocated nvmem cell | |
918 | * from devm_nvmem_cell_get. | |
919 | * | |
29143268 VG |
920 | * @dev: Device that requests the nvmem cell. |
921 | * @cell: Previously allocated nvmem cell by devm_nvmem_cell_get(). | |
69aba794 SK |
922 | */ |
923 | void devm_nvmem_cell_put(struct device *dev, struct nvmem_cell *cell) | |
924 | { | |
925 | int ret; | |
926 | ||
927 | ret = devres_release(dev, devm_nvmem_cell_release, | |
928 | devm_nvmem_cell_match, cell); | |
929 | ||
930 | WARN_ON(ret); | |
931 | } | |
932 | EXPORT_SYMBOL(devm_nvmem_cell_put); | |
933 | ||
934 | /** | |
935 | * nvmem_cell_put() - Release previously allocated nvmem cell. | |
936 | * | |
29143268 | 937 | * @cell: Previously allocated nvmem cell by nvmem_cell_get(). |
69aba794 SK |
938 | */ |
939 | void nvmem_cell_put(struct nvmem_cell *cell) | |
940 | { | |
941 | struct nvmem_device *nvmem = cell->nvmem; | |
942 | ||
943 | __nvmem_device_put(nvmem); | |
944 | nvmem_cell_drop(cell); | |
945 | } | |
946 | EXPORT_SYMBOL_GPL(nvmem_cell_put); | |
947 | ||
948 | static inline void nvmem_shift_read_buffer_in_place(struct nvmem_cell *cell, | |
949 | void *buf) | |
950 | { | |
951 | u8 *p, *b; | |
952 | int i, bit_offset = cell->bit_offset; | |
953 | ||
954 | p = b = buf; | |
955 | if (bit_offset) { | |
956 | /* First shift */ | |
957 | *b++ >>= bit_offset; | |
958 | ||
959 | /* setup rest of the bytes if any */ | |
960 | for (i = 1; i < cell->bytes; i++) { | |
961 | /* Get bits from next byte and shift them towards msb */ | |
962 | *p |= *b << (BITS_PER_BYTE - bit_offset); | |
963 | ||
964 | p = b; | |
965 | *b++ >>= bit_offset; | |
966 | } | |
967 | ||
968 | /* result fits in less bytes */ | |
969 | if (cell->bytes != DIV_ROUND_UP(cell->nbits, BITS_PER_BYTE)) | |
970 | *p-- = 0; | |
971 | } | |
972 | /* clear msb bits if any leftover in the last byte */ | |
973 | *p &= GENMASK((cell->nbits%BITS_PER_BYTE) - 1, 0); | |
974 | } | |
975 | ||
976 | static int __nvmem_cell_read(struct nvmem_device *nvmem, | |
977 | struct nvmem_cell *cell, | |
978 | void *buf, size_t *len) | |
979 | { | |
980 | int rc; | |
981 | ||
795ddd18 | 982 | rc = nvmem_reg_read(nvmem, cell->offset, buf, cell->bytes); |
69aba794 | 983 | |
287980e4 | 984 | if (rc) |
69aba794 SK |
985 | return rc; |
986 | ||
987 | /* shift bits in-place */ | |
cbf854ab | 988 | if (cell->bit_offset || cell->nbits) |
69aba794 SK |
989 | nvmem_shift_read_buffer_in_place(cell, buf); |
990 | ||
3b4a6877 VG |
991 | if (len) |
992 | *len = cell->bytes; | |
69aba794 SK |
993 | |
994 | return 0; | |
995 | } | |
996 | ||
997 | /** | |
998 | * nvmem_cell_read() - Read a given nvmem cell | |
999 | * | |
1000 | * @cell: nvmem cell to be read. | |
3b4a6877 VG |
1001 | * @len: pointer to length of cell which will be populated on successful read; |
1002 | * can be NULL. | |
69aba794 | 1003 | * |
b577fafc BN |
1004 | * Return: ERR_PTR() on error or a valid pointer to a buffer on success. The |
1005 | * buffer should be freed by the consumer with a kfree(). | |
69aba794 SK |
1006 | */ |
1007 | void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len) | |
1008 | { | |
1009 | struct nvmem_device *nvmem = cell->nvmem; | |
1010 | u8 *buf; | |
1011 | int rc; | |
1012 | ||
795ddd18 | 1013 | if (!nvmem) |
69aba794 SK |
1014 | return ERR_PTR(-EINVAL); |
1015 | ||
1016 | buf = kzalloc(cell->bytes, GFP_KERNEL); | |
1017 | if (!buf) | |
1018 | return ERR_PTR(-ENOMEM); | |
1019 | ||
1020 | rc = __nvmem_cell_read(nvmem, cell, buf, len); | |
287980e4 | 1021 | if (rc) { |
69aba794 SK |
1022 | kfree(buf); |
1023 | return ERR_PTR(rc); | |
1024 | } | |
1025 | ||
1026 | return buf; | |
1027 | } | |
1028 | EXPORT_SYMBOL_GPL(nvmem_cell_read); | |
1029 | ||
1030 | static inline void *nvmem_cell_prepare_write_buffer(struct nvmem_cell *cell, | |
1031 | u8 *_buf, int len) | |
1032 | { | |
1033 | struct nvmem_device *nvmem = cell->nvmem; | |
1034 | int i, rc, nbits, bit_offset = cell->bit_offset; | |
1035 | u8 v, *p, *buf, *b, pbyte, pbits; | |
1036 | ||
1037 | nbits = cell->nbits; | |
1038 | buf = kzalloc(cell->bytes, GFP_KERNEL); | |
1039 | if (!buf) | |
1040 | return ERR_PTR(-ENOMEM); | |
1041 | ||
1042 | memcpy(buf, _buf, len); | |
1043 | p = b = buf; | |
1044 | ||
1045 | if (bit_offset) { | |
1046 | pbyte = *b; | |
1047 | *b <<= bit_offset; | |
1048 | ||
1049 | /* setup the first byte with lsb bits from nvmem */ | |
795ddd18 | 1050 | rc = nvmem_reg_read(nvmem, cell->offset, &v, 1); |
69aba794 SK |
1051 | *b++ |= GENMASK(bit_offset - 1, 0) & v; |
1052 | ||
1053 | /* setup rest of the byte if any */ | |
1054 | for (i = 1; i < cell->bytes; i++) { | |
1055 | /* Get last byte bits and shift them towards lsb */ | |
1056 | pbits = pbyte >> (BITS_PER_BYTE - 1 - bit_offset); | |
1057 | pbyte = *b; | |
1058 | p = b; | |
1059 | *b <<= bit_offset; | |
1060 | *b++ |= pbits; | |
1061 | } | |
1062 | } | |
1063 | ||
1064 | /* if it's not end on byte boundary */ | |
1065 | if ((nbits + bit_offset) % BITS_PER_BYTE) { | |
1066 | /* setup the last byte with msb bits from nvmem */ | |
795ddd18 | 1067 | rc = nvmem_reg_read(nvmem, |
69aba794 SK |
1068 | cell->offset + cell->bytes - 1, &v, 1); |
1069 | *p |= GENMASK(7, (nbits + bit_offset) % BITS_PER_BYTE) & v; | |
1070 | ||
1071 | } | |
1072 | ||
1073 | return buf; | |
1074 | } | |
1075 | ||
1076 | /** | |
1077 | * nvmem_cell_write() - Write to a given nvmem cell | |
1078 | * | |
1079 | * @cell: nvmem cell to be written. | |
1080 | * @buf: Buffer to be written. | |
1081 | * @len: length of buffer to be written to nvmem cell. | |
1082 | * | |
1083 | * Return: length of bytes written or negative on failure. | |
1084 | */ | |
1085 | int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len) | |
1086 | { | |
1087 | struct nvmem_device *nvmem = cell->nvmem; | |
1088 | int rc; | |
1089 | ||
795ddd18 | 1090 | if (!nvmem || nvmem->read_only || |
69aba794 SK |
1091 | (cell->bit_offset == 0 && len != cell->bytes)) |
1092 | return -EINVAL; | |
1093 | ||
1094 | if (cell->bit_offset || cell->nbits) { | |
1095 | buf = nvmem_cell_prepare_write_buffer(cell, buf, len); | |
1096 | if (IS_ERR(buf)) | |
1097 | return PTR_ERR(buf); | |
1098 | } | |
1099 | ||
795ddd18 | 1100 | rc = nvmem_reg_write(nvmem, cell->offset, buf, cell->bytes); |
69aba794 SK |
1101 | |
1102 | /* free the tmp buffer */ | |
ace22170 | 1103 | if (cell->bit_offset || cell->nbits) |
69aba794 SK |
1104 | kfree(buf); |
1105 | ||
287980e4 | 1106 | if (rc) |
69aba794 SK |
1107 | return rc; |
1108 | ||
1109 | return len; | |
1110 | } | |
1111 | EXPORT_SYMBOL_GPL(nvmem_cell_write); | |
1112 | ||
e2a5402e SK |
1113 | /** |
1114 | * nvmem_device_cell_read() - Read a given nvmem device and cell | |
1115 | * | |
1116 | * @nvmem: nvmem device to read from. | |
1117 | * @info: nvmem cell info to be read. | |
1118 | * @buf: buffer pointer which will be populated on successful read. | |
1119 | * | |
1120 | * Return: length of successful bytes read on success and negative | |
1121 | * error code on error. | |
1122 | */ | |
1123 | ssize_t nvmem_device_cell_read(struct nvmem_device *nvmem, | |
1124 | struct nvmem_cell_info *info, void *buf) | |
1125 | { | |
1126 | struct nvmem_cell cell; | |
1127 | int rc; | |
1128 | ssize_t len; | |
1129 | ||
795ddd18 | 1130 | if (!nvmem) |
e2a5402e SK |
1131 | return -EINVAL; |
1132 | ||
1133 | rc = nvmem_cell_info_to_nvmem_cell(nvmem, info, &cell); | |
287980e4 | 1134 | if (rc) |
e2a5402e SK |
1135 | return rc; |
1136 | ||
1137 | rc = __nvmem_cell_read(nvmem, &cell, buf, &len); | |
287980e4 | 1138 | if (rc) |
e2a5402e SK |
1139 | return rc; |
1140 | ||
1141 | return len; | |
1142 | } | |
1143 | EXPORT_SYMBOL_GPL(nvmem_device_cell_read); | |
1144 | ||
1145 | /** | |
1146 | * nvmem_device_cell_write() - Write cell to a given nvmem device | |
1147 | * | |
1148 | * @nvmem: nvmem device to be written to. | |
29143268 | 1149 | * @info: nvmem cell info to be written. |
e2a5402e SK |
1150 | * @buf: buffer to be written to cell. |
1151 | * | |
1152 | * Return: length of bytes written or negative error code on failure. | |
1153 | * */ | |
1154 | int nvmem_device_cell_write(struct nvmem_device *nvmem, | |
1155 | struct nvmem_cell_info *info, void *buf) | |
1156 | { | |
1157 | struct nvmem_cell cell; | |
1158 | int rc; | |
1159 | ||
795ddd18 | 1160 | if (!nvmem) |
e2a5402e SK |
1161 | return -EINVAL; |
1162 | ||
1163 | rc = nvmem_cell_info_to_nvmem_cell(nvmem, info, &cell); | |
287980e4 | 1164 | if (rc) |
e2a5402e SK |
1165 | return rc; |
1166 | ||
1167 | return nvmem_cell_write(&cell, buf, cell.bytes); | |
1168 | } | |
1169 | EXPORT_SYMBOL_GPL(nvmem_device_cell_write); | |
1170 | ||
1171 | /** | |
1172 | * nvmem_device_read() - Read from a given nvmem device | |
1173 | * | |
1174 | * @nvmem: nvmem device to read from. | |
1175 | * @offset: offset in nvmem device. | |
1176 | * @bytes: number of bytes to read. | |
1177 | * @buf: buffer pointer which will be populated on successful read. | |
1178 | * | |
1179 | * Return: length of successful bytes read on success and negative | |
1180 | * error code on error. | |
1181 | */ | |
1182 | int nvmem_device_read(struct nvmem_device *nvmem, | |
1183 | unsigned int offset, | |
1184 | size_t bytes, void *buf) | |
1185 | { | |
1186 | int rc; | |
1187 | ||
795ddd18 | 1188 | if (!nvmem) |
e2a5402e SK |
1189 | return -EINVAL; |
1190 | ||
795ddd18 | 1191 | rc = nvmem_reg_read(nvmem, offset, buf, bytes); |
e2a5402e | 1192 | |
287980e4 | 1193 | if (rc) |
e2a5402e SK |
1194 | return rc; |
1195 | ||
1196 | return bytes; | |
1197 | } | |
1198 | EXPORT_SYMBOL_GPL(nvmem_device_read); | |
1199 | ||
1200 | /** | |
1201 | * nvmem_device_write() - Write cell to a given nvmem device | |
1202 | * | |
1203 | * @nvmem: nvmem device to be written to. | |
1204 | * @offset: offset in nvmem device. | |
1205 | * @bytes: number of bytes to write. | |
1206 | * @buf: buffer to be written. | |
1207 | * | |
1208 | * Return: length of bytes written or negative error code on failure. | |
1209 | * */ | |
1210 | int nvmem_device_write(struct nvmem_device *nvmem, | |
1211 | unsigned int offset, | |
1212 | size_t bytes, void *buf) | |
1213 | { | |
1214 | int rc; | |
1215 | ||
795ddd18 | 1216 | if (!nvmem) |
e2a5402e SK |
1217 | return -EINVAL; |
1218 | ||
795ddd18 | 1219 | rc = nvmem_reg_write(nvmem, offset, buf, bytes); |
e2a5402e | 1220 | |
287980e4 | 1221 | if (rc) |
e2a5402e SK |
1222 | return rc; |
1223 | ||
1224 | ||
1225 | return bytes; | |
1226 | } | |
1227 | EXPORT_SYMBOL_GPL(nvmem_device_write); | |
1228 | ||
eace75cf SK |
1229 | static int __init nvmem_init(void) |
1230 | { | |
1231 | return bus_register(&nvmem_bus_type); | |
1232 | } | |
1233 | ||
1234 | static void __exit nvmem_exit(void) | |
1235 | { | |
1236 | bus_unregister(&nvmem_bus_type); | |
1237 | } | |
1238 | ||
1239 | subsys_initcall(nvmem_init); | |
1240 | module_exit(nvmem_exit); | |
1241 | ||
1242 | MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org"); | |
1243 | MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com"); | |
1244 | MODULE_DESCRIPTION("nvmem Driver Core"); | |
1245 | MODULE_LICENSE("GPL v2"); |