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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) |
38b0774c | 138 | return -EFBIG; |
eace75cf | 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) |
fd086113 | 293 | if (!strcmp(p->name, cell_id)) { |
666d6a36 | 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; |
17eb18d6 MY |
465 | if (!nvmem->owner && config->dev->driver) |
466 | nvmem->owner = config->dev->driver->owner; | |
795ddd18 SK |
467 | nvmem->stride = config->stride; |
468 | nvmem->word_size = config->word_size; | |
469 | nvmem->size = config->size; | |
eace75cf SK |
470 | nvmem->dev.type = &nvmem_provider_type; |
471 | nvmem->dev.bus = &nvmem_bus_type; | |
472 | nvmem->dev.parent = config->dev; | |
795ddd18 SK |
473 | nvmem->priv = config->priv; |
474 | nvmem->reg_read = config->reg_read; | |
475 | nvmem->reg_write = config->reg_write; | |
eace75cf SK |
476 | np = config->dev->of_node; |
477 | nvmem->dev.of_node = np; | |
478 | dev_set_name(&nvmem->dev, "%s%d", | |
5253193d AB |
479 | config->name ? : "nvmem", |
480 | config->name ? config->id : nvmem->id); | |
eace75cf SK |
481 | |
482 | nvmem->read_only = of_property_read_bool(np, "read-only") | | |
483 | config->read_only; | |
484 | ||
811b0d65 AL |
485 | if (config->root_only) |
486 | nvmem->dev.groups = nvmem->read_only ? | |
487 | nvmem_ro_root_dev_groups : | |
488 | nvmem_rw_root_dev_groups; | |
489 | else | |
490 | nvmem->dev.groups = nvmem->read_only ? | |
491 | nvmem_ro_dev_groups : | |
492 | nvmem_rw_dev_groups; | |
eace75cf SK |
493 | |
494 | device_initialize(&nvmem->dev); | |
495 | ||
496 | dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name); | |
497 | ||
498 | rval = device_add(&nvmem->dev); | |
b6c217ab | 499 | if (rval) |
3360acdf | 500 | goto err_put_device; |
b6c217ab AL |
501 | |
502 | if (config->compat) { | |
503 | rval = nvmem_setup_compat(nvmem, config); | |
504 | if (rval) | |
3360acdf | 505 | goto err_device_del; |
eace75cf SK |
506 | } |
507 | ||
508 | if (config->cells) | |
509 | nvmem_add_cells(nvmem, config); | |
510 | ||
511 | return nvmem; | |
3360acdf JH |
512 | |
513 | err_device_del: | |
514 | device_del(&nvmem->dev); | |
515 | err_put_device: | |
516 | put_device(&nvmem->dev); | |
517 | ||
b6c217ab | 518 | return ERR_PTR(rval); |
eace75cf SK |
519 | } |
520 | EXPORT_SYMBOL_GPL(nvmem_register); | |
521 | ||
522 | /** | |
523 | * nvmem_unregister() - Unregister previously registered nvmem device | |
524 | * | |
525 | * @nvmem: Pointer to previously registered nvmem device. | |
526 | * | |
527 | * Return: Will be an negative on error or a zero on success. | |
528 | */ | |
529 | int nvmem_unregister(struct nvmem_device *nvmem) | |
530 | { | |
69aba794 SK |
531 | mutex_lock(&nvmem_mutex); |
532 | if (nvmem->users) { | |
533 | mutex_unlock(&nvmem_mutex); | |
eace75cf | 534 | return -EBUSY; |
69aba794 SK |
535 | } |
536 | mutex_unlock(&nvmem_mutex); | |
eace75cf | 537 | |
b6c217ab AL |
538 | if (nvmem->flags & FLAG_COMPAT) |
539 | device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom); | |
540 | ||
eace75cf SK |
541 | nvmem_device_remove_all_cells(nvmem); |
542 | device_del(&nvmem->dev); | |
79fbf046 | 543 | put_device(&nvmem->dev); |
eace75cf SK |
544 | |
545 | return 0; | |
546 | } | |
547 | EXPORT_SYMBOL_GPL(nvmem_unregister); | |
548 | ||
69aba794 SK |
549 | static struct nvmem_device *__nvmem_device_get(struct device_node *np, |
550 | struct nvmem_cell **cellp, | |
551 | const char *cell_id) | |
552 | { | |
553 | struct nvmem_device *nvmem = NULL; | |
554 | ||
555 | mutex_lock(&nvmem_mutex); | |
556 | ||
557 | if (np) { | |
558 | nvmem = of_nvmem_find(np); | |
559 | if (!nvmem) { | |
560 | mutex_unlock(&nvmem_mutex); | |
561 | return ERR_PTR(-EPROBE_DEFER); | |
562 | } | |
563 | } else { | |
564 | struct nvmem_cell *cell = nvmem_find_cell(cell_id); | |
565 | ||
566 | if (cell) { | |
567 | nvmem = cell->nvmem; | |
568 | *cellp = cell; | |
569 | } | |
570 | ||
571 | if (!nvmem) { | |
572 | mutex_unlock(&nvmem_mutex); | |
573 | return ERR_PTR(-ENOENT); | |
574 | } | |
575 | } | |
576 | ||
577 | nvmem->users++; | |
578 | mutex_unlock(&nvmem_mutex); | |
579 | ||
580 | if (!try_module_get(nvmem->owner)) { | |
581 | dev_err(&nvmem->dev, | |
582 | "could not increase module refcount for cell %s\n", | |
583 | nvmem->name); | |
584 | ||
585 | mutex_lock(&nvmem_mutex); | |
586 | nvmem->users--; | |
587 | mutex_unlock(&nvmem_mutex); | |
588 | ||
589 | return ERR_PTR(-EINVAL); | |
590 | } | |
591 | ||
592 | return nvmem; | |
593 | } | |
594 | ||
595 | static void __nvmem_device_put(struct nvmem_device *nvmem) | |
596 | { | |
597 | module_put(nvmem->owner); | |
598 | mutex_lock(&nvmem_mutex); | |
599 | nvmem->users--; | |
600 | mutex_unlock(&nvmem_mutex); | |
601 | } | |
602 | ||
e2a5402e SK |
603 | static struct nvmem_device *nvmem_find(const char *name) |
604 | { | |
605 | struct device *d; | |
606 | ||
9f3044c3 | 607 | d = bus_find_device_by_name(&nvmem_bus_type, NULL, name); |
e2a5402e SK |
608 | |
609 | if (!d) | |
610 | return NULL; | |
611 | ||
612 | return to_nvmem_device(d); | |
613 | } | |
614 | ||
e701c67c | 615 | #if IS_ENABLED(CONFIG_OF) |
e2a5402e SK |
616 | /** |
617 | * of_nvmem_device_get() - Get nvmem device from a given id | |
618 | * | |
29143268 | 619 | * @np: Device tree node that uses the nvmem device. |
e2a5402e SK |
620 | * @id: nvmem name from nvmem-names property. |
621 | * | |
622 | * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device | |
623 | * on success. | |
624 | */ | |
625 | struct nvmem_device *of_nvmem_device_get(struct device_node *np, const char *id) | |
626 | { | |
627 | ||
628 | struct device_node *nvmem_np; | |
629 | int index; | |
630 | ||
631 | index = of_property_match_string(np, "nvmem-names", id); | |
632 | ||
633 | nvmem_np = of_parse_phandle(np, "nvmem", index); | |
634 | if (!nvmem_np) | |
635 | return ERR_PTR(-EINVAL); | |
636 | ||
637 | return __nvmem_device_get(nvmem_np, NULL, NULL); | |
638 | } | |
639 | EXPORT_SYMBOL_GPL(of_nvmem_device_get); | |
640 | #endif | |
641 | ||
642 | /** | |
643 | * nvmem_device_get() - Get nvmem device from a given id | |
644 | * | |
29143268 VG |
645 | * @dev: Device that uses the nvmem device. |
646 | * @dev_name: name of the requested nvmem device. | |
e2a5402e SK |
647 | * |
648 | * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device | |
649 | * on success. | |
650 | */ | |
651 | struct nvmem_device *nvmem_device_get(struct device *dev, const char *dev_name) | |
652 | { | |
653 | if (dev->of_node) { /* try dt first */ | |
654 | struct nvmem_device *nvmem; | |
655 | ||
656 | nvmem = of_nvmem_device_get(dev->of_node, dev_name); | |
657 | ||
658 | if (!IS_ERR(nvmem) || PTR_ERR(nvmem) == -EPROBE_DEFER) | |
659 | return nvmem; | |
660 | ||
661 | } | |
662 | ||
663 | return nvmem_find(dev_name); | |
664 | } | |
665 | EXPORT_SYMBOL_GPL(nvmem_device_get); | |
666 | ||
667 | static int devm_nvmem_device_match(struct device *dev, void *res, void *data) | |
668 | { | |
669 | struct nvmem_device **nvmem = res; | |
670 | ||
671 | if (WARN_ON(!nvmem || !*nvmem)) | |
672 | return 0; | |
673 | ||
674 | return *nvmem == data; | |
675 | } | |
676 | ||
677 | static void devm_nvmem_device_release(struct device *dev, void *res) | |
678 | { | |
679 | nvmem_device_put(*(struct nvmem_device **)res); | |
680 | } | |
681 | ||
682 | /** | |
683 | * devm_nvmem_device_put() - put alredy got nvmem device | |
684 | * | |
29143268 | 685 | * @dev: Device that uses the nvmem device. |
e2a5402e SK |
686 | * @nvmem: pointer to nvmem device allocated by devm_nvmem_cell_get(), |
687 | * that needs to be released. | |
688 | */ | |
689 | void devm_nvmem_device_put(struct device *dev, struct nvmem_device *nvmem) | |
690 | { | |
691 | int ret; | |
692 | ||
693 | ret = devres_release(dev, devm_nvmem_device_release, | |
694 | devm_nvmem_device_match, nvmem); | |
695 | ||
696 | WARN_ON(ret); | |
697 | } | |
698 | EXPORT_SYMBOL_GPL(devm_nvmem_device_put); | |
699 | ||
700 | /** | |
701 | * nvmem_device_put() - put alredy got nvmem device | |
702 | * | |
703 | * @nvmem: pointer to nvmem device that needs to be released. | |
704 | */ | |
705 | void nvmem_device_put(struct nvmem_device *nvmem) | |
706 | { | |
707 | __nvmem_device_put(nvmem); | |
708 | } | |
709 | EXPORT_SYMBOL_GPL(nvmem_device_put); | |
710 | ||
711 | /** | |
712 | * devm_nvmem_device_get() - Get nvmem cell of device form a given id | |
713 | * | |
29143268 VG |
714 | * @dev: Device that requests the nvmem device. |
715 | * @id: name id for the requested nvmem device. | |
e2a5402e SK |
716 | * |
717 | * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_cell | |
718 | * on success. The nvmem_cell will be freed by the automatically once the | |
719 | * device is freed. | |
720 | */ | |
721 | struct nvmem_device *devm_nvmem_device_get(struct device *dev, const char *id) | |
722 | { | |
723 | struct nvmem_device **ptr, *nvmem; | |
724 | ||
725 | ptr = devres_alloc(devm_nvmem_device_release, sizeof(*ptr), GFP_KERNEL); | |
726 | if (!ptr) | |
727 | return ERR_PTR(-ENOMEM); | |
728 | ||
729 | nvmem = nvmem_device_get(dev, id); | |
730 | if (!IS_ERR(nvmem)) { | |
731 | *ptr = nvmem; | |
732 | devres_add(dev, ptr); | |
733 | } else { | |
734 | devres_free(ptr); | |
735 | } | |
736 | ||
737 | return nvmem; | |
738 | } | |
739 | EXPORT_SYMBOL_GPL(devm_nvmem_device_get); | |
740 | ||
69aba794 SK |
741 | static struct nvmem_cell *nvmem_cell_get_from_list(const char *cell_id) |
742 | { | |
743 | struct nvmem_cell *cell = NULL; | |
744 | struct nvmem_device *nvmem; | |
745 | ||
746 | nvmem = __nvmem_device_get(NULL, &cell, cell_id); | |
747 | if (IS_ERR(nvmem)) | |
748 | return ERR_CAST(nvmem); | |
749 | ||
750 | return cell; | |
751 | } | |
752 | ||
e701c67c | 753 | #if IS_ENABLED(CONFIG_OF) |
69aba794 SK |
754 | /** |
755 | * of_nvmem_cell_get() - Get a nvmem cell from given device node and cell id | |
756 | * | |
29143268 | 757 | * @np: Device tree node that uses the nvmem cell. |
fd0c478c VG |
758 | * @name: nvmem cell name from nvmem-cell-names property, or NULL |
759 | * for the cell at index 0 (the lone cell with no accompanying | |
760 | * nvmem-cell-names property). | |
69aba794 SK |
761 | * |
762 | * Return: Will be an ERR_PTR() on error or a valid pointer | |
763 | * to a struct nvmem_cell. The nvmem_cell will be freed by the | |
764 | * nvmem_cell_put(). | |
765 | */ | |
766 | struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, | |
767 | const char *name) | |
768 | { | |
769 | struct device_node *cell_np, *nvmem_np; | |
770 | struct nvmem_cell *cell; | |
771 | struct nvmem_device *nvmem; | |
772 | const __be32 *addr; | |
fd0c478c VG |
773 | int rval, len; |
774 | int index = 0; | |
69aba794 | 775 | |
fd0c478c VG |
776 | /* if cell name exists, find index to the name */ |
777 | if (name) | |
778 | index = of_property_match_string(np, "nvmem-cell-names", name); | |
69aba794 SK |
779 | |
780 | cell_np = of_parse_phandle(np, "nvmem-cells", index); | |
781 | if (!cell_np) | |
782 | return ERR_PTR(-EINVAL); | |
783 | ||
784 | nvmem_np = of_get_next_parent(cell_np); | |
785 | if (!nvmem_np) | |
786 | return ERR_PTR(-EINVAL); | |
787 | ||
788 | nvmem = __nvmem_device_get(nvmem_np, NULL, NULL); | |
aad8d097 | 789 | of_node_put(nvmem_np); |
69aba794 SK |
790 | if (IS_ERR(nvmem)) |
791 | return ERR_CAST(nvmem); | |
792 | ||
793 | addr = of_get_property(cell_np, "reg", &len); | |
794 | if (!addr || (len < 2 * sizeof(u32))) { | |
5f214ccd RH |
795 | dev_err(&nvmem->dev, "nvmem: invalid reg on %pOF\n", |
796 | cell_np); | |
69aba794 SK |
797 | rval = -EINVAL; |
798 | goto err_mem; | |
799 | } | |
800 | ||
801 | cell = kzalloc(sizeof(*cell), GFP_KERNEL); | |
802 | if (!cell) { | |
803 | rval = -ENOMEM; | |
804 | goto err_mem; | |
805 | } | |
806 | ||
807 | cell->nvmem = nvmem; | |
808 | cell->offset = be32_to_cpup(addr++); | |
809 | cell->bytes = be32_to_cpup(addr); | |
810 | cell->name = cell_np->name; | |
811 | ||
812 | addr = of_get_property(cell_np, "bits", &len); | |
813 | if (addr && len == (2 * sizeof(u32))) { | |
814 | cell->bit_offset = be32_to_cpup(addr++); | |
815 | cell->nbits = be32_to_cpup(addr); | |
816 | } | |
817 | ||
818 | if (cell->nbits) | |
819 | cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset, | |
820 | BITS_PER_BYTE); | |
821 | ||
822 | if (!IS_ALIGNED(cell->offset, nvmem->stride)) { | |
823 | dev_err(&nvmem->dev, | |
824 | "cell %s unaligned to nvmem stride %d\n", | |
825 | cell->name, nvmem->stride); | |
826 | rval = -EINVAL; | |
827 | goto err_sanity; | |
828 | } | |
829 | ||
830 | nvmem_cell_add(cell); | |
831 | ||
832 | return cell; | |
833 | ||
834 | err_sanity: | |
835 | kfree(cell); | |
836 | ||
837 | err_mem: | |
838 | __nvmem_device_put(nvmem); | |
839 | ||
840 | return ERR_PTR(rval); | |
841 | } | |
842 | EXPORT_SYMBOL_GPL(of_nvmem_cell_get); | |
843 | #endif | |
844 | ||
845 | /** | |
846 | * nvmem_cell_get() - Get nvmem cell of device form a given cell name | |
847 | * | |
29143268 VG |
848 | * @dev: Device that requests the nvmem cell. |
849 | * @cell_id: nvmem cell name to get. | |
69aba794 SK |
850 | * |
851 | * Return: Will be an ERR_PTR() on error or a valid pointer | |
852 | * to a struct nvmem_cell. The nvmem_cell will be freed by the | |
853 | * nvmem_cell_put(). | |
854 | */ | |
855 | struct nvmem_cell *nvmem_cell_get(struct device *dev, const char *cell_id) | |
856 | { | |
857 | struct nvmem_cell *cell; | |
858 | ||
859 | if (dev->of_node) { /* try dt first */ | |
860 | cell = of_nvmem_cell_get(dev->of_node, cell_id); | |
861 | if (!IS_ERR(cell) || PTR_ERR(cell) == -EPROBE_DEFER) | |
862 | return cell; | |
863 | } | |
864 | ||
865 | return nvmem_cell_get_from_list(cell_id); | |
866 | } | |
867 | EXPORT_SYMBOL_GPL(nvmem_cell_get); | |
868 | ||
869 | static void devm_nvmem_cell_release(struct device *dev, void *res) | |
870 | { | |
871 | nvmem_cell_put(*(struct nvmem_cell **)res); | |
872 | } | |
873 | ||
874 | /** | |
875 | * devm_nvmem_cell_get() - Get nvmem cell of device form a given id | |
876 | * | |
29143268 VG |
877 | * @dev: Device that requests the nvmem cell. |
878 | * @id: nvmem cell name id to get. | |
69aba794 SK |
879 | * |
880 | * Return: Will be an ERR_PTR() on error or a valid pointer | |
881 | * to a struct nvmem_cell. The nvmem_cell will be freed by the | |
882 | * automatically once the device is freed. | |
883 | */ | |
884 | struct nvmem_cell *devm_nvmem_cell_get(struct device *dev, const char *id) | |
885 | { | |
886 | struct nvmem_cell **ptr, *cell; | |
887 | ||
888 | ptr = devres_alloc(devm_nvmem_cell_release, sizeof(*ptr), GFP_KERNEL); | |
889 | if (!ptr) | |
890 | return ERR_PTR(-ENOMEM); | |
891 | ||
892 | cell = nvmem_cell_get(dev, id); | |
893 | if (!IS_ERR(cell)) { | |
894 | *ptr = cell; | |
895 | devres_add(dev, ptr); | |
896 | } else { | |
897 | devres_free(ptr); | |
898 | } | |
899 | ||
900 | return cell; | |
901 | } | |
902 | EXPORT_SYMBOL_GPL(devm_nvmem_cell_get); | |
903 | ||
904 | static int devm_nvmem_cell_match(struct device *dev, void *res, void *data) | |
905 | { | |
906 | struct nvmem_cell **c = res; | |
907 | ||
908 | if (WARN_ON(!c || !*c)) | |
909 | return 0; | |
910 | ||
911 | return *c == data; | |
912 | } | |
913 | ||
914 | /** | |
915 | * devm_nvmem_cell_put() - Release previously allocated nvmem cell | |
916 | * from devm_nvmem_cell_get. | |
917 | * | |
29143268 VG |
918 | * @dev: Device that requests the nvmem cell. |
919 | * @cell: Previously allocated nvmem cell by devm_nvmem_cell_get(). | |
69aba794 SK |
920 | */ |
921 | void devm_nvmem_cell_put(struct device *dev, struct nvmem_cell *cell) | |
922 | { | |
923 | int ret; | |
924 | ||
925 | ret = devres_release(dev, devm_nvmem_cell_release, | |
926 | devm_nvmem_cell_match, cell); | |
927 | ||
928 | WARN_ON(ret); | |
929 | } | |
930 | EXPORT_SYMBOL(devm_nvmem_cell_put); | |
931 | ||
932 | /** | |
933 | * nvmem_cell_put() - Release previously allocated nvmem cell. | |
934 | * | |
29143268 | 935 | * @cell: Previously allocated nvmem cell by nvmem_cell_get(). |
69aba794 SK |
936 | */ |
937 | void nvmem_cell_put(struct nvmem_cell *cell) | |
938 | { | |
939 | struct nvmem_device *nvmem = cell->nvmem; | |
940 | ||
941 | __nvmem_device_put(nvmem); | |
942 | nvmem_cell_drop(cell); | |
943 | } | |
944 | EXPORT_SYMBOL_GPL(nvmem_cell_put); | |
945 | ||
f7c04f16 | 946 | static void nvmem_shift_read_buffer_in_place(struct nvmem_cell *cell, void *buf) |
69aba794 SK |
947 | { |
948 | u8 *p, *b; | |
949 | int i, bit_offset = cell->bit_offset; | |
950 | ||
951 | p = b = buf; | |
952 | if (bit_offset) { | |
953 | /* First shift */ | |
954 | *b++ >>= bit_offset; | |
955 | ||
956 | /* setup rest of the bytes if any */ | |
957 | for (i = 1; i < cell->bytes; i++) { | |
958 | /* Get bits from next byte and shift them towards msb */ | |
959 | *p |= *b << (BITS_PER_BYTE - bit_offset); | |
960 | ||
961 | p = b; | |
962 | *b++ >>= bit_offset; | |
963 | } | |
964 | ||
965 | /* result fits in less bytes */ | |
966 | if (cell->bytes != DIV_ROUND_UP(cell->nbits, BITS_PER_BYTE)) | |
967 | *p-- = 0; | |
968 | } | |
969 | /* clear msb bits if any leftover in the last byte */ | |
970 | *p &= GENMASK((cell->nbits%BITS_PER_BYTE) - 1, 0); | |
971 | } | |
972 | ||
973 | static int __nvmem_cell_read(struct nvmem_device *nvmem, | |
974 | struct nvmem_cell *cell, | |
975 | void *buf, size_t *len) | |
976 | { | |
977 | int rc; | |
978 | ||
795ddd18 | 979 | rc = nvmem_reg_read(nvmem, cell->offset, buf, cell->bytes); |
69aba794 | 980 | |
287980e4 | 981 | if (rc) |
69aba794 SK |
982 | return rc; |
983 | ||
984 | /* shift bits in-place */ | |
cbf854ab | 985 | if (cell->bit_offset || cell->nbits) |
69aba794 SK |
986 | nvmem_shift_read_buffer_in_place(cell, buf); |
987 | ||
3b4a6877 VG |
988 | if (len) |
989 | *len = cell->bytes; | |
69aba794 SK |
990 | |
991 | return 0; | |
992 | } | |
993 | ||
994 | /** | |
995 | * nvmem_cell_read() - Read a given nvmem cell | |
996 | * | |
997 | * @cell: nvmem cell to be read. | |
3b4a6877 VG |
998 | * @len: pointer to length of cell which will be populated on successful read; |
999 | * can be NULL. | |
69aba794 | 1000 | * |
b577fafc BN |
1001 | * Return: ERR_PTR() on error or a valid pointer to a buffer on success. The |
1002 | * buffer should be freed by the consumer with a kfree(). | |
69aba794 SK |
1003 | */ |
1004 | void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len) | |
1005 | { | |
1006 | struct nvmem_device *nvmem = cell->nvmem; | |
1007 | u8 *buf; | |
1008 | int rc; | |
1009 | ||
795ddd18 | 1010 | if (!nvmem) |
69aba794 SK |
1011 | return ERR_PTR(-EINVAL); |
1012 | ||
1013 | buf = kzalloc(cell->bytes, GFP_KERNEL); | |
1014 | if (!buf) | |
1015 | return ERR_PTR(-ENOMEM); | |
1016 | ||
1017 | rc = __nvmem_cell_read(nvmem, cell, buf, len); | |
287980e4 | 1018 | if (rc) { |
69aba794 SK |
1019 | kfree(buf); |
1020 | return ERR_PTR(rc); | |
1021 | } | |
1022 | ||
1023 | return buf; | |
1024 | } | |
1025 | EXPORT_SYMBOL_GPL(nvmem_cell_read); | |
1026 | ||
f7c04f16 MY |
1027 | static void *nvmem_cell_prepare_write_buffer(struct nvmem_cell *cell, |
1028 | u8 *_buf, int len) | |
69aba794 SK |
1029 | { |
1030 | struct nvmem_device *nvmem = cell->nvmem; | |
1031 | int i, rc, nbits, bit_offset = cell->bit_offset; | |
1032 | u8 v, *p, *buf, *b, pbyte, pbits; | |
1033 | ||
1034 | nbits = cell->nbits; | |
1035 | buf = kzalloc(cell->bytes, GFP_KERNEL); | |
1036 | if (!buf) | |
1037 | return ERR_PTR(-ENOMEM); | |
1038 | ||
1039 | memcpy(buf, _buf, len); | |
1040 | p = b = buf; | |
1041 | ||
1042 | if (bit_offset) { | |
1043 | pbyte = *b; | |
1044 | *b <<= bit_offset; | |
1045 | ||
1046 | /* setup the first byte with lsb bits from nvmem */ | |
795ddd18 | 1047 | rc = nvmem_reg_read(nvmem, cell->offset, &v, 1); |
69aba794 SK |
1048 | *b++ |= GENMASK(bit_offset - 1, 0) & v; |
1049 | ||
1050 | /* setup rest of the byte if any */ | |
1051 | for (i = 1; i < cell->bytes; i++) { | |
1052 | /* Get last byte bits and shift them towards lsb */ | |
1053 | pbits = pbyte >> (BITS_PER_BYTE - 1 - bit_offset); | |
1054 | pbyte = *b; | |
1055 | p = b; | |
1056 | *b <<= bit_offset; | |
1057 | *b++ |= pbits; | |
1058 | } | |
1059 | } | |
1060 | ||
1061 | /* if it's not end on byte boundary */ | |
1062 | if ((nbits + bit_offset) % BITS_PER_BYTE) { | |
1063 | /* setup the last byte with msb bits from nvmem */ | |
795ddd18 | 1064 | rc = nvmem_reg_read(nvmem, |
69aba794 SK |
1065 | cell->offset + cell->bytes - 1, &v, 1); |
1066 | *p |= GENMASK(7, (nbits + bit_offset) % BITS_PER_BYTE) & v; | |
1067 | ||
1068 | } | |
1069 | ||
1070 | return buf; | |
1071 | } | |
1072 | ||
1073 | /** | |
1074 | * nvmem_cell_write() - Write to a given nvmem cell | |
1075 | * | |
1076 | * @cell: nvmem cell to be written. | |
1077 | * @buf: Buffer to be written. | |
1078 | * @len: length of buffer to be written to nvmem cell. | |
1079 | * | |
1080 | * Return: length of bytes written or negative on failure. | |
1081 | */ | |
1082 | int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len) | |
1083 | { | |
1084 | struct nvmem_device *nvmem = cell->nvmem; | |
1085 | int rc; | |
1086 | ||
795ddd18 | 1087 | if (!nvmem || nvmem->read_only || |
69aba794 SK |
1088 | (cell->bit_offset == 0 && len != cell->bytes)) |
1089 | return -EINVAL; | |
1090 | ||
1091 | if (cell->bit_offset || cell->nbits) { | |
1092 | buf = nvmem_cell_prepare_write_buffer(cell, buf, len); | |
1093 | if (IS_ERR(buf)) | |
1094 | return PTR_ERR(buf); | |
1095 | } | |
1096 | ||
795ddd18 | 1097 | rc = nvmem_reg_write(nvmem, cell->offset, buf, cell->bytes); |
69aba794 SK |
1098 | |
1099 | /* free the tmp buffer */ | |
ace22170 | 1100 | if (cell->bit_offset || cell->nbits) |
69aba794 SK |
1101 | kfree(buf); |
1102 | ||
287980e4 | 1103 | if (rc) |
69aba794 SK |
1104 | return rc; |
1105 | ||
1106 | return len; | |
1107 | } | |
1108 | EXPORT_SYMBOL_GPL(nvmem_cell_write); | |
1109 | ||
d026d70a LC |
1110 | /** |
1111 | * nvmem_cell_read_u32() - Read a cell value as an u32 | |
1112 | * | |
1113 | * @dev: Device that requests the nvmem cell. | |
1114 | * @cell_id: Name of nvmem cell to read. | |
1115 | * @val: pointer to output value. | |
1116 | * | |
1117 | * Return: 0 on success or negative errno. | |
1118 | */ | |
1119 | int nvmem_cell_read_u32(struct device *dev, const char *cell_id, u32 *val) | |
1120 | { | |
1121 | struct nvmem_cell *cell; | |
1122 | void *buf; | |
1123 | size_t len; | |
1124 | ||
1125 | cell = nvmem_cell_get(dev, cell_id); | |
1126 | if (IS_ERR(cell)) | |
1127 | return PTR_ERR(cell); | |
1128 | ||
1129 | buf = nvmem_cell_read(cell, &len); | |
1130 | if (IS_ERR(buf)) { | |
1131 | nvmem_cell_put(cell); | |
1132 | return PTR_ERR(buf); | |
1133 | } | |
1134 | if (len != sizeof(*val)) { | |
1135 | kfree(buf); | |
1136 | nvmem_cell_put(cell); | |
1137 | return -EINVAL; | |
1138 | } | |
1139 | memcpy(val, buf, sizeof(*val)); | |
1140 | ||
1141 | kfree(buf); | |
1142 | nvmem_cell_put(cell); | |
1143 | return 0; | |
1144 | } | |
1145 | EXPORT_SYMBOL_GPL(nvmem_cell_read_u32); | |
1146 | ||
e2a5402e SK |
1147 | /** |
1148 | * nvmem_device_cell_read() - Read a given nvmem device and cell | |
1149 | * | |
1150 | * @nvmem: nvmem device to read from. | |
1151 | * @info: nvmem cell info to be read. | |
1152 | * @buf: buffer pointer which will be populated on successful read. | |
1153 | * | |
1154 | * Return: length of successful bytes read on success and negative | |
1155 | * error code on error. | |
1156 | */ | |
1157 | ssize_t nvmem_device_cell_read(struct nvmem_device *nvmem, | |
1158 | struct nvmem_cell_info *info, void *buf) | |
1159 | { | |
1160 | struct nvmem_cell cell; | |
1161 | int rc; | |
1162 | ssize_t len; | |
1163 | ||
795ddd18 | 1164 | if (!nvmem) |
e2a5402e SK |
1165 | return -EINVAL; |
1166 | ||
1167 | rc = nvmem_cell_info_to_nvmem_cell(nvmem, info, &cell); | |
287980e4 | 1168 | if (rc) |
e2a5402e SK |
1169 | return rc; |
1170 | ||
1171 | rc = __nvmem_cell_read(nvmem, &cell, buf, &len); | |
287980e4 | 1172 | if (rc) |
e2a5402e SK |
1173 | return rc; |
1174 | ||
1175 | return len; | |
1176 | } | |
1177 | EXPORT_SYMBOL_GPL(nvmem_device_cell_read); | |
1178 | ||
1179 | /** | |
1180 | * nvmem_device_cell_write() - Write cell to a given nvmem device | |
1181 | * | |
1182 | * @nvmem: nvmem device to be written to. | |
29143268 | 1183 | * @info: nvmem cell info to be written. |
e2a5402e SK |
1184 | * @buf: buffer to be written to cell. |
1185 | * | |
1186 | * Return: length of bytes written or negative error code on failure. | |
1187 | * */ | |
1188 | int nvmem_device_cell_write(struct nvmem_device *nvmem, | |
1189 | struct nvmem_cell_info *info, void *buf) | |
1190 | { | |
1191 | struct nvmem_cell cell; | |
1192 | int rc; | |
1193 | ||
795ddd18 | 1194 | if (!nvmem) |
e2a5402e SK |
1195 | return -EINVAL; |
1196 | ||
1197 | rc = nvmem_cell_info_to_nvmem_cell(nvmem, info, &cell); | |
287980e4 | 1198 | if (rc) |
e2a5402e SK |
1199 | return rc; |
1200 | ||
1201 | return nvmem_cell_write(&cell, buf, cell.bytes); | |
1202 | } | |
1203 | EXPORT_SYMBOL_GPL(nvmem_device_cell_write); | |
1204 | ||
1205 | /** | |
1206 | * nvmem_device_read() - Read from a given nvmem device | |
1207 | * | |
1208 | * @nvmem: nvmem device to read from. | |
1209 | * @offset: offset in nvmem device. | |
1210 | * @bytes: number of bytes to read. | |
1211 | * @buf: buffer pointer which will be populated on successful read. | |
1212 | * | |
1213 | * Return: length of successful bytes read on success and negative | |
1214 | * error code on error. | |
1215 | */ | |
1216 | int nvmem_device_read(struct nvmem_device *nvmem, | |
1217 | unsigned int offset, | |
1218 | size_t bytes, void *buf) | |
1219 | { | |
1220 | int rc; | |
1221 | ||
795ddd18 | 1222 | if (!nvmem) |
e2a5402e SK |
1223 | return -EINVAL; |
1224 | ||
795ddd18 | 1225 | rc = nvmem_reg_read(nvmem, offset, buf, bytes); |
e2a5402e | 1226 | |
287980e4 | 1227 | if (rc) |
e2a5402e SK |
1228 | return rc; |
1229 | ||
1230 | return bytes; | |
1231 | } | |
1232 | EXPORT_SYMBOL_GPL(nvmem_device_read); | |
1233 | ||
1234 | /** | |
1235 | * nvmem_device_write() - Write cell to a given nvmem device | |
1236 | * | |
1237 | * @nvmem: nvmem device to be written to. | |
1238 | * @offset: offset in nvmem device. | |
1239 | * @bytes: number of bytes to write. | |
1240 | * @buf: buffer to be written. | |
1241 | * | |
1242 | * Return: length of bytes written or negative error code on failure. | |
1243 | * */ | |
1244 | int nvmem_device_write(struct nvmem_device *nvmem, | |
1245 | unsigned int offset, | |
1246 | size_t bytes, void *buf) | |
1247 | { | |
1248 | int rc; | |
1249 | ||
795ddd18 | 1250 | if (!nvmem) |
e2a5402e SK |
1251 | return -EINVAL; |
1252 | ||
795ddd18 | 1253 | rc = nvmem_reg_write(nvmem, offset, buf, bytes); |
e2a5402e | 1254 | |
287980e4 | 1255 | if (rc) |
e2a5402e SK |
1256 | return rc; |
1257 | ||
1258 | ||
1259 | return bytes; | |
1260 | } | |
1261 | EXPORT_SYMBOL_GPL(nvmem_device_write); | |
1262 | ||
eace75cf SK |
1263 | static int __init nvmem_init(void) |
1264 | { | |
1265 | return bus_register(&nvmem_bus_type); | |
1266 | } | |
1267 | ||
1268 | static void __exit nvmem_exit(void) | |
1269 | { | |
1270 | bus_unregister(&nvmem_bus_type); | |
1271 | } | |
1272 | ||
1273 | subsys_initcall(nvmem_init); | |
1274 | module_exit(nvmem_exit); | |
1275 | ||
1276 | MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org"); | |
1277 | MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com"); | |
1278 | MODULE_DESCRIPTION("nvmem Driver Core"); | |
1279 | MODULE_LICENSE("GPL v2"); |