Commit | Line | Data |
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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 | ||
b3db17e4 AL |
356 | /** |
357 | * nvmem_add_cells() - Add cell information to an nvmem device | |
358 | * | |
359 | * @nvmem: nvmem device to add cells to. | |
360 | * @info: nvmem cell info to add to the device | |
361 | * @ncells: number of cells in info | |
362 | * | |
363 | * Return: 0 or negative error code on failure. | |
364 | */ | |
365 | int nvmem_add_cells(struct nvmem_device *nvmem, | |
366 | const struct nvmem_cell_info *info, | |
367 | int ncells) | |
eace75cf SK |
368 | { |
369 | struct nvmem_cell **cells; | |
eace75cf SK |
370 | int i, rval; |
371 | ||
b3db17e4 | 372 | cells = kcalloc(ncells, sizeof(*cells), GFP_KERNEL); |
eace75cf SK |
373 | if (!cells) |
374 | return -ENOMEM; | |
375 | ||
b3db17e4 | 376 | for (i = 0; i < ncells; i++) { |
eace75cf SK |
377 | cells[i] = kzalloc(sizeof(**cells), GFP_KERNEL); |
378 | if (!cells[i]) { | |
379 | rval = -ENOMEM; | |
380 | goto err; | |
381 | } | |
382 | ||
383 | rval = nvmem_cell_info_to_nvmem_cell(nvmem, &info[i], cells[i]); | |
287980e4 | 384 | if (rval) { |
eace75cf SK |
385 | kfree(cells[i]); |
386 | goto err; | |
387 | } | |
388 | ||
389 | nvmem_cell_add(cells[i]); | |
390 | } | |
391 | ||
b3db17e4 | 392 | nvmem->ncells = ncells; |
eace75cf SK |
393 | /* remove tmp array */ |
394 | kfree(cells); | |
395 | ||
396 | return 0; | |
397 | err: | |
dfdf1414 | 398 | while (i--) |
eace75cf SK |
399 | nvmem_cell_drop(cells[i]); |
400 | ||
dfdf1414 RV |
401 | kfree(cells); |
402 | ||
eace75cf SK |
403 | return rval; |
404 | } | |
b3db17e4 | 405 | EXPORT_SYMBOL_GPL(nvmem_add_cells); |
eace75cf | 406 | |
b6c217ab AL |
407 | /* |
408 | * nvmem_setup_compat() - Create an additional binary entry in | |
409 | * drivers sys directory, to be backwards compatible with the older | |
410 | * drivers/misc/eeprom drivers. | |
411 | */ | |
412 | static int nvmem_setup_compat(struct nvmem_device *nvmem, | |
413 | const struct nvmem_config *config) | |
414 | { | |
415 | int rval; | |
416 | ||
417 | if (!config->base_dev) | |
418 | return -EINVAL; | |
419 | ||
420 | if (nvmem->read_only) | |
421 | nvmem->eeprom = bin_attr_ro_root_nvmem; | |
422 | else | |
423 | nvmem->eeprom = bin_attr_rw_root_nvmem; | |
424 | nvmem->eeprom.attr.name = "eeprom"; | |
425 | nvmem->eeprom.size = nvmem->size; | |
426 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
427 | nvmem->eeprom.attr.key = &eeprom_lock_key; | |
428 | #endif | |
429 | nvmem->eeprom.private = &nvmem->dev; | |
430 | nvmem->base_dev = config->base_dev; | |
431 | ||
432 | rval = device_create_bin_file(nvmem->base_dev, &nvmem->eeprom); | |
433 | if (rval) { | |
434 | dev_err(&nvmem->dev, | |
435 | "Failed to create eeprom binary file %d\n", rval); | |
436 | return rval; | |
437 | } | |
438 | ||
439 | nvmem->flags |= FLAG_COMPAT; | |
440 | ||
441 | return 0; | |
442 | } | |
443 | ||
eace75cf SK |
444 | /** |
445 | * nvmem_register() - Register a nvmem device for given nvmem_config. | |
446 | * Also creates an binary entry in /sys/bus/nvmem/devices/dev-name/nvmem | |
447 | * | |
448 | * @config: nvmem device configuration with which nvmem device is created. | |
449 | * | |
450 | * Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device | |
451 | * on success. | |
452 | */ | |
453 | ||
454 | struct nvmem_device *nvmem_register(const struct nvmem_config *config) | |
455 | { | |
456 | struct nvmem_device *nvmem; | |
eace75cf SK |
457 | int rval; |
458 | ||
459 | if (!config->dev) | |
460 | return ERR_PTR(-EINVAL); | |
461 | ||
eace75cf SK |
462 | nvmem = kzalloc(sizeof(*nvmem), GFP_KERNEL); |
463 | if (!nvmem) | |
464 | return ERR_PTR(-ENOMEM); | |
465 | ||
466 | rval = ida_simple_get(&nvmem_ida, 0, 0, GFP_KERNEL); | |
467 | if (rval < 0) { | |
468 | kfree(nvmem); | |
469 | return ERR_PTR(rval); | |
470 | } | |
471 | ||
472 | nvmem->id = rval; | |
eace75cf | 473 | nvmem->owner = config->owner; |
17eb18d6 MY |
474 | if (!nvmem->owner && config->dev->driver) |
475 | nvmem->owner = config->dev->driver->owner; | |
99897efd HK |
476 | nvmem->stride = config->stride ?: 1; |
477 | nvmem->word_size = config->word_size ?: 1; | |
795ddd18 | 478 | nvmem->size = config->size; |
eace75cf SK |
479 | nvmem->dev.type = &nvmem_provider_type; |
480 | nvmem->dev.bus = &nvmem_bus_type; | |
481 | nvmem->dev.parent = config->dev; | |
795ddd18 SK |
482 | nvmem->priv = config->priv; |
483 | nvmem->reg_read = config->reg_read; | |
484 | nvmem->reg_write = config->reg_write; | |
fc2f9970 | 485 | nvmem->dev.of_node = config->dev->of_node; |
fd0f4906 AS |
486 | |
487 | if (config->id == -1 && config->name) { | |
488 | dev_set_name(&nvmem->dev, "%s", config->name); | |
489 | } else { | |
490 | dev_set_name(&nvmem->dev, "%s%d", | |
491 | config->name ? : "nvmem", | |
492 | config->name ? config->id : nvmem->id); | |
493 | } | |
eace75cf | 494 | |
fc2f9970 | 495 | nvmem->read_only = device_property_present(config->dev, "read-only") | |
eace75cf SK |
496 | config->read_only; |
497 | ||
811b0d65 AL |
498 | if (config->root_only) |
499 | nvmem->dev.groups = nvmem->read_only ? | |
500 | nvmem_ro_root_dev_groups : | |
501 | nvmem_rw_root_dev_groups; | |
502 | else | |
503 | nvmem->dev.groups = nvmem->read_only ? | |
504 | nvmem_ro_dev_groups : | |
505 | nvmem_rw_dev_groups; | |
eace75cf SK |
506 | |
507 | device_initialize(&nvmem->dev); | |
508 | ||
509 | dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name); | |
510 | ||
511 | rval = device_add(&nvmem->dev); | |
b6c217ab | 512 | if (rval) |
3360acdf | 513 | goto err_put_device; |
b6c217ab AL |
514 | |
515 | if (config->compat) { | |
516 | rval = nvmem_setup_compat(nvmem, config); | |
517 | if (rval) | |
3360acdf | 518 | goto err_device_del; |
eace75cf SK |
519 | } |
520 | ||
521 | if (config->cells) | |
b3db17e4 | 522 | nvmem_add_cells(nvmem, config->cells, config->ncells); |
eace75cf SK |
523 | |
524 | return nvmem; | |
3360acdf JH |
525 | |
526 | err_device_del: | |
527 | device_del(&nvmem->dev); | |
528 | err_put_device: | |
529 | put_device(&nvmem->dev); | |
530 | ||
b6c217ab | 531 | return ERR_PTR(rval); |
eace75cf SK |
532 | } |
533 | EXPORT_SYMBOL_GPL(nvmem_register); | |
534 | ||
535 | /** | |
536 | * nvmem_unregister() - Unregister previously registered nvmem device | |
537 | * | |
538 | * @nvmem: Pointer to previously registered nvmem device. | |
539 | * | |
540 | * Return: Will be an negative on error or a zero on success. | |
541 | */ | |
542 | int nvmem_unregister(struct nvmem_device *nvmem) | |
543 | { | |
69aba794 SK |
544 | mutex_lock(&nvmem_mutex); |
545 | if (nvmem->users) { | |
546 | mutex_unlock(&nvmem_mutex); | |
eace75cf | 547 | return -EBUSY; |
69aba794 SK |
548 | } |
549 | mutex_unlock(&nvmem_mutex); | |
eace75cf | 550 | |
b6c217ab AL |
551 | if (nvmem->flags & FLAG_COMPAT) |
552 | device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom); | |
553 | ||
eace75cf SK |
554 | nvmem_device_remove_all_cells(nvmem); |
555 | device_del(&nvmem->dev); | |
79fbf046 | 556 | put_device(&nvmem->dev); |
eace75cf SK |
557 | |
558 | return 0; | |
559 | } | |
560 | EXPORT_SYMBOL_GPL(nvmem_unregister); | |
561 | ||
f1f50eca AS |
562 | static void devm_nvmem_release(struct device *dev, void *res) |
563 | { | |
564 | WARN_ON(nvmem_unregister(*(struct nvmem_device **)res)); | |
565 | } | |
566 | ||
567 | /** | |
568 | * devm_nvmem_register() - Register a managed nvmem device for given | |
569 | * nvmem_config. | |
570 | * Also creates an binary entry in /sys/bus/nvmem/devices/dev-name/nvmem | |
571 | * | |
b378c779 | 572 | * @dev: Device that uses the nvmem device. |
f1f50eca AS |
573 | * @config: nvmem device configuration with which nvmem device is created. |
574 | * | |
575 | * Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device | |
576 | * on success. | |
577 | */ | |
578 | struct nvmem_device *devm_nvmem_register(struct device *dev, | |
579 | const struct nvmem_config *config) | |
580 | { | |
581 | struct nvmem_device **ptr, *nvmem; | |
582 | ||
583 | ptr = devres_alloc(devm_nvmem_release, sizeof(*ptr), GFP_KERNEL); | |
584 | if (!ptr) | |
585 | return ERR_PTR(-ENOMEM); | |
586 | ||
587 | nvmem = nvmem_register(config); | |
588 | ||
589 | if (!IS_ERR(nvmem)) { | |
590 | *ptr = nvmem; | |
591 | devres_add(dev, ptr); | |
592 | } else { | |
593 | devres_free(ptr); | |
594 | } | |
595 | ||
596 | return nvmem; | |
597 | } | |
598 | EXPORT_SYMBOL_GPL(devm_nvmem_register); | |
599 | ||
600 | static int devm_nvmem_match(struct device *dev, void *res, void *data) | |
601 | { | |
602 | struct nvmem_device **r = res; | |
603 | ||
604 | return *r == data; | |
605 | } | |
606 | ||
607 | /** | |
608 | * devm_nvmem_unregister() - Unregister previously registered managed nvmem | |
609 | * device. | |
610 | * | |
b378c779 | 611 | * @dev: Device that uses the nvmem device. |
f1f50eca AS |
612 | * @nvmem: Pointer to previously registered nvmem device. |
613 | * | |
614 | * Return: Will be an negative on error or a zero on success. | |
615 | */ | |
616 | int devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem) | |
617 | { | |
618 | return devres_release(dev, devm_nvmem_release, devm_nvmem_match, nvmem); | |
619 | } | |
620 | EXPORT_SYMBOL(devm_nvmem_unregister); | |
621 | ||
622 | ||
69aba794 SK |
623 | static struct nvmem_device *__nvmem_device_get(struct device_node *np, |
624 | struct nvmem_cell **cellp, | |
625 | const char *cell_id) | |
626 | { | |
627 | struct nvmem_device *nvmem = NULL; | |
628 | ||
629 | mutex_lock(&nvmem_mutex); | |
630 | ||
631 | if (np) { | |
632 | nvmem = of_nvmem_find(np); | |
633 | if (!nvmem) { | |
634 | mutex_unlock(&nvmem_mutex); | |
635 | return ERR_PTR(-EPROBE_DEFER); | |
636 | } | |
637 | } else { | |
638 | struct nvmem_cell *cell = nvmem_find_cell(cell_id); | |
639 | ||
640 | if (cell) { | |
641 | nvmem = cell->nvmem; | |
642 | *cellp = cell; | |
643 | } | |
644 | ||
645 | if (!nvmem) { | |
646 | mutex_unlock(&nvmem_mutex); | |
647 | return ERR_PTR(-ENOENT); | |
648 | } | |
649 | } | |
650 | ||
651 | nvmem->users++; | |
652 | mutex_unlock(&nvmem_mutex); | |
653 | ||
654 | if (!try_module_get(nvmem->owner)) { | |
655 | dev_err(&nvmem->dev, | |
656 | "could not increase module refcount for cell %s\n", | |
657 | nvmem->name); | |
658 | ||
659 | mutex_lock(&nvmem_mutex); | |
660 | nvmem->users--; | |
661 | mutex_unlock(&nvmem_mutex); | |
662 | ||
663 | return ERR_PTR(-EINVAL); | |
664 | } | |
665 | ||
666 | return nvmem; | |
667 | } | |
668 | ||
669 | static void __nvmem_device_put(struct nvmem_device *nvmem) | |
670 | { | |
671 | module_put(nvmem->owner); | |
672 | mutex_lock(&nvmem_mutex); | |
673 | nvmem->users--; | |
674 | mutex_unlock(&nvmem_mutex); | |
675 | } | |
676 | ||
e2a5402e SK |
677 | static struct nvmem_device *nvmem_find(const char *name) |
678 | { | |
679 | struct device *d; | |
680 | ||
9f3044c3 | 681 | d = bus_find_device_by_name(&nvmem_bus_type, NULL, name); |
e2a5402e SK |
682 | |
683 | if (!d) | |
684 | return NULL; | |
685 | ||
686 | return to_nvmem_device(d); | |
687 | } | |
688 | ||
e701c67c | 689 | #if IS_ENABLED(CONFIG_OF) |
e2a5402e SK |
690 | /** |
691 | * of_nvmem_device_get() - Get nvmem device from a given id | |
692 | * | |
29143268 | 693 | * @np: Device tree node that uses the nvmem device. |
e2a5402e SK |
694 | * @id: nvmem name from nvmem-names property. |
695 | * | |
696 | * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device | |
697 | * on success. | |
698 | */ | |
699 | struct nvmem_device *of_nvmem_device_get(struct device_node *np, const char *id) | |
700 | { | |
701 | ||
702 | struct device_node *nvmem_np; | |
703 | int index; | |
704 | ||
705 | index = of_property_match_string(np, "nvmem-names", id); | |
706 | ||
707 | nvmem_np = of_parse_phandle(np, "nvmem", index); | |
708 | if (!nvmem_np) | |
709 | return ERR_PTR(-EINVAL); | |
710 | ||
711 | return __nvmem_device_get(nvmem_np, NULL, NULL); | |
712 | } | |
713 | EXPORT_SYMBOL_GPL(of_nvmem_device_get); | |
714 | #endif | |
715 | ||
716 | /** | |
717 | * nvmem_device_get() - Get nvmem device from a given id | |
718 | * | |
29143268 VG |
719 | * @dev: Device that uses the nvmem device. |
720 | * @dev_name: name of the requested nvmem device. | |
e2a5402e SK |
721 | * |
722 | * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device | |
723 | * on success. | |
724 | */ | |
725 | struct nvmem_device *nvmem_device_get(struct device *dev, const char *dev_name) | |
726 | { | |
727 | if (dev->of_node) { /* try dt first */ | |
728 | struct nvmem_device *nvmem; | |
729 | ||
730 | nvmem = of_nvmem_device_get(dev->of_node, dev_name); | |
731 | ||
732 | if (!IS_ERR(nvmem) || PTR_ERR(nvmem) == -EPROBE_DEFER) | |
733 | return nvmem; | |
734 | ||
735 | } | |
736 | ||
737 | return nvmem_find(dev_name); | |
738 | } | |
739 | EXPORT_SYMBOL_GPL(nvmem_device_get); | |
740 | ||
741 | static int devm_nvmem_device_match(struct device *dev, void *res, void *data) | |
742 | { | |
743 | struct nvmem_device **nvmem = res; | |
744 | ||
745 | if (WARN_ON(!nvmem || !*nvmem)) | |
746 | return 0; | |
747 | ||
748 | return *nvmem == data; | |
749 | } | |
750 | ||
751 | static void devm_nvmem_device_release(struct device *dev, void *res) | |
752 | { | |
753 | nvmem_device_put(*(struct nvmem_device **)res); | |
754 | } | |
755 | ||
756 | /** | |
757 | * devm_nvmem_device_put() - put alredy got nvmem device | |
758 | * | |
29143268 | 759 | * @dev: Device that uses the nvmem device. |
e2a5402e SK |
760 | * @nvmem: pointer to nvmem device allocated by devm_nvmem_cell_get(), |
761 | * that needs to be released. | |
762 | */ | |
763 | void devm_nvmem_device_put(struct device *dev, struct nvmem_device *nvmem) | |
764 | { | |
765 | int ret; | |
766 | ||
767 | ret = devres_release(dev, devm_nvmem_device_release, | |
768 | devm_nvmem_device_match, nvmem); | |
769 | ||
770 | WARN_ON(ret); | |
771 | } | |
772 | EXPORT_SYMBOL_GPL(devm_nvmem_device_put); | |
773 | ||
774 | /** | |
775 | * nvmem_device_put() - put alredy got nvmem device | |
776 | * | |
777 | * @nvmem: pointer to nvmem device that needs to be released. | |
778 | */ | |
779 | void nvmem_device_put(struct nvmem_device *nvmem) | |
780 | { | |
781 | __nvmem_device_put(nvmem); | |
782 | } | |
783 | EXPORT_SYMBOL_GPL(nvmem_device_put); | |
784 | ||
785 | /** | |
786 | * devm_nvmem_device_get() - Get nvmem cell of device form a given id | |
787 | * | |
29143268 VG |
788 | * @dev: Device that requests the nvmem device. |
789 | * @id: name id for the requested nvmem device. | |
e2a5402e SK |
790 | * |
791 | * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_cell | |
792 | * on success. The nvmem_cell will be freed by the automatically once the | |
793 | * device is freed. | |
794 | */ | |
795 | struct nvmem_device *devm_nvmem_device_get(struct device *dev, const char *id) | |
796 | { | |
797 | struct nvmem_device **ptr, *nvmem; | |
798 | ||
799 | ptr = devres_alloc(devm_nvmem_device_release, sizeof(*ptr), GFP_KERNEL); | |
800 | if (!ptr) | |
801 | return ERR_PTR(-ENOMEM); | |
802 | ||
803 | nvmem = nvmem_device_get(dev, id); | |
804 | if (!IS_ERR(nvmem)) { | |
805 | *ptr = nvmem; | |
806 | devres_add(dev, ptr); | |
807 | } else { | |
808 | devres_free(ptr); | |
809 | } | |
810 | ||
811 | return nvmem; | |
812 | } | |
813 | EXPORT_SYMBOL_GPL(devm_nvmem_device_get); | |
814 | ||
69aba794 SK |
815 | static struct nvmem_cell *nvmem_cell_get_from_list(const char *cell_id) |
816 | { | |
817 | struct nvmem_cell *cell = NULL; | |
818 | struct nvmem_device *nvmem; | |
819 | ||
820 | nvmem = __nvmem_device_get(NULL, &cell, cell_id); | |
821 | if (IS_ERR(nvmem)) | |
822 | return ERR_CAST(nvmem); | |
823 | ||
824 | return cell; | |
825 | } | |
826 | ||
e701c67c | 827 | #if IS_ENABLED(CONFIG_OF) |
69aba794 SK |
828 | /** |
829 | * of_nvmem_cell_get() - Get a nvmem cell from given device node and cell id | |
830 | * | |
29143268 | 831 | * @np: Device tree node that uses the nvmem cell. |
fd0c478c VG |
832 | * @name: nvmem cell name from nvmem-cell-names property, or NULL |
833 | * for the cell at index 0 (the lone cell with no accompanying | |
834 | * nvmem-cell-names property). | |
69aba794 SK |
835 | * |
836 | * Return: Will be an ERR_PTR() on error or a valid pointer | |
837 | * to a struct nvmem_cell. The nvmem_cell will be freed by the | |
838 | * nvmem_cell_put(). | |
839 | */ | |
840 | struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, | |
841 | const char *name) | |
842 | { | |
843 | struct device_node *cell_np, *nvmem_np; | |
844 | struct nvmem_cell *cell; | |
845 | struct nvmem_device *nvmem; | |
846 | const __be32 *addr; | |
fd0c478c VG |
847 | int rval, len; |
848 | int index = 0; | |
69aba794 | 849 | |
fd0c478c VG |
850 | /* if cell name exists, find index to the name */ |
851 | if (name) | |
852 | index = of_property_match_string(np, "nvmem-cell-names", name); | |
69aba794 SK |
853 | |
854 | cell_np = of_parse_phandle(np, "nvmem-cells", index); | |
855 | if (!cell_np) | |
856 | return ERR_PTR(-EINVAL); | |
857 | ||
858 | nvmem_np = of_get_next_parent(cell_np); | |
859 | if (!nvmem_np) | |
860 | return ERR_PTR(-EINVAL); | |
861 | ||
862 | nvmem = __nvmem_device_get(nvmem_np, NULL, NULL); | |
aad8d097 | 863 | of_node_put(nvmem_np); |
69aba794 SK |
864 | if (IS_ERR(nvmem)) |
865 | return ERR_CAST(nvmem); | |
866 | ||
867 | addr = of_get_property(cell_np, "reg", &len); | |
868 | if (!addr || (len < 2 * sizeof(u32))) { | |
5f214ccd RH |
869 | dev_err(&nvmem->dev, "nvmem: invalid reg on %pOF\n", |
870 | cell_np); | |
69aba794 SK |
871 | rval = -EINVAL; |
872 | goto err_mem; | |
873 | } | |
874 | ||
875 | cell = kzalloc(sizeof(*cell), GFP_KERNEL); | |
876 | if (!cell) { | |
877 | rval = -ENOMEM; | |
878 | goto err_mem; | |
879 | } | |
880 | ||
881 | cell->nvmem = nvmem; | |
882 | cell->offset = be32_to_cpup(addr++); | |
883 | cell->bytes = be32_to_cpup(addr); | |
884 | cell->name = cell_np->name; | |
885 | ||
886 | addr = of_get_property(cell_np, "bits", &len); | |
887 | if (addr && len == (2 * sizeof(u32))) { | |
888 | cell->bit_offset = be32_to_cpup(addr++); | |
889 | cell->nbits = be32_to_cpup(addr); | |
890 | } | |
891 | ||
892 | if (cell->nbits) | |
893 | cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset, | |
894 | BITS_PER_BYTE); | |
895 | ||
896 | if (!IS_ALIGNED(cell->offset, nvmem->stride)) { | |
897 | dev_err(&nvmem->dev, | |
898 | "cell %s unaligned to nvmem stride %d\n", | |
899 | cell->name, nvmem->stride); | |
900 | rval = -EINVAL; | |
901 | goto err_sanity; | |
902 | } | |
903 | ||
904 | nvmem_cell_add(cell); | |
905 | ||
906 | return cell; | |
907 | ||
908 | err_sanity: | |
909 | kfree(cell); | |
910 | ||
911 | err_mem: | |
912 | __nvmem_device_put(nvmem); | |
913 | ||
914 | return ERR_PTR(rval); | |
915 | } | |
916 | EXPORT_SYMBOL_GPL(of_nvmem_cell_get); | |
917 | #endif | |
918 | ||
919 | /** | |
920 | * nvmem_cell_get() - Get nvmem cell of device form a given cell name | |
921 | * | |
29143268 VG |
922 | * @dev: Device that requests the nvmem cell. |
923 | * @cell_id: nvmem cell name to get. | |
69aba794 SK |
924 | * |
925 | * Return: Will be an ERR_PTR() on error or a valid pointer | |
926 | * to a struct nvmem_cell. The nvmem_cell will be freed by the | |
927 | * nvmem_cell_put(). | |
928 | */ | |
929 | struct nvmem_cell *nvmem_cell_get(struct device *dev, const char *cell_id) | |
930 | { | |
931 | struct nvmem_cell *cell; | |
932 | ||
933 | if (dev->of_node) { /* try dt first */ | |
934 | cell = of_nvmem_cell_get(dev->of_node, cell_id); | |
935 | if (!IS_ERR(cell) || PTR_ERR(cell) == -EPROBE_DEFER) | |
936 | return cell; | |
937 | } | |
938 | ||
939 | return nvmem_cell_get_from_list(cell_id); | |
940 | } | |
941 | EXPORT_SYMBOL_GPL(nvmem_cell_get); | |
942 | ||
943 | static void devm_nvmem_cell_release(struct device *dev, void *res) | |
944 | { | |
945 | nvmem_cell_put(*(struct nvmem_cell **)res); | |
946 | } | |
947 | ||
948 | /** | |
949 | * devm_nvmem_cell_get() - Get nvmem cell of device form a given id | |
950 | * | |
29143268 VG |
951 | * @dev: Device that requests the nvmem cell. |
952 | * @id: nvmem cell name id to get. | |
69aba794 SK |
953 | * |
954 | * Return: Will be an ERR_PTR() on error or a valid pointer | |
955 | * to a struct nvmem_cell. The nvmem_cell will be freed by the | |
956 | * automatically once the device is freed. | |
957 | */ | |
958 | struct nvmem_cell *devm_nvmem_cell_get(struct device *dev, const char *id) | |
959 | { | |
960 | struct nvmem_cell **ptr, *cell; | |
961 | ||
962 | ptr = devres_alloc(devm_nvmem_cell_release, sizeof(*ptr), GFP_KERNEL); | |
963 | if (!ptr) | |
964 | return ERR_PTR(-ENOMEM); | |
965 | ||
966 | cell = nvmem_cell_get(dev, id); | |
967 | if (!IS_ERR(cell)) { | |
968 | *ptr = cell; | |
969 | devres_add(dev, ptr); | |
970 | } else { | |
971 | devres_free(ptr); | |
972 | } | |
973 | ||
974 | return cell; | |
975 | } | |
976 | EXPORT_SYMBOL_GPL(devm_nvmem_cell_get); | |
977 | ||
978 | static int devm_nvmem_cell_match(struct device *dev, void *res, void *data) | |
979 | { | |
980 | struct nvmem_cell **c = res; | |
981 | ||
982 | if (WARN_ON(!c || !*c)) | |
983 | return 0; | |
984 | ||
985 | return *c == data; | |
986 | } | |
987 | ||
988 | /** | |
989 | * devm_nvmem_cell_put() - Release previously allocated nvmem cell | |
990 | * from devm_nvmem_cell_get. | |
991 | * | |
29143268 VG |
992 | * @dev: Device that requests the nvmem cell. |
993 | * @cell: Previously allocated nvmem cell by devm_nvmem_cell_get(). | |
69aba794 SK |
994 | */ |
995 | void devm_nvmem_cell_put(struct device *dev, struct nvmem_cell *cell) | |
996 | { | |
997 | int ret; | |
998 | ||
999 | ret = devres_release(dev, devm_nvmem_cell_release, | |
1000 | devm_nvmem_cell_match, cell); | |
1001 | ||
1002 | WARN_ON(ret); | |
1003 | } | |
1004 | EXPORT_SYMBOL(devm_nvmem_cell_put); | |
1005 | ||
1006 | /** | |
1007 | * nvmem_cell_put() - Release previously allocated nvmem cell. | |
1008 | * | |
29143268 | 1009 | * @cell: Previously allocated nvmem cell by nvmem_cell_get(). |
69aba794 SK |
1010 | */ |
1011 | void nvmem_cell_put(struct nvmem_cell *cell) | |
1012 | { | |
1013 | struct nvmem_device *nvmem = cell->nvmem; | |
1014 | ||
1015 | __nvmem_device_put(nvmem); | |
1016 | nvmem_cell_drop(cell); | |
1017 | } | |
1018 | EXPORT_SYMBOL_GPL(nvmem_cell_put); | |
1019 | ||
f7c04f16 | 1020 | static void nvmem_shift_read_buffer_in_place(struct nvmem_cell *cell, void *buf) |
69aba794 SK |
1021 | { |
1022 | u8 *p, *b; | |
1023 | int i, bit_offset = cell->bit_offset; | |
1024 | ||
1025 | p = b = buf; | |
1026 | if (bit_offset) { | |
1027 | /* First shift */ | |
1028 | *b++ >>= bit_offset; | |
1029 | ||
1030 | /* setup rest of the bytes if any */ | |
1031 | for (i = 1; i < cell->bytes; i++) { | |
1032 | /* Get bits from next byte and shift them towards msb */ | |
1033 | *p |= *b << (BITS_PER_BYTE - bit_offset); | |
1034 | ||
1035 | p = b; | |
1036 | *b++ >>= bit_offset; | |
1037 | } | |
1038 | ||
1039 | /* result fits in less bytes */ | |
1040 | if (cell->bytes != DIV_ROUND_UP(cell->nbits, BITS_PER_BYTE)) | |
1041 | *p-- = 0; | |
1042 | } | |
1043 | /* clear msb bits if any leftover in the last byte */ | |
1044 | *p &= GENMASK((cell->nbits%BITS_PER_BYTE) - 1, 0); | |
1045 | } | |
1046 | ||
1047 | static int __nvmem_cell_read(struct nvmem_device *nvmem, | |
1048 | struct nvmem_cell *cell, | |
1049 | void *buf, size_t *len) | |
1050 | { | |
1051 | int rc; | |
1052 | ||
795ddd18 | 1053 | rc = nvmem_reg_read(nvmem, cell->offset, buf, cell->bytes); |
69aba794 | 1054 | |
287980e4 | 1055 | if (rc) |
69aba794 SK |
1056 | return rc; |
1057 | ||
1058 | /* shift bits in-place */ | |
cbf854ab | 1059 | if (cell->bit_offset || cell->nbits) |
69aba794 SK |
1060 | nvmem_shift_read_buffer_in_place(cell, buf); |
1061 | ||
3b4a6877 VG |
1062 | if (len) |
1063 | *len = cell->bytes; | |
69aba794 SK |
1064 | |
1065 | return 0; | |
1066 | } | |
1067 | ||
1068 | /** | |
1069 | * nvmem_cell_read() - Read a given nvmem cell | |
1070 | * | |
1071 | * @cell: nvmem cell to be read. | |
3b4a6877 VG |
1072 | * @len: pointer to length of cell which will be populated on successful read; |
1073 | * can be NULL. | |
69aba794 | 1074 | * |
b577fafc BN |
1075 | * Return: ERR_PTR() on error or a valid pointer to a buffer on success. The |
1076 | * buffer should be freed by the consumer with a kfree(). | |
69aba794 SK |
1077 | */ |
1078 | void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len) | |
1079 | { | |
1080 | struct nvmem_device *nvmem = cell->nvmem; | |
1081 | u8 *buf; | |
1082 | int rc; | |
1083 | ||
795ddd18 | 1084 | if (!nvmem) |
69aba794 SK |
1085 | return ERR_PTR(-EINVAL); |
1086 | ||
1087 | buf = kzalloc(cell->bytes, GFP_KERNEL); | |
1088 | if (!buf) | |
1089 | return ERR_PTR(-ENOMEM); | |
1090 | ||
1091 | rc = __nvmem_cell_read(nvmem, cell, buf, len); | |
287980e4 | 1092 | if (rc) { |
69aba794 SK |
1093 | kfree(buf); |
1094 | return ERR_PTR(rc); | |
1095 | } | |
1096 | ||
1097 | return buf; | |
1098 | } | |
1099 | EXPORT_SYMBOL_GPL(nvmem_cell_read); | |
1100 | ||
f7c04f16 MY |
1101 | static void *nvmem_cell_prepare_write_buffer(struct nvmem_cell *cell, |
1102 | u8 *_buf, int len) | |
69aba794 SK |
1103 | { |
1104 | struct nvmem_device *nvmem = cell->nvmem; | |
1105 | int i, rc, nbits, bit_offset = cell->bit_offset; | |
1106 | u8 v, *p, *buf, *b, pbyte, pbits; | |
1107 | ||
1108 | nbits = cell->nbits; | |
1109 | buf = kzalloc(cell->bytes, GFP_KERNEL); | |
1110 | if (!buf) | |
1111 | return ERR_PTR(-ENOMEM); | |
1112 | ||
1113 | memcpy(buf, _buf, len); | |
1114 | p = b = buf; | |
1115 | ||
1116 | if (bit_offset) { | |
1117 | pbyte = *b; | |
1118 | *b <<= bit_offset; | |
1119 | ||
1120 | /* setup the first byte with lsb bits from nvmem */ | |
795ddd18 | 1121 | rc = nvmem_reg_read(nvmem, cell->offset, &v, 1); |
50808bfc MM |
1122 | if (rc) |
1123 | goto err; | |
69aba794 SK |
1124 | *b++ |= GENMASK(bit_offset - 1, 0) & v; |
1125 | ||
1126 | /* setup rest of the byte if any */ | |
1127 | for (i = 1; i < cell->bytes; i++) { | |
1128 | /* Get last byte bits and shift them towards lsb */ | |
1129 | pbits = pbyte >> (BITS_PER_BYTE - 1 - bit_offset); | |
1130 | pbyte = *b; | |
1131 | p = b; | |
1132 | *b <<= bit_offset; | |
1133 | *b++ |= pbits; | |
1134 | } | |
1135 | } | |
1136 | ||
1137 | /* if it's not end on byte boundary */ | |
1138 | if ((nbits + bit_offset) % BITS_PER_BYTE) { | |
1139 | /* setup the last byte with msb bits from nvmem */ | |
795ddd18 | 1140 | rc = nvmem_reg_read(nvmem, |
69aba794 | 1141 | cell->offset + cell->bytes - 1, &v, 1); |
50808bfc MM |
1142 | if (rc) |
1143 | goto err; | |
69aba794 SK |
1144 | *p |= GENMASK(7, (nbits + bit_offset) % BITS_PER_BYTE) & v; |
1145 | ||
1146 | } | |
1147 | ||
1148 | return buf; | |
50808bfc MM |
1149 | err: |
1150 | kfree(buf); | |
1151 | return ERR_PTR(rc); | |
69aba794 SK |
1152 | } |
1153 | ||
1154 | /** | |
1155 | * nvmem_cell_write() - Write to a given nvmem cell | |
1156 | * | |
1157 | * @cell: nvmem cell to be written. | |
1158 | * @buf: Buffer to be written. | |
1159 | * @len: length of buffer to be written to nvmem cell. | |
1160 | * | |
1161 | * Return: length of bytes written or negative on failure. | |
1162 | */ | |
1163 | int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len) | |
1164 | { | |
1165 | struct nvmem_device *nvmem = cell->nvmem; | |
1166 | int rc; | |
1167 | ||
795ddd18 | 1168 | if (!nvmem || nvmem->read_only || |
69aba794 SK |
1169 | (cell->bit_offset == 0 && len != cell->bytes)) |
1170 | return -EINVAL; | |
1171 | ||
1172 | if (cell->bit_offset || cell->nbits) { | |
1173 | buf = nvmem_cell_prepare_write_buffer(cell, buf, len); | |
1174 | if (IS_ERR(buf)) | |
1175 | return PTR_ERR(buf); | |
1176 | } | |
1177 | ||
795ddd18 | 1178 | rc = nvmem_reg_write(nvmem, cell->offset, buf, cell->bytes); |
69aba794 SK |
1179 | |
1180 | /* free the tmp buffer */ | |
ace22170 | 1181 | if (cell->bit_offset || cell->nbits) |
69aba794 SK |
1182 | kfree(buf); |
1183 | ||
287980e4 | 1184 | if (rc) |
69aba794 SK |
1185 | return rc; |
1186 | ||
1187 | return len; | |
1188 | } | |
1189 | EXPORT_SYMBOL_GPL(nvmem_cell_write); | |
1190 | ||
d026d70a LC |
1191 | /** |
1192 | * nvmem_cell_read_u32() - Read a cell value as an u32 | |
1193 | * | |
1194 | * @dev: Device that requests the nvmem cell. | |
1195 | * @cell_id: Name of nvmem cell to read. | |
1196 | * @val: pointer to output value. | |
1197 | * | |
1198 | * Return: 0 on success or negative errno. | |
1199 | */ | |
1200 | int nvmem_cell_read_u32(struct device *dev, const char *cell_id, u32 *val) | |
1201 | { | |
1202 | struct nvmem_cell *cell; | |
1203 | void *buf; | |
1204 | size_t len; | |
1205 | ||
1206 | cell = nvmem_cell_get(dev, cell_id); | |
1207 | if (IS_ERR(cell)) | |
1208 | return PTR_ERR(cell); | |
1209 | ||
1210 | buf = nvmem_cell_read(cell, &len); | |
1211 | if (IS_ERR(buf)) { | |
1212 | nvmem_cell_put(cell); | |
1213 | return PTR_ERR(buf); | |
1214 | } | |
1215 | if (len != sizeof(*val)) { | |
1216 | kfree(buf); | |
1217 | nvmem_cell_put(cell); | |
1218 | return -EINVAL; | |
1219 | } | |
1220 | memcpy(val, buf, sizeof(*val)); | |
1221 | ||
1222 | kfree(buf); | |
1223 | nvmem_cell_put(cell); | |
1224 | return 0; | |
1225 | } | |
1226 | EXPORT_SYMBOL_GPL(nvmem_cell_read_u32); | |
1227 | ||
e2a5402e SK |
1228 | /** |
1229 | * nvmem_device_cell_read() - Read a given nvmem device and cell | |
1230 | * | |
1231 | * @nvmem: nvmem device to read from. | |
1232 | * @info: nvmem cell info to be read. | |
1233 | * @buf: buffer pointer which will be populated on successful read. | |
1234 | * | |
1235 | * Return: length of successful bytes read on success and negative | |
1236 | * error code on error. | |
1237 | */ | |
1238 | ssize_t nvmem_device_cell_read(struct nvmem_device *nvmem, | |
1239 | struct nvmem_cell_info *info, void *buf) | |
1240 | { | |
1241 | struct nvmem_cell cell; | |
1242 | int rc; | |
1243 | ssize_t len; | |
1244 | ||
795ddd18 | 1245 | if (!nvmem) |
e2a5402e SK |
1246 | return -EINVAL; |
1247 | ||
1248 | rc = nvmem_cell_info_to_nvmem_cell(nvmem, info, &cell); | |
287980e4 | 1249 | if (rc) |
e2a5402e SK |
1250 | return rc; |
1251 | ||
1252 | rc = __nvmem_cell_read(nvmem, &cell, buf, &len); | |
287980e4 | 1253 | if (rc) |
e2a5402e SK |
1254 | return rc; |
1255 | ||
1256 | return len; | |
1257 | } | |
1258 | EXPORT_SYMBOL_GPL(nvmem_device_cell_read); | |
1259 | ||
1260 | /** | |
1261 | * nvmem_device_cell_write() - Write cell to a given nvmem device | |
1262 | * | |
1263 | * @nvmem: nvmem device to be written to. | |
29143268 | 1264 | * @info: nvmem cell info to be written. |
e2a5402e SK |
1265 | * @buf: buffer to be written to cell. |
1266 | * | |
1267 | * Return: length of bytes written or negative error code on failure. | |
1268 | * */ | |
1269 | int nvmem_device_cell_write(struct nvmem_device *nvmem, | |
1270 | struct nvmem_cell_info *info, void *buf) | |
1271 | { | |
1272 | struct nvmem_cell cell; | |
1273 | int rc; | |
1274 | ||
795ddd18 | 1275 | if (!nvmem) |
e2a5402e SK |
1276 | return -EINVAL; |
1277 | ||
1278 | rc = nvmem_cell_info_to_nvmem_cell(nvmem, info, &cell); | |
287980e4 | 1279 | if (rc) |
e2a5402e SK |
1280 | return rc; |
1281 | ||
1282 | return nvmem_cell_write(&cell, buf, cell.bytes); | |
1283 | } | |
1284 | EXPORT_SYMBOL_GPL(nvmem_device_cell_write); | |
1285 | ||
1286 | /** | |
1287 | * nvmem_device_read() - Read from a given nvmem device | |
1288 | * | |
1289 | * @nvmem: nvmem device to read from. | |
1290 | * @offset: offset in nvmem device. | |
1291 | * @bytes: number of bytes to read. | |
1292 | * @buf: buffer pointer which will be populated on successful read. | |
1293 | * | |
1294 | * Return: length of successful bytes read on success and negative | |
1295 | * error code on error. | |
1296 | */ | |
1297 | int nvmem_device_read(struct nvmem_device *nvmem, | |
1298 | unsigned int offset, | |
1299 | size_t bytes, void *buf) | |
1300 | { | |
1301 | int rc; | |
1302 | ||
795ddd18 | 1303 | if (!nvmem) |
e2a5402e SK |
1304 | return -EINVAL; |
1305 | ||
795ddd18 | 1306 | rc = nvmem_reg_read(nvmem, offset, buf, bytes); |
e2a5402e | 1307 | |
287980e4 | 1308 | if (rc) |
e2a5402e SK |
1309 | return rc; |
1310 | ||
1311 | return bytes; | |
1312 | } | |
1313 | EXPORT_SYMBOL_GPL(nvmem_device_read); | |
1314 | ||
1315 | /** | |
1316 | * nvmem_device_write() - Write cell to a given nvmem device | |
1317 | * | |
1318 | * @nvmem: nvmem device to be written to. | |
1319 | * @offset: offset in nvmem device. | |
1320 | * @bytes: number of bytes to write. | |
1321 | * @buf: buffer to be written. | |
1322 | * | |
1323 | * Return: length of bytes written or negative error code on failure. | |
1324 | * */ | |
1325 | int nvmem_device_write(struct nvmem_device *nvmem, | |
1326 | unsigned int offset, | |
1327 | size_t bytes, void *buf) | |
1328 | { | |
1329 | int rc; | |
1330 | ||
795ddd18 | 1331 | if (!nvmem) |
e2a5402e SK |
1332 | return -EINVAL; |
1333 | ||
795ddd18 | 1334 | rc = nvmem_reg_write(nvmem, offset, buf, bytes); |
e2a5402e | 1335 | |
287980e4 | 1336 | if (rc) |
e2a5402e SK |
1337 | return rc; |
1338 | ||
1339 | ||
1340 | return bytes; | |
1341 | } | |
1342 | EXPORT_SYMBOL_GPL(nvmem_device_write); | |
1343 | ||
eace75cf SK |
1344 | static int __init nvmem_init(void) |
1345 | { | |
1346 | return bus_register(&nvmem_bus_type); | |
1347 | } | |
1348 | ||
1349 | static void __exit nvmem_exit(void) | |
1350 | { | |
1351 | bus_unregister(&nvmem_bus_type); | |
1352 | } | |
1353 | ||
1354 | subsys_initcall(nvmem_init); | |
1355 | module_exit(nvmem_exit); | |
1356 | ||
1357 | MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org"); | |
1358 | MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com"); | |
1359 | MODULE_DESCRIPTION("nvmem Driver Core"); | |
1360 | MODULE_LICENSE("GPL v2"); |