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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> | |
c1de7f43 | 22 | #include <linux/kref.h> |
eace75cf SK |
23 | #include <linux/module.h> |
24 | #include <linux/nvmem-consumer.h> | |
25 | #include <linux/nvmem-provider.h> | |
26 | #include <linux/of.h> | |
eace75cf SK |
27 | #include <linux/slab.h> |
28 | ||
29 | struct nvmem_device { | |
eace75cf SK |
30 | struct module *owner; |
31 | struct device dev; | |
32 | int stride; | |
33 | int word_size; | |
eace75cf | 34 | int id; |
c1de7f43 | 35 | struct kref refcnt; |
eace75cf SK |
36 | size_t size; |
37 | bool read_only; | |
b6c217ab AL |
38 | int flags; |
39 | struct bin_attribute eeprom; | |
40 | struct device *base_dev; | |
795ddd18 SK |
41 | nvmem_reg_read_t reg_read; |
42 | nvmem_reg_write_t reg_write; | |
43 | void *priv; | |
eace75cf SK |
44 | }; |
45 | ||
b6c217ab AL |
46 | #define FLAG_COMPAT BIT(0) |
47 | ||
eace75cf SK |
48 | struct nvmem_cell { |
49 | const char *name; | |
50 | int offset; | |
51 | int bytes; | |
52 | int bit_offset; | |
53 | int nbits; | |
54 | struct nvmem_device *nvmem; | |
55 | struct list_head node; | |
56 | }; | |
57 | ||
58 | static DEFINE_MUTEX(nvmem_mutex); | |
59 | static DEFINE_IDA(nvmem_ida); | |
60 | ||
61 | static LIST_HEAD(nvmem_cells); | |
62 | static DEFINE_MUTEX(nvmem_cells_mutex); | |
63 | ||
b6c217ab AL |
64 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
65 | static struct lock_class_key eeprom_lock_key; | |
66 | #endif | |
67 | ||
eace75cf | 68 | #define to_nvmem_device(d) container_of(d, struct nvmem_device, dev) |
795ddd18 SK |
69 | static int nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset, |
70 | void *val, size_t bytes) | |
71 | { | |
72 | if (nvmem->reg_read) | |
73 | return nvmem->reg_read(nvmem->priv, offset, val, bytes); | |
74 | ||
75 | return -EINVAL; | |
76 | } | |
77 | ||
78 | static int nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset, | |
79 | void *val, size_t bytes) | |
80 | { | |
81 | if (nvmem->reg_write) | |
82 | return nvmem->reg_write(nvmem->priv, offset, val, bytes); | |
83 | ||
84 | return -EINVAL; | |
85 | } | |
eace75cf SK |
86 | |
87 | static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj, | |
88 | struct bin_attribute *attr, | |
89 | char *buf, loff_t pos, size_t count) | |
90 | { | |
b6c217ab AL |
91 | struct device *dev; |
92 | struct nvmem_device *nvmem; | |
eace75cf SK |
93 | int rc; |
94 | ||
b6c217ab AL |
95 | if (attr->private) |
96 | dev = attr->private; | |
97 | else | |
98 | dev = container_of(kobj, struct device, kobj); | |
99 | nvmem = to_nvmem_device(dev); | |
100 | ||
eace75cf | 101 | /* Stop the user from reading */ |
7c806883 | 102 | if (pos >= nvmem->size) |
eace75cf SK |
103 | return 0; |
104 | ||
313a72ff SK |
105 | if (count < nvmem->word_size) |
106 | return -EINVAL; | |
107 | ||
eace75cf SK |
108 | if (pos + count > nvmem->size) |
109 | count = nvmem->size - pos; | |
110 | ||
111 | count = round_down(count, nvmem->word_size); | |
112 | ||
795ddd18 | 113 | rc = nvmem_reg_read(nvmem, pos, buf, count); |
eace75cf | 114 | |
287980e4 | 115 | if (rc) |
eace75cf SK |
116 | return rc; |
117 | ||
118 | return count; | |
119 | } | |
120 | ||
121 | static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj, | |
122 | struct bin_attribute *attr, | |
123 | char *buf, loff_t pos, size_t count) | |
124 | { | |
b6c217ab AL |
125 | struct device *dev; |
126 | struct nvmem_device *nvmem; | |
eace75cf SK |
127 | int rc; |
128 | ||
b6c217ab AL |
129 | if (attr->private) |
130 | dev = attr->private; | |
131 | else | |
132 | dev = container_of(kobj, struct device, kobj); | |
133 | nvmem = to_nvmem_device(dev); | |
134 | ||
eace75cf | 135 | /* Stop the user from writing */ |
7c806883 | 136 | if (pos >= nvmem->size) |
38b0774c | 137 | return -EFBIG; |
eace75cf | 138 | |
313a72ff SK |
139 | if (count < nvmem->word_size) |
140 | return -EINVAL; | |
141 | ||
eace75cf SK |
142 | if (pos + count > nvmem->size) |
143 | count = nvmem->size - pos; | |
144 | ||
145 | count = round_down(count, nvmem->word_size); | |
146 | ||
795ddd18 | 147 | rc = nvmem_reg_write(nvmem, pos, buf, count); |
eace75cf | 148 | |
287980e4 | 149 | if (rc) |
eace75cf SK |
150 | return rc; |
151 | ||
152 | return count; | |
153 | } | |
154 | ||
155 | /* default read/write permissions */ | |
156 | static struct bin_attribute bin_attr_rw_nvmem = { | |
157 | .attr = { | |
158 | .name = "nvmem", | |
159 | .mode = S_IWUSR | S_IRUGO, | |
160 | }, | |
161 | .read = bin_attr_nvmem_read, | |
162 | .write = bin_attr_nvmem_write, | |
163 | }; | |
164 | ||
165 | static struct bin_attribute *nvmem_bin_rw_attributes[] = { | |
166 | &bin_attr_rw_nvmem, | |
167 | NULL, | |
168 | }; | |
169 | ||
170 | static const struct attribute_group nvmem_bin_rw_group = { | |
171 | .bin_attrs = nvmem_bin_rw_attributes, | |
172 | }; | |
173 | ||
174 | static const struct attribute_group *nvmem_rw_dev_groups[] = { | |
175 | &nvmem_bin_rw_group, | |
176 | NULL, | |
177 | }; | |
178 | ||
179 | /* read only permission */ | |
180 | static struct bin_attribute bin_attr_ro_nvmem = { | |
181 | .attr = { | |
182 | .name = "nvmem", | |
183 | .mode = S_IRUGO, | |
184 | }, | |
185 | .read = bin_attr_nvmem_read, | |
186 | }; | |
187 | ||
188 | static struct bin_attribute *nvmem_bin_ro_attributes[] = { | |
189 | &bin_attr_ro_nvmem, | |
190 | NULL, | |
191 | }; | |
192 | ||
193 | static const struct attribute_group nvmem_bin_ro_group = { | |
194 | .bin_attrs = nvmem_bin_ro_attributes, | |
195 | }; | |
196 | ||
197 | static const struct attribute_group *nvmem_ro_dev_groups[] = { | |
198 | &nvmem_bin_ro_group, | |
199 | NULL, | |
200 | }; | |
201 | ||
811b0d65 AL |
202 | /* default read/write permissions, root only */ |
203 | static struct bin_attribute bin_attr_rw_root_nvmem = { | |
204 | .attr = { | |
205 | .name = "nvmem", | |
206 | .mode = S_IWUSR | S_IRUSR, | |
207 | }, | |
208 | .read = bin_attr_nvmem_read, | |
209 | .write = bin_attr_nvmem_write, | |
210 | }; | |
211 | ||
212 | static struct bin_attribute *nvmem_bin_rw_root_attributes[] = { | |
213 | &bin_attr_rw_root_nvmem, | |
214 | NULL, | |
215 | }; | |
216 | ||
217 | static const struct attribute_group nvmem_bin_rw_root_group = { | |
218 | .bin_attrs = nvmem_bin_rw_root_attributes, | |
219 | }; | |
220 | ||
221 | static const struct attribute_group *nvmem_rw_root_dev_groups[] = { | |
222 | &nvmem_bin_rw_root_group, | |
223 | NULL, | |
224 | }; | |
225 | ||
226 | /* read only permission, root only */ | |
227 | static struct bin_attribute bin_attr_ro_root_nvmem = { | |
228 | .attr = { | |
229 | .name = "nvmem", | |
230 | .mode = S_IRUSR, | |
231 | }, | |
232 | .read = bin_attr_nvmem_read, | |
233 | }; | |
234 | ||
235 | static struct bin_attribute *nvmem_bin_ro_root_attributes[] = { | |
236 | &bin_attr_ro_root_nvmem, | |
237 | NULL, | |
238 | }; | |
239 | ||
240 | static const struct attribute_group nvmem_bin_ro_root_group = { | |
241 | .bin_attrs = nvmem_bin_ro_root_attributes, | |
242 | }; | |
243 | ||
244 | static const struct attribute_group *nvmem_ro_root_dev_groups[] = { | |
245 | &nvmem_bin_ro_root_group, | |
246 | NULL, | |
247 | }; | |
248 | ||
eace75cf SK |
249 | static void nvmem_release(struct device *dev) |
250 | { | |
251 | struct nvmem_device *nvmem = to_nvmem_device(dev); | |
252 | ||
253 | ida_simple_remove(&nvmem_ida, nvmem->id); | |
254 | kfree(nvmem); | |
255 | } | |
256 | ||
257 | static const struct device_type nvmem_provider_type = { | |
258 | .release = nvmem_release, | |
259 | }; | |
260 | ||
261 | static struct bus_type nvmem_bus_type = { | |
262 | .name = "nvmem", | |
263 | }; | |
264 | ||
265 | static int of_nvmem_match(struct device *dev, void *nvmem_np) | |
266 | { | |
267 | return dev->of_node == nvmem_np; | |
268 | } | |
269 | ||
270 | static struct nvmem_device *of_nvmem_find(struct device_node *nvmem_np) | |
271 | { | |
272 | struct device *d; | |
273 | ||
274 | if (!nvmem_np) | |
275 | return NULL; | |
276 | ||
277 | d = bus_find_device(&nvmem_bus_type, NULL, nvmem_np, of_nvmem_match); | |
278 | ||
279 | if (!d) | |
280 | return NULL; | |
281 | ||
282 | return to_nvmem_device(d); | |
283 | } | |
284 | ||
285 | static struct nvmem_cell *nvmem_find_cell(const char *cell_id) | |
286 | { | |
287 | struct nvmem_cell *p; | |
288 | ||
666d6a36 HK |
289 | mutex_lock(&nvmem_cells_mutex); |
290 | ||
eace75cf | 291 | list_for_each_entry(p, &nvmem_cells, node) |
fd086113 | 292 | if (!strcmp(p->name, cell_id)) { |
666d6a36 | 293 | mutex_unlock(&nvmem_cells_mutex); |
eace75cf | 294 | return p; |
666d6a36 HK |
295 | } |
296 | ||
297 | mutex_unlock(&nvmem_cells_mutex); | |
eace75cf SK |
298 | |
299 | return NULL; | |
300 | } | |
301 | ||
302 | static void nvmem_cell_drop(struct nvmem_cell *cell) | |
303 | { | |
304 | mutex_lock(&nvmem_cells_mutex); | |
305 | list_del(&cell->node); | |
306 | mutex_unlock(&nvmem_cells_mutex); | |
307 | kfree(cell); | |
308 | } | |
309 | ||
310 | static void nvmem_device_remove_all_cells(const struct nvmem_device *nvmem) | |
311 | { | |
1852183e | 312 | struct nvmem_cell *cell, *p; |
eace75cf | 313 | |
1852183e | 314 | list_for_each_entry_safe(cell, p, &nvmem_cells, node) |
eace75cf SK |
315 | if (cell->nvmem == nvmem) |
316 | nvmem_cell_drop(cell); | |
eace75cf SK |
317 | } |
318 | ||
319 | static void nvmem_cell_add(struct nvmem_cell *cell) | |
320 | { | |
321 | mutex_lock(&nvmem_cells_mutex); | |
322 | list_add_tail(&cell->node, &nvmem_cells); | |
323 | mutex_unlock(&nvmem_cells_mutex); | |
324 | } | |
325 | ||
326 | static int nvmem_cell_info_to_nvmem_cell(struct nvmem_device *nvmem, | |
327 | const struct nvmem_cell_info *info, | |
328 | struct nvmem_cell *cell) | |
329 | { | |
330 | cell->nvmem = nvmem; | |
331 | cell->offset = info->offset; | |
332 | cell->bytes = info->bytes; | |
333 | cell->name = info->name; | |
334 | ||
335 | cell->bit_offset = info->bit_offset; | |
336 | cell->nbits = info->nbits; | |
337 | ||
338 | if (cell->nbits) | |
339 | cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset, | |
340 | BITS_PER_BYTE); | |
341 | ||
342 | if (!IS_ALIGNED(cell->offset, nvmem->stride)) { | |
343 | dev_err(&nvmem->dev, | |
344 | "cell %s unaligned to nvmem stride %d\n", | |
345 | cell->name, nvmem->stride); | |
346 | return -EINVAL; | |
347 | } | |
348 | ||
349 | return 0; | |
350 | } | |
351 | ||
b3db17e4 AL |
352 | /** |
353 | * nvmem_add_cells() - Add cell information to an nvmem device | |
354 | * | |
355 | * @nvmem: nvmem device to add cells to. | |
356 | * @info: nvmem cell info to add to the device | |
357 | * @ncells: number of cells in info | |
358 | * | |
359 | * Return: 0 or negative error code on failure. | |
360 | */ | |
361 | int nvmem_add_cells(struct nvmem_device *nvmem, | |
362 | const struct nvmem_cell_info *info, | |
363 | int ncells) | |
eace75cf SK |
364 | { |
365 | struct nvmem_cell **cells; | |
eace75cf SK |
366 | int i, rval; |
367 | ||
b3db17e4 | 368 | cells = kcalloc(ncells, sizeof(*cells), GFP_KERNEL); |
eace75cf SK |
369 | if (!cells) |
370 | return -ENOMEM; | |
371 | ||
b3db17e4 | 372 | for (i = 0; i < ncells; i++) { |
eace75cf SK |
373 | cells[i] = kzalloc(sizeof(**cells), GFP_KERNEL); |
374 | if (!cells[i]) { | |
375 | rval = -ENOMEM; | |
376 | goto err; | |
377 | } | |
378 | ||
379 | rval = nvmem_cell_info_to_nvmem_cell(nvmem, &info[i], cells[i]); | |
287980e4 | 380 | if (rval) { |
eace75cf SK |
381 | kfree(cells[i]); |
382 | goto err; | |
383 | } | |
384 | ||
385 | nvmem_cell_add(cells[i]); | |
386 | } | |
387 | ||
eace75cf SK |
388 | /* remove tmp array */ |
389 | kfree(cells); | |
390 | ||
391 | return 0; | |
392 | err: | |
dfdf1414 | 393 | while (i--) |
eace75cf SK |
394 | nvmem_cell_drop(cells[i]); |
395 | ||
dfdf1414 RV |
396 | kfree(cells); |
397 | ||
eace75cf SK |
398 | return rval; |
399 | } | |
b3db17e4 | 400 | EXPORT_SYMBOL_GPL(nvmem_add_cells); |
eace75cf | 401 | |
b6c217ab AL |
402 | /* |
403 | * nvmem_setup_compat() - Create an additional binary entry in | |
404 | * drivers sys directory, to be backwards compatible with the older | |
405 | * drivers/misc/eeprom drivers. | |
406 | */ | |
407 | static int nvmem_setup_compat(struct nvmem_device *nvmem, | |
408 | const struct nvmem_config *config) | |
409 | { | |
410 | int rval; | |
411 | ||
412 | if (!config->base_dev) | |
413 | return -EINVAL; | |
414 | ||
415 | if (nvmem->read_only) | |
416 | nvmem->eeprom = bin_attr_ro_root_nvmem; | |
417 | else | |
418 | nvmem->eeprom = bin_attr_rw_root_nvmem; | |
419 | nvmem->eeprom.attr.name = "eeprom"; | |
420 | nvmem->eeprom.size = nvmem->size; | |
421 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
422 | nvmem->eeprom.attr.key = &eeprom_lock_key; | |
423 | #endif | |
424 | nvmem->eeprom.private = &nvmem->dev; | |
425 | nvmem->base_dev = config->base_dev; | |
426 | ||
427 | rval = device_create_bin_file(nvmem->base_dev, &nvmem->eeprom); | |
428 | if (rval) { | |
429 | dev_err(&nvmem->dev, | |
430 | "Failed to create eeprom binary file %d\n", rval); | |
431 | return rval; | |
432 | } | |
433 | ||
434 | nvmem->flags |= FLAG_COMPAT; | |
435 | ||
436 | return 0; | |
437 | } | |
438 | ||
eace75cf SK |
439 | /** |
440 | * nvmem_register() - Register a nvmem device for given nvmem_config. | |
441 | * Also creates an binary entry in /sys/bus/nvmem/devices/dev-name/nvmem | |
442 | * | |
443 | * @config: nvmem device configuration with which nvmem device is created. | |
444 | * | |
445 | * Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device | |
446 | * on success. | |
447 | */ | |
448 | ||
449 | struct nvmem_device *nvmem_register(const struct nvmem_config *config) | |
450 | { | |
451 | struct nvmem_device *nvmem; | |
eace75cf SK |
452 | int rval; |
453 | ||
454 | if (!config->dev) | |
455 | return ERR_PTR(-EINVAL); | |
456 | ||
eace75cf SK |
457 | nvmem = kzalloc(sizeof(*nvmem), GFP_KERNEL); |
458 | if (!nvmem) | |
459 | return ERR_PTR(-ENOMEM); | |
460 | ||
461 | rval = ida_simple_get(&nvmem_ida, 0, 0, GFP_KERNEL); | |
462 | if (rval < 0) { | |
463 | kfree(nvmem); | |
464 | return ERR_PTR(rval); | |
465 | } | |
466 | ||
c1de7f43 BG |
467 | kref_init(&nvmem->refcnt); |
468 | ||
eace75cf | 469 | nvmem->id = rval; |
eace75cf | 470 | nvmem->owner = config->owner; |
17eb18d6 MY |
471 | if (!nvmem->owner && config->dev->driver) |
472 | nvmem->owner = config->dev->driver->owner; | |
99897efd HK |
473 | nvmem->stride = config->stride ?: 1; |
474 | nvmem->word_size = config->word_size ?: 1; | |
795ddd18 | 475 | nvmem->size = config->size; |
eace75cf SK |
476 | nvmem->dev.type = &nvmem_provider_type; |
477 | nvmem->dev.bus = &nvmem_bus_type; | |
478 | nvmem->dev.parent = config->dev; | |
795ddd18 SK |
479 | nvmem->priv = config->priv; |
480 | nvmem->reg_read = config->reg_read; | |
481 | nvmem->reg_write = config->reg_write; | |
fc2f9970 | 482 | nvmem->dev.of_node = config->dev->of_node; |
fd0f4906 AS |
483 | |
484 | if (config->id == -1 && config->name) { | |
485 | dev_set_name(&nvmem->dev, "%s", config->name); | |
486 | } else { | |
487 | dev_set_name(&nvmem->dev, "%s%d", | |
488 | config->name ? : "nvmem", | |
489 | config->name ? config->id : nvmem->id); | |
490 | } | |
eace75cf | 491 | |
fc2f9970 | 492 | nvmem->read_only = device_property_present(config->dev, "read-only") | |
eace75cf SK |
493 | config->read_only; |
494 | ||
811b0d65 AL |
495 | if (config->root_only) |
496 | nvmem->dev.groups = nvmem->read_only ? | |
497 | nvmem_ro_root_dev_groups : | |
498 | nvmem_rw_root_dev_groups; | |
499 | else | |
500 | nvmem->dev.groups = nvmem->read_only ? | |
501 | nvmem_ro_dev_groups : | |
502 | nvmem_rw_dev_groups; | |
eace75cf SK |
503 | |
504 | device_initialize(&nvmem->dev); | |
505 | ||
506 | dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name); | |
507 | ||
508 | rval = device_add(&nvmem->dev); | |
b6c217ab | 509 | if (rval) |
3360acdf | 510 | goto err_put_device; |
b6c217ab AL |
511 | |
512 | if (config->compat) { | |
513 | rval = nvmem_setup_compat(nvmem, config); | |
514 | if (rval) | |
3360acdf | 515 | goto err_device_del; |
eace75cf SK |
516 | } |
517 | ||
fa72d847 BG |
518 | if (config->cells) { |
519 | rval = nvmem_add_cells(nvmem, config->cells, config->ncells); | |
520 | if (rval) | |
521 | goto err_teardown_compat; | |
522 | } | |
eace75cf SK |
523 | |
524 | return nvmem; | |
3360acdf | 525 | |
fa72d847 BG |
526 | err_teardown_compat: |
527 | if (config->compat) | |
528 | device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom); | |
3360acdf JH |
529 | err_device_del: |
530 | device_del(&nvmem->dev); | |
531 | err_put_device: | |
532 | put_device(&nvmem->dev); | |
533 | ||
b6c217ab | 534 | return ERR_PTR(rval); |
eace75cf SK |
535 | } |
536 | EXPORT_SYMBOL_GPL(nvmem_register); | |
537 | ||
c1de7f43 BG |
538 | static void nvmem_device_release(struct kref *kref) |
539 | { | |
540 | struct nvmem_device *nvmem; | |
541 | ||
542 | nvmem = container_of(kref, struct nvmem_device, refcnt); | |
543 | ||
544 | if (nvmem->flags & FLAG_COMPAT) | |
545 | device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom); | |
546 | ||
547 | nvmem_device_remove_all_cells(nvmem); | |
548 | device_del(&nvmem->dev); | |
549 | put_device(&nvmem->dev); | |
550 | } | |
551 | ||
eace75cf SK |
552 | /** |
553 | * nvmem_unregister() - Unregister previously registered nvmem device | |
554 | * | |
555 | * @nvmem: Pointer to previously registered nvmem device. | |
eace75cf | 556 | */ |
bf58e882 | 557 | void nvmem_unregister(struct nvmem_device *nvmem) |
eace75cf | 558 | { |
c1de7f43 | 559 | kref_put(&nvmem->refcnt, nvmem_device_release); |
eace75cf SK |
560 | } |
561 | EXPORT_SYMBOL_GPL(nvmem_unregister); | |
562 | ||
f1f50eca AS |
563 | static void devm_nvmem_release(struct device *dev, void *res) |
564 | { | |
bf58e882 | 565 | nvmem_unregister(*(struct nvmem_device **)res); |
f1f50eca AS |
566 | } |
567 | ||
568 | /** | |
569 | * devm_nvmem_register() - Register a managed nvmem device for given | |
570 | * nvmem_config. | |
571 | * Also creates an binary entry in /sys/bus/nvmem/devices/dev-name/nvmem | |
572 | * | |
b378c779 | 573 | * @dev: Device that uses the nvmem device. |
f1f50eca AS |
574 | * @config: nvmem device configuration with which nvmem device is created. |
575 | * | |
576 | * Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device | |
577 | * on success. | |
578 | */ | |
579 | struct nvmem_device *devm_nvmem_register(struct device *dev, | |
580 | const struct nvmem_config *config) | |
581 | { | |
582 | struct nvmem_device **ptr, *nvmem; | |
583 | ||
584 | ptr = devres_alloc(devm_nvmem_release, sizeof(*ptr), GFP_KERNEL); | |
585 | if (!ptr) | |
586 | return ERR_PTR(-ENOMEM); | |
587 | ||
588 | nvmem = nvmem_register(config); | |
589 | ||
590 | if (!IS_ERR(nvmem)) { | |
591 | *ptr = nvmem; | |
592 | devres_add(dev, ptr); | |
593 | } else { | |
594 | devres_free(ptr); | |
595 | } | |
596 | ||
597 | return nvmem; | |
598 | } | |
599 | EXPORT_SYMBOL_GPL(devm_nvmem_register); | |
600 | ||
601 | static int devm_nvmem_match(struct device *dev, void *res, void *data) | |
602 | { | |
603 | struct nvmem_device **r = res; | |
604 | ||
605 | return *r == data; | |
606 | } | |
607 | ||
608 | /** | |
609 | * devm_nvmem_unregister() - Unregister previously registered managed nvmem | |
610 | * device. | |
611 | * | |
b378c779 | 612 | * @dev: Device that uses the nvmem device. |
f1f50eca AS |
613 | * @nvmem: Pointer to previously registered nvmem device. |
614 | * | |
615 | * Return: Will be an negative on error or a zero on success. | |
616 | */ | |
617 | int devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem) | |
618 | { | |
619 | return devres_release(dev, devm_nvmem_release, devm_nvmem_match, nvmem); | |
620 | } | |
621 | EXPORT_SYMBOL(devm_nvmem_unregister); | |
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 | ||
69aba794 SK |
651 | mutex_unlock(&nvmem_mutex); |
652 | ||
653 | if (!try_module_get(nvmem->owner)) { | |
654 | dev_err(&nvmem->dev, | |
655 | "could not increase module refcount for cell %s\n", | |
5db652c9 | 656 | nvmem_dev_name(nvmem)); |
69aba794 | 657 | |
69aba794 SK |
658 | return ERR_PTR(-EINVAL); |
659 | } | |
660 | ||
c1de7f43 BG |
661 | kref_get(&nvmem->refcnt); |
662 | ||
69aba794 SK |
663 | return nvmem; |
664 | } | |
665 | ||
666 | static void __nvmem_device_put(struct nvmem_device *nvmem) | |
667 | { | |
668 | module_put(nvmem->owner); | |
c1de7f43 | 669 | kref_put(&nvmem->refcnt, nvmem_device_release); |
69aba794 SK |
670 | } |
671 | ||
e2a5402e SK |
672 | static struct nvmem_device *nvmem_find(const char *name) |
673 | { | |
674 | struct device *d; | |
675 | ||
9f3044c3 | 676 | d = bus_find_device_by_name(&nvmem_bus_type, NULL, name); |
e2a5402e SK |
677 | |
678 | if (!d) | |
ca6ac25c | 679 | return ERR_PTR(-ENOENT); |
e2a5402e SK |
680 | |
681 | return to_nvmem_device(d); | |
682 | } | |
683 | ||
e701c67c | 684 | #if IS_ENABLED(CONFIG_OF) |
e2a5402e SK |
685 | /** |
686 | * of_nvmem_device_get() - Get nvmem device from a given id | |
687 | * | |
29143268 | 688 | * @np: Device tree node that uses the nvmem device. |
e2a5402e SK |
689 | * @id: nvmem name from nvmem-names property. |
690 | * | |
691 | * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device | |
692 | * on success. | |
693 | */ | |
694 | struct nvmem_device *of_nvmem_device_get(struct device_node *np, const char *id) | |
695 | { | |
696 | ||
697 | struct device_node *nvmem_np; | |
698 | int index; | |
699 | ||
700 | index = of_property_match_string(np, "nvmem-names", id); | |
701 | ||
702 | nvmem_np = of_parse_phandle(np, "nvmem", index); | |
703 | if (!nvmem_np) | |
704 | return ERR_PTR(-EINVAL); | |
705 | ||
706 | return __nvmem_device_get(nvmem_np, NULL, NULL); | |
707 | } | |
708 | EXPORT_SYMBOL_GPL(of_nvmem_device_get); | |
709 | #endif | |
710 | ||
711 | /** | |
712 | * nvmem_device_get() - Get nvmem device from a given id | |
713 | * | |
29143268 VG |
714 | * @dev: Device that uses the nvmem device. |
715 | * @dev_name: name of the requested nvmem device. | |
e2a5402e SK |
716 | * |
717 | * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device | |
718 | * on success. | |
719 | */ | |
720 | struct nvmem_device *nvmem_device_get(struct device *dev, const char *dev_name) | |
721 | { | |
722 | if (dev->of_node) { /* try dt first */ | |
723 | struct nvmem_device *nvmem; | |
724 | ||
725 | nvmem = of_nvmem_device_get(dev->of_node, dev_name); | |
726 | ||
727 | if (!IS_ERR(nvmem) || PTR_ERR(nvmem) == -EPROBE_DEFER) | |
728 | return nvmem; | |
729 | ||
730 | } | |
731 | ||
732 | return nvmem_find(dev_name); | |
733 | } | |
734 | EXPORT_SYMBOL_GPL(nvmem_device_get); | |
735 | ||
736 | static int devm_nvmem_device_match(struct device *dev, void *res, void *data) | |
737 | { | |
738 | struct nvmem_device **nvmem = res; | |
739 | ||
740 | if (WARN_ON(!nvmem || !*nvmem)) | |
741 | return 0; | |
742 | ||
743 | return *nvmem == data; | |
744 | } | |
745 | ||
746 | static void devm_nvmem_device_release(struct device *dev, void *res) | |
747 | { | |
748 | nvmem_device_put(*(struct nvmem_device **)res); | |
749 | } | |
750 | ||
751 | /** | |
752 | * devm_nvmem_device_put() - put alredy got nvmem device | |
753 | * | |
29143268 | 754 | * @dev: Device that uses the nvmem device. |
e2a5402e SK |
755 | * @nvmem: pointer to nvmem device allocated by devm_nvmem_cell_get(), |
756 | * that needs to be released. | |
757 | */ | |
758 | void devm_nvmem_device_put(struct device *dev, struct nvmem_device *nvmem) | |
759 | { | |
760 | int ret; | |
761 | ||
762 | ret = devres_release(dev, devm_nvmem_device_release, | |
763 | devm_nvmem_device_match, nvmem); | |
764 | ||
765 | WARN_ON(ret); | |
766 | } | |
767 | EXPORT_SYMBOL_GPL(devm_nvmem_device_put); | |
768 | ||
769 | /** | |
770 | * nvmem_device_put() - put alredy got nvmem device | |
771 | * | |
772 | * @nvmem: pointer to nvmem device that needs to be released. | |
773 | */ | |
774 | void nvmem_device_put(struct nvmem_device *nvmem) | |
775 | { | |
776 | __nvmem_device_put(nvmem); | |
777 | } | |
778 | EXPORT_SYMBOL_GPL(nvmem_device_put); | |
779 | ||
780 | /** | |
781 | * devm_nvmem_device_get() - Get nvmem cell of device form a given id | |
782 | * | |
29143268 VG |
783 | * @dev: Device that requests the nvmem device. |
784 | * @id: name id for the requested nvmem device. | |
e2a5402e SK |
785 | * |
786 | * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_cell | |
787 | * on success. The nvmem_cell will be freed by the automatically once the | |
788 | * device is freed. | |
789 | */ | |
790 | struct nvmem_device *devm_nvmem_device_get(struct device *dev, const char *id) | |
791 | { | |
792 | struct nvmem_device **ptr, *nvmem; | |
793 | ||
794 | ptr = devres_alloc(devm_nvmem_device_release, sizeof(*ptr), GFP_KERNEL); | |
795 | if (!ptr) | |
796 | return ERR_PTR(-ENOMEM); | |
797 | ||
798 | nvmem = nvmem_device_get(dev, id); | |
799 | if (!IS_ERR(nvmem)) { | |
800 | *ptr = nvmem; | |
801 | devres_add(dev, ptr); | |
802 | } else { | |
803 | devres_free(ptr); | |
804 | } | |
805 | ||
806 | return nvmem; | |
807 | } | |
808 | EXPORT_SYMBOL_GPL(devm_nvmem_device_get); | |
809 | ||
69aba794 SK |
810 | static struct nvmem_cell *nvmem_cell_get_from_list(const char *cell_id) |
811 | { | |
812 | struct nvmem_cell *cell = NULL; | |
813 | struct nvmem_device *nvmem; | |
814 | ||
815 | nvmem = __nvmem_device_get(NULL, &cell, cell_id); | |
816 | if (IS_ERR(nvmem)) | |
817 | return ERR_CAST(nvmem); | |
818 | ||
819 | return cell; | |
820 | } | |
821 | ||
e701c67c | 822 | #if IS_ENABLED(CONFIG_OF) |
69aba794 SK |
823 | /** |
824 | * of_nvmem_cell_get() - Get a nvmem cell from given device node and cell id | |
825 | * | |
29143268 | 826 | * @np: Device tree node that uses the nvmem cell. |
fd0c478c VG |
827 | * @name: nvmem cell name from nvmem-cell-names property, or NULL |
828 | * for the cell at index 0 (the lone cell with no accompanying | |
829 | * nvmem-cell-names property). | |
69aba794 SK |
830 | * |
831 | * Return: Will be an ERR_PTR() on error or a valid pointer | |
832 | * to a struct nvmem_cell. The nvmem_cell will be freed by the | |
833 | * nvmem_cell_put(). | |
834 | */ | |
835 | struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, | |
836 | const char *name) | |
837 | { | |
838 | struct device_node *cell_np, *nvmem_np; | |
839 | struct nvmem_cell *cell; | |
840 | struct nvmem_device *nvmem; | |
841 | const __be32 *addr; | |
fd0c478c VG |
842 | int rval, len; |
843 | int index = 0; | |
69aba794 | 844 | |
fd0c478c VG |
845 | /* if cell name exists, find index to the name */ |
846 | if (name) | |
847 | index = of_property_match_string(np, "nvmem-cell-names", name); | |
69aba794 SK |
848 | |
849 | cell_np = of_parse_phandle(np, "nvmem-cells", index); | |
850 | if (!cell_np) | |
851 | return ERR_PTR(-EINVAL); | |
852 | ||
853 | nvmem_np = of_get_next_parent(cell_np); | |
854 | if (!nvmem_np) | |
855 | return ERR_PTR(-EINVAL); | |
856 | ||
857 | nvmem = __nvmem_device_get(nvmem_np, NULL, NULL); | |
aad8d097 | 858 | of_node_put(nvmem_np); |
69aba794 SK |
859 | if (IS_ERR(nvmem)) |
860 | return ERR_CAST(nvmem); | |
861 | ||
862 | addr = of_get_property(cell_np, "reg", &len); | |
863 | if (!addr || (len < 2 * sizeof(u32))) { | |
5f214ccd RH |
864 | dev_err(&nvmem->dev, "nvmem: invalid reg on %pOF\n", |
865 | cell_np); | |
69aba794 SK |
866 | rval = -EINVAL; |
867 | goto err_mem; | |
868 | } | |
869 | ||
870 | cell = kzalloc(sizeof(*cell), GFP_KERNEL); | |
871 | if (!cell) { | |
872 | rval = -ENOMEM; | |
873 | goto err_mem; | |
874 | } | |
875 | ||
876 | cell->nvmem = nvmem; | |
877 | cell->offset = be32_to_cpup(addr++); | |
878 | cell->bytes = be32_to_cpup(addr); | |
879 | cell->name = cell_np->name; | |
880 | ||
881 | addr = of_get_property(cell_np, "bits", &len); | |
882 | if (addr && len == (2 * sizeof(u32))) { | |
883 | cell->bit_offset = be32_to_cpup(addr++); | |
884 | cell->nbits = be32_to_cpup(addr); | |
885 | } | |
886 | ||
887 | if (cell->nbits) | |
888 | cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset, | |
889 | BITS_PER_BYTE); | |
890 | ||
891 | if (!IS_ALIGNED(cell->offset, nvmem->stride)) { | |
892 | dev_err(&nvmem->dev, | |
893 | "cell %s unaligned to nvmem stride %d\n", | |
894 | cell->name, nvmem->stride); | |
895 | rval = -EINVAL; | |
896 | goto err_sanity; | |
897 | } | |
898 | ||
899 | nvmem_cell_add(cell); | |
900 | ||
901 | return cell; | |
902 | ||
903 | err_sanity: | |
904 | kfree(cell); | |
905 | ||
906 | err_mem: | |
907 | __nvmem_device_put(nvmem); | |
908 | ||
909 | return ERR_PTR(rval); | |
910 | } | |
911 | EXPORT_SYMBOL_GPL(of_nvmem_cell_get); | |
912 | #endif | |
913 | ||
914 | /** | |
915 | * nvmem_cell_get() - Get nvmem cell of device form a given cell name | |
916 | * | |
29143268 VG |
917 | * @dev: Device that requests the nvmem cell. |
918 | * @cell_id: nvmem cell name to get. | |
69aba794 SK |
919 | * |
920 | * Return: Will be an ERR_PTR() on error or a valid pointer | |
921 | * to a struct nvmem_cell. The nvmem_cell will be freed by the | |
922 | * nvmem_cell_put(). | |
923 | */ | |
924 | struct nvmem_cell *nvmem_cell_get(struct device *dev, const char *cell_id) | |
925 | { | |
926 | struct nvmem_cell *cell; | |
927 | ||
928 | if (dev->of_node) { /* try dt first */ | |
929 | cell = of_nvmem_cell_get(dev->of_node, cell_id); | |
930 | if (!IS_ERR(cell) || PTR_ERR(cell) == -EPROBE_DEFER) | |
931 | return cell; | |
932 | } | |
933 | ||
87ed1405 DA |
934 | /* NULL cell_id only allowed for device tree; invalid otherwise */ |
935 | if (!cell_id) | |
936 | return ERR_PTR(-EINVAL); | |
937 | ||
69aba794 SK |
938 | return nvmem_cell_get_from_list(cell_id); |
939 | } | |
940 | EXPORT_SYMBOL_GPL(nvmem_cell_get); | |
941 | ||
942 | static void devm_nvmem_cell_release(struct device *dev, void *res) | |
943 | { | |
944 | nvmem_cell_put(*(struct nvmem_cell **)res); | |
945 | } | |
946 | ||
947 | /** | |
948 | * devm_nvmem_cell_get() - Get nvmem cell of device form a given id | |
949 | * | |
29143268 VG |
950 | * @dev: Device that requests the nvmem cell. |
951 | * @id: nvmem cell name id to get. | |
69aba794 SK |
952 | * |
953 | * Return: Will be an ERR_PTR() on error or a valid pointer | |
954 | * to a struct nvmem_cell. The nvmem_cell will be freed by the | |
955 | * automatically once the device is freed. | |
956 | */ | |
957 | struct nvmem_cell *devm_nvmem_cell_get(struct device *dev, const char *id) | |
958 | { | |
959 | struct nvmem_cell **ptr, *cell; | |
960 | ||
961 | ptr = devres_alloc(devm_nvmem_cell_release, sizeof(*ptr), GFP_KERNEL); | |
962 | if (!ptr) | |
963 | return ERR_PTR(-ENOMEM); | |
964 | ||
965 | cell = nvmem_cell_get(dev, id); | |
966 | if (!IS_ERR(cell)) { | |
967 | *ptr = cell; | |
968 | devres_add(dev, ptr); | |
969 | } else { | |
970 | devres_free(ptr); | |
971 | } | |
972 | ||
973 | return cell; | |
974 | } | |
975 | EXPORT_SYMBOL_GPL(devm_nvmem_cell_get); | |
976 | ||
977 | static int devm_nvmem_cell_match(struct device *dev, void *res, void *data) | |
978 | { | |
979 | struct nvmem_cell **c = res; | |
980 | ||
981 | if (WARN_ON(!c || !*c)) | |
982 | return 0; | |
983 | ||
984 | return *c == data; | |
985 | } | |
986 | ||
987 | /** | |
988 | * devm_nvmem_cell_put() - Release previously allocated nvmem cell | |
989 | * from devm_nvmem_cell_get. | |
990 | * | |
29143268 VG |
991 | * @dev: Device that requests the nvmem cell. |
992 | * @cell: Previously allocated nvmem cell by devm_nvmem_cell_get(). | |
69aba794 SK |
993 | */ |
994 | void devm_nvmem_cell_put(struct device *dev, struct nvmem_cell *cell) | |
995 | { | |
996 | int ret; | |
997 | ||
998 | ret = devres_release(dev, devm_nvmem_cell_release, | |
999 | devm_nvmem_cell_match, cell); | |
1000 | ||
1001 | WARN_ON(ret); | |
1002 | } | |
1003 | EXPORT_SYMBOL(devm_nvmem_cell_put); | |
1004 | ||
1005 | /** | |
1006 | * nvmem_cell_put() - Release previously allocated nvmem cell. | |
1007 | * | |
29143268 | 1008 | * @cell: Previously allocated nvmem cell by nvmem_cell_get(). |
69aba794 SK |
1009 | */ |
1010 | void nvmem_cell_put(struct nvmem_cell *cell) | |
1011 | { | |
1012 | struct nvmem_device *nvmem = cell->nvmem; | |
1013 | ||
1014 | __nvmem_device_put(nvmem); | |
1015 | nvmem_cell_drop(cell); | |
1016 | } | |
1017 | EXPORT_SYMBOL_GPL(nvmem_cell_put); | |
1018 | ||
f7c04f16 | 1019 | static void nvmem_shift_read_buffer_in_place(struct nvmem_cell *cell, void *buf) |
69aba794 SK |
1020 | { |
1021 | u8 *p, *b; | |
1022 | int i, bit_offset = cell->bit_offset; | |
1023 | ||
1024 | p = b = buf; | |
1025 | if (bit_offset) { | |
1026 | /* First shift */ | |
1027 | *b++ >>= bit_offset; | |
1028 | ||
1029 | /* setup rest of the bytes if any */ | |
1030 | for (i = 1; i < cell->bytes; i++) { | |
1031 | /* Get bits from next byte and shift them towards msb */ | |
1032 | *p |= *b << (BITS_PER_BYTE - bit_offset); | |
1033 | ||
1034 | p = b; | |
1035 | *b++ >>= bit_offset; | |
1036 | } | |
1037 | ||
1038 | /* result fits in less bytes */ | |
1039 | if (cell->bytes != DIV_ROUND_UP(cell->nbits, BITS_PER_BYTE)) | |
1040 | *p-- = 0; | |
1041 | } | |
1042 | /* clear msb bits if any leftover in the last byte */ | |
1043 | *p &= GENMASK((cell->nbits%BITS_PER_BYTE) - 1, 0); | |
1044 | } | |
1045 | ||
1046 | static int __nvmem_cell_read(struct nvmem_device *nvmem, | |
1047 | struct nvmem_cell *cell, | |
1048 | void *buf, size_t *len) | |
1049 | { | |
1050 | int rc; | |
1051 | ||
795ddd18 | 1052 | rc = nvmem_reg_read(nvmem, cell->offset, buf, cell->bytes); |
69aba794 | 1053 | |
287980e4 | 1054 | if (rc) |
69aba794 SK |
1055 | return rc; |
1056 | ||
1057 | /* shift bits in-place */ | |
cbf854ab | 1058 | if (cell->bit_offset || cell->nbits) |
69aba794 SK |
1059 | nvmem_shift_read_buffer_in_place(cell, buf); |
1060 | ||
3b4a6877 VG |
1061 | if (len) |
1062 | *len = cell->bytes; | |
69aba794 SK |
1063 | |
1064 | return 0; | |
1065 | } | |
1066 | ||
1067 | /** | |
1068 | * nvmem_cell_read() - Read a given nvmem cell | |
1069 | * | |
1070 | * @cell: nvmem cell to be read. | |
3b4a6877 VG |
1071 | * @len: pointer to length of cell which will be populated on successful read; |
1072 | * can be NULL. | |
69aba794 | 1073 | * |
b577fafc BN |
1074 | * Return: ERR_PTR() on error or a valid pointer to a buffer on success. The |
1075 | * buffer should be freed by the consumer with a kfree(). | |
69aba794 SK |
1076 | */ |
1077 | void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len) | |
1078 | { | |
1079 | struct nvmem_device *nvmem = cell->nvmem; | |
1080 | u8 *buf; | |
1081 | int rc; | |
1082 | ||
795ddd18 | 1083 | if (!nvmem) |
69aba794 SK |
1084 | return ERR_PTR(-EINVAL); |
1085 | ||
1086 | buf = kzalloc(cell->bytes, GFP_KERNEL); | |
1087 | if (!buf) | |
1088 | return ERR_PTR(-ENOMEM); | |
1089 | ||
1090 | rc = __nvmem_cell_read(nvmem, cell, buf, len); | |
287980e4 | 1091 | if (rc) { |
69aba794 SK |
1092 | kfree(buf); |
1093 | return ERR_PTR(rc); | |
1094 | } | |
1095 | ||
1096 | return buf; | |
1097 | } | |
1098 | EXPORT_SYMBOL_GPL(nvmem_cell_read); | |
1099 | ||
f7c04f16 MY |
1100 | static void *nvmem_cell_prepare_write_buffer(struct nvmem_cell *cell, |
1101 | u8 *_buf, int len) | |
69aba794 SK |
1102 | { |
1103 | struct nvmem_device *nvmem = cell->nvmem; | |
1104 | int i, rc, nbits, bit_offset = cell->bit_offset; | |
1105 | u8 v, *p, *buf, *b, pbyte, pbits; | |
1106 | ||
1107 | nbits = cell->nbits; | |
1108 | buf = kzalloc(cell->bytes, GFP_KERNEL); | |
1109 | if (!buf) | |
1110 | return ERR_PTR(-ENOMEM); | |
1111 | ||
1112 | memcpy(buf, _buf, len); | |
1113 | p = b = buf; | |
1114 | ||
1115 | if (bit_offset) { | |
1116 | pbyte = *b; | |
1117 | *b <<= bit_offset; | |
1118 | ||
1119 | /* setup the first byte with lsb bits from nvmem */ | |
795ddd18 | 1120 | rc = nvmem_reg_read(nvmem, cell->offset, &v, 1); |
50808bfc MM |
1121 | if (rc) |
1122 | goto err; | |
69aba794 SK |
1123 | *b++ |= GENMASK(bit_offset - 1, 0) & v; |
1124 | ||
1125 | /* setup rest of the byte if any */ | |
1126 | for (i = 1; i < cell->bytes; i++) { | |
1127 | /* Get last byte bits and shift them towards lsb */ | |
1128 | pbits = pbyte >> (BITS_PER_BYTE - 1 - bit_offset); | |
1129 | pbyte = *b; | |
1130 | p = b; | |
1131 | *b <<= bit_offset; | |
1132 | *b++ |= pbits; | |
1133 | } | |
1134 | } | |
1135 | ||
1136 | /* if it's not end on byte boundary */ | |
1137 | if ((nbits + bit_offset) % BITS_PER_BYTE) { | |
1138 | /* setup the last byte with msb bits from nvmem */ | |
795ddd18 | 1139 | rc = nvmem_reg_read(nvmem, |
69aba794 | 1140 | cell->offset + cell->bytes - 1, &v, 1); |
50808bfc MM |
1141 | if (rc) |
1142 | goto err; | |
69aba794 SK |
1143 | *p |= GENMASK(7, (nbits + bit_offset) % BITS_PER_BYTE) & v; |
1144 | ||
1145 | } | |
1146 | ||
1147 | return buf; | |
50808bfc MM |
1148 | err: |
1149 | kfree(buf); | |
1150 | return ERR_PTR(rc); | |
69aba794 SK |
1151 | } |
1152 | ||
1153 | /** | |
1154 | * nvmem_cell_write() - Write to a given nvmem cell | |
1155 | * | |
1156 | * @cell: nvmem cell to be written. | |
1157 | * @buf: Buffer to be written. | |
1158 | * @len: length of buffer to be written to nvmem cell. | |
1159 | * | |
1160 | * Return: length of bytes written or negative on failure. | |
1161 | */ | |
1162 | int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len) | |
1163 | { | |
1164 | struct nvmem_device *nvmem = cell->nvmem; | |
1165 | int rc; | |
1166 | ||
795ddd18 | 1167 | if (!nvmem || nvmem->read_only || |
69aba794 SK |
1168 | (cell->bit_offset == 0 && len != cell->bytes)) |
1169 | return -EINVAL; | |
1170 | ||
1171 | if (cell->bit_offset || cell->nbits) { | |
1172 | buf = nvmem_cell_prepare_write_buffer(cell, buf, len); | |
1173 | if (IS_ERR(buf)) | |
1174 | return PTR_ERR(buf); | |
1175 | } | |
1176 | ||
795ddd18 | 1177 | rc = nvmem_reg_write(nvmem, cell->offset, buf, cell->bytes); |
69aba794 SK |
1178 | |
1179 | /* free the tmp buffer */ | |
ace22170 | 1180 | if (cell->bit_offset || cell->nbits) |
69aba794 SK |
1181 | kfree(buf); |
1182 | ||
287980e4 | 1183 | if (rc) |
69aba794 SK |
1184 | return rc; |
1185 | ||
1186 | return len; | |
1187 | } | |
1188 | EXPORT_SYMBOL_GPL(nvmem_cell_write); | |
1189 | ||
d026d70a LC |
1190 | /** |
1191 | * nvmem_cell_read_u32() - Read a cell value as an u32 | |
1192 | * | |
1193 | * @dev: Device that requests the nvmem cell. | |
1194 | * @cell_id: Name of nvmem cell to read. | |
1195 | * @val: pointer to output value. | |
1196 | * | |
1197 | * Return: 0 on success or negative errno. | |
1198 | */ | |
1199 | int nvmem_cell_read_u32(struct device *dev, const char *cell_id, u32 *val) | |
1200 | { | |
1201 | struct nvmem_cell *cell; | |
1202 | void *buf; | |
1203 | size_t len; | |
1204 | ||
1205 | cell = nvmem_cell_get(dev, cell_id); | |
1206 | if (IS_ERR(cell)) | |
1207 | return PTR_ERR(cell); | |
1208 | ||
1209 | buf = nvmem_cell_read(cell, &len); | |
1210 | if (IS_ERR(buf)) { | |
1211 | nvmem_cell_put(cell); | |
1212 | return PTR_ERR(buf); | |
1213 | } | |
1214 | if (len != sizeof(*val)) { | |
1215 | kfree(buf); | |
1216 | nvmem_cell_put(cell); | |
1217 | return -EINVAL; | |
1218 | } | |
1219 | memcpy(val, buf, sizeof(*val)); | |
1220 | ||
1221 | kfree(buf); | |
1222 | nvmem_cell_put(cell); | |
1223 | return 0; | |
1224 | } | |
1225 | EXPORT_SYMBOL_GPL(nvmem_cell_read_u32); | |
1226 | ||
e2a5402e SK |
1227 | /** |
1228 | * nvmem_device_cell_read() - Read a given nvmem device and cell | |
1229 | * | |
1230 | * @nvmem: nvmem device to read from. | |
1231 | * @info: nvmem cell info to be read. | |
1232 | * @buf: buffer pointer which will be populated on successful read. | |
1233 | * | |
1234 | * Return: length of successful bytes read on success and negative | |
1235 | * error code on error. | |
1236 | */ | |
1237 | ssize_t nvmem_device_cell_read(struct nvmem_device *nvmem, | |
1238 | struct nvmem_cell_info *info, void *buf) | |
1239 | { | |
1240 | struct nvmem_cell cell; | |
1241 | int rc; | |
1242 | ssize_t len; | |
1243 | ||
795ddd18 | 1244 | if (!nvmem) |
e2a5402e SK |
1245 | return -EINVAL; |
1246 | ||
1247 | rc = nvmem_cell_info_to_nvmem_cell(nvmem, info, &cell); | |
287980e4 | 1248 | if (rc) |
e2a5402e SK |
1249 | return rc; |
1250 | ||
1251 | rc = __nvmem_cell_read(nvmem, &cell, buf, &len); | |
287980e4 | 1252 | if (rc) |
e2a5402e SK |
1253 | return rc; |
1254 | ||
1255 | return len; | |
1256 | } | |
1257 | EXPORT_SYMBOL_GPL(nvmem_device_cell_read); | |
1258 | ||
1259 | /** | |
1260 | * nvmem_device_cell_write() - Write cell to a given nvmem device | |
1261 | * | |
1262 | * @nvmem: nvmem device to be written to. | |
29143268 | 1263 | * @info: nvmem cell info to be written. |
e2a5402e SK |
1264 | * @buf: buffer to be written to cell. |
1265 | * | |
1266 | * Return: length of bytes written or negative error code on failure. | |
1267 | * */ | |
1268 | int nvmem_device_cell_write(struct nvmem_device *nvmem, | |
1269 | struct nvmem_cell_info *info, void *buf) | |
1270 | { | |
1271 | struct nvmem_cell cell; | |
1272 | int rc; | |
1273 | ||
795ddd18 | 1274 | if (!nvmem) |
e2a5402e SK |
1275 | return -EINVAL; |
1276 | ||
1277 | rc = nvmem_cell_info_to_nvmem_cell(nvmem, info, &cell); | |
287980e4 | 1278 | if (rc) |
e2a5402e SK |
1279 | return rc; |
1280 | ||
1281 | return nvmem_cell_write(&cell, buf, cell.bytes); | |
1282 | } | |
1283 | EXPORT_SYMBOL_GPL(nvmem_device_cell_write); | |
1284 | ||
1285 | /** | |
1286 | * nvmem_device_read() - Read from a given nvmem device | |
1287 | * | |
1288 | * @nvmem: nvmem device to read from. | |
1289 | * @offset: offset in nvmem device. | |
1290 | * @bytes: number of bytes to read. | |
1291 | * @buf: buffer pointer which will be populated on successful read. | |
1292 | * | |
1293 | * Return: length of successful bytes read on success and negative | |
1294 | * error code on error. | |
1295 | */ | |
1296 | int nvmem_device_read(struct nvmem_device *nvmem, | |
1297 | unsigned int offset, | |
1298 | size_t bytes, void *buf) | |
1299 | { | |
1300 | int rc; | |
1301 | ||
795ddd18 | 1302 | if (!nvmem) |
e2a5402e SK |
1303 | return -EINVAL; |
1304 | ||
795ddd18 | 1305 | rc = nvmem_reg_read(nvmem, offset, buf, bytes); |
e2a5402e | 1306 | |
287980e4 | 1307 | if (rc) |
e2a5402e SK |
1308 | return rc; |
1309 | ||
1310 | return bytes; | |
1311 | } | |
1312 | EXPORT_SYMBOL_GPL(nvmem_device_read); | |
1313 | ||
1314 | /** | |
1315 | * nvmem_device_write() - Write cell to a given nvmem device | |
1316 | * | |
1317 | * @nvmem: nvmem device to be written to. | |
1318 | * @offset: offset in nvmem device. | |
1319 | * @bytes: number of bytes to write. | |
1320 | * @buf: buffer to be written. | |
1321 | * | |
1322 | * Return: length of bytes written or negative error code on failure. | |
1323 | * */ | |
1324 | int nvmem_device_write(struct nvmem_device *nvmem, | |
1325 | unsigned int offset, | |
1326 | size_t bytes, void *buf) | |
1327 | { | |
1328 | int rc; | |
1329 | ||
795ddd18 | 1330 | if (!nvmem) |
e2a5402e SK |
1331 | return -EINVAL; |
1332 | ||
795ddd18 | 1333 | rc = nvmem_reg_write(nvmem, offset, buf, bytes); |
e2a5402e | 1334 | |
287980e4 | 1335 | if (rc) |
e2a5402e SK |
1336 | return rc; |
1337 | ||
1338 | ||
1339 | return bytes; | |
1340 | } | |
1341 | EXPORT_SYMBOL_GPL(nvmem_device_write); | |
1342 | ||
d7b9fd16 BG |
1343 | /** |
1344 | * nvmem_dev_name() - Get the name of a given nvmem device. | |
1345 | * | |
1346 | * @nvmem: nvmem device. | |
1347 | * | |
1348 | * Return: name of the nvmem device. | |
1349 | */ | |
1350 | const char *nvmem_dev_name(struct nvmem_device *nvmem) | |
1351 | { | |
1352 | return dev_name(&nvmem->dev); | |
1353 | } | |
1354 | EXPORT_SYMBOL_GPL(nvmem_dev_name); | |
1355 | ||
eace75cf SK |
1356 | static int __init nvmem_init(void) |
1357 | { | |
1358 | return bus_register(&nvmem_bus_type); | |
1359 | } | |
1360 | ||
1361 | static void __exit nvmem_exit(void) | |
1362 | { | |
1363 | bus_unregister(&nvmem_bus_type); | |
1364 | } | |
1365 | ||
1366 | subsys_initcall(nvmem_init); | |
1367 | module_exit(nvmem_exit); | |
1368 | ||
1369 | MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org"); | |
1370 | MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com"); | |
1371 | MODULE_DESCRIPTION("nvmem Driver Core"); | |
1372 | MODULE_LICENSE("GPL v2"); |