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eace75cf SK |
1 | /* |
2 | * nvmem framework core. | |
3 | * | |
4 | * Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla@linaro.org> | |
5 | * Copyright (C) 2013 Maxime Ripard <maxime.ripard@free-electrons.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 and | |
9 | * only version 2 as published by the Free Software Foundation. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | */ | |
16 | ||
17 | #include <linux/device.h> | |
18 | #include <linux/export.h> | |
19 | #include <linux/fs.h> | |
20 | #include <linux/idr.h> | |
21 | #include <linux/init.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/nvmem-consumer.h> | |
24 | #include <linux/nvmem-provider.h> | |
25 | #include <linux/of.h> | |
26 | #include <linux/regmap.h> | |
27 | #include <linux/slab.h> | |
28 | ||
29 | struct nvmem_device { | |
30 | const char *name; | |
31 | struct regmap *regmap; | |
32 | struct module *owner; | |
33 | struct device dev; | |
34 | int stride; | |
35 | int word_size; | |
36 | int ncells; | |
37 | int id; | |
38 | int users; | |
39 | size_t size; | |
40 | bool read_only; | |
41 | }; | |
42 | ||
43 | struct nvmem_cell { | |
44 | const char *name; | |
45 | int offset; | |
46 | int bytes; | |
47 | int bit_offset; | |
48 | int nbits; | |
49 | struct nvmem_device *nvmem; | |
50 | struct list_head node; | |
51 | }; | |
52 | ||
53 | static DEFINE_MUTEX(nvmem_mutex); | |
54 | static DEFINE_IDA(nvmem_ida); | |
55 | ||
56 | static LIST_HEAD(nvmem_cells); | |
57 | static DEFINE_MUTEX(nvmem_cells_mutex); | |
58 | ||
59 | #define to_nvmem_device(d) container_of(d, struct nvmem_device, dev) | |
60 | ||
61 | static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj, | |
62 | struct bin_attribute *attr, | |
63 | char *buf, loff_t pos, size_t count) | |
64 | { | |
65 | struct device *dev = container_of(kobj, struct device, kobj); | |
66 | struct nvmem_device *nvmem = to_nvmem_device(dev); | |
67 | int rc; | |
68 | ||
69 | /* Stop the user from reading */ | |
7c806883 | 70 | if (pos >= nvmem->size) |
eace75cf SK |
71 | return 0; |
72 | ||
73 | if (pos + count > nvmem->size) | |
74 | count = nvmem->size - pos; | |
75 | ||
76 | count = round_down(count, nvmem->word_size); | |
77 | ||
78 | rc = regmap_raw_read(nvmem->regmap, pos, buf, count); | |
79 | ||
80 | if (IS_ERR_VALUE(rc)) | |
81 | return rc; | |
82 | ||
83 | return count; | |
84 | } | |
85 | ||
86 | static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj, | |
87 | struct bin_attribute *attr, | |
88 | char *buf, loff_t pos, size_t count) | |
89 | { | |
90 | struct device *dev = container_of(kobj, struct device, kobj); | |
91 | struct nvmem_device *nvmem = to_nvmem_device(dev); | |
92 | int rc; | |
93 | ||
94 | /* Stop the user from writing */ | |
7c806883 | 95 | if (pos >= nvmem->size) |
eace75cf SK |
96 | return 0; |
97 | ||
98 | if (pos + count > nvmem->size) | |
99 | count = nvmem->size - pos; | |
100 | ||
101 | count = round_down(count, nvmem->word_size); | |
102 | ||
103 | rc = regmap_raw_write(nvmem->regmap, pos, buf, count); | |
104 | ||
105 | if (IS_ERR_VALUE(rc)) | |
106 | return rc; | |
107 | ||
108 | return count; | |
109 | } | |
110 | ||
111 | /* default read/write permissions */ | |
112 | static struct bin_attribute bin_attr_rw_nvmem = { | |
113 | .attr = { | |
114 | .name = "nvmem", | |
115 | .mode = S_IWUSR | S_IRUGO, | |
116 | }, | |
117 | .read = bin_attr_nvmem_read, | |
118 | .write = bin_attr_nvmem_write, | |
119 | }; | |
120 | ||
121 | static struct bin_attribute *nvmem_bin_rw_attributes[] = { | |
122 | &bin_attr_rw_nvmem, | |
123 | NULL, | |
124 | }; | |
125 | ||
126 | static const struct attribute_group nvmem_bin_rw_group = { | |
127 | .bin_attrs = nvmem_bin_rw_attributes, | |
128 | }; | |
129 | ||
130 | static const struct attribute_group *nvmem_rw_dev_groups[] = { | |
131 | &nvmem_bin_rw_group, | |
132 | NULL, | |
133 | }; | |
134 | ||
135 | /* read only permission */ | |
136 | static struct bin_attribute bin_attr_ro_nvmem = { | |
137 | .attr = { | |
138 | .name = "nvmem", | |
139 | .mode = S_IRUGO, | |
140 | }, | |
141 | .read = bin_attr_nvmem_read, | |
142 | }; | |
143 | ||
144 | static struct bin_attribute *nvmem_bin_ro_attributes[] = { | |
145 | &bin_attr_ro_nvmem, | |
146 | NULL, | |
147 | }; | |
148 | ||
149 | static const struct attribute_group nvmem_bin_ro_group = { | |
150 | .bin_attrs = nvmem_bin_ro_attributes, | |
151 | }; | |
152 | ||
153 | static const struct attribute_group *nvmem_ro_dev_groups[] = { | |
154 | &nvmem_bin_ro_group, | |
155 | NULL, | |
156 | }; | |
157 | ||
158 | static void nvmem_release(struct device *dev) | |
159 | { | |
160 | struct nvmem_device *nvmem = to_nvmem_device(dev); | |
161 | ||
162 | ida_simple_remove(&nvmem_ida, nvmem->id); | |
163 | kfree(nvmem); | |
164 | } | |
165 | ||
166 | static const struct device_type nvmem_provider_type = { | |
167 | .release = nvmem_release, | |
168 | }; | |
169 | ||
170 | static struct bus_type nvmem_bus_type = { | |
171 | .name = "nvmem", | |
172 | }; | |
173 | ||
174 | static int of_nvmem_match(struct device *dev, void *nvmem_np) | |
175 | { | |
176 | return dev->of_node == nvmem_np; | |
177 | } | |
178 | ||
179 | static struct nvmem_device *of_nvmem_find(struct device_node *nvmem_np) | |
180 | { | |
181 | struct device *d; | |
182 | ||
183 | if (!nvmem_np) | |
184 | return NULL; | |
185 | ||
186 | d = bus_find_device(&nvmem_bus_type, NULL, nvmem_np, of_nvmem_match); | |
187 | ||
188 | if (!d) | |
189 | return NULL; | |
190 | ||
191 | return to_nvmem_device(d); | |
192 | } | |
193 | ||
194 | static struct nvmem_cell *nvmem_find_cell(const char *cell_id) | |
195 | { | |
196 | struct nvmem_cell *p; | |
197 | ||
198 | list_for_each_entry(p, &nvmem_cells, node) | |
199 | if (p && !strcmp(p->name, cell_id)) | |
200 | return p; | |
201 | ||
202 | return NULL; | |
203 | } | |
204 | ||
205 | static void nvmem_cell_drop(struct nvmem_cell *cell) | |
206 | { | |
207 | mutex_lock(&nvmem_cells_mutex); | |
208 | list_del(&cell->node); | |
209 | mutex_unlock(&nvmem_cells_mutex); | |
210 | kfree(cell); | |
211 | } | |
212 | ||
213 | static void nvmem_device_remove_all_cells(const struct nvmem_device *nvmem) | |
214 | { | |
215 | struct nvmem_cell *cell; | |
216 | struct list_head *p, *n; | |
217 | ||
218 | list_for_each_safe(p, n, &nvmem_cells) { | |
219 | cell = list_entry(p, struct nvmem_cell, node); | |
220 | if (cell->nvmem == nvmem) | |
221 | nvmem_cell_drop(cell); | |
222 | } | |
223 | } | |
224 | ||
225 | static void nvmem_cell_add(struct nvmem_cell *cell) | |
226 | { | |
227 | mutex_lock(&nvmem_cells_mutex); | |
228 | list_add_tail(&cell->node, &nvmem_cells); | |
229 | mutex_unlock(&nvmem_cells_mutex); | |
230 | } | |
231 | ||
232 | static int nvmem_cell_info_to_nvmem_cell(struct nvmem_device *nvmem, | |
233 | const struct nvmem_cell_info *info, | |
234 | struct nvmem_cell *cell) | |
235 | { | |
236 | cell->nvmem = nvmem; | |
237 | cell->offset = info->offset; | |
238 | cell->bytes = info->bytes; | |
239 | cell->name = info->name; | |
240 | ||
241 | cell->bit_offset = info->bit_offset; | |
242 | cell->nbits = info->nbits; | |
243 | ||
244 | if (cell->nbits) | |
245 | cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset, | |
246 | BITS_PER_BYTE); | |
247 | ||
248 | if (!IS_ALIGNED(cell->offset, nvmem->stride)) { | |
249 | dev_err(&nvmem->dev, | |
250 | "cell %s unaligned to nvmem stride %d\n", | |
251 | cell->name, nvmem->stride); | |
252 | return -EINVAL; | |
253 | } | |
254 | ||
255 | return 0; | |
256 | } | |
257 | ||
258 | static int nvmem_add_cells(struct nvmem_device *nvmem, | |
259 | const struct nvmem_config *cfg) | |
260 | { | |
261 | struct nvmem_cell **cells; | |
262 | const struct nvmem_cell_info *info = cfg->cells; | |
263 | int i, rval; | |
264 | ||
265 | cells = kcalloc(cfg->ncells, sizeof(*cells), GFP_KERNEL); | |
266 | if (!cells) | |
267 | return -ENOMEM; | |
268 | ||
269 | for (i = 0; i < cfg->ncells; i++) { | |
270 | cells[i] = kzalloc(sizeof(**cells), GFP_KERNEL); | |
271 | if (!cells[i]) { | |
272 | rval = -ENOMEM; | |
273 | goto err; | |
274 | } | |
275 | ||
276 | rval = nvmem_cell_info_to_nvmem_cell(nvmem, &info[i], cells[i]); | |
277 | if (IS_ERR_VALUE(rval)) { | |
278 | kfree(cells[i]); | |
279 | goto err; | |
280 | } | |
281 | ||
282 | nvmem_cell_add(cells[i]); | |
283 | } | |
284 | ||
285 | nvmem->ncells = cfg->ncells; | |
286 | /* remove tmp array */ | |
287 | kfree(cells); | |
288 | ||
289 | return 0; | |
290 | err: | |
291 | while (--i) | |
292 | nvmem_cell_drop(cells[i]); | |
293 | ||
294 | return rval; | |
295 | } | |
296 | ||
297 | /** | |
298 | * nvmem_register() - Register a nvmem device for given nvmem_config. | |
299 | * Also creates an binary entry in /sys/bus/nvmem/devices/dev-name/nvmem | |
300 | * | |
301 | * @config: nvmem device configuration with which nvmem device is created. | |
302 | * | |
303 | * Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device | |
304 | * on success. | |
305 | */ | |
306 | ||
307 | struct nvmem_device *nvmem_register(const struct nvmem_config *config) | |
308 | { | |
309 | struct nvmem_device *nvmem; | |
310 | struct device_node *np; | |
311 | struct regmap *rm; | |
312 | int rval; | |
313 | ||
314 | if (!config->dev) | |
315 | return ERR_PTR(-EINVAL); | |
316 | ||
317 | rm = dev_get_regmap(config->dev, NULL); | |
318 | if (!rm) { | |
319 | dev_err(config->dev, "Regmap not found\n"); | |
320 | return ERR_PTR(-EINVAL); | |
321 | } | |
322 | ||
323 | nvmem = kzalloc(sizeof(*nvmem), GFP_KERNEL); | |
324 | if (!nvmem) | |
325 | return ERR_PTR(-ENOMEM); | |
326 | ||
327 | rval = ida_simple_get(&nvmem_ida, 0, 0, GFP_KERNEL); | |
328 | if (rval < 0) { | |
329 | kfree(nvmem); | |
330 | return ERR_PTR(rval); | |
331 | } | |
332 | ||
333 | nvmem->id = rval; | |
334 | nvmem->regmap = rm; | |
335 | nvmem->owner = config->owner; | |
336 | nvmem->stride = regmap_get_reg_stride(rm); | |
337 | nvmem->word_size = regmap_get_val_bytes(rm); | |
338 | nvmem->size = regmap_get_max_register(rm) + nvmem->stride; | |
339 | nvmem->dev.type = &nvmem_provider_type; | |
340 | nvmem->dev.bus = &nvmem_bus_type; | |
341 | nvmem->dev.parent = config->dev; | |
342 | np = config->dev->of_node; | |
343 | nvmem->dev.of_node = np; | |
344 | dev_set_name(&nvmem->dev, "%s%d", | |
345 | config->name ? : "nvmem", config->id); | |
346 | ||
347 | nvmem->read_only = of_property_read_bool(np, "read-only") | | |
348 | config->read_only; | |
349 | ||
350 | nvmem->dev.groups = nvmem->read_only ? nvmem_ro_dev_groups : | |
351 | nvmem_rw_dev_groups; | |
352 | ||
353 | device_initialize(&nvmem->dev); | |
354 | ||
355 | dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name); | |
356 | ||
357 | rval = device_add(&nvmem->dev); | |
358 | if (rval) { | |
359 | ida_simple_remove(&nvmem_ida, nvmem->id); | |
360 | kfree(nvmem); | |
361 | return ERR_PTR(rval); | |
362 | } | |
363 | ||
364 | if (config->cells) | |
365 | nvmem_add_cells(nvmem, config); | |
366 | ||
367 | return nvmem; | |
368 | } | |
369 | EXPORT_SYMBOL_GPL(nvmem_register); | |
370 | ||
371 | /** | |
372 | * nvmem_unregister() - Unregister previously registered nvmem device | |
373 | * | |
374 | * @nvmem: Pointer to previously registered nvmem device. | |
375 | * | |
376 | * Return: Will be an negative on error or a zero on success. | |
377 | */ | |
378 | int nvmem_unregister(struct nvmem_device *nvmem) | |
379 | { | |
69aba794 SK |
380 | mutex_lock(&nvmem_mutex); |
381 | if (nvmem->users) { | |
382 | mutex_unlock(&nvmem_mutex); | |
eace75cf | 383 | return -EBUSY; |
69aba794 SK |
384 | } |
385 | mutex_unlock(&nvmem_mutex); | |
eace75cf SK |
386 | |
387 | nvmem_device_remove_all_cells(nvmem); | |
388 | device_del(&nvmem->dev); | |
389 | ||
390 | return 0; | |
391 | } | |
392 | EXPORT_SYMBOL_GPL(nvmem_unregister); | |
393 | ||
69aba794 SK |
394 | static struct nvmem_device *__nvmem_device_get(struct device_node *np, |
395 | struct nvmem_cell **cellp, | |
396 | const char *cell_id) | |
397 | { | |
398 | struct nvmem_device *nvmem = NULL; | |
399 | ||
400 | mutex_lock(&nvmem_mutex); | |
401 | ||
402 | if (np) { | |
403 | nvmem = of_nvmem_find(np); | |
404 | if (!nvmem) { | |
405 | mutex_unlock(&nvmem_mutex); | |
406 | return ERR_PTR(-EPROBE_DEFER); | |
407 | } | |
408 | } else { | |
409 | struct nvmem_cell *cell = nvmem_find_cell(cell_id); | |
410 | ||
411 | if (cell) { | |
412 | nvmem = cell->nvmem; | |
413 | *cellp = cell; | |
414 | } | |
415 | ||
416 | if (!nvmem) { | |
417 | mutex_unlock(&nvmem_mutex); | |
418 | return ERR_PTR(-ENOENT); | |
419 | } | |
420 | } | |
421 | ||
422 | nvmem->users++; | |
423 | mutex_unlock(&nvmem_mutex); | |
424 | ||
425 | if (!try_module_get(nvmem->owner)) { | |
426 | dev_err(&nvmem->dev, | |
427 | "could not increase module refcount for cell %s\n", | |
428 | nvmem->name); | |
429 | ||
430 | mutex_lock(&nvmem_mutex); | |
431 | nvmem->users--; | |
432 | mutex_unlock(&nvmem_mutex); | |
433 | ||
434 | return ERR_PTR(-EINVAL); | |
435 | } | |
436 | ||
437 | return nvmem; | |
438 | } | |
439 | ||
440 | static void __nvmem_device_put(struct nvmem_device *nvmem) | |
441 | { | |
442 | module_put(nvmem->owner); | |
443 | mutex_lock(&nvmem_mutex); | |
444 | nvmem->users--; | |
445 | mutex_unlock(&nvmem_mutex); | |
446 | } | |
447 | ||
e2a5402e SK |
448 | static int nvmem_match(struct device *dev, void *data) |
449 | { | |
450 | return !strcmp(dev_name(dev), data); | |
451 | } | |
452 | ||
453 | static struct nvmem_device *nvmem_find(const char *name) | |
454 | { | |
455 | struct device *d; | |
456 | ||
457 | d = bus_find_device(&nvmem_bus_type, NULL, (void *)name, nvmem_match); | |
458 | ||
459 | if (!d) | |
460 | return NULL; | |
461 | ||
462 | return to_nvmem_device(d); | |
463 | } | |
464 | ||
465 | #if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OF) | |
466 | /** | |
467 | * of_nvmem_device_get() - Get nvmem device from a given id | |
468 | * | |
469 | * @dev node: Device tree node that uses the nvmem device | |
470 | * @id: nvmem name from nvmem-names property. | |
471 | * | |
472 | * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device | |
473 | * on success. | |
474 | */ | |
475 | struct nvmem_device *of_nvmem_device_get(struct device_node *np, const char *id) | |
476 | { | |
477 | ||
478 | struct device_node *nvmem_np; | |
479 | int index; | |
480 | ||
481 | index = of_property_match_string(np, "nvmem-names", id); | |
482 | ||
483 | nvmem_np = of_parse_phandle(np, "nvmem", index); | |
484 | if (!nvmem_np) | |
485 | return ERR_PTR(-EINVAL); | |
486 | ||
487 | return __nvmem_device_get(nvmem_np, NULL, NULL); | |
488 | } | |
489 | EXPORT_SYMBOL_GPL(of_nvmem_device_get); | |
490 | #endif | |
491 | ||
492 | /** | |
493 | * nvmem_device_get() - Get nvmem device from a given id | |
494 | * | |
495 | * @dev : Device that uses the nvmem device | |
496 | * @id: nvmem name from nvmem-names property. | |
497 | * | |
498 | * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device | |
499 | * on success. | |
500 | */ | |
501 | struct nvmem_device *nvmem_device_get(struct device *dev, const char *dev_name) | |
502 | { | |
503 | if (dev->of_node) { /* try dt first */ | |
504 | struct nvmem_device *nvmem; | |
505 | ||
506 | nvmem = of_nvmem_device_get(dev->of_node, dev_name); | |
507 | ||
508 | if (!IS_ERR(nvmem) || PTR_ERR(nvmem) == -EPROBE_DEFER) | |
509 | return nvmem; | |
510 | ||
511 | } | |
512 | ||
513 | return nvmem_find(dev_name); | |
514 | } | |
515 | EXPORT_SYMBOL_GPL(nvmem_device_get); | |
516 | ||
517 | static int devm_nvmem_device_match(struct device *dev, void *res, void *data) | |
518 | { | |
519 | struct nvmem_device **nvmem = res; | |
520 | ||
521 | if (WARN_ON(!nvmem || !*nvmem)) | |
522 | return 0; | |
523 | ||
524 | return *nvmem == data; | |
525 | } | |
526 | ||
527 | static void devm_nvmem_device_release(struct device *dev, void *res) | |
528 | { | |
529 | nvmem_device_put(*(struct nvmem_device **)res); | |
530 | } | |
531 | ||
532 | /** | |
533 | * devm_nvmem_device_put() - put alredy got nvmem device | |
534 | * | |
535 | * @nvmem: pointer to nvmem device allocated by devm_nvmem_cell_get(), | |
536 | * that needs to be released. | |
537 | */ | |
538 | void devm_nvmem_device_put(struct device *dev, struct nvmem_device *nvmem) | |
539 | { | |
540 | int ret; | |
541 | ||
542 | ret = devres_release(dev, devm_nvmem_device_release, | |
543 | devm_nvmem_device_match, nvmem); | |
544 | ||
545 | WARN_ON(ret); | |
546 | } | |
547 | EXPORT_SYMBOL_GPL(devm_nvmem_device_put); | |
548 | ||
549 | /** | |
550 | * nvmem_device_put() - put alredy got nvmem device | |
551 | * | |
552 | * @nvmem: pointer to nvmem device that needs to be released. | |
553 | */ | |
554 | void nvmem_device_put(struct nvmem_device *nvmem) | |
555 | { | |
556 | __nvmem_device_put(nvmem); | |
557 | } | |
558 | EXPORT_SYMBOL_GPL(nvmem_device_put); | |
559 | ||
560 | /** | |
561 | * devm_nvmem_device_get() - Get nvmem cell of device form a given id | |
562 | * | |
563 | * @dev node: Device tree node that uses the nvmem cell | |
564 | * @id: nvmem name in nvmems property. | |
565 | * | |
566 | * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_cell | |
567 | * on success. The nvmem_cell will be freed by the automatically once the | |
568 | * device is freed. | |
569 | */ | |
570 | struct nvmem_device *devm_nvmem_device_get(struct device *dev, const char *id) | |
571 | { | |
572 | struct nvmem_device **ptr, *nvmem; | |
573 | ||
574 | ptr = devres_alloc(devm_nvmem_device_release, sizeof(*ptr), GFP_KERNEL); | |
575 | if (!ptr) | |
576 | return ERR_PTR(-ENOMEM); | |
577 | ||
578 | nvmem = nvmem_device_get(dev, id); | |
579 | if (!IS_ERR(nvmem)) { | |
580 | *ptr = nvmem; | |
581 | devres_add(dev, ptr); | |
582 | } else { | |
583 | devres_free(ptr); | |
584 | } | |
585 | ||
586 | return nvmem; | |
587 | } | |
588 | EXPORT_SYMBOL_GPL(devm_nvmem_device_get); | |
589 | ||
69aba794 SK |
590 | static struct nvmem_cell *nvmem_cell_get_from_list(const char *cell_id) |
591 | { | |
592 | struct nvmem_cell *cell = NULL; | |
593 | struct nvmem_device *nvmem; | |
594 | ||
595 | nvmem = __nvmem_device_get(NULL, &cell, cell_id); | |
596 | if (IS_ERR(nvmem)) | |
597 | return ERR_CAST(nvmem); | |
598 | ||
599 | return cell; | |
600 | } | |
601 | ||
602 | #if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OF) | |
603 | /** | |
604 | * of_nvmem_cell_get() - Get a nvmem cell from given device node and cell id | |
605 | * | |
606 | * @dev node: Device tree node that uses the nvmem cell | |
607 | * @id: nvmem cell name from nvmem-cell-names property. | |
608 | * | |
609 | * Return: Will be an ERR_PTR() on error or a valid pointer | |
610 | * to a struct nvmem_cell. The nvmem_cell will be freed by the | |
611 | * nvmem_cell_put(). | |
612 | */ | |
613 | struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, | |
614 | const char *name) | |
615 | { | |
616 | struct device_node *cell_np, *nvmem_np; | |
617 | struct nvmem_cell *cell; | |
618 | struct nvmem_device *nvmem; | |
619 | const __be32 *addr; | |
620 | int rval, len, index; | |
621 | ||
622 | index = of_property_match_string(np, "nvmem-cell-names", name); | |
623 | ||
624 | cell_np = of_parse_phandle(np, "nvmem-cells", index); | |
625 | if (!cell_np) | |
626 | return ERR_PTR(-EINVAL); | |
627 | ||
628 | nvmem_np = of_get_next_parent(cell_np); | |
629 | if (!nvmem_np) | |
630 | return ERR_PTR(-EINVAL); | |
631 | ||
632 | nvmem = __nvmem_device_get(nvmem_np, NULL, NULL); | |
633 | if (IS_ERR(nvmem)) | |
634 | return ERR_CAST(nvmem); | |
635 | ||
636 | addr = of_get_property(cell_np, "reg", &len); | |
637 | if (!addr || (len < 2 * sizeof(u32))) { | |
638 | dev_err(&nvmem->dev, "nvmem: invalid reg on %s\n", | |
639 | cell_np->full_name); | |
640 | rval = -EINVAL; | |
641 | goto err_mem; | |
642 | } | |
643 | ||
644 | cell = kzalloc(sizeof(*cell), GFP_KERNEL); | |
645 | if (!cell) { | |
646 | rval = -ENOMEM; | |
647 | goto err_mem; | |
648 | } | |
649 | ||
650 | cell->nvmem = nvmem; | |
651 | cell->offset = be32_to_cpup(addr++); | |
652 | cell->bytes = be32_to_cpup(addr); | |
653 | cell->name = cell_np->name; | |
654 | ||
655 | addr = of_get_property(cell_np, "bits", &len); | |
656 | if (addr && len == (2 * sizeof(u32))) { | |
657 | cell->bit_offset = be32_to_cpup(addr++); | |
658 | cell->nbits = be32_to_cpup(addr); | |
659 | } | |
660 | ||
661 | if (cell->nbits) | |
662 | cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset, | |
663 | BITS_PER_BYTE); | |
664 | ||
665 | if (!IS_ALIGNED(cell->offset, nvmem->stride)) { | |
666 | dev_err(&nvmem->dev, | |
667 | "cell %s unaligned to nvmem stride %d\n", | |
668 | cell->name, nvmem->stride); | |
669 | rval = -EINVAL; | |
670 | goto err_sanity; | |
671 | } | |
672 | ||
673 | nvmem_cell_add(cell); | |
674 | ||
675 | return cell; | |
676 | ||
677 | err_sanity: | |
678 | kfree(cell); | |
679 | ||
680 | err_mem: | |
681 | __nvmem_device_put(nvmem); | |
682 | ||
683 | return ERR_PTR(rval); | |
684 | } | |
685 | EXPORT_SYMBOL_GPL(of_nvmem_cell_get); | |
686 | #endif | |
687 | ||
688 | /** | |
689 | * nvmem_cell_get() - Get nvmem cell of device form a given cell name | |
690 | * | |
691 | * @dev node: Device tree node that uses the nvmem cell | |
692 | * @id: nvmem cell name to get. | |
693 | * | |
694 | * Return: Will be an ERR_PTR() on error or a valid pointer | |
695 | * to a struct nvmem_cell. The nvmem_cell will be freed by the | |
696 | * nvmem_cell_put(). | |
697 | */ | |
698 | struct nvmem_cell *nvmem_cell_get(struct device *dev, const char *cell_id) | |
699 | { | |
700 | struct nvmem_cell *cell; | |
701 | ||
702 | if (dev->of_node) { /* try dt first */ | |
703 | cell = of_nvmem_cell_get(dev->of_node, cell_id); | |
704 | if (!IS_ERR(cell) || PTR_ERR(cell) == -EPROBE_DEFER) | |
705 | return cell; | |
706 | } | |
707 | ||
708 | return nvmem_cell_get_from_list(cell_id); | |
709 | } | |
710 | EXPORT_SYMBOL_GPL(nvmem_cell_get); | |
711 | ||
712 | static void devm_nvmem_cell_release(struct device *dev, void *res) | |
713 | { | |
714 | nvmem_cell_put(*(struct nvmem_cell **)res); | |
715 | } | |
716 | ||
717 | /** | |
718 | * devm_nvmem_cell_get() - Get nvmem cell of device form a given id | |
719 | * | |
720 | * @dev node: Device tree node that uses the nvmem cell | |
721 | * @id: nvmem id in nvmem-names property. | |
722 | * | |
723 | * Return: Will be an ERR_PTR() on error or a valid pointer | |
724 | * to a struct nvmem_cell. The nvmem_cell will be freed by the | |
725 | * automatically once the device is freed. | |
726 | */ | |
727 | struct nvmem_cell *devm_nvmem_cell_get(struct device *dev, const char *id) | |
728 | { | |
729 | struct nvmem_cell **ptr, *cell; | |
730 | ||
731 | ptr = devres_alloc(devm_nvmem_cell_release, sizeof(*ptr), GFP_KERNEL); | |
732 | if (!ptr) | |
733 | return ERR_PTR(-ENOMEM); | |
734 | ||
735 | cell = nvmem_cell_get(dev, id); | |
736 | if (!IS_ERR(cell)) { | |
737 | *ptr = cell; | |
738 | devres_add(dev, ptr); | |
739 | } else { | |
740 | devres_free(ptr); | |
741 | } | |
742 | ||
743 | return cell; | |
744 | } | |
745 | EXPORT_SYMBOL_GPL(devm_nvmem_cell_get); | |
746 | ||
747 | static int devm_nvmem_cell_match(struct device *dev, void *res, void *data) | |
748 | { | |
749 | struct nvmem_cell **c = res; | |
750 | ||
751 | if (WARN_ON(!c || !*c)) | |
752 | return 0; | |
753 | ||
754 | return *c == data; | |
755 | } | |
756 | ||
757 | /** | |
758 | * devm_nvmem_cell_put() - Release previously allocated nvmem cell | |
759 | * from devm_nvmem_cell_get. | |
760 | * | |
761 | * @cell: Previously allocated nvmem cell by devm_nvmem_cell_get() | |
762 | */ | |
763 | void devm_nvmem_cell_put(struct device *dev, struct nvmem_cell *cell) | |
764 | { | |
765 | int ret; | |
766 | ||
767 | ret = devres_release(dev, devm_nvmem_cell_release, | |
768 | devm_nvmem_cell_match, cell); | |
769 | ||
770 | WARN_ON(ret); | |
771 | } | |
772 | EXPORT_SYMBOL(devm_nvmem_cell_put); | |
773 | ||
774 | /** | |
775 | * nvmem_cell_put() - Release previously allocated nvmem cell. | |
776 | * | |
777 | * @cell: Previously allocated nvmem cell by nvmem_cell_get() | |
778 | */ | |
779 | void nvmem_cell_put(struct nvmem_cell *cell) | |
780 | { | |
781 | struct nvmem_device *nvmem = cell->nvmem; | |
782 | ||
783 | __nvmem_device_put(nvmem); | |
784 | nvmem_cell_drop(cell); | |
785 | } | |
786 | EXPORT_SYMBOL_GPL(nvmem_cell_put); | |
787 | ||
788 | static inline void nvmem_shift_read_buffer_in_place(struct nvmem_cell *cell, | |
789 | void *buf) | |
790 | { | |
791 | u8 *p, *b; | |
792 | int i, bit_offset = cell->bit_offset; | |
793 | ||
794 | p = b = buf; | |
795 | if (bit_offset) { | |
796 | /* First shift */ | |
797 | *b++ >>= bit_offset; | |
798 | ||
799 | /* setup rest of the bytes if any */ | |
800 | for (i = 1; i < cell->bytes; i++) { | |
801 | /* Get bits from next byte and shift them towards msb */ | |
802 | *p |= *b << (BITS_PER_BYTE - bit_offset); | |
803 | ||
804 | p = b; | |
805 | *b++ >>= bit_offset; | |
806 | } | |
807 | ||
808 | /* result fits in less bytes */ | |
809 | if (cell->bytes != DIV_ROUND_UP(cell->nbits, BITS_PER_BYTE)) | |
810 | *p-- = 0; | |
811 | } | |
812 | /* clear msb bits if any leftover in the last byte */ | |
813 | *p &= GENMASK((cell->nbits%BITS_PER_BYTE) - 1, 0); | |
814 | } | |
815 | ||
816 | static int __nvmem_cell_read(struct nvmem_device *nvmem, | |
817 | struct nvmem_cell *cell, | |
818 | void *buf, size_t *len) | |
819 | { | |
820 | int rc; | |
821 | ||
822 | rc = regmap_raw_read(nvmem->regmap, cell->offset, buf, cell->bytes); | |
823 | ||
824 | if (IS_ERR_VALUE(rc)) | |
825 | return rc; | |
826 | ||
827 | /* shift bits in-place */ | |
cbf854ab | 828 | if (cell->bit_offset || cell->nbits) |
69aba794 SK |
829 | nvmem_shift_read_buffer_in_place(cell, buf); |
830 | ||
831 | *len = cell->bytes; | |
832 | ||
833 | return 0; | |
834 | } | |
835 | ||
836 | /** | |
837 | * nvmem_cell_read() - Read a given nvmem cell | |
838 | * | |
839 | * @cell: nvmem cell to be read. | |
840 | * @len: pointer to length of cell which will be populated on successful read. | |
841 | * | |
842 | * Return: ERR_PTR() on error or a valid pointer to a char * buffer on success. | |
843 | * The buffer should be freed by the consumer with a kfree(). | |
844 | */ | |
845 | void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len) | |
846 | { | |
847 | struct nvmem_device *nvmem = cell->nvmem; | |
848 | u8 *buf; | |
849 | int rc; | |
850 | ||
851 | if (!nvmem || !nvmem->regmap) | |
852 | return ERR_PTR(-EINVAL); | |
853 | ||
854 | buf = kzalloc(cell->bytes, GFP_KERNEL); | |
855 | if (!buf) | |
856 | return ERR_PTR(-ENOMEM); | |
857 | ||
858 | rc = __nvmem_cell_read(nvmem, cell, buf, len); | |
859 | if (IS_ERR_VALUE(rc)) { | |
860 | kfree(buf); | |
861 | return ERR_PTR(rc); | |
862 | } | |
863 | ||
864 | return buf; | |
865 | } | |
866 | EXPORT_SYMBOL_GPL(nvmem_cell_read); | |
867 | ||
868 | static inline void *nvmem_cell_prepare_write_buffer(struct nvmem_cell *cell, | |
869 | u8 *_buf, int len) | |
870 | { | |
871 | struct nvmem_device *nvmem = cell->nvmem; | |
872 | int i, rc, nbits, bit_offset = cell->bit_offset; | |
873 | u8 v, *p, *buf, *b, pbyte, pbits; | |
874 | ||
875 | nbits = cell->nbits; | |
876 | buf = kzalloc(cell->bytes, GFP_KERNEL); | |
877 | if (!buf) | |
878 | return ERR_PTR(-ENOMEM); | |
879 | ||
880 | memcpy(buf, _buf, len); | |
881 | p = b = buf; | |
882 | ||
883 | if (bit_offset) { | |
884 | pbyte = *b; | |
885 | *b <<= bit_offset; | |
886 | ||
887 | /* setup the first byte with lsb bits from nvmem */ | |
888 | rc = regmap_raw_read(nvmem->regmap, cell->offset, &v, 1); | |
889 | *b++ |= GENMASK(bit_offset - 1, 0) & v; | |
890 | ||
891 | /* setup rest of the byte if any */ | |
892 | for (i = 1; i < cell->bytes; i++) { | |
893 | /* Get last byte bits and shift them towards lsb */ | |
894 | pbits = pbyte >> (BITS_PER_BYTE - 1 - bit_offset); | |
895 | pbyte = *b; | |
896 | p = b; | |
897 | *b <<= bit_offset; | |
898 | *b++ |= pbits; | |
899 | } | |
900 | } | |
901 | ||
902 | /* if it's not end on byte boundary */ | |
903 | if ((nbits + bit_offset) % BITS_PER_BYTE) { | |
904 | /* setup the last byte with msb bits from nvmem */ | |
905 | rc = regmap_raw_read(nvmem->regmap, | |
906 | cell->offset + cell->bytes - 1, &v, 1); | |
907 | *p |= GENMASK(7, (nbits + bit_offset) % BITS_PER_BYTE) & v; | |
908 | ||
909 | } | |
910 | ||
911 | return buf; | |
912 | } | |
913 | ||
914 | /** | |
915 | * nvmem_cell_write() - Write to a given nvmem cell | |
916 | * | |
917 | * @cell: nvmem cell to be written. | |
918 | * @buf: Buffer to be written. | |
919 | * @len: length of buffer to be written to nvmem cell. | |
920 | * | |
921 | * Return: length of bytes written or negative on failure. | |
922 | */ | |
923 | int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len) | |
924 | { | |
925 | struct nvmem_device *nvmem = cell->nvmem; | |
926 | int rc; | |
927 | ||
928 | if (!nvmem || !nvmem->regmap || nvmem->read_only || | |
929 | (cell->bit_offset == 0 && len != cell->bytes)) | |
930 | return -EINVAL; | |
931 | ||
932 | if (cell->bit_offset || cell->nbits) { | |
933 | buf = nvmem_cell_prepare_write_buffer(cell, buf, len); | |
934 | if (IS_ERR(buf)) | |
935 | return PTR_ERR(buf); | |
936 | } | |
937 | ||
938 | rc = regmap_raw_write(nvmem->regmap, cell->offset, buf, cell->bytes); | |
939 | ||
940 | /* free the tmp buffer */ | |
ace22170 | 941 | if (cell->bit_offset || cell->nbits) |
69aba794 SK |
942 | kfree(buf); |
943 | ||
944 | if (IS_ERR_VALUE(rc)) | |
945 | return rc; | |
946 | ||
947 | return len; | |
948 | } | |
949 | EXPORT_SYMBOL_GPL(nvmem_cell_write); | |
950 | ||
e2a5402e SK |
951 | /** |
952 | * nvmem_device_cell_read() - Read a given nvmem device and cell | |
953 | * | |
954 | * @nvmem: nvmem device to read from. | |
955 | * @info: nvmem cell info to be read. | |
956 | * @buf: buffer pointer which will be populated on successful read. | |
957 | * | |
958 | * Return: length of successful bytes read on success and negative | |
959 | * error code on error. | |
960 | */ | |
961 | ssize_t nvmem_device_cell_read(struct nvmem_device *nvmem, | |
962 | struct nvmem_cell_info *info, void *buf) | |
963 | { | |
964 | struct nvmem_cell cell; | |
965 | int rc; | |
966 | ssize_t len; | |
967 | ||
968 | if (!nvmem || !nvmem->regmap) | |
969 | return -EINVAL; | |
970 | ||
971 | rc = nvmem_cell_info_to_nvmem_cell(nvmem, info, &cell); | |
972 | if (IS_ERR_VALUE(rc)) | |
973 | return rc; | |
974 | ||
975 | rc = __nvmem_cell_read(nvmem, &cell, buf, &len); | |
976 | if (IS_ERR_VALUE(rc)) | |
977 | return rc; | |
978 | ||
979 | return len; | |
980 | } | |
981 | EXPORT_SYMBOL_GPL(nvmem_device_cell_read); | |
982 | ||
983 | /** | |
984 | * nvmem_device_cell_write() - Write cell to a given nvmem device | |
985 | * | |
986 | * @nvmem: nvmem device to be written to. | |
987 | * @info: nvmem cell info to be written | |
988 | * @buf: buffer to be written to cell. | |
989 | * | |
990 | * Return: length of bytes written or negative error code on failure. | |
991 | * */ | |
992 | int nvmem_device_cell_write(struct nvmem_device *nvmem, | |
993 | struct nvmem_cell_info *info, void *buf) | |
994 | { | |
995 | struct nvmem_cell cell; | |
996 | int rc; | |
997 | ||
998 | if (!nvmem || !nvmem->regmap) | |
999 | return -EINVAL; | |
1000 | ||
1001 | rc = nvmem_cell_info_to_nvmem_cell(nvmem, info, &cell); | |
1002 | if (IS_ERR_VALUE(rc)) | |
1003 | return rc; | |
1004 | ||
1005 | return nvmem_cell_write(&cell, buf, cell.bytes); | |
1006 | } | |
1007 | EXPORT_SYMBOL_GPL(nvmem_device_cell_write); | |
1008 | ||
1009 | /** | |
1010 | * nvmem_device_read() - Read from a given nvmem device | |
1011 | * | |
1012 | * @nvmem: nvmem device to read from. | |
1013 | * @offset: offset in nvmem device. | |
1014 | * @bytes: number of bytes to read. | |
1015 | * @buf: buffer pointer which will be populated on successful read. | |
1016 | * | |
1017 | * Return: length of successful bytes read on success and negative | |
1018 | * error code on error. | |
1019 | */ | |
1020 | int nvmem_device_read(struct nvmem_device *nvmem, | |
1021 | unsigned int offset, | |
1022 | size_t bytes, void *buf) | |
1023 | { | |
1024 | int rc; | |
1025 | ||
1026 | if (!nvmem || !nvmem->regmap) | |
1027 | return -EINVAL; | |
1028 | ||
1029 | rc = regmap_raw_read(nvmem->regmap, offset, buf, bytes); | |
1030 | ||
1031 | if (IS_ERR_VALUE(rc)) | |
1032 | return rc; | |
1033 | ||
1034 | return bytes; | |
1035 | } | |
1036 | EXPORT_SYMBOL_GPL(nvmem_device_read); | |
1037 | ||
1038 | /** | |
1039 | * nvmem_device_write() - Write cell to a given nvmem device | |
1040 | * | |
1041 | * @nvmem: nvmem device to be written to. | |
1042 | * @offset: offset in nvmem device. | |
1043 | * @bytes: number of bytes to write. | |
1044 | * @buf: buffer to be written. | |
1045 | * | |
1046 | * Return: length of bytes written or negative error code on failure. | |
1047 | * */ | |
1048 | int nvmem_device_write(struct nvmem_device *nvmem, | |
1049 | unsigned int offset, | |
1050 | size_t bytes, void *buf) | |
1051 | { | |
1052 | int rc; | |
1053 | ||
1054 | if (!nvmem || !nvmem->regmap) | |
1055 | return -EINVAL; | |
1056 | ||
1057 | rc = regmap_raw_write(nvmem->regmap, offset, buf, bytes); | |
1058 | ||
1059 | if (IS_ERR_VALUE(rc)) | |
1060 | return rc; | |
1061 | ||
1062 | ||
1063 | return bytes; | |
1064 | } | |
1065 | EXPORT_SYMBOL_GPL(nvmem_device_write); | |
1066 | ||
eace75cf SK |
1067 | static int __init nvmem_init(void) |
1068 | { | |
1069 | return bus_register(&nvmem_bus_type); | |
1070 | } | |
1071 | ||
1072 | static void __exit nvmem_exit(void) | |
1073 | { | |
1074 | bus_unregister(&nvmem_bus_type); | |
1075 | } | |
1076 | ||
1077 | subsys_initcall(nvmem_init); | |
1078 | module_exit(nvmem_exit); | |
1079 | ||
1080 | MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org"); | |
1081 | MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com"); | |
1082 | MODULE_DESCRIPTION("nvmem Driver Core"); | |
1083 | MODULE_LICENSE("GPL v2"); |