1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * nvmem framework core. |
4 | * |
5 | * Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla@linaro.org> |
6 | * Copyright (C) 2013 Maxime Ripard <maxime.ripard@free-electrons.com> |
7 | */ |
8 | |
9 | #include <linux/device.h> |
10 | #include <linux/export.h> |
11 | #include <linux/fs.h> |
12 | #include <linux/idr.h> |
13 | #include <linux/init.h> |
14 | #include <linux/kref.h> |
15 | #include <linux/module.h> |
16 | #include <linux/nvmem-consumer.h> |
17 | #include <linux/nvmem-provider.h> |
18 | #include <linux/gpio/consumer.h> |
19 | #include <linux/of.h> |
20 | #include <linux/slab.h> |
21 | |
22 | struct nvmem_device { |
23 | struct module *owner; |
24 | struct device dev; |
25 | int stride; |
26 | int word_size; |
27 | int id; |
28 | struct kref refcnt; |
29 | size_t size; |
30 | bool read_only; |
31 | bool root_only; |
32 | int flags; |
33 | enum nvmem_type type; |
34 | struct bin_attribute eeprom; |
35 | struct device *base_dev; |
36 | struct list_head cells; |
37 | const struct nvmem_keepout *keepout; |
38 | unsigned int nkeepout; |
39 | nvmem_reg_read_t reg_read; |
40 | nvmem_reg_write_t reg_write; |
41 | struct gpio_desc *wp_gpio; |
42 | struct nvmem_layout *layout; |
43 | void *priv; |
44 | }; |
45 | |
46 | #define to_nvmem_device(d) container_of(d, struct nvmem_device, dev) |
47 | |
48 | #define FLAG_COMPAT BIT(0) |
49 | struct nvmem_cell_entry { |
50 | const char *name; |
51 | int offset; |
52 | size_t raw_len; |
53 | int bytes; |
54 | int bit_offset; |
55 | int nbits; |
56 | nvmem_cell_post_process_t read_post_process; |
57 | void *priv; |
58 | struct device_node *np; |
59 | struct nvmem_device *nvmem; |
60 | struct list_head node; |
61 | }; |
62 | |
63 | struct nvmem_cell { |
64 | struct nvmem_cell_entry *entry; |
65 | const char *id; |
66 | int index; |
67 | }; |
68 | |
69 | static DEFINE_MUTEX(nvmem_mutex); |
70 | static DEFINE_IDA(nvmem_ida); |
71 | |
72 | static DEFINE_MUTEX(nvmem_cell_mutex); |
73 | static LIST_HEAD(nvmem_cell_tables); |
74 | |
75 | static DEFINE_MUTEX(nvmem_lookup_mutex); |
76 | static LIST_HEAD(nvmem_lookup_list); |
77 | |
78 | static BLOCKING_NOTIFIER_HEAD(nvmem_notifier); |
79 | |
80 | static DEFINE_SPINLOCK(nvmem_layout_lock); |
81 | static LIST_HEAD(nvmem_layouts); |
82 | |
83 | static int __nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset, |
84 | void *val, size_t bytes) |
85 | { |
86 | if (nvmem->reg_read) |
87 | return nvmem->reg_read(nvmem->priv, offset, val, bytes); |
88 | |
89 | return -EINVAL; |
90 | } |
91 | |
92 | static int __nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset, |
93 | void *val, size_t bytes) |
94 | { |
95 | int ret; |
96 | |
97 | if (nvmem->reg_write) { |
98 | gpiod_set_value_cansleep(desc: nvmem->wp_gpio, value: 0); |
99 | ret = nvmem->reg_write(nvmem->priv, offset, val, bytes); |
100 | gpiod_set_value_cansleep(desc: nvmem->wp_gpio, value: 1); |
101 | return ret; |
102 | } |
103 | |
104 | return -EINVAL; |
105 | } |
106 | |
107 | static int nvmem_access_with_keepouts(struct nvmem_device *nvmem, |
108 | unsigned int offset, void *val, |
109 | size_t bytes, int write) |
110 | { |
111 | |
112 | unsigned int end = offset + bytes; |
113 | unsigned int kend, ksize; |
114 | const struct nvmem_keepout *keepout = nvmem->keepout; |
115 | const struct nvmem_keepout *keepoutend = keepout + nvmem->nkeepout; |
116 | int rc; |
117 | |
118 | /* |
119 | * Skip all keepouts before the range being accessed. |
120 | * Keepouts are sorted. |
121 | */ |
122 | while ((keepout < keepoutend) && (keepout->end <= offset)) |
123 | keepout++; |
124 | |
125 | while ((offset < end) && (keepout < keepoutend)) { |
126 | /* Access the valid portion before the keepout. */ |
127 | if (offset < keepout->start) { |
128 | kend = min(end, keepout->start); |
129 | ksize = kend - offset; |
130 | if (write) |
131 | rc = __nvmem_reg_write(nvmem, offset, val, bytes: ksize); |
132 | else |
133 | rc = __nvmem_reg_read(nvmem, offset, val, bytes: ksize); |
134 | |
135 | if (rc) |
136 | return rc; |
137 | |
138 | offset += ksize; |
139 | val += ksize; |
140 | } |
141 | |
142 | /* |
143 | * Now we're aligned to the start of this keepout zone. Go |
144 | * through it. |
145 | */ |
146 | kend = min(end, keepout->end); |
147 | ksize = kend - offset; |
148 | if (!write) |
149 | memset(val, keepout->value, ksize); |
150 | |
151 | val += ksize; |
152 | offset += ksize; |
153 | keepout++; |
154 | } |
155 | |
156 | /* |
157 | * If we ran out of keepouts but there's still stuff to do, send it |
158 | * down directly |
159 | */ |
160 | if (offset < end) { |
161 | ksize = end - offset; |
162 | if (write) |
163 | return __nvmem_reg_write(nvmem, offset, val, bytes: ksize); |
164 | else |
165 | return __nvmem_reg_read(nvmem, offset, val, bytes: ksize); |
166 | } |
167 | |
168 | return 0; |
169 | } |
170 | |
171 | static int nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset, |
172 | void *val, size_t bytes) |
173 | { |
174 | if (!nvmem->nkeepout) |
175 | return __nvmem_reg_read(nvmem, offset, val, bytes); |
176 | |
177 | return nvmem_access_with_keepouts(nvmem, offset, val, bytes, write: false); |
178 | } |
179 | |
180 | static int nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset, |
181 | void *val, size_t bytes) |
182 | { |
183 | if (!nvmem->nkeepout) |
184 | return __nvmem_reg_write(nvmem, offset, val, bytes); |
185 | |
186 | return nvmem_access_with_keepouts(nvmem, offset, val, bytes, write: true); |
187 | } |
188 | |
189 | #ifdef CONFIG_NVMEM_SYSFS |
190 | static const char * const nvmem_type_str[] = { |
191 | [NVMEM_TYPE_UNKNOWN] = "Unknown" , |
192 | [NVMEM_TYPE_EEPROM] = "EEPROM" , |
193 | [NVMEM_TYPE_OTP] = "OTP" , |
194 | [NVMEM_TYPE_BATTERY_BACKED] = "Battery backed" , |
195 | [NVMEM_TYPE_FRAM] = "FRAM" , |
196 | }; |
197 | |
198 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
199 | static struct lock_class_key eeprom_lock_key; |
200 | #endif |
201 | |
202 | static ssize_t type_show(struct device *dev, |
203 | struct device_attribute *attr, char *buf) |
204 | { |
205 | struct nvmem_device *nvmem = to_nvmem_device(dev); |
206 | |
207 | return sprintf(buf, fmt: "%s\n" , nvmem_type_str[nvmem->type]); |
208 | } |
209 | |
210 | static DEVICE_ATTR_RO(type); |
211 | |
212 | static struct attribute *nvmem_attrs[] = { |
213 | &dev_attr_type.attr, |
214 | NULL, |
215 | }; |
216 | |
217 | static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj, |
218 | struct bin_attribute *attr, char *buf, |
219 | loff_t pos, size_t count) |
220 | { |
221 | struct device *dev; |
222 | struct nvmem_device *nvmem; |
223 | int rc; |
224 | |
225 | if (attr->private) |
226 | dev = attr->private; |
227 | else |
228 | dev = kobj_to_dev(kobj); |
229 | nvmem = to_nvmem_device(dev); |
230 | |
231 | /* Stop the user from reading */ |
232 | if (pos >= nvmem->size) |
233 | return 0; |
234 | |
235 | if (!IS_ALIGNED(pos, nvmem->stride)) |
236 | return -EINVAL; |
237 | |
238 | if (count < nvmem->word_size) |
239 | return -EINVAL; |
240 | |
241 | if (pos + count > nvmem->size) |
242 | count = nvmem->size - pos; |
243 | |
244 | count = round_down(count, nvmem->word_size); |
245 | |
246 | if (!nvmem->reg_read) |
247 | return -EPERM; |
248 | |
249 | rc = nvmem_reg_read(nvmem, offset: pos, val: buf, bytes: count); |
250 | |
251 | if (rc) |
252 | return rc; |
253 | |
254 | return count; |
255 | } |
256 | |
257 | static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj, |
258 | struct bin_attribute *attr, char *buf, |
259 | loff_t pos, size_t count) |
260 | { |
261 | struct device *dev; |
262 | struct nvmem_device *nvmem; |
263 | int rc; |
264 | |
265 | if (attr->private) |
266 | dev = attr->private; |
267 | else |
268 | dev = kobj_to_dev(kobj); |
269 | nvmem = to_nvmem_device(dev); |
270 | |
271 | /* Stop the user from writing */ |
272 | if (pos >= nvmem->size) |
273 | return -EFBIG; |
274 | |
275 | if (!IS_ALIGNED(pos, nvmem->stride)) |
276 | return -EINVAL; |
277 | |
278 | if (count < nvmem->word_size) |
279 | return -EINVAL; |
280 | |
281 | if (pos + count > nvmem->size) |
282 | count = nvmem->size - pos; |
283 | |
284 | count = round_down(count, nvmem->word_size); |
285 | |
286 | if (!nvmem->reg_write) |
287 | return -EPERM; |
288 | |
289 | rc = nvmem_reg_write(nvmem, offset: pos, val: buf, bytes: count); |
290 | |
291 | if (rc) |
292 | return rc; |
293 | |
294 | return count; |
295 | } |
296 | |
297 | static umode_t nvmem_bin_attr_get_umode(struct nvmem_device *nvmem) |
298 | { |
299 | umode_t mode = 0400; |
300 | |
301 | if (!nvmem->root_only) |
302 | mode |= 0044; |
303 | |
304 | if (!nvmem->read_only) |
305 | mode |= 0200; |
306 | |
307 | if (!nvmem->reg_write) |
308 | mode &= ~0200; |
309 | |
310 | if (!nvmem->reg_read) |
311 | mode &= ~0444; |
312 | |
313 | return mode; |
314 | } |
315 | |
316 | static umode_t nvmem_bin_attr_is_visible(struct kobject *kobj, |
317 | struct bin_attribute *attr, int i) |
318 | { |
319 | struct device *dev = kobj_to_dev(kobj); |
320 | struct nvmem_device *nvmem = to_nvmem_device(dev); |
321 | |
322 | attr->size = nvmem->size; |
323 | |
324 | return nvmem_bin_attr_get_umode(nvmem); |
325 | } |
326 | |
327 | /* default read/write permissions */ |
328 | static struct bin_attribute bin_attr_rw_nvmem = { |
329 | .attr = { |
330 | .name = "nvmem" , |
331 | .mode = 0644, |
332 | }, |
333 | .read = bin_attr_nvmem_read, |
334 | .write = bin_attr_nvmem_write, |
335 | }; |
336 | |
337 | static struct bin_attribute *nvmem_bin_attributes[] = { |
338 | &bin_attr_rw_nvmem, |
339 | NULL, |
340 | }; |
341 | |
342 | static const struct attribute_group nvmem_bin_group = { |
343 | .bin_attrs = nvmem_bin_attributes, |
344 | .attrs = nvmem_attrs, |
345 | .is_bin_visible = nvmem_bin_attr_is_visible, |
346 | }; |
347 | |
348 | static const struct attribute_group *nvmem_dev_groups[] = { |
349 | &nvmem_bin_group, |
350 | NULL, |
351 | }; |
352 | |
353 | static struct bin_attribute bin_attr_nvmem_eeprom_compat = { |
354 | .attr = { |
355 | .name = "eeprom" , |
356 | }, |
357 | .read = bin_attr_nvmem_read, |
358 | .write = bin_attr_nvmem_write, |
359 | }; |
360 | |
361 | /* |
362 | * nvmem_setup_compat() - Create an additional binary entry in |
363 | * drivers sys directory, to be backwards compatible with the older |
364 | * drivers/misc/eeprom drivers. |
365 | */ |
366 | static int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem, |
367 | const struct nvmem_config *config) |
368 | { |
369 | int rval; |
370 | |
371 | if (!config->compat) |
372 | return 0; |
373 | |
374 | if (!config->base_dev) |
375 | return -EINVAL; |
376 | |
377 | if (config->type == NVMEM_TYPE_FRAM) |
378 | bin_attr_nvmem_eeprom_compat.attr.name = "fram" ; |
379 | |
380 | nvmem->eeprom = bin_attr_nvmem_eeprom_compat; |
381 | nvmem->eeprom.attr.mode = nvmem_bin_attr_get_umode(nvmem); |
382 | nvmem->eeprom.size = nvmem->size; |
383 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
384 | nvmem->eeprom.attr.key = &eeprom_lock_key; |
385 | #endif |
386 | nvmem->eeprom.private = &nvmem->dev; |
387 | nvmem->base_dev = config->base_dev; |
388 | |
389 | rval = device_create_bin_file(dev: nvmem->base_dev, attr: &nvmem->eeprom); |
390 | if (rval) { |
391 | dev_err(&nvmem->dev, |
392 | "Failed to create eeprom binary file %d\n" , rval); |
393 | return rval; |
394 | } |
395 | |
396 | nvmem->flags |= FLAG_COMPAT; |
397 | |
398 | return 0; |
399 | } |
400 | |
401 | static void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem, |
402 | const struct nvmem_config *config) |
403 | { |
404 | if (config->compat) |
405 | device_remove_bin_file(dev: nvmem->base_dev, attr: &nvmem->eeprom); |
406 | } |
407 | |
408 | #else /* CONFIG_NVMEM_SYSFS */ |
409 | |
410 | static int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem, |
411 | const struct nvmem_config *config) |
412 | { |
413 | return -ENOSYS; |
414 | } |
415 | static void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem, |
416 | const struct nvmem_config *config) |
417 | { |
418 | } |
419 | |
420 | #endif /* CONFIG_NVMEM_SYSFS */ |
421 | |
422 | static void nvmem_release(struct device *dev) |
423 | { |
424 | struct nvmem_device *nvmem = to_nvmem_device(dev); |
425 | |
426 | ida_free(&nvmem_ida, id: nvmem->id); |
427 | gpiod_put(desc: nvmem->wp_gpio); |
428 | kfree(objp: nvmem); |
429 | } |
430 | |
431 | static const struct device_type nvmem_provider_type = { |
432 | .release = nvmem_release, |
433 | }; |
434 | |
435 | static struct bus_type nvmem_bus_type = { |
436 | .name = "nvmem" , |
437 | }; |
438 | |
439 | static void nvmem_cell_entry_drop(struct nvmem_cell_entry *cell) |
440 | { |
441 | blocking_notifier_call_chain(nh: &nvmem_notifier, val: NVMEM_CELL_REMOVE, v: cell); |
442 | mutex_lock(&nvmem_mutex); |
443 | list_del(entry: &cell->node); |
444 | mutex_unlock(lock: &nvmem_mutex); |
445 | of_node_put(node: cell->np); |
446 | kfree_const(x: cell->name); |
447 | kfree(objp: cell); |
448 | } |
449 | |
450 | static void nvmem_device_remove_all_cells(const struct nvmem_device *nvmem) |
451 | { |
452 | struct nvmem_cell_entry *cell, *p; |
453 | |
454 | list_for_each_entry_safe(cell, p, &nvmem->cells, node) |
455 | nvmem_cell_entry_drop(cell); |
456 | } |
457 | |
458 | static void nvmem_cell_entry_add(struct nvmem_cell_entry *cell) |
459 | { |
460 | mutex_lock(&nvmem_mutex); |
461 | list_add_tail(new: &cell->node, head: &cell->nvmem->cells); |
462 | mutex_unlock(lock: &nvmem_mutex); |
463 | blocking_notifier_call_chain(nh: &nvmem_notifier, val: NVMEM_CELL_ADD, v: cell); |
464 | } |
465 | |
466 | static int nvmem_cell_info_to_nvmem_cell_entry_nodup(struct nvmem_device *nvmem, |
467 | const struct nvmem_cell_info *info, |
468 | struct nvmem_cell_entry *cell) |
469 | { |
470 | cell->nvmem = nvmem; |
471 | cell->offset = info->offset; |
472 | cell->raw_len = info->raw_len ?: info->bytes; |
473 | cell->bytes = info->bytes; |
474 | cell->name = info->name; |
475 | cell->read_post_process = info->read_post_process; |
476 | cell->priv = info->priv; |
477 | |
478 | cell->bit_offset = info->bit_offset; |
479 | cell->nbits = info->nbits; |
480 | cell->np = info->np; |
481 | |
482 | if (cell->nbits) |
483 | cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset, |
484 | BITS_PER_BYTE); |
485 | |
486 | if (!IS_ALIGNED(cell->offset, nvmem->stride)) { |
487 | dev_err(&nvmem->dev, |
488 | "cell %s unaligned to nvmem stride %d\n" , |
489 | cell->name ?: "<unknown>" , nvmem->stride); |
490 | return -EINVAL; |
491 | } |
492 | |
493 | return 0; |
494 | } |
495 | |
496 | static int nvmem_cell_info_to_nvmem_cell_entry(struct nvmem_device *nvmem, |
497 | const struct nvmem_cell_info *info, |
498 | struct nvmem_cell_entry *cell) |
499 | { |
500 | int err; |
501 | |
502 | err = nvmem_cell_info_to_nvmem_cell_entry_nodup(nvmem, info, cell); |
503 | if (err) |
504 | return err; |
505 | |
506 | cell->name = kstrdup_const(s: info->name, GFP_KERNEL); |
507 | if (!cell->name) |
508 | return -ENOMEM; |
509 | |
510 | return 0; |
511 | } |
512 | |
513 | /** |
514 | * nvmem_add_one_cell() - Add one cell information to an nvmem device |
515 | * |
516 | * @nvmem: nvmem device to add cells to. |
517 | * @info: nvmem cell info to add to the device |
518 | * |
519 | * Return: 0 or negative error code on failure. |
520 | */ |
521 | int nvmem_add_one_cell(struct nvmem_device *nvmem, |
522 | const struct nvmem_cell_info *info) |
523 | { |
524 | struct nvmem_cell_entry *cell; |
525 | int rval; |
526 | |
527 | cell = kzalloc(size: sizeof(*cell), GFP_KERNEL); |
528 | if (!cell) |
529 | return -ENOMEM; |
530 | |
531 | rval = nvmem_cell_info_to_nvmem_cell_entry(nvmem, info, cell); |
532 | if (rval) { |
533 | kfree(objp: cell); |
534 | return rval; |
535 | } |
536 | |
537 | nvmem_cell_entry_add(cell); |
538 | |
539 | return 0; |
540 | } |
541 | EXPORT_SYMBOL_GPL(nvmem_add_one_cell); |
542 | |
543 | /** |
544 | * nvmem_add_cells() - Add cell information to an nvmem device |
545 | * |
546 | * @nvmem: nvmem device to add cells to. |
547 | * @info: nvmem cell info to add to the device |
548 | * @ncells: number of cells in info |
549 | * |
550 | * Return: 0 or negative error code on failure. |
551 | */ |
552 | static int nvmem_add_cells(struct nvmem_device *nvmem, |
553 | const struct nvmem_cell_info *info, |
554 | int ncells) |
555 | { |
556 | int i, rval; |
557 | |
558 | for (i = 0; i < ncells; i++) { |
559 | rval = nvmem_add_one_cell(nvmem, &info[i]); |
560 | if (rval) |
561 | return rval; |
562 | } |
563 | |
564 | return 0; |
565 | } |
566 | |
567 | /** |
568 | * nvmem_register_notifier() - Register a notifier block for nvmem events. |
569 | * |
570 | * @nb: notifier block to be called on nvmem events. |
571 | * |
572 | * Return: 0 on success, negative error number on failure. |
573 | */ |
574 | int nvmem_register_notifier(struct notifier_block *nb) |
575 | { |
576 | return blocking_notifier_chain_register(nh: &nvmem_notifier, nb); |
577 | } |
578 | EXPORT_SYMBOL_GPL(nvmem_register_notifier); |
579 | |
580 | /** |
581 | * nvmem_unregister_notifier() - Unregister a notifier block for nvmem events. |
582 | * |
583 | * @nb: notifier block to be unregistered. |
584 | * |
585 | * Return: 0 on success, negative error number on failure. |
586 | */ |
587 | int nvmem_unregister_notifier(struct notifier_block *nb) |
588 | { |
589 | return blocking_notifier_chain_unregister(nh: &nvmem_notifier, nb); |
590 | } |
591 | EXPORT_SYMBOL_GPL(nvmem_unregister_notifier); |
592 | |
593 | static int nvmem_add_cells_from_table(struct nvmem_device *nvmem) |
594 | { |
595 | const struct nvmem_cell_info *info; |
596 | struct nvmem_cell_table *table; |
597 | struct nvmem_cell_entry *cell; |
598 | int rval = 0, i; |
599 | |
600 | mutex_lock(&nvmem_cell_mutex); |
601 | list_for_each_entry(table, &nvmem_cell_tables, node) { |
602 | if (strcmp(nvmem_dev_name(nvmem), table->nvmem_name) == 0) { |
603 | for (i = 0; i < table->ncells; i++) { |
604 | info = &table->cells[i]; |
605 | |
606 | cell = kzalloc(size: sizeof(*cell), GFP_KERNEL); |
607 | if (!cell) { |
608 | rval = -ENOMEM; |
609 | goto out; |
610 | } |
611 | |
612 | rval = nvmem_cell_info_to_nvmem_cell_entry(nvmem, info, cell); |
613 | if (rval) { |
614 | kfree(objp: cell); |
615 | goto out; |
616 | } |
617 | |
618 | nvmem_cell_entry_add(cell); |
619 | } |
620 | } |
621 | } |
622 | |
623 | out: |
624 | mutex_unlock(lock: &nvmem_cell_mutex); |
625 | return rval; |
626 | } |
627 | |
628 | static struct nvmem_cell_entry * |
629 | nvmem_find_cell_entry_by_name(struct nvmem_device *nvmem, const char *cell_id) |
630 | { |
631 | struct nvmem_cell_entry *iter, *cell = NULL; |
632 | |
633 | mutex_lock(&nvmem_mutex); |
634 | list_for_each_entry(iter, &nvmem->cells, node) { |
635 | if (strcmp(cell_id, iter->name) == 0) { |
636 | cell = iter; |
637 | break; |
638 | } |
639 | } |
640 | mutex_unlock(lock: &nvmem_mutex); |
641 | |
642 | return cell; |
643 | } |
644 | |
645 | static int nvmem_validate_keepouts(struct nvmem_device *nvmem) |
646 | { |
647 | unsigned int cur = 0; |
648 | const struct nvmem_keepout *keepout = nvmem->keepout; |
649 | const struct nvmem_keepout *keepoutend = keepout + nvmem->nkeepout; |
650 | |
651 | while (keepout < keepoutend) { |
652 | /* Ensure keepouts are sorted and don't overlap. */ |
653 | if (keepout->start < cur) { |
654 | dev_err(&nvmem->dev, |
655 | "Keepout regions aren't sorted or overlap.\n" ); |
656 | |
657 | return -ERANGE; |
658 | } |
659 | |
660 | if (keepout->end < keepout->start) { |
661 | dev_err(&nvmem->dev, |
662 | "Invalid keepout region.\n" ); |
663 | |
664 | return -EINVAL; |
665 | } |
666 | |
667 | /* |
668 | * Validate keepouts (and holes between) don't violate |
669 | * word_size constraints. |
670 | */ |
671 | if ((keepout->end - keepout->start < nvmem->word_size) || |
672 | ((keepout->start != cur) && |
673 | (keepout->start - cur < nvmem->word_size))) { |
674 | |
675 | dev_err(&nvmem->dev, |
676 | "Keepout regions violate word_size constraints.\n" ); |
677 | |
678 | return -ERANGE; |
679 | } |
680 | |
681 | /* Validate keepouts don't violate stride (alignment). */ |
682 | if (!IS_ALIGNED(keepout->start, nvmem->stride) || |
683 | !IS_ALIGNED(keepout->end, nvmem->stride)) { |
684 | |
685 | dev_err(&nvmem->dev, |
686 | "Keepout regions violate stride.\n" ); |
687 | |
688 | return -EINVAL; |
689 | } |
690 | |
691 | cur = keepout->end; |
692 | keepout++; |
693 | } |
694 | |
695 | return 0; |
696 | } |
697 | |
698 | static int nvmem_add_cells_from_dt(struct nvmem_device *nvmem, struct device_node *np) |
699 | { |
700 | struct nvmem_layout *layout = nvmem->layout; |
701 | struct device *dev = &nvmem->dev; |
702 | struct device_node *child; |
703 | const __be32 *addr; |
704 | int len, ret; |
705 | |
706 | for_each_child_of_node(np, child) { |
707 | struct nvmem_cell_info info = {0}; |
708 | |
709 | addr = of_get_property(node: child, name: "reg" , lenp: &len); |
710 | if (!addr) |
711 | continue; |
712 | if (len < 2 * sizeof(u32)) { |
713 | dev_err(dev, "nvmem: invalid reg on %pOF\n" , child); |
714 | of_node_put(node: child); |
715 | return -EINVAL; |
716 | } |
717 | |
718 | info.offset = be32_to_cpup(p: addr++); |
719 | info.bytes = be32_to_cpup(p: addr); |
720 | info.name = kasprintf(GFP_KERNEL, fmt: "%pOFn" , child); |
721 | |
722 | addr = of_get_property(node: child, name: "bits" , lenp: &len); |
723 | if (addr && len == (2 * sizeof(u32))) { |
724 | info.bit_offset = be32_to_cpup(p: addr++); |
725 | info.nbits = be32_to_cpup(p: addr); |
726 | } |
727 | |
728 | info.np = of_node_get(node: child); |
729 | |
730 | if (layout && layout->fixup_cell_info) |
731 | layout->fixup_cell_info(nvmem, layout, &info); |
732 | |
733 | ret = nvmem_add_one_cell(nvmem, &info); |
734 | kfree(objp: info.name); |
735 | if (ret) { |
736 | of_node_put(node: child); |
737 | return ret; |
738 | } |
739 | } |
740 | |
741 | return 0; |
742 | } |
743 | |
744 | static int nvmem_add_cells_from_legacy_of(struct nvmem_device *nvmem) |
745 | { |
746 | return nvmem_add_cells_from_dt(nvmem, np: nvmem->dev.of_node); |
747 | } |
748 | |
749 | static int nvmem_add_cells_from_fixed_layout(struct nvmem_device *nvmem) |
750 | { |
751 | struct device_node *layout_np; |
752 | int err = 0; |
753 | |
754 | layout_np = of_nvmem_layout_get_container(nvmem); |
755 | if (!layout_np) |
756 | return 0; |
757 | |
758 | if (of_device_is_compatible(device: layout_np, "fixed-layout" )) |
759 | err = nvmem_add_cells_from_dt(nvmem, np: layout_np); |
760 | |
761 | of_node_put(node: layout_np); |
762 | |
763 | return err; |
764 | } |
765 | |
766 | int __nvmem_layout_register(struct nvmem_layout *layout, struct module *owner) |
767 | { |
768 | layout->owner = owner; |
769 | |
770 | spin_lock(lock: &nvmem_layout_lock); |
771 | list_add(new: &layout->node, head: &nvmem_layouts); |
772 | spin_unlock(lock: &nvmem_layout_lock); |
773 | |
774 | blocking_notifier_call_chain(nh: &nvmem_notifier, val: NVMEM_LAYOUT_ADD, v: layout); |
775 | |
776 | return 0; |
777 | } |
778 | EXPORT_SYMBOL_GPL(__nvmem_layout_register); |
779 | |
780 | void nvmem_layout_unregister(struct nvmem_layout *layout) |
781 | { |
782 | blocking_notifier_call_chain(nh: &nvmem_notifier, val: NVMEM_LAYOUT_REMOVE, v: layout); |
783 | |
784 | spin_lock(lock: &nvmem_layout_lock); |
785 | list_del(entry: &layout->node); |
786 | spin_unlock(lock: &nvmem_layout_lock); |
787 | } |
788 | EXPORT_SYMBOL_GPL(nvmem_layout_unregister); |
789 | |
790 | static struct nvmem_layout *nvmem_layout_get(struct nvmem_device *nvmem) |
791 | { |
792 | struct device_node *layout_np; |
793 | struct nvmem_layout *l, *layout = ERR_PTR(error: -EPROBE_DEFER); |
794 | |
795 | layout_np = of_nvmem_layout_get_container(nvmem); |
796 | if (!layout_np) |
797 | return NULL; |
798 | |
799 | /* |
800 | * In case the nvmem device was built-in while the layout was built as a |
801 | * module, we shall manually request the layout driver loading otherwise |
802 | * we'll never have any match. |
803 | */ |
804 | of_request_module(np: layout_np); |
805 | |
806 | spin_lock(lock: &nvmem_layout_lock); |
807 | |
808 | list_for_each_entry(l, &nvmem_layouts, node) { |
809 | if (of_match_node(matches: l->of_match_table, node: layout_np)) { |
810 | if (try_module_get(module: l->owner)) |
811 | layout = l; |
812 | |
813 | break; |
814 | } |
815 | } |
816 | |
817 | spin_unlock(lock: &nvmem_layout_lock); |
818 | of_node_put(node: layout_np); |
819 | |
820 | return layout; |
821 | } |
822 | |
823 | static void nvmem_layout_put(struct nvmem_layout *layout) |
824 | { |
825 | if (layout) |
826 | module_put(module: layout->owner); |
827 | } |
828 | |
829 | static int nvmem_add_cells_from_layout(struct nvmem_device *nvmem) |
830 | { |
831 | struct nvmem_layout *layout = nvmem->layout; |
832 | int ret; |
833 | |
834 | if (layout && layout->add_cells) { |
835 | ret = layout->add_cells(&nvmem->dev, nvmem, layout); |
836 | if (ret) |
837 | return ret; |
838 | } |
839 | |
840 | return 0; |
841 | } |
842 | |
843 | #if IS_ENABLED(CONFIG_OF) |
844 | /** |
845 | * of_nvmem_layout_get_container() - Get OF node to layout container. |
846 | * |
847 | * @nvmem: nvmem device. |
848 | * |
849 | * Return: a node pointer with refcount incremented or NULL if no |
850 | * container exists. Use of_node_put() on it when done. |
851 | */ |
852 | struct device_node *of_nvmem_layout_get_container(struct nvmem_device *nvmem) |
853 | { |
854 | return of_get_child_by_name(node: nvmem->dev.of_node, name: "nvmem-layout" ); |
855 | } |
856 | EXPORT_SYMBOL_GPL(of_nvmem_layout_get_container); |
857 | #endif |
858 | |
859 | const void *nvmem_layout_get_match_data(struct nvmem_device *nvmem, |
860 | struct nvmem_layout *layout) |
861 | { |
862 | struct device_node __maybe_unused *layout_np; |
863 | const struct of_device_id *match; |
864 | |
865 | layout_np = of_nvmem_layout_get_container(nvmem); |
866 | match = of_match_node(matches: layout->of_match_table, node: layout_np); |
867 | |
868 | return match ? match->data : NULL; |
869 | } |
870 | EXPORT_SYMBOL_GPL(nvmem_layout_get_match_data); |
871 | |
872 | /** |
873 | * nvmem_register() - Register a nvmem device for given nvmem_config. |
874 | * Also creates a binary entry in /sys/bus/nvmem/devices/dev-name/nvmem |
875 | * |
876 | * @config: nvmem device configuration with which nvmem device is created. |
877 | * |
878 | * Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device |
879 | * on success. |
880 | */ |
881 | |
882 | struct nvmem_device *nvmem_register(const struct nvmem_config *config) |
883 | { |
884 | struct nvmem_device *nvmem; |
885 | int rval; |
886 | |
887 | if (!config->dev) |
888 | return ERR_PTR(error: -EINVAL); |
889 | |
890 | if (!config->reg_read && !config->reg_write) |
891 | return ERR_PTR(error: -EINVAL); |
892 | |
893 | nvmem = kzalloc(size: sizeof(*nvmem), GFP_KERNEL); |
894 | if (!nvmem) |
895 | return ERR_PTR(error: -ENOMEM); |
896 | |
897 | rval = ida_alloc(ida: &nvmem_ida, GFP_KERNEL); |
898 | if (rval < 0) { |
899 | kfree(objp: nvmem); |
900 | return ERR_PTR(error: rval); |
901 | } |
902 | |
903 | nvmem->id = rval; |
904 | |
905 | nvmem->dev.type = &nvmem_provider_type; |
906 | nvmem->dev.bus = &nvmem_bus_type; |
907 | nvmem->dev.parent = config->dev; |
908 | |
909 | device_initialize(dev: &nvmem->dev); |
910 | |
911 | if (!config->ignore_wp) |
912 | nvmem->wp_gpio = gpiod_get_optional(dev: config->dev, con_id: "wp" , |
913 | flags: GPIOD_OUT_HIGH); |
914 | if (IS_ERR(ptr: nvmem->wp_gpio)) { |
915 | rval = PTR_ERR(ptr: nvmem->wp_gpio); |
916 | nvmem->wp_gpio = NULL; |
917 | goto err_put_device; |
918 | } |
919 | |
920 | kref_init(kref: &nvmem->refcnt); |
921 | INIT_LIST_HEAD(list: &nvmem->cells); |
922 | |
923 | nvmem->owner = config->owner; |
924 | if (!nvmem->owner && config->dev->driver) |
925 | nvmem->owner = config->dev->driver->owner; |
926 | nvmem->stride = config->stride ?: 1; |
927 | nvmem->word_size = config->word_size ?: 1; |
928 | nvmem->size = config->size; |
929 | nvmem->root_only = config->root_only; |
930 | nvmem->priv = config->priv; |
931 | nvmem->type = config->type; |
932 | nvmem->reg_read = config->reg_read; |
933 | nvmem->reg_write = config->reg_write; |
934 | nvmem->keepout = config->keepout; |
935 | nvmem->nkeepout = config->nkeepout; |
936 | if (config->of_node) |
937 | nvmem->dev.of_node = config->of_node; |
938 | else |
939 | nvmem->dev.of_node = config->dev->of_node; |
940 | |
941 | switch (config->id) { |
942 | case NVMEM_DEVID_NONE: |
943 | rval = dev_set_name(dev: &nvmem->dev, name: "%s" , config->name); |
944 | break; |
945 | case NVMEM_DEVID_AUTO: |
946 | rval = dev_set_name(dev: &nvmem->dev, name: "%s%d" , config->name, nvmem->id); |
947 | break; |
948 | default: |
949 | rval = dev_set_name(dev: &nvmem->dev, name: "%s%d" , |
950 | config->name ? : "nvmem" , |
951 | config->name ? config->id : nvmem->id); |
952 | break; |
953 | } |
954 | |
955 | if (rval) |
956 | goto err_put_device; |
957 | |
958 | nvmem->read_only = device_property_present(dev: config->dev, propname: "read-only" ) || |
959 | config->read_only || !nvmem->reg_write; |
960 | |
961 | #ifdef CONFIG_NVMEM_SYSFS |
962 | nvmem->dev.groups = nvmem_dev_groups; |
963 | #endif |
964 | |
965 | if (nvmem->nkeepout) { |
966 | rval = nvmem_validate_keepouts(nvmem); |
967 | if (rval) |
968 | goto err_put_device; |
969 | } |
970 | |
971 | if (config->compat) { |
972 | rval = nvmem_sysfs_setup_compat(nvmem, config); |
973 | if (rval) |
974 | goto err_put_device; |
975 | } |
976 | |
977 | /* |
978 | * If the driver supplied a layout by config->layout, the module |
979 | * pointer will be NULL and nvmem_layout_put() will be a noop. |
980 | */ |
981 | nvmem->layout = config->layout ?: nvmem_layout_get(nvmem); |
982 | if (IS_ERR(ptr: nvmem->layout)) { |
983 | rval = PTR_ERR(ptr: nvmem->layout); |
984 | nvmem->layout = NULL; |
985 | |
986 | if (rval == -EPROBE_DEFER) |
987 | goto err_teardown_compat; |
988 | } |
989 | |
990 | if (config->cells) { |
991 | rval = nvmem_add_cells(nvmem, info: config->cells, ncells: config->ncells); |
992 | if (rval) |
993 | goto err_remove_cells; |
994 | } |
995 | |
996 | rval = nvmem_add_cells_from_table(nvmem); |
997 | if (rval) |
998 | goto err_remove_cells; |
999 | |
1000 | if (config->add_legacy_fixed_of_cells) { |
1001 | rval = nvmem_add_cells_from_legacy_of(nvmem); |
1002 | if (rval) |
1003 | goto err_remove_cells; |
1004 | } |
1005 | |
1006 | rval = nvmem_add_cells_from_fixed_layout(nvmem); |
1007 | if (rval) |
1008 | goto err_remove_cells; |
1009 | |
1010 | rval = nvmem_add_cells_from_layout(nvmem); |
1011 | if (rval) |
1012 | goto err_remove_cells; |
1013 | |
1014 | dev_dbg(&nvmem->dev, "Registering nvmem device %s\n" , config->name); |
1015 | |
1016 | rval = device_add(dev: &nvmem->dev); |
1017 | if (rval) |
1018 | goto err_remove_cells; |
1019 | |
1020 | blocking_notifier_call_chain(nh: &nvmem_notifier, val: NVMEM_ADD, v: nvmem); |
1021 | |
1022 | return nvmem; |
1023 | |
1024 | err_remove_cells: |
1025 | nvmem_device_remove_all_cells(nvmem); |
1026 | nvmem_layout_put(layout: nvmem->layout); |
1027 | err_teardown_compat: |
1028 | if (config->compat) |
1029 | nvmem_sysfs_remove_compat(nvmem, config); |
1030 | err_put_device: |
1031 | put_device(dev: &nvmem->dev); |
1032 | |
1033 | return ERR_PTR(error: rval); |
1034 | } |
1035 | EXPORT_SYMBOL_GPL(nvmem_register); |
1036 | |
1037 | static void nvmem_device_release(struct kref *kref) |
1038 | { |
1039 | struct nvmem_device *nvmem; |
1040 | |
1041 | nvmem = container_of(kref, struct nvmem_device, refcnt); |
1042 | |
1043 | blocking_notifier_call_chain(nh: &nvmem_notifier, val: NVMEM_REMOVE, v: nvmem); |
1044 | |
1045 | if (nvmem->flags & FLAG_COMPAT) |
1046 | device_remove_bin_file(dev: nvmem->base_dev, attr: &nvmem->eeprom); |
1047 | |
1048 | nvmem_device_remove_all_cells(nvmem); |
1049 | nvmem_layout_put(layout: nvmem->layout); |
1050 | device_unregister(dev: &nvmem->dev); |
1051 | } |
1052 | |
1053 | /** |
1054 | * nvmem_unregister() - Unregister previously registered nvmem device |
1055 | * |
1056 | * @nvmem: Pointer to previously registered nvmem device. |
1057 | */ |
1058 | void nvmem_unregister(struct nvmem_device *nvmem) |
1059 | { |
1060 | if (nvmem) |
1061 | kref_put(kref: &nvmem->refcnt, release: nvmem_device_release); |
1062 | } |
1063 | EXPORT_SYMBOL_GPL(nvmem_unregister); |
1064 | |
1065 | static void devm_nvmem_unregister(void *nvmem) |
1066 | { |
1067 | nvmem_unregister(nvmem); |
1068 | } |
1069 | |
1070 | /** |
1071 | * devm_nvmem_register() - Register a managed nvmem device for given |
1072 | * nvmem_config. |
1073 | * Also creates a binary entry in /sys/bus/nvmem/devices/dev-name/nvmem |
1074 | * |
1075 | * @dev: Device that uses the nvmem device. |
1076 | * @config: nvmem device configuration with which nvmem device is created. |
1077 | * |
1078 | * Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device |
1079 | * on success. |
1080 | */ |
1081 | struct nvmem_device *devm_nvmem_register(struct device *dev, |
1082 | const struct nvmem_config *config) |
1083 | { |
1084 | struct nvmem_device *nvmem; |
1085 | int ret; |
1086 | |
1087 | nvmem = nvmem_register(config); |
1088 | if (IS_ERR(ptr: nvmem)) |
1089 | return nvmem; |
1090 | |
1091 | ret = devm_add_action_or_reset(dev, devm_nvmem_unregister, nvmem); |
1092 | if (ret) |
1093 | return ERR_PTR(error: ret); |
1094 | |
1095 | return nvmem; |
1096 | } |
1097 | EXPORT_SYMBOL_GPL(devm_nvmem_register); |
1098 | |
1099 | static struct nvmem_device *__nvmem_device_get(void *data, |
1100 | int (*match)(struct device *dev, const void *data)) |
1101 | { |
1102 | struct nvmem_device *nvmem = NULL; |
1103 | struct device *dev; |
1104 | |
1105 | mutex_lock(&nvmem_mutex); |
1106 | dev = bus_find_device(bus: &nvmem_bus_type, NULL, data, match); |
1107 | if (dev) |
1108 | nvmem = to_nvmem_device(dev); |
1109 | mutex_unlock(lock: &nvmem_mutex); |
1110 | if (!nvmem) |
1111 | return ERR_PTR(error: -EPROBE_DEFER); |
1112 | |
1113 | if (!try_module_get(module: nvmem->owner)) { |
1114 | dev_err(&nvmem->dev, |
1115 | "could not increase module refcount for cell %s\n" , |
1116 | nvmem_dev_name(nvmem)); |
1117 | |
1118 | put_device(dev: &nvmem->dev); |
1119 | return ERR_PTR(error: -EINVAL); |
1120 | } |
1121 | |
1122 | kref_get(kref: &nvmem->refcnt); |
1123 | |
1124 | return nvmem; |
1125 | } |
1126 | |
1127 | static void __nvmem_device_put(struct nvmem_device *nvmem) |
1128 | { |
1129 | put_device(dev: &nvmem->dev); |
1130 | module_put(module: nvmem->owner); |
1131 | kref_put(kref: &nvmem->refcnt, release: nvmem_device_release); |
1132 | } |
1133 | |
1134 | #if IS_ENABLED(CONFIG_OF) |
1135 | /** |
1136 | * of_nvmem_device_get() - Get nvmem device from a given id |
1137 | * |
1138 | * @np: Device tree node that uses the nvmem device. |
1139 | * @id: nvmem name from nvmem-names property. |
1140 | * |
1141 | * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device |
1142 | * on success. |
1143 | */ |
1144 | struct nvmem_device *of_nvmem_device_get(struct device_node *np, const char *id) |
1145 | { |
1146 | |
1147 | struct device_node *nvmem_np; |
1148 | struct nvmem_device *nvmem; |
1149 | int index = 0; |
1150 | |
1151 | if (id) |
1152 | index = of_property_match_string(np, propname: "nvmem-names" , string: id); |
1153 | |
1154 | nvmem_np = of_parse_phandle(np, phandle_name: "nvmem" , index); |
1155 | if (!nvmem_np) |
1156 | return ERR_PTR(error: -ENOENT); |
1157 | |
1158 | nvmem = __nvmem_device_get(data: nvmem_np, match: device_match_of_node); |
1159 | of_node_put(node: nvmem_np); |
1160 | return nvmem; |
1161 | } |
1162 | EXPORT_SYMBOL_GPL(of_nvmem_device_get); |
1163 | #endif |
1164 | |
1165 | /** |
1166 | * nvmem_device_get() - Get nvmem device from a given id |
1167 | * |
1168 | * @dev: Device that uses the nvmem device. |
1169 | * @dev_name: name of the requested nvmem device. |
1170 | * |
1171 | * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device |
1172 | * on success. |
1173 | */ |
1174 | struct nvmem_device *nvmem_device_get(struct device *dev, const char *dev_name) |
1175 | { |
1176 | if (dev->of_node) { /* try dt first */ |
1177 | struct nvmem_device *nvmem; |
1178 | |
1179 | nvmem = of_nvmem_device_get(dev->of_node, dev_name); |
1180 | |
1181 | if (!IS_ERR(ptr: nvmem) || PTR_ERR(ptr: nvmem) == -EPROBE_DEFER) |
1182 | return nvmem; |
1183 | |
1184 | } |
1185 | |
1186 | return __nvmem_device_get(data: (void *)dev_name, match: device_match_name); |
1187 | } |
1188 | EXPORT_SYMBOL_GPL(nvmem_device_get); |
1189 | |
1190 | /** |
1191 | * nvmem_device_find() - Find nvmem device with matching function |
1192 | * |
1193 | * @data: Data to pass to match function |
1194 | * @match: Callback function to check device |
1195 | * |
1196 | * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device |
1197 | * on success. |
1198 | */ |
1199 | struct nvmem_device *nvmem_device_find(void *data, |
1200 | int (*match)(struct device *dev, const void *data)) |
1201 | { |
1202 | return __nvmem_device_get(data, match); |
1203 | } |
1204 | EXPORT_SYMBOL_GPL(nvmem_device_find); |
1205 | |
1206 | static int devm_nvmem_device_match(struct device *dev, void *res, void *data) |
1207 | { |
1208 | struct nvmem_device **nvmem = res; |
1209 | |
1210 | if (WARN_ON(!nvmem || !*nvmem)) |
1211 | return 0; |
1212 | |
1213 | return *nvmem == data; |
1214 | } |
1215 | |
1216 | static void devm_nvmem_device_release(struct device *dev, void *res) |
1217 | { |
1218 | nvmem_device_put(nvmem: *(struct nvmem_device **)res); |
1219 | } |
1220 | |
1221 | /** |
1222 | * devm_nvmem_device_put() - put alredy got nvmem device |
1223 | * |
1224 | * @dev: Device that uses the nvmem device. |
1225 | * @nvmem: pointer to nvmem device allocated by devm_nvmem_cell_get(), |
1226 | * that needs to be released. |
1227 | */ |
1228 | void devm_nvmem_device_put(struct device *dev, struct nvmem_device *nvmem) |
1229 | { |
1230 | int ret; |
1231 | |
1232 | ret = devres_release(dev, release: devm_nvmem_device_release, |
1233 | match: devm_nvmem_device_match, match_data: nvmem); |
1234 | |
1235 | WARN_ON(ret); |
1236 | } |
1237 | EXPORT_SYMBOL_GPL(devm_nvmem_device_put); |
1238 | |
1239 | /** |
1240 | * nvmem_device_put() - put alredy got nvmem device |
1241 | * |
1242 | * @nvmem: pointer to nvmem device that needs to be released. |
1243 | */ |
1244 | void nvmem_device_put(struct nvmem_device *nvmem) |
1245 | { |
1246 | __nvmem_device_put(nvmem); |
1247 | } |
1248 | EXPORT_SYMBOL_GPL(nvmem_device_put); |
1249 | |
1250 | /** |
1251 | * devm_nvmem_device_get() - Get nvmem cell of device form a given id |
1252 | * |
1253 | * @dev: Device that requests the nvmem device. |
1254 | * @id: name id for the requested nvmem device. |
1255 | * |
1256 | * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_cell |
1257 | * on success. The nvmem_cell will be freed by the automatically once the |
1258 | * device is freed. |
1259 | */ |
1260 | struct nvmem_device *devm_nvmem_device_get(struct device *dev, const char *id) |
1261 | { |
1262 | struct nvmem_device **ptr, *nvmem; |
1263 | |
1264 | ptr = devres_alloc(devm_nvmem_device_release, sizeof(*ptr), GFP_KERNEL); |
1265 | if (!ptr) |
1266 | return ERR_PTR(error: -ENOMEM); |
1267 | |
1268 | nvmem = nvmem_device_get(dev, id); |
1269 | if (!IS_ERR(ptr: nvmem)) { |
1270 | *ptr = nvmem; |
1271 | devres_add(dev, res: ptr); |
1272 | } else { |
1273 | devres_free(res: ptr); |
1274 | } |
1275 | |
1276 | return nvmem; |
1277 | } |
1278 | EXPORT_SYMBOL_GPL(devm_nvmem_device_get); |
1279 | |
1280 | static struct nvmem_cell *nvmem_create_cell(struct nvmem_cell_entry *entry, |
1281 | const char *id, int index) |
1282 | { |
1283 | struct nvmem_cell *cell; |
1284 | const char *name = NULL; |
1285 | |
1286 | cell = kzalloc(size: sizeof(*cell), GFP_KERNEL); |
1287 | if (!cell) |
1288 | return ERR_PTR(error: -ENOMEM); |
1289 | |
1290 | if (id) { |
1291 | name = kstrdup_const(s: id, GFP_KERNEL); |
1292 | if (!name) { |
1293 | kfree(objp: cell); |
1294 | return ERR_PTR(error: -ENOMEM); |
1295 | } |
1296 | } |
1297 | |
1298 | cell->id = name; |
1299 | cell->entry = entry; |
1300 | cell->index = index; |
1301 | |
1302 | return cell; |
1303 | } |
1304 | |
1305 | static struct nvmem_cell * |
1306 | nvmem_cell_get_from_lookup(struct device *dev, const char *con_id) |
1307 | { |
1308 | struct nvmem_cell_entry *cell_entry; |
1309 | struct nvmem_cell *cell = ERR_PTR(error: -ENOENT); |
1310 | struct nvmem_cell_lookup *lookup; |
1311 | struct nvmem_device *nvmem; |
1312 | const char *dev_id; |
1313 | |
1314 | if (!dev) |
1315 | return ERR_PTR(error: -EINVAL); |
1316 | |
1317 | dev_id = dev_name(dev); |
1318 | |
1319 | mutex_lock(&nvmem_lookup_mutex); |
1320 | |
1321 | list_for_each_entry(lookup, &nvmem_lookup_list, node) { |
1322 | if ((strcmp(lookup->dev_id, dev_id) == 0) && |
1323 | (strcmp(lookup->con_id, con_id) == 0)) { |
1324 | /* This is the right entry. */ |
1325 | nvmem = __nvmem_device_get(data: (void *)lookup->nvmem_name, |
1326 | match: device_match_name); |
1327 | if (IS_ERR(ptr: nvmem)) { |
1328 | /* Provider may not be registered yet. */ |
1329 | cell = ERR_CAST(ptr: nvmem); |
1330 | break; |
1331 | } |
1332 | |
1333 | cell_entry = nvmem_find_cell_entry_by_name(nvmem, |
1334 | cell_id: lookup->cell_name); |
1335 | if (!cell_entry) { |
1336 | __nvmem_device_put(nvmem); |
1337 | cell = ERR_PTR(error: -ENOENT); |
1338 | } else { |
1339 | cell = nvmem_create_cell(entry: cell_entry, id: con_id, index: 0); |
1340 | if (IS_ERR(ptr: cell)) |
1341 | __nvmem_device_put(nvmem); |
1342 | } |
1343 | break; |
1344 | } |
1345 | } |
1346 | |
1347 | mutex_unlock(lock: &nvmem_lookup_mutex); |
1348 | return cell; |
1349 | } |
1350 | |
1351 | #if IS_ENABLED(CONFIG_OF) |
1352 | static struct nvmem_cell_entry * |
1353 | nvmem_find_cell_entry_by_node(struct nvmem_device *nvmem, struct device_node *np) |
1354 | { |
1355 | struct nvmem_cell_entry *iter, *cell = NULL; |
1356 | |
1357 | mutex_lock(&nvmem_mutex); |
1358 | list_for_each_entry(iter, &nvmem->cells, node) { |
1359 | if (np == iter->np) { |
1360 | cell = iter; |
1361 | break; |
1362 | } |
1363 | } |
1364 | mutex_unlock(lock: &nvmem_mutex); |
1365 | |
1366 | return cell; |
1367 | } |
1368 | |
1369 | /** |
1370 | * of_nvmem_cell_get() - Get a nvmem cell from given device node and cell id |
1371 | * |
1372 | * @np: Device tree node that uses the nvmem cell. |
1373 | * @id: nvmem cell name from nvmem-cell-names property, or NULL |
1374 | * for the cell at index 0 (the lone cell with no accompanying |
1375 | * nvmem-cell-names property). |
1376 | * |
1377 | * Return: Will be an ERR_PTR() on error or a valid pointer |
1378 | * to a struct nvmem_cell. The nvmem_cell will be freed by the |
1379 | * nvmem_cell_put(). |
1380 | */ |
1381 | struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, const char *id) |
1382 | { |
1383 | struct device_node *cell_np, *nvmem_np; |
1384 | struct nvmem_device *nvmem; |
1385 | struct nvmem_cell_entry *cell_entry; |
1386 | struct nvmem_cell *cell; |
1387 | struct of_phandle_args cell_spec; |
1388 | int index = 0; |
1389 | int cell_index = 0; |
1390 | int ret; |
1391 | |
1392 | /* if cell name exists, find index to the name */ |
1393 | if (id) |
1394 | index = of_property_match_string(np, propname: "nvmem-cell-names" , string: id); |
1395 | |
1396 | ret = of_parse_phandle_with_optional_args(np, list_name: "nvmem-cells" , |
1397 | cells_name: "#nvmem-cell-cells" , |
1398 | index, out_args: &cell_spec); |
1399 | if (ret) |
1400 | return ERR_PTR(error: -ENOENT); |
1401 | |
1402 | if (cell_spec.args_count > 1) |
1403 | return ERR_PTR(error: -EINVAL); |
1404 | |
1405 | cell_np = cell_spec.np; |
1406 | if (cell_spec.args_count) |
1407 | cell_index = cell_spec.args[0]; |
1408 | |
1409 | nvmem_np = of_get_parent(node: cell_np); |
1410 | if (!nvmem_np) { |
1411 | of_node_put(node: cell_np); |
1412 | return ERR_PTR(error: -EINVAL); |
1413 | } |
1414 | |
1415 | /* nvmem layouts produce cells within the nvmem-layout container */ |
1416 | if (of_node_name_eq(np: nvmem_np, name: "nvmem-layout" )) { |
1417 | nvmem_np = of_get_next_parent(node: nvmem_np); |
1418 | if (!nvmem_np) { |
1419 | of_node_put(node: cell_np); |
1420 | return ERR_PTR(error: -EINVAL); |
1421 | } |
1422 | } |
1423 | |
1424 | nvmem = __nvmem_device_get(data: nvmem_np, match: device_match_of_node); |
1425 | of_node_put(node: nvmem_np); |
1426 | if (IS_ERR(ptr: nvmem)) { |
1427 | of_node_put(node: cell_np); |
1428 | return ERR_CAST(ptr: nvmem); |
1429 | } |
1430 | |
1431 | cell_entry = nvmem_find_cell_entry_by_node(nvmem, np: cell_np); |
1432 | of_node_put(node: cell_np); |
1433 | if (!cell_entry) { |
1434 | __nvmem_device_put(nvmem); |
1435 | return ERR_PTR(error: -ENOENT); |
1436 | } |
1437 | |
1438 | cell = nvmem_create_cell(entry: cell_entry, id, index: cell_index); |
1439 | if (IS_ERR(ptr: cell)) |
1440 | __nvmem_device_put(nvmem); |
1441 | |
1442 | return cell; |
1443 | } |
1444 | EXPORT_SYMBOL_GPL(of_nvmem_cell_get); |
1445 | #endif |
1446 | |
1447 | /** |
1448 | * nvmem_cell_get() - Get nvmem cell of device form a given cell name |
1449 | * |
1450 | * @dev: Device that requests the nvmem cell. |
1451 | * @id: nvmem cell name to get (this corresponds with the name from the |
1452 | * nvmem-cell-names property for DT systems and with the con_id from |
1453 | * the lookup entry for non-DT systems). |
1454 | * |
1455 | * Return: Will be an ERR_PTR() on error or a valid pointer |
1456 | * to a struct nvmem_cell. The nvmem_cell will be freed by the |
1457 | * nvmem_cell_put(). |
1458 | */ |
1459 | struct nvmem_cell *nvmem_cell_get(struct device *dev, const char *id) |
1460 | { |
1461 | struct nvmem_cell *cell; |
1462 | |
1463 | if (dev->of_node) { /* try dt first */ |
1464 | cell = of_nvmem_cell_get(dev->of_node, id); |
1465 | if (!IS_ERR(ptr: cell) || PTR_ERR(ptr: cell) == -EPROBE_DEFER) |
1466 | return cell; |
1467 | } |
1468 | |
1469 | /* NULL cell id only allowed for device tree; invalid otherwise */ |
1470 | if (!id) |
1471 | return ERR_PTR(error: -EINVAL); |
1472 | |
1473 | return nvmem_cell_get_from_lookup(dev, con_id: id); |
1474 | } |
1475 | EXPORT_SYMBOL_GPL(nvmem_cell_get); |
1476 | |
1477 | static void devm_nvmem_cell_release(struct device *dev, void *res) |
1478 | { |
1479 | nvmem_cell_put(cell: *(struct nvmem_cell **)res); |
1480 | } |
1481 | |
1482 | /** |
1483 | * devm_nvmem_cell_get() - Get nvmem cell of device form a given id |
1484 | * |
1485 | * @dev: Device that requests the nvmem cell. |
1486 | * @id: nvmem cell name id to get. |
1487 | * |
1488 | * Return: Will be an ERR_PTR() on error or a valid pointer |
1489 | * to a struct nvmem_cell. The nvmem_cell will be freed by the |
1490 | * automatically once the device is freed. |
1491 | */ |
1492 | struct nvmem_cell *devm_nvmem_cell_get(struct device *dev, const char *id) |
1493 | { |
1494 | struct nvmem_cell **ptr, *cell; |
1495 | |
1496 | ptr = devres_alloc(devm_nvmem_cell_release, sizeof(*ptr), GFP_KERNEL); |
1497 | if (!ptr) |
1498 | return ERR_PTR(error: -ENOMEM); |
1499 | |
1500 | cell = nvmem_cell_get(dev, id); |
1501 | if (!IS_ERR(ptr: cell)) { |
1502 | *ptr = cell; |
1503 | devres_add(dev, res: ptr); |
1504 | } else { |
1505 | devres_free(res: ptr); |
1506 | } |
1507 | |
1508 | return cell; |
1509 | } |
1510 | EXPORT_SYMBOL_GPL(devm_nvmem_cell_get); |
1511 | |
1512 | static int devm_nvmem_cell_match(struct device *dev, void *res, void *data) |
1513 | { |
1514 | struct nvmem_cell **c = res; |
1515 | |
1516 | if (WARN_ON(!c || !*c)) |
1517 | return 0; |
1518 | |
1519 | return *c == data; |
1520 | } |
1521 | |
1522 | /** |
1523 | * devm_nvmem_cell_put() - Release previously allocated nvmem cell |
1524 | * from devm_nvmem_cell_get. |
1525 | * |
1526 | * @dev: Device that requests the nvmem cell. |
1527 | * @cell: Previously allocated nvmem cell by devm_nvmem_cell_get(). |
1528 | */ |
1529 | void devm_nvmem_cell_put(struct device *dev, struct nvmem_cell *cell) |
1530 | { |
1531 | int ret; |
1532 | |
1533 | ret = devres_release(dev, release: devm_nvmem_cell_release, |
1534 | match: devm_nvmem_cell_match, match_data: cell); |
1535 | |
1536 | WARN_ON(ret); |
1537 | } |
1538 | EXPORT_SYMBOL(devm_nvmem_cell_put); |
1539 | |
1540 | /** |
1541 | * nvmem_cell_put() - Release previously allocated nvmem cell. |
1542 | * |
1543 | * @cell: Previously allocated nvmem cell by nvmem_cell_get(). |
1544 | */ |
1545 | void nvmem_cell_put(struct nvmem_cell *cell) |
1546 | { |
1547 | struct nvmem_device *nvmem = cell->entry->nvmem; |
1548 | |
1549 | if (cell->id) |
1550 | kfree_const(x: cell->id); |
1551 | |
1552 | kfree(objp: cell); |
1553 | __nvmem_device_put(nvmem); |
1554 | } |
1555 | EXPORT_SYMBOL_GPL(nvmem_cell_put); |
1556 | |
1557 | static void nvmem_shift_read_buffer_in_place(struct nvmem_cell_entry *cell, void *buf) |
1558 | { |
1559 | u8 *p, *b; |
1560 | int i, , bit_offset = cell->bit_offset; |
1561 | |
1562 | p = b = buf; |
1563 | if (bit_offset) { |
1564 | /* First shift */ |
1565 | *b++ >>= bit_offset; |
1566 | |
1567 | /* setup rest of the bytes if any */ |
1568 | for (i = 1; i < cell->bytes; i++) { |
1569 | /* Get bits from next byte and shift them towards msb */ |
1570 | *p |= *b << (BITS_PER_BYTE - bit_offset); |
1571 | |
1572 | p = b; |
1573 | *b++ >>= bit_offset; |
1574 | } |
1575 | } else { |
1576 | /* point to the msb */ |
1577 | p += cell->bytes - 1; |
1578 | } |
1579 | |
1580 | /* result fits in less bytes */ |
1581 | extra = cell->bytes - DIV_ROUND_UP(cell->nbits, BITS_PER_BYTE); |
1582 | while (--extra >= 0) |
1583 | *p-- = 0; |
1584 | |
1585 | /* clear msb bits if any leftover in the last byte */ |
1586 | if (cell->nbits % BITS_PER_BYTE) |
1587 | *p &= GENMASK((cell->nbits % BITS_PER_BYTE) - 1, 0); |
1588 | } |
1589 | |
1590 | static int __nvmem_cell_read(struct nvmem_device *nvmem, |
1591 | struct nvmem_cell_entry *cell, |
1592 | void *buf, size_t *len, const char *id, int index) |
1593 | { |
1594 | int rc; |
1595 | |
1596 | rc = nvmem_reg_read(nvmem, offset: cell->offset, val: buf, bytes: cell->raw_len); |
1597 | |
1598 | if (rc) |
1599 | return rc; |
1600 | |
1601 | /* shift bits in-place */ |
1602 | if (cell->bit_offset || cell->nbits) |
1603 | nvmem_shift_read_buffer_in_place(cell, buf); |
1604 | |
1605 | if (cell->read_post_process) { |
1606 | rc = cell->read_post_process(cell->priv, id, index, |
1607 | cell->offset, buf, cell->raw_len); |
1608 | if (rc) |
1609 | return rc; |
1610 | } |
1611 | |
1612 | if (len) |
1613 | *len = cell->bytes; |
1614 | |
1615 | return 0; |
1616 | } |
1617 | |
1618 | /** |
1619 | * nvmem_cell_read() - Read a given nvmem cell |
1620 | * |
1621 | * @cell: nvmem cell to be read. |
1622 | * @len: pointer to length of cell which will be populated on successful read; |
1623 | * can be NULL. |
1624 | * |
1625 | * Return: ERR_PTR() on error or a valid pointer to a buffer on success. The |
1626 | * buffer should be freed by the consumer with a kfree(). |
1627 | */ |
1628 | void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len) |
1629 | { |
1630 | struct nvmem_cell_entry *entry = cell->entry; |
1631 | struct nvmem_device *nvmem = entry->nvmem; |
1632 | u8 *buf; |
1633 | int rc; |
1634 | |
1635 | if (!nvmem) |
1636 | return ERR_PTR(error: -EINVAL); |
1637 | |
1638 | buf = kzalloc(max_t(size_t, entry->raw_len, entry->bytes), GFP_KERNEL); |
1639 | if (!buf) |
1640 | return ERR_PTR(error: -ENOMEM); |
1641 | |
1642 | rc = __nvmem_cell_read(nvmem, cell: cell->entry, buf, len, id: cell->id, index: cell->index); |
1643 | if (rc) { |
1644 | kfree(objp: buf); |
1645 | return ERR_PTR(error: rc); |
1646 | } |
1647 | |
1648 | return buf; |
1649 | } |
1650 | EXPORT_SYMBOL_GPL(nvmem_cell_read); |
1651 | |
1652 | static void *nvmem_cell_prepare_write_buffer(struct nvmem_cell_entry *cell, |
1653 | u8 *_buf, int len) |
1654 | { |
1655 | struct nvmem_device *nvmem = cell->nvmem; |
1656 | int i, rc, nbits, bit_offset = cell->bit_offset; |
1657 | u8 v, *p, *buf, *b, pbyte, pbits; |
1658 | |
1659 | nbits = cell->nbits; |
1660 | buf = kzalloc(size: cell->bytes, GFP_KERNEL); |
1661 | if (!buf) |
1662 | return ERR_PTR(error: -ENOMEM); |
1663 | |
1664 | memcpy(buf, _buf, len); |
1665 | p = b = buf; |
1666 | |
1667 | if (bit_offset) { |
1668 | pbyte = *b; |
1669 | *b <<= bit_offset; |
1670 | |
1671 | /* setup the first byte with lsb bits from nvmem */ |
1672 | rc = nvmem_reg_read(nvmem, offset: cell->offset, val: &v, bytes: 1); |
1673 | if (rc) |
1674 | goto err; |
1675 | *b++ |= GENMASK(bit_offset - 1, 0) & v; |
1676 | |
1677 | /* setup rest of the byte if any */ |
1678 | for (i = 1; i < cell->bytes; i++) { |
1679 | /* Get last byte bits and shift them towards lsb */ |
1680 | pbits = pbyte >> (BITS_PER_BYTE - 1 - bit_offset); |
1681 | pbyte = *b; |
1682 | p = b; |
1683 | *b <<= bit_offset; |
1684 | *b++ |= pbits; |
1685 | } |
1686 | } |
1687 | |
1688 | /* if it's not end on byte boundary */ |
1689 | if ((nbits + bit_offset) % BITS_PER_BYTE) { |
1690 | /* setup the last byte with msb bits from nvmem */ |
1691 | rc = nvmem_reg_read(nvmem, |
1692 | offset: cell->offset + cell->bytes - 1, val: &v, bytes: 1); |
1693 | if (rc) |
1694 | goto err; |
1695 | *p |= GENMASK(7, (nbits + bit_offset) % BITS_PER_BYTE) & v; |
1696 | |
1697 | } |
1698 | |
1699 | return buf; |
1700 | err: |
1701 | kfree(objp: buf); |
1702 | return ERR_PTR(error: rc); |
1703 | } |
1704 | |
1705 | static int __nvmem_cell_entry_write(struct nvmem_cell_entry *cell, void *buf, size_t len) |
1706 | { |
1707 | struct nvmem_device *nvmem = cell->nvmem; |
1708 | int rc; |
1709 | |
1710 | if (!nvmem || nvmem->read_only || |
1711 | (cell->bit_offset == 0 && len != cell->bytes)) |
1712 | return -EINVAL; |
1713 | |
1714 | /* |
1715 | * Any cells which have a read_post_process hook are read-only because |
1716 | * we cannot reverse the operation and it might affect other cells, |
1717 | * too. |
1718 | */ |
1719 | if (cell->read_post_process) |
1720 | return -EINVAL; |
1721 | |
1722 | if (cell->bit_offset || cell->nbits) { |
1723 | buf = nvmem_cell_prepare_write_buffer(cell, buf: buf, len); |
1724 | if (IS_ERR(ptr: buf)) |
1725 | return PTR_ERR(ptr: buf); |
1726 | } |
1727 | |
1728 | rc = nvmem_reg_write(nvmem, offset: cell->offset, val: buf, bytes: cell->bytes); |
1729 | |
1730 | /* free the tmp buffer */ |
1731 | if (cell->bit_offset || cell->nbits) |
1732 | kfree(objp: buf); |
1733 | |
1734 | if (rc) |
1735 | return rc; |
1736 | |
1737 | return len; |
1738 | } |
1739 | |
1740 | /** |
1741 | * nvmem_cell_write() - Write to a given nvmem cell |
1742 | * |
1743 | * @cell: nvmem cell to be written. |
1744 | * @buf: Buffer to be written. |
1745 | * @len: length of buffer to be written to nvmem cell. |
1746 | * |
1747 | * Return: length of bytes written or negative on failure. |
1748 | */ |
1749 | int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len) |
1750 | { |
1751 | return __nvmem_cell_entry_write(cell: cell->entry, buf, len); |
1752 | } |
1753 | |
1754 | EXPORT_SYMBOL_GPL(nvmem_cell_write); |
1755 | |
1756 | static int nvmem_cell_read_common(struct device *dev, const char *cell_id, |
1757 | void *val, size_t count) |
1758 | { |
1759 | struct nvmem_cell *cell; |
1760 | void *buf; |
1761 | size_t len; |
1762 | |
1763 | cell = nvmem_cell_get(dev, cell_id); |
1764 | if (IS_ERR(ptr: cell)) |
1765 | return PTR_ERR(ptr: cell); |
1766 | |
1767 | buf = nvmem_cell_read(cell, &len); |
1768 | if (IS_ERR(ptr: buf)) { |
1769 | nvmem_cell_put(cell); |
1770 | return PTR_ERR(ptr: buf); |
1771 | } |
1772 | if (len != count) { |
1773 | kfree(objp: buf); |
1774 | nvmem_cell_put(cell); |
1775 | return -EINVAL; |
1776 | } |
1777 | memcpy(val, buf, count); |
1778 | kfree(objp: buf); |
1779 | nvmem_cell_put(cell); |
1780 | |
1781 | return 0; |
1782 | } |
1783 | |
1784 | /** |
1785 | * nvmem_cell_read_u8() - Read a cell value as a u8 |
1786 | * |
1787 | * @dev: Device that requests the nvmem cell. |
1788 | * @cell_id: Name of nvmem cell to read. |
1789 | * @val: pointer to output value. |
1790 | * |
1791 | * Return: 0 on success or negative errno. |
1792 | */ |
1793 | int nvmem_cell_read_u8(struct device *dev, const char *cell_id, u8 *val) |
1794 | { |
1795 | return nvmem_cell_read_common(dev, cell_id, val, count: sizeof(*val)); |
1796 | } |
1797 | EXPORT_SYMBOL_GPL(nvmem_cell_read_u8); |
1798 | |
1799 | /** |
1800 | * nvmem_cell_read_u16() - Read a cell value as a u16 |
1801 | * |
1802 | * @dev: Device that requests the nvmem cell. |
1803 | * @cell_id: Name of nvmem cell to read. |
1804 | * @val: pointer to output value. |
1805 | * |
1806 | * Return: 0 on success or negative errno. |
1807 | */ |
1808 | int nvmem_cell_read_u16(struct device *dev, const char *cell_id, u16 *val) |
1809 | { |
1810 | return nvmem_cell_read_common(dev, cell_id, val, count: sizeof(*val)); |
1811 | } |
1812 | EXPORT_SYMBOL_GPL(nvmem_cell_read_u16); |
1813 | |
1814 | /** |
1815 | * nvmem_cell_read_u32() - Read a cell value as a u32 |
1816 | * |
1817 | * @dev: Device that requests the nvmem cell. |
1818 | * @cell_id: Name of nvmem cell to read. |
1819 | * @val: pointer to output value. |
1820 | * |
1821 | * Return: 0 on success or negative errno. |
1822 | */ |
1823 | int nvmem_cell_read_u32(struct device *dev, const char *cell_id, u32 *val) |
1824 | { |
1825 | return nvmem_cell_read_common(dev, cell_id, val, count: sizeof(*val)); |
1826 | } |
1827 | EXPORT_SYMBOL_GPL(nvmem_cell_read_u32); |
1828 | |
1829 | /** |
1830 | * nvmem_cell_read_u64() - Read a cell value as a u64 |
1831 | * |
1832 | * @dev: Device that requests the nvmem cell. |
1833 | * @cell_id: Name of nvmem cell to read. |
1834 | * @val: pointer to output value. |
1835 | * |
1836 | * Return: 0 on success or negative errno. |
1837 | */ |
1838 | int nvmem_cell_read_u64(struct device *dev, const char *cell_id, u64 *val) |
1839 | { |
1840 | return nvmem_cell_read_common(dev, cell_id, val, count: sizeof(*val)); |
1841 | } |
1842 | EXPORT_SYMBOL_GPL(nvmem_cell_read_u64); |
1843 | |
1844 | static const void *nvmem_cell_read_variable_common(struct device *dev, |
1845 | const char *cell_id, |
1846 | size_t max_len, size_t *len) |
1847 | { |
1848 | struct nvmem_cell *cell; |
1849 | int nbits; |
1850 | void *buf; |
1851 | |
1852 | cell = nvmem_cell_get(dev, cell_id); |
1853 | if (IS_ERR(ptr: cell)) |
1854 | return cell; |
1855 | |
1856 | nbits = cell->entry->nbits; |
1857 | buf = nvmem_cell_read(cell, len); |
1858 | nvmem_cell_put(cell); |
1859 | if (IS_ERR(ptr: buf)) |
1860 | return buf; |
1861 | |
1862 | /* |
1863 | * If nbits is set then nvmem_cell_read() can significantly exaggerate |
1864 | * the length of the real data. Throw away the extra junk. |
1865 | */ |
1866 | if (nbits) |
1867 | *len = DIV_ROUND_UP(nbits, 8); |
1868 | |
1869 | if (*len > max_len) { |
1870 | kfree(objp: buf); |
1871 | return ERR_PTR(error: -ERANGE); |
1872 | } |
1873 | |
1874 | return buf; |
1875 | } |
1876 | |
1877 | /** |
1878 | * nvmem_cell_read_variable_le_u32() - Read up to 32-bits of data as a little endian number. |
1879 | * |
1880 | * @dev: Device that requests the nvmem cell. |
1881 | * @cell_id: Name of nvmem cell to read. |
1882 | * @val: pointer to output value. |
1883 | * |
1884 | * Return: 0 on success or negative errno. |
1885 | */ |
1886 | int nvmem_cell_read_variable_le_u32(struct device *dev, const char *cell_id, |
1887 | u32 *val) |
1888 | { |
1889 | size_t len; |
1890 | const u8 *buf; |
1891 | int i; |
1892 | |
1893 | buf = nvmem_cell_read_variable_common(dev, cell_id, max_len: sizeof(*val), len: &len); |
1894 | if (IS_ERR(ptr: buf)) |
1895 | return PTR_ERR(ptr: buf); |
1896 | |
1897 | /* Copy w/ implicit endian conversion */ |
1898 | *val = 0; |
1899 | for (i = 0; i < len; i++) |
1900 | *val |= buf[i] << (8 * i); |
1901 | |
1902 | kfree(objp: buf); |
1903 | |
1904 | return 0; |
1905 | } |
1906 | EXPORT_SYMBOL_GPL(nvmem_cell_read_variable_le_u32); |
1907 | |
1908 | /** |
1909 | * nvmem_cell_read_variable_le_u64() - Read up to 64-bits of data as a little endian number. |
1910 | * |
1911 | * @dev: Device that requests the nvmem cell. |
1912 | * @cell_id: Name of nvmem cell to read. |
1913 | * @val: pointer to output value. |
1914 | * |
1915 | * Return: 0 on success or negative errno. |
1916 | */ |
1917 | int nvmem_cell_read_variable_le_u64(struct device *dev, const char *cell_id, |
1918 | u64 *val) |
1919 | { |
1920 | size_t len; |
1921 | const u8 *buf; |
1922 | int i; |
1923 | |
1924 | buf = nvmem_cell_read_variable_common(dev, cell_id, max_len: sizeof(*val), len: &len); |
1925 | if (IS_ERR(ptr: buf)) |
1926 | return PTR_ERR(ptr: buf); |
1927 | |
1928 | /* Copy w/ implicit endian conversion */ |
1929 | *val = 0; |
1930 | for (i = 0; i < len; i++) |
1931 | *val |= (uint64_t)buf[i] << (8 * i); |
1932 | |
1933 | kfree(objp: buf); |
1934 | |
1935 | return 0; |
1936 | } |
1937 | EXPORT_SYMBOL_GPL(nvmem_cell_read_variable_le_u64); |
1938 | |
1939 | /** |
1940 | * nvmem_device_cell_read() - Read a given nvmem device and cell |
1941 | * |
1942 | * @nvmem: nvmem device to read from. |
1943 | * @info: nvmem cell info to be read. |
1944 | * @buf: buffer pointer which will be populated on successful read. |
1945 | * |
1946 | * Return: length of successful bytes read on success and negative |
1947 | * error code on error. |
1948 | */ |
1949 | ssize_t nvmem_device_cell_read(struct nvmem_device *nvmem, |
1950 | struct nvmem_cell_info *info, void *buf) |
1951 | { |
1952 | struct nvmem_cell_entry cell; |
1953 | int rc; |
1954 | ssize_t len; |
1955 | |
1956 | if (!nvmem) |
1957 | return -EINVAL; |
1958 | |
1959 | rc = nvmem_cell_info_to_nvmem_cell_entry_nodup(nvmem, info, cell: &cell); |
1960 | if (rc) |
1961 | return rc; |
1962 | |
1963 | rc = __nvmem_cell_read(nvmem, cell: &cell, buf, len: &len, NULL, index: 0); |
1964 | if (rc) |
1965 | return rc; |
1966 | |
1967 | return len; |
1968 | } |
1969 | EXPORT_SYMBOL_GPL(nvmem_device_cell_read); |
1970 | |
1971 | /** |
1972 | * nvmem_device_cell_write() - Write cell to a given nvmem device |
1973 | * |
1974 | * @nvmem: nvmem device to be written to. |
1975 | * @info: nvmem cell info to be written. |
1976 | * @buf: buffer to be written to cell. |
1977 | * |
1978 | * Return: length of bytes written or negative error code on failure. |
1979 | */ |
1980 | int nvmem_device_cell_write(struct nvmem_device *nvmem, |
1981 | struct nvmem_cell_info *info, void *buf) |
1982 | { |
1983 | struct nvmem_cell_entry cell; |
1984 | int rc; |
1985 | |
1986 | if (!nvmem) |
1987 | return -EINVAL; |
1988 | |
1989 | rc = nvmem_cell_info_to_nvmem_cell_entry_nodup(nvmem, info, cell: &cell); |
1990 | if (rc) |
1991 | return rc; |
1992 | |
1993 | return __nvmem_cell_entry_write(cell: &cell, buf, len: cell.bytes); |
1994 | } |
1995 | EXPORT_SYMBOL_GPL(nvmem_device_cell_write); |
1996 | |
1997 | /** |
1998 | * nvmem_device_read() - Read from a given nvmem device |
1999 | * |
2000 | * @nvmem: nvmem device to read from. |
2001 | * @offset: offset in nvmem device. |
2002 | * @bytes: number of bytes to read. |
2003 | * @buf: buffer pointer which will be populated on successful read. |
2004 | * |
2005 | * Return: length of successful bytes read on success and negative |
2006 | * error code on error. |
2007 | */ |
2008 | int nvmem_device_read(struct nvmem_device *nvmem, |
2009 | unsigned int offset, |
2010 | size_t bytes, void *buf) |
2011 | { |
2012 | int rc; |
2013 | |
2014 | if (!nvmem) |
2015 | return -EINVAL; |
2016 | |
2017 | rc = nvmem_reg_read(nvmem, offset, val: buf, bytes); |
2018 | |
2019 | if (rc) |
2020 | return rc; |
2021 | |
2022 | return bytes; |
2023 | } |
2024 | EXPORT_SYMBOL_GPL(nvmem_device_read); |
2025 | |
2026 | /** |
2027 | * nvmem_device_write() - Write cell to a given nvmem device |
2028 | * |
2029 | * @nvmem: nvmem device to be written to. |
2030 | * @offset: offset in nvmem device. |
2031 | * @bytes: number of bytes to write. |
2032 | * @buf: buffer to be written. |
2033 | * |
2034 | * Return: length of bytes written or negative error code on failure. |
2035 | */ |
2036 | int nvmem_device_write(struct nvmem_device *nvmem, |
2037 | unsigned int offset, |
2038 | size_t bytes, void *buf) |
2039 | { |
2040 | int rc; |
2041 | |
2042 | if (!nvmem) |
2043 | return -EINVAL; |
2044 | |
2045 | rc = nvmem_reg_write(nvmem, offset, val: buf, bytes); |
2046 | |
2047 | if (rc) |
2048 | return rc; |
2049 | |
2050 | |
2051 | return bytes; |
2052 | } |
2053 | EXPORT_SYMBOL_GPL(nvmem_device_write); |
2054 | |
2055 | /** |
2056 | * nvmem_add_cell_table() - register a table of cell info entries |
2057 | * |
2058 | * @table: table of cell info entries |
2059 | */ |
2060 | void nvmem_add_cell_table(struct nvmem_cell_table *table) |
2061 | { |
2062 | mutex_lock(&nvmem_cell_mutex); |
2063 | list_add_tail(new: &table->node, head: &nvmem_cell_tables); |
2064 | mutex_unlock(lock: &nvmem_cell_mutex); |
2065 | } |
2066 | EXPORT_SYMBOL_GPL(nvmem_add_cell_table); |
2067 | |
2068 | /** |
2069 | * nvmem_del_cell_table() - remove a previously registered cell info table |
2070 | * |
2071 | * @table: table of cell info entries |
2072 | */ |
2073 | void nvmem_del_cell_table(struct nvmem_cell_table *table) |
2074 | { |
2075 | mutex_lock(&nvmem_cell_mutex); |
2076 | list_del(entry: &table->node); |
2077 | mutex_unlock(lock: &nvmem_cell_mutex); |
2078 | } |
2079 | EXPORT_SYMBOL_GPL(nvmem_del_cell_table); |
2080 | |
2081 | /** |
2082 | * nvmem_add_cell_lookups() - register a list of cell lookup entries |
2083 | * |
2084 | * @entries: array of cell lookup entries |
2085 | * @nentries: number of cell lookup entries in the array |
2086 | */ |
2087 | void nvmem_add_cell_lookups(struct nvmem_cell_lookup *entries, size_t nentries) |
2088 | { |
2089 | int i; |
2090 | |
2091 | mutex_lock(&nvmem_lookup_mutex); |
2092 | for (i = 0; i < nentries; i++) |
2093 | list_add_tail(new: &entries[i].node, head: &nvmem_lookup_list); |
2094 | mutex_unlock(lock: &nvmem_lookup_mutex); |
2095 | } |
2096 | EXPORT_SYMBOL_GPL(nvmem_add_cell_lookups); |
2097 | |
2098 | /** |
2099 | * nvmem_del_cell_lookups() - remove a list of previously added cell lookup |
2100 | * entries |
2101 | * |
2102 | * @entries: array of cell lookup entries |
2103 | * @nentries: number of cell lookup entries in the array |
2104 | */ |
2105 | void nvmem_del_cell_lookups(struct nvmem_cell_lookup *entries, size_t nentries) |
2106 | { |
2107 | int i; |
2108 | |
2109 | mutex_lock(&nvmem_lookup_mutex); |
2110 | for (i = 0; i < nentries; i++) |
2111 | list_del(entry: &entries[i].node); |
2112 | mutex_unlock(lock: &nvmem_lookup_mutex); |
2113 | } |
2114 | EXPORT_SYMBOL_GPL(nvmem_del_cell_lookups); |
2115 | |
2116 | /** |
2117 | * nvmem_dev_name() - Get the name of a given nvmem device. |
2118 | * |
2119 | * @nvmem: nvmem device. |
2120 | * |
2121 | * Return: name of the nvmem device. |
2122 | */ |
2123 | const char *nvmem_dev_name(struct nvmem_device *nvmem) |
2124 | { |
2125 | return dev_name(dev: &nvmem->dev); |
2126 | } |
2127 | EXPORT_SYMBOL_GPL(nvmem_dev_name); |
2128 | |
2129 | static int __init nvmem_init(void) |
2130 | { |
2131 | return bus_register(bus: &nvmem_bus_type); |
2132 | } |
2133 | |
2134 | static void __exit nvmem_exit(void) |
2135 | { |
2136 | bus_unregister(bus: &nvmem_bus_type); |
2137 | } |
2138 | |
2139 | subsys_initcall(nvmem_init); |
2140 | module_exit(nvmem_exit); |
2141 | |
2142 | MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org" ); |
2143 | MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com" ); |
2144 | MODULE_DESCRIPTION("nvmem Driver Core" ); |
2145 | |