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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
22struct 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 nvmem_cell_post_process_t cell_post_process;
42 struct gpio_desc *wp_gpio;
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)
49struct nvmem_cell_entry {
50 const char *name;
51 int offset;
52 int bytes;
53 int bit_offset;
54 int nbits;
55 struct device_node *np;
56 struct nvmem_device *nvmem;
57 struct list_head node;
58};
59
60struct nvmem_cell {
61 struct nvmem_cell_entry *entry;
62 const char *id;
63};
64
65static DEFINE_MUTEX(nvmem_mutex);
66static DEFINE_IDA(nvmem_ida);
67
68static DEFINE_MUTEX(nvmem_cell_mutex);
69static LIST_HEAD(nvmem_cell_tables);
70
71static DEFINE_MUTEX(nvmem_lookup_mutex);
72static LIST_HEAD(nvmem_lookup_list);
73
74static BLOCKING_NOTIFIER_HEAD(nvmem_notifier);
75
76static int __nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset,
77 void *val, size_t bytes)
78{
79 if (nvmem->reg_read)
80 return nvmem->reg_read(nvmem->priv, offset, val, bytes);
81
82 return -EINVAL;
83}
84
85static int __nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset,
86 void *val, size_t bytes)
87{
88 int ret;
89
90 if (nvmem->reg_write) {
91 gpiod_set_value_cansleep(nvmem->wp_gpio, 0);
92 ret = nvmem->reg_write(nvmem->priv, offset, val, bytes);
93 gpiod_set_value_cansleep(nvmem->wp_gpio, 1);
94 return ret;
95 }
96
97 return -EINVAL;
98}
99
100static int nvmem_access_with_keepouts(struct nvmem_device *nvmem,
101 unsigned int offset, void *val,
102 size_t bytes, int write)
103{
104
105 unsigned int end = offset + bytes;
106 unsigned int kend, ksize;
107 const struct nvmem_keepout *keepout = nvmem->keepout;
108 const struct nvmem_keepout *keepoutend = keepout + nvmem->nkeepout;
109 int rc;
110
111 /*
112 * Skip all keepouts before the range being accessed.
113 * Keepouts are sorted.
114 */
115 while ((keepout < keepoutend) && (keepout->end <= offset))
116 keepout++;
117
118 while ((offset < end) && (keepout < keepoutend)) {
119 /* Access the valid portion before the keepout. */
120 if (offset < keepout->start) {
121 kend = min(end, keepout->start);
122 ksize = kend - offset;
123 if (write)
124 rc = __nvmem_reg_write(nvmem, offset, val, ksize);
125 else
126 rc = __nvmem_reg_read(nvmem, offset, val, ksize);
127
128 if (rc)
129 return rc;
130
131 offset += ksize;
132 val += ksize;
133 }
134
135 /*
136 * Now we're aligned to the start of this keepout zone. Go
137 * through it.
138 */
139 kend = min(end, keepout->end);
140 ksize = kend - offset;
141 if (!write)
142 memset(val, keepout->value, ksize);
143
144 val += ksize;
145 offset += ksize;
146 keepout++;
147 }
148
149 /*
150 * If we ran out of keepouts but there's still stuff to do, send it
151 * down directly
152 */
153 if (offset < end) {
154 ksize = end - offset;
155 if (write)
156 return __nvmem_reg_write(nvmem, offset, val, ksize);
157 else
158 return __nvmem_reg_read(nvmem, offset, val, ksize);
159 }
160
161 return 0;
162}
163
164static int nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset,
165 void *val, size_t bytes)
166{
167 if (!nvmem->nkeepout)
168 return __nvmem_reg_read(nvmem, offset, val, bytes);
169
170 return nvmem_access_with_keepouts(nvmem, offset, val, bytes, false);
171}
172
173static int nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset,
174 void *val, size_t bytes)
175{
176 if (!nvmem->nkeepout)
177 return __nvmem_reg_write(nvmem, offset, val, bytes);
178
179 return nvmem_access_with_keepouts(nvmem, offset, val, bytes, true);
180}
181
182#ifdef CONFIG_NVMEM_SYSFS
183static const char * const nvmem_type_str[] = {
184 [NVMEM_TYPE_UNKNOWN] = "Unknown",
185 [NVMEM_TYPE_EEPROM] = "EEPROM",
186 [NVMEM_TYPE_OTP] = "OTP",
187 [NVMEM_TYPE_BATTERY_BACKED] = "Battery backed",
188 [NVMEM_TYPE_FRAM] = "FRAM",
189};
190
191#ifdef CONFIG_DEBUG_LOCK_ALLOC
192static struct lock_class_key eeprom_lock_key;
193#endif
194
195static ssize_t type_show(struct device *dev,
196 struct device_attribute *attr, char *buf)
197{
198 struct nvmem_device *nvmem = to_nvmem_device(dev);
199
200 return sprintf(buf, "%s\n", nvmem_type_str[nvmem->type]);
201}
202
203static DEVICE_ATTR_RO(type);
204
205static struct attribute *nvmem_attrs[] = {
206 &dev_attr_type.attr,
207 NULL,
208};
209
210static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj,
211 struct bin_attribute *attr, char *buf,
212 loff_t pos, size_t count)
213{
214 struct device *dev;
215 struct nvmem_device *nvmem;
216 int rc;
217
218 if (attr->private)
219 dev = attr->private;
220 else
221 dev = kobj_to_dev(kobj);
222 nvmem = to_nvmem_device(dev);
223
224 /* Stop the user from reading */
225 if (pos >= nvmem->size)
226 return 0;
227
228 if (!IS_ALIGNED(pos, nvmem->stride))
229 return -EINVAL;
230
231 if (count < nvmem->word_size)
232 return -EINVAL;
233
234 if (pos + count > nvmem->size)
235 count = nvmem->size - pos;
236
237 count = round_down(count, nvmem->word_size);
238
239 if (!nvmem->reg_read)
240 return -EPERM;
241
242 rc = nvmem_reg_read(nvmem, pos, buf, count);
243
244 if (rc)
245 return rc;
246
247 return count;
248}
249
250static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj,
251 struct bin_attribute *attr, char *buf,
252 loff_t pos, size_t count)
253{
254 struct device *dev;
255 struct nvmem_device *nvmem;
256 int rc;
257
258 if (attr->private)
259 dev = attr->private;
260 else
261 dev = kobj_to_dev(kobj);
262 nvmem = to_nvmem_device(dev);
263
264 /* Stop the user from writing */
265 if (pos >= nvmem->size)
266 return -EFBIG;
267
268 if (!IS_ALIGNED(pos, nvmem->stride))
269 return -EINVAL;
270
271 if (count < nvmem->word_size)
272 return -EINVAL;
273
274 if (pos + count > nvmem->size)
275 count = nvmem->size - pos;
276
277 count = round_down(count, nvmem->word_size);
278
279 if (!nvmem->reg_write)
280 return -EPERM;
281
282 rc = nvmem_reg_write(nvmem, pos, buf, count);
283
284 if (rc)
285 return rc;
286
287 return count;
288}
289
290static umode_t nvmem_bin_attr_get_umode(struct nvmem_device *nvmem)
291{
292 umode_t mode = 0400;
293
294 if (!nvmem->root_only)
295 mode |= 0044;
296
297 if (!nvmem->read_only)
298 mode |= 0200;
299
300 if (!nvmem->reg_write)
301 mode &= ~0200;
302
303 if (!nvmem->reg_read)
304 mode &= ~0444;
305
306 return mode;
307}
308
309static umode_t nvmem_bin_attr_is_visible(struct kobject *kobj,
310 struct bin_attribute *attr, int i)
311{
312 struct device *dev = kobj_to_dev(kobj);
313 struct nvmem_device *nvmem = to_nvmem_device(dev);
314
315 attr->size = nvmem->size;
316
317 return nvmem_bin_attr_get_umode(nvmem);
318}
319
320/* default read/write permissions */
321static struct bin_attribute bin_attr_rw_nvmem = {
322 .attr = {
323 .name = "nvmem",
324 .mode = 0644,
325 },
326 .read = bin_attr_nvmem_read,
327 .write = bin_attr_nvmem_write,
328};
329
330static struct bin_attribute *nvmem_bin_attributes[] = {
331 &bin_attr_rw_nvmem,
332 NULL,
333};
334
335static const struct attribute_group nvmem_bin_group = {
336 .bin_attrs = nvmem_bin_attributes,
337 .attrs = nvmem_attrs,
338 .is_bin_visible = nvmem_bin_attr_is_visible,
339};
340
341static const struct attribute_group *nvmem_dev_groups[] = {
342 &nvmem_bin_group,
343 NULL,
344};
345
346static struct bin_attribute bin_attr_nvmem_eeprom_compat = {
347 .attr = {
348 .name = "eeprom",
349 },
350 .read = bin_attr_nvmem_read,
351 .write = bin_attr_nvmem_write,
352};
353
354/*
355 * nvmem_setup_compat() - Create an additional binary entry in
356 * drivers sys directory, to be backwards compatible with the older
357 * drivers/misc/eeprom drivers.
358 */
359static int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem,
360 const struct nvmem_config *config)
361{
362 int rval;
363
364 if (!config->compat)
365 return 0;
366
367 if (!config->base_dev)
368 return -EINVAL;
369
370 if (config->type == NVMEM_TYPE_FRAM)
371 bin_attr_nvmem_eeprom_compat.attr.name = "fram";
372
373 nvmem->eeprom = bin_attr_nvmem_eeprom_compat;
374 nvmem->eeprom.attr.mode = nvmem_bin_attr_get_umode(nvmem);
375 nvmem->eeprom.size = nvmem->size;
376#ifdef CONFIG_DEBUG_LOCK_ALLOC
377 nvmem->eeprom.attr.key = &eeprom_lock_key;
378#endif
379 nvmem->eeprom.private = &nvmem->dev;
380 nvmem->base_dev = config->base_dev;
381
382 rval = device_create_bin_file(nvmem->base_dev, &nvmem->eeprom);
383 if (rval) {
384 dev_err(&nvmem->dev,
385 "Failed to create eeprom binary file %d\n", rval);
386 return rval;
387 }
388
389 nvmem->flags |= FLAG_COMPAT;
390
391 return 0;
392}
393
394static void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem,
395 const struct nvmem_config *config)
396{
397 if (config->compat)
398 device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);
399}
400
401#else /* CONFIG_NVMEM_SYSFS */
402
403static int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem,
404 const struct nvmem_config *config)
405{
406 return -ENOSYS;
407}
408static void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem,
409 const struct nvmem_config *config)
410{
411}
412
413#endif /* CONFIG_NVMEM_SYSFS */
414
415static void nvmem_release(struct device *dev)
416{
417 struct nvmem_device *nvmem = to_nvmem_device(dev);
418
419 ida_free(&nvmem_ida, nvmem->id);
420 gpiod_put(nvmem->wp_gpio);
421 kfree(nvmem);
422}
423
424static const struct device_type nvmem_provider_type = {
425 .release = nvmem_release,
426};
427
428static struct bus_type nvmem_bus_type = {
429 .name = "nvmem",
430};
431
432static void nvmem_cell_entry_drop(struct nvmem_cell_entry *cell)
433{
434 blocking_notifier_call_chain(&nvmem_notifier, NVMEM_CELL_REMOVE, cell);
435 mutex_lock(&nvmem_mutex);
436 list_del(&cell->node);
437 mutex_unlock(&nvmem_mutex);
438 of_node_put(cell->np);
439 kfree_const(cell->name);
440 kfree(cell);
441}
442
443static void nvmem_device_remove_all_cells(const struct nvmem_device *nvmem)
444{
445 struct nvmem_cell_entry *cell, *p;
446
447 list_for_each_entry_safe(cell, p, &nvmem->cells, node)
448 nvmem_cell_entry_drop(cell);
449}
450
451static void nvmem_cell_entry_add(struct nvmem_cell_entry *cell)
452{
453 mutex_lock(&nvmem_mutex);
454 list_add_tail(&cell->node, &cell->nvmem->cells);
455 mutex_unlock(&nvmem_mutex);
456 blocking_notifier_call_chain(&nvmem_notifier, NVMEM_CELL_ADD, cell);
457}
458
459static int nvmem_cell_info_to_nvmem_cell_entry_nodup(struct nvmem_device *nvmem,
460 const struct nvmem_cell_info *info,
461 struct nvmem_cell_entry *cell)
462{
463 cell->nvmem = nvmem;
464 cell->offset = info->offset;
465 cell->bytes = info->bytes;
466 cell->name = info->name;
467
468 cell->bit_offset = info->bit_offset;
469 cell->nbits = info->nbits;
470 cell->np = info->np;
471
472 if (cell->nbits)
473 cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset,
474 BITS_PER_BYTE);
475
476 if (!IS_ALIGNED(cell->offset, nvmem->stride)) {
477 dev_err(&nvmem->dev,
478 "cell %s unaligned to nvmem stride %d\n",
479 cell->name ?: "<unknown>", nvmem->stride);
480 return -EINVAL;
481 }
482
483 return 0;
484}
485
486static int nvmem_cell_info_to_nvmem_cell_entry(struct nvmem_device *nvmem,
487 const struct nvmem_cell_info *info,
488 struct nvmem_cell_entry *cell)
489{
490 int err;
491
492 err = nvmem_cell_info_to_nvmem_cell_entry_nodup(nvmem, info, cell);
493 if (err)
494 return err;
495
496 cell->name = kstrdup_const(info->name, GFP_KERNEL);
497 if (!cell->name)
498 return -ENOMEM;
499
500 return 0;
501}
502
503/**
504 * nvmem_add_cells() - Add cell information to an nvmem device
505 *
506 * @nvmem: nvmem device to add cells to.
507 * @info: nvmem cell info to add to the device
508 * @ncells: number of cells in info
509 *
510 * Return: 0 or negative error code on failure.
511 */
512static int nvmem_add_cells(struct nvmem_device *nvmem,
513 const struct nvmem_cell_info *info,
514 int ncells)
515{
516 struct nvmem_cell_entry **cells;
517 int i, rval;
518
519 cells = kcalloc(ncells, sizeof(*cells), GFP_KERNEL);
520 if (!cells)
521 return -ENOMEM;
522
523 for (i = 0; i < ncells; i++) {
524 cells[i] = kzalloc(sizeof(**cells), GFP_KERNEL);
525 if (!cells[i]) {
526 rval = -ENOMEM;
527 goto err;
528 }
529
530 rval = nvmem_cell_info_to_nvmem_cell_entry(nvmem, &info[i], cells[i]);
531 if (rval) {
532 kfree(cells[i]);
533 goto err;
534 }
535
536 nvmem_cell_entry_add(cells[i]);
537 }
538
539 /* remove tmp array */
540 kfree(cells);
541
542 return 0;
543err:
544 while (i--)
545 nvmem_cell_entry_drop(cells[i]);
546
547 kfree(cells);
548
549 return rval;
550}
551
552/**
553 * nvmem_register_notifier() - Register a notifier block for nvmem events.
554 *
555 * @nb: notifier block to be called on nvmem events.
556 *
557 * Return: 0 on success, negative error number on failure.
558 */
559int nvmem_register_notifier(struct notifier_block *nb)
560{
561 return blocking_notifier_chain_register(&nvmem_notifier, nb);
562}
563EXPORT_SYMBOL_GPL(nvmem_register_notifier);
564
565/**
566 * nvmem_unregister_notifier() - Unregister a notifier block for nvmem events.
567 *
568 * @nb: notifier block to be unregistered.
569 *
570 * Return: 0 on success, negative error number on failure.
571 */
572int nvmem_unregister_notifier(struct notifier_block *nb)
573{
574 return blocking_notifier_chain_unregister(&nvmem_notifier, nb);
575}
576EXPORT_SYMBOL_GPL(nvmem_unregister_notifier);
577
578static int nvmem_add_cells_from_table(struct nvmem_device *nvmem)
579{
580 const struct nvmem_cell_info *info;
581 struct nvmem_cell_table *table;
582 struct nvmem_cell_entry *cell;
583 int rval = 0, i;
584
585 mutex_lock(&nvmem_cell_mutex);
586 list_for_each_entry(table, &nvmem_cell_tables, node) {
587 if (strcmp(nvmem_dev_name(nvmem), table->nvmem_name) == 0) {
588 for (i = 0; i < table->ncells; i++) {
589 info = &table->cells[i];
590
591 cell = kzalloc(sizeof(*cell), GFP_KERNEL);
592 if (!cell) {
593 rval = -ENOMEM;
594 goto out;
595 }
596
597 rval = nvmem_cell_info_to_nvmem_cell_entry(nvmem, info, cell);
598 if (rval) {
599 kfree(cell);
600 goto out;
601 }
602
603 nvmem_cell_entry_add(cell);
604 }
605 }
606 }
607
608out:
609 mutex_unlock(&nvmem_cell_mutex);
610 return rval;
611}
612
613static struct nvmem_cell_entry *
614nvmem_find_cell_entry_by_name(struct nvmem_device *nvmem, const char *cell_id)
615{
616 struct nvmem_cell_entry *iter, *cell = NULL;
617
618 mutex_lock(&nvmem_mutex);
619 list_for_each_entry(iter, &nvmem->cells, node) {
620 if (strcmp(cell_id, iter->name) == 0) {
621 cell = iter;
622 break;
623 }
624 }
625 mutex_unlock(&nvmem_mutex);
626
627 return cell;
628}
629
630static int nvmem_validate_keepouts(struct nvmem_device *nvmem)
631{
632 unsigned int cur = 0;
633 const struct nvmem_keepout *keepout = nvmem->keepout;
634 const struct nvmem_keepout *keepoutend = keepout + nvmem->nkeepout;
635
636 while (keepout < keepoutend) {
637 /* Ensure keepouts are sorted and don't overlap. */
638 if (keepout->start < cur) {
639 dev_err(&nvmem->dev,
640 "Keepout regions aren't sorted or overlap.\n");
641
642 return -ERANGE;
643 }
644
645 if (keepout->end < keepout->start) {
646 dev_err(&nvmem->dev,
647 "Invalid keepout region.\n");
648
649 return -EINVAL;
650 }
651
652 /*
653 * Validate keepouts (and holes between) don't violate
654 * word_size constraints.
655 */
656 if ((keepout->end - keepout->start < nvmem->word_size) ||
657 ((keepout->start != cur) &&
658 (keepout->start - cur < nvmem->word_size))) {
659
660 dev_err(&nvmem->dev,
661 "Keepout regions violate word_size constraints.\n");
662
663 return -ERANGE;
664 }
665
666 /* Validate keepouts don't violate stride (alignment). */
667 if (!IS_ALIGNED(keepout->start, nvmem->stride) ||
668 !IS_ALIGNED(keepout->end, nvmem->stride)) {
669
670 dev_err(&nvmem->dev,
671 "Keepout regions violate stride.\n");
672
673 return -EINVAL;
674 }
675
676 cur = keepout->end;
677 keepout++;
678 }
679
680 return 0;
681}
682
683static int nvmem_add_cells_from_of(struct nvmem_device *nvmem)
684{
685 struct device_node *parent, *child;
686 struct device *dev = &nvmem->dev;
687 struct nvmem_cell_entry *cell;
688 const __be32 *addr;
689 int len;
690
691 parent = dev->of_node;
692
693 for_each_child_of_node(parent, child) {
694 addr = of_get_property(child, "reg", &len);
695 if (!addr)
696 continue;
697 if (len < 2 * sizeof(u32)) {
698 dev_err(dev, "nvmem: invalid reg on %pOF\n", child);
699 of_node_put(child);
700 return -EINVAL;
701 }
702
703 cell = kzalloc(sizeof(*cell), GFP_KERNEL);
704 if (!cell) {
705 of_node_put(child);
706 return -ENOMEM;
707 }
708
709 cell->nvmem = nvmem;
710 cell->offset = be32_to_cpup(addr++);
711 cell->bytes = be32_to_cpup(addr);
712 cell->name = kasprintf(GFP_KERNEL, "%pOFn", child);
713
714 addr = of_get_property(child, "bits", &len);
715 if (addr && len == (2 * sizeof(u32))) {
716 cell->bit_offset = be32_to_cpup(addr++);
717 cell->nbits = be32_to_cpup(addr);
718 }
719
720 if (cell->nbits)
721 cell->bytes = DIV_ROUND_UP(
722 cell->nbits + cell->bit_offset,
723 BITS_PER_BYTE);
724
725 if (!IS_ALIGNED(cell->offset, nvmem->stride)) {
726 dev_err(dev, "cell %s unaligned to nvmem stride %d\n",
727 cell->name, nvmem->stride);
728 /* Cells already added will be freed later. */
729 kfree_const(cell->name);
730 kfree(cell);
731 of_node_put(child);
732 return -EINVAL;
733 }
734
735 cell->np = of_node_get(child);
736 nvmem_cell_entry_add(cell);
737 }
738
739 return 0;
740}
741
742/**
743 * nvmem_register() - Register a nvmem device for given nvmem_config.
744 * Also creates a binary entry in /sys/bus/nvmem/devices/dev-name/nvmem
745 *
746 * @config: nvmem device configuration with which nvmem device is created.
747 *
748 * Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device
749 * on success.
750 */
751
752struct nvmem_device *nvmem_register(const struct nvmem_config *config)
753{
754 struct nvmem_device *nvmem;
755 int rval;
756
757 if (!config->dev)
758 return ERR_PTR(-EINVAL);
759
760 if (!config->reg_read && !config->reg_write)
761 return ERR_PTR(-EINVAL);
762
763 nvmem = kzalloc(sizeof(*nvmem), GFP_KERNEL);
764 if (!nvmem)
765 return ERR_PTR(-ENOMEM);
766
767 rval = ida_alloc(&nvmem_ida, GFP_KERNEL);
768 if (rval < 0) {
769 kfree(nvmem);
770 return ERR_PTR(rval);
771 }
772
773 nvmem->id = rval;
774
775 nvmem->dev.type = &nvmem_provider_type;
776 nvmem->dev.bus = &nvmem_bus_type;
777 nvmem->dev.parent = config->dev;
778
779 device_initialize(&nvmem->dev);
780
781 if (!config->ignore_wp)
782 nvmem->wp_gpio = gpiod_get_optional(config->dev, "wp",
783 GPIOD_OUT_HIGH);
784 if (IS_ERR(nvmem->wp_gpio)) {
785 rval = PTR_ERR(nvmem->wp_gpio);
786 nvmem->wp_gpio = NULL;
787 goto err_put_device;
788 }
789
790 kref_init(&nvmem->refcnt);
791 INIT_LIST_HEAD(&nvmem->cells);
792
793 nvmem->owner = config->owner;
794 if (!nvmem->owner && config->dev->driver)
795 nvmem->owner = config->dev->driver->owner;
796 nvmem->stride = config->stride ?: 1;
797 nvmem->word_size = config->word_size ?: 1;
798 nvmem->size = config->size;
799 nvmem->root_only = config->root_only;
800 nvmem->priv = config->priv;
801 nvmem->type = config->type;
802 nvmem->reg_read = config->reg_read;
803 nvmem->reg_write = config->reg_write;
804 nvmem->cell_post_process = config->cell_post_process;
805 nvmem->keepout = config->keepout;
806 nvmem->nkeepout = config->nkeepout;
807 if (config->of_node)
808 nvmem->dev.of_node = config->of_node;
809 else if (!config->no_of_node)
810 nvmem->dev.of_node = config->dev->of_node;
811
812 switch (config->id) {
813 case NVMEM_DEVID_NONE:
814 rval = dev_set_name(&nvmem->dev, "%s", config->name);
815 break;
816 case NVMEM_DEVID_AUTO:
817 rval = dev_set_name(&nvmem->dev, "%s%d", config->name, nvmem->id);
818 break;
819 default:
820 rval = dev_set_name(&nvmem->dev, "%s%d",
821 config->name ? : "nvmem",
822 config->name ? config->id : nvmem->id);
823 break;
824 }
825
826 if (rval)
827 goto err_put_device;
828
829 nvmem->read_only = device_property_present(config->dev, "read-only") ||
830 config->read_only || !nvmem->reg_write;
831
832#ifdef CONFIG_NVMEM_SYSFS
833 nvmem->dev.groups = nvmem_dev_groups;
834#endif
835
836 if (nvmem->nkeepout) {
837 rval = nvmem_validate_keepouts(nvmem);
838 if (rval)
839 goto err_put_device;
840 }
841
842 if (config->compat) {
843 rval = nvmem_sysfs_setup_compat(nvmem, config);
844 if (rval)
845 goto err_put_device;
846 }
847
848 if (config->cells) {
849 rval = nvmem_add_cells(nvmem, config->cells, config->ncells);
850 if (rval)
851 goto err_remove_cells;
852 }
853
854 rval = nvmem_add_cells_from_table(nvmem);
855 if (rval)
856 goto err_remove_cells;
857
858 rval = nvmem_add_cells_from_of(nvmem);
859 if (rval)
860 goto err_remove_cells;
861
862 dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name);
863
864 rval = device_add(&nvmem->dev);
865 if (rval)
866 goto err_remove_cells;
867
868 blocking_notifier_call_chain(&nvmem_notifier, NVMEM_ADD, nvmem);
869
870 return nvmem;
871
872err_remove_cells:
873 nvmem_device_remove_all_cells(nvmem);
874 if (config->compat)
875 nvmem_sysfs_remove_compat(nvmem, config);
876err_put_device:
877 put_device(&nvmem->dev);
878
879 return ERR_PTR(rval);
880}
881EXPORT_SYMBOL_GPL(nvmem_register);
882
883static void nvmem_device_release(struct kref *kref)
884{
885 struct nvmem_device *nvmem;
886
887 nvmem = container_of(kref, struct nvmem_device, refcnt);
888
889 blocking_notifier_call_chain(&nvmem_notifier, NVMEM_REMOVE, nvmem);
890
891 if (nvmem->flags & FLAG_COMPAT)
892 device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);
893
894 nvmem_device_remove_all_cells(nvmem);
895 device_unregister(&nvmem->dev);
896}
897
898/**
899 * nvmem_unregister() - Unregister previously registered nvmem device
900 *
901 * @nvmem: Pointer to previously registered nvmem device.
902 */
903void nvmem_unregister(struct nvmem_device *nvmem)
904{
905 if (nvmem)
906 kref_put(&nvmem->refcnt, nvmem_device_release);
907}
908EXPORT_SYMBOL_GPL(nvmem_unregister);
909
910static void devm_nvmem_unregister(void *nvmem)
911{
912 nvmem_unregister(nvmem);
913}
914
915/**
916 * devm_nvmem_register() - Register a managed nvmem device for given
917 * nvmem_config.
918 * Also creates a binary entry in /sys/bus/nvmem/devices/dev-name/nvmem
919 *
920 * @dev: Device that uses the nvmem device.
921 * @config: nvmem device configuration with which nvmem device is created.
922 *
923 * Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device
924 * on success.
925 */
926struct nvmem_device *devm_nvmem_register(struct device *dev,
927 const struct nvmem_config *config)
928{
929 struct nvmem_device *nvmem;
930 int ret;
931
932 nvmem = nvmem_register(config);
933 if (IS_ERR(nvmem))
934 return nvmem;
935
936 ret = devm_add_action_or_reset(dev, devm_nvmem_unregister, nvmem);
937 if (ret)
938 return ERR_PTR(ret);
939
940 return nvmem;
941}
942EXPORT_SYMBOL_GPL(devm_nvmem_register);
943
944static struct nvmem_device *__nvmem_device_get(void *data,
945 int (*match)(struct device *dev, const void *data))
946{
947 struct nvmem_device *nvmem = NULL;
948 struct device *dev;
949
950 mutex_lock(&nvmem_mutex);
951 dev = bus_find_device(&nvmem_bus_type, NULL, data, match);
952 if (dev)
953 nvmem = to_nvmem_device(dev);
954 mutex_unlock(&nvmem_mutex);
955 if (!nvmem)
956 return ERR_PTR(-EPROBE_DEFER);
957
958 if (!try_module_get(nvmem->owner)) {
959 dev_err(&nvmem->dev,
960 "could not increase module refcount for cell %s\n",
961 nvmem_dev_name(nvmem));
962
963 put_device(&nvmem->dev);
964 return ERR_PTR(-EINVAL);
965 }
966
967 kref_get(&nvmem->refcnt);
968
969 return nvmem;
970}
971
972static void __nvmem_device_put(struct nvmem_device *nvmem)
973{
974 put_device(&nvmem->dev);
975 module_put(nvmem->owner);
976 kref_put(&nvmem->refcnt, nvmem_device_release);
977}
978
979#if IS_ENABLED(CONFIG_OF)
980/**
981 * of_nvmem_device_get() - Get nvmem device from a given id
982 *
983 * @np: Device tree node that uses the nvmem device.
984 * @id: nvmem name from nvmem-names property.
985 *
986 * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device
987 * on success.
988 */
989struct nvmem_device *of_nvmem_device_get(struct device_node *np, const char *id)
990{
991
992 struct device_node *nvmem_np;
993 struct nvmem_device *nvmem;
994 int index = 0;
995
996 if (id)
997 index = of_property_match_string(np, "nvmem-names", id);
998
999 nvmem_np = of_parse_phandle(np, "nvmem", index);
1000 if (!nvmem_np)
1001 return ERR_PTR(-ENOENT);
1002
1003 nvmem = __nvmem_device_get(nvmem_np, device_match_of_node);
1004 of_node_put(nvmem_np);
1005 return nvmem;
1006}
1007EXPORT_SYMBOL_GPL(of_nvmem_device_get);
1008#endif
1009
1010/**
1011 * nvmem_device_get() - Get nvmem device from a given id
1012 *
1013 * @dev: Device that uses the nvmem device.
1014 * @dev_name: name of the requested nvmem device.
1015 *
1016 * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device
1017 * on success.
1018 */
1019struct nvmem_device *nvmem_device_get(struct device *dev, const char *dev_name)
1020{
1021 if (dev->of_node) { /* try dt first */
1022 struct nvmem_device *nvmem;
1023
1024 nvmem = of_nvmem_device_get(dev->of_node, dev_name);
1025
1026 if (!IS_ERR(nvmem) || PTR_ERR(nvmem) == -EPROBE_DEFER)
1027 return nvmem;
1028
1029 }
1030
1031 return __nvmem_device_get((void *)dev_name, device_match_name);
1032}
1033EXPORT_SYMBOL_GPL(nvmem_device_get);
1034
1035/**
1036 * nvmem_device_find() - Find nvmem device with matching function
1037 *
1038 * @data: Data to pass to match function
1039 * @match: Callback function to check device
1040 *
1041 * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device
1042 * on success.
1043 */
1044struct nvmem_device *nvmem_device_find(void *data,
1045 int (*match)(struct device *dev, const void *data))
1046{
1047 return __nvmem_device_get(data, match);
1048}
1049EXPORT_SYMBOL_GPL(nvmem_device_find);
1050
1051static int devm_nvmem_device_match(struct device *dev, void *res, void *data)
1052{
1053 struct nvmem_device **nvmem = res;
1054
1055 if (WARN_ON(!nvmem || !*nvmem))
1056 return 0;
1057
1058 return *nvmem == data;
1059}
1060
1061static void devm_nvmem_device_release(struct device *dev, void *res)
1062{
1063 nvmem_device_put(*(struct nvmem_device **)res);
1064}
1065
1066/**
1067 * devm_nvmem_device_put() - put alredy got nvmem device
1068 *
1069 * @dev: Device that uses the nvmem device.
1070 * @nvmem: pointer to nvmem device allocated by devm_nvmem_cell_get(),
1071 * that needs to be released.
1072 */
1073void devm_nvmem_device_put(struct device *dev, struct nvmem_device *nvmem)
1074{
1075 int ret;
1076
1077 ret = devres_release(dev, devm_nvmem_device_release,
1078 devm_nvmem_device_match, nvmem);
1079
1080 WARN_ON(ret);
1081}
1082EXPORT_SYMBOL_GPL(devm_nvmem_device_put);
1083
1084/**
1085 * nvmem_device_put() - put alredy got nvmem device
1086 *
1087 * @nvmem: pointer to nvmem device that needs to be released.
1088 */
1089void nvmem_device_put(struct nvmem_device *nvmem)
1090{
1091 __nvmem_device_put(nvmem);
1092}
1093EXPORT_SYMBOL_GPL(nvmem_device_put);
1094
1095/**
1096 * devm_nvmem_device_get() - Get nvmem cell of device form a given id
1097 *
1098 * @dev: Device that requests the nvmem device.
1099 * @id: name id for the requested nvmem device.
1100 *
1101 * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_cell
1102 * on success. The nvmem_cell will be freed by the automatically once the
1103 * device is freed.
1104 */
1105struct nvmem_device *devm_nvmem_device_get(struct device *dev, const char *id)
1106{
1107 struct nvmem_device **ptr, *nvmem;
1108
1109 ptr = devres_alloc(devm_nvmem_device_release, sizeof(*ptr), GFP_KERNEL);
1110 if (!ptr)
1111 return ERR_PTR(-ENOMEM);
1112
1113 nvmem = nvmem_device_get(dev, id);
1114 if (!IS_ERR(nvmem)) {
1115 *ptr = nvmem;
1116 devres_add(dev, ptr);
1117 } else {
1118 devres_free(ptr);
1119 }
1120
1121 return nvmem;
1122}
1123EXPORT_SYMBOL_GPL(devm_nvmem_device_get);
1124
1125static struct nvmem_cell *nvmem_create_cell(struct nvmem_cell_entry *entry, const char *id)
1126{
1127 struct nvmem_cell *cell;
1128 const char *name = NULL;
1129
1130 cell = kzalloc(sizeof(*cell), GFP_KERNEL);
1131 if (!cell)
1132 return ERR_PTR(-ENOMEM);
1133
1134 if (id) {
1135 name = kstrdup_const(id, GFP_KERNEL);
1136 if (!name) {
1137 kfree(cell);
1138 return ERR_PTR(-ENOMEM);
1139 }
1140 }
1141
1142 cell->id = name;
1143 cell->entry = entry;
1144
1145 return cell;
1146}
1147
1148static struct nvmem_cell *
1149nvmem_cell_get_from_lookup(struct device *dev, const char *con_id)
1150{
1151 struct nvmem_cell_entry *cell_entry;
1152 struct nvmem_cell *cell = ERR_PTR(-ENOENT);
1153 struct nvmem_cell_lookup *lookup;
1154 struct nvmem_device *nvmem;
1155 const char *dev_id;
1156
1157 if (!dev)
1158 return ERR_PTR(-EINVAL);
1159
1160 dev_id = dev_name(dev);
1161
1162 mutex_lock(&nvmem_lookup_mutex);
1163
1164 list_for_each_entry(lookup, &nvmem_lookup_list, node) {
1165 if ((strcmp(lookup->dev_id, dev_id) == 0) &&
1166 (strcmp(lookup->con_id, con_id) == 0)) {
1167 /* This is the right entry. */
1168 nvmem = __nvmem_device_get((void *)lookup->nvmem_name,
1169 device_match_name);
1170 if (IS_ERR(nvmem)) {
1171 /* Provider may not be registered yet. */
1172 cell = ERR_CAST(nvmem);
1173 break;
1174 }
1175
1176 cell_entry = nvmem_find_cell_entry_by_name(nvmem,
1177 lookup->cell_name);
1178 if (!cell_entry) {
1179 __nvmem_device_put(nvmem);
1180 cell = ERR_PTR(-ENOENT);
1181 } else {
1182 cell = nvmem_create_cell(cell_entry, con_id);
1183 if (IS_ERR(cell))
1184 __nvmem_device_put(nvmem);
1185 }
1186 break;
1187 }
1188 }
1189
1190 mutex_unlock(&nvmem_lookup_mutex);
1191 return cell;
1192}
1193
1194#if IS_ENABLED(CONFIG_OF)
1195static struct nvmem_cell_entry *
1196nvmem_find_cell_entry_by_node(struct nvmem_device *nvmem, struct device_node *np)
1197{
1198 struct nvmem_cell_entry *iter, *cell = NULL;
1199
1200 mutex_lock(&nvmem_mutex);
1201 list_for_each_entry(iter, &nvmem->cells, node) {
1202 if (np == iter->np) {
1203 cell = iter;
1204 break;
1205 }
1206 }
1207 mutex_unlock(&nvmem_mutex);
1208
1209 return cell;
1210}
1211
1212/**
1213 * of_nvmem_cell_get() - Get a nvmem cell from given device node and cell id
1214 *
1215 * @np: Device tree node that uses the nvmem cell.
1216 * @id: nvmem cell name from nvmem-cell-names property, or NULL
1217 * for the cell at index 0 (the lone cell with no accompanying
1218 * nvmem-cell-names property).
1219 *
1220 * Return: Will be an ERR_PTR() on error or a valid pointer
1221 * to a struct nvmem_cell. The nvmem_cell will be freed by the
1222 * nvmem_cell_put().
1223 */
1224struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, const char *id)
1225{
1226 struct device_node *cell_np, *nvmem_np;
1227 struct nvmem_device *nvmem;
1228 struct nvmem_cell_entry *cell_entry;
1229 struct nvmem_cell *cell;
1230 int index = 0;
1231
1232 /* if cell name exists, find index to the name */
1233 if (id)
1234 index = of_property_match_string(np, "nvmem-cell-names", id);
1235
1236 cell_np = of_parse_phandle(np, "nvmem-cells", index);
1237 if (!cell_np)
1238 return ERR_PTR(-ENOENT);
1239
1240 nvmem_np = of_get_parent(cell_np);
1241 if (!nvmem_np) {
1242 of_node_put(cell_np);
1243 return ERR_PTR(-EINVAL);
1244 }
1245
1246 nvmem = __nvmem_device_get(nvmem_np, device_match_of_node);
1247 of_node_put(nvmem_np);
1248 if (IS_ERR(nvmem)) {
1249 of_node_put(cell_np);
1250 return ERR_CAST(nvmem);
1251 }
1252
1253 cell_entry = nvmem_find_cell_entry_by_node(nvmem, cell_np);
1254 of_node_put(cell_np);
1255 if (!cell_entry) {
1256 __nvmem_device_put(nvmem);
1257 return ERR_PTR(-ENOENT);
1258 }
1259
1260 cell = nvmem_create_cell(cell_entry, id);
1261 if (IS_ERR(cell))
1262 __nvmem_device_put(nvmem);
1263
1264 return cell;
1265}
1266EXPORT_SYMBOL_GPL(of_nvmem_cell_get);
1267#endif
1268
1269/**
1270 * nvmem_cell_get() - Get nvmem cell of device form a given cell name
1271 *
1272 * @dev: Device that requests the nvmem cell.
1273 * @id: nvmem cell name to get (this corresponds with the name from the
1274 * nvmem-cell-names property for DT systems and with the con_id from
1275 * the lookup entry for non-DT systems).
1276 *
1277 * Return: Will be an ERR_PTR() on error or a valid pointer
1278 * to a struct nvmem_cell. The nvmem_cell will be freed by the
1279 * nvmem_cell_put().
1280 */
1281struct nvmem_cell *nvmem_cell_get(struct device *dev, const char *id)
1282{
1283 struct nvmem_cell *cell;
1284
1285 if (dev->of_node) { /* try dt first */
1286 cell = of_nvmem_cell_get(dev->of_node, id);
1287 if (!IS_ERR(cell) || PTR_ERR(cell) == -EPROBE_DEFER)
1288 return cell;
1289 }
1290
1291 /* NULL cell id only allowed for device tree; invalid otherwise */
1292 if (!id)
1293 return ERR_PTR(-EINVAL);
1294
1295 return nvmem_cell_get_from_lookup(dev, id);
1296}
1297EXPORT_SYMBOL_GPL(nvmem_cell_get);
1298
1299static void devm_nvmem_cell_release(struct device *dev, void *res)
1300{
1301 nvmem_cell_put(*(struct nvmem_cell **)res);
1302}
1303
1304/**
1305 * devm_nvmem_cell_get() - Get nvmem cell of device form a given id
1306 *
1307 * @dev: Device that requests the nvmem cell.
1308 * @id: nvmem cell name id to get.
1309 *
1310 * Return: Will be an ERR_PTR() on error or a valid pointer
1311 * to a struct nvmem_cell. The nvmem_cell will be freed by the
1312 * automatically once the device is freed.
1313 */
1314struct nvmem_cell *devm_nvmem_cell_get(struct device *dev, const char *id)
1315{
1316 struct nvmem_cell **ptr, *cell;
1317
1318 ptr = devres_alloc(devm_nvmem_cell_release, sizeof(*ptr), GFP_KERNEL);
1319 if (!ptr)
1320 return ERR_PTR(-ENOMEM);
1321
1322 cell = nvmem_cell_get(dev, id);
1323 if (!IS_ERR(cell)) {
1324 *ptr = cell;
1325 devres_add(dev, ptr);
1326 } else {
1327 devres_free(ptr);
1328 }
1329
1330 return cell;
1331}
1332EXPORT_SYMBOL_GPL(devm_nvmem_cell_get);
1333
1334static int devm_nvmem_cell_match(struct device *dev, void *res, void *data)
1335{
1336 struct nvmem_cell **c = res;
1337
1338 if (WARN_ON(!c || !*c))
1339 return 0;
1340
1341 return *c == data;
1342}
1343
1344/**
1345 * devm_nvmem_cell_put() - Release previously allocated nvmem cell
1346 * from devm_nvmem_cell_get.
1347 *
1348 * @dev: Device that requests the nvmem cell.
1349 * @cell: Previously allocated nvmem cell by devm_nvmem_cell_get().
1350 */
1351void devm_nvmem_cell_put(struct device *dev, struct nvmem_cell *cell)
1352{
1353 int ret;
1354
1355 ret = devres_release(dev, devm_nvmem_cell_release,
1356 devm_nvmem_cell_match, cell);
1357
1358 WARN_ON(ret);
1359}
1360EXPORT_SYMBOL(devm_nvmem_cell_put);
1361
1362/**
1363 * nvmem_cell_put() - Release previously allocated nvmem cell.
1364 *
1365 * @cell: Previously allocated nvmem cell by nvmem_cell_get().
1366 */
1367void nvmem_cell_put(struct nvmem_cell *cell)
1368{
1369 struct nvmem_device *nvmem = cell->entry->nvmem;
1370
1371 if (cell->id)
1372 kfree_const(cell->id);
1373
1374 kfree(cell);
1375 __nvmem_device_put(nvmem);
1376}
1377EXPORT_SYMBOL_GPL(nvmem_cell_put);
1378
1379static void nvmem_shift_read_buffer_in_place(struct nvmem_cell_entry *cell, void *buf)
1380{
1381 u8 *p, *b;
1382 int i, extra, bit_offset = cell->bit_offset;
1383
1384 p = b = buf;
1385 if (bit_offset) {
1386 /* First shift */
1387 *b++ >>= bit_offset;
1388
1389 /* setup rest of the bytes if any */
1390 for (i = 1; i < cell->bytes; i++) {
1391 /* Get bits from next byte and shift them towards msb */
1392 *p |= *b << (BITS_PER_BYTE - bit_offset);
1393
1394 p = b;
1395 *b++ >>= bit_offset;
1396 }
1397 } else {
1398 /* point to the msb */
1399 p += cell->bytes - 1;
1400 }
1401
1402 /* result fits in less bytes */
1403 extra = cell->bytes - DIV_ROUND_UP(cell->nbits, BITS_PER_BYTE);
1404 while (--extra >= 0)
1405 *p-- = 0;
1406
1407 /* clear msb bits if any leftover in the last byte */
1408 if (cell->nbits % BITS_PER_BYTE)
1409 *p &= GENMASK((cell->nbits % BITS_PER_BYTE) - 1, 0);
1410}
1411
1412static int __nvmem_cell_read(struct nvmem_device *nvmem,
1413 struct nvmem_cell_entry *cell,
1414 void *buf, size_t *len, const char *id)
1415{
1416 int rc;
1417
1418 rc = nvmem_reg_read(nvmem, cell->offset, buf, cell->bytes);
1419
1420 if (rc)
1421 return rc;
1422
1423 /* shift bits in-place */
1424 if (cell->bit_offset || cell->nbits)
1425 nvmem_shift_read_buffer_in_place(cell, buf);
1426
1427 if (nvmem->cell_post_process) {
1428 rc = nvmem->cell_post_process(nvmem->priv, id,
1429 cell->offset, buf, cell->bytes);
1430 if (rc)
1431 return rc;
1432 }
1433
1434 if (len)
1435 *len = cell->bytes;
1436
1437 return 0;
1438}
1439
1440/**
1441 * nvmem_cell_read() - Read a given nvmem cell
1442 *
1443 * @cell: nvmem cell to be read.
1444 * @len: pointer to length of cell which will be populated on successful read;
1445 * can be NULL.
1446 *
1447 * Return: ERR_PTR() on error or a valid pointer to a buffer on success. The
1448 * buffer should be freed by the consumer with a kfree().
1449 */
1450void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len)
1451{
1452 struct nvmem_device *nvmem = cell->entry->nvmem;
1453 u8 *buf;
1454 int rc;
1455
1456 if (!nvmem)
1457 return ERR_PTR(-EINVAL);
1458
1459 buf = kzalloc(cell->entry->bytes, GFP_KERNEL);
1460 if (!buf)
1461 return ERR_PTR(-ENOMEM);
1462
1463 rc = __nvmem_cell_read(nvmem, cell->entry, buf, len, cell->id);
1464 if (rc) {
1465 kfree(buf);
1466 return ERR_PTR(rc);
1467 }
1468
1469 return buf;
1470}
1471EXPORT_SYMBOL_GPL(nvmem_cell_read);
1472
1473static void *nvmem_cell_prepare_write_buffer(struct nvmem_cell_entry *cell,
1474 u8 *_buf, int len)
1475{
1476 struct nvmem_device *nvmem = cell->nvmem;
1477 int i, rc, nbits, bit_offset = cell->bit_offset;
1478 u8 v, *p, *buf, *b, pbyte, pbits;
1479
1480 nbits = cell->nbits;
1481 buf = kzalloc(cell->bytes, GFP_KERNEL);
1482 if (!buf)
1483 return ERR_PTR(-ENOMEM);
1484
1485 memcpy(buf, _buf, len);
1486 p = b = buf;
1487
1488 if (bit_offset) {
1489 pbyte = *b;
1490 *b <<= bit_offset;
1491
1492 /* setup the first byte with lsb bits from nvmem */
1493 rc = nvmem_reg_read(nvmem, cell->offset, &v, 1);
1494 if (rc)
1495 goto err;
1496 *b++ |= GENMASK(bit_offset - 1, 0) & v;
1497
1498 /* setup rest of the byte if any */
1499 for (i = 1; i < cell->bytes; i++) {
1500 /* Get last byte bits and shift them towards lsb */
1501 pbits = pbyte >> (BITS_PER_BYTE - 1 - bit_offset);
1502 pbyte = *b;
1503 p = b;
1504 *b <<= bit_offset;
1505 *b++ |= pbits;
1506 }
1507 }
1508
1509 /* if it's not end on byte boundary */
1510 if ((nbits + bit_offset) % BITS_PER_BYTE) {
1511 /* setup the last byte with msb bits from nvmem */
1512 rc = nvmem_reg_read(nvmem,
1513 cell->offset + cell->bytes - 1, &v, 1);
1514 if (rc)
1515 goto err;
1516 *p |= GENMASK(7, (nbits + bit_offset) % BITS_PER_BYTE) & v;
1517
1518 }
1519
1520 return buf;
1521err:
1522 kfree(buf);
1523 return ERR_PTR(rc);
1524}
1525
1526static int __nvmem_cell_entry_write(struct nvmem_cell_entry *cell, void *buf, size_t len)
1527{
1528 struct nvmem_device *nvmem = cell->nvmem;
1529 int rc;
1530
1531 if (!nvmem || nvmem->read_only ||
1532 (cell->bit_offset == 0 && len != cell->bytes))
1533 return -EINVAL;
1534
1535 if (cell->bit_offset || cell->nbits) {
1536 buf = nvmem_cell_prepare_write_buffer(cell, buf, len);
1537 if (IS_ERR(buf))
1538 return PTR_ERR(buf);
1539 }
1540
1541 rc = nvmem_reg_write(nvmem, cell->offset, buf, cell->bytes);
1542
1543 /* free the tmp buffer */
1544 if (cell->bit_offset || cell->nbits)
1545 kfree(buf);
1546
1547 if (rc)
1548 return rc;
1549
1550 return len;
1551}
1552
1553/**
1554 * nvmem_cell_write() - Write to a given nvmem cell
1555 *
1556 * @cell: nvmem cell to be written.
1557 * @buf: Buffer to be written.
1558 * @len: length of buffer to be written to nvmem cell.
1559 *
1560 * Return: length of bytes written or negative on failure.
1561 */
1562int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len)
1563{
1564 return __nvmem_cell_entry_write(cell->entry, buf, len);
1565}
1566
1567EXPORT_SYMBOL_GPL(nvmem_cell_write);
1568
1569static int nvmem_cell_read_common(struct device *dev, const char *cell_id,
1570 void *val, size_t count)
1571{
1572 struct nvmem_cell *cell;
1573 void *buf;
1574 size_t len;
1575
1576 cell = nvmem_cell_get(dev, cell_id);
1577 if (IS_ERR(cell))
1578 return PTR_ERR(cell);
1579
1580 buf = nvmem_cell_read(cell, &len);
1581 if (IS_ERR(buf)) {
1582 nvmem_cell_put(cell);
1583 return PTR_ERR(buf);
1584 }
1585 if (len != count) {
1586 kfree(buf);
1587 nvmem_cell_put(cell);
1588 return -EINVAL;
1589 }
1590 memcpy(val, buf, count);
1591 kfree(buf);
1592 nvmem_cell_put(cell);
1593
1594 return 0;
1595}
1596
1597/**
1598 * nvmem_cell_read_u8() - Read a cell value as a u8
1599 *
1600 * @dev: Device that requests the nvmem cell.
1601 * @cell_id: Name of nvmem cell to read.
1602 * @val: pointer to output value.
1603 *
1604 * Return: 0 on success or negative errno.
1605 */
1606int nvmem_cell_read_u8(struct device *dev, const char *cell_id, u8 *val)
1607{
1608 return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val));
1609}
1610EXPORT_SYMBOL_GPL(nvmem_cell_read_u8);
1611
1612/**
1613 * nvmem_cell_read_u16() - Read a cell value as a u16
1614 *
1615 * @dev: Device that requests the nvmem cell.
1616 * @cell_id: Name of nvmem cell to read.
1617 * @val: pointer to output value.
1618 *
1619 * Return: 0 on success or negative errno.
1620 */
1621int nvmem_cell_read_u16(struct device *dev, const char *cell_id, u16 *val)
1622{
1623 return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val));
1624}
1625EXPORT_SYMBOL_GPL(nvmem_cell_read_u16);
1626
1627/**
1628 * nvmem_cell_read_u32() - Read a cell value as a u32
1629 *
1630 * @dev: Device that requests the nvmem cell.
1631 * @cell_id: Name of nvmem cell to read.
1632 * @val: pointer to output value.
1633 *
1634 * Return: 0 on success or negative errno.
1635 */
1636int nvmem_cell_read_u32(struct device *dev, const char *cell_id, u32 *val)
1637{
1638 return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val));
1639}
1640EXPORT_SYMBOL_GPL(nvmem_cell_read_u32);
1641
1642/**
1643 * nvmem_cell_read_u64() - Read a cell value as a u64
1644 *
1645 * @dev: Device that requests the nvmem cell.
1646 * @cell_id: Name of nvmem cell to read.
1647 * @val: pointer to output value.
1648 *
1649 * Return: 0 on success or negative errno.
1650 */
1651int nvmem_cell_read_u64(struct device *dev, const char *cell_id, u64 *val)
1652{
1653 return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val));
1654}
1655EXPORT_SYMBOL_GPL(nvmem_cell_read_u64);
1656
1657static const void *nvmem_cell_read_variable_common(struct device *dev,
1658 const char *cell_id,
1659 size_t max_len, size_t *len)
1660{
1661 struct nvmem_cell *cell;
1662 int nbits;
1663 void *buf;
1664
1665 cell = nvmem_cell_get(dev, cell_id);
1666 if (IS_ERR(cell))
1667 return cell;
1668
1669 nbits = cell->entry->nbits;
1670 buf = nvmem_cell_read(cell, len);
1671 nvmem_cell_put(cell);
1672 if (IS_ERR(buf))
1673 return buf;
1674
1675 /*
1676 * If nbits is set then nvmem_cell_read() can significantly exaggerate
1677 * the length of the real data. Throw away the extra junk.
1678 */
1679 if (nbits)
1680 *len = DIV_ROUND_UP(nbits, 8);
1681
1682 if (*len > max_len) {
1683 kfree(buf);
1684 return ERR_PTR(-ERANGE);
1685 }
1686
1687 return buf;
1688}
1689
1690/**
1691 * nvmem_cell_read_variable_le_u32() - Read up to 32-bits of data as a little endian number.
1692 *
1693 * @dev: Device that requests the nvmem cell.
1694 * @cell_id: Name of nvmem cell to read.
1695 * @val: pointer to output value.
1696 *
1697 * Return: 0 on success or negative errno.
1698 */
1699int nvmem_cell_read_variable_le_u32(struct device *dev, const char *cell_id,
1700 u32 *val)
1701{
1702 size_t len;
1703 const u8 *buf;
1704 int i;
1705
1706 buf = nvmem_cell_read_variable_common(dev, cell_id, sizeof(*val), &len);
1707 if (IS_ERR(buf))
1708 return PTR_ERR(buf);
1709
1710 /* Copy w/ implicit endian conversion */
1711 *val = 0;
1712 for (i = 0; i < len; i++)
1713 *val |= buf[i] << (8 * i);
1714
1715 kfree(buf);
1716
1717 return 0;
1718}
1719EXPORT_SYMBOL_GPL(nvmem_cell_read_variable_le_u32);
1720
1721/**
1722 * nvmem_cell_read_variable_le_u64() - Read up to 64-bits of data as a little endian number.
1723 *
1724 * @dev: Device that requests the nvmem cell.
1725 * @cell_id: Name of nvmem cell to read.
1726 * @val: pointer to output value.
1727 *
1728 * Return: 0 on success or negative errno.
1729 */
1730int nvmem_cell_read_variable_le_u64(struct device *dev, const char *cell_id,
1731 u64 *val)
1732{
1733 size_t len;
1734 const u8 *buf;
1735 int i;
1736
1737 buf = nvmem_cell_read_variable_common(dev, cell_id, sizeof(*val), &len);
1738 if (IS_ERR(buf))
1739 return PTR_ERR(buf);
1740
1741 /* Copy w/ implicit endian conversion */
1742 *val = 0;
1743 for (i = 0; i < len; i++)
1744 *val |= (uint64_t)buf[i] << (8 * i);
1745
1746 kfree(buf);
1747
1748 return 0;
1749}
1750EXPORT_SYMBOL_GPL(nvmem_cell_read_variable_le_u64);
1751
1752/**
1753 * nvmem_device_cell_read() - Read a given nvmem device and cell
1754 *
1755 * @nvmem: nvmem device to read from.
1756 * @info: nvmem cell info to be read.
1757 * @buf: buffer pointer which will be populated on successful read.
1758 *
1759 * Return: length of successful bytes read on success and negative
1760 * error code on error.
1761 */
1762ssize_t nvmem_device_cell_read(struct nvmem_device *nvmem,
1763 struct nvmem_cell_info *info, void *buf)
1764{
1765 struct nvmem_cell_entry cell;
1766 int rc;
1767 ssize_t len;
1768
1769 if (!nvmem)
1770 return -EINVAL;
1771
1772 rc = nvmem_cell_info_to_nvmem_cell_entry_nodup(nvmem, info, &cell);
1773 if (rc)
1774 return rc;
1775
1776 rc = __nvmem_cell_read(nvmem, &cell, buf, &len, NULL);
1777 if (rc)
1778 return rc;
1779
1780 return len;
1781}
1782EXPORT_SYMBOL_GPL(nvmem_device_cell_read);
1783
1784/**
1785 * nvmem_device_cell_write() - Write cell to a given nvmem device
1786 *
1787 * @nvmem: nvmem device to be written to.
1788 * @info: nvmem cell info to be written.
1789 * @buf: buffer to be written to cell.
1790 *
1791 * Return: length of bytes written or negative error code on failure.
1792 */
1793int nvmem_device_cell_write(struct nvmem_device *nvmem,
1794 struct nvmem_cell_info *info, void *buf)
1795{
1796 struct nvmem_cell_entry cell;
1797 int rc;
1798
1799 if (!nvmem)
1800 return -EINVAL;
1801
1802 rc = nvmem_cell_info_to_nvmem_cell_entry_nodup(nvmem, info, &cell);
1803 if (rc)
1804 return rc;
1805
1806 return __nvmem_cell_entry_write(&cell, buf, cell.bytes);
1807}
1808EXPORT_SYMBOL_GPL(nvmem_device_cell_write);
1809
1810/**
1811 * nvmem_device_read() - Read from a given nvmem device
1812 *
1813 * @nvmem: nvmem device to read from.
1814 * @offset: offset in nvmem device.
1815 * @bytes: number of bytes to read.
1816 * @buf: buffer pointer which will be populated on successful read.
1817 *
1818 * Return: length of successful bytes read on success and negative
1819 * error code on error.
1820 */
1821int nvmem_device_read(struct nvmem_device *nvmem,
1822 unsigned int offset,
1823 size_t bytes, void *buf)
1824{
1825 int rc;
1826
1827 if (!nvmem)
1828 return -EINVAL;
1829
1830 rc = nvmem_reg_read(nvmem, offset, buf, bytes);
1831
1832 if (rc)
1833 return rc;
1834
1835 return bytes;
1836}
1837EXPORT_SYMBOL_GPL(nvmem_device_read);
1838
1839/**
1840 * nvmem_device_write() - Write cell to a given nvmem device
1841 *
1842 * @nvmem: nvmem device to be written to.
1843 * @offset: offset in nvmem device.
1844 * @bytes: number of bytes to write.
1845 * @buf: buffer to be written.
1846 *
1847 * Return: length of bytes written or negative error code on failure.
1848 */
1849int nvmem_device_write(struct nvmem_device *nvmem,
1850 unsigned int offset,
1851 size_t bytes, void *buf)
1852{
1853 int rc;
1854
1855 if (!nvmem)
1856 return -EINVAL;
1857
1858 rc = nvmem_reg_write(nvmem, offset, buf, bytes);
1859
1860 if (rc)
1861 return rc;
1862
1863
1864 return bytes;
1865}
1866EXPORT_SYMBOL_GPL(nvmem_device_write);
1867
1868/**
1869 * nvmem_add_cell_table() - register a table of cell info entries
1870 *
1871 * @table: table of cell info entries
1872 */
1873void nvmem_add_cell_table(struct nvmem_cell_table *table)
1874{
1875 mutex_lock(&nvmem_cell_mutex);
1876 list_add_tail(&table->node, &nvmem_cell_tables);
1877 mutex_unlock(&nvmem_cell_mutex);
1878}
1879EXPORT_SYMBOL_GPL(nvmem_add_cell_table);
1880
1881/**
1882 * nvmem_del_cell_table() - remove a previously registered cell info table
1883 *
1884 * @table: table of cell info entries
1885 */
1886void nvmem_del_cell_table(struct nvmem_cell_table *table)
1887{
1888 mutex_lock(&nvmem_cell_mutex);
1889 list_del(&table->node);
1890 mutex_unlock(&nvmem_cell_mutex);
1891}
1892EXPORT_SYMBOL_GPL(nvmem_del_cell_table);
1893
1894/**
1895 * nvmem_add_cell_lookups() - register a list of cell lookup entries
1896 *
1897 * @entries: array of cell lookup entries
1898 * @nentries: number of cell lookup entries in the array
1899 */
1900void nvmem_add_cell_lookups(struct nvmem_cell_lookup *entries, size_t nentries)
1901{
1902 int i;
1903
1904 mutex_lock(&nvmem_lookup_mutex);
1905 for (i = 0; i < nentries; i++)
1906 list_add_tail(&entries[i].node, &nvmem_lookup_list);
1907 mutex_unlock(&nvmem_lookup_mutex);
1908}
1909EXPORT_SYMBOL_GPL(nvmem_add_cell_lookups);
1910
1911/**
1912 * nvmem_del_cell_lookups() - remove a list of previously added cell lookup
1913 * entries
1914 *
1915 * @entries: array of cell lookup entries
1916 * @nentries: number of cell lookup entries in the array
1917 */
1918void nvmem_del_cell_lookups(struct nvmem_cell_lookup *entries, size_t nentries)
1919{
1920 int i;
1921
1922 mutex_lock(&nvmem_lookup_mutex);
1923 for (i = 0; i < nentries; i++)
1924 list_del(&entries[i].node);
1925 mutex_unlock(&nvmem_lookup_mutex);
1926}
1927EXPORT_SYMBOL_GPL(nvmem_del_cell_lookups);
1928
1929/**
1930 * nvmem_dev_name() - Get the name of a given nvmem device.
1931 *
1932 * @nvmem: nvmem device.
1933 *
1934 * Return: name of the nvmem device.
1935 */
1936const char *nvmem_dev_name(struct nvmem_device *nvmem)
1937{
1938 return dev_name(&nvmem->dev);
1939}
1940EXPORT_SYMBOL_GPL(nvmem_dev_name);
1941
1942static int __init nvmem_init(void)
1943{
1944 return bus_register(&nvmem_bus_type);
1945}
1946
1947static void __exit nvmem_exit(void)
1948{
1949 bus_unregister(&nvmem_bus_type);
1950}
1951
1952subsys_initcall(nvmem_init);
1953module_exit(nvmem_exit);
1954
1955MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org");
1956MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com");
1957MODULE_DESCRIPTION("nvmem Driver Core");
1958MODULE_LICENSE("GPL v2");
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
22struct 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 void *priv;
43};
44
45#define to_nvmem_device(d) container_of(d, struct nvmem_device, dev)
46
47#define FLAG_COMPAT BIT(0)
48
49struct nvmem_cell {
50 const char *name;
51 int offset;
52 int bytes;
53 int bit_offset;
54 int nbits;
55 struct device_node *np;
56 struct nvmem_device *nvmem;
57 struct list_head node;
58};
59
60static DEFINE_MUTEX(nvmem_mutex);
61static DEFINE_IDA(nvmem_ida);
62
63static DEFINE_MUTEX(nvmem_cell_mutex);
64static LIST_HEAD(nvmem_cell_tables);
65
66static DEFINE_MUTEX(nvmem_lookup_mutex);
67static LIST_HEAD(nvmem_lookup_list);
68
69static BLOCKING_NOTIFIER_HEAD(nvmem_notifier);
70
71static int __nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset,
72 void *val, size_t bytes)
73{
74 if (nvmem->reg_read)
75 return nvmem->reg_read(nvmem->priv, offset, val, bytes);
76
77 return -EINVAL;
78}
79
80static int __nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset,
81 void *val, size_t bytes)
82{
83 int ret;
84
85 if (nvmem->reg_write) {
86 gpiod_set_value_cansleep(nvmem->wp_gpio, 0);
87 ret = nvmem->reg_write(nvmem->priv, offset, val, bytes);
88 gpiod_set_value_cansleep(nvmem->wp_gpio, 1);
89 return ret;
90 }
91
92 return -EINVAL;
93}
94
95static int nvmem_access_with_keepouts(struct nvmem_device *nvmem,
96 unsigned int offset, void *val,
97 size_t bytes, int write)
98{
99
100 unsigned int end = offset + bytes;
101 unsigned int kend, ksize;
102 const struct nvmem_keepout *keepout = nvmem->keepout;
103 const struct nvmem_keepout *keepoutend = keepout + nvmem->nkeepout;
104 int rc;
105
106 /*
107 * Skip all keepouts before the range being accessed.
108 * Keepouts are sorted.
109 */
110 while ((keepout < keepoutend) && (keepout->end <= offset))
111 keepout++;
112
113 while ((offset < end) && (keepout < keepoutend)) {
114 /* Access the valid portion before the keepout. */
115 if (offset < keepout->start) {
116 kend = min(end, keepout->start);
117 ksize = kend - offset;
118 if (write)
119 rc = __nvmem_reg_write(nvmem, offset, val, ksize);
120 else
121 rc = __nvmem_reg_read(nvmem, offset, val, ksize);
122
123 if (rc)
124 return rc;
125
126 offset += ksize;
127 val += ksize;
128 }
129
130 /*
131 * Now we're aligned to the start of this keepout zone. Go
132 * through it.
133 */
134 kend = min(end, keepout->end);
135 ksize = kend - offset;
136 if (!write)
137 memset(val, keepout->value, ksize);
138
139 val += ksize;
140 offset += ksize;
141 keepout++;
142 }
143
144 /*
145 * If we ran out of keepouts but there's still stuff to do, send it
146 * down directly
147 */
148 if (offset < end) {
149 ksize = end - offset;
150 if (write)
151 return __nvmem_reg_write(nvmem, offset, val, ksize);
152 else
153 return __nvmem_reg_read(nvmem, offset, val, ksize);
154 }
155
156 return 0;
157}
158
159static int nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset,
160 void *val, size_t bytes)
161{
162 if (!nvmem->nkeepout)
163 return __nvmem_reg_read(nvmem, offset, val, bytes);
164
165 return nvmem_access_with_keepouts(nvmem, offset, val, bytes, false);
166}
167
168static int nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset,
169 void *val, size_t bytes)
170{
171 if (!nvmem->nkeepout)
172 return __nvmem_reg_write(nvmem, offset, val, bytes);
173
174 return nvmem_access_with_keepouts(nvmem, offset, val, bytes, true);
175}
176
177#ifdef CONFIG_NVMEM_SYSFS
178static const char * const nvmem_type_str[] = {
179 [NVMEM_TYPE_UNKNOWN] = "Unknown",
180 [NVMEM_TYPE_EEPROM] = "EEPROM",
181 [NVMEM_TYPE_OTP] = "OTP",
182 [NVMEM_TYPE_BATTERY_BACKED] = "Battery backed",
183 [NVMEM_TYPE_FRAM] = "FRAM",
184};
185
186#ifdef CONFIG_DEBUG_LOCK_ALLOC
187static struct lock_class_key eeprom_lock_key;
188#endif
189
190static ssize_t type_show(struct device *dev,
191 struct device_attribute *attr, char *buf)
192{
193 struct nvmem_device *nvmem = to_nvmem_device(dev);
194
195 return sprintf(buf, "%s\n", nvmem_type_str[nvmem->type]);
196}
197
198static DEVICE_ATTR_RO(type);
199
200static struct attribute *nvmem_attrs[] = {
201 &dev_attr_type.attr,
202 NULL,
203};
204
205static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj,
206 struct bin_attribute *attr, char *buf,
207 loff_t pos, size_t count)
208{
209 struct device *dev;
210 struct nvmem_device *nvmem;
211 int rc;
212
213 if (attr->private)
214 dev = attr->private;
215 else
216 dev = kobj_to_dev(kobj);
217 nvmem = to_nvmem_device(dev);
218
219 /* Stop the user from reading */
220 if (pos >= nvmem->size)
221 return 0;
222
223 if (!IS_ALIGNED(pos, nvmem->stride))
224 return -EINVAL;
225
226 if (count < nvmem->word_size)
227 return -EINVAL;
228
229 if (pos + count > nvmem->size)
230 count = nvmem->size - pos;
231
232 count = round_down(count, nvmem->word_size);
233
234 if (!nvmem->reg_read)
235 return -EPERM;
236
237 rc = nvmem_reg_read(nvmem, pos, buf, count);
238
239 if (rc)
240 return rc;
241
242 return count;
243}
244
245static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj,
246 struct bin_attribute *attr, char *buf,
247 loff_t pos, size_t count)
248{
249 struct device *dev;
250 struct nvmem_device *nvmem;
251 int rc;
252
253 if (attr->private)
254 dev = attr->private;
255 else
256 dev = kobj_to_dev(kobj);
257 nvmem = to_nvmem_device(dev);
258
259 /* Stop the user from writing */
260 if (pos >= nvmem->size)
261 return -EFBIG;
262
263 if (!IS_ALIGNED(pos, nvmem->stride))
264 return -EINVAL;
265
266 if (count < nvmem->word_size)
267 return -EINVAL;
268
269 if (pos + count > nvmem->size)
270 count = nvmem->size - pos;
271
272 count = round_down(count, nvmem->word_size);
273
274 if (!nvmem->reg_write)
275 return -EPERM;
276
277 rc = nvmem_reg_write(nvmem, pos, buf, count);
278
279 if (rc)
280 return rc;
281
282 return count;
283}
284
285static umode_t nvmem_bin_attr_get_umode(struct nvmem_device *nvmem)
286{
287 umode_t mode = 0400;
288
289 if (!nvmem->root_only)
290 mode |= 0044;
291
292 if (!nvmem->read_only)
293 mode |= 0200;
294
295 if (!nvmem->reg_write)
296 mode &= ~0200;
297
298 if (!nvmem->reg_read)
299 mode &= ~0444;
300
301 return mode;
302}
303
304static umode_t nvmem_bin_attr_is_visible(struct kobject *kobj,
305 struct bin_attribute *attr, int i)
306{
307 struct device *dev = kobj_to_dev(kobj);
308 struct nvmem_device *nvmem = to_nvmem_device(dev);
309
310 return nvmem_bin_attr_get_umode(nvmem);
311}
312
313/* default read/write permissions */
314static struct bin_attribute bin_attr_rw_nvmem = {
315 .attr = {
316 .name = "nvmem",
317 .mode = 0644,
318 },
319 .read = bin_attr_nvmem_read,
320 .write = bin_attr_nvmem_write,
321};
322
323static struct bin_attribute *nvmem_bin_attributes[] = {
324 &bin_attr_rw_nvmem,
325 NULL,
326};
327
328static const struct attribute_group nvmem_bin_group = {
329 .bin_attrs = nvmem_bin_attributes,
330 .attrs = nvmem_attrs,
331 .is_bin_visible = nvmem_bin_attr_is_visible,
332};
333
334static const struct attribute_group *nvmem_dev_groups[] = {
335 &nvmem_bin_group,
336 NULL,
337};
338
339static struct bin_attribute bin_attr_nvmem_eeprom_compat = {
340 .attr = {
341 .name = "eeprom",
342 },
343 .read = bin_attr_nvmem_read,
344 .write = bin_attr_nvmem_write,
345};
346
347/*
348 * nvmem_setup_compat() - Create an additional binary entry in
349 * drivers sys directory, to be backwards compatible with the older
350 * drivers/misc/eeprom drivers.
351 */
352static int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem,
353 const struct nvmem_config *config)
354{
355 int rval;
356
357 if (!config->compat)
358 return 0;
359
360 if (!config->base_dev)
361 return -EINVAL;
362
363 if (config->type == NVMEM_TYPE_FRAM)
364 bin_attr_nvmem_eeprom_compat.attr.name = "fram";
365
366 nvmem->eeprom = bin_attr_nvmem_eeprom_compat;
367 nvmem->eeprom.attr.mode = nvmem_bin_attr_get_umode(nvmem);
368 nvmem->eeprom.size = nvmem->size;
369#ifdef CONFIG_DEBUG_LOCK_ALLOC
370 nvmem->eeprom.attr.key = &eeprom_lock_key;
371#endif
372 nvmem->eeprom.private = &nvmem->dev;
373 nvmem->base_dev = config->base_dev;
374
375 rval = device_create_bin_file(nvmem->base_dev, &nvmem->eeprom);
376 if (rval) {
377 dev_err(&nvmem->dev,
378 "Failed to create eeprom binary file %d\n", rval);
379 return rval;
380 }
381
382 nvmem->flags |= FLAG_COMPAT;
383
384 return 0;
385}
386
387static void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem,
388 const struct nvmem_config *config)
389{
390 if (config->compat)
391 device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);
392}
393
394#else /* CONFIG_NVMEM_SYSFS */
395
396static int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem,
397 const struct nvmem_config *config)
398{
399 return -ENOSYS;
400}
401static void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem,
402 const struct nvmem_config *config)
403{
404}
405
406#endif /* CONFIG_NVMEM_SYSFS */
407
408static void nvmem_release(struct device *dev)
409{
410 struct nvmem_device *nvmem = to_nvmem_device(dev);
411
412 ida_free(&nvmem_ida, nvmem->id);
413 gpiod_put(nvmem->wp_gpio);
414 kfree(nvmem);
415}
416
417static const struct device_type nvmem_provider_type = {
418 .release = nvmem_release,
419};
420
421static struct bus_type nvmem_bus_type = {
422 .name = "nvmem",
423};
424
425static void nvmem_cell_drop(struct nvmem_cell *cell)
426{
427 blocking_notifier_call_chain(&nvmem_notifier, NVMEM_CELL_REMOVE, cell);
428 mutex_lock(&nvmem_mutex);
429 list_del(&cell->node);
430 mutex_unlock(&nvmem_mutex);
431 of_node_put(cell->np);
432 kfree_const(cell->name);
433 kfree(cell);
434}
435
436static void nvmem_device_remove_all_cells(const struct nvmem_device *nvmem)
437{
438 struct nvmem_cell *cell, *p;
439
440 list_for_each_entry_safe(cell, p, &nvmem->cells, node)
441 nvmem_cell_drop(cell);
442}
443
444static void nvmem_cell_add(struct nvmem_cell *cell)
445{
446 mutex_lock(&nvmem_mutex);
447 list_add_tail(&cell->node, &cell->nvmem->cells);
448 mutex_unlock(&nvmem_mutex);
449 blocking_notifier_call_chain(&nvmem_notifier, NVMEM_CELL_ADD, cell);
450}
451
452static int nvmem_cell_info_to_nvmem_cell_nodup(struct nvmem_device *nvmem,
453 const struct nvmem_cell_info *info,
454 struct nvmem_cell *cell)
455{
456 cell->nvmem = nvmem;
457 cell->offset = info->offset;
458 cell->bytes = info->bytes;
459 cell->name = info->name;
460
461 cell->bit_offset = info->bit_offset;
462 cell->nbits = info->nbits;
463
464 if (cell->nbits)
465 cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset,
466 BITS_PER_BYTE);
467
468 if (!IS_ALIGNED(cell->offset, nvmem->stride)) {
469 dev_err(&nvmem->dev,
470 "cell %s unaligned to nvmem stride %d\n",
471 cell->name ?: "<unknown>", nvmem->stride);
472 return -EINVAL;
473 }
474
475 return 0;
476}
477
478static int nvmem_cell_info_to_nvmem_cell(struct nvmem_device *nvmem,
479 const struct nvmem_cell_info *info,
480 struct nvmem_cell *cell)
481{
482 int err;
483
484 err = nvmem_cell_info_to_nvmem_cell_nodup(nvmem, info, cell);
485 if (err)
486 return err;
487
488 cell->name = kstrdup_const(info->name, GFP_KERNEL);
489 if (!cell->name)
490 return -ENOMEM;
491
492 return 0;
493}
494
495/**
496 * nvmem_add_cells() - Add cell information to an nvmem device
497 *
498 * @nvmem: nvmem device to add cells to.
499 * @info: nvmem cell info to add to the device
500 * @ncells: number of cells in info
501 *
502 * Return: 0 or negative error code on failure.
503 */
504static int nvmem_add_cells(struct nvmem_device *nvmem,
505 const struct nvmem_cell_info *info,
506 int ncells)
507{
508 struct nvmem_cell **cells;
509 int i, rval;
510
511 cells = kcalloc(ncells, sizeof(*cells), GFP_KERNEL);
512 if (!cells)
513 return -ENOMEM;
514
515 for (i = 0; i < ncells; i++) {
516 cells[i] = kzalloc(sizeof(**cells), GFP_KERNEL);
517 if (!cells[i]) {
518 rval = -ENOMEM;
519 goto err;
520 }
521
522 rval = nvmem_cell_info_to_nvmem_cell(nvmem, &info[i], cells[i]);
523 if (rval) {
524 kfree(cells[i]);
525 goto err;
526 }
527
528 nvmem_cell_add(cells[i]);
529 }
530
531 /* remove tmp array */
532 kfree(cells);
533
534 return 0;
535err:
536 while (i--)
537 nvmem_cell_drop(cells[i]);
538
539 kfree(cells);
540
541 return rval;
542}
543
544/**
545 * nvmem_register_notifier() - Register a notifier block for nvmem events.
546 *
547 * @nb: notifier block to be called on nvmem events.
548 *
549 * Return: 0 on success, negative error number on failure.
550 */
551int nvmem_register_notifier(struct notifier_block *nb)
552{
553 return blocking_notifier_chain_register(&nvmem_notifier, nb);
554}
555EXPORT_SYMBOL_GPL(nvmem_register_notifier);
556
557/**
558 * nvmem_unregister_notifier() - Unregister a notifier block for nvmem events.
559 *
560 * @nb: notifier block to be unregistered.
561 *
562 * Return: 0 on success, negative error number on failure.
563 */
564int nvmem_unregister_notifier(struct notifier_block *nb)
565{
566 return blocking_notifier_chain_unregister(&nvmem_notifier, nb);
567}
568EXPORT_SYMBOL_GPL(nvmem_unregister_notifier);
569
570static int nvmem_add_cells_from_table(struct nvmem_device *nvmem)
571{
572 const struct nvmem_cell_info *info;
573 struct nvmem_cell_table *table;
574 struct nvmem_cell *cell;
575 int rval = 0, i;
576
577 mutex_lock(&nvmem_cell_mutex);
578 list_for_each_entry(table, &nvmem_cell_tables, node) {
579 if (strcmp(nvmem_dev_name(nvmem), table->nvmem_name) == 0) {
580 for (i = 0; i < table->ncells; i++) {
581 info = &table->cells[i];
582
583 cell = kzalloc(sizeof(*cell), GFP_KERNEL);
584 if (!cell) {
585 rval = -ENOMEM;
586 goto out;
587 }
588
589 rval = nvmem_cell_info_to_nvmem_cell(nvmem,
590 info,
591 cell);
592 if (rval) {
593 kfree(cell);
594 goto out;
595 }
596
597 nvmem_cell_add(cell);
598 }
599 }
600 }
601
602out:
603 mutex_unlock(&nvmem_cell_mutex);
604 return rval;
605}
606
607static struct nvmem_cell *
608nvmem_find_cell_by_name(struct nvmem_device *nvmem, const char *cell_id)
609{
610 struct nvmem_cell *iter, *cell = NULL;
611
612 mutex_lock(&nvmem_mutex);
613 list_for_each_entry(iter, &nvmem->cells, node) {
614 if (strcmp(cell_id, iter->name) == 0) {
615 cell = iter;
616 break;
617 }
618 }
619 mutex_unlock(&nvmem_mutex);
620
621 return cell;
622}
623
624static int nvmem_validate_keepouts(struct nvmem_device *nvmem)
625{
626 unsigned int cur = 0;
627 const struct nvmem_keepout *keepout = nvmem->keepout;
628 const struct nvmem_keepout *keepoutend = keepout + nvmem->nkeepout;
629
630 while (keepout < keepoutend) {
631 /* Ensure keepouts are sorted and don't overlap. */
632 if (keepout->start < cur) {
633 dev_err(&nvmem->dev,
634 "Keepout regions aren't sorted or overlap.\n");
635
636 return -ERANGE;
637 }
638
639 if (keepout->end < keepout->start) {
640 dev_err(&nvmem->dev,
641 "Invalid keepout region.\n");
642
643 return -EINVAL;
644 }
645
646 /*
647 * Validate keepouts (and holes between) don't violate
648 * word_size constraints.
649 */
650 if ((keepout->end - keepout->start < nvmem->word_size) ||
651 ((keepout->start != cur) &&
652 (keepout->start - cur < nvmem->word_size))) {
653
654 dev_err(&nvmem->dev,
655 "Keepout regions violate word_size constraints.\n");
656
657 return -ERANGE;
658 }
659
660 /* Validate keepouts don't violate stride (alignment). */
661 if (!IS_ALIGNED(keepout->start, nvmem->stride) ||
662 !IS_ALIGNED(keepout->end, nvmem->stride)) {
663
664 dev_err(&nvmem->dev,
665 "Keepout regions violate stride.\n");
666
667 return -EINVAL;
668 }
669
670 cur = keepout->end;
671 keepout++;
672 }
673
674 return 0;
675}
676
677static int nvmem_add_cells_from_of(struct nvmem_device *nvmem)
678{
679 struct device_node *parent, *child;
680 struct device *dev = &nvmem->dev;
681 struct nvmem_cell *cell;
682 const __be32 *addr;
683 int len;
684
685 parent = dev->of_node;
686
687 for_each_child_of_node(parent, child) {
688 addr = of_get_property(child, "reg", &len);
689 if (!addr)
690 continue;
691 if (len < 2 * sizeof(u32)) {
692 dev_err(dev, "nvmem: invalid reg on %pOF\n", child);
693 of_node_put(child);
694 return -EINVAL;
695 }
696
697 cell = kzalloc(sizeof(*cell), GFP_KERNEL);
698 if (!cell) {
699 of_node_put(child);
700 return -ENOMEM;
701 }
702
703 cell->nvmem = nvmem;
704 cell->offset = be32_to_cpup(addr++);
705 cell->bytes = be32_to_cpup(addr);
706 cell->name = kasprintf(GFP_KERNEL, "%pOFn", child);
707
708 addr = of_get_property(child, "bits", &len);
709 if (addr && len == (2 * sizeof(u32))) {
710 cell->bit_offset = be32_to_cpup(addr++);
711 cell->nbits = be32_to_cpup(addr);
712 }
713
714 if (cell->nbits)
715 cell->bytes = DIV_ROUND_UP(
716 cell->nbits + cell->bit_offset,
717 BITS_PER_BYTE);
718
719 if (!IS_ALIGNED(cell->offset, nvmem->stride)) {
720 dev_err(dev, "cell %s unaligned to nvmem stride %d\n",
721 cell->name, nvmem->stride);
722 /* Cells already added will be freed later. */
723 kfree_const(cell->name);
724 kfree(cell);
725 of_node_put(child);
726 return -EINVAL;
727 }
728
729 cell->np = of_node_get(child);
730 nvmem_cell_add(cell);
731 }
732
733 return 0;
734}
735
736/**
737 * nvmem_register() - Register a nvmem device for given nvmem_config.
738 * Also creates a binary entry in /sys/bus/nvmem/devices/dev-name/nvmem
739 *
740 * @config: nvmem device configuration with which nvmem device is created.
741 *
742 * Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device
743 * on success.
744 */
745
746struct nvmem_device *nvmem_register(const struct nvmem_config *config)
747{
748 struct nvmem_device *nvmem;
749 int rval;
750
751 if (!config->dev)
752 return ERR_PTR(-EINVAL);
753
754 if (!config->reg_read && !config->reg_write)
755 return ERR_PTR(-EINVAL);
756
757 nvmem = kzalloc(sizeof(*nvmem), GFP_KERNEL);
758 if (!nvmem)
759 return ERR_PTR(-ENOMEM);
760
761 rval = ida_alloc(&nvmem_ida, GFP_KERNEL);
762 if (rval < 0) {
763 kfree(nvmem);
764 return ERR_PTR(rval);
765 }
766
767 if (config->wp_gpio)
768 nvmem->wp_gpio = config->wp_gpio;
769 else
770 nvmem->wp_gpio = gpiod_get_optional(config->dev, "wp",
771 GPIOD_OUT_HIGH);
772 if (IS_ERR(nvmem->wp_gpio)) {
773 ida_free(&nvmem_ida, nvmem->id);
774 rval = PTR_ERR(nvmem->wp_gpio);
775 kfree(nvmem);
776 return ERR_PTR(rval);
777 }
778
779 kref_init(&nvmem->refcnt);
780 INIT_LIST_HEAD(&nvmem->cells);
781
782 nvmem->id = rval;
783 nvmem->owner = config->owner;
784 if (!nvmem->owner && config->dev->driver)
785 nvmem->owner = config->dev->driver->owner;
786 nvmem->stride = config->stride ?: 1;
787 nvmem->word_size = config->word_size ?: 1;
788 nvmem->size = config->size;
789 nvmem->dev.type = &nvmem_provider_type;
790 nvmem->dev.bus = &nvmem_bus_type;
791 nvmem->dev.parent = config->dev;
792 nvmem->root_only = config->root_only;
793 nvmem->priv = config->priv;
794 nvmem->type = config->type;
795 nvmem->reg_read = config->reg_read;
796 nvmem->reg_write = config->reg_write;
797 nvmem->keepout = config->keepout;
798 nvmem->nkeepout = config->nkeepout;
799 if (config->of_node)
800 nvmem->dev.of_node = config->of_node;
801 else if (!config->no_of_node)
802 nvmem->dev.of_node = config->dev->of_node;
803
804 switch (config->id) {
805 case NVMEM_DEVID_NONE:
806 dev_set_name(&nvmem->dev, "%s", config->name);
807 break;
808 case NVMEM_DEVID_AUTO:
809 dev_set_name(&nvmem->dev, "%s%d", config->name, nvmem->id);
810 break;
811 default:
812 dev_set_name(&nvmem->dev, "%s%d",
813 config->name ? : "nvmem",
814 config->name ? config->id : nvmem->id);
815 break;
816 }
817
818 nvmem->read_only = device_property_present(config->dev, "read-only") ||
819 config->read_only || !nvmem->reg_write;
820
821#ifdef CONFIG_NVMEM_SYSFS
822 nvmem->dev.groups = nvmem_dev_groups;
823#endif
824
825 if (nvmem->nkeepout) {
826 rval = nvmem_validate_keepouts(nvmem);
827 if (rval) {
828 ida_free(&nvmem_ida, nvmem->id);
829 kfree(nvmem);
830 return ERR_PTR(rval);
831 }
832 }
833
834 dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name);
835
836 rval = device_register(&nvmem->dev);
837 if (rval)
838 goto err_put_device;
839
840 if (config->compat) {
841 rval = nvmem_sysfs_setup_compat(nvmem, config);
842 if (rval)
843 goto err_device_del;
844 }
845
846 if (config->cells) {
847 rval = nvmem_add_cells(nvmem, config->cells, config->ncells);
848 if (rval)
849 goto err_teardown_compat;
850 }
851
852 rval = nvmem_add_cells_from_table(nvmem);
853 if (rval)
854 goto err_remove_cells;
855
856 rval = nvmem_add_cells_from_of(nvmem);
857 if (rval)
858 goto err_remove_cells;
859
860 blocking_notifier_call_chain(&nvmem_notifier, NVMEM_ADD, nvmem);
861
862 return nvmem;
863
864err_remove_cells:
865 nvmem_device_remove_all_cells(nvmem);
866err_teardown_compat:
867 if (config->compat)
868 nvmem_sysfs_remove_compat(nvmem, config);
869err_device_del:
870 device_del(&nvmem->dev);
871err_put_device:
872 put_device(&nvmem->dev);
873
874 return ERR_PTR(rval);
875}
876EXPORT_SYMBOL_GPL(nvmem_register);
877
878static void nvmem_device_release(struct kref *kref)
879{
880 struct nvmem_device *nvmem;
881
882 nvmem = container_of(kref, struct nvmem_device, refcnt);
883
884 blocking_notifier_call_chain(&nvmem_notifier, NVMEM_REMOVE, nvmem);
885
886 if (nvmem->flags & FLAG_COMPAT)
887 device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);
888
889 nvmem_device_remove_all_cells(nvmem);
890 device_unregister(&nvmem->dev);
891}
892
893/**
894 * nvmem_unregister() - Unregister previously registered nvmem device
895 *
896 * @nvmem: Pointer to previously registered nvmem device.
897 */
898void nvmem_unregister(struct nvmem_device *nvmem)
899{
900 kref_put(&nvmem->refcnt, nvmem_device_release);
901}
902EXPORT_SYMBOL_GPL(nvmem_unregister);
903
904static void devm_nvmem_release(struct device *dev, void *res)
905{
906 nvmem_unregister(*(struct nvmem_device **)res);
907}
908
909/**
910 * devm_nvmem_register() - Register a managed nvmem device for given
911 * nvmem_config.
912 * Also creates a binary entry in /sys/bus/nvmem/devices/dev-name/nvmem
913 *
914 * @dev: Device that uses the nvmem device.
915 * @config: nvmem device configuration with which nvmem device is created.
916 *
917 * Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device
918 * on success.
919 */
920struct nvmem_device *devm_nvmem_register(struct device *dev,
921 const struct nvmem_config *config)
922{
923 struct nvmem_device **ptr, *nvmem;
924
925 ptr = devres_alloc(devm_nvmem_release, sizeof(*ptr), GFP_KERNEL);
926 if (!ptr)
927 return ERR_PTR(-ENOMEM);
928
929 nvmem = nvmem_register(config);
930
931 if (!IS_ERR(nvmem)) {
932 *ptr = nvmem;
933 devres_add(dev, ptr);
934 } else {
935 devres_free(ptr);
936 }
937
938 return nvmem;
939}
940EXPORT_SYMBOL_GPL(devm_nvmem_register);
941
942static int devm_nvmem_match(struct device *dev, void *res, void *data)
943{
944 struct nvmem_device **r = res;
945
946 return *r == data;
947}
948
949/**
950 * devm_nvmem_unregister() - Unregister previously registered managed nvmem
951 * device.
952 *
953 * @dev: Device that uses the nvmem device.
954 * @nvmem: Pointer to previously registered nvmem device.
955 *
956 * Return: Will be negative on error or zero on success.
957 */
958int devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem)
959{
960 return devres_release(dev, devm_nvmem_release, devm_nvmem_match, nvmem);
961}
962EXPORT_SYMBOL(devm_nvmem_unregister);
963
964static struct nvmem_device *__nvmem_device_get(void *data,
965 int (*match)(struct device *dev, const void *data))
966{
967 struct nvmem_device *nvmem = NULL;
968 struct device *dev;
969
970 mutex_lock(&nvmem_mutex);
971 dev = bus_find_device(&nvmem_bus_type, NULL, data, match);
972 if (dev)
973 nvmem = to_nvmem_device(dev);
974 mutex_unlock(&nvmem_mutex);
975 if (!nvmem)
976 return ERR_PTR(-EPROBE_DEFER);
977
978 if (!try_module_get(nvmem->owner)) {
979 dev_err(&nvmem->dev,
980 "could not increase module refcount for cell %s\n",
981 nvmem_dev_name(nvmem));
982
983 put_device(&nvmem->dev);
984 return ERR_PTR(-EINVAL);
985 }
986
987 kref_get(&nvmem->refcnt);
988
989 return nvmem;
990}
991
992static void __nvmem_device_put(struct nvmem_device *nvmem)
993{
994 put_device(&nvmem->dev);
995 module_put(nvmem->owner);
996 kref_put(&nvmem->refcnt, nvmem_device_release);
997}
998
999#if IS_ENABLED(CONFIG_OF)
1000/**
1001 * of_nvmem_device_get() - Get nvmem device from a given id
1002 *
1003 * @np: Device tree node that uses the nvmem device.
1004 * @id: nvmem name from nvmem-names property.
1005 *
1006 * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device
1007 * on success.
1008 */
1009struct nvmem_device *of_nvmem_device_get(struct device_node *np, const char *id)
1010{
1011
1012 struct device_node *nvmem_np;
1013 struct nvmem_device *nvmem;
1014 int index = 0;
1015
1016 if (id)
1017 index = of_property_match_string(np, "nvmem-names", id);
1018
1019 nvmem_np = of_parse_phandle(np, "nvmem", index);
1020 if (!nvmem_np)
1021 return ERR_PTR(-ENOENT);
1022
1023 nvmem = __nvmem_device_get(nvmem_np, device_match_of_node);
1024 of_node_put(nvmem_np);
1025 return nvmem;
1026}
1027EXPORT_SYMBOL_GPL(of_nvmem_device_get);
1028#endif
1029
1030/**
1031 * nvmem_device_get() - Get nvmem device from a given id
1032 *
1033 * @dev: Device that uses the nvmem device.
1034 * @dev_name: name of the requested nvmem device.
1035 *
1036 * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device
1037 * on success.
1038 */
1039struct nvmem_device *nvmem_device_get(struct device *dev, const char *dev_name)
1040{
1041 if (dev->of_node) { /* try dt first */
1042 struct nvmem_device *nvmem;
1043
1044 nvmem = of_nvmem_device_get(dev->of_node, dev_name);
1045
1046 if (!IS_ERR(nvmem) || PTR_ERR(nvmem) == -EPROBE_DEFER)
1047 return nvmem;
1048
1049 }
1050
1051 return __nvmem_device_get((void *)dev_name, device_match_name);
1052}
1053EXPORT_SYMBOL_GPL(nvmem_device_get);
1054
1055/**
1056 * nvmem_device_find() - Find nvmem device with matching function
1057 *
1058 * @data: Data to pass to match function
1059 * @match: Callback function to check device
1060 *
1061 * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device
1062 * on success.
1063 */
1064struct nvmem_device *nvmem_device_find(void *data,
1065 int (*match)(struct device *dev, const void *data))
1066{
1067 return __nvmem_device_get(data, match);
1068}
1069EXPORT_SYMBOL_GPL(nvmem_device_find);
1070
1071static int devm_nvmem_device_match(struct device *dev, void *res, void *data)
1072{
1073 struct nvmem_device **nvmem = res;
1074
1075 if (WARN_ON(!nvmem || !*nvmem))
1076 return 0;
1077
1078 return *nvmem == data;
1079}
1080
1081static void devm_nvmem_device_release(struct device *dev, void *res)
1082{
1083 nvmem_device_put(*(struct nvmem_device **)res);
1084}
1085
1086/**
1087 * devm_nvmem_device_put() - put alredy got nvmem device
1088 *
1089 * @dev: Device that uses the nvmem device.
1090 * @nvmem: pointer to nvmem device allocated by devm_nvmem_cell_get(),
1091 * that needs to be released.
1092 */
1093void devm_nvmem_device_put(struct device *dev, struct nvmem_device *nvmem)
1094{
1095 int ret;
1096
1097 ret = devres_release(dev, devm_nvmem_device_release,
1098 devm_nvmem_device_match, nvmem);
1099
1100 WARN_ON(ret);
1101}
1102EXPORT_SYMBOL_GPL(devm_nvmem_device_put);
1103
1104/**
1105 * nvmem_device_put() - put alredy got nvmem device
1106 *
1107 * @nvmem: pointer to nvmem device that needs to be released.
1108 */
1109void nvmem_device_put(struct nvmem_device *nvmem)
1110{
1111 __nvmem_device_put(nvmem);
1112}
1113EXPORT_SYMBOL_GPL(nvmem_device_put);
1114
1115/**
1116 * devm_nvmem_device_get() - Get nvmem cell of device form a given id
1117 *
1118 * @dev: Device that requests the nvmem device.
1119 * @id: name id for the requested nvmem device.
1120 *
1121 * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_cell
1122 * on success. The nvmem_cell will be freed by the automatically once the
1123 * device is freed.
1124 */
1125struct nvmem_device *devm_nvmem_device_get(struct device *dev, const char *id)
1126{
1127 struct nvmem_device **ptr, *nvmem;
1128
1129 ptr = devres_alloc(devm_nvmem_device_release, sizeof(*ptr), GFP_KERNEL);
1130 if (!ptr)
1131 return ERR_PTR(-ENOMEM);
1132
1133 nvmem = nvmem_device_get(dev, id);
1134 if (!IS_ERR(nvmem)) {
1135 *ptr = nvmem;
1136 devres_add(dev, ptr);
1137 } else {
1138 devres_free(ptr);
1139 }
1140
1141 return nvmem;
1142}
1143EXPORT_SYMBOL_GPL(devm_nvmem_device_get);
1144
1145static struct nvmem_cell *
1146nvmem_cell_get_from_lookup(struct device *dev, const char *con_id)
1147{
1148 struct nvmem_cell *cell = ERR_PTR(-ENOENT);
1149 struct nvmem_cell_lookup *lookup;
1150 struct nvmem_device *nvmem;
1151 const char *dev_id;
1152
1153 if (!dev)
1154 return ERR_PTR(-EINVAL);
1155
1156 dev_id = dev_name(dev);
1157
1158 mutex_lock(&nvmem_lookup_mutex);
1159
1160 list_for_each_entry(lookup, &nvmem_lookup_list, node) {
1161 if ((strcmp(lookup->dev_id, dev_id) == 0) &&
1162 (strcmp(lookup->con_id, con_id) == 0)) {
1163 /* This is the right entry. */
1164 nvmem = __nvmem_device_get((void *)lookup->nvmem_name,
1165 device_match_name);
1166 if (IS_ERR(nvmem)) {
1167 /* Provider may not be registered yet. */
1168 cell = ERR_CAST(nvmem);
1169 break;
1170 }
1171
1172 cell = nvmem_find_cell_by_name(nvmem,
1173 lookup->cell_name);
1174 if (!cell) {
1175 __nvmem_device_put(nvmem);
1176 cell = ERR_PTR(-ENOENT);
1177 }
1178 break;
1179 }
1180 }
1181
1182 mutex_unlock(&nvmem_lookup_mutex);
1183 return cell;
1184}
1185
1186#if IS_ENABLED(CONFIG_OF)
1187static struct nvmem_cell *
1188nvmem_find_cell_by_node(struct nvmem_device *nvmem, struct device_node *np)
1189{
1190 struct nvmem_cell *iter, *cell = NULL;
1191
1192 mutex_lock(&nvmem_mutex);
1193 list_for_each_entry(iter, &nvmem->cells, node) {
1194 if (np == iter->np) {
1195 cell = iter;
1196 break;
1197 }
1198 }
1199 mutex_unlock(&nvmem_mutex);
1200
1201 return cell;
1202}
1203
1204/**
1205 * of_nvmem_cell_get() - Get a nvmem cell from given device node and cell id
1206 *
1207 * @np: Device tree node that uses the nvmem cell.
1208 * @id: nvmem cell name from nvmem-cell-names property, or NULL
1209 * for the cell at index 0 (the lone cell with no accompanying
1210 * nvmem-cell-names property).
1211 *
1212 * Return: Will be an ERR_PTR() on error or a valid pointer
1213 * to a struct nvmem_cell. The nvmem_cell will be freed by the
1214 * nvmem_cell_put().
1215 */
1216struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, const char *id)
1217{
1218 struct device_node *cell_np, *nvmem_np;
1219 struct nvmem_device *nvmem;
1220 struct nvmem_cell *cell;
1221 int index = 0;
1222
1223 /* if cell name exists, find index to the name */
1224 if (id)
1225 index = of_property_match_string(np, "nvmem-cell-names", id);
1226
1227 cell_np = of_parse_phandle(np, "nvmem-cells", index);
1228 if (!cell_np)
1229 return ERR_PTR(-ENOENT);
1230
1231 nvmem_np = of_get_next_parent(cell_np);
1232 if (!nvmem_np)
1233 return ERR_PTR(-EINVAL);
1234
1235 nvmem = __nvmem_device_get(nvmem_np, device_match_of_node);
1236 of_node_put(nvmem_np);
1237 if (IS_ERR(nvmem))
1238 return ERR_CAST(nvmem);
1239
1240 cell = nvmem_find_cell_by_node(nvmem, cell_np);
1241 if (!cell) {
1242 __nvmem_device_put(nvmem);
1243 return ERR_PTR(-ENOENT);
1244 }
1245
1246 return cell;
1247}
1248EXPORT_SYMBOL_GPL(of_nvmem_cell_get);
1249#endif
1250
1251/**
1252 * nvmem_cell_get() - Get nvmem cell of device form a given cell name
1253 *
1254 * @dev: Device that requests the nvmem cell.
1255 * @id: nvmem cell name to get (this corresponds with the name from the
1256 * nvmem-cell-names property for DT systems and with the con_id from
1257 * the lookup entry for non-DT systems).
1258 *
1259 * Return: Will be an ERR_PTR() on error or a valid pointer
1260 * to a struct nvmem_cell. The nvmem_cell will be freed by the
1261 * nvmem_cell_put().
1262 */
1263struct nvmem_cell *nvmem_cell_get(struct device *dev, const char *id)
1264{
1265 struct nvmem_cell *cell;
1266
1267 if (dev->of_node) { /* try dt first */
1268 cell = of_nvmem_cell_get(dev->of_node, id);
1269 if (!IS_ERR(cell) || PTR_ERR(cell) == -EPROBE_DEFER)
1270 return cell;
1271 }
1272
1273 /* NULL cell id only allowed for device tree; invalid otherwise */
1274 if (!id)
1275 return ERR_PTR(-EINVAL);
1276
1277 return nvmem_cell_get_from_lookup(dev, id);
1278}
1279EXPORT_SYMBOL_GPL(nvmem_cell_get);
1280
1281static void devm_nvmem_cell_release(struct device *dev, void *res)
1282{
1283 nvmem_cell_put(*(struct nvmem_cell **)res);
1284}
1285
1286/**
1287 * devm_nvmem_cell_get() - Get nvmem cell of device form a given id
1288 *
1289 * @dev: Device that requests the nvmem cell.
1290 * @id: nvmem cell name id to get.
1291 *
1292 * Return: Will be an ERR_PTR() on error or a valid pointer
1293 * to a struct nvmem_cell. The nvmem_cell will be freed by the
1294 * automatically once the device is freed.
1295 */
1296struct nvmem_cell *devm_nvmem_cell_get(struct device *dev, const char *id)
1297{
1298 struct nvmem_cell **ptr, *cell;
1299
1300 ptr = devres_alloc(devm_nvmem_cell_release, sizeof(*ptr), GFP_KERNEL);
1301 if (!ptr)
1302 return ERR_PTR(-ENOMEM);
1303
1304 cell = nvmem_cell_get(dev, id);
1305 if (!IS_ERR(cell)) {
1306 *ptr = cell;
1307 devres_add(dev, ptr);
1308 } else {
1309 devres_free(ptr);
1310 }
1311
1312 return cell;
1313}
1314EXPORT_SYMBOL_GPL(devm_nvmem_cell_get);
1315
1316static int devm_nvmem_cell_match(struct device *dev, void *res, void *data)
1317{
1318 struct nvmem_cell **c = res;
1319
1320 if (WARN_ON(!c || !*c))
1321 return 0;
1322
1323 return *c == data;
1324}
1325
1326/**
1327 * devm_nvmem_cell_put() - Release previously allocated nvmem cell
1328 * from devm_nvmem_cell_get.
1329 *
1330 * @dev: Device that requests the nvmem cell.
1331 * @cell: Previously allocated nvmem cell by devm_nvmem_cell_get().
1332 */
1333void devm_nvmem_cell_put(struct device *dev, struct nvmem_cell *cell)
1334{
1335 int ret;
1336
1337 ret = devres_release(dev, devm_nvmem_cell_release,
1338 devm_nvmem_cell_match, cell);
1339
1340 WARN_ON(ret);
1341}
1342EXPORT_SYMBOL(devm_nvmem_cell_put);
1343
1344/**
1345 * nvmem_cell_put() - Release previously allocated nvmem cell.
1346 *
1347 * @cell: Previously allocated nvmem cell by nvmem_cell_get().
1348 */
1349void nvmem_cell_put(struct nvmem_cell *cell)
1350{
1351 struct nvmem_device *nvmem = cell->nvmem;
1352
1353 __nvmem_device_put(nvmem);
1354}
1355EXPORT_SYMBOL_GPL(nvmem_cell_put);
1356
1357static void nvmem_shift_read_buffer_in_place(struct nvmem_cell *cell, void *buf)
1358{
1359 u8 *p, *b;
1360 int i, extra, bit_offset = cell->bit_offset;
1361
1362 p = b = buf;
1363 if (bit_offset) {
1364 /* First shift */
1365 *b++ >>= bit_offset;
1366
1367 /* setup rest of the bytes if any */
1368 for (i = 1; i < cell->bytes; i++) {
1369 /* Get bits from next byte and shift them towards msb */
1370 *p |= *b << (BITS_PER_BYTE - bit_offset);
1371
1372 p = b;
1373 *b++ >>= bit_offset;
1374 }
1375 } else {
1376 /* point to the msb */
1377 p += cell->bytes - 1;
1378 }
1379
1380 /* result fits in less bytes */
1381 extra = cell->bytes - DIV_ROUND_UP(cell->nbits, BITS_PER_BYTE);
1382 while (--extra >= 0)
1383 *p-- = 0;
1384
1385 /* clear msb bits if any leftover in the last byte */
1386 if (cell->nbits % BITS_PER_BYTE)
1387 *p &= GENMASK((cell->nbits % BITS_PER_BYTE) - 1, 0);
1388}
1389
1390static int __nvmem_cell_read(struct nvmem_device *nvmem,
1391 struct nvmem_cell *cell,
1392 void *buf, size_t *len)
1393{
1394 int rc;
1395
1396 rc = nvmem_reg_read(nvmem, cell->offset, buf, cell->bytes);
1397
1398 if (rc)
1399 return rc;
1400
1401 /* shift bits in-place */
1402 if (cell->bit_offset || cell->nbits)
1403 nvmem_shift_read_buffer_in_place(cell, buf);
1404
1405 if (len)
1406 *len = cell->bytes;
1407
1408 return 0;
1409}
1410
1411/**
1412 * nvmem_cell_read() - Read a given nvmem cell
1413 *
1414 * @cell: nvmem cell to be read.
1415 * @len: pointer to length of cell which will be populated on successful read;
1416 * can be NULL.
1417 *
1418 * Return: ERR_PTR() on error or a valid pointer to a buffer on success. The
1419 * buffer should be freed by the consumer with a kfree().
1420 */
1421void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len)
1422{
1423 struct nvmem_device *nvmem = cell->nvmem;
1424 u8 *buf;
1425 int rc;
1426
1427 if (!nvmem)
1428 return ERR_PTR(-EINVAL);
1429
1430 buf = kzalloc(cell->bytes, GFP_KERNEL);
1431 if (!buf)
1432 return ERR_PTR(-ENOMEM);
1433
1434 rc = __nvmem_cell_read(nvmem, cell, buf, len);
1435 if (rc) {
1436 kfree(buf);
1437 return ERR_PTR(rc);
1438 }
1439
1440 return buf;
1441}
1442EXPORT_SYMBOL_GPL(nvmem_cell_read);
1443
1444static void *nvmem_cell_prepare_write_buffer(struct nvmem_cell *cell,
1445 u8 *_buf, int len)
1446{
1447 struct nvmem_device *nvmem = cell->nvmem;
1448 int i, rc, nbits, bit_offset = cell->bit_offset;
1449 u8 v, *p, *buf, *b, pbyte, pbits;
1450
1451 nbits = cell->nbits;
1452 buf = kzalloc(cell->bytes, GFP_KERNEL);
1453 if (!buf)
1454 return ERR_PTR(-ENOMEM);
1455
1456 memcpy(buf, _buf, len);
1457 p = b = buf;
1458
1459 if (bit_offset) {
1460 pbyte = *b;
1461 *b <<= bit_offset;
1462
1463 /* setup the first byte with lsb bits from nvmem */
1464 rc = nvmem_reg_read(nvmem, cell->offset, &v, 1);
1465 if (rc)
1466 goto err;
1467 *b++ |= GENMASK(bit_offset - 1, 0) & v;
1468
1469 /* setup rest of the byte if any */
1470 for (i = 1; i < cell->bytes; i++) {
1471 /* Get last byte bits and shift them towards lsb */
1472 pbits = pbyte >> (BITS_PER_BYTE - 1 - bit_offset);
1473 pbyte = *b;
1474 p = b;
1475 *b <<= bit_offset;
1476 *b++ |= pbits;
1477 }
1478 }
1479
1480 /* if it's not end on byte boundary */
1481 if ((nbits + bit_offset) % BITS_PER_BYTE) {
1482 /* setup the last byte with msb bits from nvmem */
1483 rc = nvmem_reg_read(nvmem,
1484 cell->offset + cell->bytes - 1, &v, 1);
1485 if (rc)
1486 goto err;
1487 *p |= GENMASK(7, (nbits + bit_offset) % BITS_PER_BYTE) & v;
1488
1489 }
1490
1491 return buf;
1492err:
1493 kfree(buf);
1494 return ERR_PTR(rc);
1495}
1496
1497/**
1498 * nvmem_cell_write() - Write to a given nvmem cell
1499 *
1500 * @cell: nvmem cell to be written.
1501 * @buf: Buffer to be written.
1502 * @len: length of buffer to be written to nvmem cell.
1503 *
1504 * Return: length of bytes written or negative on failure.
1505 */
1506int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len)
1507{
1508 struct nvmem_device *nvmem = cell->nvmem;
1509 int rc;
1510
1511 if (!nvmem || nvmem->read_only ||
1512 (cell->bit_offset == 0 && len != cell->bytes))
1513 return -EINVAL;
1514
1515 if (cell->bit_offset || cell->nbits) {
1516 buf = nvmem_cell_prepare_write_buffer(cell, buf, len);
1517 if (IS_ERR(buf))
1518 return PTR_ERR(buf);
1519 }
1520
1521 rc = nvmem_reg_write(nvmem, cell->offset, buf, cell->bytes);
1522
1523 /* free the tmp buffer */
1524 if (cell->bit_offset || cell->nbits)
1525 kfree(buf);
1526
1527 if (rc)
1528 return rc;
1529
1530 return len;
1531}
1532EXPORT_SYMBOL_GPL(nvmem_cell_write);
1533
1534static int nvmem_cell_read_common(struct device *dev, const char *cell_id,
1535 void *val, size_t count)
1536{
1537 struct nvmem_cell *cell;
1538 void *buf;
1539 size_t len;
1540
1541 cell = nvmem_cell_get(dev, cell_id);
1542 if (IS_ERR(cell))
1543 return PTR_ERR(cell);
1544
1545 buf = nvmem_cell_read(cell, &len);
1546 if (IS_ERR(buf)) {
1547 nvmem_cell_put(cell);
1548 return PTR_ERR(buf);
1549 }
1550 if (len != count) {
1551 kfree(buf);
1552 nvmem_cell_put(cell);
1553 return -EINVAL;
1554 }
1555 memcpy(val, buf, count);
1556 kfree(buf);
1557 nvmem_cell_put(cell);
1558
1559 return 0;
1560}
1561
1562/**
1563 * nvmem_cell_read_u8() - Read a cell value as a u8
1564 *
1565 * @dev: Device that requests the nvmem cell.
1566 * @cell_id: Name of nvmem cell to read.
1567 * @val: pointer to output value.
1568 *
1569 * Return: 0 on success or negative errno.
1570 */
1571int nvmem_cell_read_u8(struct device *dev, const char *cell_id, u8 *val)
1572{
1573 return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val));
1574}
1575EXPORT_SYMBOL_GPL(nvmem_cell_read_u8);
1576
1577/**
1578 * nvmem_cell_read_u16() - Read a cell value as a u16
1579 *
1580 * @dev: Device that requests the nvmem cell.
1581 * @cell_id: Name of nvmem cell to read.
1582 * @val: pointer to output value.
1583 *
1584 * Return: 0 on success or negative errno.
1585 */
1586int nvmem_cell_read_u16(struct device *dev, const char *cell_id, u16 *val)
1587{
1588 return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val));
1589}
1590EXPORT_SYMBOL_GPL(nvmem_cell_read_u16);
1591
1592/**
1593 * nvmem_cell_read_u32() - Read a cell value as a u32
1594 *
1595 * @dev: Device that requests the nvmem cell.
1596 * @cell_id: Name of nvmem cell to read.
1597 * @val: pointer to output value.
1598 *
1599 * Return: 0 on success or negative errno.
1600 */
1601int nvmem_cell_read_u32(struct device *dev, const char *cell_id, u32 *val)
1602{
1603 return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val));
1604}
1605EXPORT_SYMBOL_GPL(nvmem_cell_read_u32);
1606
1607/**
1608 * nvmem_cell_read_u64() - Read a cell value as a u64
1609 *
1610 * @dev: Device that requests the nvmem cell.
1611 * @cell_id: Name of nvmem cell to read.
1612 * @val: pointer to output value.
1613 *
1614 * Return: 0 on success or negative errno.
1615 */
1616int nvmem_cell_read_u64(struct device *dev, const char *cell_id, u64 *val)
1617{
1618 return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val));
1619}
1620EXPORT_SYMBOL_GPL(nvmem_cell_read_u64);
1621
1622static const void *nvmem_cell_read_variable_common(struct device *dev,
1623 const char *cell_id,
1624 size_t max_len, size_t *len)
1625{
1626 struct nvmem_cell *cell;
1627 int nbits;
1628 void *buf;
1629
1630 cell = nvmem_cell_get(dev, cell_id);
1631 if (IS_ERR(cell))
1632 return cell;
1633
1634 nbits = cell->nbits;
1635 buf = nvmem_cell_read(cell, len);
1636 nvmem_cell_put(cell);
1637 if (IS_ERR(buf))
1638 return buf;
1639
1640 /*
1641 * If nbits is set then nvmem_cell_read() can significantly exaggerate
1642 * the length of the real data. Throw away the extra junk.
1643 */
1644 if (nbits)
1645 *len = DIV_ROUND_UP(nbits, 8);
1646
1647 if (*len > max_len) {
1648 kfree(buf);
1649 return ERR_PTR(-ERANGE);
1650 }
1651
1652 return buf;
1653}
1654
1655/**
1656 * nvmem_cell_read_variable_le_u32() - Read up to 32-bits of data as a little endian number.
1657 *
1658 * @dev: Device that requests the nvmem cell.
1659 * @cell_id: Name of nvmem cell to read.
1660 * @val: pointer to output value.
1661 *
1662 * Return: 0 on success or negative errno.
1663 */
1664int nvmem_cell_read_variable_le_u32(struct device *dev, const char *cell_id,
1665 u32 *val)
1666{
1667 size_t len;
1668 const u8 *buf;
1669 int i;
1670
1671 buf = nvmem_cell_read_variable_common(dev, cell_id, sizeof(*val), &len);
1672 if (IS_ERR(buf))
1673 return PTR_ERR(buf);
1674
1675 /* Copy w/ implicit endian conversion */
1676 *val = 0;
1677 for (i = 0; i < len; i++)
1678 *val |= buf[i] << (8 * i);
1679
1680 kfree(buf);
1681
1682 return 0;
1683}
1684EXPORT_SYMBOL_GPL(nvmem_cell_read_variable_le_u32);
1685
1686/**
1687 * nvmem_cell_read_variable_le_u64() - Read up to 64-bits of data as a little endian number.
1688 *
1689 * @dev: Device that requests the nvmem cell.
1690 * @cell_id: Name of nvmem cell to read.
1691 * @val: pointer to output value.
1692 *
1693 * Return: 0 on success or negative errno.
1694 */
1695int nvmem_cell_read_variable_le_u64(struct device *dev, const char *cell_id,
1696 u64 *val)
1697{
1698 size_t len;
1699 const u8 *buf;
1700 int i;
1701
1702 buf = nvmem_cell_read_variable_common(dev, cell_id, sizeof(*val), &len);
1703 if (IS_ERR(buf))
1704 return PTR_ERR(buf);
1705
1706 /* Copy w/ implicit endian conversion */
1707 *val = 0;
1708 for (i = 0; i < len; i++)
1709 *val |= (uint64_t)buf[i] << (8 * i);
1710
1711 kfree(buf);
1712
1713 return 0;
1714}
1715EXPORT_SYMBOL_GPL(nvmem_cell_read_variable_le_u64);
1716
1717/**
1718 * nvmem_device_cell_read() - Read a given nvmem device and cell
1719 *
1720 * @nvmem: nvmem device to read from.
1721 * @info: nvmem cell info to be read.
1722 * @buf: buffer pointer which will be populated on successful read.
1723 *
1724 * Return: length of successful bytes read on success and negative
1725 * error code on error.
1726 */
1727ssize_t nvmem_device_cell_read(struct nvmem_device *nvmem,
1728 struct nvmem_cell_info *info, void *buf)
1729{
1730 struct nvmem_cell cell;
1731 int rc;
1732 ssize_t len;
1733
1734 if (!nvmem)
1735 return -EINVAL;
1736
1737 rc = nvmem_cell_info_to_nvmem_cell_nodup(nvmem, info, &cell);
1738 if (rc)
1739 return rc;
1740
1741 rc = __nvmem_cell_read(nvmem, &cell, buf, &len);
1742 if (rc)
1743 return rc;
1744
1745 return len;
1746}
1747EXPORT_SYMBOL_GPL(nvmem_device_cell_read);
1748
1749/**
1750 * nvmem_device_cell_write() - Write cell to a given nvmem device
1751 *
1752 * @nvmem: nvmem device to be written to.
1753 * @info: nvmem cell info to be written.
1754 * @buf: buffer to be written to cell.
1755 *
1756 * Return: length of bytes written or negative error code on failure.
1757 */
1758int nvmem_device_cell_write(struct nvmem_device *nvmem,
1759 struct nvmem_cell_info *info, void *buf)
1760{
1761 struct nvmem_cell cell;
1762 int rc;
1763
1764 if (!nvmem)
1765 return -EINVAL;
1766
1767 rc = nvmem_cell_info_to_nvmem_cell_nodup(nvmem, info, &cell);
1768 if (rc)
1769 return rc;
1770
1771 return nvmem_cell_write(&cell, buf, cell.bytes);
1772}
1773EXPORT_SYMBOL_GPL(nvmem_device_cell_write);
1774
1775/**
1776 * nvmem_device_read() - Read from a given nvmem device
1777 *
1778 * @nvmem: nvmem device to read from.
1779 * @offset: offset in nvmem device.
1780 * @bytes: number of bytes to read.
1781 * @buf: buffer pointer which will be populated on successful read.
1782 *
1783 * Return: length of successful bytes read on success and negative
1784 * error code on error.
1785 */
1786int nvmem_device_read(struct nvmem_device *nvmem,
1787 unsigned int offset,
1788 size_t bytes, void *buf)
1789{
1790 int rc;
1791
1792 if (!nvmem)
1793 return -EINVAL;
1794
1795 rc = nvmem_reg_read(nvmem, offset, buf, bytes);
1796
1797 if (rc)
1798 return rc;
1799
1800 return bytes;
1801}
1802EXPORT_SYMBOL_GPL(nvmem_device_read);
1803
1804/**
1805 * nvmem_device_write() - Write cell to a given nvmem device
1806 *
1807 * @nvmem: nvmem device to be written to.
1808 * @offset: offset in nvmem device.
1809 * @bytes: number of bytes to write.
1810 * @buf: buffer to be written.
1811 *
1812 * Return: length of bytes written or negative error code on failure.
1813 */
1814int nvmem_device_write(struct nvmem_device *nvmem,
1815 unsigned int offset,
1816 size_t bytes, void *buf)
1817{
1818 int rc;
1819
1820 if (!nvmem)
1821 return -EINVAL;
1822
1823 rc = nvmem_reg_write(nvmem, offset, buf, bytes);
1824
1825 if (rc)
1826 return rc;
1827
1828
1829 return bytes;
1830}
1831EXPORT_SYMBOL_GPL(nvmem_device_write);
1832
1833/**
1834 * nvmem_add_cell_table() - register a table of cell info entries
1835 *
1836 * @table: table of cell info entries
1837 */
1838void nvmem_add_cell_table(struct nvmem_cell_table *table)
1839{
1840 mutex_lock(&nvmem_cell_mutex);
1841 list_add_tail(&table->node, &nvmem_cell_tables);
1842 mutex_unlock(&nvmem_cell_mutex);
1843}
1844EXPORT_SYMBOL_GPL(nvmem_add_cell_table);
1845
1846/**
1847 * nvmem_del_cell_table() - remove a previously registered cell info table
1848 *
1849 * @table: table of cell info entries
1850 */
1851void nvmem_del_cell_table(struct nvmem_cell_table *table)
1852{
1853 mutex_lock(&nvmem_cell_mutex);
1854 list_del(&table->node);
1855 mutex_unlock(&nvmem_cell_mutex);
1856}
1857EXPORT_SYMBOL_GPL(nvmem_del_cell_table);
1858
1859/**
1860 * nvmem_add_cell_lookups() - register a list of cell lookup entries
1861 *
1862 * @entries: array of cell lookup entries
1863 * @nentries: number of cell lookup entries in the array
1864 */
1865void nvmem_add_cell_lookups(struct nvmem_cell_lookup *entries, size_t nentries)
1866{
1867 int i;
1868
1869 mutex_lock(&nvmem_lookup_mutex);
1870 for (i = 0; i < nentries; i++)
1871 list_add_tail(&entries[i].node, &nvmem_lookup_list);
1872 mutex_unlock(&nvmem_lookup_mutex);
1873}
1874EXPORT_SYMBOL_GPL(nvmem_add_cell_lookups);
1875
1876/**
1877 * nvmem_del_cell_lookups() - remove a list of previously added cell lookup
1878 * entries
1879 *
1880 * @entries: array of cell lookup entries
1881 * @nentries: number of cell lookup entries in the array
1882 */
1883void nvmem_del_cell_lookups(struct nvmem_cell_lookup *entries, size_t nentries)
1884{
1885 int i;
1886
1887 mutex_lock(&nvmem_lookup_mutex);
1888 for (i = 0; i < nentries; i++)
1889 list_del(&entries[i].node);
1890 mutex_unlock(&nvmem_lookup_mutex);
1891}
1892EXPORT_SYMBOL_GPL(nvmem_del_cell_lookups);
1893
1894/**
1895 * nvmem_dev_name() - Get the name of a given nvmem device.
1896 *
1897 * @nvmem: nvmem device.
1898 *
1899 * Return: name of the nvmem device.
1900 */
1901const char *nvmem_dev_name(struct nvmem_device *nvmem)
1902{
1903 return dev_name(&nvmem->dev);
1904}
1905EXPORT_SYMBOL_GPL(nvmem_dev_name);
1906
1907static int __init nvmem_init(void)
1908{
1909 return bus_register(&nvmem_bus_type);
1910}
1911
1912static void __exit nvmem_exit(void)
1913{
1914 bus_unregister(&nvmem_bus_type);
1915}
1916
1917subsys_initcall(nvmem_init);
1918module_exit(nvmem_exit);
1919
1920MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org");
1921MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com");
1922MODULE_DESCRIPTION("nvmem Driver Core");
1923MODULE_LICENSE("GPL v2");