1 // SPDX-License-Identifier: GPL-2.0
3 * nvmem framework core.
5 * Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
6 * Copyright (C) 2013 Maxime Ripard <maxime.ripard@free-electrons.com>
9 #include <linux/device.h>
10 #include <linux/export.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>
20 #include <linux/slab.h>
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;
45 #define to_nvmem_device(d) container_of(d, struct nvmem_device, dev)
47 #define FLAG_COMPAT BIT(0)
55 struct device_node *np;
56 struct nvmem_device *nvmem;
57 struct list_head node;
60 static DEFINE_MUTEX(nvmem_mutex);
61 static DEFINE_IDA(nvmem_ida);
63 static DEFINE_MUTEX(nvmem_cell_mutex);
64 static LIST_HEAD(nvmem_cell_tables);
66 static DEFINE_MUTEX(nvmem_lookup_mutex);
67 static LIST_HEAD(nvmem_lookup_list);
69 static BLOCKING_NOTIFIER_HEAD(nvmem_notifier);
71 static int __nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset,
72 void *val, size_t bytes)
75 return nvmem->reg_read(nvmem->priv, offset, val, bytes);
80 static int __nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset,
81 void *val, size_t bytes)
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);
95 static int nvmem_access_with_keepouts(struct nvmem_device *nvmem,
96 unsigned int offset, void *val,
97 size_t bytes, int write)
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;
107 * Skip all keepouts before the range being accessed.
108 * Keepouts are sorted.
110 while ((keepout < keepoutend) && (keepout->end <= offset))
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;
119 rc = __nvmem_reg_write(nvmem, offset, val, ksize);
121 rc = __nvmem_reg_read(nvmem, offset, val, ksize);
131 * Now we're aligned to the start of this keepout zone. Go
134 kend = min(end, keepout->end);
135 ksize = kend - offset;
137 memset(val, keepout->value, ksize);
145 * If we ran out of keepouts but there's still stuff to do, send it
149 ksize = end - offset;
151 return __nvmem_reg_write(nvmem, offset, val, ksize);
153 return __nvmem_reg_read(nvmem, offset, val, ksize);
159 static int nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset,
160 void *val, size_t bytes)
162 if (!nvmem->nkeepout)
163 return __nvmem_reg_read(nvmem, offset, val, bytes);
165 return nvmem_access_with_keepouts(nvmem, offset, val, bytes, false);
168 static int nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset,
169 void *val, size_t bytes)
171 if (!nvmem->nkeepout)
172 return __nvmem_reg_write(nvmem, offset, val, bytes);
174 return nvmem_access_with_keepouts(nvmem, offset, val, bytes, true);
177 #ifdef CONFIG_NVMEM_SYSFS
178 static 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",
185 #ifdef CONFIG_DEBUG_LOCK_ALLOC
186 static struct lock_class_key eeprom_lock_key;
189 static ssize_t type_show(struct device *dev,
190 struct device_attribute *attr, char *buf)
192 struct nvmem_device *nvmem = to_nvmem_device(dev);
194 return sprintf(buf, "%s\n", nvmem_type_str[nvmem->type]);
197 static DEVICE_ATTR_RO(type);
199 static struct attribute *nvmem_attrs[] = {
204 static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj,
205 struct bin_attribute *attr, char *buf,
206 loff_t pos, size_t count)
209 struct nvmem_device *nvmem;
215 dev = kobj_to_dev(kobj);
216 nvmem = to_nvmem_device(dev);
218 /* Stop the user from reading */
219 if (pos >= nvmem->size)
222 if (!IS_ALIGNED(pos, nvmem->stride))
225 if (count < nvmem->word_size)
228 if (pos + count > nvmem->size)
229 count = nvmem->size - pos;
231 count = round_down(count, nvmem->word_size);
233 if (!nvmem->reg_read)
236 rc = nvmem_reg_read(nvmem, pos, buf, count);
244 static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj,
245 struct bin_attribute *attr, char *buf,
246 loff_t pos, size_t count)
249 struct nvmem_device *nvmem;
255 dev = kobj_to_dev(kobj);
256 nvmem = to_nvmem_device(dev);
258 /* Stop the user from writing */
259 if (pos >= nvmem->size)
262 if (!IS_ALIGNED(pos, nvmem->stride))
265 if (count < nvmem->word_size)
268 if (pos + count > nvmem->size)
269 count = nvmem->size - pos;
271 count = round_down(count, nvmem->word_size);
273 if (!nvmem->reg_write)
276 rc = nvmem_reg_write(nvmem, pos, buf, count);
284 static umode_t nvmem_bin_attr_get_umode(struct nvmem_device *nvmem)
288 if (!nvmem->root_only)
291 if (!nvmem->read_only)
294 if (!nvmem->reg_write)
297 if (!nvmem->reg_read)
303 static umode_t nvmem_bin_attr_is_visible(struct kobject *kobj,
304 struct bin_attribute *attr, int i)
306 struct device *dev = kobj_to_dev(kobj);
307 struct nvmem_device *nvmem = to_nvmem_device(dev);
309 return nvmem_bin_attr_get_umode(nvmem);
312 /* default read/write permissions */
313 static struct bin_attribute bin_attr_rw_nvmem = {
318 .read = bin_attr_nvmem_read,
319 .write = bin_attr_nvmem_write,
322 static struct bin_attribute *nvmem_bin_attributes[] = {
327 static const struct attribute_group nvmem_bin_group = {
328 .bin_attrs = nvmem_bin_attributes,
329 .attrs = nvmem_attrs,
330 .is_bin_visible = nvmem_bin_attr_is_visible,
333 static const struct attribute_group *nvmem_dev_groups[] = {
338 static struct bin_attribute bin_attr_nvmem_eeprom_compat = {
342 .read = bin_attr_nvmem_read,
343 .write = bin_attr_nvmem_write,
347 * nvmem_setup_compat() - Create an additional binary entry in
348 * drivers sys directory, to be backwards compatible with the older
349 * drivers/misc/eeprom drivers.
351 static int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem,
352 const struct nvmem_config *config)
359 if (!config->base_dev)
362 nvmem->eeprom = bin_attr_nvmem_eeprom_compat;
363 nvmem->eeprom.attr.mode = nvmem_bin_attr_get_umode(nvmem);
364 nvmem->eeprom.size = nvmem->size;
365 #ifdef CONFIG_DEBUG_LOCK_ALLOC
366 nvmem->eeprom.attr.key = &eeprom_lock_key;
368 nvmem->eeprom.private = &nvmem->dev;
369 nvmem->base_dev = config->base_dev;
371 rval = device_create_bin_file(nvmem->base_dev, &nvmem->eeprom);
374 "Failed to create eeprom binary file %d\n", rval);
378 nvmem->flags |= FLAG_COMPAT;
383 static void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem,
384 const struct nvmem_config *config)
387 device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);
390 #else /* CONFIG_NVMEM_SYSFS */
392 static int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem,
393 const struct nvmem_config *config)
397 static void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem,
398 const struct nvmem_config *config)
402 #endif /* CONFIG_NVMEM_SYSFS */
404 static void nvmem_release(struct device *dev)
406 struct nvmem_device *nvmem = to_nvmem_device(dev);
408 ida_free(&nvmem_ida, nvmem->id);
409 gpiod_put(nvmem->wp_gpio);
413 static const struct device_type nvmem_provider_type = {
414 .release = nvmem_release,
417 static struct bus_type nvmem_bus_type = {
421 static void nvmem_cell_drop(struct nvmem_cell *cell)
423 blocking_notifier_call_chain(&nvmem_notifier, NVMEM_CELL_REMOVE, cell);
424 mutex_lock(&nvmem_mutex);
425 list_del(&cell->node);
426 mutex_unlock(&nvmem_mutex);
427 of_node_put(cell->np);
428 kfree_const(cell->name);
432 static void nvmem_device_remove_all_cells(const struct nvmem_device *nvmem)
434 struct nvmem_cell *cell, *p;
436 list_for_each_entry_safe(cell, p, &nvmem->cells, node)
437 nvmem_cell_drop(cell);
440 static void nvmem_cell_add(struct nvmem_cell *cell)
442 mutex_lock(&nvmem_mutex);
443 list_add_tail(&cell->node, &cell->nvmem->cells);
444 mutex_unlock(&nvmem_mutex);
445 blocking_notifier_call_chain(&nvmem_notifier, NVMEM_CELL_ADD, cell);
448 static int nvmem_cell_info_to_nvmem_cell_nodup(struct nvmem_device *nvmem,
449 const struct nvmem_cell_info *info,
450 struct nvmem_cell *cell)
453 cell->offset = info->offset;
454 cell->bytes = info->bytes;
455 cell->name = info->name;
457 cell->bit_offset = info->bit_offset;
458 cell->nbits = info->nbits;
461 cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset,
464 if (!IS_ALIGNED(cell->offset, nvmem->stride)) {
466 "cell %s unaligned to nvmem stride %d\n",
467 cell->name ?: "<unknown>", nvmem->stride);
474 static int nvmem_cell_info_to_nvmem_cell(struct nvmem_device *nvmem,
475 const struct nvmem_cell_info *info,
476 struct nvmem_cell *cell)
480 err = nvmem_cell_info_to_nvmem_cell_nodup(nvmem, info, cell);
484 cell->name = kstrdup_const(info->name, GFP_KERNEL);
492 * nvmem_add_cells() - Add cell information to an nvmem device
494 * @nvmem: nvmem device to add cells to.
495 * @info: nvmem cell info to add to the device
496 * @ncells: number of cells in info
498 * Return: 0 or negative error code on failure.
500 static int nvmem_add_cells(struct nvmem_device *nvmem,
501 const struct nvmem_cell_info *info,
504 struct nvmem_cell **cells;
507 cells = kcalloc(ncells, sizeof(*cells), GFP_KERNEL);
511 for (i = 0; i < ncells; i++) {
512 cells[i] = kzalloc(sizeof(**cells), GFP_KERNEL);
518 rval = nvmem_cell_info_to_nvmem_cell(nvmem, &info[i], cells[i]);
524 nvmem_cell_add(cells[i]);
527 /* remove tmp array */
533 nvmem_cell_drop(cells[i]);
541 * nvmem_register_notifier() - Register a notifier block for nvmem events.
543 * @nb: notifier block to be called on nvmem events.
545 * Return: 0 on success, negative error number on failure.
547 int nvmem_register_notifier(struct notifier_block *nb)
549 return blocking_notifier_chain_register(&nvmem_notifier, nb);
551 EXPORT_SYMBOL_GPL(nvmem_register_notifier);
554 * nvmem_unregister_notifier() - Unregister a notifier block for nvmem events.
556 * @nb: notifier block to be unregistered.
558 * Return: 0 on success, negative error number on failure.
560 int nvmem_unregister_notifier(struct notifier_block *nb)
562 return blocking_notifier_chain_unregister(&nvmem_notifier, nb);
564 EXPORT_SYMBOL_GPL(nvmem_unregister_notifier);
566 static int nvmem_add_cells_from_table(struct nvmem_device *nvmem)
568 const struct nvmem_cell_info *info;
569 struct nvmem_cell_table *table;
570 struct nvmem_cell *cell;
573 mutex_lock(&nvmem_cell_mutex);
574 list_for_each_entry(table, &nvmem_cell_tables, node) {
575 if (strcmp(nvmem_dev_name(nvmem), table->nvmem_name) == 0) {
576 for (i = 0; i < table->ncells; i++) {
577 info = &table->cells[i];
579 cell = kzalloc(sizeof(*cell), GFP_KERNEL);
585 rval = nvmem_cell_info_to_nvmem_cell(nvmem,
593 nvmem_cell_add(cell);
599 mutex_unlock(&nvmem_cell_mutex);
603 static struct nvmem_cell *
604 nvmem_find_cell_by_name(struct nvmem_device *nvmem, const char *cell_id)
606 struct nvmem_cell *iter, *cell = NULL;
608 mutex_lock(&nvmem_mutex);
609 list_for_each_entry(iter, &nvmem->cells, node) {
610 if (strcmp(cell_id, iter->name) == 0) {
615 mutex_unlock(&nvmem_mutex);
620 static int nvmem_validate_keepouts(struct nvmem_device *nvmem)
622 unsigned int cur = 0;
623 const struct nvmem_keepout *keepout = nvmem->keepout;
624 const struct nvmem_keepout *keepoutend = keepout + nvmem->nkeepout;
626 while (keepout < keepoutend) {
627 /* Ensure keepouts are sorted and don't overlap. */
628 if (keepout->start < cur) {
630 "Keepout regions aren't sorted or overlap.\n");
635 if (keepout->end < keepout->start) {
637 "Invalid keepout region.\n");
643 * Validate keepouts (and holes between) don't violate
644 * word_size constraints.
646 if ((keepout->end - keepout->start < nvmem->word_size) ||
647 ((keepout->start != cur) &&
648 (keepout->start - cur < nvmem->word_size))) {
651 "Keepout regions violate word_size constraints.\n");
656 /* Validate keepouts don't violate stride (alignment). */
657 if (!IS_ALIGNED(keepout->start, nvmem->stride) ||
658 !IS_ALIGNED(keepout->end, nvmem->stride)) {
661 "Keepout regions violate stride.\n");
673 static int nvmem_add_cells_from_of(struct nvmem_device *nvmem)
675 struct device_node *parent, *child;
676 struct device *dev = &nvmem->dev;
677 struct nvmem_cell *cell;
681 parent = dev->of_node;
683 for_each_child_of_node(parent, child) {
684 addr = of_get_property(child, "reg", &len);
687 if (len < 2 * sizeof(u32)) {
688 dev_err(dev, "nvmem: invalid reg on %pOF\n", child);
692 cell = kzalloc(sizeof(*cell), GFP_KERNEL);
697 cell->np = of_node_get(child);
698 cell->offset = be32_to_cpup(addr++);
699 cell->bytes = be32_to_cpup(addr);
700 cell->name = kasprintf(GFP_KERNEL, "%pOFn", child);
702 addr = of_get_property(child, "bits", &len);
703 if (addr && len == (2 * sizeof(u32))) {
704 cell->bit_offset = be32_to_cpup(addr++);
705 cell->nbits = be32_to_cpup(addr);
709 cell->bytes = DIV_ROUND_UP(
710 cell->nbits + cell->bit_offset,
713 if (!IS_ALIGNED(cell->offset, nvmem->stride)) {
714 dev_err(dev, "cell %s unaligned to nvmem stride %d\n",
715 cell->name, nvmem->stride);
716 /* Cells already added will be freed later. */
717 kfree_const(cell->name);
718 of_node_put(cell->np);
723 nvmem_cell_add(cell);
730 * nvmem_register() - Register a nvmem device for given nvmem_config.
731 * Also creates a binary entry in /sys/bus/nvmem/devices/dev-name/nvmem
733 * @config: nvmem device configuration with which nvmem device is created.
735 * Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device
739 struct nvmem_device *nvmem_register(const struct nvmem_config *config)
741 struct nvmem_device *nvmem;
745 return ERR_PTR(-EINVAL);
747 if (!config->reg_read && !config->reg_write)
748 return ERR_PTR(-EINVAL);
750 nvmem = kzalloc(sizeof(*nvmem), GFP_KERNEL);
752 return ERR_PTR(-ENOMEM);
754 rval = ida_alloc(&nvmem_ida, GFP_KERNEL);
757 return ERR_PTR(rval);
761 nvmem->wp_gpio = config->wp_gpio;
763 nvmem->wp_gpio = gpiod_get_optional(config->dev, "wp",
765 if (IS_ERR(nvmem->wp_gpio)) {
766 ida_free(&nvmem_ida, nvmem->id);
767 rval = PTR_ERR(nvmem->wp_gpio);
769 return ERR_PTR(rval);
772 kref_init(&nvmem->refcnt);
773 INIT_LIST_HEAD(&nvmem->cells);
776 nvmem->owner = config->owner;
777 if (!nvmem->owner && config->dev->driver)
778 nvmem->owner = config->dev->driver->owner;
779 nvmem->stride = config->stride ?: 1;
780 nvmem->word_size = config->word_size ?: 1;
781 nvmem->size = config->size;
782 nvmem->dev.type = &nvmem_provider_type;
783 nvmem->dev.bus = &nvmem_bus_type;
784 nvmem->dev.parent = config->dev;
785 nvmem->root_only = config->root_only;
786 nvmem->priv = config->priv;
787 nvmem->type = config->type;
788 nvmem->reg_read = config->reg_read;
789 nvmem->reg_write = config->reg_write;
790 nvmem->keepout = config->keepout;
791 nvmem->nkeepout = config->nkeepout;
793 nvmem->dev.of_node = config->of_node;
794 else if (!config->no_of_node)
795 nvmem->dev.of_node = config->dev->of_node;
797 switch (config->id) {
798 case NVMEM_DEVID_NONE:
799 dev_set_name(&nvmem->dev, "%s", config->name);
801 case NVMEM_DEVID_AUTO:
802 dev_set_name(&nvmem->dev, "%s%d", config->name, nvmem->id);
805 dev_set_name(&nvmem->dev, "%s%d",
806 config->name ? : "nvmem",
807 config->name ? config->id : nvmem->id);
811 nvmem->read_only = device_property_present(config->dev, "read-only") ||
812 config->read_only || !nvmem->reg_write;
814 #ifdef CONFIG_NVMEM_SYSFS
815 nvmem->dev.groups = nvmem_dev_groups;
818 if (nvmem->nkeepout) {
819 rval = nvmem_validate_keepouts(nvmem);
824 dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name);
826 rval = device_register(&nvmem->dev);
830 if (config->compat) {
831 rval = nvmem_sysfs_setup_compat(nvmem, config);
837 rval = nvmem_add_cells(nvmem, config->cells, config->ncells);
839 goto err_teardown_compat;
842 rval = nvmem_add_cells_from_table(nvmem);
844 goto err_remove_cells;
846 rval = nvmem_add_cells_from_of(nvmem);
848 goto err_remove_cells;
850 blocking_notifier_call_chain(&nvmem_notifier, NVMEM_ADD, nvmem);
855 nvmem_device_remove_all_cells(nvmem);
858 nvmem_sysfs_remove_compat(nvmem, config);
860 device_del(&nvmem->dev);
862 put_device(&nvmem->dev);
864 return ERR_PTR(rval);
866 EXPORT_SYMBOL_GPL(nvmem_register);
868 static void nvmem_device_release(struct kref *kref)
870 struct nvmem_device *nvmem;
872 nvmem = container_of(kref, struct nvmem_device, refcnt);
874 blocking_notifier_call_chain(&nvmem_notifier, NVMEM_REMOVE, nvmem);
876 if (nvmem->flags & FLAG_COMPAT)
877 device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);
879 nvmem_device_remove_all_cells(nvmem);
880 device_unregister(&nvmem->dev);
884 * nvmem_unregister() - Unregister previously registered nvmem device
886 * @nvmem: Pointer to previously registered nvmem device.
888 void nvmem_unregister(struct nvmem_device *nvmem)
890 kref_put(&nvmem->refcnt, nvmem_device_release);
892 EXPORT_SYMBOL_GPL(nvmem_unregister);
894 static void devm_nvmem_release(struct device *dev, void *res)
896 nvmem_unregister(*(struct nvmem_device **)res);
900 * devm_nvmem_register() - Register a managed nvmem device for given
902 * Also creates a binary entry in /sys/bus/nvmem/devices/dev-name/nvmem
904 * @dev: Device that uses the nvmem device.
905 * @config: nvmem device configuration with which nvmem device is created.
907 * Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device
910 struct nvmem_device *devm_nvmem_register(struct device *dev,
911 const struct nvmem_config *config)
913 struct nvmem_device **ptr, *nvmem;
915 ptr = devres_alloc(devm_nvmem_release, sizeof(*ptr), GFP_KERNEL);
917 return ERR_PTR(-ENOMEM);
919 nvmem = nvmem_register(config);
921 if (!IS_ERR(nvmem)) {
923 devres_add(dev, ptr);
930 EXPORT_SYMBOL_GPL(devm_nvmem_register);
932 static int devm_nvmem_match(struct device *dev, void *res, void *data)
934 struct nvmem_device **r = res;
940 * devm_nvmem_unregister() - Unregister previously registered managed nvmem
943 * @dev: Device that uses the nvmem device.
944 * @nvmem: Pointer to previously registered nvmem device.
946 * Return: Will be negative on error or zero on success.
948 int devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem)
950 return devres_release(dev, devm_nvmem_release, devm_nvmem_match, nvmem);
952 EXPORT_SYMBOL(devm_nvmem_unregister);
954 static struct nvmem_device *__nvmem_device_get(void *data,
955 int (*match)(struct device *dev, const void *data))
957 struct nvmem_device *nvmem = NULL;
960 mutex_lock(&nvmem_mutex);
961 dev = bus_find_device(&nvmem_bus_type, NULL, data, match);
963 nvmem = to_nvmem_device(dev);
964 mutex_unlock(&nvmem_mutex);
966 return ERR_PTR(-EPROBE_DEFER);
968 if (!try_module_get(nvmem->owner)) {
970 "could not increase module refcount for cell %s\n",
971 nvmem_dev_name(nvmem));
973 put_device(&nvmem->dev);
974 return ERR_PTR(-EINVAL);
977 kref_get(&nvmem->refcnt);
982 static void __nvmem_device_put(struct nvmem_device *nvmem)
984 put_device(&nvmem->dev);
985 module_put(nvmem->owner);
986 kref_put(&nvmem->refcnt, nvmem_device_release);
989 #if IS_ENABLED(CONFIG_OF)
991 * of_nvmem_device_get() - Get nvmem device from a given id
993 * @np: Device tree node that uses the nvmem device.
994 * @id: nvmem name from nvmem-names property.
996 * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device
999 struct nvmem_device *of_nvmem_device_get(struct device_node *np, const char *id)
1002 struct device_node *nvmem_np;
1003 struct nvmem_device *nvmem;
1007 index = of_property_match_string(np, "nvmem-names", id);
1009 nvmem_np = of_parse_phandle(np, "nvmem", index);
1011 return ERR_PTR(-ENOENT);
1013 nvmem = __nvmem_device_get(nvmem_np, device_match_of_node);
1014 of_node_put(nvmem_np);
1017 EXPORT_SYMBOL_GPL(of_nvmem_device_get);
1021 * nvmem_device_get() - Get nvmem device from a given id
1023 * @dev: Device that uses the nvmem device.
1024 * @dev_name: name of the requested nvmem device.
1026 * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device
1029 struct nvmem_device *nvmem_device_get(struct device *dev, const char *dev_name)
1031 if (dev->of_node) { /* try dt first */
1032 struct nvmem_device *nvmem;
1034 nvmem = of_nvmem_device_get(dev->of_node, dev_name);
1036 if (!IS_ERR(nvmem) || PTR_ERR(nvmem) == -EPROBE_DEFER)
1041 return __nvmem_device_get((void *)dev_name, device_match_name);
1043 EXPORT_SYMBOL_GPL(nvmem_device_get);
1046 * nvmem_device_find() - Find nvmem device with matching function
1048 * @data: Data to pass to match function
1049 * @match: Callback function to check device
1051 * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device
1054 struct nvmem_device *nvmem_device_find(void *data,
1055 int (*match)(struct device *dev, const void *data))
1057 return __nvmem_device_get(data, match);
1059 EXPORT_SYMBOL_GPL(nvmem_device_find);
1061 static int devm_nvmem_device_match(struct device *dev, void *res, void *data)
1063 struct nvmem_device **nvmem = res;
1065 if (WARN_ON(!nvmem || !*nvmem))
1068 return *nvmem == data;
1071 static void devm_nvmem_device_release(struct device *dev, void *res)
1073 nvmem_device_put(*(struct nvmem_device **)res);
1077 * devm_nvmem_device_put() - put alredy got nvmem device
1079 * @dev: Device that uses the nvmem device.
1080 * @nvmem: pointer to nvmem device allocated by devm_nvmem_cell_get(),
1081 * that needs to be released.
1083 void devm_nvmem_device_put(struct device *dev, struct nvmem_device *nvmem)
1087 ret = devres_release(dev, devm_nvmem_device_release,
1088 devm_nvmem_device_match, nvmem);
1092 EXPORT_SYMBOL_GPL(devm_nvmem_device_put);
1095 * nvmem_device_put() - put alredy got nvmem device
1097 * @nvmem: pointer to nvmem device that needs to be released.
1099 void nvmem_device_put(struct nvmem_device *nvmem)
1101 __nvmem_device_put(nvmem);
1103 EXPORT_SYMBOL_GPL(nvmem_device_put);
1106 * devm_nvmem_device_get() - Get nvmem cell of device form a given id
1108 * @dev: Device that requests the nvmem device.
1109 * @id: name id for the requested nvmem device.
1111 * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_cell
1112 * on success. The nvmem_cell will be freed by the automatically once the
1115 struct nvmem_device *devm_nvmem_device_get(struct device *dev, const char *id)
1117 struct nvmem_device **ptr, *nvmem;
1119 ptr = devres_alloc(devm_nvmem_device_release, sizeof(*ptr), GFP_KERNEL);
1121 return ERR_PTR(-ENOMEM);
1123 nvmem = nvmem_device_get(dev, id);
1124 if (!IS_ERR(nvmem)) {
1126 devres_add(dev, ptr);
1133 EXPORT_SYMBOL_GPL(devm_nvmem_device_get);
1135 static struct nvmem_cell *
1136 nvmem_cell_get_from_lookup(struct device *dev, const char *con_id)
1138 struct nvmem_cell *cell = ERR_PTR(-ENOENT);
1139 struct nvmem_cell_lookup *lookup;
1140 struct nvmem_device *nvmem;
1144 return ERR_PTR(-EINVAL);
1146 dev_id = dev_name(dev);
1148 mutex_lock(&nvmem_lookup_mutex);
1150 list_for_each_entry(lookup, &nvmem_lookup_list, node) {
1151 if ((strcmp(lookup->dev_id, dev_id) == 0) &&
1152 (strcmp(lookup->con_id, con_id) == 0)) {
1153 /* This is the right entry. */
1154 nvmem = __nvmem_device_get((void *)lookup->nvmem_name,
1156 if (IS_ERR(nvmem)) {
1157 /* Provider may not be registered yet. */
1158 cell = ERR_CAST(nvmem);
1162 cell = nvmem_find_cell_by_name(nvmem,
1165 __nvmem_device_put(nvmem);
1166 cell = ERR_PTR(-ENOENT);
1172 mutex_unlock(&nvmem_lookup_mutex);
1176 #if IS_ENABLED(CONFIG_OF)
1177 static struct nvmem_cell *
1178 nvmem_find_cell_by_node(struct nvmem_device *nvmem, struct device_node *np)
1180 struct nvmem_cell *iter, *cell = NULL;
1182 mutex_lock(&nvmem_mutex);
1183 list_for_each_entry(iter, &nvmem->cells, node) {
1184 if (np == iter->np) {
1189 mutex_unlock(&nvmem_mutex);
1195 * of_nvmem_cell_get() - Get a nvmem cell from given device node and cell id
1197 * @np: Device tree node that uses the nvmem cell.
1198 * @id: nvmem cell name from nvmem-cell-names property, or NULL
1199 * for the cell at index 0 (the lone cell with no accompanying
1200 * nvmem-cell-names property).
1202 * Return: Will be an ERR_PTR() on error or a valid pointer
1203 * to a struct nvmem_cell. The nvmem_cell will be freed by the
1206 struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, const char *id)
1208 struct device_node *cell_np, *nvmem_np;
1209 struct nvmem_device *nvmem;
1210 struct nvmem_cell *cell;
1213 /* if cell name exists, find index to the name */
1215 index = of_property_match_string(np, "nvmem-cell-names", id);
1217 cell_np = of_parse_phandle(np, "nvmem-cells", index);
1219 return ERR_PTR(-ENOENT);
1221 nvmem_np = of_get_next_parent(cell_np);
1223 return ERR_PTR(-EINVAL);
1225 nvmem = __nvmem_device_get(nvmem_np, device_match_of_node);
1226 of_node_put(nvmem_np);
1228 return ERR_CAST(nvmem);
1230 cell = nvmem_find_cell_by_node(nvmem, cell_np);
1232 __nvmem_device_put(nvmem);
1233 return ERR_PTR(-ENOENT);
1238 EXPORT_SYMBOL_GPL(of_nvmem_cell_get);
1242 * nvmem_cell_get() - Get nvmem cell of device form a given cell name
1244 * @dev: Device that requests the nvmem cell.
1245 * @id: nvmem cell name to get (this corresponds with the name from the
1246 * nvmem-cell-names property for DT systems and with the con_id from
1247 * the lookup entry for non-DT systems).
1249 * Return: Will be an ERR_PTR() on error or a valid pointer
1250 * to a struct nvmem_cell. The nvmem_cell will be freed by the
1253 struct nvmem_cell *nvmem_cell_get(struct device *dev, const char *id)
1255 struct nvmem_cell *cell;
1257 if (dev->of_node) { /* try dt first */
1258 cell = of_nvmem_cell_get(dev->of_node, id);
1259 if (!IS_ERR(cell) || PTR_ERR(cell) == -EPROBE_DEFER)
1263 /* NULL cell id only allowed for device tree; invalid otherwise */
1265 return ERR_PTR(-EINVAL);
1267 return nvmem_cell_get_from_lookup(dev, id);
1269 EXPORT_SYMBOL_GPL(nvmem_cell_get);
1271 static void devm_nvmem_cell_release(struct device *dev, void *res)
1273 nvmem_cell_put(*(struct nvmem_cell **)res);
1277 * devm_nvmem_cell_get() - Get nvmem cell of device form a given id
1279 * @dev: Device that requests the nvmem cell.
1280 * @id: nvmem cell name id to get.
1282 * Return: Will be an ERR_PTR() on error or a valid pointer
1283 * to a struct nvmem_cell. The nvmem_cell will be freed by the
1284 * automatically once the device is freed.
1286 struct nvmem_cell *devm_nvmem_cell_get(struct device *dev, const char *id)
1288 struct nvmem_cell **ptr, *cell;
1290 ptr = devres_alloc(devm_nvmem_cell_release, sizeof(*ptr), GFP_KERNEL);
1292 return ERR_PTR(-ENOMEM);
1294 cell = nvmem_cell_get(dev, id);
1295 if (!IS_ERR(cell)) {
1297 devres_add(dev, ptr);
1304 EXPORT_SYMBOL_GPL(devm_nvmem_cell_get);
1306 static int devm_nvmem_cell_match(struct device *dev, void *res, void *data)
1308 struct nvmem_cell **c = res;
1310 if (WARN_ON(!c || !*c))
1317 * devm_nvmem_cell_put() - Release previously allocated nvmem cell
1318 * from devm_nvmem_cell_get.
1320 * @dev: Device that requests the nvmem cell.
1321 * @cell: Previously allocated nvmem cell by devm_nvmem_cell_get().
1323 void devm_nvmem_cell_put(struct device *dev, struct nvmem_cell *cell)
1327 ret = devres_release(dev, devm_nvmem_cell_release,
1328 devm_nvmem_cell_match, cell);
1332 EXPORT_SYMBOL(devm_nvmem_cell_put);
1335 * nvmem_cell_put() - Release previously allocated nvmem cell.
1337 * @cell: Previously allocated nvmem cell by nvmem_cell_get().
1339 void nvmem_cell_put(struct nvmem_cell *cell)
1341 struct nvmem_device *nvmem = cell->nvmem;
1343 __nvmem_device_put(nvmem);
1345 EXPORT_SYMBOL_GPL(nvmem_cell_put);
1347 static void nvmem_shift_read_buffer_in_place(struct nvmem_cell *cell, void *buf)
1350 int i, extra, bit_offset = cell->bit_offset;
1355 *b++ >>= bit_offset;
1357 /* setup rest of the bytes if any */
1358 for (i = 1; i < cell->bytes; i++) {
1359 /* Get bits from next byte and shift them towards msb */
1360 *p |= *b << (BITS_PER_BYTE - bit_offset);
1363 *b++ >>= bit_offset;
1366 /* point to the msb */
1367 p += cell->bytes - 1;
1370 /* result fits in less bytes */
1371 extra = cell->bytes - DIV_ROUND_UP(cell->nbits, BITS_PER_BYTE);
1372 while (--extra >= 0)
1375 /* clear msb bits if any leftover in the last byte */
1376 *p &= GENMASK((cell->nbits%BITS_PER_BYTE) - 1, 0);
1379 static int __nvmem_cell_read(struct nvmem_device *nvmem,
1380 struct nvmem_cell *cell,
1381 void *buf, size_t *len)
1385 rc = nvmem_reg_read(nvmem, cell->offset, buf, cell->bytes);
1390 /* shift bits in-place */
1391 if (cell->bit_offset || cell->nbits)
1392 nvmem_shift_read_buffer_in_place(cell, buf);
1401 * nvmem_cell_read() - Read a given nvmem cell
1403 * @cell: nvmem cell to be read.
1404 * @len: pointer to length of cell which will be populated on successful read;
1407 * Return: ERR_PTR() on error or a valid pointer to a buffer on success. The
1408 * buffer should be freed by the consumer with a kfree().
1410 void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len)
1412 struct nvmem_device *nvmem = cell->nvmem;
1417 return ERR_PTR(-EINVAL);
1419 buf = kzalloc(cell->bytes, GFP_KERNEL);
1421 return ERR_PTR(-ENOMEM);
1423 rc = __nvmem_cell_read(nvmem, cell, buf, len);
1431 EXPORT_SYMBOL_GPL(nvmem_cell_read);
1433 static void *nvmem_cell_prepare_write_buffer(struct nvmem_cell *cell,
1436 struct nvmem_device *nvmem = cell->nvmem;
1437 int i, rc, nbits, bit_offset = cell->bit_offset;
1438 u8 v, *p, *buf, *b, pbyte, pbits;
1440 nbits = cell->nbits;
1441 buf = kzalloc(cell->bytes, GFP_KERNEL);
1443 return ERR_PTR(-ENOMEM);
1445 memcpy(buf, _buf, len);
1452 /* setup the first byte with lsb bits from nvmem */
1453 rc = nvmem_reg_read(nvmem, cell->offset, &v, 1);
1456 *b++ |= GENMASK(bit_offset - 1, 0) & v;
1458 /* setup rest of the byte if any */
1459 for (i = 1; i < cell->bytes; i++) {
1460 /* Get last byte bits and shift them towards lsb */
1461 pbits = pbyte >> (BITS_PER_BYTE - 1 - bit_offset);
1469 /* if it's not end on byte boundary */
1470 if ((nbits + bit_offset) % BITS_PER_BYTE) {
1471 /* setup the last byte with msb bits from nvmem */
1472 rc = nvmem_reg_read(nvmem,
1473 cell->offset + cell->bytes - 1, &v, 1);
1476 *p |= GENMASK(7, (nbits + bit_offset) % BITS_PER_BYTE) & v;
1487 * nvmem_cell_write() - Write to a given nvmem cell
1489 * @cell: nvmem cell to be written.
1490 * @buf: Buffer to be written.
1491 * @len: length of buffer to be written to nvmem cell.
1493 * Return: length of bytes written or negative on failure.
1495 int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len)
1497 struct nvmem_device *nvmem = cell->nvmem;
1500 if (!nvmem || nvmem->read_only ||
1501 (cell->bit_offset == 0 && len != cell->bytes))
1504 if (cell->bit_offset || cell->nbits) {
1505 buf = nvmem_cell_prepare_write_buffer(cell, buf, len);
1507 return PTR_ERR(buf);
1510 rc = nvmem_reg_write(nvmem, cell->offset, buf, cell->bytes);
1512 /* free the tmp buffer */
1513 if (cell->bit_offset || cell->nbits)
1521 EXPORT_SYMBOL_GPL(nvmem_cell_write);
1523 static int nvmem_cell_read_common(struct device *dev, const char *cell_id,
1524 void *val, size_t count)
1526 struct nvmem_cell *cell;
1530 cell = nvmem_cell_get(dev, cell_id);
1532 return PTR_ERR(cell);
1534 buf = nvmem_cell_read(cell, &len);
1536 nvmem_cell_put(cell);
1537 return PTR_ERR(buf);
1541 nvmem_cell_put(cell);
1544 memcpy(val, buf, count);
1546 nvmem_cell_put(cell);
1552 * nvmem_cell_read_u8() - Read a cell value as a u8
1554 * @dev: Device that requests the nvmem cell.
1555 * @cell_id: Name of nvmem cell to read.
1556 * @val: pointer to output value.
1558 * Return: 0 on success or negative errno.
1560 int nvmem_cell_read_u8(struct device *dev, const char *cell_id, u8 *val)
1562 return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val));
1564 EXPORT_SYMBOL_GPL(nvmem_cell_read_u8);
1567 * nvmem_cell_read_u16() - Read a cell value as a u16
1569 * @dev: Device that requests the nvmem cell.
1570 * @cell_id: Name of nvmem cell to read.
1571 * @val: pointer to output value.
1573 * Return: 0 on success or negative errno.
1575 int nvmem_cell_read_u16(struct device *dev, const char *cell_id, u16 *val)
1577 return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val));
1579 EXPORT_SYMBOL_GPL(nvmem_cell_read_u16);
1582 * nvmem_cell_read_u32() - Read a cell value as a u32
1584 * @dev: Device that requests the nvmem cell.
1585 * @cell_id: Name of nvmem cell to read.
1586 * @val: pointer to output value.
1588 * Return: 0 on success or negative errno.
1590 int nvmem_cell_read_u32(struct device *dev, const char *cell_id, u32 *val)
1592 return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val));
1594 EXPORT_SYMBOL_GPL(nvmem_cell_read_u32);
1597 * nvmem_cell_read_u64() - Read a cell value as a u64
1599 * @dev: Device that requests the nvmem cell.
1600 * @cell_id: Name of nvmem cell to read.
1601 * @val: pointer to output value.
1603 * Return: 0 on success or negative errno.
1605 int nvmem_cell_read_u64(struct device *dev, const char *cell_id, u64 *val)
1607 return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val));
1609 EXPORT_SYMBOL_GPL(nvmem_cell_read_u64);
1611 static void *nvmem_cell_read_variable_common(struct device *dev,
1612 const char *cell_id,
1613 size_t max_len, size_t *len)
1615 struct nvmem_cell *cell;
1619 cell = nvmem_cell_get(dev, cell_id);
1623 nbits = cell->nbits;
1624 buf = nvmem_cell_read(cell, len);
1625 nvmem_cell_put(cell);
1630 * If nbits is set then nvmem_cell_read() can significantly exaggerate
1631 * the length of the real data. Throw away the extra junk.
1634 *len = DIV_ROUND_UP(nbits, 8);
1636 if (*len > max_len) {
1638 return ERR_PTR(-ERANGE);
1645 * nvmem_cell_read_variable_le_u32() - Read up to 32-bits of data as a little endian number.
1647 * @dev: Device that requests the nvmem cell.
1648 * @cell_id: Name of nvmem cell to read.
1649 * @val: pointer to output value.
1651 * Return: 0 on success or negative errno.
1653 int nvmem_cell_read_variable_le_u32(struct device *dev, const char *cell_id,
1660 buf = nvmem_cell_read_variable_common(dev, cell_id, sizeof(*val), &len);
1662 return PTR_ERR(buf);
1664 /* Copy w/ implicit endian conversion */
1666 for (i = 0; i < len; i++)
1667 *val |= buf[i] << (8 * i);
1673 EXPORT_SYMBOL_GPL(nvmem_cell_read_variable_le_u32);
1676 * nvmem_cell_read_variable_le_u64() - Read up to 64-bits of data as a little endian number.
1678 * @dev: Device that requests the nvmem cell.
1679 * @cell_id: Name of nvmem cell to read.
1680 * @val: pointer to output value.
1682 * Return: 0 on success or negative errno.
1684 int nvmem_cell_read_variable_le_u64(struct device *dev, const char *cell_id,
1691 buf = nvmem_cell_read_variable_common(dev, cell_id, sizeof(*val), &len);
1693 return PTR_ERR(buf);
1695 /* Copy w/ implicit endian conversion */
1697 for (i = 0; i < len; i++)
1698 *val |= (uint64_t)buf[i] << (8 * i);
1704 EXPORT_SYMBOL_GPL(nvmem_cell_read_variable_le_u64);
1707 * nvmem_device_cell_read() - Read a given nvmem device and cell
1709 * @nvmem: nvmem device to read from.
1710 * @info: nvmem cell info to be read.
1711 * @buf: buffer pointer which will be populated on successful read.
1713 * Return: length of successful bytes read on success and negative
1714 * error code on error.
1716 ssize_t nvmem_device_cell_read(struct nvmem_device *nvmem,
1717 struct nvmem_cell_info *info, void *buf)
1719 struct nvmem_cell cell;
1726 rc = nvmem_cell_info_to_nvmem_cell_nodup(nvmem, info, &cell);
1730 rc = __nvmem_cell_read(nvmem, &cell, buf, &len);
1736 EXPORT_SYMBOL_GPL(nvmem_device_cell_read);
1739 * nvmem_device_cell_write() - Write cell to a given nvmem device
1741 * @nvmem: nvmem device to be written to.
1742 * @info: nvmem cell info to be written.
1743 * @buf: buffer to be written to cell.
1745 * Return: length of bytes written or negative error code on failure.
1747 int nvmem_device_cell_write(struct nvmem_device *nvmem,
1748 struct nvmem_cell_info *info, void *buf)
1750 struct nvmem_cell cell;
1756 rc = nvmem_cell_info_to_nvmem_cell_nodup(nvmem, info, &cell);
1760 return nvmem_cell_write(&cell, buf, cell.bytes);
1762 EXPORT_SYMBOL_GPL(nvmem_device_cell_write);
1765 * nvmem_device_read() - Read from a given nvmem device
1767 * @nvmem: nvmem device to read from.
1768 * @offset: offset in nvmem device.
1769 * @bytes: number of bytes to read.
1770 * @buf: buffer pointer which will be populated on successful read.
1772 * Return: length of successful bytes read on success and negative
1773 * error code on error.
1775 int nvmem_device_read(struct nvmem_device *nvmem,
1776 unsigned int offset,
1777 size_t bytes, void *buf)
1784 rc = nvmem_reg_read(nvmem, offset, buf, bytes);
1791 EXPORT_SYMBOL_GPL(nvmem_device_read);
1794 * nvmem_device_write() - Write cell to a given nvmem device
1796 * @nvmem: nvmem device to be written to.
1797 * @offset: offset in nvmem device.
1798 * @bytes: number of bytes to write.
1799 * @buf: buffer to be written.
1801 * Return: length of bytes written or negative error code on failure.
1803 int nvmem_device_write(struct nvmem_device *nvmem,
1804 unsigned int offset,
1805 size_t bytes, void *buf)
1812 rc = nvmem_reg_write(nvmem, offset, buf, bytes);
1820 EXPORT_SYMBOL_GPL(nvmem_device_write);
1823 * nvmem_add_cell_table() - register a table of cell info entries
1825 * @table: table of cell info entries
1827 void nvmem_add_cell_table(struct nvmem_cell_table *table)
1829 mutex_lock(&nvmem_cell_mutex);
1830 list_add_tail(&table->node, &nvmem_cell_tables);
1831 mutex_unlock(&nvmem_cell_mutex);
1833 EXPORT_SYMBOL_GPL(nvmem_add_cell_table);
1836 * nvmem_del_cell_table() - remove a previously registered cell info table
1838 * @table: table of cell info entries
1840 void nvmem_del_cell_table(struct nvmem_cell_table *table)
1842 mutex_lock(&nvmem_cell_mutex);
1843 list_del(&table->node);
1844 mutex_unlock(&nvmem_cell_mutex);
1846 EXPORT_SYMBOL_GPL(nvmem_del_cell_table);
1849 * nvmem_add_cell_lookups() - register a list of cell lookup entries
1851 * @entries: array of cell lookup entries
1852 * @nentries: number of cell lookup entries in the array
1854 void nvmem_add_cell_lookups(struct nvmem_cell_lookup *entries, size_t nentries)
1858 mutex_lock(&nvmem_lookup_mutex);
1859 for (i = 0; i < nentries; i++)
1860 list_add_tail(&entries[i].node, &nvmem_lookup_list);
1861 mutex_unlock(&nvmem_lookup_mutex);
1863 EXPORT_SYMBOL_GPL(nvmem_add_cell_lookups);
1866 * nvmem_del_cell_lookups() - remove a list of previously added cell lookup
1869 * @entries: array of cell lookup entries
1870 * @nentries: number of cell lookup entries in the array
1872 void nvmem_del_cell_lookups(struct nvmem_cell_lookup *entries, size_t nentries)
1876 mutex_lock(&nvmem_lookup_mutex);
1877 for (i = 0; i < nentries; i++)
1878 list_del(&entries[i].node);
1879 mutex_unlock(&nvmem_lookup_mutex);
1881 EXPORT_SYMBOL_GPL(nvmem_del_cell_lookups);
1884 * nvmem_dev_name() - Get the name of a given nvmem device.
1886 * @nvmem: nvmem device.
1888 * Return: name of the nvmem device.
1890 const char *nvmem_dev_name(struct nvmem_device *nvmem)
1892 return dev_name(&nvmem->dev);
1894 EXPORT_SYMBOL_GPL(nvmem_dev_name);
1896 static int __init nvmem_init(void)
1898 return bus_register(&nvmem_bus_type);
1901 static void __exit nvmem_exit(void)
1903 bus_unregister(&nvmem_bus_type);
1906 subsys_initcall(nvmem_init);
1907 module_exit(nvmem_exit);
1909 MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org");
1910 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com");
1911 MODULE_DESCRIPTION("nvmem Driver Core");
1912 MODULE_LICENSE("GPL v2");