1 files changed, 316 insertions, 256 deletions

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 3f8c7718412b..387c88c55259 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -17,32 +17,9 @@
 #include <linux/nvmem-provider.h>
 #include <linux/gpio/consumer.h>
 #include <linux/of.h>
-#include <linux/of_device.h>
 #include <linux/slab.h>
 
-struct nvmem_device {
-	struct module		*owner;
-	struct device		dev;
-	int			stride;
-	int			word_size;
-	int			id;
-	struct kref		refcnt;
-	size_t			size;
-	bool			read_only;
-	bool			root_only;
-	int			flags;
-	enum nvmem_type		type;
-	struct bin_attribute	eeprom;
-	struct device		*base_dev;
-	struct list_head	cells;
-	const struct nvmem_keepout *keepout;
-	unsigned int		nkeepout;
-	nvmem_reg_read_t	reg_read;
-	nvmem_reg_write_t	reg_write;
-	struct gpio_desc	*wp_gpio;
-	struct nvmem_layout	*layout;
-	void *priv;
-};
+#include "internals.h"
 
 #define to_nvmem_device(d) container_of(d, struct nvmem_device, dev)
 
@@ -70,17 +47,11 @@ struct nvmem_cell {
 static DEFINE_MUTEX(nvmem_mutex);
 static DEFINE_IDA(nvmem_ida);
 
-static DEFINE_MUTEX(nvmem_cell_mutex);
-static LIST_HEAD(nvmem_cell_tables);
-
 static DEFINE_MUTEX(nvmem_lookup_mutex);
 static LIST_HEAD(nvmem_lookup_list);
 
 static BLOCKING_NOTIFIER_HEAD(nvmem_notifier);
 
-static DEFINE_SPINLOCK(nvmem_layout_lock);
-static LIST_HEAD(nvmem_layouts);
-
 static int __nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset,
 			    void *val, size_t bytes)
 {
@@ -205,18 +176,41 @@ static ssize_t type_show(struct device *dev,
 {
 	struct nvmem_device *nvmem = to_nvmem_device(dev);
 
-	return sprintf(buf, "%s\n", nvmem_type_str[nvmem->type]);
+	return sysfs_emit(buf, "%s\n", nvmem_type_str[nvmem->type]);
 }
 
 static DEVICE_ATTR_RO(type);
 
+static ssize_t force_ro_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	struct nvmem_device *nvmem = to_nvmem_device(dev);
+
+	return sysfs_emit(buf, "%d\n", nvmem->read_only);
+}
+
+static ssize_t force_ro_store(struct device *dev, struct device_attribute *attr,
+			      const char *buf, size_t count)
+{
+	struct nvmem_device *nvmem = to_nvmem_device(dev);
+	int ret = kstrtobool(buf, &nvmem->read_only);
+
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(force_ro);
+
 static struct attribute *nvmem_attrs[] = {
+	&dev_attr_force_ro.attr,
 	&dev_attr_type.attr,
 	NULL,
 };
 
 static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj,
-				   struct bin_attribute *attr, char *buf,
+				   const struct bin_attribute *attr, char *buf,
 				   loff_t pos, size_t count)
 {
 	struct device *dev;
@@ -229,19 +223,12 @@ static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj,
 		dev = kobj_to_dev(kobj);
 	nvmem = to_nvmem_device(dev);
 
-	/* Stop the user from reading */
-	if (pos >= nvmem->size)
-		return 0;
-
 	if (!IS_ALIGNED(pos, nvmem->stride))
 		return -EINVAL;
 
 	if (count < nvmem->word_size)
 		return -EINVAL;
 
-	if (pos + count > nvmem->size)
-		count = nvmem->size - pos;
-
 	count = round_down(count, nvmem->word_size);
 
 	if (!nvmem->reg_read)
@@ -256,7 +243,7 @@ static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj,
 }
 
 static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj,
-				    struct bin_attribute *attr, char *buf,
+				    const struct bin_attribute *attr, char *buf,
 				    loff_t pos, size_t count)
 {
 	struct device *dev;
@@ -269,22 +256,15 @@ static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj,
 		dev = kobj_to_dev(kobj);
 	nvmem = to_nvmem_device(dev);
 
-	/* Stop the user from writing */
-	if (pos >= nvmem->size)
-		return -EFBIG;
-
 	if (!IS_ALIGNED(pos, nvmem->stride))
 		return -EINVAL;
 
 	if (count < nvmem->word_size)
 		return -EINVAL;
 
-	if (pos + count > nvmem->size)
-		count = nvmem->size - pos;
-
 	count = round_down(count, nvmem->word_size);
 
-	if (!nvmem->reg_write)
+	if (!nvmem->reg_write || nvmem->read_only)
 		return -EPERM;
 
 	rc = nvmem_reg_write(nvmem, pos, buf, count);
@@ -315,18 +295,83 @@ static umode_t nvmem_bin_attr_get_umode(struct nvmem_device *nvmem)
 }
 
 static umode_t nvmem_bin_attr_is_visible(struct kobject *kobj,
-					 struct bin_attribute *attr, int i)
+					 const struct bin_attribute *attr,
+					 int i)
 {
 	struct device *dev = kobj_to_dev(kobj);
 	struct nvmem_device *nvmem = to_nvmem_device(dev);
 
-	attr->size = nvmem->size;
-
 	return nvmem_bin_attr_get_umode(nvmem);
 }
 
+static size_t nvmem_bin_attr_size(struct kobject *kobj,
+				  const struct bin_attribute *attr,
+				  int i)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct nvmem_device *nvmem = to_nvmem_device(dev);
+
+	return nvmem->size;
+}
+
+static umode_t nvmem_attr_is_visible(struct kobject *kobj,
+				     struct attribute *attr, int i)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct nvmem_device *nvmem = to_nvmem_device(dev);
+
+	/*
+	 * If the device has no .reg_write operation, do not allow
+	 * configuration as read-write.
+	 * If the device is set as read-only by configuration, it
+	 * can be forced into read-write mode using the 'force_ro'
+	 * attribute.
+	 */
+	if (attr == &dev_attr_force_ro.attr && !nvmem->reg_write)
+		return 0;	/* Attribute not visible */
+
+	return attr->mode;
+}
+
+static struct nvmem_cell *nvmem_create_cell(struct nvmem_cell_entry *entry,
+					    const char *id, int index);
+
+static ssize_t nvmem_cell_attr_read(struct file *filp, struct kobject *kobj,
+				    const struct bin_attribute *attr, char *buf,
+				    loff_t pos, size_t count)
+{
+	struct nvmem_cell_entry *entry;
+	struct nvmem_cell *cell = NULL;
+	size_t cell_sz, read_len;
+	void *content;
+
+	entry = attr->private;
+	cell = nvmem_create_cell(entry, entry->name, 0);
+	if (IS_ERR(cell))
+		return PTR_ERR(cell);
+
+	if (!cell)
+		return -EINVAL;
+
+	content = nvmem_cell_read(cell, &cell_sz);
+	if (IS_ERR(content)) {
+		read_len = PTR_ERR(content);
+		goto destroy_cell;
+	}
+
+	read_len = min_t(unsigned int, cell_sz - pos, count);
+	memcpy(buf, content + pos, read_len);
+	kfree(content);
+
+destroy_cell:
+	kfree_const(cell->id);
+	kfree(cell);
+
+	return read_len;
+}
+
 /* default read/write permissions */
-static struct bin_attribute bin_attr_rw_nvmem = {
+static const struct bin_attribute bin_attr_rw_nvmem = {
 	.attr	= {
 		.name	= "nvmem",
 		.mode	= 0644,
@@ -335,7 +380,7 @@ static struct bin_attribute bin_attr_rw_nvmem = {
 	.write	= bin_attr_nvmem_write,
 };
 
-static struct bin_attribute *nvmem_bin_attributes[] = {
+static const struct bin_attribute *const nvmem_bin_attributes[] = {
 	&bin_attr_rw_nvmem,
 	NULL,
 };
@@ -344,6 +389,8 @@ static const struct attribute_group nvmem_bin_group = {
 	.bin_attrs	= nvmem_bin_attributes,
 	.attrs		= nvmem_attrs,
 	.is_bin_visible = nvmem_bin_attr_is_visible,
+	.bin_size	= nvmem_bin_attr_size,
+	.is_visible	= nvmem_attr_is_visible,
 };
 
 static const struct attribute_group *nvmem_dev_groups[] = {
@@ -351,7 +398,7 @@ static const struct attribute_group *nvmem_dev_groups[] = {
 	NULL,
 };
 
-static struct bin_attribute bin_attr_nvmem_eeprom_compat = {
+static const struct bin_attribute bin_attr_nvmem_eeprom_compat = {
 	.attr	= {
 		.name	= "eeprom",
 	},
@@ -375,10 +422,9 @@ static int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem,
 	if (!config->base_dev)
 		return -EINVAL;
 
-	if (config->type == NVMEM_TYPE_FRAM)
-		bin_attr_nvmem_eeprom_compat.attr.name = "fram";
-
 	nvmem->eeprom = bin_attr_nvmem_eeprom_compat;
+	if (config->type == NVMEM_TYPE_FRAM)
+		nvmem->eeprom.attr.name = "fram";
 	nvmem->eeprom.attr.mode = nvmem_bin_attr_get_umode(nvmem);
 	nvmem->eeprom.size = nvmem->size;
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
@@ -406,6 +452,71 @@ static void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem,
 		device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);
 }
 
+static int nvmem_populate_sysfs_cells(struct nvmem_device *nvmem)
+{
+	struct attribute_group group = {
+		.name	= "cells",
+	};
+	struct nvmem_cell_entry *entry;
+	const struct bin_attribute **pattrs;
+	struct bin_attribute *attrs;
+	unsigned int ncells = 0, i = 0;
+	int ret = 0;
+
+	mutex_lock(&nvmem_mutex);
+
+	if (list_empty(&nvmem->cells) || nvmem->sysfs_cells_populated)
+		goto unlock_mutex;
+
+	/* Allocate an array of attributes with a sentinel */
+	ncells = list_count_nodes(&nvmem->cells);
+	pattrs = devm_kcalloc(&nvmem->dev, ncells + 1,
+			      sizeof(struct bin_attribute *), GFP_KERNEL);
+	if (!pattrs) {
+		ret = -ENOMEM;
+		goto unlock_mutex;
+	}
+
+	attrs = devm_kcalloc(&nvmem->dev, ncells, sizeof(struct bin_attribute), GFP_KERNEL);
+	if (!attrs) {
+		ret = -ENOMEM;
+		goto unlock_mutex;
+	}
+
+	/* Initialize each attribute to take the name and size of the cell */
+	list_for_each_entry(entry, &nvmem->cells, node) {
+		sysfs_bin_attr_init(&attrs[i]);
+		attrs[i].attr.name = devm_kasprintf(&nvmem->dev, GFP_KERNEL,
+						    "%s@%x,%x", entry->name,
+						    entry->offset,
+						    entry->bit_offset);
+		attrs[i].attr.mode = 0444 & nvmem_bin_attr_get_umode(nvmem);
+		attrs[i].size = entry->bytes;
+		attrs[i].read = &nvmem_cell_attr_read;
+		attrs[i].private = entry;
+		if (!attrs[i].attr.name) {
+			ret = -ENOMEM;
+			goto unlock_mutex;
+		}
+
+		pattrs[i] = &attrs[i];
+		i++;
+	}
+
+	group.bin_attrs = pattrs;
+
+	ret = device_add_group(&nvmem->dev, &group);
+	if (ret)
+		goto unlock_mutex;
+
+	nvmem->sysfs_cells_populated = true;
+
+unlock_mutex:
+	mutex_unlock(&nvmem_mutex);
+
+	return ret;
+}
+
 #else /* CONFIG_NVMEM_SYSFS */
 
 static int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem,
@@ -433,7 +544,7 @@ static const struct device_type nvmem_provider_type = {
 	.release	= nvmem_release,
 };
 
-static struct bus_type nvmem_bus_type = {
+static const struct bus_type nvmem_bus_type = {
 	.name		= "nvmem",
 };
 
@@ -480,9 +591,11 @@ static int nvmem_cell_info_to_nvmem_cell_entry_nodup(struct nvmem_device *nvmem,
 	cell->nbits = info->nbits;
 	cell->np = info->np;
 
-	if (cell->nbits)
+	if (cell->nbits) {
 		cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset,
 					   BITS_PER_BYTE);
+		cell->raw_len = ALIGN(cell->bytes, nvmem->word_size);
+	}
 
 	if (!IS_ALIGNED(cell->offset, nvmem->stride)) {
 		dev_err(&nvmem->dev,
@@ -491,6 +604,18 @@ static int nvmem_cell_info_to_nvmem_cell_entry_nodup(struct nvmem_device *nvmem,
 		return -EINVAL;
 	}
 
+	if (!IS_ALIGNED(cell->raw_len, nvmem->word_size)) {
+		dev_err(&nvmem->dev,
+			"cell %s raw len %zd unaligned to nvmem word size %d\n",
+			cell->name ?: "<unknown>", cell->raw_len,
+			nvmem->word_size);
+
+		if (info->raw_len)
+			return -EINVAL;
+
+		cell->raw_len = ALIGN(cell->raw_len, nvmem->word_size);
+	}
+
 	return 0;
 }
 
@@ -591,41 +716,6 @@ int nvmem_unregister_notifier(struct notifier_block *nb)
 }
 EXPORT_SYMBOL_GPL(nvmem_unregister_notifier);
 
-static int nvmem_add_cells_from_table(struct nvmem_device *nvmem)
-{
-	const struct nvmem_cell_info *info;
-	struct nvmem_cell_table *table;
-	struct nvmem_cell_entry *cell;
-	int rval = 0, i;
-
-	mutex_lock(&nvmem_cell_mutex);
-	list_for_each_entry(table, &nvmem_cell_tables, node) {
-		if (strcmp(nvmem_dev_name(nvmem), table->nvmem_name) == 0) {
-			for (i = 0; i < table->ncells; i++) {
-				info = &table->cells[i];
-
-				cell = kzalloc(sizeof(*cell), GFP_KERNEL);
-				if (!cell) {
-					rval = -ENOMEM;
-					goto out;
-				}
-
-				rval = nvmem_cell_info_to_nvmem_cell_entry(nvmem, info, cell);
-				if (rval) {
-					kfree(cell);
-					goto out;
-				}
-
-				nvmem_cell_entry_add(cell);
-			}
-		}
-	}
-
-out:
-	mutex_unlock(&nvmem_cell_mutex);
-	return rval;
-}
-
 static struct nvmem_cell_entry *
 nvmem_find_cell_entry_by_name(struct nvmem_device *nvmem, const char *cell_id)
 {
@@ -698,7 +788,6 @@ static int nvmem_validate_keepouts(struct nvmem_device *nvmem)
 
 static int nvmem_add_cells_from_dt(struct nvmem_device *nvmem, struct device_node *np)
 {
-	struct nvmem_layout *layout = nvmem->layout;
 	struct device *dev = &nvmem->dev;
 	struct device_node *child;
 	const __be32 *addr;
@@ -724,12 +813,19 @@ static int nvmem_add_cells_from_dt(struct nvmem_device *nvmem, struct device_nod
 		if (addr && len == (2 * sizeof(u32))) {
 			info.bit_offset = be32_to_cpup(addr++);
 			info.nbits = be32_to_cpup(addr);
+			if (info.bit_offset >= BITS_PER_BYTE * info.bytes ||
+			    info.nbits < 1 ||
+			    info.bit_offset + info.nbits > BITS_PER_BYTE * info.bytes) {
+				dev_err(dev, "nvmem: invalid bits on %pOF\n", child);
+				of_node_put(child);
+				return -EINVAL;
+			}
 		}
 
 		info.np = of_node_get(child);
 
-		if (layout && layout->fixup_cell_info)
-			layout->fixup_cell_info(nvmem, layout, &info);
+		if (nvmem->fixup_dt_cell_info)
+			nvmem->fixup_dt_cell_info(nvmem, &info);
 
 		ret = nvmem_add_one_cell(nvmem, &info);
 		kfree(info.name);
@@ -764,107 +860,35 @@ static int nvmem_add_cells_from_fixed_layout(struct nvmem_device *nvmem)
 	return err;
 }
 
-int __nvmem_layout_register(struct nvmem_layout *layout, struct module *owner)
-{
-	layout->owner = owner;
-
-	spin_lock(&nvmem_layout_lock);
-	list_add(&layout->node, &nvmem_layouts);
-	spin_unlock(&nvmem_layout_lock);
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(__nvmem_layout_register);
-
-void nvmem_layout_unregister(struct nvmem_layout *layout)
+int nvmem_layout_register(struct nvmem_layout *layout)
 {
-	spin_lock(&nvmem_layout_lock);
-	list_del(&layout->node);
-	spin_unlock(&nvmem_layout_lock);
-}
-EXPORT_SYMBOL_GPL(nvmem_layout_unregister);
-
-static struct nvmem_layout *nvmem_layout_get(struct nvmem_device *nvmem)
-{
-	struct device_node *layout_np, *np = nvmem->dev.of_node;
-	struct nvmem_layout *l, *layout = ERR_PTR(-EPROBE_DEFER);
-
-	layout_np = of_get_child_by_name(np, "nvmem-layout");
-	if (!layout_np)
-		return NULL;
-
-	/*
-	 * In case the nvmem device was built-in while the layout was built as a
-	 * module, we shall manually request the layout driver loading otherwise
-	 * we'll never have any match.
-	 */
-	of_request_module(layout_np);
-
-	spin_lock(&nvmem_layout_lock);
-
-	list_for_each_entry(l, &nvmem_layouts, node) {
-		if (of_match_node(l->of_match_table, layout_np)) {
-			if (try_module_get(l->owner))
-				layout = l;
-
-			break;
-		}
-	}
-
-	spin_unlock(&nvmem_layout_lock);
-	of_node_put(layout_np);
-
-	return layout;
-}
+	int ret;
 
-static void nvmem_layout_put(struct nvmem_layout *layout)
-{
-	if (layout)
-		module_put(layout->owner);
-}
+	if (!layout->add_cells)
+		return -EINVAL;
 
-static int nvmem_add_cells_from_layout(struct nvmem_device *nvmem)
-{
-	struct nvmem_layout *layout = nvmem->layout;
-	int ret;
+	/* Populate the cells */
+	ret = layout->add_cells(layout);
+	if (ret)
+		return ret;
 
-	if (layout && layout->add_cells) {
-		ret = layout->add_cells(&nvmem->dev, nvmem, layout);
-		if (ret)
-			return ret;
+#ifdef CONFIG_NVMEM_SYSFS
+	ret = nvmem_populate_sysfs_cells(layout->nvmem);
+	if (ret) {
+		nvmem_device_remove_all_cells(layout->nvmem);
+		return ret;
 	}
+#endif
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(nvmem_layout_register);
 
-#if IS_ENABLED(CONFIG_OF)
-/**
- * of_nvmem_layout_get_container() - Get OF node to layout container.
- *
- * @nvmem: nvmem device.
- *
- * Return: a node pointer with refcount incremented or NULL if no
- * container exists. Use of_node_put() on it when done.
- */
-struct device_node *of_nvmem_layout_get_container(struct nvmem_device *nvmem)
-{
-	return of_get_child_by_name(nvmem->dev.of_node, "nvmem-layout");
-}
-EXPORT_SYMBOL_GPL(of_nvmem_layout_get_container);
-#endif
-
-const void *nvmem_layout_get_match_data(struct nvmem_device *nvmem,
-					struct nvmem_layout *layout)
+void nvmem_layout_unregister(struct nvmem_layout *layout)
 {
-	struct device_node __maybe_unused *layout_np;
-	const struct of_device_id *match;
-
-	layout_np = of_nvmem_layout_get_container(nvmem);
-	match = of_match_node(layout->of_match_table, layout_np);
-
-	return match ? match->data : NULL;
+	/* Keep the API even with an empty stub in case we need it later */
 }
-EXPORT_SYMBOL_GPL(nvmem_layout_get_match_data);
+EXPORT_SYMBOL_GPL(nvmem_layout_unregister);
 
 /**
  * nvmem_register() - Register a nvmem device for given nvmem_config.
@@ -916,6 +940,7 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 
 	kref_init(&nvmem->refcnt);
 	INIT_LIST_HEAD(&nvmem->cells);
+	nvmem->fixup_dt_cell_info = config->fixup_dt_cell_info;
 
 	nvmem->owner = config->owner;
 	if (!nvmem->owner && config->dev->driver)
@@ -932,7 +957,7 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 	nvmem->nkeepout = config->nkeepout;
 	if (config->of_node)
 		nvmem->dev.of_node = config->of_node;
-	else if (!config->no_of_node)
+	else
 		nvmem->dev.of_node = config->dev->of_node;
 
 	switch (config->id) {
@@ -971,30 +996,19 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 			goto err_put_device;
 	}
 
-	/*
-	 * If the driver supplied a layout by config->layout, the module
-	 * pointer will be NULL and nvmem_layout_put() will be a noop.
-	 */
-	nvmem->layout = config->layout ?: nvmem_layout_get(nvmem);
-	if (IS_ERR(nvmem->layout)) {
-		rval = PTR_ERR(nvmem->layout);
-		nvmem->layout = NULL;
-
-		if (rval == -EPROBE_DEFER)
-			goto err_teardown_compat;
-	}
-
 	if (config->cells) {
 		rval = nvmem_add_cells(nvmem, config->cells, config->ncells);
 		if (rval)
 			goto err_remove_cells;
 	}
 
-	rval = nvmem_add_cells_from_table(nvmem);
-	if (rval)
-		goto err_remove_cells;
+	if (config->add_legacy_fixed_of_cells) {
+		rval = nvmem_add_cells_from_legacy_of(nvmem);
+		if (rval)
+			goto err_remove_cells;
+	}
 
-	rval = nvmem_add_cells_from_legacy_of(nvmem);
+	rval = nvmem_add_cells_from_fixed_layout(nvmem);
 	if (rval)
 		goto err_remove_cells;
 
@@ -1004,22 +1018,28 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 	if (rval)
 		goto err_remove_cells;
 
-	rval = nvmem_add_cells_from_fixed_layout(nvmem);
+	rval = nvmem_populate_layout(nvmem);
 	if (rval)
-		goto err_remove_cells;
+		goto err_remove_dev;
 
-	rval = nvmem_add_cells_from_layout(nvmem);
+#ifdef CONFIG_NVMEM_SYSFS
+	rval = nvmem_populate_sysfs_cells(nvmem);
 	if (rval)
-		goto err_remove_cells;
+		goto err_destroy_layout;
+#endif
 
 	blocking_notifier_call_chain(&nvmem_notifier, NVMEM_ADD, nvmem);
 
 	return nvmem;
 
+#ifdef CONFIG_NVMEM_SYSFS
+err_destroy_layout:
+	nvmem_destroy_layout(nvmem);
+#endif
+err_remove_dev:
+	device_del(&nvmem->dev);
 err_remove_cells:
 	nvmem_device_remove_all_cells(nvmem);
-	nvmem_layout_put(nvmem->layout);
-err_teardown_compat:
 	if (config->compat)
 		nvmem_sysfs_remove_compat(nvmem, config);
 err_put_device:
@@ -1041,7 +1061,7 @@ static void nvmem_device_release(struct kref *kref)
 		device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);
 
 	nvmem_device_remove_all_cells(nvmem);
-	nvmem_layout_put(nvmem->layout);
+	nvmem_destroy_layout(nvmem);
 	device_unregister(&nvmem->dev);
 }
 
@@ -1214,7 +1234,7 @@ static void devm_nvmem_device_release(struct device *dev, void *res)
 }
 
 /**
- * devm_nvmem_device_put() - put alredy got nvmem device
+ * devm_nvmem_device_put() - put already got nvmem device
  *
  * @dev: Device that uses the nvmem device.
  * @nvmem: pointer to nvmem device allocated by devm_nvmem_cell_get(),
@@ -1232,7 +1252,7 @@ void devm_nvmem_device_put(struct device *dev, struct nvmem_device *nvmem)
 EXPORT_SYMBOL_GPL(devm_nvmem_device_put);
 
 /**
- * nvmem_device_put() - put alredy got nvmem device
+ * nvmem_device_put() - put already got nvmem device
  *
  * @nvmem: pointer to nvmem device that needs to be released.
  */
@@ -1243,13 +1263,13 @@ void nvmem_device_put(struct nvmem_device *nvmem)
 EXPORT_SYMBOL_GPL(nvmem_device_put);
 
 /**
- * devm_nvmem_device_get() - Get nvmem cell of device form a given id
+ * devm_nvmem_device_get() - Get nvmem device of device from a given id
  *
  * @dev: Device that requests the nvmem device.
  * @id: name id for the requested nvmem device.
  *
- * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_cell
- * on success.  The nvmem_cell will be freed by the automatically once the
+ * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device
+ * on success.  The nvmem_device will be freed by the automatically once the
  * device is freed.
  */
 struct nvmem_device *devm_nvmem_device_get(struct device *dev, const char *id)
@@ -1343,6 +1363,12 @@ nvmem_cell_get_from_lookup(struct device *dev, const char *con_id)
 	return cell;
 }
 
+static void nvmem_layout_module_put(struct nvmem_device *nvmem)
+{
+	if (nvmem->layout && nvmem->layout->dev.driver)
+		module_put(nvmem->layout->dev.driver->owner);
+}
+
 #if IS_ENABLED(CONFIG_OF)
 static struct nvmem_cell_entry *
 nvmem_find_cell_entry_by_node(struct nvmem_device *nvmem, struct device_node *np)
@@ -1361,6 +1387,18 @@ nvmem_find_cell_entry_by_node(struct nvmem_device *nvmem, struct device_node *np
 	return cell;
 }
 
+static int nvmem_layout_module_get_optional(struct nvmem_device *nvmem)
+{
+	if (!nvmem->layout)
+		return 0;
+
+	if (!nvmem->layout->dev.driver ||
+	    !try_module_get(nvmem->layout->dev.driver->owner))
+		return -EPROBE_DEFER;
+
+	return 0;
+}
+
 /**
  * of_nvmem_cell_get() - Get a nvmem cell from given device node and cell id
  *
@@ -1423,16 +1461,29 @@ struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, const char *id)
 		return ERR_CAST(nvmem);
 	}
 
+	ret = nvmem_layout_module_get_optional(nvmem);
+	if (ret) {
+		of_node_put(cell_np);
+		__nvmem_device_put(nvmem);
+		return ERR_PTR(ret);
+	}
+
 	cell_entry = nvmem_find_cell_entry_by_node(nvmem, cell_np);
 	of_node_put(cell_np);
 	if (!cell_entry) {
 		__nvmem_device_put(nvmem);
-		return ERR_PTR(-ENOENT);
+		nvmem_layout_module_put(nvmem);
+		if (nvmem->layout)
+			return ERR_PTR(-EPROBE_DEFER);
+		else
+			return ERR_PTR(-ENOENT);
 	}
 
 	cell = nvmem_create_cell(cell_entry, id, cell_index);
-	if (IS_ERR(cell))
+	if (IS_ERR(cell)) {
 		__nvmem_device_put(nvmem);
+		nvmem_layout_module_put(nvmem);
+	}
 
 	return cell;
 }
@@ -1440,7 +1491,7 @@ EXPORT_SYMBOL_GPL(of_nvmem_cell_get);
 #endif
 
 /**
- * nvmem_cell_get() - Get nvmem cell of device form a given cell name
+ * nvmem_cell_get() - Get nvmem cell of device from a given cell name
  *
  * @dev: Device that requests the nvmem cell.
  * @id: nvmem cell name to get (this corresponds with the name from the
@@ -1475,7 +1526,7 @@ static void devm_nvmem_cell_release(struct device *dev, void *res)
 }
 
 /**
- * devm_nvmem_cell_get() - Get nvmem cell of device form a given id
+ * devm_nvmem_cell_get() - Get nvmem cell of device from a given id
  *
  * @dev: Device that requests the nvmem cell.
  * @id: nvmem cell name id to get.
@@ -1546,27 +1597,36 @@ void nvmem_cell_put(struct nvmem_cell *cell)
 
 	kfree(cell);
 	__nvmem_device_put(nvmem);
+	nvmem_layout_module_put(nvmem);
 }
 EXPORT_SYMBOL_GPL(nvmem_cell_put);
 
 static void nvmem_shift_read_buffer_in_place(struct nvmem_cell_entry *cell, void *buf)
 {
 	u8 *p, *b;
-	int i, extra, bit_offset = cell->bit_offset;
+	int i, extra, bytes_offset;
+	int bit_offset = cell->bit_offset;
 
 	p = b = buf;
-	if (bit_offset) {
+
+	bytes_offset = bit_offset / BITS_PER_BYTE;
+	b += bytes_offset;
+	bit_offset %= BITS_PER_BYTE;
+
+	if (bit_offset % BITS_PER_BYTE) {
 		/* First shift */
-		*b++ >>= bit_offset;
+		*p = *b++ >> bit_offset;
 
 		/* setup rest of the bytes if any */
 		for (i = 1; i < cell->bytes; i++) {
 			/* Get bits from next byte and shift them towards msb */
-			*p |= *b << (BITS_PER_BYTE - bit_offset);
+			*p++ |= *b << (BITS_PER_BYTE - bit_offset);
 
-			p = b;
-			*b++ >>= bit_offset;
+			*p = *b++ >> bit_offset;
 		}
+	} else if (p != b) {
+		memmove(p, b, cell->bytes - bytes_offset);
+		p += cell->bytes - 1;
 	} else {
 		/* point to the msb */
 		p += cell->bytes - 1;
@@ -1715,6 +1775,8 @@ static int __nvmem_cell_entry_write(struct nvmem_cell_entry *cell, void *buf, si
 		return -EINVAL;
 
 	if (cell->bit_offset || cell->nbits) {
+		if (len != BITS_TO_BYTES(cell->nbits) && len != cell->bytes)
+			return -EINVAL;
 		buf = nvmem_cell_prepare_write_buffer(cell, buf, len);
 		if (IS_ERR(buf))
 			return PTR_ERR(buf);
@@ -2048,32 +2110,6 @@ int nvmem_device_write(struct nvmem_device *nvmem,
 EXPORT_SYMBOL_GPL(nvmem_device_write);
 
 /**
- * nvmem_add_cell_table() - register a table of cell info entries
- *
- * @table: table of cell info entries
- */
-void nvmem_add_cell_table(struct nvmem_cell_table *table)
-{
-	mutex_lock(&nvmem_cell_mutex);
-	list_add_tail(&table->node, &nvmem_cell_tables);
-	mutex_unlock(&nvmem_cell_mutex);
-}
-EXPORT_SYMBOL_GPL(nvmem_add_cell_table);
-
-/**
- * nvmem_del_cell_table() - remove a previously registered cell info table
- *
- * @table: table of cell info entries
- */
-void nvmem_del_cell_table(struct nvmem_cell_table *table)
-{
-	mutex_lock(&nvmem_cell_mutex);
-	list_del(&table->node);
-	mutex_unlock(&nvmem_cell_mutex);
-}
-EXPORT_SYMBOL_GPL(nvmem_del_cell_table);
-
-/**
  * nvmem_add_cell_lookups() - register a list of cell lookup entries
  *
  * @entries: array of cell lookup entries
@@ -2121,19 +2157,43 @@ const char *nvmem_dev_name(struct nvmem_device *nvmem)
 }
 EXPORT_SYMBOL_GPL(nvmem_dev_name);
 
+/**
+ * nvmem_dev_size() - Get the size of a given nvmem device.
+ *
+ * @nvmem: nvmem device.
+ *
+ * Return: size of the nvmem device.
+ */
+size_t nvmem_dev_size(struct nvmem_device *nvmem)
+{
+	return nvmem->size;
+}
+EXPORT_SYMBOL_GPL(nvmem_dev_size);
+
 static int __init nvmem_init(void)
 {
-	return bus_register(&nvmem_bus_type);
+	int ret;
+
+	ret = bus_register(&nvmem_bus_type);
+	if (ret)
+		return ret;
+
+	ret = nvmem_layout_bus_register();
+	if (ret)
+		bus_unregister(&nvmem_bus_type);
+
+	return ret;
 }
 
 static void __exit nvmem_exit(void)
 {
+	nvmem_layout_bus_unregister();
 	bus_unregister(&nvmem_bus_type);
 }
 
 subsys_initcall(nvmem_init);
 module_exit(nvmem_exit);
 
-MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org");
-MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com");
+MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org>");
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
 MODULE_DESCRIPTION("nvmem Driver Core");