1 files changed, 502 insertions, 282 deletions

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 23a38dcf0fc4..387c88c55259 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -19,29 +19,7 @@
 #include <linux/of.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;
-	nvmem_cell_post_process_t cell_post_process;
-	struct gpio_desc	*wp_gpio;
-	void *priv;
-};
+#include "internals.h"
 
 #define to_nvmem_device(d) container_of(d, struct nvmem_device, dev)
 
@@ -49,9 +27,12 @@ struct nvmem_device {
 struct nvmem_cell_entry {
 	const char		*name;
 	int			offset;
+	size_t			raw_len;
 	int			bytes;
 	int			bit_offset;
 	int			nbits;
+	nvmem_cell_post_process_t read_post_process;
+	void			*priv;
 	struct device_node	*np;
 	struct nvmem_device	*nvmem;
 	struct list_head	node;
@@ -60,14 +41,12 @@ struct nvmem_cell_entry {
 struct nvmem_cell {
 	struct nvmem_cell_entry *entry;
 	const char		*id;
+	int			index;
 };
 
 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);
 
@@ -197,18 +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;
@@ -221,19 +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)
@@ -248,7 +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;
@@ -261,22 +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);
@@ -307,18 +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,
@@ -327,7 +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,
 };
@@ -336,6 +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[] = {
@@ -343,7 +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",
 	},
@@ -367,10 +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
@@ -398,6 +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,
@@ -425,7 +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",
 };
 
@@ -462,15 +581,21 @@ static int nvmem_cell_info_to_nvmem_cell_entry_nodup(struct nvmem_device *nvmem,
 {
 	cell->nvmem = nvmem;
 	cell->offset = info->offset;
+	cell->raw_len = info->raw_len ?: info->bytes;
 	cell->bytes = info->bytes;
 	cell->name = info->name;
+	cell->read_post_process = info->read_post_process;
+	cell->priv = info->priv;
 
 	cell->bit_offset = info->bit_offset;
 	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,
@@ -479,6 +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;
 }
 
@@ -500,6 +637,36 @@ static int nvmem_cell_info_to_nvmem_cell_entry(struct nvmem_device *nvmem,
 }
 
 /**
+ * nvmem_add_one_cell() - Add one cell information to an nvmem device
+ *
+ * @nvmem: nvmem device to add cells to.
+ * @info: nvmem cell info to add to the device
+ *
+ * Return: 0 or negative error code on failure.
+ */
+int nvmem_add_one_cell(struct nvmem_device *nvmem,
+		       const struct nvmem_cell_info *info)
+{
+	struct nvmem_cell_entry *cell;
+	int rval;
+
+	cell = kzalloc(sizeof(*cell), GFP_KERNEL);
+	if (!cell)
+		return -ENOMEM;
+
+	rval = nvmem_cell_info_to_nvmem_cell_entry(nvmem, info, cell);
+	if (rval) {
+		kfree(cell);
+		return rval;
+	}
+
+	nvmem_cell_entry_add(cell);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nvmem_add_one_cell);
+
+/**
  * nvmem_add_cells() - Add cell information to an nvmem device
  *
  * @nvmem: nvmem device to add cells to.
@@ -512,40 +679,15 @@ static int nvmem_add_cells(struct nvmem_device *nvmem,
 		    const struct nvmem_cell_info *info,
 		    int ncells)
 {
-	struct nvmem_cell_entry **cells;
 	int i, rval;
 
-	cells = kcalloc(ncells, sizeof(*cells), GFP_KERNEL);
-	if (!cells)
-		return -ENOMEM;
-
 	for (i = 0; i < ncells; i++) {
-		cells[i] = kzalloc(sizeof(**cells), GFP_KERNEL);
-		if (!cells[i]) {
-			rval = -ENOMEM;
-			goto err;
-		}
-
-		rval = nvmem_cell_info_to_nvmem_cell_entry(nvmem, &info[i], cells[i]);
-		if (rval) {
-			kfree(cells[i]);
-			goto err;
-		}
-
-		nvmem_cell_entry_add(cells[i]);
+		rval = nvmem_add_one_cell(nvmem, &info[i]);
+		if (rval)
+			return rval;
 	}
 
-	/* remove tmp array */
-	kfree(cells);
-
 	return 0;
-err:
-	while (i--)
-		nvmem_cell_entry_drop(cells[i]);
-
-	kfree(cells);
-
-	return rval;
 }
 
 /**
@@ -574,41 +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)
 {
@@ -679,17 +786,16 @@ static int nvmem_validate_keepouts(struct nvmem_device *nvmem)
 	return 0;
 }
 
-static int nvmem_add_cells_from_of(struct nvmem_device *nvmem)
+static int nvmem_add_cells_from_dt(struct nvmem_device *nvmem, struct device_node *np)
 {
-	struct device_node *parent, *child;
 	struct device *dev = &nvmem->dev;
-	struct nvmem_cell_entry *cell;
+	struct device_node *child;
 	const __be32 *addr;
-	int len;
+	int len, ret;
 
-	parent = dev->of_node;
+	for_each_child_of_node(np, child) {
+		struct nvmem_cell_info info = {0};
 
-	for_each_child_of_node(parent, child) {
 		addr = of_get_property(child, "reg", &len);
 		if (!addr)
 			continue;
@@ -699,44 +805,90 @@ static int nvmem_add_cells_from_of(struct nvmem_device *nvmem)
 			return -EINVAL;
 		}
 
-		cell = kzalloc(sizeof(*cell), GFP_KERNEL);
-		if (!cell) {
-			of_node_put(child);
-			return -ENOMEM;
-		}
-
-		cell->nvmem = nvmem;
-		cell->offset = be32_to_cpup(addr++);
-		cell->bytes = be32_to_cpup(addr);
-		cell->name = kasprintf(GFP_KERNEL, "%pOFn", child);
+		info.offset = be32_to_cpup(addr++);
+		info.bytes = be32_to_cpup(addr);
+		info.name = kasprintf(GFP_KERNEL, "%pOFn", child);
 
 		addr = of_get_property(child, "bits", &len);
 		if (addr && len == (2 * sizeof(u32))) {
-			cell->bit_offset = be32_to_cpup(addr++);
-			cell->nbits = be32_to_cpup(addr);
+			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;
+			}
 		}
 
-		if (cell->nbits)
-			cell->bytes = DIV_ROUND_UP(
-					cell->nbits + cell->bit_offset,
-					BITS_PER_BYTE);
+		info.np = of_node_get(child);
 
-		if (!IS_ALIGNED(cell->offset, nvmem->stride)) {
-			dev_err(dev, "cell %s unaligned to nvmem stride %d\n",
-				cell->name, nvmem->stride);
-			/* Cells already added will be freed later. */
-			kfree_const(cell->name);
-			kfree(cell);
+		if (nvmem->fixup_dt_cell_info)
+			nvmem->fixup_dt_cell_info(nvmem, &info);
+
+		ret = nvmem_add_one_cell(nvmem, &info);
+		kfree(info.name);
+		if (ret) {
 			of_node_put(child);
-			return -EINVAL;
+			return ret;
 		}
+	}
+
+	return 0;
+}
+
+static int nvmem_add_cells_from_legacy_of(struct nvmem_device *nvmem)
+{
+	return nvmem_add_cells_from_dt(nvmem, nvmem->dev.of_node);
+}
+
+static int nvmem_add_cells_from_fixed_layout(struct nvmem_device *nvmem)
+{
+	struct device_node *layout_np;
+	int err = 0;
+
+	layout_np = of_nvmem_layout_get_container(nvmem);
+	if (!layout_np)
+		return 0;
 
-		cell->np = of_node_get(child);
-		nvmem_cell_entry_add(cell);
+	if (of_device_is_compatible(layout_np, "fixed-layout"))
+		err = nvmem_add_cells_from_dt(nvmem, layout_np);
+
+	of_node_put(layout_np);
+
+	return err;
+}
+
+int nvmem_layout_register(struct nvmem_layout *layout)
+{
+	int ret;
+
+	if (!layout->add_cells)
+		return -EINVAL;
+
+	/* Populate the cells */
+	ret = layout->add_cells(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);
+
+void nvmem_layout_unregister(struct nvmem_layout *layout)
+{
+	/* Keep the API even with an empty stub in case we need it later */
+}
+EXPORT_SYMBOL_GPL(nvmem_layout_unregister);
 
 /**
  * nvmem_register() - Register a nvmem device for given nvmem_config.
@@ -763,64 +915,68 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 	if (!nvmem)
 		return ERR_PTR(-ENOMEM);
 
-	rval  = ida_alloc(&nvmem_ida, GFP_KERNEL);
+	rval = ida_alloc(&nvmem_ida, GFP_KERNEL);
 	if (rval < 0) {
 		kfree(nvmem);
 		return ERR_PTR(rval);
 	}
 
-	if (config->wp_gpio)
-		nvmem->wp_gpio = config->wp_gpio;
-	else
+	nvmem->id = rval;
+
+	nvmem->dev.type = &nvmem_provider_type;
+	nvmem->dev.bus = &nvmem_bus_type;
+	nvmem->dev.parent = config->dev;
+
+	device_initialize(&nvmem->dev);
+
+	if (!config->ignore_wp)
 		nvmem->wp_gpio = gpiod_get_optional(config->dev, "wp",
 						    GPIOD_OUT_HIGH);
 	if (IS_ERR(nvmem->wp_gpio)) {
-		ida_free(&nvmem_ida, nvmem->id);
 		rval = PTR_ERR(nvmem->wp_gpio);
-		kfree(nvmem);
-		return ERR_PTR(rval);
+		nvmem->wp_gpio = NULL;
+		goto err_put_device;
 	}
 
 	kref_init(&nvmem->refcnt);
 	INIT_LIST_HEAD(&nvmem->cells);
+	nvmem->fixup_dt_cell_info = config->fixup_dt_cell_info;
 
-	nvmem->id = rval;
 	nvmem->owner = config->owner;
 	if (!nvmem->owner && config->dev->driver)
 		nvmem->owner = config->dev->driver->owner;
 	nvmem->stride = config->stride ?: 1;
 	nvmem->word_size = config->word_size ?: 1;
 	nvmem->size = config->size;
-	nvmem->dev.type = &nvmem_provider_type;
-	nvmem->dev.bus = &nvmem_bus_type;
-	nvmem->dev.parent = config->dev;
 	nvmem->root_only = config->root_only;
 	nvmem->priv = config->priv;
 	nvmem->type = config->type;
 	nvmem->reg_read = config->reg_read;
 	nvmem->reg_write = config->reg_write;
-	nvmem->cell_post_process = config->cell_post_process;
 	nvmem->keepout = config->keepout;
 	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) {
 	case NVMEM_DEVID_NONE:
-		dev_set_name(&nvmem->dev, "%s", config->name);
+		rval = dev_set_name(&nvmem->dev, "%s", config->name);
 		break;
 	case NVMEM_DEVID_AUTO:
-		dev_set_name(&nvmem->dev, "%s%d", config->name, nvmem->id);
+		rval = dev_set_name(&nvmem->dev, "%s%d", config->name, nvmem->id);
 		break;
 	default:
-		dev_set_name(&nvmem->dev, "%s%d",
+		rval = dev_set_name(&nvmem->dev, "%s%d",
 			     config->name ? : "nvmem",
 			     config->name ? config->id : nvmem->id);
 		break;
 	}
 
+	if (rval)
+		goto err_put_device;
+
 	nvmem->read_only = device_property_present(config->dev, "read-only") ||
 			   config->read_only || !nvmem->reg_write;
 
@@ -830,50 +986,62 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 
 	if (nvmem->nkeepout) {
 		rval = nvmem_validate_keepouts(nvmem);
-		if (rval) {
-			ida_free(&nvmem_ida, nvmem->id);
-			kfree(nvmem);
-			return ERR_PTR(rval);
-		}
+		if (rval)
+			goto err_put_device;
 	}
 
-	dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name);
-
-	rval = device_register(&nvmem->dev);
-	if (rval)
-		goto err_put_device;
-
 	if (config->compat) {
 		rval = nvmem_sysfs_setup_compat(nvmem, config);
 		if (rval)
-			goto err_device_del;
+			goto err_put_device;
 	}
 
 	if (config->cells) {
 		rval = nvmem_add_cells(nvmem, config->cells, config->ncells);
 		if (rval)
-			goto err_teardown_compat;
+			goto err_remove_cells;
 	}
 
-	rval = nvmem_add_cells_from_table(nvmem);
+	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_fixed_layout(nvmem);
 	if (rval)
 		goto err_remove_cells;
 
-	rval = nvmem_add_cells_from_of(nvmem);
+	dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name);
+
+	rval = device_add(&nvmem->dev);
 	if (rval)
 		goto err_remove_cells;
 
+	rval = nvmem_populate_layout(nvmem);
+	if (rval)
+		goto err_remove_dev;
+
+#ifdef CONFIG_NVMEM_SYSFS
+	rval = nvmem_populate_sysfs_cells(nvmem);
+	if (rval)
+		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);
-err_teardown_compat:
 	if (config->compat)
 		nvmem_sysfs_remove_compat(nvmem, config);
-err_device_del:
-	device_del(&nvmem->dev);
 err_put_device:
 	put_device(&nvmem->dev);
 
@@ -893,6 +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_destroy_layout(nvmem);
 	device_unregister(&nvmem->dev);
 }
 
@@ -903,13 +1072,14 @@ static void nvmem_device_release(struct kref *kref)
  */
 void nvmem_unregister(struct nvmem_device *nvmem)
 {
-	kref_put(&nvmem->refcnt, nvmem_device_release);
+	if (nvmem)
+		kref_put(&nvmem->refcnt, nvmem_device_release);
 }
 EXPORT_SYMBOL_GPL(nvmem_unregister);
 
-static void devm_nvmem_release(struct device *dev, void *res)
+static void devm_nvmem_unregister(void *nvmem)
 {
-	nvmem_unregister(*(struct nvmem_device **)res);
+	nvmem_unregister(nvmem);
 }
 
 /**
@@ -926,47 +1096,21 @@ static void devm_nvmem_release(struct device *dev, void *res)
 struct nvmem_device *devm_nvmem_register(struct device *dev,
 					 const struct nvmem_config *config)
 {
-	struct nvmem_device **ptr, *nvmem;
-
-	ptr = devres_alloc(devm_nvmem_release, sizeof(*ptr), GFP_KERNEL);
-	if (!ptr)
-		return ERR_PTR(-ENOMEM);
+	struct nvmem_device *nvmem;
+	int ret;
 
 	nvmem = nvmem_register(config);
+	if (IS_ERR(nvmem))
+		return nvmem;
 
-	if (!IS_ERR(nvmem)) {
-		*ptr = nvmem;
-		devres_add(dev, ptr);
-	} else {
-		devres_free(ptr);
-	}
+	ret = devm_add_action_or_reset(dev, devm_nvmem_unregister, nvmem);
+	if (ret)
+		return ERR_PTR(ret);
 
 	return nvmem;
 }
 EXPORT_SYMBOL_GPL(devm_nvmem_register);
 
-static int devm_nvmem_match(struct device *dev, void *res, void *data)
-{
-	struct nvmem_device **r = res;
-
-	return *r == data;
-}
-
-/**
- * devm_nvmem_unregister() - Unregister previously registered managed nvmem
- * device.
- *
- * @dev: Device that uses the nvmem device.
- * @nvmem: Pointer to previously registered nvmem device.
- *
- * Return: Will be negative on error or zero on success.
- */
-int devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem)
-{
-	return devres_release(dev, devm_nvmem_release, devm_nvmem_match, nvmem);
-}
-EXPORT_SYMBOL(devm_nvmem_unregister);
-
 static struct nvmem_device *__nvmem_device_get(void *data,
 			int (*match)(struct device *dev, const void *data))
 {
@@ -1090,7 +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(),
@@ -1108,7 +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.
  */
@@ -1119,13 +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)
@@ -1148,7 +1292,8 @@ struct nvmem_device *devm_nvmem_device_get(struct device *dev, const char *id)
 }
 EXPORT_SYMBOL_GPL(devm_nvmem_device_get);
 
-static struct nvmem_cell *nvmem_create_cell(struct nvmem_cell_entry *entry, const char *id)
+static struct nvmem_cell *nvmem_create_cell(struct nvmem_cell_entry *entry,
+					    const char *id, int index)
 {
 	struct nvmem_cell *cell;
 	const char *name = NULL;
@@ -1167,6 +1312,7 @@ static struct nvmem_cell *nvmem_create_cell(struct nvmem_cell_entry *entry, cons
 
 	cell->id = name;
 	cell->entry = entry;
+	cell->index = index;
 
 	return cell;
 }
@@ -1205,7 +1351,7 @@ nvmem_cell_get_from_lookup(struct device *dev, const char *con_id)
 				__nvmem_device_put(nvmem);
 				cell = ERR_PTR(-ENOENT);
 			} else {
-				cell = nvmem_create_cell(cell_entry, con_id);
+				cell = nvmem_create_cell(cell_entry, con_id, 0);
 				if (IS_ERR(cell))
 					__nvmem_device_put(nvmem);
 			}
@@ -1217,6 +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)
@@ -1235,6 +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
  *
@@ -1253,34 +1417,73 @@ struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, const char *id)
 	struct nvmem_device *nvmem;
 	struct nvmem_cell_entry *cell_entry;
 	struct nvmem_cell *cell;
+	struct of_phandle_args cell_spec;
 	int index = 0;
+	int cell_index = 0;
+	int ret;
 
 	/* if cell name exists, find index to the name */
 	if (id)
 		index = of_property_match_string(np, "nvmem-cell-names", id);
 
-	cell_np = of_parse_phandle(np, "nvmem-cells", index);
-	if (!cell_np)
+	ret = of_parse_phandle_with_optional_args(np, "nvmem-cells",
+						  "#nvmem-cell-cells",
+						  index, &cell_spec);
+	if (ret)
 		return ERR_PTR(-ENOENT);
 
-	nvmem_np = of_get_next_parent(cell_np);
-	if (!nvmem_np)
+	if (cell_spec.args_count > 1)
+		return ERR_PTR(-EINVAL);
+
+	cell_np = cell_spec.np;
+	if (cell_spec.args_count)
+		cell_index = cell_spec.args[0];
+
+	nvmem_np = of_get_parent(cell_np);
+	if (!nvmem_np) {
+		of_node_put(cell_np);
 		return ERR_PTR(-EINVAL);
+	}
+
+	/* nvmem layouts produce cells within the nvmem-layout container */
+	if (of_node_name_eq(nvmem_np, "nvmem-layout")) {
+		nvmem_np = of_get_next_parent(nvmem_np);
+		if (!nvmem_np) {
+			of_node_put(cell_np);
+			return ERR_PTR(-EINVAL);
+		}
+	}
 
 	nvmem = __nvmem_device_get(nvmem_np, device_match_of_node);
 	of_node_put(nvmem_np);
-	if (IS_ERR(nvmem))
+	if (IS_ERR(nvmem)) {
+		of_node_put(cell_np);
 		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);
-	if (IS_ERR(cell))
+	cell = nvmem_create_cell(cell_entry, id, cell_index);
+	if (IS_ERR(cell)) {
 		__nvmem_device_put(nvmem);
+		nvmem_layout_module_put(nvmem);
+	}
 
 	return cell;
 }
@@ -1288,7 +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
@@ -1323,7 +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.
@@ -1394,27 +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;
@@ -1431,12 +1643,12 @@ static void nvmem_shift_read_buffer_in_place(struct nvmem_cell_entry *cell, void
 }
 
 static int __nvmem_cell_read(struct nvmem_device *nvmem,
-		      struct nvmem_cell_entry *cell,
-		      void *buf, size_t *len, const char *id)
+			     struct nvmem_cell_entry *cell,
+			     void *buf, size_t *len, const char *id, int index)
 {
 	int rc;
 
-	rc = nvmem_reg_read(nvmem, cell->offset, buf, cell->bytes);
+	rc = nvmem_reg_read(nvmem, cell->offset, buf, cell->raw_len);
 
 	if (rc)
 		return rc;
@@ -1445,9 +1657,9 @@ static int __nvmem_cell_read(struct nvmem_device *nvmem,
 	if (cell->bit_offset || cell->nbits)
 		nvmem_shift_read_buffer_in_place(cell, buf);
 
-	if (nvmem->cell_post_process) {
-		rc = nvmem->cell_post_process(nvmem->priv, id,
-					      cell->offset, buf, cell->bytes);
+	if (cell->read_post_process) {
+		rc = cell->read_post_process(cell->priv, id, index,
+					     cell->offset, buf, cell->raw_len);
 		if (rc)
 			return rc;
 	}
@@ -1470,18 +1682,19 @@ static int __nvmem_cell_read(struct nvmem_device *nvmem,
  */
 void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len)
 {
-	struct nvmem_device *nvmem = cell->entry->nvmem;
+	struct nvmem_cell_entry *entry = cell->entry;
+	struct nvmem_device *nvmem = entry->nvmem;
 	u8 *buf;
 	int rc;
 
 	if (!nvmem)
 		return ERR_PTR(-EINVAL);
 
-	buf = kzalloc(cell->entry->bytes, GFP_KERNEL);
+	buf = kzalloc(max_t(size_t, entry->raw_len, entry->bytes), GFP_KERNEL);
 	if (!buf)
 		return ERR_PTR(-ENOMEM);
 
-	rc = __nvmem_cell_read(nvmem, cell->entry, buf, len, cell->id);
+	rc = __nvmem_cell_read(nvmem, cell->entry, buf, len, cell->id, cell->index);
 	if (rc) {
 		kfree(buf);
 		return ERR_PTR(rc);
@@ -1553,7 +1766,17 @@ static int __nvmem_cell_entry_write(struct nvmem_cell_entry *cell, void *buf, si
 	    (cell->bit_offset == 0 && len != cell->bytes))
 		return -EINVAL;
 
+	/*
+	 * Any cells which have a read_post_process hook are read-only because
+	 * we cannot reverse the operation and it might affect other cells,
+	 * too.
+	 */
+	if (cell->read_post_process)
+		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);
@@ -1794,7 +2017,7 @@ ssize_t nvmem_device_cell_read(struct nvmem_device *nvmem,
 	if (rc)
 		return rc;
 
-	rc = __nvmem_cell_read(nvmem, &cell, buf, &len, NULL);
+	rc = __nvmem_cell_read(nvmem, &cell, buf, &len, NULL, 0);
 	if (rc)
 		return rc;
 
@@ -1887,32 +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
@@ -1960,20 +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");
-MODULE_LICENSE("GPL v2");