// SPDX-License-Identifier: GPL-2.0
/*
* nvmem framework core.
*
* Copyright (C) 2015 Srinivas Kandagatla <[email protected]>
* Copyright (C) 2013 Maxime Ripard <[email protected]>
*/
#include <linux/device.h>
#include <linux/export.h>
#include <linux/fs.h>
#include <linux/idr.h>
#include <linux/init.h>
#include <linux/kref.h>
#include <linux/module.h>
#include <linux/nvmem-consumer.h>
#include <linux/nvmem-provider.h>
#include <linux/gpio/consumer.h>
#include <linux/of.h>
#include <linux/slab.h>
#include "internals.h"
#define to_nvmem_device(d) container_of(d, struct nvmem_device, dev)
#define FLAG_COMPAT BIT(0)
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;
};
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);
static BLOCKING_NOTIFIER_HEAD(nvmem_notifier);
static int __nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset,
void *val, size_t bytes)
{
if (nvmem->reg_read)
return nvmem->reg_read(nvmem->priv, offset, val, bytes);
return -EINVAL;
}
static int __nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset,
void *val, size_t bytes)
{
int ret;
if (nvmem->reg_write) {
gpiod_set_value_cansleep(nvmem->wp_gpio, 0);
ret = nvmem->reg_write(nvmem->priv, offset, val, bytes);
gpiod_set_value_cansleep(nvmem->wp_gpio, 1);
return ret;
}
return -EINVAL;
}
static int nvmem_access_with_keepouts(struct nvmem_device *nvmem,
unsigned int offset, void *val,
size_t bytes, int write)
{
unsigned int end = offset + bytes;
unsigned int kend, ksize;
const struct nvmem_keepout *keepout = nvmem->keepout;
const struct nvmem_keepout *keepoutend = keepout + nvmem->nkeepout;
int rc;
/*
* Skip all keepouts before the range being accessed.
* Keepouts are sorted.
*/
while ((keepout < keepoutend) && (keepout->end <= offset))
keepout++;
while ((offset < end) && (keepout < keepoutend)) {
/* Access the valid portion before the keepout. */
if (offset < keepout->start) {
kend = min(end, keepout->start);
ksize = kend - offset;
if (write)
rc = __nvmem_reg_write(nvmem, offset, val, ksize);
else
rc = __nvmem_reg_read(nvmem, offset, val, ksize);
if (rc)
return rc;
offset += ksize;
val += ksize;
}
/*
* Now we're aligned to the start of this keepout zone. Go
* through it.
*/
kend = min(end, keepout->end);
ksize = kend - offset;
if (!write)
memset(val, keepout->value, ksize);
val += ksize;
offset += ksize;
keepout++;
}
/*
* If we ran out of keepouts but there's still stuff to do, send it
* down directly
*/
if (offset < end) {
ksize = end - offset;
if (write)
return __nvmem_reg_write(nvmem, offset, val, ksize);
else
return __nvmem_reg_read(nvmem, offset, val, ksize);
}
return 0;
}
static int nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset,
void *val, size_t bytes)
{
if (!nvmem->nkeepout)
return __nvmem_reg_read(nvmem, offset, val, bytes);
return nvmem_access_with_keepouts(nvmem, offset, val, bytes, false);
}
static int nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset,
void *val, size_t bytes)
{
if (!nvmem->nkeepout)
return __nvmem_reg_write(nvmem, offset, val, bytes);
return nvmem_access_with_keepouts(nvmem, offset, val, bytes, true);
}
#ifdef CONFIG_NVMEM_SYSFS
static const char * const nvmem_type_str[] = {
[NVMEM_TYPE_UNKNOWN] = "Unknown",
[NVMEM_TYPE_EEPROM] = "EEPROM",
[NVMEM_TYPE_OTP] = "OTP",
[NVMEM_TYPE_BATTERY_BACKED] = "Battery backed",
[NVMEM_TYPE_FRAM] = "FRAM",
};
#ifdef CONFIG_DEBUG_LOCK_ALLOC
static struct lock_class_key eeprom_lock_key;
#endif
static ssize_t type_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct nvmem_device *nvmem = to_nvmem_device(dev);
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,
loff_t pos, size_t count)
{
struct device *dev;
struct nvmem_device *nvmem;
int rc;
if (attr->private)
dev = attr->private;
else
dev = kobj_to_dev(kobj);
nvmem = to_nvmem_device(dev);
if (!IS_ALIGNED(pos, nvmem->stride))
return -EINVAL;
if (count < nvmem->word_size)
return -EINVAL;
count = round_down(count, nvmem->word_size);
if (!nvmem->reg_read)
return -EPERM;
rc = nvmem_reg_read(nvmem, pos, buf, count);
if (rc)
return rc;
return count;
}
static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj,
struct bin_attribute *attr, char *buf,
loff_t pos, size_t count)
{
struct device *dev;
struct nvmem_device *nvmem;
int rc;
if (attr->private)
dev = attr->private;
else
dev = kobj_to_dev(kobj);
nvmem = to_nvmem_device(dev);
if (!IS_ALIGNED(pos, nvmem->stride))
return -EINVAL;
if (count < nvmem->word_size)
return -EINVAL;
count = round_down(count, nvmem->word_size);
if (!nvmem->reg_write)
return -EPERM;
rc = nvmem_reg_write(nvmem, pos, buf, count);
if (rc)
return rc;
return count;
}
static umode_t nvmem_bin_attr_get_umode(struct nvmem_device *nvmem)
{
umode_t mode = 0400;
if (!nvmem->root_only)
mode |= 0044;
if (!nvmem->read_only)
mode |= 0200;
if (!nvmem->reg_write)
mode &= ~0200;
if (!nvmem->reg_read)
mode &= ~0444;
return mode;
}
static umode_t nvmem_bin_attr_is_visible(struct kobject *kobj,
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 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,
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 = {
.attr = {
.name = "nvmem",
.mode = 0644,
},
.read = bin_attr_nvmem_read,
.write = bin_attr_nvmem_write,
};
static struct bin_attribute *nvmem_bin_attributes[] = {
&bin_attr_rw_nvmem,
NULL,
};
static const struct attribute_group nvmem_bin_group = {
.bin_attrs = nvmem_bin_attributes,
.attrs = nvmem_attrs,
.is_bin_visible = nvmem_bin_attr_is_visible,
.is_visible = nvmem_attr_is_visible,
};
static const struct attribute_group *nvmem_dev_groups[] = {
&nvmem_bin_group,
NULL,
};
static struct bin_attribute bin_attr_nvmem_eeprom_compat = {
.attr = {
.name = "eeprom",
},
.read = bin_attr_nvmem_read,
.write = bin_attr_nvmem_write,
};
/*
* nvmem_setup_compat() - Create an additional binary entry in
* drivers sys directory, to be backwards compatible with the older
* drivers/misc/eeprom drivers.
*/
static int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem,
const struct nvmem_config *config)
{
int rval;
if (!config->compat)
return 0;
if (!config->base_dev)
return -EINVAL;
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
nvmem->eeprom.attr.key = &eeprom_lock_key;
#endif
nvmem->eeprom.private = &nvmem->dev;
nvmem->base_dev = config->base_dev;
rval = device_create_bin_file(nvmem->base_dev, &nvmem->eeprom);
if (rval) {
dev_err(&nvmem->dev,
"Failed to create eeprom binary file %d\n", rval);
return rval;
}
nvmem->flags |= FLAG_COMPAT;
return 0;
}
static void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem,
const struct nvmem_config *config)
{
if (config->compat)
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;
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);
group.bin_attrs = devm_kcalloc(&nvmem->dev, ncells + 1,
sizeof(struct bin_attribute *), GFP_KERNEL);
if (!group.bin_attrs) {
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;
}
group.bin_attrs[i] = &attrs[i];
i++;
}
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,
const struct nvmem_config *config)
{
return -ENOSYS;
}
static void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem,
const struct nvmem_config *config)
{
}
#endif /* CONFIG_NVMEM_SYSFS */
static void nvmem_release(struct device *dev)
{
struct nvmem_device *nvmem = to_nvmem_device(dev);
ida_free(&nvmem_ida, nvmem->id);
gpiod_put(nvmem->wp_gpio);
kfree(nvmem);
}
static const struct device_type nvmem_provider_type = {
.release = nvmem_release,
};
static struct bus_type nvmem_bus_type = {
.name = "nvmem",
};
static void nvmem_cell_entry_drop(struct nvmem_cell_entry *cell)
{
blocking_notifier_call_chain(&nvmem_notifier, NVMEM_CELL_REMOVE, cell);
mutex_lock(&nvmem_mutex);
list_del(&cell->node);
mutex_unlock(&nvmem_mutex);
of_node_put(cell->np);
kfree_const(cell->name);
kfree(cell);
}
static void nvmem_device_remove_all_cells(const struct nvmem_device *nvmem)
{
struct nvmem_cell_entry *cell, *p;
list_for_each_entry_safe(cell, p, &nvmem->cells, node)
nvmem_cell_entry_drop(cell);
}
static void nvmem_cell_entry_add(struct nvmem_cell_entry *cell)
{
mutex_lock(&nvmem_mutex);
list_add_tail(&cell->node, &cell->nvmem->cells);
mutex_unlock(&nvmem_mutex);
blocking_notifier_call_chain(&nvmem_notifier, NVMEM_CELL_ADD, cell);
}
static int nvmem_cell_info_to_nvmem_cell_entry_nodup(struct nvmem_device *nvmem,
const struct nvmem_cell_info *info,
struct nvmem_cell_entry *cell)
{
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)
cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset,
BITS_PER_BYTE);
if (!IS_ALIGNED(cell->offset, nvmem->stride)) {
dev_err(&nvmem->dev,
"cell %s unaligned to nvmem stride %d\n",
cell->name ?: "<unknown>", nvmem->stride);
return -EINVAL;
}
return 0;
}
static int nvmem_cell_info_to_nvmem_cell_entry(struct nvmem_device *nvmem,
const struct nvmem_cell_info *info,
struct nvmem_cell_entry *cell)
{
int err;
err = nvmem_cell_info_to_nvmem_cell_entry_nodup(nvmem, info, cell);
if (err)
return err;
cell->name = kstrdup_const(info->name, GFP_KERNEL);
if (!cell->name)
return -ENOMEM;
return 0;
}
/**
* 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.
* @info: nvmem cell info to add to the device
* @ncells: number of cells in info
*
* Return: 0 or negative error code on failure.
*/
static int nvmem_add_cells(struct nvmem_device *nvmem,
const struct nvmem_cell_info *info,
int ncells)
{
int i, rval;
for (i = 0; i < ncells; i++) {
rval = nvmem_add_one_cell(nvmem, &info[i]);
if (rval)
return rval;
}
return 0;
}
/**
* nvmem_register_notifier() - Register a notifier block for nvmem events.
*
* @nb: notifier block to be called on nvmem events.
*
* Return: 0 on success, negative error number on failure.
*/
int nvmem_register_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_register(&nvmem_notifier, nb);
}
EXPORT_SYMBOL_GPL(nvmem_register_notifier);
/**
* nvmem_unregister_notifier() - Unregister a notifier block for nvmem events.
*
* @nb: notifier block to be unregistered.
*
* Return: 0 on success, negative error number on failure.
*/
int nvmem_unregister_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_unregister(&nvmem_notifier, 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)
{
struct nvmem_cell_entry *iter, *cell = NULL;
mutex_lock(&nvmem_mutex);
list_for_each_entry(iter, &nvmem->cells, node) {
if (strcmp(cell_id, iter->name) == 0) {
cell = iter;
break;
}
}
mutex_unlock(&nvmem_mutex);
return cell;
}
static int nvmem_validate_keepouts(struct nvmem_device *nvmem)
{
unsigned int cur = 0;
const struct nvmem_keepout *keepout = nvmem->keepout;
const struct nvmem_keepout *keepoutend = keepout + nvmem->nkeepout;
while (keepout < keepoutend) {
/* Ensure keepouts are sorted and don't overlap. */
if (keepout->start < cur) {
dev_err(&nvmem->dev,
"Keepout regions aren't sorted or overlap.\n");
return -ERANGE;
}
if (keepout->end < keepout->start) {
dev_err(&nvmem->dev,
"Invalid keepout region.\n");
return -EINVAL;
}
/*
* Validate keepouts (and holes between) don't violate
* word_size constraints.
*/
if ((keepout->end - keepout->start < nvmem->word_size) ||
((keepout->start != cur) &&
(keepout->start - cur < nvmem->word_size))) {
dev_err(&nvmem->dev,
"Keepout regions violate word_size constraints.\n");
return -ERANGE;
}
/* Validate keepouts don't violate stride (alignment). */
if (!IS_ALIGNED(keepout->start, nvmem->stride) ||
!IS_ALIGNED(keepout->end, nvmem->stride)) {
dev_err(&nvmem->dev,
"Keepout regions violate stride.\n");
return -EINVAL;
}
cur = keepout->end;
keepout++;
}
return 0;
}
static int nvmem_add_cells_from_dt(struct nvmem_device *nvmem, struct device_node *np)
{
struct device *dev = &nvmem->dev;
struct device_node *child;
const __be32 *addr;
int len, ret;
for_each_child_of_node(np, child) {
struct nvmem_cell_info info = {0};
addr = of_get_property(child, "reg", &len);
if (!addr)
continue;
if (len < 2 * sizeof(u32)) {
dev_err(dev, "nvmem: invalid reg on %pOF\n", child);
of_node_put(child);
return -EINVAL;
}
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))) {
info.bit_offset = be32_to_cpup(addr++);
info.nbits = be32_to_cpup(addr);
if (info.bit_offset >= BITS_PER_BYTE || info.nbits < 1) {
dev_err(dev, "nvmem: invalid bits on %pOF\n", child);
of_node_put(child);
return -EINVAL;
}
}
info.np = of_node_get(child);
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 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;
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.
* Also creates a binary entry in /sys/bus/nvmem/devices/dev-name/nvmem
*
* @config: nvmem device configuration with which nvmem device is created.
*
* Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device
* on success.
*/
struct nvmem_device *nvmem_register(const struct nvmem_config *config)
{
struct nvmem_device *nvmem;
int rval;
if (!config->dev)
return ERR_PTR(-EINVAL);
if (!config->reg_read && !config->reg_write)
return ERR_PTR(-EINVAL);
nvmem = kzalloc(sizeof(*nvmem), GFP_KERNEL);
if (!nvmem)
return ERR_PTR(-ENOMEM);
rval = ida_alloc(&nvmem_ida, GFP_KERNEL);
if (rval < 0) {
kfree(nvmem);
return ERR_PTR(rval);
}
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)) {
rval = PTR_ERR(nvmem->wp_gpio);
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->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->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->keepout = config->keepout;
nvmem->nkeepout = config->nkeepout;
if (config->of_node)
nvmem->dev.of_node = config->of_node;
else
nvmem->dev.of_node = config->dev->of_node;
switch (config->id) {
case NVMEM_DEVID_NONE:
rval = dev_set_name(&nvmem->dev, "%s", config->name);
break;
case NVMEM_DEVID_AUTO:
rval = dev_set_name(&nvmem->dev, "%s%d", config->name, nvmem->id);
break;
default:
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;
#ifdef CONFIG_NVMEM_SYSFS
nvmem->dev.groups = nvmem_dev_groups;
#endif
if (nvmem->nkeepout) {
rval = nvmem_validate_keepouts(nvmem);
if (rval)
goto err_put_device;
}
if (config->compat) {
rval = nvmem_sysfs_setup_compat(nvmem, config);
if (rval)
goto err_put_device;
}
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_fixed_layout(nvmem);
if (rval)
goto err_remove_cells;
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);
if (config->compat)
nvmem_sysfs_remove_compat(nvmem, config);
err_put_device:
put_device(&nvmem->dev);
return ERR_PTR(rval);
}
EXPORT_SYMBOL_GPL(nvmem_register);
static void nvmem_device_release(struct kref *kref)
{
struct nvmem_device *nvmem;
nvmem = container_of(kref, struct nvmem_device, refcnt);
blocking_notifier_call_chain(&nvmem_notifier, NVMEM_REMOVE, nvmem);
if (nvmem->flags & FLAG_COMPAT)
device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);
nvmem_device_remove_all_cells(nvmem);
nvmem_destroy_layout(nvmem);
device_unregister(&nvmem->dev);
}
/**
* nvmem_unregister() - Unregister previously registered nvmem device
*
* @nvmem: Pointer to previously registered nvmem device.
*/
void nvmem_unregister(struct nvmem_device *nvmem)
{
if (nvmem)
kref_put(&nvmem->refcnt, nvmem_device_release);
}
EXPORT_SYMBOL_GPL(nvmem_unregister);
static void devm_nvmem_unregister(void *nvmem)
{
nvmem_unregister(nvmem);
}
/**
* devm_nvmem_register() - Register a managed nvmem device for given
* nvmem_config.
* Also creates a binary entry in /sys/bus/nvmem/devices/dev-name/nvmem
*
* @dev: Device that uses the nvmem device.
* @config: nvmem device configuration with which nvmem device is created.
*
* Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device
* on success.
*/
struct nvmem_device *devm_nvmem_register(struct device *dev,
const struct nvmem_config *config)
{
struct nvmem_device *nvmem;
int ret;
nvmem = nvmem_register(config);
if (IS_ERR(nvmem))
return nvmem;
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 struct nvmem_device *__nvmem_device_get(void *data,
int (*match)(struct device *dev, const void *data))
{
struct nvmem_device *nvmem = NULL;
struct device *dev;
mutex_lock(&nvmem_mutex);
dev = bus_find_device(&nvmem_bus_type, NULL, data, match);
if (dev)
nvmem = to_nvmem_device(dev);
mutex_unlock(&nvmem_mutex);
if (!nvmem)
return ERR_PTR(-EPROBE_DEFER);
if (!try_module_get(nvmem->owner)) {
dev_err(&nvmem->dev,
"could not increase module refcount for cell %s\n",
nvmem_dev_name(nvmem));
put_device(&nvmem->dev);
return ERR_PTR(-EINVAL);
}
kref_get(&nvmem->refcnt);
return nvmem;
}
static void __nvmem_device_put(struct nvmem_device *nvmem)
{
put_device(&nvmem->dev);
module_put(nvmem->owner);
kref_put(&nvmem->refcnt, nvmem_device_release);
}
#if IS_ENABLED(CONFIG_OF)
/**
* of_nvmem_device_get() - Get nvmem device from a given id
*
* @np: Device tree node that uses the nvmem device.
* @id: nvmem name from nvmem-names property.
*
* Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device
* on success.
*/
struct nvmem_device *of_nvmem_device_get(struct device_node *np, const char *id)
{
struct device_node *nvmem_np;
struct nvmem_device *nvmem;
int index = 0;
if (id)
index = of_property_match_string(np, "nvmem-names", id);
nvmem_np = of_parse_phandle(np, "nvmem", index);
if (!nvmem_np)
return ERR_PTR(-ENOENT);
nvmem = __nvmem_device_get(nvmem_np, device_match_of_node);
of_node_put(nvmem_np);
return nvmem;
}
EXPORT_SYMBOL_GPL(of_nvmem_device_get);
#endif
/**
* nvmem_device_get() - Get nvmem device from a given id
*
* @dev: Device that uses the nvmem device.
* @dev_name: name of the requested nvmem device.
*
* Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device
* on success.
*/
struct nvmem_device *nvmem_device_get(struct device *dev, const char *dev_name)
{
if (dev->of_node) { /* try dt first */
struct nvmem_device *nvmem;
nvmem = of_nvmem_device_get(dev->of_node, dev_name);
if (!IS_ERR(nvmem) || PTR_ERR(nvmem) == -EPROBE_DEFER)
return nvmem;
}
return __nvmem_device_get((void *)dev_name, device_match_name);
}
EXPORT_SYMBOL_GPL(nvmem_device_get);
/**
* nvmem_device_find() - Find nvmem device with matching function
*
* @data: Data to pass to match function
* @match: Callback function to check device
*
* Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device
* on success.
*/
struct nvmem_device *nvmem_device_find(void *data,
int (*match)(struct device *dev, const void *data))
{
return __nvmem_device_get(data, match);
}
EXPORT_SYMBOL_GPL(nvmem_device_find);
static int devm_nvmem_device_match(struct device *dev, void *res, void *data)
{
struct nvmem_device **nvmem = res;
if (WARN_ON(!nvmem || !*nvmem))
return 0;
return *nvmem == data;
}
static void devm_nvmem_device_release(struct device *dev, void *res)
{
nvmem_device_put(*(struct nvmem_device **)res);
}
/**
* devm_nvmem_device_put() - put alredy got nvmem device
*
* @dev: Device that uses the nvmem device.
* @nvmem: pointer to nvmem device allocated by devm_nvmem_cell_get(),
* that needs to be released.
*/
void devm_nvmem_device_put(struct device *dev, struct nvmem_device *nvmem)
{
int ret;
ret = devres_release(dev, devm_nvmem_device_release,
devm_nvmem_device_match, nvmem);
WARN_ON(ret);
}
EXPORT_SYMBOL_GPL(devm_nvmem_device_put);
/**
* nvmem_device_put() - put alredy got nvmem device
*
* @nvmem: pointer to nvmem device that needs to be released.
*/
void nvmem_device_put(struct nvmem_device *nvmem)
{
__nvmem_device_put(nvmem);
}
EXPORT_SYMBOL_GPL(nvmem_device_put);
/**
* devm_nvmem_device_get() - Get nvmem device of device form 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_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)
{
struct nvmem_device **ptr, *nvmem;
ptr = devres_alloc(devm_nvmem_device_release, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return ERR_PTR(-ENOMEM);
nvmem = nvmem_device_get(dev, id);
if (!IS_ERR(nvmem)) {
*ptr = nvmem;
devres_add(dev, ptr);
} else {
devres_free(ptr);
}
return nvmem;
}
EXPORT_SYMBOL_GPL(devm_nvmem_device_get);
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;
cell = kzalloc(sizeof(*cell), GFP_KERNEL);
if (!cell)
return ERR_PTR(-ENOMEM);
if (id) {
name = kstrdup_const(id, GFP_KERNEL);
if (!name) {
kfree(cell);
return ERR_PTR(-ENOMEM);
}
}
cell->id = name;
cell->entry = entry;
cell->index = index;
return cell;
}
static struct nvmem_cell *
nvmem_cell_get_from_lookup(struct device *dev, const char *con_id)
{
struct nvmem_cell_entry *cell_entry;
struct nvmem_cell *cell = ERR_PTR(-ENOENT);
struct nvmem_cell_lookup *lookup;
struct nvmem_device *nvmem;
const char *dev_id;
if (!dev)
return ERR_PTR(-EINVAL);
dev_id = dev_name(dev);
mutex_lock(&nvmem_lookup_mutex);
list_for_each_entry(lookup, &nvmem_lookup_list, node) {
if ((strcmp(lookup->dev_id, dev_id) == 0) &&
(strcmp(lookup->con_id, con_id) == 0)) {
/* This is the right entry. */
nvmem = __nvmem_device_get((void *)lookup->nvmem_name,
device_match_name);
if (IS_ERR(nvmem)) {
/* Provider may not be registered yet. */
cell = ERR_CAST(nvmem);
break;
}
cell_entry = nvmem_find_cell_entry_by_name(nvmem,
lookup->cell_name);
if (!cell_entry) {
__nvmem_device_put(nvmem);
cell = ERR_PTR(-ENOENT);
} else {
cell = nvmem_create_cell(cell_entry, con_id, 0);
if (IS_ERR(cell))
__nvmem_device_put(nvmem);
}
break;
}
}
mutex_unlock(&nvmem_lookup_mutex);
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)
{
struct nvmem_cell_entry *iter, *cell = NULL;
mutex_lock(&nvmem_mutex);
list_for_each_entry(iter, &nvmem->cells, node) {
if (np == iter->np) {
cell = iter;
break;
}
}
mutex_unlock(&nvmem_mutex);
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
*
* @np: Device tree node that uses the nvmem cell.
* @id: nvmem cell name from nvmem-cell-names property, or NULL
* for the cell at index 0 (the lone cell with no accompanying
* nvmem-cell-names property).
*
* Return: Will be an ERR_PTR() on error or a valid pointer
* to a struct nvmem_cell. The nvmem_cell will be freed by the
* nvmem_cell_put().
*/
struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, const char *id)
{
struct device_node *cell_np, *nvmem_np;
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);
ret = of_parse_phandle_with_optional_args(np, "nvmem-cells",
"#nvmem-cell-cells",
index, &cell_spec);
if (ret)
return ERR_PTR(-ENOENT);
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)) {
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);
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)) {
__nvmem_device_put(nvmem);
nvmem_layout_module_put(nvmem);
}
return cell;
}
EXPORT_SYMBOL_GPL(of_nvmem_cell_get);
#endif
/**
* nvmem_cell_get() - Get nvmem cell of device form a given cell name
*
* @dev: Device that requests the nvmem cell.
* @id: nvmem cell name to get (this corresponds with the name from the
* nvmem-cell-names property for DT systems and with the con_id from
* the lookup entry for non-DT systems).
*
* Return: Will be an ERR_PTR() on error or a valid pointer
* to a struct nvmem_cell. The nvmem_cell will be freed by the
* nvmem_cell_put().
*/
struct nvmem_cell *nvmem_cell_get(struct device *dev, const char *id)
{
struct nvmem_cell *cell;
if (dev->of_node) { /* try dt first */
cell = of_nvmem_cell_get(dev->of_node, id);
if (!IS_ERR(cell) || PTR_ERR(cell) == -EPROBE_DEFER)
return cell;
}
/* NULL cell id only allowed for device tree; invalid otherwise */
if (!id)
return ERR_PTR(-EINVAL);
return nvmem_cell_get_from_lookup(dev, id);
}
EXPORT_SYMBOL_GPL(nvmem_cell_get);
static void devm_nvmem_cell_release(struct device *dev, void *res)
{
nvmem_cell_put(*(struct nvmem_cell **)res);
}
/**
* devm_nvmem_cell_get() - Get nvmem cell of device form a given id
*
* @dev: Device that requests the nvmem cell.
* @id: nvmem cell name id to get.
*
* Return: Will be an ERR_PTR() on error or a valid pointer
* to a struct nvmem_cell. The nvmem_cell will be freed by the
* automatically once the device is freed.
*/
struct nvmem_cell *devm_nvmem_cell_get(struct device *dev, const char *id)
{
struct nvmem_cell **ptr, *cell;
ptr = devres_alloc(devm_nvmem_cell_release, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return ERR_PTR(-ENOMEM);
cell = nvmem_cell_get(dev, id);
if (!IS_ERR(cell)) {
*ptr = cell;
devres_add(dev, ptr);
} else {
devres_free(ptr);
}
return cell;
}
EXPORT_SYMBOL_GPL(devm_nvmem_cell_get);
static int devm_nvmem_cell_match(struct device *dev, void *res, void *data)
{
struct nvmem_cell **c = res;
if (WARN_ON(!c || !*c))
return 0;
return *c == data;
}
/**
* devm_nvmem_cell_put() - Release previously allocated nvmem cell
* from devm_nvmem_cell_get.
*
* @dev: Device that requests the nvmem cell.
* @cell: Previously allocated nvmem cell by devm_nvmem_cell_get().
*/
void devm_nvmem_cell_put(struct device *dev, struct nvmem_cell *cell)
{
int ret;
ret = devres_release(dev, devm_nvmem_cell_release,
devm_nvmem_cell_match, cell);
WARN_ON(ret);
}
EXPORT_SYMBOL(devm_nvmem_cell_put);
/**
* nvmem_cell_put() - Release previously allocated nvmem cell.
*
* @cell: Previously allocated nvmem cell by nvmem_cell_get().
*/
void nvmem_cell_put(struct nvmem_cell *cell)
{
struct nvmem_device *nvmem = cell->entry->nvmem;
if (cell->id)
kfree_const(cell->id);
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;
p = b = buf;
if (bit_offset) {
/* First shift */
*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;
*b++ >>= bit_offset;
}
} else {
/* point to the msb */
p += cell->bytes - 1;
}
/* result fits in less bytes */
extra = cell->bytes - DIV_ROUND_UP(cell->nbits, BITS_PER_BYTE);
while (--extra >= 0)
*p-- = 0;
/* clear msb bits if any leftover in the last byte */
if (cell->nbits % BITS_PER_BYTE)
*p &= GENMASK((cell->nbits % BITS_PER_BYTE) - 1, 0);
}
static int __nvmem_cell_read(struct nvmem_device *nvmem,
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->raw_len);
if (rc)
return rc;
/* shift bits in-place */
if (cell->bit_offset || cell->nbits)
nvmem_shift_read_buffer_in_place(cell, buf);
if (cell->read_post_process) {
rc = cell->read_post_process(cell->priv, id, index,
cell->offset, buf, cell->raw_len);
if (rc)
return rc;
}
if (len)
*len = cell->bytes;
return 0;
}
/**
* nvmem_cell_read() - Read a given nvmem cell
*
* @cell: nvmem cell to be read.
* @len: pointer to length of cell which will be populated on successful read;
* can be NULL.
*
* Return: ERR_PTR() on error or a valid pointer to a buffer on success. The
* buffer should be freed by the consumer with a kfree().
*/
void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len)
{
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(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, cell->index);
if (rc) {
kfree(buf);
return ERR_PTR(rc);
}
return buf;
}
EXPORT_SYMBOL_GPL(nvmem_cell_read);
static void *nvmem_cell_prepare_write_buffer(struct nvmem_cell_entry *cell,
u8 *_buf, int len)
{
struct nvmem_device *nvmem = cell->nvmem;
int i, rc, nbits, bit_offset = cell->bit_offset;
u8 v, *p, *buf, *b, pbyte, pbits;
nbits = cell->nbits;
buf = kzalloc(cell->bytes, GFP_KERNEL);
if (!buf)
return ERR_PTR(-ENOMEM);
memcpy(buf, _buf, len);
p = b = buf;
if (bit_offset) {
pbyte = *b;
*b <<= bit_offset;
/* setup the first byte with lsb bits from nvmem */
rc = nvmem_reg_read(nvmem, cell->offset, &v, 1);
if (rc)
goto err;
*b++ |= GENMASK(bit_offset - 1, 0) & v;
/* setup rest of the byte if any */
for (i = 1; i < cell->bytes; i++) {
/* Get last byte bits and shift them towards lsb */
pbits = pbyte >> (BITS_PER_BYTE - 1 - bit_offset);
pbyte = *b;
p = b;
*b <<= bit_offset;
*b++ |= pbits;
}
}
/* if it's not end on byte boundary */
if ((nbits + bit_offset) % BITS_PER_BYTE) {
/* setup the last byte with msb bits from nvmem */
rc = nvmem_reg_read(nvmem,
cell->offset + cell->bytes - 1, &v, 1);
if (rc)
goto err;
*p |= GENMASK(7, (nbits + bit_offset) % BITS_PER_BYTE) & v;
}
return buf;
err:
kfree(buf);
return ERR_PTR(rc);
}
static int __nvmem_cell_entry_write(struct nvmem_cell_entry *cell, void *buf, size_t len)
{
struct nvmem_device *nvmem = cell->nvmem;
int rc;
if (!nvmem || nvmem->read_only ||
(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) {
buf = nvmem_cell_prepare_write_buffer(cell, buf, len);
if (IS_ERR(buf))
return PTR_ERR(buf);
}
rc = nvmem_reg_write(nvmem, cell->offset, buf, cell->bytes);
/* free the tmp buffer */
if (cell->bit_offset || cell->nbits)
kfree(buf);
if (rc)
return rc;
return len;
}
/**
* nvmem_cell_write() - Write to a given nvmem cell
*
* @cell: nvmem cell to be written.
* @buf: Buffer to be written.
* @len: length of buffer to be written to nvmem cell.
*
* Return: length of bytes written or negative on failure.
*/
int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len)
{
return __nvmem_cell_entry_write(cell->entry, buf, len);
}
EXPORT_SYMBOL_GPL(nvmem_cell_write);
static int nvmem_cell_read_common(struct device *dev, const char *cell_id,
void *val, size_t count)
{
struct nvmem_cell *cell;
void *buf;
size_t len;
cell = nvmem_cell_get(dev, cell_id);
if (IS_ERR(cell))
return PTR_ERR(cell);
buf = nvmem_cell_read(cell, &len);
if (IS_ERR(buf)) {
nvmem_cell_put(cell);
return PTR_ERR(buf);
}
if (len != count) {
kfree(buf);
nvmem_cell_put(cell);
return -EINVAL;
}
memcpy(val, buf, count);
kfree(buf);
nvmem_cell_put(cell);
return 0;
}
/**
* nvmem_cell_read_u8() - Read a cell value as a u8
*
* @dev: Device that requests the nvmem cell.
* @cell_id: Name of nvmem cell to read.
* @val: pointer to output value.
*
* Return: 0 on success or negative errno.
*/
int nvmem_cell_read_u8(struct device *dev, const char *cell_id, u8 *val)
{
return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val));
}
EXPORT_SYMBOL_GPL(nvmem_cell_read_u8);
/**
* nvmem_cell_read_u16() - Read a cell value as a u16
*
* @dev: Device that requests the nvmem cell.
* @cell_id: Name of nvmem cell to read.
* @val: pointer to output value.
*
* Return: 0 on success or negative errno.
*/
int nvmem_cell_read_u16(struct device *dev, const char *cell_id, u16 *val)
{
return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val));
}
EXPORT_SYMBOL_GPL(nvmem_cell_read_u16);
/**
* nvmem_cell_read_u32() - Read a cell value as a u32
*
* @dev: Device that requests the nvmem cell.
* @cell_id: Name of nvmem cell to read.
* @val: pointer to output value.
*
* Return: 0 on success or negative errno.
*/
int nvmem_cell_read_u32(struct device *dev, const char *cell_id, u32 *val)
{
return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val));
}
EXPORT_SYMBOL_GPL(nvmem_cell_read_u32);
/**
* nvmem_cell_read_u64() - Read a cell value as a u64
*
* @dev: Device that requests the nvmem cell.
* @cell_id: Name of nvmem cell to read.
* @val: pointer to output value.
*
* Return: 0 on success or negative errno.
*/
int nvmem_cell_read_u64(struct device *dev, const char *cell_id, u64 *val)
{
return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val));
}
EXPORT_SYMBOL_GPL(nvmem_cell_read_u64);
static const void *nvmem_cell_read_variable_common(struct device *dev,
const char *cell_id,
size_t max_len, size_t *len)
{
struct nvmem_cell *cell;
int nbits;
void *buf;
cell = nvmem_cell_get(dev, cell_id);
if (IS_ERR(cell))
return cell;
nbits = cell->entry->nbits;
buf = nvmem_cell_read(cell, len);
nvmem_cell_put(cell);
if (IS_ERR(buf))
return buf;
/*
* If nbits is set then nvmem_cell_read() can significantly exaggerate
* the length of the real data. Throw away the extra junk.
*/
if (nbits)
*len = DIV_ROUND_UP(nbits, 8);
if (*len > max_len) {
kfree(buf);
return ERR_PTR(-ERANGE);
}
return buf;
}
/**
* nvmem_cell_read_variable_le_u32() - Read up to 32-bits of data as a little endian number.
*
* @dev: Device that requests the nvmem cell.
* @cell_id: Name of nvmem cell to read.
* @val: pointer to output value.
*
* Return: 0 on success or negative errno.
*/
int nvmem_cell_read_variable_le_u32(struct device *dev, const char *cell_id,
u32 *val)
{
size_t len;
const u8 *buf;
int i;
buf = nvmem_cell_read_variable_common(dev, cell_id, sizeof(*val), &len);
if (IS_ERR(buf))
return PTR_ERR(buf);
/* Copy w/ implicit endian conversion */
*val = 0;
for (i = 0; i < len; i++)
*val |= buf[i] << (8 * i);
kfree(buf);
return 0;
}
EXPORT_SYMBOL_GPL(nvmem_cell_read_variable_le_u32);
/**
* nvmem_cell_read_variable_le_u64() - Read up to 64-bits of data as a little endian number.
*
* @dev: Device that requests the nvmem cell.
* @cell_id: Name of nvmem cell to read.
* @val: pointer to output value.
*
* Return: 0 on success or negative errno.
*/
int nvmem_cell_read_variable_le_u64(struct device *dev, const char *cell_id,
u64 *val)
{
size_t len;
const u8 *buf;
int i;
buf = nvmem_cell_read_variable_common(dev, cell_id, sizeof(*val), &len);
if (IS_ERR(buf))
return PTR_ERR(buf);
/* Copy w/ implicit endian conversion */
*val = 0;
for (i = 0; i < len; i++)
*val |= (uint64_t)buf[i] << (8 * i);
kfree(buf);
return 0;
}
EXPORT_SYMBOL_GPL(nvmem_cell_read_variable_le_u64);
/**
* nvmem_device_cell_read() - Read a given nvmem device and cell
*
* @nvmem: nvmem device to read from.
* @info: nvmem cell info to be read.
* @buf: buffer pointer which will be populated on successful read.
*
* Return: length of successful bytes read on success and negative
* error code on error.
*/
ssize_t nvmem_device_cell_read(struct nvmem_device *nvmem,
struct nvmem_cell_info *info, void *buf)
{
struct nvmem_cell_entry cell;
int rc;
ssize_t len;
if (!nvmem)
return -EINVAL;
rc = nvmem_cell_info_to_nvmem_cell_entry_nodup(nvmem, info, &cell);
if (rc)
return rc;
rc = __nvmem_cell_read(nvmem, &cell, buf, &len, NULL, 0);
if (rc)
return rc;
return len;
}
EXPORT_SYMBOL_GPL(nvmem_device_cell_read);
/**
* nvmem_device_cell_write() - Write cell to a given nvmem device
*
* @nvmem: nvmem device to be written to.
* @info: nvmem cell info to be written.
* @buf: buffer to be written to cell.
*
* Return: length of bytes written or negative error code on failure.
*/
int nvmem_device_cell_write(struct nvmem_device *nvmem,
struct nvmem_cell_info *info, void *buf)
{
struct nvmem_cell_entry cell;
int rc;
if (!nvmem)
return -EINVAL;
rc = nvmem_cell_info_to_nvmem_cell_entry_nodup(nvmem, info, &cell);
if (rc)
return rc;
return __nvmem_cell_entry_write(&cell, buf, cell.bytes);
}
EXPORT_SYMBOL_GPL(nvmem_device_cell_write);
/**
* nvmem_device_read() - Read from a given nvmem device
*
* @nvmem: nvmem device to read from.
* @offset: offset in nvmem device.
* @bytes: number of bytes to read.
* @buf: buffer pointer which will be populated on successful read.
*
* Return: length of successful bytes read on success and negative
* error code on error.
*/
int nvmem_device_read(struct nvmem_device *nvmem,
unsigned int offset,
size_t bytes, void *buf)
{
int rc;
if (!nvmem)
return -EINVAL;
rc = nvmem_reg_read(nvmem, offset, buf, bytes);
if (rc)
return rc;
return bytes;
}
EXPORT_SYMBOL_GPL(nvmem_device_read);
/**
* nvmem_device_write() - Write cell to a given nvmem device
*
* @nvmem: nvmem device to be written to.
* @offset: offset in nvmem device.
* @bytes: number of bytes to write.
* @buf: buffer to be written.
*
* Return: length of bytes written or negative error code on failure.
*/
int nvmem_device_write(struct nvmem_device *nvmem,
unsigned int offset,
size_t bytes, void *buf)
{
int rc;
if (!nvmem)
return -EINVAL;
rc = nvmem_reg_write(nvmem, offset, buf, bytes);
if (rc)
return rc;
return bytes;
}
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
* @nentries: number of cell lookup entries in the array
*/
void nvmem_add_cell_lookups(struct nvmem_cell_lookup *entries, size_t nentries)
{
int i;
mutex_lock(&nvmem_lookup_mutex);
for (i = 0; i < nentries; i++)
list_add_tail(&entries[i].node, &nvmem_lookup_list);
mutex_unlock(&nvmem_lookup_mutex);
}
EXPORT_SYMBOL_GPL(nvmem_add_cell_lookups);
/**
* nvmem_del_cell_lookups() - remove a list of previously added cell lookup
* entries
*
* @entries: array of cell lookup entries
* @nentries: number of cell lookup entries in the array
*/
void nvmem_del_cell_lookups(struct nvmem_cell_lookup *entries, size_t nentries)
{
int i;
mutex_lock(&nvmem_lookup_mutex);
for (i = 0; i < nentries; i++)
list_del(&entries[i].node);
mutex_unlock(&nvmem_lookup_mutex);
}
EXPORT_SYMBOL_GPL(nvmem_del_cell_lookups);
/**
* nvmem_dev_name() - Get the name of a given nvmem device.
*
* @nvmem: nvmem device.
*
* Return: name of the nvmem device.
*/
const char *nvmem_dev_name(struct nvmem_device *nvmem)
{
return dev_name(&nvmem->dev);
}
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)
{
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 <[email protected]");
MODULE_AUTHOR("Maxime Ripard <[email protected]");
MODULE_DESCRIPTION("nvmem Driver Core");
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