linux/drivers/nvmem/core.c
Greg Kroah-Hartman 8d8fc146dd nvmem: core: switch to use device_add_groups()
devm_device_add_groups() is being removed from the kernel, so move the
nvmem driver to use device_add_groups() instead.  The logic is
identical, when the device is removed the driver core will properly
clean up and remove the groups, and the memory used by the attribute
groups will be freed because it was created with dev_* calls, so this is
functionally identical overall.

Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20240430084921.33387-7-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-03 07:26:38 +02:00

2212 lines
50 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* nvmem framework core.
*
* Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
* Copyright (C) 2013 Maxime Ripard <maxime.ripard@free-electrons.com>
*/
#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 sprintf(buf, "%s\n", nvmem_type_str[nvmem->type]);
}
static DEVICE_ATTR_RO(type);
static struct attribute *nvmem_attrs[] = {
&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);
/* 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)
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);
/* 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)
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 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,
};
/* Cell attributes will be dynamically allocated */
static struct attribute_group nvmem_cells_group = {
.name = "cells",
};
static const struct attribute_group *nvmem_dev_groups[] = {
&nvmem_bin_group,
NULL,
};
static const struct attribute_group *nvmem_cells_groups[] = {
&nvmem_cells_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;
if (config->type == NVMEM_TYPE_FRAM)
bin_attr_nvmem_eeprom_compat.attr.name = "fram";
nvmem->eeprom = bin_attr_nvmem_eeprom_compat;
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 bin_attribute **cells_attrs, *attrs;
struct nvmem_cell_entry *entry;
unsigned int ncells = 0, i = 0;
int ret = 0;
mutex_lock(&nvmem_mutex);
if (list_empty(&nvmem->cells) || nvmem->sysfs_cells_populated) {
nvmem_cells_group.bin_attrs = NULL;
goto unlock_mutex;
}
/* Allocate an array of attributes with a sentinel */
ncells = list_count_nodes(&nvmem->cells);
cells_attrs = devm_kcalloc(&nvmem->dev, ncells + 1,
sizeof(struct bin_attribute *), GFP_KERNEL);
if (!cells_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;
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;
}
cells_attrs[i] = &attrs[i];
i++;
}
nvmem_cells_group.bin_attrs = cells_attrs;
ret = device_add_groups(&nvmem->dev, nvmem_cells_groups);
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 cell 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_cell
* on success. The nvmem_cell 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 <srinivas.kandagatla@linaro.org");
MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com");
MODULE_DESCRIPTION("nvmem Driver Core");