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![Axel Lin](/assets/img/avatar_default.png)
A tmp buffer is allocated if cell->bit_offset || cell->nbits. So the tmp buffer needs to be freed at the same condition to avoid leak. Signed-off-by: Axel Lin <axel.lin@ingics.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1083 lines
24 KiB
C
1083 lines
24 KiB
C
/*
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* nvmem framework core.
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*
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* Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
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* Copyright (C) 2013 Maxime Ripard <maxime.ripard@free-electrons.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 and
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* only version 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/device.h>
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#include <linux/export.h>
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#include <linux/fs.h>
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#include <linux/idr.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/nvmem-consumer.h>
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#include <linux/nvmem-provider.h>
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#include <linux/of.h>
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#include <linux/regmap.h>
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#include <linux/slab.h>
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struct nvmem_device {
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const char *name;
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struct regmap *regmap;
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struct module *owner;
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struct device dev;
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int stride;
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int word_size;
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int ncells;
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int id;
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int users;
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size_t size;
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bool read_only;
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};
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struct nvmem_cell {
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const char *name;
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int offset;
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int bytes;
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int bit_offset;
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int nbits;
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struct nvmem_device *nvmem;
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struct list_head node;
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};
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static DEFINE_MUTEX(nvmem_mutex);
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static DEFINE_IDA(nvmem_ida);
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static LIST_HEAD(nvmem_cells);
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static DEFINE_MUTEX(nvmem_cells_mutex);
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#define to_nvmem_device(d) container_of(d, struct nvmem_device, dev)
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static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj,
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struct bin_attribute *attr,
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char *buf, loff_t pos, size_t count)
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{
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struct device *dev = container_of(kobj, struct device, kobj);
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struct nvmem_device *nvmem = to_nvmem_device(dev);
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int rc;
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/* Stop the user from reading */
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if (pos >= nvmem->size)
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return 0;
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if (pos + count > nvmem->size)
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count = nvmem->size - pos;
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count = round_down(count, nvmem->word_size);
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rc = regmap_raw_read(nvmem->regmap, pos, buf, count);
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if (IS_ERR_VALUE(rc))
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return rc;
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return count;
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}
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static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj,
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struct bin_attribute *attr,
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char *buf, loff_t pos, size_t count)
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{
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struct device *dev = container_of(kobj, struct device, kobj);
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struct nvmem_device *nvmem = to_nvmem_device(dev);
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int rc;
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/* Stop the user from writing */
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if (pos >= nvmem->size)
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return 0;
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if (pos + count > nvmem->size)
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count = nvmem->size - pos;
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count = round_down(count, nvmem->word_size);
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rc = regmap_raw_write(nvmem->regmap, pos, buf, count);
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if (IS_ERR_VALUE(rc))
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return rc;
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return count;
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}
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/* default read/write permissions */
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static struct bin_attribute bin_attr_rw_nvmem = {
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.attr = {
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.name = "nvmem",
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.mode = S_IWUSR | S_IRUGO,
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},
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.read = bin_attr_nvmem_read,
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.write = bin_attr_nvmem_write,
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};
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static struct bin_attribute *nvmem_bin_rw_attributes[] = {
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&bin_attr_rw_nvmem,
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NULL,
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};
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static const struct attribute_group nvmem_bin_rw_group = {
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.bin_attrs = nvmem_bin_rw_attributes,
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};
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static const struct attribute_group *nvmem_rw_dev_groups[] = {
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&nvmem_bin_rw_group,
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NULL,
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};
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/* read only permission */
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static struct bin_attribute bin_attr_ro_nvmem = {
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.attr = {
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.name = "nvmem",
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.mode = S_IRUGO,
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},
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.read = bin_attr_nvmem_read,
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};
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static struct bin_attribute *nvmem_bin_ro_attributes[] = {
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&bin_attr_ro_nvmem,
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NULL,
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};
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static const struct attribute_group nvmem_bin_ro_group = {
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.bin_attrs = nvmem_bin_ro_attributes,
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};
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static const struct attribute_group *nvmem_ro_dev_groups[] = {
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&nvmem_bin_ro_group,
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NULL,
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};
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static void nvmem_release(struct device *dev)
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{
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struct nvmem_device *nvmem = to_nvmem_device(dev);
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ida_simple_remove(&nvmem_ida, nvmem->id);
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kfree(nvmem);
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}
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static const struct device_type nvmem_provider_type = {
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.release = nvmem_release,
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};
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static struct bus_type nvmem_bus_type = {
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.name = "nvmem",
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};
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static int of_nvmem_match(struct device *dev, void *nvmem_np)
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{
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return dev->of_node == nvmem_np;
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}
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static struct nvmem_device *of_nvmem_find(struct device_node *nvmem_np)
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{
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struct device *d;
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if (!nvmem_np)
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return NULL;
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d = bus_find_device(&nvmem_bus_type, NULL, nvmem_np, of_nvmem_match);
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if (!d)
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return NULL;
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return to_nvmem_device(d);
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}
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static struct nvmem_cell *nvmem_find_cell(const char *cell_id)
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{
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struct nvmem_cell *p;
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list_for_each_entry(p, &nvmem_cells, node)
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if (p && !strcmp(p->name, cell_id))
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return p;
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return NULL;
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}
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static void nvmem_cell_drop(struct nvmem_cell *cell)
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{
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mutex_lock(&nvmem_cells_mutex);
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list_del(&cell->node);
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mutex_unlock(&nvmem_cells_mutex);
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kfree(cell);
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}
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static void nvmem_device_remove_all_cells(const struct nvmem_device *nvmem)
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{
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struct nvmem_cell *cell;
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struct list_head *p, *n;
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list_for_each_safe(p, n, &nvmem_cells) {
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cell = list_entry(p, struct nvmem_cell, node);
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if (cell->nvmem == nvmem)
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nvmem_cell_drop(cell);
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}
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}
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static void nvmem_cell_add(struct nvmem_cell *cell)
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{
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mutex_lock(&nvmem_cells_mutex);
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list_add_tail(&cell->node, &nvmem_cells);
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mutex_unlock(&nvmem_cells_mutex);
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}
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static int nvmem_cell_info_to_nvmem_cell(struct nvmem_device *nvmem,
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const struct nvmem_cell_info *info,
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struct nvmem_cell *cell)
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{
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cell->nvmem = nvmem;
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cell->offset = info->offset;
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cell->bytes = info->bytes;
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cell->name = info->name;
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cell->bit_offset = info->bit_offset;
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cell->nbits = info->nbits;
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if (cell->nbits)
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cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset,
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BITS_PER_BYTE);
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if (!IS_ALIGNED(cell->offset, nvmem->stride)) {
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dev_err(&nvmem->dev,
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"cell %s unaligned to nvmem stride %d\n",
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cell->name, nvmem->stride);
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return -EINVAL;
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}
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return 0;
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}
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static int nvmem_add_cells(struct nvmem_device *nvmem,
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const struct nvmem_config *cfg)
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{
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struct nvmem_cell **cells;
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const struct nvmem_cell_info *info = cfg->cells;
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int i, rval;
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cells = kcalloc(cfg->ncells, sizeof(*cells), GFP_KERNEL);
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if (!cells)
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return -ENOMEM;
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for (i = 0; i < cfg->ncells; i++) {
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cells[i] = kzalloc(sizeof(**cells), GFP_KERNEL);
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if (!cells[i]) {
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rval = -ENOMEM;
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goto err;
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}
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rval = nvmem_cell_info_to_nvmem_cell(nvmem, &info[i], cells[i]);
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if (IS_ERR_VALUE(rval)) {
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kfree(cells[i]);
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goto err;
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}
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nvmem_cell_add(cells[i]);
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}
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nvmem->ncells = cfg->ncells;
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/* remove tmp array */
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kfree(cells);
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return 0;
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err:
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while (--i)
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nvmem_cell_drop(cells[i]);
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return rval;
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}
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/**
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* nvmem_register() - Register a nvmem device for given nvmem_config.
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* Also creates an binary entry in /sys/bus/nvmem/devices/dev-name/nvmem
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*
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* @config: nvmem device configuration with which nvmem device is created.
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*
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* Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device
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* on success.
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*/
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struct nvmem_device *nvmem_register(const struct nvmem_config *config)
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{
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struct nvmem_device *nvmem;
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struct device_node *np;
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struct regmap *rm;
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int rval;
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if (!config->dev)
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return ERR_PTR(-EINVAL);
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rm = dev_get_regmap(config->dev, NULL);
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if (!rm) {
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dev_err(config->dev, "Regmap not found\n");
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return ERR_PTR(-EINVAL);
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}
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nvmem = kzalloc(sizeof(*nvmem), GFP_KERNEL);
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if (!nvmem)
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return ERR_PTR(-ENOMEM);
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rval = ida_simple_get(&nvmem_ida, 0, 0, GFP_KERNEL);
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if (rval < 0) {
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kfree(nvmem);
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return ERR_PTR(rval);
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}
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nvmem->id = rval;
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nvmem->regmap = rm;
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nvmem->owner = config->owner;
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nvmem->stride = regmap_get_reg_stride(rm);
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nvmem->word_size = regmap_get_val_bytes(rm);
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nvmem->size = regmap_get_max_register(rm) + nvmem->stride;
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nvmem->dev.type = &nvmem_provider_type;
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nvmem->dev.bus = &nvmem_bus_type;
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nvmem->dev.parent = config->dev;
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np = config->dev->of_node;
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nvmem->dev.of_node = np;
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dev_set_name(&nvmem->dev, "%s%d",
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config->name ? : "nvmem", config->id);
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nvmem->read_only = of_property_read_bool(np, "read-only") |
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config->read_only;
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nvmem->dev.groups = nvmem->read_only ? nvmem_ro_dev_groups :
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nvmem_rw_dev_groups;
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device_initialize(&nvmem->dev);
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dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name);
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rval = device_add(&nvmem->dev);
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if (rval) {
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ida_simple_remove(&nvmem_ida, nvmem->id);
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kfree(nvmem);
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return ERR_PTR(rval);
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}
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if (config->cells)
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nvmem_add_cells(nvmem, config);
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return nvmem;
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}
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EXPORT_SYMBOL_GPL(nvmem_register);
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/**
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* nvmem_unregister() - Unregister previously registered nvmem device
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*
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* @nvmem: Pointer to previously registered nvmem device.
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*
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* Return: Will be an negative on error or a zero on success.
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*/
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int nvmem_unregister(struct nvmem_device *nvmem)
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{
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mutex_lock(&nvmem_mutex);
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if (nvmem->users) {
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mutex_unlock(&nvmem_mutex);
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return -EBUSY;
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}
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mutex_unlock(&nvmem_mutex);
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nvmem_device_remove_all_cells(nvmem);
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device_del(&nvmem->dev);
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return 0;
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}
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EXPORT_SYMBOL_GPL(nvmem_unregister);
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static struct nvmem_device *__nvmem_device_get(struct device_node *np,
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struct nvmem_cell **cellp,
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const char *cell_id)
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{
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struct nvmem_device *nvmem = NULL;
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mutex_lock(&nvmem_mutex);
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if (np) {
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nvmem = of_nvmem_find(np);
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if (!nvmem) {
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mutex_unlock(&nvmem_mutex);
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return ERR_PTR(-EPROBE_DEFER);
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}
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} else {
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struct nvmem_cell *cell = nvmem_find_cell(cell_id);
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if (cell) {
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nvmem = cell->nvmem;
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*cellp = cell;
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}
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if (!nvmem) {
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mutex_unlock(&nvmem_mutex);
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return ERR_PTR(-ENOENT);
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}
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}
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nvmem->users++;
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mutex_unlock(&nvmem_mutex);
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if (!try_module_get(nvmem->owner)) {
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dev_err(&nvmem->dev,
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"could not increase module refcount for cell %s\n",
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nvmem->name);
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mutex_lock(&nvmem_mutex);
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nvmem->users--;
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mutex_unlock(&nvmem_mutex);
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return ERR_PTR(-EINVAL);
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}
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return nvmem;
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}
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static void __nvmem_device_put(struct nvmem_device *nvmem)
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{
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module_put(nvmem->owner);
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mutex_lock(&nvmem_mutex);
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nvmem->users--;
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mutex_unlock(&nvmem_mutex);
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}
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static int nvmem_match(struct device *dev, void *data)
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{
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return !strcmp(dev_name(dev), data);
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}
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static struct nvmem_device *nvmem_find(const char *name)
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{
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struct device *d;
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d = bus_find_device(&nvmem_bus_type, NULL, (void *)name, nvmem_match);
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if (!d)
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return NULL;
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return to_nvmem_device(d);
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}
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|
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#if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OF)
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/**
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* of_nvmem_device_get() - Get nvmem device from a given id
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*
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* @dev node: Device tree node that uses the nvmem device
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* @id: nvmem name from nvmem-names property.
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*
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* Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device
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* on success.
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*/
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struct nvmem_device *of_nvmem_device_get(struct device_node *np, const char *id)
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{
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|
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struct device_node *nvmem_np;
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int index;
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index = of_property_match_string(np, "nvmem-names", id);
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|
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nvmem_np = of_parse_phandle(np, "nvmem", index);
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if (!nvmem_np)
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return ERR_PTR(-EINVAL);
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|
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return __nvmem_device_get(nvmem_np, NULL, NULL);
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}
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EXPORT_SYMBOL_GPL(of_nvmem_device_get);
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#endif
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|
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/**
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* nvmem_device_get() - Get nvmem device from a given id
|
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*
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* @dev : Device that uses the nvmem device
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* @id: nvmem name from nvmem-names property.
|
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*
|
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* Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device
|
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* on success.
|
|
*/
|
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struct nvmem_device *nvmem_device_get(struct device *dev, const char *dev_name)
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{
|
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if (dev->of_node) { /* try dt first */
|
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struct nvmem_device *nvmem;
|
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|
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nvmem = of_nvmem_device_get(dev->of_node, dev_name);
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|
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if (!IS_ERR(nvmem) || PTR_ERR(nvmem) == -EPROBE_DEFER)
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return nvmem;
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|
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}
|
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|
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return nvmem_find(dev_name);
|
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}
|
|
EXPORT_SYMBOL_GPL(nvmem_device_get);
|
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|
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static int devm_nvmem_device_match(struct device *dev, void *res, void *data)
|
|
{
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struct nvmem_device **nvmem = res;
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|
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if (WARN_ON(!nvmem || !*nvmem))
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return 0;
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|
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return *nvmem == data;
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}
|
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|
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static void devm_nvmem_device_release(struct device *dev, void *res)
|
|
{
|
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nvmem_device_put(*(struct nvmem_device **)res);
|
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}
|
|
|
|
/**
|
|
* devm_nvmem_device_put() - put alredy got nvmem device
|
|
*
|
|
* @nvmem: pointer to nvmem device allocated by devm_nvmem_cell_get(),
|
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* that needs to be released.
|
|
*/
|
|
void devm_nvmem_device_put(struct device *dev, struct nvmem_device *nvmem)
|
|
{
|
|
int ret;
|
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|
|
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 node: Device tree node that uses the nvmem cell
|
|
* @id: nvmem name in nvmems property.
|
|
*
|
|
* 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_cell_get_from_list(const char *cell_id)
|
|
{
|
|
struct nvmem_cell *cell = NULL;
|
|
struct nvmem_device *nvmem;
|
|
|
|
nvmem = __nvmem_device_get(NULL, &cell, cell_id);
|
|
if (IS_ERR(nvmem))
|
|
return ERR_CAST(nvmem);
|
|
|
|
return cell;
|
|
}
|
|
|
|
#if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OF)
|
|
/**
|
|
* of_nvmem_cell_get() - Get a nvmem cell from given device node and cell id
|
|
*
|
|
* @dev node: Device tree node that uses the nvmem cell
|
|
* @id: nvmem cell name from 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 *name)
|
|
{
|
|
struct device_node *cell_np, *nvmem_np;
|
|
struct nvmem_cell *cell;
|
|
struct nvmem_device *nvmem;
|
|
const __be32 *addr;
|
|
int rval, len, index;
|
|
|
|
index = of_property_match_string(np, "nvmem-cell-names", name);
|
|
|
|
cell_np = of_parse_phandle(np, "nvmem-cells", index);
|
|
if (!cell_np)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
nvmem_np = of_get_next_parent(cell_np);
|
|
if (!nvmem_np)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
nvmem = __nvmem_device_get(nvmem_np, NULL, NULL);
|
|
if (IS_ERR(nvmem))
|
|
return ERR_CAST(nvmem);
|
|
|
|
addr = of_get_property(cell_np, "reg", &len);
|
|
if (!addr || (len < 2 * sizeof(u32))) {
|
|
dev_err(&nvmem->dev, "nvmem: invalid reg on %s\n",
|
|
cell_np->full_name);
|
|
rval = -EINVAL;
|
|
goto err_mem;
|
|
}
|
|
|
|
cell = kzalloc(sizeof(*cell), GFP_KERNEL);
|
|
if (!cell) {
|
|
rval = -ENOMEM;
|
|
goto err_mem;
|
|
}
|
|
|
|
cell->nvmem = nvmem;
|
|
cell->offset = be32_to_cpup(addr++);
|
|
cell->bytes = be32_to_cpup(addr);
|
|
cell->name = cell_np->name;
|
|
|
|
addr = of_get_property(cell_np, "bits", &len);
|
|
if (addr && len == (2 * sizeof(u32))) {
|
|
cell->bit_offset = be32_to_cpup(addr++);
|
|
cell->nbits = be32_to_cpup(addr);
|
|
}
|
|
|
|
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, nvmem->stride);
|
|
rval = -EINVAL;
|
|
goto err_sanity;
|
|
}
|
|
|
|
nvmem_cell_add(cell);
|
|
|
|
return cell;
|
|
|
|
err_sanity:
|
|
kfree(cell);
|
|
|
|
err_mem:
|
|
__nvmem_device_put(nvmem);
|
|
|
|
return ERR_PTR(rval);
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_nvmem_cell_get);
|
|
#endif
|
|
|
|
/**
|
|
* nvmem_cell_get() - Get nvmem cell of device form a given cell name
|
|
*
|
|
* @dev node: Device tree node that uses the nvmem cell
|
|
* @id: nvmem cell name 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
|
|
* nvmem_cell_put().
|
|
*/
|
|
struct nvmem_cell *nvmem_cell_get(struct device *dev, const char *cell_id)
|
|
{
|
|
struct nvmem_cell *cell;
|
|
|
|
if (dev->of_node) { /* try dt first */
|
|
cell = of_nvmem_cell_get(dev->of_node, cell_id);
|
|
if (!IS_ERR(cell) || PTR_ERR(cell) == -EPROBE_DEFER)
|
|
return cell;
|
|
}
|
|
|
|
return nvmem_cell_get_from_list(cell_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 node: Device tree node that uses the nvmem cell
|
|
* @id: nvmem id in nvmem-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
|
|
* 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.
|
|
*
|
|
* @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->nvmem;
|
|
|
|
__nvmem_device_put(nvmem);
|
|
nvmem_cell_drop(cell);
|
|
}
|
|
EXPORT_SYMBOL_GPL(nvmem_cell_put);
|
|
|
|
static inline void nvmem_shift_read_buffer_in_place(struct nvmem_cell *cell,
|
|
void *buf)
|
|
{
|
|
u8 *p, *b;
|
|
int i, 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;
|
|
}
|
|
|
|
/* result fits in less bytes */
|
|
if (cell->bytes != DIV_ROUND_UP(cell->nbits, BITS_PER_BYTE))
|
|
*p-- = 0;
|
|
}
|
|
/* clear msb bits if any leftover in the last byte */
|
|
*p &= GENMASK((cell->nbits%BITS_PER_BYTE) - 1, 0);
|
|
}
|
|
|
|
static int __nvmem_cell_read(struct nvmem_device *nvmem,
|
|
struct nvmem_cell *cell,
|
|
void *buf, size_t *len)
|
|
{
|
|
int rc;
|
|
|
|
rc = regmap_raw_read(nvmem->regmap, cell->offset, buf, cell->bytes);
|
|
|
|
if (IS_ERR_VALUE(rc))
|
|
return rc;
|
|
|
|
/* shift bits in-place */
|
|
if (cell->bit_offset || cell->nbits)
|
|
nvmem_shift_read_buffer_in_place(cell, buf);
|
|
|
|
*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.
|
|
*
|
|
* Return: ERR_PTR() on error or a valid pointer to a char * 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_device *nvmem = cell->nvmem;
|
|
u8 *buf;
|
|
int rc;
|
|
|
|
if (!nvmem || !nvmem->regmap)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
buf = kzalloc(cell->bytes, GFP_KERNEL);
|
|
if (!buf)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
rc = __nvmem_cell_read(nvmem, cell, buf, len);
|
|
if (IS_ERR_VALUE(rc)) {
|
|
kfree(buf);
|
|
return ERR_PTR(rc);
|
|
}
|
|
|
|
return buf;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nvmem_cell_read);
|
|
|
|
static inline void *nvmem_cell_prepare_write_buffer(struct nvmem_cell *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 = regmap_raw_read(nvmem->regmap, cell->offset, &v, 1);
|
|
*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 = regmap_raw_read(nvmem->regmap,
|
|
cell->offset + cell->bytes - 1, &v, 1);
|
|
*p |= GENMASK(7, (nbits + bit_offset) % BITS_PER_BYTE) & v;
|
|
|
|
}
|
|
|
|
return buf;
|
|
}
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
struct nvmem_device *nvmem = cell->nvmem;
|
|
int rc;
|
|
|
|
if (!nvmem || !nvmem->regmap || nvmem->read_only ||
|
|
(cell->bit_offset == 0 && len != cell->bytes))
|
|
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 = regmap_raw_write(nvmem->regmap, cell->offset, buf, cell->bytes);
|
|
|
|
/* free the tmp buffer */
|
|
if (cell->bit_offset || cell->nbits)
|
|
kfree(buf);
|
|
|
|
if (IS_ERR_VALUE(rc))
|
|
return rc;
|
|
|
|
return len;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nvmem_cell_write);
|
|
|
|
/**
|
|
* 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 cell;
|
|
int rc;
|
|
ssize_t len;
|
|
|
|
if (!nvmem || !nvmem->regmap)
|
|
return -EINVAL;
|
|
|
|
rc = nvmem_cell_info_to_nvmem_cell(nvmem, info, &cell);
|
|
if (IS_ERR_VALUE(rc))
|
|
return rc;
|
|
|
|
rc = __nvmem_cell_read(nvmem, &cell, buf, &len);
|
|
if (IS_ERR_VALUE(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 cell;
|
|
int rc;
|
|
|
|
if (!nvmem || !nvmem->regmap)
|
|
return -EINVAL;
|
|
|
|
rc = nvmem_cell_info_to_nvmem_cell(nvmem, info, &cell);
|
|
if (IS_ERR_VALUE(rc))
|
|
return rc;
|
|
|
|
return nvmem_cell_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 || !nvmem->regmap)
|
|
return -EINVAL;
|
|
|
|
rc = regmap_raw_read(nvmem->regmap, offset, buf, bytes);
|
|
|
|
if (IS_ERR_VALUE(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 || !nvmem->regmap)
|
|
return -EINVAL;
|
|
|
|
rc = regmap_raw_write(nvmem->regmap, offset, buf, bytes);
|
|
|
|
if (IS_ERR_VALUE(rc))
|
|
return rc;
|
|
|
|
|
|
return bytes;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nvmem_device_write);
|
|
|
|
static int __init nvmem_init(void)
|
|
{
|
|
return bus_register(&nvmem_bus_type);
|
|
}
|
|
|
|
static void __exit nvmem_exit(void)
|
|
{
|
|
bus_unregister(&nvmem_bus_type);
|
|
}
|
|
|
|
subsys_initcall(nvmem_init);
|
|
module_exit(nvmem_exit);
|
|
|
|
MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org");
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MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com");
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MODULE_DESCRIPTION("nvmem Driver Core");
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MODULE_LICENSE("GPL v2");
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