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fd3bb8f54a
Introduce support into the nvmem core for arrays of register ranges that should not result in actual device access. For these regions a constant byte (repeated) is returned instead on read, and writes are quietly ignored and returned as successful. This is useful for instance if certain efuse regions are protected from access by Linux because they contain secret info to another part of the system (like an integrated modem). Signed-off-by: Evan Green <evgreen@chromium.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20201127102837.19366-3-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1813 lines
41 KiB
C
1813 lines
41 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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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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#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/kref.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/gpio/consumer.h>
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#include <linux/of.h>
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#include <linux/slab.h>
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struct nvmem_device {
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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 id;
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struct kref refcnt;
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size_t size;
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bool read_only;
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bool root_only;
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int flags;
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enum nvmem_type type;
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struct bin_attribute eeprom;
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struct device *base_dev;
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struct list_head cells;
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const struct nvmem_keepout *keepout;
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unsigned int nkeepout;
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nvmem_reg_read_t reg_read;
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nvmem_reg_write_t reg_write;
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struct gpio_desc *wp_gpio;
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void *priv;
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};
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#define to_nvmem_device(d) container_of(d, struct nvmem_device, dev)
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#define FLAG_COMPAT BIT(0)
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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 device_node *np;
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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 DEFINE_MUTEX(nvmem_cell_mutex);
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static LIST_HEAD(nvmem_cell_tables);
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static DEFINE_MUTEX(nvmem_lookup_mutex);
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static LIST_HEAD(nvmem_lookup_list);
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static BLOCKING_NOTIFIER_HEAD(nvmem_notifier);
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static int __nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset,
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void *val, size_t bytes)
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{
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if (nvmem->reg_read)
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return nvmem->reg_read(nvmem->priv, offset, val, bytes);
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return -EINVAL;
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}
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static int __nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset,
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void *val, size_t bytes)
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{
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int ret;
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if (nvmem->reg_write) {
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gpiod_set_value_cansleep(nvmem->wp_gpio, 0);
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ret = nvmem->reg_write(nvmem->priv, offset, val, bytes);
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gpiod_set_value_cansleep(nvmem->wp_gpio, 1);
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return ret;
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}
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return -EINVAL;
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}
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static int nvmem_access_with_keepouts(struct nvmem_device *nvmem,
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unsigned int offset, void *val,
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size_t bytes, int write)
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{
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unsigned int end = offset + bytes;
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unsigned int kend, ksize;
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const struct nvmem_keepout *keepout = nvmem->keepout;
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const struct nvmem_keepout *keepoutend = keepout + nvmem->nkeepout;
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int rc;
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/*
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* Skip all keepouts before the range being accessed.
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* Keepouts are sorted.
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*/
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while ((keepout < keepoutend) && (keepout->end <= offset))
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keepout++;
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while ((offset < end) && (keepout < keepoutend)) {
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/* Access the valid portion before the keepout. */
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if (offset < keepout->start) {
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kend = min(end, keepout->start);
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ksize = kend - offset;
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if (write)
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rc = __nvmem_reg_write(nvmem, offset, val, ksize);
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else
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rc = __nvmem_reg_read(nvmem, offset, val, ksize);
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if (rc)
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return rc;
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offset += ksize;
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val += ksize;
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}
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/*
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* Now we're aligned to the start of this keepout zone. Go
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* through it.
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*/
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kend = min(end, keepout->end);
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ksize = kend - offset;
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if (!write)
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memset(val, keepout->value, ksize);
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val += ksize;
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offset += ksize;
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keepout++;
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}
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/*
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* If we ran out of keepouts but there's still stuff to do, send it
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* down directly
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*/
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if (offset < end) {
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ksize = end - offset;
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if (write)
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return __nvmem_reg_write(nvmem, offset, val, ksize);
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else
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return __nvmem_reg_read(nvmem, offset, val, ksize);
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}
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return 0;
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}
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static int nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset,
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void *val, size_t bytes)
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{
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if (!nvmem->nkeepout)
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return __nvmem_reg_read(nvmem, offset, val, bytes);
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return nvmem_access_with_keepouts(nvmem, offset, val, bytes, false);
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}
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static int nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset,
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void *val, size_t bytes)
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{
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if (!nvmem->nkeepout)
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return __nvmem_reg_write(nvmem, offset, val, bytes);
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return nvmem_access_with_keepouts(nvmem, offset, val, bytes, true);
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}
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#ifdef CONFIG_NVMEM_SYSFS
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static const char * const nvmem_type_str[] = {
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[NVMEM_TYPE_UNKNOWN] = "Unknown",
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[NVMEM_TYPE_EEPROM] = "EEPROM",
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[NVMEM_TYPE_OTP] = "OTP",
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[NVMEM_TYPE_BATTERY_BACKED] = "Battery backed",
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};
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#ifdef CONFIG_DEBUG_LOCK_ALLOC
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static struct lock_class_key eeprom_lock_key;
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#endif
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static ssize_t type_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct nvmem_device *nvmem = to_nvmem_device(dev);
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return sprintf(buf, "%s\n", nvmem_type_str[nvmem->type]);
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}
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static DEVICE_ATTR_RO(type);
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static struct attribute *nvmem_attrs[] = {
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&dev_attr_type.attr,
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NULL,
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};
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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, char *buf,
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loff_t pos, size_t count)
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{
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struct device *dev;
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struct nvmem_device *nvmem;
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int rc;
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if (attr->private)
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dev = attr->private;
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else
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dev = kobj_to_dev(kobj);
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nvmem = to_nvmem_device(dev);
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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 (!IS_ALIGNED(pos, nvmem->stride))
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return -EINVAL;
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if (count < nvmem->word_size)
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return -EINVAL;
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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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if (!nvmem->reg_read)
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return -EPERM;
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rc = nvmem_reg_read(nvmem, pos, buf, count);
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if (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, char *buf,
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loff_t pos, size_t count)
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{
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struct device *dev;
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struct nvmem_device *nvmem;
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int rc;
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if (attr->private)
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dev = attr->private;
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else
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dev = kobj_to_dev(kobj);
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nvmem = to_nvmem_device(dev);
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/* Stop the user from writing */
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if (pos >= nvmem->size)
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return -EFBIG;
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if (!IS_ALIGNED(pos, nvmem->stride))
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return -EINVAL;
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if (count < nvmem->word_size)
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return -EINVAL;
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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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if (!nvmem->reg_write)
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return -EPERM;
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rc = nvmem_reg_write(nvmem, pos, buf, count);
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if (rc)
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return rc;
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return count;
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}
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static umode_t nvmem_bin_attr_get_umode(struct nvmem_device *nvmem)
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{
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umode_t mode = 0400;
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if (!nvmem->root_only)
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mode |= 0044;
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if (!nvmem->read_only)
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mode |= 0200;
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if (!nvmem->reg_write)
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mode &= ~0200;
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if (!nvmem->reg_read)
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mode &= ~0444;
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return mode;
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}
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static umode_t nvmem_bin_attr_is_visible(struct kobject *kobj,
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struct bin_attribute *attr, int i)
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{
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struct device *dev = kobj_to_dev(kobj);
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struct nvmem_device *nvmem = to_nvmem_device(dev);
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return nvmem_bin_attr_get_umode(nvmem);
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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 = 0644,
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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_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_group = {
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.bin_attrs = nvmem_bin_attributes,
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.attrs = nvmem_attrs,
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.is_bin_visible = nvmem_bin_attr_is_visible,
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};
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static const struct attribute_group *nvmem_dev_groups[] = {
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&nvmem_bin_group,
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NULL,
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};
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static struct bin_attribute bin_attr_nvmem_eeprom_compat = {
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.attr = {
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.name = "eeprom",
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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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/*
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* nvmem_setup_compat() - Create an additional binary entry in
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* drivers sys directory, to be backwards compatible with the older
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* drivers/misc/eeprom drivers.
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*/
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static int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem,
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const struct nvmem_config *config)
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{
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int rval;
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if (!config->compat)
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return 0;
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if (!config->base_dev)
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return -EINVAL;
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nvmem->eeprom = bin_attr_nvmem_eeprom_compat;
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nvmem->eeprom.attr.mode = nvmem_bin_attr_get_umode(nvmem);
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nvmem->eeprom.size = nvmem->size;
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#ifdef CONFIG_DEBUG_LOCK_ALLOC
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nvmem->eeprom.attr.key = &eeprom_lock_key;
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#endif
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nvmem->eeprom.private = &nvmem->dev;
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nvmem->base_dev = config->base_dev;
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rval = device_create_bin_file(nvmem->base_dev, &nvmem->eeprom);
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if (rval) {
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dev_err(&nvmem->dev,
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"Failed to create eeprom binary file %d\n", rval);
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return rval;
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}
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nvmem->flags |= FLAG_COMPAT;
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return 0;
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}
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static void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem,
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const struct nvmem_config *config)
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{
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if (config->compat)
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device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);
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}
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#else /* CONFIG_NVMEM_SYSFS */
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static int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem,
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const struct nvmem_config *config)
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{
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return -ENOSYS;
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}
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static void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem,
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const struct nvmem_config *config)
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{
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}
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#endif /* CONFIG_NVMEM_SYSFS */
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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_free(&nvmem_ida, nvmem->id);
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gpiod_put(nvmem->wp_gpio);
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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 void nvmem_cell_drop(struct nvmem_cell *cell)
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{
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blocking_notifier_call_chain(&nvmem_notifier, NVMEM_CELL_REMOVE, cell);
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mutex_lock(&nvmem_mutex);
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list_del(&cell->node);
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mutex_unlock(&nvmem_mutex);
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of_node_put(cell->np);
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kfree_const(cell->name);
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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, *p;
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list_for_each_entry_safe(cell, p, &nvmem->cells, node)
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nvmem_cell_drop(cell);
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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_mutex);
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list_add_tail(&cell->node, &cell->nvmem->cells);
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mutex_unlock(&nvmem_mutex);
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blocking_notifier_call_chain(&nvmem_notifier, NVMEM_CELL_ADD, cell);
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}
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static int nvmem_cell_info_to_nvmem_cell_nodup(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 ?: "<unknown>", 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_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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int err;
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err = nvmem_cell_info_to_nvmem_cell_nodup(nvmem, info, cell);
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if (err)
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return err;
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cell->name = kstrdup_const(info->name, GFP_KERNEL);
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if (!cell->name)
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return -ENOMEM;
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return 0;
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}
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/**
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* nvmem_add_cells() - Add cell information to an nvmem device
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*
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* @nvmem: nvmem device to add cells to.
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* @info: nvmem cell info to add to the device
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* @ncells: number of cells in info
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*
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* Return: 0 or negative error code on failure.
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*/
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static int nvmem_add_cells(struct nvmem_device *nvmem,
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const struct nvmem_cell_info *info,
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int ncells)
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{
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struct nvmem_cell **cells;
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int i, rval;
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cells = kcalloc(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 < 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 (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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/* 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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kfree(cells);
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return rval;
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}
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/**
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* nvmem_register_notifier() - Register a notifier block for nvmem events.
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*
|
|
* @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 *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(nvmem,
|
|
info,
|
|
cell);
|
|
if (rval) {
|
|
kfree(cell);
|
|
goto out;
|
|
}
|
|
|
|
nvmem_cell_add(cell);
|
|
}
|
|
}
|
|
}
|
|
|
|
out:
|
|
mutex_unlock(&nvmem_cell_mutex);
|
|
return rval;
|
|
}
|
|
|
|
static struct nvmem_cell *
|
|
nvmem_find_cell_by_name(struct nvmem_device *nvmem, const char *cell_id)
|
|
{
|
|
struct nvmem_cell *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_of(struct nvmem_device *nvmem)
|
|
{
|
|
struct device_node *parent, *child;
|
|
struct device *dev = &nvmem->dev;
|
|
struct nvmem_cell *cell;
|
|
const __be32 *addr;
|
|
int len;
|
|
|
|
parent = dev->of_node;
|
|
|
|
for_each_child_of_node(parent, child) {
|
|
addr = of_get_property(child, "reg", &len);
|
|
if (!addr || (len < 2 * sizeof(u32))) {
|
|
dev_err(dev, "nvmem: invalid reg on %pOF\n", child);
|
|
return -EINVAL;
|
|
}
|
|
|
|
cell = kzalloc(sizeof(*cell), GFP_KERNEL);
|
|
if (!cell)
|
|
return -ENOMEM;
|
|
|
|
cell->nvmem = nvmem;
|
|
cell->np = of_node_get(child);
|
|
cell->offset = be32_to_cpup(addr++);
|
|
cell->bytes = be32_to_cpup(addr);
|
|
cell->name = kasprintf(GFP_KERNEL, "%pOFn", child);
|
|
|
|
addr = of_get_property(child, "bits", &len);
|
|
if (addr && len == (2 * sizeof(u32))) {
|
|
cell->bit_offset = be32_to_cpup(addr++);
|
|
cell->nbits = be32_to_cpup(addr);
|
|
}
|
|
|
|
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(dev, "cell %s unaligned to nvmem stride %d\n",
|
|
cell->name, nvmem->stride);
|
|
/* Cells already added will be freed later. */
|
|
kfree_const(cell->name);
|
|
kfree(cell);
|
|
return -EINVAL;
|
|
}
|
|
|
|
nvmem_cell_add(cell);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* 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);
|
|
}
|
|
|
|
if (config->wp_gpio)
|
|
nvmem->wp_gpio = config->wp_gpio;
|
|
else
|
|
nvmem->wp_gpio = gpiod_get_optional(config->dev, "wp",
|
|
GPIOD_OUT_HIGH);
|
|
if (IS_ERR(nvmem->wp_gpio)) {
|
|
ida_free(&nvmem_ida, nvmem->id);
|
|
rval = PTR_ERR(nvmem->wp_gpio);
|
|
kfree(nvmem);
|
|
return ERR_PTR(rval);
|
|
}
|
|
|
|
kref_init(&nvmem->refcnt);
|
|
INIT_LIST_HEAD(&nvmem->cells);
|
|
|
|
nvmem->id = rval;
|
|
nvmem->owner = config->owner;
|
|
if (!nvmem->owner && config->dev->driver)
|
|
nvmem->owner = config->dev->driver->owner;
|
|
nvmem->stride = config->stride ?: 1;
|
|
nvmem->word_size = config->word_size ?: 1;
|
|
nvmem->size = config->size;
|
|
nvmem->dev.type = &nvmem_provider_type;
|
|
nvmem->dev.bus = &nvmem_bus_type;
|
|
nvmem->dev.parent = config->dev;
|
|
nvmem->root_only = config->root_only;
|
|
nvmem->priv = config->priv;
|
|
nvmem->type = config->type;
|
|
nvmem->reg_read = config->reg_read;
|
|
nvmem->reg_write = config->reg_write;
|
|
nvmem->keepout = config->keepout;
|
|
nvmem->nkeepout = config->nkeepout;
|
|
if (!config->no_of_node)
|
|
nvmem->dev.of_node = config->dev->of_node;
|
|
|
|
switch (config->id) {
|
|
case NVMEM_DEVID_NONE:
|
|
dev_set_name(&nvmem->dev, "%s", config->name);
|
|
break;
|
|
case NVMEM_DEVID_AUTO:
|
|
dev_set_name(&nvmem->dev, "%s%d", config->name, nvmem->id);
|
|
break;
|
|
default:
|
|
dev_set_name(&nvmem->dev, "%s%d",
|
|
config->name ? : "nvmem",
|
|
config->name ? config->id : nvmem->id);
|
|
break;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name);
|
|
|
|
rval = device_register(&nvmem->dev);
|
|
if (rval)
|
|
goto err_put_device;
|
|
|
|
if (config->compat) {
|
|
rval = nvmem_sysfs_setup_compat(nvmem, config);
|
|
if (rval)
|
|
goto err_device_del;
|
|
}
|
|
|
|
if (config->cells) {
|
|
rval = nvmem_add_cells(nvmem, config->cells, config->ncells);
|
|
if (rval)
|
|
goto err_teardown_compat;
|
|
}
|
|
|
|
rval = nvmem_add_cells_from_table(nvmem);
|
|
if (rval)
|
|
goto err_remove_cells;
|
|
|
|
rval = nvmem_add_cells_from_of(nvmem);
|
|
if (rval)
|
|
goto err_remove_cells;
|
|
|
|
blocking_notifier_call_chain(&nvmem_notifier, NVMEM_ADD, nvmem);
|
|
|
|
return nvmem;
|
|
|
|
err_remove_cells:
|
|
nvmem_device_remove_all_cells(nvmem);
|
|
err_teardown_compat:
|
|
if (config->compat)
|
|
nvmem_sysfs_remove_compat(nvmem, config);
|
|
err_device_del:
|
|
device_del(&nvmem->dev);
|
|
err_put_device:
|
|
put_device(&nvmem->dev);
|
|
|
|
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);
|
|
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)
|
|
{
|
|
kref_put(&nvmem->refcnt, nvmem_device_release);
|
|
}
|
|
EXPORT_SYMBOL_GPL(nvmem_unregister);
|
|
|
|
static void devm_nvmem_release(struct device *dev, void *res)
|
|
{
|
|
nvmem_unregister(*(struct nvmem_device **)res);
|
|
}
|
|
|
|
/**
|
|
* 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 **ptr, *nvmem;
|
|
|
|
ptr = devres_alloc(devm_nvmem_release, sizeof(*ptr), GFP_KERNEL);
|
|
if (!ptr)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
nvmem = nvmem_register(config);
|
|
|
|
if (!IS_ERR(nvmem)) {
|
|
*ptr = nvmem;
|
|
devres_add(dev, ptr);
|
|
} else {
|
|
devres_free(ptr);
|
|
}
|
|
|
|
return nvmem;
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_nvmem_register);
|
|
|
|
static int devm_nvmem_match(struct device *dev, void *res, void *data)
|
|
{
|
|
struct nvmem_device **r = res;
|
|
|
|
return *r == data;
|
|
}
|
|
|
|
/**
|
|
* devm_nvmem_unregister() - Unregister previously registered managed nvmem
|
|
* device.
|
|
*
|
|
* @dev: Device that uses the nvmem device.
|
|
* @nvmem: Pointer to previously registered nvmem device.
|
|
*
|
|
* Return: Will be negative on error or zero on success.
|
|
*/
|
|
int devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem)
|
|
{
|
|
return devres_release(dev, devm_nvmem_release, devm_nvmem_match, nvmem);
|
|
}
|
|
EXPORT_SYMBOL(devm_nvmem_unregister);
|
|
|
|
static struct nvmem_device *__nvmem_device_get(void *data,
|
|
int (*match)(struct device *dev, const void *data))
|
|
{
|
|
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_cell_get_from_lookup(struct device *dev, const char *con_id)
|
|
{
|
|
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 = nvmem_find_cell_by_name(nvmem,
|
|
lookup->cell_name);
|
|
if (!cell) {
|
|
__nvmem_device_put(nvmem);
|
|
cell = ERR_PTR(-ENOENT);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
mutex_unlock(&nvmem_lookup_mutex);
|
|
return cell;
|
|
}
|
|
|
|
#if IS_ENABLED(CONFIG_OF)
|
|
static struct nvmem_cell *
|
|
nvmem_find_cell_by_node(struct nvmem_device *nvmem, struct device_node *np)
|
|
{
|
|
struct nvmem_cell *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;
|
|
}
|
|
|
|
/**
|
|
* 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 *cell;
|
|
int index = 0;
|
|
|
|
/* if cell name exists, find index to the name */
|
|
if (id)
|
|
index = of_property_match_string(np, "nvmem-cell-names", id);
|
|
|
|
cell_np = of_parse_phandle(np, "nvmem-cells", index);
|
|
if (!cell_np)
|
|
return ERR_PTR(-ENOENT);
|
|
|
|
nvmem_np = of_get_next_parent(cell_np);
|
|
if (!nvmem_np)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
nvmem = __nvmem_device_get(nvmem_np, device_match_of_node);
|
|
of_node_put(nvmem_np);
|
|
if (IS_ERR(nvmem))
|
|
return ERR_CAST(nvmem);
|
|
|
|
cell = nvmem_find_cell_by_node(nvmem, cell_np);
|
|
if (!cell) {
|
|
__nvmem_device_put(nvmem);
|
|
return ERR_PTR(-ENOENT);
|
|
}
|
|
|
|
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->nvmem;
|
|
|
|
__nvmem_device_put(nvmem);
|
|
}
|
|
EXPORT_SYMBOL_GPL(nvmem_cell_put);
|
|
|
|
static void nvmem_shift_read_buffer_in_place(struct nvmem_cell *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 */
|
|
*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 = nvmem_reg_read(nvmem, cell->offset, buf, cell->bytes);
|
|
|
|
if (rc)
|
|
return rc;
|
|
|
|
/* shift bits in-place */
|
|
if (cell->bit_offset || cell->nbits)
|
|
nvmem_shift_read_buffer_in_place(cell, buf);
|
|
|
|
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_device *nvmem = cell->nvmem;
|
|
u8 *buf;
|
|
int rc;
|
|
|
|
if (!nvmem)
|
|
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 (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 *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);
|
|
}
|
|
|
|
/**
|
|
* 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->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 = 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;
|
|
}
|
|
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);
|
|
|
|
/**
|
|
* 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)
|
|
return -EINVAL;
|
|
|
|
rc = nvmem_cell_info_to_nvmem_cell_nodup(nvmem, info, &cell);
|
|
if (rc)
|
|
return rc;
|
|
|
|
rc = __nvmem_cell_read(nvmem, &cell, buf, &len);
|
|
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 cell;
|
|
int rc;
|
|
|
|
if (!nvmem)
|
|
return -EINVAL;
|
|
|
|
rc = nvmem_cell_info_to_nvmem_cell_nodup(nvmem, info, &cell);
|
|
if (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)
|
|
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);
|
|
|
|
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");
|
|
MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com");
|
|
MODULE_DESCRIPTION("nvmem Driver Core");
|
|
MODULE_LICENSE("GPL v2");
|