1920 lines
44 KiB
C
1920 lines
44 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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[NVMEM_TYPE_FRAM] = "FRAM",
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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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if (config->type == NVMEM_TYPE_FRAM)
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bin_attr_nvmem_eeprom_compat.attr.name = "fram";
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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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*
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* @nb: notifier block to be called on nvmem events.
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*
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* Return: 0 on success, negative error number on failure.
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*/
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int nvmem_register_notifier(struct notifier_block *nb)
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{
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return blocking_notifier_chain_register(&nvmem_notifier, nb);
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}
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EXPORT_SYMBOL_GPL(nvmem_register_notifier);
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/**
|
|
* 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)
|
|
continue;
|
|
if (len < 2 * sizeof(u32)) {
|
|
dev_err(dev, "nvmem: invalid reg on %pOF\n", child);
|
|
of_node_put(child);
|
|
return -EINVAL;
|
|
}
|
|
|
|
cell = kzalloc(sizeof(*cell), GFP_KERNEL);
|
|
if (!cell) {
|
|
of_node_put(child);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
cell->nvmem = nvmem;
|
|
cell->offset = be32_to_cpup(addr++);
|
|
cell->bytes = be32_to_cpup(addr);
|
|
cell->name = kasprintf(GFP_KERNEL, "%pOFn", child);
|
|
|
|
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);
|
|
of_node_put(child);
|
|
return -EINVAL;
|
|
}
|
|
|
|
cell->np = of_node_get(child);
|
|
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->of_node)
|
|
nvmem->dev.of_node = config->of_node;
|
|
else 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);
|
|
|
|
static const void *nvmem_cell_read_variable_common(struct device *dev,
|
|
const char *cell_id,
|
|
size_t max_len, size_t *len)
|
|
{
|
|
struct nvmem_cell *cell;
|
|
int nbits;
|
|
void *buf;
|
|
|
|
cell = nvmem_cell_get(dev, cell_id);
|
|
if (IS_ERR(cell))
|
|
return cell;
|
|
|
|
nbits = cell->nbits;
|
|
buf = nvmem_cell_read(cell, len);
|
|
nvmem_cell_put(cell);
|
|
if (IS_ERR(buf))
|
|
return buf;
|
|
|
|
/*
|
|
* If nbits is set then nvmem_cell_read() can significantly exaggerate
|
|
* the length of the real data. Throw away the extra junk.
|
|
*/
|
|
if (nbits)
|
|
*len = DIV_ROUND_UP(nbits, 8);
|
|
|
|
if (*len > max_len) {
|
|
kfree(buf);
|
|
return ERR_PTR(-ERANGE);
|
|
}
|
|
|
|
return buf;
|
|
}
|
|
|
|
/**
|
|
* nvmem_cell_read_variable_le_u32() - Read up to 32-bits of data as a little endian number.
|
|
*
|
|
* @dev: Device that requests the nvmem cell.
|
|
* @cell_id: Name of nvmem cell to read.
|
|
* @val: pointer to output value.
|
|
*
|
|
* Return: 0 on success or negative errno.
|
|
*/
|
|
int nvmem_cell_read_variable_le_u32(struct device *dev, const char *cell_id,
|
|
u32 *val)
|
|
{
|
|
size_t len;
|
|
const u8 *buf;
|
|
int i;
|
|
|
|
buf = nvmem_cell_read_variable_common(dev, cell_id, sizeof(*val), &len);
|
|
if (IS_ERR(buf))
|
|
return PTR_ERR(buf);
|
|
|
|
/* Copy w/ implicit endian conversion */
|
|
*val = 0;
|
|
for (i = 0; i < len; i++)
|
|
*val |= buf[i] << (8 * i);
|
|
|
|
kfree(buf);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nvmem_cell_read_variable_le_u32);
|
|
|
|
/**
|
|
* nvmem_cell_read_variable_le_u64() - Read up to 64-bits of data as a little endian number.
|
|
*
|
|
* @dev: Device that requests the nvmem cell.
|
|
* @cell_id: Name of nvmem cell to read.
|
|
* @val: pointer to output value.
|
|
*
|
|
* Return: 0 on success or negative errno.
|
|
*/
|
|
int nvmem_cell_read_variable_le_u64(struct device *dev, const char *cell_id,
|
|
u64 *val)
|
|
{
|
|
size_t len;
|
|
const u8 *buf;
|
|
int i;
|
|
|
|
buf = nvmem_cell_read_variable_common(dev, cell_id, sizeof(*val), &len);
|
|
if (IS_ERR(buf))
|
|
return PTR_ERR(buf);
|
|
|
|
/* Copy w/ implicit endian conversion */
|
|
*val = 0;
|
|
for (i = 0; i < len; i++)
|
|
*val |= (uint64_t)buf[i] << (8 * i);
|
|
|
|
kfree(buf);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nvmem_cell_read_variable_le_u64);
|
|
|
|
/**
|
|
* nvmem_device_cell_read() - Read a given nvmem device and cell
|
|
*
|
|
* @nvmem: nvmem device to read from.
|
|
* @info: nvmem cell info to be read.
|
|
* @buf: buffer pointer which will be populated on successful read.
|
|
*
|
|
* Return: length of successful bytes read on success and negative
|
|
* error code on error.
|
|
*/
|
|
ssize_t nvmem_device_cell_read(struct nvmem_device *nvmem,
|
|
struct nvmem_cell_info *info, void *buf)
|
|
{
|
|
struct nvmem_cell 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");
|