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path: root/drivers/nvmem/core.c
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Diffstat (limited to 'drivers/nvmem/core.c')
-rw-r--r--drivers/nvmem/core.c316
1 files changed, 51 insertions, 265 deletions
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index f24008b66826..c7892c3da91f 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -17,27 +17,7 @@
#include <linux/nvmem-provider.h>
#include <linux/of.h>
#include <linux/slab.h>
-
-struct nvmem_device {
- struct module *owner;
- struct device dev;
- int stride;
- int word_size;
- int id;
- struct kref refcnt;
- size_t size;
- bool read_only;
- int flags;
- enum nvmem_type type;
- struct bin_attribute eeprom;
- struct device *base_dev;
- struct list_head cells;
- nvmem_reg_read_t reg_read;
- nvmem_reg_write_t reg_write;
- void *priv;
-};
-
-#define FLAG_COMPAT BIT(0)
+#include "nvmem.h"
struct nvmem_cell {
const char *name;
@@ -61,18 +41,7 @@ static LIST_HEAD(nvmem_lookup_list);
static BLOCKING_NOTIFIER_HEAD(nvmem_notifier);
-static const char * const nvmem_type_str[] = {
- [NVMEM_TYPE_UNKNOWN] = "Unknown",
- [NVMEM_TYPE_EEPROM] = "EEPROM",
- [NVMEM_TYPE_OTP] = "OTP",
- [NVMEM_TYPE_BATTERY_BACKED] = "Battery backed",
-};
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-static struct lock_class_key eeprom_lock_key;
-#endif
-
-#define to_nvmem_device(d) container_of(d, struct nvmem_device, dev)
static int nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset,
void *val, size_t bytes)
{
@@ -91,187 +60,6 @@ static int nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset,
return -EINVAL;
}
-static ssize_t type_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct nvmem_device *nvmem = to_nvmem_device(dev);
-
- return sprintf(buf, "%s\n", nvmem_type_str[nvmem->type]);
-}
-
-static DEVICE_ATTR_RO(type);
-
-static struct attribute *nvmem_attrs[] = {
- &dev_attr_type.attr,
- NULL,
-};
-
-static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj,
- struct bin_attribute *attr,
- char *buf, loff_t pos, size_t count)
-{
- struct device *dev;
- struct nvmem_device *nvmem;
- int rc;
-
- if (attr->private)
- dev = attr->private;
- else
- dev = container_of(kobj, struct device, kobj);
- nvmem = to_nvmem_device(dev);
-
- /* Stop the user from reading */
- if (pos >= nvmem->size)
- return 0;
-
- if (count < nvmem->word_size)
- return -EINVAL;
-
- if (pos + count > nvmem->size)
- count = nvmem->size - pos;
-
- count = round_down(count, nvmem->word_size);
-
- rc = nvmem_reg_read(nvmem, pos, buf, count);
-
- if (rc)
- return rc;
-
- return count;
-}
-
-static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj,
- struct bin_attribute *attr,
- char *buf, loff_t pos, size_t count)
-{
- struct device *dev;
- struct nvmem_device *nvmem;
- int rc;
-
- if (attr->private)
- dev = attr->private;
- else
- dev = container_of(kobj, struct device, kobj);
- nvmem = to_nvmem_device(dev);
-
- /* Stop the user from writing */
- if (pos >= nvmem->size)
- return -EFBIG;
-
- if (count < nvmem->word_size)
- return -EINVAL;
-
- if (pos + count > nvmem->size)
- count = nvmem->size - pos;
-
- count = round_down(count, nvmem->word_size);
-
- rc = nvmem_reg_write(nvmem, pos, buf, count);
-
- if (rc)
- return rc;
-
- return count;
-}
-
-/* default read/write permissions */
-static struct bin_attribute bin_attr_rw_nvmem = {
- .attr = {
- .name = "nvmem",
- .mode = 0644,
- },
- .read = bin_attr_nvmem_read,
- .write = bin_attr_nvmem_write,
-};
-
-static struct bin_attribute *nvmem_bin_rw_attributes[] = {
- &bin_attr_rw_nvmem,
- NULL,
-};
-
-static const struct attribute_group nvmem_bin_rw_group = {
- .bin_attrs = nvmem_bin_rw_attributes,
- .attrs = nvmem_attrs,
-};
-
-static const struct attribute_group *nvmem_rw_dev_groups[] = {
- &nvmem_bin_rw_group,
- NULL,
-};
-
-/* read only permission */
-static struct bin_attribute bin_attr_ro_nvmem = {
- .attr = {
- .name = "nvmem",
- .mode = 0444,
- },
- .read = bin_attr_nvmem_read,
-};
-
-static struct bin_attribute *nvmem_bin_ro_attributes[] = {
- &bin_attr_ro_nvmem,
- NULL,
-};
-
-static const struct attribute_group nvmem_bin_ro_group = {
- .bin_attrs = nvmem_bin_ro_attributes,
- .attrs = nvmem_attrs,
-};
-
-static const struct attribute_group *nvmem_ro_dev_groups[] = {
- &nvmem_bin_ro_group,
- NULL,
-};
-
-/* default read/write permissions, root only */
-static struct bin_attribute bin_attr_rw_root_nvmem = {
- .attr = {
- .name = "nvmem",
- .mode = 0600,
- },
- .read = bin_attr_nvmem_read,
- .write = bin_attr_nvmem_write,
-};
-
-static struct bin_attribute *nvmem_bin_rw_root_attributes[] = {
- &bin_attr_rw_root_nvmem,
- NULL,
-};
-
-static const struct attribute_group nvmem_bin_rw_root_group = {
- .bin_attrs = nvmem_bin_rw_root_attributes,
- .attrs = nvmem_attrs,
-};
-
-static const struct attribute_group *nvmem_rw_root_dev_groups[] = {
- &nvmem_bin_rw_root_group,
- NULL,
-};
-
-/* read only permission, root only */
-static struct bin_attribute bin_attr_ro_root_nvmem = {
- .attr = {
- .name = "nvmem",
- .mode = 0400,
- },
- .read = bin_attr_nvmem_read,
-};
-
-static struct bin_attribute *nvmem_bin_ro_root_attributes[] = {
- &bin_attr_ro_root_nvmem,
- NULL,
-};
-
-static const struct attribute_group nvmem_bin_ro_root_group = {
- .bin_attrs = nvmem_bin_ro_root_attributes,
- .attrs = nvmem_attrs,
-};
-
-static const struct attribute_group *nvmem_ro_root_dev_groups[] = {
- &nvmem_bin_ro_root_group,
- NULL,
-};
-
static void nvmem_release(struct device *dev)
{
struct nvmem_device *nvmem = to_nvmem_device(dev);
@@ -422,43 +210,6 @@ err:
return rval;
}
-/*
- * nvmem_setup_compat() - Create an additional binary entry in
- * drivers sys directory, to be backwards compatible with the older
- * drivers/misc/eeprom drivers.
- */
-static int nvmem_setup_compat(struct nvmem_device *nvmem,
- const struct nvmem_config *config)
-{
- int rval;
-
- if (!config->base_dev)
- return -EINVAL;
-
- if (nvmem->read_only)
- nvmem->eeprom = bin_attr_ro_root_nvmem;
- else
- nvmem->eeprom = bin_attr_rw_root_nvmem;
- nvmem->eeprom.attr.name = "eeprom";
- nvmem->eeprom.size = nvmem->size;
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
- nvmem->eeprom.attr.key = &eeprom_lock_key;
-#endif
- nvmem->eeprom.private = &nvmem->dev;
- nvmem->base_dev = config->base_dev;
-
- rval = device_create_bin_file(nvmem->base_dev, &nvmem->eeprom);
- if (rval) {
- dev_err(&nvmem->dev,
- "Failed to create eeprom binary file %d\n", rval);
- return rval;
- }
-
- nvmem->flags |= FLAG_COMPAT;
-
- return 0;
-}
-
/**
* nvmem_register_notifier() - Register a notifier block for nvmem events.
*
@@ -651,14 +402,7 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
nvmem->read_only = device_property_present(config->dev, "read-only") ||
config->read_only || !nvmem->reg_write;
- if (config->root_only)
- nvmem->dev.groups = nvmem->read_only ?
- nvmem_ro_root_dev_groups :
- nvmem_rw_root_dev_groups;
- else
- nvmem->dev.groups = nvmem->read_only ?
- nvmem_ro_dev_groups :
- nvmem_rw_dev_groups;
+ nvmem->dev.groups = nvmem_sysfs_get_groups(nvmem, config);
device_initialize(&nvmem->dev);
@@ -669,7 +413,7 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
goto err_put_device;
if (config->compat) {
- rval = nvmem_setup_compat(nvmem, config);
+ rval = nvmem_sysfs_setup_compat(nvmem, config);
if (rval)
goto err_device_del;
}
@@ -696,7 +440,7 @@ err_remove_cells:
nvmem_device_remove_all_cells(nvmem);
err_teardown_compat:
if (config->compat)
- device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);
+ nvmem_sysfs_remove_compat(nvmem, config);
err_device_del:
device_del(&nvmem->dev);
err_put_device:
@@ -1166,7 +910,7 @@ 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, bit_offset = cell->bit_offset;
+ int i, extra, bit_offset = cell->bit_offset;
p = b = buf;
if (bit_offset) {
@@ -1181,11 +925,16 @@ static void nvmem_shift_read_buffer_in_place(struct nvmem_cell *cell, void *buf)
p = b;
*b++ >>= bit_offset;
}
-
- /* result fits in less bytes */
- if (cell->bytes != DIV_ROUND_UP(cell->nbits, BITS_PER_BYTE))
- *p-- = 0;
+ } 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);
}
@@ -1335,6 +1084,43 @@ int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len)
EXPORT_SYMBOL_GPL(nvmem_cell_write);
/**
+ * nvmem_cell_read_u16() - Read a cell value as an 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)
+{
+ 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 != sizeof(*val)) {
+ kfree(buf);
+ nvmem_cell_put(cell);
+ return -EINVAL;
+ }
+ memcpy(val, buf, sizeof(*val));
+ kfree(buf);
+ nvmem_cell_put(cell);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(nvmem_cell_read_u16);
+
+/**
* nvmem_cell_read_u32() - Read a cell value as an u32
*
* @dev: Device that requests the nvmem cell.