blob: 98efb7b5660d9bb7596e41413d5ea3c04fb63436 [file] [log] [blame]
/* SPDX-License-Identifier: GPL-2.0 */
* nvmem framework provider.
* Copyright (C) 2015 Srinivas Kandagatla <>
* Copyright (C) 2013 Maxime Ripard <>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/gpio/consumer.h>
struct nvmem_device;
struct nvmem_cell_info;
typedef int (*nvmem_reg_read_t)(void *priv, unsigned int offset,
void *val, size_t bytes);
typedef int (*nvmem_reg_write_t)(void *priv, unsigned int offset,
void *val, size_t bytes);
/* used for vendor specific post processing of cell data */
typedef int (*nvmem_cell_post_process_t)(void *priv, const char *id, unsigned int offset,
void *buf, size_t bytes);
enum nvmem_type {
#define NVMEM_DEVID_NONE (-1)
#define NVMEM_DEVID_AUTO (-2)
* struct nvmem_keepout - NVMEM register keepout range.
* @start: The first byte offset to avoid.
* @end: One beyond the last byte offset to avoid.
* @value: The byte to fill reads with for this region.
struct nvmem_keepout {
unsigned int start;
unsigned int end;
unsigned char value;
* struct nvmem_config - NVMEM device configuration
* @dev: Parent device.
* @name: Optional name.
* @id: Optional device ID used in full name. Ignored if name is NULL.
* @owner: Pointer to exporter module. Used for refcounting.
* @cells: Optional array of pre-defined NVMEM cells.
* @ncells: Number of elements in cells.
* @keepout: Optional array of keepout ranges (sorted ascending by start).
* @nkeepout: Number of elements in the keepout array.
* @type: Type of the nvmem storage
* @read_only: Device is read-only.
* @root_only: Device is accessibly to root only.
* @of_node: If given, this will be used instead of the parent's of_node.
* @no_of_node: Device should not use the parent's of_node even if it's !NULL.
* @reg_read: Callback to read data.
* @reg_write: Callback to write data.
* @cell_post_process: Callback for vendor specific post processing of cell data
* @size: Device size.
* @word_size: Minimum read/write access granularity.
* @stride: Minimum read/write access stride.
* @priv: User context passed to read/write callbacks.
* @wp-gpio: Write protect pin
* Note: A default "nvmem<id>" name will be assigned to the device if
* no name is specified in its configuration. In such case "<id>" is
* generated with ida_simple_get() and provided id field is ignored.
* Note: Specifying name and setting id to -1 implies a unique device
* whose name is provided as-is (kept unaltered).
struct nvmem_config {
struct device *dev;
const char *name;
int id;
struct module *owner;
struct gpio_desc *wp_gpio;
const struct nvmem_cell_info *cells;
int ncells;
const struct nvmem_keepout *keepout;
unsigned int nkeepout;
enum nvmem_type type;
bool read_only;
bool root_only;
struct device_node *of_node;
bool no_of_node;
nvmem_reg_read_t reg_read;
nvmem_reg_write_t reg_write;
nvmem_cell_post_process_t cell_post_process;
int size;
int word_size;
int stride;
void *priv;
/* To be only used by old driver/misc/eeprom drivers */
bool compat;
struct device *base_dev;
* struct nvmem_cell_table - NVMEM cell definitions for given provider
* @nvmem_name: Provider name.
* @cells: Array of cell definitions.
* @ncells: Number of cell definitions in the array.
* @node: List node.
* This structure together with related helper functions is provided for users
* that don't can't access the nvmem provided structure but wish to register
* cell definitions for it e.g. board files registering an EEPROM device.
struct nvmem_cell_table {
const char *nvmem_name;
const struct nvmem_cell_info *cells;
size_t ncells;
struct list_head node;
struct nvmem_device *nvmem_register(const struct nvmem_config *cfg);
void nvmem_unregister(struct nvmem_device *nvmem);
struct nvmem_device *devm_nvmem_register(struct device *dev,
const struct nvmem_config *cfg);
int devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem);
void nvmem_add_cell_table(struct nvmem_cell_table *table);
void nvmem_del_cell_table(struct nvmem_cell_table *table);
static inline struct nvmem_device *nvmem_register(const struct nvmem_config *c)
static inline void nvmem_unregister(struct nvmem_device *nvmem) {}
static inline struct nvmem_device *
devm_nvmem_register(struct device *dev, const struct nvmem_config *c)
return nvmem_register(c);
static inline int
devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem)
static inline void nvmem_add_cell_table(struct nvmem_cell_table *table) {}
static inline void nvmem_del_cell_table(struct nvmem_cell_table *table) {}
#endif /* CONFIG_NVMEM */
#endif /* ifndef _LINUX_NVMEM_PROVIDER_H */