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/* SPDX-License-Identifier: GPL-2.0 */
/*
* nvmem framework provider.
*
* Copyright (C) 2015 Srinivas Kandagatla <[email protected]>
* Copyright (C) 2013 Maxime Ripard <[email protected]>
*/
#ifndef _LINUX_NVMEM_PROVIDER_H
#define _LINUX_NVMEM_PROVIDER_H
#include <linux/device.h>
#include <linux/device/driver.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/gpio/consumer.h>
struct nvmem_device;
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, int index,
unsigned int offset, void *buf,
size_t bytes);
enum nvmem_type {
NVMEM_TYPE_UNKNOWN = 0,
NVMEM_TYPE_EEPROM,
NVMEM_TYPE_OTP,
NVMEM_TYPE_BATTERY_BACKED,
NVMEM_TYPE_FRAM,
};
#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_cell_info - NVMEM cell description
* @name: Name.
* @offset: Offset within the NVMEM device.
* @raw_len: Length of raw data (without post processing).
* @bytes: Length of the cell.
* @bit_offset: Bit offset if cell is smaller than a byte.
* @nbits: Number of bits.
* @np: Optional device_node pointer.
* @read_post_process: Callback for optional post processing of cell data
* on reads.
* @priv: Opaque data passed to the read_post_process hook.
*/
struct nvmem_cell_info {
const char *name;
unsigned int offset;
size_t raw_len;
unsigned int bytes;
unsigned int bit_offset;
unsigned int nbits;
struct device_node *np;
nvmem_cell_post_process_t read_post_process;
void *priv;
};
/**
* 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.
* @add_legacy_fixed_of_cells: Read fixed NVMEM cells from old OF syntax.
* @fixup_dt_cell_info: Will be called before a cell is added. Can be
* used to modify the nvmem_cell_info.
* @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.
* @reg_read: Callback to read data.
* @reg_write: Callback to write 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.
* @ignore_wp: Write Protect pin is managed by the provider.
* @layout: Fixed layout associated with this nvmem device.
*
* 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;
const struct nvmem_cell_info *cells;
int ncells;
bool add_legacy_fixed_of_cells;
void (*fixup_dt_cell_info)(struct nvmem_device *nvmem,
struct nvmem_cell_info *cell);
const struct nvmem_keepout *keepout;
unsigned int nkeepout;
enum nvmem_type type;
bool read_only;
bool root_only;
bool ignore_wp;
struct nvmem_layout *layout;
struct device_node *of_node;
nvmem_reg_read_t reg_read;
nvmem_reg_write_t reg_write;
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_layout - NVMEM layout definitions
*
* @dev: Device-model layout device.
* @nvmem: The underlying NVMEM device
* @add_cells: Will be called if a nvmem device is found which
* has this layout. The function will add layout
* specific cells with nvmem_add_one_cell().
*
* A nvmem device can hold a well defined structure which can just be
* evaluated during runtime. For example a TLV list, or a list of "name=val"
* pairs. A nvmem layout can parse the nvmem device and add appropriate
* cells.
*/
struct nvmem_layout {
struct device dev;
struct nvmem_device *nvmem;
int (*add_cells)(struct nvmem_layout *layout);
};
struct nvmem_layout_driver {
struct device_driver driver;
int (*probe)(struct nvmem_layout *layout);
void (*remove)(struct nvmem_layout *layout);
};
#if IS_ENABLED(CONFIG_NVMEM)
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);
void nvmem_add_cell_table(struct nvmem_cell_table *table);
void nvmem_del_cell_table(struct nvmem_cell_table *table);
int nvmem_add_one_cell(struct nvmem_device *nvmem,
const struct nvmem_cell_info *info);
int nvmem_layout_register(struct nvmem_layout *layout);
void nvmem_layout_unregister(struct nvmem_layout *layout);
int nvmem_layout_driver_register(struct nvmem_layout_driver *drv);
void nvmem_layout_driver_unregister(struct nvmem_layout_driver *drv);
#define module_nvmem_layout_driver(__nvmem_layout_driver) \
module_driver(__nvmem_layout_driver, nvmem_layout_driver_register, \
nvmem_layout_driver_unregister)
#else
static inline struct nvmem_device *nvmem_register(const struct nvmem_config *c)
{
return ERR_PTR(-EOPNOTSUPP);
}
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 void nvmem_add_cell_table(struct nvmem_cell_table *table) {}
static inline void nvmem_del_cell_table(struct nvmem_cell_table *table) {}
static inline int nvmem_add_one_cell(struct nvmem_device *nvmem,
const struct nvmem_cell_info *info)
{
return -EOPNOTSUPP;
}
static inline int nvmem_layout_register(struct nvmem_layout *layout)
{
return -EOPNOTSUPP;
}
static inline void nvmem_layout_unregister(struct nvmem_layout *layout) {}
#endif /* CONFIG_NVMEM */
#if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OF)
/**
* of_nvmem_layout_get_container() - Get OF node of layout container
*
* @nvmem: nvmem device
*
* Return: a node pointer with refcount incremented or NULL if no
* container exists. Use of_node_put() on it when done.
*/
struct device_node *of_nvmem_layout_get_container(struct nvmem_device *nvmem);
#else /* CONFIG_NVMEM && CONFIG_OF */
static inline struct device_node *of_nvmem_layout_get_container(struct nvmem_device *nvmem)
{
return NULL;
}
#endif /* CONFIG_NVMEM && CONFIG_OF */
#endif /* ifndef _LINUX_NVMEM_PROVIDER_H */
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