LXR linux/include/linux/nvmem-provider.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * nvmem framework provider.
   4 *
   5 * Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
   6 * Copyright (C) 2013 Maxime Ripard <maxime.ripard@free-electrons.com>
   7 */
   8
   9#ifndef _LINUX_NVMEM_PROVIDER_H
  10#define _LINUX_NVMEM_PROVIDER_H
  11
  12#include <linux/err.h>
  13#include <linux/errno.h>
  14
  15struct nvmem_device;
  16struct nvmem_cell_info;
  17typedef int (*nvmem_reg_read_t)(void *priv, unsigned int offset,
  18                                void *val, size_t bytes);
  19typedef int (*nvmem_reg_write_t)(void *priv, unsigned int offset,
  20                                 void *val, size_t bytes);
  21
  22enum nvmem_type {
  23        NVMEM_TYPE_UNKNOWN = 0,
  24        NVMEM_TYPE_EEPROM,
  25        NVMEM_TYPE_OTP,
  26        NVMEM_TYPE_BATTERY_BACKED,
  27};
  28
  29/**
  30 * struct nvmem_config - NVMEM device configuration
  31 *
  32 * @dev:        Parent device.
  33 * @name:       Optional name.
  34 * @id:         Optional device ID used in full name. Ignored if name is NULL.
  35 * @owner:      Pointer to exporter module. Used for refcounting.
  36 * @cells:      Optional array of pre-defined NVMEM cells.
  37 * @ncells:     Number of elements in cells.
  38 * @type:       Type of the nvmem storage
  39 * @read_only:  Device is read-only.
  40 * @root_only:  Device is accessibly to root only.
  41 * @no_of_node: Device should not use the parent's of_node even if it's !NULL.
  42 * @reg_read:   Callback to read data.
  43 * @reg_write:  Callback to write data.
  44 * @size:       Device size.
  45 * @word_size:  Minimum read/write access granularity.
  46 * @stride:     Minimum read/write access stride.
  47 * @priv:       User context passed to read/write callbacks.
  48 *
  49 * Note: A default "nvmem<id>" name will be assigned to the device if
  50 * no name is specified in its configuration. In such case "<id>" is
  51 * generated with ida_simple_get() and provided id field is ignored.
  52 *
  53 * Note: Specifying name and setting id to -1 implies a unique device
  54 * whose name is provided as-is (kept unaltered).
  55 */
  56struct nvmem_config {
  57        struct device           *dev;
  58        const char              *name;
  59        int                     id;
  60        struct module           *owner;
  61        const struct nvmem_cell_info    *cells;
  62        int                     ncells;
  63        enum nvmem_type         type;
  64        bool                    read_only;
  65        bool                    root_only;
  66        bool                    no_of_node;
  67        nvmem_reg_read_t        reg_read;
  68        nvmem_reg_write_t       reg_write;
  69        int     size;
  70        int     word_size;
  71        int     stride;
  72        void    *priv;
  73        /* To be only used by old driver/misc/eeprom drivers */
  74        bool                    compat;
  75        struct device           *base_dev;
  76};
  77
  78/**
  79 * struct nvmem_cell_table - NVMEM cell definitions for given provider
  80 *
  81 * @nvmem_name:         Provider name.
  82 * @cells:              Array of cell definitions.
  83 * @ncells:             Number of cell definitions in the array.
  84 * @node:               List node.
  85 *
  86 * This structure together with related helper functions is provided for users
  87 * that don't can't access the nvmem provided structure but wish to register
  88 * cell definitions for it e.g. board files registering an EEPROM device.
  89 */
  90struct nvmem_cell_table {
  91        const char              *nvmem_name;
  92        const struct nvmem_cell_info    *cells;
  93        size_t                  ncells;
  94        struct list_head        node;
  95};
  96
  97#if IS_ENABLED(CONFIG_NVMEM)
  98
  99struct nvmem_device *nvmem_register(const struct nvmem_config *cfg);
 100void nvmem_unregister(struct nvmem_device *nvmem);
 101
 102struct nvmem_device *devm_nvmem_register(struct device *dev,
 103                                         const struct nvmem_config *cfg);
 104
 105int devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem);
 106
 107void nvmem_add_cell_table(struct nvmem_cell_table *table);
 108void nvmem_del_cell_table(struct nvmem_cell_table *table);
 109
 110#else
 111
 112static inline struct nvmem_device *nvmem_register(const struct nvmem_config *c)
 113{
 114        return ERR_PTR(-EOPNOTSUPP);
 115}
 116
 117static inline void nvmem_unregister(struct nvmem_device *nvmem) {}
 118
 119static inline struct nvmem_device *
 120devm_nvmem_register(struct device *dev, const struct nvmem_config *c)
 121{
 122        return nvmem_register(c);
 123}
 124
 125static inline int
 126devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem)
 127{
 128        return -EOPNOTSUPP;
 129}
 130
 131static inline void nvmem_add_cell_table(struct nvmem_cell_table *table) {}
 132static inline void nvmem_del_cell_table(struct nvmem_cell_table *table) {}
 133
 134#endif /* CONFIG_NVMEM */
 135#endif  /* ifndef _LINUX_NVMEM_PROVIDER_H */
 136