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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_H10#define _LINUX_NVMEM_PROVIDER_H11 12#include <linux/device.h>13#include <linux/device/driver.h>14#include <linux/err.h>15#include <linux/errno.h>16#include <linux/gpio/consumer.h>17 18struct nvmem_device;19typedef int (*nvmem_reg_read_t)(void *priv, unsigned int offset,20 void *val, size_t bytes);21typedef int (*nvmem_reg_write_t)(void *priv, unsigned int offset,22 void *val, size_t bytes);23/* used for vendor specific post processing of cell data */24typedef int (*nvmem_cell_post_process_t)(void *priv, const char *id, int index,25 unsigned int offset, void *buf,26 size_t bytes);27 28enum nvmem_type {29 NVMEM_TYPE_UNKNOWN = 0,30 NVMEM_TYPE_EEPROM,31 NVMEM_TYPE_OTP,32 NVMEM_TYPE_BATTERY_BACKED,33 NVMEM_TYPE_FRAM,34};35 36#define NVMEM_DEVID_NONE (-1)37#define NVMEM_DEVID_AUTO (-2)38 39/**40 * struct nvmem_keepout - NVMEM register keepout range.41 *42 * @start: The first byte offset to avoid.43 * @end: One beyond the last byte offset to avoid.44 * @value: The byte to fill reads with for this region.45 */46struct nvmem_keepout {47 unsigned int start;48 unsigned int end;49 unsigned char value;50};51 52/**53 * struct nvmem_cell_info - NVMEM cell description54 * @name: Name.55 * @offset: Offset within the NVMEM device.56 * @raw_len: Length of raw data (without post processing).57 * @bytes: Length of the cell.58 * @bit_offset: Bit offset if cell is smaller than a byte.59 * @nbits: Number of bits.60 * @np: Optional device_node pointer.61 * @read_post_process: Callback for optional post processing of cell data62 * on reads.63 * @priv: Opaque data passed to the read_post_process hook.64 */65struct nvmem_cell_info {66 const char *name;67 unsigned int offset;68 size_t raw_len;69 unsigned int bytes;70 unsigned int bit_offset;71 unsigned int nbits;72 struct device_node *np;73 nvmem_cell_post_process_t read_post_process;74 void *priv;75};76 77/**78 * struct nvmem_config - NVMEM device configuration79 *80 * @dev: Parent device.81 * @name: Optional name.82 * @id: Optional device ID used in full name. Ignored if name is NULL.83 * @owner: Pointer to exporter module. Used for refcounting.84 * @cells: Optional array of pre-defined NVMEM cells.85 * @ncells: Number of elements in cells.86 * @add_legacy_fixed_of_cells: Read fixed NVMEM cells from old OF syntax.87 * @fixup_dt_cell_info: Will be called before a cell is added. Can be88 * used to modify the nvmem_cell_info.89 * @keepout: Optional array of keepout ranges (sorted ascending by start).90 * @nkeepout: Number of elements in the keepout array.91 * @type: Type of the nvmem storage92 * @read_only: Device is read-only.93 * @root_only: Device is accessibly to root only.94 * @of_node: If given, this will be used instead of the parent's of_node.95 * @reg_read: Callback to read data.96 * @reg_write: Callback to write data.97 * @size: Device size.98 * @word_size: Minimum read/write access granularity.99 * @stride: Minimum read/write access stride.100 * @priv: User context passed to read/write callbacks.101 * @ignore_wp: Write Protect pin is managed by the provider.102 * @layout: Fixed layout associated with this nvmem device.103 *104 * Note: A default "nvmem<id>" name will be assigned to the device if105 * no name is specified in its configuration. In such case "<id>" is106 * generated with ida_simple_get() and provided id field is ignored.107 *108 * Note: Specifying name and setting id to -1 implies a unique device109 * whose name is provided as-is (kept unaltered).110 */111struct nvmem_config {112 struct device *dev;113 const char *name;114 int id;115 struct module *owner;116 const struct nvmem_cell_info *cells;117 int ncells;118 bool add_legacy_fixed_of_cells;119 void (*fixup_dt_cell_info)(struct nvmem_device *nvmem,120 struct nvmem_cell_info *cell);121 const struct nvmem_keepout *keepout;122 unsigned int nkeepout;123 enum nvmem_type type;124 bool read_only;125 bool root_only;126 bool ignore_wp;127 struct nvmem_layout *layout;128 struct device_node *of_node;129 nvmem_reg_read_t reg_read;130 nvmem_reg_write_t reg_write;131 int size;132 int word_size;133 int stride;134 void *priv;135 /* To be only used by old driver/misc/eeprom drivers */136 bool compat;137 struct device *base_dev;138};139 140/**141 * struct nvmem_cell_table - NVMEM cell definitions for given provider142 *143 * @nvmem_name: Provider name.144 * @cells: Array of cell definitions.145 * @ncells: Number of cell definitions in the array.146 * @node: List node.147 *148 * This structure together with related helper functions is provided for users149 * that don't can't access the nvmem provided structure but wish to register150 * cell definitions for it e.g. board files registering an EEPROM device.151 */152struct nvmem_cell_table {153 const char *nvmem_name;154 const struct nvmem_cell_info *cells;155 size_t ncells;156 struct list_head node;157};158 159/**160 * struct nvmem_layout - NVMEM layout definitions161 *162 * @dev: Device-model layout device.163 * @nvmem: The underlying NVMEM device164 * @add_cells: Will be called if a nvmem device is found which165 * has this layout. The function will add layout166 * specific cells with nvmem_add_one_cell().167 *168 * A nvmem device can hold a well defined structure which can just be169 * evaluated during runtime. For example a TLV list, or a list of "name=val"170 * pairs. A nvmem layout can parse the nvmem device and add appropriate171 * cells.172 */173struct nvmem_layout {174 struct device dev;175 struct nvmem_device *nvmem;176 int (*add_cells)(struct nvmem_layout *layout);177};178 179struct nvmem_layout_driver {180 struct device_driver driver;181 int (*probe)(struct nvmem_layout *layout);182 void (*remove)(struct nvmem_layout *layout);183};184 185#if IS_ENABLED(CONFIG_NVMEM)186 187struct nvmem_device *nvmem_register(const struct nvmem_config *cfg);188void nvmem_unregister(struct nvmem_device *nvmem);189 190struct nvmem_device *devm_nvmem_register(struct device *dev,191 const struct nvmem_config *cfg);192 193void nvmem_add_cell_table(struct nvmem_cell_table *table);194void nvmem_del_cell_table(struct nvmem_cell_table *table);195 196int nvmem_add_one_cell(struct nvmem_device *nvmem,197 const struct nvmem_cell_info *info);198 199int nvmem_layout_register(struct nvmem_layout *layout);200void nvmem_layout_unregister(struct nvmem_layout *layout);201 202#define nvmem_layout_driver_register(drv) \203 __nvmem_layout_driver_register(drv, THIS_MODULE)204int __nvmem_layout_driver_register(struct nvmem_layout_driver *drv,205 struct module *owner);206void nvmem_layout_driver_unregister(struct nvmem_layout_driver *drv);207#define module_nvmem_layout_driver(__nvmem_layout_driver) \208 module_driver(__nvmem_layout_driver, nvmem_layout_driver_register, \209 nvmem_layout_driver_unregister)210 211#else212 213static inline struct nvmem_device *nvmem_register(const struct nvmem_config *c)214{215 return ERR_PTR(-EOPNOTSUPP);216}217 218static inline void nvmem_unregister(struct nvmem_device *nvmem) {}219 220static inline struct nvmem_device *221devm_nvmem_register(struct device *dev, const struct nvmem_config *c)222{223 return nvmem_register(c);224}225 226static inline void nvmem_add_cell_table(struct nvmem_cell_table *table) {}227static inline void nvmem_del_cell_table(struct nvmem_cell_table *table) {}228static inline int nvmem_add_one_cell(struct nvmem_device *nvmem,229 const struct nvmem_cell_info *info)230{231 return -EOPNOTSUPP;232}233 234static inline int nvmem_layout_register(struct nvmem_layout *layout)235{236 return -EOPNOTSUPP;237}238 239static inline void nvmem_layout_unregister(struct nvmem_layout *layout) {}240 241#endif /* CONFIG_NVMEM */242 243#if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OF)244 245/**246 * of_nvmem_layout_get_container() - Get OF node of layout container247 *248 * @nvmem: nvmem device249 *250 * Return: a node pointer with refcount incremented or NULL if no251 * container exists. Use of_node_put() on it when done.252 */253struct device_node *of_nvmem_layout_get_container(struct nvmem_device *nvmem);254 255#else /* CONFIG_NVMEM && CONFIG_OF */256 257static inline struct device_node *of_nvmem_layout_get_container(struct nvmem_device *nvmem)258{259 return NULL;260}261 262#endif /* CONFIG_NVMEM && CONFIG_OF */263 264#endif /* ifndef _LINUX_NVMEM_PROVIDER_H */265