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 15 struct nvmem_device; 16 struct nvmem_cell_info; 17 typedef int (*nvmem_reg_read_t)(void *priv, unsigned int offset, 18 void *val, size_t bytes); 19 typedef int (*nvmem_reg_write_t)(void *priv, unsigned int offset, 20 void *val, size_t bytes); 21 22 enum 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 */ 56 struct 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 */ 90 struct 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 99 struct nvmem_device *nvmem_register(const struct nvmem_config *cfg); 100 void nvmem_unregister(struct nvmem_device *nvmem); 101 102 struct nvmem_device *devm_nvmem_register(struct device *dev, 103 const struct nvmem_config *cfg); 104 105 int devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem); 106 107 void nvmem_add_cell_table(struct nvmem_cell_table *table); 108 void nvmem_del_cell_table(struct nvmem_cell_table *table); 109 110 #else 111 112 static inline struct nvmem_device *nvmem_register(const struct nvmem_config *c) 113 { 114 return ERR_PTR(-EOPNOTSUPP); 115 } 116 117 static inline void nvmem_unregister(struct nvmem_device *nvmem) {} 118 119 static inline struct nvmem_device * 120 devm_nvmem_register(struct device *dev, const struct nvmem_config *c) 121 { 122 return nvmem_register(c); 123 } 124 125 static inline int 126 devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem) 127 { 128 return -EOPNOTSUPP; 129 } 130 131 static inline void nvmem_add_cell_table(struct nvmem_cell_table *table) {} 132 static inline void nvmem_del_cell_table(struct nvmem_cell_table *table) {} 133 134 #endif /* CONFIG_NVMEM */ 135 #endif /* ifndef _LINUX_NVMEM_PROVIDER_H */ 136