1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * nvmem framework provider. 4 * 5 * Copyright (C) 2015 Srinivas Kandagatla <[email protected]> 6 * Copyright (C) 2013 Maxime Ripard <[email protected]> 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 #include <linux/gpio/consumer.h> 15 16 struct nvmem_device; 17 struct nvmem_cell_info; 18 typedef int (*nvmem_reg_read_t)(void *priv, unsigned int offset, 19 void *val, size_t bytes); 20 typedef int (*nvmem_reg_write_t)(void *priv, unsigned int offset, 21 void *val, size_t bytes); 22 23 enum nvmem_type { 24 NVMEM_TYPE_UNKNOWN = 0, 25 NVMEM_TYPE_EEPROM, 26 NVMEM_TYPE_OTP, 27 NVMEM_TYPE_BATTERY_BACKED, 28 }; 29 30 /** 31 * struct nvmem_config - NVMEM device configuration 32 * 33 * @dev: Parent device. 34 * @name: Optional name. 35 * @id: Optional device ID used in full name. Ignored if name is NULL. 36 * @owner: Pointer to exporter module. Used for refcounting. 37 * @cells: Optional array of pre-defined NVMEM cells. 38 * @ncells: Number of elements in cells. 39 * @type: Type of the nvmem storage 40 * @read_only: Device is read-only. 41 * @root_only: Device is accessibly to root only. 42 * @no_of_node: Device should not use the parent's of_node even if it's !NULL. 43 * @reg_read: Callback to read data. 44 * @reg_write: Callback to write data. 45 * @size: Device size. 46 * @word_size: Minimum read/write access granularity. 47 * @stride: Minimum read/write access stride. 48 * @priv: User context passed to read/write callbacks. 49 * @wp-gpio: Write protect pin 50 * 51 * Note: A default "nvmem<id>" name will be assigned to the device if 52 * no name is specified in its configuration. In such case "<id>" is 53 * generated with ida_simple_get() and provided id field is ignored. 54 * 55 * Note: Specifying name and setting id to -1 implies a unique device 56 * whose name is provided as-is (kept unaltered). 57 */ 58 struct nvmem_config { 59 struct device *dev; 60 const char *name; 61 int id; 62 struct module *owner; 63 struct gpio_desc *wp_gpio; 64 const struct nvmem_cell_info *cells; 65 int ncells; 66 enum nvmem_type type; 67 bool read_only; 68 bool root_only; 69 bool no_of_node; 70 nvmem_reg_read_t reg_read; 71 nvmem_reg_write_t reg_write; 72 int size; 73 int word_size; 74 int stride; 75 void *priv; 76 /* To be only used by old driver/misc/eeprom drivers */ 77 bool compat; 78 struct device *base_dev; 79 }; 80 81 /** 82 * struct nvmem_cell_table - NVMEM cell definitions for given provider 83 * 84 * @nvmem_name: Provider name. 85 * @cells: Array of cell definitions. 86 * @ncells: Number of cell definitions in the array. 87 * @node: List node. 88 * 89 * This structure together with related helper functions is provided for users 90 * that don't can't access the nvmem provided structure but wish to register 91 * cell definitions for it e.g. board files registering an EEPROM device. 92 */ 93 struct nvmem_cell_table { 94 const char *nvmem_name; 95 const struct nvmem_cell_info *cells; 96 size_t ncells; 97 struct list_head node; 98 }; 99 100 #if IS_ENABLED(CONFIG_NVMEM) 101 102 struct nvmem_device *nvmem_register(const struct nvmem_config *cfg); 103 void nvmem_unregister(struct nvmem_device *nvmem); 104 105 struct nvmem_device *devm_nvmem_register(struct device *dev, 106 const struct nvmem_config *cfg); 107 108 int devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem); 109 110 void nvmem_add_cell_table(struct nvmem_cell_table *table); 111 void nvmem_del_cell_table(struct nvmem_cell_table *table); 112 113 #else 114 115 static inline struct nvmem_device *nvmem_register(const struct nvmem_config *c) 116 { 117 return ERR_PTR(-EOPNOTSUPP); 118 } 119 120 static inline void nvmem_unregister(struct nvmem_device *nvmem) {} 121 122 static inline struct nvmem_device * 123 devm_nvmem_register(struct device *dev, const struct nvmem_config *c) 124 { 125 return nvmem_register(c); 126 } 127 128 static inline int 129 devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem) 130 { 131 return -EOPNOTSUPP; 132 } 133 134 static inline void nvmem_add_cell_table(struct nvmem_cell_table *table) {} 135 static inline void nvmem_del_cell_table(struct nvmem_cell_table *table) {} 136 137 #endif /* CONFIG_NVMEM */ 138 #endif /* ifndef _LINUX_NVMEM_PROVIDER_H */ 139