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 NVMEM_TYPE_FRAM, 29 }; 30 31 #define NVMEM_DEVID_NONE (-1) 32 #define NVMEM_DEVID_AUTO (-2) 33 34 /** 35 * struct nvmem_keepout - NVMEM register keepout range. 36 * 37 * @start: The first byte offset to avoid. 38 * @end: One beyond the last byte offset to avoid. 39 * @value: The byte to fill reads with for this region. 40 */ 41 struct nvmem_keepout { 42 unsigned int start; 43 unsigned int end; 44 unsigned char value; 45 }; 46 47 /** 48 * struct nvmem_config - NVMEM device configuration 49 * 50 * @dev: Parent device. 51 * @name: Optional name. 52 * @id: Optional device ID used in full name. Ignored if name is NULL. 53 * @owner: Pointer to exporter module. Used for refcounting. 54 * @cells: Optional array of pre-defined NVMEM cells. 55 * @ncells: Number of elements in cells. 56 * @keepout: Optional array of keepout ranges (sorted ascending by start). 57 * @nkeepout: Number of elements in the keepout array. 58 * @type: Type of the nvmem storage 59 * @read_only: Device is read-only. 60 * @root_only: Device is accessibly to root only. 61 * @of_node: If given, this will be used instead of the parent's of_node. 62 * @no_of_node: Device should not use the parent's of_node even if it's !NULL. 63 * @reg_read: Callback to read data. 64 * @reg_write: Callback to write data. 65 * @size: Device size. 66 * @word_size: Minimum read/write access granularity. 67 * @stride: Minimum read/write access stride. 68 * @priv: User context passed to read/write callbacks. 69 * @wp-gpio: Write protect pin 70 * 71 * Note: A default "nvmem<id>" name will be assigned to the device if 72 * no name is specified in its configuration. In such case "<id>" is 73 * generated with ida_simple_get() and provided id field is ignored. 74 * 75 * Note: Specifying name and setting id to -1 implies a unique device 76 * whose name is provided as-is (kept unaltered). 77 */ 78 struct nvmem_config { 79 struct device *dev; 80 const char *name; 81 int id; 82 struct module *owner; 83 struct gpio_desc *wp_gpio; 84 const struct nvmem_cell_info *cells; 85 int ncells; 86 const struct nvmem_keepout *keepout; 87 unsigned int nkeepout; 88 enum nvmem_type type; 89 bool read_only; 90 bool root_only; 91 struct device_node *of_node; 92 bool no_of_node; 93 nvmem_reg_read_t reg_read; 94 nvmem_reg_write_t reg_write; 95 int size; 96 int word_size; 97 int stride; 98 void *priv; 99 /* To be only used by old driver/misc/eeprom drivers */ 100 bool compat; 101 struct device *base_dev; 102 }; 103 104 /** 105 * struct nvmem_cell_table - NVMEM cell definitions for given provider 106 * 107 * @nvmem_name: Provider name. 108 * @cells: Array of cell definitions. 109 * @ncells: Number of cell definitions in the array. 110 * @node: List node. 111 * 112 * This structure together with related helper functions is provided for users 113 * that don't can't access the nvmem provided structure but wish to register 114 * cell definitions for it e.g. board files registering an EEPROM device. 115 */ 116 struct nvmem_cell_table { 117 const char *nvmem_name; 118 const struct nvmem_cell_info *cells; 119 size_t ncells; 120 struct list_head node; 121 }; 122 123 #if IS_ENABLED(CONFIG_NVMEM) 124 125 struct nvmem_device *nvmem_register(const struct nvmem_config *cfg); 126 void nvmem_unregister(struct nvmem_device *nvmem); 127 128 struct nvmem_device *devm_nvmem_register(struct device *dev, 129 const struct nvmem_config *cfg); 130 131 int devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem); 132 133 void nvmem_add_cell_table(struct nvmem_cell_table *table); 134 void nvmem_del_cell_table(struct nvmem_cell_table *table); 135 136 #else 137 138 static inline struct nvmem_device *nvmem_register(const struct nvmem_config *c) 139 { 140 return ERR_PTR(-EOPNOTSUPP); 141 } 142 143 static inline void nvmem_unregister(struct nvmem_device *nvmem) {} 144 145 static inline struct nvmem_device * 146 devm_nvmem_register(struct device *dev, const struct nvmem_config *c) 147 { 148 return nvmem_register(c); 149 } 150 151 static inline int 152 devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem) 153 { 154 return -EOPNOTSUPP; 155 } 156 157 static inline void nvmem_add_cell_table(struct nvmem_cell_table *table) {} 158 static inline void nvmem_del_cell_table(struct nvmem_cell_table *table) {} 159 160 #endif /* CONFIG_NVMEM */ 161 #endif /* ifndef _LINUX_NVMEM_PROVIDER_H */ 162