name : nvmem-provider.h /* SPDX-License-Identifier: GPL-2.0 */ /* * nvmem framework provider. * * Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla@linaro.org> * Copyright (C) 2013 Maxime Ripard <maxime.ripard@free-electrons.com> */ #ifndef _LINUX_NVMEM_PROVIDER_H #define _LINUX_NVMEM_PROVIDER_H #include <linux/device.h> #include <linux/device/driver.h> #include <linux/err.h> #include <linux/errno.h> #include <linux/gpio/consumer.h> struct nvmem_device; typedef int (*nvmem_reg_read_t)(void *priv, unsigned int offset, void *val, size_t bytes); typedef int (*nvmem_reg_write_t)(void *priv, unsigned int offset, void *val, size_t bytes); /* used for vendor specific post processing of cell data */ typedef int (*nvmem_cell_post_process_t)(void *priv, const char *id, int index, unsigned int offset, void *buf, size_t bytes); enum nvmem_type { NVMEM_TYPE_UNKNOWN = 0, NVMEM_TYPE_EEPROM, NVMEM_TYPE_OTP, NVMEM_TYPE_BATTERY_BACKED, NVMEM_TYPE_FRAM, }; #define NVMEM_DEVID_NONE (-1) #define NVMEM_DEVID_AUTO (-2) /** * struct nvmem_keepout - NVMEM register keepout range. * * @start: The first byte offset to avoid. * @end: One beyond the last byte offset to avoid. * @value: The byte to fill reads with for this region. */ struct nvmem_keepout { unsigned int start; unsigned int end; unsigned char value; }; /** * struct nvmem_cell_info - NVMEM cell description * @name: Name. * @offset: Offset within the NVMEM device. * @raw_len: Length of raw data (without post processing). * @bytes: Length of the cell. * @bit_offset: Bit offset if cell is smaller than a byte. * @nbits: Number of bits. * @np: Optional device_node pointer. * @read_post_process: Callback for optional post processing of cell data * on reads. * @priv: Opaque data passed to the read_post_process hook. */ struct nvmem_cell_info { const char *name; unsigned int offset; size_t raw_len; unsigned int bytes; unsigned int bit_offset; unsigned int nbits; struct device_node *np; nvmem_cell_post_process_t read_post_process; void *priv; }; /** * struct nvmem_config - NVMEM device configuration * * @dev: Parent device. * @name: Optional name. * @id: Optional device ID used in full name. Ignored if name is NULL. * @owner: Pointer to exporter module. Used for refcounting. * @cells: Optional array of pre-defined NVMEM cells. * @ncells: Number of elements in cells. * @add_legacy_fixed_of_cells: Read fixed NVMEM cells from old OF syntax. * @fixup_dt_cell_info: Will be called before a cell is added. Can be * used to modify the nvmem_cell_info. * @keepout: Optional array of keepout ranges (sorted ascending by start). * @nkeepout: Number of elements in the keepout array. * @type: Type of the nvmem storage * @read_only: Device is read-only. * @root_only: Device is accessibly to root only. * @of_node: If given, this will be used instead of the parent's of_node. * @reg_read: Callback to read data. * @reg_write: Callback to write data. * @size: Device size. * @word_size: Minimum read/write access granularity. * @stride: Minimum read/write access stride. * @priv: User context passed to read/write callbacks. * @ignore_wp: Write Protect pin is managed by the provider. * @layout: Fixed layout associated with this nvmem device. * * Note: A default "nvmem<id>" name will be assigned to the device if * no name is specified in its configuration. In such case "<id>" is * generated with ida_simple_get() and provided id field is ignored. * * Note: Specifying name and setting id to -1 implies a unique device * whose name is provided as-is (kept unaltered). */ struct nvmem_config { struct device *dev; const char *name; int id; struct module *owner; const struct nvmem_cell_info *cells; int ncells; bool add_legacy_fixed_of_cells; void (*fixup_dt_cell_info)(struct nvmem_device *nvmem, struct nvmem_cell_info *cell); const struct nvmem_keepout *keepout; unsigned int nkeepout; enum nvmem_type type; bool read_only; bool root_only; bool ignore_wp; struct nvmem_layout *layout; struct device_node *of_node; nvmem_reg_read_t reg_read; nvmem_reg_write_t reg_write; int size; int word_size; int stride; void *priv; /* To be only used by old driver/misc/eeprom drivers */ bool compat; struct device *base_dev; }; /** * struct nvmem_cell_table - NVMEM cell definitions for given provider * * @nvmem_name: Provider name. * @cells: Array of cell definitions. * @ncells: Number of cell definitions in the array. * @node: List node. * * This structure together with related helper functions is provided for users * that don't can't access the nvmem provided structure but wish to register * cell definitions for it e.g. board files registering an EEPROM device. */ struct nvmem_cell_table { const char *nvmem_name; const struct nvmem_cell_info *cells; size_t ncells; struct list_head node; }; /** * struct nvmem_layout - NVMEM layout definitions * * @dev: Device-model layout device. * @nvmem: The underlying NVMEM device * @add_cells: Will be called if a nvmem device is found which * has this layout. The function will add layout * specific cells with nvmem_add_one_cell(). * * A nvmem device can hold a well defined structure which can just be * evaluated during runtime. For example a TLV list, or a list of "name=val" * pairs. A nvmem layout can parse the nvmem device and add appropriate * cells. */ struct nvmem_layout { struct device dev; struct nvmem_device *nvmem; int (*add_cells)(struct nvmem_layout *layout); }; struct nvmem_layout_driver { struct device_driver driver; int (*probe)(struct nvmem_layout *layout); void (*remove)(struct nvmem_layout *layout); }; #if IS_ENABLED(CONFIG_NVMEM) struct nvmem_device *nvmem_register(const struct nvmem_config *cfg); void nvmem_unregister(struct nvmem_device *nvmem); struct nvmem_device *devm_nvmem_register(struct device *dev, const struct nvmem_config *cfg); void nvmem_add_cell_table(struct nvmem_cell_table *table); void nvmem_del_cell_table(struct nvmem_cell_table *table); int nvmem_add_one_cell(struct nvmem_device *nvmem, const struct nvmem_cell_info *info); int nvmem_layout_register(struct nvmem_layout *layout); void nvmem_layout_unregister(struct nvmem_layout *layout); int nvmem_layout_driver_register(struct nvmem_layout_driver *drv); void nvmem_layout_driver_unregister(struct nvmem_layout_driver *drv); #define module_nvmem_layout_driver(__nvmem_layout_driver) \ module_driver(__nvmem_layout_driver, nvmem_layout_driver_register, \ nvmem_layout_driver_unregister) #else static inline struct nvmem_device *nvmem_register(const struct nvmem_config *c) { return ERR_PTR(-EOPNOTSUPP); } static inline void nvmem_unregister(struct nvmem_device *nvmem) {} static inline struct nvmem_device * devm_nvmem_register(struct device *dev, const struct nvmem_config *c) { return nvmem_register(c); } static inline void nvmem_add_cell_table(struct nvmem_cell_table *table) {} static inline void nvmem_del_cell_table(struct nvmem_cell_table *table) {} static inline int nvmem_add_one_cell(struct nvmem_device *nvmem, const struct nvmem_cell_info *info) { return -EOPNOTSUPP; } static inline int nvmem_layout_register(struct nvmem_layout *layout) { return -EOPNOTSUPP; } static inline void nvmem_layout_unregister(struct nvmem_layout *layout) {} #endif /* CONFIG_NVMEM */ #if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OF) /** * of_nvmem_layout_get_container() - Get OF node of layout container * * @nvmem: nvmem device * * Return: a node pointer with refcount incremented or NULL if no * container exists. Use of_node_put() on it when done. */ struct device_node *of_nvmem_layout_get_container(struct nvmem_device *nvmem); #else /* CONFIG_NVMEM && CONFIG_OF */ static inline struct device_node *of_nvmem_layout_get_container(struct nvmem_device *nvmem) { return NULL; } #endif /* CONFIG_NVMEM && CONFIG_OF */ #endif /* ifndef _LINUX_NVMEM_PROVIDER_H */