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Diffstat (limited to 'include/linux/nvmem-provider.h')
| -rw-r--r-- | include/linux/nvmem-provider.h | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h new file mode 100644 index 000000000..dae26295e --- /dev/null +++ b/include/linux/nvmem-provider.h @@ -0,0 +1,251 @@ +/* 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/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. + * @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. + * @no_of_node: Device should not use the parent's of_node even if it's !NULL. + * @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; + 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; + bool no_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 + * + * @name: Layout name. + * @of_match_table: Open firmware match table. + * @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(). + * @fixup_cell_info: Will be called before a cell is added. Can be + * used to modify the nvmem_cell_info. + * @owner: Pointer to struct module. + * @node: List node. + * + * 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 { + const char *name; + const struct of_device_id *of_match_table; + int (*add_cells)(struct device *dev, struct nvmem_device *nvmem, + struct nvmem_layout *layout); + void (*fixup_cell_info)(struct nvmem_device *nvmem, + struct nvmem_layout *layout, + struct nvmem_cell_info *cell); + + /* private */ + struct module *owner; + struct list_head node; +}; + +#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, struct module *owner); +#define nvmem_layout_register(layout) \ + __nvmem_layout_register(layout, THIS_MODULE) +void nvmem_layout_unregister(struct nvmem_layout *layout); + +const void *nvmem_layout_get_match_data(struct nvmem_device *nvmem, + struct nvmem_layout *layout); + +#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) {} + +static inline const void * +nvmem_layout_get_match_data(struct nvmem_device *nvmem, + struct nvmem_layout *layout) +{ + return NULL; +} + +#endif /* CONFIG_NVMEM */ + +#define module_nvmem_layout_driver(__layout_driver) \ + module_driver(__layout_driver, nvmem_layout_register, \ + nvmem_layout_unregister) + +#endif /* ifndef _LINUX_NVMEM_PROVIDER_H */ |