linux/include/linux/nvmem-provider.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * nvmem framework provider.
 *
 * Copyright (C) 2015 Srinivas Kandagatla <[email protected]>
 * Copyright (C) 2013 Maxime Ripard <[email protected]>
 */

#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;
nvmem_reg_read_t;
nvmem_reg_write_t;
/* used for vendor specific post processing of cell data */
nvmem_cell_post_process_t;

enum nvmem_type {};

#define NVMEM_DEVID_NONE
#define NVMEM_DEVID_AUTO

/**
 * 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 {};

/**
 * 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 {};

/**
 * 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 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 {};

/**
 * 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 nvmem_layout_driver {};

#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);

#define nvmem_layout_driver_register(drv)
int __nvmem_layout_driver_register(struct nvmem_layout_driver *drv,
				   struct module *owner);
void nvmem_layout_driver_unregister(struct nvmem_layout_driver *drv);
#define module_nvmem_layout_driver(__nvmem_layout_driver)

#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 */