u-boot/include/regmap.h

/*
 * Copyright (c) 2015 Google, Inc
 * Written by Simon Glass <sjg@chromium.org>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#ifndef __REGMAP_H
#define __REGMAP_H

/**
 * struct regmap_range - a register map range
 *
 * @start:	Start address
 * @size:	Size in bytes
 */
struct regmap_range {
	ulong start;
	ulong size;
};

/**
 * struct regmap - a way of accessing hardware/bus registers
 *
 * @base:	Base address of register map
 * @range_count: Number of ranges available within the map
 * @range:	Pointer to the list of ranges, allocated if @range_count > 1
 * @base_range:	If @range_count is <= 1, @range points here
 */
struct regmap {
	phys_addr_t base;
	int range_count;
	struct regmap_range *range, base_range;
};

/*
 * Interface to provide access to registers either through a direct memory
 * bus or through a peripheral bus like I2C, SPI.
 */
int regmap_write(struct regmap *map, uint offset, uint val);
int regmap_read(struct regmap *map, uint offset, uint *valp);

#define regmap_write32(map, ptr, member, val) \
	regmap_write(map, (uint32_t *)(ptr)->member - (uint32_t *)(ptr), val)

#define regmap_read32(map, ptr, member, valp) \
	regmap_read(map, (uint32_t *)(ptr)->member - (uint32_t *)(ptr), valp)

/**
 * regmap_init_mem() - Set up a new register map that uses memory access
 *
 * Use regmap_uninit() to free it.
 *
 * @dev:	Device that uses this map
 * @mapp:	Returns allocated map
 */
int regmap_init_mem(struct udevice *dev, struct regmap **mapp);

/**
 * regmap_init_mem_platdata() - Set up a new memory register map for of-platdata
 *
 * This creates a new regmap with a list of regions passed in, rather than
 * using the device tree. It only supports 32-bit machines.
 *
 * Use regmap_uninit() to free it.
 *
 * @dev:	Device that uses this map
 * @reg:	List of address, size pairs
 * @count:	Number of pairs (e.g. 1 if the regmap has a single entry)
 * @mapp:	Returns allocated map
 */
int regmap_init_mem_platdata(struct udevice *dev, u32 *reg, int count,
			     struct regmap **mapp);

/**
 * regmap_get_range() - Obtain the base memory address of a regmap range
 *
 * @map:	Regmap to query
 * @range_num:	Range to look up
 */
void *regmap_get_range(struct regmap *map, unsigned int range_num);

/**
 * regmap_uninit() - free a previously inited regmap
 */
int regmap_uninit(struct regmap *map);

#endif