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/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Copyright (c) 2015 Google, Inc
* Written by Simon Glass <sjg@chromium.org>
*/
#ifndef __REGMAP_H
#define __REGMAP_H
#include <linux/delay.h>
/**
* DOC: Overview
*
* Regmaps are an abstraction mechanism that allows device drivers to access
* register maps irrespective of the underlying bus architecture. This entails
* that for devices that support multiple busses (e.g. I2C and SPI for a GPIO
* expander chip) only one driver has to be written. This driver will
* instantiate a regmap with a backend depending on the bus the device is
* attached to, and use the regmap API to access the register map through that
* bus transparently.
*
* Read and write functions are supplied, which can read/write data of
* arbitrary length from/to the regmap.
*
* The endianness of regmap accesses is selectable for each map through device
* tree settings via the boolean "little-endian", "big-endian", and
* "native-endian" properties.
*
* Furthermore, the register map described by a regmap can be split into
* multiple disjoint areas called ranges. In this way, register maps with
* "holes", i.e. areas of addressable memory that are not part of the register
* map, can be accessed in a concise manner.
*
* Currently, only a bare "mem" backend for regmaps is supported, which
* accesses the register map as regular IO-mapped memory.
*/
/**
* enum regmap_size_t - Access sizes for regmap reads and writes
*
* @REGMAP_SIZE_8: 8-bit read/write access size
* @REGMAP_SIZE_16: 16-bit read/write access size
* @REGMAP_SIZE_32: 32-bit read/write access size
* @REGMAP_SIZE_64: 64-bit read/write access size
*/
enum regmap_size_t {
REGMAP_SIZE_8 = 1,
REGMAP_SIZE_16 = 2,
REGMAP_SIZE_32 = 4,
REGMAP_SIZE_64 = 8,
};
/**
* enum regmap_endianness_t - Endianness for regmap reads and writes
*
* @REGMAP_NATIVE_ENDIAN: Native endian read/write accesses
* @REGMAP_LITTLE_ENDIAN: Little endian read/write accesses
* @REGMAP_BIG_ENDIAN: Big endian read/write accesses
*/
enum regmap_endianness_t {
REGMAP_NATIVE_ENDIAN,
REGMAP_LITTLE_ENDIAN,
REGMAP_BIG_ENDIAN,
};
/**
* struct regmap_range - a register map range
*
* @start: Start address
* @size: Size in bytes
*/
struct regmap_range {
ulong start;
ulong size;
};
struct regmap_bus;
/**
* struct regmap_config - Configure the behaviour of a regmap
*
* @width: Width of the read/write operations. Defaults to
* REGMAP_SIZE_32 if set to 0.
* @reg_offset_shift Left shift the register offset by this value before
* performing read or write.
*/
struct regmap_config {
enum regmap_size_t width;
u32 reg_offset_shift;
};
/**
* struct regmap - a way of accessing hardware/bus registers
*
* @width: Width of the read/write operations. Defaults to
* REGMAP_SIZE_32 if set to 0.
* @reg_offset_shift Left shift the register offset by this value before
* performing read or write.
* @range_count: Number of ranges available within the map
* @ranges: Array of ranges
*/
struct regmap {
enum regmap_endianness_t endianness;
enum regmap_size_t width;
u32 reg_offset_shift;
int range_count;
struct regmap_range ranges[0];
};
/*
* Interface to provide access to registers either through a direct memory
* bus or through a peripheral bus like I2C, SPI.
*/
/**
* regmap_write() - Write a value to a regmap
*
* @map: Regmap to write to
* @offset: Offset in the regmap to write to
* @val: Data to write to the regmap at the specified offset
*
* Return: 0 if OK, -ve on error
*/
int regmap_write(struct regmap *map, uint offset, uint val);
/**
* regmap_read() - Read a value from a regmap
*
* @map: Regmap to read from
* @offset: Offset in the regmap to read from
* @valp: Pointer to the buffer to receive the data read from the regmap
* at the specified offset
*
* Return: 0 if OK, -ve on error
*/
int regmap_read(struct regmap *map, uint offset, uint *valp);
/**
* regmap_raw_write() - Write a value of specified length to a regmap
*
* @map: Regmap to write to
* @offset: Offset in the regmap to write to
* @val: Value to write to the regmap at the specified offset
* @val_len: Length of the data to be written to the regmap
*
* Note that this function will, as opposed to regmap_write, write data of
* arbitrary length to the regmap, and not just the size configured in the
* regmap (defaults to 32-bit) and is thus a generalized version of
* regmap_write.
*
* Return: 0 if OK, -ve on error
*/
int regmap_raw_write(struct regmap *map, uint offset, const void *val,
size_t val_len);
/**
* regmap_raw_read() - Read a value of specified length from a regmap
*
* @map: Regmap to read from
* @offset: Offset in the regmap to read from
* @valp: Pointer to the buffer to receive the data read from the regmap
* at the specified offset
* @val_len: Length of the data to be read from the regmap
*
* Note that this function will, as opposed to regmap_read, read data of
* arbitrary length from the regmap, and not just the size configured in the
* regmap (defaults to 32-bit) and is thus a generalized version of
* regmap_read.
*
* Return: 0 if OK, -ve on error
*/
int regmap_raw_read(struct regmap *map, uint offset, void *valp,
size_t val_len);
/**
* regmap_raw_write_range() - Write a value of specified length to a range of a
* regmap
*
* @map: Regmap to write to
* @range_num: Number of the range in the regmap to write to
* @offset: Offset in the regmap to write to
* @val: Value to write to the regmap at the specified offset
* @val_len: Length of the data to be written to the regmap
*
* Return: 0 if OK, -ve on error
*/
int regmap_raw_write_range(struct regmap *map, uint range_num, uint offset,
const void *val, size_t val_len);
/**
* regmap_raw_read_range() - Read a value of specified length from a range of a
* regmap
*
* @map: Regmap to read from
* @range_num: Number of the range in the regmap to write to
* @offset: Offset in the regmap to read from
* @valp: Pointer to the buffer to receive the data read from the regmap
* at the specified offset
* @val_len: Length of the data to be read from the regmap
*
* Return: 0 if OK, -ve on error
*/
int regmap_raw_read_range(struct regmap *map, uint range_num, uint offset,
void *valp, size_t val_len);
/**
* regmap_range_set() - Set a value in a regmap range described by a struct
* @map: Regmap in which a value should be set
* @range: Range of the regmap in which a value should be set
* @type: Structure type that describes the memory layout of the regmap range
* @member: Member of the describing structure that should be set in the regmap
* range
* @val: Value which should be written to the regmap range
*/
#define regmap_range_set(map, range, type, member, val) \
do { \
typeof(((type *)0)->member) __tmp = val; \
regmap_raw_write_range(map, range, offsetof(type, member), \
&__tmp, sizeof(((type *)0)->member)); \
} while (0)
/**
* regmap_set() - Set a value in a regmap described by a struct
* @map: Regmap in which a value should be set
* @type: Structure type that describes the memory layout of the regmap
* @member: Member of the describing structure that should be set in the regmap
* @val: Value which should be written to the regmap
*/
#define regmap_set(map, type, member, val) \
regmap_range_set(map, 0, type, member, val)
/**
* regmap_range_get() - Get a value from a regmap range described by a struct
* @map: Regmap from which a value should be read
* @range: Range of the regmap from which a value should be read
* @type: Structure type that describes the memory layout of the regmap
* range
* @member: Member of the describing structure that should be read in the
* regmap range
* @valp: Variable that receives the value read from the regmap range
*/
#define regmap_range_get(map, range, type, member, valp) \
regmap_raw_read_range(map, range, offsetof(type, member), \
(void *)valp, sizeof(((type *)0)->member))
/**
* regmap_get() - Get a value from a regmap described by a struct
* @map: Regmap from which a value should be read
* @type: Structure type that describes the memory layout of the regmap
* range
* @member: Member of the describing structure that should be read in the
* regmap
* @valp: Variable that receives the value read from the regmap
*/
#define regmap_get(map, type, member, valp) \
regmap_range_get(map, 0, type, member, valp)
/**
* regmap_read_poll_timeout - Poll until a condition is met or a timeout occurs
*
* @map: Regmap to read from
* @addr: Offset to poll
* @val: Unsigned integer variable to read the value into
* @cond: Break condition (usually involving @val)
* @sleep_us: Maximum time to sleep between reads in us (0 tight-loops).
* @timeout_ms: Timeout in ms, 0 means never timeout
* @test_add_time: Used for sandbox testing - amount of time to add after
* starting the loop (0 if not testing)
*
* Returns 0 on success and -ETIMEDOUT upon a timeout or the regmap_read
* error return value in case of a error read. In the two former cases,
* the last read value at @addr is stored in @val. Must not be called
* from atomic context if sleep_us or timeout_us are used.
*
* This is modelled after the regmap_read_poll_timeout macros in linux but
* with millisecond timeout.
*
* The _test version is for sandbox testing only. Do not use this in normal
* code as it advances the timer.
*/
#define regmap_read_poll_timeout_test(map, addr, val, cond, sleep_us, \
timeout_ms, test_add_time) \
({ \
unsigned long __start = get_timer(0); \
int __ret; \
for (;;) { \
__ret = regmap_read((map), (addr), &(val)); \
if (__ret) \
break; \
if (cond) \
break; \
if (IS_ENABLED(CONFIG_SANDBOX) && test_add_time) \
timer_test_add_offset(test_add_time); \
if ((timeout_ms) && get_timer(__start) > (timeout_ms)) { \
__ret = regmap_read((map), (addr), &(val)); \
break; \
} \
if ((sleep_us)) \
udelay((sleep_us)); \
} \
__ret ?: ((cond) ? 0 : -ETIMEDOUT); \
})
#define regmap_read_poll_timeout(map, addr, val, cond, sleep_us, timeout_ms) \
regmap_read_poll_timeout_test(map, addr, val, cond, sleep_us, \
timeout_ms, 0) \
/**
* regmap_update_bits() - Perform a read/modify/write using a mask
*
* @map: The map returned by regmap_init_mem*()
* @offset: Offset of the memory
* @mask: Mask to apply to the read value
* @val: Value to OR with the read value after masking. Note that any
* bits set in @val which are not set in @mask are ignored
* Return: 0 if OK, -ve on error
*/
int regmap_update_bits(struct regmap *map, uint offset, uint mask, uint val);
/**
* regmap_init_mem() - Set up a new register map that uses memory access
*
* @node: Device node that uses this map
* @mapp: Returns allocated map
* Return: 0 if OK, -ve on error
*
* Use regmap_uninit() to free it.
*/
int regmap_init_mem(ofnode node, struct regmap **mapp);
/**
* regmap_init_mem_platdata() - Set up a new memory register map for
* of-platdata
*
* @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
* Return: 0 if OK, -ve on error
*
* 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.
*
*/
int regmap_init_mem_platdata(struct udevice *dev, fdt_val_t *reg, int count,
struct regmap **mapp);
int regmap_init_mem_index(ofnode node, struct regmap **mapp, int index);
/**
* regmap_init_mem_range() - Set up a new memory region for ofnode with the
* specified range.
*
* @node: The ofnode for the map.
* @r_start: Start of the range.
* @r_size: Size of the range.
* @mapp: Returns allocated map.
*
* Return: 0 in success, -errno otherwise
*
* This creates a regmap with one range where instead of extracting the range
* from 'node', it is created based on the parameters specified. This is
* useful when a driver needs to calculate the base of the regmap at runtime,
* and can't specify it in device tree.
*/
int regmap_init_mem_range(ofnode node, ulong r_start, ulong r_size,
struct regmap **mapp);
/**
* devm_regmap_init() - Initialise register map (device managed)
*
* @dev: Device that will be interacted with
* @bus: Bus-specific callbacks to use with device (IGNORED)
* @bus_context: Data passed to bus-specific callbacks (IGNORED)
* @config: Configuration for register map
*
* @Return a valid pointer to a struct regmap or a ERR_PTR() on error.
* The structure is automatically freed when the device is unbound
*/
struct regmap *devm_regmap_init(struct udevice *dev,
const struct regmap_bus *bus,
void *bus_context,
const struct regmap_config *config);
/**
* regmap_get_range() - Obtain the base memory address of a regmap range
*
* @map: Regmap to query
* @range_num: Range to look up
* Return: Pointer to the range in question if OK, NULL on error
*/
void *regmap_get_range(struct regmap *map, unsigned int range_num);
/**
* regmap_uninit() - free a previously inited regmap
*
* @map: Regmap to free
* Return: 0 if OK, -ve on error
*/
int regmap_uninit(struct regmap *map);
#endif