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Diffstat (limited to 'include/regmap.h')
| -rw-r--r-- | include/regmap.h | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/include/regmap.h b/include/regmap.h new file mode 100644 index 0000000..0854200 --- /dev/null +++ b/include/regmap.h @@ -0,0 +1,352 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Copyright (c) 2015 Google, Inc + * Written by Simon Glass <sjg@chromium.org> + */ + +#ifndef __REGMAP_H +#define __REGMAP_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 - a way of accessing hardware/bus registers + * + * @range_count: Number of ranges available within the map + * @ranges: Array of ranges + */ +struct regmap { + enum regmap_endianness_t endianness; + 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 32-bit 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 + * + * Note that this function will only write values of 32 bit width to the + * regmap; if the size of data to be read is different, the regmap_raw_write + * function can be used. + * + * Return: 0 if OK, -ve on error + */ +int regmap_write(struct regmap *map, uint offset, uint val); + +/** + * regmap_read() - Read a 32-bit 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 + * + * Note that this function will only read values of 32 bit width from the + * regmap; if the size of data to be read is different, the regmap_raw_read + * function can be used. + * + * 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 32-bit values, 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 32-bit values, 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 apply to the value to write + * 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_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 |