diff options
Diffstat (limited to 'include/regmap.h')
| -rw-r--r-- | include/regmap.h | 232 |
1 files changed, 219 insertions, 13 deletions
diff --git a/include/regmap.h b/include/regmap.h index 6a574eaa41..b2b733fda6 100644 --- a/include/regmap.h +++ b/include/regmap.h @@ -8,6 +8,61 @@ #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 @@ -21,10 +76,11 @@ struct regmap_range { /** * struct regmap - a way of accessing hardware/bus registers * - * @range_count: Number of ranges available within the map - * @ranges: Array of ranges + * @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]; }; @@ -33,14 +89,155 @@ struct regmap { * 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); -#define regmap_write32(map, ptr, member, val) \ - regmap_write(map, (uint32_t *)(ptr)->member - (uint32_t *)(ptr), val) +/** + * 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)) -#define regmap_read32(map, ptr, member, valp) \ - regmap_read(map, (uint32_t *)(ptr)->member - (uint32_t *)(ptr), valp) +/** + * 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_update_bits() - Perform a read/modify/write using a mask @@ -49,31 +246,36 @@ int regmap_read(struct regmap *map, uint offset, uint *valp); * @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 * - * Use regmap_uninit() to free it. - * * @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 + * 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. * - * @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, fdt_val_t *reg, int count, struct regmap **mapp); @@ -83,11 +285,15 @@ int regmap_init_mem_platdata(struct udevice *dev, fdt_val_t *reg, int count, * * @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); |