1 /* SPDX-License-Identifier: GPL-2.0+ */
3 * Copyright (c) 2015 Google, Inc
4 * Written by Simon Glass <sjg@chromium.org>
13 * Regmaps are an abstraction mechanism that allows device drivers to access
14 * register maps irrespective of the underlying bus architecture. This entails
15 * that for devices that support multiple busses (e.g. I2C and SPI for a GPIO
16 * expander chip) only one driver has to be written. This driver will
17 * instantiate a regmap with a backend depending on the bus the device is
18 * attached to, and use the regmap API to access the register map through that
21 * Read and write functions are supplied, which can read/write data of
22 * arbitrary length from/to the regmap.
24 * The endianness of regmap accesses is selectable for each map through device
25 * tree settings via the boolean "little-endian", "big-endian", and
26 * "native-endian" properties.
28 * Furthermore, the register map described by a regmap can be split into
29 * multiple disjoint areas called ranges. In this way, register maps with
30 * "holes", i.e. areas of addressable memory that are not part of the register
31 * map, can be accessed in a concise manner.
33 * Currently, only a bare "mem" backend for regmaps is supported, which
34 * accesses the register map as regular IO-mapped memory.
38 * enum regmap_size_t - Access sizes for regmap reads and writes
40 * @REGMAP_SIZE_8: 8-bit read/write access size
41 * @REGMAP_SIZE_16: 16-bit read/write access size
42 * @REGMAP_SIZE_32: 32-bit read/write access size
43 * @REGMAP_SIZE_64: 64-bit read/write access size
53 * enum regmap_endianness_t - Endianness for regmap reads and writes
55 * @REGMAP_NATIVE_ENDIAN: Native endian read/write accesses
56 * @REGMAP_LITTLE_ENDIAN: Little endian read/write accesses
57 * @REGMAP_BIG_ENDIAN: Big endian read/write accesses
59 enum regmap_endianness_t {
66 * struct regmap_range - a register map range
68 * @start: Start address
69 * @size: Size in bytes
77 * struct regmap - a way of accessing hardware/bus registers
79 * @range_count: Number of ranges available within the map
80 * @ranges: Array of ranges
83 enum regmap_endianness_t endianness;
85 struct regmap_range ranges[0];
89 * Interface to provide access to registers either through a direct memory
90 * bus or through a peripheral bus like I2C, SPI.
94 * regmap_write() - Write a 32-bit value to a regmap
96 * @map: Regmap to write to
97 * @offset: Offset in the regmap to write to
98 * @val: Data to write to the regmap at the specified offset
100 * Note that this function will only write values of 32 bit width to the
101 * regmap; if the size of data to be read is different, the regmap_raw_write
102 * function can be used.
104 * Return: 0 if OK, -ve on error
106 int regmap_write(struct regmap *map, uint offset, uint val);
109 * regmap_read() - Read a 32-bit value from a regmap
111 * @map: Regmap to read from
112 * @offset: Offset in the regmap to read from
113 * @valp: Pointer to the buffer to receive the data read from the regmap
114 * at the specified offset
116 * Note that this function will only read values of 32 bit width from the
117 * regmap; if the size of data to be read is different, the regmap_raw_read
118 * function can be used.
120 * Return: 0 if OK, -ve on error
122 int regmap_read(struct regmap *map, uint offset, uint *valp);
125 * regmap_raw_write() - Write a value of specified length to a regmap
127 * @map: Regmap to write to
128 * @offset: Offset in the regmap to write to
129 * @val: Value to write to the regmap at the specified offset
130 * @val_len: Length of the data to be written to the regmap
132 * Note that this function will, as opposed to regmap_write, write data of
133 * arbitrary length to the regmap, and not just 32-bit values, and is thus a
134 * generalized version of regmap_write.
136 * Return: 0 if OK, -ve on error
138 int regmap_raw_write(struct regmap *map, uint offset, const void *val,
142 * regmap_raw_read() - Read a value of specified length from a regmap
144 * @map: Regmap to read from
145 * @offset: Offset in the regmap to read from
146 * @valp: Pointer to the buffer to receive the data read from the regmap
147 * at the specified offset
148 * @val_len: Length of the data to be read from the regmap
150 * Note that this function will, as opposed to regmap_read, read data of
151 * arbitrary length from the regmap, and not just 32-bit values, and is thus a
152 * generalized version of regmap_read.
154 * Return: 0 if OK, -ve on error
156 int regmap_raw_read(struct regmap *map, uint offset, void *valp,
160 * regmap_raw_write_range() - Write a value of specified length to a range of a
163 * @map: Regmap to write to
164 * @range_num: Number of the range in the regmap to write to
165 * @offset: Offset in the regmap to write to
166 * @val: Value to write to the regmap at the specified offset
167 * @val_len: Length of the data to be written to the regmap
169 * Return: 0 if OK, -ve on error
171 int regmap_raw_write_range(struct regmap *map, uint range_num, uint offset,
172 const void *val, size_t val_len);
175 * regmap_raw_read_range() - Read a value of specified length from a range of a
178 * @map: Regmap to read from
179 * @range_num: Number of the range in the regmap to write to
180 * @offset: Offset in the regmap to read from
181 * @valp: Pointer to the buffer to receive the data read from the regmap
182 * at the specified offset
183 * @val_len: Length of the data to be read from the regmap
185 * Return: 0 if OK, -ve on error
187 int regmap_raw_read_range(struct regmap *map, uint range_num, uint offset,
188 void *valp, size_t val_len);
191 * regmap_range_set() - Set a value in a regmap range described by a struct
192 * @map: Regmap in which a value should be set
193 * @range: Range of the regmap in which a value should be set
194 * @type: Structure type that describes the memory layout of the regmap range
195 * @member: Member of the describing structure that should be set in the regmap
197 * @val: Value which should be written to the regmap range
199 #define regmap_range_set(map, range, type, member, val) \
201 typeof(((type *)0)->member) __tmp = val; \
202 regmap_raw_write_range(map, range, offsetof(type, member), \
203 &__tmp, sizeof(((type *)0)->member)); \
207 * regmap_set() - Set a value in a regmap described by a struct
208 * @map: Regmap in which a value should be set
209 * @type: Structure type that describes the memory layout of the regmap
210 * @member: Member of the describing structure that should be set in the regmap
211 * @val: Value which should be written to the regmap
213 #define regmap_set(map, type, member, val) \
214 regmap_range_set(map, 0, type, member, val)
217 * regmap_range_get() - Get a value from a regmap range described by a struct
218 * @map: Regmap from which a value should be read
219 * @range: Range of the regmap from which a value should be read
220 * @type: Structure type that describes the memory layout of the regmap
222 * @member: Member of the describing structure that should be read in the
224 * @valp: Variable that receives the value read from the regmap range
226 #define regmap_range_get(map, range, type, member, valp) \
227 regmap_raw_read_range(map, range, offsetof(type, member), \
228 (void *)valp, sizeof(((type *)0)->member))
231 * regmap_get() - Get a value from a regmap described by a struct
232 * @map: Regmap from which a value should be read
233 * @type: Structure type that describes the memory layout of the regmap
235 * @member: Member of the describing structure that should be read in the
237 * @valp: Variable that receives the value read from the regmap
239 #define regmap_get(map, type, member, valp) \
240 regmap_range_get(map, 0, type, member, valp)
243 * regmap_read_poll_timeout - Poll until a condition is met or a timeout occurs
245 * @map: Regmap to read from
246 * @addr: Offset to poll
247 * @val: Unsigned integer variable to read the value into
248 * @cond: Break condition (usually involving @val)
249 * @sleep_us: Maximum time to sleep between reads in us (0 tight-loops).
250 * @timeout_ms: Timeout in ms, 0 means never timeout
252 * Returns 0 on success and -ETIMEDOUT upon a timeout or the regmap_read
253 * error return value in case of a error read. In the two former cases,
254 * the last read value at @addr is stored in @val. Must not be called
255 * from atomic context if sleep_us or timeout_us are used.
257 * This is modelled after the regmap_read_poll_timeout macros in linux but
258 * with millisecond timeout.
260 #define regmap_read_poll_timeout(map, addr, val, cond, sleep_us, timeout_ms) \
262 unsigned long __start = get_timer(0); \
265 __ret = regmap_read((map), (addr), &(val)); \
270 if ((timeout_ms) && get_timer(__start) > (timeout_ms)) { \
271 __ret = regmap_read((map), (addr), &(val)); \
275 udelay((sleep_us)); \
277 __ret ?: ((cond) ? 0 : -ETIMEDOUT); \
281 * regmap_update_bits() - Perform a read/modify/write using a mask
283 * @map: The map returned by regmap_init_mem*()
284 * @offset: Offset of the memory
285 * @mask: Mask to apply to the read value
286 * @val: Value to apply to the value to write
287 * Return: 0 if OK, -ve on error
289 int regmap_update_bits(struct regmap *map, uint offset, uint mask, uint val);
292 * regmap_init_mem() - Set up a new register map that uses memory access
294 * @node: Device node that uses this map
295 * @mapp: Returns allocated map
296 * Return: 0 if OK, -ve on error
298 * Use regmap_uninit() to free it.
300 int regmap_init_mem(ofnode node, struct regmap **mapp);
303 * regmap_init_mem_platdata() - Set up a new memory register map for
306 * @dev: Device that uses this map
307 * @reg: List of address, size pairs
308 * @count: Number of pairs (e.g. 1 if the regmap has a single entry)
309 * @mapp: Returns allocated map
310 * Return: 0 if OK, -ve on error
312 * This creates a new regmap with a list of regions passed in, rather than
313 * using the device tree. It only supports 32-bit machines.
315 * Use regmap_uninit() to free it.
318 int regmap_init_mem_platdata(struct udevice *dev, fdt_val_t *reg, int count,
319 struct regmap **mapp);
322 * regmap_get_range() - Obtain the base memory address of a regmap range
324 * @map: Regmap to query
325 * @range_num: Range to look up
326 * Return: Pointer to the range in question if OK, NULL on error
328 void *regmap_get_range(struct regmap *map, unsigned int range_num);
331 * regmap_uninit() - free a previously inited regmap
333 * @map: Regmap to free
334 * Return: 0 if OK, -ve on error
336 int regmap_uninit(struct regmap *map);