Mon, 29 Oct 2018 12:16:37 +0100
Updates for doxygen
0 | 1 | /* |
2 | * MIT License | |
3 | * | |
4 | * Copyright (c) 2017 David Antliff | |
5 | * Copyright (c) 2017 Chris Morgan <chmorgan@gmail.com> | |
6 | * | |
7 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
8 | * of this software and associated documentation files (the "Software"), to deal | |
9 | * in the Software without restriction, including without limitation the rights | |
10 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
11 | * copies of the Software, and to permit persons to whom the Software is | |
12 | * furnished to do so, subject to the following conditions: | |
13 | * | |
14 | * The above copyright notice and this permission notice shall be included in all | |
15 | * copies or substantial portions of the Software. | |
16 | * | |
17 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
18 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
19 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
20 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
21 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
22 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE | |
23 | * SOFTWARE. | |
24 | */ | |
25 | ||
26 | /** | |
27 | * @file | |
28 | * @brief Interface definitions for the 1-Wire bus component. | |
29 | * | |
30 | * This component provides structures and functions that are useful for communicating | |
31 | * with devices connected to a Maxim Integrated 1-Wire® bus via a single GPIO. | |
32 | * | |
33 | * Currently only externally powered devices are supported. Parasitic power is not supported. | |
34 | */ | |
35 | ||
36 | #ifndef ONE_WIRE_BUS_H | |
37 | #define ONE_WIRE_BUS_H | |
38 | ||
39 | #include <stdint.h> | |
40 | #include <stdbool.h> | |
41 | #include <stddef.h> | |
42 | ||
43 | #ifdef __cplusplus | |
44 | extern "C" { | |
45 | #endif | |
46 | ||
47 | ||
48 | // ROM commands | |
29 | 49 | #define OWB_ROM_SEARCH 0xF0 ///< Command ROM search |
50 | #define OWB_ROM_READ 0x33 ///< ROM read | |
51 | #define OWB_ROM_MATCH 0x55 ///< ROM address match | |
52 | #define OWB_ROM_SKIP 0xCC ///< Skip device | |
53 | #define OWB_ROM_SEARCH_ALARM 0xEC ///< Search device with alarm set | |
0 | 54 | |
55 | #define OWB_ROM_CODE_STRING_LENGTH (17) ///< Typical length of OneWire bus ROM ID as ASCII hex string, including null terminator | |
56 | ||
57 | struct owb_driver; | |
58 | ||
59 | /** | |
60 | * @brief Structure containing 1-Wire bus information relevant to a single instance. | |
61 | */ | |
62 | typedef struct | |
63 | { | |
64 | const struct _OneWireBus_Timing * timing; ///< Pointer to timing information | |
65 | bool use_crc; ///< True if CRC checks are to be used when retrieving information from a device on the bus | |
66 | ||
67 | const struct owb_driver *driver; | |
68 | } OneWireBus; | |
69 | ||
70 | /** | |
71 | * @brief Represents a 1-Wire ROM Code. This is a sequence of eight bytes, where | |
72 | * the first byte is the family number, then the following 6 bytes form the | |
73 | * serial number. The final byte is the CRC8 check byte. | |
74 | */ | |
75 | typedef union | |
76 | { | |
77 | /// Provides access via field names | |
78 | struct fields | |
79 | { | |
80 | uint8_t family[1]; ///< family identifier (1 byte, LSB - read/write first) | |
81 | uint8_t serial_number[6]; ///< serial number (6 bytes) | |
82 | uint8_t crc[1]; ///< CRC check byte (1 byte, MSB - read/write last) | |
83 | } fields; ///< Provides access via field names | |
84 | ||
85 | uint8_t bytes[8]; ///< Provides raw byte access | |
86 | ||
87 | } OneWireBus_ROMCode; | |
88 | ||
89 | /** | |
90 | * @brief Represents the state of a device search on the 1-Wire bus. | |
91 | * | |
92 | * Pass a pointer to this structure to owb_search_first() and | |
93 | * owb_search_next() to iterate through detected devices on the bus. | |
94 | */ | |
95 | typedef struct | |
96 | { | |
97 | OneWireBus_ROMCode rom_code; | |
98 | int last_discrepancy; | |
99 | int last_family_discrepancy; | |
100 | int last_device_flag; | |
101 | } OneWireBus_SearchState; | |
102 | ||
29 | 103 | /** |
104 | * @brief Status codes | |
105 | */ | |
0 | 106 | typedef enum |
107 | { | |
29 | 108 | OWB_STATUS_OK, ///< Ok |
109 | OWB_STATUS_NOT_INITIALIZED, ///< Init error | |
110 | OWB_STATUS_PARAMETER_NULL, ///< NULL parameter | |
111 | OWB_STATUS_DEVICE_NOT_RESPONDING, ///< Device does not respond | |
112 | OWB_STATUS_CRC_FAILED, ///< CRC error | |
113 | OWB_STATUS_TOO_MANY_BITS, ///< Too many bits | |
114 | OWB_STATUS_HW_ERROR ///< Hardware error | |
0 | 115 | } owb_status; |
116 | ||
117 | /** NOTE: Driver assumes that (*init) was called prior to any other methods */ | |
118 | struct owb_driver | |
119 | { | |
120 | const char* name; | |
121 | ||
122 | owb_status (*uninitialize)(const OneWireBus * bus); | |
123 | ||
124 | owb_status (*reset)(const OneWireBus * bus, bool *is_present); | |
125 | ||
126 | /** NOTE: The data is shifted out of the low bits, eg. it is written in the order of lsb to msb */ | |
127 | owb_status (*write_bits)(const OneWireBus *bus, uint8_t out, int number_of_bits_to_write); | |
128 | ||
129 | /** NOTE: Data is read into the high bits, eg. each bit read is shifted down before the next bit is read */ | |
130 | owb_status (*read_bits)(const OneWireBus *bus, uint8_t *in, int number_of_bits_to_read); | |
131 | }; | |
132 | ||
133 | #define container_of(ptr, type, member) ({ \ | |
134 | const typeof( ((type *)0)->member ) *__mptr = (ptr); \ | |
135 | (type *)( (char *)__mptr - offsetof(type,member) );}) | |
136 | ||
137 | /** | |
138 | * @brief call to release resources after completing use of the OneWireBus | |
29 | 139 | * @param[in] bus Pointer to initialised bus instance. |
140 | * @return status | |
0 | 141 | */ |
142 | owb_status owb_uninitialize(OneWireBus * bus); | |
143 | ||
144 | /** | |
145 | * @brief Enable or disable use of CRC checks on device communications. | |
146 | * @param[in] bus Pointer to initialised bus instance. | |
147 | * @param[in] use_crc True to enable CRC checks, false to disable. | |
148 | * @return status | |
149 | */ | |
150 | owb_status owb_use_crc(OneWireBus * bus, bool use_crc); | |
151 | ||
152 | /** | |
153 | * @brief Read ROM code from device - only works when there is a single device on the bus. | |
154 | * @param[in] bus Pointer to initialised bus instance. | |
155 | * @param[out] rom_code the value read from the device's rom | |
156 | * @return status | |
157 | */ | |
158 | owb_status owb_read_rom(const OneWireBus * bus, OneWireBus_ROMCode *rom_code); | |
159 | ||
160 | /** | |
161 | * @brief Verify the device specified by ROM code is present. | |
162 | * @param[in] bus Pointer to initialised bus instance. | |
163 | * @param[in] rom_code ROM code to verify. | |
164 | * @param[out] is_present set to true if a device is present, false if not | |
165 | * @return status | |
166 | */ | |
167 | owb_status owb_verify_rom(const OneWireBus * bus, OneWireBus_ROMCode rom_code, bool* is_present); | |
168 | ||
169 | /** | |
170 | * @brief Reset the 1-Wire bus. | |
171 | * @param[in] bus Pointer to initialised bus instance. | |
29 | 172 | * @param[out] a_device_present set to true if at least one device is present on the bus |
0 | 173 | * @return status |
174 | */ | |
175 | owb_status owb_reset(const OneWireBus * bus, bool* a_device_present); | |
176 | ||
177 | /** | |
178 | * @brief Write a single byte to the 1-Wire bus. | |
179 | * @param[in] bus Pointer to initialised bus instance. | |
180 | * @param[in] data Byte value to write to bus. | |
181 | * @return status | |
182 | */ | |
183 | owb_status owb_write_byte(const OneWireBus * bus, uint8_t data); | |
184 | ||
185 | /** | |
186 | * @brief Read a single byte from the 1-Wire bus. | |
187 | * @param[in] bus Pointer to initialised bus instance. | |
188 | * @param[out] out The byte value read from the bus. | |
189 | * @return status | |
190 | */ | |
191 | owb_status owb_read_byte(const OneWireBus * bus, uint8_t *out); | |
192 | ||
193 | /** | |
194 | * @brief Read a number of bytes from the 1-Wire bus. | |
195 | * @param[in] bus Pointer to initialised bus instance. | |
196 | * @param[in, out] buffer Pointer to buffer to receive read data. | |
197 | * @param[in] len Number of bytes to read, must not exceed length of receive buffer. | |
198 | * @return status. | |
199 | */ | |
200 | owb_status owb_read_bytes(const OneWireBus * bus, uint8_t * buffer, size_t len); | |
201 | ||
202 | /** | |
203 | * @brief Write a number of bytes to the 1-Wire bus. | |
204 | * @param[in] bus Pointer to initialised bus instance. | |
205 | * @param[in] buffer Pointer to buffer to write data from. | |
206 | * @param[in] len Number of bytes to write. | |
207 | * @return status | |
208 | */ | |
209 | owb_status owb_write_bytes(const OneWireBus * bus, const uint8_t * buffer, size_t len); | |
210 | ||
211 | /** | |
212 | * @brief Write a ROM code to the 1-Wire bus ensuring LSB is sent first. | |
213 | * @param[in] bus Pointer to initialised bus instance. | |
214 | * @param[in] rom_code ROM code to write to bus. | |
215 | * @return status | |
216 | */ | |
217 | owb_status owb_write_rom_code(const OneWireBus * bus, OneWireBus_ROMCode rom_code); | |
218 | ||
219 | /** | |
220 | * @brief 1-Wire 8-bit CRC lookup. | |
221 | * @param[in] crc Starting CRC value. Pass in prior CRC to accumulate. | |
222 | * @param[in] data Byte to feed into CRC. | |
223 | * @return Resultant CRC value. | |
224 | * Should be zero if last byte was the CRC byte and the CRC matches. | |
225 | */ | |
226 | uint8_t owb_crc8_byte(uint8_t crc, uint8_t data); | |
227 | ||
228 | /** | |
229 | * @brief 1-Wire 8-bit CRC lookup with accumulation over a block of bytes. | |
230 | * @param[in] crc Starting CRC value. Pass in prior CRC to accumulate. | |
231 | * @param[in] data Array of bytes to feed into CRC. | |
232 | * @param[in] len Length of data array in bytes. | |
233 | * @return Resultant CRC value. | |
234 | * Should be zero if last byte was the CRC byte and the CRC matches. | |
235 | */ | |
236 | uint8_t owb_crc8_bytes(uint8_t crc, const uint8_t * data, size_t len); | |
237 | ||
238 | /** | |
239 | * @brief Locates the first device on the 1-Wire bus, if present. | |
240 | * @param[in] bus Pointer to initialised bus instance. | |
241 | * @param[in,out] state Pointer to an existing search state structure. | |
242 | * @param[out] found_device True if a device is found, false if no devices are found. | |
243 | * If a device is found, the ROM Code can be obtained from the state. | |
244 | * @return status | |
245 | */ | |
246 | owb_status owb_search_first(const OneWireBus * bus, OneWireBus_SearchState * state, bool *found_device); | |
247 | ||
248 | /** | |
249 | * @brief Locates the next device on the 1-Wire bus, if present, starting from | |
250 | * the provided state. Further calls will yield additional devices, if present. | |
251 | * @param[in] bus Pointer to initialised bus instance. | |
252 | * @param[in,out] state Pointer to an existing search state structure. | |
253 | * @param[out] found_device True if a device is found, false if no devices are found. | |
254 | * If a device is found, the ROM Code can be obtained from the state. | |
255 | * @return status | |
256 | */ | |
257 | owb_status owb_search_next(const OneWireBus * bus, OneWireBus_SearchState * state, bool *found_device); | |
258 | ||
259 | /** | |
260 | * @brief Create a string representation of a ROM code, most significant byte (CRC8) first. | |
261 | * @param[in] rom_code The ROM code to convert to string representation. | |
262 | * @param[out] buffer The destination for the string representation. It will be null terminated. | |
263 | * @param[in] len The length of the buffer in bytes. 64-bit ROM codes require 16 characters | |
264 | * to represent as a string, plus a null terminator, for 17 bytes. | |
265 | * See OWB_ROM_CODE_STRING_LENGTH. | |
266 | * @return pointer to the byte beyond the last byte written | |
267 | */ | |
268 | char * owb_string_from_rom_code(OneWireBus_ROMCode rom_code, char * buffer, size_t len); | |
269 | ||
270 | #include "owb_gpio.h" | |
271 | #include "owb_rmt.h" | |
272 | ||
273 | #ifdef __cplusplus | |
274 | } | |
275 | #endif | |
276 | ||
277 | #endif // ONE_WIRE_BUS_H |