1 /*
2 * Author: Brendan Le Foll <brendan.le.foll@intel.com>
3 * Copyright (c) 2014 Intel Corporation.
4 *
5 * Code is modified from the RoadNarrows-robotics i2c library (distributed under
6 * the MIT license, license is included verbatim under src/i2c/LICENSE)
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining
9 * a copy of this software and associated documentation files (the
10 * "Software"), to deal in the Software without restriction, including
11 * without limitation the rights to use, copy, modify, merge, publish,
12 * distribute, sublicense, and/or sell copies of the Software, and to
13 * permit persons to whom the Software is furnished to do so, subject to
14 * the following conditions:
15 *
16 * The above copyright notice and this permission notice shall be
17 * included in all copies or substantial portions of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
20 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
21 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
22 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
23 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
24 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
25 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
26 */
27
28 #include "i2c.h"
29 #include "mraa_internal.h"
30
31 #include <stdlib.h>
32 #include <unistd.h>
33 #include <fcntl.h>
34 #include <inttypes.h>
35 #include <sys/types.h>
36 #include <sys/errno.h>
37 #include <sys/ioctl.h>
38 #include "linux/i2c-dev.h"
39
40
41 typedef union i2c_smbus_data_union {
42 uint8_t byte; ///< data byte
43 unsigned short word; ///< data short word
44 uint8_t block[I2C_SMBUS_BLOCK_MAX + 2];
45 ///< block[0] is used for length and one more for PEC
46 } i2c_smbus_data_t;
47
48 typedef struct i2c_smbus_ioctl_data_struct {
49 uint8_t read_write; ///< operation direction
50 uint8_t command; ///< ioctl command
51 int size; ///< data size
52 i2c_smbus_data_t* data; ///< data
53 } i2c_smbus_ioctl_data_t;
54
55
56 // static mraa_adv_func_t* func_table;
57
58 int
mraa_i2c_smbus_access(int fh,uint8_t read_write,uint8_t command,int size,i2c_smbus_data_t * data)59 mraa_i2c_smbus_access(int fh, uint8_t read_write, uint8_t command, int size, i2c_smbus_data_t* data)
60 {
61 i2c_smbus_ioctl_data_t args;
62
63 args.read_write = read_write;
64 args.command = command;
65 args.size = size;
66 args.data = data;
67
68 return ioctl(fh, I2C_SMBUS, &args);
69 }
70
71 static mraa_i2c_context
mraa_i2c_init_internal(mraa_adv_func_t * advance_func,unsigned int bus)72 mraa_i2c_init_internal(mraa_adv_func_t* advance_func, unsigned int bus)
73 {
74 mraa_result_t status = MRAA_SUCCESS;
75
76 if (advance_func == NULL)
77 return NULL;
78
79 mraa_i2c_context dev = (mraa_i2c_context) calloc(1, sizeof(struct _i2c));
80 if (dev == NULL) {
81 syslog(LOG_CRIT, "i2c: Failed to allocate memory for context");
82 return NULL;
83 }
84
85 dev->advance_func = advance_func;
86 dev->busnum = bus;
87
88 if (IS_FUNC_DEFINED(dev, i2c_init_pre)) {
89 status = advance_func->i2c_init_pre(bus);
90 if (status != MRAA_SUCCESS)
91 goto init_internal_cleanup;
92 }
93
94 if (IS_FUNC_DEFINED(dev, i2c_init_bus_replace)) {
95 status = dev->advance_func->i2c_init_bus_replace(dev);
96 if (status != MRAA_SUCCESS)
97 goto init_internal_cleanup;
98 } else {
99 char filepath[32];
100 snprintf(filepath, 32, "/dev/i2c-%u", bus);
101 if ((dev->fh = open(filepath, O_RDWR)) < 1) {
102 syslog(LOG_ERR, "i2c: Failed to open requested i2c port %s", filepath);
103 status = MRAA_ERROR_NO_RESOURCES;
104 goto init_internal_cleanup;
105 }
106
107 if (ioctl(dev->fh, I2C_FUNCS, &dev->funcs) < 0) {
108 syslog(LOG_CRIT, "i2c: Failed to get I2C_FUNC map from device");
109 dev->funcs = 0;
110 }
111 }
112
113 if (IS_FUNC_DEFINED(dev, i2c_init_post)) {
114 status = dev->advance_func->i2c_init_post(dev);
115 if (status != MRAA_SUCCESS)
116 goto init_internal_cleanup;
117 }
118
119
120 init_internal_cleanup:
121 if (status == MRAA_SUCCESS) {
122 return dev;
123 } else {
124 if (dev != NULL)
125 free(dev);
126 return NULL;
127 }
128 }
129
130
131 mraa_i2c_context
mraa_i2c_init(int bus)132 mraa_i2c_init(int bus)
133 {
134 mraa_board_t* board = plat;
135 if (board == NULL) {
136 syslog(LOG_ERR, "i2c: Platform Not Initialised");
137 return NULL;
138 }
139
140 if (mraa_is_sub_platform_id(bus)) {
141 syslog(LOG_NOTICE, "i2c: Using sub platform");
142 board = board->sub_platform;
143 if (board == NULL) {
144 syslog(LOG_ERR, "i2c: Sub platform Not Initialised");
145 return NULL;
146 }
147 bus = mraa_get_sub_platform_index(bus);
148 }
149 syslog(LOG_NOTICE, "i2c: Selected bus %d", bus);
150
151 if (board->i2c_bus_count == 0) {
152 syslog(LOG_ERR, "No i2c buses defined in platform");
153 return NULL;
154 }
155 if (bus >= board->i2c_bus_count) {
156 syslog(LOG_ERR, "Above i2c bus count");
157 return NULL;
158 }
159
160 if (board->i2c_bus[bus].bus_id == -1) {
161 syslog(LOG_ERR, "Invalid i2c bus, moving to default i2c bus");
162 bus = board->def_i2c_bus;
163 }
164 if (!board->no_bus_mux) {
165 int pos = board->i2c_bus[bus].sda;
166 if (board->pins[pos].i2c.mux_total > 0) {
167 if (mraa_setup_mux_mapped(board->pins[pos].i2c) != MRAA_SUCCESS) {
168 syslog(LOG_ERR, "i2c: Failed to set-up i2c sda multiplexer");
169 return NULL;
170 }
171 }
172
173 pos = board->i2c_bus[bus].scl;
174 if (board->pins[pos].i2c.mux_total > 0) {
175 if (mraa_setup_mux_mapped(board->pins[pos].i2c) != MRAA_SUCCESS) {
176 syslog(LOG_ERR, "i2c: Failed to set-up i2c scl multiplexer");
177 return NULL;
178 }
179 }
180 }
181
182 return mraa_i2c_init_internal(board->adv_func, (unsigned int) board->i2c_bus[bus].bus_id);
183 }
184
185
186 mraa_i2c_context
mraa_i2c_init_raw(unsigned int bus)187 mraa_i2c_init_raw(unsigned int bus)
188 {
189 return mraa_i2c_init_internal(plat == NULL ? NULL : plat->adv_func, bus);
190 }
191
192
193 mraa_result_t
mraa_i2c_frequency(mraa_i2c_context dev,mraa_i2c_mode_t mode)194 mraa_i2c_frequency(mraa_i2c_context dev, mraa_i2c_mode_t mode)
195 {
196 if (IS_FUNC_DEFINED(dev, i2c_set_frequency_replace)) {
197 return dev->advance_func->i2c_set_frequency_replace(dev, mode);
198 }
199 return MRAA_ERROR_FEATURE_NOT_SUPPORTED;
200 }
201
202 int
mraa_i2c_read(mraa_i2c_context dev,uint8_t * data,int length)203 mraa_i2c_read(mraa_i2c_context dev, uint8_t* data, int length)
204 {
205 int bytes_read = 0;
206 if (IS_FUNC_DEFINED(dev, i2c_read_replace)) {
207 bytes_read = dev->advance_func->i2c_read_replace(dev, data, length);
208 }
209 else {
210 bytes_read = read(dev->fh, data, length);
211 }
212 if (bytes_read == length) {
213 return length;
214 }
215
216 return 0;
217 }
218
219 uint8_t
mraa_i2c_read_byte(mraa_i2c_context dev)220 mraa_i2c_read_byte(mraa_i2c_context dev)
221 {
222 if (IS_FUNC_DEFINED(dev, i2c_read_byte_replace))
223 return dev->advance_func->i2c_read_byte_replace(dev);
224 i2c_smbus_data_t d;
225 if (mraa_i2c_smbus_access(dev->fh, I2C_SMBUS_READ, I2C_NOCMD, I2C_SMBUS_BYTE, &d) < 0) {
226 syslog(LOG_ERR, "i2c: Failed to write");
227 return 0;
228 }
229 return 0x0FF & d.byte;
230 }
231
232 uint8_t
mraa_i2c_read_byte_data(mraa_i2c_context dev,uint8_t command)233 mraa_i2c_read_byte_data(mraa_i2c_context dev, uint8_t command)
234 {
235 if (IS_FUNC_DEFINED(dev, i2c_read_byte_data_replace))
236 return dev->advance_func->i2c_read_byte_data_replace(dev, command);
237 i2c_smbus_data_t d;
238 if (mraa_i2c_smbus_access(dev->fh, I2C_SMBUS_READ, command, I2C_SMBUS_BYTE_DATA, &d) < 0) {
239 syslog(LOG_ERR, "i2c: Failed to write");
240 return 0;
241 }
242 return 0x0FF & d.byte;
243 }
244
245 uint16_t
mraa_i2c_read_word_data(mraa_i2c_context dev,uint8_t command)246 mraa_i2c_read_word_data(mraa_i2c_context dev, uint8_t command)
247 {
248 if (IS_FUNC_DEFINED(dev, i2c_read_word_data_replace))
249 return dev->advance_func->i2c_read_word_data_replace(dev, command);
250 i2c_smbus_data_t d;
251 if (mraa_i2c_smbus_access(dev->fh, I2C_SMBUS_READ, command, I2C_SMBUS_WORD_DATA, &d) < 0) {
252 syslog(LOG_ERR, "i2c: Failed to write");
253 return 0;
254 }
255 return 0xFFFF & d.word;
256 }
257
258 int
mraa_i2c_read_bytes_data(mraa_i2c_context dev,uint8_t command,uint8_t * data,int length)259 mraa_i2c_read_bytes_data(mraa_i2c_context dev, uint8_t command, uint8_t* data, int length)
260 {
261 if (IS_FUNC_DEFINED(dev, i2c_read_bytes_data_replace))
262 return dev->advance_func->i2c_read_bytes_data_replace(dev, command, data, length);
263 struct i2c_rdwr_ioctl_data d;
264 struct i2c_msg m[2];
265
266 m[0].addr = dev->addr;
267 m[0].flags = 0x00;
268 m[0].len = 1;
269 m[0].buf = &command;
270 m[1].addr = dev->addr;
271 m[1].flags = I2C_M_RD;
272 m[1].len = length;
273 m[1].buf = data;
274
275 d.msgs = m;
276 d.nmsgs = 2;
277
278 return ioctl(dev->fh, I2C_RDWR, &d) < 0 ? -1 : length;
279 }
280
281 mraa_result_t
mraa_i2c_write(mraa_i2c_context dev,const uint8_t * data,int length)282 mraa_i2c_write(mraa_i2c_context dev, const uint8_t* data, int length)
283 {
284 if (IS_FUNC_DEFINED(dev, i2c_write_replace))
285 return dev->advance_func->i2c_write_replace(dev, data, length);
286 i2c_smbus_data_t d;
287 int i;
288 uint8_t command = data[0];
289
290 data = &data[1];
291 length = length - 1;
292 if (length > I2C_SMBUS_I2C_BLOCK_MAX) {
293 length = I2C_SMBUS_I2C_BLOCK_MAX;
294 }
295
296 for (i = 1; i <= length; i++) {
297 d.block[i] = data[i - 1];
298 }
299 d.block[0] = length;
300
301 return mraa_i2c_smbus_access(dev->fh, I2C_SMBUS_WRITE, command, I2C_SMBUS_I2C_BLOCK_DATA, &d);
302 }
303
304 mraa_result_t
mraa_i2c_write_byte(mraa_i2c_context dev,const uint8_t data)305 mraa_i2c_write_byte(mraa_i2c_context dev, const uint8_t data)
306 {
307 if (IS_FUNC_DEFINED(dev, i2c_write_byte_replace)) {
308 return dev->advance_func->i2c_write_byte_replace(dev, data);
309 } else {
310 if (mraa_i2c_smbus_access(dev->fh, I2C_SMBUS_WRITE, data, I2C_SMBUS_BYTE, NULL) < 0) {
311 syslog(LOG_ERR, "i2c: Failed to write");
312 return MRAA_ERROR_INVALID_HANDLE;
313 }
314 return MRAA_SUCCESS;
315 }
316 }
317
318 mraa_result_t
mraa_i2c_write_byte_data(mraa_i2c_context dev,const uint8_t data,const uint8_t command)319 mraa_i2c_write_byte_data(mraa_i2c_context dev, const uint8_t data, const uint8_t command)
320 {
321 if (IS_FUNC_DEFINED(dev, i2c_write_byte_data_replace))
322 return dev->advance_func->i2c_write_byte_data_replace(dev, data, command);
323 i2c_smbus_data_t d;
324 d.byte = data;
325 if (mraa_i2c_smbus_access(dev->fh, I2C_SMBUS_WRITE, command, I2C_SMBUS_BYTE_DATA, &d) < 0) {
326 syslog(LOG_ERR, "i2c: Failed to write");
327 return MRAA_ERROR_INVALID_HANDLE;
328 }
329 return MRAA_SUCCESS;
330 }
331
332 mraa_result_t
mraa_i2c_write_word_data(mraa_i2c_context dev,const uint16_t data,const uint8_t command)333 mraa_i2c_write_word_data(mraa_i2c_context dev, const uint16_t data, const uint8_t command)
334 {
335 if (IS_FUNC_DEFINED(dev, i2c_write_word_data_replace))
336 return dev->advance_func->i2c_write_word_data_replace(dev, data, command);
337 i2c_smbus_data_t d;
338 d.word = data;
339 if (mraa_i2c_smbus_access(dev->fh, I2C_SMBUS_WRITE, command, I2C_SMBUS_WORD_DATA, &d) < 0) {
340 syslog(LOG_ERR, "i2c: Failed to write");
341 return MRAA_ERROR_INVALID_HANDLE;
342 }
343 return MRAA_SUCCESS;
344 }
345
346 mraa_result_t
mraa_i2c_address(mraa_i2c_context dev,uint8_t addr)347 mraa_i2c_address(mraa_i2c_context dev, uint8_t addr)
348 {
349 if (dev == NULL) {
350 return MRAA_ERROR_INVALID_HANDLE;
351 }
352
353 dev->addr = (int) addr;
354 if (IS_FUNC_DEFINED(dev, i2c_address_replace)) {
355 return dev->advance_func->i2c_address_replace(dev, addr);
356 } else {
357 if (ioctl(dev->fh, I2C_SLAVE_FORCE, addr) < 0) {
358 syslog(LOG_ERR, "i2c: Failed to set slave address %d", addr);
359 return MRAA_ERROR_INVALID_HANDLE;
360 }
361 return MRAA_SUCCESS;
362 }
363 }
364
365
366 mraa_result_t
mraa_i2c_stop(mraa_i2c_context dev)367 mraa_i2c_stop(mraa_i2c_context dev)
368 {
369 free(dev);
370 return MRAA_SUCCESS;
371 }
372
373