2 * Author: Brendan Le Foll <brendan.le.foll@intel.com>
3 * Copyright (c) 2014 Intel Corporation.
5 * Code is modified from the RoadNarrows-robotics i2c library (distributed under
6 * the MIT license, license is included verbatim under src/i2c/LICENSE)
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:
16 * The above copyright notice and this permission notice shall be
17 * included in all copies or substantial portions of the Software.
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.
29 #include "mraa_internal.h"
35 #include <sys/types.h>
36 #include <sys/errno.h>
37 #include <sys/ioctl.h>
38 #include "linux/i2c-dev.h"
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
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;
56 // static mraa_adv_func_t* func_table;
59 mraa_i2c_smbus_access(int fh, uint8_t read_write, uint8_t command, int size, i2c_smbus_data_t* data)
61 i2c_smbus_ioctl_data_t args;
63 args.read_write = read_write;
64 args.command = command;
68 return ioctl(fh, I2C_SMBUS, &args);
71 static mraa_i2c_context
72 mraa_i2c_init_internal(mraa_adv_func_t* advance_func, unsigned int bus)
74 mraa_result_t status = MRAA_SUCCESS;
76 if (advance_func == NULL)
79 mraa_i2c_context dev = (mraa_i2c_context) malloc(sizeof(struct _i2c));
81 syslog(LOG_CRIT, "i2c: Failed to allocate memory for context");
85 dev->advance_func = advance_func;
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;
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;
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;
107 if (ioctl(dev->fh, I2C_FUNCS, &dev->funcs) < 0) {
108 syslog(LOG_CRIT, "i2c: Failed to get I2C_FUNC map from device");
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;
120 init_internal_cleanup:
121 if (status == MRAA_SUCCESS) {
132 mraa_i2c_init(int bus)
134 mraa_board_t* board = plat;
136 syslog(LOG_ERR, "i2c: Platform Not Initialised");
140 if (mraa_is_sub_platform_id(bus)) {
141 syslog(LOG_NOTICE, "i2c: Using sub platform");
142 board = board->sub_platform;
144 syslog(LOG_ERR, "i2c: Sub platform Not Initialised");
147 bus = mraa_get_sub_platform_index(bus);
149 syslog(LOG_NOTICE, "i2c: Selected bus %d", bus);
151 if (board->i2c_bus_count == 0) {
152 syslog(LOG_ERR, "No i2c buses defined in platform");
155 if (bus >= board->i2c_bus_count) {
156 syslog(LOG_ERR, "Above i2c bus count");
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;
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");
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");
181 return mraa_i2c_init_internal(board->adv_func, (unsigned int) board->i2c_bus[bus].bus_id);
186 mraa_i2c_init_raw(unsigned int bus)
188 return mraa_i2c_init_internal(plat == NULL ? NULL : plat->adv_func, bus);
193 mraa_i2c_frequency(mraa_i2c_context dev, mraa_i2c_mode_t mode)
195 if (IS_FUNC_DEFINED(dev, i2c_set_frequency_replace)) {
196 return dev->advance_func->i2c_set_frequency_replace(dev, mode);
198 return MRAA_ERROR_FEATURE_NOT_SUPPORTED;
202 mraa_i2c_read(mraa_i2c_context dev, uint8_t* data, int length)
205 if (IS_FUNC_DEFINED(dev, i2c_read_replace))
206 bytes_read = dev->advance_func->i2c_read_replace(dev, data, length);
208 bytes_read = read(dev->fh, data, length);
209 if (bytes_read == length)
216 mraa_i2c_read_byte(mraa_i2c_context dev)
218 if (IS_FUNC_DEFINED(dev, i2c_read_byte_replace))
219 return dev->advance_func->i2c_read_byte_replace(dev);
221 if (mraa_i2c_smbus_access(dev->fh, I2C_SMBUS_READ, I2C_NOCMD, I2C_SMBUS_BYTE, &d) < 0) {
222 syslog(LOG_ERR, "i2c: Failed to write");
225 return 0x0FF & d.byte;
229 mraa_i2c_read_byte_data(mraa_i2c_context dev, uint8_t command)
231 if (IS_FUNC_DEFINED(dev, i2c_read_byte_data_replace))
232 return dev->advance_func->i2c_read_byte_data_replace(dev, command);
234 if (mraa_i2c_smbus_access(dev->fh, I2C_SMBUS_READ, command, I2C_SMBUS_BYTE_DATA, &d) < 0) {
235 syslog(LOG_ERR, "i2c: Failed to write");
238 return 0x0FF & d.byte;
242 mraa_i2c_read_word_data(mraa_i2c_context dev, uint8_t command)
244 if (IS_FUNC_DEFINED(dev, i2c_read_word_data_replace))
245 return dev->advance_func->i2c_read_word_data_replace(dev, command);
247 if (mraa_i2c_smbus_access(dev->fh, I2C_SMBUS_READ, command, I2C_SMBUS_WORD_DATA, &d) < 0) {
248 syslog(LOG_ERR, "i2c: Failed to write");
251 return 0xFFFF & d.word;
255 mraa_i2c_read_bytes_data(mraa_i2c_context dev, uint8_t command, uint8_t* data, int length)
257 if (IS_FUNC_DEFINED(dev, i2c_read_bytes_data_replace))
258 return dev->advance_func->i2c_read_bytes_data_replace(dev, command, data, length);
259 struct i2c_rdwr_ioctl_data d;
262 m[0].addr = dev->addr;
266 m[1].addr = dev->addr;
267 m[1].flags = I2C_M_RD;
274 return ioctl(dev->fh, I2C_RDWR, &d) < 0 ? -1 : length;
278 mraa_i2c_write(mraa_i2c_context dev, const uint8_t* data, int length)
280 if (IS_FUNC_DEFINED(dev, i2c_write_replace))
281 return dev->advance_func->i2c_write_replace(dev, data, length);
284 uint8_t command = data[0];
288 if (length > I2C_SMBUS_I2C_BLOCK_MAX) {
289 length = I2C_SMBUS_I2C_BLOCK_MAX;
292 for (i = 1; i <= length; i++) {
293 d.block[i] = data[i - 1];
297 return mraa_i2c_smbus_access(dev->fh, I2C_SMBUS_WRITE, command, I2C_SMBUS_I2C_BLOCK_DATA, &d);
301 mraa_i2c_write_byte(mraa_i2c_context dev, const uint8_t data)
303 if (IS_FUNC_DEFINED(dev, i2c_write_byte_replace)) {
304 return dev->advance_func->i2c_write_byte_replace(dev, data);
306 if (mraa_i2c_smbus_access(dev->fh, I2C_SMBUS_WRITE, data, I2C_SMBUS_BYTE, NULL) < 0) {
307 syslog(LOG_ERR, "i2c: Failed to write");
308 return MRAA_ERROR_INVALID_HANDLE;
315 mraa_i2c_write_byte_data(mraa_i2c_context dev, const uint8_t data, const uint8_t command)
317 if (IS_FUNC_DEFINED(dev, i2c_write_byte_data_replace))
318 return dev->advance_func->i2c_write_byte_data_replace(dev, data, command);
321 if (mraa_i2c_smbus_access(dev->fh, I2C_SMBUS_WRITE, command, I2C_SMBUS_BYTE_DATA, &d) < 0) {
322 syslog(LOG_ERR, "i2c: Failed to write");
323 return MRAA_ERROR_INVALID_HANDLE;
329 mraa_i2c_write_word_data(mraa_i2c_context dev, const uint16_t data, const uint8_t command)
331 if (IS_FUNC_DEFINED(dev, i2c_write_word_data_replace))
332 return dev->advance_func->i2c_write_word_data_replace(dev, data, command);
335 if (mraa_i2c_smbus_access(dev->fh, I2C_SMBUS_WRITE, command, I2C_SMBUS_WORD_DATA, &d) < 0) {
336 syslog(LOG_ERR, "i2c: Failed to write");
337 return MRAA_ERROR_INVALID_HANDLE;
343 mraa_i2c_address(mraa_i2c_context dev, uint8_t addr)
346 return MRAA_ERROR_INVALID_HANDLE;
349 dev->addr = (int) addr;
350 if (IS_FUNC_DEFINED(dev, i2c_address_replace)) {
351 return dev->advance_func->i2c_address_replace(dev, addr);
353 if (ioctl(dev->fh, I2C_SLAVE_FORCE, addr) < 0) {
354 syslog(LOG_ERR, "i2c: Failed to set slave address %d", addr);
355 return MRAA_ERROR_INVALID_HANDLE;
363 mraa_i2c_stop(mraa_i2c_context dev)