1 #include "i2c.hpp" 2 3 #include <fcntl.h> 4 #include <sys/ioctl.h> 5 #include <sys/stat.h> 6 #include <unistd.h> 7 8 #include <cassert> 9 #include <cerrno> 10 11 extern "C" 12 { 13 #include <i2c/smbus.h> 14 #include <linux/i2c-dev.h> 15 #include <linux/i2c.h> 16 } 17 18 namespace i2c 19 { 20 21 unsigned long I2CDevice::getFuncs() 22 { 23 // If functionality has not been cached 24 if (cachedFuncs == NO_FUNCS) 25 { 26 // Get functionality from adapter 27 int ret = 0, retries = 0; 28 do 29 { 30 ret = ioctl(fd, I2C_FUNCS, &cachedFuncs); 31 } while ((ret < 0) && (++retries <= maxRetries)); 32 33 if (ret < 0) 34 { 35 throw I2CException("Failed to get funcs", busStr, devAddr, errno); 36 } 37 } 38 39 return cachedFuncs; 40 } 41 42 void I2CDevice::checkReadFuncs(int type) 43 { 44 unsigned long funcs = getFuncs(); 45 switch (type) 46 { 47 case I2C_SMBUS_BYTE: 48 if (!(funcs & I2C_FUNC_SMBUS_READ_BYTE)) 49 { 50 throw I2CException("Missing SMBUS_READ_BYTE", busStr, devAddr); 51 } 52 break; 53 case I2C_SMBUS_BYTE_DATA: 54 if (!(funcs & I2C_FUNC_SMBUS_READ_BYTE_DATA)) 55 { 56 throw I2CException("Missing SMBUS_READ_BYTE_DATA", busStr, 57 devAddr); 58 } 59 break; 60 case I2C_SMBUS_WORD_DATA: 61 if (!(funcs & I2C_FUNC_SMBUS_READ_WORD_DATA)) 62 { 63 throw I2CException("Missing SMBUS_READ_WORD_DATA", busStr, 64 devAddr); 65 } 66 break; 67 case I2C_SMBUS_BLOCK_DATA: 68 if (!(funcs & I2C_FUNC_SMBUS_READ_BLOCK_DATA)) 69 { 70 throw I2CException("Missing SMBUS_READ_BLOCK_DATA", busStr, 71 devAddr); 72 } 73 break; 74 case I2C_SMBUS_I2C_BLOCK_DATA: 75 if (!(funcs & I2C_FUNC_SMBUS_READ_I2C_BLOCK)) 76 { 77 throw I2CException("Missing I2C_FUNC_SMBUS_READ_I2C_BLOCK", 78 busStr, devAddr); 79 } 80 break; 81 default: 82 fprintf(stderr, "Unexpected read size type: %d\n", type); 83 assert(false); 84 break; 85 } 86 } 87 88 void I2CDevice::checkWriteFuncs(int type) 89 { 90 unsigned long funcs = getFuncs(); 91 switch (type) 92 { 93 case I2C_SMBUS_BYTE: 94 if (!(funcs & I2C_FUNC_SMBUS_WRITE_BYTE)) 95 { 96 throw I2CException("Missing SMBUS_WRITE_BYTE", busStr, devAddr); 97 } 98 break; 99 case I2C_SMBUS_BYTE_DATA: 100 if (!(funcs & I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) 101 { 102 throw I2CException("Missing SMBUS_WRITE_BYTE_DATA", busStr, 103 devAddr); 104 } 105 break; 106 case I2C_SMBUS_WORD_DATA: 107 if (!(funcs & I2C_FUNC_SMBUS_WRITE_WORD_DATA)) 108 { 109 throw I2CException("Missing SMBUS_WRITE_WORD_DATA", busStr, 110 devAddr); 111 } 112 break; 113 case I2C_SMBUS_BLOCK_DATA: 114 if (!(funcs & I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)) 115 { 116 throw I2CException("Missing SMBUS_WRITE_BLOCK_DATA", busStr, 117 devAddr); 118 } 119 break; 120 case I2C_SMBUS_I2C_BLOCK_DATA: 121 if (!(funcs & I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)) 122 { 123 throw I2CException("Missing I2C_FUNC_SMBUS_WRITE_I2C_BLOCK", 124 busStr, devAddr); 125 } 126 break; 127 default: 128 fprintf(stderr, "Unexpected write size type: %d\n", type); 129 assert(false); 130 } 131 } 132 133 void I2CDevice::open() 134 { 135 if (isOpen()) 136 { 137 throw I2CException("Device already open", busStr, devAddr); 138 } 139 140 int retries = 0; 141 do 142 { 143 fd = ::open(busStr.c_str(), O_RDWR); 144 } while ((fd == -1) && (++retries <= maxRetries)); 145 146 if (fd == -1) 147 { 148 throw I2CException("Failed to open", busStr, devAddr, errno); 149 } 150 151 retries = 0; 152 int ret = 0; 153 do 154 { 155 ret = ioctl(fd, I2C_SLAVE, devAddr); 156 } while ((ret < 0) && (++retries <= maxRetries)); 157 158 if (ret < 0) 159 { 160 // Close device since setting slave address failed 161 closeWithoutException(); 162 163 throw I2CException("Failed to set I2C_SLAVE", busStr, devAddr, errno); 164 } 165 } 166 167 void I2CDevice::close() 168 { 169 checkIsOpen(); 170 171 int ret = 0, retries = 0; 172 do 173 { 174 ret = ::close(fd); 175 } while ((ret == -1) && (++retries <= maxRetries)); 176 177 if (ret == -1) 178 { 179 throw I2CException("Failed to close", busStr, devAddr, errno); 180 } 181 182 fd = INVALID_FD; 183 cachedFuncs = NO_FUNCS; 184 } 185 186 void I2CDevice::read(uint8_t& data) 187 { 188 checkIsOpen(); 189 checkReadFuncs(I2C_SMBUS_BYTE); 190 191 int ret = 0, retries = 0; 192 do 193 { 194 ret = i2c_smbus_read_byte(fd); 195 } while ((ret < 0) && (++retries <= maxRetries)); 196 197 if (ret < 0) 198 { 199 throw I2CException("Failed to read byte", busStr, devAddr, errno); 200 } 201 202 data = static_cast<uint8_t>(ret); 203 } 204 205 void I2CDevice::read(uint8_t addr, uint8_t& data) 206 { 207 checkIsOpen(); 208 checkReadFuncs(I2C_SMBUS_BYTE_DATA); 209 210 int ret = 0, retries = 0; 211 do 212 { 213 ret = i2c_smbus_read_byte_data(fd, addr); 214 } while ((ret < 0) && (++retries <= maxRetries)); 215 216 if (ret < 0) 217 { 218 throw I2CException("Failed to read byte data", busStr, devAddr, errno); 219 } 220 221 data = static_cast<uint8_t>(ret); 222 } 223 224 void I2CDevice::read(uint8_t addr, uint16_t& data) 225 { 226 checkIsOpen(); 227 checkReadFuncs(I2C_SMBUS_WORD_DATA); 228 229 int ret = 0, retries = 0; 230 do 231 { 232 ret = i2c_smbus_read_word_data(fd, addr); 233 } while ((ret < 0) && (++retries <= maxRetries)); 234 235 if (ret < 0) 236 { 237 throw I2CException("Failed to read word data", busStr, devAddr, errno); 238 } 239 240 data = static_cast<uint16_t>(ret); 241 } 242 243 void I2CDevice::read(uint8_t addr, uint8_t& size, uint8_t* data, Mode mode) 244 { 245 checkIsOpen(); 246 247 int ret = -1, retries = 0; 248 switch (mode) 249 { 250 case Mode::SMBUS: 251 checkReadFuncs(I2C_SMBUS_BLOCK_DATA); 252 do 253 { 254 ret = i2c_smbus_read_block_data(fd, addr, data); 255 } while ((ret < 0) && (++retries <= maxRetries)); 256 break; 257 case Mode::I2C: 258 checkReadFuncs(I2C_SMBUS_I2C_BLOCK_DATA); 259 do 260 { 261 ret = i2c_smbus_read_i2c_block_data(fd, addr, size, data); 262 } while ((ret < 0) && (++retries <= maxRetries)); 263 if (ret != size) 264 { 265 throw I2CException("Failed to read i2c block data", busStr, 266 devAddr, errno); 267 } 268 break; 269 } 270 271 if (ret < 0) 272 { 273 throw I2CException("Failed to read block data", busStr, devAddr, errno); 274 } 275 276 size = static_cast<uint8_t>(ret); 277 } 278 279 void I2CDevice::write(uint8_t data) 280 { 281 checkIsOpen(); 282 checkWriteFuncs(I2C_SMBUS_BYTE); 283 284 int ret = 0, retries = 0; 285 do 286 { 287 ret = i2c_smbus_write_byte(fd, data); 288 } while ((ret < 0) && (++retries <= maxRetries)); 289 290 if (ret < 0) 291 { 292 throw I2CException("Failed to write byte", busStr, devAddr, errno); 293 } 294 } 295 296 void I2CDevice::write(uint8_t addr, uint8_t data) 297 { 298 checkIsOpen(); 299 checkWriteFuncs(I2C_SMBUS_BYTE_DATA); 300 301 int ret = 0, retries = 0; 302 do 303 { 304 ret = i2c_smbus_write_byte_data(fd, addr, data); 305 } while ((ret < 0) && (++retries <= maxRetries)); 306 307 if (ret < 0) 308 { 309 throw I2CException("Failed to write byte data", busStr, devAddr, errno); 310 } 311 } 312 313 void I2CDevice::write(uint8_t addr, uint16_t data) 314 { 315 checkIsOpen(); 316 checkWriteFuncs(I2C_SMBUS_WORD_DATA); 317 318 int ret = 0, retries = 0; 319 do 320 { 321 ret = i2c_smbus_write_word_data(fd, addr, data); 322 } while ((ret < 0) && (++retries <= maxRetries)); 323 324 if (ret < 0) 325 { 326 throw I2CException("Failed to write word data", busStr, devAddr, errno); 327 } 328 } 329 330 void I2CDevice::write(uint8_t addr, uint8_t size, const uint8_t* data, 331 Mode mode) 332 { 333 checkIsOpen(); 334 335 int ret = -1, retries = 0; 336 switch (mode) 337 { 338 case Mode::SMBUS: 339 checkWriteFuncs(I2C_SMBUS_BLOCK_DATA); 340 do 341 { 342 ret = i2c_smbus_write_block_data(fd, addr, size, data); 343 } while ((ret < 0) && (++retries <= maxRetries)); 344 break; 345 case Mode::I2C: 346 checkWriteFuncs(I2C_SMBUS_I2C_BLOCK_DATA); 347 do 348 { 349 ret = i2c_smbus_write_i2c_block_data(fd, addr, size, data); 350 } while ((ret < 0) && (++retries <= maxRetries)); 351 break; 352 } 353 354 if (ret < 0) 355 { 356 throw I2CException("Failed to write block data", busStr, devAddr, 357 errno); 358 } 359 } 360 361 std::unique_ptr<I2CInterface> I2CDevice::create(uint8_t busId, uint8_t devAddr, 362 InitialState initialState, 363 int maxRetries) 364 { 365 std::unique_ptr<I2CDevice> dev( 366 new I2CDevice(busId, devAddr, initialState, maxRetries)); 367 return dev; 368 } 369 370 std::unique_ptr<I2CInterface> create(uint8_t busId, uint8_t devAddr, 371 I2CInterface::InitialState initialState, 372 int maxRetries) 373 { 374 return I2CDevice::create(busId, devAddr, initialState, maxRetries); 375 } 376 377 } // namespace i2c 378