1 /** 2 * @file i2c.h 3 * @brief Inter-integrated circuit (I2C) communications interface driver. 4 */ 5 6 /****************************************************************************** 7 * 8 * Copyright (C) 2022-2023 Maxim Integrated Products, Inc. (now owned by 9 * Analog Devices, Inc.), 10 * Copyright (C) 2023-2024 Analog Devices, Inc. 11 * 12 * Licensed under the Apache License, Version 2.0 (the "License"); 13 * you may not use this file except in compliance with the License. 14 * You may obtain a copy of the License at 15 * 16 * http://www.apache.org/licenses/LICENSE-2.0 17 * 18 * Unless required by applicable law or agreed to in writing, software 19 * distributed under the License is distributed on an "AS IS" BASIS, 20 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 21 * See the License for the specific language governing permissions and 22 * limitations under the License. 23 * 24 ******************************************************************************/ 25 26 /* Define to prevent redundant inclusion */ 27 #ifndef LIBRARIES_PERIPHDRIVERS_INCLUDE_MAX32675_I2C_H_ 28 #define LIBRARIES_PERIPHDRIVERS_INCLUDE_MAX32675_I2C_H_ 29 30 #include <stdint.h> 31 #include <stdbool.h> 32 #include "mxc_sys.h" 33 #include "i2c_regs.h" 34 #include "dma_regs.h" 35 36 #ifdef __cplusplus 37 extern "C" { 38 #endif 39 40 /** 41 * @defgroup i2c I2C 42 * @ingroup periphlibs 43 * @{ 44 */ 45 46 /***** Definitions *****/ 47 #define MXC_I2C_STD_MODE 100000 48 #define MXC_I2C_FAST_SPEED 400000 49 #define MXC_I2C_FASTPLUS_SPEED 1000000 50 #define MXC_I2C_HIGH_SPEED 3400000 51 52 typedef struct _i2c_req_t mxc_i2c_req_t; 53 54 /** 55 * @brief The callback used by the MXC_I2C_ReadByteInteractive() function. 56 * 57 * The callback routine used by the MXC_I2C_ReadByteInteractive() function. This 58 * function allows the application to determine whether the byte received 59 * should be acknowledged or not. 60 * 61 * @param i2c Pointer to I2C registers (selects the I2C block used.) 62 * @param byte The byte received. 63 * 64 * @return 0 if the byte should not be acknowledged (NACK), non-zero to 65 * acknowledge the byte. 66 */ 67 typedef int (*mxc_i2c_getAck_t)(mxc_i2c_regs_t *i2c, unsigned char byte); 68 69 /** 70 * @brief The callback routine used by the MXC_I2C_MasterTransactionAsync() 71 * function to indicate the transaction has completed. 72 * 73 * @param req The details of the transaction. 74 * @param result 0 if all bytes are acknowledged, 1 if any byte 75 * transmitted is not acknowledged, negative if error. 76 * See \ref MXC_Error_Codes for the list of error codes. 77 */ 78 typedef void (*mxc_i2c_complete_cb_t)(mxc_i2c_req_t *req, int result); 79 80 /** 81 * @brief The callback routine used by the I2C Read/Write FIFO DMA 82 * functions to indicate the transaction has completed. 83 * 84 * @param len The length of data actually read/written 85 * @param result See \ref MXC_Error_Codes for the list of error codes. 86 */ 87 typedef void (*mxc_i2c_dma_complete_cb_t)(int len, int result); 88 89 /** 90 * @brief The information required to perform a complete I2C transaction as 91 * the bus master. 92 * 93 * The information required to perform a complete I2C transaction as the bus 94 * master. This structure is used by the MXC_I2C_MasterTransaction() and 95 * MXC_I2C_MasterTransactionAsync() functions. 96 */ 97 struct _i2c_req_t { 98 mxc_i2c_regs_t *i2c; ///< Pointer to I2C registers (selects the 99 ///< I2C block used.) 100 unsigned int addr; ///< The 7-bit or 10-bit address of the slave. 101 unsigned char *tx_buf; ///< The buffer containing the bytes to write. 102 unsigned int tx_len; ///< The number of bytes to write. On return 103 ///< from the function, this will be set to 104 ///< the number of bytes actually transmitted. 105 unsigned char *rx_buf; ///< The buffer to read the data into. 106 unsigned int rx_len; ///< The number of bytes to read. On return 107 ///< from the function, this will be set to 108 ///< the number of bytes actually received. 109 int restart; ///< Controls whether the transaction is 110 ///< terminated with a stop or repeated start 111 ///< condition. Use 0 for a stop, non-zero 112 ///< for repeated start. 113 mxc_i2c_complete_cb_t callback; ///< The callback used to indicate the 114 ///< transaction is complete or an error has 115 ///< occurred. This field may be set to NULL 116 ///< if no indication is necessary. This 117 ///< field is only used by the 118 ///< MXC_I2C_MasterTransactionAsync() function. 119 ///< MXC_I2C_MasterTransaction() ignores the 120 ///< callback field. 121 }; 122 123 /** 124 * @brief The list of events reported by the MXC_I2C_SlaveTransaction() and 125 * MXC_I2C_SlaveTransactionAsync() functions. 126 * 127 * The list of events reported by the MXC_I2C_SlaveTransaction() and 128 * MXC_I2C_SlaveTransactionAsync() functions. It is up to the calling 129 * application to handle these events. 130 */ 131 typedef enum { 132 MXC_I2C_EVT_MASTER_WR, ///< A slave address match occurred with the master 133 ///< requesting a write to the slave. 134 MXC_I2C_EVT_MASTER_RD, ///< A slave address match occurred with the master 135 ///< requesting a read from the slave. 136 MXC_I2C_EVT_RX_THRESH, ///< The receive FIFO contains more bytes than its 137 ///< threshold level. 138 MXC_I2C_EVT_TX_THRESH, ///< The transmit FIFO contains fewer bytes than its 139 ///< threshold level. 140 MXC_I2C_EVT_TRANS_COMP, ///< The transaction has ended. 141 MXC_I2C_EVT_UNDERFLOW, ///< The master has attempted a read when the 142 ///< transmit FIFO was empty. 143 MXC_I2C_EVT_OVERFLOW, ///< The master has written data when the receive 144 ///< FIFO was already full. 145 } mxc_i2c_slave_event_t; 146 147 /** 148 * @brief The callback routine used by the MXC_I2C_SlaveTransaction() and 149 * MXC_I2C_SlaveTransactionAsync functions to handle the various I2C 150 * slave events. 151 * 152 * @param i2c Pointer to I2C registers (selects the I2C block used.) 153 * @param event The event that occurred to trigger this callback. 154 * @param data This field is used to pass Success/Fail for the 155 * MXC_I2C_EVT_TRANS_COMP event. 156 * 157 * @return The return value is only used in the case of an MXC_I2C_EVT_RX_THRESH 158 * event. In this case, the return specifies if the last byte 159 * received should be acknowledged or not. Return 0 to acknowledge, 160 * non-zero to not acknowledge. The return value is ignored for all 161 * other event types. 162 */ 163 typedef int (*mxc_i2c_slave_handler_t)(mxc_i2c_regs_t *i2c, mxc_i2c_slave_event_t event, 164 void *data); 165 166 /***** Function Prototypes *****/ 167 168 /* ************************************************************************* */ 169 /* Control/Configuration functions */ 170 /* ************************************************************************* */ 171 172 /** 173 * @brief Initialize and enable I2C peripheral. 174 * 175 * @note On default this function enables I2C peripheral clock and i2c gpio pins. 176 * if you wish to manage clock and gpio related things in upper level instead of here. 177 * Define MSDK_NO_GPIO_CLK_INIT flag in project.mk file. 178 * By this flag this function will remove clock and gpio related codes from file. 179 * 180 * @param i2c Pointer to I2C registers (selects the I2C block used.) 181 * @param masterMode Whether to put the device in master or slave mode. Use 182 * non-zero 183 * for master mode, and zero for slave mode. 184 * @param slaveAddr 7-bit or 10-bit address to use when in slave mode. 185 * This parameter is ignored when masterMode is non-zero. 186 * 187 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 188 */ 189 int MXC_I2C_Init(mxc_i2c_regs_t *i2c, int masterMode, unsigned int slaveAddr); 190 191 /** 192 * @brief Initialize and enable I2C peripheral. 193 * @note Set idx to 0, multiple I2C instances acting as slaves is not yet 194 * supported. 195 * 196 * @param i2c Pointer to I2C registers (selects the I2C block used.) 197 * @param slaveAddr 7-bit or 10-bit address to use when in slave mode. 198 * This parameter is ignored when masterMode is non-zero. 199 * @param idx Index of the I2C slave instance. 200 * 201 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 202 */ 203 int MXC_I2C_SetSlaveAddr(mxc_i2c_regs_t *i2c, unsigned int slaveAddr, int idx); 204 205 /** 206 * @brief Disable and shutdown I2C peripheral. 207 * 208 * @param i2c Pointer to I2C registers (selects the I2C block used.) 209 * 210 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 211 */ 212 int MXC_I2C_Shutdown(mxc_i2c_regs_t *i2c); 213 214 /** 215 * @brief Reset the I2C peripheral. 216 * @note The peripheral will need to be initialized with MXC_I2C_Init() before use 217 * 218 * @param i2c Pointer to I2C registers (selects the I2C block used.) 219 * 220 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 221 */ 222 int MXC_I2C_Reset(mxc_i2c_regs_t *i2c); 223 224 /** 225 * @brief Set the frequency of the I2C interface. 226 * 227 * @param i2c Pointer to I2C registers (selects the I2C block used.) 228 * @param hz The desired frequency in Hertz. 229 * 230 * @return Negative if error, otherwise actual speed set. See \ref 231 * MXC_Error_Codes for the list of error return codes. 232 */ 233 int MXC_I2C_SetFrequency(mxc_i2c_regs_t *i2c, unsigned int hz); 234 235 /** 236 * @brief Get the frequency of the I2C interface. 237 * 238 * @param i2c Pointer to I2C registers (selects the I2C block used.) 239 * 240 * @return The I2C bus frequency in Hertz 241 */ 242 unsigned int MXC_I2C_GetFrequency(mxc_i2c_regs_t *i2c); 243 244 /** 245 * @brief Checks if the given I2C bus can be placed in sleep more. 246 * 247 * This functions checks to see if there are any on-going I2C transactions in 248 * progress. If there are transactions in progress, the application should 249 * wait until the I2C bus is free before entering a low-power state. 250 * 251 * @param i2c Pointer to I2C registers (selects the I2C block used.) 252 * 253 * @return #E_NO_ERROR if ready, and non-zero if busy or error. See \ref 254 * MXC_Error_Codes for the list of error return codes. 255 */ 256 int MXC_I2C_ReadyForSleep(mxc_i2c_regs_t *i2c); 257 258 /** 259 * @brief Enables or disables clock stretching by the slave. 260 * 261 * Enables or disables clock stretching by the slave. This function has no 262 * affect when operating as the master. 263 * 264 * @param i2c Pointer to I2C registers (selects the I2C block used.) 265 * @param enable Enables clock stretching if non-zero, disables if zero. 266 * 267 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 268 */ 269 int MXC_I2C_SetClockStretching(mxc_i2c_regs_t *i2c, int enable); 270 271 /** 272 * @brief Determines if clock stretching has been enabled. 273 * 274 * @param i2c Pointer to I2C registers (selects the I2C block used.) 275 * 276 * @return Zero if clock stretching is disabled, non-zero otherwise 277 */ 278 int MXC_I2C_GetClockStretching(mxc_i2c_regs_t *i2c); 279 280 /** 281 * @brief Initializes the DMA for I2C DMA transactions. 282 * 283 * This function will release any acquired DMA channels before reacquiring and 284 * reconfiguring selected I2C DMA TX or RX channels. 285 * 286 * @param i2c Pointer to I2C registers (selects the I2C block used). 287 * @param dma Pointer to DMA registers (selects the DMA block used). 288 * @param use_dma_tx If true, acquire and configure DMA TX channel, else release any 289 * acquired DMA TX channel. 290 * @param use_dma_rx If true, acquire and configure DMA RX channel, else release any 291 * acquired DMA RX channel. 292 * 293 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 294 */ 295 int MXC_I2C_DMA_Init(mxc_i2c_regs_t *i2c, mxc_dma_regs_t *dma, bool use_dma_tx, bool use_dma_rx); 296 297 /** 298 * @brief Retreive the DMA TX Channel associated with I2C instance. 299 * 300 * @param i2c Pointer to I2C registers (selects the I2C block used). 301 * 302 * @return If successful, the DMA TX Channel number is returned. Otherwise, see 303 * \ref MXC_Error_Codes for a list of return codes. 304 */ 305 int MXC_I2C_DMA_GetTXChannel(mxc_i2c_regs_t *i2c); 306 307 /** 308 * @brief Retreive the DMA RX Channel associated with I2C instance. 309 * 310 * @param i2c Pointer to I2C registers (selects the I2C block used). 311 * 312 * @return If successful, the DMA RX Channel number is returned. Otherwise, see 313 * \ref MXC_Error_Codes for a list of return codes. 314 */ 315 int MXC_I2C_DMA_GetRXChannel(mxc_i2c_regs_t *i2c); 316 317 /** 318 * @brief Sets the I2C instance's DMA TX/RX request select. 319 * 320 * @param i2c Pointer to I2C registers (selects the I2C block used). 321 * @param txData Pointer to transmit buffer. 322 * @param rxData Pointer to receive buffer. 323 * 324 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 325 */ 326 int MXC_I2C_DMA_SetRequestSelect(mxc_i2c_regs_t *i2c, uint8_t *txData, uint8_t *rxData); 327 328 /* ************************************************************************* */ 329 /* Low-level functions */ 330 /* ************************************************************************* */ 331 332 /** 333 * @brief Generate a start (or repeated start) condition on the I2C bus. 334 * 335 * Generate a start (or repeated start) condition on the I2C bus. This 336 * function may opt to delay the actual generation of the start condition 337 * until data is actually transferred. 338 * 339 * @param i2c Pointer to I2C registers (selects the I2C block used.) 340 * 341 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 342 */ 343 int MXC_I2C_Start(mxc_i2c_regs_t *i2c); 344 345 /** 346 * @brief Generate a stop condition on the I2C bus. 347 * 348 * @param i2c Pointer to I2C registers (selects the I2C block used.) 349 * 350 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 351 */ 352 int MXC_I2C_Stop(mxc_i2c_regs_t *i2c); 353 354 /** 355 * @brief Write a single byte to the I2C bus. 356 * 357 * Write a single byte to the I2C bus. This function assumes the I2C bus is 358 * already in the proper state (i.e. a start condition has already been 359 * generated and the bus is in the write phase of an I2C transaction). If any 360 * bytes are pending in the FIFO (i.e. in the case of clock stretching), this 361 * function will return E_OVERFLOW. 362 * 363 * @param i2c Pointer to I2C registers (selects the I2C block used.) 364 * @param byte The byte to transmit. 365 * 366 * @return 0 if byte is acknowledged, 1 if not acknowledged, negative if 367 * error. See \ref MXC_Error_Codes for the list of error return codes. 368 */ 369 int MXC_I2C_WriteByte(mxc_i2c_regs_t *i2c, unsigned char byte); 370 371 /** 372 * @brief Read a single byte from the I2C bus. 373 * 374 * Read a single byte from the I2C bus. This function assumes the I2C bus is 375 * already in the proper state (i.e. a start condition has already been 376 * generated and the bus is in the read phase of an I2C transaction). If the FIFO 377 * is empty, this function will return E_UNDERFLOW. 378 * 379 * @param i2c Pointer to I2C registers (selects the I2C block used.) 380 * @param byte Pointer to the byte to read into. 381 * @param ack Whether or not to acknowledge the byte once received. 382 * 383 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 384 */ 385 int MXC_I2C_ReadByte(mxc_i2c_regs_t *i2c, unsigned char *byte, int ack); 386 387 /** 388 * @brief Read a single byte from the I2C bus. 389 * 390 * Read a single byte from the I2C bus. After the byte is received, the 391 * provided callback will be used to determine if the byte should be 392 * acknowledged or not before continuing with the rest of the transaction. 393 * This function assumes the I2C bus is already in the proper state (i.e. a 394 * start condition has already been generated and the bus is in the read 395 * phase of an I2C transaction). This function must be called with clock 396 * stretching enabled. 397 * 398 * @param i2c Pointer to I2C registers (selects the I2C block used.) 399 * @param byte Pointer to the byte to read into. 400 * @param getAck A function to be called to determine whether or not 401 * to acknowledge the byte once received. A non-zero 402 * return value will acknowledge the byte. If this 403 * parameter is set to NULL or its return value is 0, 404 * the byte received will not be acknowledged (i.e., it 405 * will be NACKed). 406 * 407 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 408 */ 409 int MXC_I2C_ReadByteInteractive(mxc_i2c_regs_t *i2c, unsigned char *byte, mxc_i2c_getAck_t getAck); 410 411 /** 412 * @brief Write multiple bytes to the I2C bus. 413 * 414 * Write multiple bytes to the I2C bus. This function assumes the I2C bus is 415 * already in the proper state (i.e. a start condition has already been 416 * generated and the bus is in the write phase of an I2C transaction). 417 * 418 * @param i2c Pointer to I2C registers (selects the I2C block used.) 419 * @param bytes The buffer containing the bytes to transmit. 420 * @param len The number of bytes to write. On return from the 421 * function, this will be set to the number of bytes 422 * actually transmitted. 423 * 424 * @return 0 if all bytes are acknowledged, 1 if any byte transmitted is not 425 * acknowledged, negative if error. See \ref MXC_Error_Codes for the 426 * list of error return codes. 427 */ 428 int MXC_I2C_Write(mxc_i2c_regs_t *i2c, unsigned char *bytes, unsigned int *len); 429 430 /** 431 * @brief Read multiple bytes from the I2C bus. 432 * 433 * Read multiple byte from the I2C bus. This function assumes the I2C bus is 434 * already in the proper state (i.e. a start condition has already been 435 * generated and the bus is in the read phase of an I2C transaction). 436 * 437 * @param i2c Pointer to I2C registers (selects the I2C block used.) 438 * @param bytes The buffer to read the data into. 439 * @param len The number of bytes to read. On return from the 440 * function, this will be set to the number of bytes 441 * actually received. 442 * @param ack Whether or not to acknowledge the last byte once it is 443 * received. All previous bytes will be acknowledged. 444 * 445 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 446 */ 447 int MXC_I2C_Read(mxc_i2c_regs_t *i2c, unsigned char *bytes, unsigned int *len, int ack); 448 449 /** 450 * @brief Unloads bytes from the receive FIFO. 451 * 452 * @param i2c Pointer to I2C registers (selects the I2C block used.) 453 * @param bytes The buffer to read the data into. 454 * @param len The number of bytes to read. 455 * 456 * @return The number of bytes actually read. 457 */ 458 int MXC_I2C_ReadRXFIFO(mxc_i2c_regs_t *i2c, volatile unsigned char *bytes, unsigned int len); 459 460 /** 461 * @brief Unloads bytes from the receive FIFO using DMA for longer reads. 462 * 463 * @note The operation is not complete until the callback has been called 464 * 465 * @param i2c Pointer to I2C registers (selects the I2C block used.) 466 * @param bytes The buffer to read the data into. 467 * @param len The number of bytes to read. 468 * @param callback The function to call when the read is complete 469 * 470 * @return See \ref MXC_Error_Codes for a list of return values. 471 */ 472 int MXC_I2C_ReadRXFIFODMA(mxc_i2c_regs_t *i2c, unsigned char *bytes, unsigned int len, 473 mxc_i2c_dma_complete_cb_t callback); 474 475 /** 476 * @brief Get the number of bytes currently available in the receive FIFO. 477 * 478 * @param i2c Pointer to I2C registers (selects the I2C block used.) 479 * 480 * @return The number of bytes available. 481 */ 482 int MXC_I2C_GetRXFIFOAvailable(mxc_i2c_regs_t *i2c); 483 484 /** 485 * @brief Loads bytes into the transmit FIFO. 486 * 487 * @param i2c Pointer to I2C registers (selects the I2C block used.) 488 * @param bytes The buffer containing the bytes to write 489 * @param len The number of bytes to write. 490 * 491 * @return The number of bytes actually written. 492 */ 493 int MXC_I2C_WriteTXFIFO(mxc_i2c_regs_t *i2c, volatile unsigned char *bytes, unsigned int len); 494 495 /** 496 * @brief Loads bytes into the transmit FIFO using DMA for longer writes. 497 * 498 * @note The operation is not complete until the callback has been called 499 * @param i2c Pointer to I2C registers (selects the I2C block used.) 500 * @param bytes The buffer containing the bytes to write 501 * @param len The number of bytes to write. 502 * @param callback The function to call when the read is complete 503 * 504 * @return See \ref MXC_Error_Codes for a list of return values 505 */ 506 int MXC_I2C_WriteTXFIFODMA(mxc_i2c_regs_t *i2c, unsigned char *bytes, unsigned int len, 507 mxc_i2c_dma_complete_cb_t callback); 508 509 /** 510 * @brief Get the amount of free space available in the transmit FIFO. 511 * 512 * @param i2c Pointer to I2C registers (selects the I2C block used.) 513 * 514 * @return The number of bytes available. 515 */ 516 int MXC_I2C_GetTXFIFOAvailable(mxc_i2c_regs_t *i2c); 517 518 /** 519 * @brief Removes and discards all bytes currently in the receive FIFO. 520 * 521 * @param i2c Pointer to I2C registers (selects the I2C block used.) 522 */ 523 void MXC_I2C_ClearRXFIFO(mxc_i2c_regs_t *i2c); 524 525 /** 526 * @brief Removes and discards all bytes currently in the transmit FIFO. 527 * 528 * @param i2c Pointer to I2C registers (selects the I2C block used.) 529 */ 530 void MXC_I2C_ClearTXFIFO(mxc_i2c_regs_t *i2c); 531 532 /** 533 * @brief Get the presently set interrupt flags. 534 * 535 * @param i2c Pointer to I2C registers (selects the I2C block used.) 536 * @param flags0 Pointer to store flags currently set in interrupt register intfl0. 537 * @param flags1 Pointer to store flags currently set in interrupt register intfl1. 538 * 539 * @return See \ref MXC_Error_Codes for a list of return values 540 */ 541 int MXC_I2C_GetFlags(mxc_i2c_regs_t *i2c, unsigned int *flags0, unsigned int *flags1); 542 543 /** 544 * @brief Clears the Interrupt Flags. 545 * 546 * @param i2c Pointer to I2C registers (selects the I2C block used.) 547 * @param flags0 Flags to be cleared in interrupt register intfl0. 548 * @param flags1 Flags to be cleared in interrupt register intfl1. 549 */ 550 void MXC_I2C_ClearFlags(mxc_i2c_regs_t *i2c, unsigned int flags0, unsigned int flags1); 551 552 /** 553 * @brief Enable Interrupts. 554 * 555 * @param i2c Pointer to I2C registers (selects the I2C block used.) 556 * @param flags0 Interrupts to be enabled in int->en0 557 * @param flags1 Interrupts to be enabled in int->en1 558 */ 559 void MXC_I2C_EnableInt(mxc_i2c_regs_t *i2c, unsigned int flags0, unsigned int flags1); 560 561 /** 562 * @brief Disable Interrupts. 563 * 564 * @param i2c Pointer to I2C registers (selects the I2C block used.) 565 * @param flags0 Interrupts to be disabled in int->en0 566 * @param flags1 Interrupts to be disabled in int->en1 567 */ 568 void MXC_I2C_DisableInt(mxc_i2c_regs_t *i2c, unsigned int flags0, unsigned int flags1); 569 570 /** 571 * @brief Enables the slave preload mode 572 * 573 * Use this mode to preload the slave TX FIFO with data that can be sent when 574 * the slave is addressed for a read operation without software intervention. 575 * 576 * @param i2c Pointer to I2C registers (selects the I2C block used.) 577 */ 578 void MXC_I2C_EnablePreload(mxc_i2c_regs_t *i2c); 579 580 /** 581 * @brief Disable the slave preload mode 582 * 583 * @param i2c Pointer to I2C registers (selects the I2C block used.) 584 */ 585 void MXC_I2C_DisablePreload(mxc_i2c_regs_t *i2c); 586 587 /** 588 * @brief Enables the slave to respond to the general call address 589 * 590 * @param i2c Pointer to I2C registers (selects the I2C block used.) 591 */ 592 void MXC_I2C_EnableGeneralCall(mxc_i2c_regs_t *i2c); 593 594 /** 595 * @brief Prevents the slave from responding to the general call address 596 * 597 * @param i2c Pointer to I2C registers (selects the I2C block used.) 598 */ 599 void MXC_I2C_DisableGeneralCall(mxc_i2c_regs_t *i2c); 600 601 /** 602 * @brief Set the I2C Timeout 603 * 604 * The I2C timeout determines the amount of time the master will wait while the 605 * slave is stretching the clock, and the amount of time the slave will stretch 606 * the clock while waiting for software to unload the fifo. 607 * 608 * @param i2c Pointer to I2C registers (selects the I2C block used.) 609 * @param timeout Timeout in uS 610 */ 611 void MXC_I2C_SetTimeout(mxc_i2c_regs_t *i2c, unsigned int timeout); 612 613 /** 614 * @brief Get the current I2C timeout 615 * 616 * @param i2c Pointer to I2C registers (selects the I2C block used.) 617 * 618 * @return The current timeout in uS 619 */ 620 unsigned int MXC_I2C_GetTimeout(mxc_i2c_regs_t *i2c); 621 622 /** 623 * @brief Attempts to recover the I2C bus, ensuring the I2C lines are idle. 624 * 625 * Attempts to recover and reset an I2C bus by sending I2C clocks. During 626 * each clock cycle, the SDA line is cycled to determine if the master has 627 * control of the line. The following steps are performed to create one SCL 628 * clock cycle: 629 * 1. Drive SCL low 630 * 2. Verify SCL is low 631 * 3. Drive SDA low 632 * 4. Verify SDA is low 633 * 5. Release SDA allowing it to return high 634 * 6. Verify SDA is high 635 * 7. Release SCL allowing it to return high. 636 * 8. Verify SCL is high 637 * If any of the steps fail, the bus is considered to still be busy and the 638 * sequence is repeated up to the requested number of times. If all steps 639 * succeed, a final stop condition is generated on the I2C bus. 640 * 641 * @param i2c Pointer to I2C registers (selects the I2C block used.) 642 * @param retries Number of times to attempt the clock cycle sequence. 643 * 644 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 645 */ 646 int MXC_I2C_Recover(mxc_i2c_regs_t *i2c, unsigned int retries); 647 648 /* ************************************************************************* */ 649 /* Transaction level functions */ 650 /* ************************************************************************* */ 651 652 /** 653 * @brief Performs a blocking I2C Master transaction. 654 * 655 * Performs a blocking I2C transaction. These actions will be performed: 656 * 1. If necessary, generate a start condition on the bus. 657 * 2. Send the slave address with the low bit set to 0 (indicating a write). 658 * 3. Transmit req->tx_len bytes of req->tx_buff. 659 * 4. Generate a repeated start condition on the bus. 660 * 5. Send the slave address with the low bit set to 1 (indicating a read). 661 * 6. Receive req->rx_len bytes into req->rx_buf, acknowledging each byte. 662 * 7. Generate a stop (or repeated start) condition on the bus. 663 * Steps 3-6 will be skipped if req->tx_len and req->rx_len are both 0. 664 * Steps 2-4 will be skipped if req->tx_len equals 0. 665 * Steps 4-6 will be skipped if req->rx_len equals 0. 666 * 667 * @param req Pointer to details of the transaction 668 * 669 * @return 0 if all bytes are acknowledged, 1 if any byte transmitted is not 670 * acknowledged, negative if error. See \ref MXC_Error_Codes for the 671 * list of error return codes. 672 */ 673 int MXC_I2C_MasterTransaction(mxc_i2c_req_t *req); 674 675 /** 676 * @brief Performs a non-blocking I2C Master transaction. 677 * 678 * Performs a non-blocking I2C transaction. These actions will be performed: 679 * 1. If necessary, generate a start condition on the bus. 680 * 2. Send the slave address with the low bit set to 0 (indicating a write). 681 * 3. Transmit req->tx_len bytes of req->tx_buff. 682 * 4. Generate a repeated start condition on the bus. 683 * 5. Send the slave address with the low bit set to 1 (indicating a read). 684 * 6. Receive req->rx_len bytes into req->rx_buf, acknowledging each byte. 685 * 7. Generate a stop (or repeated start) condition on the bus. 686 * 8. Execute req->callback to indicate the transaction is complete. 687 * Steps 3-6 will be skipped if tx_len and rx_len are both 0. 688 * Steps 2-4 will be skipped if tx_len equals 0. 689 * Steps 4-6 will be skipped if rx_len equals 0. 690 * 691 * @note MXC_I2C_AsyncHandler() must be called periodically for this function 692 * to operate properly. Ideally from the I2C ISR. 693 * 694 * @param req Pointer to details of the transaction. The memory 695 * used by this parameter must remain available until 696 * the callback is executed. 697 * 698 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 699 */ 700 int MXC_I2C_MasterTransactionAsync(mxc_i2c_req_t *req); 701 702 /** 703 * @brief Performs a non-blocking I2C Master transaction using DMA for reduced time 704 * in the ISR. This function initializes the DMA and acquires DMA channels 705 * if MXC_I2C_DMA_Init(...) was not called earlier. 706 * 707 * It is recommended to initialize the DMA by calling MXC_I2C_DMA_Init(...) function 708 * before calling MXC_I2C_MasterTransactionDMA(...). This provides flexibility in 709 * setting up generic DMA channel vectors during run-time without knowing what DMA 710 * channels will be acquired beforehand. 711 * 712 * Performs a non-blocking I2C transaction. These actions will be performed: 713 * 1. If necessary, generate a start condition on the bus. 714 * 2. Send the slave address with the low bit set to 0 (indicating a write). 715 * 3. Transmit req->tx_len bytes of req->tx_buff. 716 * 4. Generate a repeated start condition on the bus. 717 * 5. Send the slave address with the low bit set to 1 (indicating a read). 718 * 6. Receive req->rx_len bytes into req->rx_buf, acknowledging each byte. 719 * 7. Generate a stop (or repeated start) condition on the bus. 720 * 8. Execute req->callback to indicate the transaction is complete. 721 * Steps 3-6 will be skipped if tx_len and rx_len are both 0. 722 * Steps 2-4 will be skipped if tx_len equals 0. 723 * Steps 4-6 will be skipped if rx_len equals 0. 724 * 725 * @note MXC_I2C_AsyncHandler() must be called periodically for this function 726 * to operate properly. Ideally from the I2C ISR. 727 * 728 * @param req Pointer to details of the transaction. The memory 729 * used by this parameter must remain available until 730 * the callback is executed. 731 * 732 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 733 */ 734 int MXC_I2C_MasterTransactionDMA(mxc_i2c_req_t *req); 735 736 /** 737 * @brief Performs a blocking I2C Slave transaction. 738 * 739 * Performs a blocking I2C transaction. This function will block until a 740 * complete transaction with this slave has been performed. A transaction 741 * begins with the master addressing the slave and ends with a repeated start 742 * condition, a stop condition, or a bus error. The provided callback 743 * function will be called for these events: 744 * - A slave address match occurs with the master requesting a write to 745 * the slave. 746 * - A slave address match occurs with the master requesting a read from 747 * the slave. 748 * - The receive FIFO crosses the set threshold (see 749 * MXC_I2C_SetRXThreshold()). The callback code should unload the receive 750 * FIFO (see MXC_I2C_ReadFIFO()) to allow the master to send more data. 751 * The return value of the callback function will determine if the 752 * last byte received should be acknowledged or not. Return 0 to 753 * acknowledge, non-zero to not acknowledge. 754 * - The transmit FIFO crosses the set threshold (see 755 * MXC_I2C_SetTXThreshold()). If the master is expected to read more 756 * data from this slave, the callback code should add data to the 757 * transmit FIFO (see MXC_I2C_WriteFIFO()). 758 * - The transaction ends. If the master was writing to the slave, the 759 * receive FIFO may still contain valid data that needs to be 760 * retreived (see MXC_I2C_ReadFIFO()). 761 * - The transmit FIFO underflows because the master requests data when 762 * the transmit FIFO is empty. 763 * - The receive FIFO overflows because the master writes data while the 764 * receive FIFO was full. 765 * 766 * If clock stretching is disabled, careful attention must be paid to the timing 767 * of the callback to avoid losing data on write or unintentionally nacking a read. 768 * 769 * @param i2c Pointer to I2C registers (selects the I2C block used.) 770 * @param callback The function to be called when an I2C event occurs. 771 * 772 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 773 */ 774 int MXC_I2C_SlaveTransaction(mxc_i2c_regs_t *i2c, mxc_i2c_slave_handler_t callback); 775 776 /** 777 * @brief Performs a non-blocking I2C Slave transaction. 778 * 779 * Performs a non-blocking I2C transaction. This request will remain active 780 * until a complete transaction with this slave has been performed. A 781 * transaction begins with the master begins with the master addressing the 782 * slave and ends with a repeated start condition, a stop condition, or a bus 783 * error. The provided callback function will be called for these events: 784 * - A slave address match occurs with the master requesting a write to 785 * the slave. 786 * - A slave address match occurs with the master requesting a read from 787 * the slave. 788 * - The receive FIFO crosses the set threshold (see 789 * MXC_I2C_SetRXThreshold()). The callback code should unload the receive 790 * FIFO (see MXC_I2C_ReadFIFO()) to allow the master to send more data. 791 * The return value of the callback function will determine if the 792 * last byte received should be acknowledged or not. Return 0 to 793 * acknowledge, non-zero to not acknowledge. 794 * - The transmit FIFO crosses the set threshold (see 795 * MXC_I2C_SetTXThreshold()). If the master is expected to read more 796 * data from this slave, the callback code should add data to the 797 * transmit FIFO (see MXC_I2C_WriteFIFO()). 798 * - The transaction ends. If the master was writing to the slave, the 799 * receive FIFO may still contain valid data that needs to be 800 * retreived (see MXC_I2C_ReadFIFO()). 801 * - The transmit FIFO underflows because the master requests data when 802 * the transmit FIFO is empty. 803 * - The receive FIFO overflows because the master writes data while the 804 * receive FIFO was full. 805 * 806 * If clock stretching is disabled, careful attention must be paid to the timing 807 * of the callback to avoid losing data on write or unintentionally nacking a read. 808 * 809 * @note MXC_I2C_AsyncHandler() must be called peridocally for this function 810 * to operate properly. 811 * 812 * @param i2c Pointer to I2C registers (selects the I2C block used.) 813 * @param callback The function to be called when an I2C event occurs. 814 * 815 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 816 */ 817 int MXC_I2C_SlaveTransactionAsync(mxc_i2c_regs_t *i2c, mxc_i2c_slave_handler_t callback); 818 819 /** 820 * @brief Set the receive threshold level. 821 * 822 * When operating as a master, the function sets the receive threshold level 823 * for when the master should unload the receive FIFO. Smaller values may 824 * consume more CPU cycles, but decrease the chances of the master delaying 825 * the generation of I2C bus clocks because it has no room in the FIFO to 826 * receive data. Larger values may consume fewer CPU cycles, but risk delays 827 * of the I2C clock. When operating as a slave, this function sets the number 828 * of bytes the slave transaction functions should receive before issuing a 829 * call to their callback function. Smaller values may consume more CPU 830 * cycles, but reduce the risk of missing data from the master due to the 831 * recieve FIFO being full. Larger values may reduce the number of CPU 832 * cycles, but may cause bytes sent from the master to be missed. 833 * 834 * @param i2c Pointer to I2C registers (selects the I2C block used.) 835 * @param numBytes The threshold level to set. This value must be 836 * between 0 and 8 inclusive. 837 * 838 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 839 */ 840 int MXC_I2C_SetRXThreshold(mxc_i2c_regs_t *i2c, unsigned int numBytes); 841 842 /** 843 * @brief Get the current receive threshold level. 844 * 845 * @param i2c Pointer to I2C registers (selects the I2C block used.) 846 * 847 * @return The receive threshold value (in bytes). 848 */ 849 unsigned int MXC_I2C_GetRXThreshold(mxc_i2c_regs_t *i2c); 850 851 /** 852 * @brief Set the transmit threshold level. 853 * 854 * When operating as a master, the function sets the transmit threshold level 855 * for when the master should add additional bytes to the transmit FIFO. 856 * Larger values may consume more CPU cycles, but decrease the chances of the 857 * master delaying the generation of I2C bus clocks because it has no data in 858 * the FIFO to transmit. Smaller values may consume fewer CPU cycles, but 859 * risk delays of the I2C clock. When operating as a slave, this function 860 * sets the number of bytes the slave transaction functions should transmit 861 * before issuing a call to their callback function. Larger values may 862 * consume more CPU cycles, but reduce the risk of not having data ready when 863 * the master requests it. Smaller values may reduce the number of CPU 864 * cycles, but may cause the master to read from an empty FIFO. (The master 865 * will read 0xFF in this case.) 866 * 867 * @param i2c Pointer to I2C registers (selects the I2C block used.) 868 * @param numBytes The threshold level to set. This value must be 869 * between 0 and 8 inclusive. 870 * 871 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 872 */ 873 int MXC_I2C_SetTXThreshold(mxc_i2c_regs_t *i2c, unsigned int numBytes); 874 875 /** 876 * @brief Get the current transmit threshold level. 877 * 878 * @param i2c Pointer to I2C registers (selects the I2C block used.) 879 * 880 * @return The transmit threshold value (in bytes). 881 */ 882 unsigned int MXC_I2C_GetTXThreshold(mxc_i2c_regs_t *i2c); 883 884 /** 885 * @brief Stop any asynchronous requests in progress. 886 * 887 * Stop any asynchronous requests in progress. Any callbacks associated with 888 * the active transaction will be NOT executed. 889 * 890 * @param i2c Pointer to I2C registers (selects the I2C block used.) 891 */ 892 void MXC_I2C_AsyncStop(mxc_i2c_regs_t *i2c); 893 894 /** 895 * @brief Abort any asynchronous requests in progress. 896 * 897 * Abort any asynchronous requests in progress. Any callbacks associated with 898 * the active transaction will be executed to indicate when the transaction 899 * has been terminated. 900 * 901 * @param i2c Pointer to I2C registers (selects the I2C block used.) 902 */ 903 void MXC_I2C_AbortAsync(mxc_i2c_regs_t *i2c); 904 905 /** 906 * @brief The processing function for asynchronous transactions. 907 * 908 * When using the asynchronous functions, the application must call this 909 * function periodically. This can be done from within the I2C interrupt 910 * handler or periodically by the application if I2C interrupts are disabled. 911 * 912 * @param i2c Pointer to I2C registers (selects the I2C block used.) 913 */ 914 void MXC_I2C_AsyncHandler(mxc_i2c_regs_t *i2c); 915 916 /** 917 * @brief The processing function for DMA transactions. 918 * 919 * When using the DMA functions, the application must call this 920 * function periodically. This can be done from within the DMA Interrupt Handler. 921 * 922 * @param ch DMA channel 923 * @param error Error status 924 */ 925 void MXC_I2C_DMACallback(int ch, int error); 926 927 /**@} end of group i2c */ 928 929 #ifdef __cplusplus 930 } 931 #endif 932 933 #endif // LIBRARIES_PERIPHDRIVERS_INCLUDE_MAX32675_I2C_H_ 934
