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_MAX32662_I2C_H_ 28 #define LIBRARIES_PERIPHDRIVERS_INCLUDE_MAX32662_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 * @brief The callback used by the MXC_I2C_ReadByteInteractive() function. 55 * 56 * The callback routine used by the MXC_I2C_ReadByteInteractive() function. This 57 * function allows the application to determine whether the byte received 58 * should be acknowledged or not. 59 * 60 * @param i2c Pointer to I2C registers (selects the I2C block used.) 61 * @param byte The byte received. 62 * 63 * @return 0 if the byte should not be acknowledged (NACK), non-zero to 64 * acknowledge the byte. 65 */ 66 typedef int (*mxc_i2c_getAck_t)(mxc_i2c_regs_t *i2c, unsigned char byte); 67 68 /** 69 * @brief The callback routine used by the MXC_I2C_MasterTransactionAsync() 70 * function to indicate the transaction has completed. 71 * 72 * @param req The details of the transaction. 73 * @param result 0 if all bytes are acknowledged, 1 if any byte 74 * transmitted is not acknowledged, negative if error. 75 * See \ref MXC_Error_Codes for the list of error codes. 76 */ 77 typedef void (*mxc_i2c_complete_cb_t)(mxc_i2c_req_t *req, int result); 78 79 /** 80 * @brief The callback routine used by the I2C Read/Write FIFO DMA 81 * functions to indicate the transaction has completed. 82 * 83 * @param len The length of data actually read/written 84 * @param result See \ref MXC_Error_Codes for the list of error codes. 85 */ 86 typedef void (*mxc_i2c_dma_complete_cb_t)(int len, int result); 87 88 /** 89 * @brief The information required to perform a complete I2C transaction as 90 * the bus master. 91 * 92 * The information required to perform a complete I2C transaction as the bus 93 * master. This structure is used by the MXC_I2C_MasterTransaction() and 94 * MXC_I2C_MasterTransactionAsync() functions. 95 */ 96 struct _i2c_req_t { 97 mxc_i2c_regs_t *i2c; ///< Pointer to I2C registers (selects the 98 ///< I2C block used.) 99 unsigned int addr; ///< The 7-bit or 10-bit address of the slave. 100 unsigned char *tx_buf; ///< The buffer containing the bytes to write. 101 unsigned int tx_len; ///< The number of bytes to write. On return 102 ///< from the function, this will be set to 103 ///< the number of bytes actually transmitted. 104 unsigned char *rx_buf; ///< The buffer to read the data into. 105 unsigned int rx_len; ///< The number of bytes to read. On return 106 ///< from the function, this will be set to 107 ///< the number of bytes actually received. 108 int restart; ///< Controls whether the transaction is 109 ///< terminated with a stop or repeated start 110 ///< condition. Use 0 for a stop, non-zero 111 ///< for repeated start. 112 mxc_i2c_complete_cb_t callback; ///< The callback used to indicate the 113 ///< transaction is complete or an error has 114 ///< occurred. This field may be set to NULL 115 ///< if no indication is necessary. This 116 ///< field is only used by the 117 ///< MXC_I2C_MasterTransactionAsync() function. 118 ///< MXC_I2C_MasterTransaction() ignores the 119 ///< callback field. 120 }; 121 122 /** 123 * @brief The list of events reported by the MXC_I2C_SlaveTransaction() and 124 * MXC_I2C_SlaveTransactionAsync() functions. 125 * 126 * The list of events reported by the MXC_I2C_SlaveTransaction() and 127 * MXC_I2C_SlaveTransactionAsync() functions. It is up to the calling 128 * application to handle these events. 129 */ 130 typedef enum { 131 MXC_I2C_EVT_MASTER_WR, ///< A slave address match occurred with the master 132 ///< requesting a write to the slave. 133 MXC_I2C_EVT_MASTER_RD, ///< A slave address match occurred with the master 134 ///< requesting a read from the slave. 135 MXC_I2C_EVT_RX_THRESH, ///< The receive FIFO contains more bytes than its 136 ///< threshold level. 137 MXC_I2C_EVT_TX_THRESH, ///< The transmit FIFO contains fewer bytes than its 138 ///< threshold level. 139 MXC_I2C_EVT_TRANS_COMP, ///< The transaction has ended. 140 MXC_I2C_EVT_UNDERFLOW, ///< The master has attempted a read when the 141 ///< transmit FIFO was empty. 142 MXC_I2C_EVT_OVERFLOW, ///< The master has written data when the receive 143 ///< FIFO was already full. 144 } mxc_i2c_slave_event_t; 145 146 /** 147 * @brief The callback routine used by the MXC_I2C_SlaveTransaction() and 148 * MXC_I2C_SlaveTransactionAsync functions to handle the various I2C 149 * slave events. 150 * 151 * @param i2c Pointer to I2C registers (selects the I2C block used.) 152 * @param event The event that occurred to trigger this callback. 153 * @param data This field is used to pass Success/Fail for the 154 * MXC_I2C_EVT_TRANS_COMP event. 155 * 156 * @return The return value is only used in the case of an MXC_I2C_EVT_RX_THRESH 157 * event. In this case, the return specifies if the last byte 158 * received should be acknowledged or not. Return 0 to acknowledge, 159 * non-zero to not acknowledge. The return value is ignored for all 160 * other event types. 161 */ 162 typedef int (*mxc_i2c_slave_handler_t)(mxc_i2c_regs_t *i2c, mxc_i2c_slave_event_t event, 163 void *data); 164 165 /***** Function Prototypes *****/ 166 167 /* ************************************************************************* */ 168 /* Control/Configuration functions */ 169 /* ************************************************************************* */ 170 171 /** 172 * @brief Initialize and enable I2C peripheral. 173 * 174 * @note On default this function enables I2C peripheral clock and i2c gpio pins. 175 * if you wish to manage clock and gpio related things in upper level instead of here. 176 * Define MSDK_NO_GPIO_CLK_INIT flag in project.mk file. 177 * By this flag this function will remove clock and gpio related codes from file. 178 * 179 * @param i2c Pointer to I2C registers (selects the I2C block used.) 180 * @param masterMode Whether to put the device in master or slave mode. Use 181 * non-zero 182 * for master mode, and zero for slave mode. 183 * @param slaveAddr 7-bit or 10-bit address to use when in slave mode. 184 * This parameter is ignored when masterMode is non-zero. 185 * 186 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 187 */ 188 int MXC_I2C_Init(mxc_i2c_regs_t *i2c, int masterMode, unsigned int slaveAddr); 189 190 /** 191 * @brief Set slave address for I2C instances acting as slaves on the bus. 192 * @note Set idx to zero, multiple I2C instances acting as slaves on the 193 * bus is not yet supported. 194 * 195 * @param i2c Pointer to I2C registers (selects the I2C block used.) 196 * @param slaveAddr 7-bit or 10-bit address to use when in slave mode. 197 * This parameter is ignored when masterMode is non-zero. 198 * @param idx Index of the I2C slave. 199 * 200 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 201 */ 202 int MXC_I2C_SetSlaveAddr(mxc_i2c_regs_t *i2c, unsigned int slaveAddr, int idx); 203 204 /** 205 * @brief Disable and shutdown I2C peripheral. 206 * 207 * @param i2c Pointer to I2C registers (selects the I2C block used.) 208 * 209 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 210 */ 211 int MXC_I2C_Shutdown(mxc_i2c_regs_t *i2c); 212 213 /** 214 * @brief Reset the I2C peripheral. 215 * @note The peripheral will need to be initialized with MXC_I2C_Init() before use 216 * 217 * @param i2c Pointer to I2C registers (selects the I2C block used.) 218 * 219 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 220 */ 221 int MXC_I2C_Reset(mxc_i2c_regs_t *i2c); 222 223 /** 224 * @brief Set the frequency of the I2C interface. 225 * 226 * @param i2c Pointer to I2C registers (selects the I2C block used.) 227 * @param hz The desired frequency in Hertz. 228 * 229 * @return Negative if error, otherwise actual speed set. See \ref 230 * MXC_Error_Codes for the list of error return codes. 231 */ 232 int MXC_I2C_SetFrequency(mxc_i2c_regs_t *i2c, unsigned int hz); 233 234 /** 235 * @brief Get the frequency of the I2C interface. 236 * 237 * @param i2c Pointer to I2C registers (selects the I2C block used.) 238 * 239 * @return The I2C bus frequency in Hertz 240 */ 241 int MXC_I2C_GetFrequency(mxc_i2c_regs_t *i2c); 242 243 /** 244 * @brief Checks if the given I2C bus can be placed in sleep more. 245 * 246 * This functions checks to see if there are any on-going I2C transactions in 247 * progress. If there are transactions in progress, the application should 248 * wait until the I2C bus is free before entering a low-power state. 249 * 250 * @param i2c Pointer to I2C registers (selects the I2C block used.) 251 * 252 * @return #E_NO_ERROR if ready, and non-zero if busy or error. See \ref 253 * MXC_Error_Codes for the list of error return codes. 254 */ 255 int MXC_I2C_ReadyForSleep(mxc_i2c_regs_t *i2c); 256 257 /** 258 * @brief Enables or disables clock stretching by the slave. 259 * 260 * Enables or disables clock stretching by the slave. This function has no 261 * affect when operating as the master. 262 * 263 * @param i2c Pointer to I2C registers (selects the I2C block used.) 264 * @param enable Enables clock stretching if non-zero, disables if zero. 265 * 266 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 267 */ 268 int MXC_I2C_SetClockStretching(mxc_i2c_regs_t *i2c, int enable); 269 270 /** 271 * @brief Determines if clock stretching has been enabled. 272 * 273 * @param i2c Pointer to I2C registers (selects the I2C block used.) 274 * 275 * @return Zero if clock stretching is disabled, non-zero otherwise 276 */ 277 int MXC_I2C_GetClockStretching(mxc_i2c_regs_t *i2c); 278 279 /** 280 * @brief Initializes the DMA for I2C DMA transactions. 281 * 282 * This function will release any acquired DMA channels before reacquiring and 283 * reconfiguring selected I2C DMA TX or RX channels. 284 * 285 * @param i2c Pointer to I2C registers (selects the I2C block used). 286 * @param dma Pointer to DMA registers (selects the DMA block used). 287 * @param use_dma_tx If true, acquire and configure DMA TX channel, else release any 288 * acquired DMA TX channel. 289 * @param use_dma_rx If true, acquire and configure DMA RX channel, else release any 290 * acquired DMA RX channel. 291 * 292 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 293 */ 294 int MXC_I2C_DMA_Init(mxc_i2c_regs_t *i2c, mxc_dma_regs_t *dma, bool use_dma_tx, bool use_dma_rx); 295 296 /** 297 * @brief Retreive the DMA TX Channel associated with I2C instance. 298 * 299 * @param i2c Pointer to I2C registers (selects the I2C block used). 300 * 301 * @return If successful, the DMA TX Channel number is returned. Otherwise, see 302 * \ref MXC_Error_Codes for a list of return codes. 303 */ 304 int MXC_I2C_DMA_GetTXChannel(mxc_i2c_regs_t *i2c); 305 306 /** 307 * @brief Retreive the DMA RX Channel associated with I2C instance. 308 * 309 * @param i2c Pointer to I2C registers (selects the I2C block used). 310 * 311 * @return If successful, the DMA RX Channel number is returned. Otherwise, see 312 * \ref MXC_Error_Codes for a list of return codes. 313 */ 314 int MXC_I2C_DMA_GetRXChannel(mxc_i2c_regs_t *i2c); 315 316 /** 317 * @brief Sets the I2C instance's DMA TX/RX request select. 318 * 319 * @param i2c Pointer to I2C registers (selects the I2C block used). 320 * @param txData Pointer to transmit buffer. 321 * @param rxData Pointer to receive buffer. 322 * 323 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 324 */ 325 int MXC_I2C_DMA_SetRequestSelect(mxc_i2c_regs_t *i2c, uint8_t *txData, uint8_t *rxData); 326 327 /* ************************************************************************* */ 328 /* Low-level functions */ 329 /* ************************************************************************* */ 330 331 /** 332 * @brief Generate a start (or repeated start) condition on the I2C bus. 333 * 334 * Generate a start (or repeated start) condition on the I2C bus. This 335 * function may opt to delay the actual generation of the start condition 336 * until data is actually transferred. 337 * 338 * @param i2c Pointer to I2C registers (selects the I2C block used.) 339 * 340 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 341 */ 342 int MXC_I2C_Start(mxc_i2c_regs_t *i2c); 343 344 /** 345 * @brief Generate a stop condition on the I2C bus. 346 * 347 * @param i2c Pointer to I2C registers (selects the I2C block used.) 348 * 349 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 350 */ 351 int MXC_I2C_Stop(mxc_i2c_regs_t *i2c); 352 353 /** 354 * @brief Write a single byte to the I2C bus. 355 * 356 * Write a single byte to the I2C bus. This function assumes the I2C bus is 357 * already in the proper state (i.e. a start condition has already been 358 * generated and the bus is in the write phase of an I2C transaction). If any 359 * bytes are pending in the FIFO (i.e. in the case of clock stretching), this 360 * function will return E_OVERFLOW. 361 * 362 * @param i2c Pointer to I2C registers (selects the I2C block used.) 363 * @param byte The byte to transmit. 364 * 365 * @return 0 if byte is acknowledged, 1 if not acknowledged, negative if 366 * error. See \ref MXC_Error_Codes for the list of error return codes. 367 */ 368 int MXC_I2C_WriteByte(mxc_i2c_regs_t *i2c, unsigned char byte); 369 370 /** 371 * @brief Read a single byte from the I2C bus. 372 * 373 * Read a single byte from the I2C bus. This function assumes the I2C bus is 374 * already in the proper state (i.e. a start condition has already been 375 * generated and the bus is in the read phase of an I2C transaction). If the FIFO 376 * is empty, this function will return E_UNDERFLOW. 377 * 378 * @param i2c Pointer to I2C registers (selects the I2C block used.) 379 * @param byte Pointer to the byte to read into. 380 * @param ack Whether or not to acknowledge the byte once received. 381 * 382 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 383 */ 384 int MXC_I2C_ReadByte(mxc_i2c_regs_t *i2c, unsigned char *byte, int ack); 385 386 /** 387 * @brief Read a single byte from the I2C bus. 388 * 389 * Read a single byte from the I2C bus. After the byte is received, the 390 * provided callback will be used to determine if the byte should be 391 * acknowledged or not before continuing with the rest of the transaction. 392 * This function assumes the I2C bus is already in the proper state (i.e. a 393 * start condition has already been generated and the bus is in the read 394 * phase of an I2C transaction). This function must be called with clock 395 * stretching enabled. 396 * 397 * @param i2c Pointer to I2C registers (selects the I2C block used.) 398 * @param byte Pointer to the byte to read into. 399 * @param getAck A function to be called to determine whether or not 400 * to acknowledge the byte once received. A non-zero 401 * return value will acknowledge the byte. If this 402 * parameter is set to NULL or its return value is 0, 403 * the byte received will not be acknowledged (i.e., it 404 * will be NACKed). 405 * 406 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 407 */ 408 int MXC_I2C_ReadByteInteractive(mxc_i2c_regs_t *i2c, unsigned char *byte, mxc_i2c_getAck_t getAck); 409 410 /** 411 * @brief Write multiple bytes to the I2C bus. 412 * 413 * Write multiple bytes to the I2C bus. This function assumes the I2C bus is 414 * already in the proper state (i.e. a start condition has already been 415 * generated and the bus is in the write phase of an I2C transaction). 416 * 417 * @param i2c Pointer to I2C registers (selects the I2C block used.) 418 * @param bytes The buffer containing the bytes to transmit. 419 * @param len The number of bytes to write. On return from the 420 * function, this will be set to the number of bytes 421 * actually transmitted. 422 * 423 * @return 0 if all bytes are acknowledged, 1 if any byte transmitted is not 424 * acknowledged, negative if error. See \ref MXC_Error_Codes for the 425 * list of error return codes. 426 */ 427 int MXC_I2C_Write(mxc_i2c_regs_t *i2c, unsigned char *bytes, unsigned int *len); 428 429 /** 430 * @brief Read multiple bytes from the I2C bus. 431 * 432 * Read multiple byte from the I2C bus. This function assumes the I2C bus is 433 * already in the proper state (i.e. a start condition has already been 434 * generated and the bus is in the read phase of an I2C transaction). 435 * 436 * @param i2c Pointer to I2C registers (selects the I2C block used.) 437 * @param bytes The buffer to read the data into. 438 * @param len The number of bytes to read. On return from the 439 * function, this will be set to the number of bytes 440 * actually received. 441 * @param ack Whether or not to acknowledge the last byte once it is 442 * received. All previous bytes will be acknowledged. 443 * 444 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 445 */ 446 int MXC_I2C_Read(mxc_i2c_regs_t *i2c, unsigned char *bytes, unsigned int *len, int ack); 447 448 /** 449 * @brief Unloads bytes from the receive FIFO. 450 * 451 * @param i2c Pointer to I2C registers (selects the I2C block used.) 452 * @param bytes The buffer to read the data into. 453 * @param len The number of bytes to read. 454 * 455 * @return The number of bytes actually read. 456 */ 457 int MXC_I2C_ReadRXFIFO(mxc_i2c_regs_t *i2c, volatile unsigned char *bytes, unsigned int len); 458 459 /** 460 * @brief Unloads bytes from the receive FIFO using DMA for longer reads. 461 * 462 * @note The operation is not complete until the callback has been called 463 * 464 * @param i2c Pointer to I2C registers (selects the I2C block used.) 465 * @param bytes The buffer to read the data into. 466 * @param len The number of bytes to read. 467 * @param callback The function to call when the read is complete 468 * 469 * @return See \ref MXC_Error_Codes for a list of return values. 470 */ 471 int MXC_I2C_ReadRXFIFODMA(mxc_i2c_regs_t *i2c, unsigned char *bytes, unsigned int len, 472 mxc_i2c_dma_complete_cb_t callback); 473 474 /** 475 * @brief Get the number of bytes currently available in the receive FIFO. 476 * 477 * @param i2c Pointer to I2C registers (selects the I2C block used.) 478 * 479 * @return The number of bytes available. 480 */ 481 int MXC_I2C_GetRXFIFOAvailable(mxc_i2c_regs_t *i2c); 482 483 /** 484 * @brief Loads bytes into the transmit FIFO. 485 * 486 * @param i2c Pointer to I2C registers (selects the I2C block used.) 487 * @param bytes The buffer containing the bytes to write 488 * @param len The number of bytes to write. 489 * 490 * @return The number of bytes actually written. 491 */ 492 int MXC_I2C_WriteTXFIFO(mxc_i2c_regs_t *i2c, volatile unsigned char *bytes, unsigned int len); 493 494 /** 495 * @brief Loads bytes into the transmit FIFO using DMA for longer writes. 496 * 497 * @note The operation is not complete until the callback has been called 498 * @param i2c Pointer to I2C registers (selects the I2C block used.) 499 * @param bytes The buffer containing the bytes to write 500 * @param len The number of bytes to write. 501 * @param callback The function to call when the read is complete 502 * 503 * @return See \ref MXC_Error_Codes for a list of return values 504 */ 505 int MXC_I2C_WriteTXFIFODMA(mxc_i2c_regs_t *i2c, unsigned char *bytes, unsigned int len, 506 mxc_i2c_dma_complete_cb_t callback); 507 508 /** 509 * @brief Get the amount of free space available in the transmit FIFO. 510 * 511 * @param i2c Pointer to I2C registers (selects the I2C block used.) 512 * 513 * @return The number of bytes available. 514 */ 515 int MXC_I2C_GetTXFIFOAvailable(mxc_i2c_regs_t *i2c); 516 517 /** 518 * @brief Removes and discards all bytes currently in the receive FIFO. 519 * 520 * @param i2c Pointer to I2C registers (selects the I2C block used.) 521 */ 522 void MXC_I2C_ClearRXFIFO(mxc_i2c_regs_t *i2c); 523 524 /** 525 * @brief Removes and discards all bytes currently in the transmit FIFO. 526 * 527 * @param i2c Pointer to I2C registers (selects the I2C block used.) 528 */ 529 void MXC_I2C_ClearTXFIFO(mxc_i2c_regs_t *i2c); 530 531 /** 532 * @brief Get the presently set interrupt flags. 533 * 534 * @param i2c Pointer to I2C registers (selects the I2C block used.) 535 * @param flags0 Pointer to variable to store interrupt status for interrupt register intfl0. 536 * @param flags1 Pointer to variable to store interrupt status for interrupt register intfl1. 537 */ 538 int MXC_I2C_GetFlags(mxc_i2c_regs_t *i2c, unsigned int *flags0, unsigned int *flags1); 539 540 /** 541 * @brief Clears the Interrupt Flags. 542 * 543 * @param i2c Pointer to I2C registers (selects the I2C block used.) 544 * @param flags0 Flags to clear in interrupt register intfl0. 545 * @param flags1 Flags to clear in interrupt register intfl1. 546 */ 547 void MXC_I2C_ClearFlags(mxc_i2c_regs_t *i2c, unsigned int flags0, unsigned int flags1); 548 549 /** 550 * @brief Enable Interrupts. 551 * 552 * @param i2c Pointer to I2C registers (selects the I2C block used.) 553 * @param flags0 Interrupts to be enabled in int->en0 554 * @param flags1 Interrupts to be enabled in int->en1 555 */ 556 void MXC_I2C_EnableInt(mxc_i2c_regs_t *i2c, unsigned int flags0, unsigned int flags1); 557 558 /** 559 * @brief Disable Interrupts. 560 * 561 * @param i2c Pointer to I2C registers (selects the I2C block used.) 562 * @param flags0 Interrupts to be disabled in int->en0 563 * @param flags1 Interrupts to be disabled in int->en1 564 */ 565 void MXC_I2C_DisableInt(mxc_i2c_regs_t *i2c, unsigned int flags0, unsigned int flags1); 566 567 /** 568 * @brief Enables the slave preload mode 569 * 570 * Use this mode to preload the slave TX FIFO with data that can be sent when 571 * the slave is addressed for a read operation without software intervention. 572 * 573 * @param i2c Pointer to I2C registers (selects the I2C block used.) 574 */ 575 void MXC_I2C_EnablePreload(mxc_i2c_regs_t *i2c); 576 577 /** 578 * @brief Disable the slave preload mode 579 * 580 * @param i2c Pointer to I2C registers (selects the I2C block used.) 581 */ 582 void MXC_I2C_DisablePreload(mxc_i2c_regs_t *i2c); 583 584 /** 585 * @brief Enables the slave to respond to the general call address 586 * 587 * @param i2c Pointer to I2C registers (selects the I2C block used.) 588 */ 589 void MXC_I2C_EnableGeneralCall(mxc_i2c_regs_t *i2c); 590 591 /** 592 * @brief Prevents the slave from responding to the general call address 593 * 594 * @param i2c Pointer to I2C registers (selects the I2C block used.) 595 */ 596 void MXC_I2C_DisableGeneralCall(mxc_i2c_regs_t *i2c); 597 598 /** 599 * @brief Set the I2C Timeout 600 * 601 * The I2C timeout determines the amount of time the master will wait while the 602 * slave is stretching the clock, and the amount of time the slave will stretch 603 * the clock while waiting for software to unload the fifo. 604 * 605 * @param i2c Pointer to I2C registers (selects the I2C block used.) 606 * @param timeout Timeout in uS 607 */ 608 void MXC_I2C_SetTimeout(mxc_i2c_regs_t *i2c, unsigned int timeout); 609 610 /** 611 * @brief Get the current I2C timeout 612 * 613 * @param i2c Pointer to I2C registers (selects the I2C block used.) 614 * 615 * @return The current timeout in uS 616 */ 617 unsigned int MXC_I2C_GetTimeout(mxc_i2c_regs_t *i2c); 618 619 /** 620 * @brief Attempts to recover the I2C bus, ensuring the I2C lines are idle. 621 * 622 * Attempts to recover and reset an I2C bus by sending I2C clocks. During 623 * each clock cycle, the SDA line is cycled to determine if the master has 624 * control of the line. The following steps are performed to create one SCL 625 * clock cycle: 626 * 1. Drive SCL low 627 * 2. Verify SCL is low 628 * 3. Drive SDA low 629 * 4. Verify SDA is low 630 * 5. Release SDA allowing it to return high 631 * 6. Verify SDA is high 632 * 7. Release SCL allowing it to return high. 633 * 8. Verify SCL is high 634 * If any of the steps fail, the bus is considered to still be busy and the 635 * sequence is repeated up to the requested number of times. If all steps 636 * succeed, a final stop condition is generated on the I2C bus. 637 * 638 * @param i2c Pointer to I2C registers (selects the I2C block used.) 639 * @param retries Number of times to attempt the clock cycle sequence. 640 * 641 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 642 */ 643 int MXC_I2C_Recover(mxc_i2c_regs_t *i2c, unsigned int retries); 644 645 /* ************************************************************************* */ 646 /* Transaction level functions */ 647 /* ************************************************************************* */ 648 649 /** 650 * @brief Performs a blocking I2C master transaction. 651 * 652 * Performs a blocking I2C master transaction. These actions will be performed: 653 * 1. If necessary, generate a start condition on the bus. 654 * 2. Send the slave address with the low bit set to 0 (indicating a write). 655 * 3. Transmit req->tx_len bytes of req->tx_buff. 656 * 4. Generate a repeated start condition on the bus. 657 * 5. Send the slave address with the low bit set to 1 (indicating a read). 658 * 6. Receive req->rx_len bytes into req->rx_buf, acknowledging each byte. 659 * 7. Generate a stop (or repeated start) condition on the bus. 660 * Steps 3-6 will be skipped if req->tx_len and req->rx_len are both 0. 661 * Steps 2-4 will be skipped if req->tx_len equals 0. 662 * Steps 4-6 will be skipped if req->rx_len equals 0. 663 * 664 * @param req Pointer to details of the transaction 665 * 666 * @return 0 if all bytes are acknowledged, 1 if any byte transmitted is not 667 * acknowledged, negative if error. See \ref MXC_Error_Codes for the 668 * list of error return codes. 669 */ 670 int MXC_I2C_MasterTransaction(mxc_i2c_req_t *req); 671 672 /** 673 * @brief Performs a non-blocking I2C master transaction. 674 * 675 * Performs a non-blocking I2C master transaction. These actions will be performed: 676 * 1. If necessary, generate a start condition on the bus. 677 * 2. Send the slave address with the low bit set to 0 (indicating a write). 678 * 3. Transmit req->tx_len bytes of req->tx_buff. 679 * 4. Generate a repeated start condition on the bus. 680 * 5. Send the slave address with the low bit set to 1 (indicating a read). 681 * 6. Receive req->rx_len bytes into req->rx_buf, acknowledging each byte. 682 * 7. Generate a stop (or repeated start) condition on the bus. 683 * 8. Execute req->callback to indicate the transaction is complete. 684 * Steps 3-6 will be skipped if tx_len and rx_len are both 0. 685 * Steps 2-4 will be skipped if tx_len equals 0. 686 * Steps 4-6 will be skipped if rx_len equals 0. 687 * 688 * @note MXC_I2C_AsyncHandler() must be called periodically for this function 689 * to operate properly. Ideally from the I2C ISR. 690 * 691 * @param req Pointer to details of the transaction. The memory 692 * used by this parameter must remain available until 693 * the callback is executed. 694 * 695 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 696 */ 697 int MXC_I2C_MasterTransactionAsync(mxc_i2c_req_t *req); 698 699 /** 700 * @brief Performs a non-blocking I2C Master transaction using DMA for reduced time 701 * in the ISR. This function initializes the DMA and acquires DMA channels 702 * if MXC_I2C_DMA_Init(...) was not called earlier. 703 * 704 * It is recommended to initialize the DMA by calling MXC_I2C_DMA_Init(...) function 705 * before calling MXC_I2C_MasterTransactionDMA(...). This provides flexibility in 706 * setting up generic DMA channel vectors during run-time without knowing what DMA 707 * channels will be acquired beforehand. 708 * 709 * Performs a non-blocking I2C transaction. These actions will be performed: 710 * 1. If necessary, generate a start condition on the bus. 711 * 2. Send the slave address with the low bit set to 0 (indicating a write). 712 * 3. Transmit req->tx_len bytes of req->tx_buff. 713 * 4. Generate a repeated start condition on the bus. 714 * 5. Send the slave address with the low bit set to 1 (indicating a read). 715 * 6. Receive req->rx_len bytes into req->rx_buf, acknowledging each byte. 716 * 7. Generate a stop (or repeated start) condition on the bus. 717 * 8. Execute req->callback to indicate the transaction is complete. 718 * Steps 3-6 will be skipped if tx_len and rx_len are both 0. 719 * Steps 2-4 will be skipped if tx_len equals 0. 720 * Steps 4-6 will be skipped if rx_len equals 0. 721 * 722 * @note MXC_I2C_AsyncHandler() must be called periodically for this function 723 * to operate properly. Ideally from the I2C ISR. 724 * 725 * @param req Pointer to details of the transaction. The memory 726 * used by this parameter must remain available until 727 * the callback is executed. 728 * 729 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 730 */ 731 int MXC_I2C_MasterTransactionDMA(mxc_i2c_req_t *req); 732 733 /** 734 * @brief Performs a blocking I2C slave transaction. 735 * 736 * Performs a blocking I2C slave transaction. This function will block until a 737 * complete transaction with this slave has been performed. A transaction 738 * begins with the master addressing the slave and ends with a repeated start 739 * condition, a stop condition, or a bus error. The provided callback 740 * function will be called for these events: 741 * - A slave address match occurs with the master requesting a write to 742 * the slave. 743 * - A slave address match occurs with the master requesting a read from 744 * the slave. 745 * - The receive FIFO crosses the set threshold (see 746 * MXC_I2C_SetRXThreshold()). The callback code should unload the receive 747 * FIFO (see MXC_I2C_ReadFIFO()) to allow the master to send more data. 748 * The return value of the callback function will determine if the 749 * last byte received should be acknowledged or not. Return 0 to 750 * acknowledge, non-zero to not acknowledge. 751 * - The transmit FIFO crosses the set threshold (see 752 * MXC_I2C_SetTXThreshold()). If the master is expected to read more 753 * data from this slave, the callback code should add data to the 754 * transmit FIFO (see MXC_I2C_WriteFIFO()). 755 * - The transaction ends. If the master was writing to the slave, the 756 * receive FIFO may still contain valid data that needs to be 757 * retreived (see MXC_I2C_ReadFIFO()). 758 * - The transmit FIFO underflows because the master requests data when 759 * the transmit FIFO is empty. 760 * - The receive FIFO overflows because the master writes data while the 761 * receive FIFO was full. 762 * 763 * If clock stretching is disabled, careful attention must be paid to the timing 764 * of the callback to avoid losing data on write or unintentionally nacking a read. 765 * 766 * @param i2c Pointer to I2C registers (selects the I2C block used.) 767 * @param callback The function to be called when an I2C event occurs. 768 * 769 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 770 */ 771 int MXC_I2C_SlaveTransaction(mxc_i2c_regs_t *i2c, mxc_i2c_slave_handler_t callback); 772 773 /** 774 * @brief Performs a non-blocking I2C slave transaction. 775 * 776 * Performs a non-blocking I2C slave transaction. This request will remain active 777 * until a complete transaction with this slave has been performed. A 778 * transaction begins with the master begins with the master addressing the 779 * slave and ends with a repeated start condition, a stop condition, or a bus 780 * error. The provided callback function will be called for these events: 781 * - A slave address match occurs with the master requesting a write to 782 * the slave. 783 * - A slave address match occurs with the master requesting a read from 784 * the slave. 785 * - The receive FIFO crosses the set threshold (see 786 * MXC_I2C_SetRXThreshold()). The callback code should unload the receive 787 * FIFO (see MXC_I2C_ReadFIFO()) to allow the master to send more data. 788 * The return value of the callback function will determine if the 789 * last byte received should be acknowledged or not. Return 0 to 790 * acknowledge, non-zero to not acknowledge. 791 * - The transmit FIFO crosses the set threshold (see 792 * MXC_I2C_SetTXThreshold()). If the master is expected to read more 793 * data from this slave, the callback code should add data to the 794 * transmit FIFO (see MXC_I2C_WriteFIFO()). 795 * - The transaction ends. If the master was writing to the slave, the 796 * receive FIFO may still contain valid data that needs to be 797 * retreived (see MXC_I2C_ReadFIFO()). 798 * - The transmit FIFO underflows because the master requests data when 799 * the transmit FIFO is empty. 800 * - The receive FIFO overflows because the master writes data while the 801 * receive FIFO was full. 802 * 803 * If clock stretching is disabled, careful attention must be paid to the timing 804 * of the callback to avoid losing data on write or unintentionally nacking a read. 805 * 806 * @note MXC_I2C_AsyncHandler() must be called peridocally for this function 807 * to operate properly. 808 * 809 * @param i2c Pointer to I2C registers (selects the I2C block used.) 810 * @param callback The function to be called when an I2C event occurs. 811 * 812 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 813 */ 814 int MXC_I2C_SlaveTransactionAsync(mxc_i2c_regs_t *i2c, mxc_i2c_slave_handler_t callback); 815 816 /** 817 * @brief Set the receive threshold level. 818 * 819 * When operating as a master, the function sets the receive threshold level 820 * for when the master should unload the receive FIFO. Smaller values may 821 * consume more CPU cycles, but decrease the chances of the master delaying 822 * the generation of I2C bus clocks because it has no room in the FIFO to 823 * receive data. Larger values may consume fewer CPU cycles, but risk delays 824 * of the I2C clock. When operating as a slave, this function sets the number 825 * of bytes the slave transaction functions should receive before issuing a 826 * call to their callback function. Smaller values may consume more CPU 827 * cycles, but reduce the risk of missing data from the master due to the 828 * recieve FIFO being full. Larger values may reduce the number of CPU 829 * cycles, but may cause bytes sent from the master to be missed. 830 * 831 * @param i2c Pointer to I2C registers (selects the I2C block used.) 832 * @param numBytes The threshold level to set. This value must be 833 * between 0 and 8 inclusive. 834 * 835 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 836 */ 837 int MXC_I2C_SetRXThreshold(mxc_i2c_regs_t *i2c, unsigned int numBytes); 838 839 /** 840 * @brief Get the current receive threshold level. 841 * 842 * @param i2c Pointer to I2C registers (selects the I2C block used.) 843 * 844 * @return The receive threshold value (in bytes). 845 */ 846 int MXC_I2C_GetRXThreshold(mxc_i2c_regs_t *i2c); 847 848 /** 849 * @brief Set the transmit threshold level. 850 * 851 * When operating as a master, the function sets the transmit threshold level 852 * for when the master should add additional bytes to the transmit FIFO. 853 * Larger values may consume more CPU cycles, but decrease the chances of the 854 * master delaying the generation of I2C bus clocks because it has no data in 855 * the FIFO to transmit. Smaller values may consume fewer CPU cycles, but 856 * risk delays of the I2C clock. When operating as a slave, this function 857 * sets the number of bytes the slave transaction functions should transmit 858 * before issuing a call to their callback function. Larger values may 859 * consume more CPU cycles, but reduce the risk of not having data ready when 860 * the master requests it. Smaller values may reduce the number of CPU 861 * cycles, but may cause the master to read from an empty FIFO. (The master 862 * will read 0xFF in this case.) 863 * 864 * @param i2c Pointer to I2C registers (selects the I2C block used.) 865 * @param numBytes The threshold level to set. This value must be 866 * between 0 and 8 inclusive. 867 * 868 * @return Success/Fail, see \ref MXC_Error_Codes for a list of return codes. 869 */ 870 int MXC_I2C_SetTXThreshold(mxc_i2c_regs_t *i2c, unsigned int numBytes); 871 872 /** 873 * @brief Get the current transmit threshold level. 874 * 875 * @param i2c Pointer to I2C registers (selects the I2C block used.) 876 * 877 * @return The transmit threshold value (in bytes). 878 */ 879 int MXC_I2C_GetTXThreshold(mxc_i2c_regs_t *i2c); 880 881 /** 882 * @brief Stop any asynchronous requests in progress. 883 * 884 * Stop any asynchronous requests in progress. Any callbacks associated with 885 * the active transaction will be NOT executed. 886 * 887 * @param i2c Pointer to I2C registers (selects the I2C block used.) 888 */ 889 void MXC_I2C_AsyncStop(mxc_i2c_regs_t *i2c); 890 891 /** 892 * @brief Abort any asynchronous requests in progress. 893 * 894 * Abort any asynchronous requests in progress. Any callbacks associated with 895 * the active transaction will be executed to indicate when the transaction 896 * has been terminated. 897 * 898 * @param i2c Pointer to I2C registers (selects the I2C block used.) 899 */ 900 void MXC_I2C_AbortAsync(mxc_i2c_regs_t *i2c); 901 902 /** 903 * @brief The processing function for asynchronous transactions. 904 * 905 * When using the asynchronous functions, the application must call this 906 * function periodically. This can be done from within the I2C interrupt 907 * handler or periodically by the application if I2C interrupts are disabled. 908 * 909 * @param i2c Pointer to I2C registers (selects the I2C block used.) 910 */ 911 void MXC_I2C_AsyncHandler(mxc_i2c_regs_t *i2c); 912 913 /** 914 * @brief The processing function for DMA transactions. 915 * 916 * When using the DMA functions, the application must call this 917 * function periodically. This can be done from within the DMA Interrupt Handler. 918 * 919 * @param ch DMA channel 920 * @param error Error status 921 */ 922 void MXC_I2C_DMACallback(int ch, int error); 923 924 /**@} end of group i2c */ 925 926 #ifdef __cplusplus 927 } 928 #endif 929 930 #endif // LIBRARIES_PERIPHDRIVERS_INCLUDE_MAX32662_I2C_H_ 931
