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   1 /******************************************************************************
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  18 *
  19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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  29 * this Software without prior written authorization from Xilinx.
  30 *
  31 ******************************************************************************/
  32 /*****************************************************************************/
  33 /**
  34 * @file xiicps_slave.c
  35 * @addtogroup iicps_v3_0
  36 * @{
  37 *
  38 * Handles slave transfers
  39 *
  40 * <pre> MODIFICATION HISTORY:
  41 *
  42 * Ver   Who Date     Changes
  43 * ----- --  -------- ---------------------------------------------
  44 * 1.00a jz  01/30/10 First release
  45 * 1.04a kpc 08/30/13 Avoid buffer overwrite in SlaveRecvData function
  46 * 3.00  sk      01/31/15 Modified the code according to MISRAC 2012 Compliant.
  47 *
  48 * </pre>
  49 *
  50 ******************************************************************************/
  51
  52 /***************************** Include Files *********************************/
  53 #include "xiicps.h"
  54
  55 /************************** Constant Definitions *****************************/
  56
  57 /**************************** Type Definitions *******************************/
  58
  59 /***************** Macros (Inline Functions) Definitions *********************/
  60
  61 /************************** Function Prototypes ******************************/
  62 extern s32 TransmitFifoFill(XIicPs *InstancePtr);
  63
  64 static s32 SlaveRecvData(XIicPs *InstancePtr);
  65
  66 /************************* Variable Definitions *****************************/
  67
  68 /*****************************************************************************/
  69 /**
  70 * This function sets up the device to be a slave.
  71 *
  72 * @param        InstancePtr is a pointer to the XIicPs instance.
  73 * @param        SlaveAddr is the address of the slave we are receiving from.
  74 *
  75 * @return       None.
  76 *
  77 * @note
  78 *       Interrupt is always enabled no matter the tranfer is interrupt-
  79 *       driven or polled mode. Whether device will be interrupted or not
  80 *       depends on whether the device is connected to an interrupt
  81 *       controller and interrupt for the device is enabled.
  82 *
  83 ****************************************************************************/
  84 void XIicPs_SetupSlave(XIicPs *InstancePtr, u16 SlaveAddr)
  85 {
  86         u32 ControlReg;
  87         u32 BaseAddr;
  88
  89         Xil_AssertVoid(InstancePtr != NULL);
  90         Xil_AssertVoid(InstancePtr->IsReady == (u32)XIL_COMPONENT_IS_READY);
  91         Xil_AssertVoid(XIICPS_ADDR_MASK >= SlaveAddr);
  92
  93         BaseAddr = InstancePtr->Config.BaseAddress;
  94
  95         ControlReg = XIicPs_In32(BaseAddr + XIICPS_CR_OFFSET);
  96
  97         /*
  98          * Set up master, AckEn, nea and also clear fifo.
  99          */
 100         ControlReg |= (u32)XIICPS_CR_ACKEN_MASK | (u32)XIICPS_CR_CLR_FIFO_MASK;
 101         ControlReg |= (u32)XIICPS_CR_NEA_MASK;
 102         ControlReg &= (u32)(~XIICPS_CR_MS_MASK);
 103
 104         XIicPs_WriteReg(BaseAddr, XIICPS_CR_OFFSET,
 105                           ControlReg);
 106
 107         XIicPs_DisableAllInterrupts(BaseAddr);
 108
 109         XIicPs_WriteReg(InstancePtr->Config.BaseAddress,
 110                           XIICPS_ADDR_OFFSET, (u32)SlaveAddr);
 111
 112         return;
 113 }
 114
 115 /*****************************************************************************/
 116 /**
 117 * This function setup a slave interrupt-driven send. It set the repeated
 118 * start for the device is the tranfer size is larger than FIFO depth.
 119 * Data processing for the send is initiated by the interrupt handler.
 120 *
 121 * @param        InstancePtr is a pointer to the XIicPs instance.
 122 * @param        MsgPtr is the pointer to the send buffer.
 123 * @param        ByteCount is the number of bytes to be sent.
 124 *
 125 * @return       None.
 126 *
 127 * @note         This send routine is for interrupt-driven transfer only.
 128 *
 129 ****************************************************************************/
 130 void XIicPs_SlaveSend(XIicPs *InstancePtr, u8 *MsgPtr, s32 ByteCount)
 131 {
 132         u32 BaseAddr;
 133
 134         /*
 135          * Assert validates the input arguments
 136          */
 137         Xil_AssertVoid(InstancePtr != NULL);
 138         Xil_AssertVoid(MsgPtr != NULL);
 139         Xil_AssertVoid(InstancePtr->IsReady == (u32)XIL_COMPONENT_IS_READY);
 140
 141
 142         BaseAddr = InstancePtr->Config.BaseAddress;
 143         InstancePtr->SendBufferPtr = MsgPtr;
 144         InstancePtr->SendByteCount = ByteCount;
 145         InstancePtr->RecvBufferPtr = NULL;
 146
 147         XIicPs_EnableInterrupts(BaseAddr,
 148                         (u32)XIICPS_IXR_DATA_MASK | (u32)XIICPS_IXR_COMP_MASK |
 149                         (u32)XIICPS_IXR_TO_MASK | (u32)XIICPS_IXR_NACK_MASK |
 150                         (u32)XIICPS_IXR_TX_OVR_MASK);
 151 }
 152
 153 /*****************************************************************************/
 154 /**
 155 * This function setup a slave interrupt-driven receive.
 156 * Data processing for the receive is handled by the interrupt handler.
 157 *
 158 * @param        InstancePtr is a pointer to the XIicPs instance.
 159 * @param        MsgPtr is the pointer to the receive buffer.
 160 * @param        ByteCount is the number of bytes to be received.
 161 *
 162 * @return       None.
 163 *
 164 * @note         This routine is for interrupt-driven transfer only.
 165 *
 166 ****************************************************************************/
 167 void XIicPs_SlaveRecv(XIicPs *InstancePtr, u8 *MsgPtr, s32 ByteCount)
 168 {
 169         /*
 170          * Assert validates the input arguments.
 171          */
 172         Xil_AssertVoid(InstancePtr != NULL);
 173         Xil_AssertVoid(MsgPtr != NULL);
 174         Xil_AssertVoid(InstancePtr->IsReady == (u32)XIL_COMPONENT_IS_READY);
 175
 176
 177         InstancePtr->RecvBufferPtr = MsgPtr;
 178         InstancePtr->RecvByteCount = ByteCount;
 179         InstancePtr->SendBufferPtr = NULL;
 180
 181         XIicPs_EnableInterrupts(InstancePtr->Config.BaseAddress,
 182                 (u32)XIICPS_IXR_DATA_MASK | (u32)XIICPS_IXR_COMP_MASK |
 183                 (u32)XIICPS_IXR_NACK_MASK | (u32)XIICPS_IXR_TO_MASK |
 184                 (u32)XIICPS_IXR_RX_OVR_MASK | (u32)XIICPS_IXR_RX_UNF_MASK);
 185
 186 }
 187
 188 /*****************************************************************************/
 189 /**
 190 * This function sends  a buffer in polled mode as a slave.
 191 *
 192 * @param        InstancePtr is a pointer to the XIicPs instance.
 193 * @param        MsgPtr is the pointer to the send buffer.
 194 * @param        ByteCount is the number of bytes to be sent.
 195 *
 196 * @return
 197 *               - XST_SUCCESS if everything went well.
 198 *               - XST_FAILURE if master sends us data or master terminates the
 199 *               transfer before all data has sent out.
 200 *
 201 * @note         This send routine is for polled mode transfer only.
 202 *
 203 ****************************************************************************/
 204 s32 XIicPs_SlaveSendPolled(XIicPs *InstancePtr, u8 *MsgPtr, s32 ByteCount)
 205 {
 206         u32 IntrStatusReg;
 207         u32 StatusReg;
 208         u32 BaseAddr;
 209         s32 Tmp;
 210         s32 BytesToSend;
 211         s32 Error = 0;
 212         s32 Status = (s32)XST_SUCCESS;
 213         u32 Value;
 214
 215         /*
 216          * Assert validates the input arguments.
 217          */
 218         Xil_AssertNonvoid(InstancePtr != NULL);
 219         Xil_AssertNonvoid(MsgPtr != NULL);
 220         Xil_AssertNonvoid(InstancePtr->IsReady == (u32)XIL_COMPONENT_IS_READY);
 221
 222         BaseAddr = InstancePtr->Config.BaseAddress;
 223         InstancePtr->SendBufferPtr = MsgPtr;
 224         InstancePtr->SendByteCount = ByteCount;
 225
 226         /*
 227          * Use RXRW bit in status register to wait master to start a read.
 228          */
 229         StatusReg = XIicPs_ReadReg(BaseAddr, XIICPS_SR_OFFSET);
 230         while (((StatusReg & XIICPS_SR_RXRW_MASK) == 0U) &&
 231                                 ((!Error) != 0)) {
 232
 233                 /*
 234                  * If master tries to send us data, it is an error.
 235                  */
 236                 if ((StatusReg & XIICPS_SR_RXDV_MASK) != 0x0U) {
 237                         Error = 1;
 238                 }
 239
 240                 StatusReg = XIicPs_ReadReg(BaseAddr, XIICPS_SR_OFFSET);
 241         }
 242
 243         if (Error != 0) {
 244                 Status = (s32)XST_FAILURE;
 245         } else {
 246
 247                 /*
 248                  * Clear the interrupt status register.
 249                  */
 250                 IntrStatusReg = XIicPs_ReadReg(BaseAddr, XIICPS_ISR_OFFSET);
 251                 XIicPs_WriteReg(BaseAddr, XIICPS_ISR_OFFSET, IntrStatusReg);
 252
 253                 /*
 254                  * Send data as long as there is more data to send and
 255                  * there are no errors.
 256                  */
 257                 Value = (InstancePtr->SendByteCount > (s32)0) &&
 258                                                 ((!Error) != 0);
 259                 while (Value != (u32)0x00U) {
 260
 261                         /*
 262                          * Find out how many can be sent.
 263                          */
 264                         BytesToSend = InstancePtr->SendByteCount;
 265                         if (BytesToSend > (s32)(XIICPS_FIFO_DEPTH)) {
 266                                 BytesToSend = (s32)(XIICPS_FIFO_DEPTH);
 267                         }
 268
 269                         for(Tmp = 0; Tmp < BytesToSend; Tmp ++) {
 270                                 XIicPs_SendByte(InstancePtr);
 271                         }
 272
 273                         StatusReg = XIicPs_ReadReg(BaseAddr, XIICPS_SR_OFFSET);
 274
 275                         /*
 276                          * Wait for master to read the data out of fifo.
 277                          */
 278                         while (((StatusReg & XIICPS_SR_TXDV_MASK) != (u32)0x00U) &&
 279                                                         ((!Error) != 0)) {
 280
 281                                 /*
 282                                  * If master terminates the transfer before all data is
 283                                  * sent, it is an error.
 284                                  */
 285                                 IntrStatusReg = XIicPs_ReadReg(BaseAddr,
 286                                 XIICPS_ISR_OFFSET);
 287                                 if ((IntrStatusReg & XIICPS_IXR_NACK_MASK) != 0x0U) {
 288                                         Error = 1;
 289                                 }
 290
 291                                 /* Clear ISR.
 292                                  */
 293                                 XIicPs_WriteReg(BaseAddr, XIICPS_ISR_OFFSET,
 294                                                         IntrStatusReg);
 295
 296                                 StatusReg = XIicPs_ReadReg(BaseAddr,
 297                                                 XIICPS_SR_OFFSET);
 298                         }
 299                         Value = (InstancePtr->SendByteCount > (s32)0U) &&
 300                                                         ((!Error) != 0);
 301                 }
 302         }
 303         if (Error != 0) {
 304         Status = (s32)XST_FAILURE;
 305         }
 306
 307         return Status;
 308 }
 309 /*****************************************************************************/
 310 /**
 311 * This function receives a buffer in polled mode as a slave.
 312 *
 313 * @param        InstancePtr is a pointer to the XIicPs instance.
 314 * @param        MsgPtr is the pointer to the receive buffer.
 315 * @param        ByteCount is the number of bytes to be received.
 316 *
 317 * @return
 318 *               - XST_SUCCESS if everything went well.
 319 *               - XST_FAILURE if timed out.
 320 *
 321 * @note         This receive routine is for polled mode transfer only.
 322 *
 323 ****************************************************************************/
 324 s32 XIicPs_SlaveRecvPolled(XIicPs *InstancePtr, u8 *MsgPtr, s32 ByteCount)
 325 {
 326         u32 IntrStatusReg;
 327         u32 StatusReg;
 328         u32 BaseAddr;
 329         s32 Count;
 330
 331         /*
 332          * Assert validates the input arguments.
 333          */
 334         Xil_AssertNonvoid(InstancePtr != NULL);
 335         Xil_AssertNonvoid(MsgPtr != NULL);
 336         Xil_AssertNonvoid(InstancePtr->IsReady == (u32)XIL_COMPONENT_IS_READY);
 337
 338         BaseAddr = InstancePtr->Config.BaseAddress;
 339         InstancePtr->RecvBufferPtr = MsgPtr;
 340         InstancePtr->RecvByteCount = ByteCount;
 341
 342         StatusReg = XIicPs_ReadReg(BaseAddr, XIICPS_SR_OFFSET);
 343
 344         /*
 345          * Clear the interrupt status register.
 346          */
 347         IntrStatusReg = XIicPs_ReadReg(BaseAddr, XIICPS_ISR_OFFSET);
 348         XIicPs_WriteReg(BaseAddr, XIICPS_ISR_OFFSET, IntrStatusReg);
 349
 350         /*
 351          * Clear the status register.
 352          */
 353         StatusReg = XIicPs_ReadReg(BaseAddr, XIICPS_SR_OFFSET);
 354         XIicPs_WriteReg(BaseAddr, XIICPS_SR_OFFSET, StatusReg);
 355
 356         StatusReg = XIicPs_ReadReg(BaseAddr, XIICPS_SR_OFFSET);
 357         Count = InstancePtr->RecvByteCount;
 358         while (Count > (s32)0) {
 359
 360                 /* Wait for master to put data */
 361                 while ((StatusReg & XIICPS_SR_RXDV_MASK) == 0U) {
 362                     StatusReg = XIicPs_ReadReg(BaseAddr, XIICPS_SR_OFFSET);
 363
 364                         /*
 365                          * If master terminates the transfer before we get all
 366                          * the data or the master tries to read from us,
 367                          * it is an error.
 368                          */
 369                         IntrStatusReg = XIicPs_ReadReg(BaseAddr,
 370                                                 XIICPS_ISR_OFFSET);
 371                         if (((IntrStatusReg & (XIICPS_IXR_DATA_MASK |
 372                                         XIICPS_IXR_COMP_MASK))!=0x0U) &&
 373                                 ((StatusReg & XIICPS_SR_RXDV_MASK) == 0U) &&
 374                                 ((InstancePtr->RecvByteCount > 0) != 0x0U)) {
 375
 376                                 return (s32)XST_FAILURE;
 377                         }
 378
 379                         /*
 380                          * Clear the interrupt status register.
 381                          */
 382                         XIicPs_WriteReg(BaseAddr, XIICPS_ISR_OFFSET,
 383                         IntrStatusReg);
 384                 }
 385
 386                 /*
 387                  * Read all data from FIFO.
 388                  */
 389                 while (((StatusReg & XIICPS_SR_RXDV_MASK)!=0x0U) &&
 390                          ((InstancePtr->RecvByteCount > 0) != 0x0U)){
 391
 392                         XIicPs_RecvByte(InstancePtr);
 393
 394                         StatusReg = XIicPs_ReadReg(BaseAddr,
 395                                 XIICPS_SR_OFFSET);
 396                 }
 397                 Count = InstancePtr->RecvByteCount;
 398         }
 399
 400         return (s32)XST_SUCCESS;
 401 }
 402
 403 /*****************************************************************************/
 404 /**
 405 * The interrupt handler for slave mode. It does the protocol handling for
 406 * the interrupt-driven transfers.
 407 *
 408 * Completion events and errors are signaled to upper layer for proper
 409 * handling.
 410 *
 411 * <pre>
 412 *
 413 * The interrupts that are handled are:
 414 * - DATA
 415 *       If the instance is sending, it means that the master wants to read more
 416 *       data from us. Send more data, and check whether we are done with this
 417 *       send.
 418 *
 419 *       If the instance is receiving, it means that the master has writen
 420 *       more data to us. Receive more data, and check whether we are done with
 421 *       with this receive.
 422 *
 423 * - COMP
 424 *       This marks that stop sequence has been sent from the master, transfer
 425 *       is about to terminate. However, for receiving, the master may have
 426 *       written us some data, so receive that first.
 427 *
 428 *       It is an error if the amount of transfered data is less than expected.
 429 *
 430 * - NAK
 431 *       This marks that master does not want our data. It is for send only.
 432 *
 433 * - Other interrupts
 434 *       These interrupts are marked as error.
 435 *
 436 * </pre>
 437 *
 438 * @param        InstancePtr is a pointer to the XIicPs instance.
 439 *
 440 * @return       None.
 441 *
 442 * @note         None.
 443 *
 444 ****************************************************************************/
 445 void XIicPs_SlaveInterruptHandler(XIicPs *InstancePtr)
 446 {
 447         u32 IntrStatusReg;
 448         u32 IsSend = 0U;
 449         u32 StatusEvent = 0U;
 450         s32 LeftOver;
 451         u32 BaseAddr;
 452
 453         /*
 454          * Assert validates the input arguments.
 455          */
 456         Xil_AssertVoid(InstancePtr != NULL);
 457         Xil_AssertVoid(InstancePtr->IsReady == (u32)XIL_COMPONENT_IS_READY);
 458
 459         BaseAddr = InstancePtr->Config.BaseAddress;
 460
 461         /*
 462          * Read the Interrupt status register.
 463          */
 464         IntrStatusReg = XIicPs_ReadReg(BaseAddr, XIICPS_ISR_OFFSET);
 465
 466         /*
 467          * Write the status back to clear the interrupts so no events are missed
 468          * while processing this interrupt.
 469          */
 470         XIicPs_WriteReg(BaseAddr, XIICPS_ISR_OFFSET, IntrStatusReg);
 471
 472         /*
 473          * Use the Mask register AND with the Interrupt Status register so
 474          * disabled interrupts are not processed.
 475          */
 476         IntrStatusReg &= ~(XIicPs_ReadReg(BaseAddr, XIICPS_IMR_OFFSET));
 477
 478         /*
 479          * Determine whether the device is sending.
 480          */
 481         if (InstancePtr->RecvBufferPtr == NULL) {
 482                 IsSend = 1U;
 483         }
 484
 485         /* Data interrupt
 486          *
 487          * This means master wants to do more data transfers.
 488          * Also check for completion of transfer, signal upper layer if done.
 489          */
 490         if ((u32)0U != (IntrStatusReg & XIICPS_IXR_DATA_MASK)) {
 491                 if (IsSend != 0x0U) {
 492                         LeftOver = TransmitFifoFill(InstancePtr);
 493                                 /*
 494                                  * We may finish send here
 495                                  */
 496                                 if (LeftOver == 0) {
 497                                         StatusEvent |=
 498                                                 XIICPS_EVENT_COMPLETE_SEND;
 499                                 }
 500                 } else {
 501                         LeftOver = SlaveRecvData(InstancePtr);
 502
 503                         /* We may finish the receive here */
 504                         if (LeftOver == 0) {
 505                                 StatusEvent |= XIICPS_EVENT_COMPLETE_RECV;
 506                         }
 507                 }
 508         }
 509
 510         /*
 511          * Complete interrupt.
 512          *
 513          * In slave mode, it means the master has done with this transfer, so
 514          * we signal the application using completion event.
 515          */
 516         if (0U != (IntrStatusReg & XIICPS_IXR_COMP_MASK)) {
 517                 if (IsSend != 0x0U) {
 518                         if (InstancePtr->SendByteCount > 0) {
 519                                 StatusEvent |= XIICPS_EVENT_ERROR;
 520                         }else {
 521                                 StatusEvent |= XIICPS_EVENT_COMPLETE_SEND;
 522                         }
 523                 } else {
 524                         LeftOver = SlaveRecvData(InstancePtr);
 525                         if (LeftOver > 0) {
 526                                 StatusEvent |= XIICPS_EVENT_ERROR;
 527                         } else {
 528                                 StatusEvent |= XIICPS_EVENT_COMPLETE_RECV;
 529                         }
 530                 }
 531         }
 532
 533         /*
 534          * Nack interrupt, pass this information to application.
 535          */
 536         if (0U != (IntrStatusReg & XIICPS_IXR_NACK_MASK)) {
 537                 StatusEvent |= XIICPS_EVENT_NACK;
 538         }
 539
 540         /*
 541          * All other interrupts are treated as error.
 542          */
 543         if (0U != (IntrStatusReg & (XIICPS_IXR_TO_MASK |
 544                                 XIICPS_IXR_RX_UNF_MASK |
 545                                 XIICPS_IXR_TX_OVR_MASK |
 546                                 XIICPS_IXR_RX_OVR_MASK))){
 547
 548                 StatusEvent |= XIICPS_EVENT_ERROR;
 549         }
 550
 551         /*
 552          * Signal application if there are any events.
 553          */
 554         if (0U != StatusEvent) {
 555                 InstancePtr->StatusHandler(InstancePtr->CallBackRef,
 556                                            StatusEvent);
 557         }
 558 }
 559
 560 /*****************************************************************************/
 561 /*
 562 *
 563 * This function handles continuation of receiving data. It is invoked
 564 * from interrupt handler.
 565 *
 566 * @param        InstancePtr is a pointer to the XIicPs instance.
 567 *
 568 * @return       Number of bytes still expected by the instance.
 569 *
 570 * @note         None.
 571 *
 572 ****************************************************************************/
 573 static s32 SlaveRecvData(XIicPs *InstancePtr)
 574 {
 575         u32 StatusReg;
 576         u32 BaseAddr;
 577
 578         BaseAddr = InstancePtr->Config.BaseAddress;
 579
 580         StatusReg = XIicPs_ReadReg(BaseAddr, XIICPS_SR_OFFSET);
 581
 582         while (((StatusReg & XIICPS_SR_RXDV_MASK)!=0x0U) &&
 583                         ((InstancePtr->RecvByteCount > 0) != 0x0U)) {
 584                 XIicPs_RecvByte(InstancePtr);
 585                 StatusReg = XIicPs_ReadReg(BaseAddr, XIICPS_SR_OFFSET);
 586         }
 587
 588         return InstancePtr->RecvByteCount;
 589 }
 590 /** @} */