drivers/rf/pn532/pn532_bus_i2c.c

   1 /**************************************************************************/
   2 /*!
   3     @file     pn532_bus_i2c.c
   4     @author   K. Townsend (microBuilder.eu)
   5
   6     @section LICENSE
   7
   8     Software License Agreement (BSD License)
   9
  10     Copyright (c) 2012, microBuilder SARL
  11     All rights reserved.
  12
  13     Redistribution and use in source and binary forms, with or without
  14     modification, are permitted provided that the following conditions are met:
  15     1. Redistributions of source code must retain the above copyright
  16     notice, this list of conditions and the following disclaimer.
  17     2. Redistributions in binary form must reproduce the above copyright
  18     notice, this list of conditions and the following disclaimer in the
  19     documentation and/or other materials provided with the distribution.
  20     3. Neither the name of the copyright holders nor the
  21     names of its contributors may be used to endorse or promote products
  22     derived from this software without specific prior written permission.
  23
  24     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
  25     EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  26     WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  27     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
  28     DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  29     (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  30     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  31     ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  32     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  33     SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  34 */
  35 /**************************************************************************/
  36 #include <string.h>
  37
  38 #include "pn532.h"
  39 #include "pn532_bus.h"
  40
  41 #ifdef PN532_BUS_I2C
  42
  43 #include "core/systick/systick.h"
  44 #include "core/gpio/gpio.h"
  45 #include "core/i2c/i2c.h"
  46
  47 extern volatile uint8_t   I2CMasterBuffer[I2C_BUFSIZE];
  48 extern volatile uint8_t   I2CSlaveBuffer[I2C_BUFSIZE];
  49 extern volatile uint32_t  I2CReadLength, I2CWriteLength;
  50
  51 /* ======================================================================
  52    PRIVATE FUNCTIONS
  53    ====================================================================== */
  54
  55 /**************************************************************************/
  56 /*!
  57     @brief  Writes an 8 bit value over I2C
  58
  59     @note   Possible error messages are:
  60
  61             - PN532_ERROR_I2C_NACK
  62 */
  63 /**************************************************************************/
  64 pn532_error_t pn532_bus_i2c_WriteData (const byte_t * pbtData, const size_t szData)
  65 {
  66   uint32_t i2cState;
  67
  68   // Clear write buffers
  69   uint32_t i;
  70   for ( i = 0; i < I2C_BUFSIZE; i++ )
  71   {
  72     I2CMasterBuffer[i] = 0x00;
  73   }
  74
  75   // Send the specified bytes
  76   I2CWriteLength = szData+1;
  77   I2CReadLength = 0;
  78   I2CMasterBuffer[0] = PN532_I2C_ADDRESS;         // I2C device address
  79   for ( i = 0; i < szData; i++ )
  80   {
  81     I2CMasterBuffer[i+1] = pbtData[i];
  82   }
  83   i2cState = i2cEngine();
  84
  85   // Check if we got an ACK
  86   if ((i2cState == I2CSTATE_NACK) || (i2cState == I2CSTATE_SLA_NACK))
  87   {
  88     // I2C slave didn't acknowledge the master transfer
  89     // The PN532 probably isn't connected properly or the
  90     // bus select pins are in the wrong state
  91     return PN532_ERROR_I2C_NACK;
  92   }
  93
  94   return PN532_ERROR_NONE;
  95 }
  96
  97 /**************************************************************************/
  98 /*!
  99     @brief    Checks the 'IRQ' pin to know if the PN532 is ready to send
 100               a response or not
 101
 102     @note     The IRQ bit may stay high intentionally, and this isn't
 103               always an error condition.  When PN532_COMMAND_INLISTPASSIVETARGET
 104               is sent, for example, the PN532 will wait until a card
 105               enters the magnetic field, and IRQ will remain high since
 106               there is no response ready yet.  The IRQ pin will go low
 107               as soon as a card enters the magentic field and the data
 108               has been retrieved from it.
 109
 110     @returns  1 if a response is ready, 0 if the PN532 is still busy or a
 111               timeout occurred
 112 */
 113 /**************************************************************************/
 114 uint8_t pn532_bus_i2c_WaitForReady(void)
 115 {
 116   uint8_t busy = 1;
 117   // uint8_t busyTimeout = 0;
 118
 119   while (busy)
 120   {
 121     // For now, we wait forever until a command is ready
 122     // ToDo: Add user-specified timeout
 123     busy = gpioGetValue(PN532_I2C_IRQPORT, PN532_I2C_IRQPIN);
 124     systickDelay(1);
 125     // busyTimeout++;
 126     // if (busyTimeout == PN532_I2C_READYTIMEOUT)
 127     // {
 128     //   return false;
 129     // }
 130   }
 131
 132   return true;
 133 }
 134
 135 /**************************************************************************/
 136 /*!
 137     @brief  Builds a standard PN532 frame using the supplied data
 138
 139     @param  pbtFrame  Pointer to the field that will hold the frame data
 140     @param  pszFrame  Pointer to the field that will hold the frame length
 141     @param  pbtData   Pointer to the data to insert in a frame
 142     @param  swData    Length of the data to insert in bytes
 143
 144     @note   Possible error messages are:
 145
 146             - PN532_ERROR_EXTENDEDFRAME
 147 */
 148 /**************************************************************************/
 149 pn532_error_t pn532_bus_i2c_BuildFrame(byte_t * pbtFrame, size_t * pszFrame, const byte_t * pbtData, const size_t szData)
 150 {
 151   if (szData > PN532_NORMAL_FRAME__DATA_MAX_LEN)
 152   {
 153     // Extended frames currently unsupported
 154     return PN532_ERROR_EXTENDEDFRAME;
 155   }
 156
 157   // LEN - Packet length = data length (len) + checksum (1) + end of stream marker (1)
 158   pbtFrame[3] = szData + 1;
 159   // LCS - Packet length checksum
 160   pbtFrame[4] = 256 - (szData + 1);
 161   // TFI
 162   pbtFrame[5] = 0xD4;
 163   // DATA - Copy the PN53X command into the packet buffer
 164   memcpy (pbtFrame + 6, pbtData, szData);
 165
 166   // DCS - Calculate data payload checksum
 167   byte_t btDCS = (256 - 0xD4);
 168   size_t szPos;
 169   for (szPos = 0; szPos < szData; szPos++)
 170   {
 171     btDCS -= pbtData[szPos];
 172   }
 173   pbtFrame[6 + szData] = btDCS;
 174
 175   // 0x00 - End of stream marker
 176   pbtFrame[szData + 7] = 0x00;
 177
 178   (*pszFrame) = szData + PN532_NORMAL_FRAME__OVERHEAD;
 179
 180   return PN532_ERROR_NONE;
 181 }
 182
 183 /* ======================================================================
 184    PUBLIC FUNCTIONS
 185    ====================================================================== */
 186
 187 /**************************************************************************/
 188 /*!
 189     @brief  Initialises I2C and configures the PN532 HW
 190 */
 191 /**************************************************************************/
 192 void pn532_bus_HWInit(void)
 193 {
 194   #ifdef PN532_DEBUGMODE
 195   PN532_DEBUG("Initialising I2C %s", CFG_PRINTF_NEWLINE);
 196   #endif
 197   i2cInit(I2CMASTER);
 198
 199   // Set IRQ pin to input
 200   gpioSetDir(PN532_I2C_IRQPORT, PN532_I2C_IRQPIN, gpioDirection_Input);
 201
 202   // Set reset pin as output and reset device
 203   gpioSetDir(PN532_RSTPD_PORT, PN532_RSTPD_PIN, gpioDirection_Output);
 204   #ifdef PN532_DEBUGMODE
 205   PN532_DEBUG("Resetting the PN532...\r\n");
 206   #endif
 207   gpioSetValue(PN532_RSTPD_PORT, PN532_RSTPD_PIN, 0);
 208   systickDelay(400);
 209   gpioSetValue(PN532_RSTPD_PORT, PN532_RSTPD_PIN, 1);
 210
 211   // Wait for the PN532 to finish booting
 212   systickDelay(100);
 213 }
 214
 215 /**************************************************************************/
 216 /*!
 217     @brief  Sends the specified command to the PN532, automatically
 218             creating an appropriate frame for it
 219
 220     @param  pdbData   Pointer to the byte data to send
 221     @param  szData    Length in bytes of the data to send
 222
 223     @note   Possible error messages are:
 224
 225             - PN532_ERROR_EXTENDEDFRAME       // Extended frames not supported
 226             - PN532_ERROR_BUSY                // Already busy with a command
 227             - PN532_ERROR_I2C_NACK            // No ACK on I2C
 228             - PN532_ERROR_READYSTATUSTIMEOUT  // Timeout waiting for ready bit
 229             - PN532_ERROR_INVALIDACK          // No ACK frame received
 230 */
 231 /**************************************************************************/
 232 pn532_error_t pn532_bus_SendCommand(const byte_t * pbtData, const size_t szData)
 233 {
 234   pn532_error_t error = PN532_ERROR_NONE;
 235   pn532_pcb_t *pn532 = pn532GetPCB();
 236
 237   // Check if we're busy
 238   if (pn532->state == PN532_STATE_BUSY)
 239   {
 240     return PN532_ERROR_BUSY;
 241   }
 242
 243   // Flag the stack as busy
 244   pn532->state = PN532_STATE_BUSY;
 245
 246   // --------------------------------------------------------------------
 247   // Send the command frame
 248   // --------------------------------------------------------------------
 249   byte_t abtFrame[PN532_BUFFER_LEN] = { 0x00, 0x00, 0xff };
 250   size_t szFrame = 0;
 251
 252   // Build the frame
 253   pn532_bus_i2c_BuildFrame (abtFrame, &szFrame, pbtData, szData);
 254
 255   // Keep track of the last command that was sent
 256   pn532->lastCommand = pbtData[0];
 257
 258   // Output the frame data for debugging if requested
 259   #ifdef PN532_DEBUGMODE
 260   PN532_DEBUG("Sending  (%02d): ", szFrame);
 261   pn532PrintHex(abtFrame, szFrame);
 262   #endif
 263
 264   // Send data to the PN532
 265   error = pn532_bus_i2c_WriteData(abtFrame, szFrame);
 266
 267   if (error == PN532_ERROR_I2C_NACK)
 268   {
 269     // Most likely error is PN532_ERROR_I2C_NACK
 270     // meaning no I2C ACK received from the PN532
 271     #ifdef PN532_DEBUGMODE
 272     PN532_DEBUG ("No ACK received on I2C bus%s", CFG_PRINTF_NEWLINE);
 273     #endif
 274     pn532->state = PN532_STATE_READY;
 275     return error;
 276   }
 277
 278   // --------------------------------------------------------------------
 279   // Wait for the IRQ/Ready flag
 280   // --------------------------------------------------------------------
 281   if (!(pn532_bus_i2c_WaitForReady()))
 282   {
 283     pn532->state = PN532_STATE_READY;
 284     #ifdef PN532_DEBUGMODE
 285     PN532_DEBUG ("Timed out waiting for IRQ/Ready%s", CFG_PRINTF_NEWLINE);
 286     #endif
 287     return PN532_ERROR_READYSTATUSTIMEOUT;
 288   }
 289
 290   // --------------------------------------------------------------------
 291   // Read the ACK frame
 292   // --------------------------------------------------------------------
 293   uint32_t i;
 294   // Clear buffer
 295   for ( i = 0; i < I2C_BUFSIZE; i++ )
 296   {
 297     I2CMasterBuffer[i] = 0x00;
 298   }
 299   I2CWriteLength = 0;
 300   I2CReadLength = 7;  // ACK + Ready bit = 7
 301   I2CMasterBuffer[0] = PN532_I2C_ADDRESS | PN532_I2C_READBIT;
 302   i2cEngine();
 303
 304   // Make sure the received ACK matches the prototype
 305   const byte_t abtAck[6] = { 0x00, 0x00, 0xff, 0x00, 0xff, 0x00 };
 306   byte_t abtRxBuf[6];
 307   // memcpy(abtRxBuf, I2CSlaveBuffer+1, 6);
 308   for ( i = 0; i < 6; i++ )
 309   {
 310     abtRxBuf[i] = I2CSlaveBuffer[i+1];
 311   }
 312   if (0 != (memcmp (abtRxBuf, abtAck, 6)))
 313   {
 314     #ifdef PN532_DEBUGMODE
 315     PN532_DEBUG ("Invalid ACK: ");
 316     pn532PrintHex(abtRxBuf, 6);
 317     PN532_DEBUG("%s", CFG_PRINTF_NEWLINE);
 318     #endif
 319     pn532->state = PN532_STATE_READY;
 320     return PN532_ERROR_INVALIDACK;
 321   }
 322
 323   // --------------------------------------------------------------------
 324   // Wait for the post-ACK IRQ/Ready flag
 325   // --------------------------------------------------------------------
 326   if (!(pn532_bus_i2c_WaitForReady()))
 327   {
 328     pn532->state = PN532_STATE_READY;
 329     #ifdef PN532_DEBUGMODE
 330     PN532_DEBUG ("Timed out waiting for IRQ/Ready%s", CFG_PRINTF_NEWLINE);
 331     #endif
 332     return PN532_ERROR_READYSTATUSTIMEOUT;
 333   }
 334
 335   pn532->state = PN532_STATE_READY;
 336   return PN532_ERROR_NONE;
 337 }
 338
 339 /**************************************************************************/
 340 /*!
 341     @brief  Reads a response from the PN532
 342
 343     @note   Possible error message are:
 344
 345             - PN532_ERROR_BUSY
 346             - PN532_ERROR_RESPONSEBUFFEREMPTY
 347             - PN532_ERROR_PREAMBLEMISMATCH
 348             - PN532_ERROR_APPLEVELERROR
 349             - PN532_ERROR_EXTENDEDFRAME
 350             - PN532_ERROR_LENCHECKSUMMISMATCH
 351 */
 352 /**************************************************************************/
 353 pn532_error_t pn532_bus_ReadResponse(byte_t * pbtResponse, size_t * pszRxLen)
 354 {
 355   pn532_pcb_t *pn532 = pn532GetPCB();
 356
 357   // Check if we're busy
 358   if (pn532->state == PN532_STATE_BUSY)
 359   {
 360     return PN532_ERROR_BUSY;
 361   }
 362
 363   // Flag the stack as busy
 364   pn532->state = PN532_STATE_BUSY;
 365
 366   // Reset the app error flag
 367   pn532->appError = PN532_APPERROR_NONE;
 368
 369   uint32_t i;
 370   for ( i = 0; i < I2C_BUFSIZE; i++ )
 371   {
 372     I2CMasterBuffer[i] = 0x00;
 373   }
 374   I2CWriteLength = 0;
 375   I2CReadLength = I2C_BUFSIZE;
 376   I2CMasterBuffer[0] = PN532_I2C_ADDRESS | PN532_I2C_READBIT;
 377   i2cEngine();
 378
 379   // Display the raw response data for debugging if requested
 380   #ifdef PN532_DEBUGMODE
 381   PN532_DEBUG("Received (%02d): ", I2C_BUFSIZE-1);
 382   pn532PrintHex(pbtResponse, I2C_BUFSIZE-1);
 383   #endif
 384
 385   // Use the full I2C buffer size for now (until we're sure we have a good frame)
 386   *pszRxLen = I2C_BUFSIZE - 1;
 387
 388   // Fill the response buffer from I2C (skipping the leading 'ready' bit when using I2C)
 389   // memcpy(pbtResponse, I2CSlaveBuffer+1, I2C_BUFSIZE-1);
 390   for ( i = 0; i < I2C_BUFSIZE-1; i++ )
 391   {
 392     pbtResponse[i] = I2CSlaveBuffer[i+1];
 393   }
 394
 395   // Check the frame type
 396   if ((0x01 == pbtResponse[3]) && (0xff == pbtResponse[4]))
 397   {
 398     // Error frame
 399     #ifdef PN532_DEBUGMODE
 400     PN532_DEBUG("Application level error (0x%02x)%s", pbtResponse[5], CFG_PRINTF_NEWLINE);
 401     #endif
 402     // Set application error message ID
 403     pn532->appError = pbtResponse[5];
 404     pn532->state = PN532_STATE_READY;
 405     return PN532_ERROR_APPLEVELERROR;
 406   }
 407   else if ((0xff == pbtResponse[3]) && (0xff == pbtResponse[4]))
 408   {
 409     // Extended frame
 410     #ifdef PN532_DEBUGMODE
 411     PN532_DEBUG("Extended frames currently unsupported%s", CFG_PRINTF_NEWLINE);
 412     #endif
 413     pn532->state = PN532_STATE_READY;
 414     return PN532_ERROR_EXTENDEDFRAME;
 415   }
 416   else
 417   {
 418     // Normal frame
 419     if (256 != (pbtResponse[3] + pbtResponse[4]))
 420     {
 421       // TODO: Retry
 422       #ifdef PN532_DEBUGMODE
 423       PN532_DEBUG("Length checksum mismatch%s", CFG_PRINTF_NEWLINE);
 424       #endif
 425       pn532->state = PN532_STATE_READY;
 426       return PN532_ERROR_LENCHECKSUMMISMATCH;
 427     }
 428   }
 429
 430   // Figure out how large the response really is
 431   // Response Frame Len = pbtResponse[3] + 7 (00 00 FF LEN LCS TFI [DATA] DCS)
 432   *pszRxLen = pbtResponse[3] + 7;
 433
 434   pn532->state = PN532_STATE_READY;
 435   return PN532_ERROR_NONE;
 436 }
 437
 438 /**************************************************************************/
 439 /*!
 440     @brief      Sends the wakeup sequence to the PN532.
 441
 442     @note   Possible error message are:
 443
 444             - PN532_ERROR_BUSY
 445             - PN532_ERROR_I2C_NACK            // No I2C ACK
 446             - PN532_ERROR_READYSTATUSTIMEOUT  // Timed out waiting for ready bit
 447 */
 448 /**************************************************************************/
 449 pn532_error_t pn532_bus_Wakeup(void)
 450 {
 451   pn532_error_t error = PN532_ERROR_NONE;
 452   byte_t abtWakeUp[] = { 0x55,0x55,0x00,0x00,0x00,0x00,0x00,0xff,0x03,0xfd,0xd4,0x14,0x01,0x17,0x00,0x00,0xff,0x03,0xfd,0xd4,0x14,0x01,0x17,0x00 };
 453   uint32_t i;
 454
 455   pn532_pcb_t *pn532 = pn532GetPCB();
 456
 457   #ifdef PN532_DEBUGMODE
 458   PN532_DEBUG("Sending Wakeup Sequence%s", CFG_PRINTF_NEWLINE);
 459   #endif
 460   error = pn532_bus_i2c_WriteData(abtWakeUp,sizeof(abtWakeUp));
 461   systickDelay(100);
 462
 463   // Wait for the IRQ/Ready flag to indicate a response is ready
 464   if (!(pn532_bus_i2c_WaitForReady()))
 465   {
 466     error = PN532_ERROR_READYSTATUSTIMEOUT;
 467   }
 468
 469   // Read and discard the ACK frame
 470   for ( i = 0; i < I2C_BUFSIZE; i++ )
 471   {
 472     I2CMasterBuffer[i] = 0x00;
 473   }
 474   I2CWriteLength = 0;
 475   I2CReadLength = 7;  // ACK + Ready bit = 7
 476   I2CMasterBuffer[0] = PN532_I2C_ADDRESS | PN532_I2C_READBIT;
 477   i2cEngine();
 478   systickDelay(1);
 479
 480   // Wait for the IRQ/Ready flag to indicate a response is ready
 481   if (!(pn532_bus_i2c_WaitForReady()))
 482   {
 483     error = PN532_ERROR_READYSTATUSTIMEOUT;
 484   }
 485
 486   pn532->state = PN532_STATE_READY;
 487   return error;
 488 }
 489
 490 #endif  // #ifdef PN532_BUS_I2C