minor iso14443a timing fixes to avoid select errors:

* take setup frame guard time (SFGT) into account
* adjust iso14a_timeout by FPGA delays
* don't give up on first WUPA. Retry several times

diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c
index 89ef23d484bfb836b776422c773a2702e2c65c57..a0fe232671e86418eda924b0c52857e58a03bb7e 100644 (file)
--- a/armsrc/iso14443a.c
+++ b/armsrc/iso14443a.c
@@ -189,33 +189,15 @@ void iso14a_set_trigger(bool enable) {
 
 
 void iso14a_set_timeout(uint32_t timeout) {
-       iso14a_timeout = timeout;
-       if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443A Timeout set to %ld (%dms)", iso14a_timeout, iso14a_timeout / 106);
+       iso14a_timeout = timeout - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/(16*8);
+       if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443A Timeout set to %ld (%dms)", timeout, timeout / 106);
 }
 
 
-static void iso14a_set_ATS_timeout(uint8_t *ats) {
-
-       uint8_t tb1;
-       uint8_t fwi; 
-       uint32_t fwt;
-       
-       if (ats[0] > 1) {                                                       // there is a format byte T0
-               if ((ats[1] & 0x20) == 0x20) {                  // there is an interface byte TB(1)
-                       if ((ats[1] & 0x10) == 0x10) {          // there is an interface byte TA(1) preceding TB(1)
-                               tb1 = ats[3];
-                       } else {
-                               tb1 = ats[2];
-                       }
-                       fwi = (tb1 & 0xf0) >> 4;                        // frame waiting indicator (FWI)
-                       fwt = 256 * 16 * (1 << fwi);            // frame waiting time (FWT) in 1/fc
-                       
-                       iso14a_set_timeout(fwt/(8*16));
-               }
-       }
+uint32_t iso14a_get_timeout(void) {
+       return iso14a_timeout + (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/(16*8);
 }
 
-
 //-----------------------------------------------------------------------------
 // Generate the parity value for a byte sequence
 //
@@ -1277,7 +1259,7 @@ static void PrepareDelayedTransfer(uint16_t delay)
 // Transmit the command (to the tag) that was placed in ToSend[].
 // Parameter timing:
 // if NULL: transfer at next possible time, taking into account
-//                     request guard time and frame delay time
+//                     request guard time, startup frame guard time and frame delay time
 // if == 0:    transfer immediately and return time of transfer
 // if != 0: delay transfer until time specified
 //-------------------------------------------------------------------------------------
@@ -1685,6 +1667,59 @@ int ReaderReceive(uint8_t *receivedAnswer, uint8_t *parity)
        return Demod.len;
 }
 
+
+static void iso14a_set_ATS_times(uint8_t *ats) {
+
+       uint8_t tb1;
+       uint8_t fwi, sfgi; 
+       uint32_t fwt, sfgt;
+       
+       if (ats[0] > 1) {                                                       // there is a format byte T0
+               if ((ats[1] & 0x20) == 0x20) {                  // there is an interface byte TB(1)
+                       if ((ats[1] & 0x10) == 0x10) {          // there is an interface byte TA(1) preceding TB(1)
+                               tb1 = ats[3];
+                       } else {
+                               tb1 = ats[2];
+                       }
+                       fwi = (tb1 & 0xf0) >> 4;                        // frame waiting time integer (FWI)
+                       if (fwi != 15) {
+                               fwt = 256 * 16 * (1 << fwi);    // frame waiting time (FWT) in 1/fc
+                               iso14a_set_timeout(fwt/(8*16));
+                       }
+                       sfgi = tb1 & 0x0f;                                      // startup frame guard time integer (SFGI)
+                       if (sfgi != 0 && sfgi != 15) {
+                               sfgt = 256 * 16 * (1 << sfgi);  // startup frame guard time (SFGT) in 1/fc
+                               NextTransferTime = MAX(NextTransferTime, Demod.endTime + (sfgt - DELAY_AIR2ARM_AS_READER - DELAY_ARM2AIR_AS_READER)/16);
+                       }
+               }
+       }
+}
+
+
+static int GetATQA(uint8_t *resp, uint8_t *resp_par) {
+
+#define WUPA_RETRY_TIMEOUT     10      // 10ms
+       uint8_t wupa[]       = { 0x52 };  // 0x26 - REQA  0x52 - WAKE-UP
+
+       uint32_t save_iso14a_timeout = iso14a_get_timeout();
+       iso14a_set_timeout(1236/(16*8)+1);              // response to WUPA is expected at exactly 1236/fc. No need to wait longer.
+       
+       uint32_t start_time = GetTickCount();
+       int len;
+       
+       // we may need several tries if we did send an unknown command or a wrong authentication before...
+       do {
+               // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
+               ReaderTransmitBitsPar(wupa, 7, NULL, NULL);
+               // Receive the ATQA
+               len = ReaderReceive(resp, resp_par);
+       } while (len == 0 && GetTickCount() <= start_time + WUPA_RETRY_TIMEOUT);
+                       
+       iso14a_set_timeout(save_iso14a_timeout);
+       return len;
+}
+
+
 // performs iso14443a anticollision (optional) and card select procedure
 // fills the uid and cuid pointer unless NULL
 // fills the card info record unless NULL
@@ -1692,7 +1727,6 @@ int ReaderReceive(uint8_t *receivedAnswer, uint8_t *parity)
 // and num_cascades must be set (1: 4 Byte UID, 2: 7 Byte UID, 3: 10 Byte UID)
 // requests ATS unless no_rats is true
 int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, uint32_t *cuid_ptr, bool anticollision, uint8_t num_cascades, bool no_rats) {
-       uint8_t wupa[]       = { 0x52 };  // 0x26 - REQA  0x52 - WAKE-UP
        uint8_t sel_all[]    = { 0x93,0x20 };
        uint8_t sel_uid[]    = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
        uint8_t rats[]       = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
@@ -1712,11 +1746,9 @@ int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, u
                p_hi14a_card->ats_len = 0;
        }
 
-       // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
-    ReaderTransmitBitsPar(wupa, 7, NULL, NULL);
-       
-       // Receive the ATQA
-       if(!ReaderReceive(resp, resp_par)) return 0;
+       if (!GetATQA(resp, resp_par)) {
+               return 0;
+       }
 
        if(p_hi14a_card) {
                memcpy(p_hi14a_card->atqa, resp, 2);
@@ -1845,8 +1877,9 @@ int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, u
                // reset the PCB block number
                iso14_pcb_blocknum = 0;
 
-               // set default timeout based on ATS
-               iso14a_set_ATS_timeout(resp);
+               // set default timeout and delay next transfer based on ATS
+               iso14a_set_ATS_times(resp);
+               
        }
        return 1;       
 }