feat(nfc): probe ISO-DEP activation

ql-application/threadx/interface/custom_app/nfc.c

@@ -44,6 +44,10 @@ static volatile int g_nfc_irq_trigger = 0;
 #endif
 
 #if (NFC_WORK_MODE == NFC_WORK_MODE_CARD_EMULATION)
+#define NFC_CARD_FRAME_MAX          64
+#define NFC_CARD_SESSION_POLLS      200
+#define NFC_CARD_SESSION_POLL_MS    1
+
 static void nfc_card_emulation_log_status(const char *reason)
 {
     printf("NFC card emulation %s: cmd=%02X irq=%02X err=%02X status1=%02X status2=%02X fifo=%02X\r\n",
@@ -56,6 +60,52 @@ static void nfc_card_emulation_log_status(const char *reason)
            DP1312EA_ReadRawRC(FIFOLevelReg));
 }
 
+static u8 nfc_card_emulation_read_frame(u8 *frame, u8 capacity)
+{
+    u8 fifo_len = DP1312EA_ReadRawRC(FIFOLevelReg) & 0x7F;
+    u8 read_len = fifo_len;
+
+    if (read_len > capacity) {
+        read_len = capacity;
+    }
+
+    if (read_len > 0) {
+        DP1312EA_ReadFIFO(frame, read_len);
+    }
+
+    while (read_len < fifo_len) {
+        (void)DP1312EA_ReadRawRC(FIFODataReg);
+        read_len++;
+    }
+
+    return fifo_len > capacity ? capacity : fifo_len;
+}
+
+static void nfc_card_emulation_log_frame(const char *prefix,
+                                         const u8 *frame,
+                                         u8 length)
+{
+    u8 i;
+
+    printf("NFC %s (%u):", prefix, length);
+    for (i = 0; i < length; i++) {
+        printf(" %02X", frame[i]);
+    }
+    printf("\r\n");
+}
+
+static void nfc_card_emulation_send_frame(const u8 *frame, u8 length)
+{
+    DP1312EA_WriteRawRC(ComIrqReg, 0x7F);
+    DP1312EA_SetBitMask(FIFOLevelReg, 0x80);
+    DP1312EA_WriteFIFO((u8 *)frame, length);
+
+    /* AutoColl leaves Transceive active and waiting for StartSend. */
+    DP1312EA_SetBitMask(TxModeReg, 0x80);
+    DP1312EA_SetBitMask(RxModeReg, 0x80);
+    DP1312EA_WriteRawRC(BitFramingReg, 0x80);
+}
+
 static void nfc_card_emulation_start(void)
 {
     DP1312EA_WriteRawRC(CommandReg, DP1312EA_IDLE);
@@ -65,11 +115,19 @@ static void nfc_card_emulation_start(void)
 
     DP1312EA_Simulate_Card();
     nfc_card_emulation_log_status("started");
-    printf("NFC phase-1 target: ATQA=44 00, UID=08 AA BB CC, SAK=00\r\n");
+    printf("NFC phase-2 probe: ATQA=44 00, UID=08 AA BB CC, SAK=00\r\n");
 }
 
 static void nfc_card_emulation_task(void)
 {
+    static const u8 ats[] = {
+        0x03, /* TL: three ATS bytes */
+        0x24, /* TB(1) present, FSCI=4 (48-byte frame size) */
+        0x80  /* FWI=8 (~77 ms frame waiting time), SFGI=0 */
+    };
+    u8 frame[NFC_CARD_FRAME_MAX];
+    u8 frame_len;
+    u16 poll_count;
     u8 last_command = 0xFF;
     u8 command;
 
@@ -83,18 +141,50 @@ static void nfc_card_emulation_task(void)
             last_command = command;
         }
 
-        if (command != DP1312EA_AUTOCOLL) {
-            /*
-             * AutoColl normally exits after selection or on an RF/error event.
-             * Phase 1 has no ISO14443-4 handler yet, so allow the phone time to
-             * finish its probe, then arm AutoColl again for the next tap.
-             */
-            ql_rtos_task_sleep_ms(500);
+        if (command == DP1312EA_TRANSCEIVE) {
+            frame_len = nfc_card_emulation_read_frame(frame, sizeof(frame));
+            nfc_card_emulation_log_frame("activation RX", frame, frame_len);
+
+            if (frame_len == 2 && frame[0] == 0xE0) {
+                nfc_card_emulation_send_frame(ats, sizeof(ats));
+                nfc_card_emulation_log_frame("ATS TX", ats, sizeof(ats));
+
+                for (poll_count = 0;
+                     poll_count < NFC_CARD_SESSION_POLLS;
+                     poll_count++) {
+                    u8 irq = DP1312EA_ReadRawRC(ComIrqReg);
+                    u8 error = DP1312EA_ReadRawRC(ErrorReg);
+
+                    if (error != 0) {
+                        nfc_card_emulation_log_status("ISO-DEP error");
+                        break;
+                    }
+
+                    if ((irq & 0x20) != 0 &&
+                        (DP1312EA_ReadRawRC(FIFOLevelReg) & 0x7F) != 0) {
+                        frame_len = nfc_card_emulation_read_frame(
+                            frame, sizeof(frame));
+                        nfc_card_emulation_log_frame(
+                            "first ISO-DEP RX", frame, frame_len);
+                        break;
+                    }
+
+                    ql_rtos_task_sleep_ms(NFC_CARD_SESSION_POLL_MS);
+                }
+            } else {
+                printf("NFC activation frame is not RATS\r\n");
+            }
+
+            nfc_card_emulation_log_status("session complete");
+            nfc_card_emulation_start();
+            last_command = DP1312EA_AUTOCOLL;
+        } else if (command != DP1312EA_AUTOCOLL) {
+            nfc_card_emulation_log_status("unexpected command");
             nfc_card_emulation_start();
             last_command = DP1312EA_AUTOCOLL;
         }
 
-        ql_rtos_task_sleep_ms(20);
+        ql_rtos_task_sleep_ms(1);
     }
 }
 #endif
@@ -121,7 +211,7 @@ static void nfc_irq_wake(void *args)
 void ql_nfc_task_thread(void *arvg)
 {
 #if (NFC_WORK_MODE == NFC_WORK_MODE_CARD_EMULATION)
-    printf("NFC work mode: CARD_EMULATION (phase 1)\r\n");
+    printf("NFC work mode: CARD_EMULATION (phase 2 probe)\r\n");
     nfc_card_emulation_task();
 #else
     s8 read_status;