sniff: add WT timeout detection using USART timeout (TC is not required)
Change-Id: I4ec6e812e7e1eb91005027d2e864fc315550d79c
diff --git a/firmware/libcommon/source/sniffer.c b/firmware/libcommon/source/sniffer.c
index bada46e..8a94c8a 100644
--- a/firmware/libcommon/source/sniffer.c
+++ b/firmware/libcommon/source/sniffer.c
@@ -193,11 +193,9 @@
switch (iso_state_new) {
case ISO7816_S_RESET:
update_fidi(&sniff_usart, 0x11); /* reset baud rate to default Di/Fi values */
- // TODO disable USART and TC
break;
case ISO7816_S_WAIT_ATR:
rbuf_reset(&sniff_buffer); /* reset buffer for new communication */
- // TODO enable USART and TC
break;
case ISO7816_S_IN_ATR:
atr_i = 0;
@@ -614,6 +612,30 @@
/* Store sniffed data into buffer (also clear interrupt */
rbuf_write(&sniff_buffer, byte);
}
+ /* Verify it WT timeout occurred, to detect unresponsive card */
+ if (csr & US_CSR_TIMEOUT) {
+ /* Stop timeout until next character is received */
+ sniff_usart.base->US_CR |= US_CR_STTTO;
+ /* Use timeout to detect end of ATR/PPS/TPDU */
+ switch (iso_state) {
+ case ISO7816_S_RESET:
+ case ISO7816_S_WAIT_ATR:
+ break;
+ case ISO7816_S_IN_ATR:
+ change_state(ISO7816_S_WAIT_ATR);
+ break;
+ case ISO7816_S_WAIT_TPDU:
+ break;
+ case ISO7816_S_WAIT_PPS_RSP:
+ case ISO7816_S_IN_TPDU:
+ case ISO7816_S_IN_PPS_REQ:
+ case ISO7816_S_IN_PPS_RSP:
+ change_state(ISO7816_S_WAIT_TPDU);
+ break;
+ default:
+ break;
+ }
+ }
}
/** PIO interrupt service routine to checks if the card reset line has changed
@@ -700,8 +722,10 @@
ISO7816_Init(&sniff_usart, CLK_SLAVE);
/* Only receive data when sniffing */
USART_SetReceiverEnabled(sniff_usart.base, 1);
- /* Enable interrupt to indicate when data has been received */
- USART_EnableIt(sniff_usart.base, US_IER_RXRDY);
+ /* Enable Receiver time-out WT to detect unresponsive cards */
+ sniff_usart.base->US_RTOR = 9600-12; /* -12 because the timer starts at the end of the 12 ETU frame */
+ /* Enable interrupt to indicate when data has been received or timeout occurred */
+ USART_EnableIt(sniff_usart.base, US_IER_RXRDY | US_IER_TIMEOUT);
/* Enable interrupt requests for the USART peripheral */
NVIC_EnableIRQ(IRQ_USART_SIM);