sniff: add WT timeout detection using USART timeout (TC is not required)

Change-Id: I4ec6e812e7e1eb91005027d2e864fc315550d79c
This commit is contained in:
Kevin Redon 2018-06-27 16:42:56 +02:00
parent 15a3384e9a
commit 6123460055
1 changed files with 28 additions and 4 deletions

View File

@ -193,11 +193,9 @@ static void change_state(enum iso7816_3_sniff_state iso_state_new)
switch (iso_state_new) {
case ISO7816_S_RESET:
update_fidi(sniff_usart.base, 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;
@ -613,6 +611,30 @@ void Sniffer_usart_isr(void)
/* 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
@ -699,8 +721,10 @@ void Sniffer_init(void)
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);