cardem: use TC_ETU to trigger ATR sending

this changes how ATR is handled.
the ATR is also printed when set (as important debug information).
the test is also updated to correspond to the new mechanism (
simulating the timeout before sending the ATR)

Change-Id: I69df797e2feadffa9f5f977cb71b69386cee7cd0

1 files changed, 76 insertions, 22 deletions

diff --git a/firmware/libcommon/source/card_emu.c b/firmware/libcommon/source/card_emu.c
index 25ec36a..51fd923 100644
--- a/firmware/libcommon/source/card_emu.c
+++ b/firmware/libcommon/source/card_emu.c
@@ -1,6 +1,7 @@
 /* ISO7816-3 state machine for the card side
  *
  * (C) 2010-2017 by Harald Welte <laforge@gnumonks.org>
+ * (C) 2018 by sysmocom -s.f.m.c. GmbH, Author: Kevin Redon <kredon@sysmocom.de>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -296,32 +297,39 @@ static void card_set_state(struct card_handle *ch,
 		card_emu_uart_enable(ch->uart_chan, 0);
 		break;
 	case ISO_S_WAIT_ATR:
-		set_pts_state(ch, PTS_S_WAIT_REQ_PTSS);
 		/* Reset to initial Fi / Di ratio */
 		ch->fi = 1;
 		ch->di = 1;
 		emu_update_fidi(ch);
+		/* the ATR should only be sent 400 to 40k clock cycles after the RESET.
+		 * we use the tc_etu mechanism to wait this time.
+		 * since the initial ETU is Fd=372/Dd=1 clock cycles long, we have to wait 2-107 ETU.
+		 */
+		tc_etu_set_wtime(ch->tc_chan, 2);
+		/* ensure the TC_ETU timer is enabled */
+		tc_etu_enable(ch->tc_chan);
+		break;
+	case ISO_S_IN_ATR:
 		/* initialize to default WI, this will be overwritten if we
-		 * receive TC2, and it will be programmed into hardware after
+		 * send TC2, and it will be programmed into hardware after
 		 * ATR is finished */
 		ch->wi = ISO7816_3_DEFAULT_WI;
 		/* update waiting time to initial waiting time */
 		ch->waiting_time = ISO7816_3_INIT_WTIME;
+		/* set initial waiting time */
 		tc_etu_set_wtime(ch->tc_chan, ch->waiting_time);
 		/* Set ATR sub-state to initial state */
 		ch->atr.idx = 0;
-		//set_atr_state(ch, ATR_S_WAIT_TS);
-		/* Notice that we are just coming out of reset */
-		//ch->sh.flags |= SIMTRACE_FLAG_ATR;
+		/* enable USART transmission to reader */
 		card_emu_uart_enable(ch->uart_chan, ENABLE_TX);
-		break;
+		/* trigger USART TX IRQ to sent first ATR byte TS */
+		card_emu_uart_interrupt(ch->uart_chan);
 		break;
 	case ISO_S_WAIT_TPDU:
 		/* enable the receiver, disable transmitter */
 		set_tpdu_state(ch, TPDU_S_WAIT_CLA);
 		card_emu_uart_enable(ch->uart_chan, ENABLE_RX);
 		break;
-	case ISO_S_IN_ATR:
 	case ISO_S_IN_PTS:
 	case ISO_S_IN_TPDU:
 		/* do nothing */
@@ -329,6 +337,47 @@ static void card_set_state(struct card_handle *ch,
 	}
 }
 
+/**********************************************************************
+ * ATR handling
+ **********************************************************************/
+
+/*! Transmit ATR data to reader
+ *  @param[in] ch card interface connected to reader
+ *  @return numbers of bytes transmitted
+ */
+static int tx_byte_atr(struct card_handle *ch)
+{
+	if (NULL == ch) {
+		TRACE_ERROR("ATR TX: no card handle provided\n\r");
+		return 0;
+	}
+	if (ISO_S_IN_ATR != ch->state) {
+		TRACE_ERROR("%u: ATR TX: no in ATR state\n\r", ch->num);
+		return 0;
+	}
+
+	/* Transmit ATR */
+	if (ch->atr.idx < ch->atr.len) {
+		uint8_t byte = ch->atr.atr[ch->atr.idx++];
+		card_emu_uart_tx(ch->uart_chan, byte);
+		TRACE_DEBUG("%u: ATR TX: %02x\n\r", ch->num, byte);
+		return 1;
+	} else { /* The ATR has been completely transmitted */
+		/* TODO update WI using optional TC2 and then update WT */
+		//ch->wi = ISO7816_3_DEFAULT_WI;
+		/* update waiting time */
+		//ch->waiting_time = ISO7816_3_INIT_WTIME;
+		//tc_etu_set_wtime(ch->tc_chan, ch->waiting_time);
+		/* reset PTS to initial state */
+		set_pts_state(ch, PTS_S_WAIT_REQ_PTSS);
+		/* go to next state */
+		card_set_state(ch, ISO_S_WAIT_TPDU);
+		return 0;
+	}
+
+	/* return number of bytes transmitted */
+	return 1;
+}
 
 /**********************************************************************
  * PTS / PPS handling
@@ -793,17 +842,7 @@ int card_emu_tx_byte(struct card_handle *ch)
 
 	switch (ch->state) {
 	case ISO_S_IN_ATR:
-		if (ch->atr.idx < ch->atr.len) {
-			uint8_t byte;
-			byte = ch->atr.atr[ch->atr.idx++];
-			rc = 1;
-
-			card_emu_uart_tx(ch->uart_chan, byte);
-
-			/* detect end of ATR */
-			if (ch->atr.idx >= ch->atr.len)
-				card_set_state(ch, ISO_S_WAIT_TPDU);
-		}
+		rc = tx_byte_atr(ch);
 		break;
 	case ISO_S_IN_PTS:
 		rc = tx_byte_pts(ch);
@@ -898,9 +937,8 @@ void card_emu_io_statechg(struct card_handle *ch, enum card_io io, int active)
 			if (ch->vcc_active && ch->clocked) {
 				/* enable the TC/ETU counter once reset has been released */
 				tc_etu_enable(ch->tc_chan);
+				/* prepare to send the ATR */
 				card_set_state(ch, ISO_S_WAIT_ATR);
-				/* FIXME: wait 400 to 40k clock cycles before sending ATR */
-				card_set_state(ch, ISO_S_IN_ATR);
 			}
 		} else if (active && !ch->in_reset) {
 			TRACE_INFO("%u: RST asserted\r\n", ch->num);
@@ -921,7 +959,15 @@ int card_emu_set_atr(struct card_handle *ch, const uint8_t *atr, uint8_t len)
 	ch->atr.len = len;
 	ch->atr.idx = 0;
 
-	/* FIXME: race condition with trasmitting ATR to reader? */
+#if TRACE_LEVEL >= TRACE_LEVEL_INFO 
+	uint8_t i;
+	TRACE_INFO("%u: ATR set: ", ch->num);
+	for (i = 0; i < ch->atr.len; i++) {
+		TRACE_INFO_WP("%02x ", atr[i]);
+	}
+	TRACE_INFO_WP("\n\r");
+#endif
+	/* FIXME: race condition with transmitting ATR to reader? */
 
 	return 0;
 }
@@ -952,7 +998,15 @@ void tc_etu_wtime_half_expired(void *handle)
 void tc_etu_wtime_expired(void *handle)
 {
 	struct card_handle *ch = handle;
-	TRACE_ERROR("%u: wtime_exp\r\n", ch->num);
+	switch (ch->state) {
+	case ISO_S_WAIT_ATR:
+		/* ISO 7816-3 6.2.1 time tc has passed, we can now send the ATR */
+		card_set_state(ch, ISO_S_IN_ATR);
+		break;
+	default:
+		TRACE_ERROR("%u: wtime_exp\r\n", ch->num);
+		break;
+	}
 }
 
 /* shortest ATR found in smartcard_list.txt */