simtrace: add TC based waiting time counter, signal ATR / expiry via USB

1 files changed, 124 insertions, 0 deletions

diff --git a/firmware/src/simtrace/tc_etu.c b/firmware/src/simtrace/tc_etu.c
new file mode 100644
index 0000000..93d2da0
--- /dev/null
+++ b/firmware/src/simtrace/tc_etu.c
@@ -0,0 +1,124 @@
+/* SimTrace TC (Timer / Clock) support code
+ * (C) 2006 by Harald Welte <hwelte@hmw-consulting.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 
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#include <lib_AT91SAM7.h>
+#include <AT91SAM7.h>
+#include <os/dbgu.h>
+
+#include "../openpcd.h"
+
+static AT91PS_TCB tcb;
+static AT91PS_TC tcetu = AT91C_BASE_TC0;
+
+static u_int16_t waiting_time = 9600;
+static u_int16_t clocks_per_etu = 372;
+static u_int16_t wait_events;
+
+static __ramfunc void tc_etu_irq(void)
+{
+	u_int32_t sr = tcetu->TC_SR;
+	static u_int16_t nr_events;
+
+	if (sr & AT91C_TC_ETRGS) {
+		/* external trigger, i.e. we have seen a bit on I/O */
+		//DEBUGPCR("tE");
+		nr_events = 0;
+		/* Make sure we don't accept any additional external trigger */
+		tcetu->TC_CMR &= ~AT91C_TC_ENETRG;
+	}
+
+	if (sr & AT91C_TC_CPCS) {
+		/* Compare C event has occurred, i.e. 1 etu expired */
+		//DEBUGPCR("tC");
+		nr_events++;
+		if (nr_events >= wait_events) {
+			/* enable external triggers again to catch start bit */
+			tcetu->TC_CMR |= AT91C_TC_ENETRG;
+
+			/* disable and re-enable clock to make it stop */
+			tcetu->TC_CCR = AT91C_TC_CLKDIS;
+			tcetu->TC_CCR = AT91C_TC_CLKEN;
+
+			//DEBUGPCR("%u", nr_events);
+
+			/* Indicate that the waiting time has expired */
+			iso7816_wtime_expired();
+		}
+	}
+}
+
+static void recalc_nr_events(void)
+{
+	wait_events = waiting_time/12;
+	/* clocks_per_etu * 12 equals 'sbit + 8 data bits + parity + 2 stop bits */
+	tcetu->TC_RC = clocks_per_etu * 12;
+}
+
+void tc_etu_set_wtime(u_int16_t wtime)
+{
+	waiting_time = wtime;
+	recalc_nr_events();
+}
+
+void tc_etu_set_etu(u_int16_t etu)
+{
+	clocks_per_etu = etu;
+	recalc_nr_events();
+}
+
+void tc_etu_init(void)
+{
+	/* Cfg PA4(TCLK0), PA0(TIOA0), PA1(TIOB0) */
+	AT91F_PIO_CfgPeriph(AT91C_BASE_PIOA, 0, 
+			    AT91C_PA4_TCLK0 | AT91C_PA0_TIOA0 | AT91C_PA1_TIOB0);
+
+	AT91F_PMC_EnablePeriphClock(AT91C_BASE_PMC, 
+				    ((unsigned int) 1 << AT91C_ID_TC0));
+
+	/* Connect TCLK0 to XC0 */
+	tcb->TCB_BMR &= ~(AT91C_TCB_TC0XC0S);
+	tcb->TCB_BMR |=  AT91C_TCB_TC0XC0S_TCLK0;
+
+	/* Register Interrupt handler */
+	AT91F_AIC_ConfigureIt(AT91C_BASE_AIC, AT91C_ID_TC0,
+			      OPENPCD_IRQ_PRIO_TC_FDT,
+			      AT91C_AIC_SRCTYPE_INT_HIGH_LEVEL, &tc_etu_irq);
+	AT91F_AIC_EnableIt(AT91C_BASE_AIC, AT91C_ID_TC0);
+
+	/* enable interrupts for Compare-C and External Trigger */
+	tcetu->TC_IER = AT91C_TC_CPCS | AT91C_TC_ETRGS;
+
+	tcetu->TC_CMR = AT91C_TC_CLKS_XC0 |	/* XC0 (TCLK0) clock */
+		        AT91C_TC_WAVE |		/* Wave Mode */
+		        AT91C_TC_ETRGEDG_FALLING |/* Ext trig on falling edge */
+		        AT91C_TC_EEVT_TIOB |	/* Ext trigger is TIOB0 */
+		        AT91C_TC_ENETRG | 	/* Enable ext. trigger */
+		        AT91C_TC_WAVESEL_UP_AUTO |/* Wave mode UP */
+		        AT91C_TC_ACPA_SET |	/* Set TIOA0 on A compare */
+		        AT91C_TC_ACPC_CLEAR |	/* Clear TIOA0 on C compare */
+		        AT91C_TC_ASWTRG_CLEAR;	/* Clear TIOa0 on software trigger */
+
+	tc_etu_set_etu(372);
+
+	/* Enable master clock for TC0 */
+	tcetu->TC_CCR = AT91C_TC_CLKEN;
+
+	/* Reset to start timers */
+	tcb->TCB_BCR = 1;
+}