Prevent late frames by spinning in SSC CP0 IRQ till end of short frame reception

Fix tc_cdiv_set_divider. again.
Reverse the polarity!   (of the ssc transmit clock)


git-svn-id: https://svn.openpcd.org:2342/trunk@381 6dc7ffe9-61d6-0310-9af1-9938baff3ed1

4 files changed, 34 insertions, 8 deletions

diff --git a/openpicc/application/decoder_miller.c b/openpicc/application/decoder_miller.c
index ca0a192..8f2aedb 100644
--- a/openpicc/application/decoder_miller.c
+++ b/openpicc/application/decoder_miller.c
@@ -46,14 +46,21 @@
 #include "openpicc.h"
 #include "dbgu.h"
 #include "decoder.h"
+#include "iso14443_layer3a.h"
 
-
+#ifdef FOUR_TIMES_OVERSAMPLING
 #define OVERSAMPLING_RATE	4
 
 /* definitions for four-times oversampling */
 #define SEQ_X	0x4
 #define SEQ_Y	0x0
 #define SEQ_Z	0x1
+#else
+#define OVERSAMPLING_RATE	2
+#define SEQ_X   0x2
+#define SEQ_Y   0x0
+#define SEQ_Z   0x1
+#endif
 
 /* decode a single sampled bit */
 static inline u_int8_t miller_decode_sampled_bit(u_int32_t sampled_bit)
diff --git a/openpicc/application/ssc_picc.c b/openpicc/application/ssc_picc.c
index 98f9e46..ce507fd 100644
--- a/openpicc/application/ssc_picc.c
+++ b/openpicc/application/ssc_picc.c
@@ -313,7 +313,7 @@ void ssc_tx_start(ssc_dma_tx_buffer_t *buf)
 	ssc->SSC_TFMR = ((data_len-1) & 0x1f) |
 			(((num_data-1) & 0x0f) << 8) | 
 			(((sync_len-1) & 0x0f) << 16);
-	ssc->SSC_TCMR = 0x01 | AT91C_SSC_CKO_NONE | start_cond;
+	ssc->SSC_TCMR = 0x01 | AT91C_SSC_CKO_NONE | AT91C_SSC_CKI | start_cond;
 	
 	AT91F_PDC_SetTx(tx_pdc, buf->data, num_data);
 	AT91F_PDC_SetNextTx(tx_pdc, 0, 0);
@@ -381,11 +381,27 @@ static void __ramfunc ssc_irq(void)
 	portBASE_TYPE task_woken = pdFALSE;
 
 	u_int32_t ssc_sr = ssc->SSC_SR;
+	u_int32_t orig_ssc_sr = ssc_sr;
 	int i, emptyframe = 0;
 	u_int32_t *tmp;
 	ssc_dma_rx_buffer_t *inbuf=NULL;
 	DEBUGP("ssc_sr=0x%08x, mode=%u: ", ssc_sr, ssc_state.mode);
 	
+	if (ssc_sr & AT91C_SSC_CP0 && ssc_state.mode == SSC_MODE_14443A_SHORT) {
+		/* Short frame, busy loop till the frame is received completely to
+		 * prevent a second irq entrance delay when the actual frame end 
+		 * irq is raised. (The scheduler masks interrupts for about 56us,
+		 * which is too much for anticollision.) */
+		 int i = 0;
+		 vLedBlinkRed();
+		 while( ! ((ssc_sr=ssc->SSC_SR) & AT91C_SSC_ENDRX) ) {
+		 	i++;
+		 	if(i > 9600) break;
+		 }
+		 ssc_sr |= orig_ssc_sr;
+		 vLedSetRed(1);
+	}
+	
 	if (ssc_sr & AT91C_SSC_ENDRX) {
 		/* Ignore empty frames */
 		if (ssc_state.mode == SSC_MODE_CONTINUOUS) {
diff --git a/openpicc/application/tc_cdiv.c b/openpicc/application/tc_cdiv.c
index d389214..08b8efe 100644
--- a/openpicc/application/tc_cdiv.c
+++ b/openpicc/application/tc_cdiv.c
@@ -27,11 +27,12 @@
 
 #include "openpicc.h"
 #include "tc_cdiv.h"
+#include "led.h"
 
 AT91PS_TCB tcb = AT91C_BASE_TCB;
 
 /* set carrier divider to a specific */
-void tc_cdiv_set_divider(u_int16_t div)
+void __ramfunc tc_cdiv_set_divider(u_int16_t div)
 {
 	tcb->TCB_TC0.TC_RC = div;
 
@@ -43,11 +44,13 @@ void tc_cdiv_set_divider(u_int16_t div)
 	 * In order to not lose phase information when doing that we'll busy wait till CV is
 	 * zero modulo the new RC.*/
 	/*tc_cdiv_phase_add(tcb->TCB_TC0.TC_RC-(tcb->TCB_TC0.TC_CV%tcb->TCB_TC0.TC_RC));*/
-	if(tcb->TCB_TC0.TC_CV > div) while(tcb->TCB_TC0.TC_CV % div != 0);
-	tcb->TCB_TC0.TC_CCR = AT91C_TC_SWTRG;
+	if(tcb->TCB_TC0.TC_CV > div) {
+		while(tcb->TCB_TC0.TC_CV % div != 0);
+		tcb->TCB_TC0.TC_CCR = AT91C_TC_SWTRG;
+	}
 }
 
-void tc_cdiv_phase_add(int16_t inc)
+void __ramfunc tc_cdiv_phase_add(int16_t inc)
 {
 	tcb->TCB_TC0.TC_RA = (tcb->TCB_TC0.TC_RA + inc) % tcb->TCB_TC0.TC_RC;
 	tcb->TCB_TC0.TC_RB = (tcb->TCB_TC0.TC_RB + inc) % tcb->TCB_TC0.TC_RC;
diff --git a/openpicc/application/tc_cdiv.h b/openpicc/application/tc_cdiv.h
index 33ff5b9..04d8ed0 100644
--- a/openpicc/application/tc_cdiv.h
+++ b/openpicc/application/tc_cdiv.h
@@ -7,8 +7,8 @@
 
 extern AT91PS_TCB tcb;
 
-extern void tc_cdiv_phase_add(int16_t inc);
-extern void tc_cdiv_set_divider(u_int16_t div);
+extern void __ramfunc tc_cdiv_phase_add(int16_t inc);
+extern void __ramfunc tc_cdiv_set_divider(u_int16_t div);
 
 static inline void tc_cdiv_phase_inc(void)
 {