add SSC code

git-svn-id: https://svn.openpcd.org:2342/trunk@88 6dc7ffe9-61d6-0310-9af1-9938baff3ed1

3 files changed, 171 insertions, 1 deletions

diff --git a/openpcd/firmware/Makefile b/openpcd/firmware/Makefile
index f9bc515..387a1c0 100644
--- a/openpcd/firmware/Makefile
+++ b/openpcd/firmware/Makefile
@@ -75,7 +75,7 @@ SRC =
 SRCARM  = lib/lib_AT91SAM7.c src/pcd_enumerate.c src/fifo.c src/dbgu.c \
 	  src/led.c src/rc632.c src/rc632_highlevel.c src/req_ctx.c \
 	  src/trigger.c src/main.c src/syscalls.c src/pwm.c src/tc.c \
-	  src/usb_handler.c \
+	  src/usb_handler.c src/ssc.c \
 	  src/$(TARGET).c src/start/Cstartup_SAM7.c 
 
 SRCARM += src/rfid_layer2_iso14443a.c
diff --git a/openpcd/firmware/src/ssc.c b/openpcd/firmware/src/ssc.c
new file mode 100644
index 0000000..5be7171
--- /dev/null
+++ b/openpcd/firmware/src/ssc.c
@@ -0,0 +1,157 @@
+/* AT91SAM7 SSC controller routines for OpenPCD
+ * (C) 2006 by Harald Welte <hwelte@hmw-consulting.de>
+ *
+ * We use SSC for both TX and RX side.
+ *
+ * RX side is interconnected with MFOUT of RC632
+ *
+ * TX side is interconnected with MFIN of RC632
+ */
+
+#include <errno.h>
+#include <sys/types.h>
+#include <lib_AT91SAM7.h>
+
+#include "openpcd.h"
+#include "dbgu.h"
+
+static AT91PS_SSC ssc = AT91C_BASE_SSC;
+static AT91PS_PDC rx_pdc;
+
+struct ssc_state {
+	struct req_ctx *rx_ctx[2];
+};
+
+static struct ssc_state ssc_state;
+
+/* Try to refill RX dma descriptors. Return values:
+ *  0) no dma descriptors empty
+ *  1) filled next/secondary descriptor
+ *  2) filled both primary and secondary descriptor
+ * -1) no free request contexts to use
+ * -2) only one free request context, but two free descriptors
+ */
+static int8_t ssc_rx_refill(void)
+{
+	struct req_ctx *rctx;
+	
+	rctx = req_ctx_find_get(RCTX_STATE_FREE, RCTX_STATE_SSC_RX_BUSY);
+	if (!rctx) {
+		DEBUGPCRF("no rctx for refill!");
+		return -1;
+	}
+
+	if (AT91F_PDC_IsRxEmpty(rx_pdc)) {
+		DEBUGPCRF("filling primary SSC RX dma ctx");
+		AT91F_PDC_SetRx(rx_pdc, &rctx->rx.data[MAX_HDRSIZE],
+				MAX_REQSIZE);
+		ssc_state.rx_ctx[0] = rctx;
+
+		/* If primary is empty, secondary must be empty, too */
+		rctx = req_ctx_find_get(RCTX_STATE_FREE, 
+					RCTX_STATE_SSC_RX_BUSY);
+		if (!rctx) {
+			DEBUGPCRF("no rctx for secondary refill!");
+			return -2;
+		}
+	}
+
+	if (AT91F_PDC_IsNextRxEmpty(rx_pdc)) {
+		DEBUGPCRF("filling secondary SSC RX dma ctx");
+		AT91F_PDC_SetNextRx(rx_pdc, &rctx->rx.data[MAX_HDRSIZE],
+				    MAX_REQSIZE);
+		ssc_state.rx_ctx[1] = rctx;
+		return 2;
+	} else {
+		/* we were unable to fill*/
+		DEBUGPCRF("prim/secnd DMA busy, can't refill");
+		req_ctx_put(rctx);	
+		return 0;
+	}
+}
+
+static void ssc_irq(void)
+{
+	u_int32_t ssc_sr = ssc->SSC_SR;
+	DEBUGPCRF("ssc_sr=0x%08x", ssc_sr);
+
+	if (ssc_sr & (AT91C_SSC_ENDRX | AT91C_SSC_TXBUFE)) {
+		/* Mark primary RCTX as ready to send for usb */
+		req_ctx_set_state(ssc_state.rx_ctx[0], 
+				  RCTX_STATE_UDP_EP2_PENDING);
+		/* second buffer gets propagated to primary */
+		ssc_state.rx_ctx[0] = ssc_state.rx_ctx[1];
+		ssc_state.rx_ctx[1] = NULL;
+
+		if (ssc_sr & AT91C_SSC_TXBUFE) {
+			DEBUGPCRF("TXBUFE, shouldn't happen!");
+			req_ctx_set_state(ssc_state.rx_ctx[0],
+					  RCTX_STATE_UDP_EP2_PENDING);
+		}
+		ssc_rx_refill();
+	}
+
+	if (ssc_sr & AT91C_SSC_OVRUN)
+		DEBUGPCRF("Rx Overrun, shouldn't happen!");
+}
+
+void ssc_rx_start(void)
+{
+	DEBUGPCRF("starting SSC RX\n");	
+	/* 're'fill DMA descriptors */
+	//ssc_rx_refill();
+
+	/* Enable Reception */
+	AT91F_SSC_EnableRx(ssc);
+}
+
+void ssc_rx_stop(void)
+{
+	/* Disable reception */
+	AT91F_SSC_DisableRx(ssc);
+}
+
+void ssc_tx_init(void)
+{
+	/* IMPORTANT: Disable PA23 (PWM0) output, since it is connected to 
+	 * PA17 !! */
+	AT91F_PIO_CfgInput(AT91C_BASE_PIOA, OPENPCD_PIO_MFIN_PWM);
+	AT91F_PIO_CfgPeriph(AT91C_BASE_PIOA, OPENPCD_PIO_MFIN_SSC_TX | 
+			    OPENPCD_PIO_MFOUT_SSC_RX | OPENPCD_PIO_SSP_CKIN,
+			    0);
+}
+
+void ssc_rx_init(void)
+{
+	rx_pdc = (AT91PS_PDC) &(ssc->SSC_RPR);
+
+	AT91F_SSC_CfgPMC();
+	AT91F_AIC_ConfigureIt(AT91C_BASE_AIC, AT91C_ID_SSC,
+			      OPENPCD_IRQ_PRIO_SSC,
+			      AT91C_AIC_SRCTYPE_INT_HIGH_LEVEL, &ssc_irq);
+	AT91F_AIC_EnableIt(AT91C_BASE_AIC, AT91C_ID_SSC);
+
+	/* Reset */
+	ssc->SSC_CR = AT91C_SSC_SWRST;
+
+	/* don't divide clock */
+	ssc->SSC_CMR = 0;
+
+	ssc->SSC_RCMR = AT91C_SSC_CKS_RK | AT91C_SSC_CKO_NONE |
+			AT91C_SSC_START_CONTINOUS;
+	/* Data bits per Data N = 32-1,  Data words per Frame = 16-1*/
+	ssc->SSC_RFMR = 31 | AT91C_SSC_MSBF | (15 << 8);
+
+	/* Enable RX interrupts */
+	AT91F_SSC_EnableIt(ssc, AT91C_SSC_OVRUN |
+			   AT91C_SSC_ENDRX | AT91C_SSC_RXBUFF);
+}
+
+void ssc_fini(void)
+{
+	AT91F_SSC_DisableTx(ssc);
+	AT91F_SSC_DisableRx(ssc);
+	AT91F_SSC_DisableIt(ssc, 0xfff);
+	AT91F_PMC_DisablePeriphClock(AT91C_BASE_PMC, 
+				 ((unsigned int) 1 << AT91C_ID_SSC));
+}
diff --git a/openpcd/firmware/src/ssc.h b/openpcd/firmware/src/ssc.h
new file mode 100644
index 0000000..73450ab
--- /dev/null
+++ b/openpcd/firmware/src/ssc.h
@@ -0,0 +1,13 @@
+#ifndef _SSC_H
+#define _SSC_H
+
+extern void ssc_rx_start(void);
+extern void ssc_rx_stop(void);
+
+/* Rx/Tx initialization separate, since Tx disables PWM output ! */
+extern void ssc_tx_init(void);
+extern void ssc_rx_init(void);
+
+extern void ssc_fini(void);
+
+#endif