Remove dp_low_read() and use exception protected dp_read()

src/exception.c

@@ -26,7 +26,6 @@ struct exception *innermost_exception;
 void raise_exception(uint32_t type, const char *msg)
 {
 	struct exception *e;
-	DEBUG_WARN("Exception: %s\n", msg);
 	for (e = innermost_exception; e; e = e->outer) {
 		if (e->mask & type) {
 			e->type = type;
@@ -35,6 +34,7 @@ void raise_exception(uint32_t type, const char *msg)
 			longjmp(e->jmpbuf, type);
 		}
 	}
+	DEBUG_WARN("Unhandled exception: %s\n", msg);
 	abort();
 }
 

src/platforms/hosted/cmsis_dap.c

@@ -415,36 +415,6 @@ int dap_jtag_dp_init(ADIv5_DP_t *dp)
 
 #define SWD_SEQUENCE_IN 0x80
 #define DAP_SWD_SEQUENCE 0x1d
-/* DAP_SWD_SEQUENCE does not do auto turnaround*/
-static bool dap_dp_low_read(ADIv5_DP_t *dp, uint16_t addr, uint32_t *res)
-{
-	(void)dp;
-	unsigned int paket_request = make_packet_request(ADIV5_LOW_READ, addr);
-	uint8_t buf[32] = {
-		DAP_SWD_SEQUENCE,
-		5,
-		8,
-		paket_request,
-		4 + SWD_SEQUENCE_IN,  /* one turn-around + read 3 bit ACK */
-		32 + SWD_SEQUENCE_IN, /* read 32 bit data */
-		1 + SWD_SEQUENCE_IN,  /* read parity bit */
-		1,                    /* one bit turn around to drive SWDIO */
-		0
-	};
-	dbg_dap_cmd(buf, sizeof(buf), 9);
-	if (buf[0])
-		DEBUG_WARN("dap_dp_low_read failed\n");
-	uint32_t ack = (buf[1] >> 1) & 7;
-	uint32_t data = (buf[2] << 0) + (buf[3] << 8) + (buf[4] << 16)
-		+ (buf[5] << 24);
-	int parity = __builtin_parity(data);
-	bool ret = ((parity != buf[6]) || (ack != 1));
-	*res = data;
-	DEBUG_PROBE("dap_dp_low_read ack %d, res %08" PRIx32 ", parity %s\n", ack,
-			   data, (ret)? "ERR": "OK");
-	return ret;
-}
-
 static bool dap_dp_low_write(ADIv5_DP_t *dp, uint16_t addr, const uint32_t data)
 {
 	DEBUG_PROBE("dap_dp_low_write %08" PRIx32 "\n", data);
@@ -485,7 +455,6 @@ int dap_swdptap_init(ADIv5_DP_t *dp)
 	dap_reset_link(false);
 	if (has_swd_sequence) {
 		/* DAP_SWD_SEQUENCE does not do auto turnaround, use own!*/
-		dp->dp_low_read = dap_dp_low_read;
 		dp->dp_low_write = dap_dp_low_write;
 	} else {
 		dp->error = dap_dp_error;

src/target/adiv5.h

@@ -173,8 +173,6 @@ typedef struct ADIv5_DP_s {
 	/* dp_low_write returns true if no OK resonse. */
 	bool (*dp_low_write)(struct ADIv5_DP_s *dp, uint16_t addr,
 						 const uint32_t data);
-	/* dp_low_read returns true with parity error */
-	bool (*dp_low_read)(struct ADIv5_DP_s *dp, uint16_t addr, uint32_t *data);
 	uint32_t (*dp_read)(struct ADIv5_DP_s *dp, uint16_t addr);
 	uint32_t (*error)(struct ADIv5_DP_s *dp);
 	uint32_t (*low_access)(struct ADIv5_DP_s *dp, uint8_t RnW,

src/target/adiv5_swdp.c

@@ -61,14 +61,6 @@ bool firmware_dp_low_write(ADIv5_DP_t *dp, uint16_t addr, const uint32_t data)
 	return (res != 1);
 }
 
-static bool firmware_dp_low_read(ADIv5_DP_t *dp, uint16_t addr, uint32_t *res)
-{
-	unsigned int request =  make_packet_request(ADIV5_LOW_READ, addr & 0xf);
-	dp->seq_out(request, 8);
-	dp->seq_in(3);
-    return dp->seq_in_parity(res, 32);
-}
-
 /* Try first the dormant to SWD procedure.
  * If target id given, scan DPs 0 .. 15 on that device and return.
  * Otherwise
@@ -78,7 +70,6 @@ int adiv5_swdp_scan(uint32_t targetid)
 	target_list_free();
 	ADIv5_DP_t idp = {
 		.dp_low_write = firmware_dp_low_write,
-		.dp_low_read = firmware_dp_low_read,
 		.error = firmware_swdp_error,
 		.dp_read = firmware_swdp_read,
 		.low_access = firmware_swdp_low_access,
@@ -108,8 +99,7 @@ int adiv5_swdp_scan(uint32_t targetid)
 		dp_line_reset(initial_dp);
 		volatile struct exception e;
 		TRY_CATCH (e, EXCEPTION_ALL) {
-			idcode = initial_dp->low_access(initial_dp, ADIV5_LOW_READ,
+			idcode = initial_dp->dp_read(initial_dp, ADIV5_DP_IDCODE);
-										   ADIV5_DP_IDCODE, 0);
 		}
 		if (e.type || initial_dp->fault) {
 			is_v2 = false;
@@ -121,8 +111,7 @@ int adiv5_swdp_scan(uint32_t targetid)
 			initial_dp->fault = 0;
 			volatile struct exception e2;
 			TRY_CATCH (e2, EXCEPTION_ALL) {
-				idcode = initial_dp->low_access(initial_dp, ADIV5_LOW_READ,
+				idcode = initial_dp->dp_read(initial_dp, ADIV5_DP_IDCODE);
-									  ADIV5_DP_IDCODE, 0);
 			}
 			if (e2.type || initial_dp->fault) {
 				DEBUG_WARN("No usable DP found\n");
@@ -153,16 +142,19 @@ int adiv5_swdp_scan(uint32_t targetid)
 	} else {
 		target_id = targetid;
 	}
-	int nr_dps = (is_v2) ? 16: 1;
+	volatile int nr_dps = (is_v2) ? 16: 1;
-	uint32_t dp_targetid;
+	volatile uint32_t dp_targetid;
-	for (int i = 0; i < nr_dps; i++) {
+	for (volatile int i = 0; i < nr_dps; i++) {
 		if (is_v2) {
 			dp_line_reset(initial_dp);
 			dp_targetid = (i << 28) | (target_id & 0x0fffffff);
 			initial_dp->dp_low_write(initial_dp, ADIV5_DP_TARGETSEL,
 									dp_targetid);
-			if (initial_dp->dp_low_read(initial_dp, ADIV5_DP_IDCODE,
+			volatile struct exception e;
-										&idcode)) {
+			TRY_CATCH (e, EXCEPTION_ALL) {
+				idcode = initial_dp->dp_read(initial_dp, ADIV5_DP_IDCODE);
+			}
+			if (e.type || initial_dp->fault) {
 				continue;
 			}
 		} else {
@@ -202,8 +194,8 @@ uint32_t firmware_swdp_read(ADIv5_DP_t *dp, uint16_t addr)
 		 * => Reselect with right target! */
 		dp_line_reset(dp);
 		dp->dp_low_write(dp, ADIV5_DP_TARGETSEL, dp->targetid);
-		uint32_t dummy;
+		dp->dp_read(dp, ADIV5_DP_IDCODE);
-		dp->dp_low_read(dp, ADIV5_DP_IDCODE, &dummy);
+		/* Exception here is unexpected, so do not catch */
 	}
 	uint32_t err, clr = 0;
 	err = adiv5_dp_read(dp, ADIV5_DP_CTRLSTAT) &