target/riscv: remove duplicate `dtmcontrol_scan()`

Also avoid receiving data if the value is discarded on the call-site.

Change-Id: Ied87b551536a00d9fad469b9843cccae1976e6b6
Signed-off-by: Evgeniy Naydanov <evgeniy.naydanov@syntacore.com>

4 files changed, 19 insertions, 81 deletions

diff --git a/src/target/riscv/riscv-011.c b/src/target/riscv/riscv-011.c
index 0715de5..abb1c3b 100644
--- a/src/target/riscv/riscv-011.c
+++ b/src/target/riscv/riscv-011.c
@@ -273,38 +273,6 @@ static uint16_t dram_address(unsigned int index)
 		return 0x40 + index - 0x10;
 }
 
-static int dtmcontrol_scan(struct target *target, uint32_t out, uint32_t *in_ptr)
-{
-	struct scan_field field;
-	uint8_t in_value[4];
-	uint8_t out_value[4] = { 0 };
-
-	buf_set_u32(out_value, 0, 32, out);
-
-	jtag_add_ir_scan(target->tap, &select_dtmcontrol, TAP_IDLE);
-
-	field.num_bits = 32;
-	field.out_value = out_value;
-	field.in_value = in_value;
-	jtag_add_dr_scan(target->tap, 1, &field, TAP_IDLE);
-
-	/* Always return to dbus. */
-	jtag_add_ir_scan(target->tap, &select_dbus, TAP_IDLE);
-
-	int retval = jtag_execute_queue();
-	if (retval != ERROR_OK) {
-		LOG_ERROR("failed jtag scan: %d", retval);
-		return retval;
-	}
-
-	uint32_t in = buf_get_u32(field.in_value, 0, 32);
-	LOG_DEBUG("DTMCONTROL: 0x%x -> 0x%x", out, in);
-
-	if (in_ptr)
-		*in_ptr = in;
-	return ERROR_OK;
-}
-
 static uint32_t idcode_scan(struct target *target)
 {
 	struct scan_field field;
diff --git a/src/target/riscv/riscv-013.c b/src/target/riscv/riscv-013.c
index ae36a06..ab2f8e4 100644
--- a/src/target/riscv/riscv-013.c
+++ b/src/target/riscv/riscv-013.c
@@ -433,41 +433,6 @@ static void select_dmi(struct target *target)
 	jtag_add_ir_scan(target->tap, &select_dbus, TAP_IDLE);
 }
 
-static int dtmcontrol_scan(struct target *target, uint32_t out, uint32_t *in_ptr)
-{
-	struct scan_field field;
-	uint8_t in_value[4];
-	uint8_t out_value[4] = { 0 };
-
-	if (bscan_tunnel_ir_width != 0)
-		return dtmcontrol_scan_via_bscan(target, out, in_ptr);
-
-	buf_set_u32(out_value, 0, 32, out);
-
-	jtag_add_ir_scan(target->tap, &select_dtmcontrol, TAP_IDLE);
-
-	field.num_bits = 32;
-	field.out_value = out_value;
-	field.in_value = in_value;
-	jtag_add_dr_scan(target->tap, 1, &field, TAP_IDLE);
-
-	/* Always return to dmi. */
-	select_dmi(target);
-
-	int retval = jtag_execute_queue();
-	if (retval != ERROR_OK) {
-		LOG_ERROR("failed jtag scan: %d", retval);
-		return retval;
-	}
-
-	uint32_t in = buf_get_u32(field.in_value, 0, 32);
-	LOG_DEBUG("DTMCS: 0x%x -> 0x%x", out, in);
-
-	if (in_ptr)
-		*in_ptr = in;
-	return ERROR_OK;
-}
-
 static int increase_dmi_busy_delay(struct target *target)
 {
 	RISCV013_INFO(info);
diff --git a/src/target/riscv/riscv.c b/src/target/riscv/riscv.c
index 267d20d..b49cede 100644
--- a/src/target/riscv/riscv.c
+++ b/src/target/riscv/riscv.c
@@ -383,22 +383,23 @@ int dtmcontrol_scan_via_bscan(struct target *target, uint32_t out, uint32_t *in_
 	return ERROR_OK;
 }
 
-static int dtmcontrol_scan(struct target *target, uint32_t out, uint32_t *in_ptr)
+/* TODO: rename "dtmcontrol"-> "dtmcs" */
+int dtmcontrol_scan(struct target *target, uint32_t out, uint32_t *in_ptr)
 {
-	struct scan_field field;
-	uint8_t in_value[4];
-	uint8_t out_value[4] = { 0 };
+	uint8_t value[4];
 
 	if (bscan_tunnel_ir_width != 0)
 		return dtmcontrol_scan_via_bscan(target, out, in_ptr);
 
-	buf_set_u32(out_value, 0, 32, out);
+	buf_set_u32(value, 0, 32, out);
 
 	jtag_add_ir_scan(target->tap, &select_dtmcontrol, TAP_IDLE);
 
-	field.num_bits = 32;
-	field.out_value = out_value;
-	field.in_value = in_value;
+	struct scan_field field = {
+		.num_bits = 32,
+		.out_value = value,
+		.in_value = in_ptr ? value : NULL
+	};
 	jtag_add_dr_scan(target->tap, 1, &field, TAP_IDLE);
 
 	/* Always return to dbus. */
@@ -406,15 +407,18 @@ static int dtmcontrol_scan(struct target *target, uint32_t out, uint32_t *in_ptr
 
 	int retval = jtag_execute_queue();
 	if (retval != ERROR_OK) {
-		LOG_TARGET_ERROR(target, "dtmcontrol scan failed, error code = %d", retval);
+		LOG_TARGET_ERROR(target, "dtmcs scan failed, error code = %d", retval);
 		return retval;
 	}
 
-	uint32_t in = buf_get_u32(field.in_value, 0, 32);
-	LOG_DEBUG("DTMCONTROL: 0x%x -> 0x%x", out, in);
-
-	if (in_ptr)
+	if (in_ptr) {
+		assert(field.in_value);
+		uint32_t in = buf_get_u32(field.in_value, 0, 32);
+		LOG_TARGET_DEBUG(target, "DTMCS: 0x%" PRIx32 " -> 0x%" PRIx32, out, in);
 		*in_ptr = in;
+	} else {
+		LOG_TARGET_DEBUG(target, "DTMCS: 0x%" PRIx32 " -> ?", out);
+	}
 	return ERROR_OK;
 }
 
diff --git a/src/target/riscv/riscv.h b/src/target/riscv/riscv.h
index a25aac8..a3973e8 100644
--- a/src/target/riscv/riscv.h
+++ b/src/target/riscv/riscv.h
@@ -362,12 +362,13 @@ extern struct scan_field select_dtmcontrol;
 extern struct scan_field select_dbus;
 extern struct scan_field select_idcode;
 
+int dtmcontrol_scan(struct target *target, uint32_t out, uint32_t *in_ptr);
+
 extern struct scan_field *bscan_tunneled_select_dmi;
 extern uint32_t bscan_tunneled_select_dmi_num_fields;
 typedef enum { BSCAN_TUNNEL_NESTED_TAP, BSCAN_TUNNEL_DATA_REGISTER } bscan_tunnel_type_t;
 extern int bscan_tunnel_ir_width;
 
-int dtmcontrol_scan_via_bscan(struct target *target, uint32_t out, uint32_t *in_ptr);
 void select_dmi_via_bscan(struct target *target);
 
 /*** OpenOCD Interface */