arm_adi_v5: add API send_sequence() and use it

The method to send an arbitrary sequence to DAP depends on the
transport and is thus different on JTAG and SWD. This is already
coded in dap_to_jtag() and dap_to_swd().

Add a new API send_sequence() in struct dap_ops.
Add the implementations of send_sequence() in adi_v5_jtag.c and
adi_v5_swd.c
Rewrite dap_to_jtag() and dap_to_swd() using the new API.
Move the enum swd_special_seq in arm_adi_v5.h to solve a circular
dependencies among swd.h and arm_adi_v5.h

Change-Id: I9db13a00f129761eab283783c094cfff2dd92610
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/4902
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>

src/jtag/swd.h

@@ -213,14 +213,6 @@ static const uint8_t swd_seq_dormant_to_jtag[] = {
 };
 static const unsigned swd_seq_dormant_to_jtag_len = 160;
 
-enum swd_special_seq {
-	LINE_RESET,
-	JTAG_TO_SWD,
-	SWD_TO_JTAG,
-	SWD_TO_DORMANT,
-	DORMANT_TO_SWD,
-};
-
 struct swd_driver {
 	/**
 	 * Initialize the debug link so it can perform SWD operations.

src/target/adi_v5_jtag.c

@@ -38,6 +38,7 @@
 #include "arm_adi_v5.h"
 #include <helper/time_support.h>
 #include <helper/list.h>
+#include <jtag/swd.h>
 
 /*#define DEBUG_WAIT*/
 
@@ -663,6 +664,28 @@ static int jtag_check_reconnect(struct adiv5_dap *dap)
 	return ERROR_OK;
 }
 
+static int jtag_send_sequence(struct adiv5_dap *dap, enum swd_special_seq seq)
+{
+	int retval;
+
+	switch (seq) {
+	case JTAG_TO_SWD:
+		retval =  jtag_add_tms_seq(swd_seq_jtag_to_swd_len,
+				swd_seq_jtag_to_swd, TAP_INVALID);
+		break;
+	case SWD_TO_JTAG:
+		retval = jtag_add_tms_seq(swd_seq_swd_to_jtag_len,
+				swd_seq_swd_to_jtag, TAP_RESET);
+		break;
+	default:
+		LOG_ERROR("Sequence %d not supported", seq);
+		return ERROR_FAIL;
+	}
+	if (retval == ERROR_OK)
+		retval = jtag_execute_queue();
+	return retval;
+}
+
 static int jtag_dp_q_read(struct adiv5_dap *dap, unsigned reg,
 		uint32_t *data)
 {
@@ -782,6 +805,7 @@ static int jtag_dp_sync(struct adiv5_dap *dap)
 */
 const struct dap_ops jtag_dp_ops = {
 	.connect             = jtag_connect,
+	.send_sequence       = jtag_send_sequence,
 	.queue_dp_read       = jtag_dp_q_read,
 	.queue_dp_write      = jtag_dp_q_write,
 	.queue_ap_read       = jtag_ap_q_read,

src/target/adi_v5_swd.c

@@ -142,6 +142,14 @@ static int swd_connect(struct adiv5_dap *dap)
 	return status;
 }
 
+static int swd_send_sequence(struct adiv5_dap *dap, enum swd_special_seq seq)
+{
+	const struct swd_driver *swd = adiv5_dap_swd_driver(dap);
+	assert(swd);
+
+	return swd->switch_seq(seq);
+}
+
 static inline int check_sync(struct adiv5_dap *dap)
 {
 	return do_sync ? swd_run_inner(dap) : ERROR_OK;
@@ -320,6 +328,7 @@ static void swd_quit(struct adiv5_dap *dap)
 
 const struct dap_ops swd_dap_ops = {
 	.connect = swd_connect,
+	.send_sequence = swd_send_sequence,
 	.queue_dp_read = swd_queue_dp_read,
 	.queue_dp_write = swd_queue_dp_write,
 	.queue_ap_read = swd_queue_ap_read,

src/target/arm_adi_v5.c

@@ -804,26 +804,9 @@ int mem_ap_init(struct adiv5_ap *ap)
  */
 int dap_to_swd(struct adiv5_dap *dap)
 {
-	int retval;
-
 	LOG_DEBUG("Enter SWD mode");
 
-	if (transport_is_jtag()) {
+	return dap_send_sequence(dap, JTAG_TO_SWD);
-		retval =  jtag_add_tms_seq(swd_seq_jtag_to_swd_len,
-				swd_seq_jtag_to_swd, TAP_INVALID);
-		if (retval == ERROR_OK)
-			retval = jtag_execute_queue();
-		return retval;
-	}
-
-	if (transport_is_swd()) {
-		const struct swd_driver *swd = adiv5_dap_swd_driver(dap);
-
-		return swd->switch_seq(JTAG_TO_SWD);
-	}
-
-	LOG_ERROR("Nor JTAG nor SWD transport");
-	return ERROR_FAIL;
 }
 
 /**
@@ -839,26 +822,9 @@ int dap_to_swd(struct adiv5_dap *dap)
  */
 int dap_to_jtag(struct adiv5_dap *dap)
 {
-	int retval;
-
 	LOG_DEBUG("Enter JTAG mode");
 
-	if (transport_is_jtag()) {
+	return dap_send_sequence(dap, SWD_TO_JTAG);
-		retval = jtag_add_tms_seq(swd_seq_swd_to_jtag_len,
-				swd_seq_swd_to_jtag, TAP_RESET);
-		if (retval == ERROR_OK)
-			retval = jtag_execute_queue();
-		return retval;
-	}
-
-	if (transport_is_swd()) {
-		const struct swd_driver *swd = adiv5_dap_swd_driver(dap);
-
-		return swd->switch_seq(SWD_TO_JTAG);
-	}
-
-	LOG_ERROR("Nor JTAG nor SWD transport");
-	return ERROR_FAIL;
 }
 
 /* CID interpretation -- see ARM IHI 0029B section 3

src/target/arm_adi_v5.h

@@ -158,6 +158,15 @@
 #define DP_APSEL_MAX        (255)
 #define DP_APSEL_INVALID    (-1)
 
+/* FIXME: not SWD specific; should be renamed, e.g. adiv5_special_seq */
+enum swd_special_seq {
+	LINE_RESET,
+	JTAG_TO_SWD,
+	SWD_TO_JTAG,
+	SWD_TO_DORMANT,
+	DORMANT_TO_SWD,
+};
+
 /**
  * This represents an ARM Debug Interface (v5) Access Port (AP).
  * Most common is a MEM-AP, for memory access.
@@ -291,6 +300,10 @@ struct adiv5_dap {
 struct dap_ops {
 	/** connect operation for SWD */
 	int (*connect)(struct adiv5_dap *dap);
+
+	/** send a sequence to the DAP */
+	int (*send_sequence)(struct adiv5_dap *dap, enum swd_special_seq seq);
+
 	/** DP register read. */
 	int (*queue_dp_read)(struct adiv5_dap *dap, unsigned reg,
 			uint32_t *data);
@@ -338,6 +351,21 @@ enum ap_type {
 	AP_TYPE_AHB5_AP = 0x5,  /* AHB5 Memory-AP. */
 };
 
+/**
+ * Send an adi-v5 sequence to the DAP.
+ *
+ * @param dap The DAP used for reading.
+ * @param seq The sequence to send.
+ *
+ * @return ERROR_OK for success, else a fault code.
+ */
+static inline int dap_send_sequence(struct adiv5_dap *dap,
+		enum swd_special_seq seq)
+{
+	assert(dap->ops != NULL);
+	return dap->ops->send_sequence(dap, seq);
+}
+
 /**
  * Queue a DP register read.
  * Note that not all DP registers are readable; also, that JTAG and SWD