arm_adi_v5: put SWJ-DP back to JTAG mode at exit

When SWD mode is used, current OpenOCD code left the SWJ-DP in
SWD mode at exit. Also, current code is unable to switch back the
SWJ-DP in JTAG at next run, thus a power cycle of both target and
interface is required in order to run OpenOCD in JTAG mode again.

Put the SWJ-DP back to JTAG mode before exit from OpenOCD.

Use switch_seq(SWD_TO_JTAG) instead of dap_to_jtag(), because the
latter is not implemented on some interfaces. This is aligned
with the use of switch_seq(JTAG_TO_SWD) in swd_connect().

Change-Id: I55d3faebe60d6402037ec39dd9700dc5f17c53b0
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/4493
Tested-by: jenkins
Reviewed-by: Bohdan Tymkiv <bhdt@cypress.com>
Reviewed-by: Matthias Welwarsky <matthias@welwarsky.de>

src/target/adi_v5_swd.c

@@ -276,6 +276,16 @@ static int swd_run(struct adiv5_dap *dap)
 	return swd_run_inner(dap);
 }
 
+/** Put the SWJ-DP back to JTAG mode */
+static void swd_quit(struct adiv5_dap *dap)
+{
+	const struct swd_driver *swd = adiv5_dap_swd_driver(dap);
+
+	swd->switch_seq(SWD_TO_JTAG);
+	/* flush the queue before exit */
+	swd->run();
+}
+
 const struct dap_ops swd_dap_ops = {
 	.connect = swd_connect,
 	.queue_dp_read = swd_queue_dp_read,
@@ -284,6 +294,7 @@ const struct dap_ops swd_dap_ops = {
 	.queue_ap_write = swd_queue_ap_write,
 	.queue_ap_abort = swd_queue_ap_abort,
 	.run = swd_run,
+	.quit = swd_quit,
 };
 
 /*

src/target/arm_adi_v5.h

@@ -286,6 +286,9 @@ struct dap_ops {
 	/** Executes all queued DAP operations but doesn't check
 	 * sticky error conditions */
 	int (*sync)(struct adiv5_dap *dap);
+
+	/** Optional; called at OpenOCD exit */
+	void (*quit)(struct adiv5_dap *dap);
 };
 
 /*

src/target/arm_dap.c

@@ -132,8 +132,13 @@ static int dap_init_all(void)
 int dap_cleanup_all(void)
 {
 	struct arm_dap_object *obj, *tmp;
+	struct adiv5_dap *dap;
 
 	list_for_each_entry_safe(obj, tmp, &all_dap, lh) {
+		dap = &obj->dap;
+		if (dap->ops && dap->ops->quit)
+			dap->ops->quit(dap);
+
 		free(obj->name);
 		free(obj);
 	}