topic: add reset functions for SWD

Add swd_init_reset and swd_add_reset.
Add adapter_assert_reset and adapter_deassert_reset, and call them instead
of JTAG reset functions.

Change-Id: Ib2551c6fbb45513e0ae0dc331cfe3ee3f922298a
Signed-off-by: Simon Qian <simonqian.openocd@gmail.com>
Reviewed-on: http://openocd.zylin.com/526
Tested-by: jenkins
Reviewed-by: Freddie Chopin <freddie.chopin@gmail.com>
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>

src/jtag/core.c

@@ -33,6 +33,7 @@
 #endif
 
 #include "jtag.h"
+#include "swd.h"
 #include "interface.h"
 #include <transport/transport.h>
 
@@ -606,6 +607,46 @@ void jtag_add_clocks(int num_cycles)
 	}
 }
 
+void swd_add_reset(int req_srst)
+{
+	if (req_srst) {
+		if (!(jtag_reset_config & RESET_HAS_SRST)) {
+			LOG_ERROR("BUG: can't assert SRST");
+			jtag_set_error(ERROR_FAIL);
+			return;
+		}
+		req_srst = 1;
+	}
+
+	/* Maybe change SRST signal state */
+	if (jtag_srst != req_srst) {
+		int retval;
+
+		retval = interface_jtag_add_reset(0, req_srst);
+		if (retval != ERROR_OK)
+			jtag_set_error(retval);
+		else
+			retval = jtag_execute_queue();
+
+		if (retval != ERROR_OK) {
+			LOG_ERROR("TRST/SRST error");
+			return;
+		}
+
+		/* SRST resets everything hooked up to that signal */
+		jtag_srst = req_srst;
+		if (jtag_srst) {
+			LOG_DEBUG("SRST line asserted");
+			if (adapter_nsrst_assert_width)
+				jtag_add_sleep(adapter_nsrst_assert_width * 1000);
+		} else {
+			LOG_DEBUG("SRST line released");
+			if (adapter_nsrst_delay)
+				jtag_add_sleep(adapter_nsrst_delay * 1000);
+		}
+	}
+}
+
 void jtag_add_reset(int req_tlr_or_trst, int req_srst)
 {
 	int trst_with_tlr = 0;
@@ -1455,6 +1496,20 @@ int adapter_quit(void)
 	return ERROR_OK;
 }
 
+int swd_init_reset(struct command_context *cmd_ctx)
+{
+	int retval = adapter_init(cmd_ctx);
+	if (retval != ERROR_OK)
+		return retval;
+
+	LOG_DEBUG("Initializing with hard SRST reset");
+
+	if (jtag_reset_config & RESET_HAS_SRST)
+		swd_add_reset(1);
+	swd_add_reset(0);
+	retval = jtag_execute_queue();
+	return retval;
+}
 
 int jtag_init_reset(struct command_context *cmd_ctx)
 {
@@ -1738,3 +1793,32 @@ bool transport_is_jtag(void)
 {
 	return get_current_transport() == &jtag_transport;
 }
+
+void adapter_assert_reset(void)
+{
+	if (transport_is_jtag()) {
+		if (jtag_reset_config & RESET_SRST_PULLS_TRST)
+			jtag_add_reset(1, 1);
+		else
+			jtag_add_reset(0, 1);
+	} else if (transport_is_swd())
+		swd_add_reset(1);
+	else if (get_current_transport() != NULL)
+		LOG_ERROR("reset is not supported on %s",
+			get_current_transport()->name);
+	else
+		LOG_ERROR("transport is not selected");
+}
+
+void adapter_deassert_reset(void)
+{
+	if (transport_is_jtag())
+		jtag_add_reset(0, 0);
+	else if (transport_is_swd())
+		swd_add_reset(0);
+	else if (get_current_transport() != NULL)
+		LOG_ERROR("reset is not supported on %s",
+			get_current_transport()->name);
+	else
+		LOG_ERROR("transport is not selected");
+}

src/jtag/interface.h

@@ -304,4 +304,7 @@ extern const char *jtag_only[];
 
 extern const struct swd_driver *swd;
 
+void adapter_assert_reset(void);
+void adapter_deassert_reset(void);
+
 #endif /* OPENOCD_JTAG_INTERFACE_H */

src/jtag/swd.h

@@ -17,6 +17,9 @@
  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  ***************************************************************************/
 
+#ifndef SWD_H
+#define SWD_H
+
 /* Bits in SWD command packets, written from host to target
  * first bit on the wire is START
  */
@@ -128,4 +131,9 @@ struct swd_driver {
 	int *(*trace)(bool swo);
 };
 
+int swd_init_reset(struct command_context *cmd_ctx);
+void swd_add_reset(int req_srst);
+
 bool transport_is_swd(void);
+
+#endif /* SWD_H */

src/jtag/tcl.c

@@ -33,6 +33,7 @@
 #endif
 
 #include "jtag.h"
+#include "swd.h"
 #include "minidriver.h"
 #include "interface.h"
 #include "interfaces.h"
@@ -672,6 +673,7 @@ static int jim_jtag_arp_init(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 
 static int jim_jtag_arp_init_reset(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 {
+	int e = ERROR_OK;
 	Jim_GetOptInfo goi;
 	Jim_GetOpt_Setup(&goi, interp, argc-1, argv + 1);
 	if (goi.argc != 0) {
@@ -679,7 +681,11 @@ static int jim_jtag_arp_init_reset(Jim_Interp *interp, int argc, Jim_Obj *const
 		return JIM_ERR;
 	}
 	struct command_context *context = current_command_context(interp);
-	int e = jtag_init_reset(context);
+	if (transport_is_jtag())
+		e = jtag_init_reset(context);
+	else if (transport_is_swd())
+		e = swd_init_reset(context);
+
 	if (e != ERROR_OK) {
 		Jim_Obj *eObj = Jim_NewIntObj(goi.interp, e);
 		Jim_SetResultFormatted(goi.interp, "error: %#s", eObj);