arm_adi_v5: Add ability to ignore the CSYSPWRUPACK bit

The CTRL/STAT register in the ARM DAP DP has a debug power up
ack bit and a system power up ack bit. Some devices do not set
the system power up ack bit until sometime later. To avoid having
the initial target examination fail due to this or to have a
sticky bit error report claim power failure due to this a user
can now specify that this bit should be ignored.

Change-Id: I2451234bbe904984e29562ef6f616cc6d6f60732
Signed-off-by: Eric Katzfey <eric.katzfey@mentalbee.com>
Signed-off-by: Matthias Welwarsky <matthias.welwarsky@sysgo.com>
Reviewed-on: http://openocd.zylin.com/3710
Tested-by: jenkins
Reviewed-by: Matthias Welwarsky <matthias@welwarsky.de>

5 files changed, 38 insertions, 10 deletions

diff --git a/doc/openocd.texi b/doc/openocd.texi
index 3069b37..967c637 100644
--- a/doc/openocd.texi
+++ b/doc/openocd.texi
@@ -3786,6 +3786,11 @@ a TAP doesn't conform to the JTAG specification.
 to verify that instruction scans work correctly.
 Such scans are not used by OpenOCD except to verify that
 there seems to be no problems with JTAG scan chain operations.
+@item @code{-ignore-syspwrupack}
+@*Specify this to ignore the CSYSPWRUPACK bit in the ARM DAP DP CTRL/STAT
+register during initial examination and when checking the sticky error bit.
+This bit is normally checked after setting the CSYSPWRUPREQ bit, but some
+devices do not set the ack bit until sometime later.
 @end itemize
 @end deffn
 
@@ -4021,11 +4026,21 @@ instead of "@option{-chain-position} @var{dotted.name}" when the target is creat
 
 The @command{dap} command group supports the following sub-commands:
 
-@deffn Command {dap create} dap_name @option{-chain-position} dotted.name
+@deffn Command {dap create} dap_name @option{-chain-position} dotted.name configparams...
 Declare a DAP instance named @var{dap_name} linked to the JTAG tap
 @var{dotted.name}. This also creates a new command (@command{dap_name})
 which is used for various purposes including additional configuration.
 There can only be one DAP for each JTAG tap in the system.
+
+A DAP may also provide optional @var{configparams}:
+
+@itemize @bullet
+@item @code{-ignore-syspwrupack}
+@*Specify this to ignore the CSYSPWRUPACK bit in the ARM DAP DP CTRL/STAT
+register during initial examination and when checking the sticky error bit.
+This bit is normally checked after setting the CSYSPWRUPREQ bit, but some
+devices do not set the ack bit until sometime later.
+@end itemize
 @end deffn
 
 @deffn Command {dap names}
diff --git a/src/target/adi_v5_jtag.c b/src/target/adi_v5_jtag.c
index dc02379..8c20611 100644
--- a/src/target/adi_v5_jtag.c
+++ b/src/target/adi_v5_jtag.c
@@ -553,7 +553,7 @@ static int jtagdp_overrun_check(struct adiv5_dap *dap)
 static int jtagdp_transaction_endcheck(struct adiv5_dap *dap)
 {
 	int retval;
-	uint32_t ctrlstat;
+	uint32_t ctrlstat, pwrmask;
 
 	/* too expensive to call keep_alive() here */
 
@@ -571,8 +571,10 @@ static int jtagdp_transaction_endcheck(struct adiv5_dap *dap)
 	if (ctrlstat & SSTICKYERR) {
 		LOG_DEBUG("jtag-dp: CTRL/STAT 0x%" PRIx32, ctrlstat);
 		/* Check power to debug regions */
-		if ((ctrlstat & (CDBGPWRUPREQ | CDBGPWRUPACK | CSYSPWRUPREQ | CSYSPWRUPACK)) !=
-						(CDBGPWRUPREQ | CDBGPWRUPACK | CSYSPWRUPREQ | CSYSPWRUPACK)) {
+		pwrmask = CDBGPWRUPREQ | CDBGPWRUPACK | CSYSPWRUPREQ;
+		if (!dap->ignore_syspwrupack)
+			pwrmask |= CSYSPWRUPACK;
+		if ((ctrlstat & pwrmask) != pwrmask) {
 			LOG_ERROR("Debug regions are unpowered, an unexpected reset might have happened");
 			dap->do_reconnect = true;
 		}
diff --git a/src/target/arm_adi_v5.c b/src/target/arm_adi_v5.c
index 2b7d7b2..f9b51cd 100644
--- a/src/target/arm_adi_v5.c
+++ b/src/target/arm_adi_v5.c
@@ -676,12 +676,14 @@ int dap_dp_init(struct adiv5_dap *dap)
 	if (retval != ERROR_OK)
 		return retval;
 
-	LOG_DEBUG("DAP: wait CSYSPWRUPACK");
-	retval = dap_dp_poll_register(dap, DP_CTRL_STAT,
-				      CSYSPWRUPACK, CSYSPWRUPACK,
-				      DAP_POWER_DOMAIN_TIMEOUT);
-	if (retval != ERROR_OK)
-		return retval;
+	if (!dap->ignore_syspwrupack) {
+		LOG_DEBUG("DAP: wait CSYSPWRUPACK");
+		retval = dap_dp_poll_register(dap, DP_CTRL_STAT,
+					      CSYSPWRUPACK, CSYSPWRUPACK,
+					      DAP_POWER_DOMAIN_TIMEOUT);
+		if (retval != ERROR_OK)
+			return retval;
+	}
 
 	retval = dap_queue_dp_read(dap, DP_CTRL_STAT, NULL);
 	if (retval != ERROR_OK)
diff --git a/src/target/arm_adi_v5.h b/src/target/arm_adi_v5.h
index aa5fa42..bc56116 100644
--- a/src/target/arm_adi_v5.h
+++ b/src/target/arm_adi_v5.h
@@ -244,6 +244,10 @@ struct adiv5_dap {
 	 * should be performed before the next access.
 	 */
 	bool do_reconnect;
+
+	/** Flag saying whether to ignore the syspwrupack flag in DAP. Some devices
+	 *  do not set this bit until later in the bringup sequence */
+	bool ignore_syspwrupack;
 };
 
 /**
diff --git a/src/target/arm_dap.c b/src/target/arm_dap.c
index 692feb3..797feb5 100644
--- a/src/target/arm_dap.c
+++ b/src/target/arm_dap.c
@@ -141,10 +141,12 @@ int dap_cleanup_all(void)
 
 enum dap_cfg_param {
 	CFG_CHAIN_POSITION,
+	CFG_IGNORE_SYSPWRUPACK,
 };
 
 static const Jim_Nvp nvp_config_opts[] = {
 	{ .name = "-chain-position",   .value = CFG_CHAIN_POSITION },
+	{ .name = "-ignore-syspwrupack", .value = CFG_IGNORE_SYSPWRUPACK },
 	{ .name = NULL, .value = -1 }
 };
 
@@ -177,6 +179,9 @@ static int dap_configure(Jim_GetOptInfo *goi, struct arm_dap_object *dap)
 			/* loop for more */
 			break;
 		}
+		case CFG_IGNORE_SYSPWRUPACK:
+			dap->dap.ignore_syspwrupack = true;
+			break;
 		default:
 			break;
 		}