arm_adi_v5: Split ahbap_debugport_init

This function does two separate things, powering up the DP and setting
up a MEM-AP. But the DP needs to be powered before even searching for a
MEM-AP to initialize and targets may have multiple MEM-APs that need
initializing.

Split the function into dap_dp_init() and mem_ap_init() and change all
call sites to use the appropriate one.

Change-Id: I92f55e09754a93f3f01dd8e5aa1ffdf60c856126
Signed-off-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
Reviewed-on: http://openocd.zylin.com/3151
Tested-by: jenkins
Reviewed-by: Matthias Welwarsky <matthias@welwarsky.de>

5 files changed, 74 insertions, 46 deletions

diff --git a/src/target/adi_v5_swd.c b/src/target/adi_v5_swd.c
index f832142..9bd1f93 100644
--- a/src/target/adi_v5_swd.c
+++ b/src/target/adi_v5_swd.c
@@ -112,7 +112,9 @@ static int swd_connect(struct adiv5_dap *dap)
 	/* Note, debugport_init() does setup too */
 	jtag_interface->swd->switch_seq(JTAG_TO_SWD);
 
+	/* Make sure we don't try to perform any other accesses before the DPIDR read. */
 	dap->do_reconnect = false;
+	dap->dp_bank_value = 0;
 
 	swd_queue_dp_read(dap, DP_IDCODE, &idcode);
 
diff --git a/src/target/arm_adi_v5.c b/src/target/arm_adi_v5.c
index 5d55d51..0cc1b5c 100644
--- a/src/target/arm_adi_v5.c
+++ b/src/target/arm_adi_v5.c
@@ -645,45 +645,33 @@ struct adiv5_dap *dap_init(void)
 		/* Number of bits for tar autoincrement, impl. dep. at least 10 */
 		dap->ap[i].tar_autoincr_block = (1<<10);
 	}
+	dap->ap_current = -1;
+	dap->ap_bank_value = -1;
+	dap->dp_bank_value = -1;
 	return dap;
 }
 
 /**
  * Initialize a DAP.  This sets up the power domains, prepares the DP
- * for further use, and arranges to use AP #0 for all AP operations
- * until dap_ap-select() changes that policy.
+ * for further use and activates overrun checking.
  *
  * @param dap The DAP being initialized.
- *
- * @todo Rename this.  We also need an initialization scheme which account
- * for SWD transports not just JTAG; that will need to address differences
- * in layering.  (JTAG is useful without any debug target; but not SWD.)
- * And this may not even use an AHB-AP ... e.g. DAP-Lite uses an APB-AP.
  */
-int ahbap_debugport_init(struct adiv5_ap *ap)
+int dap_dp_init(struct adiv5_dap *dap)
 {
-	/* check that we support packed transfers */
-	uint32_t csw, cfg;
 	int retval;
-	struct adiv5_dap *dap = ap->dap;
 
 	LOG_DEBUG(" ");
-
 	/* JTAG-DP or SWJ-DP, in JTAG mode
 	 * ... for SWD mode this is patched as part
 	 * of link switchover
+	 * FIXME: This should already be setup by the respective transport specific DAP creation.
 	 */
 	if (!dap->ops)
 		dap->ops = &jtag_dp_ops;
 
-	/* Default MEM-AP setup.
-	 *
-	 * REVISIT AP #0 may be an inappropriate default for this.
-	 * Should we probe, or take a hint from the caller?
-	 * Presumably we can ignore the possibility of multiple APs.
-	 */
 	dap->ap_current = -1;
-	dap_ap_select(dap, ap->ap_num);
+	dap->ap_bank_value = -1;
 	dap->last_read = NULL;
 
 	for (size_t i = 0; i < 10; i++) {
@@ -726,6 +714,7 @@ int ahbap_debugport_init(struct adiv5_ap *ap)
 		retval = dap_queue_dp_read(dap, DP_CTRL_STAT, NULL);
 		if (retval != ERROR_OK)
 			continue;
+
 		/* With debug power on we can activate OVERRUN checking */
 		dap->dp_ctrl_stat = CDBGPWRUPREQ | CSYSPWRUPREQ | CORUNDETECT;
 		retval = dap_queue_dp_write(dap, DP_CTRL_STAT, dap->dp_ctrl_stat);
@@ -735,18 +724,6 @@ int ahbap_debugport_init(struct adiv5_ap *ap)
 		if (retval != ERROR_OK)
 			continue;
 
-		retval = dap_setup_accessport(dap, CSW_8BIT | CSW_ADDRINC_PACKED, 0);
-		if (retval != ERROR_OK)
-			continue;
-
-		retval = dap_queue_ap_read(dap, MEM_AP_REG_CSW, &csw);
-		if (retval != ERROR_OK)
-			continue;
-
-		retval = dap_queue_ap_read(dap, MEM_AP_REG_CFG, &cfg);
-		if (retval != ERROR_OK)
-			continue;
-
 		retval = dap_run(dap);
 		if (retval != ERROR_OK)
 			continue;
@@ -754,6 +731,38 @@ int ahbap_debugport_init(struct adiv5_ap *ap)
 		break;
 	}
 
+	return retval;
+}
+
+/**
+ * Initialize a DAP.  This sets up the power domains, prepares the DP
+ * for further use, and arranges to use AP #0 for all AP operations
+ * until dap_ap-select() changes that policy.
+ *
+ * @param ap The MEM-AP being initialized.
+ */
+int mem_ap_init(struct adiv5_ap *ap)
+{
+	/* check that we support packed transfers */
+	uint32_t csw, cfg;
+	int retval;
+	struct adiv5_dap *dap = ap->dap;
+
+	dap_ap_select(dap, ap->ap_num);
+
+	retval = dap_setup_accessport(dap, CSW_8BIT | CSW_ADDRINC_PACKED, 0);
+	if (retval != ERROR_OK)
+		return retval;
+
+	retval = dap_queue_ap_read(dap, MEM_AP_REG_CSW, &csw);
+	if (retval != ERROR_OK)
+		return retval;
+
+	retval = dap_queue_ap_read(dap, MEM_AP_REG_CFG, &cfg);
+	if (retval != ERROR_OK)
+		return retval;
+
+	retval = dap_run(dap);
 	if (retval != ERROR_OK)
 		return retval;
 
diff --git a/src/target/arm_adi_v5.h b/src/target/arm_adi_v5.h
index faf725f..8672036 100644
--- a/src/target/arm_adi_v5.h
+++ b/src/target/arm_adi_v5.h
@@ -488,7 +488,8 @@ int mem_ap_sel_write_buf_noincr(struct adiv5_ap *ap,
 struct adiv5_dap *dap_init(void);
 
 /* Initialisation of the debug system, power domains and registers */
-int ahbap_debugport_init(struct adiv5_ap *ap);
+int dap_dp_init(struct adiv5_dap *dap);
+int mem_ap_init(struct adiv5_ap *ap);
 
 /* Probe the AP for ROM Table location */
 int dap_get_debugbase(struct adiv5_ap *ap,
diff --git a/src/target/cortex_a.c b/src/target/cortex_a.c
index f95985a..0923f88 100644
--- a/src/target/cortex_a.c
+++ b/src/target/cortex_a.c
@@ -2910,6 +2910,12 @@ static int cortex_a_examine_first(struct target *target)
 	int retval = ERROR_OK;
 	uint32_t didr, ctypr, ttypr, cpuid, dbg_osreg;
 
+	retval = dap_dp_init(swjdp);
+	if (retval != ERROR_OK) {
+		LOG_ERROR("Could not initialize the debug port");
+		return retval;
+	}
+
 	/* Search for the APB-AB - it is needed for access to debug registers */
 	retval = dap_find_ap(swjdp, AP_TYPE_APB_AP, &armv7a->debug_ap);
 	if (retval != ERROR_OK) {
@@ -2917,24 +2923,28 @@ static int cortex_a_examine_first(struct target *target)
 		return retval;
 	}
 
-	/* We do one extra read to ensure DAP is configured,
-	 * we call ahbap_debugport_init(swjdp) instead
-	 */
-	retval = ahbap_debugport_init(armv7a->debug_ap);
-	if (retval != ERROR_OK)
+	retval = mem_ap_init(armv7a->debug_ap);
+	if (retval != ERROR_OK) {
+		LOG_ERROR("Could not initialize the APB-AP");
 		return retval;
+	}
 
-	/* Search for the AHB-AB */
+	/* Search for the AHB-AB.
+	 * REVISIT: We should search for AXI-AP as well and make sure the AP's MEMTYPE says it
+	 * can access system memory. */
+	armv7a->memory_ap_available = false;
 	retval = dap_find_ap(swjdp, AP_TYPE_AHB_AP, &armv7a->memory_ap);
-	if (retval != ERROR_OK) {
+	if (retval == ERROR_OK) {
+		retval = mem_ap_init(armv7a->memory_ap);
+		if (retval == ERROR_OK)
+			armv7a->memory_ap_available = true;
+		else
+			LOG_WARNING("Could not initialize AHB-AP for memory access - using APB-AP");
+	} else {
 		/* AHB-AP not found - use APB-AP */
 		LOG_DEBUG("Could not find AHB-AP - using APB-AP for memory access");
-		armv7a->memory_ap_available = false;
-	} else {
-		armv7a->memory_ap_available = true;
 	}
 
-
 	if (!target->dbgbase_set) {
 		uint32_t dbgbase;
 		/* Get ROM Table base */
diff --git a/src/target/cortex_m.c b/src/target/cortex_m.c
index d92cfce..ca230f3 100644
--- a/src/target/cortex_m.c
+++ b/src/target/cortex_m.c
@@ -1063,7 +1063,7 @@ static int cortex_m_assert_reset(struct target *target)
 		if (retval != ERROR_OK)
 			LOG_DEBUG("Ignoring AP write error right after reset");
 
-		retval = ahbap_debugport_init(armv7m->debug_ap);
+		retval = dap_dp_init(armv7m->debug_ap->dap);
 		if (retval != ERROR_OK) {
 			LOG_ERROR("DP initialisation failed");
 			return retval;
@@ -1109,7 +1109,7 @@ static int cortex_m_deassert_reset(struct target *target)
 
 	if ((jtag_reset_config & RESET_HAS_SRST) &&
 	    !(jtag_reset_config & RESET_SRST_NO_GATING)) {
-		int retval = ahbap_debugport_init(armv7m->debug_ap);
+		int retval = dap_dp_init(armv7m->debug_ap->dap);
 		if (retval != ERROR_OK) {
 			LOG_ERROR("DP initialisation failed");
 			return retval;
@@ -1891,6 +1891,12 @@ int cortex_m_examine(struct target *target)
 	struct adiv5_dap *swjdp = cortex_m->armv7m.arm.dap;
 	struct armv7m_common *armv7m = target_to_armv7m(target);
 
+	retval = dap_dp_init(swjdp);
+	if (retval != ERROR_OK) {
+		LOG_ERROR("Could not initialize the debug port");
+		return retval;
+	}
+
 	/* Search for the MEM-AP */
 	retval = dap_find_ap(swjdp, AP_TYPE_AHB_AP, &armv7m->debug_ap);
 	if (retval != ERROR_OK) {
@@ -1904,7 +1910,7 @@ int cortex_m_examine(struct target *target)
 	/* stlink shares the examine handler but does not support
 	 * all its calls */
 	if (!armv7m->stlink) {
-		retval = ahbap_debugport_init(armv7m->debug_ap);
+		retval = mem_ap_init(armv7m->debug_ap);
 		if (retval != ERROR_OK)
 			return retval;
 	}