adi_v5: Fix wrong ap value

Problem
dap->ap_current is register value, not field value.
it restores invalid ap when it calls dap_ap_select(dap, ap_old) later.

* assume the current ap is 1, dap->ap_current value would be (1 << 24).
ap_old = dap->ap_current;   <-- ap_old = 1<<24 = 0x1000000.
...
dap_ap_select(dap, ap_old); <-- select 0x1000000, not 1.
* All AP registers accessing fail afterwards.

One of the reproducible case(s): CORE residents in AP >= 1
  dap_lookup_cs_component() being used to find PE(*).
  In most cases, PE would be found in AP==0, hence the problem is hidden.
  When AP number is 1, dap->ap_current would have the value of 1<<24.
  Anyone get the AP value with dap->ap_current and resotre it later would
  select the wrong AP and all accessing later would fail.

  The ARM Versatile and/or FPGA would have better chance to provide this
  kind of environment that PE residents in AP>=1. As they have an 'umbrella'
  system at AP0, and main system at AP>=1.

  * PE: Processing Element. AKA Core. See ARM Glossary at
    http://infocenter.arm.com/help/topic/com.arm.doc.aeg0014g/ABCDEFGH.html

Fix
Use dap_ap_get_select() to get ap value.
a. Retrieve current ap value by calling dap_ap_get_select();
     src/flash/nor/kinetis.c
     src/target/arm_adi_v5.c

b. The code is correct (dap->ap_current >> 24), but it's better to use
   dap_ap_get_select() so everything could be synchronized.
     src/flash/nor/sim3x.c

Change-Id: I97b5a13a3fc5506cf287e299c6c35699374de74f
Signed-off-by: Alamy Liu <alamy.liu@gmail.com>
Reviewed-on: http://openocd.zylin.com/2935
Reviewed-by: Andreas Färber <afaerber@suse.de>
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-by: Matthias Welwarsky <matthias@welwarsky.de>

3 files changed, 7 insertions, 7 deletions

diff --git a/src/flash/nor/kinetis.c b/src/flash/nor/kinetis.c
index ce5807ff..17952790 100644
--- a/src/flash/nor/kinetis.c
+++ b/src/flash/nor/kinetis.c
@@ -316,7 +316,7 @@ COMMAND_HANDLER(kinetis_mdm_mass_erase)
 	}
 
 	int retval;
-	const uint8_t original_ap = dap->ap_current;
+	const uint8_t original_ap = dap_ap_get_select(dap);
 
 	/*
 	 * ... Power on the processor, or if power has already been
@@ -420,7 +420,7 @@ COMMAND_HANDLER(kinetis_check_flash_security_status)
 
 	uint32_t val;
 	int retval;
-	const uint8_t origninal_ap = dap->ap_current;
+	const uint8_t origninal_ap = dap_ap_get_select(dap);
 
 	dap_ap_select(dap, 1);
 
diff --git a/src/flash/nor/sim3x.c b/src/flash/nor/sim3x.c
index 2a870028..0a5906c1 100644
--- a/src/flash/nor/sim3x.c
+++ b/src/flash/nor/sim3x.c
@@ -959,7 +959,7 @@ COMMAND_HANDLER(sim3x_mass_erase)
 		return ERROR_FAIL;
 	}
 
-	const uint8_t origninal_ap = dap->ap_current >> 24;
+	const uint8_t origninal_ap = dap_ap_get_select(dap);
 	dap_ap_select(dap, SIM3X_AP);
 
 	ret = ap_read_register(dap, SIM3X_AP_ID, &val);
@@ -1017,7 +1017,7 @@ COMMAND_HANDLER(sim3x_lock)
 			return ERROR_FAIL;
 		}
 	} else {
-		const uint8_t origninal_ap = dap->ap_current >> 24;
+		const uint8_t origninal_ap = dap_ap_get_select(dap);
 		dap_ap_select(dap, SIM3X_AP);
 
 		/* check SIM3X_AP_ID */
diff --git a/src/target/arm_adi_v5.c b/src/target/arm_adi_v5.c
index f7e58d08..c2929ef7 100644
--- a/src/target/arm_adi_v5.c
+++ b/src/target/arm_adi_v5.c
@@ -844,7 +844,7 @@ int dap_get_debugbase(struct adiv5_dap *dap, int ap,
 	if (ap >= 256)
 		return ERROR_COMMAND_SYNTAX_ERROR;
 
-	ap_old = dap->ap_current;
+	ap_old = dap_ap_get_select(dap);
 	dap_ap_select(dap, ap);
 
 	retval = dap_queue_ap_read(dap, AP_REG_BASE, dbgbase);
@@ -873,7 +873,7 @@ int dap_lookup_cs_component(struct adiv5_dap *dap, int ap,
 		return ERROR_COMMAND_SYNTAX_ERROR;
 
 	*addr = 0;
-	ap_old = dap->ap_current;
+	ap_old = dap_ap_get_select(dap);
 	dap_ap_select(dap, ap);
 
 	do {
@@ -1408,7 +1408,7 @@ static int dap_info_command(struct command_context *cmd_ctx,
 	if (retval != ERROR_OK)
 		return retval;
 
-	ap_old = dap->ap_current;
+	ap_old = dap_ap_get_select(dap);
 	dap_ap_select(dap, ap);
 
 	/* Now we read ROM table ID registers, ref. ARM IHI 0029B sec  */