From: Hellosun Wu <wujiheng.tw@gmail.com>
Date: Wed, 8 Nov 2017 09:04:11 +0000 (+0800)
Subject: nds32: Avoid detected JTAG clock
X-Git-Url: https://git.sur5r.net/?a=commitdiff_plain;h=e36c2f2da47a4f038b6c5647d135e0b6f8d3b708;p=openocd

nds32: Avoid detected JTAG clock

AICE2 doesn't support scan for the maximum clock frequency of
JTAG chain. It will cause USB command timeout.

Change-Id: I41d1e3be387b6ed5a4dd0be663385a5f053fbcf9
Signed-off-by: Hellosun Wu <wujiheng.tw@gmail.com>
Reviewed-on: http://openocd.zylin.com/4292
Tested-by: jenkins
Reviewed-by: Hsiangkai Wang <hsiangkai@gmail.com>
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>
---

diff --git a/src/jtag/aice/aice_usb.c b/src/jtag/aice/aice_usb.c
index 50468f37..d77b26b1 100644
--- a/src/jtag/aice/aice_usb.c
+++ b/src/jtag/aice/aice_usb.c
@@ -2289,37 +2289,39 @@ get_delay:
 
 static int aice_usb_set_clock(int set_clock)
 {
-	if (aice_write_ctrl(AICE_WRITE_CTRL_TCK_CONTROL,
-				AICE_TCK_CONTROL_TCK_SCAN) != ERROR_OK)
-		return ERROR_FAIL;
+	if (set_clock & AICE_TCK_CONTROL_TCK_SCAN) {
+		if (aice_write_ctrl(AICE_WRITE_CTRL_TCK_CONTROL,
+					AICE_TCK_CONTROL_TCK_SCAN) != ERROR_OK)
+			return ERROR_FAIL;
 
-	/* Read out TCK_SCAN clock value */
-	uint32_t scan_clock;
-	if (aice_read_ctrl(AICE_READ_CTRL_GET_ICE_STATE, &scan_clock) != ERROR_OK)
-		return ERROR_FAIL;
+		/* Read out TCK_SCAN clock value */
+		uint32_t scan_clock;
+		if (aice_read_ctrl(AICE_READ_CTRL_GET_ICE_STATE, &scan_clock) != ERROR_OK)
+			return ERROR_FAIL;
 
-	scan_clock &= 0x0F;
+		scan_clock &= 0x0F;
 
-	uint32_t scan_base_freq;
-	if (scan_clock & 0x8)
-		scan_base_freq = 48000; /* 48 MHz */
-	else
-		scan_base_freq = 30000; /* 30 MHz */
+		uint32_t scan_base_freq;
+		if (scan_clock & 0x8)
+			scan_base_freq = 48000; /* 48 MHz */
+		else
+			scan_base_freq = 30000; /* 30 MHz */
 
-	uint32_t set_base_freq;
-	if (set_clock & 0x8)
-		set_base_freq = 48000;
-	else
-		set_base_freq = 30000;
+		uint32_t set_base_freq;
+		if (set_clock & 0x8)
+			set_base_freq = 48000;
+		else
+			set_base_freq = 30000;
 
-	uint32_t set_freq;
-	uint32_t scan_freq;
-	set_freq = set_base_freq >> (set_clock & 0x7);
-	scan_freq = scan_base_freq >> (scan_clock & 0x7);
+		uint32_t set_freq;
+		uint32_t scan_freq;
+		set_freq = set_base_freq >> (set_clock & 0x7);
+		scan_freq = scan_base_freq >> (scan_clock & 0x7);
 
-	if (scan_freq < set_freq) {
-		LOG_ERROR("User specifies higher jtag clock than TCK_SCAN clock");
-		return ERROR_FAIL;
+		if (scan_freq < set_freq) {
+			LOG_ERROR("User specifies higher jtag clock than TCK_SCAN clock");
+			return ERROR_FAIL;
+		}
 	}
 
 	if (aice_write_ctrl(AICE_WRITE_CTRL_TCK_CONTROL, set_clock) != ERROR_OK)
diff --git a/src/jtag/aice/aice_usb.h b/src/jtag/aice/aice_usb.h
index 2911ae56..15cc1f60 100644
--- a/src/jtag/aice/aice_usb.h
+++ b/src/jtag/aice/aice_usb.h
@@ -71,6 +71,7 @@
 
 /* Constants for AICE command WRITE_CTRL:TCK_CONTROL */
 #define AICE_TCK_CONTROL_TCK3048		0x08
+#define AICE_TCK_CONTROL_TCK_SCAN		0x10
 
 /* Constants for AICE command WRITE_CTRL:JTAG_PIN_CONTROL */
 #define AICE_JTAG_PIN_CONTROL_SRST		0x01