target/armv7m_trace: Calculate prescaler for external capture devices

This fixes a regression introduced in "2dc88e1479f29ef0141b05bfcd907ad9a3e2d54c"

Change-Id: I04dc19ed30118a4c499b83732700b2ee0fdb67b6
Signed-off-by: Marc Schink <dev@zapb.de>
Reviewed-on: http://openocd.zylin.com/5610
Tested-by: jenkins
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>

diff --git a/src/jtag/drivers/jlink.c b/src/jtag/drivers/jlink.c
index 80202ed29cb0bf861148929fab7c4096e7ff9bce..1baf3454e3f3aae3adfaf9e5519e8b82a7dc5995 100644 (file)
--- a/src/jtag/drivers/jlink.c
+++ b/src/jtag/drivers/jlink.c
@@ -1324,18 +1324,16 @@ static int config_trace(bool enabled, enum tpiu_pin_protocol pin_protocol,
        uint32_t min_freq;
        uint32_t max_freq;
 
+       trace_enabled = enabled;
+
        if (!jaylink_has_cap(caps, JAYLINK_DEV_CAP_SWO)) {
-               LOG_ERROR("Trace capturing is not supported by the device.");
-               return ERROR_FAIL;
-       }
+               if (!enabled)
+                       return ERROR_OK;
 
-       if (pin_protocol != TPIU_PIN_PROTOCOL_ASYNC_UART) {
-               LOG_ERROR("Selected pin protocol is not supported.");
+               LOG_ERROR("Trace capturing is not supported by the device.");
                return ERROR_FAIL;
        }
 
-       trace_enabled = enabled;
-
        ret = jaylink_swo_stop(devh);
 
        if (ret != JAYLINK_OK) {
@@ -1354,6 +1352,11 @@ static int config_trace(bool enabled, enum tpiu_pin_protocol pin_protocol,
                return ERROR_OK;
        }
 
+       if (pin_protocol != TPIU_PIN_PROTOCOL_ASYNC_UART) {
+               LOG_ERROR("Selected pin protocol is not supported.");
+               return ERROR_FAIL;
+       }
+
        buffer_size = calculate_trace_buffer_size();
 
        if (!buffer_size) {

diff --git a/src/target/armv7m_trace.c b/src/target/armv7m_trace.c
index 853362f7eab610ca5cf724e36498ff8307b35424..6b368f7a09c4ce65372f9324e97fa58c69f9bced 100644 (file)
--- a/src/target/armv7m_trace.c
+++ b/src/target/armv7m_trace.c
@@ -68,6 +68,22 @@ int armv7m_trace_tpiu_config(struct target *target)
        if (retval != ERROR_OK)
                return retval;
 
+       if (trace_config->config_type == TRACE_CONFIG_TYPE_EXTERNAL) {
+               prescaler = trace_config->traceclkin_freq / trace_config->trace_freq;
+
+               if (trace_config->traceclkin_freq % trace_config->trace_freq) {
+                       prescaler++;
+
+                       int trace_freq = trace_config->traceclkin_freq / prescaler;
+                       LOG_INFO("Can not obtain %u trace port frequency from %u "
+                               "TRACECLKIN frequency, using %u instead",
+                               trace_config->trace_freq, trace_config->traceclkin_freq,
+                               trace_freq);
+
+                       trace_config->trace_freq = trace_freq;
+               }
+       }
+
        if (!trace_config->trace_freq) {
                LOG_ERROR("Trace port frequency is 0, can't enable TPIU");
                return ERROR_FAIL;