target/armv7m_trace: Calculate prescaler for external capture devices

[openocd.git] / src / target / armv7m_trace.c

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;