#include <jtag/swd.h>
#include <jtag/commands.h>
#include <jtag/drivers/jtag_usb_common.h>
+#include <target/cortex_m.h>
#include <libjaylink/libjaylink.h>
static unsigned int swd_buffer_size = JLINK_TAP_BUFFER_SIZE;
+/* Maximum SWO frequency deviation. */
+#define SWO_MAX_FREQ_DEV 0.03
+
/* 256 byte non-volatile memory */
struct device_config {
uint8_t usb_address;
return tmp & 0xffffff00;
}
-static bool check_trace_freq(struct jaylink_swo_speed speed,
- uint32_t trace_freq)
+static bool calculate_swo_prescaler(unsigned int traceclkin_freq,
+ uint32_t trace_freq, uint16_t *prescaler)
{
- double min;
+ unsigned int presc;
double deviation;
+
+ presc = ((1.0 - SWO_MAX_FREQ_DEV) * traceclkin_freq) / trace_freq + 1;
+
+ if (presc > TPIU_ACPR_MAX_SWOSCALER)
+ return false;
+
+ deviation = fabs(1.0 - ((double)trace_freq * presc / traceclkin_freq));
+
+ if (deviation > SWO_MAX_FREQ_DEV)
+ return false;
+
+ *prescaler = presc;
+
+ return true;
+}
+
+static bool detect_swo_freq_and_prescaler(struct jaylink_swo_speed speed,
+ unsigned int traceclkin_freq, uint32_t *trace_freq,
+ uint16_t *prescaler)
+{
uint32_t divider;
+ unsigned int presc;
+ double deviation;
+
+ for (divider = speed.min_div; divider <= speed.max_div; divider++) {
+ *trace_freq = speed.freq / divider;
+ presc = ((1.0 - SWO_MAX_FREQ_DEV) * traceclkin_freq) / *trace_freq + 1;
- min = fabs(1.0 - (speed.freq / ((double)trace_freq * speed.min_div)));
+ if (presc > TPIU_ACPR_MAX_SWOSCALER)
+ break;
- for (divider = speed.min_div; divider < speed.max_div; divider++) {
- deviation = fabs(1.0 - (speed.freq / ((double)trace_freq * divider)));
+ deviation = fabs(1.0 - ((double)*trace_freq * presc / traceclkin_freq));
- if (deviation < 0.03) {
- LOG_DEBUG("Found suitable frequency divider %u with deviation of "
- "%.02f %%.", divider, deviation);
+ if (deviation <= SWO_MAX_FREQ_DEV) {
+ *prescaler = presc;
return true;
}
-
- if (deviation < min)
- min = deviation;
}
- LOG_ERROR("Selected trace frequency is not supported by the device. "
- "Please choose a different trace frequency.");
- LOG_ERROR("Maximum permitted deviation is 3.00 %%, but only %.02f %% "
- "could be achieved.", min * 100);
-
return false;
}
static int config_trace(bool enabled, enum tpiu_pin_protocol pin_protocol,
- uint32_t port_size, unsigned int *trace_freq)
+ uint32_t port_size, unsigned int *trace_freq,
+ unsigned int traceclkin_freq, uint16_t *prescaler)
{
int ret;
uint32_t buffer_size;
struct jaylink_swo_speed speed;
+ uint32_t divider;
+ uint32_t min_freq;
+ uint32_t max_freq;
if (!jaylink_has_cap(caps, JAYLINK_DEV_CAP_SWO)) {
LOG_ERROR("Trace capturing is not supported by the device.");
return ERROR_FAIL;
}
- if (!*trace_freq)
- *trace_freq = speed.freq / speed.min_div;
+ if (*trace_freq > 0) {
+ divider = speed.freq / *trace_freq;
+ min_freq = speed.freq / speed.max_div;
+ max_freq = speed.freq / speed.min_div;
+
+ if (*trace_freq > max_freq) {
+ LOG_INFO("Given SWO frequency too high, using %u Hz instead.",
+ max_freq);
+ *trace_freq = max_freq;
+ } else if (*trace_freq < min_freq) {
+ LOG_INFO("Given SWO frequency too low, using %u Hz instead.",
+ min_freq);
+ *trace_freq = min_freq;
+ } else if (*trace_freq != speed.freq / divider) {
+ *trace_freq = speed.freq / divider;
+
+ LOG_INFO("Given SWO frequency is not supported by the device, "
+ "using %u Hz instead.", *trace_freq);
+ }
- if (!check_trace_freq(speed, *trace_freq))
- return ERROR_FAIL;
+ if (!calculate_swo_prescaler(traceclkin_freq, *trace_freq,
+ prescaler)) {
+ LOG_ERROR("SWO frequency is not suitable. Please choose a "
+ "different frequency or use auto-detection.");
+ return ERROR_FAIL;
+ }
+ } else {
+ LOG_INFO("Trying to auto-detect SWO frequency.");
- LOG_DEBUG("Using %u bytes device memory for trace capturing.", buffer_size);
+ if (!detect_swo_freq_and_prescaler(speed, traceclkin_freq, trace_freq,
+ prescaler)) {
+ LOG_ERROR("Maximum permitted frequency deviation of %.02f %% "
+ "could not be achieved.", SWO_MAX_FREQ_DEV);
+ LOG_ERROR("Auto-detection of SWO frequency failed.");
+ return ERROR_FAIL;
+ }
+
+ LOG_INFO("Using SWO frequency of %u Hz.", *trace_freq);
+ }
ret = jaylink_swo_start(devh, JAYLINK_SWO_MODE_UART, *trace_freq,
buffer_size);
return ERROR_FAIL;
}
+ LOG_DEBUG("Using %u bytes device memory for trace capturing.",
+ buffer_size);
+
/*
* Adjust the SWD transaction buffer size as starting SWO capturing
* allocates device internal memory.