return ret;
}
-/* Called by libusb (as triggered by handle_event()) when a transfer comes in.
- * Only channel data comes in asynchronously, and all transfers for this are
- * queued up beforehand, so this just needs so chuck the incoming data onto
- * the libsigrok session bus.
- */
-static void receive_transfer(struct libusb_transfer *transfer)
+static void send_chunk(struct context *ctx, unsigned char *buf,
+ int num_samples)
{
struct sr_datafeed_packet packet;
struct sr_datafeed_analog analog;
- struct context *ctx;
float ch1, ch2, range;
int num_probes, data_offset, i;
- ctx = transfer->user_data;
- sr_dbg("hantek-dso: receive_transfer(): status %d received %d bytes",
- transfer->status, transfer->actual_length);
-
- if (transfer->actual_length == 0)
- /* Nothing to send to the bus. */
- return;
-
- ctx->current_transfer += transfer->actual_length;
- sr_dbg("hantek-dso: got %d of %d in frame", ctx->current_transfer, ctx->framesize * 2);
-
num_probes = (ctx->ch1_enabled && ctx->ch2_enabled) ? 2 : 1;
packet.type = SR_DF_ANALOG;
packet.payload = &analog;
/* TODO: support for 5xxx series 9-bit samples */
- analog.num_samples = transfer->actual_length / 2;
+ analog.num_samples = num_samples;
analog.mq = SR_MQ_VOLTAGE;
analog.unit = SR_UNIT_VOLT;
analog.data = g_try_malloc(analog.num_samples * sizeof(float) * num_probes);
/* TODO: support for 5xxx series 9-bit samples */
if (ctx->ch1_enabled) {
range = ((float)vdivs[ctx->voltage_ch1].p / vdivs[ctx->voltage_ch1].q) * 8;
- ch1 = range / 255 * *(transfer->buffer + i * 2 + 1);
+ ch1 = range / 255 * *(buf + i * 2 + 1);
/* Value is centered around 0V. */
ch1 -= range / 2;
analog.data[data_offset++] = ch1;
}
if (ctx->ch2_enabled) {
range = ((float)vdivs[ctx->voltage_ch2].p / vdivs[ctx->voltage_ch2].q) * 8;
- ch2 = range / 255 * *(transfer->buffer + i * 2);
+ ch2 = range / 255 * *(buf + i * 2);
ch2 -= range / 2;
analog.data[data_offset++] = ch2;
}
}
+ sr_session_send(ctx->cb_data, &packet);
+
+}
+
+/* Called by libusb (as triggered by handle_event()) when a transfer comes in.
+ * Only channel data comes in asynchronously, and all transfers for this are
+ * queued up beforehand, so this just needs so chuck the incoming data onto
+ * the libsigrok session bus.
+ */
+static void receive_transfer(struct libusb_transfer *transfer)
+{
+ struct sr_datafeed_packet packet;
+ struct context *ctx;
+ int num_samples, pre;
+
+ ctx = transfer->user_data;
+ sr_dbg("hantek-dso: receive_transfer(): status %d received %d bytes",
+ transfer->status, transfer->actual_length);
+
+ if (transfer->actual_length == 0)
+ /* Nothing to send to the bus. */
+ return;
+
+ num_samples = transfer->actual_length / 2;
+
+ sr_dbg("hantek-dso: got %d-%d/%d samples in frame", ctx->samp_received + 1,
+ ctx->samp_received + num_samples, ctx->framesize);
+
+ /* The device always sends a full frame, but the beginning of the frame
+ * doesn't represent the trigger point. The offset at which the trigger
+ * happened came in with the capture state, so we need to start sending
+ * from there up the session bus. The samples in the frame buffer before
+ * that trigger point came after the end of the device's frame buffer was
+ * reached, and it wrapped around to overwrite up until the trigger point.
+ */
+ if (ctx->samp_received < ctx->trigger_offset) {
+ /* Trigger point not yet reached. */
+ if (ctx->samp_received + num_samples < ctx->trigger_offset) {
+ /* The entire chunk is before the trigger point. */
+ memcpy(ctx->framebuf + ctx->samp_buffered * 2,
+ transfer->buffer, num_samples * 2);
+ ctx->samp_buffered += num_samples;
+ } else {
+ /* This chunk hits or overruns the trigger point.
+ * Store the part before the trigger fired, and
+ * send the rest up to the session bus. */
+ pre = ctx->trigger_offset - ctx->samp_received;
+ memcpy(ctx->framebuf + ctx->samp_buffered * 2,
+ transfer->buffer, pre * 2);
+ ctx->samp_buffered += pre;
+
+ /* The rest of this chunk starts with the trigger point. */
+ sr_dbg("hantek-dso: reached trigger point, %d samples buffered",
+ ctx->samp_buffered);
+
+ /* Avoid the corner case where the chunk ended at
+ * exactly the trigger point. */
+ if (num_samples > pre)
+ send_chunk(ctx, transfer->buffer + pre * 2,
+ num_samples - pre);
+ }
+ } else {
+ /* Already past the trigger point, just send it all out. */
+ send_chunk(ctx, transfer->buffer,
+ num_samples);
+ }
+
+ ctx->samp_received += num_samples;
+
+ /* Everything in this transfer was either copied to the buffer or
+ * sent to the session bus. */
g_free(transfer->buffer);
libusb_free_transfer(transfer);
- sr_session_send(ctx->cb_data, &packet);
- if (ctx->current_transfer >= ctx->framesize * 2) {
- /* That's the last chunk in this frame. */
+ if (ctx->samp_received >= ctx->framesize) {
+ /* That was the last chunk in this frame. Send the buffered
+ * pre-trigger samples out now, in one big chunk. */
+ sr_dbg("hantek-dso: end of frame, sending %d pre-trigger buffered samples",
+ ctx->samp_buffered);
+ send_chunk(ctx, ctx->framebuf, ctx->samp_buffered);
+
+ /* Mark the end of this frame. */
packet.type = SR_DF_FRAME_END;
sr_session_send(ctx->cb_data, &packet);
packet.type = SR_DF_END;
sr_session_send(ctx->cb_data, &packet);
} else {
- ctx->current_transfer = 0;
ctx->dev_state = NEW_CAPTURE;
}
}
struct sr_datafeed_packet packet;
struct timeval tv;
struct context *ctx;
+ int num_probes;
uint32_t trigger_offset;
uint8_t capturestate;
/* no data yet */
break;
case CAPTURE_READY_8BIT:
+ /* Remember where in the captured frame the trigger is. */
+ ctx->trigger_offset = trigger_offset;
+
+ num_probes = (ctx->ch1_enabled && ctx->ch2_enabled) ? 2 : 1;
+ ctx->framebuf = g_try_malloc(ctx->framesize * num_probes * 2);
+ ctx->samp_buffered = ctx->samp_received = 0;
+
/* Tell the scope to send us the first frame. */
if (dso_get_channeldata(ctx, receive_transfer) != SR_OK)
break;
projects / libsigrok.git / commitdiff