demo: Implement logic triggering.

Analog triggers and other items still need more work.

src/hardware/demo/api.c

@@ -143,6 +143,8 @@ static GSList *scan(struct sr_dev_driver *di, GSList *options)
 	devc->logic_pattern = DEFAULT_LOGIC_PATTERN;
 	devc->num_analog_channels = num_analog_channels;
 	devc->limit_frames = limit_frames;
+	devc->capture_ratio = 20;
+	devc->stl = NULL;
 
 	if (num_logic_channels > 0) {
 		/* Logic channels, all in one channel group. */
@@ -434,6 +436,7 @@ static int dev_acquisition_start(const struct sr_dev_inst *sdi)
 	uint8_t mask;
 	GHashTableIter iter;
 	void *value;
+	struct sr_trigger *trigger;
 
 	devc = sdi->priv;
 	devc->sent_samples = 0;
@@ -499,6 +502,18 @@ static int dev_acquisition_start(const struct sr_dev_inst *sdi)
 	devc->spent_us = 0;
 	devc->step = 0;
 
+	/* Store Triggers to stl and preset trigger_fired */
+	if ((trigger = sr_session_trigger_get(sdi->session))) {
+		int pre_trigger_samples = 0;
+		if (devc->limit_samples > 0)
+			pre_trigger_samples = (devc->capture_ratio * devc->limit_samples) / 100;
+		devc->stl = soft_trigger_logic_new(sdi, trigger, pre_trigger_samples);
+		if (!devc->stl)
+			return SR_ERR_MALLOC;
+		devc->trigger_fired = FALSE;
+	} else
+		devc->trigger_fired = TRUE;
+
 	return SR_OK;
 }
 
@@ -514,6 +529,11 @@ static int dev_acquisition_stop(struct sr_dev_inst *sdi)
 
 	std_session_send_df_end(sdi);
 
+	if (devc->stl) {
+		soft_trigger_logic_free(devc->stl);
+		devc->stl = NULL;
+	}
+
 	return SR_OK;
 }
 

src/hardware/demo/protocol.c

@@ -456,6 +456,8 @@ SR_PRIV int demo_prepare_data(int fd, int revents, void *cb_data)
 	void *value;
 	uint64_t samples_todo, logic_done, analog_done, analog_sent, sending_now;
 	int64_t elapsed_us, limit_us, todo_us;
+	int64_t trigger_offset;
+	int pre_trigger_samples;
 
 	(void)fd;
 	(void)revents;
@@ -520,18 +522,32 @@ SR_PRIV int demo_prepare_data(int fd, int revents, void *cb_data)
 			sending_now = MIN(samples_todo - logic_done,
 					LOGIC_BUFSIZE / devc->logic_unitsize);
 			logic_generator(sdi, sending_now * devc->logic_unitsize);
+			/* Trigger */
+			if (!devc->trigger_fired) {
+				trigger_offset = soft_trigger_logic_check(devc->stl,
+						devc->logic_data, sending_now * devc->logic_unitsize, 
+						&pre_trigger_samples);
+				if (trigger_offset > -1)
+					devc->trigger_fired = TRUE;
+					logic_done = pre_trigger_samples;
+			} else
+				trigger_offset = 0;
+
+			/* Remaining data */
+			if (devc->trigger_fired && trigger_offset < (unsigned int)sending_now) {
 				packet.type = SR_DF_LOGIC;
 				packet.payload = &logic;
-			logic.length = sending_now * devc->logic_unitsize;
+				logic.length = (sending_now - trigger_offset) * devc->logic_unitsize;
 				logic.unitsize = devc->logic_unitsize;
-			logic.data = devc->logic_data;
+				logic.data = devc->logic_data + trigger_offset * devc->logic_unitsize;
 				logic_fixup_feed(devc, &logic);
 				sr_session_send(sdi, &packet);
-			logic_done += sending_now;
+				logic_done += sending_now - trigger_offset;
+			}
 		}
 
 		/* Analog, one channel at a time */
-		if (analog_done < samples_todo) {
+		if (devc->trigger_fired && analog_done < samples_todo) {
 			analog_sent = 0;
 
 			g_hash_table_iter_init(&iter, devc->ch_ag);
@@ -542,16 +558,17 @@ SR_PRIV int demo_prepare_data(int fd, int revents, void *cb_data)
 			}
 			analog_done += analog_sent;
 		}
-	}
-	/* At this point, both logic_done and analog_done should be
-	 * exactly equal to samples_todo, or else.
+
+		/* If trigger didn't happen continue to next iteration
+		 * Allow the client to stop this process
 		 */
-	if (logic_done != samples_todo || analog_done != samples_todo) {
-		sr_err("BUG: Sample count mismatch.");
-		return G_SOURCE_REMOVE;
+		if (!devc->trigger_fired)
+			break;
 	}
-	devc->sent_samples += samples_todo;
-	devc->sent_frame_samples += samples_todo;
+
+	uint64_t min = MIN(logic_done, analog_done);
+	devc->sent_samples += min;
+	devc->sent_frame_samples += min;
 	devc->spent_us += todo_us;
 
 	if (devc->limit_frames && devc->sent_frame_samples >= SAMPLES_PER_FRAME) {

src/hardware/demo/protocol.h

@@ -119,6 +119,8 @@ struct dev_context {
 	uint8_t first_partial_logic_mask;
 	/* Triggers */
 	uint64_t capture_ratio;
+	gboolean trigger_fired;
+	struct soft_trigger_logic *stl;
 };
 
 static const char *analog_pattern_str[] = {

src/soft-trigger.c

@@ -26,6 +26,22 @@
 #define LOG_PREFIX "soft-trigger"
 /* @endcond */
 
+static size_t logic_channel_unitsize(GSList *channels)
+{
+	size_t number = 0;
+	struct sr_channel *channel;
+	GSList *l;
+
+	for (l = channels; l; l = l->next) {
+		channel = l->data;
+		if (channel->type == SR_CHANNEL_LOGIC)
+			number += 1;
+	}
+	sr_dbg("number of logic channels: %d", (int) number);
+	return (number + 7) / 8;
+} 
+
+
 SR_PRIV struct soft_trigger_logic *soft_trigger_logic_new(
 		const struct sr_dev_inst *sdi, struct sr_trigger *trigger,
 		int pre_trigger_samples)
@@ -35,7 +51,8 @@ SR_PRIV struct soft_trigger_logic *soft_trigger_logic_new(
 	stl = g_malloc0(sizeof(struct soft_trigger_logic));
 	stl->sdi = sdi;
 	stl->trigger = trigger;
-	stl->unitsize = (g_slist_length(sdi->channels) + 7) / 8;
+	/* Retreive number of logic channels, unitsize */
+	stl->unitsize = logic_channel_unitsize(sdi->channels);
 	stl->prev_sample = g_malloc0(stl->unitsize);
 	stl->pre_trigger_size = stl->unitsize * pre_trigger_samples;
 	stl->pre_trigger_buffer = g_try_malloc(stl->pre_trigger_size);