]> sigrok.org Git - libsigrok.git/blobdiff - src/hardware/asix-sigma/protocol.c
asix-sigma: rephrase submission of logic data to session feed
[libsigrok.git] / src / hardware / asix-sigma / protocol.c
index f9e54089cb5ef270f5bda887339fe53686c74c87..1a667d48d74d44c3c341d3cc4c9620b783b087bd 100644 (file)
@@ -655,6 +655,157 @@ SR_PRIV int sigma_set_samplerate(const struct sr_dev_inst *sdi, uint64_t sampler
        return ret;
 }
 
+/*
+ * Arrange for a session feed submit buffer. A queue where a number of
+ * samples gets accumulated to reduce the number of send calls. Which
+ * also enforces an optional sample count limit for data acquisition.
+ *
+ * The buffer holds up to CHUNK_SIZE bytes. The unit size is fixed (the
+ * driver provides a fixed channel layout regardless of samplerate).
+ */
+
+#define CHUNK_SIZE     (4 * 1024 * 1024)
+
+struct submit_buffer {
+       size_t unit_size;
+       size_t max_samples, curr_samples;
+       uint8_t *sample_data;
+       uint8_t *write_pointer;
+       struct sr_dev_inst *sdi;
+       struct sr_datafeed_packet packet;
+       struct sr_datafeed_logic logic;
+       struct sr_sw_limits limit_samples;
+};
+
+static int alloc_submit_buffer(struct sr_dev_inst *sdi)
+{
+       struct dev_context *devc;
+       struct submit_buffer *buffer;
+       size_t size;
+
+       devc = sdi->priv;
+
+       buffer = g_malloc0(sizeof(*buffer));
+       devc->buffer = buffer;
+
+       buffer->unit_size = sizeof(uint16_t);
+       size = CHUNK_SIZE;
+       size /= buffer->unit_size;
+       buffer->max_samples = size;
+       size *= buffer->unit_size;
+       buffer->sample_data = g_try_malloc0(size);
+       if (!buffer->sample_data)
+               return SR_ERR_MALLOC;
+       buffer->write_pointer = buffer->sample_data;
+       sr_sw_limits_init(&buffer->limit_samples);
+
+       buffer->sdi = sdi;
+       memset(&buffer->logic, 0, sizeof(buffer->logic));
+       buffer->logic.unitsize = buffer->unit_size;
+       buffer->logic.data = buffer->sample_data;
+       memset(&buffer->packet, 0, sizeof(buffer->packet));
+       buffer->packet.type = SR_DF_LOGIC;
+       buffer->packet.payload = &buffer->logic;
+
+       return SR_OK;
+}
+
+static int setup_submit_buffer(struct dev_context *devc)
+{
+       struct submit_buffer *buffer;
+       int ret;
+       GVariant *data;
+       uint64_t total;
+
+       buffer = devc->buffer;
+
+       total = devc->limit_samples;
+       if (total) {
+               data = g_variant_new_uint64(total);
+               ret = sr_sw_limits_config_set(&buffer->limit_samples,
+                       SR_CONF_LIMIT_SAMPLES, data);
+               g_variant_unref(data);
+               if (ret != SR_OK)
+                       return ret;
+       }
+
+       sr_sw_limits_acquisition_start(&buffer->limit_samples);
+
+       return SR_OK;
+}
+
+static void free_submit_buffer(struct dev_context *devc)
+{
+       struct submit_buffer *buffer;
+
+       if (!devc)
+               return;
+
+       buffer = devc->buffer;
+       if (!buffer)
+               return;
+       devc->buffer = NULL;
+
+       g_free(buffer->sample_data);
+       g_free(buffer);
+}
+
+static int flush_submit_buffer(struct dev_context *devc)
+{
+       struct submit_buffer *buffer;
+       int ret;
+
+       buffer = devc->buffer;
+
+       /* Is queued sample data available? */
+       if (!buffer->curr_samples)
+               return SR_OK;
+
+       /* Submit to the session feed. */
+       buffer->logic.length = buffer->curr_samples * buffer->unit_size;
+       ret = sr_session_send(buffer->sdi, &buffer->packet);
+       if (ret != SR_OK)
+               return ret;
+
+       /* Rewind queue position. */
+       buffer->curr_samples = 0;
+       buffer->write_pointer = buffer->sample_data;
+
+       return SR_OK;
+}
+
+static int addto_submit_buffer(struct dev_context *devc,
+       uint16_t sample, size_t count)
+{
+       struct submit_buffer *buffer;
+       int ret;
+
+       buffer = devc->buffer;
+       if (sr_sw_limits_check(&buffer->limit_samples))
+               count = 0;
+
+       /*
+        * Individually accumulate and check each sample, such that
+        * accumulation between flushes won't exceed local storage, and
+        * enforcement of user specified limits is exact.
+        */
+       while (count--) {
+               WL16(buffer->write_pointer, sample);
+               buffer->write_pointer += buffer->unit_size;
+               buffer->curr_samples++;
+               if (buffer->curr_samples == buffer->max_samples) {
+                       ret = flush_submit_buffer(devc);
+                       if (ret != SR_OK)
+                               return ret;
+               }
+               sr_sw_limits_update_samples_read(&buffer->limit_samples, 1);
+               if (sr_sw_limits_check(&buffer->limit_samples))
+                       break;
+       }
+
+       return SR_OK;
+}
+
 /*
  * In 100 and 200 MHz mode, only a single pin rising/falling can be
  * set as trigger. In other modes, two rising/falling triggers can be set,
@@ -770,6 +921,48 @@ static int get_trigger_offset(uint8_t *samples, uint16_t last_sample,
        return i & 0x7;
 }
 
+static gboolean sample_matches_trigger(struct dev_context *devc, uint16_t sample)
+{
+       /* TODO
+        * Check whether the combination of this very sample and the
+        * previous state match the configured trigger condition. This
+        * improves the resolution of the trigger marker's position.
+        * The hardware provided position is coarse, and may point to
+        * a position before the actual match.
+        *
+        * See the previous get_trigger_offset() implementation. This
+        * code needs to get re-used here.
+        */
+       (void)devc;
+       (void)sample;
+       (void)get_trigger_offset;
+
+       return FALSE;
+}
+
+static int check_and_submit_sample(struct dev_context *devc,
+       uint16_t sample, size_t count, gboolean check_trigger)
+{
+       gboolean triggered;
+       int ret;
+
+       triggered = check_trigger && sample_matches_trigger(devc, sample);
+       if (triggered) {
+               ret = flush_submit_buffer(devc);
+               if (ret != SR_OK)
+                       return ret;
+               ret = std_session_send_df_trigger(devc->buffer->sdi);
+               if (ret != SR_OK)
+                       return ret;
+       }
+
+       ret = addto_submit_buffer(devc, sample, count);
+       if (ret != SR_OK)
+               return ret;
+
+       return SR_OK;
+}
+
 /*
  * Return the timestamp of "DRAM cluster".
  */
@@ -832,173 +1025,66 @@ static uint16_t sigma_deinterlace_200mhz_data(uint16_t indata, int idx)
        return outdata;
 }
 
-static void store_sr_sample(uint8_t *samples, int idx, uint16_t data)
-{
-       samples[2 * idx + 0] = (data >> 0) & 0xff;
-       samples[2 * idx + 1] = (data >> 8) & 0xff;
-}
-
-/*
- * Local wrapper around sr_session_send() calls. Make sure to not send
- * more samples to the session's datafeed than what was requested by a
- * previously configured (optional) sample count.
- */
-static void sigma_session_send(struct sr_dev_inst *sdi,
-                               struct sr_datafeed_packet *packet)
-{
-       struct dev_context *devc;
-       struct sr_datafeed_logic *logic;
-       uint64_t send_now;
-
-       devc = sdi->priv;
-       if (devc->limit_samples) {
-               logic = (void *)packet->payload;
-               send_now = logic->length / logic->unitsize;
-               if (devc->sent_samples + send_now > devc->limit_samples) {
-                       send_now = devc->limit_samples - devc->sent_samples;
-                       logic->length = send_now * logic->unitsize;
-               }
-               if (!send_now)
-                       return;
-               devc->sent_samples += send_now;
-       }
-
-       sr_session_send(sdi, packet);
-}
-
-/*
- * This size translates to: number of events per row (strictly speaking
- * 448, assuming "up to 512" does not harm here) times the sample data's
- * unit size (16 bits), times the maximum number of samples per event (4).
- */
-#define SAMPLES_BUFFER_SIZE    (ROW_LENGTH_U16 * sizeof(uint16_t) * 4)
-
-static void sigma_decode_dram_cluster(struct sigma_dram_cluster *dram_cluster,
-                                     unsigned int events_in_cluster,
-                                     unsigned int triggered,
-                                     struct sr_dev_inst *sdi)
+static void sigma_decode_dram_cluster(struct dev_context *devc,
+       struct sigma_dram_cluster *dram_cluster,
+       size_t events_in_cluster, gboolean triggered)
 {
-       struct dev_context *devc = sdi->priv;
-       struct sigma_state *ss = &devc->state;
-       struct sr_datafeed_packet packet;
-       struct sr_datafeed_logic logic;
+       struct sigma_state *ss;
        uint16_t tsdiff, ts, sample, item16;
-       uint8_t samples[SAMPLES_BUFFER_SIZE];
-       uint8_t *send_ptr;
-       size_t send_count, trig_count;
        unsigned int i;
-       int j;
-
-       ts = sigma_dram_cluster_ts(dram_cluster);
-       tsdiff = ts - ss->lastts;
-       ss->lastts = ts + EVENTS_PER_CLUSTER;
 
-       packet.type = SR_DF_LOGIC;
-       packet.payload = &logic;
-       logic.unitsize = 2;
-       logic.data = samples;
+       if (!devc->use_triggers || !ASIX_SIGMA_WITH_TRIGGER)
+               triggered = FALSE;
 
        /*
         * If this cluster is not adjacent to the previously received
         * cluster, then send the appropriate number of samples with the
         * previous values to the sigrok session. This "decodes RLE".
         *
-        * TODO Improve (mostly: generalize) support for queueing data
-        * before submission to the session bus. This implementation
-        * happens to work for "up to 1024 samples" despite the "up to
-        * 512 entities of 16 bits", due to the "up to 4 sample points
-        * per event" factor. A better implementation would eliminate
-        * these magic numbers.
+        * These samples cannot match the trigger since they just repeat
+        * the previously submitted data pattern. (This assumption holds
+        * for simple level and edge triggers. It would not for timed or
+        * counted conditions, which currently are not supported.)
         */
-       for (ts = 0; ts < tsdiff; ts++) {
-               i = ts % 1024;
-               store_sr_sample(samples, i, ss->lastsample);
-
-               /*
-                * If we have 1024 samples ready or we're at the
-                * end of submitting the padding samples, submit
-                * the packet to Sigrok. Since constant data is
-                * sent, duplication of data for rates above 50MHz
-                * is simple.
-                */
-               if ((i == 1023) || (ts == tsdiff - 1)) {
-                       logic.length = (i + 1) * logic.unitsize;
-                       for (j = 0; j < devc->samples_per_event; j++)
-                               sigma_session_send(sdi, &packet);
-               }
+       ss = &devc->state;
+       ts = sigma_dram_cluster_ts(dram_cluster);
+       tsdiff = ts - ss->lastts;
+       if (tsdiff > 0) {
+               size_t count;
+               count = tsdiff * devc->samples_per_event;
+               (void)check_and_submit_sample(devc, ss->lastsample, count, FALSE);
        }
+       ss->lastts = ts + EVENTS_PER_CLUSTER;
 
        /*
-        * Parse the samples in current cluster and prepare them
-        * to be submitted to Sigrok. Cope with memory layouts that
-        * vary with the samplerate.
+        * Grab sample data from the current cluster and prepare their
+        * submission to the session feed. Handle samplerate dependent
+        * memory layout of sample data. Accumulation of data chunks
+        * before submission is transparent to this code path, specific
+        * buffer depth is neither assumed nor required here.
         */
-       send_ptr = &samples[0];
-       send_count = 0;
        sample = 0;
        for (i = 0; i < events_in_cluster; i++) {
                item16 = sigma_dram_cluster_data(dram_cluster, i);
                if (devc->cur_samplerate == SR_MHZ(200)) {
                        sample = sigma_deinterlace_200mhz_data(item16, 0);
-                       store_sr_sample(samples, send_count++, sample);
+                       check_and_submit_sample(devc, sample, 1, triggered);
                        sample = sigma_deinterlace_200mhz_data(item16, 1);
-                       store_sr_sample(samples, send_count++, sample);
+                       check_and_submit_sample(devc, sample, 1, triggered);
                        sample = sigma_deinterlace_200mhz_data(item16, 2);
-                       store_sr_sample(samples, send_count++, sample);
+                       check_and_submit_sample(devc, sample, 1, triggered);
                        sample = sigma_deinterlace_200mhz_data(item16, 3);
-                       store_sr_sample(samples, send_count++, sample);
+                       check_and_submit_sample(devc, sample, 1, triggered);
                } else if (devc->cur_samplerate == SR_MHZ(100)) {
                        sample = sigma_deinterlace_100mhz_data(item16, 0);
-                       store_sr_sample(samples, send_count++, sample);
+                       check_and_submit_sample(devc, sample, 1, triggered);
                        sample = sigma_deinterlace_100mhz_data(item16, 1);
-                       store_sr_sample(samples, send_count++, sample);
+                       check_and_submit_sample(devc, sample, 1, triggered);
                } else {
                        sample = item16;
-                       store_sr_sample(samples, send_count++, sample);
-               }
-       }
-
-       /*
-        * If a trigger position applies, then provide the datafeed with
-        * the first part of data up to that position, then send the
-        * trigger marker.
-        */
-       int trigger_offset = 0;
-       if (triggered) {
-               /*
-                * Trigger is not always accurate to sample because of
-                * pipeline delay. However, it always triggers before
-                * the actual event. We therefore look at the next
-                * samples to pinpoint the exact position of the trigger.
-                */
-               trigger_offset = get_trigger_offset(samples,
-                                       ss->lastsample, &devc->trigger);
-
-               if (trigger_offset > 0) {
-                       trig_count = trigger_offset * devc->samples_per_event;
-                       packet.type = SR_DF_LOGIC;
-                       logic.length = trig_count * logic.unitsize;
-                       sigma_session_send(sdi, &packet);
-                       send_ptr += trig_count * logic.unitsize;
-                       send_count -= trig_count;
+                       check_and_submit_sample(devc, sample, 1, triggered);
                }
-
-               /* Only send trigger if explicitly enabled. */
-               if (devc->use_triggers)
-                       std_session_send_df_trigger(sdi);
-       }
-
-       /*
-        * Send the data after the trigger, or all of the received data
-        * if no trigger position applies.
-        */
-       if (send_count) {
-               packet.type = SR_DF_LOGIC;
-               logic.length = send_count * logic.unitsize;
-               logic.data = send_ptr;
-               sigma_session_send(sdi, &packet);
        }
-
        ss->lastsample = sample;
 }
 
@@ -1011,24 +1097,20 @@ static void sigma_decode_dram_cluster(struct sigma_dram_cluster *dram_cluster,
  * For 50 MHz and below, events contain one sample for each channel,
  * spread 20 ns apart.
  */
-static int decode_chunk_ts(struct sigma_dram_line *dram_line,
-                          uint16_t events_in_line,
-                          uint32_t trigger_event,
-                          struct sr_dev_inst *sdi)
+static int decode_chunk_ts(struct dev_context *devc,
+       struct sigma_dram_line *dram_line,
+       size_t events_in_line, size_t trigger_event)
 {
        struct sigma_dram_cluster *dram_cluster;
-       struct dev_context *devc;
        unsigned int clusters_in_line;
        unsigned int events_in_cluster;
        unsigned int i;
-       uint32_t trigger_cluster, triggered;
+       uint32_t trigger_cluster;
 
-       devc = sdi->priv;
        clusters_in_line = events_in_line;
        clusters_in_line += EVENTS_PER_CLUSTER - 1;
        clusters_in_line /= EVENTS_PER_CLUSTER;
        trigger_cluster = ~0;
-       triggered = 0;
 
        /* Check if trigger is in this chunk. */
        if (trigger_event < EVENTS_PER_ROW) {
@@ -1053,9 +1135,8 @@ static int decode_chunk_ts(struct sigma_dram_line *dram_line,
                        events_in_cluster = EVENTS_PER_CLUSTER;
                }
 
-               triggered = (i == trigger_cluster);
-               sigma_decode_dram_cluster(dram_cluster, events_in_cluster,
-                                         triggered, sdi);
+               sigma_decode_dram_cluster(devc, dram_cluster,
+                       events_in_cluster, i == trigger_cluster);
        }
 
        return SR_OK;
@@ -1075,6 +1156,7 @@ static int download_capture(struct sr_dev_inst *sdi)
        uint32_t dl_first_line, dl_line;
        uint32_t dl_events_in_line;
        uint32_t trg_line, trg_event;
+       int ret;
 
        devc = sdi->priv;
        dl_events_in_line = EVENTS_PER_ROW;
@@ -1135,6 +1217,12 @@ static int download_capture(struct sr_dev_inst *sdi)
        dram_line = g_try_malloc0(chunks_per_read * sizeof(*dram_line));
        if (!dram_line)
                return FALSE;
+       ret = alloc_submit_buffer(sdi);
+       if (ret != SR_OK)
+               return FALSE;
+       ret = setup_submit_buffer(devc);
+       if (ret != SR_OK)
+               return FALSE;
        dl_lines_done = 0;
        while (dl_lines_total > dl_lines_done) {
                /* We can download only up-to 32 DRAM lines in one go! */
@@ -1164,12 +1252,14 @@ static int download_capture(struct sr_dev_inst *sdi)
                        if (dl_lines_done + i == trg_line)
                                trigger_event = trg_event;
 
-                       decode_chunk_ts(dram_line + i, dl_events_in_line,
-                                       trigger_event, sdi);
+                       decode_chunk_ts(devc, dram_line + i,
+                               dl_events_in_line, trigger_event);
                }
 
                dl_lines_done += dl_lines_curr;
        }
+       flush_submit_buffer(devc);
+       free_submit_buffer(devc);
        g_free(dram_line);
 
        std_session_send_df_end(sdi);