+/*
+ * This is a unified protocol driver for the DS1000 and DS2000 series.
+ *
+ * DS1000 support tested with a Rigol DS1102D.
+ *
+ * DS2000 support tested with a Rigol DS2072 using firmware version 01.01.00.02.
+ *
+ * The Rigol DS2000 series scopes try to adhere to the IEEE 488.2 (I think)
+ * standard. If you want to read it - it costs real money...
+ *
+ * Every response from the scope has a linefeed appended because the
+ * standard says so. In principle this could be ignored because sending the
+ * next command clears the output queue of the scope. This driver tries to
+ * avoid doing that because it may cause an error being generated inside the
+ * scope and who knows what bugs the firmware has WRT this.
+ *
+ * Waveform data is transferred in a format called "arbitrary block program
+ * data" specified in IEEE 488.2. See Agilents programming manuals for their
+ * 2000/3000 series scopes for a nice description.
+ *
+ * Each data block from the scope has a header, e.g. "#900000001400".
+ * The '#' marks the start of a block.
+ * Next is one ASCII decimal digit between 1 and 9, this gives the number of
+ * ASCII decimal digits following.
+ * Last are the ASCII decimal digits giving the number of bytes (not
+ * samples!) in the block.
+ *
+ * After this header as many data bytes as indicated follow.
+ *
+ * Each data block has a trailing linefeed too.
+ */
+
+static int get_cfg(const struct sr_dev_inst *sdi, char *cmd, char *reply, size_t maxlen);
+static int get_cfg_int(const struct sr_dev_inst *sdi, char *cmd, int *i);
+
+static int parse_int(const char *str, int *ret)
+{
+ char *e;
+ long tmp;
+
+ errno = 0;
+ tmp = strtol(str, &e, 10);
+ if (e == str || *e != '\0') {
+ sr_dbg("Failed to parse integer: '%s'", str);
+ return SR_ERR;
+ }
+ if (errno) {
+ sr_dbg("Failed to parse integer: '%s', numerical overflow", str);
+ return SR_ERR;
+ }
+ if (tmp > INT_MAX || tmp < INT_MIN) {
+ sr_dbg("Failed to parse integer: '%s', value to large/small", str);
+ return SR_ERR;
+ }
+
+ *ret = (int)tmp;
+ return SR_OK;
+}
+
+/* Set the next event to wait for in rigol_ds_receive */
+static void rigol_ds_set_wait_event(struct dev_context *devc, enum wait_events event)
+{
+ if (event == WAIT_STOP)
+ devc->wait_status = 2;
+ else
+ devc->wait_status = 1;
+ devc->wait_event = event;
+}
+
+/*
+ * Waiting for a event will return a timeout after 2 to 3 seconds in order
+ * to not block the application.
+ */
+static int rigol_ds_event_wait(const struct sr_dev_inst *sdi, char status1, char status2)
+{
+ char buf[20];
+ struct dev_context *devc;
+ time_t start;
+
+ if (!(devc = sdi->priv))
+ return SR_ERR;
+
+ start = time(NULL);
+
+ /*
+ * Trigger status may return:
+ * "TD" or "T'D" - triggered
+ * "AUTO" - autotriggered
+ * "RUN" - running
+ * "WAIT" - waiting for trigger
+ * "STOP" - stopped
+ */
+
+ if (devc->wait_status == 1) {
+ do {
+ if (time(NULL) - start >= 3) {
+ sr_dbg("Timeout waiting for trigger");
+ return SR_ERR_TIMEOUT;
+ }
+
+ if (get_cfg(sdi, ":TRIG:STAT?", buf, sizeof(buf)) != SR_OK)
+ return SR_ERR;
+ } while (buf[0] == status1 || buf[0] == status2);
+
+ devc->wait_status = 2;
+ }
+ if (devc->wait_status == 2) {
+ do {
+ if (time(NULL) - start >= 3) {
+ sr_dbg("Timeout waiting for trigger");
+ return SR_ERR_TIMEOUT;
+ }
+
+ if (get_cfg(sdi, ":TRIG:STAT?", buf, sizeof(buf)) != SR_OK)
+ return SR_ERR;
+ } while (buf[0] != status1 && buf[0] != status2);
+
+ rigol_ds_set_wait_event(devc, WAIT_NONE);
+ }
+
+ return SR_OK;
+}
+
+/*
+ * For live capture we need to wait for a new trigger event to ensure that
+ * sample data is not returned twice.
+ *
+ * Unfortunately this will never really work because for sufficiently fast
+ * timebases and trigger rates it just can't catch the status changes.
+ *
+ * What would be needed is a trigger event register with autoreset like the
+ * Agilents have. The Rigols don't seem to have anything like this.
+ *
+ * The workaround is to only wait for the trigger when the timebase is slow
+ * enough. Of course this means that for faster timebases sample data can be
+ * returned multiple times, this effect is mitigated somewhat by sleeping
+ * for about one sweep time in that case.
+ */
+static int rigol_ds_trigger_wait(const struct sr_dev_inst *sdi)
+{
+ struct dev_context *devc;
+ long s;
+
+ if (!(devc = sdi->priv))
+ return SR_ERR;
+
+ /*
+ * If timebase < 50 msecs/DIV just sleep about one sweep time except
+ * for really fast sweeps.
+ */
+ if (devc->timebase < 0.0499)
+ {
+ if (devc->timebase > 0.99e-6) {
+ /*
+ * Timebase * num hor. divs * 85(%) * 1e6(usecs) / 100
+ * -> 85 percent of sweep time
+ */
+ s = (devc->timebase * devc->model->num_horizontal_divs
+ * 85e6) / 100L;
+ sr_spew("Sleeping for %ld usecs instead of trigger-wait", s);
+ g_usleep(s);
+ }
+ rigol_ds_set_wait_event(devc, WAIT_NONE);
+ return SR_OK;
+ } else {
+ return rigol_ds_event_wait(sdi, 'T', 'A');
+ }
+}
+
+/* Wait for scope to got to "Stop" in single shot mode */
+static int rigol_ds_stop_wait(const struct sr_dev_inst *sdi)
+{
+ return rigol_ds_event_wait(sdi, 'S', 'S');
+}
+
+/* Check that a single shot acquisition actually succeeded on the DS2000 */
+static int rigol_ds_check_stop(const struct sr_dev_inst *sdi)
+{
+ struct dev_context *devc;
+ struct sr_probe *probe;
+ int tmp;
+
+ if (!(devc = sdi->priv))
+ return SR_ERR;
+
+ probe = devc->channel_entry->data;
+
+ if (sr_scpi_send(sdi->conn, ":WAV:SOUR CHAN%d",
+ probe->index + 1) != SR_OK)
+ return SR_ERR;
+ /* Check that the number of samples will be accepted */
+ if (sr_scpi_send(sdi->conn, ":WAV:POIN %d;*OPC", devc->analog_frame_size) != SR_OK)
+ return SR_ERR;
+ if (get_cfg_int(sdi, "*ESR?", &tmp) != SR_OK)
+ return SR_ERR;
+ /*
+ * If we get an "Execution error" the scope went from "Single" to
+ * "Stop" without actually triggering. There is no waveform
+ * displayed and trying to download one will fail - the scope thinks
+ * it has 1400 samples (like display memory) and the driver thinks
+ * it has a different number of samples.
+ *
+ * In that case just try to capture something again. Might still
+ * fail in interesting ways.
+ *
+ * Ain't firmware fun?
+ */
+ if (tmp & 0x10) {
+ sr_warn("Single shot acquisition failed, retrying...");
+ /* Sleep a bit, otherwise the single shot will often fail */
+ g_usleep(500000);
+ sr_scpi_send(sdi->conn, ":SING");
+ rigol_ds_set_wait_event(devc, WAIT_STOP);
+ return SR_ERR;
+ }
+
+ return SR_OK;
+}
+
+/* Wait for enough data becoming available in scope output buffer */
+static int rigol_ds_block_wait(const struct sr_dev_inst *sdi)
+{
+ char buf[30];
+ struct dev_context *devc;
+ time_t start;
+ int len;
+
+ if (!(devc = sdi->priv))
+ return SR_ERR;
+
+ start = time(NULL);
+
+ do {
+ if (time(NULL) - start >= 3) {
+ sr_dbg("Timeout waiting for data block");
+ return SR_ERR_TIMEOUT;
+ }
+
+ /*
+ * The scope copies data really slowly from sample
+ * memory to its output buffer, so try not to bother
+ * it too much with SCPI requests but don't wait too
+ * long for short sample frame sizes.
+ */
+ g_usleep(devc->analog_frame_size < 15000 ? 100000 : 1000000);
+
+ /* "READ,nnnn" (still working) or "IDLE,nnnn" (finished) */
+ if (get_cfg(sdi, ":WAV:STAT?", buf, sizeof(buf)) != SR_OK)
+ return SR_ERR;
+
+ if (parse_int(buf + 5, &len) != SR_OK)
+ return SR_ERR;
+ } while (buf[0] == 'R' && len < 1000000);
+
+ rigol_ds_set_wait_event(devc, WAIT_NONE);
+
+ return SR_OK;
+}
+
+/* Start capturing a new frameset */
+SR_PRIV int rigol_ds_capture_start(const struct sr_dev_inst *sdi)
+{
+ struct dev_context *devc;
+
+ if (!(devc = sdi->priv))
+ return SR_ERR;
+
+ sr_dbg("Starting data capture for frameset %lu of %lu",
+ devc->num_frames + 1, devc->limit_frames);
+
+ if (sr_scpi_send(sdi->conn, ":WAV:FORM BYTE") != SR_OK)
+ return SR_ERR;
+ if (devc->data_source == DATA_SOURCE_LIVE) {
+ if (sr_scpi_send(sdi->conn, ":WAV:MODE NORM") != SR_OK)
+ return SR_ERR;
+ rigol_ds_set_wait_event(devc, WAIT_TRIGGER);
+ } else {
+ if (sr_scpi_send(sdi->conn, ":WAV:MODE RAW") != SR_OK)
+ return SR_ERR;
+ if (sr_scpi_send(sdi->conn, ":SING", devc->analog_frame_size) != SR_OK)
+ return SR_ERR;
+ rigol_ds_set_wait_event(devc, WAIT_STOP);
+ }
+
+ return SR_OK;
+}
+
+/* Start reading data from the current channel */
+SR_PRIV int rigol_ds_channel_start(const struct sr_dev_inst *sdi)
+{
+ struct dev_context *devc;
+ struct sr_probe *probe;
+
+ if (!(devc = sdi->priv))
+ return SR_ERR;
+
+ probe = devc->channel_entry->data;
+
+ sr_dbg("Starting reading data from channel %d", probe->index + 1);
+
+ if (devc->model->protocol == PROTOCOL_LEGACY) {
+ if (probe->type == SR_PROBE_LOGIC) {
+ if (sr_scpi_send(sdi->conn, ":WAV:DATA? DIG") != SR_OK)
+ return SR_ERR;
+ } else {
+ if (sr_scpi_send(sdi->conn, ":WAV:DATA? CHAN%d",
+ probe->index + 1) != SR_OK)
+ return SR_ERR;
+ }
+ } else {
+ if (sr_scpi_send(sdi->conn, ":WAV:SOUR CHAN%d",
+ probe->index + 1) != SR_OK)
+ return SR_ERR;
+ if (devc->data_source != DATA_SOURCE_LIVE) {
+ if (sr_scpi_send(sdi->conn, ":WAV:RES") != SR_OK)
+ return SR_ERR;
+ if (sr_scpi_send(sdi->conn, ":WAV:BEG") != SR_OK)
+ return SR_ERR;
+ rigol_ds_set_wait_event(devc, WAIT_BLOCK);
+ } else
+ rigol_ds_set_wait_event(devc, WAIT_NONE);
+ }
+
+ devc->num_frame_samples = 0;
+ devc->num_block_bytes = 0;
+
+ return SR_OK;
+}
+
+/* Read the header of a data block */
+static int rigol_ds_read_header(struct sr_scpi_dev_inst *scpi)
+{
+ char start[3], length[10];
+ int len, tmp;
+
+ /* Read the hashsign and length digit. */
+ tmp = sr_scpi_read_data(scpi, start, 2);
+ start[2] = '\0';
+ if (tmp != 2)
+ {
+ sr_err("Failed to read first two bytes of data block header.");
+ return -1;
+ }
+ if (start[0] != '#' || !isdigit(start[1]) || start[1] == '0')
+ {
+ sr_err("Received invalid data block header start '%s'.", start);
+ return -1;
+ }
+ len = atoi(start + 1);
+
+ /* Read the data length. */
+ tmp = sr_scpi_read_data(scpi, length, len);
+ length[len] = '\0';
+ if (tmp != len)
+ {
+ sr_err("Failed to read %d bytes of data block length.", len);
+ return -1;
+ }
+ if (parse_int(length, &len) != SR_OK)
+ {
+ sr_err("Received invalid data block length '%s'.", length);
+ return -1;
+ }
+
+ sr_dbg("Received data block header: %s%s -> block length %d", start, length, len);
+
+ return len;
+}
+