+
+static int
+ols_set_basic_trigger_stage(const struct ols_basic_trigger_desc *trigger_desc,
+ struct sr_serial_dev_inst *serial, int stage)
+{
+ uint8_t cmd, arg[4];
+
+ cmd = CMD_SET_BASIC_TRIGGER_MASK0 + stage * 4;
+ if (ols_send_longdata(serial, cmd, trigger_desc->trigger_mask[stage]) != SR_OK)
+ return SR_ERR;
+
+ cmd = CMD_SET_BASIC_TRIGGER_VALUE0 + stage * 4;
+ if (ols_send_longdata(serial, cmd, trigger_desc->trigger_value[stage]) != SR_OK)
+ return SR_ERR;
+
+ cmd = CMD_SET_BASIC_TRIGGER_CONFIG0 + stage * 4;
+ arg[0] = arg[1] = arg[3] = 0x00;
+ arg[2] = stage;
+ if (stage == trigger_desc->num_stages - 1)
+ /* Last stage, fire when this one matches. */
+ arg[3] |= TRIGGER_START;
+ if (send_longcommand(serial, cmd, arg) != SR_OK)
+ return SR_ERR;
+
+ return SR_OK;
+}
+
+SR_PRIV int ols_prepare_acquisition(const struct sr_dev_inst *sdi)
+{
+ int ret;
+
+ struct dev_context *devc = sdi->priv;
+ struct sr_serial_dev_inst *serial = sdi->conn;
+
+ int num_changroups = 0;
+ uint8_t changroup_mask = 0;
+ uint32_t channel_mask = ols_channel_mask(sdi);
+ for (unsigned int i = 0; i < 4; i++) {
+ if (channel_mask & (0xff << (i * 8))) {
+ changroup_mask |= (1 << i);
+ num_changroups++;
+ }
+ }
+
+ /*
+ * Limit readcount to prevent reading past the end of the hardware
+ * buffer. Rather read too many samples than too few.
+ */
+ uint32_t samplecount =
+ MIN(devc->max_samples / num_changroups, devc->limit_samples);
+ uint32_t readcount = (samplecount + 3) / 4;
+ uint32_t delaycount;
+
+ /* Basic triggers. */
+ struct ols_basic_trigger_desc basic_trigger_desc;
+ if (convert_trigger(sdi, &basic_trigger_desc) != SR_OK) {
+ sr_err("Failed to configure channels.");
+ return SR_ERR;
+ }
+ if (basic_trigger_desc.num_stages > 0) {
+ /*
+ * According to http://mygizmos.org/ols/Logic-Sniffer-FPGA-Spec.pdf
+ * reset command must be send prior each arm command
+ */
+ sr_dbg("Send reset command before trigger configure");
+ if (ols_send_reset(serial) != SR_OK)
+ return SR_ERR;
+
+ delaycount = readcount * (1 - devc->capture_ratio / 100.0);
+ devc->trigger_at_smpl = (readcount - delaycount) * 4 -
+ basic_trigger_desc.num_stages;
+ for (int i = 0; i < basic_trigger_desc.num_stages; i++) {
+ sr_dbg("Setting OLS stage %d trigger.", i);
+ if ((ret = ols_set_basic_trigger_stage(
+ &basic_trigger_desc, serial, i)) != SR_OK)
+ return ret;
+ }
+ } else {
+ /* No triggers configured, force trigger on first stage. */
+ sr_dbg("Forcing trigger at stage 0.");
+ basic_trigger_desc.num_stages = 1;
+ if ((ret = ols_set_basic_trigger_stage(&basic_trigger_desc,
+ serial, 0)) != SR_OK)
+ return ret;
+ delaycount = readcount;
+ }
+
+ /* Samplerate. */
+ sr_dbg("Setting samplerate to %" PRIu64 "Hz (divider %u)",
+ devc->cur_samplerate, devc->cur_samplerate_divider);
+ if (ols_send_longdata(serial, CMD_SET_DIVIDER,
+ devc->cur_samplerate_divider & 0x00FFFFFF) != SR_OK)
+ return SR_ERR;
+
+ /* Send sample limit and pre/post-trigger capture ratio. */
+ sr_dbg("Setting sample limit %d, trigger point at %d",
+ (readcount - 1) * 4, (delaycount - 1) * 4);
+
+ if (devc->max_samples > 256 * 1024) {
+ if (ols_send_longdata(serial, CMD_CAPTURE_READCOUNT,
+ readcount - 1) != SR_OK)
+ return SR_ERR;
+ if (ols_send_longdata(serial, CMD_CAPTURE_DELAYCOUNT,
+ delaycount - 1) != SR_OK)
+ return SR_ERR;
+ } else {
+ uint8_t arg[4];
+ WL16(&arg[0], readcount - 1);
+ WL16(&arg[2], delaycount - 1);
+ if (send_longcommand(serial, CMD_CAPTURE_SIZE, arg) != SR_OK)
+ return SR_ERR;
+ }
+
+ /* Flag register. */
+ sr_dbg("Setting intpat %s, extpat %s, RLE %s, noise_filter %s, demux %s, "
+ "%s clock%s",
+ devc->capture_flags & CAPTURE_FLAG_INTERNAL_TEST_MODE ? "on" :
+ "off",
+ devc->capture_flags & CAPTURE_FLAG_EXTERNAL_TEST_MODE ? "on" :
+ "off",
+ devc->capture_flags & CAPTURE_FLAG_RLE ? "on" : "off",
+ devc->capture_flags & CAPTURE_FLAG_NOISE_FILTER ? "on" : "off",
+ devc->capture_flags & CAPTURE_FLAG_DEMUX ? "on" : "off",
+ devc->capture_flags & CAPTURE_FLAG_CLOCK_EXTERNAL ? "external" :
+ "internal",
+ devc->capture_flags & CAPTURE_FLAG_CLOCK_EXTERNAL ?
+ (devc->capture_flags & CAPTURE_FLAG_INVERT_EXT_CLOCK ?
+ " on falling edge" :
+ "on rising edge") :
+ "");
+
+ /*
+ * Enable/disable OLS channel groups in the flag register according
+ * to the channel mask. 1 means "disable channel".
+ */
+ devc->capture_flags &= ~0x3c;
+ devc->capture_flags |= ~(changroup_mask << 2) & 0x3c;
+
+ /* RLE mode is always zero, for now. */
+
+ if (ols_send_longdata(serial, CMD_SET_FLAGS, devc->capture_flags) != SR_OK)
+ return SR_ERR;
+
+ return SR_OK;
+}