]> sigrok.org Git - libsigrok.git/blobdiff - hardware/hantek-dso/api.c
sr: add new driver API call: scan()
[libsigrok.git] / hardware / hantek-dso / api.c
index fbfa9cbd449dc7251c1ddc018d86a7fb15037711..40303fee1c2e9d643a82bc465800af5357b6f1d5 100644 (file)
 #include <string.h>
 #include <sys/time.h>
 #include <inttypes.h>
-#include <arpa/inet.h>
 #include <glib.h>
 #include <libusb.h>
-#include "sigrok.h"
-#include "sigrok-internal.h"
+#include "libsigrok.h"
+#include "libsigrok-internal.h"
 #include "config.h"
 #include "dso.h"
 
 
-/* Max time in ms before we want to check on events */
+/* Max time in ms before we want to check on USB events */
+/* TODO tune this properly */
 #define TICK    1
 
-static int capabilities[] = {
+static const int hwcaps[] = {
        SR_HWCAP_OSCILLOSCOPE,
+       SR_HWCAP_LIMIT_SAMPLES,
        SR_HWCAP_CONTINUOUS,
+       SR_HWCAP_TIMEBASE,
+       SR_HWCAP_BUFFERSIZE,
+       SR_HWCAP_TRIGGER_SOURCE,
+       SR_HWCAP_TRIGGER_SLOPE,
+       SR_HWCAP_HORIZ_TRIGGERPOS,
+       SR_HWCAP_FILTER,
+       SR_HWCAP_VDIV,
+       SR_HWCAP_COUPLING,
        0,
 };
 
@@ -51,27 +60,100 @@ static const char *probe_names[] = {
        NULL,
 };
 
-static struct dso_profile dev_profiles[] = {
-       {       0x04b4, 0x2090,
-               0x04b5, 0x2090,
+static const struct dso_profile dev_profiles[] = {
+       {       0x04b4, 0x2090, 0x04b5, 0x2090,
                "Hantek", "DSO-2090",
-               NULL, 2,
-               FIRMWARE_DIR "/hantek-dso-2090.fw" },
-       { 0, 0, 0, 0, 0, 0, 0, 0, 0 }
+               FIRMWARE_DIR "/hantek-dso-2xxx.fw" },
+       {       0x04b4, 0x2150, 0x04b5, 0x2150,
+               "Hantek", "DSO-2150",
+               FIRMWARE_DIR "/hantek-dso-2xxx.fw" },
+       {       0x04b4, 0x2250, 0x04b5, 0x2250,
+               "Hantek", "DSO-2250",
+               FIRMWARE_DIR "/hantek-dso-2xxx.fw" },
+       {       0x04b4, 0x5200, 0x04b5, 0x5200,
+               "Hantek", "DSO-5200",
+               FIRMWARE_DIR "/hantek-dso-5xxx.fw" },
+       {       0x04b4, 0x520a, 0x04b5, 0x520a,
+               "Hantek", "DSO-5200A",
+               FIRMWARE_DIR "/hantek-dso-5xxx.fw" },
+       { 0, 0, 0, 0, 0, 0, 0 },
 };
 
+static const uint64_t buffersizes[] = {
+       10240,
+       32768,
+       /* TODO: 65535 */
+       0,
+};
+
+static const struct sr_rational timebases[] = {
+       /* microseconds */
+       { 10, 1000000 },
+       { 20, 1000000 },
+       { 40, 1000000 },
+       { 100, 1000000 },
+       { 200, 1000000 },
+       { 400, 1000000 },
+       /* milliseconds */
+       { 1, 1000 },
+       { 2, 1000 },
+       { 4, 1000 },
+       { 10, 1000 },
+       { 20, 1000 },
+       { 40, 1000 },
+       { 100, 1000 },
+       { 200, 1000 },
+       { 400, 1000 },
+       { 0, 0},
+};
+
+static const struct sr_rational vdivs[] = {
+       /* millivolts */
+       { 10, 1000 },
+       { 20, 1000 },
+       { 50, 1000 },
+       { 100, 1000 },
+       { 200, 1000 },
+       { 500, 1000 },
+       /* volts */
+       { 1, 1 },
+       { 2, 1 },
+       { 5, 1 },
+       { 0, 0 },
+};
+
+static const char *trigger_sources[] = {
+       "CH1",
+       "CH2",
+       "EXT",
+       /* TODO: forced */
+       NULL,
+};
+
+static const char *filter_targets[] = {
+       "CH1",
+       "CH2",
+       /* TODO: "TRIGGER", */
+       NULL,
+};
+
+static const char *coupling[] = {
+       "AC",
+       "DC",
+       "GND",
+       NULL,
+};
 
 SR_PRIV libusb_context *usb_context = NULL;
 SR_PRIV GSList *dev_insts = NULL;
 
-
-static struct sr_dev_inst *dso_dev_new(int index, struct dso_profile *prof)
+static struct sr_dev_inst *dso_dev_new(int index, const struct dso_profile *prof)
 {
        struct sr_dev_inst *sdi;
        struct context *ctx;
 
        sdi = sr_dev_inst_new(index, SR_ST_INITIALIZING,
-               prof->vendor, prof->model, prof->model_version);
+               prof->vendor, prof->model, NULL);
        if (!sdi)
                return NULL;
 
@@ -91,10 +173,9 @@ static struct sr_dev_inst *dso_dev_new(int index, struct dso_profile *prof)
        ctx->voffset_ch1 = DEFAULT_VERT_OFFSET;
        ctx->voffset_ch2 = DEFAULT_VERT_OFFSET;
        ctx->voffset_trigger = DEFAULT_VERT_TRIGGERPOS;
-       ctx->selected_channel = DEFAULT_SELECTED_CHANNEL;
        ctx->framesize = DEFAULT_FRAMESIZE;
        ctx->triggerslope = SLOPE_POSITIVE;
-       ctx->triggersource = DEFAULT_TRIGGER_SOURCE;
+       ctx->triggersource = g_strdup(DEFAULT_TRIGGER_SOURCE);
        ctx->triggerposition = DEFAULT_HORIZ_TRIGGERPOS;
        sdi->priv = ctx;
        dev_insts = g_slist_append(dev_insts, sdi);
@@ -102,45 +183,49 @@ static struct sr_dev_inst *dso_dev_new(int index, struct dso_profile *prof)
        return sdi;
 }
 
-static int configure_probes(struct context *ctx, GSList *probes)
+static int configure_probes(struct context *ctx, const GSList *probes)
 {
-       struct sr_probe *probe;
-       GSList *l;
+       const struct sr_probe *probe;
+       const GSList *l;
 
+       ctx->ch1_enabled = ctx->ch2_enabled = FALSE;
        for (l = probes; l; l = l->next) {
                probe = (struct sr_probe *)l->data;
-               if (probe->index == 0)
+               if (probe->index == 1)
                        ctx->ch1_enabled = probe->enabled;
-               else if (probe->index == 1)
+               else if (probe->index == 2)
                        ctx->ch2_enabled = probe->enabled;
        }
 
        return SR_OK;
 }
 
-static int hw_init(const char *devinfo)
+static int hw_init(void)
 {
-       struct sr_dev_inst *sdi;
-       struct libusb_device_descriptor des;
-       struct dso_profile *prof;
-       struct context *ctx;
-       libusb_device **devlist;
-       int err, devcnt, i, j;
-
-       /* Avoid compiler warnings. */
-       (void)devinfo;
 
        if (libusb_init(&usb_context) != 0) {
                sr_err("hantek-dso: Failed to initialize USB.");
-               return 0;
+               return SR_ERR;
        }
 
+       return SR_OK;
+}
+
+static int hw_scan(void)
+{
+       struct sr_dev_inst *sdi;
+       struct libusb_device_descriptor des;
+       const struct dso_profile *prof;
+       struct context *ctx;
+       libusb_device **devlist;
+       int devcnt, ret, i, j;
+
        /* Find all Hantek DSO devices and upload firmware to all of them. */
        devcnt = 0;
        libusb_get_device_list(usb_context, &devlist);
        for (i = 0; devlist[i]; i++) {
-               if ((err = libusb_get_device_descriptor(devlist[i], &des))) {
-                       sr_err("hantek-dso: failed to get device descriptor: %d", err);
+               if ((ret = libusb_get_device_descriptor(devlist[i], &des))) {
+                       sr_err("hantek-dso: failed to get device descriptor: %d", ret);
                        continue;
                }
 
@@ -156,7 +241,7 @@ static int hw_init(const char *devinfo)
                                if (ezusb_upload_firmware(devlist[i], USB_CONFIGURATION,
                                                prof->firmware) == SR_OK)
                                        /* Remember when the firmware on this device was updated */
-                                       g_get_current_time(&ctx->fw_updated);
+                                       ctx->fw_updated = g_get_monotonic_time();
                                else
                                        sr_err("hantek-dso: firmware upload failed for "
                                               "device %d", devcnt);
@@ -191,33 +276,34 @@ static int hw_init(const char *devinfo)
 
 static int hw_dev_open(int dev_index)
 {
-       GTimeVal cur_time;
        struct sr_dev_inst *sdi;
        struct context *ctx;
-       int timediff, err;
+       int64_t timediff_us, timediff_ms;
+       int err;
 
        if (!(sdi = sr_dev_inst_get(dev_insts, dev_index)))
                return SR_ERR_ARG;
        ctx = sdi->priv;
 
        /*
-        * if the firmware was recently uploaded, wait up to MAX_RENUM_DELAY ms
+        * if the firmware was recently uploaded, wait up to MAX_RENUM_DELAY_MS
         * for the FX2 to renumerate
         */
-       err = 0;
-       if (GTV_TO_MSEC(ctx->fw_updated) > 0) {
+       err = SR_ERR;
+       if (ctx->fw_updated > 0) {
                sr_info("hantek-dso: waiting for device to reset");
                /* takes at least 300ms for the FX2 to be gone from the USB bus */
                g_usleep(300 * 1000);
-               timediff = 0;
-               while (timediff < MAX_RENUM_DELAY) {
+               timediff_ms = 0;
+               while (timediff_ms < MAX_RENUM_DELAY_MS) {
                        if ((err = dso_open(dev_index)) == SR_OK)
                                break;
                        g_usleep(100 * 1000);
-                       g_get_current_time(&cur_time);
-                       timediff = GTV_TO_MSEC(cur_time) - GTV_TO_MSEC(ctx->fw_updated);
+                       timediff_us = g_get_monotonic_time() - ctx->fw_updated;
+                       timediff_ms = timediff_us / 1000;
+                       sr_spew("hantek-dso: waited %" PRIi64 " ms", timediff_ms);
                }
-               sr_info("hantek-dso: device came back after %d ms", timediff);
+               sr_info("hantek-dso: device came back after %d ms", timediff_ms);
        } else {
                err = dso_open(dev_index);
        }
@@ -268,6 +354,8 @@ static int hw_cleanup(void)
                }
                dso_close(sdi);
                sr_usb_dev_inst_free(ctx->usb);
+               g_free(ctx->triggersource);
+
                sr_dev_inst_free(sdi);
        }
 
@@ -281,16 +369,14 @@ static int hw_cleanup(void)
        return SR_OK;
 }
 
-static void *hw_get_device_info(int dev_index, int dev_info_id)
+static const void *hw_dev_info_get(int dev_index, int dev_info_id)
 {
        struct sr_dev_inst *sdi;
-       struct context *ctx;
-       void *info;
+       const void *info;
        uint64_t tmp;
 
        if (!(sdi = sr_dev_inst_get(dev_insts, dev_index)))
                return NULL;
-       ctx = sdi->priv;
 
        info = NULL;
        switch (dev_info_id) {
@@ -298,11 +384,29 @@ static void *hw_get_device_info(int dev_index, int dev_info_id)
                info = sdi;
                break;
        case SR_DI_NUM_PROBES:
-               info = GINT_TO_POINTER(ctx->profile->num_probes);
+               info = GINT_TO_POINTER(NUM_PROBES);
                break;
        case SR_DI_PROBE_NAMES:
                info = probe_names;
                break;
+       case SR_DI_BUFFERSIZES:
+               info = buffersizes;
+               break;
+       case SR_DI_TIMEBASES:
+               info = timebases;
+               break;
+       case SR_DI_TRIGGER_SOURCES:
+               info = trigger_sources;
+               break;
+       case SR_DI_FILTERS:
+               info = filter_targets;
+               break;
+       case SR_DI_VDIVS:
+               info = vdivs;
+               break;
+       case SR_DI_COUPLING:
+               info = coupling;
+               break;
        /* TODO remove this */
        case SR_DI_CUR_SAMPLERATE:
                info = &tmp;
@@ -312,27 +416,30 @@ static void *hw_get_device_info(int dev_index, int dev_info_id)
        return info;
 }
 
-static int hw_get_status(int device_index)
+static int hw_dev_status_get(int dev_index)
 {
        struct sr_dev_inst *sdi;
 
-       if (!(sdi = sr_dev_inst_get(dev_insts, device_index)))
+       if (!(sdi = sr_dev_inst_get(dev_insts, dev_index)))
                return SR_ST_NOT_FOUND;
 
        return sdi->status;
 }
 
-static int *hwcap_get_all(void)
+static const int *hw_hwcap_get_all(void)
 {
-
-       return capabilities;
+       return hwcaps;
 }
 
-static int hw_dev_config_set(int dev_index, int hwcap, void *value)
+static int hw_dev_config_set(int dev_index, int hwcap, const void *value)
 {
        struct sr_dev_inst *sdi;
        struct context *ctx;
-       int tmp, ret;
+       struct sr_rational tmp_rat;
+       float tmp_float;
+       uint64_t tmp_u64;
+       int ret, i;
+       char **targets;
 
        if (!(sdi = sr_dev_inst_get(dev_insts, dev_index)))
                return SR_ERR;
@@ -340,16 +447,108 @@ static int hw_dev_config_set(int dev_index, int hwcap, void *value)
        if (sdi->status != SR_ST_ACTIVE)
                return SR_ERR;
 
+       ret = SR_OK;
        ctx = sdi->priv;
        switch (hwcap) {
+       case SR_HWCAP_LIMIT_FRAMES:
+               ctx->limit_frames = *(const uint64_t *)value;
+               break;
        case SR_HWCAP_PROBECONFIG:
-               ret = configure_probes(ctx, (GSList *) value);
+               ret = configure_probes(ctx, (const GSList *)value);
+               break;
+       case SR_HWCAP_TRIGGER_SLOPE:
+               tmp_u64 = *(const int *)value;
+               if (tmp_u64 != SLOPE_NEGATIVE && tmp_u64 != SLOPE_POSITIVE)
+                       ret = SR_ERR_ARG;
+               ctx->triggerslope = tmp_u64;
+               break;
+       case SR_HWCAP_HORIZ_TRIGGERPOS:
+               tmp_float = *(const float *)value;
+               if (tmp_float < 0.0 || tmp_float > 1.0) {
+                       sr_err("hantek-dso: trigger position should be between 0.0 and 1.0");
+                       ret = SR_ERR_ARG;
+               } else
+                       ctx->triggerposition = tmp_float;
+               break;
+       case SR_HWCAP_BUFFERSIZE:
+               tmp_u64 = *(const int *)value;
+               for (i = 0; buffersizes[i]; i++) {
+                       if (buffersizes[i] == tmp_u64) {
+                               ctx->framesize = tmp_u64;
+                               break;
+                       }
+               }
+               if (buffersizes[i] == 0)
+                       ret = SR_ERR_ARG;
+               break;
+       case SR_HWCAP_TIMEBASE:
+               tmp_rat = *(const struct sr_rational *)value;
+               for (i = 0; timebases[i].p && timebases[i].q; i++) {
+                       if (timebases[i].p == tmp_rat.p
+                                       && timebases[i].q == tmp_rat.q) {
+                               ctx->timebase = i;
+                               break;
+                       }
+               }
+               if (timebases[i].p == 0 && timebases[i].q == 0)
+                       ret = SR_ERR_ARG;
+               break;
+       case SR_HWCAP_TRIGGER_SOURCE:
+               for (i = 0; trigger_sources[i]; i++) {
+                       if (!strcmp(value, trigger_sources[i])) {
+                               ctx->triggersource = g_strdup(value);
+                               break;
+                       }
+               }
+               if (trigger_sources[i] == 0)
+                       ret = SR_ERR_ARG;
+               break;
+       case SR_HWCAP_FILTER:
+               ctx->filter_ch1 = ctx->filter_ch2 = ctx->filter_trigger = 0;
+               targets = g_strsplit(value, ",", 0);
+               for (i = 0; targets[i]; i++) {
+                       if (targets[i] == '\0')
+                               /* Empty filter string can be used to clear them all. */
+                               ;
+                       else if (!strcmp(targets[i], "CH1"))
+                               ctx->filter_ch1 = TRUE;
+                       else if (!strcmp(targets[i], "CH2"))
+                               ctx->filter_ch2 = TRUE;
+                       else if (!strcmp(targets[i], "TRIGGER"))
+                               ctx->filter_trigger = TRUE;
+                       else {
+                               sr_err("invalid filter target %s", targets[i]);
+                               ret = SR_ERR_ARG;
+                       }
+               }
+               g_strfreev(targets);
                break;
-       case SR_HWCAP_TRIGGERSLOPE:
-               tmp = *(int *)value;
-               if (tmp != SLOPE_NEGATIVE && tmp != SLOPE_POSITIVE)
+       case SR_HWCAP_VDIV:
+               /* TODO not supporting vdiv per channel yet */
+               tmp_rat = *(const struct sr_rational *)value;
+               for (i = 0; vdivs[i].p && vdivs[i].q; i++) {
+                       if (vdivs[i].p == tmp_rat.p
+                                       && vdivs[i].q == tmp_rat.q) {
+                               ctx->voltage_ch1 = i;
+                               ctx->voltage_ch2 = i;
+                               break;
+                       }
+               }
+               if (vdivs[i].p == 0 && vdivs[i].q == 0)
                        ret = SR_ERR_ARG;
-               ctx->triggerslope = tmp;
+               break;
+       case SR_HWCAP_COUPLING:
+               /* TODO not supporting coupling per channel yet */
+               for (i = 0; coupling[i]; i++) {
+                       if (!strcmp(value, coupling[i])) {
+                               ctx->coupling_ch1 = i;
+                               ctx->coupling_ch2 = i;
+                               break;
+                       }
+               }
+               if (coupling[i] == 0)
+                       ret = SR_ERR_ARG;
+               break;
        default:
                ret = SR_ERR_ARG;
        }
@@ -357,6 +556,52 @@ static int hw_dev_config_set(int dev_index, int hwcap, void *value)
        return ret;
 }
 
+static void send_chunk(struct context *ctx, unsigned char *buf,
+               int num_samples)
+{
+       struct sr_datafeed_packet packet;
+       struct sr_datafeed_analog analog;
+       float ch1, ch2, range;
+       int num_probes, data_offset, i;
+
+       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 = num_samples;
+       analog.mq = SR_MQ_VOLTAGE;
+       analog.unit = SR_UNIT_VOLT;
+       analog.data = g_try_malloc(analog.num_samples * sizeof(float) * num_probes);
+       data_offset = 0;
+       for (i = 0; i < analog.num_samples; i++) {
+               /* The device always sends data for both channels. If a channel
+                * is disabled, it contains a copy of the enabled channel's
+                * data. However, we only send the requested channels to the bus.
+                *
+                * Voltage values are encoded as a value 0-255 (0-512 on the 5200*),
+                * where the value is a point in the range represented by the vdiv
+                * setting. There are 8 vertical divs, so e.g. 500mV/div represents
+                * 4V peak-to-peak where 0 = -2V and 255 = +2V.
+                */
+               /* 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 * *(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 * *(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
@@ -365,10 +610,8 @@ static int hw_dev_config_set(int dev_index, int hwcap, void *value)
 static void receive_transfer(struct libusb_transfer *transfer)
 {
        struct sr_datafeed_packet packet;
-       struct sr_datafeed_analog analog;
        struct context *ctx;
-       float ch1, ch2;
-       int i;
+       int num_samples, pre;
 
        ctx = transfer->user_data;
        sr_dbg("hantek-dso: receive_transfer(): status %d received %d bytes",
@@ -378,37 +621,88 @@ static void receive_transfer(struct libusb_transfer *transfer)
                /* 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);
-       if (ctx->current_transfer >= ctx->framesize * 2) {
-               ctx->current_transfer = 0;
-               ctx->dev_state = NEW_CAPTURE;
-       }
+       num_samples = transfer->actual_length / 2;
 
-       packet.type = SR_DF_ANALOG;
-       packet.payload = &analog;
-       analog.num_samples = transfer->actual_length / 2;
-       analog.data = g_try_malloc(analog.num_samples * sizeof(float) * ctx->profile->num_probes);
-       for (i = 0; i < analog.num_samples; i++) {
-               /* Hardcoded for two channels, since the order/encoding is specific. */
-               /* TODO: support for 5xxx series 9-bit samples */
-               ch2 = (*(transfer->buffer + i * 2) / 255.0);
-               ch1 = (*(transfer->buffer + i * 2 + 1) / 255.0);
-               analog.data[i * ctx->profile->num_probes] = ch1;
-               analog.data[i * ctx->profile->num_probes + 1] = ch2;
+       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->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);
+
+               if (ctx->limit_frames && ++ctx->num_frames == ctx->limit_frames) {
+                       /* Terminate session */
+                       /* TODO: don't leave pending USB transfers hanging */
+                       packet.type = SR_DF_END;
+                       sr_session_send(ctx->cb_data, &packet);
+               } else {
+                       ctx->dev_state = NEW_CAPTURE;
+               }
+       }
 
 }
 
 static int handle_event(int fd, int revents, void *cb_data)
 {
+       struct sr_datafeed_packet packet;
        struct timeval tv;
        struct context *ctx;
-       int capturestate;
+       int num_probes;
+       uint32_t trigger_offset;
+       uint8_t capturestate;
 
        /* Avoid compiler warnings. */
        (void)fd;
@@ -425,8 +719,8 @@ static int handle_event(int fd, int revents, void *cb_data)
                        return TRUE;
                if (dso_enable_trigger(ctx) != SR_OK)
                        return TRUE;
-               if (dso_force_trigger(ctx) != SR_OK)
-                       return TRUE;
+//             if (dso_force_trigger(ctx) != SR_OK)
+//                     return TRUE;
                sr_dbg("hantek-dso: successfully requested next chunk");
                ctx->dev_state = CAPTURE;
                return TRUE;
@@ -434,12 +728,11 @@ static int handle_event(int fd, int revents, void *cb_data)
        if (ctx->dev_state != CAPTURE)
                return TRUE;
 
-       if ((capturestate = dso_get_capturestate(ctx)) == CAPTURE_UNKNOWN) {
-               /* Generated by the function, not the hardware. */
+       if ((dso_get_capturestate(ctx, &capturestate, &trigger_offset)) != SR_OK)
                return TRUE;
-       }
 
        sr_dbg("hantek-dso: capturestate %d", capturestate);
+       sr_dbg("hantek-dso: trigger offset 0x%.6x", trigger_offset);
        switch (capturestate) {
        case CAPTURE_EMPTY:
                if (++ctx->capture_empty_count >= MAX_CAPTURE_EMPTY) {
@@ -448,8 +741,8 @@ static int handle_event(int fd, int revents, void *cb_data)
                                break;
                        if (dso_enable_trigger(ctx) != SR_OK)
                                break;
-                       if (dso_force_trigger(ctx) != SR_OK)
-                               break;
+//                     if (dso_force_trigger(ctx) != SR_OK)
+//                             break;
                        sr_dbg("hantek-dso: successfully requested next chunk");
                }
                break;
@@ -457,18 +750,25 @@ static int handle_event(int fd, int revents, void *cb_data)
                /* 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;
-//             /* Current frame is on the way, make sure the scope
-//              * sends us the next one. */
-//             if (dso_capture_start(ctx) != SR_OK)
-//                     break;
-//             if (dso_enable_trigger(ctx) != SR_OK)
-//                     break;
-//             if (dso_force_trigger(ctx) != SR_OK)
-//                     break;
+
+               /* Don't hit the state machine again until we're done fetching
+                * the data we just told the scope to send.
+                */
                ctx->dev_state = FETCH_DATA;
+
+               /* Tell the frontend a new frame is on the way. */
+               packet.type = SR_DF_FRAME_BEGIN;
+               sr_session_send(cb_data, &packet);
                break;
        case CAPTURE_READY_9BIT:
                /* TODO */
@@ -484,7 +784,7 @@ static int handle_event(int fd, int revents, void *cb_data)
        return TRUE;
 }
 
-static int hw_start_acquisition(int device_index, void *cb_data)
+static int hw_dev_acquisition_start(int dev_index, void *cb_data)
 {
        const struct libusb_pollfd **lupfd;
        struct sr_datafeed_packet packet;
@@ -494,7 +794,7 @@ static int hw_start_acquisition(int device_index, void *cb_data)
        struct context *ctx;
        int i;
 
-       if (!(sdi = sr_dev_inst_get(dev_insts, device_index)))
+       if (!(sdi = sr_dev_inst_get(dev_insts, dev_index)))
                return SR_ERR;
 
        if (sdi->status != SR_ST_ACTIVE)
@@ -526,7 +826,7 @@ static int hw_start_acquisition(int device_index, void *cb_data)
        /* Send metadata about the SR_DF_ANALOG packets to come. */
        packet.type = SR_DF_META_ANALOG;
        packet.payload = &meta;
-       meta.num_probes = ctx->profile->num_probes;
+       meta.num_probes = NUM_PROBES;
        sr_session_send(cb_data, &packet);
 
        return SR_OK;
@@ -535,13 +835,13 @@ static int hw_start_acquisition(int device_index, void *cb_data)
 /* TODO: doesn't really cancel pending transfers so they might come in after
  * SR_DF_END is sent.
  */
-static int hw_stop_acquisition(int device_index, gpointer session_device_id)
+static int hw_dev_acquisition_stop(int dev_index, void *cb_data)
 {
        struct sr_datafeed_packet packet;
        struct sr_dev_inst *sdi;
        struct context *ctx;
 
-       if (!(sdi = sr_dev_inst_get(dev_insts, device_index)))
+       if (!(sdi = sr_dev_inst_get(dev_insts, dev_index)))
                return SR_ERR;
 
        if (sdi->status != SR_ST_ACTIVE)
@@ -551,23 +851,24 @@ static int hw_stop_acquisition(int device_index, gpointer session_device_id)
        ctx->dev_state = IDLE;
 
        packet.type = SR_DF_END;
-       sr_session_send(session_device_id, &packet);
+       sr_session_send(cb_data, &packet);
 
        return SR_OK;
 }
 
-SR_PRIV struct sr_dev_driver hantek_dso_plugin_info = {
+SR_PRIV struct sr_dev_driver hantek_dso_driver_info = {
        .name = "hantek-dso",
        .longname = "Hantek DSO",
        .api_version = 1,
        .init = hw_init,
        .cleanup = hw_cleanup,
+       .scan = hw_scan,
        .dev_open = hw_dev_open,
        .dev_close = hw_dev_close,
-       .dev_info_get = hw_get_device_info,
-       .dev_status_get = hw_get_status,
-       .hwcap_get_all = hwcap_get_all,
+       .dev_info_get = hw_dev_info_get,
+       .dev_status_get = hw_dev_status_get,
+       .hwcap_get_all = hw_hwcap_get_all,
        .dev_config_set = hw_dev_config_set,
-       .dev_acquisition_start = hw_start_acquisition,
-       .dev_acquisition_stop = hw_stop_acquisition,
+       .dev_acquisition_start = hw_dev_acquisition_start,
+       .dev_acquisition_stop = hw_dev_acquisition_stop,
 };