DSView/libsigrok4DSL/session_driver.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2013 Bert Vermeulen <bert@biot.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "libsigrok.h"
#include "libsigrok-internal.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/time.h>
#include <zip.h>
#include <assert.h>
#include <string.h>

/* Message logging helpers with subsystem-specific prefix string. */
#define LOG_PREFIX "virtual-session: "
#define sr_log(l, s, args...) sr_log(l, LOG_PREFIX s, ## args)
#define sr_spew(s, args...) sr_spew(LOG_PREFIX s, ## args)
#define sr_dbg(s, args...) sr_dbg(LOG_PREFIX s, ## args)
#define sr_info(s, args...) sr_info(LOG_PREFIX s, ## args)
#define sr_warn(s, args...) sr_warn(LOG_PREFIX s, ## args)
#define sr_err(s, args...) sr_err(LOG_PREFIX s, ## args)

/* size of payloads sent across the session bus */
/** @cond PRIVATE */
#define CHUNKSIZE (512 * 1024)
#define UNITLEN 64
/** @endcond */

static uint64_t samplerates[1];
static uint64_t samplecounts[1];

static const char *maxHeights[] = {
    "1X",
    "2X",
    "3X",
    "4X",
    "5X",
};
static const uint64_t vdivs[] = {
    SR_mV(10),
    SR_mV(20),
    SR_mV(50),
    SR_mV(100),
    SR_mV(200),
    SR_mV(500),
    SR_V(1),
    SR_V(2),
};

struct session_vdev {
    int version;
	char *sessionfile;
	char *capturefile;
	struct zip *archive;
	struct zip_file *capfile;
    void *buf;
    void *logic_buf;
	int bytes_read;
    int cur_channel;
    int cur_block;
    int num_blocks;
    gboolean file_opened;
	uint64_t samplerate;
    uint64_t total_samples;
    int64_t trig_time;
    uint64_t trig_pos;
	int num_probes;
    int enabled_probes;
    uint64_t timebase;
    uint8_t unit_bits;
    uint8_t max_height;
    struct sr_status mstatus;
};

static GSList *dev_insts = NULL;

static const int hwoptions[] = {
    SR_CONF_MAX_HEIGHT,
};

static const int32_t probeOptions[] = {
    SR_CONF_PROBE_MAP_UNIT,
    SR_CONF_PROBE_MAP_MIN,
    SR_CONF_PROBE_MAP_MAX,
};

static const char *probeMapUnits[] = {
    "V",
    "A",
    "℃",
    "℉",
    "g",
    "m",
    "m/s",
};

static int trans_data(struct sr_dev_inst *sdi)
{
    // translate for old format
    struct session_vdev *vdev = sdi->priv;
    GSList *l;
    struct sr_channel *probe;

    assert(vdev->buf != NULL);
    assert(vdev->logic_buf != NULL);
    assert(CHUNKSIZE % UNITLEN == 0);

    //int bytes = ceil(vdev->num_probes / 8.0);
    int bytes = 2;
    uint8_t *src_ptr = (uint8_t *)vdev->buf;
    uint64_t *dest_ptr = (uint64_t *)vdev->logic_buf;
    for (int k = 0; k < CHUNKSIZE / (UNITLEN * bytes); k++) {
        src_ptr = (uint8_t *)vdev->buf + (k * bytes * UNITLEN);
        for (l = sdi->channels; l; l = l->next) {
            probe = l->data;
            if (!probe->enabled)
                continue;
            uint64_t mask = 1ULL << probe->index;
            uint64_t result = 0;
            for (int j = 0; j < UNITLEN; j++) {
                if (*(uint64_t *)(src_ptr + j * bytes) & mask)
                    result += 1ULL << j;
            }
            *dest_ptr++ = result;
        }
    }

    return SR_OK;
}

static int receive_data(int fd, int revents, const struct sr_dev_inst *cb_sdi)
{
	struct sr_dev_inst *sdi;
    struct session_vdev *vdev = NULL;
	struct sr_datafeed_packet packet;
	struct sr_datafeed_logic logic;
    struct sr_datafeed_dso dso;
    struct sr_datafeed_analog analog;
	GSList *l;
    int ret;
    char file_name[32];
    struct sr_channel *probe = NULL;
    GSList *pl;
    int channel;

	(void)fd;
    //(void)revents;

	sr_dbg("Feed chunk.");

    ret = 0;
    packet.status = SR_PKT_OK;
	for (l = dev_insts; l; l = l->next) {
		sdi = l->data;
		vdev = sdi->priv;
		if (!vdev)
			/* already done with this instance */
			continue;

        assert(vdev->unit_bits > 0);
        assert(vdev->cur_channel >= 0);
        if (vdev->cur_channel < vdev->num_probes) {
            if (vdev->version == 1) {
                ret = zip_fread(vdev->capfile, vdev->buf, CHUNKSIZE);
            } else if (vdev->version == 2) {
                channel = vdev->cur_channel;
                pl = sdi->channels;
                while (channel--)
                    pl = pl->next;
                probe = (struct sr_channel *)pl->data;

                if (!vdev->file_opened) {
                    char *type_name = (probe->type == SR_CHANNEL_LOGIC) ? "L" :
                                (probe->type == SR_CHANNEL_DSO) ? "O" :
                                (probe->type == SR_CHANNEL_ANALOG) ? "A" : "U";
                    snprintf(file_name, 31, "%s-%d/%d", type_name,
                             sdi->mode == LOGIC ? probe->index : 0, vdev->cur_block);
                    if (!(vdev->capfile = zip_fopen(vdev->archive, file_name, 0))) {
                        sr_err("Failed to open capture file '%s' in "
                               "session file '%s'.", file_name, vdev->sessionfile);
                    } else {
                        vdev->file_opened = TRUE;
                    }
                }
                if (vdev->file_opened)
                    ret = zip_fread(vdev->capfile, vdev->buf, CHUNKSIZE);
            }

            if (!vdev->file_opened) {
                packet.type = SR_DF_END;
                packet.status = SR_PKT_SOURCE_ERROR;
                sr_session_send(cb_sdi, &packet);
                sr_session_source_remove(-1);
                return FALSE;
            }

            if (ret > 0) {
                if (sdi->mode == DSO) {
                    packet.type = SR_DF_DSO;
                    packet.payload = &dso;
                    dso.num_samples = ret / vdev->num_probes;
                    dso.data = vdev->buf;
                    dso.probes = sdi->channels;
                    dso.mq = SR_MQ_VOLTAGE;
                    dso.unit = SR_UNIT_VOLT;
                    dso.mqflags = SR_MQFLAG_AC;
                } else if (sdi->mode == ANALOG){
                    packet.type = SR_DF_ANALOG;
                    packet.payload = &analog;
                    analog.probes = sdi->channels;
                    analog.num_samples = ret / vdev->num_probes / ((vdev->unit_bits + 7) / 8);
                    analog.unit_bits = vdev->unit_bits;
                    analog.mq = SR_MQ_VOLTAGE;
                    analog.unit = SR_UNIT_VOLT;
                    analog.mqflags = SR_MQFLAG_AC;
                    analog.data = vdev->buf;
                } else {
                    packet.type = SR_DF_LOGIC;
                    packet.payload = &logic;
                    logic.length = ret;
                    logic.format = (vdev->version == 2) ? LA_SPLIT_DATA : LA_CROSS_DATA;
                    if (probe)
                        logic.index = probe->index;
                    else
                        logic.index = 0;
                    logic.order = vdev->cur_channel;

                    if (vdev->version == 1) {
                        logic.length = ret / 16 * vdev->enabled_probes;
                        logic.data = vdev->logic_buf;
                        trans_data(sdi);
                    } else if (vdev->version == 2) {
                        logic.length = ret;
                        logic.data = vdev->buf;
                    }
                }
                vdev->bytes_read += ret;
                sr_session_send(cb_sdi, &packet);
            } else {
                /* done with this capture file */
                zip_fclose(vdev->capfile);

                if (vdev->version == 1) {
                    vdev->cur_channel++;
                } else if (vdev->version == 2) {
                    vdev->file_opened = FALSE;
                    vdev->cur_block++;
                    if (vdev->cur_block == vdev->num_blocks) {
                        vdev->cur_block = 0;
                        vdev->cur_channel++;
                    }
                }
            }
        }
	}

    if (!vdev ||
        vdev->cur_channel >= vdev->num_probes ||
        revents == -1) {
		packet.type = SR_DF_END;
		sr_session_send(cb_sdi, &packet);
		sr_session_source_remove(-1);
	}

	return TRUE;
}

/* driver callbacks */
static int dev_clear(void);

static int init(struct sr_context *sr_ctx)
{
	(void)sr_ctx;

	return SR_OK;
}

static int dev_clear(void)
{
	GSList *l;

	for (l = dev_insts; l; l = l->next)
		sr_dev_inst_free(l->data);
	g_slist_free(dev_insts);
	dev_insts = NULL;

	return SR_OK;
}

static int dev_open(struct sr_dev_inst *sdi)
{
	if (!(sdi->priv = g_try_malloc0(sizeof(struct session_vdev)))) {
		sr_err("%s: sdi->priv malloc failed", __func__);
		return SR_ERR_MALLOC;
	}

    struct session_vdev *vdev;
    vdev = sdi->priv;
    if (!(vdev->buf = g_try_malloc(CHUNKSIZE + sizeof(uint64_t)))) {
        sr_err("%s: vdev->buf malloc failed", __func__);
        return SR_ERR_MALLOC;
    }
    vdev->trig_pos = 0;
    vdev->trig_time = 0;
    vdev->cur_block = 0;
    vdev->cur_channel = 0;
    vdev->file_opened = FALSE;
    vdev->num_blocks = 0;
    vdev->unit_bits = 1;
    vdev->max_height = 0;

	dev_insts = g_slist_append(dev_insts, sdi);

	return SR_OK;
}

static int dev_close(struct sr_dev_inst *sdi)
{
    const struct session_vdev *const vdev = sdi->priv;
    g_free(vdev->sessionfile);
    g_free(vdev->capturefile);
    g_free(vdev->buf);
    if (vdev->logic_buf)
        g_free(vdev->logic_buf);

    g_free(sdi->priv);
    sdi->priv = NULL;

    return SR_OK;
}

static int config_get(int id, GVariant **data, const struct sr_dev_inst *sdi,
                      const struct sr_channel *ch,
                      const struct sr_channel_group *cg)
{
    (void)cg;

	struct session_vdev *vdev;

	switch (id) {
	case SR_CONF_SAMPLERATE:
		if (sdi) {
			vdev = sdi->priv;
			*data = g_variant_new_uint64(vdev->samplerate);
		} else
			return SR_ERR;
		break;
    case SR_CONF_LIMIT_SAMPLES:
        if (sdi) {
            vdev = sdi->priv;
            *data = g_variant_new_uint64(vdev->total_samples);
        } else
            return SR_ERR;
        break;
    case SR_CONF_TRIGGER_TIME:
        if (sdi) {
            vdev = sdi->priv;
            *data = g_variant_new_int64(vdev->trig_time);
        } else
            return SR_ERR;
        break;
    case SR_CONF_TIMEBASE:
        if (sdi) {
            vdev = sdi->priv;
            *data = g_variant_new_uint64(vdev->timebase);
        } else
            return SR_ERR;
        break;
    case SR_CONF_MAX_TIMEBASE:
        if (!sdi)
            return SR_ERR;
        *data = g_variant_new_uint64(MAX_TIMEBASE);
        break;
    case SR_CONF_UNIT_BITS:
        if (sdi) {
            vdev = sdi->priv;
            *data = g_variant_new_byte(vdev->unit_bits);
        } else
            return SR_ERR;
        break;
    case SR_CONF_PROBE_EN:
        if (sdi && ch) {
            *data = g_variant_new_boolean(ch->enabled);
        } else
            return SR_ERR;
        break;
    case SR_CONF_PROBE_COUPLING:
        if (sdi && ch) {
            *data = g_variant_new_byte(ch->coupling);
        } else
            return SR_ERR;
        break;
    case SR_CONF_PROBE_VDIV:
        if (sdi && ch) {
            *data = g_variant_new_uint64(ch->vdiv);
        } else
            return SR_ERR;
        break;
    case SR_CONF_PROBE_FACTOR:
        if (sdi && ch) {
            *data = g_variant_new_uint64(ch->vfactor);
        } else
            return SR_ERR;
        break;
    case SR_CONF_PROBE_VPOS:
        if (sdi && ch) {
            *data = g_variant_new_double(ch->vpos);
        } else
            return SR_ERR;
        break;
    case SR_CONF_PROBE_MAP_UNIT:
        if (!sdi || !ch)
            return SR_ERR;
        *data = g_variant_new_string(ch->map_unit);
        break;
    case SR_CONF_PROBE_MAP_MIN:
        if (!sdi || !ch)
            return SR_ERR;
        *data = g_variant_new_double(ch->map_min);
        break;
    case SR_CONF_PROBE_MAP_MAX:
        if (!sdi || !ch)
            return SR_ERR;
        *data = g_variant_new_double(ch->map_max);
        break;
    case SR_CONF_TRIGGER_VALUE:
        if (sdi && ch) {
            *data = g_variant_new_byte(ch->trig_value);
        } else
            return SR_ERR;
        break;
    case SR_CONF_MAX_DSO_SAMPLERATE:
        if (!sdi)
            return SR_ERR;
        vdev = sdi->priv;
        *data = g_variant_new_uint64(vdev->samplerate);
        break;
    case SR_CONF_MAX_DSO_SAMPLELIMITS:
        if (!sdi)
            return SR_ERR;
        vdev = sdi->priv;
        *data = g_variant_new_uint64(vdev->total_samples);
        break;
    case SR_CONF_HW_DEPTH:
        if (!sdi)
            return SR_ERR;
        vdev = sdi->priv;
        *data = g_variant_new_uint64(vdev->total_samples);
        break;
    case SR_CONF_MAX_HEIGHT:
        if (!sdi)
            return SR_ERR;
        vdev = sdi->priv;
        *data = g_variant_new_string(maxHeights[vdev->max_height]);
        break;
    case SR_CONF_MAX_HEIGHT_VALUE:
        if (!sdi)
            return SR_ERR;
        vdev = sdi->priv;
        *data = g_variant_new_byte(vdev->max_height);
        break;
    case SR_CONF_VLD_CH_NUM:
        if (!sdi)
            return SR_ERR;
        vdev = sdi->priv;
        *data = g_variant_new_int16(vdev->num_probes);
        break;
    case SR_CONF_FILE_VERSION:
        if (!sdi)
            return SR_ERR;
        vdev = sdi->priv;
        *data = g_variant_new_int16(vdev->version);
        break;
    default:
		return SR_ERR_ARG;
	}

	return SR_OK;
}

static int config_set(int id, GVariant *data, struct sr_dev_inst *sdi,
                      struct sr_channel *ch,
                      struct sr_channel_group *cg)
{
    (void)cg;

	struct session_vdev *vdev;
    const char *stropt;
    unsigned int i;

	vdev = sdi->priv;

	switch (id) {
	case SR_CONF_SAMPLERATE:
		vdev->samplerate = g_variant_get_uint64(data);
        samplerates[0] = vdev->samplerate;
		sr_info("Setting samplerate to %" PRIu64 ".", vdev->samplerate);
		break;
    case SR_CONF_TIMEBASE:
        vdev->timebase = g_variant_get_uint64(data);
        sr_info("Setting timebase to %" PRIu64 ".", vdev->timebase);
        break;
    case SR_CONF_UNIT_BITS:
        vdev->unit_bits = g_variant_get_byte(data);
        sr_info("Setting unit bits to %d.", vdev->unit_bits);
        break;
    case SR_CONF_SESSIONFILE:
        vdev->sessionfile = g_strdup(g_variant_get_bytestring(data));
		sr_info("Setting sessionfile to '%s'.", vdev->sessionfile);
		break;
	case SR_CONF_CAPTUREFILE:
        vdev->capturefile = g_strdup(g_variant_get_bytestring(data));
		sr_info("Setting capturefile to '%s'.", vdev->capturefile);
		break;
    case SR_CONF_FILE_VERSION:
        vdev->version = g_variant_get_int16(data);
        sr_info("Setting file version to '%d'.", vdev->version);
        break;
    case SR_CONF_LIMIT_SAMPLES:
        vdev->total_samples = g_variant_get_uint64(data);
        samplecounts[0] = vdev->total_samples;
        sr_info("Setting limit samples to %" PRIu64 ".", vdev->total_samples);
        break;
    case SR_CONF_TRIGGER_TIME:
        vdev->trig_time = g_variant_get_int64(data);
        sr_info("Setting trigger time to %" PRId64 ".", vdev->trig_time);
        break;
    case SR_CONF_TRIGGER_POS:
        vdev->trig_pos = g_variant_get_uint64(data);
        sr_info("Setting trigger position to %" PRIu64 ".", vdev->trig_pos);
        break;
    case SR_CONF_NUM_BLOCKS:
        vdev->num_blocks = g_variant_get_uint64(data);
        sr_info("Setting block number to %" PRIu64 ".", vdev->num_blocks);
        break;
    case SR_CONF_CAPTURE_NUM_PROBES:
		vdev->num_probes = g_variant_get_uint64(data);
        if (sdi->mode == LOGIC) {
            if (!(vdev->logic_buf = g_try_malloc(CHUNKSIZE/16*vdev->num_probes))) {
                sr_err("%s: vdev->logic_buf malloc failed", __func__);
            }
        }
		break;
    case SR_CONF_PROBE_EN:
        ch->enabled = g_variant_get_boolean(data);
        break;
    case SR_CONF_PROBE_COUPLING:
        ch->coupling = g_variant_get_byte(data);
        break;
    case SR_CONF_PROBE_VDIV:
        ch->vdiv = g_variant_get_uint64(data);
        break;
    case SR_CONF_PROBE_FACTOR:
        ch->vfactor = g_variant_get_uint64(data);
        break;
    case SR_CONF_PROBE_VPOS:
        ch->vpos = g_variant_get_double(data);
        break;
    case SR_CONF_PROBE_MAP_UNIT:
        ch->map_unit = g_variant_get_string(data, NULL);
        break;
    case SR_CONF_PROBE_MAP_MIN:
        ch->map_min = g_variant_get_double(data);
        break;
    case SR_CONF_PROBE_MAP_MAX:
        ch->map_max = g_variant_get_double(data);
        break;
    case SR_CONF_TRIGGER_VALUE:
        ch->trig_value = g_variant_get_byte(data);
        break;
    case SR_CONF_STATUS_PERIOD:
        if (ch->index == 0)
            vdev->mstatus.ch0_period = g_variant_get_uint64(data);
        else
            vdev->mstatus.ch1_period = g_variant_get_uint64(data);
        break;
    case SR_CONF_STATUS_PCNT:
        if (ch->index == 0)
            vdev->mstatus.ch0_pcnt = g_variant_get_uint64(data);
        else
            vdev->mstatus.ch1_pcnt = g_variant_get_uint64(data);
        break;
    case SR_CONF_STATUS_MAX:
        if (ch->index == 0)
            vdev->mstatus.ch0_max = g_variant_get_uint64(data);
        else
            vdev->mstatus.ch1_max = g_variant_get_uint64(data);
        break;
    case SR_CONF_STATUS_MIN:
        if (ch->index == 0)
            vdev->mstatus.ch0_min = g_variant_get_uint64(data);
        else
            vdev->mstatus.ch1_min = g_variant_get_uint64(data);
        break;
    case SR_CONF_MAX_HEIGHT:
        stropt = g_variant_get_string(data, NULL);
        for (i = 0; i < ARRAY_SIZE(maxHeights); i++) {
            if (!strcmp(stropt, maxHeights[i])) {
                vdev->max_height = i;
                break;
            }
        }
        sr_dbg("%s: setting Signal Max Height to %d",
            __func__, vdev->max_height);
        break;
    default:
		sr_err("Unknown capability: %d.", id);
		return SR_ERR;
	}

	return SR_OK;
}

static int config_list(int key, GVariant **data,
                       const struct sr_dev_inst *sdi,
                       const struct sr_channel_group *cg)
{
    (void)cg;

    GVariant *gvar;
    GVariantBuilder gvb;

	(void)sdi;

	switch (key) {
    case SR_CONF_DEVICE_OPTIONS:
//		*data = g_variant_new_fixed_array(G_VARIANT_TYPE_INT32,
//				hwcaps, ARRAY_SIZE(hwcaps), sizeof(int32_t));
        *data = g_variant_new_from_data(G_VARIANT_TYPE("ai"),
                hwoptions, ARRAY_SIZE(hwoptions)*sizeof(int32_t), TRUE, NULL, NULL);
        break;
    case SR_CONF_SAMPLERATE:
        g_variant_builder_init(&gvb, G_VARIANT_TYPE("a{sv}"));
//		gvar = g_variant_new_fixed_array(G_VARIANT_TYPE("t"), samplerates,
//				ARRAY_SIZE(samplerates), sizeof(uint64_t));
        gvar = g_variant_new_from_data(G_VARIANT_TYPE("at"),
                samplerates, ARRAY_SIZE(samplerates)*sizeof(uint64_t), TRUE, NULL, NULL);
        g_variant_builder_add(&gvb, "{sv}", "samplerates", gvar);
        *data = g_variant_builder_end(&gvb);
        break;
    case SR_CONF_LIMIT_SAMPLES:
        g_variant_builder_init(&gvb, G_VARIANT_TYPE("a{sv}"));
        gvar = g_variant_new_from_data(G_VARIANT_TYPE("at"),
                samplecounts, ARRAY_SIZE(samplecounts)*sizeof(uint64_t), TRUE, NULL, NULL);
        g_variant_builder_add(&gvb, "{sv}", "samplecounts", gvar);
        *data = g_variant_builder_end(&gvb);
        break;
    case SR_CONF_MAX_HEIGHT:
        *data = g_variant_new_strv(maxHeights, ARRAY_SIZE(maxHeights));
        break;

    case SR_CONF_PROBE_CONFIGS:
        *data = g_variant_new_from_data(G_VARIANT_TYPE("ai"),
                probeOptions, ARRAY_SIZE(probeOptions)*sizeof(int32_t), TRUE, NULL, NULL);
        break;
    case SR_CONF_PROBE_VDIV:
        g_variant_builder_init(&gvb, G_VARIANT_TYPE("a{sv}"));
        gvar = g_variant_new_from_data(G_VARIANT_TYPE("at"),
                vdivs, ARRAY_SIZE(vdivs)*sizeof(uint64_t), TRUE, NULL, NULL);
        g_variant_builder_add(&gvb, "{sv}", "vdivs", gvar);
        *data = g_variant_builder_end(&gvb);
        break;
    case SR_CONF_PROBE_MAP_UNIT:
        *data = g_variant_new_strv(probeMapUnits, ARRAY_SIZE(probeMapUnits));
        break;
    default:
		return SR_ERR_ARG;
	}

	return SR_OK;
}

static int dev_status_get(const struct sr_dev_inst *sdi, struct sr_status *status, gboolean prg, int begin, int end)
{
    (void)prg;
    (void)begin;
    (void)end;

    struct session_vdev *vdev;

    if (sdi) {
        vdev = sdi->priv;
        *status = vdev->mstatus;
        return SR_OK;
    } else {
        return SR_ERR;
    }
}

static int dev_acquisition_start(struct sr_dev_inst *sdi,
		void *cb_data)
{
    (void)cb_data;

	struct zip_stat zs;
	struct session_vdev *vdev;
    struct sr_datafeed_packet packet;
	int ret;
    GSList *l;
    struct sr_channel *probe;

	vdev = sdi->priv;
    vdev->enabled_probes = 0;
    packet.status = SR_PKT_OK;

	sr_info("Opening archive %s file %s", vdev->sessionfile,
		vdev->capturefile);

	if (!(vdev->archive = zip_open(vdev->sessionfile, 0, &ret))) {
		sr_err("Failed to open session file '%s': "
		       "zip error %d\n", vdev->sessionfile, ret);
		return SR_ERR;
	}

    if (vdev->version == 1) {
        if (zip_stat(vdev->archive, vdev->capturefile, 0, &zs) == -1) {
            sr_err("Failed to check capture file '%s' in "
                   "session file '%s'.", vdev->capturefile, vdev->sessionfile);
            return SR_ERR;
        }

        if (!(vdev->capfile = zip_fopen(vdev->archive, vdev->capturefile, 0))) {
            sr_err("Failed to open capture file '%s' in "
                   "session file '%s'.", vdev->capturefile, vdev->sessionfile);
            return SR_ERR;
        }
        vdev->file_opened = TRUE;
        vdev->cur_channel = vdev->num_probes - 1;
    } else {
        if (sdi->mode == LOGIC)
            vdev->cur_channel = 0;
        else
            vdev->cur_channel = vdev->num_probes - 1;
    }

    for (l = sdi->channels; l; l = l->next) {
        probe = l->data;
        if (probe->enabled)
            vdev->enabled_probes++;
    }

	/* Send header packet to the session bus. */
    std_session_send_df_header(sdi, LOG_PREFIX);

    /* Send trigger packet to the session bus */
    if (vdev->trig_pos != 0) {
        struct ds_trigger_pos session_trigger;
        if (sdi->mode == DSO)
            session_trigger.real_pos = vdev->trig_pos * vdev->enabled_probes / vdev->num_probes;
        else
            session_trigger.real_pos = vdev->trig_pos;
        packet.type = SR_DF_TRIGGER;
        packet.payload = &session_trigger;
        sr_session_send(sdi, &packet);
    }

	/* freewheeling source */
    sr_session_source_add(-1, 0, 0, receive_data, sdi);

	return SR_OK;
}

/** @private */
SR_PRIV struct sr_dev_driver session_driver = {
    .name = "virtual-session",
    .longname = "Session-emulating driver",
    .api_version = 1,
    .init = init,
    .cleanup = dev_clear,
    .scan = NULL,
    .dev_list = NULL,
    .dev_mode_list = NULL,
    .dev_clear = dev_clear,
    .config_get = config_get,
    .config_set = config_set,
    .config_list = config_list,
    .dev_open = dev_open,
    .dev_close = dev_close,
    .dev_status_get = dev_status_get,
    .dev_acquisition_start = dev_acquisition_start,
    .dev_acquisition_stop = NULL,
    .priv = NULL,
};