[libsigrok.git] / src / hardware / victor-dmm / api.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2012 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 <glib.h>
#include <libusb.h>
#include <stdlib.h>
#include <string.h>
#include "libsigrok.h"
#include "libsigrok-internal.h"
#include "protocol.h"

#define VICTOR_VID 0x1244
#define VICTOR_PID 0xd237
#define VICTOR_VENDOR "Victor"
#define VICTOR_INTERFACE 0
#define VICTOR_ENDPOINT LIBUSB_ENDPOINT_IN | 1

SR_PRIV struct sr_dev_driver victor_dmm_driver_info;
static struct sr_dev_driver *di = &victor_dmm_driver_info;
static int dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data);

static const uint32_t hwopts[] = {
	SR_CONF_CONN,
};

static const uint32_t hwcaps[] = {
	SR_CONF_MULTIMETER,
	SR_CONF_LIMIT_MSEC,
	SR_CONF_LIMIT_SAMPLES,
	SR_CONF_CONTINUOUS,
};

static int init(struct sr_context *sr_ctx)
{
	return std_init(sr_ctx, di, LOG_PREFIX);
}

static GSList *scan(GSList *options)
{
	struct drv_context *drvc;
	struct dev_context *devc;
	struct sr_dev_inst *sdi;
	struct sr_channel *ch;
	struct libusb_device_descriptor des;
	libusb_device **devlist;
	GSList *devices;
	int ret, devcnt, i;

	(void)options;

	drvc = di->priv;

	devices = NULL;
	libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
	for (i = 0; devlist[i]; i++) {
		if ((ret = libusb_get_device_descriptor(devlist[i], &des)) != 0) {
			sr_warn("Failed to get device descriptor: %s",
					libusb_error_name(ret));
			continue;
		}

		if (des.idVendor != VICTOR_VID || des.idProduct != VICTOR_PID)
			continue;

		devcnt = g_slist_length(drvc->instances);
		if (!(sdi = sr_dev_inst_new(devcnt, SR_ST_INACTIVE,
				VICTOR_VENDOR, NULL, NULL)))
			return NULL;
		sdi->driver = di;

		if (!(devc = g_try_malloc0(sizeof(struct dev_context))))
			return NULL;
		sdi->priv = devc;

		if (!(ch = sr_channel_new(0, SR_CHANNEL_ANALOG, TRUE, "P1")))
			return NULL;
		sdi->channels = g_slist_append(NULL, ch);

		if (!(sdi->conn = sr_usb_dev_inst_new(libusb_get_bus_number(devlist[i]),
				libusb_get_device_address(devlist[i]), NULL)))
			return NULL;
		sdi->inst_type = SR_INST_USB;

		drvc->instances = g_slist_append(drvc->instances, sdi);
		devices = g_slist_append(devices, sdi);
	}
	libusb_free_device_list(devlist, 1);

	return devices;
}

static GSList *dev_list(void)
{
	return ((struct drv_context *)(di->priv))->instances;
}

static int dev_open(struct sr_dev_inst *sdi)
{
	struct drv_context *drvc = di->priv;
	struct sr_usb_dev_inst *usb;
	libusb_device **devlist;
	int ret, i;

	if (!di->priv) {
		sr_err("Driver was not initialized.");
		return SR_ERR;
	}

	usb = sdi->conn;

	libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
	for (i = 0; devlist[i]; i++) {
		if (libusb_get_bus_number(devlist[i]) != usb->bus
				|| libusb_get_device_address(devlist[i]) != usb->address)
			continue;
		if ((ret = libusb_open(devlist[i], &usb->devhdl))) {
			sr_err("Failed to open device: %s.", libusb_error_name(ret));
			return SR_ERR;
		}
		break;
	}
	libusb_free_device_list(devlist, 1);
	if (!devlist[i]) {
		sr_err("Device not found.");
		return SR_ERR;
	}

	/* The device reports as HID class, so the kernel would have
	 * claimed it. */
	if (libusb_kernel_driver_active(usb->devhdl, 0) == 1) {
		if ((ret = libusb_detach_kernel_driver(usb->devhdl, 0)) < 0) {
			sr_err("Failed to detach kernel driver: %s.",
			       libusb_error_name(ret));
			return SR_ERR;
		}
	}

	if ((ret = libusb_claim_interface(usb->devhdl,
			VICTOR_INTERFACE))) {
		sr_err("Failed to claim interface: %s.", libusb_error_name(ret));
		return SR_ERR;
	}
	sdi->status = SR_ST_ACTIVE;

	return SR_OK;
}

static int dev_close(struct sr_dev_inst *sdi)
{
	struct sr_usb_dev_inst *usb;

	if (!di->priv) {
		sr_err("Driver was not initialized.");
		return SR_ERR;
	}

	usb = sdi->conn;

	if (!usb->devhdl)
		/*  Nothing to do. */
		return SR_OK;

	libusb_release_interface(usb->devhdl, VICTOR_INTERFACE);
	libusb_close(usb->devhdl);
	usb->devhdl = NULL;
	sdi->status = SR_ST_INACTIVE;

	return SR_OK;
}

static int cleanup(void)
{
	int ret;
	struct drv_context *drvc;

	if (!(drvc = di->priv))
		/* Can get called on an unused driver, doesn't matter. */
		return SR_OK;


	ret = std_dev_clear(di, NULL);
	g_free(drvc);
	di->priv = NULL;

	return ret;
}

static int config_get(uint32_t key, GVariant **data, const struct sr_dev_inst *sdi,
		const struct sr_channel_group *cg)
{
	struct sr_usb_dev_inst *usb;
	char str[128];

	(void)cg;

	switch (key) {
	case SR_CONF_CONN:
		if (!sdi || !sdi->conn)
			return SR_ERR_ARG;
		usb = sdi->conn;
		snprintf(str, 128, "%d.%d", usb->bus, usb->address);
		*data = g_variant_new_string(str);
		break;
	default:
		return SR_ERR_NA;
	}

	return SR_OK;
}

static int config_set(uint32_t key, GVariant *data, const struct sr_dev_inst *sdi,
		const struct sr_channel_group *cg)
{
	struct dev_context *devc;
	gint64 now;
	int ret;

	(void)cg;

	if (sdi->status != SR_ST_ACTIVE)
		return SR_ERR_DEV_CLOSED;

	if (!di->priv) {
		sr_err("Driver was not initialized.");
		return SR_ERR;
	}

	devc = sdi->priv;
	ret = SR_OK;
	switch (key) {
	case SR_CONF_LIMIT_MSEC:
		devc->limit_msec = g_variant_get_uint64(data);
		now = g_get_monotonic_time() / 1000;
		devc->end_time = now + devc->limit_msec;
		sr_dbg("Setting time limit to %" PRIu64 "ms.",
		       devc->limit_msec);
		break;
	case SR_CONF_LIMIT_SAMPLES:
		devc->limit_samples = g_variant_get_uint64(data);
		sr_dbg("Setting sample limit to %" PRIu64 ".",
		       devc->limit_samples);
		break;
	default:
		ret = SR_ERR_NA;
	}

	return ret;
}

static int config_list(uint32_t key, GVariant **data, const struct sr_dev_inst *sdi,
		const struct sr_channel_group *cg)
{
	(void)sdi;
	(void)cg;

	switch (key) {
	case SR_CONF_SCAN_OPTIONS:
		*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
				hwopts, ARRAY_SIZE(hwopts), sizeof(uint32_t));
		break;
	case SR_CONF_DEVICE_OPTIONS:
		*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
				hwcaps, ARRAY_SIZE(hwcaps), sizeof(uint32_t));
		break;
	default:
		return SR_ERR_NA;
	}

	return SR_OK;
}

static void receive_transfer(struct libusb_transfer *transfer)
{
	struct dev_context *devc;
	struct sr_dev_inst *sdi;
	int ret;

	sdi = transfer->user_data;
	devc = sdi->priv;
	if (transfer->status == LIBUSB_TRANSFER_NO_DEVICE) {
		/* USB device was unplugged. */
		dev_acquisition_stop(sdi, sdi);
	} else if (transfer->status == LIBUSB_TRANSFER_COMPLETED) {
		sr_dbg("Got %d-byte packet.", transfer->actual_length);
		if (transfer->actual_length == DMM_DATA_SIZE) {
			victor_dmm_receive_data(sdi, transfer->buffer);
			if (devc->limit_samples) {
				if (devc->num_samples >= devc->limit_samples)
					dev_acquisition_stop(sdi, sdi);
			}
		}
	}
	/* Anything else is either an error or a timeout, which is fine:
	 * we were just going to send another transfer request anyway. */

	if (sdi->status == SR_ST_ACTIVE) {
		/* Send the same request again. */
		if ((ret = libusb_submit_transfer(transfer) != 0)) {
			sr_err("Unable to resubmit transfer: %s.",
			       libusb_error_name(ret));
			g_free(transfer->buffer);
			libusb_free_transfer(transfer);
			dev_acquisition_stop(sdi, sdi);
		}
	} else {
		/* This was the last transfer we're going to receive, so
		 * clean up now. */
		g_free(transfer->buffer);
		libusb_free_transfer(transfer);
	}
}

static int handle_events(int fd, int revents, void *cb_data)
{
	struct dev_context *devc;
	struct drv_context *drvc = di->priv;
	struct sr_datafeed_packet packet;
	struct sr_dev_inst *sdi;
	struct timeval tv;
	gint64 now;

	(void)fd;
	(void)revents;

	sdi = cb_data;
	devc = sdi->priv;

	if (devc->limit_msec) {
		now = g_get_monotonic_time() / 1000;
		if (now > devc->end_time)
			dev_acquisition_stop(sdi, sdi);
	}

	if (sdi->status == SR_ST_STOPPING) {
		usb_source_remove(sdi->session, drvc->sr_ctx);

		dev_close(sdi);

		packet.type = SR_DF_END;
		sr_session_send(cb_data, &packet);
	}

	memset(&tv, 0, sizeof(struct timeval));
	libusb_handle_events_timeout_completed(drvc->sr_ctx->libusb_ctx, &tv,
					       NULL);

	return TRUE;
}

static int dev_acquisition_start(const struct sr_dev_inst *sdi, void *cb_data)
{
	struct dev_context *devc;
	struct drv_context *drvc = di->priv;
	struct sr_usb_dev_inst *usb;
	struct libusb_transfer *transfer;
	int ret;
	unsigned char *buf;

	if (sdi->status != SR_ST_ACTIVE)
		return SR_ERR_DEV_CLOSED;

	if (!di->priv) {
		sr_err("Driver was not initialized.");
		return SR_ERR;
	}

	devc = sdi->priv;
	usb = sdi->conn;
	devc->cb_data = cb_data;

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

	usb_source_add(sdi->session, drvc->sr_ctx, 100,
			handle_events, (void *)sdi);

	buf = g_try_malloc(DMM_DATA_SIZE);
	transfer = libusb_alloc_transfer(0);
	/* Each transfer request gets 100ms to arrive before it's restarted.
	 * The device only sends 1 transfer/second no matter how many
	 * times you ask, but we want to keep step with the USB events
	 * handling above. */
	libusb_fill_interrupt_transfer(transfer, usb->devhdl,
			VICTOR_ENDPOINT, buf, DMM_DATA_SIZE, receive_transfer,
			cb_data, 100);
	if ((ret = libusb_submit_transfer(transfer) != 0)) {
		sr_err("Unable to submit transfer: %s.", libusb_error_name(ret));
		libusb_free_transfer(transfer);
		g_free(buf);
		return SR_ERR;
	}

	return SR_OK;
}

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

	if (!di->priv) {
		sr_err("Driver was not initialized.");
		return SR_ERR;
	}

	if (sdi->status != SR_ST_ACTIVE) {
		sr_err("Device not active, can't stop acquisition.");
		return SR_ERR;
	}

	sdi->status = SR_ST_STOPPING;

	return SR_OK;
}

SR_PRIV struct sr_dev_driver victor_dmm_driver_info = {
	.name = "victor-dmm",
	.longname = "Victor DMMs",
	.api_version = 1,
	.init = init,
	.cleanup = cleanup,
	.scan = scan,
	.dev_list = dev_list,
	.dev_clear = NULL,
	.config_get = config_get,
	.config_set = config_set,
	.config_list = config_list,
	.dev_open = dev_open,
	.dev_close = dev_close,
	.dev_acquisition_start = dev_acquisition_start,
	.dev_acquisition_stop = dev_acquisition_stop,
	.priv = NULL,
};
Commit	Line	Data
	1	/*
	2	* This file is part of the libsigrok project.
	3	*
	4	* Copyright (C) 2012 Bert Vermeulen <bert@biot.com>
	5	*
	6	* This program is free software: you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation, either version 3 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	18	*/
	19
	20	#include <glib.h>
	21	#include <libusb.h>
	22	#include <stdlib.h>
	23	#include <string.h>
	24	#include "libsigrok.h"
	25	#include "libsigrok-internal.h"
	26	#include "protocol.h"
	27
	28	#define VICTOR_VID 0x1244
	29	#define VICTOR_PID 0xd237
	30	#define VICTOR_VENDOR "Victor"
	31	#define VICTOR_INTERFACE 0
	32	#define VICTOR_ENDPOINT LIBUSB_ENDPOINT_IN \| 1
	33
	34	SR_PRIV struct sr_dev_driver victor_dmm_driver_info;
	35	static struct sr_dev_driver *di = &victor_dmm_driver_info;
	36	static int dev_acquisition_stop(struct sr_dev_inst sdi, void cb_data);
	37
	38	static const uint32_t hwopts[] = {
	39	SR_CONF_CONN,
	40	};
	41
	42	static const uint32_t hwcaps[] = {
	43	SR_CONF_MULTIMETER,
	44	SR_CONF_LIMIT_MSEC,
	45	SR_CONF_LIMIT_SAMPLES,
	46	SR_CONF_CONTINUOUS,
	47	};
	48
	49	static int init(struct sr_context *sr_ctx)
	50	{
	51	return std_init(sr_ctx, di, LOG_PREFIX);
	52	}
	53
	54	static GSList scan(GSList options)
	55	{
	56	struct drv_context *drvc;
	57	struct dev_context *devc;
	58	struct sr_dev_inst *sdi;
	59	struct sr_channel *ch;
	60	struct libusb_device_descriptor des;
	61	libusb_device **devlist;
	62	GSList *devices;
	63	int ret, devcnt, i;
	64
	65	(void)options;
	66
	67	drvc = di->priv;
	68
	69	devices = NULL;
	70	libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
	71	for (i = 0; devlist[i]; i++) {
	72	if ((ret = libusb_get_device_descriptor(devlist[i], &des)) != 0) {
	73	sr_warn("Failed to get device descriptor: %s",
	74	libusb_error_name(ret));
	75	continue;
	76	}
	77
	78	if (des.idVendor != VICTOR_VID \|\| des.idProduct != VICTOR_PID)
	79	continue;
	80
	81	devcnt = g_slist_length(drvc->instances);
	82	if (!(sdi = sr_dev_inst_new(devcnt, SR_ST_INACTIVE,
	83	VICTOR_VENDOR, NULL, NULL)))
	84	return NULL;
	85	sdi->driver = di;
	86
	87	if (!(devc = g_try_malloc0(sizeof(struct dev_context))))
	88	return NULL;
	89	sdi->priv = devc;
	90
	91	if (!(ch = sr_channel_new(0, SR_CHANNEL_ANALOG, TRUE, "P1")))
	92	return NULL;
	93	sdi->channels = g_slist_append(NULL, ch);
	94
	95	if (!(sdi->conn = sr_usb_dev_inst_new(libusb_get_bus_number(devlist[i]),
	96	libusb_get_device_address(devlist[i]), NULL)))
	97	return NULL;
	98	sdi->inst_type = SR_INST_USB;
	99
	100	drvc->instances = g_slist_append(drvc->instances, sdi);
	101	devices = g_slist_append(devices, sdi);
	102	}
	103	libusb_free_device_list(devlist, 1);
	104
	105	return devices;
	106	}
	107
	108	static GSList *dev_list(void)
	109	{
	110	return ((struct drv_context *)(di->priv))->instances;
	111	}
	112
	113	static int dev_open(struct sr_dev_inst *sdi)
	114	{
	115	struct drv_context *drvc = di->priv;
	116	struct sr_usb_dev_inst *usb;
	117	libusb_device **devlist;
	118	int ret, i;
	119
	120	if (!di->priv) {
	121	sr_err("Driver was not initialized.");
	122	return SR_ERR;
	123	}
	124
	125	usb = sdi->conn;
	126
	127	libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
	128	for (i = 0; devlist[i]; i++) {
	129	if (libusb_get_bus_number(devlist[i]) != usb->bus
	130	\|\| libusb_get_device_address(devlist[i]) != usb->address)
	131	continue;
	132	if ((ret = libusb_open(devlist[i], &usb->devhdl))) {
	133	sr_err("Failed to open device: %s.", libusb_error_name(ret));
	134	return SR_ERR;
	135	}
	136	break;
	137	}
	138	libusb_free_device_list(devlist, 1);
	139	if (!devlist[i]) {
	140	sr_err("Device not found.");
	141	return SR_ERR;
	142	}
	143
	144	/* The device reports as HID class, so the kernel would have
	145	* claimed it. */
	146	if (libusb_kernel_driver_active(usb->devhdl, 0) == 1) {
	147	if ((ret = libusb_detach_kernel_driver(usb->devhdl, 0)) < 0) {
	148	sr_err("Failed to detach kernel driver: %s.",
	149	libusb_error_name(ret));
	150	return SR_ERR;
	151	}
	152	}
	153
	154	if ((ret = libusb_claim_interface(usb->devhdl,
	155	VICTOR_INTERFACE))) {
	156	sr_err("Failed to claim interface: %s.", libusb_error_name(ret));
	157	return SR_ERR;
	158	}
	159	sdi->status = SR_ST_ACTIVE;
	160
	161	return SR_OK;
	162	}
	163
	164	static int dev_close(struct sr_dev_inst *sdi)
	165	{
	166	struct sr_usb_dev_inst *usb;
	167
	168	if (!di->priv) {
	169	sr_err("Driver was not initialized.");
	170	return SR_ERR;
	171	}
	172
	173	usb = sdi->conn;
	174
	175	if (!usb->devhdl)
	176	/* Nothing to do. */
	177	return SR_OK;
	178
	179	libusb_release_interface(usb->devhdl, VICTOR_INTERFACE);
	180	libusb_close(usb->devhdl);
	181	usb->devhdl = NULL;
	182	sdi->status = SR_ST_INACTIVE;
	183
	184	return SR_OK;
	185	}
	186
	187	static int cleanup(void)
	188	{
	189	int ret;
	190	struct drv_context *drvc;
	191
	192	if (!(drvc = di->priv))
	193	/* Can get called on an unused driver, doesn't matter. */
	194	return SR_OK;
	195
	196
	197	ret = std_dev_clear(di, NULL);
	198	g_free(drvc);
	199	di->priv = NULL;
	200
	201	return ret;
	202	}
	203
	204	static int config_get(uint32_t key, GVariant *data, const struct sr_dev_inst sdi,
	205	const struct sr_channel_group *cg)
	206	{
	207	struct sr_usb_dev_inst *usb;
	208	char str[128];
	209
	210	(void)cg;
	211
	212	switch (key) {
	213	case SR_CONF_CONN:
	214	if (!sdi \|\| !sdi->conn)
	215	return SR_ERR_ARG;
	216	usb = sdi->conn;
	217	snprintf(str, 128, "%d.%d", usb->bus, usb->address);
	218	*data = g_variant_new_string(str);
	219	break;
	220	default:
	221	return SR_ERR_NA;
	222	}
	223
	224	return SR_OK;
	225	}
	226
	227	static int config_set(uint32_t key, GVariant data, const struct sr_dev_inst sdi,
	228	const struct sr_channel_group *cg)
	229	{
	230	struct dev_context *devc;
	231	gint64 now;
	232	int ret;
	233
	234	(void)cg;
	235
	236	if (sdi->status != SR_ST_ACTIVE)
	237	return SR_ERR_DEV_CLOSED;
	238
	239	if (!di->priv) {
	240	sr_err("Driver was not initialized.");
	241	return SR_ERR;
	242	}
	243
	244	devc = sdi->priv;
	245	ret = SR_OK;
	246	switch (key) {
	247	case SR_CONF_LIMIT_MSEC:
	248	devc->limit_msec = g_variant_get_uint64(data);
	249	now = g_get_monotonic_time() / 1000;
	250	devc->end_time = now + devc->limit_msec;
	251	sr_dbg("Setting time limit to %" PRIu64 "ms.",
	252	devc->limit_msec);
	253	break;
	254	case SR_CONF_LIMIT_SAMPLES:
	255	devc->limit_samples = g_variant_get_uint64(data);
	256	sr_dbg("Setting sample limit to %" PRIu64 ".",
	257	devc->limit_samples);
	258	break;
	259	default:
	260	ret = SR_ERR_NA;
	261	}
	262
	263	return ret;
	264	}
	265
	266	static int config_list(uint32_t key, GVariant *data, const struct sr_dev_inst sdi,
	267	const struct sr_channel_group *cg)
	268	{
	269	(void)sdi;
	270	(void)cg;
	271
	272	switch (key) {
	273	case SR_CONF_SCAN_OPTIONS:
	274	*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
	275	hwopts, ARRAY_SIZE(hwopts), sizeof(uint32_t));
	276	break;
	277	case SR_CONF_DEVICE_OPTIONS:
	278	*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
	279	hwcaps, ARRAY_SIZE(hwcaps), sizeof(uint32_t));
	280	break;
	281	default:
	282	return SR_ERR_NA;
	283	}
	284
	285	return SR_OK;
	286	}
	287
	288	static void receive_transfer(struct libusb_transfer *transfer)
	289	{
	290	struct dev_context *devc;
	291	struct sr_dev_inst *sdi;
	292	int ret;
	293
	294	sdi = transfer->user_data;
	295	devc = sdi->priv;
	296	if (transfer->status == LIBUSB_TRANSFER_NO_DEVICE) {
	297	/* USB device was unplugged. */
	298	dev_acquisition_stop(sdi, sdi);
	299	} else if (transfer->status == LIBUSB_TRANSFER_COMPLETED) {
	300	sr_dbg("Got %d-byte packet.", transfer->actual_length);
	301	if (transfer->actual_length == DMM_DATA_SIZE) {
	302	victor_dmm_receive_data(sdi, transfer->buffer);
	303	if (devc->limit_samples) {
	304	if (devc->num_samples >= devc->limit_samples)
	305	dev_acquisition_stop(sdi, sdi);
	306	}
	307	}
	308	}
	309	/* Anything else is either an error or a timeout, which is fine:
	310	* we were just going to send another transfer request anyway. */
	311
	312	if (sdi->status == SR_ST_ACTIVE) {
	313	/* Send the same request again. */
	314	if ((ret = libusb_submit_transfer(transfer) != 0)) {
	315	sr_err("Unable to resubmit transfer: %s.",
	316	libusb_error_name(ret));
	317	g_free(transfer->buffer);
	318	libusb_free_transfer(transfer);
	319	dev_acquisition_stop(sdi, sdi);
	320	}
	321	} else {
	322	/* This was the last transfer we're going to receive, so
	323	* clean up now. */
	324	g_free(transfer->buffer);
	325	libusb_free_transfer(transfer);
	326	}
	327	}
	328
	329	static int handle_events(int fd, int revents, void *cb_data)
	330	{
	331	struct dev_context *devc;
	332	struct drv_context *drvc = di->priv;
	333	struct sr_datafeed_packet packet;
	334	struct sr_dev_inst *sdi;
	335	struct timeval tv;
	336	gint64 now;
	337
	338	(void)fd;
	339	(void)revents;
	340
	341	sdi = cb_data;
	342	devc = sdi->priv;
	343
	344	if (devc->limit_msec) {
	345	now = g_get_monotonic_time() / 1000;
	346	if (now > devc->end_time)
	347	dev_acquisition_stop(sdi, sdi);
	348	}
	349
	350	if (sdi->status == SR_ST_STOPPING) {
	351	usb_source_remove(sdi->session, drvc->sr_ctx);
	352
	353	dev_close(sdi);
	354
	355	packet.type = SR_DF_END;
	356	sr_session_send(cb_data, &packet);
	357	}
	358
	359	memset(&tv, 0, sizeof(struct timeval));
	360	libusb_handle_events_timeout_completed(drvc->sr_ctx->libusb_ctx, &tv,
	361	NULL);
	362
	363	return TRUE;
	364	}
	365
	366	static int dev_acquisition_start(const struct sr_dev_inst sdi, void cb_data)
	367	{
	368	struct dev_context *devc;
	369	struct drv_context *drvc = di->priv;
	370	struct sr_usb_dev_inst *usb;
	371	struct libusb_transfer *transfer;
	372	int ret;
	373	unsigned char *buf;
	374
	375	if (sdi->status != SR_ST_ACTIVE)
	376	return SR_ERR_DEV_CLOSED;
	377
	378	if (!di->priv) {
	379	sr_err("Driver was not initialized.");
	380	return SR_ERR;
	381	}
	382
	383	devc = sdi->priv;
	384	usb = sdi->conn;
	385	devc->cb_data = cb_data;
	386
	387	/* Send header packet to the session bus. */
	388	std_session_send_df_header(cb_data, LOG_PREFIX);
	389
	390	usb_source_add(sdi->session, drvc->sr_ctx, 100,
	391	handle_events, (void *)sdi);
	392
	393	buf = g_try_malloc(DMM_DATA_SIZE);
	394	transfer = libusb_alloc_transfer(0);
	395	/* Each transfer request gets 100ms to arrive before it's restarted.
	396	* The device only sends 1 transfer/second no matter how many
	397	* times you ask, but we want to keep step with the USB events
	398	* handling above. */
	399	libusb_fill_interrupt_transfer(transfer, usb->devhdl,
	400	VICTOR_ENDPOINT, buf, DMM_DATA_SIZE, receive_transfer,
	401	cb_data, 100);
	402	if ((ret = libusb_submit_transfer(transfer) != 0)) {
	403	sr_err("Unable to submit transfer: %s.", libusb_error_name(ret));
	404	libusb_free_transfer(transfer);
	405	g_free(buf);
	406	return SR_ERR;
	407	}
	408
	409	return SR_OK;
	410	}
	411
	412	static int dev_acquisition_stop(struct sr_dev_inst sdi, void cb_data)
	413	{
	414	(void)cb_data;
	415
	416	if (!di->priv) {
	417	sr_err("Driver was not initialized.");
	418	return SR_ERR;
	419	}
	420
	421	if (sdi->status != SR_ST_ACTIVE) {
	422	sr_err("Device not active, can't stop acquisition.");
	423	return SR_ERR;
	424	}
	425
	426	sdi->status = SR_ST_STOPPING;
	427
	428	return SR_OK;
	429	}
	430
	431	SR_PRIV struct sr_dev_driver victor_dmm_driver_info = {
	432	.name = "victor-dmm",
	433	.longname = "Victor DMMs",
	434	.api_version = 1,
	435	.init = init,
	436	.cleanup = cleanup,
	437	.scan = scan,
	438	.dev_list = dev_list,
	439	.dev_clear = NULL,
	440	.config_get = config_get,
	441	.config_set = config_set,
	442	.config_list = config_list,
	443	.dev_open = dev_open,
	444	.dev_close = dev_close,
	445	.dev_acquisition_start = dev_acquisition_start,
	446	.dev_acquisition_stop = dev_acquisition_stop,
	447	.priv = NULL,
	448	};