[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 drvopts[] = {
	SR_CONF_MULTIMETER,
};
static const uint32_t scanopts[] = {
	SR_CONF_CONN,
};

static const uint32_t devopts[] = {
	SR_CONF_CONTINUOUS,
	SR_CONF_LIMIT_SAMPLES | SR_CONF_SET,
	SR_CONF_LIMIT_MSEC | SR_CONF_SET,
	SR_CONF_CONN | SR_CONF_GET,
};

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 libusb_device_descriptor des;
	libusb_device **devlist;
	GSList *devices;
	int ret, i;
	char connection_id[64];

	(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;

		usb_get_port_path(devlist[i], connection_id, sizeof(connection_id));

		sdi = g_malloc0(sizeof(struct sr_dev_inst));
		sdi->status = SR_ST_INACTIVE;
		sdi->vendor = g_strdup(VICTOR_VENDOR);
		sdi->driver = di;
		sdi->connection_id = g_strdup(connection_id);
		devc = g_malloc0(sizeof(struct dev_context));
		sdi->priv = devc;

		sr_channel_new(sdi, 0, SR_CHANNEL_ANALOG, TRUE, "P1");

		sdi->conn = sr_usb_dev_inst_new(libusb_get_bus_number(devlist[i]),
				libusb_get_device_address(devlist[i]), 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;
	char connection_id[64];

	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++) {
		usb_get_port_path(devlist[i], connection_id, sizeof(connection_id));
		if (strcmp(sdi->connection_id, connection_id))
			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,
				scanopts, ARRAY_SIZE(scanopts), sizeof(uint32_t));
		break;
	case SR_CONF_DEVICE_OPTIONS:
		if (!sdi)
			*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
					drvopts, ARRAY_SIZE(drvopts), sizeof(uint32_t));
		else
			*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
					devopts, ARRAY_SIZE(devopts), 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 drvopts[] = {
	39	SR_CONF_MULTIMETER,
	40	};
	41	static const uint32_t scanopts[] = {
	42	SR_CONF_CONN,
	43	};
	44
	45	static const uint32_t devopts[] = {
	46	SR_CONF_CONTINUOUS,
	47	SR_CONF_LIMIT_SAMPLES \| SR_CONF_SET,
	48	SR_CONF_LIMIT_MSEC \| SR_CONF_SET,
	49	SR_CONF_CONN \| SR_CONF_GET,
	50	};
	51
	52	static int init(struct sr_context *sr_ctx)
	53	{
	54	return std_init(sr_ctx, di, LOG_PREFIX);
	55	}
	56
	57	static GSList scan(GSList options)
	58	{
	59	struct drv_context *drvc;
	60	struct dev_context *devc;
	61	struct sr_dev_inst *sdi;
	62	struct libusb_device_descriptor des;
	63	libusb_device **devlist;
	64	GSList *devices;
	65	int ret, i;
	66	char connection_id[64];
	67
	68	(void)options;
	69
	70	drvc = di->priv;
	71
	72	devices = NULL;
	73	libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
	74	for (i = 0; devlist[i]; i++) {
	75	if ((ret = libusb_get_device_descriptor(devlist[i], &des)) != 0) {
	76	sr_warn("Failed to get device descriptor: %s",
	77	libusb_error_name(ret));
	78	continue;
	79	}
	80
	81	if (des.idVendor != VICTOR_VID \|\| des.idProduct != VICTOR_PID)
	82	continue;
	83
	84	usb_get_port_path(devlist[i], connection_id, sizeof(connection_id));
	85
	86	sdi = g_malloc0(sizeof(struct sr_dev_inst));
	87	sdi->status = SR_ST_INACTIVE;
	88	sdi->vendor = g_strdup(VICTOR_VENDOR);
	89	sdi->driver = di;
	90	sdi->connection_id = g_strdup(connection_id);
	91	devc = g_malloc0(sizeof(struct dev_context));
	92	sdi->priv = devc;
	93
	94	sr_channel_new(sdi, 0, SR_CHANNEL_ANALOG, TRUE, "P1");
	95
	96	sdi->conn = sr_usb_dev_inst_new(libusb_get_bus_number(devlist[i]),
	97	libusb_get_device_address(devlist[i]), 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	char connection_id[64];
	120
	121	if (!di->priv) {
	122	sr_err("Driver was not initialized.");
	123	return SR_ERR;
	124	}
	125
	126	usb = sdi->conn;
	127
	128	libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
	129	for (i = 0; devlist[i]; i++) {
	130	usb_get_port_path(devlist[i], connection_id, sizeof(connection_id));
	131	if (strcmp(sdi->connection_id, connection_id))
	132	continue;
	133	if ((ret = libusb_open(devlist[i], &usb->devhdl))) {
	134	sr_err("Failed to open device: %s.", libusb_error_name(ret));
	135	return SR_ERR;
	136	}
	137	break;
	138	}
	139	libusb_free_device_list(devlist, 1);
	140	if (!devlist[i]) {
	141	sr_err("Device not found.");
	142	return SR_ERR;
	143	}
	144
	145	/* The device reports as HID class, so the kernel would have
	146	* claimed it. */
	147	if (libusb_kernel_driver_active(usb->devhdl, 0) == 1) {
	148	if ((ret = libusb_detach_kernel_driver(usb->devhdl, 0)) < 0) {
	149	sr_err("Failed to detach kernel driver: %s.",
	150	libusb_error_name(ret));
	151	return SR_ERR;
	152	}
	153	}
	154
	155	if ((ret = libusb_claim_interface(usb->devhdl,
	156	VICTOR_INTERFACE))) {
	157	sr_err("Failed to claim interface: %s.", libusb_error_name(ret));
	158	return SR_ERR;
	159	}
	160	sdi->status = SR_ST_ACTIVE;
	161
	162	return SR_OK;
	163	}
	164
	165	static int dev_close(struct sr_dev_inst *sdi)
	166	{
	167	struct sr_usb_dev_inst *usb;
	168
	169	if (!di->priv) {
	170	sr_err("Driver was not initialized.");
	171	return SR_ERR;
	172	}
	173
	174	usb = sdi->conn;
	175
	176	if (!usb->devhdl)
	177	/* Nothing to do. */
	178	return SR_OK;
	179
	180	libusb_release_interface(usb->devhdl, VICTOR_INTERFACE);
	181	libusb_close(usb->devhdl);
	182	usb->devhdl = NULL;
	183	sdi->status = SR_ST_INACTIVE;
	184
	185	return SR_OK;
	186	}
	187
	188	static int cleanup(void)
	189	{
	190	int ret;
	191	struct drv_context *drvc;
	192
	193	if (!(drvc = di->priv))
	194	/* Can get called on an unused driver, doesn't matter. */
	195	return SR_OK;
	196
	197
	198	ret = std_dev_clear(di, NULL);
	199	g_free(drvc);
	200	di->priv = NULL;
	201
	202	return ret;
	203	}
	204
	205	static int config_get(uint32_t key, GVariant *data, const struct sr_dev_inst sdi,
	206	const struct sr_channel_group *cg)
	207	{
	208	struct sr_usb_dev_inst *usb;
	209	char str[128];
	210
	211	(void)cg;
	212
	213	switch (key) {
	214	case SR_CONF_CONN:
	215	if (!sdi \|\| !sdi->conn)
	216	return SR_ERR_ARG;
	217	usb = sdi->conn;
	218	snprintf(str, 128, "%d.%d", usb->bus, usb->address);
	219	*data = g_variant_new_string(str);
	220	break;
	221	default:
	222	return SR_ERR_NA;
	223	}
	224
	225	return SR_OK;
	226	}
	227
	228	static int config_set(uint32_t key, GVariant data, const struct sr_dev_inst sdi,
	229	const struct sr_channel_group *cg)
	230	{
	231	struct dev_context *devc;
	232	gint64 now;
	233	int ret;
	234
	235	(void)cg;
	236
	237	if (sdi->status != SR_ST_ACTIVE)
	238	return SR_ERR_DEV_CLOSED;
	239
	240	if (!di->priv) {
	241	sr_err("Driver was not initialized.");
	242	return SR_ERR;
	243	}
	244
	245	devc = sdi->priv;
	246	ret = SR_OK;
	247	switch (key) {
	248	case SR_CONF_LIMIT_MSEC:
	249	devc->limit_msec = g_variant_get_uint64(data);
	250	now = g_get_monotonic_time() / 1000;
	251	devc->end_time = now + devc->limit_msec;
	252	sr_dbg("Setting time limit to %" PRIu64 "ms.",
	253	devc->limit_msec);
	254	break;
	255	case SR_CONF_LIMIT_SAMPLES:
	256	devc->limit_samples = g_variant_get_uint64(data);
	257	sr_dbg("Setting sample limit to %" PRIu64 ".",
	258	devc->limit_samples);
	259	break;
	260	default:
	261	ret = SR_ERR_NA;
	262	}
	263
	264	return ret;
	265	}
	266
	267	static int config_list(uint32_t key, GVariant *data, const struct sr_dev_inst sdi,
	268	const struct sr_channel_group *cg)
	269	{
	270	(void)sdi;
	271	(void)cg;
	272
	273	switch (key) {
	274	case SR_CONF_SCAN_OPTIONS:
	275	*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
	276	scanopts, ARRAY_SIZE(scanopts), sizeof(uint32_t));
	277	break;
	278	case SR_CONF_DEVICE_OPTIONS:
	279	if (!sdi)
	280	*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
	281	drvopts, ARRAY_SIZE(drvopts), sizeof(uint32_t));
	282	else
	283	*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
	284	devopts, ARRAY_SIZE(devopts), sizeof(uint32_t));
	285	break;
	286	default:
	287	return SR_ERR_NA;
	288	}
	289
	290	return SR_OK;
	291	}
	292
	293	static void receive_transfer(struct libusb_transfer *transfer)
	294	{
	295	struct dev_context *devc;
	296	struct sr_dev_inst *sdi;
	297	int ret;
	298
	299	sdi = transfer->user_data;
	300	devc = sdi->priv;
	301	if (transfer->status == LIBUSB_TRANSFER_NO_DEVICE) {
	302	/* USB device was unplugged. */
	303	dev_acquisition_stop(sdi, sdi);
	304	} else if (transfer->status == LIBUSB_TRANSFER_COMPLETED) {
	305	sr_dbg("Got %d-byte packet.", transfer->actual_length);
	306	if (transfer->actual_length == DMM_DATA_SIZE) {
	307	victor_dmm_receive_data(sdi, transfer->buffer);
	308	if (devc->limit_samples) {
	309	if (devc->num_samples >= devc->limit_samples)
	310	dev_acquisition_stop(sdi, sdi);
	311	}
	312	}
	313	}
	314	/* Anything else is either an error or a timeout, which is fine:
	315	* we were just going to send another transfer request anyway. */
	316
	317	if (sdi->status == SR_ST_ACTIVE) {
	318	/* Send the same request again. */
	319	if ((ret = libusb_submit_transfer(transfer) != 0)) {
	320	sr_err("Unable to resubmit transfer: %s.",
	321	libusb_error_name(ret));
	322	g_free(transfer->buffer);
	323	libusb_free_transfer(transfer);
	324	dev_acquisition_stop(sdi, sdi);
	325	}
	326	} else {
	327	/* This was the last transfer we're going to receive, so
	328	* clean up now. */
	329	g_free(transfer->buffer);
	330	libusb_free_transfer(transfer);
	331	}
	332	}
	333
	334	static int handle_events(int fd, int revents, void *cb_data)
	335	{
	336	struct dev_context *devc;
	337	struct drv_context *drvc = di->priv;
	338	struct sr_datafeed_packet packet;
	339	struct sr_dev_inst *sdi;
	340	struct timeval tv;
	341	gint64 now;
	342
	343	(void)fd;
	344	(void)revents;
	345
	346	sdi = cb_data;
	347	devc = sdi->priv;
	348
	349	if (devc->limit_msec) {
	350	now = g_get_monotonic_time() / 1000;
	351	if (now > devc->end_time)
	352	dev_acquisition_stop(sdi, sdi);
	353	}
	354
	355	if (sdi->status == SR_ST_STOPPING) {
	356	usb_source_remove(sdi->session, drvc->sr_ctx);
	357
	358	dev_close(sdi);
	359
	360	packet.type = SR_DF_END;
	361	sr_session_send(cb_data, &packet);
	362	}
	363
	364	memset(&tv, 0, sizeof(struct timeval));
	365	libusb_handle_events_timeout_completed(drvc->sr_ctx->libusb_ctx, &tv,
	366	NULL);
	367
	368	return TRUE;
	369	}
	370
	371	static int dev_acquisition_start(const struct sr_dev_inst sdi, void cb_data)
	372	{
	373	struct dev_context *devc;
	374	struct drv_context *drvc = di->priv;
	375	struct sr_usb_dev_inst *usb;
	376	struct libusb_transfer *transfer;
	377	int ret;
	378	unsigned char *buf;
	379
	380	if (sdi->status != SR_ST_ACTIVE)
	381	return SR_ERR_DEV_CLOSED;
	382
	383	if (!di->priv) {
	384	sr_err("Driver was not initialized.");
	385	return SR_ERR;
	386	}
	387
	388	devc = sdi->priv;
	389	usb = sdi->conn;
	390	devc->cb_data = cb_data;
	391
	392	/* Send header packet to the session bus. */
	393	std_session_send_df_header(cb_data, LOG_PREFIX);
	394
	395	usb_source_add(sdi->session, drvc->sr_ctx, 100,
	396	handle_events, (void *)sdi);
	397
	398	buf = g_try_malloc(DMM_DATA_SIZE);
	399	transfer = libusb_alloc_transfer(0);
	400	/* Each transfer request gets 100ms to arrive before it's restarted.
	401	* The device only sends 1 transfer/second no matter how many
	402	* times you ask, but we want to keep step with the USB events
	403	* handling above. */
	404	libusb_fill_interrupt_transfer(transfer, usb->devhdl,
	405	VICTOR_ENDPOINT, buf, DMM_DATA_SIZE, receive_transfer,
	406	cb_data, 100);
	407	if ((ret = libusb_submit_transfer(transfer) != 0)) {
	408	sr_err("Unable to submit transfer: %s.", libusb_error_name(ret));
	409	libusb_free_transfer(transfer);
	410	g_free(buf);
	411	return SR_ERR;
	412	}
	413
	414	return SR_OK;
	415	}
	416
	417	static int dev_acquisition_stop(struct sr_dev_inst sdi, void cb_data)
	418	{
	419	(void)cb_data;
	420
	421	if (!di->priv) {
	422	sr_err("Driver was not initialized.");
	423	return SR_ERR;
	424	}
	425
	426	if (sdi->status != SR_ST_ACTIVE) {
	427	sr_err("Device not active, can't stop acquisition.");
	428	return SR_ERR;
	429	}
	430
	431	sdi->status = SR_ST_STOPPING;
	432
	433	return SR_OK;
	434	}
	435
	436	SR_PRIV struct sr_dev_driver victor_dmm_driver_info = {
	437	.name = "victor-dmm",
	438	.longname = "Victor DMMs",
	439	.api_version = 1,
	440	.init = init,
	441	.cleanup = cleanup,
	442	.scan = scan,
	443	.dev_list = dev_list,
	444	.dev_clear = NULL,
	445	.config_get = config_get,
	446	.config_set = config_set,
	447	.config_list = config_list,
	448	.dev_open = dev_open,
	449	.dev_close = dev_close,
	450	.dev_acquisition_start = dev_acquisition_start,
	451	.dev_acquisition_stop = dev_acquisition_stop,
	452	.priv = NULL,
	453	};