[libsigrok.git] / 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 int32_t hwopts[] = {
	SR_CONF_CONN,
};

static const int32_t hwcaps[] = {
	SR_CONF_MULTIMETER,
	SR_CONF_LIMIT_MSEC,
	SR_CONF_LIMIT_SAMPLES,
	SR_CONF_CONTINUOUS,
};

static int dev_clear(void)
{
	return std_dev_clear(di, NULL);
}

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_probe *probe;
	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 (!(probe = sr_probe_new(0, SR_PROBE_ANALOG, TRUE, "P1")))
			return NULL;
		sdi->probes = g_slist_append(NULL, probe);

		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 = dev_clear();
	g_free(drvc);
	di->priv = NULL;

	return ret;
}

static int config_get(int id, GVariant **data, const struct sr_dev_inst *sdi,
		const struct sr_probe_group *probe_group)
{
	struct sr_usb_dev_inst *usb;
	char str[128];

	(void)probe_group;

	switch (id) {
	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(int id, GVariant *data, const struct sr_dev_inst *sdi,
		const struct sr_probe_group *probe_group)
{
	struct dev_context *devc;
	gint64 now;
	int ret;

	(void)probe_group;

	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 (id) {
	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(int key, GVariant **data, const struct sr_dev_inst *sdi,
		const struct sr_probe_group *probe_group)
{
	(void)sdi;
	(void)probe_group;

	switch (key) {
	case SR_CONF_SCAN_OPTIONS:
		*data = g_variant_new_fixed_array(G_VARIANT_TYPE_INT32,
				hwopts, ARRAY_SIZE(hwopts), sizeof(int32_t));
		break;
	case SR_CONF_DEVICE_OPTIONS:
		*data = g_variant_new_fixed_array(G_VARIANT_TYPE_INT32,
				hwcaps, ARRAY_SIZE(hwcaps), sizeof(int32_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;
	int i;

	(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) {
		for (i = 0; devc->usbfd[i] != -1; i++)
			sr_source_remove(devc->usbfd[i]);

		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;
	const struct libusb_pollfd **pfd;
	struct sr_usb_dev_inst *usb;
	struct libusb_transfer *transfer;
	int ret, i;
	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);

	pfd = libusb_get_pollfds(drvc->sr_ctx->libusb_ctx);
	for (i = 0; pfd[i]; i++) {
		/* Handle USB events every 100ms, for decent latency. */
		sr_source_add(pfd[i]->fd, pfd[i]->events, 100,
				handle_events, (void *)sdi);
		/* We'll need to remove this fd later. */
		devc->usbfd[i] = pfd[i]->fd;
	}
	devc->usbfd[i] = -1;

	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 = dev_clear,
	.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 int32_t hwopts[] = {
	39	SR_CONF_CONN,
	40	};
	41
	42	static const int32_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 dev_clear(void)
	50	{
	51	return std_dev_clear(di, NULL);
	52	}
	53
	54	static int init(struct sr_context *sr_ctx)
	55	{
	56	return std_init(sr_ctx, di, LOG_PREFIX);
	57	}
	58
	59	static GSList scan(GSList options)
	60	{
	61	struct drv_context *drvc;
	62	struct dev_context *devc;
	63	struct sr_dev_inst *sdi;
	64	struct sr_probe *probe;
	65	struct libusb_device_descriptor des;
	66	libusb_device **devlist;
	67	GSList *devices;
	68	int ret, devcnt, i;
	69
	70	(void)options;
	71
	72	drvc = di->priv;
	73
	74	devices = NULL;
	75	libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
	76	for (i = 0; devlist[i]; i++) {
	77	if ((ret = libusb_get_device_descriptor(devlist[i], &des)) != 0) {
	78	sr_warn("Failed to get device descriptor: %s",
	79	libusb_error_name(ret));
	80	continue;
	81	}
	82
	83	if (des.idVendor != VICTOR_VID \|\| des.idProduct != VICTOR_PID)
	84	continue;
	85
	86	devcnt = g_slist_length(drvc->instances);
	87	if (!(sdi = sr_dev_inst_new(devcnt, SR_ST_INACTIVE,
	88	VICTOR_VENDOR, NULL, NULL)))
	89	return NULL;
	90	sdi->driver = di;
	91
	92	if (!(devc = g_try_malloc0(sizeof(struct dev_context))))
	93	return NULL;
	94	sdi->priv = devc;
	95
	96	if (!(probe = sr_probe_new(0, SR_PROBE_ANALOG, TRUE, "P1")))
	97	return NULL;
	98	sdi->probes = g_slist_append(NULL, probe);
	99
	100	if (!(sdi->conn = sr_usb_dev_inst_new(libusb_get_bus_number(devlist[i]),
	101	libusb_get_device_address(devlist[i]), NULL)))
	102	return NULL;
	103	sdi->inst_type = SR_INST_USB;
	104
	105	drvc->instances = g_slist_append(drvc->instances, sdi);
	106	devices = g_slist_append(devices, sdi);
	107	}
	108	libusb_free_device_list(devlist, 1);
	109
	110	return devices;
	111	}
	112
	113	static GSList *dev_list(void)
	114	{
	115	return ((struct drv_context *)(di->priv))->instances;
	116	}
	117
	118	static int dev_open(struct sr_dev_inst *sdi)
	119	{
	120	struct drv_context *drvc = di->priv;
	121	struct sr_usb_dev_inst *usb;
	122	libusb_device **devlist;
	123	int ret, i;
	124
	125	if (!di->priv) {
	126	sr_err("Driver was not initialized.");
	127	return SR_ERR;
	128	}
	129
	130	usb = sdi->conn;
	131
	132	libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
	133	for (i = 0; devlist[i]; i++) {
	134	if (libusb_get_bus_number(devlist[i]) != usb->bus
	135	\|\| libusb_get_device_address(devlist[i]) != usb->address)
	136	continue;
	137	if ((ret = libusb_open(devlist[i], &usb->devhdl))) {
	138	sr_err("Failed to open device: %s.", libusb_error_name(ret));
	139	return SR_ERR;
	140	}
	141	break;
	142	}
	143	libusb_free_device_list(devlist, 1);
	144	if (!devlist[i]) {
	145	sr_err("Device not found.");
	146	return SR_ERR;
	147	}
	148
	149	/* The device reports as HID class, so the kernel would have
	150	* claimed it. */
	151	if (libusb_kernel_driver_active(usb->devhdl, 0) == 1) {
	152	if ((ret = libusb_detach_kernel_driver(usb->devhdl, 0)) < 0) {
	153	sr_err("Failed to detach kernel driver: %s.",
	154	libusb_error_name(ret));
	155	return SR_ERR;
	156	}
	157	}
	158
	159	if ((ret = libusb_claim_interface(usb->devhdl,
	160	VICTOR_INTERFACE))) {
	161	sr_err("Failed to claim interface: %s.", libusb_error_name(ret));
	162	return SR_ERR;
	163	}
	164	sdi->status = SR_ST_ACTIVE;
	165
	166	return SR_OK;
	167	}
	168
	169	static int dev_close(struct sr_dev_inst *sdi)
	170	{
	171	struct sr_usb_dev_inst *usb;
	172
	173	if (!di->priv) {
	174	sr_err("Driver was not initialized.");
	175	return SR_ERR;
	176	}
	177
	178	usb = sdi->conn;
	179
	180	if (!usb->devhdl)
	181	/* Nothing to do. */
	182	return SR_OK;
	183
	184	libusb_release_interface(usb->devhdl, VICTOR_INTERFACE);
	185	libusb_close(usb->devhdl);
	186	usb->devhdl = NULL;
	187	sdi->status = SR_ST_INACTIVE;
	188
	189	return SR_OK;
	190	}
	191
	192	static int cleanup(void)
	193	{
	194	int ret;
	195	struct drv_context *drvc;
	196
	197	if (!(drvc = di->priv))
	198	/* Can get called on an unused driver, doesn't matter. */
	199	return SR_OK;
	200
	201	ret = dev_clear();
	202	g_free(drvc);
	203	di->priv = NULL;
	204
	205	return ret;
	206	}
	207
	208	static int config_get(int id, GVariant *data, const struct sr_dev_inst sdi,
	209	const struct sr_probe_group *probe_group)
	210	{
	211	struct sr_usb_dev_inst *usb;
	212	char str[128];
	213
	214	(void)probe_group;
	215
	216	switch (id) {
	217	case SR_CONF_CONN:
	218	if (!sdi \|\| !sdi->conn)
	219	return SR_ERR_ARG;
	220	usb = sdi->conn;
	221	snprintf(str, 128, "%d.%d", usb->bus, usb->address);
	222	*data = g_variant_new_string(str);
	223	break;
	224	default:
	225	return SR_ERR_NA;
	226	}
	227
	228	return SR_OK;
	229	}
	230
	231	static int config_set(int id, GVariant data, const struct sr_dev_inst sdi,
	232	const struct sr_probe_group *probe_group)
	233	{
	234	struct dev_context *devc;
	235	gint64 now;
	236	int ret;
	237
	238	(void)probe_group;
	239
	240	if (sdi->status != SR_ST_ACTIVE)
	241	return SR_ERR_DEV_CLOSED;
	242
	243	if (!di->priv) {
	244	sr_err("Driver was not initialized.");
	245	return SR_ERR;
	246	}
	247
	248	devc = sdi->priv;
	249	ret = SR_OK;
	250	switch (id) {
	251	case SR_CONF_LIMIT_MSEC:
	252	devc->limit_msec = g_variant_get_uint64(data);
	253	now = g_get_monotonic_time() / 1000;
	254	devc->end_time = now + devc->limit_msec;
	255	sr_dbg("Setting time limit to %" PRIu64 "ms.",
	256	devc->limit_msec);
	257	break;
	258	case SR_CONF_LIMIT_SAMPLES:
	259	devc->limit_samples = g_variant_get_uint64(data);
	260	sr_dbg("Setting sample limit to %" PRIu64 ".",
	261	devc->limit_samples);
	262	break;
	263	default:
	264	ret = SR_ERR_NA;
	265	}
	266
	267	return ret;
	268	}
	269
	270	static int config_list(int key, GVariant *data, const struct sr_dev_inst sdi,
	271	const struct sr_probe_group *probe_group)
	272	{
	273	(void)sdi;
	274	(void)probe_group;
	275
	276	switch (key) {
	277	case SR_CONF_SCAN_OPTIONS:
	278	*data = g_variant_new_fixed_array(G_VARIANT_TYPE_INT32,
	279	hwopts, ARRAY_SIZE(hwopts), sizeof(int32_t));
	280	break;
	281	case SR_CONF_DEVICE_OPTIONS:
	282	*data = g_variant_new_fixed_array(G_VARIANT_TYPE_INT32,
	283	hwcaps, ARRAY_SIZE(hwcaps), sizeof(int32_t));
	284	break;
	285	default:
	286	return SR_ERR_NA;
	287	}
	288
	289	return SR_OK;
	290	}
	291
	292	static void receive_transfer(struct libusb_transfer *transfer)
	293	{
	294	struct dev_context *devc;
	295	struct sr_dev_inst *sdi;
	296	int ret;
	297
	298	sdi = transfer->user_data;
	299	devc = sdi->priv;
	300	if (transfer->status == LIBUSB_TRANSFER_NO_DEVICE) {
	301	/* USB device was unplugged. */
	302	dev_acquisition_stop(sdi, sdi);
	303	} else if (transfer->status == LIBUSB_TRANSFER_COMPLETED) {
	304	sr_dbg("Got %d-byte packet.", transfer->actual_length);
	305	if (transfer->actual_length == DMM_DATA_SIZE) {
	306	victor_dmm_receive_data(sdi, transfer->buffer);
	307	if (devc->limit_samples) {
	308	if (devc->num_samples >= devc->limit_samples)
	309	dev_acquisition_stop(sdi, sdi);
	310	}
	311	}
	312	}
	313	/* Anything else is either an error or a timeout, which is fine:
	314	* we were just going to send another transfer request anyway. */
	315
	316	if (sdi->status == SR_ST_ACTIVE) {
	317	/* Send the same request again. */
	318	if ((ret = libusb_submit_transfer(transfer) != 0)) {
	319	sr_err("Unable to resubmit transfer: %s.",
	320	libusb_error_name(ret));
	321	g_free(transfer->buffer);
	322	libusb_free_transfer(transfer);
	323	dev_acquisition_stop(sdi, sdi);
	324	}
	325	} else {
	326	/* This was the last transfer we're going to receive, so
	327	* clean up now. */
	328	g_free(transfer->buffer);
	329	libusb_free_transfer(transfer);
	330	}
	331	}
	332
	333	static int handle_events(int fd, int revents, void *cb_data)
	334	{
	335	struct dev_context *devc;
	336	struct drv_context *drvc = di->priv;
	337	struct sr_datafeed_packet packet;
	338	struct sr_dev_inst *sdi;
	339	struct timeval tv;
	340	gint64 now;
	341	int i;
	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	for (i = 0; devc->usbfd[i] != -1; i++)
	357	sr_source_remove(devc->usbfd[i]);
	358
	359	dev_close(sdi);
	360
	361	packet.type = SR_DF_END;
	362	sr_session_send(cb_data, &packet);
	363	}
	364
	365	memset(&tv, 0, sizeof(struct timeval));
	366	libusb_handle_events_timeout_completed(drvc->sr_ctx->libusb_ctx, &tv,
	367	NULL);
	368
	369	return TRUE;
	370	}
	371
	372	static int dev_acquisition_start(const struct sr_dev_inst sdi, void cb_data)
	373	{
	374	struct dev_context *devc;
	375	struct drv_context *drvc = di->priv;
	376	const struct libusb_pollfd **pfd;
	377	struct sr_usb_dev_inst *usb;
	378	struct libusb_transfer *transfer;
	379	int ret, i;
	380	unsigned char *buf;
	381
	382	if (sdi->status != SR_ST_ACTIVE)
	383	return SR_ERR_DEV_CLOSED;
	384
	385	if (!di->priv) {
	386	sr_err("Driver was not initialized.");
	387	return SR_ERR;
	388	}
	389
	390	devc = sdi->priv;
	391	usb = sdi->conn;
	392	devc->cb_data = cb_data;
	393
	394	/* Send header packet to the session bus. */
	395	std_session_send_df_header(cb_data, LOG_PREFIX);
	396
	397	pfd = libusb_get_pollfds(drvc->sr_ctx->libusb_ctx);
	398	for (i = 0; pfd[i]; i++) {
	399	/* Handle USB events every 100ms, for decent latency. */
	400	sr_source_add(pfd[i]->fd, pfd[i]->events, 100,
	401	handle_events, (void *)sdi);
	402	/* We'll need to remove this fd later. */
	403	devc->usbfd[i] = pfd[i]->fd;
	404	}
	405	devc->usbfd[i] = -1;
	406
	407	buf = g_try_malloc(DMM_DATA_SIZE);
	408	transfer = libusb_alloc_transfer(0);
	409	/* Each transfer request gets 100ms to arrive before it's restarted.
	410	* The device only sends 1 transfer/second no matter how many
	411	* times you ask, but we want to keep step with the USB events
	412	* handling above. */
	413	libusb_fill_interrupt_transfer(transfer, usb->devhdl,
	414	VICTOR_ENDPOINT, buf, DMM_DATA_SIZE, receive_transfer,
	415	cb_data, 100);
	416	if ((ret = libusb_submit_transfer(transfer) != 0)) {
	417	sr_err("Unable to submit transfer: %s.", libusb_error_name(ret));
	418	libusb_free_transfer(transfer);
	419	g_free(buf);
	420	return SR_ERR;
	421	}
	422
	423	return SR_OK;
	424	}
	425
	426	static int dev_acquisition_stop(struct sr_dev_inst sdi, void cb_data)
	427	{
	428	(void)cb_data;
	429
	430	if (!di->priv) {
	431	sr_err("Driver was not initialized.");
	432	return SR_ERR;
	433	}
	434
	435	if (sdi->status != SR_ST_ACTIVE) {
	436	sr_err("Device not active, can't stop acquisition.");
	437	return SR_ERR;
	438	}
	439
	440	sdi->status = SR_ST_STOPPING;
	441
	442	return SR_OK;
	443	}
	444
	445	SR_PRIV struct sr_dev_driver victor_dmm_driver_info = {
	446	.name = "victor-dmm",
	447	.longname = "Victor DMMs",
	448	.api_version = 1,
	449	.init = init,
	450	.cleanup = cleanup,
	451	.scan = scan,
	452	.dev_list = dev_list,
	453	.dev_clear = dev_clear,
	454	.config_get = config_get,
	455	.config_set = config_set,
	456	.config_list = config_list,
	457	.dev_open = dev_open,
	458	.dev_close = dev_close,
	459	.dev_acquisition_start = dev_acquisition_start,
	460	.dev_acquisition_stop = dev_acquisition_stop,
	461	.priv = NULL,
	462	};