[libsigrok.git] / src / hardware / lascar-el-usb / 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 <config.h>
#include <glib.h>
#include <libusb.h>
#include <libsigrok/libsigrok.h>
#include "libsigrok-internal.h"
#include "protocol.h"

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

static const uint32_t drvopts[] = {
	SR_CONF_THERMOMETER,
	SR_CONF_HYGROMETER,
};

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

static GSList *scan(struct sr_dev_driver *di, GSList *options)
{
	struct drv_context *drvc;
	struct sr_dev_inst *sdi;
	struct sr_usb_dev_inst *usb;
	struct sr_config *src;
	GSList *usb_devices, *devices, *l;
	const char *conn;

	drvc = di->context;

	conn = NULL;
	for (l = options; l; l = l->next) {
		src = l->data;
		switch (src->key) {
		case SR_CONF_CONN:
			conn = g_variant_get_string(src->data, NULL);
			break;
		}
	}
	if (!conn)
		return NULL;

	devices = NULL;
	if ((usb_devices = sr_usb_find(drvc->sr_ctx->libusb_ctx, conn))) {
		/* We have a list of sr_usb_dev_inst matching the connection
		 * string. Wrap them in sr_dev_inst and we're done. */
		for (l = usb_devices; l; l = l->next) {
			usb = l->data;
			if (!(sdi = lascar_scan(usb->bus, usb->address))) {
				/* Not a Lascar EL-USB. */
				g_free(usb);
				continue;
			}
			sdi->inst_type = SR_INST_USB;
			sdi->conn = usb;
			devices = g_slist_append(devices, sdi);
		}
		g_slist_free(usb_devices);
	} else
		g_slist_free_full(usb_devices, g_free);

	return std_scan_complete(di, devices);
}

static int dev_open(struct sr_dev_inst *sdi)
{
	struct sr_dev_driver *di = sdi->driver;
	struct drv_context *drvc = di->context;;
	struct sr_usb_dev_inst *usb;
	int ret;

	usb = sdi->conn;

	if (sr_usb_open(drvc->sr_ctx->libusb_ctx, usb) != SR_OK)
		return SR_ERR;

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

	return SR_OK;
}

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

	usb = sdi->conn;

	if (!usb->devhdl)
		return SR_ERR_BUG;

	libusb_release_interface(usb->devhdl, LASCAR_INTERFACE);
	libusb_close(usb->devhdl);
	usb->devhdl = NULL;

	return SR_OK;
}

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

	(void)cg;

	devc = sdi->priv;
	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;
	case SR_CONF_DATALOG:
		if (!sdi)
			return SR_ERR_ARG;
		if ((ret = lascar_is_logging(sdi)) == -1)
			return SR_ERR;
		*data = g_variant_new_boolean(ret ? TRUE : FALSE);
		break;
	case SR_CONF_LIMIT_SAMPLES:
		*data = g_variant_new_uint64(devc->limit_samples);
		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;
	int ret;

	(void)cg;

	devc = sdi->priv;
	ret = SR_OK;
	switch (key) {
	case SR_CONF_DATALOG:
		if (g_variant_get_boolean(data))
			ret = lascar_start_logging(sdi);
		else
			ret = lascar_stop_logging(sdi);
		break;
	case SR_CONF_LIMIT_SAMPLES:
		devc->limit_samples = g_variant_get_uint64(data);
		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)
{
	return STD_CONFIG_LIST(key, data, sdi, cg, scanopts, drvopts, devopts);
}

static void LIBUSB_CALL mark_xfer(struct libusb_transfer *xfer)
{

	if (xfer->status == LIBUSB_TRANSFER_COMPLETED)
		xfer->user_data = GINT_TO_POINTER(1);
	else
		xfer->user_data = GINT_TO_POINTER(-1);

}

/* The Lascar software, in its infinite ignorance, reads a set of four
 * bytes from the device config struct and interprets it as a float.
 * That only works because they only use windows, and only on x86. However
 * we may be running on any architecture, any operating system. So we have
 * to convert these four bytes as the Lascar software would on windows/x86,
 * to the local representation of a float.
 * The source format is little-endian, with IEEE 754-2008 BINARY32 encoding. */
static float binary32_le_to_float(unsigned char *buf)
{
	GFloatIEEE754 f;

	f.v_float = 0;
	f.mpn.sign = (buf[3] & 0x80) ? 1 : 0;
	f.mpn.biased_exponent = (buf[3] << 1) | (buf[2] >> 7);
	f.mpn.mantissa = buf[0] | (buf[1] << 8) | ((buf[2] & 0x7f) << 16);

	return f.v_float;
}

static int lascar_proc_config(const struct sr_dev_inst *sdi)
{
	struct dev_context *devc;
	struct sr_usb_dev_inst *usb;
	int dummy, ret;

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

	if (lascar_get_config(usb->devhdl, devc->config, &dummy) != SR_OK)
		return SR_ERR;

	ret = SR_OK;
	switch (devc->profile->logformat) {
	case LOG_TEMP_RH:
		devc->sample_size = 2;
		devc->temp_unit = devc->config[0x2e] | (devc->config[0x2f] << 8);
		if (devc->temp_unit != 0 && devc->temp_unit != 1) {
			sr_dbg("invalid temperature unit %d", devc->temp_unit);
			/* Default to Celsius, we're all adults here. */
			devc->temp_unit = 0;
		} else
			sr_dbg("temperature unit is %s", devc->temp_unit
					? "Fahrenheit" : "Celsius");
		break;
	case LOG_CO:
		devc->sample_size = 2;
		devc->co_high = binary32_le_to_float(devc->config + 0x24);
		devc->co_low = binary32_le_to_float(devc->config + 0x28);
		sr_dbg("EL-USB-CO calibration high %f low %f", devc->co_high,
				devc->co_low);
		break;
	default:
		ret = SR_ERR_ARG;
	}
	devc->logged_samples = devc->config[0x1e] | (devc->config[0x1f] << 8);
	sr_dbg("device log contains %d samples.", devc->logged_samples);

	return ret;
}

static int dev_acquisition_start(const struct sr_dev_inst *sdi)
{
	struct sr_dev_driver *di = sdi->driver;
	struct sr_datafeed_packet packet;
	struct sr_datafeed_meta meta;
	struct sr_config *src;
	struct dev_context *devc;
	struct drv_context *drvc;
	struct sr_usb_dev_inst *usb;
	struct libusb_transfer *xfer_in, *xfer_out;
	struct timeval tv;
	uint64_t interval;
	int ret;
	unsigned char cmd[3], resp[4], *buf;

	drvc = di->context;
	devc = sdi->priv;
	usb = sdi->conn;

	if (lascar_proc_config(sdi) != SR_OK)
		return SR_ERR;

	sr_dbg("Starting log retrieval.");

	std_session_send_df_header(sdi);

	interval = (devc->config[0x1c] | (devc->config[0x1d] << 8)) * 1000;
	packet.type = SR_DF_META;
	packet.payload = &meta;
	src = sr_config_new(SR_CONF_SAMPLE_INTERVAL, g_variant_new_uint64(interval));
	meta.config = g_slist_append(NULL, src);
	sr_session_send(sdi, &packet);
	g_free(src);

	if (devc->logged_samples == 0) {
		/* This ensures the frontend knows the session is done. */
		std_session_send_df_end(sdi);
		return SR_OK;
	}

	if (!(xfer_in = libusb_alloc_transfer(0)) ||
			!(xfer_out = libusb_alloc_transfer(0)))
		return SR_ERR;

	libusb_control_transfer(usb->devhdl, LIBUSB_REQUEST_TYPE_VENDOR,
			0x00, 0xffff, 0x00, NULL, 0, 50);
	libusb_control_transfer(usb->devhdl, LIBUSB_REQUEST_TYPE_VENDOR,
			0x02, 0x0002, 0x00, NULL, 0, 50);
	libusb_control_transfer(usb->devhdl, LIBUSB_REQUEST_TYPE_VENDOR,
			0x02, 0x0001, 0x00, NULL, 0, 50);

	/* Flush input. The F321 requires this. */
	while (libusb_bulk_transfer(usb->devhdl, LASCAR_EP_IN, resp,
			256, &ret, 5) == 0 && ret > 0)
		;

	libusb_fill_bulk_transfer(xfer_in, usb->devhdl, LASCAR_EP_IN,
			resp, sizeof(resp), mark_xfer, 0, BULK_XFER_TIMEOUT);
	if (libusb_submit_transfer(xfer_in) != 0) {
		libusb_free_transfer(xfer_in);
		libusb_free_transfer(xfer_out);
		return SR_ERR;
	}

	cmd[0] = 0x03;
	cmd[1] = 0xff;
	cmd[2] = 0xff;
	libusb_fill_bulk_transfer(xfer_out, usb->devhdl, LASCAR_EP_OUT,
			cmd, 3, mark_xfer, 0, 100);
	if (libusb_submit_transfer(xfer_out) != 0) {
		libusb_free_transfer(xfer_in);
		libusb_free_transfer(xfer_out);
		return SR_ERR;
	}

	tv.tv_sec = 0;
	tv.tv_usec = 0;
	while (!xfer_in->user_data || !xfer_out->user_data) {
		g_usleep(SLEEP_US_LONG);
		libusb_handle_events_timeout(drvc->sr_ctx->libusb_ctx, &tv);
	}
	if (xfer_in->user_data != GINT_TO_POINTER(1) ||
			xfer_out->user_data != GINT_TO_POINTER(1)) {
		sr_dbg("no response to log transfer request");
		libusb_free_transfer(xfer_in);
		libusb_free_transfer(xfer_out);
		return SR_ERR;
	}
	if (xfer_in->actual_length != 3 || xfer_in->buffer[0] != 2) {
		sr_dbg("invalid response to log transfer request");
		libusb_free_transfer(xfer_in);
		libusb_free_transfer(xfer_out);
		return SR_ERR;
	}
	devc->log_size = xfer_in->buffer[1] + (xfer_in->buffer[2] << 8);
	libusb_free_transfer(xfer_out);

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

	buf = g_malloc(4096);
	libusb_fill_bulk_transfer(xfer_in, usb->devhdl, LASCAR_EP_IN,
			buf, 4096, lascar_el_usb_receive_transfer,
			(struct sr_dev_inst *)sdi, 100);
	if ((ret = libusb_submit_transfer(xfer_in) != 0)) {
		sr_err("Unable to submit transfer: %s.", libusb_error_name(ret));
		libusb_free_transfer(xfer_in);
		g_free(buf);
		return SR_ERR;
	}

	return SR_OK;
}

static int dev_acquisition_stop(struct sr_dev_inst *sdi)
{
	sdi->status = SR_ST_STOPPING;
	/* TODO: free ongoing transfers? */

	return SR_OK;
}

SR_PRIV struct sr_dev_driver lascar_el_usb_driver_info = {
	.name = "lascar-el-usb",
	.longname = "Lascar EL-USB",
	.api_version = 1,
	.init = std_init,
	.cleanup = std_cleanup,
	.scan = scan,
	.dev_list = std_dev_list,
	.dev_clear = std_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,
	.context = NULL,
};
SR_REGISTER_DEV_DRIVER(lascar_el_usb_driver_info);
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 <config.h>
	21	#include <glib.h>
	22	#include <libusb.h>
	23	#include <libsigrok/libsigrok.h>
	24	#include "libsigrok-internal.h"
	25	#include "protocol.h"
	26
	27	static const uint32_t scanopts[] = {
	28	SR_CONF_CONN,
	29	};
	30
	31	static const uint32_t drvopts[] = {
	32	SR_CONF_THERMOMETER,
	33	SR_CONF_HYGROMETER,
	34	};
	35
	36	static const uint32_t devopts[] = {
	37	SR_CONF_CONN \| SR_CONF_GET,
	38	SR_CONF_LIMIT_SAMPLES \| SR_CONF_GET \| SR_CONF_SET,
	39	SR_CONF_DATALOG \| SR_CONF_GET \| SR_CONF_SET,
	40	};
	41
	42	static GSList scan(struct sr_dev_driver di, GSList *options)
	43	{
	44	struct drv_context *drvc;
	45	struct sr_dev_inst *sdi;
	46	struct sr_usb_dev_inst *usb;
	47	struct sr_config *src;
	48	GSList usb_devices, devices, *l;
	49	const char *conn;
	50
	51	drvc = di->context;
	52
	53	conn = NULL;
	54	for (l = options; l; l = l->next) {
	55	src = l->data;
	56	switch (src->key) {
	57	case SR_CONF_CONN:
	58	conn = g_variant_get_string(src->data, NULL);
	59	break;
	60	}
	61	}
	62	if (!conn)
	63	return NULL;
	64
	65	devices = NULL;
	66	if ((usb_devices = sr_usb_find(drvc->sr_ctx->libusb_ctx, conn))) {
	67	/* We have a list of sr_usb_dev_inst matching the connection
	68	* string. Wrap them in sr_dev_inst and we're done. */
	69	for (l = usb_devices; l; l = l->next) {
	70	usb = l->data;
	71	if (!(sdi = lascar_scan(usb->bus, usb->address))) {
	72	/* Not a Lascar EL-USB. */
	73	g_free(usb);
	74	continue;
	75	}
	76	sdi->inst_type = SR_INST_USB;
	77	sdi->conn = usb;
	78	devices = g_slist_append(devices, sdi);
	79	}
	80	g_slist_free(usb_devices);
	81	} else
	82	g_slist_free_full(usb_devices, g_free);
	83
	84	return std_scan_complete(di, devices);
	85	}
	86
	87	static int dev_open(struct sr_dev_inst *sdi)
	88	{
	89	struct sr_dev_driver *di = sdi->driver;
	90	struct drv_context *drvc = di->context;;
	91	struct sr_usb_dev_inst *usb;
	92	int ret;
	93
	94	usb = sdi->conn;
	95
	96	if (sr_usb_open(drvc->sr_ctx->libusb_ctx, usb) != SR_OK)
	97	return SR_ERR;
	98
	99	if ((ret = libusb_claim_interface(usb->devhdl, LASCAR_INTERFACE))) {
	100	sr_err("Failed to claim interface: %s.", libusb_error_name(ret));
	101	return SR_ERR;
	102	}
	103
	104	return SR_OK;
	105	}
	106
	107	static int dev_close(struct sr_dev_inst *sdi)
	108	{
	109	struct sr_usb_dev_inst *usb;
	110
	111	usb = sdi->conn;
	112
	113	if (!usb->devhdl)
	114	return SR_ERR_BUG;
	115
	116	libusb_release_interface(usb->devhdl, LASCAR_INTERFACE);
	117	libusb_close(usb->devhdl);
	118	usb->devhdl = NULL;
	119
	120	return SR_OK;
	121	}
	122
	123	static int config_get(uint32_t key, GVariant *data, const struct sr_dev_inst sdi,
	124	const struct sr_channel_group *cg)
	125	{
	126	struct dev_context *devc;
	127	struct sr_usb_dev_inst *usb;
	128	int ret;
	129	char str[128];
	130
	131	(void)cg;
	132
	133	devc = sdi->priv;
	134	switch (key) {
	135	case SR_CONF_CONN:
	136	if (!sdi \|\| !sdi->conn)
	137	return SR_ERR_ARG;
	138	usb = sdi->conn;
	139	snprintf(str, 128, "%d.%d", usb->bus, usb->address);
	140	*data = g_variant_new_string(str);
	141	break;
	142	case SR_CONF_DATALOG:
	143	if (!sdi)
	144	return SR_ERR_ARG;
	145	if ((ret = lascar_is_logging(sdi)) == -1)
	146	return SR_ERR;
	147	*data = g_variant_new_boolean(ret ? TRUE : FALSE);
	148	break;
	149	case SR_CONF_LIMIT_SAMPLES:
	150	*data = g_variant_new_uint64(devc->limit_samples);
	151	break;
	152	default:
	153	return SR_ERR_NA;
	154	}
	155
	156	return SR_OK;
	157	}
	158
	159	static int config_set(uint32_t key, GVariant data, const struct sr_dev_inst sdi,
	160	const struct sr_channel_group *cg)
	161	{
	162	struct dev_context *devc;
	163	int ret;
	164
	165	(void)cg;
	166
	167	devc = sdi->priv;
	168	ret = SR_OK;
	169	switch (key) {
	170	case SR_CONF_DATALOG:
	171	if (g_variant_get_boolean(data))
	172	ret = lascar_start_logging(sdi);
	173	else
	174	ret = lascar_stop_logging(sdi);
	175	break;
	176	case SR_CONF_LIMIT_SAMPLES:
	177	devc->limit_samples = g_variant_get_uint64(data);
	178	break;
	179	default:
	180	ret = SR_ERR_NA;
	181	}
	182
	183	return ret;
	184	}
	185
	186	static int config_list(uint32_t key, GVariant *data, const struct sr_dev_inst sdi,
	187	const struct sr_channel_group *cg)
	188	{
	189	return STD_CONFIG_LIST(key, data, sdi, cg, scanopts, drvopts, devopts);
	190	}
	191
	192	static void LIBUSB_CALL mark_xfer(struct libusb_transfer *xfer)
	193	{
	194
	195	if (xfer->status == LIBUSB_TRANSFER_COMPLETED)
	196	xfer->user_data = GINT_TO_POINTER(1);
	197	else
	198	xfer->user_data = GINT_TO_POINTER(-1);
	199
	200	}
	201
	202	/* The Lascar software, in its infinite ignorance, reads a set of four
	203	* bytes from the device config struct and interprets it as a float.
	204	* That only works because they only use windows, and only on x86. However
	205	* we may be running on any architecture, any operating system. So we have
	206	* to convert these four bytes as the Lascar software would on windows/x86,
	207	* to the local representation of a float.
	208	* The source format is little-endian, with IEEE 754-2008 BINARY32 encoding. */
	209	static float binary32_le_to_float(unsigned char *buf)
	210	{
	211	GFloatIEEE754 f;
	212
	213	f.v_float = 0;
	214	f.mpn.sign = (buf[3] & 0x80) ? 1 : 0;
	215	f.mpn.biased_exponent = (buf[3] << 1) \| (buf[2] >> 7);
	216	f.mpn.mantissa = buf[0] \| (buf[1] << 8) \| ((buf[2] & 0x7f) << 16);
	217
	218	return f.v_float;
	219	}
	220
	221	static int lascar_proc_config(const struct sr_dev_inst *sdi)
	222	{
	223	struct dev_context *devc;
	224	struct sr_usb_dev_inst *usb;
	225	int dummy, ret;
	226
	227	devc = sdi->priv;
	228	usb = sdi->conn;
	229
	230	if (lascar_get_config(usb->devhdl, devc->config, &dummy) != SR_OK)
	231	return SR_ERR;
	232
	233	ret = SR_OK;
	234	switch (devc->profile->logformat) {
	235	case LOG_TEMP_RH:
	236	devc->sample_size = 2;
	237	devc->temp_unit = devc->config[0x2e] \| (devc->config[0x2f] << 8);
	238	if (devc->temp_unit != 0 && devc->temp_unit != 1) {
	239	sr_dbg("invalid temperature unit %d", devc->temp_unit);
	240	/* Default to Celsius, we're all adults here. */
	241	devc->temp_unit = 0;
	242	} else
	243	sr_dbg("temperature unit is %s", devc->temp_unit
	244	? "Fahrenheit" : "Celsius");
	245	break;
	246	case LOG_CO:
	247	devc->sample_size = 2;
	248	devc->co_high = binary32_le_to_float(devc->config + 0x24);
	249	devc->co_low = binary32_le_to_float(devc->config + 0x28);
	250	sr_dbg("EL-USB-CO calibration high %f low %f", devc->co_high,
	251	devc->co_low);
	252	break;
	253	default:
	254	ret = SR_ERR_ARG;
	255	}
	256	devc->logged_samples = devc->config[0x1e] \| (devc->config[0x1f] << 8);
	257	sr_dbg("device log contains %d samples.", devc->logged_samples);
	258
	259	return ret;
	260	}
	261
	262	static int dev_acquisition_start(const struct sr_dev_inst *sdi)
	263	{
	264	struct sr_dev_driver *di = sdi->driver;
	265	struct sr_datafeed_packet packet;
	266	struct sr_datafeed_meta meta;
	267	struct sr_config *src;
	268	struct dev_context *devc;
	269	struct drv_context *drvc;
	270	struct sr_usb_dev_inst *usb;
	271	struct libusb_transfer xfer_in, xfer_out;
	272	struct timeval tv;
	273	uint64_t interval;
	274	int ret;
	275	unsigned char cmd[3], resp[4], *buf;
	276
	277	drvc = di->context;
	278	devc = sdi->priv;
	279	usb = sdi->conn;
	280
	281	if (lascar_proc_config(sdi) != SR_OK)
	282	return SR_ERR;
	283
	284	sr_dbg("Starting log retrieval.");
	285
	286	std_session_send_df_header(sdi);
	287
	288	interval = (devc->config[0x1c] \| (devc->config[0x1d] << 8)) * 1000;
	289	packet.type = SR_DF_META;
	290	packet.payload = &meta;
	291	src = sr_config_new(SR_CONF_SAMPLE_INTERVAL, g_variant_new_uint64(interval));
	292	meta.config = g_slist_append(NULL, src);
	293	sr_session_send(sdi, &packet);
	294	g_free(src);
	295
	296	if (devc->logged_samples == 0) {
	297	/* This ensures the frontend knows the session is done. */
	298	std_session_send_df_end(sdi);
	299	return SR_OK;
	300	}
	301
	302	if (!(xfer_in = libusb_alloc_transfer(0)) \|\|
	303	!(xfer_out = libusb_alloc_transfer(0)))
	304	return SR_ERR;
	305
	306	libusb_control_transfer(usb->devhdl, LIBUSB_REQUEST_TYPE_VENDOR,
	307	0x00, 0xffff, 0x00, NULL, 0, 50);
	308	libusb_control_transfer(usb->devhdl, LIBUSB_REQUEST_TYPE_VENDOR,
	309	0x02, 0x0002, 0x00, NULL, 0, 50);
	310	libusb_control_transfer(usb->devhdl, LIBUSB_REQUEST_TYPE_VENDOR,
	311	0x02, 0x0001, 0x00, NULL, 0, 50);
	312
	313	/* Flush input. The F321 requires this. */
	314	while (libusb_bulk_transfer(usb->devhdl, LASCAR_EP_IN, resp,
	315	256, &ret, 5) == 0 && ret > 0)
	316	;
	317
	318	libusb_fill_bulk_transfer(xfer_in, usb->devhdl, LASCAR_EP_IN,
	319	resp, sizeof(resp), mark_xfer, 0, BULK_XFER_TIMEOUT);
	320	if (libusb_submit_transfer(xfer_in) != 0) {
	321	libusb_free_transfer(xfer_in);
	322	libusb_free_transfer(xfer_out);
	323	return SR_ERR;
	324	}
	325
	326	cmd[0] = 0x03;
	327	cmd[1] = 0xff;
	328	cmd[2] = 0xff;
	329	libusb_fill_bulk_transfer(xfer_out, usb->devhdl, LASCAR_EP_OUT,
	330	cmd, 3, mark_xfer, 0, 100);
	331	if (libusb_submit_transfer(xfer_out) != 0) {
	332	libusb_free_transfer(xfer_in);
	333	libusb_free_transfer(xfer_out);
	334	return SR_ERR;
	335	}
	336
	337	tv.tv_sec = 0;
	338	tv.tv_usec = 0;
	339	while (!xfer_in->user_data \|\| !xfer_out->user_data) {
	340	g_usleep(SLEEP_US_LONG);
	341	libusb_handle_events_timeout(drvc->sr_ctx->libusb_ctx, &tv);
	342	}
	343	if (xfer_in->user_data != GINT_TO_POINTER(1) \|\|
	344	xfer_out->user_data != GINT_TO_POINTER(1)) {
	345	sr_dbg("no response to log transfer request");
	346	libusb_free_transfer(xfer_in);
	347	libusb_free_transfer(xfer_out);
	348	return SR_ERR;
	349	}
	350	if (xfer_in->actual_length != 3 \|\| xfer_in->buffer[0] != 2) {
	351	sr_dbg("invalid response to log transfer request");
	352	libusb_free_transfer(xfer_in);
	353	libusb_free_transfer(xfer_out);
	354	return SR_ERR;
	355	}
	356	devc->log_size = xfer_in->buffer[1] + (xfer_in->buffer[2] << 8);
	357	libusb_free_transfer(xfer_out);
	358
	359	usb_source_add(sdi->session, drvc->sr_ctx, 100,
	360	lascar_el_usb_handle_events, (void *)sdi);
	361
	362	buf = g_malloc(4096);
	363	libusb_fill_bulk_transfer(xfer_in, usb->devhdl, LASCAR_EP_IN,
	364	buf, 4096, lascar_el_usb_receive_transfer,
	365	(struct sr_dev_inst *)sdi, 100);
	366	if ((ret = libusb_submit_transfer(xfer_in) != 0)) {
	367	sr_err("Unable to submit transfer: %s.", libusb_error_name(ret));
	368	libusb_free_transfer(xfer_in);
	369	g_free(buf);
	370	return SR_ERR;
	371	}
	372
	373	return SR_OK;
	374	}
	375
	376	static int dev_acquisition_stop(struct sr_dev_inst *sdi)
	377	{
	378	sdi->status = SR_ST_STOPPING;
	379	/* TODO: free ongoing transfers? */
	380
	381	return SR_OK;
	382	}
	383
	384	SR_PRIV struct sr_dev_driver lascar_el_usb_driver_info = {
	385	.name = "lascar-el-usb",
	386	.longname = "Lascar EL-USB",
	387	.api_version = 1,
	388	.init = std_init,
	389	.cleanup = std_cleanup,
	390	.scan = scan,
	391	.dev_list = std_dev_list,
	392	.dev_clear = std_dev_clear,
	393	.config_get = config_get,
	394	.config_set = config_set,
	395	.config_list = config_list,
	396	.dev_open = dev_open,
	397	.dev_close = dev_close,
	398	.dev_acquisition_start = dev_acquisition_start,
	399	.dev_acquisition_stop = dev_acquisition_stop,
	400	.context = NULL,
	401	};
	402	SR_REGISTER_DEV_DRIVER(lascar_el_usb_driver_info);