[libsigrok.git] / src / hardware / hantek-4032l / protocol.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2016 Andreas Zschunke <andreas.zschunke@gmx.net>
 * Copyright (C) 2017 Andrej Valek <andy@skyrain.eu>
 * Copyright (C) 2017 Uwe Hermann <uwe@hermann-uwe.de>
 *
 * 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 "protocol.h"

#define H4032L_USB_TIMEOUT 500

enum h4032l_cmd {
	CMD_RESET = 0x00b3, /* Also arms the logic analyzer. */
	CMD_CONFIGURE = 0x2b1a,
	CMD_STATUS = 0x4b3a,
	CMD_GET = 0x6b5a
};

struct h4032l_status_packet {
	uint32_t magic;
	uint32_t values;
	uint32_t status;
};

static void finish_acquisition(struct sr_dev_inst *sdi)
{
	struct drv_context *drvc = sdi->driver->context;

	std_session_send_df_end(sdi);
	usb_source_remove(sdi->session, drvc->sr_ctx);
}

static void free_transfer(struct libusb_transfer *transfer)
{
	struct sr_dev_inst *sdi = transfer->user_data;
	struct dev_context *devc = sdi->priv;

	transfer->buffer = NULL;
	libusb_free_transfer(transfer);
	devc->usb_transfer = NULL;

	finish_acquisition(sdi);
}

SR_PRIV int h4032l_receive_data(int fd, int revents, void *cb_data)
{
	struct timeval tv;
	struct drv_context *drvc;

	(void)fd;
	(void)revents;

	drvc = (struct drv_context *)cb_data;

	tv.tv_sec = tv.tv_usec = 0;
	libusb_handle_events_timeout(drvc->sr_ctx->libusb_ctx, &tv);

	return TRUE;
}

void LIBUSB_CALL h4032l_usb_callback(struct libusb_transfer *transfer)
{
	const struct sr_dev_inst *sdi = transfer->user_data;
	struct dev_context *devc = sdi->priv;
	struct drv_context *drvc = sdi->driver->context;
	struct sr_usb_dev_inst *usb = sdi->conn;
	gboolean cmd = FALSE;
	uint32_t max_samples = 512 / sizeof(uint32_t);
	uint32_t *buffer;
	struct h4032l_status_packet *status;
	struct sr_datafeed_packet packet;
	struct sr_datafeed_logic logic;
	uint32_t number_samples;
	int ret;

	/*
	 * If acquisition has already ended, just free any queued up
	 * transfers that come in.
	 */
	if (devc->acq_aborted) {
		free_transfer(transfer);
		return;
	}

	if (transfer->status != LIBUSB_TRANSFER_COMPLETED)
		sr_dbg("%s error: %d.", __func__, transfer->status);

	buffer = (uint32_t *)transfer->buffer;

	switch (devc->status) {
	case H4032L_STATUS_IDLE:
		sr_err("USB callback called in idle.");
		break;
	case H4032L_STATUS_CMD_CONFIGURE:
		/* Select status request as next. */
		cmd = TRUE;
		devc->cmd_pkt.cmd = CMD_STATUS;
		devc->status = H4032L_STATUS_CMD_STATUS;
		break;
	case H4032L_STATUS_CMD_STATUS:
		/* Select status request as next. */
		devc->status = H4032L_STATUS_RESPONSE_STATUS;
		break;
	case H4032L_STATUS_RESPONSE_STATUS:
		/*
		 * Check magic and if status is complete, then select
		 * First Transfer as next.
		 */
		status = (struct h4032l_status_packet *)transfer->buffer;
		if (status->magic != H4032L_STATUS_PACKET_MAGIC) {
			devc->status = H4032L_STATUS_RESPONSE_STATUS;
		} else if (status->status == 2) {
			devc->status = H4032L_STATUS_RESPONSE_STATUS_CONTINUE;
		} else {
			devc->status = H4032L_STATUS_RESPONSE_STATUS_RETRY;
		}
		break;
	case H4032L_STATUS_RESPONSE_STATUS_RETRY:
		devc->status = H4032L_STATUS_CMD_STATUS;
		devc->cmd_pkt.cmd = CMD_STATUS;
		cmd = TRUE;
		break;
	case H4032L_STATUS_RESPONSE_STATUS_CONTINUE:
		devc->status = H4032L_STATUS_CMD_GET;
		devc->cmd_pkt.cmd = CMD_GET;
		cmd = TRUE;
		break;
	case H4032L_STATUS_CMD_GET:
		devc->status = H4032L_STATUS_FIRST_TRANSFER;
		break;
	case H4032L_STATUS_FIRST_TRANSFER:
		/* Drop packets until H4032L_START_PACKET_MAGIC. */
		if (buffer[0] != H4032L_START_PACKET_MAGIC) {
			sr_dbg("Mismatch magic number of start poll.");
			break;
		}
		devc->status = H4032L_STATUS_TRANSFER;
		max_samples--;
		buffer++;
		/* Fallthrough. */
	case H4032L_STATUS_TRANSFER:
		number_samples = (devc->remaining_samples < max_samples) ? devc->remaining_samples : max_samples;
		devc->remaining_samples -= number_samples;
		packet.type = SR_DF_LOGIC;
		packet.payload = &logic;
		logic.length = number_samples * sizeof(uint32_t);
		logic.unitsize = sizeof(uint32_t);
		logic.data = buffer;
		sr_session_send(sdi, &packet);
		sr_dbg("Remaining: %d %08X %08X.", devc->remaining_samples,
			buffer[0], buffer[1]);
		if (devc->remaining_samples == 0) {
			std_session_send_df_end(sdi);
			usb_source_remove(sdi->session, drvc->sr_ctx);
			devc->status = H4032L_STATUS_IDLE;
			if (buffer[number_samples] != H4032L_END_PACKET_MAGIC)
				sr_err("Mismatch magic number of end poll.");
		}
		break;
	}

	if (devc->status != H4032L_STATUS_IDLE) {
		if (cmd) {
			/* Setup new USB cmd packet, reuse transfer object. */
			sr_dbg("New command: %d.", devc->status);
			libusb_fill_bulk_transfer(transfer, usb->devhdl,
				2 | LIBUSB_ENDPOINT_OUT,
				(unsigned char *)&devc->cmd_pkt,
				sizeof(struct h4032l_cmd_pkt),
				h4032l_usb_callback, (void *)sdi,
				H4032L_USB_TIMEOUT);
		} else {
			/* Setup new USB poll packet, reuse transfer object. */
			sr_dbg("Poll: %d.", devc->status);
			libusb_fill_bulk_transfer(transfer, usb->devhdl,
				6 | LIBUSB_ENDPOINT_IN,
				devc->buffer, ARRAY_SIZE(devc->buffer),
				h4032l_usb_callback,
				(void *)sdi, H4032L_USB_TIMEOUT);
		}
		/* Send prepared USB packet. */
		if ((ret = libusb_submit_transfer(transfer)) != 0) {
			sr_err("Failed to submit transfer: %s.",
			       libusb_error_name(ret));
			devc->status = H4032L_STATUS_IDLE;
		}
	} else {
		sr_dbg("Now idle.");
	}

	if (devc->status == H4032L_STATUS_IDLE)
		free_transfer(transfer);
}

uint16_t h4032l_voltage2pwm(double voltage)
{
	/*
	 * word PwmA - channel A Vref PWM value, pseudocode:
	 * -6V < ThresholdVoltage < +6V
	 * Vref = 1.8 - ThresholdVoltage
	 * if Vref > 10.0
	 * 	Vref = 10.0
	 * if Vref < -5.0
	 * 	Vref = -5.0
	 * pwm = ToInt((Vref + 5.0) / 15.0 * 4096.0)
	 * if pwm > 4095
	 * 	pwm = 4095
	 */
	voltage = 1.8 - voltage;
	if (voltage > 10.0)
		voltage = 10.0;
	else if (voltage < -5.0)
		voltage = -5.0;

	return (uint16_t) ((voltage + 5.0) * (4096.0 / 15.0));
}

SR_PRIV int h4032l_start(const struct sr_dev_inst *sdi)
{
	struct dev_context *devc = sdi->priv;
	struct sr_usb_dev_inst *usb = sdi->conn;
	struct libusb_transfer *transfer;
	unsigned char buffer[] = {0x0f, 0x03, 0x03, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
	int ret;

	/* Send reset command to arm the logic analyzer. */
	if ((ret = libusb_control_transfer(usb->devhdl,
		LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_ENDPOINT_OUT, CMD_RESET,
		0x00, 0x00, buffer, ARRAY_SIZE(buffer), H4032L_USB_TIMEOUT)) < 0) {
		sr_err("Failed to send vendor request %s.", libusb_error_name(ret));
		return SR_ERR;
	}

	/* Wait for reset vendor request. */
	g_usleep(20 * 1000);

	/* Send configure command. */
	devc->cmd_pkt.cmd = CMD_CONFIGURE;
	devc->status = H4032L_STATUS_CMD_CONFIGURE;
	devc->remaining_samples = devc->cmd_pkt.sample_size;

	transfer = libusb_alloc_transfer(0);

	libusb_fill_bulk_transfer(transfer, usb->devhdl,
		2 | LIBUSB_ENDPOINT_OUT, (unsigned char *)&devc->cmd_pkt,
		sizeof(struct h4032l_cmd_pkt), h4032l_usb_callback,
		(void *)sdi, H4032L_USB_TIMEOUT);

	if ((ret = libusb_submit_transfer(transfer)) != 0) {
		sr_err("Failed to submit transfer: %s.", libusb_error_name(ret));
		libusb_free_transfer(transfer);
		return SR_ERR;
	}

	std_session_send_df_header(sdi);

	return SR_OK;
}

SR_PRIV int h4032l_dev_open(struct sr_dev_inst *sdi)
{
	struct drv_context *drvc = sdi->driver->context;
	struct sr_usb_dev_inst *usb = sdi->conn;
	struct libusb_device_descriptor des;
	libusb_device **devlist;
	int ret = SR_ERR, i, device_count;
	char connection_id[64];

	device_count = libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
	if (device_count < 0) {
		sr_err("Failed to get device list: %s.",
		       libusb_error_name(device_count));
		return SR_ERR;
	}

	for (i = 0; i < device_count; i++) {
		libusb_get_device_descriptor(devlist[i], &des);

		if (des.idVendor != H4032L_USB_VENDOR ||
		    des.idProduct != H4032L_USB_PRODUCT)
			continue;

		if ((sdi->status == SR_ST_INITIALIZING) ||
		    (sdi->status == SR_ST_INACTIVE)) {
			/* Check device by its physical USB bus/port address. */
			usb_get_port_path(devlist[i], connection_id,
					  sizeof(connection_id));
			if (strcmp(sdi->connection_id, connection_id))
				/* This is not the one. */
				continue;
		}

		if (!(ret = libusb_open(devlist[i], &usb->devhdl))) {
			if (usb->address == 0xff)
				/*
				 * First time we touch this device after FW
				 * upload, so we don't know the address yet.
				 */
				usb->address =
				    libusb_get_device_address(devlist[i]);
		} else {
			sr_err("Failed to open device: %s.",
			       libusb_error_name(ret));
			ret = SR_ERR;
			break;
		}

		ret = SR_OK;
		break;
	}

	libusb_free_device_list(devlist, 1);
	return ret;
}
Commit	Line	Data
6a25fa42 AZ	1	/*
	2	* This file is part of the libsigrok project.
	3	*
5089a143 AZ	4	* Copyright (C) 2016 Andreas Zschunke <andreas.zschunke@gmx.net>
	5	* Copyright (C) 2017 Andrej Valek <andy@skyrain.eu>
	6	* Copyright (C) 2017 Uwe Hermann <uwe@hermann-uwe.de>
6a25fa42 AZ	7	*
	8	* This program is free software: you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation, either version 3 of the License, or
	11	* (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	20	*/
	21
	22	#include <config.h>
	23	#include "protocol.h"
	24
5089a143 AZ	25	#define H4032L_USB_TIMEOUT 500
	26
	27	enum h4032l_cmd {
74c4c174 AV	28	CMD_RESET = 0x00b3, /* Also arms the logic analyzer. */
74c4c174 AV	29	CMD_CONFIGURE = 0x2b1a,
5089a143 AZ	30	CMD_STATUS = 0x4b3a,
	31	CMD_GET = 0x6b5a
	32	};
	33
e80e1858	34	struct h4032l_status_packet {
5089a143 AZ	35	uint32_t magic;
	36	uint32_t values;
	37	uint32_t status;
	38	};
	39
a5b9880e AV	40	static void finish_acquisition(struct sr_dev_inst *sdi)
	41	{
	42	struct drv_context *drvc = sdi->driver->context;
	43
	44	std_session_send_df_end(sdi);
	45	usb_source_remove(sdi->session, drvc->sr_ctx);
	46	}
	47
	48	static void free_transfer(struct libusb_transfer *transfer)
	49	{
	50	struct sr_dev_inst *sdi = transfer->user_data;
	51	struct dev_context *devc = sdi->priv;
	52
	53	transfer->buffer = NULL;
	54	libusb_free_transfer(transfer);
	55	devc->usb_transfer = NULL;
	56
	57	finish_acquisition(sdi);
	58	}
	59
5089a143	60	SR_PRIV int h4032l_receive_data(int fd, int revents, void *cb_data)
6a25fa42	61	{
5089a143 AZ	62	struct timeval tv;
5089a143 AZ	63	struct drv_context *drvc;
6a25fa42 AZ	64
6a25fa42 AZ	65	(void)fd;
5089a143 AZ	66	(void)revents;
	67
	68	drvc = (struct drv_context *)cb_data;
	69
	70	tv.tv_sec = tv.tv_usec = 0;
	71	libusb_handle_events_timeout(drvc->sr_ctx->libusb_ctx, &tv);
6a25fa42	72
5089a143 AZ	73	return TRUE;
5089a143 AZ	74	}
6a25fa42	75
5089a143 AZ	76	void LIBUSB_CALL h4032l_usb_callback(struct libusb_transfer *transfer)
	77	{
	78	const struct sr_dev_inst *sdi = transfer->user_data;
	79	struct dev_context *devc = sdi->priv;
	80	struct drv_context *drvc = sdi->driver->context;
	81	struct sr_usb_dev_inst *usb = sdi->conn;
	82	gboolean cmd = FALSE;
	83	uint32_t max_samples = 512 / sizeof(uint32_t);
	84	uint32_t *buffer;
	85	struct h4032l_status_packet *status;
	86	struct sr_datafeed_packet packet;
	87	struct sr_datafeed_logic logic;
	88	uint32_t number_samples;
	89	int ret;
6a25fa42	90
a5b9880e AV	91	/*
	92	* If acquisition has already ended, just free any queued up
	93	* transfers that come in.
	94	*/
	95	if (devc->acq_aborted) {
	96	free_transfer(transfer);
	97	return;
	98	}
	99
74c4c174 AV	100	if (transfer->status != LIBUSB_TRANSFER_COMPLETED)
74c4c174 AV	101	sr_dbg("%s error: %d.", __func__, transfer->status);
6a25fa42	102
5089a143 AZ	103	buffer = (uint32_t *)transfer->buffer;
	104
	105	switch (devc->status) {
	106	case H4032L_STATUS_IDLE:
	107	sr_err("USB callback called in idle.");
	108	break;
	109	case H4032L_STATUS_CMD_CONFIGURE:
	110	/* Select status request as next. */
	111	cmd = TRUE;
	112	devc->cmd_pkt.cmd = CMD_STATUS;
	113	devc->status = H4032L_STATUS_CMD_STATUS;
	114	break;
	115	case H4032L_STATUS_CMD_STATUS:
	116	/* Select status request as next. */
	117	devc->status = H4032L_STATUS_RESPONSE_STATUS;
	118	break;
	119	case H4032L_STATUS_RESPONSE_STATUS:
	120	/*
	121	* Check magic and if status is complete, then select
	122	* First Transfer as next.
	123	*/
	124	status = (struct h4032l_status_packet *)transfer->buffer;
	125	if (status->magic != H4032L_STATUS_PACKET_MAGIC) {
74c4c174	126	devc->status = H4032L_STATUS_RESPONSE_STATUS;
5089a143 AZ	127	} else if (status->status == 2) {
	128	devc->status = H4032L_STATUS_RESPONSE_STATUS_CONTINUE;
	129	} else {
	130	devc->status = H4032L_STATUS_RESPONSE_STATUS_RETRY;
	131	}
	132	break;
	133	case H4032L_STATUS_RESPONSE_STATUS_RETRY:
	134	devc->status = H4032L_STATUS_CMD_STATUS;
	135	devc->cmd_pkt.cmd = CMD_STATUS;
	136	cmd = TRUE;
	137	break;
	138	case H4032L_STATUS_RESPONSE_STATUS_CONTINUE:
	139	devc->status = H4032L_STATUS_CMD_GET;
	140	devc->cmd_pkt.cmd = CMD_GET;
	141	cmd = TRUE;
	142	break;
	143	case H4032L_STATUS_CMD_GET:
	144	devc->status = H4032L_STATUS_FIRST_TRANSFER;
	145	break;
	146	case H4032L_STATUS_FIRST_TRANSFER:
74c4c174	147	/* Drop packets until H4032L_START_PACKET_MAGIC. */
5089a143	148	if (buffer[0] != H4032L_START_PACKET_MAGIC) {
74c4c174	149	sr_dbg("Mismatch magic number of start poll.");
5089a143 AZ	150	break;
	151	}
	152	devc->status = H4032L_STATUS_TRANSFER;
	153	max_samples--;
	154	buffer++;
97200156	155	/* Fallthrough. */
5089a143 AZ	156	case H4032L_STATUS_TRANSFER:
	157	number_samples = (devc->remaining_samples < max_samples) ? devc->remaining_samples : max_samples;
	158	devc->remaining_samples -= number_samples;
	159	packet.type = SR_DF_LOGIC;
	160	packet.payload = &logic;
	161	logic.length = number_samples * sizeof(uint32_t);
	162	logic.unitsize = sizeof(uint32_t);
	163	logic.data = buffer;
	164	sr_session_send(sdi, &packet);
	165	sr_dbg("Remaining: %d %08X %08X.", devc->remaining_samples,
	166	buffer[0], buffer[1]);
	167	if (devc->remaining_samples == 0) {
	168	std_session_send_df_end(sdi);
	169	usb_source_remove(sdi->session, drvc->sr_ctx);
	170	devc->status = H4032L_STATUS_IDLE;
	171	if (buffer[number_samples] != H4032L_END_PACKET_MAGIC)
	172	sr_err("Mismatch magic number of end poll.");
	173	}
	174	break;
	175	}
	176
	177	if (devc->status != H4032L_STATUS_IDLE) {
	178	if (cmd) {
	179	/* Setup new USB cmd packet, reuse transfer object. */
	180	sr_dbg("New command: %d.", devc->status);
	181	libusb_fill_bulk_transfer(transfer, usb->devhdl,
	182	2 \| LIBUSB_ENDPOINT_OUT,
	183	(unsigned char *)&devc->cmd_pkt,
	184	sizeof(struct h4032l_cmd_pkt),
	185	h4032l_usb_callback, (void *)sdi,
	186	H4032L_USB_TIMEOUT);
	187	} else {
	188	/* Setup new USB poll packet, reuse transfer object. */
	189	sr_dbg("Poll: %d.", devc->status);
	190	libusb_fill_bulk_transfer(transfer, usb->devhdl,
	191	6 \| LIBUSB_ENDPOINT_IN,
	192	devc->buffer, ARRAY_SIZE(devc->buffer),
	193	h4032l_usb_callback,
	194	(void *)sdi, H4032L_USB_TIMEOUT);
	195	}
4868f15a	196	/* Send prepared USB packet. */
5089a143 AZ	197	if ((ret = libusb_submit_transfer(transfer)) != 0) {
	198	sr_err("Failed to submit transfer: %s.",
	199	libusb_error_name(ret));
	200	devc->status = H4032L_STATUS_IDLE;
	201	}
	202	} else {
	203	sr_dbg("Now idle.");
	204	}
	205
	206	if (devc->status == H4032L_STATUS_IDLE)
a5b9880e	207	free_transfer(transfer);
5089a143 AZ	208	}
	209
	210	uint16_t h4032l_voltage2pwm(double voltage)
	211	{
	212	/*
	213	* word PwmA - channel A Vref PWM value, pseudocode:
	214	* -6V < ThresholdVoltage < +6V
	215	* Vref = 1.8 - ThresholdVoltage
	216	* if Vref > 10.0
	217	* Vref = 10.0
	218	* if Vref < -5.0
	219	* Vref = -5.0
	220	* pwm = ToInt((Vref + 5.0) / 15.0 * 4096.0)
	221	* if pwm > 4095
	222	* pwm = 4095
	223	*/
	224	voltage = 1.8 - voltage;
	225	if (voltage > 10.0)
	226	voltage = 10.0;
	227	else if (voltage < -5.0)
	228	voltage = -5.0;
	229
	230	return (uint16_t) ((voltage + 5.0) * (4096.0 / 15.0));
	231	}
	232
	233	SR_PRIV int h4032l_start(const struct sr_dev_inst *sdi)
	234	{
	235	struct dev_context *devc = sdi->priv;
	236	struct sr_usb_dev_inst *usb = sdi->conn;
	237	struct libusb_transfer *transfer;
74c4c174	238	unsigned char buffer[] = {0x0f, 0x03, 0x03, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
5089a143 AZ	239	int ret;
5089a143 AZ	240
74c4c174 AV	241	/* Send reset command to arm the logic analyzer. */
	242	if ((ret = libusb_control_transfer(usb->devhdl,
	243	LIBUSB_REQUEST_TYPE_VENDOR \| LIBUSB_ENDPOINT_OUT, CMD_RESET,
	244	0x00, 0x00, buffer, ARRAY_SIZE(buffer), H4032L_USB_TIMEOUT)) < 0) {
	245	sr_err("Failed to send vendor request %s.", libusb_error_name(ret));
	246	return SR_ERR;
	247	}
	248
	249	/* Wait for reset vendor request. */
	250	g_usleep(20 * 1000);
	251
	252	/* Send configure command. */
5089a143 AZ	253	devc->cmd_pkt.cmd = CMD_CONFIGURE;
	254	devc->status = H4032L_STATUS_CMD_CONFIGURE;
	255	devc->remaining_samples = devc->cmd_pkt.sample_size;
	256
	257	transfer = libusb_alloc_transfer(0);
	258
	259	libusb_fill_bulk_transfer(transfer, usb->devhdl,
	260	2 \| LIBUSB_ENDPOINT_OUT, (unsigned char *)&devc->cmd_pkt,
	261	sizeof(struct h4032l_cmd_pkt), h4032l_usb_callback,
	262	(void *)sdi, H4032L_USB_TIMEOUT);
	263
	264	if ((ret = libusb_submit_transfer(transfer)) != 0) {
	265	sr_err("Failed to submit transfer: %s.", libusb_error_name(ret));
	266	libusb_free_transfer(transfer);
	267	return SR_ERR;
	268	}
	269
	270	std_session_send_df_header(sdi);
	271
	272	return SR_OK;
	273	}
	274
	275	SR_PRIV int h4032l_dev_open(struct sr_dev_inst *sdi)
	276	{
	277	struct drv_context *drvc = sdi->driver->context;
	278	struct sr_usb_dev_inst *usb = sdi->conn;
	279	struct libusb_device_descriptor des;
	280	libusb_device **devlist;
	281	int ret = SR_ERR, i, device_count;
	282	char connection_id[64];
	283
	284	device_count = libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
	285	if (device_count < 0) {
	286	sr_err("Failed to get device list: %s.",
	287	libusb_error_name(device_count));
	288	return SR_ERR;
	289	}
	290
	291	for (i = 0; i < device_count; i++) {
	292	libusb_get_device_descriptor(devlist[i], &des);
	293
	294	if (des.idVendor != H4032L_USB_VENDOR \|\|
	295	des.idProduct != H4032L_USB_PRODUCT)
	296	continue;
	297
	298	if ((sdi->status == SR_ST_INITIALIZING) \|\|
	299	(sdi->status == SR_ST_INACTIVE)) {
	300	/* Check device by its physical USB bus/port address. */
	301	usb_get_port_path(devlist[i], connection_id,
	302	sizeof(connection_id));
	303	if (strcmp(sdi->connection_id, connection_id))
	304	/* This is not the one. */
	305	continue;
	306	}
	307
	308	if (!(ret = libusb_open(devlist[i], &usb->devhdl))) {
	309	if (usb->address == 0xff)
	310	/*
	311	* First time we touch this device after FW
	312	* upload, so we don't know the address yet.
	313	*/
	314	usb->address =
	315	libusb_get_device_address(devlist[i]);
	316	} else {
317	sr_err("Failed to open device: %s.",
318	libusb_error_name(ret));
319	ret = SR_ERR;
320	break;
321	}
322
323	ret = SR_OK;
324	break;
325	}
326
327	libusb_free_device_list(devlist, 1);
328	return ret;
6a25fa42	329	}