[libsigrok.git] / src / scpi / scpi_usbtmc_libusb.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2014 Aurelien Jacobs <aurel@gnuage.org>
 *
 * 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 <string.h>
#include <libsigrok/libsigrok.h>
#include "libsigrok-internal.h"

#define LOG_PREFIX "scpi_usbtmc"

#define MAX_TRANSFER_LENGTH 2048
#define TRANSFER_TIMEOUT 1000

struct scpi_usbtmc_libusb {
	struct sr_context *ctx;
	struct sr_usb_dev_inst *usb;
	int detached_kernel_driver;
	uint8_t interface;
	uint8_t bulk_in_ep;
	uint8_t bulk_out_ep;
	uint8_t interrupt_ep;
	uint8_t usbtmc_int_cap;
	uint8_t usbtmc_dev_cap;
	uint8_t usb488_dev_cap;
	uint8_t bTag;
	uint8_t bulkin_attributes;
	uint8_t buffer[MAX_TRANSFER_LENGTH];
	int response_length;
	int response_bytes_read;
	int remaining_length;
	int rigol_ds1000;
};

/* Some USBTMC-specific enums, as defined in the USBTMC standard. */
#define SUBCLASS_USBTMC  0x03
#define USBTMC_USB488    0x01

enum {
	/* USBTMC control requests */
	INITIATE_ABORT_BULK_OUT     =   1,
	CHECK_ABORT_BULK_OUT_STATUS =   2,
	INITIATE_ABORT_BULK_IN      =   3,
	CHECK_ABORT_BULK_IN_STATUS  =   4,
	INITIATE_CLEAR              =   5,
	CHECK_CLEAR_STATUS          =   6,
	GET_CAPABILITIES            =   7,
	INDICATOR_PULSE             =  64,

	/* USB488 control requests */
	READ_STATUS_BYTE            = 128,
	REN_CONTROL                 = 160,
	GO_TO_LOCAL                 = 161,
	LOCAL_LOCKOUT               = 162,
};

/* USBTMC capabilities */
#define USBTMC_INT_CAP_LISTEN_ONLY 0x01
#define USBTMC_INT_CAP_TALK_ONLY   0x02
#define USBTMC_INT_CAP_INDICATOR   0x04

#define USBTMC_DEV_CAP_TERMCHAR    0x01

#define USB488_DEV_CAP_DT1         0x01
#define USB488_DEV_CAP_RL1         0x02
#define USB488_DEV_CAP_SR1         0x04
#define USB488_DEV_CAP_SCPI        0x08

/* Bulk messages constants */
#define USBTMC_BULK_HEADER_SIZE  12

/* Bulk MsgID values */
#define DEV_DEP_MSG_OUT         1
#define REQUEST_DEV_DEP_MSG_IN  2
#define DEV_DEP_MSG_IN          2

/* bmTransferAttributes */
#define EOM                0x01
#define TERM_CHAR_ENABLED  0x02

static GSList *scpi_usbtmc_libusb_scan(struct drv_context *drvc)
{
	struct libusb_device **devlist;
	struct libusb_device_descriptor des;
	struct libusb_config_descriptor *confdes;
	const struct libusb_interface_descriptor *intfdes;
	GSList *resources = NULL;
	int confidx, intfidx, ret, i;
	char *res;

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

		for (confidx = 0; confidx < des.bNumConfigurations; confidx++) {
			if ((ret = libusb_get_config_descriptor(devlist[i], confidx, &confdes)) < 0) {
				sr_dbg("Failed to get configuration descriptor: %s, "
				       "ignoring device.", libusb_error_name(ret));
				break;
			}
			for (intfidx = 0; intfidx < confdes->bNumInterfaces; intfidx++) {
				intfdes = confdes->interface[intfidx].altsetting;
				if (intfdes->bInterfaceClass    != LIBUSB_CLASS_APPLICATION ||
				    intfdes->bInterfaceSubClass != SUBCLASS_USBTMC          ||
				    intfdes->bInterfaceProtocol != USBTMC_USB488)
					continue;
				sr_dbg("Found USBTMC device (VID:PID = %04x:%04x, "
				       "bus.address = %d.%d).", des.idVendor, des.idProduct,
				       libusb_get_bus_number(devlist[i]),
				       libusb_get_device_address(devlist[i]));
				res = g_strdup_printf("usbtmc/%d.%d",
				                      libusb_get_bus_number(devlist[i]),
				                      libusb_get_device_address(devlist[i]));
				resources = g_slist_append(resources, res);
			}
			libusb_free_config_descriptor(confdes);
		}
	}
	libusb_free_device_list(devlist, 1);

	sr_dbg("Found %d device(s).", g_slist_length(resources));

	return resources;
}

static int scpi_usbtmc_libusb_dev_inst_new(void *priv, struct drv_context *drvc,
		const char *resource, char **params, const char *serialcomm)
{
	struct scpi_usbtmc_libusb *uscpi = priv;
	GSList *devices;

	(void)resource;
	(void)serialcomm;

	if (!params || !params[1]) {
		sr_err("Invalid parameters.");
		return SR_ERR;
	}

	uscpi->ctx = drvc->sr_ctx;
	devices = sr_usb_find(uscpi->ctx->libusb_ctx, params[1]);
	if (g_slist_length(devices) != 1) {
		sr_err("Failed to find USB device '%s'.", params[1]);
		g_slist_free_full(devices, (GDestroyNotify)sr_usb_dev_inst_free);
		return SR_ERR;
	}
	uscpi->usb = devices->data;
	g_slist_free(devices);

	return SR_OK;
}

static int scpi_usbtmc_libusb_open(void *priv)
{
	struct scpi_usbtmc_libusb *uscpi = priv;
	struct sr_usb_dev_inst *usb = uscpi->usb;
	struct libusb_device *dev;
	struct libusb_device_descriptor des;
	struct libusb_config_descriptor *confdes;
	const struct libusb_interface_descriptor *intfdes;
	const struct libusb_endpoint_descriptor *ep;
	int confidx, intfidx, epidx, config = 0;
	uint8_t capabilities[24];
	int ret, found = 0;

	if (usb->devhdl)
		return SR_OK;

	if (sr_usb_open(uscpi->ctx->libusb_ctx, usb) != SR_OK)
		return SR_ERR;

	dev = libusb_get_device(usb->devhdl);
	if ((ret = libusb_get_device_descriptor(dev, &des)) < 0) {
		sr_err("Failed to get device descriptor: %s.",
		       libusb_error_name(ret));
		return SR_ERR;
	}

	for (confidx = 0; confidx < des.bNumConfigurations; confidx++) {
		if ((ret = libusb_get_config_descriptor(dev, confidx, &confdes)) < 0) {
			sr_dbg("Failed to get configuration descriptor: %s, "
			       "ignoring device.", libusb_error_name(ret));
			continue;
		}
		for (intfidx = 0; intfidx < confdes->bNumInterfaces; intfidx++) {
			intfdes = confdes->interface[intfidx].altsetting;
			if (intfdes->bInterfaceClass    != LIBUSB_CLASS_APPLICATION ||
			    intfdes->bInterfaceSubClass != SUBCLASS_USBTMC          ||
			    intfdes->bInterfaceProtocol != USBTMC_USB488)
				continue;
			uscpi->interface = intfdes->bInterfaceNumber;
			config = confdes->bConfigurationValue;
			sr_dbg("Interface %d configuration %d.", uscpi->interface, config);
			for (epidx = 0; epidx < intfdes->bNumEndpoints; epidx++) {
				ep = &intfdes->endpoint[epidx];
				if (ep->bmAttributes == LIBUSB_TRANSFER_TYPE_BULK &&
				    !(ep->bEndpointAddress & (LIBUSB_ENDPOINT_DIR_MASK))) {
					uscpi->bulk_out_ep = ep->bEndpointAddress;
					sr_dbg("Bulk OUT EP %d", uscpi->bulk_out_ep);
				}
				if (ep->bmAttributes == LIBUSB_TRANSFER_TYPE_BULK &&
				    ep->bEndpointAddress & (LIBUSB_ENDPOINT_DIR_MASK)) {
					uscpi->bulk_in_ep = ep->bEndpointAddress;
					sr_dbg("Bulk IN EP %d", uscpi->bulk_in_ep & 0x7f);
				}
				if (ep->bmAttributes == LIBUSB_TRANSFER_TYPE_INTERRUPT &&
				    ep->bEndpointAddress & (LIBUSB_ENDPOINT_DIR_MASK)) {
					uscpi->interrupt_ep = ep->bEndpointAddress;
					sr_dbg("Interrupt EP %d", uscpi->interrupt_ep & 0x7f);
				}
			}
			found = 1;
			uscpi->rigol_ds1000 = des.idVendor  == 0x1ab1 &&
			                      des.idProduct == 0x0588;
		}
		libusb_free_config_descriptor(confdes);
		if (found)
			break;
	}

	if (!found) {
		sr_err("Failed to find USBTMC interface.");
		return SR_ERR;
	}

	if (libusb_kernel_driver_active(usb->devhdl, uscpi->interface) == 1) {
		if ((ret = libusb_detach_kernel_driver(usb->devhdl,
		                                       uscpi->interface)) < 0) {
			sr_err("Failed to detach kernel driver: %s.",
			       libusb_error_name(ret));
			return SR_ERR;
		}
		uscpi->detached_kernel_driver = 1;
	}

	if ((ret = libusb_set_configuration(usb->devhdl, config)) < 0) {
		sr_err("Failed to set configuration: %s.",
		       libusb_error_name(ret));
		return SR_ERR;
	}

	if ((ret = libusb_claim_interface(usb->devhdl, uscpi->interface)) < 0) {
		sr_err("Failed to claim interface: %s.",
		       libusb_error_name(ret));
		return SR_ERR;
	}

	if (!uscpi->rigol_ds1000) {
	if ((ret = libusb_clear_halt(usb->devhdl, uscpi->bulk_in_ep)) < 0) {
		sr_err("Failed to clear halt/stall condition for EP %d: %s.",
		       uscpi->bulk_in_ep, libusb_error_name(ret));
		return SR_ERR;
	}
	if ((ret = libusb_clear_halt(usb->devhdl, uscpi->bulk_out_ep)) < 0) {
		sr_err("Failed to clear halt/stall condition for EP %d: %s.",
		       uscpi->bulk_out_ep, libusb_error_name(ret));
		return SR_ERR;
	}
	if ((ret = libusb_clear_halt(usb->devhdl, uscpi->interrupt_ep)) < 0) {
		sr_err("Failed to clear halt/stall condition for EP %d: %s.",
		       uscpi->interrupt_ep, libusb_error_name(ret));
		return SR_ERR;
	}
	}

	/* Get capabilities. */
	ret = libusb_control_transfer(usb->devhdl,
	                              LIBUSB_ENDPOINT_IN         |
	                              LIBUSB_REQUEST_TYPE_CLASS  |
	                              LIBUSB_RECIPIENT_INTERFACE,
	                              GET_CAPABILITIES, 0,
	                              uscpi->interface,
	                              capabilities, sizeof(capabilities),
	                              TRANSFER_TIMEOUT);
	if (ret == sizeof(capabilities)) {
		uscpi->usbtmc_int_cap = capabilities[ 4];
		uscpi->usbtmc_dev_cap = capabilities[ 5];
		uscpi->usb488_dev_cap = capabilities[15];
	}
	sr_dbg("Device capabilities: %s%s%s%s%s, %s, %s",
	       uscpi->usb488_dev_cap & USB488_DEV_CAP_SCPI       ? "SCPI, "    : "",
	       uscpi->usbtmc_dev_cap & USBTMC_DEV_CAP_TERMCHAR   ? "TermChar, ": "",
	       uscpi->usbtmc_int_cap & USBTMC_INT_CAP_LISTEN_ONLY? "L3, " :
	       uscpi->usbtmc_int_cap & USBTMC_INT_CAP_TALK_ONLY  ? ""     : "L4, ",
	       uscpi->usbtmc_int_cap & USBTMC_INT_CAP_TALK_ONLY  ? "T5, " :
	       uscpi->usbtmc_int_cap & USBTMC_INT_CAP_LISTEN_ONLY? ""     : "T6, ",
	       uscpi->usb488_dev_cap & USB488_DEV_CAP_SR1        ? "SR1"  : "SR0",
	       uscpi->usb488_dev_cap & USB488_DEV_CAP_RL1        ? "RL1"  : "RL0",
	       uscpi->usb488_dev_cap & USB488_DEV_CAP_DT1        ? "DT1"  : "DT0");

	return SR_OK;
}

static int scpi_usbtmc_libusb_source_add(struct sr_session *session,
		void *priv, int events, int timeout, sr_receive_data_callback cb,
		void *cb_data)
{
	struct scpi_usbtmc_libusb *uscpi = priv;
	(void)events;
	return usb_source_add(session, uscpi->ctx, timeout, cb, cb_data);
}

static int scpi_usbtmc_libusb_source_remove(struct sr_session *session,
		void *priv)
{
	struct scpi_usbtmc_libusb *uscpi = priv;
	return usb_source_remove(session, uscpi->ctx);
}

static void usbtmc_bulk_out_header_write(void *header, uint8_t MsgID,
                                         uint8_t bTag,
                                         uint32_t TransferSize,
                                         uint8_t bmTransferAttributes,
                                         char TermChar)
{
	  W8(header+ 0, MsgID);
	  W8(header+ 1, bTag);
	  W8(header+ 2, ~bTag);
	  W8(header+ 3, 0);
	WL32(header+ 4, TransferSize);
	  W8(header+ 8, bmTransferAttributes);
	  W8(header+ 9, TermChar);
	WL16(header+10, 0);
}

static int usbtmc_bulk_in_header_read(void *header, uint8_t MsgID,
                                      unsigned char bTag,
                                      int32_t *TransferSize,
                                      uint8_t *bmTransferAttributes)
{
	if (R8(header+0) != MsgID ||
	    R8(header+1) != bTag  ||
	    R8(header+2) != (unsigned char)~bTag)
		return SR_ERR;
	if (TransferSize)
		*TransferSize = RL32(header+4);
	if (bmTransferAttributes)
		*bmTransferAttributes = R8(header+8);
	return SR_OK;
}

static int scpi_usbtmc_bulkout(struct scpi_usbtmc_libusb *uscpi,
                               uint8_t msg_id, const void *data, int32_t size,
                               uint8_t transfer_attributes)
{
	struct sr_usb_dev_inst *usb = uscpi->usb;
	int padded_size, ret, transferred;

	if (data && size+USBTMC_BULK_HEADER_SIZE+3 > (int)sizeof(uscpi->buffer)) {
		sr_err("USBTMC bulk out transfer is too big.");
		return SR_ERR;
	}

	uscpi->bTag++;
	uscpi->bTag += !uscpi->bTag;  /* bTag == 0 is invalid so avoid it. */

	usbtmc_bulk_out_header_write(uscpi->buffer, msg_id, uscpi->bTag,
	                             size, transfer_attributes, 0);
	if (data)
		memcpy(uscpi->buffer+USBTMC_BULK_HEADER_SIZE, data, size);
	else
		size = 0;
	size += USBTMC_BULK_HEADER_SIZE;
	padded_size = (size + 3) & ~0x3;
	memset(uscpi->buffer+size, 0, padded_size - size);

	ret = libusb_bulk_transfer(usb->devhdl, uscpi->bulk_out_ep,
	                           uscpi->buffer, padded_size, &transferred,
	                           TRANSFER_TIMEOUT);
	if (ret < 0) {
		sr_err("USBTMC bulk out transfer error: %s.",
		       libusb_error_name(ret));
		return SR_ERR;
	}

	if (transferred < padded_size) {
		sr_dbg("USBTMC bulk out partial transfer (%d/%d bytes).",
		       transferred, padded_size);
		return SR_ERR;
	}

	return transferred - USBTMC_BULK_HEADER_SIZE;
}

static int scpi_usbtmc_bulkin_start(struct scpi_usbtmc_libusb *uscpi,
                                    uint8_t msg_id, void *data, int32_t size,
                                    uint8_t *transfer_attributes)
{
	struct sr_usb_dev_inst *usb = uscpi->usb;
	int ret, transferred, message_size;

	ret = libusb_bulk_transfer(usb->devhdl, uscpi->bulk_in_ep, data, size,
	                           &transferred, TRANSFER_TIMEOUT);
	if (ret < 0) {
		sr_err("USBTMC bulk in transfer error: %s.",
		       libusb_error_name(ret));
		return SR_ERR;
	}

	if (usbtmc_bulk_in_header_read(data, msg_id, uscpi->bTag, &message_size,
	                               transfer_attributes) != SR_OK) {
		sr_err("USBTMC invalid bulk in header.");
		return SR_ERR;
	}

	message_size += USBTMC_BULK_HEADER_SIZE;
	uscpi->response_length = MIN(transferred, message_size);
	uscpi->response_bytes_read = USBTMC_BULK_HEADER_SIZE;
	uscpi->remaining_length = message_size - uscpi->response_length;

	return transferred - USBTMC_BULK_HEADER_SIZE;
}

static int scpi_usbtmc_bulkin_continue(struct scpi_usbtmc_libusb *uscpi,
                                       void *data, int size)
{
	struct sr_usb_dev_inst *usb = uscpi->usb;
	int ret, transferred;

	ret = libusb_bulk_transfer(usb->devhdl, uscpi->bulk_in_ep, data, size,
	                           &transferred, TRANSFER_TIMEOUT);
	if (ret < 0) {
		sr_err("USBTMC bulk in transfer error: %s.",
		       libusb_error_name(ret));
		return SR_ERR;
	}

	uscpi->response_length = MIN(transferred, uscpi->remaining_length);
	uscpi->response_bytes_read = 0;
	uscpi->remaining_length -= uscpi->response_length;

	return transferred;
}

static int scpi_usbtmc_libusb_send(void *priv, const char *command)
{
	struct scpi_usbtmc_libusb *uscpi = priv;

	if (scpi_usbtmc_bulkout(uscpi, DEV_DEP_MSG_OUT,
	                        command, strlen(command), EOM) <= 0)
		return SR_ERR;

	sr_spew("Successfully sent SCPI command: '%s'.", command);

	return SR_OK;
}

static int scpi_usbtmc_libusb_read_begin(void *priv)
{
	struct scpi_usbtmc_libusb *uscpi = priv;

	uscpi->remaining_length = 0;

	if (scpi_usbtmc_bulkout(uscpi, REQUEST_DEV_DEP_MSG_IN,
	    NULL, INT32_MAX, 0) < 0)
		return SR_ERR;
	if (scpi_usbtmc_bulkin_start(uscpi, DEV_DEP_MSG_IN,
	                             uscpi->buffer, sizeof(uscpi->buffer),
	                             &uscpi->bulkin_attributes) < 0)
		return SR_ERR;

	return SR_OK;
}

static int scpi_usbtmc_libusb_read_data(void *priv, char *buf, int maxlen)
{
	struct scpi_usbtmc_libusb *uscpi = priv;
	int read_length;

	if (uscpi->response_bytes_read >= uscpi->response_length) {
		if (uscpi->remaining_length > 0) {
			if (scpi_usbtmc_bulkin_continue(uscpi, uscpi->buffer,
			                                sizeof(uscpi->buffer)) <= 0)
				return SR_ERR;
		} else {
			if (uscpi->bulkin_attributes & EOM)
				return SR_ERR;
			if (scpi_usbtmc_libusb_read_begin(uscpi) < 0)
				return SR_ERR;
		}
	}

	read_length = MIN(uscpi->response_length - uscpi->response_bytes_read, maxlen);

	memcpy(buf, uscpi->buffer + uscpi->response_bytes_read, read_length);

	uscpi->response_bytes_read += read_length;

	return read_length;
}

static int scpi_usbtmc_libusb_read_complete(void *priv)
{
	struct scpi_usbtmc_libusb *uscpi = priv;
	return uscpi->response_bytes_read >= uscpi->response_length &&
	       uscpi->remaining_length <= 0 &&
	       uscpi->bulkin_attributes & EOM;
}

static int scpi_usbtmc_libusb_close(void *priv)
{
	int ret;
	struct scpi_usbtmc_libusb *uscpi = priv;
	struct sr_usb_dev_inst *usb = uscpi->usb;

	if (!usb->devhdl)
		return SR_ERR;

	if (!uscpi->rigol_ds1000) {
	if ((ret = libusb_clear_halt(usb->devhdl, uscpi->bulk_in_ep)) < 0)
		sr_err("Failed to clear halt/stall condition for EP %d: %s.",
		       uscpi->bulk_in_ep, libusb_error_name(ret));
	if ((ret = libusb_clear_halt(usb->devhdl, uscpi->bulk_out_ep)) < 0)
		sr_err("Failed to clear halt/stall condition for EP %d: %s.",
		       uscpi->bulk_out_ep, libusb_error_name(ret));
	if ((ret = libusb_clear_halt(usb->devhdl, uscpi->interrupt_ep)) < 0)
		sr_err("Failed to clear halt/stall condition for EP %d: %s.",
		       uscpi->interrupt_ep, libusb_error_name(ret));
	}

	if ((ret = libusb_release_interface(usb->devhdl, uscpi->interface)) < 0)
		sr_err("Failed to release interface: %s.",
		       libusb_error_name(ret));
	
	if (uscpi->detached_kernel_driver) {
		if ((ret = libusb_attach_kernel_driver(usb->devhdl,
						uscpi->interface)) < 0)
			sr_err("Failed to re-attach kernel driver: %s.",
			       libusb_error_name(ret));

		uscpi->detached_kernel_driver = 0;
	}
	libusb_close(usb->devhdl);
	usb->devhdl = NULL;

	return SR_OK;
}

static void scpi_usbtmc_libusb_free(void *priv)
{
	struct scpi_usbtmc_libusb *uscpi = priv;
	sr_usb_dev_inst_free(uscpi->usb);
}

SR_PRIV const struct sr_scpi_dev_inst scpi_usbtmc_libusb_dev = {
	.name          = "USBTMC",
	.prefix        = "usbtmc",
	.priv_size     = sizeof(struct scpi_usbtmc_libusb),
	.scan          = scpi_usbtmc_libusb_scan,
	.dev_inst_new  = scpi_usbtmc_libusb_dev_inst_new,
	.open          = scpi_usbtmc_libusb_open,
	.source_add    = scpi_usbtmc_libusb_source_add,
	.source_remove = scpi_usbtmc_libusb_source_remove,
	.send          = scpi_usbtmc_libusb_send,
	.read_begin    = scpi_usbtmc_libusb_read_begin,
	.read_data     = scpi_usbtmc_libusb_read_data,
	.read_complete = scpi_usbtmc_libusb_read_complete,
	.close         = scpi_usbtmc_libusb_close,
	.free          = scpi_usbtmc_libusb_free,
};
Commit	Line	Data
20ed3cee AJ	1	/*
	2	* This file is part of the libsigrok project.
	3	*
	4	* Copyright (C) 2014 Aurelien Jacobs <aurel@gnuage.org>
	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 <string.h>
c1aae900	21	#include <libsigrok/libsigrok.h>
20ed3cee AJ	22	#include "libsigrok-internal.h"
	23
	24	#define LOG_PREFIX "scpi_usbtmc"
	25
	26	#define MAX_TRANSFER_LENGTH 2048
	27	#define TRANSFER_TIMEOUT 1000
	28
	29	struct scpi_usbtmc_libusb {
	30	struct sr_context *ctx;
	31	struct sr_usb_dev_inst *usb;
	32	int detached_kernel_driver;
	33	uint8_t interface;
	34	uint8_t bulk_in_ep;
	35	uint8_t bulk_out_ep;
	36	uint8_t interrupt_ep;
	37	uint8_t usbtmc_int_cap;
	38	uint8_t usbtmc_dev_cap;
	39	uint8_t usb488_dev_cap;
	40	uint8_t bTag;
	41	uint8_t bulkin_attributes;
	42	uint8_t buffer[MAX_TRANSFER_LENGTH];
	43	int response_length;
	44	int response_bytes_read;
	45	int remaining_length;
50e6311a	46	int rigol_ds1000;
20ed3cee AJ	47	};
	48
	49	/* Some USBTMC-specific enums, as defined in the USBTMC standard. */
	50	#define SUBCLASS_USBTMC 0x03
	51	#define USBTMC_USB488 0x01
	52
	53	enum {
	54	/* USBTMC control requests */
	55	INITIATE_ABORT_BULK_OUT = 1,
	56	CHECK_ABORT_BULK_OUT_STATUS = 2,
	57	INITIATE_ABORT_BULK_IN = 3,
	58	CHECK_ABORT_BULK_IN_STATUS = 4,
	59	INITIATE_CLEAR = 5,
	60	CHECK_CLEAR_STATUS = 6,
	61	GET_CAPABILITIES = 7,
	62	INDICATOR_PULSE = 64,
	63
	64	/* USB488 control requests */
	65	READ_STATUS_BYTE = 128,
	66	REN_CONTROL = 160,
	67	GO_TO_LOCAL = 161,
	68	LOCAL_LOCKOUT = 162,
	69	};
	70
	71	/* USBTMC capabilities */
	72	#define USBTMC_INT_CAP_LISTEN_ONLY 0x01
	73	#define USBTMC_INT_CAP_TALK_ONLY 0x02
	74	#define USBTMC_INT_CAP_INDICATOR 0x04
	75
	76	#define USBTMC_DEV_CAP_TERMCHAR 0x01
	77
	78	#define USB488_DEV_CAP_DT1 0x01
	79	#define USB488_DEV_CAP_RL1 0x02
	80	#define USB488_DEV_CAP_SR1 0x04
	81	#define USB488_DEV_CAP_SCPI 0x08
	82
	83	/* Bulk messages constants */
	84	#define USBTMC_BULK_HEADER_SIZE 12
	85
	86	/* Bulk MsgID values */
	87	#define DEV_DEP_MSG_OUT 1
	88	#define REQUEST_DEV_DEP_MSG_IN 2
	89	#define DEV_DEP_MSG_IN 2
	90
	91	/* bmTransferAttributes */
	92	#define EOM 0x01
	93	#define TERM_CHAR_ENABLED 0x02
	94
20ed3cee AJ	95	static GSList scpi_usbtmc_libusb_scan(struct drv_context drvc)
	96	{
	97	struct libusb_device **devlist;
	98	struct libusb_device_descriptor des;
	99	struct libusb_config_descriptor *confdes;
	100	const struct libusb_interface_descriptor *intfdes;
	101	GSList *resources = NULL;
	102	int confidx, intfidx, ret, i;
	103	char *res;
	104
52f6951c UH	105	ret = libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
	106	if (ret < 0) {
	107	sr_err("Failed to get device list: %s.",
	108	libusb_error_name(ret));
	109	return NULL;
	110	}
20ed3cee	111	for (i = 0; devlist[i]; i++) {
d8cbd659	112	if ((ret = libusb_get_device_descriptor(devlist[i], &des)) < 0) {
20ed3cee AJ	113	sr_err("Failed to get device descriptor: %s.",
	114	libusb_error_name(ret));
	115	continue;
	116	}
	117
	118	for (confidx = 0; confidx < des.bNumConfigurations; confidx++) {
9ad05e6c UH	119	if ((ret = libusb_get_config_descriptor(devlist[i], confidx, &confdes)) < 0) {
	120	sr_dbg("Failed to get configuration descriptor: %s, "
	121	"ignoring device.", libusb_error_name(ret));
20ed3cee AJ	122	break;
	123	}
	124	for (intfidx = 0; intfidx < confdes->bNumInterfaces; intfidx++) {
	125	intfdes = confdes->interface[intfidx].altsetting;
	126	if (intfdes->bInterfaceClass != LIBUSB_CLASS_APPLICATION \|\|
	127	intfdes->bInterfaceSubClass != SUBCLASS_USBTMC \|\|
	128	intfdes->bInterfaceProtocol != USBTMC_USB488)
	129	continue;
	130	sr_dbg("Found USBTMC device (VID:PID = %04x:%04x, "
	131	"bus.address = %d.%d).", des.idVendor, des.idProduct,
	132	libusb_get_bus_number(devlist[i]),
	133	libusb_get_device_address(devlist[i]));
	134	res = g_strdup_printf("usbtmc/%d.%d",
	135	libusb_get_bus_number(devlist[i]),
	136	libusb_get_device_address(devlist[i]));
	137	resources = g_slist_append(resources, res);
	138	}
	139	libusb_free_config_descriptor(confdes);
	140	}
	141	}
	142	libusb_free_device_list(devlist, 1);
	143
	144	sr_dbg("Found %d device(s).", g_slist_length(resources));
	145
	146	return resources;
	147	}
	148
	149	static int scpi_usbtmc_libusb_dev_inst_new(void priv, struct drv_context drvc,
	150	const char resource, char params, const char serialcomm)
	151	{
	152	struct scpi_usbtmc_libusb *uscpi = priv;
	153	GSList *devices;
	154
	155	(void)resource;
	156	(void)serialcomm;
	157
	158	if (!params \|\| !params[1]) {
	159	sr_err("Invalid parameters.");
	160	return SR_ERR;
	161	}
	162
	163	uscpi->ctx = drvc->sr_ctx;
	164	devices = sr_usb_find(uscpi->ctx->libusb_ctx, params[1]);
	165	if (g_slist_length(devices) != 1) {
	166	sr_err("Failed to find USB device '%s'.", params[1]);
	167	g_slist_free_full(devices, (GDestroyNotify)sr_usb_dev_inst_free);
	168	return SR_ERR;
	169	}
	170	uscpi->usb = devices->data;
	171	g_slist_free(devices);
	172
	173	return SR_OK;
	174	}
	175
	176	static int scpi_usbtmc_libusb_open(void *priv)
	177	{
	178	struct scpi_usbtmc_libusb *uscpi = priv;
	179	struct sr_usb_dev_inst *usb = uscpi->usb;
	180	struct libusb_device *dev;
	181	struct libusb_device_descriptor des;
	182	struct libusb_config_descriptor *confdes;
	183	const struct libusb_interface_descriptor *intfdes;
	184	const struct libusb_endpoint_descriptor *ep;
	185	int confidx, intfidx, epidx, config = 0;
186	uint8_t capabilities[24];
187	int ret, found = 0;
188
189	if (usb->devhdl)
190	return SR_OK;
191
192	if (sr_usb_open(uscpi->ctx->libusb_ctx, usb) != SR_OK)
193	return SR_ERR;
194
195	dev = libusb_get_device(usb->devhdl);
d8cbd659	196	if ((ret = libusb_get_device_descriptor(dev, &des)) < 0) {
20ed3cee AJ	197	sr_err("Failed to get device descriptor: %s.",
	198	libusb_error_name(ret));
	199	return SR_ERR;
	200	}
	201
	202	for (confidx = 0; confidx < des.bNumConfigurations; confidx++) {
9ad05e6c UH	203	if ((ret = libusb_get_config_descriptor(dev, confidx, &confdes)) < 0) {
	204	sr_dbg("Failed to get configuration descriptor: %s, "
	205	"ignoring device.", libusb_error_name(ret));
20ed3cee AJ	206	continue;
	207	}
	208	for (intfidx = 0; intfidx < confdes->bNumInterfaces; intfidx++) {
	209	intfdes = confdes->interface[intfidx].altsetting;
	210	if (intfdes->bInterfaceClass != LIBUSB_CLASS_APPLICATION \|\|
	211	intfdes->bInterfaceSubClass != SUBCLASS_USBTMC \|\|
	212	intfdes->bInterfaceProtocol != USBTMC_USB488)
	213	continue;
	214	uscpi->interface = intfdes->bInterfaceNumber;
20ed3cee	215	config = confdes->bConfigurationValue;
e82d34a9	216	sr_dbg("Interface %d configuration %d.", uscpi->interface, config);
20ed3cee AJ	217	for (epidx = 0; epidx < intfdes->bNumEndpoints; epidx++) {
	218	ep = &intfdes->endpoint[epidx];
	219	if (ep->bmAttributes == LIBUSB_TRANSFER_TYPE_BULK &&
	220	!(ep->bEndpointAddress & (LIBUSB_ENDPOINT_DIR_MASK))) {
	221	uscpi->bulk_out_ep = ep->bEndpointAddress;
	222	sr_dbg("Bulk OUT EP %d", uscpi->bulk_out_ep);
	223	}
	224	if (ep->bmAttributes == LIBUSB_TRANSFER_TYPE_BULK &&
	225	ep->bEndpointAddress & (LIBUSB_ENDPOINT_DIR_MASK)) {
	226	uscpi->bulk_in_ep = ep->bEndpointAddress;
e82d34a9	227	sr_dbg("Bulk IN EP %d", uscpi->bulk_in_ep & 0x7f);
20ed3cee AJ	228	}
	229	if (ep->bmAttributes == LIBUSB_TRANSFER_TYPE_INTERRUPT &&
	230	ep->bEndpointAddress & (LIBUSB_ENDPOINT_DIR_MASK)) {
	231	uscpi->interrupt_ep = ep->bEndpointAddress;
e82d34a9	232	sr_dbg("Interrupt EP %d", uscpi->interrupt_ep & 0x7f);
20ed3cee AJ	233	}
	234	}
	235	found = 1;
50e6311a AJ	236	uscpi->rigol_ds1000 = des.idVendor == 0x1ab1 &&
50e6311a AJ	237	des.idProduct == 0x0588;
20ed3cee AJ	238	}
	239	libusb_free_config_descriptor(confdes);
	240	if (found)
	241	break;
	242	}
	243
	244	if (!found) {
52f6951c	245	sr_err("Failed to find USBTMC interface.");
20ed3cee AJ	246	return SR_ERR;
	247	}
	248
	249	if (libusb_kernel_driver_active(usb->devhdl, uscpi->interface) == 1) {
	250	if ((ret = libusb_detach_kernel_driver(usb->devhdl,
	251	uscpi->interface)) < 0) {
52f6951c UH	252	sr_err("Failed to detach kernel driver: %s.",
52f6951c UH	253	libusb_error_name(ret));
20ed3cee AJ	254	return SR_ERR;
	255	}
	256	uscpi->detached_kernel_driver = 1;
	257	}
	258
d8cbd659	259	if ((ret = libusb_set_configuration(usb->devhdl, config)) < 0) {
52f6951c UH	260	sr_err("Failed to set configuration: %s.",
52f6951c UH	261	libusb_error_name(ret));
20ed3cee AJ	262	return SR_ERR;
	263	}
	264
d8cbd659	265	if ((ret = libusb_claim_interface(usb->devhdl, uscpi->interface)) < 0) {
52f6951c UH	266	sr_err("Failed to claim interface: %s.",
52f6951c UH	267	libusb_error_name(ret));
20ed3cee AJ	268	return SR_ERR;
	269	}
	270
f589a6d4	271	if (!uscpi->rigol_ds1000) {
52f6951c UH	272	if ((ret = libusb_clear_halt(usb->devhdl, uscpi->bulk_in_ep)) < 0) {
	273	sr_err("Failed to clear halt/stall condition for EP %d: %s.",
	274	uscpi->bulk_in_ep, libusb_error_name(ret));
	275	return SR_ERR;
	276	}
	277	if ((ret = libusb_clear_halt(usb->devhdl, uscpi->bulk_out_ep)) < 0) {
	278	sr_err("Failed to clear halt/stall condition for EP %d: %s.",
	279	uscpi->bulk_out_ep, libusb_error_name(ret));
	280	return SR_ERR;
	281	}
	282	if ((ret = libusb_clear_halt(usb->devhdl, uscpi->interrupt_ep)) < 0) {
	283	sr_err("Failed to clear halt/stall condition for EP %d: %s.",
	284	uscpi->interrupt_ep, libusb_error_name(ret));
	285	return SR_ERR;
	286	}
f589a6d4	287	}
20ed3cee	288
52f6951c	289	/* Get capabilities. */
20ed3cee AJ	290	ret = libusb_control_transfer(usb->devhdl,
	291	LIBUSB_ENDPOINT_IN \|
	292	LIBUSB_REQUEST_TYPE_CLASS \|
	293	LIBUSB_RECIPIENT_INTERFACE,
	294	GET_CAPABILITIES, 0,
	295	uscpi->interface,
	296	capabilities, sizeof(capabilities),
	297	TRANSFER_TIMEOUT);
	298	if (ret == sizeof(capabilities)) {
	299	uscpi->usbtmc_int_cap = capabilities[ 4];
	300	uscpi->usbtmc_dev_cap = capabilities[ 5];
	301	uscpi->usb488_dev_cap = capabilities[15];
	302	}
52f6951c	303	sr_dbg("Device capabilities: %s%s%s%s%s, %s, %s",
20ed3cee AJ	304	uscpi->usb488_dev_cap & USB488_DEV_CAP_SCPI ? "SCPI, " : "",
	305	uscpi->usbtmc_dev_cap & USBTMC_DEV_CAP_TERMCHAR ? "TermChar, ": "",
	306	uscpi->usbtmc_int_cap & USBTMC_INT_CAP_LISTEN_ONLY? "L3, " :
	307	uscpi->usbtmc_int_cap & USBTMC_INT_CAP_TALK_ONLY ? "" : "L4, ",
	308	uscpi->usbtmc_int_cap & USBTMC_INT_CAP_TALK_ONLY ? "T5, " :
	309	uscpi->usbtmc_int_cap & USBTMC_INT_CAP_LISTEN_ONLY? "" : "T6, ",
	310	uscpi->usb488_dev_cap & USB488_DEV_CAP_SR1 ? "SR1" : "SR0",
	311	uscpi->usb488_dev_cap & USB488_DEV_CAP_RL1 ? "RL1" : "RL0",
	312	uscpi->usb488_dev_cap & USB488_DEV_CAP_DT1 ? "DT1" : "DT0");
	313
	314	return SR_OK;
	315	}
	316
102f1239 BV	317	static int scpi_usbtmc_libusb_source_add(struct sr_session *session,
	318	void *priv, int events, int timeout, sr_receive_data_callback cb,
	319	void *cb_data)
20ed3cee AJ	320	{
	321	struct scpi_usbtmc_libusb *uscpi = priv;
	322	(void)events;
102f1239	323	return usb_source_add(session, uscpi->ctx, timeout, cb, cb_data);
20ed3cee AJ	324	}
20ed3cee AJ	325
102f1239 BV	326	static int scpi_usbtmc_libusb_source_remove(struct sr_session *session,
102f1239 BV	327	void *priv)
20ed3cee AJ	328	{
20ed3cee AJ	329	struct scpi_usbtmc_libusb *uscpi = priv;
102f1239	330	return usb_source_remove(session, uscpi->ctx);
20ed3cee AJ	331	}
	332
	333	static void usbtmc_bulk_out_header_write(void *header, uint8_t MsgID,
	334	uint8_t bTag,
	335	uint32_t TransferSize,
	336	uint8_t bmTransferAttributes,
	337	char TermChar)
	338	{
	339	W8(header+ 0, MsgID);
	340	W8(header+ 1, bTag);
	341	W8(header+ 2, ~bTag);
	342	W8(header+ 3, 0);
	343	WL32(header+ 4, TransferSize);
	344	W8(header+ 8, bmTransferAttributes);
	345	W8(header+ 9, TermChar);
	346	WL16(header+10, 0);
	347	}
	348
	349	static int usbtmc_bulk_in_header_read(void *header, uint8_t MsgID,
	350	unsigned char bTag,
	351	int32_t *TransferSize,
	352	uint8_t *bmTransferAttributes)
	353	{
	354	if (R8(header+0) != MsgID \|\|
	355	R8(header+1) != bTag \|\|
	356	R8(header+2) != (unsigned char)~bTag)
	357	return SR_ERR;
	358	if (TransferSize)
	359	*TransferSize = RL32(header+4);
	360	if (bmTransferAttributes)
	361	*bmTransferAttributes = R8(header+8);
	362	return SR_OK;
	363	}
	364
	365	static int scpi_usbtmc_bulkout(struct scpi_usbtmc_libusb *uscpi,
	366	uint8_t msg_id, const void *data, int32_t size,
	367	uint8_t transfer_attributes)
	368	{
	369	struct sr_usb_dev_inst *usb = uscpi->usb;
	370	int padded_size, ret, transferred;
	371
	372	if (data && size+USBTMC_BULK_HEADER_SIZE+3 > (int)sizeof(uscpi->buffer)) {
52f6951c	373	sr_err("USBTMC bulk out transfer is too big.");
20ed3cee AJ	374	return SR_ERR;
	375	}
	376
	377	uscpi->bTag++;
52f6951c	378	uscpi->bTag += !uscpi->bTag; /* bTag == 0 is invalid so avoid it. */
20ed3cee AJ	379
	380	usbtmc_bulk_out_header_write(uscpi->buffer, msg_id, uscpi->bTag,
	381	size, transfer_attributes, 0);
	382	if (data)
	383	memcpy(uscpi->buffer+USBTMC_BULK_HEADER_SIZE, data, size);
	384	else
	385	size = 0;
	386	size += USBTMC_BULK_HEADER_SIZE;
	387	padded_size = (size + 3) & ~0x3;
	388	memset(uscpi->buffer+size, 0, padded_size - size);
	389
	390	ret = libusb_bulk_transfer(usb->devhdl, uscpi->bulk_out_ep,
	391	uscpi->buffer, padded_size, &transferred,
	392	TRANSFER_TIMEOUT);
d8cbd659	393	if (ret < 0) {
52f6951c UH	394	sr_err("USBTMC bulk out transfer error: %s.",
52f6951c UH	395	libusb_error_name(ret));
20ed3cee AJ	396	return SR_ERR;
	397	}
	398
	399	if (transferred < padded_size) {
52f6951c	400	sr_dbg("USBTMC bulk out partial transfer (%d/%d bytes).",
20ed3cee AJ	401	transferred, padded_size);
	402	return SR_ERR;
	403	}
	404
	405	return transferred - USBTMC_BULK_HEADER_SIZE;
	406	}
	407
	408	static int scpi_usbtmc_bulkin_start(struct scpi_usbtmc_libusb *uscpi,
	409	uint8_t msg_id, void *data, int32_t size,
	410	uint8_t *transfer_attributes)
	411	{
	412	struct sr_usb_dev_inst *usb = uscpi->usb;
	413	int ret, transferred, message_size;
	414
	415	ret = libusb_bulk_transfer(usb->devhdl, uscpi->bulk_in_ep, data, size,
	416	&transferred, TRANSFER_TIMEOUT);
d8cbd659	417	if (ret < 0) {
52f6951c UH	418	sr_err("USBTMC bulk in transfer error: %s.",
52f6951c UH	419	libusb_error_name(ret));
20ed3cee AJ	420	return SR_ERR;
	421	}
	422
	423	if (usbtmc_bulk_in_header_read(data, msg_id, uscpi->bTag, &message_size,
	424	transfer_attributes) != SR_OK) {
52f6951c	425	sr_err("USBTMC invalid bulk in header.");
20ed3cee AJ	426	return SR_ERR;
	427	}
	428
	429	message_size += USBTMC_BULK_HEADER_SIZE;
	430	uscpi->response_length = MIN(transferred, message_size);
	431	uscpi->response_bytes_read = USBTMC_BULK_HEADER_SIZE;
	432	uscpi->remaining_length = message_size - uscpi->response_length;
	433
	434	return transferred - USBTMC_BULK_HEADER_SIZE;
	435	}
	436
	437	static int scpi_usbtmc_bulkin_continue(struct scpi_usbtmc_libusb *uscpi,
	438	void *data, int size)
	439	{
	440	struct sr_usb_dev_inst *usb = uscpi->usb;
	441	int ret, transferred;
	442
	443	ret = libusb_bulk_transfer(usb->devhdl, uscpi->bulk_in_ep, data, size,
	444	&transferred, TRANSFER_TIMEOUT);
d8cbd659	445	if (ret < 0) {
52f6951c UH	446	sr_err("USBTMC bulk in transfer error: %s.",
52f6951c UH	447	libusb_error_name(ret));
20ed3cee AJ	448	return SR_ERR;
	449	}
	450
	451	uscpi->response_length = MIN(transferred, uscpi->remaining_length);
	452	uscpi->response_bytes_read = 0;
	453	uscpi->remaining_length -= uscpi->response_length;
	454
	455	return transferred;
	456	}
	457
	458	static int scpi_usbtmc_libusb_send(void priv, const char command)
	459	{
	460	struct scpi_usbtmc_libusb *uscpi = priv;
	461
	462	if (scpi_usbtmc_bulkout(uscpi, DEV_DEP_MSG_OUT,
	463	command, strlen(command), EOM) <= 0)
	464	return SR_ERR;
	465
	466	sr_spew("Successfully sent SCPI command: '%s'.", command);
	467
	468	return SR_OK;
	469	}
	470
	471	static int scpi_usbtmc_libusb_read_begin(void *priv)
	472	{
	473	struct scpi_usbtmc_libusb *uscpi = priv;
	474
	475	uscpi->remaining_length = 0;
	476
	477	if (scpi_usbtmc_bulkout(uscpi, REQUEST_DEV_DEP_MSG_IN,
	478	NULL, INT32_MAX, 0) < 0)
	479	return SR_ERR;
	480	if (scpi_usbtmc_bulkin_start(uscpi, DEV_DEP_MSG_IN,
	481	uscpi->buffer, sizeof(uscpi->buffer),
	482	&uscpi->bulkin_attributes) < 0)
	483	return SR_ERR;
	484
	485	return SR_OK;
	486	}
	487
	488	static int scpi_usbtmc_libusb_read_data(void priv, char buf, int maxlen)
	489	{
	490	struct scpi_usbtmc_libusb *uscpi = priv;
	491	int read_length;
	492
	493	if (uscpi->response_bytes_read >= uscpi->response_length) {
	494	if (uscpi->remaining_length > 0) {
	495	if (scpi_usbtmc_bulkin_continue(uscpi, uscpi->buffer,
	496	sizeof(uscpi->buffer)) <= 0)
	497	return SR_ERR;
	498	} else {
	499	if (uscpi->bulkin_attributes & EOM)
	500	return SR_ERR;
	501	if (scpi_usbtmc_libusb_read_begin(uscpi) < 0)
	502	return SR_ERR;
	503	}
	504	}
	505
	506	read_length = MIN(uscpi->response_length - uscpi->response_bytes_read, maxlen);
	507
	508	memcpy(buf, uscpi->buffer + uscpi->response_bytes_read, read_length);
	509
	510	uscpi->response_bytes_read += read_length;
	511
512	return read_length;
513	}
514
515	static int scpi_usbtmc_libusb_read_complete(void *priv)
516	{
517	struct scpi_usbtmc_libusb *uscpi = priv;
518	return uscpi->response_bytes_read >= uscpi->response_length &&
519	uscpi->remaining_length <= 0 &&
520	uscpi->bulkin_attributes & EOM;
521	}
522
523	static int scpi_usbtmc_libusb_close(void *priv)
524	{
52f6951c	525	int ret;
20ed3cee AJ	526	struct scpi_usbtmc_libusb *uscpi = priv;
	527	struct sr_usb_dev_inst *usb = uscpi->usb;
	528
	529	if (!usb->devhdl)
	530	return SR_ERR;
	531
f589a6d4	532	if (!uscpi->rigol_ds1000) {
52f6951c UH	533	if ((ret = libusb_clear_halt(usb->devhdl, uscpi->bulk_in_ep)) < 0)
	534	sr_err("Failed to clear halt/stall condition for EP %d: %s.",
	535	uscpi->bulk_in_ep, libusb_error_name(ret));
	536	if ((ret = libusb_clear_halt(usb->devhdl, uscpi->bulk_out_ep)) < 0)
	537	sr_err("Failed to clear halt/stall condition for EP %d: %s.",
	538	uscpi->bulk_out_ep, libusb_error_name(ret));
	539	if ((ret = libusb_clear_halt(usb->devhdl, uscpi->interrupt_ep)) < 0)
	540	sr_err("Failed to clear halt/stall condition for EP %d: %s.",
	541	uscpi->interrupt_ep, libusb_error_name(ret));
f589a6d4	542	}
52f6951c UH	543
	544	if ((ret = libusb_release_interface(usb->devhdl, uscpi->interface)) < 0)
	545	sr_err("Failed to release interface: %s.",
	546	libusb_error_name(ret));
	547
20ed3cee	548	if (uscpi->detached_kernel_driver) {
52f6951c UH	549	if ((ret = libusb_attach_kernel_driver(usb->devhdl,
	550	uscpi->interface)) < 0)
	551	sr_err("Failed to re-attach kernel driver: %s.",
	552	libusb_error_name(ret));
	553
20ed3cee AJ	554	uscpi->detached_kernel_driver = 0;
	555	}
	556	libusb_close(usb->devhdl);
	557	usb->devhdl = NULL;
	558
	559	return SR_OK;
	560	}
	561
	562	static void scpi_usbtmc_libusb_free(void *priv)
	563	{
	564	struct scpi_usbtmc_libusb *uscpi = priv;
	565	sr_usb_dev_inst_free(uscpi->usb);
	566	}
	567
20ed3cee AJ	568	SR_PRIV const struct sr_scpi_dev_inst scpi_usbtmc_libusb_dev = {
	569	.name = "USBTMC",
	570	.prefix = "usbtmc",
	571	.priv_size = sizeof(struct scpi_usbtmc_libusb),
	572	.scan = scpi_usbtmc_libusb_scan,
	573	.dev_inst_new = scpi_usbtmc_libusb_dev_inst_new,
	574	.open = scpi_usbtmc_libusb_open,
	575	.source_add = scpi_usbtmc_libusb_source_add,
	576	.source_remove = scpi_usbtmc_libusb_source_remove,
	577	.send = scpi_usbtmc_libusb_send,
	578	.read_begin = scpi_usbtmc_libusb_read_begin,
	579	.read_data = scpi_usbtmc_libusb_read_data,
	580	.read_complete = scpi_usbtmc_libusb_read_complete,
	581	.close = scpi_usbtmc_libusb_close,
	582	.free = scpi_usbtmc_libusb_free,
	583	};