[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 <config.h>
#include <string.h>
#include <libsigrok/libsigrok.h>
#include "libsigrok-internal.h"
#include "scpi.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 status codes */
#define USBTMC_STATUS_SUCCESS      0x01

/* 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++) {
		libusb_get_device_descriptor(devlist[i], &des);

		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], status;
	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);
	libusb_get_device_descriptor(dev, &des);

	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");

	if (uscpi->usb488_dev_cap & USB488_DEV_CAP_RL1) {
		sr_dbg("Locking out local control.");
		ret = libusb_control_transfer(usb->devhdl,
				LIBUSB_ENDPOINT_IN         |
				LIBUSB_REQUEST_TYPE_CLASS  |
				LIBUSB_RECIPIENT_INTERFACE,
				REN_CONTROL, 1,
				uscpi->interface,
				&status, 1,
				TRANSFER_TIMEOUT);
		if (ret < 0 || status != USBTMC_STATUS_SUCCESS) {
			sr_dbg("Failed to enter REN state.");
			return SR_OK;
		}
		ret = libusb_control_transfer(usb->devhdl,
				LIBUSB_ENDPOINT_IN         |
				LIBUSB_REQUEST_TYPE_CLASS  |
				LIBUSB_RECIPIENT_INTERFACE,
				LOCAL_LOCKOUT, 1,
				uscpi->interface,
				&status, 1,
				TRANSFER_TIMEOUT);
		if (ret < 0 || status != USBTMC_STATUS_SUCCESS)
			sr_dbg("Failed to enter local lockout state.");
	}

	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;
	uint8_t status;

	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 (uscpi->usb488_dev_cap & USB488_DEV_CAP_RL1) {
		sr_dbg("Returning local control.");
		ret = libusb_control_transfer(usb->devhdl,
				LIBUSB_ENDPOINT_IN         |
				LIBUSB_REQUEST_TYPE_CLASS  |
				LIBUSB_RECIPIENT_INTERFACE,
				GO_TO_LOCAL, 1,
				uscpi->interface,
				&status, 1,
				TRANSFER_TIMEOUT);
		if (ret < 0 || status != USBTMC_STATUS_SUCCESS)
			sr_dbg("Failed to clear local lockout state.");
	}

	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;
	}
	sr_usb_close(usb);

	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
6ec6c43b	20	#include <config.h>
20ed3cee	21	#include <string.h>
c1aae900	22	#include <libsigrok/libsigrok.h>
20ed3cee	23	#include "libsigrok-internal.h"
5a1afc09	24	#include "scpi.h"
20ed3cee AJ	25
	26	#define LOG_PREFIX "scpi_usbtmc"
	27
	28	#define MAX_TRANSFER_LENGTH 2048
	29	#define TRANSFER_TIMEOUT 1000
	30
	31	struct scpi_usbtmc_libusb {
	32	struct sr_context *ctx;
	33	struct sr_usb_dev_inst *usb;
	34	int detached_kernel_driver;
	35	uint8_t interface;
	36	uint8_t bulk_in_ep;
	37	uint8_t bulk_out_ep;
	38	uint8_t interrupt_ep;
	39	uint8_t usbtmc_int_cap;
	40	uint8_t usbtmc_dev_cap;
	41	uint8_t usb488_dev_cap;
	42	uint8_t bTag;
	43	uint8_t bulkin_attributes;
	44	uint8_t buffer[MAX_TRANSFER_LENGTH];
	45	int response_length;
	46	int response_bytes_read;
	47	int remaining_length;
50e6311a	48	int rigol_ds1000;
20ed3cee AJ	49	};
	50
	51	/* Some USBTMC-specific enums, as defined in the USBTMC standard. */
	52	#define SUBCLASS_USBTMC 0x03
	53	#define USBTMC_USB488 0x01
	54
	55	enum {
	56	/* USBTMC control requests */
	57	INITIATE_ABORT_BULK_OUT = 1,
	58	CHECK_ABORT_BULK_OUT_STATUS = 2,
	59	INITIATE_ABORT_BULK_IN = 3,
	60	CHECK_ABORT_BULK_IN_STATUS = 4,
	61	INITIATE_CLEAR = 5,
	62	CHECK_CLEAR_STATUS = 6,
	63	GET_CAPABILITIES = 7,
	64	INDICATOR_PULSE = 64,
	65
	66	/* USB488 control requests */
	67	READ_STATUS_BYTE = 128,
	68	REN_CONTROL = 160,
	69	GO_TO_LOCAL = 161,
	70	LOCAL_LOCKOUT = 162,
	71	};
	72
baed0211 BV	73	/* USBTMC status codes */
	74	#define USBTMC_STATUS_SUCCESS 0x01
	75
20ed3cee AJ	76	/* USBTMC capabilities */
	77	#define USBTMC_INT_CAP_LISTEN_ONLY 0x01
	78	#define USBTMC_INT_CAP_TALK_ONLY 0x02
	79	#define USBTMC_INT_CAP_INDICATOR 0x04
	80
	81	#define USBTMC_DEV_CAP_TERMCHAR 0x01
	82
	83	#define USB488_DEV_CAP_DT1 0x01
	84	#define USB488_DEV_CAP_RL1 0x02
	85	#define USB488_DEV_CAP_SR1 0x04
	86	#define USB488_DEV_CAP_SCPI 0x08
	87
	88	/* Bulk messages constants */
	89	#define USBTMC_BULK_HEADER_SIZE 12
	90
	91	/* Bulk MsgID values */
	92	#define DEV_DEP_MSG_OUT 1
	93	#define REQUEST_DEV_DEP_MSG_IN 2
	94	#define DEV_DEP_MSG_IN 2
	95
	96	/* bmTransferAttributes */
	97	#define EOM 0x01
	98	#define TERM_CHAR_ENABLED 0x02
	99
20ed3cee AJ	100	static GSList scpi_usbtmc_libusb_scan(struct drv_context drvc)
	101	{
	102	struct libusb_device **devlist;
	103	struct libusb_device_descriptor des;
	104	struct libusb_config_descriptor *confdes;
	105	const struct libusb_interface_descriptor *intfdes;
	106	GSList *resources = NULL;
	107	int confidx, intfidx, ret, i;
	108	char *res;
	109
52f6951c UH	110	ret = libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
	111	if (ret < 0) {
	112	sr_err("Failed to get device list: %s.",
	113	libusb_error_name(ret));
	114	return NULL;
	115	}
20ed3cee	116	for (i = 0; devlist[i]; i++) {
2a8f2d41	117	libusb_get_device_descriptor(devlist[i], &des);
20ed3cee AJ	118
20ed3cee AJ	119	for (confidx = 0; confidx < des.bNumConfigurations; confidx++) {
9ad05e6c UH	120	if ((ret = libusb_get_config_descriptor(devlist[i], confidx, &confdes)) < 0) {
	121	sr_dbg("Failed to get configuration descriptor: %s, "
	122	"ignoring device.", libusb_error_name(ret));
20ed3cee AJ	123	break;
	124	}
	125	for (intfidx = 0; intfidx < confdes->bNumInterfaces; intfidx++) {
	126	intfdes = confdes->interface[intfidx].altsetting;
	127	if (intfdes->bInterfaceClass != LIBUSB_CLASS_APPLICATION \|\|
	128	intfdes->bInterfaceSubClass != SUBCLASS_USBTMC \|\|
	129	intfdes->bInterfaceProtocol != USBTMC_USB488)
	130	continue;
	131	sr_dbg("Found USBTMC device (VID:PID = %04x:%04x, "
	132	"bus.address = %d.%d).", des.idVendor, des.idProduct,
	133	libusb_get_bus_number(devlist[i]),
	134	libusb_get_device_address(devlist[i]));
	135	res = g_strdup_printf("usbtmc/%d.%d",
	136	libusb_get_bus_number(devlist[i]),
	137	libusb_get_device_address(devlist[i]));
	138	resources = g_slist_append(resources, res);
	139	}
	140	libusb_free_config_descriptor(confdes);
	141	}
	142	}
	143	libusb_free_device_list(devlist, 1);
	144
	145	sr_dbg("Found %d device(s).", g_slist_length(resources));
	146
	147	return resources;
	148	}
	149
	150	static int scpi_usbtmc_libusb_dev_inst_new(void priv, struct drv_context drvc,
	151	const char resource, char params, const char serialcomm)
	152	{
	153	struct scpi_usbtmc_libusb *uscpi = priv;
	154	GSList *devices;
	155
	156	(void)resource;
	157	(void)serialcomm;
	158
	159	if (!params \|\| !params[1]) {
	160	sr_err("Invalid parameters.");
	161	return SR_ERR;
	162	}
	163
	164	uscpi->ctx = drvc->sr_ctx;
	165	devices = sr_usb_find(uscpi->ctx->libusb_ctx, params[1]);
	166	if (g_slist_length(devices) != 1) {
	167	sr_err("Failed to find USB device '%s'.", params[1]);
	168	g_slist_free_full(devices, (GDestroyNotify)sr_usb_dev_inst_free);
	169	return SR_ERR;
	170	}
	171	uscpi->usb = devices->data;
	172	g_slist_free(devices);
	173
	174	return SR_OK;
	175	}
	176
	177	static int scpi_usbtmc_libusb_open(void *priv)
	178	{
	179	struct scpi_usbtmc_libusb *uscpi = priv;
	180	struct sr_usb_dev_inst *usb = uscpi->usb;
	181	struct libusb_device *dev;
	182	struct libusb_device_descriptor des;
	183	struct libusb_config_descriptor *confdes;
	184	const struct libusb_interface_descriptor *intfdes;
	185	const struct libusb_endpoint_descriptor *ep;
	186	int confidx, intfidx, epidx, config = 0;
baed0211	187	uint8_t capabilities[24], status;
20ed3cee AJ	188	int ret, found = 0;
	189
	190	if (usb->devhdl)
	191	return SR_OK;
	192
	193	if (sr_usb_open(uscpi->ctx->libusb_ctx, usb) != SR_OK)
	194	return SR_ERR;
	195
	196	dev = libusb_get_device(usb->devhdl);
2a8f2d41	197	libusb_get_device_descriptor(dev, &des);
20ed3cee AJ	198
20ed3cee AJ	199	for (confidx = 0; confidx < des.bNumConfigurations; confidx++) {
9ad05e6c UH	200	if ((ret = libusb_get_config_descriptor(dev, confidx, &confdes)) < 0) {
	201	sr_dbg("Failed to get configuration descriptor: %s, "
	202	"ignoring device.", libusb_error_name(ret));
20ed3cee AJ	203	continue;
	204	}
	205	for (intfidx = 0; intfidx < confdes->bNumInterfaces; intfidx++) {
	206	intfdes = confdes->interface[intfidx].altsetting;
	207	if (intfdes->bInterfaceClass != LIBUSB_CLASS_APPLICATION \|\|
	208	intfdes->bInterfaceSubClass != SUBCLASS_USBTMC \|\|
	209	intfdes->bInterfaceProtocol != USBTMC_USB488)
	210	continue;
	211	uscpi->interface = intfdes->bInterfaceNumber;
20ed3cee	212	config = confdes->bConfigurationValue;
e82d34a9	213	sr_dbg("Interface %d configuration %d.", uscpi->interface, config);
20ed3cee AJ	214	for (epidx = 0; epidx < intfdes->bNumEndpoints; epidx++) {
	215	ep = &intfdes->endpoint[epidx];
	216	if (ep->bmAttributes == LIBUSB_TRANSFER_TYPE_BULK &&
	217	!(ep->bEndpointAddress & (LIBUSB_ENDPOINT_DIR_MASK))) {
	218	uscpi->bulk_out_ep = ep->bEndpointAddress;
	219	sr_dbg("Bulk OUT EP %d", uscpi->bulk_out_ep);
	220	}
	221	if (ep->bmAttributes == LIBUSB_TRANSFER_TYPE_BULK &&
	222	ep->bEndpointAddress & (LIBUSB_ENDPOINT_DIR_MASK)) {
	223	uscpi->bulk_in_ep = ep->bEndpointAddress;
e82d34a9	224	sr_dbg("Bulk IN EP %d", uscpi->bulk_in_ep & 0x7f);
20ed3cee AJ	225	}
	226	if (ep->bmAttributes == LIBUSB_TRANSFER_TYPE_INTERRUPT &&
	227	ep->bEndpointAddress & (LIBUSB_ENDPOINT_DIR_MASK)) {
	228	uscpi->interrupt_ep = ep->bEndpointAddress;
e82d34a9	229	sr_dbg("Interrupt EP %d", uscpi->interrupt_ep & 0x7f);
20ed3cee AJ	230	}
	231	}
	232	found = 1;
50e6311a AJ	233	uscpi->rigol_ds1000 = des.idVendor == 0x1ab1 &&
50e6311a AJ	234	des.idProduct == 0x0588;
20ed3cee AJ	235	}
	236	libusb_free_config_descriptor(confdes);
	237	if (found)
	238	break;
	239	}
	240
	241	if (!found) {
52f6951c	242	sr_err("Failed to find USBTMC interface.");
20ed3cee AJ	243	return SR_ERR;
	244	}
	245
	246	if (libusb_kernel_driver_active(usb->devhdl, uscpi->interface) == 1) {
	247	if ((ret = libusb_detach_kernel_driver(usb->devhdl,
	248	uscpi->interface)) < 0) {
52f6951c UH	249	sr_err("Failed to detach kernel driver: %s.",
52f6951c UH	250	libusb_error_name(ret));
20ed3cee AJ	251	return SR_ERR;
	252	}
	253	uscpi->detached_kernel_driver = 1;
	254	}
	255
d8cbd659	256	if ((ret = libusb_set_configuration(usb->devhdl, config)) < 0) {
52f6951c UH	257	sr_err("Failed to set configuration: %s.",
52f6951c UH	258	libusb_error_name(ret));
20ed3cee AJ	259	return SR_ERR;
	260	}
	261
d8cbd659	262	if ((ret = libusb_claim_interface(usb->devhdl, uscpi->interface)) < 0) {
52f6951c UH	263	sr_err("Failed to claim interface: %s.",
52f6951c UH	264	libusb_error_name(ret));
20ed3cee AJ	265	return SR_ERR;
	266	}
	267
f589a6d4	268	if (!uscpi->rigol_ds1000) {
52f6951c UH	269	if ((ret = libusb_clear_halt(usb->devhdl, uscpi->bulk_in_ep)) < 0) {
	270	sr_err("Failed to clear halt/stall condition for EP %d: %s.",
	271	uscpi->bulk_in_ep, libusb_error_name(ret));
	272	return SR_ERR;
	273	}
	274	if ((ret = libusb_clear_halt(usb->devhdl, uscpi->bulk_out_ep)) < 0) {
	275	sr_err("Failed to clear halt/stall condition for EP %d: %s.",
	276	uscpi->bulk_out_ep, libusb_error_name(ret));
	277	return SR_ERR;
	278	}
	279	if ((ret = libusb_clear_halt(usb->devhdl, uscpi->interrupt_ep)) < 0) {
	280	sr_err("Failed to clear halt/stall condition for EP %d: %s.",
	281	uscpi->interrupt_ep, libusb_error_name(ret));
	282	return SR_ERR;
	283	}
f589a6d4	284	}
20ed3cee	285
52f6951c	286	/* Get capabilities. */
20ed3cee AJ	287	ret = libusb_control_transfer(usb->devhdl,
	288	LIBUSB_ENDPOINT_IN \|
	289	LIBUSB_REQUEST_TYPE_CLASS \|
	290	LIBUSB_RECIPIENT_INTERFACE,
	291	GET_CAPABILITIES, 0,
	292	uscpi->interface,
	293	capabilities, sizeof(capabilities),
	294	TRANSFER_TIMEOUT);
	295	if (ret == sizeof(capabilities)) {
	296	uscpi->usbtmc_int_cap = capabilities[ 4];
	297	uscpi->usbtmc_dev_cap = capabilities[ 5];
	298	uscpi->usb488_dev_cap = capabilities[15];
	299	}
52f6951c	300	sr_dbg("Device capabilities: %s%s%s%s%s, %s, %s",
20ed3cee AJ	301	uscpi->usb488_dev_cap & USB488_DEV_CAP_SCPI ? "SCPI, " : "",
	302	uscpi->usbtmc_dev_cap & USBTMC_DEV_CAP_TERMCHAR ? "TermChar, ": "",
	303	uscpi->usbtmc_int_cap & USBTMC_INT_CAP_LISTEN_ONLY? "L3, " :
	304	uscpi->usbtmc_int_cap & USBTMC_INT_CAP_TALK_ONLY ? "" : "L4, ",
	305	uscpi->usbtmc_int_cap & USBTMC_INT_CAP_TALK_ONLY ? "T5, " :
	306	uscpi->usbtmc_int_cap & USBTMC_INT_CAP_LISTEN_ONLY? "" : "T6, ",
	307	uscpi->usb488_dev_cap & USB488_DEV_CAP_SR1 ? "SR1" : "SR0",
	308	uscpi->usb488_dev_cap & USB488_DEV_CAP_RL1 ? "RL1" : "RL0",
	309	uscpi->usb488_dev_cap & USB488_DEV_CAP_DT1 ? "DT1" : "DT0");
	310
baed0211 BV	311	if (uscpi->usb488_dev_cap & USB488_DEV_CAP_RL1) {
	312	sr_dbg("Locking out local control.");
	313	ret = libusb_control_transfer(usb->devhdl,
	314	LIBUSB_ENDPOINT_IN \|
	315	LIBUSB_REQUEST_TYPE_CLASS \|
	316	LIBUSB_RECIPIENT_INTERFACE,
	317	REN_CONTROL, 1,
	318	uscpi->interface,
	319	&status, 1,
	320	TRANSFER_TIMEOUT);
	321	if (ret < 0 \|\| status != USBTMC_STATUS_SUCCESS) {
	322	sr_dbg("Failed to enter REN state.");
	323	return SR_OK;
	324	}
	325	ret = libusb_control_transfer(usb->devhdl,
	326	LIBUSB_ENDPOINT_IN \|
	327	LIBUSB_REQUEST_TYPE_CLASS \|
	328	LIBUSB_RECIPIENT_INTERFACE,
	329	LOCAL_LOCKOUT, 1,
	330	uscpi->interface,
	331	&status, 1,
	332	TRANSFER_TIMEOUT);
	333	if (ret < 0 \|\| status != USBTMC_STATUS_SUCCESS)
	334	sr_dbg("Failed to enter local lockout state.");
	335	}
	336
20ed3cee AJ	337	return SR_OK;
	338	}
	339
102f1239 BV	340	static int scpi_usbtmc_libusb_source_add(struct sr_session *session,
	341	void *priv, int events, int timeout, sr_receive_data_callback cb,
	342	void *cb_data)
20ed3cee AJ	343	{
	344	struct scpi_usbtmc_libusb *uscpi = priv;
	345	(void)events;
102f1239	346	return usb_source_add(session, uscpi->ctx, timeout, cb, cb_data);
20ed3cee AJ	347	}
20ed3cee AJ	348
102f1239 BV	349	static int scpi_usbtmc_libusb_source_remove(struct sr_session *session,
102f1239 BV	350	void *priv)
20ed3cee AJ	351	{
20ed3cee AJ	352	struct scpi_usbtmc_libusb *uscpi = priv;
102f1239	353	return usb_source_remove(session, uscpi->ctx);
20ed3cee AJ	354	}
	355
	356	static void usbtmc_bulk_out_header_write(void *header, uint8_t MsgID,
	357	uint8_t bTag,
	358	uint32_t TransferSize,
	359	uint8_t bmTransferAttributes,
	360	char TermChar)
	361	{
	362	W8(header+ 0, MsgID);
	363	W8(header+ 1, bTag);
	364	W8(header+ 2, ~bTag);
	365	W8(header+ 3, 0);
	366	WL32(header+ 4, TransferSize);
	367	W8(header+ 8, bmTransferAttributes);
	368	W8(header+ 9, TermChar);
	369	WL16(header+10, 0);
	370	}
	371
	372	static int usbtmc_bulk_in_header_read(void *header, uint8_t MsgID,
	373	unsigned char bTag,
	374	int32_t *TransferSize,
	375	uint8_t *bmTransferAttributes)
	376	{
	377	if (R8(header+0) != MsgID \|\|
	378	R8(header+1) != bTag \|\|
	379	R8(header+2) != (unsigned char)~bTag)
	380	return SR_ERR;
	381	if (TransferSize)
	382	*TransferSize = RL32(header+4);
	383	if (bmTransferAttributes)
	384	*bmTransferAttributes = R8(header+8);
	385	return SR_OK;
	386	}
	387
	388	static int scpi_usbtmc_bulkout(struct scpi_usbtmc_libusb *uscpi,
	389	uint8_t msg_id, const void *data, int32_t size,
	390	uint8_t transfer_attributes)
	391	{
	392	struct sr_usb_dev_inst *usb = uscpi->usb;
	393	int padded_size, ret, transferred;
	394
	395	if (data && size+USBTMC_BULK_HEADER_SIZE+3 > (int)sizeof(uscpi->buffer)) {
52f6951c	396	sr_err("USBTMC bulk out transfer is too big.");
20ed3cee AJ	397	return SR_ERR;
	398	}
	399
	400	uscpi->bTag++;
52f6951c	401	uscpi->bTag += !uscpi->bTag; /* bTag == 0 is invalid so avoid it. */
20ed3cee AJ	402
	403	usbtmc_bulk_out_header_write(uscpi->buffer, msg_id, uscpi->bTag,
	404	size, transfer_attributes, 0);
	405	if (data)
	406	memcpy(uscpi->buffer+USBTMC_BULK_HEADER_SIZE, data, size);
	407	else
	408	size = 0;
	409	size += USBTMC_BULK_HEADER_SIZE;
	410	padded_size = (size + 3) & ~0x3;
	411	memset(uscpi->buffer+size, 0, padded_size - size);
	412
	413	ret = libusb_bulk_transfer(usb->devhdl, uscpi->bulk_out_ep,
	414	uscpi->buffer, padded_size, &transferred,
	415	TRANSFER_TIMEOUT);
d8cbd659	416	if (ret < 0) {
52f6951c UH	417	sr_err("USBTMC bulk out transfer error: %s.",
52f6951c UH	418	libusb_error_name(ret));
20ed3cee AJ	419	return SR_ERR;
	420	}
	421
	422	if (transferred < padded_size) {
52f6951c	423	sr_dbg("USBTMC bulk out partial transfer (%d/%d bytes).",
20ed3cee AJ	424	transferred, padded_size);
	425	return SR_ERR;
	426	}
	427
	428	return transferred - USBTMC_BULK_HEADER_SIZE;
	429	}
	430
	431	static int scpi_usbtmc_bulkin_start(struct scpi_usbtmc_libusb *uscpi,
	432	uint8_t msg_id, void *data, int32_t size,
	433	uint8_t *transfer_attributes)
	434	{
	435	struct sr_usb_dev_inst *usb = uscpi->usb;
	436	int ret, transferred, message_size;
	437
	438	ret = libusb_bulk_transfer(usb->devhdl, uscpi->bulk_in_ep, data, size,
	439	&transferred, TRANSFER_TIMEOUT);
d8cbd659	440	if (ret < 0) {
52f6951c UH	441	sr_err("USBTMC bulk in transfer error: %s.",
52f6951c UH	442	libusb_error_name(ret));
20ed3cee AJ	443	return SR_ERR;
	444	}
	445
	446	if (usbtmc_bulk_in_header_read(data, msg_id, uscpi->bTag, &message_size,
	447	transfer_attributes) != SR_OK) {
52f6951c	448	sr_err("USBTMC invalid bulk in header.");
20ed3cee AJ	449	return SR_ERR;
	450	}
	451
	452	message_size += USBTMC_BULK_HEADER_SIZE;
	453	uscpi->response_length = MIN(transferred, message_size);
	454	uscpi->response_bytes_read = USBTMC_BULK_HEADER_SIZE;
	455	uscpi->remaining_length = message_size - uscpi->response_length;
	456
	457	return transferred - USBTMC_BULK_HEADER_SIZE;
	458	}
	459
	460	static int scpi_usbtmc_bulkin_continue(struct scpi_usbtmc_libusb *uscpi,
	461	void *data, int size)
	462	{
	463	struct sr_usb_dev_inst *usb = uscpi->usb;
	464	int ret, transferred;
	465
	466	ret = libusb_bulk_transfer(usb->devhdl, uscpi->bulk_in_ep, data, size,
	467	&transferred, TRANSFER_TIMEOUT);
d8cbd659	468	if (ret < 0) {
52f6951c UH	469	sr_err("USBTMC bulk in transfer error: %s.",
52f6951c UH	470	libusb_error_name(ret));
20ed3cee AJ	471	return SR_ERR;
	472	}
	473
	474	uscpi->response_length = MIN(transferred, uscpi->remaining_length);
	475	uscpi->response_bytes_read = 0;
	476	uscpi->remaining_length -= uscpi->response_length;
	477
	478	return transferred;
	479	}
	480
	481	static int scpi_usbtmc_libusb_send(void priv, const char command)
	482	{
	483	struct scpi_usbtmc_libusb *uscpi = priv;
	484
	485	if (scpi_usbtmc_bulkout(uscpi, DEV_DEP_MSG_OUT,
	486	command, strlen(command), EOM) <= 0)
	487	return SR_ERR;
	488
	489	sr_spew("Successfully sent SCPI command: '%s'.", command);
	490
	491	return SR_OK;
	492	}
	493
	494	static int scpi_usbtmc_libusb_read_begin(void *priv)
	495	{
	496	struct scpi_usbtmc_libusb *uscpi = priv;
	497
	498	uscpi->remaining_length = 0;
	499
	500	if (scpi_usbtmc_bulkout(uscpi, REQUEST_DEV_DEP_MSG_IN,
	501	NULL, INT32_MAX, 0) < 0)
	502	return SR_ERR;
	503	if (scpi_usbtmc_bulkin_start(uscpi, DEV_DEP_MSG_IN,
	504	uscpi->buffer, sizeof(uscpi->buffer),
	505	&uscpi->bulkin_attributes) < 0)
	506	return SR_ERR;
	507
	508	return SR_OK;
	509	}
	510
	511	static int scpi_usbtmc_libusb_read_data(void priv, char buf, int maxlen)
	512	{
	513	struct scpi_usbtmc_libusb *uscpi = priv;
	514	int read_length;
	515
	516	if (uscpi->response_bytes_read >= uscpi->response_length) {
	517	if (uscpi->remaining_length > 0) {
	518	if (scpi_usbtmc_bulkin_continue(uscpi, uscpi->buffer,
	519	sizeof(uscpi->buffer)) <= 0)
	520	return SR_ERR;
	521	} else {
	522	if (uscpi->bulkin_attributes & EOM)
	523	return SR_ERR;
	524	if (scpi_usbtmc_libusb_read_begin(uscpi) < 0)
	525	return SR_ERR;
	526	}
	527	}
	528
	529	read_length = MIN(uscpi->response_length - uscpi->response_bytes_read, maxlen);
	530
	531	memcpy(buf, uscpi->buffer + uscpi->response_bytes_read, read_length);
	532
	533	uscpi->response_bytes_read += read_length;
	534
535	return read_length;
536	}
537
538	static int scpi_usbtmc_libusb_read_complete(void *priv)
539	{
540	struct scpi_usbtmc_libusb *uscpi = priv;
541	return uscpi->response_bytes_read >= uscpi->response_length &&
542	uscpi->remaining_length <= 0 &&
543	uscpi->bulkin_attributes & EOM;
544	}
545
546	static int scpi_usbtmc_libusb_close(void *priv)
547	{
52f6951c	548	int ret;
20ed3cee AJ	549	struct scpi_usbtmc_libusb *uscpi = priv;
20ed3cee AJ	550	struct sr_usb_dev_inst *usb = uscpi->usb;
baed0211	551	uint8_t status;
20ed3cee AJ	552
	553	if (!usb->devhdl)
	554	return SR_ERR;
	555
f589a6d4	556	if (!uscpi->rigol_ds1000) {
52f6951c UH	557	if ((ret = libusb_clear_halt(usb->devhdl, uscpi->bulk_in_ep)) < 0)
	558	sr_err("Failed to clear halt/stall condition for EP %d: %s.",
	559	uscpi->bulk_in_ep, libusb_error_name(ret));
	560	if ((ret = libusb_clear_halt(usb->devhdl, uscpi->bulk_out_ep)) < 0)
	561	sr_err("Failed to clear halt/stall condition for EP %d: %s.",
	562	uscpi->bulk_out_ep, libusb_error_name(ret));
	563	if ((ret = libusb_clear_halt(usb->devhdl, uscpi->interrupt_ep)) < 0)
	564	sr_err("Failed to clear halt/stall condition for EP %d: %s.",
	565	uscpi->interrupt_ep, libusb_error_name(ret));
f589a6d4	566	}
52f6951c	567
baed0211 BV	568	if (uscpi->usb488_dev_cap & USB488_DEV_CAP_RL1) {
	569	sr_dbg("Returning local control.");
	570	ret = libusb_control_transfer(usb->devhdl,
	571	LIBUSB_ENDPOINT_IN \|
	572	LIBUSB_REQUEST_TYPE_CLASS \|
	573	LIBUSB_RECIPIENT_INTERFACE,
	574	GO_TO_LOCAL, 1,
	575	uscpi->interface,
	576	&status, 1,
	577	TRANSFER_TIMEOUT);
	578	if (ret < 0 \|\| status != USBTMC_STATUS_SUCCESS)
	579	sr_dbg("Failed to clear local lockout state.");
	580	}
	581
52f6951c UH	582	if ((ret = libusb_release_interface(usb->devhdl, uscpi->interface)) < 0)
	583	sr_err("Failed to release interface: %s.",
	584	libusb_error_name(ret));
	585
20ed3cee	586	if (uscpi->detached_kernel_driver) {
52f6951c UH	587	if ((ret = libusb_attach_kernel_driver(usb->devhdl,
	588	uscpi->interface)) < 0)
	589	sr_err("Failed to re-attach kernel driver: %s.",
	590	libusb_error_name(ret));
	591
20ed3cee AJ	592	uscpi->detached_kernel_driver = 0;
20ed3cee AJ	593	}
0b2b92f6	594	sr_usb_close(usb);
20ed3cee AJ	595
	596	return SR_OK;
	597	}
	598
	599	static void scpi_usbtmc_libusb_free(void *priv)
	600	{
	601	struct scpi_usbtmc_libusb *uscpi = priv;
	602	sr_usb_dev_inst_free(uscpi->usb);
	603	}
	604
20ed3cee AJ	605	SR_PRIV const struct sr_scpi_dev_inst scpi_usbtmc_libusb_dev = {
	606	.name = "USBTMC",
	607	.prefix = "usbtmc",
	608	.priv_size = sizeof(struct scpi_usbtmc_libusb),
	609	.scan = scpi_usbtmc_libusb_scan,
	610	.dev_inst_new = scpi_usbtmc_libusb_dev_inst_new,
	611	.open = scpi_usbtmc_libusb_open,
	612	.source_add = scpi_usbtmc_libusb_source_add,
	613	.source_remove = scpi_usbtmc_libusb_source_remove,
	614	.send = scpi_usbtmc_libusb_send,
	615	.read_begin = scpi_usbtmc_libusb_read_begin,
	616	.read_data = scpi_usbtmc_libusb_read_data,
	617	.read_complete = scpi_usbtmc_libusb_read_complete,
	618	.close = scpi_usbtmc_libusb_close,
	619	.free = scpi_usbtmc_libusb_free,
	620	};