libsigrok/backend.c

96 lines
2.4 KiB
C

/*
* This file is part of the sigrok project.
*
* Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com>
* Copyright (C) 2012 Peter Stuge <peter@stuge.se>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <glib.h>
#include "libsigrok.h"
#include "libsigrok-internal.h"
/**
* Initialize libsigrok.
*
* This function must be called before any other libsigrok function.
*
* @param ctx Pointer to a libsigrok context struct pointer. Must not be NULL.
* This will be a pointer to a newly allocated libsigrok context
* object upon success, and is undefined upon errors.
*
* @return SR_OK upon success, a (negative) error code otherwise. Upon errors
* the 'ctx' pointer is undefined and should not be used. Upon success,
* the context will be free'd by sr_exit() as part of the libsigrok
* shutdown.
*/
SR_API int sr_init(struct sr_context **ctx)
{
int ret = SR_ERR;
struct sr_context *context;
if (!ctx) {
sr_err("%s(): libsigrok context was NULL.", __func__);
return SR_ERR;
}
/* + 1 to handle when struct sr_context has no members. */
context = g_try_malloc0(sizeof(struct sr_context) + 1);
if (!context) {
ret = SR_ERR_MALLOC;
goto done;
}
#ifdef HAVE_LIBUSB_1_0
ret = libusb_init(&context->libusb_ctx);
if (LIBUSB_SUCCESS == ret) {
sr_err("libusb_init() returned %s.\n", libusb_error_name(ret));
goto done;
}
#endif
*ctx = context;
ret = SR_OK;
done:
return ret;
}
/**
* Shutdown libsigrok.
*
* @param ctx Pointer to a libsigrok context struct. Must not be NULL.
*
* @return SR_OK upon success, a (negative) error code otherwise.
*/
SR_API int sr_exit(struct sr_context *ctx)
{
if (!ctx) {
sr_err("%s(): libsigrok context was NULL.", __func__);
return SR_ERR;
}
sr_hw_cleanup_all();
#ifdef HAVE_LIBUSB_1_0
libusb_exit(ctx->libusb_ctx);
#endif
g_free(ctx);
return SR_OK;
}