tools/usb/ffs-aio-example/multibuff/host_app/test.c

Source file repositories/reference/linux-study-clean/tools/usb/ffs-aio-example/multibuff/host_app/test.c

File Facts

System
Linux kernel
Corpus path
tools/usb/ffs-aio-example/multibuff/host_app/test.c
Extension
.c
Size
4399 bytes
Lines
176
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

struct test_state {
	libusb_device *found;
	libusb_context *ctx;
	libusb_device_handle *handle;
	int attached;
};

/*
 * test_init - initialize test program
 */

int test_init(struct test_state *state)
{
	int i, ret;
	ssize_t cnt;
	libusb_device **list;

	state->found = NULL;
	state->ctx = NULL;
	state->handle = NULL;
	state->attached = 0;

	ret = libusb_init(&state->ctx);
	if (ret) {
		printf("cannot init libusb: %s\n", libusb_error_name(ret));
		return 1;
	}

	cnt = libusb_get_device_list(state->ctx, &list);
	if (cnt <= 0) {
		printf("no devices found\n");
		goto error1;
	}

	for (i = 0; i < cnt; ++i) {
		libusb_device *dev = list[i];
		struct libusb_device_descriptor desc;
		ret = libusb_get_device_descriptor(dev, &desc);
		if (ret) {
			printf("unable to get device descriptor: %s\n",
			       libusb_error_name(ret));
			goto error2;
		}
		if (desc.idVendor == VENDOR && desc.idProduct == PRODUCT) {
			state->found = dev;
			break;
		}
	}

	if (!state->found) {
		printf("no devices found\n");
		goto error2;
	}

	ret = libusb_open(state->found, &state->handle);
	if (ret) {
		printf("cannot open device: %s\n", libusb_error_name(ret));
		goto error2;
	}

	if (libusb_claim_interface(state->handle, 0)) {
		ret = libusb_detach_kernel_driver(state->handle, 0);
		if (ret) {
			printf("unable to detach kernel driver: %s\n",
			       libusb_error_name(ret));
			goto error3;
		}
		state->attached = 1;
		ret = libusb_claim_interface(state->handle, 0);
		if (ret) {
			printf("cannot claim interface: %s\n",
			       libusb_error_name(ret));
			goto error4;
		}
	}

	return 0;

error4:
	if (state->attached == 1)
		libusb_attach_kernel_driver(state->handle, 0);

error3:
	libusb_close(state->handle);

error2:
	libusb_free_device_list(list, 1);

error1:
	libusb_exit(state->ctx);

Annotation

Implementation Notes