drivers/usb/misc/lvstest.c

Source file repositories/reference/linux-study-clean/drivers/usb/misc/lvstest.c

File Facts

System
Linux kernel
Corpus path
drivers/usb/misc/lvstest.c
Extension
.c
Size
11992 bytes
Lines
477
Domain
Driver Families
Bucket
drivers/usb
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct lvs_rh {
	/* root hub interface */
	struct usb_interface *intf;
	/* if lvs device connected */
	bool present;
	/* port no at which lvs device is present */
	int portnum;
	/* urb buffer */
	u8 buffer[8];
	/* class descriptor */
	struct usb_hub_descriptor descriptor;
	/* urb for polling interrupt pipe */
	struct urb *urb;
	/* LVH RH work */
	struct work_struct	rh_work;
	/* RH port status */
	struct usb_port_status port_status;
};

static struct usb_device *create_lvs_device(struct usb_interface *intf)
{
	struct usb_device *udev, *hdev;
	struct usb_hcd *hcd;
	struct lvs_rh *lvs = usb_get_intfdata(intf);

	if (!lvs->present) {
		dev_err(&intf->dev, "No LVS device is present\n");
		return NULL;
	}

	hdev = interface_to_usbdev(intf);
	hcd = bus_to_hcd(hdev->bus);

	udev = usb_alloc_dev(hdev, hdev->bus, lvs->portnum);
	if (!udev) {
		dev_err(&intf->dev, "Could not allocate lvs udev\n");
		return NULL;
	}
	udev->speed = USB_SPEED_SUPER;
	udev->ep0.desc.wMaxPacketSize = cpu_to_le16(512);
	usb_set_device_state(udev, USB_STATE_DEFAULT);

	if (hcd->driver->enable_device) {
		if (hcd->driver->enable_device(hcd, udev) < 0) {
			dev_err(&intf->dev, "Failed to enable\n");
			usb_put_dev(udev);
			return NULL;
		}
	}

	return udev;
}

static void destroy_lvs_device(struct usb_device *udev)
{
	struct usb_device *hdev = udev->parent;
	struct usb_hcd *hcd = bus_to_hcd(hdev->bus);

	if (hcd->driver->free_dev)
		hcd->driver->free_dev(hcd, udev);

	usb_put_dev(udev);
}

static int lvs_rh_clear_port_feature(struct usb_device *hdev,
		int port1, int feature)
{
	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
		USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1,
		NULL, 0, 1000);
}

static int lvs_rh_set_port_feature(struct usb_device *hdev,
		int port1, int feature)
{
	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
		USB_REQ_SET_FEATURE, USB_RT_PORT, feature, port1,
		NULL, 0, 1000);
}

static ssize_t u3_entry_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	struct usb_interface *intf = to_usb_interface(dev);
	struct usb_device *hdev = interface_to_usbdev(intf);
	struct lvs_rh *lvs = usb_get_intfdata(intf);
	struct usb_device *udev;
	int ret;

	udev = create_lvs_device(intf);

Annotation

Implementation Notes