drivers/hid/usbhid/usbmouse.c

Source file repositories/reference/linux-study-clean/drivers/hid/usbhid/usbmouse.c

File Facts

System
Linux kernel
Corpus path
drivers/hid/usbhid/usbmouse.c
Extension
.c
Size
5992 bytes
Lines
238
Domain
Driver Families
Bucket
drivers/hid
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 usb_mouse {
	char name[128];
	char phys[64];
	struct usb_device *usbdev;
	struct input_dev *dev;
	struct urb *irq;

	signed char *data;
	dma_addr_t data_dma;
};

static void usb_mouse_irq(struct urb *urb)
{
	struct usb_mouse *mouse = urb->context;
	signed char *data = mouse->data;
	struct input_dev *dev = mouse->dev;
	int status;

	switch (urb->status) {
	case 0:			/* success */
		break;
	case -ECONNRESET:	/* unlink */
	case -ENOENT:
	case -ESHUTDOWN:
		return;
	/* -EPIPE:  should clear the halt */
	default:		/* error */
		goto resubmit;
	}

	input_report_key(dev, BTN_LEFT,   data[0] & 0x01);
	input_report_key(dev, BTN_RIGHT,  data[0] & 0x02);
	input_report_key(dev, BTN_MIDDLE, data[0] & 0x04);
	input_report_key(dev, BTN_SIDE,   data[0] & 0x08);
	input_report_key(dev, BTN_EXTRA,  data[0] & 0x10);

	input_report_rel(dev, REL_X,     data[1]);
	input_report_rel(dev, REL_Y,     data[2]);
	input_report_rel(dev, REL_WHEEL, data[3]);

	input_sync(dev);
resubmit:
	status = usb_submit_urb (urb, GFP_ATOMIC);
	if (status)
		dev_err(&mouse->usbdev->dev,
			"can't resubmit intr, %s-%s/input0, status %d\n",
			mouse->usbdev->bus->bus_name,
			mouse->usbdev->devpath, status);
}

static int usb_mouse_open(struct input_dev *dev)
{
	struct usb_mouse *mouse = input_get_drvdata(dev);

	mouse->irq->dev = mouse->usbdev;
	if (usb_submit_urb(mouse->irq, GFP_KERNEL))
		return -EIO;

	return 0;
}

static void usb_mouse_close(struct input_dev *dev)
{
	struct usb_mouse *mouse = input_get_drvdata(dev);

	usb_kill_urb(mouse->irq);
}

static int usb_mouse_probe(struct usb_interface *intf, const struct usb_device_id *id)
{
	struct usb_device *dev = interface_to_usbdev(intf);
	struct usb_host_interface *interface;
	struct usb_endpoint_descriptor *endpoint;
	struct usb_mouse *mouse;
	struct input_dev *input_dev;
	struct seq_buf mouse_name;
	int pipe, maxp;
	int error = -ENOMEM;
	size_t len;

	interface = intf->cur_altsetting;

	if (interface->desc.bNumEndpoints != 1)
		return -ENODEV;

	endpoint = &interface->endpoint[0].desc;
	if (!usb_endpoint_is_int_in(endpoint))
		return -ENODEV;

	pipe = usb_rcvintpipe(dev, endpoint->bEndpointAddress);

Annotation

Implementation Notes