drivers/input/joystick/pxrc.c

Source file repositories/reference/linux-study-clean/drivers/input/joystick/pxrc.c

File Facts

System
Linux kernel
Corpus path
drivers/input/joystick/pxrc.c
Extension
.c
Size
6518 bytes
Lines
276
Domain
Driver Families
Bucket
drivers/input
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 pxrc {
	struct input_dev	*input;
	struct usb_interface	*intf;
	struct urb		*urb;
	struct mutex		pm_mutex;
	bool			is_open;
	char			phys[64];
};

static void pxrc_usb_irq(struct urb *urb)
{
	struct pxrc *pxrc = urb->context;
	u8 *data = urb->transfer_buffer;
	int error;

	switch (urb->status) {
	case 0:
		/* success */
		break;
	case -ETIME:
		/* this urb is timing out */
		dev_dbg(&pxrc->intf->dev,
			"%s - urb timed out - was the device unplugged?\n",
			__func__);
		return;
	case -ECONNRESET:
	case -ENOENT:
	case -ESHUTDOWN:
	case -EPIPE:
		/* this urb is terminated, clean up */
		dev_dbg(&pxrc->intf->dev, "%s - urb shutting down with status: %d\n",
			__func__, urb->status);
		return;
	default:
		dev_dbg(&pxrc->intf->dev, "%s - nonzero urb status received: %d\n",
			__func__, urb->status);
		goto exit;
	}

	if (urb->actual_length == 8) {
		input_report_abs(pxrc->input, ABS_X, data[0]);
		input_report_abs(pxrc->input, ABS_Y, data[2]);
		input_report_abs(pxrc->input, ABS_RX, data[3]);
		input_report_abs(pxrc->input, ABS_RY, data[4]);
		input_report_abs(pxrc->input, ABS_RUDDER, data[5]);
		input_report_abs(pxrc->input, ABS_THROTTLE, data[6]);
		input_report_abs(pxrc->input, ABS_MISC, data[7]);

		input_report_key(pxrc->input, BTN_A, data[1]);
	}

exit:
	/* Resubmit to fetch new fresh URBs */
	error = usb_submit_urb(urb, GFP_ATOMIC);
	if (error && error != -EPERM)
		dev_err(&pxrc->intf->dev,
			"%s - usb_submit_urb failed with result: %d",
			__func__, error);
}

static int pxrc_open(struct input_dev *input)
{
	struct pxrc *pxrc = input_get_drvdata(input);
	int error;

	guard(mutex)(&pxrc->pm_mutex);
	error = usb_submit_urb(pxrc->urb, GFP_KERNEL);
	if (error) {
		dev_err(&pxrc->intf->dev,
			"%s - usb_submit_urb failed, error: %d\n",
			__func__, error);
		return -EIO;
	}

	pxrc->is_open = true;
	return 0;
}

static void pxrc_close(struct input_dev *input)
{
	struct pxrc *pxrc = input_get_drvdata(input);

	guard(mutex)(&pxrc->pm_mutex);
	usb_kill_urb(pxrc->urb);
	pxrc->is_open = false;
}

static void pxrc_free_urb(void *_pxrc)
{
	struct pxrc *pxrc = _pxrc;

Annotation

Implementation Notes