1 files changed, 350 insertions, 0 deletions
diff --git a/drivers/media/usb/uvc/uvc_status.c b/drivers/media/usb/uvc/uvc_status.c
new file mode 100644
index 000000000..4a92c989c
--- /dev/null
+++ b/drivers/media/usb/uvc/uvc_status.c
@@ -0,0 +1,350 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *      uvc_status.c  --  USB Video Class driver - Status endpoint
+ *
+ *      Copyright (C) 2005-2009
+ *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ */
+
+#include <asm/barrier.h>
+#include <linux/kernel.h>
+#include <linux/input.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <linux/usb/input.h>
+
+#include "uvcvideo.h"
+
+/* --------------------------------------------------------------------------
+ * Input device
+ */
+#ifdef CONFIG_USB_VIDEO_CLASS_INPUT_EVDEV
+static int uvc_input_init(struct uvc_device *dev)
+{
+	struct input_dev *input;
+	int ret;
+
+	input = input_allocate_device();
+	if (input == NULL)
+		return -ENOMEM;
+
+	usb_make_path(dev->udev, dev->input_phys, sizeof(dev->input_phys));
+	strlcat(dev->input_phys, "/button", sizeof(dev->input_phys));
+
+	input->name = dev->name;
+	input->phys = dev->input_phys;
+	usb_to_input_id(dev->udev, &input->id);
+	input->dev.parent = &dev->intf->dev;
+
+	__set_bit(EV_KEY, input->evbit);
+	__set_bit(KEY_CAMERA, input->keybit);
+
+	if ((ret = input_register_device(input)) < 0)
+		goto error;
+
+	dev->input = input;
+	return 0;
+
+error:
+	input_free_device(input);
+	return ret;
+}
+
+static void uvc_input_unregister(struct uvc_device *dev)
+{
+	if (dev->input)
+		input_unregister_device(dev->input);
+}
+
+static void uvc_input_report_key(struct uvc_device *dev, unsigned int code,
+	int value)
+{
+	if (dev->input) {
+		input_report_key(dev->input, code, value);
+		input_sync(dev->input);
+	}
+}
+
+#else
+#define uvc_input_init(dev)
+#define uvc_input_unregister(dev)
+#define uvc_input_report_key(dev, code, value)
+#endif /* CONFIG_USB_VIDEO_CLASS_INPUT_EVDEV */
+
+/* --------------------------------------------------------------------------
+ * Status interrupt endpoint
+ */
+struct uvc_streaming_status {
+	u8	bStatusType;
+	u8	bOriginator;
+	u8	bEvent;
+	u8	bValue[];
+} __packed;
+
+struct uvc_control_status {
+	u8	bStatusType;
+	u8	bOriginator;
+	u8	bEvent;
+	u8	bSelector;
+	u8	bAttribute;
+	u8	bValue[];
+} __packed;
+
+static void uvc_event_streaming(struct uvc_device *dev,
+				struct uvc_streaming_status *status, int len)
+{
+	if (len < 3) {
+		uvc_dbg(dev, STATUS,
+			"Invalid streaming status event received\n");
+		return;
+	}
+
+	if (status->bEvent == 0) {
+		if (len < 4)
+			return;
+		uvc_dbg(dev, STATUS, "Button (intf %u) %s len %d\n",
+			status->bOriginator,
+			status->bValue[0] ? "pressed" : "released", len);
+		uvc_input_report_key(dev, KEY_CAMERA, status->bValue[0]);
+	} else {
+		uvc_dbg(dev, STATUS, "Stream %u error event %02x len %d\n",
+			status->bOriginator, status->bEvent, len);
+	}
+}
+
+#define UVC_CTRL_VALUE_CHANGE	0
+#define UVC_CTRL_INFO_CHANGE	1
+#define UVC_CTRL_FAILURE_CHANGE	2
+#define UVC_CTRL_MIN_CHANGE	3
+#define UVC_CTRL_MAX_CHANGE	4
+
+static struct uvc_control *uvc_event_entity_find_ctrl(struct uvc_entity *entity,
+						      u8 selector)
+{
+	struct uvc_control *ctrl;
+	unsigned int i;
+
+	for (i = 0, ctrl = entity->controls; i < entity->ncontrols; i++, ctrl++)
+		if (ctrl->info.selector == selector)
+			return ctrl;
+
+	return NULL;
+}
+
+static struct uvc_control *uvc_event_find_ctrl(struct uvc_device *dev,
+					const struct uvc_control_status *status,
+					struct uvc_video_chain **chain)
+{
+	list_for_each_entry((*chain), &dev->chains, list) {
+		struct uvc_entity *entity;
+		struct uvc_control *ctrl;
+
+		list_for_each_entry(entity, &(*chain)->entities, chain) {
+			if (entity->id != status->bOriginator)
+				continue;
+
+			ctrl = uvc_event_entity_find_ctrl(entity,
+							  status->bSelector);
+			if (ctrl)
+				return ctrl;
+		}
+	}
+
+	return NULL;
+}
+
+static bool uvc_event_control(struct urb *urb,
+			      const struct uvc_control_status *status, int len)
+{
+	static const char *attrs[] = { "value", "info", "failure", "min", "max" };
+	struct uvc_device *dev = urb->context;
+	struct uvc_video_chain *chain;
+	struct uvc_control *ctrl;
+
+	if (len < 6 || status->bEvent != 0 ||
+	    status->bAttribute >= ARRAY_SIZE(attrs)) {
+		uvc_dbg(dev, STATUS, "Invalid control status event received\n");
+		return false;
+	}
+
+	uvc_dbg(dev, STATUS, "Control %u/%u %s change len %d\n",
+		status->bOriginator, status->bSelector,
+		attrs[status->bAttribute], len);
+
+	/* Find the control. */
+	ctrl = uvc_event_find_ctrl(dev, status, &chain);
+	if (!ctrl)
+		return false;
+
+	switch (status->bAttribute) {
+	case UVC_CTRL_VALUE_CHANGE:
+		return uvc_ctrl_status_event_async(urb, chain, ctrl,
+						   status->bValue);
+
+	case UVC_CTRL_INFO_CHANGE:
+	case UVC_CTRL_FAILURE_CHANGE:
+	case UVC_CTRL_MIN_CHANGE:
+	case UVC_CTRL_MAX_CHANGE:
+		break;
+	}
+
+	return false;
+}
+
+static void uvc_status_complete(struct urb *urb)
+{
+	struct uvc_device *dev = urb->context;
+	int len, ret;
+
+	switch (urb->status) {
+	case 0:
+		break;
+
+	case -ENOENT:		/* usb_kill_urb() called. */
+	case -ECONNRESET:	/* usb_unlink_urb() called. */
+	case -ESHUTDOWN:	/* The endpoint is being disabled. */
+	case -EPROTO:		/* Device is disconnected (reported by some host controllers). */
+		return;
+
+	default:
+		dev_warn(&dev->udev->dev,
+			 "Non-zero status (%d) in status completion handler.\n",
+			 urb->status);
+		return;
+	}
+
+	len = urb->actual_length;
+	if (len > 0) {
+		switch (dev->status[0] & 0x0f) {
+		case UVC_STATUS_TYPE_CONTROL: {
+			struct uvc_control_status *status =
+				(struct uvc_control_status *)dev->status;
+
+			if (uvc_event_control(urb, status, len))
+				/* The URB will be resubmitted in work context. */
+				return;
+			break;
+		}
+
+		case UVC_STATUS_TYPE_STREAMING: {
+			struct uvc_streaming_status *status =
+				(struct uvc_streaming_status *)dev->status;
+
+			uvc_event_streaming(dev, status, len);
+			break;
+		}
+
+		default:
+			uvc_dbg(dev, STATUS, "Unknown status event type %u\n",
+				dev->status[0]);
+			break;
+		}
+	}
+
+	/* Resubmit the URB. */
+	urb->interval = dev->int_ep->desc.bInterval;
+	ret = usb_submit_urb(urb, GFP_ATOMIC);
+	if (ret < 0)
+		dev_err(&dev->udev->dev,
+			"Failed to resubmit status URB (%d).\n", ret);
+}
+
+int uvc_status_init(struct uvc_device *dev)
+{
+	struct usb_host_endpoint *ep = dev->int_ep;
+	unsigned int pipe;
+	int interval;
+
+	if (ep == NULL)
+		return 0;
+
+	uvc_input_init(dev);
+
+	dev->status = kzalloc(UVC_MAX_STATUS_SIZE, GFP_KERNEL);
+	if (dev->status == NULL)
+		return -ENOMEM;
+
+	dev->int_urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (dev->int_urb == NULL) {
+		kfree(dev->status);
+		return -ENOMEM;
+	}
+
+	pipe = usb_rcvintpipe(dev->udev, ep->desc.bEndpointAddress);
+
+	/*
+	 * For high-speed interrupt endpoints, the bInterval value is used as
+	 * an exponent of two. Some developers forgot about it.
+	 */
+	interval = ep->desc.bInterval;
+	if (interval > 16 && dev->udev->speed == USB_SPEED_HIGH &&
+	    (dev->quirks & UVC_QUIRK_STATUS_INTERVAL))
+		interval = fls(interval) - 1;
+
+	usb_fill_int_urb(dev->int_urb, dev->udev, pipe,
+		dev->status, UVC_MAX_STATUS_SIZE, uvc_status_complete,
+		dev, interval);
+
+	return 0;
+}
+
+void uvc_status_unregister(struct uvc_device *dev)
+{
+	usb_kill_urb(dev->int_urb);
+	uvc_input_unregister(dev);
+}
+
+void uvc_status_cleanup(struct uvc_device *dev)
+{
+	usb_free_urb(dev->int_urb);
+	kfree(dev->status);
+}
+
+int uvc_status_start(struct uvc_device *dev, gfp_t flags)
+{
+	if (dev->int_urb == NULL)
+		return 0;
+
+	return usb_submit_urb(dev->int_urb, flags);
+}
+
+void uvc_status_stop(struct uvc_device *dev)
+{
+	struct uvc_ctrl_work *w = &dev->async_ctrl;
+
+	/*
+	 * Prevent the asynchronous control handler from requeing the URB. The
+	 * barrier is needed so the flush_status change is visible to other
+	 * CPUs running the asynchronous handler before usb_kill_urb() is
+	 * called below.
+	 */
+	smp_store_release(&dev->flush_status, true);
+
+	/*
+	 * Cancel any pending asynchronous work. If any status event was queued,
+	 * process it synchronously.
+	 */
+	if (cancel_work_sync(&w->work))
+		uvc_ctrl_status_event(w->chain, w->ctrl, w->data);
+
+	/* Kill the urb. */
+	usb_kill_urb(dev->int_urb);
+
+	/*
+	 * The URB completion handler may have queued asynchronous work. This
+	 * won't resubmit the URB as flush_status is set, but it needs to be
+	 * cancelled before returning or it could then race with a future
+	 * uvc_status_start() call.
+	 */
+	if (cancel_work_sync(&w->work))
+		uvc_ctrl_status_event(w->chain, w->ctrl, w->data);
+
+	/*
+	 * From this point, there are no events on the queue and the status URB
+	 * is dead. No events will be queued until uvc_status_start() is called.
+	 * The barrier is needed to make sure that flush_status is visible to
+	 * uvc_ctrl_status_event_work() when uvc_status_start() will be called
+	 * again.
+	 */
+	smp_store_release(&dev->flush_status, false);
+}