diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/media/usb/uvc/uvc_status.c | 350 |
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); +} |