android_kernel_xiaomi_sdm845/drivers/media/video/uvc/uvc_status.c
Laurent Pinchart 04a37e0f32 V4L/DVB (11837): uvcvideo: Start status polling on device open
Most UVC camera include an interrupt endpoint to report control value changes,
video streaming errors and camera button events. The USB controller
continuously polls the interrupt endpoint to retrieve such events. This
prevents the device from being auto-suspended, and thus consumes power.

Reporting video streaming errors don't make sense when the V4L2 device is
closed. Control value changes are probably useless as well if nobody listens to
the events, although caching will probably have to be completely disabled then.
No polling is thus be required when /dev/videoX is not opened.

To enable auto-suspend and save power do not poll the interrupt endpoint until
the device is open. We lose the ability to detect button events if no
application is using the camera.

http://bugzilla.kernel.org/show_bug.cgi?id=11948

Signed-off-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2009-06-16 18:21:10 -03:00

237 lines
5.4 KiB
C

/*
* uvc_status.c -- USB Video Class driver - Status endpoint
*
* Copyright (C) 2007-2009
* Laurent Pinchart (laurent.pinchart@skynet.be)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
*/
#include <linux/kernel.h>
#include <linux/input.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_cleanup(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_cleanup(dev)
#define uvc_input_report_key(dev, code, value)
#endif /* CONFIG_USB_VIDEO_CLASS_INPUT_EVDEV */
/* --------------------------------------------------------------------------
* Status interrupt endpoint
*/
static void uvc_event_streaming(struct uvc_device *dev, __u8 *data, int len)
{
if (len < 3) {
uvc_trace(UVC_TRACE_STATUS, "Invalid streaming status event "
"received.\n");
return;
}
if (data[2] == 0) {
if (len < 4)
return;
uvc_trace(UVC_TRACE_STATUS, "Button (intf %u) %s len %d\n",
data[1], data[3] ? "pressed" : "released", len);
uvc_input_report_key(dev, KEY_CAMERA, data[3]);
} else {
uvc_trace(UVC_TRACE_STATUS, "Stream %u error event %02x %02x "
"len %d.\n", data[1], data[2], data[3], len);
}
}
static void uvc_event_control(struct uvc_device *dev, __u8 *data, int len)
{
char *attrs[3] = { "value", "info", "failure" };
if (len < 6 || data[2] != 0 || data[4] > 2) {
uvc_trace(UVC_TRACE_STATUS, "Invalid control status event "
"received.\n");
return;
}
uvc_trace(UVC_TRACE_STATUS, "Control %u/%u %s change len %d.\n",
data[1], data[3], attrs[data[4]], len);
}
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 controller). */
return;
default:
uvc_printk(KERN_WARNING, "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:
uvc_event_control(dev, dev->status, len);
break;
case UVC_STATUS_TYPE_STREAMING:
uvc_event_streaming(dev, dev->status, len);
break;
default:
uvc_printk(KERN_INFO, "unknown event type %u.\n",
dev->status[0]);
break;
}
}
/* Resubmit the URB. */
urb->interval = dev->int_ep->desc.bInterval;
if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
uvc_printk(KERN_ERR, "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_cleanup(struct uvc_device *dev)
{
usb_kill_urb(dev->int_urb);
usb_free_urb(dev->int_urb);
kfree(dev->status);
uvc_input_cleanup(dev);
}
int uvc_status_start(struct uvc_device *dev)
{
if (dev->int_urb == NULL)
return 0;
return usb_submit_urb(dev->int_urb, GFP_KERNEL);
}
void uvc_status_stop(struct uvc_device *dev)
{
usb_kill_urb(dev->int_urb);
}
int uvc_status_suspend(struct uvc_device *dev)
{
if (atomic_read(&dev->users))
usb_kill_urb(dev->int_urb);
return 0;
}
int uvc_status_resume(struct uvc_device *dev)
{
if (dev->int_urb == NULL || atomic_read(&dev->users) == 0)
return 0;
return usb_submit_urb(dev->int_urb, GFP_NOIO);
}