path: root/uvc.c

/*
 * UVC protocol handling
 *
 * Copyright (C) 2010 Ideas on board SPRL <laurent.pinchart@ideasonboard.com>
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 */

#include <errno.h>
#include <linux/usb/ch9.h>
#include <linux/usb/g_uvc.h>
#include <linux/usb/video.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>

#include "configfs.h"
#include "events.h"
#include "stream.h"
#include "tools.h"
#include "uvc.h"
#include "v4l2.h"

struct uvc_device *uvc_open(const char *devname, struct uvc_stream *stream)
{
	struct uvc_device *dev;

	dev = malloc(sizeof *dev);
	if (dev == NULL)
		return NULL;

	memset(dev, 0, sizeof *dev);
	dev->stream = stream;

	dev->vdev = v4l2_open(devname);
	if (dev->vdev == NULL) {
		free(dev);
		return NULL;
	}

	return dev;
}

void uvc_close(struct uvc_device *dev)
{
	v4l2_close(dev->vdev);
	dev->vdev = NULL;

	free(dev);
}

/* ---------------------------------------------------------------------------
 * Request processing
 */

static void
uvc_fill_streaming_control(struct uvc_device *dev,
			   struct uvc_streaming_control *ctrl,
			   int iformat, int iframe, unsigned int ival)
{
	const struct uvc_function_config_format *format;
	const struct uvc_function_config_frame *frame;
	unsigned int i;

	/*
	 * Restrict the iformat, iframe and ival to valid values. Negative
	 * values for iformat or iframe will result in the maximum valid value
	 * being selected.
	 */
        iformat = clamp((unsigned int)iformat, 1U,
                        dev->fc->streaming.num_formats);
	format = &dev->fc->streaming.formats[iformat-1];

	iframe = clamp((unsigned int)iframe, 1U, format->num_frames);
	frame = &format->frames[iframe-1];

	for (i = 0; i < frame->num_intervals; ++i) {
		if (ival <= frame->intervals[i]) {
			ival = frame->intervals[i];
			break;
		}
	}

	if (i == frame->num_intervals)
		ival = frame->intervals[frame->num_intervals-1];

	memset(ctrl, 0, sizeof *ctrl);

	ctrl->bmHint = 1;
	ctrl->bFormatIndex = iformat;
	ctrl->bFrameIndex = iframe ;
	ctrl->dwFrameInterval = ival;

	switch (format->fcc) {
	case V4L2_PIX_FMT_YUYV:
		ctrl->dwMaxVideoFrameSize = frame->width * frame->height * 2;
		break;
	case V4L2_PIX_FMT_MJPEG:
		ctrl->dwMaxVideoFrameSize = dev->maxsize;
		break;
	}

	ctrl->dwMaxPayloadTransferSize = dev->fc->streaming.ep.wMaxPacketSize;
	ctrl->bmFramingInfo = 3;
	ctrl->bPreferedVersion = 1;
	ctrl->bMaxVersion = 1;
}

static void
uvc_events_process_standard(struct uvc_device *dev,
			    const struct usb_ctrlrequest *ctrl,
			    struct uvc_request_data *resp)
{
	printf("standard request\n");
	(void)dev;
	(void)ctrl;
	(void)resp;
}

static void
uvc_events_process_control(struct uvc_device *dev, uint8_t req, uint8_t cs,
			   struct uvc_request_data *resp)
{
	printf("control request (req %02x cs %02x)\n", req, cs);
	(void)dev;
	(void)resp;
}

static void
uvc_events_process_streaming(struct uvc_device *dev, uint8_t req, uint8_t cs,
			     struct uvc_request_data *resp)
{
	struct uvc_streaming_control *ctrl;

	printf("streaming request (req %02x cs %02x)\n", req, cs);

	if (cs != UVC_VS_PROBE_CONTROL && cs != UVC_VS_COMMIT_CONTROL)
		return;

	ctrl = (struct uvc_streaming_control *)&resp->data;
	resp->length = sizeof *ctrl;

	switch (req) {
	case UVC_SET_CUR:
		dev->control = cs;
		resp->length = 34;
		break;

	case UVC_GET_CUR:
		if (cs == UVC_VS_PROBE_CONTROL)
			memcpy(ctrl, &dev->probe, sizeof *ctrl);
		else
			memcpy(ctrl, &dev->commit, sizeof *ctrl);
		break;

	case UVC_GET_MIN:
	case UVC_GET_MAX:
	case UVC_GET_DEF:
		uvc_fill_streaming_control(dev, ctrl, req == UVC_GET_MAX ? -1 : 1,
					   req == UVC_GET_MAX ? -1 : 1, 0);
		break;

	case UVC_GET_RES:
		memset(ctrl, 0, sizeof *ctrl);
		break;

	case UVC_GET_LEN:
		resp->data[0] = 0x00;
		resp->data[1] = 0x22;
		resp->length = 2;
		break;

	case UVC_GET_INFO:
		resp->data[0] = 0x03;
		resp->length = 1;
		break;
	}
}

static void
uvc_events_process_class(struct uvc_device *dev,
			 const struct usb_ctrlrequest *ctrl,
			 struct uvc_request_data *resp)
{
	unsigned int interface = ctrl->wIndex & 0xff;

	if ((ctrl->bRequestType & USB_RECIP_MASK) != USB_RECIP_INTERFACE)
		return;

	if (interface == dev->fc->control.intf.bInterfaceNumber)
		uvc_events_process_control(dev, ctrl->bRequest, ctrl->wValue >> 8, resp);
	else if (interface == dev->fc->streaming.intf.bInterfaceNumber)
		uvc_events_process_streaming(dev, ctrl->bRequest, ctrl->wValue >> 8, resp);
}

static void
uvc_events_process_setup(struct uvc_device *dev,
			 const struct usb_ctrlrequest *ctrl,
			 struct uvc_request_data *resp)
{
	dev->control = 0;

	printf("bRequestType %02x bRequest %02x wValue %04x wIndex %04x "
		"wLength %04x\n", ctrl->bRequestType, ctrl->bRequest,
		ctrl->wValue, ctrl->wIndex, ctrl->wLength);

	switch (ctrl->bRequestType & USB_TYPE_MASK) {
	case USB_TYPE_STANDARD:
		uvc_events_process_standard(dev, ctrl, resp);
		break;

	case USB_TYPE_CLASS:
		uvc_events_process_class(dev, ctrl, resp);
		break;

	default:
		break;
	}
}

static void
uvc_events_process_data(struct uvc_device *dev,
			const struct uvc_request_data *data)
{
	const struct uvc_streaming_control *ctrl =
		(const struct uvc_streaming_control *)&data->data;
	struct uvc_streaming_control *target;

	switch (dev->control) {
	case UVC_VS_PROBE_CONTROL:
		printf("setting probe control, length = %d\n", data->length);
		target = &dev->probe;
		break;

	case UVC_VS_COMMIT_CONTROL:
		printf("setting commit control, length = %d\n", data->length);
		target = &dev->commit;
		break;

	default:
		printf("setting unknown control, length = %d\n", data->length);
		return;
	}

	uvc_fill_streaming_control(dev, target, ctrl->bFormatIndex,
				   ctrl->bFrameIndex, ctrl->dwFrameInterval);

	if (dev->control == UVC_VS_COMMIT_CONTROL) {
		const struct uvc_function_config_format *format;
		const struct uvc_function_config_frame *frame;

		format = &dev->fc->streaming.formats[target->bFormatIndex-1];
		frame = &format->frames[target->bFrameIndex-1];

		dev->fcc = format->fcc;
		dev->width = frame->width;
		dev->height = frame->height;

		uvc_stream_set_format(dev->stream);
	}
}

static void uvc_events_process(void *d)
{
	struct uvc_device *dev = d;
	struct v4l2_event v4l2_event;
	const struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;
	struct uvc_request_data resp;
	int ret;

	ret = ioctl(dev->vdev->fd, VIDIOC_DQEVENT, &v4l2_event);
	if (ret < 0) {
		printf("VIDIOC_DQEVENT failed: %s (%d)\n", strerror(errno),
			errno);
		return;
	}

	memset(&resp, 0, sizeof resp);
	resp.length = -EL2HLT;

	switch (v4l2_event.type) {
	case UVC_EVENT_CONNECT:
	case UVC_EVENT_DISCONNECT:
		return;

	case UVC_EVENT_SETUP:
		uvc_events_process_setup(dev, &uvc_event->req, &resp);
		break;

	case UVC_EVENT_DATA:
		uvc_events_process_data(dev, &uvc_event->data);
		return;

	case UVC_EVENT_STREAMON:
		uvc_stream_enable(dev->stream, 1);
		return;

	case UVC_EVENT_STREAMOFF:
		uvc_stream_enable(dev->stream, 0);
		return;
	}

	ioctl(dev->vdev->fd, UVCIOC_SEND_RESPONSE, &resp);
	if (ret < 0) {
		printf("UVCIOC_S_EVENT failed: %s (%d)\n", strerror(errno),
			errno);
		return;
	}
}

void uvc_events_init(struct uvc_device *dev, struct events *events)
{
	struct v4l2_event_subscription sub;

	/* Default to the minimum values. */
	uvc_fill_streaming_control(dev, &dev->probe, 1, 1, 0);
	uvc_fill_streaming_control(dev, &dev->commit, 1, 1, 0);

	memset(&sub, 0, sizeof sub);
	sub.type = UVC_EVENT_SETUP;
	ioctl(dev->vdev->fd, VIDIOC_SUBSCRIBE_EVENT, &sub);
	sub.type = UVC_EVENT_DATA;
	ioctl(dev->vdev->fd, VIDIOC_SUBSCRIBE_EVENT, &sub);
	sub.type = UVC_EVENT_STREAMON;
	ioctl(dev->vdev->fd, VIDIOC_SUBSCRIBE_EVENT, &sub);
	sub.type = UVC_EVENT_STREAMOFF;
	ioctl(dev->vdev->fd, VIDIOC_SUBSCRIBE_EVENT, &sub);

	events_watch_fd(events, dev->vdev->fd, EVENT_EXCEPTION,
			uvc_events_process, dev);
}

void uvc_set_config(struct uvc_device *dev, struct uvc_function_config *fc)
{
	dev->fc = fc;
}