sn9c102_core.c

linux下sn9c102芯片的数码相机的驱动程序。

		void *pos, *sof, *eof;

		len = urb->iso_frame_desc[i].actual_length;
		status = urb->iso_frame_desc[i].status;
		pos = urb->iso_frame_desc[i].offset + urb->transfer_buffer;

		if (status) {
			DBG(3, "Error in isochronous frame")
			(*f)->state = F_ERROR;
			continue;
		}

		PDBGG("Isochrnous frame: length %u, #%u i", len, i)

		/*
		   NOTE: It is probably correct to assume that SOF and EOF
		         headers do not occur between two consecutive packets,
		         but who knows..Whatever is the truth, this assumption
		         doesn't introduce bugs.
		*/

redo:
		sof = sn9c102_find_sof_header(cam, pos, len);
		if (!sof) {
			eof = sn9c102_find_eof_header(cam, pos, len);
			if ((*f)->state == F_GRABBING) {
end_of_frame:
				img = len;

				if (eof)
					img = (eof > pos) ? eof - pos - 1 : 0;

				if ((*f)->buf.bytesused+img > imagesize) {
					u32 b = (*f)->buf.bytesused + img -
					        imagesize;
					img = imagesize - (*f)->buf.bytesused;
					DBG(3, "Expected EOF not found: "
					       "video frame cut")
					if (eof)
						DBG(3, "Exceeded limit: +%u "
						       "bytes", (unsigned)(b))
				}

				memcpy((*f)->bufmem + (*f)->buf.bytesused, pos,
				       img);

				if ((*f)->buf.bytesused == 0)
					do_gettimeofday(&(*f)->buf.timestamp);

				(*f)->buf.bytesused += img;

				if ((*f)->buf.bytesused == imagesize ||
				    (cam->sensor->pix_format.pixelformat ==
				                V4L2_PIX_FMT_SN9C10X && eof)) {
					u32 b = (*f)->buf.bytesused;
					(*f)->state = F_DONE;
					(*f)->buf.sequence= ++cam->frame_count;
					spin_lock_irqsave(&cam->queue_lock,
					                  lock_flags);
					list_move_tail(&(*f)->frame,
					               &cam->outqueue);
					if (!list_empty(&cam->inqueue))
						(*f) = list_entry(
						        cam->inqueue.next,
						        struct sn9c102_frame_t,
						        frame );
					else
						(*f) = NULL;
					spin_unlock_irqrestore(&cam->queue_lock
					                       , lock_flags);
					memcpy(cam->sysfs.frame_header,
					       cam->sof_header,
					       sizeof(sn9c102_sof_header_t));
					DBG(3, "Video frame captured: "
					       "%lu bytes", (unsigned long)(b))

					if (!(*f))
						goto resubmit_urb;

				} else if (eof) {
					(*f)->state = F_ERROR;
					DBG(3, "Not expected EOF after %lu "
					       "bytes of image data", 
					  (unsigned long)((*f)->buf.bytesused))
				}

				if (sof) /* (1) */
					goto start_of_frame;

			} else if (eof) {
				DBG(3, "EOF without SOF")
				continue;

			} else {
				PDBGG("Ignoring pointless isochronous frame")
				continue;
			}

		} else if ((*f)->state == F_QUEUED || (*f)->state == F_ERROR) {
start_of_frame:
			(*f)->state = F_GRABBING;
			(*f)->buf.bytesused = 0;
			len -= (sof - pos);
			pos = sof;
			DBG(3, "SOF detected: new video frame")
			if (len)
				goto redo;

		} else if ((*f)->state == F_GRABBING) {
			eof = sn9c102_find_eof_header(cam, pos, len);
			if (eof && eof < sof)
				goto end_of_frame; /* (1) */
			else {
				if (cam->sensor->pix_format.pixelformat ==
				    V4L2_PIX_FMT_SN9C10X) {
					eof = sof-sizeof(sn9c102_sof_header_t);
					goto end_of_frame;
				} else {
					DBG(3, "SOF before expected EOF after "
					       "%lu bytes of image data", 
					  (unsigned long)((*f)->buf.bytesused))
					goto start_of_frame;
				}
			}
		}
	}

resubmit_urb:
	urb->dev = cam->usbdev;
	err = usb_submit_urb(urb, GFP_ATOMIC);
	if (err < 0 && err != -EPERM) {
		cam->state |= DEV_MISCONFIGURED;
		DBG(1, "usb_submit_urb() failed")
	}

	wake_up_interruptible(&cam->wait_frame);
}


static int sn9c102_start_transfer(struct sn9c102_device* cam)
{
	struct usb_device *udev = cam->usbdev;
	struct urb* urb;
	const unsigned int wMaxPacketSize[] = {0, 128, 256, 384, 512,
	                                       680, 800, 900, 1023};
	const unsigned int psz = wMaxPacketSize[SN9C102_ALTERNATE_SETTING];
	s8 i, j;
	int err = 0;

	for (i = 0; i < SN9C102_URBS; i++) {
		cam->transfer_buffer[i] = kmalloc(SN9C102_ISO_PACKETS * psz,
		                                  GFP_KERNEL);
		if (!cam->transfer_buffer[i]) {
			err = -ENOMEM;
			DBG(1, "Not enough memory")
			goto free_buffers;
		}
	}

	for (i = 0; i < SN9C102_URBS; i++) {
		urb = usb_alloc_urb(SN9C102_ISO_PACKETS, GFP_KERNEL);
		cam->urb[i] = urb;
		if (!urb) {
			err = -ENOMEM;
			DBG(1, "usb_alloc_urb() failed")
			goto free_urbs;
		}
		urb->dev = udev;
		urb->context = cam;
		urb->pipe = usb_rcvisocpipe(udev, 1);
		urb->transfer_flags = URB_ISO_ASAP;
		urb->number_of_packets = SN9C102_ISO_PACKETS;
		urb->complete = sn9c102_urb_complete;
		urb->transfer_buffer = cam->transfer_buffer[i];
		urb->transfer_buffer_length = psz * SN9C102_ISO_PACKETS;
		urb->interval = 1;
		for (j = 0; j < SN9C102_ISO_PACKETS; j++) {
			urb->iso_frame_desc[j].offset = psz * j;
			urb->iso_frame_desc[j].length = psz;
		}
	}

	/* Enable video */
	if (!(cam->reg[0x01] & 0x04)) {
		err = sn9c102_write_reg(cam, cam->reg[0x01] | 0x04, 0x01);
		if (err) {
			err = -EIO;
			DBG(1, "I/O hardware error")
			goto free_urbs;
		}
	}

	err = usb_set_interface(udev, 0, SN9C102_ALTERNATE_SETTING);
	if (err) {
		DBG(1, "usb_set_interface() failed")
		goto free_urbs;
	}

	cam->frame_current = NULL;

	for (i = 0; i < SN9C102_URBS; i++) {
		err = usb_submit_urb(cam->urb[i], GFP_KERNEL);
		if (err) {
			for (j = i-1; j >= 0; j--)
				usb_kill_urb(cam->urb[j]);
			DBG(1, "usb_submit_urb() failed, error %d", err)
			goto free_urbs;
		}
	}

	return 0;

free_urbs:
	for (i = 0; (i < SN9C102_URBS) &&  cam->urb[i]; i++)
		usb_free_urb(cam->urb[i]);

free_buffers:
	for (i = 0; (i < SN9C102_URBS) && cam->transfer_buffer[i]; i++)
		kfree(cam->transfer_buffer[i]);

	return err;
}


static int sn9c102_stop_transfer(struct sn9c102_device* cam)
{
	struct usb_device *udev = cam->usbdev;
	s8 i;
	int err = 0;

	if (cam->state & DEV_DISCONNECTED)
		return 0;

	for (i = SN9C102_URBS-1; i >= 0; i--) {
		usb_kill_urb(cam->urb[i]);
		usb_free_urb(cam->urb[i]);
		kfree(cam->transfer_buffer[i]);
	}

	err = usb_set_interface(udev, 0, 0); /* 0 Mb/s */
	if (err)
		DBG(3, "usb_set_interface() failed")

	return err;
}


int sn9c102_stream_interrupt(struct sn9c102_device* cam)
{
	int err = 0;

	cam->stream = STREAM_INTERRUPT;
	err = wait_event_timeout(cam->wait_stream,
	                         (cam->stream == STREAM_OFF) ||
	                         (cam->state & DEV_DISCONNECTED),
	                         SN9C102_URB_TIMEOUT);
	if (cam->state & DEV_DISCONNECTED)
		return -ENODEV;
	else if (err) {
		cam->state |= DEV_MISCONFIGURED;
		DBG(1, "The camera is misconfigured. To use it, close and "
		       "open /dev/video%d again.", cam->v4ldev->minor)
		return err;
	}

	return 0;
}

/*****************************************************************************/

static u8 sn9c102_strtou8(const char* buff, size_t len, ssize_t* count)
{
	char str[5];
	char* endp;
	unsigned long val;

	if (len < 4) {
		strncpy(str, buff, len);
		str[len+1] = '\0';
	} else {
		strncpy(str, buff, 4);
		str[4] = '\0';
	}

	val = simple_strtoul(str, &endp, 0);

	*count = 0;
	if (val <= 0xff)
		*count = (ssize_t)(endp - str);
	if ((*count) && (len == *count+1) && (buff[*count] == '\n'))
		*count += 1;

	return (u8)val;
}

/*
   NOTE 1: being inside one of the following methods implies that the v4l
           device exists for sure (see kobjects and reference counters)
   NOTE 2: buffers are PAGE_SIZE long
*/

static ssize_t sn9c102_show_reg(struct class_device* cd, char* buf)
{
	struct sn9c102_device* cam;
	ssize_t count;

	if (down_interruptible(&sn9c102_sysfs_lock))
		return -ERESTARTSYS;

	cam = video_get_drvdata(to_video_device(cd));
	if (!cam) {
		up(&sn9c102_sysfs_lock);
		return -ENODEV;
	}

	count = sprintf(buf, "%u\n", cam->sysfs.reg);

	up(&sn9c102_sysfs_lock);

	return count;
} 


static ssize_t 
sn9c102_store_reg(struct class_device* cd, const char* buf, size_t len)
{
	struct sn9c102_device* cam;
	u8 index;
	ssize_t count;

	if (down_interruptible(&sn9c102_sysfs_lock))
		return -ERESTARTSYS;

	cam = video_get_drvdata(to_video_device(cd));
	if (!cam) {
		up(&sn9c102_sysfs_lock);
		return -ENODEV;
	}

	index = sn9c102_strtou8(buf, len, &count);
	if (index > 0x1f || !count) {
		up(&sn9c102_sysfs_lock);
		return -EINVAL;
	}

	cam->sysfs.reg = index;

	DBG(2, "Moved SN9C10X register index to 0x%02X", cam->sysfs.reg)
	DBG(3, "Written bytes: %zd", count)

	up(&sn9c102_sysfs_lock);

	return count;
}


static ssize_t sn9c102_show_val(struct class_device* cd, char* buf)
{
	struct sn9c102_device* cam;
	ssize_t count;
	int val;

	if (down_interruptible(&sn9c102_sysfs_lock))
		return -ERESTARTSYS;

	cam = video_get_drvdata(to_video_device(cd));
	if (!cam) {
		up(&sn9c102_sysfs_lock);
		return -ENODEV;
	}

	if ((val = sn9c102_read_reg(cam, cam->sysfs.reg)) < 0) {
		up(&sn9c102_sysfs_lock);
		return -EIO;
	}

	count = sprintf(buf, "%d\n", val);

	DBG(3, "Read bytes: %zd", count)

	up(&sn9c102_sysfs_lock);

	return count;
} 


static ssize_t
sn9c102_store_val(struct class_device* cd, const char* buf, size_t len)
{
	struct sn9c102_device* cam;
	u8 value;
	ssize_t count;
	int err;

	if (down_interruptible(&sn9c102_sysfs_lock))
		return -ERESTARTSYS;

	cam = video_get_drvdata(to_video_device(cd));
	if (!cam) {
		up(&sn9c102_sysfs_lock);
		return -ENODEV;
	}

	value = sn9c102_strtou8(buf, len, &count);
	if (!count) {
		up(&sn9c102_sysfs_lock);
		return -EINVAL;
	}

	err = sn9c102_write_reg(cam, value, cam->sysfs.reg);
	if (err) {
		up(&sn9c102_sysfs_lock);
		return -EIO;
	}

	DBG(2, "Written SN9C10X reg. 0x%02X, val. 0x%02X",
	    cam->sysfs.reg, value)
	DBG(3, "Written bytes: %zd", count)

	up(&sn9c102_sysfs_lock);

	return count;
}


static ssize_t sn9c102_show_i2c_reg(struct class_device* cd, char* buf)
{
	struct sn9c102_device* cam;
	ssize_t count;

	if (down_interruptible(&sn9c102_sysfs_lock))
		return -ERESTARTSYS;

	cam = video_get_drvdata(to_video_device(cd));
	if (!cam) {
		up(&sn9c102_sysfs_lock);
		return -ENODEV;
	}

	count = sprintf(buf, "%u\n", cam->sysfs.i2c_reg);

	DBG(3, "Read bytes: %zd", count)

	up(&sn9c102_sysfs_lock);

	return count;
}


static ssize_t 
sn9c102_store_i2c_reg(struct class_device* cd, const char* buf, size_t len)
{
	struct sn9c102_device* cam;
	u8 index;
	ssize_t count;

	if (down_interruptible(&sn9c102_sysfs_lock))
		return -ERESTARTSYS;

	cam = video_get_drvdata(to_video_device(cd));
	if (!cam) {
		up(&sn9c102_sysfs_lock);
		return -ENODEV;
	}

	index = sn9c102_strtou8(buf, len, &count);
	if (!count) {
		up(&sn9c102_sysfs_lock);
		return -EINVAL;
	}

	cam->sysfs.i2c_reg = index;

	DBG(2, "Moved sensor register index to 0x%02X", cam->sysfs.i2c_reg)
	DBG(3, "Written bytes: %zd", count)

	up(&sn9c102_sysfs_lock);

	return count;
}


static ssize_t sn9c102_show_i2c_val(struct class_device* cd, char* buf)
{
	struct sn9c102_device* cam;
	ssize_t count;
	int val;

	if (down_interruptible(&sn9c102_sysfs_lock))
		return -ERESTARTSYS;

	cam = video_get_drvdata(to_video_device(cd));
	if (!cam) {
		up(&sn9c102_sysfs_lock);
		return -ENODEV;
	}

	if (!(cam->sensor->sysfs_ops & SN9C102_I2C_READ)) {
		up(&sn9c102_sysfs_lock);
		return -ENOSYS;
	}

	if ((val = sn9c102_i2c_read(cam, cam->sysfs.i2c_reg)) < 0) {
		up(&sn9c102_sysfs_lock);
		return -EIO;
	}

	count = sprintf(buf, "%d\n", val);

	DBG(3, "Read bytes: %zd", count)

	up(&sn9c102_sysfs_lock);

	return count;
} 


static ssize_t
sn9c102_store_i2c_val(struct class_device* cd, const char* buf, size_t len)
{
	struct sn9c102_device* cam;
	u8 value;
	ssize_t count;
	int err;

	if (down_interruptible(&sn9c102_sysfs_lock))
		return -ERESTARTSYS;

	cam = video_get_drvdata(to_video_device(cd));
	if (!cam) {
		up(&sn9c102_sysfs_lock);
		return -ENODEV;
	}

	if (!(cam->sensor->sysfs_ops & SN9C102_I2C_WRITE)) {
		up(&sn9c102_sysfs_lock);
		return -ENOSYS;
	}

	value = sn9c102_strtou8(buf, len, &count);