V4L/DVB (3599a): Move drivers/usb/media to drivers/media/video

Because of historic reasons, there are two separate directories with
V4L stuff. Most drivers are located at driver/media/video. However, some
code for USB Webcams were inserted under drivers/usb/media.

This makes difficult for module authors to know were things should be.
Also, makes Kconfig menu confusing for normal users.

This patch moves all V4L content under drivers/usb/media to
drivers/media/video, and fixes Kconfig/Makefile entries.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

5 files changed, 2714 insertions, 0 deletions

diff --git a/drivers/media/video/zc0301/Makefile b/drivers/media/video/zc0301/Makefile
new file mode 100644
index 00000000000..d749199d8f0
--- /dev/null
+++ b/drivers/media/video/zc0301/Makefile
@@ -0,0 +1,3 @@
+zc0301-objs     := zc0301_core.o zc0301_pas202bcb.o
+
+obj-$(CONFIG_USB_ZC0301)        += zc0301.o
diff --git a/drivers/media/video/zc0301/zc0301.h b/drivers/media/video/zc0301/zc0301.h
new file mode 100644
index 00000000000..8e0655140e6
--- /dev/null
+++ b/drivers/media/video/zc0301/zc0301.h
@@ -0,0 +1,192 @@
+/***************************************************************************
+ * V4L2 driver for ZC0301 Image Processor and Control Chip                 *
+ *                                                                         *
+ * Copyright (C) 2006 by Luca Risolia <luca.risolia@studio.unibo.it>       *
+ *                                                                         *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.               *
+ ***************************************************************************/
+
+#ifndef _ZC0301_H_
+#define _ZC0301_H_
+
+#include <linux/version.h>
+#include <linux/usb.h>
+#include <linux/videodev2.h>
+#include <media/v4l2-common.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/time.h>
+#include <linux/wait.h>
+#include <linux/types.h>
+#include <linux/param.h>
+#include <linux/mutex.h>
+#include <linux/rwsem.h>
+#include <linux/stddef.h>
+#include <linux/string.h>
+
+#include "zc0301_sensor.h"
+
+/*****************************************************************************/
+
+#define ZC0301_DEBUG
+#define ZC0301_DEBUG_LEVEL         2
+#define ZC0301_MAX_DEVICES         64
+#define ZC0301_FORCE_MUNMAP        0
+#define ZC0301_MAX_FRAMES          32
+#define ZC0301_COMPRESSION_QUALITY 0
+#define ZC0301_URBS                2
+#define ZC0301_ISO_PACKETS         7
+#define ZC0301_ALTERNATE_SETTING   7
+#define ZC0301_URB_TIMEOUT         msecs_to_jiffies(2 * ZC0301_ISO_PACKETS)
+#define ZC0301_CTRL_TIMEOUT        100
+#define ZC0301_FRAME_TIMEOUT       2
+
+/*****************************************************************************/
+
+ZC0301_ID_TABLE
+ZC0301_SENSOR_TABLE
+
+enum zc0301_frame_state {
+	F_UNUSED,
+	F_QUEUED,
+	F_GRABBING,
+	F_DONE,
+	F_ERROR,
+};
+
+struct zc0301_frame_t {
+	void* bufmem;
+	struct v4l2_buffer buf;
+	enum zc0301_frame_state state;
+	struct list_head frame;
+	unsigned long vma_use_count;
+};
+
+enum zc0301_dev_state {
+	DEV_INITIALIZED = 0x01,
+	DEV_DISCONNECTED = 0x02,
+	DEV_MISCONFIGURED = 0x04,
+};
+
+enum zc0301_io_method {
+	IO_NONE,
+	IO_READ,
+	IO_MMAP,
+};
+
+enum zc0301_stream_state {
+	STREAM_OFF,
+	STREAM_INTERRUPT,
+	STREAM_ON,
+};
+
+struct zc0301_module_param {
+	u8 force_munmap;
+	u16 frame_timeout;
+};
+
+static DECLARE_RWSEM(zc0301_disconnect);
+
+struct zc0301_device {
+	struct video_device* v4ldev;
+
+	struct zc0301_sensor sensor;
+
+	struct usb_device* usbdev;
+	struct urb* urb[ZC0301_URBS];
+	void* transfer_buffer[ZC0301_URBS];
+	u8* control_buffer;
+
+	struct zc0301_frame_t *frame_current, frame[ZC0301_MAX_FRAMES];
+	struct list_head inqueue, outqueue;
+	u32 frame_count, nbuffers, nreadbuffers;
+
+	enum zc0301_io_method io;
+	enum zc0301_stream_state stream;
+
+	struct v4l2_jpegcompression compression;
+
+	struct zc0301_module_param module_param;
+
+	enum zc0301_dev_state state;
+	u8 users;
+
+	struct mutex dev_mutex, fileop_mutex;
+	spinlock_t queue_lock;
+	wait_queue_head_t open, wait_frame, wait_stream;
+};
+
+/*****************************************************************************/
+
+struct zc0301_device*
+zc0301_match_id(struct zc0301_device* cam, const struct usb_device_id *id)
+{
+	return usb_match_id(usb_ifnum_to_if(cam->usbdev, 0), id) ? cam : NULL;
+}
+
+void
+zc0301_attach_sensor(struct zc0301_device* cam, struct zc0301_sensor* sensor)
+{
+	memcpy(&cam->sensor, sensor, sizeof(struct zc0301_sensor));
+}
+
+/*****************************************************************************/
+
+#undef DBG
+#undef KDBG
+#ifdef ZC0301_DEBUG
+#	define DBG(level, fmt, args...)                                       \
+do {                                                                          \
+	if (debug >= (level)) {                                               \
+		if ((level) == 1)                                             \
+			dev_err(&cam->usbdev->dev, fmt "\n", ## args);        \
+		else if ((level) == 2)                                        \
+			dev_info(&cam->usbdev->dev, fmt "\n", ## args);       \
+		else if ((level) >= 3)                                        \
+			dev_info(&cam->usbdev->dev, "[%s:%d] " fmt "\n",      \
+			         __FUNCTION__, __LINE__ , ## args);           \
+	}                                                                     \
+} while (0)
+#	define KDBG(level, fmt, args...)                                      \
+do {                                                                          \
+	if (debug >= (level)) {                                               \
+		if ((level) == 1 || (level) == 2)                             \
+			pr_info("zc0301: " fmt "\n", ## args);                \
+		else if ((level) == 3)                                        \
+			pr_debug("zc0301: [%s:%d] " fmt "\n", __FUNCTION__,   \
+			         __LINE__ , ## args);                         \
+	}                                                                     \
+} while (0)
+#	define V4LDBG(level, name, cmd)                                       \
+do {                                                                          \
+	if (debug >= (level))                                                 \
+		v4l_print_ioctl(name, cmd);                                   \
+} while (0)
+#else
+#	define DBG(level, fmt, args...) do {;} while(0)
+#	define KDBG(level, fmt, args...) do {;} while(0)
+#	define V4LDBG(level, name, cmd) do {;} while(0)
+#endif
+
+#undef PDBG
+#define PDBG(fmt, args...)                                                    \
+dev_info(&cam->usbdev->dev, "[%s:%d] " fmt "\n",                              \
+         __FUNCTION__, __LINE__ , ## args)
+
+#undef PDBGG
+#define PDBGG(fmt, args...) do {;} while(0) /* placeholder */
+
+#endif /* _ZC0301_H_ */
diff --git a/drivers/media/video/zc0301/zc0301_core.c b/drivers/media/video/zc0301/zc0301_core.c
new file mode 100644
index 00000000000..4036c6268bf
--- /dev/null
+++ b/drivers/media/video/zc0301/zc0301_core.c
@@ -0,0 +1,2055 @@
+/***************************************************************************
+ * Video4Linux2 driver for ZC0301 Image Processor and Control Chip         *
+ *                                                                         *
+ * Copyright (C) 2006 by Luca Risolia <luca.risolia@studio.unibo.it>       *
+ *                                                                         *
+ * Informations about the chip internals needed to enable the I2C protocol *
+ * have been taken from the documentation of the ZC030x Video4Linux1       *
+ * driver written by Andrew Birkett <andy@nobugs.org>                      *
+ *                                                                         *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.               *
+ ***************************************************************************/
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/param.h>
+#include <linux/moduleparam.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/delay.h>
+#include <linux/compiler.h>
+#include <linux/ioctl.h>
+#include <linux/poll.h>
+#include <linux/stat.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <linux/page-flags.h>
+#include <linux/byteorder/generic.h>
+#include <asm/page.h>
+#include <asm/uaccess.h>
+
+#include "zc0301.h"
+
+/*****************************************************************************/
+
+#define ZC0301_MODULE_NAME    "V4L2 driver for ZC0301 "                       \
+                              "Image Processor and Control Chip"
+#define ZC0301_MODULE_AUTHOR  "(C) 2006 Luca Risolia"
+#define ZC0301_AUTHOR_EMAIL   "<luca.risolia@studio.unibo.it>"
+#define ZC0301_MODULE_LICENSE "GPL"
+#define ZC0301_MODULE_VERSION "1:1.03"
+#define ZC0301_MODULE_VERSION_CODE  KERNEL_VERSION(1, 0, 3)
+
+/*****************************************************************************/
+
+MODULE_DEVICE_TABLE(usb, zc0301_id_table);
+
+MODULE_AUTHOR(ZC0301_MODULE_AUTHOR " " ZC0301_AUTHOR_EMAIL);
+MODULE_DESCRIPTION(ZC0301_MODULE_NAME);
+MODULE_VERSION(ZC0301_MODULE_VERSION);
+MODULE_LICENSE(ZC0301_MODULE_LICENSE);
+
+static short video_nr[] = {[0 ... ZC0301_MAX_DEVICES-1] = -1};
+module_param_array(video_nr, short, NULL, 0444);
+MODULE_PARM_DESC(video_nr,
+                 "\n<-1|n[,...]> Specify V4L2 minor mode number."
+                 "\n -1 = use next available (default)"
+                 "\n  n = use minor number n (integer >= 0)"
+                 "\nYou can specify up to "
+                 __MODULE_STRING(ZC0301_MAX_DEVICES) " cameras this way."
+                 "\nFor example:"
+                 "\nvideo_nr=-1,2,-1 would assign minor number 2 to"
+                 "\nthe second registered camera and use auto for the first"
+                 "\none and for every other camera."
+                 "\n");
+
+static short force_munmap[] = {[0 ... ZC0301_MAX_DEVICES-1] =
+                               ZC0301_FORCE_MUNMAP};
+module_param_array(force_munmap, bool, NULL, 0444);
+MODULE_PARM_DESC(force_munmap,
+                 "\n<0|1[,...]> Force the application to unmap previously"
+                 "\nmapped buffer memory before calling any VIDIOC_S_CROP or"
+                 "\nVIDIOC_S_FMT ioctl's. Not all the applications support"
+                 "\nthis feature. This parameter is specific for each"
+                 "\ndetected camera."
+                 "\n 0 = do not force memory unmapping"
+                 "\n 1 = force memory unmapping (save memory)"
+                 "\nDefault value is "__MODULE_STRING(SN9C102_FORCE_MUNMAP)"."
+                 "\n");
+
+static unsigned int frame_timeout[] = {[0 ... ZC0301_MAX_DEVICES-1] =
+                                       ZC0301_FRAME_TIMEOUT};
+module_param_array(frame_timeout, uint, NULL, 0644);
+MODULE_PARM_DESC(frame_timeout,
+                 "\n<n[,...]> Timeout for a video frame in seconds."
+                 "\nThis parameter is specific for each detected camera."
+                 "\nDefault value is "__MODULE_STRING(ZC0301_FRAME_TIMEOUT)"."
+                 "\n");
+
+#ifdef ZC0301_DEBUG
+static unsigned short debug = ZC0301_DEBUG_LEVEL;
+module_param(debug, ushort, 0644);
+MODULE_PARM_DESC(debug,
+                 "\n<n> Debugging information level, from 0 to 3:"
+                 "\n0 = none (use carefully)"
+                 "\n1 = critical errors"
+                 "\n2 = significant informations"
+                 "\n3 = more verbose messages"
+                 "\nLevel 3 is useful for testing only, when only "
+                 "one device is used."
+                 "\nDefault value is "__MODULE_STRING(ZC0301_DEBUG_LEVEL)"."
+                 "\n");
+#endif
+
+/*****************************************************************************/
+
+static u32
+zc0301_request_buffers(struct zc0301_device* cam, u32 count,
+                       enum zc0301_io_method io)
+{
+	struct v4l2_pix_format* p = &(cam->sensor.pix_format);
+	struct v4l2_rect* r = &(cam->sensor.cropcap.bounds);
+	const size_t imagesize = cam->module_param.force_munmap ||
+	                         io == IO_READ ?
+	                         (p->width * p->height * p->priv) / 8 :
+	                         (r->width * r->height * p->priv) / 8;
+	void* buff = NULL;
+	u32 i;
+
+	if (count > ZC0301_MAX_FRAMES)
+		count = ZC0301_MAX_FRAMES;
+
+	cam->nbuffers = count;
+	while (cam->nbuffers > 0) {
+		if ((buff = vmalloc_32(cam->nbuffers * PAGE_ALIGN(imagesize))))
+			break;
+		cam->nbuffers--;
+	}
+
+	for (i = 0; i < cam->nbuffers; i++) {
+		cam->frame[i].bufmem = buff + i*PAGE_ALIGN(imagesize);
+		cam->frame[i].buf.index = i;
+		cam->frame[i].buf.m.offset = i*PAGE_ALIGN(imagesize);
+		cam->frame[i].buf.length = imagesize;
+		cam->frame[i].buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+		cam->frame[i].buf.sequence = 0;
+		cam->frame[i].buf.field = V4L2_FIELD_NONE;
+		cam->frame[i].buf.memory = V4L2_MEMORY_MMAP;
+		cam->frame[i].buf.flags = 0;
+	}
+
+	return cam->nbuffers;
+}
+
+
+static void zc0301_release_buffers(struct zc0301_device* cam)
+{
+	if (cam->nbuffers) {
+		vfree(cam->frame[0].bufmem);
+		cam->nbuffers = 0;
+	}
+	cam->frame_current = NULL;
+}
+
+
+static void zc0301_empty_framequeues(struct zc0301_device* cam)
+{
+	u32 i;
+
+	INIT_LIST_HEAD(&cam->inqueue);
+	INIT_LIST_HEAD(&cam->outqueue);
+
+	for (i = 0; i < ZC0301_MAX_FRAMES; i++) {
+		cam->frame[i].state = F_UNUSED;
+		cam->frame[i].buf.bytesused = 0;
+	}
+}
+
+
+static void zc0301_requeue_outqueue(struct zc0301_device* cam)
+{
+	struct zc0301_frame_t *i;
+
+	list_for_each_entry(i, &cam->outqueue, frame) {
+		i->state = F_QUEUED;
+		list_add(&i->frame, &cam->inqueue);
+	}
+
+	INIT_LIST_HEAD(&cam->outqueue);
+}
+
+
+static void zc0301_queue_unusedframes(struct zc0301_device* cam)
+{
+	unsigned long lock_flags;
+	u32 i;
+
+	for (i = 0; i < cam->nbuffers; i++)
+		if (cam->frame[i].state == F_UNUSED) {
+			cam->frame[i].state = F_QUEUED;
+			spin_lock_irqsave(&cam->queue_lock, lock_flags);
+			list_add_tail(&cam->frame[i].frame, &cam->inqueue);
+			spin_unlock_irqrestore(&cam->queue_lock, lock_flags);
+		}
+}
+
+/*****************************************************************************/
+
+int zc0301_write_reg(struct zc0301_device* cam, u16 index, u16 value)
+{
+	struct usb_device* udev = cam->usbdev;
+	int res;
+
+	res = usb_control_msg(udev, usb_sndctrlpipe(udev, 0), 0xa0, 0x40,
+	                      value, index, NULL, 0, ZC0301_CTRL_TIMEOUT);
+	if (res < 0) {
+		DBG(3, "Failed to write a register (index 0x%04X, "
+		       "value 0x%02X, error %d)",index, value, res);
+		return -1;
+	}
+
+	return 0;
+}
+
+
+int zc0301_read_reg(struct zc0301_device* cam, u16 index)
+{
+	struct usb_device* udev = cam->usbdev;
+	u8* buff = cam->control_buffer;
+	int res;
+
+	res = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), 0xa1, 0xc0,
+	                      0x0001, index, buff, 1, ZC0301_CTRL_TIMEOUT);
+	if (res < 0)
+		DBG(3, "Failed to read a register (index 0x%04X, error %d)",
+		    index, res);
+
+	PDBGG("Read: index 0x%04X, value: 0x%04X", index, (int)(*buff));
+
+	return (res >= 0) ? (int)(*buff) : -1;
+}
+
+
+int zc0301_i2c_read(struct zc0301_device* cam, u16 address, u8 length)
+{
+	int err = 0, res, r0, r1;
+
+	err += zc0301_write_reg(cam, 0x0092, address);
+	err += zc0301_write_reg(cam, 0x0090, 0x02);
+
+	msleep(1);
+
+	res = zc0301_read_reg(cam, 0x0091);
+	if (res < 0)
+		err += res;
+	r0 = zc0301_read_reg(cam, 0x0095);
+	if (r0 < 0)
+		err += r0;
+	r1 = zc0301_read_reg(cam, 0x0096);
+	if (r1 < 0)
+		err += r1;
+
+	res = (length <= 1) ? r0 : r0 | (r1 << 8);
+
+	if (err)
+		DBG(3, "I2C read failed at address 0x%04X, value: 0x%04X",
+		    address, res);
+
+
+	PDBGG("I2C read: address 0x%04X, value: 0x%04X", address, res);
+
+	return err ? -1 : res;
+}
+
+
+int zc0301_i2c_write(struct zc0301_device* cam, u16 address, u16 value)
+{
+	int err = 0, res;
+
+	err += zc0301_write_reg(cam, 0x0092, address);
+	err += zc0301_write_reg(cam, 0x0093, value & 0xff);
+	err += zc0301_write_reg(cam, 0x0094, value >> 8);
+	err += zc0301_write_reg(cam, 0x0090, 0x01);
+
+	msleep(1);
+
+	res = zc0301_read_reg(cam, 0x0091);
+	if (res < 0)
+		err += res;
+
+	if (err)
+		DBG(3, "I2C write failed at address 0x%04X, value: 0x%04X",
+		    address, value);
+
+	PDBGG("I2C write: address 0x%04X, value: 0x%04X", address, value);
+
+	return err ? -1 : 0;
+}
+
+/*****************************************************************************/
+
+static void zc0301_urb_complete(struct urb *urb, struct pt_regs* regs)
+{
+	struct zc0301_device* cam = urb->context;
+	struct zc0301_frame_t** f;
+	size_t imagesize;
+	u8 i;
+	int err = 0;
+
+	if (urb->status == -ENOENT)
+		return;
+
+	f = &cam->frame_current;
+
+	if (cam->stream == STREAM_INTERRUPT) {
+		cam->stream = STREAM_OFF;
+		if ((*f))
+			(*f)->state = F_QUEUED;
+		DBG(3, "Stream interrupted");
+		wake_up(&cam->wait_stream);
+	}
+
+	if (cam->state & DEV_DISCONNECTED)
+		return;
+
+	if (cam->state & DEV_MISCONFIGURED) {
+		wake_up_interruptible(&cam->wait_frame);
+		return;
+	}
+
+	if (cam->stream == STREAM_OFF || list_empty(&cam->inqueue))
+		goto resubmit_urb;
+
+	if (!(*f))
+		(*f) = list_entry(cam->inqueue.next, struct zc0301_frame_t,
+		                  frame);
+
+	imagesize = (cam->sensor.pix_format.width *
+	             cam->sensor.pix_format.height *
+	             cam->sensor.pix_format.priv) / 8;
+
+	for (i = 0; i < urb->number_of_packets; i++) {
+		unsigned int len, status;
+		void *pos;
+		u16* soi;
+		u8 sof;
+
+		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;
+		}
+
+		sof = (*(soi = pos) == 0xd8ff);
+
+		PDBGG("Isochrnous frame: length %u, #%u i,", len, i);
+
+		if ((*f)->state == F_QUEUED || (*f)->state == F_ERROR)
+start_of_frame:
+			if (sof) {
+				(*f)->state = F_GRABBING;
+				(*f)->buf.bytesused = 0;
+				do_gettimeofday(&(*f)->buf.timestamp);
+				DBG(3, "SOF detected: new video frame");
+			}
+
+		if ((*f)->state == F_GRABBING) {
+			if (sof && (*f)->buf.bytesused)
+					goto end_of_frame;
+
+			if ((*f)->buf.bytesused + len > imagesize) {
+				DBG(3, "Video frame size exceeded");
+				(*f)->state = F_ERROR;
+				continue;
+			}
+
+			memcpy((*f)->bufmem+(*f)->buf.bytesused, pos, len);
+			(*f)->buf.bytesused += len;
+
+			if ((*f)->buf.bytesused == imagesize) {
+				u32 b;
+end_of_frame:
+				b = (*f)->buf.bytesused;
+				(*f)->state = F_DONE;
+				(*f)->buf.sequence= ++cam->frame_count;
+				spin_lock(&cam->queue_lock);
+				list_move_tail(&(*f)->frame, &cam->outqueue);
+				if (!list_empty(&cam->inqueue))
+					(*f) = list_entry(cam->inqueue.next,
+					               struct zc0301_frame_t,
+					                  frame);
+				else
+					(*f) = NULL;
+				spin_unlock(&cam->queue_lock);
+				DBG(3, "Video frame captured: : %lu bytes",
+				       (unsigned long)(b));
+
+				if (!(*f))
+					goto resubmit_urb;
+
+				if (sof)
+					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 zc0301_start_transfer(struct zc0301_device* cam)
+{
+	struct usb_device *udev = cam->usbdev;
+	struct urb* urb;
+	const unsigned int wMaxPacketSize[] = {0, 128, 192, 256, 384,
+	                                       512, 768, 1023};
+	const unsigned int psz = wMaxPacketSize[ZC0301_ALTERNATE_SETTING];
+	s8 i, j;
+	int err = 0;
+
+	for (i = 0; i < ZC0301_URBS; i++) {
+		cam->transfer_buffer[i] = kzalloc(ZC0301_ISO_PACKETS * psz,
+		                                  GFP_KERNEL);
+		if (!cam->transfer_buffer[i]) {
+			err = -ENOMEM;
+			DBG(1, "Not enough memory");
+			goto free_buffers;
+		}
+	}
+
+	for (i = 0; i < ZC0301_URBS; i++) {
+		urb = usb_alloc_urb(ZC0301_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 = ZC0301_ISO_PACKETS;
+		urb->complete = zc0301_urb_complete;
+		urb->transfer_buffer = cam->transfer_buffer[i];
+		urb->transfer_buffer_length = psz * ZC0301_ISO_PACKETS;
+		urb->interval = 1;
+		for (j = 0; j < ZC0301_ISO_PACKETS; j++) {
+			urb->iso_frame_desc[j].offset = psz * j;
+			urb->iso_frame_desc[j].length = psz;
+		}
+	}
+
+	err = usb_set_interface(udev, 0, ZC0301_ALTERNATE_SETTING);
+	if (err) {
+		DBG(1, "usb_set_interface() failed");
+		goto free_urbs;
+	}
+
+	cam->frame_current = NULL;
+
+	for (i = 0; i < ZC0301_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 < ZC0301_URBS) &&  cam->urb[i]; i++)
+		usb_free_urb(cam->urb[i]);
+
+free_buffers:
+	for (i = 0; (i < ZC0301_URBS) && cam->transfer_buffer[i]; i++)
+		kfree(cam->transfer_buffer[i]);
+
+	return err;
+}
+
+
+static int zc0301_stop_transfer(struct zc0301_device* cam)
+{
+	struct usb_device *udev = cam->usbdev;
+	s8 i;
+	int err = 0;
+
+	if (cam->state & DEV_DISCONNECTED)
+		return 0;
+
+	for (i = ZC0301_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;
+}
+
+
+static int zc0301_stream_interrupt(struct zc0301_device* cam)
+{
+	long timeout;
+
+	cam->stream = STREAM_INTERRUPT;
+	timeout = wait_event_timeout(cam->wait_stream,
+	                             (cam->stream == STREAM_OFF) ||
+	                             (cam->state & DEV_DISCONNECTED),
+	                             ZC0301_URB_TIMEOUT);
+	if (cam->state & DEV_DISCONNECTED)
+		return -ENODEV;
+	else if (cam->stream != STREAM_OFF) {
+		cam->state |= DEV_MISCONFIGURED;
+		DBG(1, "URB timeout reached. The camera is misconfigured. To "
+		       "use it, close and open /dev/video%d again.",
+		    cam->v4ldev->minor);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+/*****************************************************************************/
+
+static int
+zc0301_set_compression(struct zc0301_device* cam,
+                       struct v4l2_jpegcompression* compression)
+{
+	int r, err = 0;
+
+	if ((r = zc0301_read_reg(cam, 0x0008)) < 0)
+		err += r;
+	err += zc0301_write_reg(cam, 0x0008, r | 0x11 | compression->quality);
+
+	return err ? -EIO : 0;
+}
+
+
+static int zc0301_init(struct zc0301_device* cam)
+{
+	struct zc0301_sensor* s = &cam->sensor;
+	struct v4l2_control ctrl;
+	struct v4l2_queryctrl *qctrl;
+	struct v4l2_rect* rect;
+	u8 i = 0;
+	int err = 0;
+
+	if (!(cam->state & DEV_INITIALIZED)) {
+		init_waitqueue_head(&cam->open);
+		qctrl = s->qctrl;
+		rect = &(s->cropcap.defrect);
+		cam->compression.quality = ZC0301_COMPRESSION_QUALITY;
+	} else { /* use current values */
+		qctrl = s->_qctrl;
+		rect = &(s->_rect);
+	}
+
+	if (s->init) {
+		err = s->init(cam);
+		if (err) {
+			DBG(3, "Sensor initialization failed");
+			return err;
+		}
+	}
+
+	if ((err = zc0301_set_compression(cam, &cam->compression))) {
+		DBG(3, "set_compression() failed");
+		return err;
+	}
+
+	if (s->set_crop)
+		if ((err = s->set_crop(cam, rect))) {
+			DBG(3, "set_crop() failed");
+			return err;
+		}
+
+	if (s->set_ctrl) {
+		for (i = 0; i < ARRAY_SIZE(s->qctrl); i++)
+			if (s->qctrl[i].id != 0 &&
+			    !(s->qctrl[i].flags & V4L2_CTRL_FLAG_DISABLED)) {
+				ctrl.id = s->qctrl[i].id;
+				ctrl.value = qctrl[i].default_value;
+				err = s->set_ctrl(cam, &ctrl);
+				if (err) {
+					DBG(3, "Set %s control failed",
+					    s->qctrl[i].name);
+					return err;
+				}
+				DBG(3, "Image sensor supports '%s' control",
+				    s->qctrl[i].name);
+			}
+	}
+
+	if (!(cam->state & DEV_INITIALIZED)) {
+		mutex_init(&cam->fileop_mutex);
+		spin_lock_init(&cam->queue_lock);
+		init_waitqueue_head(&cam->wait_frame);
+		init_waitqueue_head(&cam->wait_stream);
+		cam->nreadbuffers = 2;
+		memcpy(s->_qctrl, s->qctrl, sizeof(s->qctrl));
+		memcpy(&(s->_rect), &(s->cropcap.defrect),
+		       sizeof(struct v4l2_rect));
+		cam->state |= DEV_INITIALIZED;
+	}
+
+	DBG(2, "Initialization succeeded");
+	return 0;
+}
+
+
+static void zc0301_release_resources(struct zc0301_device* cam)
+{
+	DBG(2, "V4L2 device /dev/video%d deregistered", cam->v4ldev->minor);
+	video_set_drvdata(cam->v4ldev, NULL);
+	video_unregister_device(cam->v4ldev);
+	kfree(cam->control_buffer);
+}
+
+/*****************************************************************************/
+
+static int zc0301_open(struct inode* inode, struct file* filp)
+{
+	struct zc0301_device* cam;
+	int err = 0;
+
+	/*
+	   This is the only safe way to prevent race conditions with
+	   disconnect
+	*/
+	if (!down_read_trylock(&zc0301_disconnect))
+		return -ERESTARTSYS;
+
+	cam = video_get_drvdata(video_devdata(filp));
+
+	if (mutex_lock_interruptible(&cam->dev_mutex)) {
+		up_read(&zc0301_disconnect);
+		return -ERESTARTSYS;
+	}
+
+	if (cam->users) {
+		DBG(2, "Device /dev/video%d is busy...", cam->v4ldev->minor);
+		if ((filp->f_flags & O_NONBLOCK) ||
+		    (filp->f_flags & O_NDELAY)) {
+			err = -EWOULDBLOCK;
+			goto out;
+		}
+		mutex_unlock(&cam->dev_mutex);
+		err = wait_event_interruptible_exclusive(cam->open,
+		                                  cam->state & DEV_DISCONNECTED
+		                                         || !cam->users);
+		if (err) {
+			up_read(&zc0301_disconnect);
+			return err;
+		}
+		if (cam->state & DEV_DISCONNECTED) {
+			up_read(&zc0301_disconnect);
+			return -ENODEV;
+		}
+		mutex_lock(&cam->dev_mutex);
+	}
+
+
+	if (cam->state & DEV_MISCONFIGURED) {
+		err = zc0301_init(cam);
+		if (err) {
+			DBG(1, "Initialization failed again. "
+			       "I will retry on next open().");
+			goto out;
+		}
+		cam->state &= ~DEV_MISCONFIGURED;
+	}
+
+	if ((err = zc0301_start_transfer(cam)))
+		goto out;
+
+	filp->private_data = cam;
+	cam->users++;
+	cam->io = IO_NONE;
+	cam->stream = STREAM_OFF;
+	cam->nbuffers = 0;
+	cam->frame_count = 0;
+	zc0301_empty_framequeues(cam);
+
+	DBG(3, "Video device /dev/video%d is open", cam->v4ldev->minor);
+
+out:
+	mutex_unlock(&cam->dev_mutex);
+	up_read(&zc0301_disconnect);
+	return err;
+}
+
+
+static int zc0301_release(struct inode* inode, struct file* filp)
+{
+	struct zc0301_device* cam = video_get_drvdata(video_devdata(filp));
+
+	mutex_lock(&cam->dev_mutex); /* prevent disconnect() to be called */
+
+	zc0301_stop_transfer(cam);
+
+	zc0301_release_buffers(cam);
+
+	if (cam->state & DEV_DISCONNECTED) {
+		zc0301_release_resources(cam);
+		usb_put_dev(cam->usbdev);
+		mutex_unlock(&cam->dev_mutex);
+		kfree(cam);
+		return 0;
+	}
+
+	cam->users--;
+	wake_up_interruptible_nr(&cam->open, 1);
+
+	DBG(3, "Video device /dev/video%d closed", cam->v4ldev->minor);
+
+	mutex_unlock(&cam->dev_mutex);
+
+	return 0;
+}
+
+
+static ssize_t
+zc0301_read(struct file* filp, char __user * buf, size_t count, loff_t* f_pos)
+{
+	struct zc0301_device* cam = video_get_drvdata(video_devdata(filp));
+	struct zc0301_frame_t* f, * i;
+	unsigned long lock_flags;
+	long timeout;
+	int err = 0;
+
+	if (mutex_lock_interruptible(&cam->fileop_mutex))
+		return -ERESTARTSYS;
+
+	if (cam->state & DEV_DISCONNECTED) {
+		DBG(1, "Device not present");
+		mutex_unlock(&cam->fileop_mutex);
+		return -ENODEV;
+	}
+
+	if (cam->state & DEV_MISCONFIGURED) {
+		DBG(1, "The camera is misconfigured. Close and open it "
+		       "again.");
+		mutex_unlock(&cam->fileop_mutex);
+		return -EIO;
+	}
+
+	if (cam->io == IO_MMAP) {
+		DBG(3, "Close and open the device again to choose the read "
+		       "method");
+		mutex_unlock(&cam->fileop_mutex);
+		return -EINVAL;
+	}
+
+	if (cam->io == IO_NONE) {
+		if (!zc0301_request_buffers(cam, cam->nreadbuffers, IO_READ)) {
+			DBG(1, "read() failed, not enough memory");
+			mutex_unlock(&cam->fileop_mutex);
+			return -ENOMEM;
+		}
+		cam->io = IO_READ;
+		cam->stream = STREAM_ON;
+	}
+
+	if (list_empty(&cam->inqueue)) {
+		if (!list_empty(&cam->outqueue))
+			zc0301_empty_framequeues(cam);
+		zc0301_queue_unusedframes(cam);
+	}
+
+	if (!count) {
+		mutex_unlock(&cam->fileop_mutex);
+		return 0;
+	}
+
+	if (list_empty(&cam->outqueue)) {
+		if (filp->f_flags & O_NONBLOCK) {
+			mutex_unlock(&cam->fileop_mutex);
+			return -EAGAIN;
+		}
+		timeout = wait_event_interruptible_timeout
+		          ( cam->wait_frame,
+		            (!list_empty(&cam->outqueue)) ||
+		            (cam->state & DEV_DISCONNECTED) ||
+		            (cam->state & DEV_MISCONFIGURED),
+		            cam->module_param.frame_timeout *
+		            1000 * msecs_to_jiffies(1) );
+		if (timeout < 0) {
+			mutex_unlock(&cam->fileop_mutex);
+			return timeout;
+		}
+		if (cam->state & DEV_DISCONNECTED) {
+			mutex_unlock(&cam->fileop_mutex);
+			return -ENODEV;
+		}
+		if (!timeout || (cam->state & DEV_MISCONFIGURED)) {
+			mutex_unlock(&cam->fileop_mutex);
+			return -EIO;
+		}
+	}
+
+	f = list_entry(cam->outqueue.prev, struct zc0301_frame_t, frame);
+
+	if (count > f->buf.bytesused)
+		count = f->buf.bytesused;
+
+	if (copy_to_user(buf, f->bufmem, count)) {
+		err = -EFAULT;
+		goto exit;
+	}
+	*f_pos += count;
+
+exit:
+	spin_lock_irqsave(&cam->queue_lock, lock_flags);
+	list_for_each_entry(i, &cam->outqueue, frame)
+		i->state = F_UNUSED;
+	INIT_LIST_HEAD(&cam->outqueue);
+	spin_unlock_irqrestore(&cam->queue_lock, lock_flags);
+
+	zc0301_queue_unusedframes(cam);
+
+	PDBGG("