/*
   * cpia_usb CPiA USB driver
   *
   * Supports CPiA based parallel port Video Camera's.
   *
   * Copyright (C) 1999        Jochen Scharrlach <Jochen.Scharrlach@schwaben.de>
   * Copyright (C) 1999, 2000  Johannes Erdfelt <johannes@erdfelt.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., 675 Mass Ave, Cambridge, MA 02139, USA.
   */
  
  /* define _CPIA_DEBUG_ for verbose debug output (see cpia.h) */

  /* #define _CPIA_DEBUG_  1 */

  
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/init.h>
  #include <linux/wait.h>
  #include <linux/list.h>
  #include <linux/slab.h>
  #include <linux/vmalloc.h>
  #include <linux/usb.h>
  
  #include "cpia.h"
  
  #define USB_REQ_CPIA_GRAB_FRAME			0xC1
  #define USB_REQ_CPIA_UPLOAD_FRAME		0xC2
  #define  WAIT_FOR_NEXT_FRAME			0
  #define  FORCE_FRAME_UPLOAD			1
  
  #define FRAMES_PER_DESC		10
  #define FRAME_SIZE_PER_DESC	960	/* Shouldn't be hardcoded */
  #define CPIA_NUMSBUF		2
  #define STREAM_BUF_SIZE		(PAGE_SIZE * 4)
  #define SCRATCH_BUF_SIZE	(STREAM_BUF_SIZE * 2)
  
  struct cpia_sbuf {
  	char *data;
  	struct urb *urb;
  };
  
  #define FRAMEBUF_LEN (CPIA_MAX_FRAME_SIZE+100)
  enum framebuf_status {
  	FRAME_EMPTY,
  	FRAME_READING,
  	FRAME_READY,
  	FRAME_ERROR,
  };
  
  struct framebuf {
  	int length;
  	enum framebuf_status status;
  	u8 data[FRAMEBUF_LEN];
  	struct framebuf *next;
  };
  
  struct usb_cpia {
  	/* Device structure */
  	struct usb_device *dev;
  
  	unsigned char iface;
  	wait_queue_head_t wq_stream;
  
  	int cursbuf;		/* Current receiving sbuf */
  	struct cpia_sbuf sbuf[CPIA_NUMSBUF];		/* Double buffering */
  
  	int streaming;
  	int open;
  	int present;
  	struct framebuf *buffers[3];
  	struct framebuf *curbuff, *workbuff;
  };
  
  static int cpia_usb_open(void *privdata);
  static int cpia_usb_registerCallback(void *privdata, void (*cb) (void *cbdata),

  				     void *cbdata);

  static int cpia_usb_transferCmd(void *privdata, u8 *command, u8 *data);
  static int cpia_usb_streamStart(void *privdata);
  static int cpia_usb_streamStop(void *privdata);
  static int cpia_usb_streamRead(void *privdata, u8 *frame, int noblock);
  static int cpia_usb_close(void *privdata);
  
  #define ABOUT "USB driver for Vision CPiA based cameras"
  
  static struct cpia_camera_ops cpia_usb_ops = {
  	cpia_usb_open,
  	cpia_usb_registerCallback,
  	cpia_usb_transferCmd,
  	cpia_usb_streamStart,
  	cpia_usb_streamStop,
  	cpia_usb_streamRead,
  	cpia_usb_close,
  	0,
  	THIS_MODULE
  };
  
  static LIST_HEAD(cam_list);
  static spinlock_t cam_list_lock_usb;

  static void cpia_usb_complete(struct urb *urb)

  {
  	int i;
  	char *cdata;
  	struct usb_cpia *ucpia;
  
  	if (!urb || !urb->context)
  		return;
  
  	ucpia = (struct usb_cpia *) urb->context;
  
  	if (!ucpia->dev || !ucpia->streaming || !ucpia->present || !ucpia->open)
  		return;
  
  	if (ucpia->workbuff->status == FRAME_EMPTY) {
  		ucpia->workbuff->status = FRAME_READING;
  		ucpia->workbuff->length = 0;
  	}

  	for (i = 0; i < urb->number_of_packets; i++) {
  		int n = urb->iso_frame_desc[i].actual_length;
  		int st = urb->iso_frame_desc[i].status;
  
  		cdata = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
  
  		if (st)
  			printk(KERN_DEBUG "cpia data error: [%d] len=%d, status=%X
  ", i, n, st);
  
  		if (FRAMEBUF_LEN < ucpia->workbuff->length + n) {
  			printk(KERN_DEBUG "cpia: scratch buf overflow!scr_len: %d, n: %d
  ", ucpia->workbuff->length, n);
  			return;
  		}

  		if (n) {

  			if ((ucpia->workbuff->length > 0) ||

  			    (0x19 == cdata[0] && 0x68 == cdata[1])) {
  				memcpy(ucpia->workbuff->data + ucpia->workbuff->length, cdata, n);
  				ucpia->workbuff->length += n;
  			} else
  				DBG("Ignoring packet!
  ");
  		} else {
  			if (ucpia->workbuff->length > 4 &&
  			    0xff == ucpia->workbuff->data[ucpia->workbuff->length-1] &&
  			    0xff == ucpia->workbuff->data[ucpia->workbuff->length-2] &&
  			    0xff == ucpia->workbuff->data[ucpia->workbuff->length-3] &&
  			    0xff == ucpia->workbuff->data[ucpia->workbuff->length-4]) {
  				ucpia->workbuff->status = FRAME_READY;
  				ucpia->curbuff = ucpia->workbuff;
  				ucpia->workbuff = ucpia->workbuff->next;
  				ucpia->workbuff->status = FRAME_EMPTY;
  				ucpia->workbuff->length = 0;

  				if (waitqueue_active(&ucpia->wq_stream))
  					wake_up_interruptible(&ucpia->wq_stream);
  			}
  		}
  	}
  
  	/* resubmit */
  	urb->dev = ucpia->dev;
  	if ((i = usb_submit_urb(urb, GFP_ATOMIC)) != 0)

  		printk(KERN_ERR "%s: usb_submit_urb ret %d
  ", __func__,  i);

  }
  
  static int cpia_usb_open(void *privdata)
  {
  	struct usb_cpia *ucpia = (struct usb_cpia *) privdata;
  	struct urb *urb;
  	int ret, retval = 0, fx, err;

  	if (!ucpia)
  		return -EINVAL;
  
  	ucpia->sbuf[0].data = kmalloc(FRAMES_PER_DESC * FRAME_SIZE_PER_DESC, GFP_KERNEL);
  	if (!ucpia->sbuf[0].data)
  		return -EINVAL;
  
  	ucpia->sbuf[1].data = kmalloc(FRAMES_PER_DESC * FRAME_SIZE_PER_DESC, GFP_KERNEL);
  	if (!ucpia->sbuf[1].data) {
  		retval = -EINVAL;
  		goto error_0;
  	}

  	ret = usb_set_interface(ucpia->dev, ucpia->iface, 3);
  	if (ret < 0) {
  		printk(KERN_ERR "cpia_usb_open: usb_set_interface error (ret = %d)
  ", ret);
  		retval = -EBUSY;
  		goto error_1;
  	}
  
  	ucpia->buffers[0]->status = FRAME_EMPTY;
  	ucpia->buffers[0]->length = 0;
  	ucpia->buffers[1]->status = FRAME_EMPTY;
  	ucpia->buffers[1]->length = 0;
  	ucpia->buffers[2]->status = FRAME_EMPTY;
  	ucpia->buffers[2]->length = 0;
  	ucpia->curbuff = ucpia->buffers[0];
  	ucpia->workbuff = ucpia->buffers[1];
  
  	/* We double buffer the Iso lists, and also know the polling
  	 * interval is every frame (1 == (1 << (bInterval -1))).
  	 */
  	urb = usb_alloc_urb(FRAMES_PER_DESC, GFP_KERNEL);
  	if (!urb) {
  		printk(KERN_ERR "cpia_init_isoc: usb_alloc_urb 0
  ");
  		retval = -ENOMEM;
  		goto error_1;
  	}
  
  	ucpia->sbuf[0].urb = urb;
  	urb->dev = ucpia->dev;
  	urb->context = ucpia;
  	urb->pipe = usb_rcvisocpipe(ucpia->dev, 1);
  	urb->transfer_flags = URB_ISO_ASAP;
  	urb->transfer_buffer = ucpia->sbuf[0].data;
  	urb->complete = cpia_usb_complete;
  	urb->number_of_packets = FRAMES_PER_DESC;
  	urb->interval = 1;
  	urb->transfer_buffer_length = FRAME_SIZE_PER_DESC * FRAMES_PER_DESC;
  	for (fx = 0; fx < FRAMES_PER_DESC; fx++) {
  		urb->iso_frame_desc[fx].offset = FRAME_SIZE_PER_DESC * fx;
  		urb->iso_frame_desc[fx].length = FRAME_SIZE_PER_DESC;
  	}
  
  	urb = usb_alloc_urb(FRAMES_PER_DESC, GFP_KERNEL);
  	if (!urb) {
  		printk(KERN_ERR "cpia_init_isoc: usb_alloc_urb 1
  ");
  		retval = -ENOMEM;
  		goto error_urb0;
  	}
  
  	ucpia->sbuf[1].urb = urb;
  	urb->dev = ucpia->dev;
  	urb->context = ucpia;
  	urb->pipe = usb_rcvisocpipe(ucpia->dev, 1);
  	urb->transfer_flags = URB_ISO_ASAP;
  	urb->transfer_buffer = ucpia->sbuf[1].data;
  	urb->complete = cpia_usb_complete;
  	urb->number_of_packets = FRAMES_PER_DESC;
  	urb->interval = 1;
  	urb->transfer_buffer_length = FRAME_SIZE_PER_DESC * FRAMES_PER_DESC;
  	for (fx = 0; fx < FRAMES_PER_DESC; fx++) {
  		urb->iso_frame_desc[fx].offset = FRAME_SIZE_PER_DESC * fx;
  		urb->iso_frame_desc[fx].length = FRAME_SIZE_PER_DESC;
  	}
  
  	/* queue the ISO urbs, and resubmit in the completion handler */
  	err = usb_submit_urb(ucpia->sbuf[0].urb, GFP_KERNEL);
  	if (err) {
  		printk(KERN_ERR "cpia_init_isoc: usb_submit_urb 0 ret %d
  ",
  			err);
  		goto error_urb1;
  	}
  	err = usb_submit_urb(ucpia->sbuf[1].urb, GFP_KERNEL);
  	if (err) {
  		printk(KERN_ERR "cpia_init_isoc: usb_submit_urb 1 ret %d
  ",
  			err);
  		goto error_urb1;
  	}
  
  	ucpia->streaming = 1;
  	ucpia->open = 1;
  
  	return 0;
  
  error_urb1:		/* free urb 1 */
  	usb_free_urb(ucpia->sbuf[1].urb);
  	ucpia->sbuf[1].urb = NULL;
  error_urb0:		/* free urb 0 */
  	usb_free_urb(ucpia->sbuf[0].urb);
  	ucpia->sbuf[0].urb = NULL;
  error_1:
  	kfree (ucpia->sbuf[1].data);
  	ucpia->sbuf[1].data = NULL;
  error_0:
  	kfree (ucpia->sbuf[0].data);
  	ucpia->sbuf[0].data = NULL;

  	return retval;
  }
  
  //
  // convenience functions
  //
  
  /****************************************************************************
   *
   *  WritePacket
   *
   ***************************************************************************/
  static int WritePacket(struct usb_device *udev, const u8 *packet, u8 *buf, size_t size)
  {
  	if (!packet)
  		return -EINVAL;
  
  	return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
  			 packet[1] + (packet[0] << 8),
  			 USB_TYPE_VENDOR | USB_RECIP_DEVICE,

  			 packet[2] + (packet[3] << 8),

  			 packet[4] + (packet[5] << 8), buf, size, 1000);
  }
  
  /****************************************************************************
   *
   *  ReadPacket
   *
   ***************************************************************************/
  static int ReadPacket(struct usb_device *udev, u8 *packet, u8 *buf, size_t size)
  {
  	if (!packet || size <= 0)
  		return -EINVAL;
  
  	return usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
  			 packet[1] + (packet[0] << 8),
  			 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,

  			 packet[2] + (packet[3] << 8),

  			 packet[4] + (packet[5] << 8), buf, size, 1000);
  }
  
  static int cpia_usb_transferCmd(void *privdata, u8 *command, u8 *data)
  {
  	int err = 0;
  	int databytes;
  	struct usb_cpia *ucpia = (struct usb_cpia *)privdata;
  	struct usb_device *udev = ucpia->dev;
  
  	if (!udev) {
  		DBG("Internal driver error: udev is NULL
  ");
  		return -EINVAL;
  	}
  
  	if (!command) {
  		DBG("Internal driver error: command is NULL
  ");
  		return -EINVAL;
  	}
  
  	databytes = (((int)command[7])<<8) | command[6];
  
  	if (command[0] == DATA_IN) {
  		u8 buffer[8];
  
  		if (!data) {
  			DBG("Internal driver error: data is NULL
  ");
  			return -EINVAL;
  		}
  
  		err = ReadPacket(udev, command, buffer, 8);
  		if (err < 0)
  			return err;
  
  		memcpy(data, buffer, databytes);
  	} else if(command[0] == DATA_OUT)
  		WritePacket(udev, command, data, databytes);
  	else {
  		DBG("Unexpected first byte of command: %x
  ", command[0]);
  		err = -EINVAL;
  	}
  
  	return 0;
  }
  
  static int cpia_usb_registerCallback(void *privdata, void (*cb) (void *cbdata),
  	void *cbdata)
  {
  	return -ENODEV;
  }
  
  static int cpia_usb_streamStart(void *privdata)
  {
  	return -ENODEV;
  }
  
  static int cpia_usb_streamStop(void *privdata)
  {
  	return -ENODEV;
  }
  
  static int cpia_usb_streamRead(void *privdata, u8 *frame, int noblock)
  {
  	struct usb_cpia *ucpia = (struct usb_cpia *) privdata;
  	struct framebuf *mybuff;
  
  	if (!ucpia || !ucpia->present)
  		return -1;

  	if (ucpia->curbuff->status != FRAME_READY)
  		interruptible_sleep_on(&ucpia->wq_stream);
  	else
  		DBG("Frame already waiting!
  ");
  
  	mybuff = ucpia->curbuff;
  
  	if (!mybuff)
  		return -1;

  	if (mybuff->status != FRAME_READY || mybuff->length < 4) {
  		DBG("Something went wrong!
  ");
  		return -1;
  	}
  
  	memcpy(frame, mybuff->data, mybuff->length);
  	mybuff->status = FRAME_EMPTY;

  /*   DBG("read done, %d bytes, Header: %x/%x, Footer: %x%x%x%x
  ",  */
  /*       mybuff->length, frame[0], frame[1], */
  /*       frame[mybuff->length-4], frame[mybuff->length-3],  */
  /*       frame[mybuff->length-2], frame[mybuff->length-1]); */
  
  	return mybuff->length;
  }
  
  static void cpia_usb_free_resources(struct usb_cpia *ucpia, int try)
  {
  	if (!ucpia->streaming)
  		return;
  
  	ucpia->streaming = 0;
  
  	/* Set packet size to 0 */
  	if (try) {
  		int ret;
  
  		ret = usb_set_interface(ucpia->dev, ucpia->iface, 0);
  		if (ret < 0) {
  			printk(KERN_ERR "usb_set_interface error (ret = %d)
  ", ret);
  			return;
  		}
  	}
  
  	/* Unschedule all of the iso td's */
  	if (ucpia->sbuf[1].urb) {
  		usb_kill_urb(ucpia->sbuf[1].urb);
  		usb_free_urb(ucpia->sbuf[1].urb);
  		ucpia->sbuf[1].urb = NULL;
  	}

  	kfree(ucpia->sbuf[1].data);
  	ucpia->sbuf[1].data = NULL;

  	if (ucpia->sbuf[0].urb) {
  		usb_kill_urb(ucpia->sbuf[0].urb);
  		usb_free_urb(ucpia->sbuf[0].urb);
  		ucpia->sbuf[0].urb = NULL;
  	}

  	kfree(ucpia->sbuf[0].data);
  	ucpia->sbuf[0].data = NULL;

  }
  
  static int cpia_usb_close(void *privdata)
  {
  	struct usb_cpia *ucpia = (struct usb_cpia *) privdata;
  
  	if(!ucpia)
  		return -ENODEV;
  
  	ucpia->open = 0;
  
  	/* ucpia->present = 0 protects against trying to reset the
  	 * alt setting if camera is physically disconnected while open */
  	cpia_usb_free_resources(ucpia, ucpia->present);
  
  	return 0;
  }

  /* Probing and initializing */
  
  static int cpia_probe(struct usb_interface *intf,
  		      const struct usb_device_id *id)
  {
  	struct usb_device *udev = interface_to_usbdev(intf);
  	struct usb_host_interface *interface;
  	struct usb_cpia *ucpia;
  	struct cam_data *cam;
  	int ret;

  	/* A multi-config CPiA camera? */
  	if (udev->descriptor.bNumConfigurations != 1)
  		return -ENODEV;
  
  	interface = intf->cur_altsetting;
  
  	printk(KERN_INFO "USB CPiA camera found
  ");

  	ucpia = kzalloc(sizeof(*ucpia), GFP_KERNEL);

  	if (!ucpia) {
  		printk(KERN_ERR "couldn't kmalloc cpia struct
  ");
  		return -ENOMEM;
  	}

  	ucpia->dev = udev;
  	ucpia->iface = interface->desc.bInterfaceNumber;
  	init_waitqueue_head(&ucpia->wq_stream);
  
  	ucpia->buffers[0] = vmalloc(sizeof(*ucpia->buffers[0]));
  	if (!ucpia->buffers[0]) {
  		printk(KERN_ERR "couldn't vmalloc frame buffer 0
  ");
  		goto fail_alloc_0;
  	}
  
  	ucpia->buffers[1] = vmalloc(sizeof(*ucpia->buffers[1]));
  	if (!ucpia->buffers[1]) {
  		printk(KERN_ERR "couldn't vmalloc frame buffer 1
  ");
  		goto fail_alloc_1;
  	}
  
  	ucpia->buffers[2] = vmalloc(sizeof(*ucpia->buffers[2]));
  	if (!ucpia->buffers[2]) {
  		printk(KERN_ERR "couldn't vmalloc frame buffer 2
  ");
  		goto fail_alloc_2;
  	}
  
  	ucpia->buffers[0]->next = ucpia->buffers[1];
  	ucpia->buffers[1]->next = ucpia->buffers[2];
  	ucpia->buffers[2]->next = ucpia->buffers[0];
  
  	ret = usb_set_interface(udev, ucpia->iface, 0);
  	if (ret < 0) {
  		printk(KERN_ERR "cpia_probe: usb_set_interface error (ret = %d)
  ", ret);
  		/* goto fail_all; */
  	}
  
  	/* Before register_camera, important */
  	ucpia->present = 1;

  	cam = cpia_register_camera(&cpia_usb_ops, ucpia);
  	if (!cam) {
  		LOG("failed to cpia_register_camera
  ");
  		goto fail_all;
  	}
  
  	spin_lock( &cam_list_lock_usb );
  	list_add( &cam->cam_data_list, &cam_list );
  	spin_unlock( &cam_list_lock_usb );
  
  	usb_set_intfdata(intf, cam);
  	return 0;
  
  fail_all:
  	vfree(ucpia->buffers[2]);
  	ucpia->buffers[2] = NULL;
  fail_alloc_2:
  	vfree(ucpia->buffers[1]);
  	ucpia->buffers[1] = NULL;
  fail_alloc_1:
  	vfree(ucpia->buffers[0]);
  	ucpia->buffers[0] = NULL;
  fail_alloc_0:
  	kfree(ucpia);
  	return -EIO;
  }
  
  static void cpia_disconnect(struct usb_interface *intf);
  
  static struct usb_device_id cpia_id_table [] = {
  	{ USB_DEVICE(0x0553, 0x0002) },
  	{ USB_DEVICE(0x0813, 0x0001) },
  	{ }					/* Terminating entry */
  };
  
  MODULE_DEVICE_TABLE (usb, cpia_id_table);
  MODULE_LICENSE("GPL");
  
  
  static struct usb_driver cpia_driver = {

  	.name		= "cpia",
  	.probe		= cpia_probe,
  	.disconnect	= cpia_disconnect,
  	.id_table	= cpia_id_table,
  };
  
  static void cpia_disconnect(struct usb_interface *intf)
  {
  	struct cam_data *cam = usb_get_intfdata(intf);
  	struct usb_cpia *ucpia;
  	struct usb_device *udev;

  	usb_set_intfdata(intf, NULL);
  	if (!cam)
  		return;
  
  	ucpia = (struct usb_cpia *) cam->lowlevel_data;
  	spin_lock( &cam_list_lock_usb );
  	list_del(&cam->cam_data_list);
  	spin_unlock( &cam_list_lock_usb );

  	ucpia->present = 0;
  
  	cpia_unregister_camera(cam);
  	if(ucpia->open)
  		cpia_usb_close(cam->lowlevel_data);
  
  	ucpia->curbuff->status = FRAME_ERROR;
  
  	if (waitqueue_active(&ucpia->wq_stream))
  		wake_up_interruptible(&ucpia->wq_stream);
  
  	udev = interface_to_usbdev(intf);
  
  	ucpia->curbuff = ucpia->workbuff = NULL;

  	vfree(ucpia->buffers[2]);
  	ucpia->buffers[2] = NULL;

  	vfree(ucpia->buffers[1]);
  	ucpia->buffers[1] = NULL;

  	vfree(ucpia->buffers[0]);
  	ucpia->buffers[0] = NULL;

  
  	cam->lowlevel_data = NULL;
  	kfree(ucpia);
  }
  
  static int __init usb_cpia_init(void)
  {

  	printk(KERN_INFO "%s v%d.%d.%d
  ",ABOUT,

  	       CPIA_USB_MAJ_VER,CPIA_USB_MIN_VER,CPIA_USB_PATCH_VER);
  
  	spin_lock_init(&cam_list_lock_usb);
  	return usb_register(&cpia_driver);
  }
  
  static void __exit usb_cpia_cleanup(void)
  {
  	usb_deregister(&cpia_driver);
  }
  
  
  module_init (usb_cpia_init);
  module_exit (usb_cpia_cleanup);