/* radio-cadet.c - A video4linux driver for the ADS Cadet AM/FM Radio Card
   *
   * by Fred Gleason <fredg@wava.com>
   * Version 0.3.3
   *
   * (Loosely) based on code for the Aztech radio card by
   *
   * Russell Kroll    (rkroll@exploits.org)
   * Quay Ly
   * Donald Song

   * Jason Lewis      (jlewis@twilight.vtc.vsc.edu)

   * Scott McGrath    (smcgrath@twilight.vtc.vsc.edu)
   * William McGrath  (wmcgrath@twilight.vtc.vsc.edu)
   *
   * History:
   * 2000-04-29	Russell Kroll <rkroll@exploits.org>
   *		Added ISAPnP detection for Linux 2.3/2.4
   *
   * 2001-01-10	Russell Kroll <rkroll@exploits.org>
   *		Removed dead CONFIG_RADIO_CADET_PORT code
   *		PnP detection on load is now default (no args necessary)
   *
   * 2002-01-17	Adam Belay <ambx1@neo.rr.com>
   *		Updated to latest pnp code
   *

   * 2003-01-31	Alan Cox <alan@lxorguk.ukuu.org.uk>

   *		Cleaned up locking, delay code, general odds and ends

   *
   * 2006-07-30	Hans J. Koch <koch@hjk-az.de>
   *		Changed API to V4L2

   */
  
  #include <linux/module.h>	/* Modules 			*/
  #include <linux/init.h>		/* Initdata			*/

  #include <linux/ioport.h>	/* request_region		*/

  #include <linux/delay.h>	/* udelay			*/

  #include <linux/videodev2.h>	/* V4L2 API defs		*/

  #include <linux/param.h>
  #include <linux/pnp.h>

  #include <linux/sched.h>

  #include <linux/io.h>		/* outb, outb_p			*/

  #include <media/v4l2-device.h>
  #include <media/v4l2-ioctl.h>
  
  MODULE_AUTHOR("Fred Gleason, Russell Kroll, Quay Lu, Donald Song, Jason Lewis, Scott McGrath, William McGrath");
  MODULE_DESCRIPTION("A driver for the ADS Cadet AM/FM/RDS radio card.");
  MODULE_LICENSE("GPL");

  MODULE_VERSION("0.3.4");

  
  static int io = -1;		/* default to isapnp activation */
  static int radio_nr = -1;
  
  module_param(io, int, 0);
  MODULE_PARM_DESC(io, "I/O address of Cadet card (0x330,0x332,0x334,0x336,0x338,0x33a,0x33c,0x33e)");
  module_param(radio_nr, int, 0);

  #define RDS_BUFFER 256

  #define RDS_RX_FLAG 1
  #define MBS_RX_FLAG 2

  struct cadet {
  	struct v4l2_device v4l2_dev;
  	struct video_device vdev;
  	int io;
  	int users;
  	int curtuner;
  	int tunestat;
  	int sigstrength;
  	wait_queue_head_t read_queue;
  	struct timer_list readtimer;
  	__u8 rdsin, rdsout, rdsstat;
  	unsigned char rdsbuf[RDS_BUFFER];
  	struct mutex lock;
  	int reading;

  };

  static struct cadet cadet_card;

  
  /*
   * Signal Strength Threshold Values

   * The V4L API spec does not define any particular unit for the signal

   * strength value.  These values are in microvolts of RF at the tuner's input.
   */

  static __u16 sigtable[2][4] = {
  	{  5, 10, 30,  150 },
  	{ 28, 40, 63, 1000 }
  };

  static int cadet_getstereo(struct cadet *dev)

  {

  	int ret = V4L2_TUNER_SUB_MONO;

  
  	if (dev->curtuner != 0)	/* Only FM has stereo capability! */

  		return V4L2_TUNER_SUB_MONO;

  	mutex_lock(&dev->lock);
  	outb(7, dev->io);          /* Select tuner control */
  	if ((inb(dev->io + 1) & 0x40) == 0)

  		ret = V4L2_TUNER_SUB_STEREO;

  	mutex_unlock(&dev->lock);

  	return ret;

  }

  static unsigned cadet_gettune(struct cadet *dev)

  {

  	int curvol, i;
  	unsigned fifo = 0;

  	/*
  	 * Prepare for read
  	 */

  	mutex_lock(&dev->lock);

  	outb(7, dev->io);       /* Select tuner control */
  	curvol = inb(dev->io + 1); /* Save current volume/mute setting */
  	outb(0x00, dev->io + 1);  /* Ensure WRITE-ENABLE is LOW */
  	dev->tunestat = 0xffff;

  	/*
  	 * Read the shift register
  	 */

  	for (i = 0; i < 25; i++) {
  		fifo = (fifo << 1) | ((inb(dev->io + 1) >> 7) & 0x01);
  		if (i < 24) {
  			outb(0x01, dev->io + 1);
  			dev->tunestat &= inb(dev->io + 1);
  			outb(0x00, dev->io + 1);

  		}
  	}
  
  	/*
  	 * Restore volume/mute setting
  	 */

  	outb(curvol, dev->io + 1);
  	mutex_unlock(&dev->lock);

  
  	return fifo;
  }

  static unsigned cadet_getfreq(struct cadet *dev)

  {

  	int i;

  	unsigned freq = 0, test, fifo = 0;

  
  	/*
  	 * Read current tuning
  	 */

  	fifo = cadet_gettune(dev);

  	/*
  	 * Convert to actual frequency
  	 */

  	if (dev->curtuner == 0) {    /* FM */
  		test = 12500;
  		for (i = 0; i < 14; i++) {
  			if ((fifo & 0x01) != 0)
  				freq += test;
  			test = test << 1;
  			fifo = fifo >> 1;

  		}

  		freq -= 10700000;           /* IF frequency is 10.7 MHz */
  		freq = (freq * 16) / 1000000;   /* Make it 1/16 MHz */

  	}

  	if (dev->curtuner == 1)    /* AM */
  		freq = ((fifo & 0x7fff) - 2010) * 16;

  	return freq;

  }

  static void cadet_settune(struct cadet *dev, unsigned fifo)

  {

  	int i;
  	unsigned test;

  	mutex_lock(&dev->lock);

  	outb(7, dev->io);                /* Select tuner control */

  	/*
  	 * Write the shift register
  	 */

  	test = 0;
  	test = (fifo >> 23) & 0x02;      /* Align data for SDO */
  	test |= 0x1c;                /* SDM=1, SWE=1, SEN=1, SCK=0 */
  	outb(7, dev->io);                /* Select tuner control */
  	outb(test, dev->io + 1);           /* Initialize for write */
  	for (i = 0; i < 25; i++) {
  		test |= 0x01;              /* Toggle SCK High */
  		outb(test, dev->io + 1);
  		test &= 0xfe;              /* Toggle SCK Low */
  		outb(test, dev->io + 1);
  		fifo = fifo << 1;            /* Prepare the next bit */
  		test = 0x1c | ((fifo >> 23) & 0x02);
  		outb(test, dev->io + 1);

  	}

  	mutex_unlock(&dev->lock);

  }

  static void cadet_setfreq(struct cadet *dev, unsigned freq)

  {

  	unsigned fifo;

  	int i, j, test;

  	int curvol;

  	/*
  	 * Formulate a fifo command
  	 */

  	fifo = 0;
  	if (dev->curtuner == 0) {    /* FM */
  		test = 102400;
  		freq = (freq * 1000) / 16;       /* Make it kHz */
  		freq += 10700;               /* IF is 10700 kHz */
  		for (i = 0; i < 14; i++) {
  			fifo = fifo << 1;
  			if (freq >= test) {
  				fifo |= 0x01;
  				freq -= test;

  			}

  			test = test >> 1;

  		}

  	}

  	if (dev->curtuner == 1) {    /* AM */
  		fifo = (freq / 16) + 2010;            /* Make it kHz */
  		fifo |= 0x100000;            /* Select AM Band */

  	}

  	/*
  	 * Save current volume/mute setting
  	 */

  	mutex_lock(&dev->lock);
  	outb(7, dev->io);                /* Select tuner control */
  	curvol = inb(dev->io + 1);
  	mutex_unlock(&dev->lock);

  
  	/*
  	 * Tune the card
  	 */

  	for (j = 3; j > -1; j--) {
  		cadet_settune(dev, fifo | (j << 16));

  		mutex_lock(&dev->lock);
  		outb(7, dev->io);         /* Select tuner control */
  		outb(curvol, dev->io + 1);
  		mutex_unlock(&dev->lock);

  		msleep(100);

  		cadet_gettune(dev);
  		if ((dev->tunestat & 0x40) == 0) {   /* Tuned */
  			dev->sigstrength = sigtable[dev->curtuner][j];

  			return;
  		}
  	}

  	dev->sigstrength = 0;

  }

  static int cadet_getvol(struct cadet *dev)

  {
  	int ret = 0;

  	mutex_lock(&dev->lock);

  	outb(7, dev->io);                /* Select tuner control */
  	if ((inb(dev->io + 1) & 0x20) != 0)

  		ret = 0xffff;

  	mutex_unlock(&dev->lock);

  	return ret;

  }

  static void cadet_setvol(struct cadet *dev, int vol)

  {

  	mutex_lock(&dev->lock);
  	outb(7, dev->io);                /* Select tuner control */
  	if (vol > 0)
  		outb(0x20, dev->io + 1);

  	else

  		outb(0x00, dev->io + 1);
  	mutex_unlock(&dev->lock);

  }

  static void cadet_handler(unsigned long data)

  {

  	struct cadet *dev = (void *)data;

  	/* Service the RDS fifo */
  	if (mutex_trylock(&dev->lock)) {
  		outb(0x3, dev->io);       /* Select RDS Decoder Control */
  		if ((inb(dev->io + 1) & 0x20) != 0)

  			printk(KERN_CRIT "cadet: RDS fifo overflow
  ");

  		outb(0x80, dev->io);      /* Select RDS fifo */
  		while ((inb(dev->io) & 0x80) != 0) {
  			dev->rdsbuf[dev->rdsin] = inb(dev->io + 1);
  			if (dev->rdsin == dev->rdsout)

  				printk(KERN_WARNING "cadet: RDS buffer overflow
  ");

  			else

  				dev->rdsin++;

  		}

  		mutex_unlock(&dev->lock);

  	}
  
  	/*
  	 * Service pending read
  	 */

  	if (dev->rdsin != dev->rdsout)
  		wake_up_interruptible(&dev->read_queue);

  	/*

  	 * Clean up and exit
  	 */

  	init_timer(&dev->readtimer);
  	dev->readtimer.function = cadet_handler;
  	dev->readtimer.data = (unsigned long)0;
  	dev->readtimer.expires = jiffies + msecs_to_jiffies(50);
  	add_timer(&dev->readtimer);

  }

  static ssize_t cadet_read(struct file *file, char __user *data, size_t count, loff_t *ppos)

  {

  	struct cadet *dev = video_drvdata(file);

  	unsigned char readbuf[RDS_BUFFER];

  	int i = 0;

  	mutex_lock(&dev->lock);

  	if (dev->rdsstat == 0) {

  		dev->rdsstat = 1;
  		outb(0x80, dev->io);        /* Select RDS fifo */

  		init_timer(&dev->readtimer);
  		dev->readtimer.function = cadet_handler;
  		dev->readtimer.data = (unsigned long)dev;
  		dev->readtimer.expires = jiffies + msecs_to_jiffies(50);
  		add_timer(&dev->readtimer);

  	}

  	if (dev->rdsin == dev->rdsout) {

  		mutex_unlock(&dev->lock);

  		if (file->f_flags & O_NONBLOCK)
  			return -EWOULDBLOCK;

  		interruptible_sleep_on(&dev->read_queue);

  		mutex_lock(&dev->lock);

  	}

  	while (i < count && dev->rdsin != dev->rdsout)
  		readbuf[i++] = dev->rdsbuf[dev->rdsout++];

  	mutex_unlock(&dev->lock);

  	if (copy_to_user(data, readbuf, i))

  		return -EFAULT;

  	return i;
  }

  static int vidioc_querycap(struct file *file, void *priv,
  				struct v4l2_capability *v)
  {

  	strlcpy(v->driver, "ADS Cadet", sizeof(v->driver));
  	strlcpy(v->card, "ADS Cadet", sizeof(v->card));
  	strlcpy(v->bus_info, "ISA", sizeof(v->bus_info));

  	v->capabilities = V4L2_CAP_TUNER | V4L2_CAP_RADIO |
  			  V4L2_CAP_READWRITE | V4L2_CAP_RDS_CAPTURE;

  	return 0;
  }

  static int vidioc_g_tuner(struct file *file, void *priv,
  				struct v4l2_tuner *v)

  {

  	struct cadet *dev = video_drvdata(file);

  	v->type = V4L2_TUNER_RADIO;
  	switch (v->index) {
  	case 0:

  		strlcpy(v->name, "FM", sizeof(v->name));

  		v->capability = V4L2_TUNER_CAP_STEREO | V4L2_TUNER_CAP_RDS |
  			V4L2_TUNER_CAP_RDS_BLOCK_IO;

  		v->rangelow = 1400;     /* 87.5 MHz */
  		v->rangehigh = 1728;    /* 108.0 MHz */

  		v->rxsubchans = cadet_getstereo(dev);
  		switch (v->rxsubchans) {

  		case V4L2_TUNER_SUB_MONO:
  			v->audmode = V4L2_TUNER_MODE_MONO;
  			break;
  		case V4L2_TUNER_SUB_STEREO:
  			v->audmode = V4L2_TUNER_MODE_STEREO;
  			break;

  		default:
  			break;

  		}

  		v->rxsubchans |= V4L2_TUNER_SUB_RDS;

  		break;
  	case 1:

  		strlcpy(v->name, "AM", sizeof(v->name));

  		v->capability = V4L2_TUNER_CAP_LOW;
  		v->rangelow = 8320;      /* 520 kHz */
  		v->rangehigh = 26400;    /* 1650 kHz */
  		v->rxsubchans = V4L2_TUNER_SUB_MONO;
  		v->audmode = V4L2_TUNER_MODE_MONO;
  		break;
  	default:
  		return -EINVAL;
  	}

  	v->signal = dev->sigstrength; /* We might need to modify scaling of this */

  	return 0;
  }

  static int vidioc_s_tuner(struct file *file, void *priv,
  				struct v4l2_tuner *v)
  {

  	struct cadet *dev = video_drvdata(file);
  
  	if (v->index != 0 && v->index != 1)

  		return -EINVAL;

  	dev->curtuner = v->index;

  	return 0;
  }

  static int vidioc_g_frequency(struct file *file, void *priv,
  				struct v4l2_frequency *f)
  {

  	struct cadet *dev = video_drvdata(file);
  
  	f->tuner = dev->curtuner;

  	f->type = V4L2_TUNER_RADIO;

  	f->frequency = cadet_getfreq(dev);

  	return 0;
  }
  
  
  static int vidioc_s_frequency(struct file *file, void *priv,
  				struct v4l2_frequency *f)
  {

  	struct cadet *dev = video_drvdata(file);

  	if (f->type != V4L2_TUNER_RADIO)
  		return -EINVAL;

  	if (dev->curtuner == 0 && (f->frequency < 1400 || f->frequency > 1728))

  		return -EINVAL;

  	if (dev->curtuner == 1 && (f->frequency < 8320 || f->frequency > 26400))

  		return -EINVAL;

  	cadet_setfreq(dev, f->frequency);

  	return 0;
  }
  
  static int vidioc_queryctrl(struct file *file, void *priv,
  				struct v4l2_queryctrl *qc)
  {

  	switch (qc->id) {
  	case V4L2_CID_AUDIO_MUTE:
  		return v4l2_ctrl_query_fill(qc, 0, 1, 1, 1);
  	case V4L2_CID_AUDIO_VOLUME:
  		return v4l2_ctrl_query_fill(qc, 0, 0xff, 1, 0xff);

  	}
  	return -EINVAL;
  }

  static int vidioc_g_ctrl(struct file *file, void *priv,
  				struct v4l2_control *ctrl)
  {

  	struct cadet *dev = video_drvdata(file);
  
  	switch (ctrl->id) {

  	case V4L2_CID_AUDIO_MUTE: /* TODO: Handle this correctly */

  		ctrl->value = (cadet_getvol(dev) == 0);

  		break;
  	case V4L2_CID_AUDIO_VOLUME:

  		ctrl->value = cadet_getvol(dev);

  		break;
  	default:
  		return -EINVAL;

  	}

  	return 0;

  }

  static int vidioc_s_ctrl(struct file *file, void *priv,
  				struct v4l2_control *ctrl)

  {

  	struct cadet *dev = video_drvdata(file);

  	switch (ctrl->id){
  	case V4L2_CID_AUDIO_MUTE: /* TODO: Handle this correctly */
  		if (ctrl->value)

  			cadet_setvol(dev, 0);

  		else

  			cadet_setvol(dev, 0xffff);

  		break;
  	case V4L2_CID_AUDIO_VOLUME:

  		cadet_setvol(dev, ctrl->value);

  		break;
  	default:
  		return -EINVAL;
  	}
  	return 0;
  }

  static int vidioc_g_input(struct file *filp, void *priv, unsigned int *i)
  {
  	*i = 0;
  	return 0;
  }
  
  static int vidioc_s_input(struct file *filp, void *priv, unsigned int i)
  {

  	return i ? -EINVAL : 0;
  }
  
  static int vidioc_g_audio(struct file *file, void *priv,
  				struct v4l2_audio *a)
  {
  	a->index = 0;
  	strlcpy(a->name, "Radio", sizeof(a->name));
  	a->capability = V4L2_AUDCAP_STEREO;

  	return 0;
  }
  
  static int vidioc_s_audio(struct file *file, void *priv,
  				struct v4l2_audio *a)
  {

  	return a->index ? -EINVAL : 0;

  }

  static int cadet_open(struct file *file)

  {

  	struct cadet *dev = video_drvdata(file);

  	mutex_lock(&dev->lock);

  	dev->users++;
  	if (1 == dev->users)
  		init_waitqueue_head(&dev->read_queue);

  	mutex_unlock(&dev->lock);

  	return 0;
  }

  static int cadet_release(struct file *file)

  {

  	struct cadet *dev = video_drvdata(file);

  	mutex_lock(&dev->lock);

  	dev->users--;
  	if (0 == dev->users) {
  		del_timer_sync(&dev->readtimer);
  		dev->rdsstat = 0;

  	}

  	mutex_unlock(&dev->lock);

  	return 0;
  }

  static unsigned int cadet_poll(struct file *file, struct poll_table_struct *wait)

  {

  	struct cadet *dev = video_drvdata(file);
  
  	poll_wait(file, &dev->read_queue, wait);
  	if (dev->rdsin != dev->rdsout)

  		return POLLIN | POLLRDNORM;

  	return 0;
  }

  static const struct v4l2_file_operations cadet_fops = {

  	.owner		= THIS_MODULE,
  	.open		= cadet_open,
  	.release       	= cadet_release,
  	.read		= cadet_read,

  	.unlocked_ioctl	= video_ioctl2,

  	.poll		= cadet_poll,

  };

  static const struct v4l2_ioctl_ops cadet_ioctl_ops = {

  	.vidioc_querycap    = vidioc_querycap,
  	.vidioc_g_tuner     = vidioc_g_tuner,
  	.vidioc_s_tuner     = vidioc_s_tuner,
  	.vidioc_g_frequency = vidioc_g_frequency,
  	.vidioc_s_frequency = vidioc_s_frequency,
  	.vidioc_queryctrl   = vidioc_queryctrl,
  	.vidioc_g_ctrl      = vidioc_g_ctrl,
  	.vidioc_s_ctrl      = vidioc_s_ctrl,
  	.vidioc_g_audio     = vidioc_g_audio,
  	.vidioc_s_audio     = vidioc_s_audio,
  	.vidioc_g_input     = vidioc_g_input,
  	.vidioc_s_input     = vidioc_s_input,

  };

  #ifdef CONFIG_PNP

  static struct pnp_device_id cadet_pnp_devices[] = {
  	/* ADS Cadet AM/FM Radio Card */
  	{.id = "MSM0c24", .driver_data = 0},
  	{.id = ""}
  };
  
  MODULE_DEVICE_TABLE(pnp, cadet_pnp_devices);

  static int cadet_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)

  {
  	if (!dev)
  		return -ENODEV;
  	/* only support one device */
  	if (io > 0)
  		return -EBUSY;

  	if (!pnp_port_valid(dev, 0))

  		return -ENODEV;

  
  	io = pnp_port_start(dev, 0);

  	printk(KERN_INFO "radio-cadet: PnP reports device at %#x
  ", io);

  
  	return io;
  }
  
  static struct pnp_driver cadet_pnp_driver = {
  	.name		= "radio-cadet",
  	.id_table	= cadet_pnp_devices,
  	.probe		= cadet_pnp_probe,
  	.remove		= NULL,
  };

  #else
  static struct pnp_driver cadet_pnp_driver;
  #endif

  static void cadet_probe(struct cadet *dev)

  {

  	static int iovals[8] = { 0x330, 0x332, 0x334, 0x336, 0x338, 0x33a, 0x33c, 0x33e };

  	int i;

  	for (i = 0; i < 8; i++) {
  		dev->io = iovals[i];
  		if (request_region(dev->io, 2, "cadet-probe")) {
  			cadet_setfreq(dev, 1410);
  			if (cadet_getfreq(dev) == 1410) {
  				release_region(dev->io, 2);
  				return;

  			}

  			release_region(dev->io, 2);

  		}
  	}

  	dev->io = -1;

  }

  /*

   * io should only be set if the user has used something like
   * isapnp (the userspace program) to initialize this card for us
   */
  
  static int __init cadet_init(void)
  {

  	struct cadet *dev = &cadet_card;
  	struct v4l2_device *v4l2_dev = &dev->v4l2_dev;
  	int res;

  	strlcpy(v4l2_dev->name, "cadet", sizeof(v4l2_dev->name));
  	mutex_init(&dev->lock);
  
  	/* If a probe was requested then probe ISAPnP first (safest) */

  	if (io < 0)
  		pnp_register_driver(&cadet_pnp_driver);

  	dev->io = io;

  	/* If that fails then probe unsafely if probe is requested */
  	if (dev->io < 0)
  		cadet_probe(dev);

  	/* Else we bail out */
  	if (dev->io < 0) {

  #ifdef MODULE

  		v4l2_err(v4l2_dev, "you must set an I/O address with io=0x330, 0x332, 0x334,
  ");
  		v4l2_err(v4l2_dev, "0x336, 0x338, 0x33a, 0x33c or 0x33e
  ");

  #endif

  		goto fail;

  	}

  	if (!request_region(dev->io, 2, "cadet"))
  		goto fail;
  
  	res = v4l2_device_register(NULL, v4l2_dev);
  	if (res < 0) {
  		release_region(dev->io, 2);
  		v4l2_err(v4l2_dev, "could not register v4l2_device
  ");

  		goto fail;

  	}
  
  	strlcpy(dev->vdev.name, v4l2_dev->name, sizeof(dev->vdev.name));
  	dev->vdev.v4l2_dev = v4l2_dev;
  	dev->vdev.fops = &cadet_fops;
  	dev->vdev.ioctl_ops = &cadet_ioctl_ops;
  	dev->vdev.release = video_device_release_empty;
  	video_set_drvdata(&dev->vdev, dev);
  
  	if (video_register_device(&dev->vdev, VFL_TYPE_RADIO, radio_nr) < 0) {
  		v4l2_device_unregister(v4l2_dev);
  		release_region(dev->io, 2);

  		goto fail;
  	}

  	v4l2_info(v4l2_dev, "ADS Cadet Radio Card at 0x%x
  ", dev->io);

  	return 0;
  fail:
  	pnp_unregister_driver(&cadet_pnp_driver);

  	return -ENODEV;

  }

  static void __exit cadet_exit(void)

  {

  	struct cadet *dev = &cadet_card;
  
  	video_unregister_device(&dev->vdev);
  	v4l2_device_unregister(&dev->v4l2_dev);
  	release_region(dev->io, 2);

  	pnp_unregister_driver(&cadet_pnp_driver);
  }
  
  module_init(cadet_init);

  module_exit(cadet_exit);