/* 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>
  #include <media/v4l2-ctrls.h>
  #include <media/v4l2-fh.h>
  #include <media/v4l2-event.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;
  	struct v4l2_ctrl_handler ctrl_handler;
  	int io;
  	bool is_fm_band;
  	u32 curfreq;
  	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] = {
  	{ 1835, 2621,  4128, 65535 },
  	{ 2185, 4369, 13107, 65535 },
  };
  
  static const struct v4l2_frequency_band bands[] = {
  	{
  		.index = 0,
  		.type = V4L2_TUNER_RADIO,
  		.capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_FREQ_BANDS,
  		.rangelow = 8320,      /* 520 kHz */
  		.rangehigh = 26400,    /* 1650 kHz */
  		.modulation = V4L2_BAND_MODULATION_AM,
  	}, {
  		.index = 1,
  		.type = V4L2_TUNER_RADIO,
  		.capability = V4L2_TUNER_CAP_STEREO | V4L2_TUNER_CAP_RDS |
  			V4L2_TUNER_CAP_RDS_BLOCK_IO | V4L2_TUNER_CAP_LOW |
  			V4L2_TUNER_CAP_FREQ_BANDS,
  		.rangelow = 1400000,   /* 87.5 MHz */
  		.rangehigh = 1728000,  /* 108.0 MHz */
  		.modulation = V4L2_BAND_MODULATION_FM,
  	},
  };
  
  
  static int cadet_getstereo(struct cadet *dev)
  {
  	int ret = V4L2_TUNER_SUB_MONO;
  
  	if (!dev->is_fm_band)	/* Only FM has stereo capability! */
  		return V4L2_TUNER_SUB_MONO;
  
  	outb(7, dev->io);          /* Select tuner control */
  	if ((inb(dev->io + 1) & 0x40) == 0)
  		ret = V4L2_TUNER_SUB_STEREO;
  	return ret;
  }
  
  static unsigned cadet_gettune(struct cadet *dev)
  {
  	int curvol, i;
  	unsigned fifo = 0;
  
  	/*
  	 * Prepare for read
  	 */
  
  	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);
  	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->is_fm_band)    /* AM */
  		return ((fifo & 0x7fff) - 450) * 16;
  
  	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) / 1000;   /* Make it 1/16 kHz */
  	return freq;
  }
  
  static void cadet_settune(struct cadet *dev, unsigned fifo)
  {
  	int i;
  	unsigned test;
  
  	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);
  	}
  }
  
  static void cadet_setfreq(struct cadet *dev, unsigned freq)
  {
  	unsigned fifo;
  	int i, j, test;
  	int curvol;
  
  	freq = clamp(freq, bands[dev->is_fm_band].rangelow,
  			   bands[dev->is_fm_band].rangehigh);
  	dev->curfreq = freq;
  	/*
  	 * Formulate a fifo command
  	 */
  	fifo = 0;
  	if (dev->is_fm_band) {    /* FM */
  		test = 102400;
  		freq = freq / 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;
  		}
  	} else {	/* AM */
  		fifo = (freq / 16) + 450;	/* Make it kHz */
  		fifo |= 0x100000;		/* Select AM Band */
  	}
  
  	/*
  	 * Save current volume/mute setting
  	 */
  
  	outb(7, dev->io);                /* Select tuner control */
  	curvol = inb(dev->io + 1);
  
  	/*
  	 * Tune the card
  	 */
  	for (j = 3; j > -1; j--) {
  		cadet_settune(dev, fifo | (j << 16));
  
  		outb(7, dev->io);         /* Select tuner control */
  		outb(curvol, dev->io + 1);
  
  		msleep(100);
  
  		cadet_gettune(dev);
  		if ((dev->tunestat & 0x40) == 0) {   /* Tuned */
  			dev->sigstrength = sigtable[dev->is_fm_band][j];
  			goto reset_rds;
  		}
  	}
  	dev->sigstrength = 0;
  reset_rds:
  	outb(3, dev->io);
  	outb(inb(dev->io + 1) & 0x7f, dev->io + 1);
  }
  
  
  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 + 1 == 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 = data;
  	dev->readtimer.expires = jiffies + msecs_to_jiffies(50);
  	add_timer(&dev->readtimer);
  }
  
  static void cadet_start_rds(struct cadet *dev)
  {
  	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);
  }
  
  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)
  		cadet_start_rds(dev);
  	if (dev->rdsin == dev->rdsout) {
  		if (file->f_flags & O_NONBLOCK) {
  			i = -EWOULDBLOCK;
  			goto unlock;
  		}
  		mutex_unlock(&dev->lock);
  		interruptible_sleep_on(&dev->read_queue);
  		mutex_lock(&dev->lock);
  	}
  	while (i < count && dev->rdsin != dev->rdsout)
  		readbuf[i++] = dev->rdsbuf[dev->rdsout++];
  
  	if (i && copy_to_user(data, readbuf, i))
  		i = -EFAULT;
  unlock:
  	mutex_unlock(&dev->lock);
  	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->device_caps = V4L2_CAP_TUNER | V4L2_CAP_RADIO |
  			  V4L2_CAP_READWRITE | V4L2_CAP_RDS_CAPTURE;
  	v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS;
  	return 0;
  }
  
  static int vidioc_g_tuner(struct file *file, void *priv,
  				struct v4l2_tuner *v)
  {
  	struct cadet *dev = video_drvdata(file);
  
  	if (v->index)
  		return -EINVAL;
  	v->type = V4L2_TUNER_RADIO;
  	strlcpy(v->name, "Radio", sizeof(v->name));
  	v->capability = bands[0].capability | bands[1].capability;
  	v->rangelow = bands[0].rangelow;	   /* 520 kHz (start of AM band) */
  	v->rangehigh = bands[1].rangehigh;    /* 108.0 MHz (end of FM band) */
  	if (dev->is_fm_band) {
  		v->rxsubchans = cadet_getstereo(dev);
  		outb(3, dev->io);
  		outb(inb(dev->io + 1) & 0x7f, dev->io + 1);
  		mdelay(100);
  		outb(3, dev->io);
  		if (inb(dev->io + 1) & 0x80)
  			v->rxsubchans |= V4L2_TUNER_SUB_RDS;
  	} else {
  		v->rangelow = 8320;      /* 520 kHz */
  		v->rangehigh = 26400;    /* 1650 kHz */
  		v->rxsubchans = V4L2_TUNER_SUB_MONO;
  	}
  	v->audmode = V4L2_TUNER_MODE_STEREO;
  	v->signal = dev->sigstrength; /* We might need to modify scaling of this */
  	return 0;
  }
  
  static int vidioc_s_tuner(struct file *file, void *priv,
  				const struct v4l2_tuner *v)
  {
  	return v->index ? -EINVAL : 0;
  }
  
  static int vidioc_enum_freq_bands(struct file *file, void *priv,
  				struct v4l2_frequency_band *band)
  {
  	if (band->tuner)
  		return -EINVAL;
  	if (band->index >= ARRAY_SIZE(bands))
  		return -EINVAL;
  	*band = bands[band->index];
  	return 0;
  }
  
  static int vidioc_g_frequency(struct file *file, void *priv,
  				struct v4l2_frequency *f)
  {
  	struct cadet *dev = video_drvdata(file);
  
  	if (f->tuner)
  		return -EINVAL;
  	f->type = V4L2_TUNER_RADIO;
  	f->frequency = dev->curfreq;
  	return 0;
  }
  
  
  static int vidioc_s_frequency(struct file *file, void *priv,
  				const struct v4l2_frequency *f)
  {
  	struct cadet *dev = video_drvdata(file);
  
  	if (f->tuner)
  		return -EINVAL;
  	dev->is_fm_band =
  		f->frequency >= (bands[0].rangehigh + bands[1].rangelow) / 2;
  	cadet_setfreq(dev, f->frequency);
  	return 0;
  }
  
  static int cadet_s_ctrl(struct v4l2_ctrl *ctrl)
  {
  	struct cadet *dev = container_of(ctrl->handler, struct cadet, ctrl_handler);
  
  	switch (ctrl->id) {
  	case V4L2_CID_AUDIO_MUTE:
  		outb(7, dev->io);                /* Select tuner control */
  		if (ctrl->val)
  			outb(0x00, dev->io + 1);
  		else
  			outb(0x20, dev->io + 1);
  		return 0;
  	}
  	return -EINVAL;
  }
  
  static int cadet_open(struct file *file)
  {
  	struct cadet *dev = video_drvdata(file);
  	int err;
  
  	mutex_lock(&dev->lock);
  	err = v4l2_fh_open(file);
  	if (err)
  		goto fail;
  	if (v4l2_fh_is_singular_file(file))
  		init_waitqueue_head(&dev->read_queue);
  fail:
  	mutex_unlock(&dev->lock);
  	return err;
  }
  
  static int cadet_release(struct file *file)
  {
  	struct cadet *dev = video_drvdata(file);
  
  	mutex_lock(&dev->lock);
  	if (v4l2_fh_is_singular_file(file) && dev->rdsstat) {
  		del_timer_sync(&dev->readtimer);
  		dev->rdsstat = 0;
  	}
  	v4l2_fh_release(file);
  	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);
  	unsigned long req_events = poll_requested_events(wait);
  	unsigned int res = v4l2_ctrl_poll(file, wait);
  
  	poll_wait(file, &dev->read_queue, wait);
  	if (dev->rdsstat == 0 && (req_events & (POLLIN | POLLRDNORM))) {
  		mutex_lock(&dev->lock);
  		if (dev->rdsstat == 0)
  			cadet_start_rds(dev);
  		mutex_unlock(&dev->lock);
  	}
  	if (dev->rdsin != dev->rdsout)
  		res |= POLLIN | POLLRDNORM;
  	return res;
  }
  
  
  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_enum_freq_bands = vidioc_enum_freq_bands,
  	.vidioc_log_status  = v4l2_ctrl_log_status,
  	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
  	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
  };
  
  static const struct v4l2_ctrl_ops cadet_ctrl_ops = {
  	.s_ctrl = cadet_s_ctrl,
  };
  
  #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, bands[1].rangelow);
  			if (cadet_getfreq(dev) == bands[1].rangelow) {
  				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;
  	struct v4l2_ctrl_handler *hdl;
  	int res = -ENODEV;
  
  	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;
  	}
  
  	hdl = &dev->ctrl_handler;
  	v4l2_ctrl_handler_init(hdl, 2);
  	v4l2_ctrl_new_std(hdl, &cadet_ctrl_ops,
  			V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
  	v4l2_dev->ctrl_handler = hdl;
  	if (hdl->error) {
  		res = hdl->error;
  		v4l2_err(v4l2_dev, "Could not register controls
  ");
  		goto err_hdl;
  	}
  
  	dev->is_fm_band = true;
  	dev->curfreq = bands[dev->is_fm_band].rangelow;
  	cadet_setfreq(dev, dev->curfreq);
  	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;
  	dev->vdev.lock = &dev->lock;
  	set_bit(V4L2_FL_USE_FH_PRIO, &dev->vdev.flags);
  	video_set_drvdata(&dev->vdev, dev);
  
  	res = video_register_device(&dev->vdev, VFL_TYPE_RADIO, radio_nr);
  	if (res < 0)
  		goto err_hdl;
  	v4l2_info(v4l2_dev, "ADS Cadet Radio Card at 0x%x
  ", dev->io);
  	return 0;
  err_hdl:
  	v4l2_ctrl_handler_free(hdl);
  	v4l2_device_unregister(v4l2_dev);
  	release_region(dev->io, 2);
  fail:
  	pnp_unregister_driver(&cadet_pnp_driver);
  	return res;
  }
  
  static void __exit cadet_exit(void)
  {
  	struct cadet *dev = &cadet_card;
  
  	video_unregister_device(&dev->vdev);
  	v4l2_ctrl_handler_free(&dev->ctrl_handler);
  	v4l2_device_unregister(&dev->v4l2_dev);
  	outb(7, dev->io);	/* Mute */
  	outb(0x00, dev->io + 1);
  	release_region(dev->io, 2);
  	pnp_unregister_driver(&cadet_pnp_driver);
  }
  
  module_init(cadet_init);
  module_exit(cadet_exit);