/* SF16FMI radio driver for Linux radio support
 * heavily based on rtrack driver...
 * (c) 1997 M. Kirkwood
 * (c) 1998 Petr Vandrovec, vandrove@vc.cvut.cz
 *
 * Fitted to new interface by Alan Cox <alan@lxorguk.ukuu.org.uk>
 * Made working and cleaned up functions <mikael.hedin@irf.se>
 * Support for ISAPnP by Ladislav Michl <ladis@psi.cz>
 *
 * Notes on the hardware
 *
 *  Frequency control is done digitally -- ie out(port,encodefreq(95.8));
 *  No volume control - only mute/unmute - you have to use line volume
 *  control on SB-part of SF16FMI
 *
 * Converted to V4L2 API by Mauro Carvalho Chehab <mchehab@infradead.org>
 */

#include <linux/version.h>
#include <linux/kernel.h>	/* __setup			*/
#include <linux/module.h>	/* Modules 			*/
#include <linux/init.h>		/* Initdata			*/
#include <linux/ioport.h>	/* request_region		*/
#include <linux/delay.h>	/* udelay			*/
#include <linux/isapnp.h>
#include <linux/mutex.h>
#include <linux/videodev2.h>	/* kernel radio structs		*/
#include <linux/io.h>		/* outb, outb_p			*/
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>

MODULE_AUTHOR("Petr Vandrovec, vandrove@vc.cvut.cz and M. Kirkwood");
MODULE_DESCRIPTION("A driver for the SF16MI radio.");
MODULE_LICENSE("GPL");

static int io = -1;
static int radio_nr = -1;

module_param(io, int, 0);
MODULE_PARM_DESC(io, "I/O address of the SF16MI card (0x284 or 0x384)");
module_param(radio_nr, int, 0);

#define RADIO_VERSION KERNEL_VERSION(0, 0, 2)

struct fmi
{
	struct v4l2_device v4l2_dev;
	struct video_device vdev;
	int io;
	int curvol; /* 1 or 0 */
	unsigned long curfreq; /* freq in kHz */
	struct mutex lock;
};

static struct fmi fmi_card;
static struct pnp_dev *dev;

/* freq is in 1/16 kHz to internal number, hw precision is 50 kHz */
/* It is only useful to give freq in interval of 800 (=0.05Mhz),
 * other bits will be truncated, e.g 92.7400016 -> 92.7, but
 * 92.7400017 -> 92.75
 */
#define RSF16_ENCODE(x)	((x) / 800 + 214)
#define RSF16_MINFREQ (87 * 16000)
#define RSF16_MAXFREQ (108 * 16000)

static void outbits(int bits, unsigned int data, int io)
{
	while (bits--) {
		if (data & 1) {
			outb(5, io);
			udelay(6);
			outb(7, io);
			udelay(6);
		} else {
			outb(1, io);
			udelay(6);
			outb(3, io);
			udelay(6);
		}
		data >>= 1;
	}
}

static inline void fmi_mute(struct fmi *fmi)
{
	mutex_lock(&fmi->lock);
	outb(0x00, fmi->io);
	mutex_unlock(&fmi->lock);
}

static inline void fmi_unmute(struct fmi *fmi)
{
	mutex_lock(&fmi->lock);
	outb(0x08, fmi->io);
	mutex_unlock(&fmi->lock);
}

static inline int fmi_setfreq(struct fmi *fmi, unsigned long freq)
{
	mutex_lock(&fmi->lock);
	fmi->curfreq = freq;

	outbits(16, RSF16_ENCODE(freq), fmi->io);
	outbits(8, 0xC0, fmi->io);
	msleep(143);		/* was schedule_timeout(HZ/7) */
	mutex_unlock(&fmi->lock);
	if (fmi->curvol)
		fmi_unmute(fmi);
	return 0;
}

static inline int fmi_getsigstr(struct fmi *fmi)
{
	int val;
	int res;

	mutex_lock(&fmi->lock);
	val = fmi->curvol ? 0x08 : 0x00;	/* unmute/mute */
	outb(val, fmi->io);
	outb(val | 0x10, fmi->io);
	msleep(143); 		/* was schedule_timeout(HZ/7) */
	res = (int)inb(fmi->io + 1);
	outb(val, fmi->io);

	mutex_unlock(&fmi->lock);
	return (res & 2) ? 0 : 0xFFFF;
}

static int vidioc_querycap(struct file *file, void  *priv,
					struct v4l2_capability *v)
{
	strlcpy(v->driver, "radio-sf16fmi", sizeof(v->driver));
	strlcpy(v->card, "SF16-FMx radio", sizeof(v->card));
	strlcpy(v->bus_info, "ISA", sizeof(v->bus_info));
	v->version = RADIO_VERSION;
	v->capabilities = V4L2_CAP_TUNER | V4L2_CAP_RADIO;
	return 0;
}

static int vidioc_g_tuner(struct file *file, void *priv,
					struct v4l2_tuner *v)
{
	struct fmi *fmi = video_drvdata(file);

	if (v->index > 0)
		return -EINVAL;

	strlcpy(v->name, "FM", sizeof(v->name));
	v->type = V4L2_TUNER_RADIO;
	v->rangelow = RSF16_MINFREQ;
	v->rangehigh = RSF16_MAXFREQ;
	v->rxsubchans = V4L2_TUNER_SUB_MONO | V4L2_TUNER_SUB_STEREO;
	v->capability = V4L2_TUNER_CAP_LOW;
	v->audmode = V4L2_TUNER_MODE_STEREO;
	v->signal = fmi_getsigstr(fmi);
	return 0;
}

static int vidioc_s_tuner(struct file *file, void *priv,
					struct v4l2_tuner *v)
{
	return v->index ? -EINVAL : 0;
}

static int vidioc_s_frequency(struct file *file, void *priv,
					struct v4l2_frequency *f)
{
	struct fmi *fmi = video_drvdata(file);

	if (f->frequency < RSF16_MINFREQ ||
			f->frequency > RSF16_MAXFREQ)
		return -EINVAL;
	/* rounding in steps of 800 to match the freq
	   that will be used */
	fmi_setfreq(fmi, (f->frequency / 800) * 800);
	return 0;
}

static int vidioc_g_frequency(struct file *file, void *priv,
					struct v4l2_frequency *f)
{
	struct fmi *fmi = video_drvdata(file);

	f->type = V4L2_TUNER_RADIO;
	f->frequency = fmi->curfreq;
	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);
	}
	return -EINVAL;
}

static int vidioc_g_ctrl(struct file *file, void *priv,
					struct v4l2_control *ctrl)
{
	struct fmi *fmi = video_drvdata(file);

	switch (ctrl->id) {
	case V4L2_CID_AUDIO_MUTE:
		ctrl->value = fmi->curvol;
		return 0;
	}
	return -EINVAL;
}

static int vidioc_s_ctrl(struct file *file, void *priv,
					struct v4l2_control *ctrl)
{
	struct fmi *fmi = video_drvdata(file);

	switch (ctrl->id) {
	case V4L2_CID_AUDIO_MUTE:
		if (ctrl->value)
			fmi_mute(fmi);
		else
			fmi_unmute(fmi);
		fmi->curvol = ctrl->value;
		return 0;
	}
	return -EINVAL;
}

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 const struct v4l2_file_operations fmi_fops = {
	.owner		= THIS_MODULE,
	.ioctl		= video_ioctl2,
};

static const struct v4l2_ioctl_ops fmi_ioctl_ops = {
	.vidioc_querycap    = vidioc_querycap,
	.vidioc_g_tuner     = vidioc_g_tuner,
	.vidioc_s_tuner     = vidioc_s_tuner,
	.vidioc_g_audio     = vidioc_g_audio,
	.vidioc_s_audio     = vidioc_s_audio,
	.vidioc_g_input     = vidioc_g_input,
	.vidioc_s_input     = vidioc_s_input,
	.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,
};

/* ladis: this is my card. does any other types exist? */
static struct isapnp_device_id id_table[] __devinitdata = {
	{	ISAPNP_ANY_ID, ISAPNP_ANY_ID,
		ISAPNP_VENDOR('M','F','R'), ISAPNP_FUNCTION(0xad10), 0},
	{	ISAPNP_CARD_END, },
};

MODULE_DEVICE_TABLE(isapnp, id_table);

static int __init isapnp_fmi_probe(void)
{
	int i = 0;

	while (id_table[i].card_vendor != 0 && dev == NULL) {
		dev = pnp_find_dev(NULL, id_table[i].vendor,
				   id_table[i].function, NULL);
		i++;
	}

	if (!dev)
		return -ENODEV;
	if (pnp_device_attach(dev) < 0)
		return -EAGAIN;
	if (pnp_activate_dev(dev) < 0) {
		printk(KERN_ERR "radio-sf16fmi: PnP configure failed (out of resources?)\n");
		pnp_device_detach(dev);
		return -ENOMEM;
	}
	if (!pnp_port_valid(dev, 0)) {
		pnp_device_detach(dev);
		return -ENODEV;
	}

	i = pnp_port_start(dev, 0);
	printk(KERN_INFO "radio-sf16fmi: PnP reports card at %#x\n", i);

	return i;
}

static int __init fmi_init(void)
{
	struct fmi *fmi = &fmi_card;
	struct v4l2_device *v4l2_dev = &fmi->v4l2_dev;
	int res;

	if (io < 0)
		io = isapnp_fmi_probe();
	strlcpy(v4l2_dev->name, "sf16fmi", sizeof(v4l2_dev->name));
	fmi->io = io;
	if (fmi->io < 0) {
		v4l2_err(v4l2_dev, "No PnP card found.\n");
		return fmi->io;
	}
	if (!request_region(io, 2, "radio-sf16fmi")) {
		v4l2_err(v4l2_dev, "port 0x%x already in use\n", fmi->io);
		pnp_device_detach(dev);
		return -EBUSY;
	}

	res = v4l2_device_register(NULL, v4l2_dev);
	if (res < 0) {
		release_region(fmi->io, 2);
		pnp_device_detach(dev);
		v4l2_err(v4l2_dev, "Could not register v4l2_device\n");
		return res;
	}

	strlcpy(fmi->vdev.name, v4l2_dev->name, sizeof(fmi->vdev.name));
	fmi->vdev.v4l2_dev = v4l2_dev;
	fmi->vdev.fops = &fmi_fops;
	fmi->vdev.ioctl_ops = &fmi_ioctl_ops;
	fmi->vdev.release = video_device_release_empty;
	video_set_drvdata(&fmi->vdev, fmi);

	mutex_init(&fmi->lock);

	if (video_register_device(&fmi->vdev, VFL_TYPE_RADIO, radio_nr) < 0) {
		v4l2_device_unregister(v4l2_dev);
		release_region(fmi->io, 2);
		pnp_device_detach(dev);
		return -EINVAL;
	}

	v4l2_info(v4l2_dev, "card driver at 0x%x\n", fmi->io);
	/* mute card - prevents noisy bootups */
	fmi_mute(fmi);
	return 0;
}

static void __exit fmi_exit(void)
{
	struct fmi *fmi = &fmi_card;

	video_unregister_device(&fmi->vdev);
	v4l2_device_unregister(&fmi->v4l2_dev);
	release_region(fmi->io, 2);
	if (dev)
		pnp_device_detach(dev);
}

module_init(fmi_init);
module_exit(fmi_exit);