/* 
 * Guillemot Maxi Radio FM 2000 PCI radio card driver for Linux 
 * (C) 2001 Dimitromanolakis Apostolos <apdim@grecian.net>
 *
 * Based in the radio Maestro PCI driver. Actually it uses the same chip
 * for radio but different pci controller.
 *
 * I didn't have any specs I reversed engineered the protocol from
 * the windows driver (radio.dll). 
 *
 * The card uses the TEA5757 chip that includes a search function but it
 * is useless as I haven't found any way to read back the frequency. If 
 * anybody does please mail me.
 *
 * For the pdf file see:
 * http://www.semiconductors.philips.com/pip/TEA5757H/V1
 * 
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/semaphore.h>
#include <linux/pci.h>
#include <linux/videodev.h>

#define DRIVER_VERSION	"0.7"

#ifndef PCI_VENDOR_ID_GUILLEMOT
#define PCI_VENDOR_ID_GUILLEMOT 0x5046
#endif

#ifndef PCI_DEVICE_ID_GUILLEMOT
#define PCI_DEVICE_ID_GUILLEMOT_MAXIRADIO 0x1001
#endif


/* TEA5757 pin mappings */
const int clk = 1, data = 2, wren = 4, mo_st = 8, power = 16 ;


#define FREQ_LO		 50*16000
#define FREQ_HI		150*16000

#define FREQ_IF         171200 /* 10.7*16000   */
#define FREQ_STEP       200    /* 12.5*16      */

#define FREQ2BITS(x)	((( (unsigned int)(x)+FREQ_IF+(FREQ_STEP<<1))\
			/(FREQ_STEP<<2))<<2) /* (x==fmhz*16*1000) -> bits */

#define BITS2FREQ(x)	((x) * FREQ_STEP - FREQ_IF)


static int radio_open(struct video_device *, int);
static int radio_ioctl(struct video_device *, unsigned int, void *);
static void radio_close(struct video_device *);


/* if anybody knows how to find all the cards from the video_device... */
int found; 
__u16 io_ports[16];

static struct video_device maxiradio_radio=
{
	name:		"Maxi Radio FM2000 radio",
	type:		VID_TYPE_TUNER,
	hardware:	VID_HARDWARE_SF16MI,
	open:		radio_open,
	close:		radio_close,
	ioctl:		radio_ioctl,
};

static struct radio_device
{
	__u16	io,	/* base of Maestro card radio io (GPIO_DATA)*/
		muted,	/* VIDEO_AUDIO_MUTE */
		stereo,	/* VIDEO_TUNER_STEREO_ON */	
		tuned;	/* signal strength (0 or 0xffff) */
		
	unsigned long freq;
	
	struct  semaphore lock;
} radio_unit = {0, 0, 0, 0, };


static void sleep_125ms(void)
{
	current->state = TASK_INTERRUPTIBLE;
	schedule_timeout(HZ >> 3);
}


static void outbit(unsigned long bit, __u16 io)
{
	if(bit != 0)
		{
			outb(  power|wren|data     ,io); udelay(4);
			outb(  power|wren|data|clk ,io); udelay(4);
			outb(  power|wren|data     ,io); udelay(4);
		}
	else	
		{
			outb(  power|wren          ,io); udelay(4);
			outb(  power|wren|clk      ,io); udelay(4);
			outb(  power|wren          ,io); udelay(4);
		}
}

static void turn_power(__u16 io, int p)
{
	if(p != 0) outb(power, io); else outb(0,io);
}


static void set_freq(__u16 io, __u32 data)
{
	unsigned long int si;
	int bl;
	
	/* TEA5757 shift register bits (see pdf) */

	outbit(0,io); // 24  search 
	outbit(1,io); // 23  search up/down
	
	outbit(0,io); // 22  stereo/mono

	outbit(0,io); // 21  band
	outbit(0,io); // 20  band (only 00=FM works I think)

	outbit(0,io); // 19  port ?
	outbit(0,io); // 18  port ?
	
	outbit(0,io); // 17  search level
	outbit(0,io); // 16  search level
 
  si = 0x8000;
	for(bl = 1; bl <= 16 ; bl++) { outbit(data & si,io); si >>=1; }
	
	outb(power,io);
}

static int get_stereo(__u16 io)
{	
	outb(power,io); udelay(2);
	return !(inb(io) & mo_st);
}

static int get_tune(__u16 io)
{	
	outb(power+clk,io); udelay(2);
	return !(inb(io) & mo_st);
}


inline static int radio_function(struct video_device *dev, 
				 unsigned int cmd, void *arg)
{
	struct radio_device *card=dev->priv;
	switch(cmd) {
		case VIDIOCGCAP: {
			struct video_capability v;
			
			strcpy(v.name, "Maxi Radio FM2000 radio");
			v.type=VID_TYPE_TUNER;
			v.channels=v.audios=1;
			v.maxwidth=v.maxheight=v.minwidth=v.minheight=0;
			
			if(copy_to_user(arg,&v,sizeof(v)))
				return -EFAULT;
			return 0;
		}
		case VIDIOCGTUNER: {
			struct video_tuner v;
			
			if(copy_from_user(&v, arg,sizeof(v))!=0)
				return -EFAULT;
				
			if(v.tuner)
				return -EINVAL;
				
			card->stereo = get_stereo(card->io);
			card->tuned = get_tune(card->io);
			
			v.flags = VIDEO_TUNER_LOW | card->stereo;
			v.signal = card->tuned;
			
			strcpy(v.name, "FM");
			
			v.rangelow = FREQ_LO;
			v.rangehigh = FREQ_HI;
			v.mode = VIDEO_MODE_AUTO;
			if(copy_to_user(arg,&v, sizeof(v)))
				return -EFAULT;
		        return 0;
		}
		case VIDIOCSTUNER: {
			struct video_tuner v;
			if(copy_from_user(&v, arg, sizeof(v)))
				return -EFAULT;
			if(v.tuner!=0)
				return -EINVAL;
			return 0;
		}
		case VIDIOCGFREQ: {
			unsigned long tmp=card->freq;
			
			if(copy_to_user(arg, &tmp, sizeof(tmp)))
				return -EFAULT;
				
			return 0;
		}
		
		case VIDIOCSFREQ: {
			unsigned long tmp;
			
			if(copy_from_user(&tmp, arg, sizeof(tmp)))
				return -EFAULT;
				
			if ( tmp<FREQ_LO || tmp>FREQ_HI )
				return -EINVAL;
				
			set_freq(card->io, FREQ2BITS(tmp));
			sleep_125ms();

			return 0;
		}
		case VIDIOCGAUDIO: {	
			struct video_audio v;
			strcpy(v.name, "Radio");
			v.audio=v.volume=v.bass=v.treble=v.balance=v.step=0;
			v.flags=VIDEO_AUDIO_MUTABLE | card->muted;
			v.mode=VIDEO_SOUND_STEREO;
			if(copy_to_user(arg,&v, sizeof(v)))
				return -EFAULT;
			return 0;		
		}
		case VIDIOCSAUDIO: {
			struct video_audio v;
			
			if(copy_from_user(&v, arg, sizeof(v)))
				return -EFAULT;
				
			if(v.audio)
				return -EINVAL;
				
			{
				card->muted = v.flags & VIDEO_AUDIO_MUTE;
				
				if(card->muted) turn_power(card->io, 0); else turn_power(card->io, 1);
				
				return 0;
			}
		}
		case VIDIOCGUNIT: {
			struct video_unit v;
			v.video=VIDEO_NO_UNIT;
			v.vbi=VIDEO_NO_UNIT;
			v.radio=dev->minor;
			v.audio=0;
			v.teletext=VIDEO_NO_UNIT;
			if(copy_to_user(arg, &v, sizeof(v)))
				return -EFAULT;
			return 0;		
		}
		default: return -ENOIOCTLCMD;
	}
}

static int radio_ioctl(struct video_device *dev, unsigned int cmd, void *arg)
{
	struct radio_device *card=dev->priv;
	int ret;
	down(&card->lock);
	ret = radio_function(dev, cmd, arg);
	up(&card->lock);
	return ret;
}

static int radio_open(struct video_device *dev, int flags)
{
	MOD_INC_USE_COUNT;
	return 0;
}

static void radio_close(struct video_device *dev)
{
	MOD_DEC_USE_COUNT;
}


inline static __u16 radio_install(struct pci_dev *pcidev);

MODULE_AUTHOR("Dimitromanolakis Apostolos, apdim@grecian.net");
MODULE_DESCRIPTION("Radio driver for the Guillemot Maxi Radio FM2000 radio.");

EXPORT_NO_SYMBOLS;

void __exit maxiradio_radio_exit(void)
{
	int k;
	
	video_unregister_device(&maxiradio_radio);

	for(k=0;k<found;k++) release_region(io_ports[k],4);
}

int __init maxiradio_radio_init(void)
{
	struct pci_dev *pcidev = NULL;
	if(!pci_present())
		return -ENODEV;
	
	found = 0;

	while((pcidev = pci_find_device(PCI_VENDOR_ID_GUILLEMOT, 
							PCI_DEVICE_ID_GUILLEMOT_MAXIRADIO,
						  pcidev)))
		found += radio_install(pcidev);
		
	if(found == 0) {
		printk(KERN_INFO "radio-maxiradio: no devices found.\n");
		return -ENODEV;
	}

	printk(KERN_INFO "radio-maxiradio: %d device(s) found.\n",found);
	return 0;
}

module_init(maxiradio_radio_init);
module_exit(maxiradio_radio_exit);

inline static __u16 radio_install(struct pci_dev *pcidev)
{
	radio_unit.io = pcidev->resource[0].start;

	pci_enable_device(pcidev);
	maxiradio_radio.priv = &radio_unit;
	init_MUTEX(&radio_unit.lock);
	
	if(video_register_device(&maxiradio_radio, VFL_TYPE_RADIO)==-1) {
		printk("radio-maxiradio: can't register device!");
			return 0;
		}
		
		
		printk(KERN_INFO "radio-maxiradio: version "
		       DRIVER_VERSION 
		       " time " 
		       __TIME__ "  "
		       __DATE__
		       "\n");
					 
		printk(KERN_INFO 
			"radio-maxiradio: found Guillemot MAXI Radio device (io = 0x%x)\n",
			radio_unit.io
			);


	if(!request_region(radio_unit.io, 4, "Maxi Radio FM 2000"))
		{
			printk(KERN_ERR "radio-maxiradio: port 0x%x already in use\n",
			radio_unit.io);
			
			return 0;
		}

	io_ports[found] = radio_unit.io;
					 
	return 1;
}