drivers/media/radio/radio-gemtek.c - kernel/skids - Git at Google

 /* GemTek radio card driver for Linux (C) 1998 Jonas Munsin <jmunsin@iki.fi>
  *
  * GemTek hasn't released any specs on the card, so the protocol had to
  * be reverse engineered with dosemu.
  *
  * Besides the protocol changes, this is mostly a copy of:
  *
  *    RadioTrack II driver for Linux radio support (C) 1998 Ben Pfaff
  *
  *    Based on RadioTrack I/RadioReveal (C) 1997 M. Kirkwood
  *    Converted to new API by Alan Cox <alan@lxorguk.ukuu.org.uk>
  *    Various bugfixes and enhancements by Russell Kroll <rkroll@exploits.org>
  *
  * TODO: Allow for more than one of these foolish entities :-)
  *
  * Converted to V4L2 API by Mauro Carvalho Chehab <mchehab@infradead.org>
  */

 #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>	/* kernel radio structs		*/
 #include <linux/version.h>	/* for KERNEL_VERSION MACRO	*/
 #include <linux/mutex.h>
 #include <linux/io.h>		/* outb, outb_p			*/
 #include <media/v4l2-ioctl.h>
 #include <media/v4l2-device.h>

 #define RADIO_VERSION KERNEL_VERSION(0, 0, 3)

 /*
  * Module info.
  */

 MODULE_AUTHOR("Jonas Munsin, Pekka Seppänen <pexu@kapsi.fi>");
 MODULE_DESCRIPTION("A driver for the GemTek Radio card.");
 MODULE_LICENSE("GPL");

 /*
  * Module params.
  */

 #ifndef CONFIG_RADIO_GEMTEK_PORT
 #define CONFIG_RADIO_GEMTEK_PORT -1
 #endif
 #ifndef CONFIG_RADIO_GEMTEK_PROBE
 #define CONFIG_RADIO_GEMTEK_PROBE 1
 #endif

 static int io		= CONFIG_RADIO_GEMTEK_PORT;
 static int probe	= CONFIG_RADIO_GEMTEK_PROBE;
 static int hardmute;
 static int shutdown	= 1;
 static int keepmuted	= 1;
 static int initmute	= 1;
 static int radio_nr	= -1;

 module_param(io, int, 0444);
 MODULE_PARM_DESC(io, "Force I/O port for the GemTek Radio card if automatic "
 	 "probing is disabled or fails. The most common I/O ports are: 0x20c "
 	 "0x30c, 0x24c or 0x34c (0x20c, 0x248 and 0x28c have been reported to "
 	 "work for the combined sound/radiocard).");

 module_param(probe, bool, 0444);
 MODULE_PARM_DESC(probe, "Enable automatic device probing. Note: only the most "
 	"common I/O ports used by the card are probed.");

 module_param(hardmute, bool, 0644);
 MODULE_PARM_DESC(hardmute, "Enable `hard muting' by shutting down PLL, may "
 	 "reduce static noise.");

 module_param(shutdown, bool, 0644);
 MODULE_PARM_DESC(shutdown, "Enable shutting down PLL and muting line when "
 	 "module is unloaded.");

 module_param(keepmuted, bool, 0644);
 MODULE_PARM_DESC(keepmuted, "Keep card muted even when frequency is changed.");

 module_param(initmute, bool, 0444);
 MODULE_PARM_DESC(initmute, "Mute card when module is loaded.");

 module_param(radio_nr, int, 0444);

 /*
  * Functions for controlling the card.
  */
 #define GEMTEK_LOWFREQ	(87*16000)
 #define GEMTEK_HIGHFREQ	(108*16000)

 /*
  * Frequency calculation constants.  Intermediate frequency 10.52 MHz (nominal
  * value 10.7 MHz), reference divisor 6.39 kHz (nominal 6.25 kHz).
  */
 #define FSCALE		8
 #define IF_OFFSET	((unsigned int)(10.52 * 16000 * (1<<FSCALE)))
 #define REF_FREQ	((unsigned int)(6.39 * 16 * (1<<FSCALE)))

 #define GEMTEK_CK		0x01	/* Clock signal			*/
 #define GEMTEK_DA		0x02	/* Serial data			*/
 #define GEMTEK_CE		0x04	/* Chip enable			*/
 #define GEMTEK_NS		0x08	/* No signal			*/
 #define GEMTEK_MT		0x10	/* Line mute			*/
 #define GEMTEK_STDF_3_125_KHZ	0x01	/* Standard frequency 3.125 kHz	*/
 #define GEMTEK_PLL_OFF		0x07	/* PLL off			*/

 #define BU2614_BUS_SIZE	32	/* BU2614 / BU2614FS bus size		*/

 #define SHORT_DELAY 5		/* usec */
 #define LONG_DELAY 75		/* usec */

 struct gemtek {
 	struct v4l2_device v4l2_dev;
 	struct video_device vdev;
 	struct mutex lock;
 	unsigned long lastfreq;
 	int muted;
 	int verified;
 	int io;
 	u32 bu2614data;
 };

 static struct gemtek gemtek_card;

 #define BU2614_FREQ_BITS 	16 /* D0..D15, Frequency data		*/
 #define BU2614_PORT_BITS	3 /* P0..P2, Output port control data	*/
 #define BU2614_VOID_BITS	4 /* unused 				*/
 #define BU2614_FMES_BITS	1 /* CT, Frequency measurement beginning data */
 #define BU2614_STDF_BITS	3 /* R0..R2, Standard frequency data	*/
 #define BU2614_SWIN_BITS	1 /* S, Switch between FMIN / AMIN	*/
 #define BU2614_SWAL_BITS        1 /* PS, Swallow counter division (AMIN only)*/
 #define BU2614_VOID2_BITS	1 /* unused				*/
 #define BU2614_FMUN_BITS	1 /* GT, Frequency measurement time & unlock */
 #define BU2614_TEST_BITS	1 /* TS, Test data is input		*/

 #define BU2614_FREQ_SHIFT 	0
 #define BU2614_PORT_SHIFT	(BU2614_FREQ_BITS + BU2614_FREQ_SHIFT)
 #define BU2614_VOID_SHIFT	(BU2614_PORT_BITS + BU2614_PORT_SHIFT)
 #define BU2614_FMES_SHIFT	(BU2614_VOID_BITS + BU2614_VOID_SHIFT)
 #define BU2614_STDF_SHIFT	(BU2614_FMES_BITS + BU2614_FMES_SHIFT)
 #define BU2614_SWIN_SHIFT	(BU2614_STDF_BITS + BU2614_STDF_SHIFT)
 #define BU2614_SWAL_SHIFT	(BU2614_SWIN_BITS + BU2614_SWIN_SHIFT)
 #define BU2614_VOID2_SHIFT	(BU2614_SWAL_BITS + BU2614_SWAL_SHIFT)
 #define BU2614_FMUN_SHIFT	(BU2614_VOID2_BITS + BU2614_VOID2_SHIFT)
 #define BU2614_TEST_SHIFT	(BU2614_FMUN_BITS + BU2614_FMUN_SHIFT)

 #define MKMASK(field)	(((1<<BU2614_##field##_BITS) - 1) << \
 			BU2614_##field##_SHIFT)
 #define BU2614_PORT_MASK	MKMASK(PORT)
 #define BU2614_FREQ_MASK	MKMASK(FREQ)
 #define BU2614_VOID_MASK	MKMASK(VOID)
 #define BU2614_FMES_MASK	MKMASK(FMES)
 #define BU2614_STDF_MASK	MKMASK(STDF)
 #define BU2614_SWIN_MASK	MKMASK(SWIN)
 #define BU2614_SWAL_MASK	MKMASK(SWAL)
 #define BU2614_VOID2_MASK	MKMASK(VOID2)
 #define BU2614_FMUN_MASK	MKMASK(FMUN)
 #define BU2614_TEST_MASK	MKMASK(TEST)

 /*
  * Set data which will be sent to BU2614FS.
  */
 #define gemtek_bu2614_set(dev, field, data) ((dev)->bu2614data = \
 	((dev)->bu2614data & ~field##_MASK) | ((data) << field##_SHIFT))

 /*
  * Transmit settings to BU2614FS over GemTek IC.
  */
 static void gemtek_bu2614_transmit(struct gemtek *gt)
 {
 	int i, bit, q, mute;

 	mutex_lock(&gt->lock);

 	mute = gt->muted ? GEMTEK_MT : 0x00;

 	outb_p(mute | GEMTEK_DA | GEMTEK_CK, gt->io);
 	udelay(SHORT_DELAY);
 	outb_p(mute | GEMTEK_CE | GEMTEK_DA | GEMTEK_CK, gt->io);
 	udelay(LONG_DELAY);

 	for (i = 0, q = gt->bu2614data; i < 32; i++, q >>= 1) {
 		bit = (q & 1) ? GEMTEK_DA : 0;
 		outb_p(mute | GEMTEK_CE | bit, gt->io);
 		udelay(SHORT_DELAY);
 		outb_p(mute | GEMTEK_CE | bit | GEMTEK_CK, gt->io);
 		udelay(SHORT_DELAY);
 	}

 	outb_p(mute | GEMTEK_DA | GEMTEK_CK, gt->io);
 	udelay(SHORT_DELAY);
 	outb_p(mute | GEMTEK_CE | GEMTEK_DA | GEMTEK_CK, gt->io);
 	udelay(LONG_DELAY);

 	mutex_unlock(&gt->lock);
 }

 /*
  * Calculate divisor from FM-frequency for BU2614FS (3.125 KHz STDF expected).
  */
 static unsigned long gemtek_convfreq(unsigned long freq)
 {
 	return ((freq<<FSCALE) + IF_OFFSET + REF_FREQ/2) / REF_FREQ;
 }

 /*
  * Set FM-frequency.
  */
 static void gemtek_setfreq(struct gemtek *gt, unsigned long freq)
 {
 	if (keepmuted && hardmute && gt->muted)
 		return;

 	freq = clamp_val(freq, GEMTEK_LOWFREQ, GEMTEK_HIGHFREQ);

 	gt->lastfreq = freq;
 	gt->muted = 0;

 	gemtek_bu2614_set(gt, BU2614_PORT, 0);
 	gemtek_bu2614_set(gt, BU2614_FMES, 0);
 	gemtek_bu2614_set(gt, BU2614_SWIN, 0);	/* FM-mode	*/
 	gemtek_bu2614_set(gt, BU2614_SWAL, 0);
 	gemtek_bu2614_set(gt, BU2614_FMUN, 1);	/* GT bit set	*/
 	gemtek_bu2614_set(gt, BU2614_TEST, 0);

 	gemtek_bu2614_set(gt, BU2614_STDF, GEMTEK_STDF_3_125_KHZ);
 	gemtek_bu2614_set(gt, BU2614_FREQ, gemtek_convfreq(freq));

 	gemtek_bu2614_transmit(gt);
 }

 /*
  * Set mute flag.
  */
 static void gemtek_mute(struct gemtek *gt)
 {
 	int i;

 	gt->muted = 1;

 	if (hardmute) {
 		/* Turn off PLL, disable data output */
 		gemtek_bu2614_set(gt, BU2614_PORT, 0);
 		gemtek_bu2614_set(gt, BU2614_FMES, 0);	/* CT bit off	*/
 		gemtek_bu2614_set(gt, BU2614_SWIN, 0);	/* FM-mode	*/
 		gemtek_bu2614_set(gt, BU2614_SWAL, 0);
 		gemtek_bu2614_set(gt, BU2614_FMUN, 0);	/* GT bit off	*/
 		gemtek_bu2614_set(gt, BU2614_TEST, 0);
 		gemtek_bu2614_set(gt, BU2614_STDF, GEMTEK_PLL_OFF);
 		gemtek_bu2614_set(gt, BU2614_FREQ, 0);
 		gemtek_bu2614_transmit(gt);
 		return;
 	}

 	mutex_lock(&gt->lock);

 	/* Read bus contents (CE, CK and DA). */
 	i = inb_p(gt->io);
 	/* Write it back with mute flag set. */
 	outb_p((i >> 5) | GEMTEK_MT, gt->io);
 	udelay(SHORT_DELAY);

 	mutex_unlock(&gt->lock);
 }

 /*
  * Unset mute flag.
  */
 static void gemtek_unmute(struct gemtek *gt)
 {
 	int i;

 	gt->muted = 0;
 	if (hardmute) {
 		/* Turn PLL back on. */
 		gemtek_setfreq(gt, gt->lastfreq);
 		return;
 	}
 	mutex_lock(&gt->lock);

 	i = inb_p(gt->io);
 	outb_p(i >> 5, gt->io);
 	udelay(SHORT_DELAY);

 	mutex_unlock(&gt->lock);
 }

 /*
  * Get signal strength (= stereo status).
  */
 static inline int gemtek_getsigstr(struct gemtek *gt)
 {
 	int sig;

 	mutex_lock(&gt->lock);
 	sig = inb_p(gt->io) & GEMTEK_NS ? 0 : 1;
 	mutex_unlock(&gt->lock);
 	return sig;
 }

 /*
  * Check if requested card acts like GemTek Radio card.
  */
 static int gemtek_verify(struct gemtek *gt, int port)
 {
 	int i, q;

 	if (gt->verified == port)
 		return 1;

 	mutex_lock(&gt->lock);

 	q = inb_p(port);	/* Read bus contents before probing. */
 	/* Try to turn on CE, CK and DA respectively and check if card responds
 	   properly. */
 	for (i = 0; i < 3; ++i) {
 		outb_p(1 << i, port);
 		udelay(SHORT_DELAY);

 		if ((inb_p(port) & (~GEMTEK_NS)) != (0x17 | (1 << (i + 5)))) {
 			mutex_unlock(&gt->lock);
 			return 0;
 		}
 	}
 	outb_p(q >> 5, port);	/* Write bus contents back. */
 	udelay(SHORT_DELAY);

 	mutex_unlock(&gt->lock);
 	gt->verified = port;

 	return 1;
 }

 /*
  * Automatic probing for card.
  */
 static int gemtek_probe(struct gemtek *gt)
 {
 	struct v4l2_device *v4l2_dev = &gt->v4l2_dev;
 	int ioports[] = { 0x20c, 0x30c, 0x24c, 0x34c, 0x248, 0x28c };
 	int i;

 	if (!probe) {
 		v4l2_info(v4l2_dev, "Automatic device probing disabled.\n");
 		return -1;
 	}

 	v4l2_info(v4l2_dev, "Automatic device probing enabled.\n");

 	for (i = 0; i < ARRAY_SIZE(ioports); ++i) {
 		v4l2_info(v4l2_dev, "Trying I/O port 0x%x...\n", ioports[i]);

 		if (!request_region(ioports[i], 1, "gemtek-probe")) {
 			v4l2_warn(v4l2_dev, "I/O port 0x%x busy!\n",
 			       ioports[i]);
 			continue;
 		}

 		if (gemtek_verify(gt, ioports[i])) {
 			v4l2_info(v4l2_dev, "Card found from I/O port "
 			       "0x%x!\n", ioports[i]);

 			release_region(ioports[i], 1);
 			gt->io = ioports[i];
 			return gt->io;
 		}

 		release_region(ioports[i], 1);
 	}

 	v4l2_err(v4l2_dev, "Automatic probing failed!\n");
 	return -1;
 }

 /*
  * Video 4 Linux stuff.
  */

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

 static int vidioc_querycap(struct file *file, void *priv,
 			   struct v4l2_capability *v)
 {
 	strlcpy(v->driver, "radio-gemtek", sizeof(v->driver));
 	strlcpy(v->card, "GemTek", 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 gemtek *gt = video_drvdata(file);

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

 	strlcpy(v->name, "FM", sizeof(v->name));
 	v->type = V4L2_TUNER_RADIO;
 	v->rangelow = GEMTEK_LOWFREQ;
 	v->rangehigh = GEMTEK_HIGHFREQ;
 	v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO;
 	v->signal = 0xffff * gemtek_getsigstr(gt);
 	if (v->signal) {
 		v->audmode = V4L2_TUNER_MODE_STEREO;
 		v->rxsubchans = V4L2_TUNER_SUB_STEREO;
 	} else {
 		v->audmode = V4L2_TUNER_MODE_MONO;
 		v->rxsubchans = V4L2_TUNER_SUB_MONO;
 	}
 	return 0;
 }

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

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

 	if (f->tuner != 0)
 		return -EINVAL;
 	f->type = V4L2_TUNER_RADIO;
 	f->frequency = gt->lastfreq;
 	return 0;
 }

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

 	if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
 		return -EINVAL;
 	gemtek_setfreq(gt, 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, 0);
 	default:
 		return -EINVAL;
 	}
 }

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

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

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

 	switch (ctrl->id) {
 	case V4L2_CID_AUDIO_MUTE:
 		if (ctrl->value)
 			gemtek_mute(gt);
 		else
 			gemtek_unmute(gt);
 		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 != 0) ? -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 != 0) ? -EINVAL : 0;
 }

 static const struct v4l2_ioctl_ops gemtek_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
 };

 /*
  * Initialization / cleanup related stuff.
  */

 static int __init gemtek_init(void)
 {
 	struct gemtek *gt = &gemtek_card;
 	struct v4l2_device *v4l2_dev = &gt->v4l2_dev;
 	int res;

 	strlcpy(v4l2_dev->name, "gemtek", sizeof(v4l2_dev->name));

 	v4l2_info(v4l2_dev, "GemTek Radio card driver: v0.0.3\n");

 	mutex_init(&gt->lock);

 	gt->verified = -1;
 	gt->io = io;
 	gemtek_probe(gt);
 	if (gt->io) {
 		if (!request_region(gt->io, 1, "gemtek")) {
 			v4l2_err(v4l2_dev, "I/O port 0x%x already in use.\n", gt->io);
 			return -EBUSY;
 		}

 		if (!gemtek_verify(gt, gt->io))
 			v4l2_warn(v4l2_dev, "Card at I/O port 0x%x does not "
 			       "respond properly, check your "
 			       "configuration.\n", gt->io);
 		else
 			v4l2_info(v4l2_dev, "Using I/O port 0x%x.\n", gt->io);
 	} else if (probe) {
 		v4l2_err(v4l2_dev, "Automatic probing failed and no "
 		       "fixed I/O port defined.\n");
 		return -ENODEV;
 	} else {
 		v4l2_err(v4l2_dev, "Automatic probing disabled but no fixed "
 		       "I/O port defined.");
 		return -EINVAL;
 	}

 	res = v4l2_device_register(NULL, v4l2_dev);
 	if (res < 0) {
 		v4l2_err(v4l2_dev, "Could not register v4l2_device\n");
 		release_region(gt->io, 1);
 		return res;
 	}

 	strlcpy(gt->vdev.name, v4l2_dev->name, sizeof(gt->vdev.name));
 	gt->vdev.v4l2_dev = v4l2_dev;
 	gt->vdev.fops = &gemtek_fops;
 	gt->vdev.ioctl_ops = &gemtek_ioctl_ops;
 	gt->vdev.release = video_device_release_empty;
 	video_set_drvdata(&gt->vdev, gt);

 	if (video_register_device(&gt->vdev, VFL_TYPE_RADIO, radio_nr) < 0) {
 		v4l2_device_unregister(v4l2_dev);
 		release_region(gt->io, 1);
 		return -EBUSY;
 	}

 	/* Set defaults */
 	gt->lastfreq = GEMTEK_LOWFREQ;
 	gt->bu2614data = 0;

 	if (initmute)
 		gemtek_mute(gt);

 	return 0;
 }

 /*
  * Module cleanup
  */
 static void __exit gemtek_exit(void)
 {
 	struct gemtek *gt = &gemtek_card;
 	struct v4l2_device *v4l2_dev = &gt->v4l2_dev;

 	if (shutdown) {
 		hardmute = 1;	/* Turn off PLL */
 		gemtek_mute(gt);
 	} else {
 		v4l2_info(v4l2_dev, "Module unloaded but card not muted!\n");
 	}

 	video_unregister_device(&gt->vdev);
 	v4l2_device_unregister(&gt->v4l2_dev);
 	release_region(gt->io, 1);
 }

 module_init(gemtek_init);
 module_exit(gemtek_exit);
	/* GemTek radio card driver for Linux (C) 1998 Jonas Munsin <jmunsin@iki.fi>
	*
	* GemTek hasn't released any specs on the card, so the protocol had to
	* be reverse engineered with dosemu.
	*
	* Besides the protocol changes, this is mostly a copy of:
	*
	* RadioTrack II driver for Linux radio support (C) 1998 Ben Pfaff
	*
	* Based on RadioTrack I/RadioReveal (C) 1997 M. Kirkwood
	* Converted to new API by Alan Cox <alan@lxorguk.ukuu.org.uk>
	* Various bugfixes and enhancements by Russell Kroll <rkroll@exploits.org>
	*
	* TODO: Allow for more than one of these foolish entities :-)
	*
	* Converted to V4L2 API by Mauro Carvalho Chehab <mchehab@infradead.org>
	*/

	#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> /* kernel radio structs */
	#include <linux/version.h> /* for KERNEL_VERSION MACRO */
	#include <linux/mutex.h>
	#include <linux/io.h> /* outb, outb_p */
	#include <media/v4l2-ioctl.h>
	#include <media/v4l2-device.h>

	#define RADIO_VERSION KERNEL_VERSION(0, 0, 3)

	/*
	* Module info.
	*/

	MODULE_AUTHOR("Jonas Munsin, Pekka Seppänen <pexu@kapsi.fi>");
	MODULE_DESCRIPTION("A driver for the GemTek Radio card.");
	MODULE_LICENSE("GPL");

	/*
	* Module params.
	*/

	#ifndef CONFIG_RADIO_GEMTEK_PORT
	#define CONFIG_RADIO_GEMTEK_PORT -1
	#endif
	#ifndef CONFIG_RADIO_GEMTEK_PROBE
	#define CONFIG_RADIO_GEMTEK_PROBE 1
	#endif

	static int io = CONFIG_RADIO_GEMTEK_PORT;
	static int probe = CONFIG_RADIO_GEMTEK_PROBE;
	static int hardmute;
	static int shutdown = 1;
	static int keepmuted = 1;
	static int initmute = 1;
	static int radio_nr = -1;

	module_param(io, int, 0444);
	MODULE_PARM_DESC(io, "Force I/O port for the GemTek Radio card if automatic "
	"probing is disabled or fails. The most common I/O ports are: 0x20c "
	"0x30c, 0x24c or 0x34c (0x20c, 0x248 and 0x28c have been reported to "
	"work for the combined sound/radiocard).");

	module_param(probe, bool, 0444);
	MODULE_PARM_DESC(probe, "Enable automatic device probing. Note: only the most "
	"common I/O ports used by the card are probed.");

	module_param(hardmute, bool, 0644);
	MODULE_PARM_DESC(hardmute, "Enable `hard muting' by shutting down PLL, may "
	"reduce static noise.");

	module_param(shutdown, bool, 0644);
	MODULE_PARM_DESC(shutdown, "Enable shutting down PLL and muting line when "
	"module is unloaded.");

	module_param(keepmuted, bool, 0644);
	MODULE_PARM_DESC(keepmuted, "Keep card muted even when frequency is changed.");

	module_param(initmute, bool, 0444);
	MODULE_PARM_DESC(initmute, "Mute card when module is loaded.");

	module_param(radio_nr, int, 0444);

	/*
	* Functions for controlling the card.
	*/
	#define GEMTEK_LOWFREQ (87*16000)
	#define GEMTEK_HIGHFREQ (108*16000)

	/*
	* Frequency calculation constants. Intermediate frequency 10.52 MHz (nominal
	* value 10.7 MHz), reference divisor 6.39 kHz (nominal 6.25 kHz).
	*/
	#define FSCALE 8
	#define IF_OFFSET ((unsigned int)(10.52 * 16000 * (1<<FSCALE)))
	#define REF_FREQ ((unsigned int)(6.39 * 16 * (1<<FSCALE)))

	#define GEMTEK_CK 0x01 /* Clock signal */
	#define GEMTEK_DA 0x02 /* Serial data */
	#define GEMTEK_CE 0x04 /* Chip enable */
	#define GEMTEK_NS 0x08 /* No signal */
	#define GEMTEK_MT 0x10 /* Line mute */
	#define GEMTEK_STDF_3_125_KHZ 0x01 /* Standard frequency 3.125 kHz */
	#define GEMTEK_PLL_OFF 0x07 /* PLL off */

	#define BU2614_BUS_SIZE 32 /* BU2614 / BU2614FS bus size */

	#define SHORT_DELAY 5 /* usec */
	#define LONG_DELAY 75 /* usec */

	struct gemtek {
	struct v4l2_device v4l2_dev;
	struct video_device vdev;
	struct mutex lock;
	unsigned long lastfreq;
	int muted;
	int verified;
	int io;
	u32 bu2614data;
	};

	static struct gemtek gemtek_card;

	#define BU2614_FREQ_BITS 16 /* D0..D15, Frequency data */
	#define BU2614_PORT_BITS 3 /* P0..P2, Output port control data */
	#define BU2614_VOID_BITS 4 /* unused */
	#define BU2614_FMES_BITS 1 /* CT, Frequency measurement beginning data */
	#define BU2614_STDF_BITS 3 /* R0..R2, Standard frequency data */
	#define BU2614_SWIN_BITS 1 /* S, Switch between FMIN / AMIN */
	#define BU2614_SWAL_BITS 1 /* PS, Swallow counter division (AMIN only)*/
	#define BU2614_VOID2_BITS 1 /* unused */
	#define BU2614_FMUN_BITS 1 /* GT, Frequency measurement time & unlock */
	#define BU2614_TEST_BITS 1 /* TS, Test data is input */

	#define BU2614_FREQ_SHIFT 0
	#define BU2614_PORT_SHIFT (BU2614_FREQ_BITS + BU2614_FREQ_SHIFT)
	#define BU2614_VOID_SHIFT (BU2614_PORT_BITS + BU2614_PORT_SHIFT)
	#define BU2614_FMES_SHIFT (BU2614_VOID_BITS + BU2614_VOID_SHIFT)
	#define BU2614_STDF_SHIFT (BU2614_FMES_BITS + BU2614_FMES_SHIFT)
	#define BU2614_SWIN_SHIFT (BU2614_STDF_BITS + BU2614_STDF_SHIFT)
	#define BU2614_SWAL_SHIFT (BU2614_SWIN_BITS + BU2614_SWIN_SHIFT)
	#define BU2614_VOID2_SHIFT (BU2614_SWAL_BITS + BU2614_SWAL_SHIFT)
	#define BU2614_FMUN_SHIFT (BU2614_VOID2_BITS + BU2614_VOID2_SHIFT)
	#define BU2614_TEST_SHIFT (BU2614_FMUN_BITS + BU2614_FMUN_SHIFT)

	#define MKMASK(field) (((1<<BU2614_##field##_BITS) - 1) << \
	BU2614_##field##_SHIFT)
	#define BU2614_PORT_MASK MKMASK(PORT)
	#define BU2614_FREQ_MASK MKMASK(FREQ)
	#define BU2614_VOID_MASK MKMASK(VOID)
	#define BU2614_FMES_MASK MKMASK(FMES)
	#define BU2614_STDF_MASK MKMASK(STDF)
	#define BU2614_SWIN_MASK MKMASK(SWIN)
	#define BU2614_SWAL_MASK MKMASK(SWAL)
	#define BU2614_VOID2_MASK MKMASK(VOID2)
	#define BU2614_FMUN_MASK MKMASK(FMUN)
	#define BU2614_TEST_MASK MKMASK(TEST)

	/*
	* Set data which will be sent to BU2614FS.
	*/
	#define gemtek_bu2614_set(dev, field, data) ((dev)->bu2614data = \
	((dev)->bu2614data & ~field##_MASK) \| ((data) << field##_SHIFT))

	/*
	* Transmit settings to BU2614FS over GemTek IC.
	*/
	static void gemtek_bu2614_transmit(struct gemtek *gt)
	{
	int i, bit, q, mute;

	mutex_lock(&gt->lock);

	mute = gt->muted ? GEMTEK_MT : 0x00;

	outb_p(mute \| GEMTEK_DA \| GEMTEK_CK, gt->io);
	udelay(SHORT_DELAY);
	outb_p(mute \| GEMTEK_CE \| GEMTEK_DA \| GEMTEK_CK, gt->io);
	udelay(LONG_DELAY);

	for (i = 0, q = gt->bu2614data; i < 32; i++, q >>= 1) {
	bit = (q & 1) ? GEMTEK_DA : 0;
	outb_p(mute \| GEMTEK_CE \| bit, gt->io);
	udelay(SHORT_DELAY);
	outb_p(mute \| GEMTEK_CE \| bit \| GEMTEK_CK, gt->io);
	udelay(SHORT_DELAY);
	}

	outb_p(mute \| GEMTEK_DA \| GEMTEK_CK, gt->io);
	udelay(SHORT_DELAY);
	outb_p(mute \| GEMTEK_CE \| GEMTEK_DA \| GEMTEK_CK, gt->io);
	udelay(LONG_DELAY);

	mutex_unlock(&gt->lock);
	}

	/*
	* Calculate divisor from FM-frequency for BU2614FS (3.125 KHz STDF expected).
	*/
	static unsigned long gemtek_convfreq(unsigned long freq)
	{
	return ((freq<<FSCALE) + IF_OFFSET + REF_FREQ/2) / REF_FREQ;
	}

	/*
	* Set FM-frequency.
	*/
	static void gemtek_setfreq(struct gemtek *gt, unsigned long freq)
	{
	if (keepmuted && hardmute && gt->muted)
	return;

	freq = clamp_val(freq, GEMTEK_LOWFREQ, GEMTEK_HIGHFREQ);

	gt->lastfreq = freq;
	gt->muted = 0;

	gemtek_bu2614_set(gt, BU2614_PORT, 0);
	gemtek_bu2614_set(gt, BU2614_FMES, 0);
	gemtek_bu2614_set(gt, BU2614_SWIN, 0); /* FM-mode */
	gemtek_bu2614_set(gt, BU2614_SWAL, 0);
	gemtek_bu2614_set(gt, BU2614_FMUN, 1); /* GT bit set */
	gemtek_bu2614_set(gt, BU2614_TEST, 0);

	gemtek_bu2614_set(gt, BU2614_STDF, GEMTEK_STDF_3_125_KHZ);
	gemtek_bu2614_set(gt, BU2614_FREQ, gemtek_convfreq(freq));

	gemtek_bu2614_transmit(gt);
	}

	/*
	* Set mute flag.
	*/
	static void gemtek_mute(struct gemtek *gt)
	{
	int i;

	gt->muted = 1;

	if (hardmute) {
	/* Turn off PLL, disable data output */
	gemtek_bu2614_set(gt, BU2614_PORT, 0);
	gemtek_bu2614_set(gt, BU2614_FMES, 0); /* CT bit off */
	gemtek_bu2614_set(gt, BU2614_SWIN, 0); /* FM-mode */
	gemtek_bu2614_set(gt, BU2614_SWAL, 0);
	gemtek_bu2614_set(gt, BU2614_FMUN, 0); /* GT bit off */
	gemtek_bu2614_set(gt, BU2614_TEST, 0);
	gemtek_bu2614_set(gt, BU2614_STDF, GEMTEK_PLL_OFF);
	gemtek_bu2614_set(gt, BU2614_FREQ, 0);
	gemtek_bu2614_transmit(gt);
	return;
	}

	mutex_lock(&gt->lock);

	/* Read bus contents (CE, CK and DA). */
	i = inb_p(gt->io);
	/* Write it back with mute flag set. */
	outb_p((i >> 5) \| GEMTEK_MT, gt->io);
	udelay(SHORT_DELAY);

	mutex_unlock(&gt->lock);
	}

	/*
	* Unset mute flag.
	*/
	static void gemtek_unmute(struct gemtek *gt)
	{
	int i;

	gt->muted = 0;
	if (hardmute) {
	/* Turn PLL back on. */
	gemtek_setfreq(gt, gt->lastfreq);
	return;
	}
	mutex_lock(&gt->lock);

	i = inb_p(gt->io);
	outb_p(i >> 5, gt->io);
	udelay(SHORT_DELAY);

	mutex_unlock(&gt->lock);
	}

	/*
	* Get signal strength (= stereo status).
	*/
	static inline int gemtek_getsigstr(struct gemtek *gt)
	{
	int sig;

	mutex_lock(&gt->lock);
	sig = inb_p(gt->io) & GEMTEK_NS ? 0 : 1;
	mutex_unlock(&gt->lock);
	return sig;
	}

	/*
	* Check if requested card acts like GemTek Radio card.
	*/
	static int gemtek_verify(struct gemtek *gt, int port)
	{
	int i, q;

	if (gt->verified == port)
	return 1;

	mutex_lock(&gt->lock);

	q = inb_p(port); /* Read bus contents before probing. */
	/* Try to turn on CE, CK and DA respectively and check if card responds
	properly. */
	for (i = 0; i < 3; ++i) {
	outb_p(1 << i, port);
	udelay(SHORT_DELAY);

	if ((inb_p(port) & (~GEMTEK_NS)) != (0x17 \| (1 << (i + 5)))) {
	mutex_unlock(&gt->lock);
	return 0;
	}
	}
	outb_p(q >> 5, port); /* Write bus contents back. */
	udelay(SHORT_DELAY);

	mutex_unlock(&gt->lock);
	gt->verified = port;

	return 1;
	}

	/*
	* Automatic probing for card.
	*/
	static int gemtek_probe(struct gemtek *gt)
	{
	struct v4l2_device *v4l2_dev = &gt->v4l2_dev;
	int ioports[] = { 0x20c, 0x30c, 0x24c, 0x34c, 0x248, 0x28c };
	int i;

	if (!probe) {
	v4l2_info(v4l2_dev, "Automatic device probing disabled.\n");
	return -1;
	}

	v4l2_info(v4l2_dev, "Automatic device probing enabled.\n");

	for (i = 0; i < ARRAY_SIZE(ioports); ++i) {
	v4l2_info(v4l2_dev, "Trying I/O port 0x%x...\n", ioports[i]);

	if (!request_region(ioports[i], 1, "gemtek-probe")) {
	v4l2_warn(v4l2_dev, "I/O port 0x%x busy!\n",
	ioports[i]);
	continue;
	}

	if (gemtek_verify(gt, ioports[i])) {
	v4l2_info(v4l2_dev, "Card found from I/O port "
	"0x%x!\n", ioports[i]);

	release_region(ioports[i], 1);
	gt->io = ioports[i];
	return gt->io;
	}

	release_region(ioports[i], 1);
	}

	v4l2_err(v4l2_dev, "Automatic probing failed!\n");
	return -1;
	}

	/*
	* Video 4 Linux stuff.
	*/

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

	static int vidioc_querycap(struct file file, void priv,
	struct v4l2_capability *v)
	{
	strlcpy(v->driver, "radio-gemtek", sizeof(v->driver));
	strlcpy(v->card, "GemTek", 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 gemtek *gt = video_drvdata(file);

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

	strlcpy(v->name, "FM", sizeof(v->name));
	v->type = V4L2_TUNER_RADIO;
	v->rangelow = GEMTEK_LOWFREQ;
	v->rangehigh = GEMTEK_HIGHFREQ;
	v->capability = V4L2_TUNER_CAP_LOW \| V4L2_TUNER_CAP_STEREO;
	v->signal = 0xffff * gemtek_getsigstr(gt);
	if (v->signal) {
	v->audmode = V4L2_TUNER_MODE_STEREO;
	v->rxsubchans = V4L2_TUNER_SUB_STEREO;
	} else {
	v->audmode = V4L2_TUNER_MODE_MONO;
	v->rxsubchans = V4L2_TUNER_SUB_MONO;
	}
	return 0;
	}

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

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

	if (f->tuner != 0)
	return -EINVAL;
	f->type = V4L2_TUNER_RADIO;
	f->frequency = gt->lastfreq;
	return 0;
	}

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

	if (f->tuner != 0 \|\| f->type != V4L2_TUNER_RADIO)
	return -EINVAL;
	gemtek_setfreq(gt, 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, 0);
	default:
	return -EINVAL;
	}
	}

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

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

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

	switch (ctrl->id) {
	case V4L2_CID_AUDIO_MUTE:
	if (ctrl->value)
	gemtek_mute(gt);
	else
	gemtek_unmute(gt);
	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 != 0) ? -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 != 0) ? -EINVAL : 0;
	}

	static const struct v4l2_ioctl_ops gemtek_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
	};

	/*
	* Initialization / cleanup related stuff.
	*/

	static int __init gemtek_init(void)
	{
	struct gemtek *gt = &gemtek_card;
	struct v4l2_device *v4l2_dev = &gt->v4l2_dev;
	int res;

	strlcpy(v4l2_dev->name, "gemtek", sizeof(v4l2_dev->name));

	v4l2_info(v4l2_dev, "GemTek Radio card driver: v0.0.3\n");

	mutex_init(&gt->lock);

	gt->verified = -1;
	gt->io = io;
	gemtek_probe(gt);
	if (gt->io) {
	if (!request_region(gt->io, 1, "gemtek")) {
	v4l2_err(v4l2_dev, "I/O port 0x%x already in use.\n", gt->io);
	return -EBUSY;
	}

	if (!gemtek_verify(gt, gt->io))
	v4l2_warn(v4l2_dev, "Card at I/O port 0x%x does not "
	"respond properly, check your "
	"configuration.\n", gt->io);
	else
	v4l2_info(v4l2_dev, "Using I/O port 0x%x.\n", gt->io);
	} else if (probe) {
	v4l2_err(v4l2_dev, "Automatic probing failed and no "
	"fixed I/O port defined.\n");
	return -ENODEV;
	} else {
	v4l2_err(v4l2_dev, "Automatic probing disabled but no fixed "
	"I/O port defined.");
	return -EINVAL;
	}

	res = v4l2_device_register(NULL, v4l2_dev);
	if (res < 0) {
	v4l2_err(v4l2_dev, "Could not register v4l2_device\n");
	release_region(gt->io, 1);
	return res;
	}

	strlcpy(gt->vdev.name, v4l2_dev->name, sizeof(gt->vdev.name));
	gt->vdev.v4l2_dev = v4l2_dev;
	gt->vdev.fops = &gemtek_fops;
	gt->vdev.ioctl_ops = &gemtek_ioctl_ops;
	gt->vdev.release = video_device_release_empty;
	video_set_drvdata(&gt->vdev, gt);

	if (video_register_device(&gt->vdev, VFL_TYPE_RADIO, radio_nr) < 0) {
	v4l2_device_unregister(v4l2_dev);
	release_region(gt->io, 1);
	return -EBUSY;
	}

	/* Set defaults */
	gt->lastfreq = GEMTEK_LOWFREQ;
	gt->bu2614data = 0;

	if (initmute)
	gemtek_mute(gt);

	return 0;
	}

	/*
	* Module cleanup
	*/
	static void __exit gemtek_exit(void)
	{
	struct gemtek *gt = &gemtek_card;
	struct v4l2_device *v4l2_dev = &gt->v4l2_dev;

	if (shutdown) {
	hardmute = 1; /* Turn off PLL */
	gemtek_mute(gt);
	} else {
	v4l2_info(v4l2_dev, "Module unloaded but card not muted!\n");
	}

	video_unregister_device(&gt->vdev);
	v4l2_device_unregister(&gt->v4l2_dev);
	release_region(gt->io, 1);
	}

	module_init(gemtek_init);
	module_exit(gemtek_exit);