1// SPDX-License-Identifier: GPL-2.0-only
2/* radio-cadet.c - A video4linux driver for the ADS Cadet AM/FM Radio Card
3 *
4 * by Fred Gleason <fredg@wava.com>
5 * Version 0.3.3
6 *
7 * (Loosely) based on code for the Aztech radio card by
8 *
9 * Russell Kroll    (rkroll@exploits.org)
10 * Quay Ly
11 * Donald Song
12 * Jason Lewis      (jlewis@twilight.vtc.vsc.edu)
13 * Scott McGrath    (smcgrath@twilight.vtc.vsc.edu)
14 * William McGrath  (wmcgrath@twilight.vtc.vsc.edu)
15 *
16 * History:
17 * 2000-04-29	Russell Kroll <rkroll@exploits.org>
18 *		Added ISAPnP detection for Linux 2.3/2.4
19 *
20 * 2001-01-10	Russell Kroll <rkroll@exploits.org>
21 *		Removed dead CONFIG_RADIO_CADET_PORT code
22 *		PnP detection on load is now default (no args necessary)
23 *
24 * 2002-01-17	Adam Belay <ambx1@neo.rr.com>
25 *		Updated to latest pnp code
26 *
27 * 2003-01-31	Alan Cox <alan@lxorguk.ukuu.org.uk>
28 *		Cleaned up locking, delay code, general odds and ends
29 *
30 * 2006-07-30	Hans J. Koch <koch@hjk-az.de>
31 *		Changed API to V4L2
32 */
33
34#include <linux/module.h>	/* Modules			*/
35#include <linux/init.h>		/* Initdata			*/
36#include <linux/ioport.h>	/* request_region		*/
37#include <linux/delay.h>	/* udelay			*/
38#include <linux/videodev2.h>	/* V4L2 API defs		*/
39#include <linux/param.h>
40#include <linux/pnp.h>
41#include <linux/sched.h>
42#include <linux/io.h>		/* outb, outb_p			*/
43#include <media/v4l2-device.h>
44#include <media/v4l2-ioctl.h>
45#include <media/v4l2-ctrls.h>
46#include <media/v4l2-fh.h>
47#include <media/v4l2-event.h>
48
49MODULE_AUTHOR("Fred Gleason, Russell Kroll, Quay Lu, Donald Song, Jason Lewis, Scott McGrath, William McGrath");
50MODULE_DESCRIPTION("A driver for the ADS Cadet AM/FM/RDS radio card.");
51MODULE_LICENSE("GPL");
52MODULE_VERSION("0.3.4");
53
54static int io = -1;		/* default to isapnp activation */
55static int radio_nr = -1;
56
57module_param(io, int, 0);
58MODULE_PARM_DESC(io, "I/O address of Cadet card (0x330,0x332,0x334,0x336,0x338,0x33a,0x33c,0x33e)");
59module_param(radio_nr, int, 0);
60
61#define RDS_BUFFER 256
62#define RDS_RX_FLAG 1
63#define MBS_RX_FLAG 2
64
65struct cadet {
66	struct v4l2_device v4l2_dev;
67	struct video_device vdev;
68	struct v4l2_ctrl_handler ctrl_handler;
69	int io;
70	bool is_fm_band;
71	u32 curfreq;
72	int tunestat;
73	int sigstrength;
74	wait_queue_head_t read_queue;
75	struct timer_list readtimer;
76	u8 rdsin, rdsout, rdsstat;
77	unsigned char rdsbuf[RDS_BUFFER];
78	struct mutex lock;
79	int reading;
80};
81
82static struct cadet cadet_card;
83
84/*
85 * Signal Strength Threshold Values
86 * The V4L API spec does not define any particular unit for the signal
87 * strength value.  These values are in microvolts of RF at the tuner's input.
88 */
89static u16 sigtable[2][4] = {
90	{ 1835, 2621,  4128, 65535 },
91	{ 2185, 4369, 13107, 65535 },
92};
93
94static const struct v4l2_frequency_band bands[] = {
95	{
96		.index = 0,
97		.type = V4L2_TUNER_RADIO,
98		.capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_FREQ_BANDS,
99		.rangelow = 8320,      /* 520 kHz */
100		.rangehigh = 26400,    /* 1650 kHz */
101		.modulation = V4L2_BAND_MODULATION_AM,
102	}, {
103		.index = 1,
104		.type = V4L2_TUNER_RADIO,
105		.capability = V4L2_TUNER_CAP_STEREO | V4L2_TUNER_CAP_RDS |
106			V4L2_TUNER_CAP_RDS_BLOCK_IO | V4L2_TUNER_CAP_LOW |
107			V4L2_TUNER_CAP_FREQ_BANDS,
108		.rangelow = 1400000,   /* 87.5 MHz */
109		.rangehigh = 1728000,  /* 108.0 MHz */
110		.modulation = V4L2_BAND_MODULATION_FM,
111	},
112};
113
114
115static int cadet_getstereo(struct cadet *dev)
116{
117	int ret = V4L2_TUNER_SUB_MONO;
118
119	if (!dev->is_fm_band)	/* Only FM has stereo capability! */
120		return V4L2_TUNER_SUB_MONO;
121
122	outb(7, dev->io);          /* Select tuner control */
123	if ((inb(dev->io + 1) & 0x40) == 0)
124		ret = V4L2_TUNER_SUB_STEREO;
125	return ret;
126}
127
128static unsigned cadet_gettune(struct cadet *dev)
129{
130	int curvol, i;
131	unsigned fifo = 0;
132
133	/*
134	 * Prepare for read
135	 */
136
137	outb(7, dev->io);       /* Select tuner control */
138	curvol = inb(dev->io + 1); /* Save current volume/mute setting */
139	outb(0x00, dev->io + 1);  /* Ensure WRITE-ENABLE is LOW */
140	dev->tunestat = 0xffff;
141
142	/*
143	 * Read the shift register
144	 */
145	for (i = 0; i < 25; i++) {
146		fifo = (fifo << 1) | ((inb(dev->io + 1) >> 7) & 0x01);
147		if (i < 24) {
148			outb(0x01, dev->io + 1);
149			dev->tunestat &= inb(dev->io + 1);
150			outb(0x00, dev->io + 1);
151		}
152	}
153
154	/*
155	 * Restore volume/mute setting
156	 */
157	outb(curvol, dev->io + 1);
158	return fifo;
159}
160
161static unsigned cadet_getfreq(struct cadet *dev)
162{
163	int i;
164	unsigned freq = 0, test, fifo = 0;
165
166	/*
167	 * Read current tuning
168	 */
169	fifo = cadet_gettune(dev);
170
171	/*
172	 * Convert to actual frequency
173	 */
174	if (!dev->is_fm_band)    /* AM */
175		return ((fifo & 0x7fff) - 450) * 16;
176
177	test = 12500;
178	for (i = 0; i < 14; i++) {
179		if ((fifo & 0x01) != 0)
180			freq += test;
181		test = test << 1;
182		fifo = fifo >> 1;
183	}
184	freq -= 10700000;           /* IF frequency is 10.7 MHz */
185	freq = (freq * 16) / 1000;   /* Make it 1/16 kHz */
186	return freq;
187}
188
189static void cadet_settune(struct cadet *dev, unsigned fifo)
190{
191	int i;
192	unsigned test;
193
194	outb(7, dev->io);                /* Select tuner control */
195	/*
196	 * Write the shift register
197	 */
198	test = 0;
199	test = (fifo >> 23) & 0x02;      /* Align data for SDO */
200	test |= 0x1c;                /* SDM=1, SWE=1, SEN=1, SCK=0 */
201	outb(7, dev->io);                /* Select tuner control */
202	outb(test, dev->io + 1);           /* Initialize for write */
203	for (i = 0; i < 25; i++) {
204		test |= 0x01;              /* Toggle SCK High */
205		outb(test, dev->io + 1);
206		test &= 0xfe;              /* Toggle SCK Low */
207		outb(test, dev->io + 1);
208		fifo = fifo << 1;            /* Prepare the next bit */
209		test = 0x1c | ((fifo >> 23) & 0x02);
210		outb(test, dev->io + 1);
211	}
212}
213
214static void cadet_setfreq(struct cadet *dev, unsigned freq)
215{
216	unsigned fifo;
217	int i, j, test;
218	int curvol;
219
220	freq = clamp(freq, bands[dev->is_fm_band].rangelow,
221			   bands[dev->is_fm_band].rangehigh);
222	dev->curfreq = freq;
223	/*
224	 * Formulate a fifo command
225	 */
226	fifo = 0;
227	if (dev->is_fm_band) {    /* FM */
228		test = 102400;
229		freq = freq / 16;       /* Make it kHz */
230		freq += 10700;               /* IF is 10700 kHz */
231		for (i = 0; i < 14; i++) {
232			fifo = fifo << 1;
233			if (freq >= test) {
234				fifo |= 0x01;
235				freq -= test;
236			}
237			test = test >> 1;
238		}
239	} else {	/* AM */
240		fifo = (freq / 16) + 450;	/* Make it kHz */
241		fifo |= 0x100000;		/* Select AM Band */
242	}
243
244	/*
245	 * Save current volume/mute setting
246	 */
247
248	outb(7, dev->io);                /* Select tuner control */
249	curvol = inb(dev->io + 1);
250
251	/*
252	 * Tune the card
253	 */
254	for (j = 3; j > -1; j--) {
255		cadet_settune(dev, fifo | (j << 16));
256
257		outb(7, dev->io);         /* Select tuner control */
258		outb(curvol, dev->io + 1);
259
260		msleep(100);
261
262		cadet_gettune(dev);
263		if ((dev->tunestat & 0x40) == 0) {   /* Tuned */
264			dev->sigstrength = sigtable[dev->is_fm_band][j];
265			goto reset_rds;
266		}
267	}
268	dev->sigstrength = 0;
269reset_rds:
270	outb(3, dev->io);
271	outb(inb(dev->io + 1) & 0x7f, dev->io + 1);
272}
273
274static bool cadet_has_rds_data(struct cadet *dev)
275{
276	bool result;
277
278	mutex_lock(&dev->lock);
279	result = dev->rdsin != dev->rdsout;
280	mutex_unlock(&dev->lock);
281	return result;
282}
283
284
285static void cadet_handler(struct timer_list *t)
286{
287	struct cadet *dev = from_timer(dev, t, readtimer);
288
289	/* Service the RDS fifo */
290	if (mutex_trylock(&dev->lock)) {
291		outb(0x3, dev->io);       /* Select RDS Decoder Control */
292		if ((inb(dev->io + 1) & 0x20) != 0)
293			pr_err("cadet: RDS fifo overflow\n");
294		outb(0x80, dev->io);      /* Select RDS fifo */
295
296		while ((inb(dev->io) & 0x80) != 0) {
297			dev->rdsbuf[dev->rdsin] = inb(dev->io + 1);
298			if (dev->rdsin + 1 != dev->rdsout)
299				dev->rdsin++;
300		}
301		mutex_unlock(&dev->lock);
302	}
303
304	/*
305	 * Service pending read
306	 */
307	if (cadet_has_rds_data(dev))
308		wake_up_interruptible(&dev->read_queue);
309
310	/*
311	 * Clean up and exit
312	 */
313	dev->readtimer.expires = jiffies + msecs_to_jiffies(50);
314	add_timer(&dev->readtimer);
315}
316
317static void cadet_start_rds(struct cadet *dev)
318{
319	dev->rdsstat = 1;
320	outb(0x80, dev->io);        /* Select RDS fifo */
321	timer_setup(&dev->readtimer, cadet_handler, 0);
322	dev->readtimer.expires = jiffies + msecs_to_jiffies(50);
323	add_timer(&dev->readtimer);
324}
325
326static ssize_t cadet_read(struct file *file, char __user *data, size_t count, loff_t *ppos)
327{
328	struct cadet *dev = video_drvdata(file);
329	unsigned char readbuf[RDS_BUFFER];
330	int i = 0;
331
332	mutex_lock(&dev->lock);
333	if (dev->rdsstat == 0)
334		cadet_start_rds(dev);
335	mutex_unlock(&dev->lock);
336
337	if (!cadet_has_rds_data(dev) && (file->f_flags & O_NONBLOCK))
338		return -EWOULDBLOCK;
339	i = wait_event_interruptible(dev->read_queue, cadet_has_rds_data(dev));
340	if (i)
341		return i;
342
343	mutex_lock(&dev->lock);
344	while (i < count && dev->rdsin != dev->rdsout)
345		readbuf[i++] = dev->rdsbuf[dev->rdsout++];
346	mutex_unlock(&dev->lock);
347
348	if (i && copy_to_user(data, readbuf, i))
349		return -EFAULT;
350	return i;
351}
352
353
354static int vidioc_querycap(struct file *file, void *priv,
355				struct v4l2_capability *v)
356{
357	strscpy(v->driver, "ADS Cadet", sizeof(v->driver));
358	strscpy(v->card, "ADS Cadet", sizeof(v->card));
359	strscpy(v->bus_info, "ISA:radio-cadet", sizeof(v->bus_info));
360	return 0;
361}
362
363static int vidioc_g_tuner(struct file *file, void *priv,
364				struct v4l2_tuner *v)
365{
366	struct cadet *dev = video_drvdata(file);
367
368	if (v->index)
369		return -EINVAL;
370	v->type = V4L2_TUNER_RADIO;
371	strscpy(v->name, "Radio", sizeof(v->name));
372	v->capability = bands[0].capability | bands[1].capability;
373	v->rangelow = bands[0].rangelow;	   /* 520 kHz (start of AM band) */
374	v->rangehigh = bands[1].rangehigh;    /* 108.0 MHz (end of FM band) */
375	if (dev->is_fm_band) {
376		v->rxsubchans = cadet_getstereo(dev);
377		outb(3, dev->io);
378		outb(inb(dev->io + 1) & 0x7f, dev->io + 1);
379		mdelay(100);
380		outb(3, dev->io);
381		if (inb(dev->io + 1) & 0x80)
382			v->rxsubchans |= V4L2_TUNER_SUB_RDS;
383	} else {
384		v->rangelow = 8320;      /* 520 kHz */
385		v->rangehigh = 26400;    /* 1650 kHz */
386		v->rxsubchans = V4L2_TUNER_SUB_MONO;
387	}
388	v->audmode = V4L2_TUNER_MODE_STEREO;
389	v->signal = dev->sigstrength; /* We might need to modify scaling of this */
390	return 0;
391}
392
393static int vidioc_s_tuner(struct file *file, void *priv,
394				const struct v4l2_tuner *v)
395{
396	return v->index ? -EINVAL : 0;
397}
398
399static int vidioc_enum_freq_bands(struct file *file, void *priv,
400				struct v4l2_frequency_band *band)
401{
402	if (band->tuner)
403		return -EINVAL;
404	if (band->index >= ARRAY_SIZE(bands))
405		return -EINVAL;
406	*band = bands[band->index];
407	return 0;
408}
409
410static int vidioc_g_frequency(struct file *file, void *priv,
411				struct v4l2_frequency *f)
412{
413	struct cadet *dev = video_drvdata(file);
414
415	if (f->tuner)
416		return -EINVAL;
417	f->type = V4L2_TUNER_RADIO;
418	f->frequency = dev->curfreq;
419	return 0;
420}
421
422
423static int vidioc_s_frequency(struct file *file, void *priv,
424				const struct v4l2_frequency *f)
425{
426	struct cadet *dev = video_drvdata(file);
427
428	if (f->tuner)
429		return -EINVAL;
430	dev->is_fm_band =
431		f->frequency >= (bands[0].rangehigh + bands[1].rangelow) / 2;
432	cadet_setfreq(dev, f->frequency);
433	return 0;
434}
435
436static int cadet_s_ctrl(struct v4l2_ctrl *ctrl)
437{
438	struct cadet *dev = container_of(ctrl->handler, struct cadet, ctrl_handler);
439
440	switch (ctrl->id) {
441	case V4L2_CID_AUDIO_MUTE:
442		outb(7, dev->io);                /* Select tuner control */
443		if (ctrl->val)
444			outb(0x00, dev->io + 1);
445		else
446			outb(0x20, dev->io + 1);
447		return 0;
448	}
449	return -EINVAL;
450}
451
452static int cadet_open(struct file *file)
453{
454	struct cadet *dev = video_drvdata(file);
455	int err;
456
457	mutex_lock(&dev->lock);
458	err = v4l2_fh_open(file);
459	if (err)
460		goto fail;
461	if (v4l2_fh_is_singular_file(file))
462		init_waitqueue_head(&dev->read_queue);
463fail:
464	mutex_unlock(&dev->lock);
465	return err;
466}
467
468static int cadet_release(struct file *file)
469{
470	struct cadet *dev = video_drvdata(file);
471
472	mutex_lock(&dev->lock);
473	if (v4l2_fh_is_singular_file(file) && dev->rdsstat) {
474		del_timer_sync(&dev->readtimer);
475		dev->rdsstat = 0;
476	}
477	v4l2_fh_release(file);
478	mutex_unlock(&dev->lock);
479	return 0;
480}
481
482static __poll_t cadet_poll(struct file *file, struct poll_table_struct *wait)
483{
484	struct cadet *dev = video_drvdata(file);
485	__poll_t req_events = poll_requested_events(wait);
486	__poll_t res = v4l2_ctrl_poll(file, wait);
487
488	poll_wait(file, &dev->read_queue, wait);
489	if (dev->rdsstat == 0 && (req_events & (EPOLLIN | EPOLLRDNORM))) {
490		mutex_lock(&dev->lock);
491		if (dev->rdsstat == 0)
492			cadet_start_rds(dev);
493		mutex_unlock(&dev->lock);
494	}
495	if (cadet_has_rds_data(dev))
496		res |= EPOLLIN | EPOLLRDNORM;
497	return res;
498}
499
500
501static const struct v4l2_file_operations cadet_fops = {
502	.owner		= THIS_MODULE,
503	.open		= cadet_open,
504	.release	= cadet_release,
505	.read		= cadet_read,
506	.unlocked_ioctl	= video_ioctl2,
507	.poll		= cadet_poll,
508};
509
510static const struct v4l2_ioctl_ops cadet_ioctl_ops = {
511	.vidioc_querycap    = vidioc_querycap,
512	.vidioc_g_tuner     = vidioc_g_tuner,
513	.vidioc_s_tuner     = vidioc_s_tuner,
514	.vidioc_g_frequency = vidioc_g_frequency,
515	.vidioc_s_frequency = vidioc_s_frequency,
516	.vidioc_enum_freq_bands = vidioc_enum_freq_bands,
517	.vidioc_log_status  = v4l2_ctrl_log_status,
518	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
519	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
520};
521
522static const struct v4l2_ctrl_ops cadet_ctrl_ops = {
523	.s_ctrl = cadet_s_ctrl,
524};
525
526#ifdef CONFIG_PNP
527
528static const struct pnp_device_id cadet_pnp_devices[] = {
529	/* ADS Cadet AM/FM Radio Card */
530	{.id = "MSM0c24", .driver_data = 0},
531	{.id = ""}
532};
533
534MODULE_DEVICE_TABLE(pnp, cadet_pnp_devices);
535
536static int cadet_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
537{
538	if (!dev)
539		return -ENODEV;
540	/* only support one device */
541	if (io > 0)
542		return -EBUSY;
543
544	if (!pnp_port_valid(dev, 0))
545		return -ENODEV;
546
547	io = pnp_port_start(dev, 0);
548
549	printk(KERN_INFO "radio-cadet: PnP reports device at %#x\n", io);
550
551	return io;
552}
553
554static struct pnp_driver cadet_pnp_driver = {
555	.name		= "radio-cadet",
556	.id_table	= cadet_pnp_devices,
557	.probe		= cadet_pnp_probe,
558	.remove		= NULL,
559};
560
561#else
562static struct pnp_driver cadet_pnp_driver;
563#endif
564
565static void cadet_probe(struct cadet *dev)
566{
567	static int iovals[8] = { 0x330, 0x332, 0x334, 0x336, 0x338, 0x33a, 0x33c, 0x33e };
568	int i;
569
570	for (i = 0; i < 8; i++) {
571		dev->io = iovals[i];
572		if (request_region(dev->io, 2, "cadet-probe")) {
573			cadet_setfreq(dev, bands[1].rangelow);
574			if (cadet_getfreq(dev) == bands[1].rangelow) {
575				release_region(dev->io, 2);
576				return;
577			}
578			release_region(dev->io, 2);
579		}
580	}
581	dev->io = -1;
582}
583
584/*
585 * io should only be set if the user has used something like
586 * isapnp (the userspace program) to initialize this card for us
587 */
588
589static int __init cadet_init(void)
590{
591	struct cadet *dev = &cadet_card;
592	struct v4l2_device *v4l2_dev = &dev->v4l2_dev;
593	struct v4l2_ctrl_handler *hdl;
594	int res = -ENODEV;
595
596	strscpy(v4l2_dev->name, "cadet", sizeof(v4l2_dev->name));
597	mutex_init(&dev->lock);
598
599	/* If a probe was requested then probe ISAPnP first (safest) */
600	if (io < 0)
601		pnp_register_driver(&cadet_pnp_driver);
602	dev->io = io;
603
604	/* If that fails then probe unsafely if probe is requested */
605	if (dev->io < 0)
606		cadet_probe(dev);
607
608	/* Else we bail out */
609	if (dev->io < 0) {
610#ifdef MODULE
611		v4l2_err(v4l2_dev, "you must set an I/O address with io=0x330, 0x332, 0x334,\n");
612		v4l2_err(v4l2_dev, "0x336, 0x338, 0x33a, 0x33c or 0x33e\n");
613#endif
614		goto fail;
615	}
616	if (!request_region(dev->io, 2, "cadet"))
617		goto fail;
618
619	res = v4l2_device_register(NULL, v4l2_dev);
620	if (res < 0) {
621		release_region(dev->io, 2);
622		v4l2_err(v4l2_dev, "could not register v4l2_device\n");
623		goto fail;
624	}
625
626	hdl = &dev->ctrl_handler;
627	v4l2_ctrl_handler_init(hdl, 2);
628	v4l2_ctrl_new_std(hdl, &cadet_ctrl_ops,
629			V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
630	v4l2_dev->ctrl_handler = hdl;
631	if (hdl->error) {
632		res = hdl->error;
633		v4l2_err(v4l2_dev, "Could not register controls\n");
634		goto err_hdl;
635	}
636
637	dev->is_fm_band = true;
638	dev->curfreq = bands[dev->is_fm_band].rangelow;
639	cadet_setfreq(dev, dev->curfreq);
640	strscpy(dev->vdev.name, v4l2_dev->name, sizeof(dev->vdev.name));
641	dev->vdev.v4l2_dev = v4l2_dev;
642	dev->vdev.fops = &cadet_fops;
643	dev->vdev.ioctl_ops = &cadet_ioctl_ops;
644	dev->vdev.release = video_device_release_empty;
645	dev->vdev.lock = &dev->lock;
646	dev->vdev.device_caps = V4L2_CAP_TUNER | V4L2_CAP_RADIO |
647				V4L2_CAP_READWRITE | V4L2_CAP_RDS_CAPTURE;
648	video_set_drvdata(&dev->vdev, dev);
649
650	res = video_register_device(&dev->vdev, VFL_TYPE_RADIO, radio_nr);
651	if (res < 0)
652		goto err_hdl;
653	v4l2_info(v4l2_dev, "ADS Cadet Radio Card at 0x%x\n", dev->io);
654	return 0;
655err_hdl:
656	v4l2_ctrl_handler_free(hdl);
657	v4l2_device_unregister(v4l2_dev);
658	release_region(dev->io, 2);
659fail:
660	pnp_unregister_driver(&cadet_pnp_driver);
661	return res;
662}
663
664static void __exit cadet_exit(void)
665{
666	struct cadet *dev = &cadet_card;
667
668	video_unregister_device(&dev->vdev);
669	v4l2_ctrl_handler_free(&dev->ctrl_handler);
670	v4l2_device_unregister(&dev->v4l2_dev);
671	outb(7, dev->io);	/* Mute */
672	outb(0x00, dev->io + 1);
673	release_region(dev->io, 2);
674	pnp_unregister_driver(&cadet_pnp_driver);
675}
676
677module_init(cadet_init);
678module_exit(cadet_exit);
679
680