1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Miro PCM20 radio driver for Linux radio support
4 * (c) 1998 Ruurd Reitsma <R.A.Reitsma@wbmt.tudelft.nl>
5 * Thanks to Norberto Pellici for the ACI device interface specification
6 * The API part is based on the radiotrack driver by M. Kirkwood
7 * This driver relies on the aci mixer provided by the snd-miro
8 * ALSA driver.
9 * Look there for further info...
10 *
11 * From the original miro RDS sources:
12 *
13 *  (c) 2001 Robert Siemer <Robert.Siemer@gmx.de>
14 *
15 *  Many thanks to Fred Seidel <seidel@metabox.de>, the
16 *  designer of the RDS decoder hardware. With his help
17 *  I was able to code this driver.
18 *  Thanks also to Norberto Pellicci, Dominic Mounteney
19 *  <DMounteney@pinnaclesys.com> and www.teleauskunft.de
20 *  for good hints on finding Fred. It was somewhat hard
21 *  to locate him here in Germany... [:
22 *
23 * This code has been reintroduced and converted to use
24 * the new V4L2 RDS API by:
25 *
26 * Hans Verkuil <hans.verkuil@cisco.com>
27 */
28
29#include <linux/module.h>
30#include <linux/init.h>
31#include <linux/io.h>
32#include <linux/delay.h>
33#include <linux/videodev2.h>
34#include <linux/kthread.h>
35#include <media/v4l2-device.h>
36#include <media/v4l2-ioctl.h>
37#include <media/v4l2-ctrls.h>
38#include <media/v4l2-fh.h>
39#include <media/v4l2-event.h>
40#include <sound/aci.h>
41
42#define RDS_DATASHIFT          2   /* Bit 2 */
43#define RDS_DATAMASK        (1 << RDS_DATASHIFT)
44#define RDS_BUSYMASK        0x10   /* Bit 4 */
45#define RDS_CLOCKMASK       0x08   /* Bit 3 */
46#define RDS_DATA(x)         (((x) >> RDS_DATASHIFT) & 1)
47
48#define RDS_STATUS      0x01
49#define RDS_STATIONNAME 0x02
50#define RDS_TEXT        0x03
51#define RDS_ALTFREQ     0x04
52#define RDS_TIMEDATE    0x05
53#define RDS_PI_CODE     0x06
54#define RDS_PTYTATP     0x07
55#define RDS_RESET       0x08
56#define RDS_RXVALUE     0x09
57
58static int radio_nr = -1;
59module_param(radio_nr, int, 0);
60MODULE_PARM_DESC(radio_nr, "Set radio device number (/dev/radioX).  Default: -1 (autodetect)");
61
62struct pcm20 {
63	struct v4l2_device v4l2_dev;
64	struct video_device vdev;
65	struct v4l2_ctrl_handler ctrl_handler;
66	struct v4l2_ctrl *rds_pty;
67	struct v4l2_ctrl *rds_ps_name;
68	struct v4l2_ctrl *rds_radio_test;
69	struct v4l2_ctrl *rds_ta;
70	struct v4l2_ctrl *rds_tp;
71	struct v4l2_ctrl *rds_ms;
72	/* thread for periodic RDS status checking */
73	struct task_struct *kthread;
74	unsigned long freq;
75	u32 audmode;
76	struct snd_miro_aci *aci;
77	struct mutex lock;
78};
79
80static struct pcm20 pcm20_card = {
81	.freq = 87 * 16000,
82	.audmode = V4L2_TUNER_MODE_STEREO,
83};
84
85
86static int rds_waitread(struct snd_miro_aci *aci)
87{
88	u8 byte;
89	int i = 2000;
90
91	do {
92		byte = inb(aci->aci_port + ACI_REG_RDS);
93		i--;
94	} while ((byte & RDS_BUSYMASK) && i);
95
96	/*
97	 * It's magic, but without this the data that you read later on
98	 * is unreliable and full of bit errors. With this 1 usec delay
99	 * everything is fine.
100	 */
101	udelay(1);
102	return i ? byte : -1;
103}
104
105static int rds_rawwrite(struct snd_miro_aci *aci, u8 byte)
106{
107	if (rds_waitread(aci) >= 0) {
108		outb(byte, aci->aci_port + ACI_REG_RDS);
109		return 0;
110	}
111	return -1;
112}
113
114static int rds_write(struct snd_miro_aci *aci, u8 byte)
115{
116	u8 sendbuffer[8];
117	int i;
118
119	for (i = 7; i >= 0; i--)
120		sendbuffer[7 - i] = (byte & (1 << i)) ? RDS_DATAMASK : 0;
121	sendbuffer[0] |= RDS_CLOCKMASK;
122
123	for (i = 0; i < 8; i++)
124		rds_rawwrite(aci, sendbuffer[i]);
125	return 0;
126}
127
128static int rds_readcycle_nowait(struct snd_miro_aci *aci)
129{
130	outb(0, aci->aci_port + ACI_REG_RDS);
131	return rds_waitread(aci);
132}
133
134static int rds_readcycle(struct snd_miro_aci *aci)
135{
136	if (rds_rawwrite(aci, 0) < 0)
137		return -1;
138	return rds_waitread(aci);
139}
140
141static int rds_ack(struct snd_miro_aci *aci)
142{
143	int i = rds_readcycle(aci);
144
145	if (i < 0)
146		return -1;
147	if (i & RDS_DATAMASK)
148		return 0;  /* ACK  */
149	return 1;  /* NACK */
150}
151
152static int rds_cmd(struct snd_miro_aci *aci, u8 cmd, u8 databuffer[], u8 datasize)
153{
154	int i, j;
155
156	rds_write(aci, cmd);
157
158	/* RDS_RESET doesn't need further processing */
159	if (cmd == RDS_RESET)
160		return 0;
161	if (rds_ack(aci))
162		return -EIO;
163	if (datasize == 0)
164		return 0;
165
166	/* to be able to use rds_readcycle_nowait()
167	   I have to waitread() here */
168	if (rds_waitread(aci) < 0)
169		return -1;
170
171	memset(databuffer, 0, datasize);
172
173	for (i = 0; i < 8 * datasize; i++) {
174		j = rds_readcycle_nowait(aci);
175		if (j < 0)
176			return -EIO;
177		databuffer[i / 8] |= RDS_DATA(j) << (7 - (i % 8));
178	}
179	return 0;
180}
181
182static int pcm20_setfreq(struct pcm20 *dev, unsigned long freq)
183{
184	unsigned char freql;
185	unsigned char freqh;
186	struct snd_miro_aci *aci = dev->aci;
187
188	freq /= 160;
189	if (!(aci->aci_version == 0x07 || aci->aci_version >= 0xb0))
190		freq /= 10;  /* I don't know exactly which version
191			      * needs this hack */
192	freql = freq & 0xff;
193	freqh = freq >> 8;
194
195	rds_cmd(aci, RDS_RESET, NULL, 0);
196	return snd_aci_cmd(aci, ACI_WRITE_TUNE, freql, freqh);
197}
198
199static int vidioc_querycap(struct file *file, void *priv,
200				struct v4l2_capability *v)
201{
202	struct pcm20 *dev = video_drvdata(file);
203
204	strscpy(v->driver, "Miro PCM20", sizeof(v->driver));
205	strscpy(v->card, "Miro PCM20", sizeof(v->card));
206	snprintf(v->bus_info, sizeof(v->bus_info), "ISA:%s", dev->v4l2_dev.name);
207	return 0;
208}
209
210static bool sanitize(char *p, int size)
211{
212	int i;
213	bool ret = true;
214
215	for (i = 0; i < size; i++) {
216		if (p[i] < 32) {
217			p[i] = ' ';
218			ret = false;
219		}
220	}
221	return ret;
222}
223
224static int vidioc_g_tuner(struct file *file, void *priv,
225				struct v4l2_tuner *v)
226{
227	struct pcm20 *dev = video_drvdata(file);
228	int res;
229	u8 buf;
230
231	if (v->index)
232		return -EINVAL;
233	strscpy(v->name, "FM", sizeof(v->name));
234	v->type = V4L2_TUNER_RADIO;
235	v->rangelow = 87*16000;
236	v->rangehigh = 108*16000;
237	res = snd_aci_cmd(dev->aci, ACI_READ_TUNERSTATION, -1, -1);
238	v->signal = (res & 0x80) ? 0 : 0xffff;
239	/* Note: stereo detection does not work if the audio is muted,
240	   it will default to mono in that case. */
241	res = snd_aci_cmd(dev->aci, ACI_READ_TUNERSTEREO, -1, -1);
242	v->rxsubchans = (res & 0x40) ? V4L2_TUNER_SUB_MONO :
243					V4L2_TUNER_SUB_STEREO;
244	v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
245			V4L2_TUNER_CAP_RDS | V4L2_TUNER_CAP_RDS_CONTROLS;
246	v->audmode = dev->audmode;
247	res = rds_cmd(dev->aci, RDS_RXVALUE, &buf, 1);
248	if (res >= 0 && buf)
249		v->rxsubchans |= V4L2_TUNER_SUB_RDS;
250	return 0;
251}
252
253static int vidioc_s_tuner(struct file *file, void *priv,
254				const struct v4l2_tuner *v)
255{
256	struct pcm20 *dev = video_drvdata(file);
257
258	if (v->index)
259		return -EINVAL;
260	if (v->audmode > V4L2_TUNER_MODE_STEREO)
261		dev->audmode = V4L2_TUNER_MODE_STEREO;
262	else
263		dev->audmode = v->audmode;
264	snd_aci_cmd(dev->aci, ACI_SET_TUNERMONO,
265			dev->audmode == V4L2_TUNER_MODE_MONO, -1);
266	return 0;
267}
268
269static int vidioc_g_frequency(struct file *file, void *priv,
270				struct v4l2_frequency *f)
271{
272	struct pcm20 *dev = video_drvdata(file);
273
274	if (f->tuner != 0)
275		return -EINVAL;
276
277	f->type = V4L2_TUNER_RADIO;
278	f->frequency = dev->freq;
279	return 0;
280}
281
282
283static int vidioc_s_frequency(struct file *file, void *priv,
284				const struct v4l2_frequency *f)
285{
286	struct pcm20 *dev = video_drvdata(file);
287
288	if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
289		return -EINVAL;
290
291	dev->freq = clamp_t(u32, f->frequency, 87 * 16000U, 108 * 16000U);
292	pcm20_setfreq(dev, dev->freq);
293	return 0;
294}
295
296static int pcm20_s_ctrl(struct v4l2_ctrl *ctrl)
297{
298	struct pcm20 *dev = container_of(ctrl->handler, struct pcm20, ctrl_handler);
299
300	switch (ctrl->id) {
301	case V4L2_CID_AUDIO_MUTE:
302		snd_aci_cmd(dev->aci, ACI_SET_TUNERMUTE, ctrl->val, -1);
303		return 0;
304	}
305	return -EINVAL;
306}
307
308static int pcm20_thread(void *data)
309{
310	struct pcm20 *dev = data;
311	const unsigned no_rds_start_counter = 5;
312	const unsigned sleep_msecs = 2000;
313	unsigned no_rds_counter = no_rds_start_counter;
314
315	for (;;) {
316		char text_buffer[66];
317		u8 buf;
318		int res;
319
320		msleep_interruptible(sleep_msecs);
321
322		if (kthread_should_stop())
323			break;
324
325		res = rds_cmd(dev->aci, RDS_RXVALUE, &buf, 1);
326		if (res)
327			continue;
328		if (buf == 0) {
329			if (no_rds_counter == 0)
330				continue;
331			no_rds_counter--;
332			if (no_rds_counter)
333				continue;
334
335			/*
336			 * No RDS seen for no_rds_start_counter * sleep_msecs
337			 * milliseconds, clear all RDS controls to their
338			 * default values.
339			 */
340			v4l2_ctrl_s_ctrl_string(dev->rds_ps_name, "");
341			v4l2_ctrl_s_ctrl(dev->rds_ms, 1);
342			v4l2_ctrl_s_ctrl(dev->rds_ta, 0);
343			v4l2_ctrl_s_ctrl(dev->rds_tp, 0);
344			v4l2_ctrl_s_ctrl(dev->rds_pty, 0);
345			v4l2_ctrl_s_ctrl_string(dev->rds_radio_test, "");
346			continue;
347		}
348		no_rds_counter = no_rds_start_counter;
349
350		res = rds_cmd(dev->aci, RDS_STATUS, &buf, 1);
351		if (res)
352			continue;
353		if ((buf >> 3) & 1) {
354			res = rds_cmd(dev->aci, RDS_STATIONNAME, text_buffer, 8);
355			text_buffer[8] = 0;
356			if (!res && sanitize(text_buffer, 8))
357				v4l2_ctrl_s_ctrl_string(dev->rds_ps_name, text_buffer);
358		}
359		if ((buf >> 6) & 1) {
360			u8 pty;
361
362			res = rds_cmd(dev->aci, RDS_PTYTATP, &pty, 1);
363			if (!res) {
364				v4l2_ctrl_s_ctrl(dev->rds_ms, !!(pty & 0x01));
365				v4l2_ctrl_s_ctrl(dev->rds_ta, !!(pty & 0x02));
366				v4l2_ctrl_s_ctrl(dev->rds_tp, !!(pty & 0x80));
367				v4l2_ctrl_s_ctrl(dev->rds_pty, (pty >> 2) & 0x1f);
368			}
369		}
370		if ((buf >> 4) & 1) {
371			res = rds_cmd(dev->aci, RDS_TEXT, text_buffer, 65);
372			text_buffer[65] = 0;
373			if (!res && sanitize(text_buffer + 1, 64))
374				v4l2_ctrl_s_ctrl_string(dev->rds_radio_test, text_buffer + 1);
375		}
376	}
377	return 0;
378}
379
380static int pcm20_open(struct file *file)
381{
382	struct pcm20 *dev = video_drvdata(file);
383	int res = v4l2_fh_open(file);
384
385	if (!res && v4l2_fh_is_singular_file(file) &&
386	    IS_ERR_OR_NULL(dev->kthread)) {
387		dev->kthread = kthread_run(pcm20_thread, dev, "%s",
388					   dev->v4l2_dev.name);
389		if (IS_ERR(dev->kthread)) {
390			v4l2_err(&dev->v4l2_dev, "kernel_thread() failed\n");
391			v4l2_fh_release(file);
392			return PTR_ERR(dev->kthread);
393		}
394	}
395	return res;
396}
397
398static int pcm20_release(struct file *file)
399{
400	struct pcm20 *dev = video_drvdata(file);
401
402	if (v4l2_fh_is_singular_file(file) && !IS_ERR_OR_NULL(dev->kthread)) {
403		kthread_stop(dev->kthread);
404		dev->kthread = NULL;
405	}
406	return v4l2_fh_release(file);
407}
408
409static const struct v4l2_file_operations pcm20_fops = {
410	.owner		= THIS_MODULE,
411	.open		= pcm20_open,
412	.poll		= v4l2_ctrl_poll,
413	.release	= pcm20_release,
414	.unlocked_ioctl	= video_ioctl2,
415};
416
417static const struct v4l2_ioctl_ops pcm20_ioctl_ops = {
418	.vidioc_querycap    = vidioc_querycap,
419	.vidioc_g_tuner     = vidioc_g_tuner,
420	.vidioc_s_tuner     = vidioc_s_tuner,
421	.vidioc_g_frequency = vidioc_g_frequency,
422	.vidioc_s_frequency = vidioc_s_frequency,
423	.vidioc_log_status  = v4l2_ctrl_log_status,
424	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
425	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
426};
427
428static const struct v4l2_ctrl_ops pcm20_ctrl_ops = {
429	.s_ctrl = pcm20_s_ctrl,
430};
431
432static int __init pcm20_init(void)
433{
434	struct pcm20 *dev = &pcm20_card;
435	struct v4l2_device *v4l2_dev = &dev->v4l2_dev;
436	struct v4l2_ctrl_handler *hdl;
437	int res;
438
439	dev->aci = snd_aci_get_aci();
440	if (dev->aci == NULL) {
441		v4l2_err(v4l2_dev,
442			 "you must load the snd-miro driver first!\n");
443		return -ENODEV;
444	}
445	strscpy(v4l2_dev->name, "radio-miropcm20", sizeof(v4l2_dev->name));
446	mutex_init(&dev->lock);
447
448	res = v4l2_device_register(NULL, v4l2_dev);
449	if (res < 0) {
450		v4l2_err(v4l2_dev, "could not register v4l2_device\n");
451		return -EINVAL;
452	}
453
454	hdl = &dev->ctrl_handler;
455	v4l2_ctrl_handler_init(hdl, 7);
456	v4l2_ctrl_new_std(hdl, &pcm20_ctrl_ops,
457			V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
458	dev->rds_pty = v4l2_ctrl_new_std(hdl, NULL,
459			V4L2_CID_RDS_RX_PTY, 0, 0x1f, 1, 0);
460	dev->rds_ps_name = v4l2_ctrl_new_std(hdl, NULL,
461			V4L2_CID_RDS_RX_PS_NAME, 0, 8, 8, 0);
462	dev->rds_radio_test = v4l2_ctrl_new_std(hdl, NULL,
463			V4L2_CID_RDS_RX_RADIO_TEXT, 0, 64, 64, 0);
464	dev->rds_ta = v4l2_ctrl_new_std(hdl, NULL,
465			V4L2_CID_RDS_RX_TRAFFIC_ANNOUNCEMENT, 0, 1, 1, 0);
466	dev->rds_tp = v4l2_ctrl_new_std(hdl, NULL,
467			V4L2_CID_RDS_RX_TRAFFIC_PROGRAM, 0, 1, 1, 0);
468	dev->rds_ms = v4l2_ctrl_new_std(hdl, NULL,
469			V4L2_CID_RDS_RX_MUSIC_SPEECH, 0, 1, 1, 1);
470	v4l2_dev->ctrl_handler = hdl;
471	if (hdl->error) {
472		res = hdl->error;
473		v4l2_err(v4l2_dev, "Could not register control\n");
474		goto err_hdl;
475	}
476	strscpy(dev->vdev.name, v4l2_dev->name, sizeof(dev->vdev.name));
477	dev->vdev.v4l2_dev = v4l2_dev;
478	dev->vdev.fops = &pcm20_fops;
479	dev->vdev.ioctl_ops = &pcm20_ioctl_ops;
480	dev->vdev.release = video_device_release_empty;
481	dev->vdev.lock = &dev->lock;
482	dev->vdev.device_caps = V4L2_CAP_TUNER | V4L2_CAP_RADIO |
483				V4L2_CAP_RDS_CAPTURE;
484	video_set_drvdata(&dev->vdev, dev);
485	snd_aci_cmd(dev->aci, ACI_SET_TUNERMONO,
486			dev->audmode == V4L2_TUNER_MODE_MONO, -1);
487	pcm20_setfreq(dev, dev->freq);
488
489	if (video_register_device(&dev->vdev, VFL_TYPE_RADIO, radio_nr) < 0)
490		goto err_hdl;
491
492	v4l2_info(v4l2_dev, "Mirosound PCM20 Radio tuner\n");
493	return 0;
494err_hdl:
495	v4l2_ctrl_handler_free(hdl);
496	v4l2_device_unregister(v4l2_dev);
497	return -EINVAL;
498}
499
500MODULE_AUTHOR("Ruurd Reitsma, Krzysztof Helt");
501MODULE_DESCRIPTION("A driver for the Miro PCM20 radio card.");
502MODULE_LICENSE("GPL");
503
504static void __exit pcm20_cleanup(void)
505{
506	struct pcm20 *dev = &pcm20_card;
507
508	video_unregister_device(&dev->vdev);
509	snd_aci_cmd(dev->aci, ACI_SET_TUNERMUTE, 1, -1);
510	v4l2_ctrl_handler_free(&dev->ctrl_handler);
511	v4l2_device_unregister(&dev->v4l2_dev);
512}
513
514module_init(pcm20_init);
515module_exit(pcm20_cleanup);
516