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 
58 static int radio_nr = -1;
59 module_param(radio_nr, int, 0);
60 MODULE_PARM_DESC(radio_nr, "Set radio device number (/dev/radioX).  Default: -1 (autodetect)");
61 
62 struct 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 
80 static struct pcm20 pcm20_card = {
81 	.freq = 87 * 16000,
82 	.audmode = V4L2_TUNER_MODE_STEREO,
83 };
84 
85 
86 static 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 
105 static 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 
114 static 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 
128 static 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 
134 static 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 
141 static 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 
152 static 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 
182 static 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 
199 static 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 
210 static 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 
224 static 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 
253 static 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 
269 static 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 
283 static 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 
296 static 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 
308 static 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 
380 static 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 
398 static 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 
409 static 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 
417 static 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 
428 static const struct v4l2_ctrl_ops pcm20_ctrl_ops = {
429 	.s_ctrl = pcm20_s_ctrl,
430 };
431 
432 static 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;
494 err_hdl:
495 	v4l2_ctrl_handler_free(hdl);
496 	v4l2_device_unregister(v4l2_dev);
497 	return -EINVAL;
498 }
499 
500 MODULE_AUTHOR("Ruurd Reitsma, Krzysztof Helt");
501 MODULE_DESCRIPTION("A driver for the Miro PCM20 radio card.");
502 MODULE_LICENSE("GPL");
503 
504 static 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 
514 module_init(pcm20_init);
515 module_exit(pcm20_cleanup);
516