radio-miropcm20.c

  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 <hverkuil@kernel.org>
 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	strscpy(v->driver, "Miro PCM20", sizeof(v->driver));
203	strscpy(v->card, "Miro PCM20", sizeof(v->card));
204	strscpy(v->bus_info, "ISA:radio-miropcm20", sizeof(v->bus_info));
205	return 0;
206}
207
208static bool sanitize(char *p, int size)
209{
210	int i;
211	bool ret = true;
212
213	for (i = 0; i < size; i++) {
214		if (p[i] < 32) {
215			p[i] = ' ';
216			ret = false;
217		}
218	}
219	return ret;
220}
221
222static int vidioc_g_tuner(struct file *file, void *priv,
223				struct v4l2_tuner *v)
224{
225	struct pcm20 *dev = video_drvdata(file);
226	int res;
227	u8 buf;
228
229	if (v->index)
230		return -EINVAL;
231	strscpy(v->name, "FM", sizeof(v->name));
232	v->type = V4L2_TUNER_RADIO;
233	v->rangelow = 87*16000;
234	v->rangehigh = 108*16000;
235	res = snd_aci_cmd(dev->aci, ACI_READ_TUNERSTATION, -1, -1);
236	v->signal = (res & 0x80) ? 0 : 0xffff;
237	/* Note: stereo detection does not work if the audio is muted,
238	   it will default to mono in that case. */
239	res = snd_aci_cmd(dev->aci, ACI_READ_TUNERSTEREO, -1, -1);
240	v->rxsubchans = (res & 0x40) ? V4L2_TUNER_SUB_MONO :
241					V4L2_TUNER_SUB_STEREO;
242	v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
243			V4L2_TUNER_CAP_RDS | V4L2_TUNER_CAP_RDS_CONTROLS;
244	v->audmode = dev->audmode;
245	res = rds_cmd(dev->aci, RDS_RXVALUE, &buf, 1);
246	if (res >= 0 && buf)
247		v->rxsubchans |= V4L2_TUNER_SUB_RDS;
248	return 0;
249}
250
251static int vidioc_s_tuner(struct file *file, void *priv,
252				const struct v4l2_tuner *v)
253{
254	struct pcm20 *dev = video_drvdata(file);
255
256	if (v->index)
257		return -EINVAL;
258	if (v->audmode > V4L2_TUNER_MODE_STEREO)
259		dev->audmode = V4L2_TUNER_MODE_STEREO;
260	else
261		dev->audmode = v->audmode;
262	snd_aci_cmd(dev->aci, ACI_SET_TUNERMONO,
263			dev->audmode == V4L2_TUNER_MODE_MONO, -1);
264	return 0;
265}
266
267static int vidioc_g_frequency(struct file *file, void *priv,
268				struct v4l2_frequency *f)
269{
270	struct pcm20 *dev = video_drvdata(file);
271
272	if (f->tuner != 0)
273		return -EINVAL;
274
275	f->type = V4L2_TUNER_RADIO;
276	f->frequency = dev->freq;
277	return 0;
278}
279
280
281static int vidioc_s_frequency(struct file *file, void *priv,
282				const struct v4l2_frequency *f)
283{
284	struct pcm20 *dev = video_drvdata(file);
285
286	if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
287		return -EINVAL;
288
289	dev->freq = clamp_t(u32, f->frequency, 87 * 16000U, 108 * 16000U);
290	pcm20_setfreq(dev, dev->freq);
291	return 0;
292}
293
294static int pcm20_s_ctrl(struct v4l2_ctrl *ctrl)
295{
296	struct pcm20 *dev = container_of(ctrl->handler, struct pcm20, ctrl_handler);
297
298	switch (ctrl->id) {
299	case V4L2_CID_AUDIO_MUTE:
300		snd_aci_cmd(dev->aci, ACI_SET_TUNERMUTE, ctrl->val, -1);
301		return 0;
302	}
303	return -EINVAL;
304}
305
306static int pcm20_thread(void *data)
307{
308	struct pcm20 *dev = data;
309	const unsigned no_rds_start_counter = 5;
310	const unsigned sleep_msecs = 2000;
311	unsigned no_rds_counter = no_rds_start_counter;
312
313	for (;;) {
314		char text_buffer[66];
315		u8 buf;
316		int res;
317
318		msleep_interruptible(sleep_msecs);
319
320		if (kthread_should_stop())
321			break;
322
323		res = rds_cmd(dev->aci, RDS_RXVALUE, &buf, 1);
324		if (res)
325			continue;
326		if (buf == 0) {
327			if (no_rds_counter == 0)
328				continue;
329			no_rds_counter--;
330			if (no_rds_counter)
331				continue;
332
333			/*
334			 * No RDS seen for no_rds_start_counter * sleep_msecs
335			 * milliseconds, clear all RDS controls to their
336			 * default values.
337			 */
338			v4l2_ctrl_s_ctrl_string(dev->rds_ps_name, "");
339			v4l2_ctrl_s_ctrl(dev->rds_ms, 1);
340			v4l2_ctrl_s_ctrl(dev->rds_ta, 0);
341			v4l2_ctrl_s_ctrl(dev->rds_tp, 0);
342			v4l2_ctrl_s_ctrl(dev->rds_pty, 0);
343			v4l2_ctrl_s_ctrl_string(dev->rds_radio_test, "");
344			continue;
345		}
346		no_rds_counter = no_rds_start_counter;
347
348		res = rds_cmd(dev->aci, RDS_STATUS, &buf, 1);
349		if (res)
350			continue;
351		if ((buf >> 3) & 1) {
352			res = rds_cmd(dev->aci, RDS_STATIONNAME, text_buffer, 8);
353			text_buffer[8] = 0;
354			if (!res && sanitize(text_buffer, 8))
355				v4l2_ctrl_s_ctrl_string(dev->rds_ps_name, text_buffer);
356		}
357		if ((buf >> 6) & 1) {
358			u8 pty;
359
360			res = rds_cmd(dev->aci, RDS_PTYTATP, &pty, 1);
361			if (!res) {
362				v4l2_ctrl_s_ctrl(dev->rds_ms, !!(pty & 0x01));
363				v4l2_ctrl_s_ctrl(dev->rds_ta, !!(pty & 0x02));
364				v4l2_ctrl_s_ctrl(dev->rds_tp, !!(pty & 0x80));
365				v4l2_ctrl_s_ctrl(dev->rds_pty, (pty >> 2) & 0x1f);
366			}
367		}
368		if ((buf >> 4) & 1) {
369			res = rds_cmd(dev->aci, RDS_TEXT, text_buffer, 65);
370			text_buffer[65] = 0;
371			if (!res && sanitize(text_buffer + 1, 64))
372				v4l2_ctrl_s_ctrl_string(dev->rds_radio_test, text_buffer + 1);
373		}
374	}
375	return 0;
376}
377
378static int pcm20_open(struct file *file)
379{
380	struct pcm20 *dev = video_drvdata(file);
381	int res = v4l2_fh_open(file);
382
383	if (!res && v4l2_fh_is_singular_file(file) &&
384	    IS_ERR_OR_NULL(dev->kthread)) {
385		dev->kthread = kthread_run(pcm20_thread, dev, "%s",
386					   dev->v4l2_dev.name);
387		if (IS_ERR(dev->kthread)) {
388			v4l2_err(&dev->v4l2_dev, "kernel_thread() failed\n");
389			v4l2_fh_release(file);
390			return PTR_ERR(dev->kthread);
391		}
392	}
393	return res;
394}
395
396static int pcm20_release(struct file *file)
397{
398	struct pcm20 *dev = video_drvdata(file);
399
400	if (v4l2_fh_is_singular_file(file) && !IS_ERR_OR_NULL(dev->kthread)) {
401		kthread_stop(dev->kthread);
402		dev->kthread = NULL;
403	}
404	return v4l2_fh_release(file);
405}
406
407static const struct v4l2_file_operations pcm20_fops = {
408	.owner		= THIS_MODULE,
409	.open		= pcm20_open,
410	.poll		= v4l2_ctrl_poll,
411	.release	= pcm20_release,
412	.unlocked_ioctl	= video_ioctl2,
413};
414
415static const struct v4l2_ioctl_ops pcm20_ioctl_ops = {
416	.vidioc_querycap    = vidioc_querycap,
417	.vidioc_g_tuner     = vidioc_g_tuner,
418	.vidioc_s_tuner     = vidioc_s_tuner,
419	.vidioc_g_frequency = vidioc_g_frequency,
420	.vidioc_s_frequency = vidioc_s_frequency,
421	.vidioc_log_status  = v4l2_ctrl_log_status,
422	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
423	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
424};
425
426static const struct v4l2_ctrl_ops pcm20_ctrl_ops = {
427	.s_ctrl = pcm20_s_ctrl,
428};
429
430static int __init pcm20_init(void)
431{
432	struct pcm20 *dev = &pcm20_card;
433	struct v4l2_device *v4l2_dev = &dev->v4l2_dev;
434	struct v4l2_ctrl_handler *hdl;
435	int res;
436
437	dev->aci = snd_aci_get_aci();
438	if (dev->aci == NULL) {
439		v4l2_err(v4l2_dev,
440			 "you must load the snd-miro driver first!\n");
441		return -ENODEV;
442	}
443	strscpy(v4l2_dev->name, "radio-miropcm20", sizeof(v4l2_dev->name));
444	mutex_init(&dev->lock);
445
446	res = v4l2_device_register(NULL, v4l2_dev);
447	if (res < 0) {
448		v4l2_err(v4l2_dev, "could not register v4l2_device\n");
449		return -EINVAL;
450	}
451
452	hdl = &dev->ctrl_handler;
453	v4l2_ctrl_handler_init(hdl, 7);
454	v4l2_ctrl_new_std(hdl, &pcm20_ctrl_ops,
455			V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
456	dev->rds_pty = v4l2_ctrl_new_std(hdl, NULL,
457			V4L2_CID_RDS_RX_PTY, 0, 0x1f, 1, 0);
458	dev->rds_ps_name = v4l2_ctrl_new_std(hdl, NULL,
459			V4L2_CID_RDS_RX_PS_NAME, 0, 8, 8, 0);
460	dev->rds_radio_test = v4l2_ctrl_new_std(hdl, NULL,
461			V4L2_CID_RDS_RX_RADIO_TEXT, 0, 64, 64, 0);
462	dev->rds_ta = v4l2_ctrl_new_std(hdl, NULL,
463			V4L2_CID_RDS_RX_TRAFFIC_ANNOUNCEMENT, 0, 1, 1, 0);
464	dev->rds_tp = v4l2_ctrl_new_std(hdl, NULL,
465			V4L2_CID_RDS_RX_TRAFFIC_PROGRAM, 0, 1, 1, 0);
466	dev->rds_ms = v4l2_ctrl_new_std(hdl, NULL,
467			V4L2_CID_RDS_RX_MUSIC_SPEECH, 0, 1, 1, 1);
468	v4l2_dev->ctrl_handler = hdl;
469	if (hdl->error) {
470		res = hdl->error;
471		v4l2_err(v4l2_dev, "Could not register control\n");
472		goto err_hdl;
473	}
474	strscpy(dev->vdev.name, v4l2_dev->name, sizeof(dev->vdev.name));
475	dev->vdev.v4l2_dev = v4l2_dev;
476	dev->vdev.fops = &pcm20_fops;
477	dev->vdev.ioctl_ops = &pcm20_ioctl_ops;
478	dev->vdev.release = video_device_release_empty;
479	dev->vdev.lock = &dev->lock;
480	dev->vdev.device_caps = V4L2_CAP_TUNER | V4L2_CAP_RADIO |
481				V4L2_CAP_RDS_CAPTURE;
482	video_set_drvdata(&dev->vdev, dev);
483	snd_aci_cmd(dev->aci, ACI_SET_TUNERMONO,
484			dev->audmode == V4L2_TUNER_MODE_MONO, -1);
485	pcm20_setfreq(dev, dev->freq);
486
487	if (video_register_device(&dev->vdev, VFL_TYPE_RADIO, radio_nr) < 0)
488		goto err_hdl;
489
490	v4l2_info(v4l2_dev, "Mirosound PCM20 Radio tuner\n");
491	return 0;
492err_hdl:
493	v4l2_ctrl_handler_free(hdl);
494	v4l2_device_unregister(v4l2_dev);
495	return -EINVAL;
496}
497
498MODULE_AUTHOR("Ruurd Reitsma, Krzysztof Helt");
499MODULE_DESCRIPTION("A driver for the Miro PCM20 radio card.");
500MODULE_LICENSE("GPL");
501
502static void __exit pcm20_cleanup(void)
503{
504	struct pcm20 *dev = &pcm20_card;
505
506	video_unregister_device(&dev->vdev);
507	snd_aci_cmd(dev->aci, ACI_SET_TUNERMUTE, 1, -1);
508	v4l2_ctrl_handler_free(&dev->ctrl_handler);
509	v4l2_device_unregister(&dev->v4l2_dev);
510}
511
512module_init(pcm20_init);
513module_exit(pcm20_cleanup);