xref: /openbmc/linux/drivers/media/radio/radio-miropcm20.c (revision 0898782247ae533d1f4e47a06bc5d4870931b284)
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  
rds_waitread(struct snd_miro_aci * aci)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  
rds_rawwrite(struct snd_miro_aci * aci,u8 byte)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  
rds_write(struct snd_miro_aci * aci,u8 byte)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  
rds_readcycle_nowait(struct snd_miro_aci * aci)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  
rds_readcycle(struct snd_miro_aci * aci)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  
rds_ack(struct snd_miro_aci * aci)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  
rds_cmd(struct snd_miro_aci * aci,u8 cmd,u8 databuffer[],u8 datasize)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  
pcm20_setfreq(struct pcm20 * dev,unsigned long freq)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  
vidioc_querycap(struct file * file,void * priv,struct v4l2_capability * v)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  
sanitize(char * p,int size)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  
vidioc_g_tuner(struct file * file,void * priv,struct v4l2_tuner * v)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  
vidioc_s_tuner(struct file * file,void * priv,const struct v4l2_tuner * v)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  
vidioc_g_frequency(struct file * file,void * priv,struct v4l2_frequency * f)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  
vidioc_s_frequency(struct file * file,void * priv,const struct v4l2_frequency * f)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  
pcm20_s_ctrl(struct v4l2_ctrl * ctrl)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  
pcm20_thread(void * data)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  
pcm20_open(struct file * file)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  
pcm20_release(struct file * file)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  
pcm20_init(void)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  
pcm20_cleanup(void)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