1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  FM Driver for Connectivity chip of Texas Instruments.
4  *  This file provides interfaces to V4L2 subsystem.
5  *
6  *  This module registers with V4L2 subsystem as Radio
7  *  data system interface (/dev/radio). During the registration,
8  *  it will expose two set of function pointers.
9  *
10  *    1) File operation related API (open, close, read, write, poll...etc).
11  *    2) Set of V4L2 IOCTL complaint API.
12  *
13  *  Copyright (C) 2011 Texas Instruments
14  *  Author: Raja Mani <raja_mani@ti.com>
15  *  Author: Manjunatha Halli <manjunatha_halli@ti.com>
16  */
17 
18 #include <linux/export.h>
19 
20 #include "fmdrv.h"
21 #include "fmdrv_v4l2.h"
22 #include "fmdrv_common.h"
23 #include "fmdrv_rx.h"
24 #include "fmdrv_tx.h"
25 
26 static struct video_device gradio_dev;
27 static u8 radio_disconnected;
28 
29 /* -- V4L2 RADIO (/dev/radioX) device file operation interfaces --- */
30 
31 /* Read RX RDS data */
32 static ssize_t fm_v4l2_fops_read(struct file *file, char __user * buf,
33 					size_t count, loff_t *ppos)
34 {
35 	u8 rds_mode;
36 	int ret;
37 	struct fmdev *fmdev;
38 
39 	fmdev = video_drvdata(file);
40 
41 	if (!radio_disconnected) {
42 		fmerr("FM device is already disconnected\n");
43 		return -EIO;
44 	}
45 
46 	if (mutex_lock_interruptible(&fmdev->mutex))
47 		return -ERESTARTSYS;
48 
49 	/* Turn on RDS mode if it is disabled */
50 	ret = fm_rx_get_rds_mode(fmdev, &rds_mode);
51 	if (ret < 0) {
52 		fmerr("Unable to read current rds mode\n");
53 		goto read_unlock;
54 	}
55 
56 	if (rds_mode == FM_RDS_DISABLE) {
57 		ret = fmc_set_rds_mode(fmdev, FM_RDS_ENABLE);
58 		if (ret < 0) {
59 			fmerr("Failed to enable rds mode\n");
60 			goto read_unlock;
61 		}
62 	}
63 
64 	/* Copy RDS data from internal buffer to user buffer */
65 	ret = fmc_transfer_rds_from_internal_buff(fmdev, file, buf, count);
66 read_unlock:
67 	mutex_unlock(&fmdev->mutex);
68 	return ret;
69 }
70 
71 /* Write TX RDS data */
72 static ssize_t fm_v4l2_fops_write(struct file *file, const char __user * buf,
73 		size_t count, loff_t *ppos)
74 {
75 	struct tx_rds rds;
76 	int ret;
77 	struct fmdev *fmdev;
78 
79 	ret = copy_from_user(&rds, buf, sizeof(rds));
80 	rds.text[sizeof(rds.text) - 1] = '\0';
81 	fmdbg("(%d)type: %d, text %s, af %d\n",
82 		   ret, rds.text_type, rds.text, rds.af_freq);
83 	if (ret)
84 		return -EFAULT;
85 
86 	fmdev = video_drvdata(file);
87 	if (mutex_lock_interruptible(&fmdev->mutex))
88 		return -ERESTARTSYS;
89 	fm_tx_set_radio_text(fmdev, rds.text, rds.text_type);
90 	fm_tx_set_af(fmdev, rds.af_freq);
91 	mutex_unlock(&fmdev->mutex);
92 
93 	return sizeof(rds);
94 }
95 
96 static __poll_t fm_v4l2_fops_poll(struct file *file, struct poll_table_struct *pts)
97 {
98 	int ret;
99 	struct fmdev *fmdev;
100 
101 	fmdev = video_drvdata(file);
102 	mutex_lock(&fmdev->mutex);
103 	ret = fmc_is_rds_data_available(fmdev, file, pts);
104 	mutex_unlock(&fmdev->mutex);
105 	if (ret < 0)
106 		return EPOLLIN | EPOLLRDNORM;
107 
108 	return 0;
109 }
110 
111 /*
112  * Handle open request for "/dev/radioX" device.
113  * Start with FM RX mode as default.
114  */
115 static int fm_v4l2_fops_open(struct file *file)
116 {
117 	int ret;
118 	struct fmdev *fmdev = NULL;
119 
120 	/* Don't allow multiple open */
121 	if (radio_disconnected) {
122 		fmerr("FM device is already opened\n");
123 		return -EBUSY;
124 	}
125 
126 	fmdev = video_drvdata(file);
127 
128 	if (mutex_lock_interruptible(&fmdev->mutex))
129 		return -ERESTARTSYS;
130 	ret = fmc_prepare(fmdev);
131 	if (ret < 0) {
132 		fmerr("Unable to prepare FM CORE\n");
133 		goto open_unlock;
134 	}
135 
136 	fmdbg("Load FM RX firmware..\n");
137 
138 	ret = fmc_set_mode(fmdev, FM_MODE_RX);
139 	if (ret < 0) {
140 		fmerr("Unable to load FM RX firmware\n");
141 		goto open_unlock;
142 	}
143 	radio_disconnected = 1;
144 
145 open_unlock:
146 	mutex_unlock(&fmdev->mutex);
147 	return ret;
148 }
149 
150 static int fm_v4l2_fops_release(struct file *file)
151 {
152 	int ret;
153 	struct fmdev *fmdev;
154 
155 	fmdev = video_drvdata(file);
156 	if (!radio_disconnected) {
157 		fmdbg("FM device is already closed\n");
158 		return 0;
159 	}
160 
161 	mutex_lock(&fmdev->mutex);
162 	ret = fmc_set_mode(fmdev, FM_MODE_OFF);
163 	if (ret < 0) {
164 		fmerr("Unable to turn off the chip\n");
165 		goto release_unlock;
166 	}
167 
168 	ret = fmc_release(fmdev);
169 	if (ret < 0) {
170 		fmerr("FM CORE release failed\n");
171 		goto release_unlock;
172 	}
173 	radio_disconnected = 0;
174 
175 release_unlock:
176 	mutex_unlock(&fmdev->mutex);
177 	return ret;
178 }
179 
180 /* V4L2 RADIO (/dev/radioX) device IOCTL interfaces */
181 static int fm_v4l2_vidioc_querycap(struct file *file, void *priv,
182 		struct v4l2_capability *capability)
183 {
184 	strscpy(capability->driver, FM_DRV_NAME, sizeof(capability->driver));
185 	strscpy(capability->card, FM_DRV_CARD_SHORT_NAME,
186 		sizeof(capability->card));
187 	sprintf(capability->bus_info, "UART");
188 	return 0;
189 }
190 
191 static int fm_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
192 {
193 	struct fmdev *fmdev = container_of(ctrl->handler,
194 			struct fmdev, ctrl_handler);
195 
196 	switch (ctrl->id) {
197 	case  V4L2_CID_TUNE_ANTENNA_CAPACITOR:
198 		ctrl->val = fm_tx_get_tune_cap_val(fmdev);
199 		break;
200 	default:
201 		fmwarn("%s: Unknown IOCTL: %d\n", __func__, ctrl->id);
202 		break;
203 	}
204 
205 	return 0;
206 }
207 
208 static int fm_v4l2_s_ctrl(struct v4l2_ctrl *ctrl)
209 {
210 	struct fmdev *fmdev = container_of(ctrl->handler,
211 			struct fmdev, ctrl_handler);
212 
213 	switch (ctrl->id) {
214 	case V4L2_CID_AUDIO_VOLUME:	/* set volume */
215 		return fm_rx_set_volume(fmdev, (u16)ctrl->val);
216 
217 	case V4L2_CID_AUDIO_MUTE:	/* set mute */
218 		return fmc_set_mute_mode(fmdev, (u8)ctrl->val);
219 
220 	case V4L2_CID_TUNE_POWER_LEVEL:
221 		/* set TX power level - ext control */
222 		return fm_tx_set_pwr_lvl(fmdev, (u8)ctrl->val);
223 
224 	case V4L2_CID_TUNE_PREEMPHASIS:
225 		return fm_tx_set_preemph_filter(fmdev, (u8) ctrl->val);
226 
227 	default:
228 		return -EINVAL;
229 	}
230 }
231 
232 static int fm_v4l2_vidioc_g_audio(struct file *file, void *priv,
233 		struct v4l2_audio *audio)
234 {
235 	memset(audio, 0, sizeof(*audio));
236 	strscpy(audio->name, "Radio", sizeof(audio->name));
237 	audio->capability = V4L2_AUDCAP_STEREO;
238 
239 	return 0;
240 }
241 
242 static int fm_v4l2_vidioc_s_audio(struct file *file, void *priv,
243 		const struct v4l2_audio *audio)
244 {
245 	if (audio->index != 0)
246 		return -EINVAL;
247 
248 	return 0;
249 }
250 
251 /* Get tuner attributes. If current mode is NOT RX, return error */
252 static int fm_v4l2_vidioc_g_tuner(struct file *file, void *priv,
253 		struct v4l2_tuner *tuner)
254 {
255 	struct fmdev *fmdev = video_drvdata(file);
256 	u32 bottom_freq;
257 	u32 top_freq;
258 	u16 stereo_mono_mode;
259 	u16 rssilvl;
260 	int ret;
261 
262 	if (tuner->index != 0)
263 		return -EINVAL;
264 
265 	if (fmdev->curr_fmmode != FM_MODE_RX)
266 		return -EPERM;
267 
268 	ret = fm_rx_get_band_freq_range(fmdev, &bottom_freq, &top_freq);
269 	if (ret != 0)
270 		return ret;
271 
272 	ret = fm_rx_get_stereo_mono(fmdev, &stereo_mono_mode);
273 	if (ret != 0)
274 		return ret;
275 
276 	ret = fm_rx_get_rssi_level(fmdev, &rssilvl);
277 	if (ret != 0)
278 		return ret;
279 
280 	strscpy(tuner->name, "FM", sizeof(tuner->name));
281 	tuner->type = V4L2_TUNER_RADIO;
282 	/* Store rangelow and rangehigh freq in unit of 62.5 Hz */
283 	tuner->rangelow = bottom_freq * 16;
284 	tuner->rangehigh = top_freq * 16;
285 	tuner->rxsubchans = V4L2_TUNER_SUB_MONO | V4L2_TUNER_SUB_STEREO |
286 	((fmdev->rx.rds.flag == FM_RDS_ENABLE) ? V4L2_TUNER_SUB_RDS : 0);
287 	tuner->capability = V4L2_TUNER_CAP_STEREO | V4L2_TUNER_CAP_RDS |
288 			    V4L2_TUNER_CAP_LOW |
289 			    V4L2_TUNER_CAP_HWSEEK_BOUNDED |
290 			    V4L2_TUNER_CAP_HWSEEK_WRAP;
291 	tuner->audmode = (stereo_mono_mode ?
292 			  V4L2_TUNER_MODE_MONO : V4L2_TUNER_MODE_STEREO);
293 
294 	/*
295 	 * Actual rssi value lies in between -128 to +127.
296 	 * Convert this range from 0 to 255 by adding +128
297 	 */
298 	rssilvl += 128;
299 
300 	/*
301 	 * Return signal strength value should be within 0 to 65535.
302 	 * Find out correct signal radio by multiplying (65535/255) = 257
303 	 */
304 	tuner->signal = rssilvl * 257;
305 	tuner->afc = 0;
306 
307 	return ret;
308 }
309 
310 /*
311  * Set tuner attributes. If current mode is NOT RX, set to RX.
312  * Currently, we set only audio mode (mono/stereo) and RDS state (on/off).
313  * Should we set other tuner attributes, too?
314  */
315 static int fm_v4l2_vidioc_s_tuner(struct file *file, void *priv,
316 		const struct v4l2_tuner *tuner)
317 {
318 	struct fmdev *fmdev = video_drvdata(file);
319 	u16 aud_mode;
320 	u8 rds_mode;
321 	int ret;
322 
323 	if (tuner->index != 0)
324 		return -EINVAL;
325 
326 	aud_mode = (tuner->audmode == V4L2_TUNER_MODE_STEREO) ?
327 			FM_STEREO_MODE : FM_MONO_MODE;
328 	rds_mode = (tuner->rxsubchans & V4L2_TUNER_SUB_RDS) ?
329 			FM_RDS_ENABLE : FM_RDS_DISABLE;
330 
331 	if (fmdev->curr_fmmode != FM_MODE_RX) {
332 		ret = fmc_set_mode(fmdev, FM_MODE_RX);
333 		if (ret < 0) {
334 			fmerr("Failed to set RX mode\n");
335 			return ret;
336 		}
337 	}
338 
339 	ret = fmc_set_stereo_mono(fmdev, aud_mode);
340 	if (ret < 0) {
341 		fmerr("Failed to set RX stereo/mono mode\n");
342 		return ret;
343 	}
344 
345 	ret = fmc_set_rds_mode(fmdev, rds_mode);
346 	if (ret < 0)
347 		fmerr("Failed to set RX RDS mode\n");
348 
349 	return ret;
350 }
351 
352 /* Get tuner or modulator radio frequency */
353 static int fm_v4l2_vidioc_g_freq(struct file *file, void *priv,
354 		struct v4l2_frequency *freq)
355 {
356 	struct fmdev *fmdev = video_drvdata(file);
357 	int ret;
358 
359 	ret = fmc_get_freq(fmdev, &freq->frequency);
360 	if (ret < 0) {
361 		fmerr("Failed to get frequency\n");
362 		return ret;
363 	}
364 
365 	/* Frequency unit of 62.5 Hz*/
366 	freq->frequency = (u32) freq->frequency * 16;
367 
368 	return 0;
369 }
370 
371 /* Set tuner or modulator radio frequency */
372 static int fm_v4l2_vidioc_s_freq(struct file *file, void *priv,
373 		const struct v4l2_frequency *freq)
374 {
375 	struct fmdev *fmdev = video_drvdata(file);
376 
377 	/*
378 	 * As V4L2_TUNER_CAP_LOW is set 1 user sends the frequency
379 	 * in units of 62.5 Hz.
380 	 */
381 	return fmc_set_freq(fmdev, freq->frequency / 16);
382 }
383 
384 /* Set hardware frequency seek. If current mode is NOT RX, set it RX. */
385 static int fm_v4l2_vidioc_s_hw_freq_seek(struct file *file, void *priv,
386 		const struct v4l2_hw_freq_seek *seek)
387 {
388 	struct fmdev *fmdev = video_drvdata(file);
389 	int ret;
390 
391 	if (file->f_flags & O_NONBLOCK)
392 		return -EWOULDBLOCK;
393 
394 	if (fmdev->curr_fmmode != FM_MODE_RX) {
395 		ret = fmc_set_mode(fmdev, FM_MODE_RX);
396 		if (ret != 0) {
397 			fmerr("Failed to set RX mode\n");
398 			return ret;
399 		}
400 	}
401 
402 	ret = fm_rx_seek(fmdev, seek->seek_upward, seek->wrap_around,
403 			seek->spacing);
404 	if (ret < 0)
405 		fmerr("RX seek failed - %d\n", ret);
406 
407 	return ret;
408 }
409 /* Get modulator attributes. If mode is not TX, return no attributes. */
410 static int fm_v4l2_vidioc_g_modulator(struct file *file, void *priv,
411 		struct v4l2_modulator *mod)
412 {
413 	struct fmdev *fmdev = video_drvdata(file);
414 
415 	if (mod->index != 0)
416 		return -EINVAL;
417 
418 	if (fmdev->curr_fmmode != FM_MODE_TX)
419 		return -EPERM;
420 
421 	mod->txsubchans = ((fmdev->tx_data.aud_mode == FM_STEREO_MODE) ?
422 				V4L2_TUNER_SUB_STEREO : V4L2_TUNER_SUB_MONO) |
423 				((fmdev->tx_data.rds.flag == FM_RDS_ENABLE) ?
424 				V4L2_TUNER_SUB_RDS : 0);
425 
426 	mod->capability = V4L2_TUNER_CAP_STEREO | V4L2_TUNER_CAP_RDS |
427 				V4L2_TUNER_CAP_LOW;
428 
429 	return 0;
430 }
431 
432 /* Set modulator attributes. If mode is not TX, set to TX. */
433 static int fm_v4l2_vidioc_s_modulator(struct file *file, void *priv,
434 		const struct v4l2_modulator *mod)
435 {
436 	struct fmdev *fmdev = video_drvdata(file);
437 	u8 rds_mode;
438 	u16 aud_mode;
439 	int ret;
440 
441 	if (mod->index != 0)
442 		return -EINVAL;
443 
444 	if (fmdev->curr_fmmode != FM_MODE_TX) {
445 		ret = fmc_set_mode(fmdev, FM_MODE_TX);
446 		if (ret != 0) {
447 			fmerr("Failed to set TX mode\n");
448 			return ret;
449 		}
450 	}
451 
452 	aud_mode = (mod->txsubchans & V4L2_TUNER_SUB_STEREO) ?
453 			FM_STEREO_MODE : FM_MONO_MODE;
454 	rds_mode = (mod->txsubchans & V4L2_TUNER_SUB_RDS) ?
455 			FM_RDS_ENABLE : FM_RDS_DISABLE;
456 	ret = fm_tx_set_stereo_mono(fmdev, aud_mode);
457 	if (ret < 0) {
458 		fmerr("Failed to set mono/stereo mode for TX\n");
459 		return ret;
460 	}
461 	ret = fm_tx_set_rds_mode(fmdev, rds_mode);
462 	if (ret < 0)
463 		fmerr("Failed to set rds mode for TX\n");
464 
465 	return ret;
466 }
467 
468 static const struct v4l2_file_operations fm_drv_fops = {
469 	.owner = THIS_MODULE,
470 	.read = fm_v4l2_fops_read,
471 	.write = fm_v4l2_fops_write,
472 	.poll = fm_v4l2_fops_poll,
473 	.unlocked_ioctl = video_ioctl2,
474 	.open = fm_v4l2_fops_open,
475 	.release = fm_v4l2_fops_release,
476 };
477 
478 static const struct v4l2_ctrl_ops fm_ctrl_ops = {
479 	.s_ctrl = fm_v4l2_s_ctrl,
480 	.g_volatile_ctrl = fm_g_volatile_ctrl,
481 };
482 static const struct v4l2_ioctl_ops fm_drv_ioctl_ops = {
483 	.vidioc_querycap = fm_v4l2_vidioc_querycap,
484 	.vidioc_g_audio = fm_v4l2_vidioc_g_audio,
485 	.vidioc_s_audio = fm_v4l2_vidioc_s_audio,
486 	.vidioc_g_tuner = fm_v4l2_vidioc_g_tuner,
487 	.vidioc_s_tuner = fm_v4l2_vidioc_s_tuner,
488 	.vidioc_g_frequency = fm_v4l2_vidioc_g_freq,
489 	.vidioc_s_frequency = fm_v4l2_vidioc_s_freq,
490 	.vidioc_s_hw_freq_seek = fm_v4l2_vidioc_s_hw_freq_seek,
491 	.vidioc_g_modulator = fm_v4l2_vidioc_g_modulator,
492 	.vidioc_s_modulator = fm_v4l2_vidioc_s_modulator
493 };
494 
495 /* V4L2 RADIO device parent structure */
496 static const struct video_device fm_viddev_template = {
497 	.fops = &fm_drv_fops,
498 	.ioctl_ops = &fm_drv_ioctl_ops,
499 	.name = FM_DRV_NAME,
500 	.release = video_device_release_empty,
501 	/*
502 	 * To ensure both the tuner and modulator ioctls are accessible we
503 	 * set the vfl_dir to M2M to indicate this.
504 	 *
505 	 * It is not really a mem2mem device of course, but it can both receive
506 	 * and transmit using the same radio device. It's the only radio driver
507 	 * that does this and it should really be split in two radio devices,
508 	 * but that would affect applications using this driver.
509 	 */
510 	.vfl_dir = VFL_DIR_M2M,
511 	.device_caps = V4L2_CAP_HW_FREQ_SEEK | V4L2_CAP_TUNER | V4L2_CAP_RADIO |
512 		       V4L2_CAP_MODULATOR | V4L2_CAP_AUDIO |
513 		       V4L2_CAP_READWRITE | V4L2_CAP_RDS_CAPTURE,
514 };
515 
516 int fm_v4l2_init_video_device(struct fmdev *fmdev, int radio_nr)
517 {
518 	struct v4l2_ctrl *ctrl;
519 	int ret;
520 
521 	strscpy(fmdev->v4l2_dev.name, FM_DRV_NAME,
522 		sizeof(fmdev->v4l2_dev.name));
523 	ret = v4l2_device_register(NULL, &fmdev->v4l2_dev);
524 	if (ret < 0)
525 		return ret;
526 
527 	/* Init mutex for core locking */
528 	mutex_init(&fmdev->mutex);
529 
530 	/* Setup FM driver's V4L2 properties */
531 	gradio_dev = fm_viddev_template;
532 
533 	video_set_drvdata(&gradio_dev, fmdev);
534 
535 	gradio_dev.lock = &fmdev->mutex;
536 	gradio_dev.v4l2_dev = &fmdev->v4l2_dev;
537 
538 	/* Register with V4L2 subsystem as RADIO device */
539 	if (video_register_device(&gradio_dev, VFL_TYPE_RADIO, radio_nr)) {
540 		v4l2_device_unregister(&fmdev->v4l2_dev);
541 		fmerr("Could not register video device\n");
542 		return -ENOMEM;
543 	}
544 
545 	fmdev->radio_dev = &gradio_dev;
546 
547 	/* Register to v4l2 ctrl handler framework */
548 	fmdev->radio_dev->ctrl_handler = &fmdev->ctrl_handler;
549 
550 	ret = v4l2_ctrl_handler_init(&fmdev->ctrl_handler, 5);
551 	if (ret < 0) {
552 		fmerr("(fmdev): Can't init ctrl handler\n");
553 		v4l2_ctrl_handler_free(&fmdev->ctrl_handler);
554 		video_unregister_device(fmdev->radio_dev);
555 		v4l2_device_unregister(&fmdev->v4l2_dev);
556 		return -EBUSY;
557 	}
558 
559 	/*
560 	 * Following controls are handled by V4L2 control framework.
561 	 * Added in ascending ID order.
562 	 */
563 	v4l2_ctrl_new_std(&fmdev->ctrl_handler, &fm_ctrl_ops,
564 			V4L2_CID_AUDIO_VOLUME, FM_RX_VOLUME_MIN,
565 			FM_RX_VOLUME_MAX, 1, FM_RX_VOLUME_MAX);
566 
567 	v4l2_ctrl_new_std(&fmdev->ctrl_handler, &fm_ctrl_ops,
568 			V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
569 
570 	v4l2_ctrl_new_std_menu(&fmdev->ctrl_handler, &fm_ctrl_ops,
571 			V4L2_CID_TUNE_PREEMPHASIS, V4L2_PREEMPHASIS_75_uS,
572 			0, V4L2_PREEMPHASIS_75_uS);
573 
574 	v4l2_ctrl_new_std(&fmdev->ctrl_handler, &fm_ctrl_ops,
575 			V4L2_CID_TUNE_POWER_LEVEL, FM_PWR_LVL_LOW,
576 			FM_PWR_LVL_HIGH, 1, FM_PWR_LVL_HIGH);
577 
578 	ctrl = v4l2_ctrl_new_std(&fmdev->ctrl_handler, &fm_ctrl_ops,
579 			V4L2_CID_TUNE_ANTENNA_CAPACITOR, 0,
580 			255, 1, 255);
581 
582 	if (ctrl)
583 		ctrl->flags |= V4L2_CTRL_FLAG_VOLATILE;
584 
585 	return 0;
586 }
587 
588 void *fm_v4l2_deinit_video_device(void)
589 {
590 	struct fmdev *fmdev;
591 
592 
593 	fmdev = video_get_drvdata(&gradio_dev);
594 
595 	/* Unregister to v4l2 ctrl handler framework*/
596 	v4l2_ctrl_handler_free(&fmdev->ctrl_handler);
597 
598 	/* Unregister RADIO device from V4L2 subsystem */
599 	video_unregister_device(&gradio_dev);
600 
601 	v4l2_device_unregister(&fmdev->v4l2_dev);
602 
603 	return fmdev;
604 }
605