vivid-sdr-cap.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * vivid-sdr-cap.c - software defined radio support functions.
  4 *
  5 * Copyright 2014 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
  6 */
  7
  8#include <linux/errno.h>
  9#include <linux/kernel.h>
 10#include <linux/delay.h>
 11#include <linux/kthread.h>
 12#include <linux/freezer.h>
 13#include <linux/math64.h>
 14#include <linux/videodev2.h>
 15#include <linux/v4l2-dv-timings.h>
 16#include <media/v4l2-common.h>
 17#include <media/v4l2-event.h>
 18#include <media/v4l2-dv-timings.h>
 19#include <linux/fixp-arith.h>
 20#include <linux/jiffies.h>
 21
 22#include "vivid-core.h"
 23#include "vivid-ctrls.h"
 24#include "vivid-sdr-cap.h"
 25
 26/* stream formats */
 27struct vivid_format {
 28	u32	pixelformat;
 29	u32	buffersize;
 30};
 31
 32/* format descriptions for capture and preview */
 33static const struct vivid_format formats[] = {
 34	{
 35		.pixelformat	= V4L2_SDR_FMT_CU8,
 36		.buffersize	= SDR_CAP_SAMPLES_PER_BUF * 2,
 37	}, {
 38		.pixelformat	= V4L2_SDR_FMT_CS8,
 39		.buffersize	= SDR_CAP_SAMPLES_PER_BUF * 2,
 40	},
 41};
 42
 43static const struct v4l2_frequency_band bands_adc[] = {
 44	{
 45		.tuner = 0,
 46		.type = V4L2_TUNER_ADC,
 47		.index = 0,
 48		.capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS,
 49		.rangelow   =  300000,
 50		.rangehigh  =  300000,
 51	},
 52	{
 53		.tuner = 0,
 54		.type = V4L2_TUNER_ADC,
 55		.index = 1,
 56		.capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS,
 57		.rangelow   =  900001,
 58		.rangehigh  = 2800000,
 59	},
 60	{
 61		.tuner = 0,
 62		.type = V4L2_TUNER_ADC,
 63		.index = 2,
 64		.capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS,
 65		.rangelow   = 3200000,
 66		.rangehigh  = 3200000,
 67	},
 68};
 69
 70/* ADC band midpoints */
 71#define BAND_ADC_0 ((bands_adc[0].rangehigh + bands_adc[1].rangelow) / 2)
 72#define BAND_ADC_1 ((bands_adc[1].rangehigh + bands_adc[2].rangelow) / 2)
 73
 74static const struct v4l2_frequency_band bands_fm[] = {
 75	{
 76		.tuner = 1,
 77		.type = V4L2_TUNER_RF,
 78		.index = 0,
 79		.capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS,
 80		.rangelow   =    50000000,
 81		.rangehigh  =  2000000000,
 82	},
 83};
 84
 85static void vivid_thread_sdr_cap_tick(struct vivid_dev *dev)
 86{
 87	struct vivid_buffer *sdr_cap_buf = NULL;
 88
 89	dprintk(dev, 1, "SDR Capture Thread Tick\n");
 90
 91	/* Drop a certain percentage of buffers. */
 92	if (dev->perc_dropped_buffers &&
 93	    get_random_u32_below(100) < dev->perc_dropped_buffers)
 94		return;
 95
 96	spin_lock(&dev->slock);
 97	if (!list_empty(&dev->sdr_cap_active)) {
 98		sdr_cap_buf = list_entry(dev->sdr_cap_active.next,
 99					 struct vivid_buffer, list);
100		list_del(&sdr_cap_buf->list);
101	}
102	spin_unlock(&dev->slock);
103
104	if (sdr_cap_buf) {
105		sdr_cap_buf->vb.sequence = dev->sdr_cap_with_seq_wrap_count;
106		v4l2_ctrl_request_setup(sdr_cap_buf->vb.vb2_buf.req_obj.req,
107					&dev->ctrl_hdl_sdr_cap);
108		v4l2_ctrl_request_complete(sdr_cap_buf->vb.vb2_buf.req_obj.req,
109					   &dev->ctrl_hdl_sdr_cap);
110		vivid_sdr_cap_process(dev, sdr_cap_buf);
111		sdr_cap_buf->vb.vb2_buf.timestamp =
112			ktime_get_ns() + dev->time_wrap_offset;
113		vb2_buffer_done(&sdr_cap_buf->vb.vb2_buf, dev->dqbuf_error ?
114				VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
115		dev->dqbuf_error = false;
116	}
117}
118
119static int vivid_thread_sdr_cap(void *data)
120{
121	struct vivid_dev *dev = data;
122	u64 samples_since_start;
123	u64 buffers_since_start;
124	u64 next_jiffies_since_start;
125	unsigned long jiffies_since_start;
126	unsigned long cur_jiffies;
127	unsigned wait_jiffies;
128
129	dprintk(dev, 1, "SDR Capture Thread Start\n");
130
131	set_freezable();
132
133	/* Resets frame counters */
134	dev->sdr_cap_seq_offset = 0;
135	dev->sdr_cap_seq_count = 0;
136	dev->jiffies_sdr_cap = jiffies;
137	dev->sdr_cap_seq_resync = false;
138	if (dev->time_wrap)
139		dev->time_wrap_offset = dev->time_wrap - ktime_get_ns();
140	else
141		dev->time_wrap_offset = 0;
142
143	for (;;) {
144		try_to_freeze();
145		if (kthread_should_stop())
146			break;
147
148		if (!mutex_trylock(&dev->mutex)) {
149			schedule();
150			continue;
151		}
152
153		cur_jiffies = jiffies;
154		if (dev->sdr_cap_seq_resync) {
155			dev->jiffies_sdr_cap = cur_jiffies;
156			dev->sdr_cap_seq_offset = dev->sdr_cap_seq_count + 1;
157			dev->sdr_cap_seq_count = 0;
158			dev->sdr_cap_seq_resync = false;
159		}
160		/* Calculate the number of jiffies since we started streaming */
161		jiffies_since_start = cur_jiffies - dev->jiffies_sdr_cap;
162		/* Get the number of buffers streamed since the start */
163		buffers_since_start =
164			(u64)jiffies_since_start * dev->sdr_adc_freq +
165				      (HZ * SDR_CAP_SAMPLES_PER_BUF) / 2;
166		do_div(buffers_since_start, HZ * SDR_CAP_SAMPLES_PER_BUF);
167
168		/*
169		 * After more than 0xf0000000 (rounded down to a multiple of
170		 * 'jiffies-per-day' to ease jiffies_to_msecs calculation)
171		 * jiffies have passed since we started streaming reset the
172		 * counters and keep track of the sequence offset.
173		 */
174		if (jiffies_since_start > JIFFIES_RESYNC) {
175			dev->jiffies_sdr_cap = cur_jiffies;
176			dev->sdr_cap_seq_offset = buffers_since_start;
177			buffers_since_start = 0;
178		}
179		dev->sdr_cap_seq_count =
180			buffers_since_start + dev->sdr_cap_seq_offset;
181		dev->sdr_cap_with_seq_wrap_count = dev->sdr_cap_seq_count - dev->sdr_cap_seq_start;
182
183		vivid_thread_sdr_cap_tick(dev);
184		mutex_unlock(&dev->mutex);
185
186		/*
187		 * Calculate the number of samples streamed since we started,
188		 * not including the current buffer.
189		 */
190		samples_since_start = buffers_since_start * SDR_CAP_SAMPLES_PER_BUF;
191
192		/* And the number of jiffies since we started */
193		jiffies_since_start = jiffies - dev->jiffies_sdr_cap;
194
195		/* Increase by the number of samples in one buffer */
196		samples_since_start += SDR_CAP_SAMPLES_PER_BUF;
197		/*
198		 * Calculate when that next buffer is supposed to start
199		 * in jiffies since we started streaming.
200		 */
201		next_jiffies_since_start = samples_since_start * HZ +
202					   dev->sdr_adc_freq / 2;
203		do_div(next_jiffies_since_start, dev->sdr_adc_freq);
204		/* If it is in the past, then just schedule asap */
205		if (next_jiffies_since_start < jiffies_since_start)
206			next_jiffies_since_start = jiffies_since_start;
207
208		wait_jiffies = next_jiffies_since_start - jiffies_since_start;
209		if (!time_is_after_jiffies(cur_jiffies + wait_jiffies))
210			continue;
211
212		wait_queue_head_t wait;
213
214		init_waitqueue_head(&wait);
215		wait_event_interruptible_timeout(wait, kthread_should_stop(),
216					cur_jiffies + wait_jiffies - jiffies);
217	}
218	dprintk(dev, 1, "SDR Capture Thread End\n");
219	return 0;
220}
221
222static int sdr_cap_queue_setup(struct vb2_queue *vq,
223		       unsigned *nbuffers, unsigned *nplanes,
224		       unsigned sizes[], struct device *alloc_devs[])
225{
226	/* 2 = max 16-bit sample returned */
227	u32 size = SDR_CAP_SAMPLES_PER_BUF * 2;
228
229	if (*nplanes)
230		return sizes[0] < size ? -EINVAL : 0;
231
232	*nplanes = 1;
233	sizes[0] = size;
234	return 0;
235}
236
237static int sdr_cap_buf_prepare(struct vb2_buffer *vb)
238{
239	struct vivid_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
240	unsigned size = SDR_CAP_SAMPLES_PER_BUF * 2;
241
242	dprintk(dev, 1, "%s\n", __func__);
243
244	if (dev->buf_prepare_error) {
245		/*
246		 * Error injection: test what happens if buf_prepare() returns
247		 * an error.
248		 */
249		dev->buf_prepare_error = false;
250		return -EINVAL;
251	}
252	if (vb2_plane_size(vb, 0) < size) {
253		dprintk(dev, 1, "%s data will not fit into plane (%lu < %u)\n",
254				__func__, vb2_plane_size(vb, 0), size);
255		return -EINVAL;
256	}
257	vb2_set_plane_payload(vb, 0, size);
258
259	return 0;
260}
261
262static void sdr_cap_buf_queue(struct vb2_buffer *vb)
263{
264	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
265	struct vivid_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
266	struct vivid_buffer *buf = container_of(vbuf, struct vivid_buffer, vb);
267
268	dprintk(dev, 1, "%s\n", __func__);
269
270	spin_lock(&dev->slock);
271	list_add_tail(&buf->list, &dev->sdr_cap_active);
272	spin_unlock(&dev->slock);
273}
274
275static int sdr_cap_start_streaming(struct vb2_queue *vq, unsigned count)
276{
277	struct vivid_dev *dev = vb2_get_drv_priv(vq);
278	int err = 0;
279
280	dprintk(dev, 1, "%s\n", __func__);
281	dev->sdr_cap_seq_start = dev->seq_wrap * 128;
282	if (dev->start_streaming_error) {
283		dev->start_streaming_error = false;
284		err = -EINVAL;
285	} else if (dev->kthread_sdr_cap == NULL) {
286		dev->kthread_sdr_cap = kthread_run(vivid_thread_sdr_cap, dev,
287				"%s-sdr-cap", dev->v4l2_dev.name);
288
289		if (IS_ERR(dev->kthread_sdr_cap)) {
290			v4l2_err(&dev->v4l2_dev, "kernel_thread() failed\n");
291			err = PTR_ERR(dev->kthread_sdr_cap);
292			dev->kthread_sdr_cap = NULL;
293		}
294	}
295	if (err) {
296		struct vivid_buffer *buf, *tmp;
297
298		list_for_each_entry_safe(buf, tmp, &dev->sdr_cap_active, list) {
299			list_del(&buf->list);
300			vb2_buffer_done(&buf->vb.vb2_buf,
301					VB2_BUF_STATE_QUEUED);
302		}
303	}
304	return err;
305}
306
307/* abort streaming and wait for last buffer */
308static void sdr_cap_stop_streaming(struct vb2_queue *vq)
309{
310	struct vivid_dev *dev = vb2_get_drv_priv(vq);
311
312	if (dev->kthread_sdr_cap == NULL)
313		return;
314
315	while (!list_empty(&dev->sdr_cap_active)) {
316		struct vivid_buffer *buf;
317
318		buf = list_entry(dev->sdr_cap_active.next,
319				struct vivid_buffer, list);
320		list_del(&buf->list);
321		v4l2_ctrl_request_complete(buf->vb.vb2_buf.req_obj.req,
322					   &dev->ctrl_hdl_sdr_cap);
323		vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
324	}
325
326	/* shutdown control thread */
327	kthread_stop(dev->kthread_sdr_cap);
328	dev->kthread_sdr_cap = NULL;
329}
330
331static void sdr_cap_buf_request_complete(struct vb2_buffer *vb)
332{
333	struct vivid_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
334
335	v4l2_ctrl_request_complete(vb->req_obj.req, &dev->ctrl_hdl_sdr_cap);
336}
337
338const struct vb2_ops vivid_sdr_cap_qops = {
339	.queue_setup		= sdr_cap_queue_setup,
340	.buf_prepare		= sdr_cap_buf_prepare,
341	.buf_queue		= sdr_cap_buf_queue,
342	.start_streaming	= sdr_cap_start_streaming,
343	.stop_streaming		= sdr_cap_stop_streaming,
344	.buf_request_complete	= sdr_cap_buf_request_complete,
345};
346
347int vivid_sdr_enum_freq_bands(struct file *file, void *priv,
348		struct v4l2_frequency_band *band)
349{
350	switch (band->tuner) {
351	case 0:
352		if (band->index >= ARRAY_SIZE(bands_adc))
353			return -EINVAL;
354		*band = bands_adc[band->index];
355		return 0;
356	case 1:
357		if (band->index >= ARRAY_SIZE(bands_fm))
358			return -EINVAL;
359		*band = bands_fm[band->index];
360		return 0;
361	default:
362		return -EINVAL;
363	}
364}
365
366int vivid_sdr_g_frequency(struct file *file, void *priv,
367		struct v4l2_frequency *vf)
368{
369	struct vivid_dev *dev = video_drvdata(file);
370
371	switch (vf->tuner) {
372	case 0:
373		vf->frequency = dev->sdr_adc_freq;
374		vf->type = V4L2_TUNER_ADC;
375		return 0;
376	case 1:
377		vf->frequency = dev->sdr_fm_freq;
378		vf->type = V4L2_TUNER_RF;
379		return 0;
380	default:
381		return -EINVAL;
382	}
383}
384
385int vivid_sdr_s_frequency(struct file *file, void *priv,
386		const struct v4l2_frequency *vf)
387{
388	struct vivid_dev *dev = video_drvdata(file);
389	unsigned freq = vf->frequency;
390	unsigned band;
391
392	switch (vf->tuner) {
393	case 0:
394		if (vf->type != V4L2_TUNER_ADC)
395			return -EINVAL;
396		if (freq < BAND_ADC_0)
397			band = 0;
398		else if (freq < BAND_ADC_1)
399			band = 1;
400		else
401			band = 2;
402
403		freq = clamp_t(unsigned, freq,
404				bands_adc[band].rangelow,
405				bands_adc[band].rangehigh);
406
407		if (vb2_is_streaming(&dev->vb_sdr_cap_q) &&
408		    freq != dev->sdr_adc_freq) {
409			/* resync the thread's timings */
410			dev->sdr_cap_seq_resync = true;
411		}
412		dev->sdr_adc_freq = freq;
413		return 0;
414	case 1:
415		if (vf->type != V4L2_TUNER_RF)
416			return -EINVAL;
417		dev->sdr_fm_freq = clamp_t(unsigned, freq,
418				bands_fm[0].rangelow,
419				bands_fm[0].rangehigh);
420		return 0;
421	default:
422		return -EINVAL;
423	}
424}
425
426int vivid_sdr_g_tuner(struct file *file, void *priv, struct v4l2_tuner *vt)
427{
428	switch (vt->index) {
429	case 0:
430		strscpy(vt->name, "ADC", sizeof(vt->name));
431		vt->type = V4L2_TUNER_ADC;
432		vt->capability =
433			V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS;
434		vt->rangelow = bands_adc[0].rangelow;
435		vt->rangehigh = bands_adc[2].rangehigh;
436		return 0;
437	case 1:
438		strscpy(vt->name, "RF", sizeof(vt->name));
439		vt->type = V4L2_TUNER_RF;
440		vt->capability =
441			V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS;
442		vt->rangelow = bands_fm[0].rangelow;
443		vt->rangehigh = bands_fm[0].rangehigh;
444		return 0;
445	default:
446		return -EINVAL;
447	}
448}
449
450int vivid_sdr_s_tuner(struct file *file, void *priv, const struct v4l2_tuner *vt)
451{
452	if (vt->index > 1)
453		return -EINVAL;
454	return 0;
455}
456
457int vidioc_enum_fmt_sdr_cap(struct file *file, void *priv, struct v4l2_fmtdesc *f)
458{
459	if (f->index >= ARRAY_SIZE(formats))
460		return -EINVAL;
461	f->pixelformat = formats[f->index].pixelformat;
462	return 0;
463}
464
465int vidioc_g_fmt_sdr_cap(struct file *file, void *priv, struct v4l2_format *f)
466{
467	struct vivid_dev *dev = video_drvdata(file);
468
469	f->fmt.sdr.pixelformat = dev->sdr_pixelformat;
470	f->fmt.sdr.buffersize = dev->sdr_buffersize;
471	return 0;
472}
473
474int vidioc_s_fmt_sdr_cap(struct file *file, void *priv, struct v4l2_format *f)
475{
476	struct vivid_dev *dev = video_drvdata(file);
477	struct vb2_queue *q = &dev->vb_sdr_cap_q;
478	int i;
479
480	if (vb2_is_busy(q))
481		return -EBUSY;
482
483	for (i = 0; i < ARRAY_SIZE(formats); i++) {
484		if (formats[i].pixelformat == f->fmt.sdr.pixelformat) {
485			dev->sdr_pixelformat = formats[i].pixelformat;
486			dev->sdr_buffersize = formats[i].buffersize;
487			f->fmt.sdr.buffersize = formats[i].buffersize;
488			return 0;
489		}
490	}
491	dev->sdr_pixelformat = formats[0].pixelformat;
492	dev->sdr_buffersize = formats[0].buffersize;
493	f->fmt.sdr.pixelformat = formats[0].pixelformat;
494	f->fmt.sdr.buffersize = formats[0].buffersize;
495	return 0;
496}
497
498int vidioc_try_fmt_sdr_cap(struct file *file, void *priv, struct v4l2_format *f)
499{
500	int i;
501
502	for (i = 0; i < ARRAY_SIZE(formats); i++) {
503		if (formats[i].pixelformat == f->fmt.sdr.pixelformat) {
504			f->fmt.sdr.buffersize = formats[i].buffersize;
505			return 0;
506		}
507	}
508	f->fmt.sdr.pixelformat = formats[0].pixelformat;
509	f->fmt.sdr.buffersize = formats[0].buffersize;
510	return 0;
511}
512
513#define FIXP_N    (15)
514#define FIXP_FRAC (1 << FIXP_N)
515#define FIXP_2PI  ((int)(2 * 3.141592653589 * FIXP_FRAC))
516#define M_100000PI (3.14159 * 100000)
517
518void vivid_sdr_cap_process(struct vivid_dev *dev, struct vivid_buffer *buf)
519{
520	u8 *vbuf = vb2_plane_vaddr(&buf->vb.vb2_buf, 0);
521	unsigned long i;
522	unsigned long plane_size = vb2_plane_size(&buf->vb.vb2_buf, 0);
523	s64 s64tmp;
524	s32 src_phase_step;
525	s32 mod_phase_step;
526	s32 fixp_i;
527	s32 fixp_q;
528
529	/* calculate phase step */
530	#define BEEP_FREQ 1000 /* 1kHz beep */
531	src_phase_step = DIV_ROUND_CLOSEST(FIXP_2PI * BEEP_FREQ,
532					   dev->sdr_adc_freq);
533
534	for (i = 0; i < plane_size; i += 2) {
535		mod_phase_step = fixp_cos32_rad(dev->sdr_fixp_src_phase,
536						FIXP_2PI) >> (31 - FIXP_N);
537
538		dev->sdr_fixp_src_phase += src_phase_step;
539		s64tmp = (s64) mod_phase_step * dev->sdr_fm_deviation;
540		dev->sdr_fixp_mod_phase += div_s64(s64tmp, M_100000PI);
541
542		/*
543		 * Transfer phase angle to [0, 2xPI] in order to avoid variable
544		 * overflow and make it suitable for cosine implementation
545		 * used, which does not support negative angles.
546		 */
547		dev->sdr_fixp_src_phase %= FIXP_2PI;
548		dev->sdr_fixp_mod_phase %= FIXP_2PI;
549
550		if (dev->sdr_fixp_mod_phase < 0)
551			dev->sdr_fixp_mod_phase += FIXP_2PI;
552
553		fixp_i = fixp_cos32_rad(dev->sdr_fixp_mod_phase, FIXP_2PI);
554		fixp_q = fixp_sin32_rad(dev->sdr_fixp_mod_phase, FIXP_2PI);
555
556		/* Normalize fraction values represented with 32 bit precision
557		 * to fixed point representation with FIXP_N bits */
558		fixp_i >>= (31 - FIXP_N);
559		fixp_q >>= (31 - FIXP_N);
560
561		switch (dev->sdr_pixelformat) {
562		case V4L2_SDR_FMT_CU8:
563			/* convert 'fixp float' to u8 [0, +255] */
564			/* u8 = X * 127.5 + 127.5; X is float [-1.0, +1.0] */
565			fixp_i = fixp_i * 1275 + FIXP_FRAC * 1275;
566			fixp_q = fixp_q * 1275 + FIXP_FRAC * 1275;
567			*vbuf++ = DIV_ROUND_CLOSEST(fixp_i, FIXP_FRAC * 10);
568			*vbuf++ = DIV_ROUND_CLOSEST(fixp_q, FIXP_FRAC * 10);
569			break;
570		case V4L2_SDR_FMT_CS8:
571			/* convert 'fixp float' to s8 [-128, +127] */
572			/* s8 = X * 127.5 - 0.5; X is float [-1.0, +1.0] */
573			fixp_i = fixp_i * 1275 - FIXP_FRAC * 5;
574			fixp_q = fixp_q * 1275 - FIXP_FRAC * 5;
575			*vbuf++ = DIV_ROUND_CLOSEST(fixp_i, FIXP_FRAC * 10);
576			*vbuf++ = DIV_ROUND_CLOSEST(fixp_q, FIXP_FRAC * 10);
577			break;
578		default:
579			break;
580		}
581	}
582}