linux/drivers/media/platform/vivid/vivid-sdr-cap.c
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   1/*
   2 * vivid-sdr-cap.c - software defined radio support functions.
   3 *
   4 * Copyright 2014 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
   5 *
   6 * This program is free software; you may redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; version 2 of the License.
   9 *
  10 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  11 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  12 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  13 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  14 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  15 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  16 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  17 * SOFTWARE.
  18 */
  19
  20#include <linux/errno.h>
  21#include <linux/kernel.h>
  22#include <linux/delay.h>
  23#include <linux/kthread.h>
  24#include <linux/freezer.h>
  25#include <linux/videodev2.h>
  26#include <linux/v4l2-dv-timings.h>
  27#include <media/v4l2-common.h>
  28#include <media/v4l2-event.h>
  29#include <media/v4l2-dv-timings.h>
  30#include <linux/fixp-arith.h>
  31
  32#include "vivid-core.h"
  33#include "vivid-ctrls.h"
  34#include "vivid-sdr-cap.h"
  35
  36static const struct v4l2_frequency_band bands_adc[] = {
  37        {
  38                .tuner = 0,
  39                .type = V4L2_TUNER_ADC,
  40                .index = 0,
  41                .capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS,
  42                .rangelow   =  300000,
  43                .rangehigh  =  300000,
  44        },
  45        {
  46                .tuner = 0,
  47                .type = V4L2_TUNER_ADC,
  48                .index = 1,
  49                .capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS,
  50                .rangelow   =  900001,
  51                .rangehigh  = 2800000,
  52        },
  53        {
  54                .tuner = 0,
  55                .type = V4L2_TUNER_ADC,
  56                .index = 2,
  57                .capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS,
  58                .rangelow   = 3200000,
  59                .rangehigh  = 3200000,
  60        },
  61};
  62
  63/* ADC band midpoints */
  64#define BAND_ADC_0 ((bands_adc[0].rangehigh + bands_adc[1].rangelow) / 2)
  65#define BAND_ADC_1 ((bands_adc[1].rangehigh + bands_adc[2].rangelow) / 2)
  66
  67static const struct v4l2_frequency_band bands_fm[] = {
  68        {
  69                .tuner = 1,
  70                .type = V4L2_TUNER_RF,
  71                .index = 0,
  72                .capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS,
  73                .rangelow   =    50000000,
  74                .rangehigh  =  2000000000,
  75        },
  76};
  77
  78static void vivid_thread_sdr_cap_tick(struct vivid_dev *dev)
  79{
  80        struct vivid_buffer *sdr_cap_buf = NULL;
  81
  82        dprintk(dev, 1, "SDR Capture Thread Tick\n");
  83
  84        /* Drop a certain percentage of buffers. */
  85        if (dev->perc_dropped_buffers &&
  86            prandom_u32_max(100) < dev->perc_dropped_buffers)
  87                return;
  88
  89        spin_lock(&dev->slock);
  90        if (!list_empty(&dev->sdr_cap_active)) {
  91                sdr_cap_buf = list_entry(dev->sdr_cap_active.next,
  92                                         struct vivid_buffer, list);
  93                list_del(&sdr_cap_buf->list);
  94        }
  95        spin_unlock(&dev->slock);
  96
  97        if (sdr_cap_buf) {
  98                sdr_cap_buf->vb.v4l2_buf.sequence = dev->sdr_cap_seq_count;
  99                vivid_sdr_cap_process(dev, sdr_cap_buf);
 100                v4l2_get_timestamp(&sdr_cap_buf->vb.v4l2_buf.timestamp);
 101                sdr_cap_buf->vb.v4l2_buf.timestamp.tv_sec += dev->time_wrap_offset;
 102                vb2_buffer_done(&sdr_cap_buf->vb, dev->dqbuf_error ?
 103                                VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
 104                dev->dqbuf_error = false;
 105        }
 106}
 107
 108static int vivid_thread_sdr_cap(void *data)
 109{
 110        struct vivid_dev *dev = data;
 111        u64 samples_since_start;
 112        u64 buffers_since_start;
 113        u64 next_jiffies_since_start;
 114        unsigned long jiffies_since_start;
 115        unsigned long cur_jiffies;
 116        unsigned wait_jiffies;
 117
 118        dprintk(dev, 1, "SDR Capture Thread Start\n");
 119
 120        set_freezable();
 121
 122        /* Resets frame counters */
 123        dev->sdr_cap_seq_offset = 0;
 124        if (dev->seq_wrap)
 125                dev->sdr_cap_seq_offset = 0xffffff80U;
 126        dev->jiffies_sdr_cap = jiffies;
 127        dev->sdr_cap_seq_resync = false;
 128
 129        for (;;) {
 130                try_to_freeze();
 131                if (kthread_should_stop())
 132                        break;
 133
 134                mutex_lock(&dev->mutex);
 135                cur_jiffies = jiffies;
 136                if (dev->sdr_cap_seq_resync) {
 137                        dev->jiffies_sdr_cap = cur_jiffies;
 138                        dev->sdr_cap_seq_offset = dev->sdr_cap_seq_count + 1;
 139                        dev->sdr_cap_seq_count = 0;
 140                        dev->sdr_cap_seq_resync = false;
 141                }
 142                /* Calculate the number of jiffies since we started streaming */
 143                jiffies_since_start = cur_jiffies - dev->jiffies_sdr_cap;
 144                /* Get the number of buffers streamed since the start */
 145                buffers_since_start = (u64)jiffies_since_start * dev->sdr_adc_freq +
 146                                      (HZ * SDR_CAP_SAMPLES_PER_BUF) / 2;
 147                do_div(buffers_since_start, HZ * SDR_CAP_SAMPLES_PER_BUF);
 148
 149                /*
 150                 * After more than 0xf0000000 (rounded down to a multiple of
 151                 * 'jiffies-per-day' to ease jiffies_to_msecs calculation)
 152                 * jiffies have passed since we started streaming reset the
 153                 * counters and keep track of the sequence offset.
 154                 */
 155                if (jiffies_since_start > JIFFIES_RESYNC) {
 156                        dev->jiffies_sdr_cap = cur_jiffies;
 157                        dev->sdr_cap_seq_offset = buffers_since_start;
 158                        buffers_since_start = 0;
 159                }
 160                dev->sdr_cap_seq_count = buffers_since_start + dev->sdr_cap_seq_offset;
 161
 162                vivid_thread_sdr_cap_tick(dev);
 163                mutex_unlock(&dev->mutex);
 164
 165                /*
 166                 * Calculate the number of samples streamed since we started,
 167                 * not including the current buffer.
 168                 */
 169                samples_since_start = buffers_since_start * SDR_CAP_SAMPLES_PER_BUF;
 170
 171                /* And the number of jiffies since we started */
 172                jiffies_since_start = jiffies - dev->jiffies_sdr_cap;
 173
 174                /* Increase by the number of samples in one buffer */
 175                samples_since_start += SDR_CAP_SAMPLES_PER_BUF;
 176                /*
 177                 * Calculate when that next buffer is supposed to start
 178                 * in jiffies since we started streaming.
 179                 */
 180                next_jiffies_since_start = samples_since_start * HZ +
 181                                           dev->sdr_adc_freq / 2;
 182                do_div(next_jiffies_since_start, dev->sdr_adc_freq);
 183                /* If it is in the past, then just schedule asap */
 184                if (next_jiffies_since_start < jiffies_since_start)
 185                        next_jiffies_since_start = jiffies_since_start;
 186
 187                wait_jiffies = next_jiffies_since_start - jiffies_since_start;
 188                schedule_timeout_interruptible(wait_jiffies ? wait_jiffies : 1);
 189        }
 190        dprintk(dev, 1, "SDR Capture Thread End\n");
 191        return 0;
 192}
 193
 194static int sdr_cap_queue_setup(struct vb2_queue *vq, const struct v4l2_format *fmt,
 195                       unsigned *nbuffers, unsigned *nplanes,
 196                       unsigned sizes[], void *alloc_ctxs[])
 197{
 198        /* 2 = max 16-bit sample returned */
 199        sizes[0] = SDR_CAP_SAMPLES_PER_BUF * 2;
 200        *nplanes = 1;
 201        return 0;
 202}
 203
 204static int sdr_cap_buf_prepare(struct vb2_buffer *vb)
 205{
 206        struct vivid_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
 207        unsigned size = SDR_CAP_SAMPLES_PER_BUF * 2;
 208
 209        dprintk(dev, 1, "%s\n", __func__);
 210
 211        if (dev->buf_prepare_error) {
 212                /*
 213                 * Error injection: test what happens if buf_prepare() returns
 214                 * an error.
 215                 */
 216                dev->buf_prepare_error = false;
 217                return -EINVAL;
 218        }
 219        if (vb2_plane_size(vb, 0) < size) {
 220                dprintk(dev, 1, "%s data will not fit into plane (%lu < %u)\n",
 221                                __func__, vb2_plane_size(vb, 0), size);
 222                return -EINVAL;
 223        }
 224        vb2_set_plane_payload(vb, 0, size);
 225
 226        return 0;
 227}
 228
 229static void sdr_cap_buf_queue(struct vb2_buffer *vb)
 230{
 231        struct vivid_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
 232        struct vivid_buffer *buf = container_of(vb, struct vivid_buffer, vb);
 233
 234        dprintk(dev, 1, "%s\n", __func__);
 235
 236        spin_lock(&dev->slock);
 237        list_add_tail(&buf->list, &dev->sdr_cap_active);
 238        spin_unlock(&dev->slock);
 239}
 240
 241static int sdr_cap_start_streaming(struct vb2_queue *vq, unsigned count)
 242{
 243        struct vivid_dev *dev = vb2_get_drv_priv(vq);
 244        int err = 0;
 245
 246        dprintk(dev, 1, "%s\n", __func__);
 247        dev->sdr_cap_seq_count = 0;
 248        if (dev->start_streaming_error) {
 249                dev->start_streaming_error = false;
 250                err = -EINVAL;
 251        } else if (dev->kthread_sdr_cap == NULL) {
 252                dev->kthread_sdr_cap = kthread_run(vivid_thread_sdr_cap, dev,
 253                                "%s-sdr-cap", dev->v4l2_dev.name);
 254
 255                if (IS_ERR(dev->kthread_sdr_cap)) {
 256                        v4l2_err(&dev->v4l2_dev, "kernel_thread() failed\n");
 257                        err = PTR_ERR(dev->kthread_sdr_cap);
 258                        dev->kthread_sdr_cap = NULL;
 259                }
 260        }
 261        if (err) {
 262                struct vivid_buffer *buf, *tmp;
 263
 264                list_for_each_entry_safe(buf, tmp, &dev->sdr_cap_active, list) {
 265                        list_del(&buf->list);
 266                        vb2_buffer_done(&buf->vb, VB2_BUF_STATE_QUEUED);
 267                }
 268        }
 269        return err;
 270}
 271
 272/* abort streaming and wait for last buffer */
 273static void sdr_cap_stop_streaming(struct vb2_queue *vq)
 274{
 275        struct vivid_dev *dev = vb2_get_drv_priv(vq);
 276
 277        if (dev->kthread_sdr_cap == NULL)
 278                return;
 279
 280        while (!list_empty(&dev->sdr_cap_active)) {
 281                struct vivid_buffer *buf;
 282
 283                buf = list_entry(dev->sdr_cap_active.next, struct vivid_buffer, list);
 284                list_del(&buf->list);
 285                vb2_buffer_done(&buf->vb, VB2_BUF_STATE_ERROR);
 286        }
 287
 288        /* shutdown control thread */
 289        mutex_unlock(&dev->mutex);
 290        kthread_stop(dev->kthread_sdr_cap);
 291        dev->kthread_sdr_cap = NULL;
 292        mutex_lock(&dev->mutex);
 293}
 294
 295const struct vb2_ops vivid_sdr_cap_qops = {
 296        .queue_setup            = sdr_cap_queue_setup,
 297        .buf_prepare            = sdr_cap_buf_prepare,
 298        .buf_queue              = sdr_cap_buf_queue,
 299        .start_streaming        = sdr_cap_start_streaming,
 300        .stop_streaming         = sdr_cap_stop_streaming,
 301        .wait_prepare           = vb2_ops_wait_prepare,
 302        .wait_finish            = vb2_ops_wait_finish,
 303};
 304
 305int vivid_sdr_enum_freq_bands(struct file *file, void *fh, struct v4l2_frequency_band *band)
 306{
 307        switch (band->tuner) {
 308        case 0:
 309                if (band->index >= ARRAY_SIZE(bands_adc))
 310                        return -EINVAL;
 311                *band = bands_adc[band->index];
 312                return 0;
 313        case 1:
 314                if (band->index >= ARRAY_SIZE(bands_fm))
 315                        return -EINVAL;
 316                *band = bands_fm[band->index];
 317                return 0;
 318        default:
 319                return -EINVAL;
 320        }
 321}
 322
 323int vivid_sdr_g_frequency(struct file *file, void *fh, struct v4l2_frequency *vf)
 324{
 325        struct vivid_dev *dev = video_drvdata(file);
 326
 327        switch (vf->tuner) {
 328        case 0:
 329                vf->frequency = dev->sdr_adc_freq;
 330                vf->type = V4L2_TUNER_ADC;
 331                return 0;
 332        case 1:
 333                vf->frequency = dev->sdr_fm_freq;
 334                vf->type = V4L2_TUNER_RF;
 335                return 0;
 336        default:
 337                return -EINVAL;
 338        }
 339}
 340
 341int vivid_sdr_s_frequency(struct file *file, void *fh, const struct v4l2_frequency *vf)
 342{
 343        struct vivid_dev *dev = video_drvdata(file);
 344        unsigned freq = vf->frequency;
 345        unsigned band;
 346
 347        switch (vf->tuner) {
 348        case 0:
 349                if (vf->type != V4L2_TUNER_ADC)
 350                        return -EINVAL;
 351                if (freq < BAND_ADC_0)
 352                        band = 0;
 353                else if (freq < BAND_ADC_1)
 354                        band = 1;
 355                else
 356                        band = 2;
 357
 358                freq = clamp_t(unsigned, freq,
 359                                bands_adc[band].rangelow,
 360                                bands_adc[band].rangehigh);
 361
 362                if (vb2_is_streaming(&dev->vb_sdr_cap_q) &&
 363                    freq != dev->sdr_adc_freq) {
 364                        /* resync the thread's timings */
 365                        dev->sdr_cap_seq_resync = true;
 366                }
 367                dev->sdr_adc_freq = freq;
 368                return 0;
 369        case 1:
 370                if (vf->type != V4L2_TUNER_RF)
 371                        return -EINVAL;
 372                dev->sdr_fm_freq = clamp_t(unsigned, freq,
 373                                bands_fm[0].rangelow,
 374                                bands_fm[0].rangehigh);
 375                return 0;
 376        default:
 377                return -EINVAL;
 378        }
 379}
 380
 381int vivid_sdr_g_tuner(struct file *file, void *fh, struct v4l2_tuner *vt)
 382{
 383        switch (vt->index) {
 384        case 0:
 385                strlcpy(vt->name, "ADC", sizeof(vt->name));
 386                vt->type = V4L2_TUNER_ADC;
 387                vt->capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS;
 388                vt->rangelow = bands_adc[0].rangelow;
 389                vt->rangehigh = bands_adc[2].rangehigh;
 390                return 0;
 391        case 1:
 392                strlcpy(vt->name, "RF", sizeof(vt->name));
 393                vt->type = V4L2_TUNER_RF;
 394                vt->capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS;
 395                vt->rangelow = bands_fm[0].rangelow;
 396                vt->rangehigh = bands_fm[0].rangehigh;
 397                return 0;
 398        default:
 399                return -EINVAL;
 400        }
 401}
 402
 403int vivid_sdr_s_tuner(struct file *file, void *fh, const struct v4l2_tuner *vt)
 404{
 405        if (vt->index > 1)
 406                return -EINVAL;
 407        return 0;
 408}
 409
 410int vidioc_enum_fmt_sdr_cap(struct file *file, void *fh, struct v4l2_fmtdesc *f)
 411{
 412        if (f->index)
 413                return -EINVAL;
 414        f->pixelformat = V4L2_SDR_FMT_CU8;
 415        strlcpy(f->description, "IQ U8", sizeof(f->description));
 416        return 0;
 417}
 418
 419int vidioc_g_fmt_sdr_cap(struct file *file, void *fh, struct v4l2_format *f)
 420{
 421        f->fmt.sdr.pixelformat = V4L2_SDR_FMT_CU8;
 422        f->fmt.sdr.buffersize = SDR_CAP_SAMPLES_PER_BUF * 2;
 423        memset(f->fmt.sdr.reserved, 0, sizeof(f->fmt.sdr.reserved));
 424        return 0;
 425}
 426
 427#define FIXP_N    (15)
 428#define FIXP_FRAC (1 << FIXP_N)
 429#define FIXP_2PI  ((int)(2 * 3.141592653589 * FIXP_FRAC))
 430
 431void vivid_sdr_cap_process(struct vivid_dev *dev, struct vivid_buffer *buf)
 432{
 433        u8 *vbuf = vb2_plane_vaddr(&buf->vb, 0);
 434        unsigned long i;
 435        unsigned long plane_size = vb2_plane_size(&buf->vb, 0);
 436        s32 src_phase_step;
 437        s32 mod_phase_step;
 438        s32 fixp_i;
 439        s32 fixp_q;
 440
 441        /*
 442         * TODO: Generated beep tone goes very crackly when sample rate is
 443         * increased to ~1Msps or more. That is because of huge rounding error
 444         * of phase angle caused by used cosine implementation.
 445         */
 446
 447        /* calculate phase step */
 448        #define BEEP_FREQ 1000 /* 1kHz beep */
 449        src_phase_step = DIV_ROUND_CLOSEST(FIXP_2PI * BEEP_FREQ,
 450                        dev->sdr_adc_freq);
 451
 452        for (i = 0; i < plane_size; i += 2) {
 453                mod_phase_step = fixp_cos32_rad(dev->sdr_fixp_src_phase,
 454                                                FIXP_2PI) >> (31 - FIXP_N);
 455
 456                dev->sdr_fixp_src_phase += src_phase_step;
 457                dev->sdr_fixp_mod_phase += mod_phase_step / 4;
 458
 459                /*
 460                 * Transfer phases to [0 / 2xPI] in order to avoid variable
 461                 * overflow and make it suitable for cosine implementation
 462                 * used, which does not support negative angles.
 463                 */
 464                while (dev->sdr_fixp_mod_phase < FIXP_2PI)
 465                        dev->sdr_fixp_mod_phase += FIXP_2PI;
 466                while (dev->sdr_fixp_mod_phase > FIXP_2PI)
 467                        dev->sdr_fixp_mod_phase -= FIXP_2PI;
 468
 469                while (dev->sdr_fixp_src_phase > FIXP_2PI)
 470                        dev->sdr_fixp_src_phase -= FIXP_2PI;
 471
 472                fixp_i = fixp_cos32_rad(dev->sdr_fixp_mod_phase, FIXP_2PI);
 473                fixp_q = fixp_sin32_rad(dev->sdr_fixp_mod_phase, FIXP_2PI);
 474
 475                /* Normalize fraction values represented with 32 bit precision
 476                 * to fixed point representation with FIXP_N bits */
 477                fixp_i >>= (31 - FIXP_N);
 478                fixp_q >>= (31 - FIXP_N);
 479
 480                /* convert 'fixp float' to u8 */
 481                /* u8 = X * 127.5f + 127.5f; where X is float [-1.0 / +1.0] */
 482                fixp_i = fixp_i * 1275 + FIXP_FRAC * 1275;
 483                fixp_q = fixp_q * 1275 + FIXP_FRAC * 1275;
 484                *vbuf++ = DIV_ROUND_CLOSEST(fixp_i, FIXP_FRAC * 10);
 485                *vbuf++ = DIV_ROUND_CLOSEST(fixp_q, FIXP_FRAC * 10);
 486        }
 487}
 488