575 lines
15 KiB
C
575 lines
15 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* vivid-sdr-cap.c - software defined radio support functions.
|
|
*
|
|
* Copyright 2014 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
|
|
*/
|
|
|
|
#include <linux/errno.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/kthread.h>
|
|
#include <linux/freezer.h>
|
|
#include <linux/math64.h>
|
|
#include <linux/videodev2.h>
|
|
#include <linux/v4l2-dv-timings.h>
|
|
#include <media/v4l2-common.h>
|
|
#include <media/v4l2-event.h>
|
|
#include <media/v4l2-dv-timings.h>
|
|
#include <linux/fixp-arith.h>
|
|
#include <linux/jiffies.h>
|
|
|
|
#include "vivid-core.h"
|
|
#include "vivid-ctrls.h"
|
|
#include "vivid-sdr-cap.h"
|
|
|
|
/* stream formats */
|
|
struct vivid_format {
|
|
u32 pixelformat;
|
|
u32 buffersize;
|
|
};
|
|
|
|
/* format descriptions for capture and preview */
|
|
static const struct vivid_format formats[] = {
|
|
{
|
|
.pixelformat = V4L2_SDR_FMT_CU8,
|
|
.buffersize = SDR_CAP_SAMPLES_PER_BUF * 2,
|
|
}, {
|
|
.pixelformat = V4L2_SDR_FMT_CS8,
|
|
.buffersize = SDR_CAP_SAMPLES_PER_BUF * 2,
|
|
},
|
|
};
|
|
|
|
static const struct v4l2_frequency_band bands_adc[] = {
|
|
{
|
|
.tuner = 0,
|
|
.type = V4L2_TUNER_ADC,
|
|
.index = 0,
|
|
.capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS,
|
|
.rangelow = 300000,
|
|
.rangehigh = 300000,
|
|
},
|
|
{
|
|
.tuner = 0,
|
|
.type = V4L2_TUNER_ADC,
|
|
.index = 1,
|
|
.capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS,
|
|
.rangelow = 900001,
|
|
.rangehigh = 2800000,
|
|
},
|
|
{
|
|
.tuner = 0,
|
|
.type = V4L2_TUNER_ADC,
|
|
.index = 2,
|
|
.capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS,
|
|
.rangelow = 3200000,
|
|
.rangehigh = 3200000,
|
|
},
|
|
};
|
|
|
|
/* ADC band midpoints */
|
|
#define BAND_ADC_0 ((bands_adc[0].rangehigh + bands_adc[1].rangelow) / 2)
|
|
#define BAND_ADC_1 ((bands_adc[1].rangehigh + bands_adc[2].rangelow) / 2)
|
|
|
|
static const struct v4l2_frequency_band bands_fm[] = {
|
|
{
|
|
.tuner = 1,
|
|
.type = V4L2_TUNER_RF,
|
|
.index = 0,
|
|
.capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS,
|
|
.rangelow = 50000000,
|
|
.rangehigh = 2000000000,
|
|
},
|
|
};
|
|
|
|
static void vivid_thread_sdr_cap_tick(struct vivid_dev *dev)
|
|
{
|
|
struct vivid_buffer *sdr_cap_buf = NULL;
|
|
|
|
dprintk(dev, 1, "SDR Capture Thread Tick\n");
|
|
|
|
/* Drop a certain percentage of buffers. */
|
|
if (dev->perc_dropped_buffers &&
|
|
get_random_u32_below(100) < dev->perc_dropped_buffers)
|
|
return;
|
|
|
|
spin_lock(&dev->slock);
|
|
if (!list_empty(&dev->sdr_cap_active)) {
|
|
sdr_cap_buf = list_entry(dev->sdr_cap_active.next,
|
|
struct vivid_buffer, list);
|
|
list_del(&sdr_cap_buf->list);
|
|
}
|
|
spin_unlock(&dev->slock);
|
|
|
|
if (sdr_cap_buf) {
|
|
sdr_cap_buf->vb.sequence = dev->sdr_cap_with_seq_wrap_count;
|
|
v4l2_ctrl_request_setup(sdr_cap_buf->vb.vb2_buf.req_obj.req,
|
|
&dev->ctrl_hdl_sdr_cap);
|
|
v4l2_ctrl_request_complete(sdr_cap_buf->vb.vb2_buf.req_obj.req,
|
|
&dev->ctrl_hdl_sdr_cap);
|
|
vivid_sdr_cap_process(dev, sdr_cap_buf);
|
|
sdr_cap_buf->vb.vb2_buf.timestamp =
|
|
ktime_get_ns() + dev->time_wrap_offset;
|
|
vb2_buffer_done(&sdr_cap_buf->vb.vb2_buf, dev->dqbuf_error ?
|
|
VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
|
|
dev->dqbuf_error = false;
|
|
}
|
|
}
|
|
|
|
static int vivid_thread_sdr_cap(void *data)
|
|
{
|
|
struct vivid_dev *dev = data;
|
|
u64 samples_since_start;
|
|
u64 buffers_since_start;
|
|
u64 next_jiffies_since_start;
|
|
unsigned long jiffies_since_start;
|
|
unsigned long cur_jiffies;
|
|
unsigned wait_jiffies;
|
|
|
|
dprintk(dev, 1, "SDR Capture Thread Start\n");
|
|
|
|
set_freezable();
|
|
|
|
/* Resets frame counters */
|
|
dev->sdr_cap_seq_offset = 0;
|
|
dev->sdr_cap_seq_count = 0;
|
|
dev->jiffies_sdr_cap = jiffies;
|
|
dev->sdr_cap_seq_resync = false;
|
|
if (dev->time_wrap)
|
|
dev->time_wrap_offset = dev->time_wrap - ktime_get_ns();
|
|
else
|
|
dev->time_wrap_offset = 0;
|
|
|
|
for (;;) {
|
|
try_to_freeze();
|
|
if (kthread_should_stop())
|
|
break;
|
|
|
|
if (!mutex_trylock(&dev->mutex)) {
|
|
schedule();
|
|
continue;
|
|
}
|
|
|
|
cur_jiffies = jiffies;
|
|
if (dev->sdr_cap_seq_resync) {
|
|
dev->jiffies_sdr_cap = cur_jiffies;
|
|
dev->sdr_cap_seq_offset = dev->sdr_cap_seq_count + 1;
|
|
dev->sdr_cap_seq_count = 0;
|
|
dev->sdr_cap_seq_resync = false;
|
|
}
|
|
/* Calculate the number of jiffies since we started streaming */
|
|
jiffies_since_start = cur_jiffies - dev->jiffies_sdr_cap;
|
|
/* Get the number of buffers streamed since the start */
|
|
buffers_since_start =
|
|
(u64)jiffies_since_start * dev->sdr_adc_freq +
|
|
(HZ * SDR_CAP_SAMPLES_PER_BUF) / 2;
|
|
do_div(buffers_since_start, HZ * SDR_CAP_SAMPLES_PER_BUF);
|
|
|
|
/*
|
|
* After more than 0xf0000000 (rounded down to a multiple of
|
|
* 'jiffies-per-day' to ease jiffies_to_msecs calculation)
|
|
* jiffies have passed since we started streaming reset the
|
|
* counters and keep track of the sequence offset.
|
|
*/
|
|
if (jiffies_since_start > JIFFIES_RESYNC) {
|
|
dev->jiffies_sdr_cap = cur_jiffies;
|
|
dev->sdr_cap_seq_offset = buffers_since_start;
|
|
buffers_since_start = 0;
|
|
}
|
|
dev->sdr_cap_seq_count =
|
|
buffers_since_start + dev->sdr_cap_seq_offset;
|
|
dev->sdr_cap_with_seq_wrap_count = dev->sdr_cap_seq_count - dev->sdr_cap_seq_start;
|
|
|
|
vivid_thread_sdr_cap_tick(dev);
|
|
mutex_unlock(&dev->mutex);
|
|
|
|
/*
|
|
* Calculate the number of samples streamed since we started,
|
|
* not including the current buffer.
|
|
*/
|
|
samples_since_start = buffers_since_start * SDR_CAP_SAMPLES_PER_BUF;
|
|
|
|
/* And the number of jiffies since we started */
|
|
jiffies_since_start = jiffies - dev->jiffies_sdr_cap;
|
|
|
|
/* Increase by the number of samples in one buffer */
|
|
samples_since_start += SDR_CAP_SAMPLES_PER_BUF;
|
|
/*
|
|
* Calculate when that next buffer is supposed to start
|
|
* in jiffies since we started streaming.
|
|
*/
|
|
next_jiffies_since_start = samples_since_start * HZ +
|
|
dev->sdr_adc_freq / 2;
|
|
do_div(next_jiffies_since_start, dev->sdr_adc_freq);
|
|
/* If it is in the past, then just schedule asap */
|
|
if (next_jiffies_since_start < jiffies_since_start)
|
|
next_jiffies_since_start = jiffies_since_start;
|
|
|
|
wait_jiffies = next_jiffies_since_start - jiffies_since_start;
|
|
while (time_is_after_jiffies(cur_jiffies + wait_jiffies) &&
|
|
!kthread_should_stop())
|
|
schedule();
|
|
}
|
|
dprintk(dev, 1, "SDR Capture Thread End\n");
|
|
return 0;
|
|
}
|
|
|
|
static int sdr_cap_queue_setup(struct vb2_queue *vq,
|
|
unsigned *nbuffers, unsigned *nplanes,
|
|
unsigned sizes[], struct device *alloc_devs[])
|
|
{
|
|
/* 2 = max 16-bit sample returned */
|
|
sizes[0] = SDR_CAP_SAMPLES_PER_BUF * 2;
|
|
*nplanes = 1;
|
|
return 0;
|
|
}
|
|
|
|
static int sdr_cap_buf_prepare(struct vb2_buffer *vb)
|
|
{
|
|
struct vivid_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
|
|
unsigned size = SDR_CAP_SAMPLES_PER_BUF * 2;
|
|
|
|
dprintk(dev, 1, "%s\n", __func__);
|
|
|
|
if (dev->buf_prepare_error) {
|
|
/*
|
|
* Error injection: test what happens if buf_prepare() returns
|
|
* an error.
|
|
*/
|
|
dev->buf_prepare_error = false;
|
|
return -EINVAL;
|
|
}
|
|
if (vb2_plane_size(vb, 0) < size) {
|
|
dprintk(dev, 1, "%s data will not fit into plane (%lu < %u)\n",
|
|
__func__, vb2_plane_size(vb, 0), size);
|
|
return -EINVAL;
|
|
}
|
|
vb2_set_plane_payload(vb, 0, size);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void sdr_cap_buf_queue(struct vb2_buffer *vb)
|
|
{
|
|
struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
|
|
struct vivid_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
|
|
struct vivid_buffer *buf = container_of(vbuf, struct vivid_buffer, vb);
|
|
|
|
dprintk(dev, 1, "%s\n", __func__);
|
|
|
|
spin_lock(&dev->slock);
|
|
list_add_tail(&buf->list, &dev->sdr_cap_active);
|
|
spin_unlock(&dev->slock);
|
|
}
|
|
|
|
static int sdr_cap_start_streaming(struct vb2_queue *vq, unsigned count)
|
|
{
|
|
struct vivid_dev *dev = vb2_get_drv_priv(vq);
|
|
int err = 0;
|
|
|
|
dprintk(dev, 1, "%s\n", __func__);
|
|
dev->sdr_cap_seq_start = dev->seq_wrap * 128;
|
|
if (dev->start_streaming_error) {
|
|
dev->start_streaming_error = false;
|
|
err = -EINVAL;
|
|
} else if (dev->kthread_sdr_cap == NULL) {
|
|
dev->kthread_sdr_cap = kthread_run(vivid_thread_sdr_cap, dev,
|
|
"%s-sdr-cap", dev->v4l2_dev.name);
|
|
|
|
if (IS_ERR(dev->kthread_sdr_cap)) {
|
|
v4l2_err(&dev->v4l2_dev, "kernel_thread() failed\n");
|
|
err = PTR_ERR(dev->kthread_sdr_cap);
|
|
dev->kthread_sdr_cap = NULL;
|
|
}
|
|
}
|
|
if (err) {
|
|
struct vivid_buffer *buf, *tmp;
|
|
|
|
list_for_each_entry_safe(buf, tmp, &dev->sdr_cap_active, list) {
|
|
list_del(&buf->list);
|
|
vb2_buffer_done(&buf->vb.vb2_buf,
|
|
VB2_BUF_STATE_QUEUED);
|
|
}
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/* abort streaming and wait for last buffer */
|
|
static void sdr_cap_stop_streaming(struct vb2_queue *vq)
|
|
{
|
|
struct vivid_dev *dev = vb2_get_drv_priv(vq);
|
|
|
|
if (dev->kthread_sdr_cap == NULL)
|
|
return;
|
|
|
|
while (!list_empty(&dev->sdr_cap_active)) {
|
|
struct vivid_buffer *buf;
|
|
|
|
buf = list_entry(dev->sdr_cap_active.next,
|
|
struct vivid_buffer, list);
|
|
list_del(&buf->list);
|
|
v4l2_ctrl_request_complete(buf->vb.vb2_buf.req_obj.req,
|
|
&dev->ctrl_hdl_sdr_cap);
|
|
vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
|
|
}
|
|
|
|
/* shutdown control thread */
|
|
kthread_stop(dev->kthread_sdr_cap);
|
|
dev->kthread_sdr_cap = NULL;
|
|
}
|
|
|
|
static void sdr_cap_buf_request_complete(struct vb2_buffer *vb)
|
|
{
|
|
struct vivid_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
|
|
|
|
v4l2_ctrl_request_complete(vb->req_obj.req, &dev->ctrl_hdl_sdr_cap);
|
|
}
|
|
|
|
const struct vb2_ops vivid_sdr_cap_qops = {
|
|
.queue_setup = sdr_cap_queue_setup,
|
|
.buf_prepare = sdr_cap_buf_prepare,
|
|
.buf_queue = sdr_cap_buf_queue,
|
|
.start_streaming = sdr_cap_start_streaming,
|
|
.stop_streaming = sdr_cap_stop_streaming,
|
|
.buf_request_complete = sdr_cap_buf_request_complete,
|
|
.wait_prepare = vb2_ops_wait_prepare,
|
|
.wait_finish = vb2_ops_wait_finish,
|
|
};
|
|
|
|
int vivid_sdr_enum_freq_bands(struct file *file, void *fh,
|
|
struct v4l2_frequency_band *band)
|
|
{
|
|
switch (band->tuner) {
|
|
case 0:
|
|
if (band->index >= ARRAY_SIZE(bands_adc))
|
|
return -EINVAL;
|
|
*band = bands_adc[band->index];
|
|
return 0;
|
|
case 1:
|
|
if (band->index >= ARRAY_SIZE(bands_fm))
|
|
return -EINVAL;
|
|
*band = bands_fm[band->index];
|
|
return 0;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
int vivid_sdr_g_frequency(struct file *file, void *fh,
|
|
struct v4l2_frequency *vf)
|
|
{
|
|
struct vivid_dev *dev = video_drvdata(file);
|
|
|
|
switch (vf->tuner) {
|
|
case 0:
|
|
vf->frequency = dev->sdr_adc_freq;
|
|
vf->type = V4L2_TUNER_ADC;
|
|
return 0;
|
|
case 1:
|
|
vf->frequency = dev->sdr_fm_freq;
|
|
vf->type = V4L2_TUNER_RF;
|
|
return 0;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
int vivid_sdr_s_frequency(struct file *file, void *fh,
|
|
const struct v4l2_frequency *vf)
|
|
{
|
|
struct vivid_dev *dev = video_drvdata(file);
|
|
unsigned freq = vf->frequency;
|
|
unsigned band;
|
|
|
|
switch (vf->tuner) {
|
|
case 0:
|
|
if (vf->type != V4L2_TUNER_ADC)
|
|
return -EINVAL;
|
|
if (freq < BAND_ADC_0)
|
|
band = 0;
|
|
else if (freq < BAND_ADC_1)
|
|
band = 1;
|
|
else
|
|
band = 2;
|
|
|
|
freq = clamp_t(unsigned, freq,
|
|
bands_adc[band].rangelow,
|
|
bands_adc[band].rangehigh);
|
|
|
|
if (vb2_is_streaming(&dev->vb_sdr_cap_q) &&
|
|
freq != dev->sdr_adc_freq) {
|
|
/* resync the thread's timings */
|
|
dev->sdr_cap_seq_resync = true;
|
|
}
|
|
dev->sdr_adc_freq = freq;
|
|
return 0;
|
|
case 1:
|
|
if (vf->type != V4L2_TUNER_RF)
|
|
return -EINVAL;
|
|
dev->sdr_fm_freq = clamp_t(unsigned, freq,
|
|
bands_fm[0].rangelow,
|
|
bands_fm[0].rangehigh);
|
|
return 0;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
int vivid_sdr_g_tuner(struct file *file, void *fh, struct v4l2_tuner *vt)
|
|
{
|
|
switch (vt->index) {
|
|
case 0:
|
|
strscpy(vt->name, "ADC", sizeof(vt->name));
|
|
vt->type = V4L2_TUNER_ADC;
|
|
vt->capability =
|
|
V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS;
|
|
vt->rangelow = bands_adc[0].rangelow;
|
|
vt->rangehigh = bands_adc[2].rangehigh;
|
|
return 0;
|
|
case 1:
|
|
strscpy(vt->name, "RF", sizeof(vt->name));
|
|
vt->type = V4L2_TUNER_RF;
|
|
vt->capability =
|
|
V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS;
|
|
vt->rangelow = bands_fm[0].rangelow;
|
|
vt->rangehigh = bands_fm[0].rangehigh;
|
|
return 0;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
int vivid_sdr_s_tuner(struct file *file, void *fh, const struct v4l2_tuner *vt)
|
|
{
|
|
if (vt->index > 1)
|
|
return -EINVAL;
|
|
return 0;
|
|
}
|
|
|
|
int vidioc_enum_fmt_sdr_cap(struct file *file, void *fh, struct v4l2_fmtdesc *f)
|
|
{
|
|
if (f->index >= ARRAY_SIZE(formats))
|
|
return -EINVAL;
|
|
f->pixelformat = formats[f->index].pixelformat;
|
|
return 0;
|
|
}
|
|
|
|
int vidioc_g_fmt_sdr_cap(struct file *file, void *fh, struct v4l2_format *f)
|
|
{
|
|
struct vivid_dev *dev = video_drvdata(file);
|
|
|
|
f->fmt.sdr.pixelformat = dev->sdr_pixelformat;
|
|
f->fmt.sdr.buffersize = dev->sdr_buffersize;
|
|
return 0;
|
|
}
|
|
|
|
int vidioc_s_fmt_sdr_cap(struct file *file, void *fh, struct v4l2_format *f)
|
|
{
|
|
struct vivid_dev *dev = video_drvdata(file);
|
|
struct vb2_queue *q = &dev->vb_sdr_cap_q;
|
|
int i;
|
|
|
|
if (vb2_is_busy(q))
|
|
return -EBUSY;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(formats); i++) {
|
|
if (formats[i].pixelformat == f->fmt.sdr.pixelformat) {
|
|
dev->sdr_pixelformat = formats[i].pixelformat;
|
|
dev->sdr_buffersize = formats[i].buffersize;
|
|
f->fmt.sdr.buffersize = formats[i].buffersize;
|
|
return 0;
|
|
}
|
|
}
|
|
dev->sdr_pixelformat = formats[0].pixelformat;
|
|
dev->sdr_buffersize = formats[0].buffersize;
|
|
f->fmt.sdr.pixelformat = formats[0].pixelformat;
|
|
f->fmt.sdr.buffersize = formats[0].buffersize;
|
|
return 0;
|
|
}
|
|
|
|
int vidioc_try_fmt_sdr_cap(struct file *file, void *fh, struct v4l2_format *f)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(formats); i++) {
|
|
if (formats[i].pixelformat == f->fmt.sdr.pixelformat) {
|
|
f->fmt.sdr.buffersize = formats[i].buffersize;
|
|
return 0;
|
|
}
|
|
}
|
|
f->fmt.sdr.pixelformat = formats[0].pixelformat;
|
|
f->fmt.sdr.buffersize = formats[0].buffersize;
|
|
return 0;
|
|
}
|
|
|
|
#define FIXP_N (15)
|
|
#define FIXP_FRAC (1 << FIXP_N)
|
|
#define FIXP_2PI ((int)(2 * 3.141592653589 * FIXP_FRAC))
|
|
#define M_100000PI (3.14159 * 100000)
|
|
|
|
void vivid_sdr_cap_process(struct vivid_dev *dev, struct vivid_buffer *buf)
|
|
{
|
|
u8 *vbuf = vb2_plane_vaddr(&buf->vb.vb2_buf, 0);
|
|
unsigned long i;
|
|
unsigned long plane_size = vb2_plane_size(&buf->vb.vb2_buf, 0);
|
|
s64 s64tmp;
|
|
s32 src_phase_step;
|
|
s32 mod_phase_step;
|
|
s32 fixp_i;
|
|
s32 fixp_q;
|
|
|
|
/* calculate phase step */
|
|
#define BEEP_FREQ 1000 /* 1kHz beep */
|
|
src_phase_step = DIV_ROUND_CLOSEST(FIXP_2PI * BEEP_FREQ,
|
|
dev->sdr_adc_freq);
|
|
|
|
for (i = 0; i < plane_size; i += 2) {
|
|
mod_phase_step = fixp_cos32_rad(dev->sdr_fixp_src_phase,
|
|
FIXP_2PI) >> (31 - FIXP_N);
|
|
|
|
dev->sdr_fixp_src_phase += src_phase_step;
|
|
s64tmp = (s64) mod_phase_step * dev->sdr_fm_deviation;
|
|
dev->sdr_fixp_mod_phase += div_s64(s64tmp, M_100000PI);
|
|
|
|
/*
|
|
* Transfer phase angle to [0, 2xPI] in order to avoid variable
|
|
* overflow and make it suitable for cosine implementation
|
|
* used, which does not support negative angles.
|
|
*/
|
|
dev->sdr_fixp_src_phase %= FIXP_2PI;
|
|
dev->sdr_fixp_mod_phase %= FIXP_2PI;
|
|
|
|
if (dev->sdr_fixp_mod_phase < 0)
|
|
dev->sdr_fixp_mod_phase += FIXP_2PI;
|
|
|
|
fixp_i = fixp_cos32_rad(dev->sdr_fixp_mod_phase, FIXP_2PI);
|
|
fixp_q = fixp_sin32_rad(dev->sdr_fixp_mod_phase, FIXP_2PI);
|
|
|
|
/* Normalize fraction values represented with 32 bit precision
|
|
* to fixed point representation with FIXP_N bits */
|
|
fixp_i >>= (31 - FIXP_N);
|
|
fixp_q >>= (31 - FIXP_N);
|
|
|
|
switch (dev->sdr_pixelformat) {
|
|
case V4L2_SDR_FMT_CU8:
|
|
/* convert 'fixp float' to u8 [0, +255] */
|
|
/* u8 = X * 127.5 + 127.5; X is float [-1.0, +1.0] */
|
|
fixp_i = fixp_i * 1275 + FIXP_FRAC * 1275;
|
|
fixp_q = fixp_q * 1275 + FIXP_FRAC * 1275;
|
|
*vbuf++ = DIV_ROUND_CLOSEST(fixp_i, FIXP_FRAC * 10);
|
|
*vbuf++ = DIV_ROUND_CLOSEST(fixp_q, FIXP_FRAC * 10);
|
|
break;
|
|
case V4L2_SDR_FMT_CS8:
|
|
/* convert 'fixp float' to s8 [-128, +127] */
|
|
/* s8 = X * 127.5 - 0.5; X is float [-1.0, +1.0] */
|
|
fixp_i = fixp_i * 1275 - FIXP_FRAC * 5;
|
|
fixp_q = fixp_q * 1275 - FIXP_FRAC * 5;
|
|
*vbuf++ = DIV_ROUND_CLOSEST(fixp_i, FIXP_FRAC * 10);
|
|
*vbuf++ = DIV_ROUND_CLOSEST(fixp_q, FIXP_FRAC * 10);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
}
|