// 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 "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 &&
            prandom_u32_max(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_seq_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;
        if (dev->seq_wrap)
                dev->sdr_cap_seq_offset = 0xffffff80U;
        dev->jiffies_sdr_cap = jiffies;
        dev->sdr_cap_seq_resync = false;

        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;

                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 (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_count = 0;
        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;
                }
        }
}