// SPDX-License-Identifier: GPL-2.0-only
/*
 * vivid-radio-common.c - common radio rx/tx 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/videodev2.h>

#include "vivid-core.h"
#include "vivid-ctrls.h"
#include "vivid-radio-common.h"
#include "vivid-rds-gen.h"

/*
 * These functions are shared between the vivid receiver and transmitter
 * since both use the same frequency bands.
 */

const struct v4l2_frequency_band vivid_radio_bands[TOT_BANDS] = {
        /* Band FM */
        {
                .type = V4L2_TUNER_RADIO,
                .index = 0,
                .capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
                              V4L2_TUNER_CAP_FREQ_BANDS,
                .rangelow   = FM_FREQ_RANGE_LOW,
                .rangehigh  = FM_FREQ_RANGE_HIGH,
                .modulation = V4L2_BAND_MODULATION_FM,
        },
        /* Band AM */
        {
                .type = V4L2_TUNER_RADIO,
                .index = 1,
                .capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_FREQ_BANDS,
                .rangelow   = AM_FREQ_RANGE_LOW,
                .rangehigh  = AM_FREQ_RANGE_HIGH,
                .modulation = V4L2_BAND_MODULATION_AM,
        },
        /* Band SW */
        {
                .type = V4L2_TUNER_RADIO,
                .index = 2,
                .capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_FREQ_BANDS,
                .rangelow   = SW_FREQ_RANGE_LOW,
                .rangehigh  = SW_FREQ_RANGE_HIGH,
                .modulation = V4L2_BAND_MODULATION_AM,
        },
};

/*
 * Initialize the RDS generator. If we can loop, then the RDS generator
 * is set up with the values from the RDS TX controls, otherwise it
 * will fill in standard values using one of two alternates.
 */
void vivid_radio_rds_init(struct vivid_dev *dev)
{
        struct vivid_rds_gen *rds = &dev->rds_gen;
        bool alt = dev->radio_rx_rds_use_alternates;

        /* Do nothing, blocks will be filled by the transmitter */
        if (dev->radio_rds_loop && !dev->radio_tx_rds_controls)
                return;

        if (dev->radio_rds_loop) {
                v4l2_ctrl_lock(dev->radio_tx_rds_pi);
                rds->picode = dev->radio_tx_rds_pi->cur.val;
                rds->pty = dev->radio_tx_rds_pty->cur.val;
                rds->mono_stereo = dev->radio_tx_rds_mono_stereo->cur.val;
                rds->art_head = dev->radio_tx_rds_art_head->cur.val;
                rds->compressed = dev->radio_tx_rds_compressed->cur.val;
                rds->dyn_pty = dev->radio_tx_rds_dyn_pty->cur.val;
                rds->ta = dev->radio_tx_rds_ta->cur.val;
                rds->tp = dev->radio_tx_rds_tp->cur.val;
                rds->ms = dev->radio_tx_rds_ms->cur.val;
                strscpy(rds->psname,
                        dev->radio_tx_rds_psname->p_cur.p_char,
                        sizeof(rds->psname));
                strscpy(rds->radiotext,
                        dev->radio_tx_rds_radiotext->p_cur.p_char + alt * 64,
                        sizeof(rds->radiotext));
                v4l2_ctrl_unlock(dev->radio_tx_rds_pi);
        } else {
                vivid_rds_gen_fill(rds, dev->radio_rx_freq, alt);
        }
        if (dev->radio_rx_rds_controls) {
                v4l2_ctrl_s_ctrl(dev->radio_rx_rds_pty, rds->pty);
                v4l2_ctrl_s_ctrl(dev->radio_rx_rds_ta, rds->ta);
                v4l2_ctrl_s_ctrl(dev->radio_rx_rds_tp, rds->tp);
                v4l2_ctrl_s_ctrl(dev->radio_rx_rds_ms, rds->ms);
                v4l2_ctrl_s_ctrl_string(dev->radio_rx_rds_psname, rds->psname);
                v4l2_ctrl_s_ctrl_string(dev->radio_rx_rds_radiotext, rds->radiotext);
                if (!dev->radio_rds_loop)
                        dev->radio_rx_rds_use_alternates = !dev->radio_rx_rds_use_alternates;
        }
        vivid_rds_generate(rds);
}

/*
 * Calculate the emulated signal quality taking into account the frequency
 * the transmitter is using.
 */
static void vivid_radio_calc_sig_qual(struct vivid_dev *dev)
{
        int mod = 16000;
        int delta = 800;
        int sig_qual, sig_qual_tx = mod;

        /*
         * For SW and FM there is a channel every 1000 kHz, for AM there is one
         * every 100 kHz.
         */
        if (dev->radio_rx_freq <= AM_FREQ_RANGE_HIGH) {
                mod /= 10;
                delta /= 10;
        }
        sig_qual = (dev->radio_rx_freq + delta) % mod - delta;
        if (dev->has_radio_tx)
                sig_qual_tx = dev->radio_rx_freq - dev->radio_tx_freq;
        if (abs(sig_qual_tx) <= abs(sig_qual)) {
                sig_qual = sig_qual_tx;
                /*
                 * Zero the internal rds buffer if we are going to loop
                 * rds blocks.
                 */
                if (!dev->radio_rds_loop && !dev->radio_tx_rds_controls)
                        memset(dev->rds_gen.data, 0,
                               sizeof(dev->rds_gen.data));
                dev->radio_rds_loop = dev->radio_rx_freq >= FM_FREQ_RANGE_LOW;
        } else {
                dev->radio_rds_loop = false;
        }
        if (dev->radio_rx_freq <= AM_FREQ_RANGE_HIGH)
                sig_qual *= 10;
        dev->radio_rx_sig_qual = sig_qual;
}

int vivid_radio_g_frequency(struct file *file, const unsigned *pfreq, struct v4l2_frequency *vf)
{
        if (vf->tuner != 0)
                return -EINVAL;
        vf->frequency = *pfreq;
        return 0;
}

int vivid_radio_s_frequency(struct file *file, unsigned *pfreq, const struct v4l2_frequency *vf)
{
        struct vivid_dev *dev = video_drvdata(file);
        unsigned freq;
        unsigned band;

        if (vf->tuner != 0)
                return -EINVAL;

        if (vf->frequency >= (FM_FREQ_RANGE_LOW + SW_FREQ_RANGE_HIGH) / 2)
                band = BAND_FM;
        else if (vf->frequency <= (AM_FREQ_RANGE_HIGH + SW_FREQ_RANGE_LOW) / 2)
                band = BAND_AM;
        else
                band = BAND_SW;

        freq = clamp_t(u32, vf->frequency, vivid_radio_bands[band].rangelow,
                                           vivid_radio_bands[band].rangehigh);
        *pfreq = freq;

        /*
         * For both receiver and transmitter recalculate the signal quality
         * (since that depends on both frequencies) and re-init the rds
         * generator.
         */
        vivid_radio_calc_sig_qual(dev);
        vivid_radio_rds_init(dev);
        return 0;
}