// SPDX-License-Identifier: GPL-2.0-only
/* DVB frontend part of the Linux driver for TwinhanDTV Alpha/MagicBoxII USB2.0
 * DVB-T receiver.
 *
 * Copyright (C) 2004-5 Patrick Boettcher (patrick.boettcher@posteo.de)
 *
 * Thanks to Twinhan who kindly provided hardware and information.
 *
 * see Documentation/driver-api/media/drivers/dvb-usb.rst for more information
 */
#include "vp7045.h"

/* It is a Zarlink MT352 within a Samsung Tuner (DNOS404ZH102A) - 040929 - AAT
 *
 * Programming is hidden inside the firmware, so set_frontend is very easy.
 * Even though there is a Firmware command that one can use to access the demod
 * via its registers. This is used for status information.
 */

struct vp7045_fe_state {
        struct dvb_frontend fe;
        struct dvb_usb_device *d;
};

static int vp7045_fe_read_status(struct dvb_frontend *fe,
                                 enum fe_status *status)
{
        struct vp7045_fe_state *state = fe->demodulator_priv;
        u8 s0 = vp7045_read_reg(state->d,0x00),
           s1 = vp7045_read_reg(state->d,0x01),
           s3 = vp7045_read_reg(state->d,0x03);

        *status = 0;
        if (s0 & (1 << 4))
                *status |= FE_HAS_CARRIER;
        if (s0 & (1 << 1))
                *status |= FE_HAS_VITERBI;
        if (s0 & (1 << 5))
                *status |= FE_HAS_LOCK;
        if (s1 & (1 << 1))
                *status |= FE_HAS_SYNC;
        if (s3 & (1 << 6))
                *status |= FE_HAS_SIGNAL;

        if ((*status & (FE_HAS_CARRIER | FE_HAS_VITERBI | FE_HAS_SYNC)) !=
                        (FE_HAS_CARRIER | FE_HAS_VITERBI | FE_HAS_SYNC))
                *status &= ~FE_HAS_LOCK;

        return 0;
}

static int vp7045_fe_read_ber(struct dvb_frontend* fe, u32 *ber)
{
        struct vp7045_fe_state *state = fe->demodulator_priv;
        *ber = (vp7045_read_reg(state->d, 0x0D) << 16) |
               (vp7045_read_reg(state->d, 0x0E) << 8) |
                vp7045_read_reg(state->d, 0x0F);
        return 0;
}

static int vp7045_fe_read_unc_blocks(struct dvb_frontend* fe, u32 *unc)
{
        struct vp7045_fe_state *state = fe->demodulator_priv;
        *unc = (vp7045_read_reg(state->d, 0x10) << 8) |
                    vp7045_read_reg(state->d, 0x11);
        return 0;
}

static int vp7045_fe_read_signal_strength(struct dvb_frontend* fe, u16 *strength)
{
        struct vp7045_fe_state *state = fe->demodulator_priv;
        u16 signal = (vp7045_read_reg(state->d, 0x14) << 8) |
                vp7045_read_reg(state->d, 0x15);

        *strength = ~signal;
        return 0;
}

static int vp7045_fe_read_snr(struct dvb_frontend* fe, u16 *snr)
{
        struct vp7045_fe_state *state = fe->demodulator_priv;
        u8 _snr = vp7045_read_reg(state->d, 0x09);
        *snr = (_snr << 8) | _snr;
        return 0;
}

static int vp7045_fe_init(struct dvb_frontend* fe)
{
        return 0;
}

static int vp7045_fe_sleep(struct dvb_frontend* fe)
{
        return 0;
}

static int vp7045_fe_get_tune_settings(struct dvb_frontend* fe, struct dvb_frontend_tune_settings *tune)
{
        tune->min_delay_ms = 800;
        return 0;
}

static int vp7045_fe_set_frontend(struct dvb_frontend *fe)
{
        struct dtv_frontend_properties *fep = &fe->dtv_property_cache;
        struct vp7045_fe_state *state = fe->demodulator_priv;
        u8 buf[5];
        u32 freq = fep->frequency / 1000;

        buf[0] = (freq >> 16) & 0xff;
        buf[1] = (freq >>  8) & 0xff;
        buf[2] =  freq        & 0xff;
        buf[3] = 0;

        switch (fep->bandwidth_hz) {
        case 8000000:
                buf[4] = 8;
                break;
        case 7000000:
                buf[4] = 7;
                break;
        case 6000000:
                buf[4] = 6;
                break;
        default:
                return -EINVAL;
        }

        vp7045_usb_op(state->d,LOCK_TUNER_COMMAND,buf,5,NULL,0,200);
        return 0;
}

static void vp7045_fe_release(struct dvb_frontend* fe)
{
        struct vp7045_fe_state *state = fe->demodulator_priv;
        kfree(state);
}

static const struct dvb_frontend_ops vp7045_fe_ops;

struct dvb_frontend * vp7045_fe_attach(struct dvb_usb_device *d)
{
        struct vp7045_fe_state *s = kzalloc_obj(struct vp7045_fe_state);
        if (s == NULL)
                goto error;

        s->d = d;
        memcpy(&s->fe.ops, &vp7045_fe_ops, sizeof(struct dvb_frontend_ops));
        s->fe.demodulator_priv = s;

        return &s->fe;
error:
        return NULL;
}


static const struct dvb_frontend_ops vp7045_fe_ops = {
        .delsys = { SYS_DVBT },
        .info = {
                .name                   = "Twinhan VP7045/46 USB DVB-T",
                .frequency_min_hz       =  44250 * kHz,
                .frequency_max_hz       = 867250 * kHz,
                .frequency_stepsize_hz  =      1 * kHz,
                .caps = FE_CAN_INVERSION_AUTO |
                                FE_CAN_FEC_1_2 | FE_CAN_FEC_2_3 | FE_CAN_FEC_3_4 |
                                FE_CAN_FEC_5_6 | FE_CAN_FEC_7_8 | FE_CAN_FEC_AUTO |
                                FE_CAN_QPSK | FE_CAN_QAM_16 | FE_CAN_QAM_64 | FE_CAN_QAM_AUTO |
                                FE_CAN_TRANSMISSION_MODE_AUTO |
                                FE_CAN_GUARD_INTERVAL_AUTO |
                                FE_CAN_RECOVER |
                                FE_CAN_HIERARCHY_AUTO,
        },

        .release = vp7045_fe_release,

        .init = vp7045_fe_init,
        .sleep = vp7045_fe_sleep,

        .set_frontend = vp7045_fe_set_frontend,
        .get_tune_settings = vp7045_fe_get_tune_settings,

        .read_status = vp7045_fe_read_status,
        .read_ber = vp7045_fe_read_ber,
        .read_signal_strength = vp7045_fe_read_signal_strength,
        .read_snr = vp7045_fe_read_snr,
        .read_ucblocks = vp7045_fe_read_unc_blocks,
};