// SPDX-License-Identifier: GPL-2.0-only
/* Frontend part of the Linux driver for the WideView/ Yakumo/ Hama/
 * Typhoon/ Yuan DVB-T USB2.0 receiver.
 *
 * Copyright (C) 2005 Patrick Boettcher <patrick.boettcher@posteo.de>
 *
 * see Documentation/driver-api/media/drivers/dvb-usb.rst for more information
 */
#include "dtt200u.h"

struct dtt200u_fe_state {
        struct dvb_usb_device *d;

        enum fe_status stat;

        struct dtv_frontend_properties fep;
        struct dvb_frontend frontend;

        unsigned char data[80];
        struct mutex data_mutex;
};

static int dtt200u_fe_read_status(struct dvb_frontend *fe,
                                  enum fe_status *stat)
{
        struct dtt200u_fe_state *state = fe->demodulator_priv;
        int ret;

        mutex_lock(&state->data_mutex);
        state->data[0] = GET_TUNE_STATUS;

        ret = dvb_usb_generic_rw(state->d, state->data, 1, state->data, 3, 0);
        if (ret < 0) {
                *stat = 0;
                mutex_unlock(&state->data_mutex);
                return ret;
        }

        switch (state->data[0]) {
                case 0x01:
                        *stat = FE_HAS_SIGNAL | FE_HAS_CARRIER |
                                FE_HAS_VITERBI | FE_HAS_SYNC | FE_HAS_LOCK;
                        break;
                case 0x00: /* pending */
                        *stat = FE_TIMEDOUT; /* during set_frontend */
                        break;
                default:
                case 0x02: /* failed */
                        *stat = 0;
                        break;
        }
        mutex_unlock(&state->data_mutex);
        return 0;
}

static int dtt200u_fe_read_ber(struct dvb_frontend* fe, u32 *ber)
{
        struct dtt200u_fe_state *state = fe->demodulator_priv;
        int ret;

        mutex_lock(&state->data_mutex);
        state->data[0] = GET_VIT_ERR_CNT;

        ret = dvb_usb_generic_rw(state->d, state->data, 1, state->data, 3, 0);
        if (ret >= 0)
                *ber = (state->data[0] << 16) | (state->data[1] << 8) | state->data[2];

        mutex_unlock(&state->data_mutex);
        return ret;
}

static int dtt200u_fe_read_unc_blocks(struct dvb_frontend* fe, u32 *unc)
{
        struct dtt200u_fe_state *state = fe->demodulator_priv;
        int ret;

        mutex_lock(&state->data_mutex);
        state->data[0] = GET_RS_UNCOR_BLK_CNT;

        ret = dvb_usb_generic_rw(state->d, state->data, 1, state->data, 2, 0);
        if (ret >= 0)
                *unc = (state->data[0] << 8) | state->data[1];

        mutex_unlock(&state->data_mutex);
        return ret;
}

static int dtt200u_fe_read_signal_strength(struct dvb_frontend* fe, u16 *strength)
{
        struct dtt200u_fe_state *state = fe->demodulator_priv;
        int ret;

        mutex_lock(&state->data_mutex);
        state->data[0] = GET_AGC;

        ret = dvb_usb_generic_rw(state->d, state->data, 1, state->data, 1, 0);
        if (ret >= 0)
                *strength = (state->data[0] << 8) | state->data[0];

        mutex_unlock(&state->data_mutex);
        return ret;
}

static int dtt200u_fe_read_snr(struct dvb_frontend* fe, u16 *snr)
{
        struct dtt200u_fe_state *state = fe->demodulator_priv;
        int ret;

        mutex_lock(&state->data_mutex);
        state->data[0] = GET_SNR;

        ret = dvb_usb_generic_rw(state->d, state->data, 1, state->data, 1, 0);
        if (ret >= 0)
                *snr = ~((state->data[0] << 8) | state->data[0]);

        mutex_unlock(&state->data_mutex);
        return ret;
}

static int dtt200u_fe_init(struct dvb_frontend* fe)
{
        struct dtt200u_fe_state *state = fe->demodulator_priv;
        int ret;

        mutex_lock(&state->data_mutex);
        state->data[0] = SET_INIT;

        ret = dvb_usb_generic_write(state->d, state->data, 1);
        mutex_unlock(&state->data_mutex);

        return ret;
}

static int dtt200u_fe_sleep(struct dvb_frontend* fe)
{
        return dtt200u_fe_init(fe);
}

static int dtt200u_fe_get_tune_settings(struct dvb_frontend* fe, struct dvb_frontend_tune_settings *tune)
{
        tune->min_delay_ms = 1500;
        tune->step_size = 0;
        tune->max_drift = 0;
        return 0;
}

static int dtt200u_fe_set_frontend(struct dvb_frontend *fe)
{
        struct dtv_frontend_properties *fep = &fe->dtv_property_cache;
        struct dtt200u_fe_state *state = fe->demodulator_priv;
        int ret;
        u16 freq = fep->frequency / 250000;

        mutex_lock(&state->data_mutex);
        state->data[0] = SET_BANDWIDTH;
        switch (fep->bandwidth_hz) {
        case 8000000:
                state->data[1] = 8;
                break;
        case 7000000:
                state->data[1] = 7;
                break;
        case 6000000:
                state->data[1] = 6;
                break;
        default:
                ret = -EINVAL;
                goto ret;
        }

        ret = dvb_usb_generic_write(state->d, state->data, 2);
        if (ret < 0)
                goto ret;

        state->data[0] = SET_RF_FREQ;
        state->data[1] = freq & 0xff;
        state->data[2] = (freq >> 8) & 0xff;
        ret = dvb_usb_generic_write(state->d, state->data, 3);
        if (ret < 0)
                goto ret;

ret:
        mutex_unlock(&state->data_mutex);
        return ret;
}

static int dtt200u_fe_get_frontend(struct dvb_frontend* fe,
                                   struct dtv_frontend_properties *fep)
{
        struct dtt200u_fe_state *state = fe->demodulator_priv;

        memcpy(fep, &state->fep, sizeof(struct dtv_frontend_properties));
        return 0;
}

static void dtt200u_fe_release(struct dvb_frontend* fe)
{
        struct dtt200u_fe_state *state = fe->demodulator_priv;
        kfree(state);
}

static const struct dvb_frontend_ops dtt200u_fe_ops;

struct dvb_frontend* dtt200u_fe_attach(struct dvb_usb_device *d)
{
        struct dtt200u_fe_state* state = NULL;

        /* allocate memory for the internal state */
        state = kzalloc_obj(struct dtt200u_fe_state);
        if (state == NULL)
                goto error;

        deb_info("attaching frontend dtt200u\n");

        state->d = d;
        mutex_init(&state->data_mutex);

        memcpy(&state->frontend.ops,&dtt200u_fe_ops,sizeof(struct dvb_frontend_ops));
        state->frontend.demodulator_priv = state;

        return &state->frontend;
error:
        return NULL;
}

static const struct dvb_frontend_ops dtt200u_fe_ops = {
        .delsys = { SYS_DVBT },
        .info = {
                .name                   = "WideView USB DVB-T",
                .frequency_min_hz       =  44250 * kHz,
                .frequency_max_hz       = 867250 * kHz,
                .frequency_stepsize_hz  =    250 * 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 = dtt200u_fe_release,

        .init = dtt200u_fe_init,
        .sleep = dtt200u_fe_sleep,

        .set_frontend = dtt200u_fe_set_frontend,
        .get_frontend = dtt200u_fe_get_frontend,
        .get_tune_settings = dtt200u_fe_get_tune_settings,

        .read_status = dtt200u_fe_read_status,
        .read_ber = dtt200u_fe_read_ber,
        .read_signal_strength = dtt200u_fe_read_signal_strength,
        .read_snr = dtt200u_fe_read_snr,
        .read_ucblocks = dtt200u_fe_read_unc_blocks,
};