// SPDX-License-Identifier: GPL-2.0-only
/*
 *  pvrusb2-dvb.c - linux-dvb api interface to the pvrusb2 driver.
 *
 *  Copyright (C) 2007, 2008 Michael Krufky <mkrufky@linuxtv.org>
 */

#include <linux/kthread.h>
#include <linux/freezer.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <media/dvbdev.h>
#include "pvrusb2-debug.h"
#include "pvrusb2-hdw-internal.h"
#include "pvrusb2-hdw.h"
#include "pvrusb2-io.h"
#include "pvrusb2-dvb.h"

DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr);

static int pvr2_dvb_feed_func(struct pvr2_dvb_adapter *adap)
{
        int ret;
        unsigned int count;
        struct pvr2_buffer *bp;
        struct pvr2_stream *stream;

        pvr2_trace(PVR2_TRACE_DVB_FEED, "dvb feed thread started");
        set_freezable();

        stream = adap->channel.stream->stream;

        for (;;) {
                if (kthread_should_stop()) break;

                bp = pvr2_stream_get_ready_buffer(stream);
                if (bp != NULL) {
                        count = pvr2_buffer_get_count(bp);
                        if (count) {
                                dvb_dmx_swfilter(
                                        &adap->demux,
                                        adap->buffer_storage[
                                            pvr2_buffer_get_id(bp)],
                                        count);
                        } else {
                                ret = pvr2_buffer_get_status(bp);
                                if (ret < 0) break;
                        }
                        ret = pvr2_buffer_queue(bp);
                        if (ret < 0) break;

                        /* Since we know we did something to a buffer,
                           just go back and try again.  No point in
                           blocking unless we really ran out of
                           buffers to process. */
                        continue;
                }


                /* Wait until more buffers become available or we're
                   told not to wait any longer. */
                ret = wait_event_freezable(adap->buffer_wait_data,
                    (pvr2_stream_get_ready_count(stream) > 0) ||
                    kthread_should_stop());
                if (ret < 0) break;
        }

        /* If we get here and ret is < 0, then an error has occurred.
           Probably would be a good idea to communicate that to DVB core... */

        pvr2_trace(PVR2_TRACE_DVB_FEED, "dvb feed thread stopped");

        return 0;
}

static int pvr2_dvb_feed_thread(void *data)
{
        int stat = pvr2_dvb_feed_func(data);

        while (!kthread_should_stop()) {
                set_current_state(TASK_INTERRUPTIBLE);
                schedule();
        }
        return stat;
}

static void pvr2_dvb_notify(void *ptr)
{
        struct pvr2_dvb_adapter *adap = ptr;

        wake_up(&adap->buffer_wait_data);
}

static void pvr2_dvb_stream_end(struct pvr2_dvb_adapter *adap)
{
        unsigned int idx;
        struct pvr2_stream *stream;

        if (adap->thread) {
                kthread_stop(adap->thread);
                adap->thread = NULL;
        }

        if (adap->channel.stream) {
                stream = adap->channel.stream->stream;
        } else {
                stream = NULL;
        }
        if (stream) {
                pvr2_hdw_set_streaming(adap->channel.hdw, 0);
                pvr2_stream_set_callback(stream, NULL, NULL);
                pvr2_stream_kill(stream);
                pvr2_stream_set_buffer_count(stream, 0);
                pvr2_channel_claim_stream(&adap->channel, NULL);
        }

        if (adap->stream_run) {
                for (idx = 0; idx < PVR2_DVB_BUFFER_COUNT; idx++) {
                        if (!(adap->buffer_storage[idx])) continue;
                        kfree(adap->buffer_storage[idx]);
                        adap->buffer_storage[idx] = NULL;
                }
                adap->stream_run = 0;
        }
}

static int pvr2_dvb_stream_do_start(struct pvr2_dvb_adapter *adap)
{
        struct pvr2_context *pvr = adap->channel.mc_head;
        unsigned int idx;
        int ret;
        struct pvr2_buffer *bp;
        struct pvr2_stream *stream = NULL;

        if (adap->stream_run) return -EIO;

        ret = pvr2_channel_claim_stream(&adap->channel, &pvr->video_stream);
        /* somebody else already has the stream */
        if (ret < 0) return ret;

        stream = adap->channel.stream->stream;

        for (idx = 0; idx < PVR2_DVB_BUFFER_COUNT; idx++) {
                adap->buffer_storage[idx] = kmalloc(PVR2_DVB_BUFFER_SIZE,
                                                    GFP_KERNEL);
                if (!(adap->buffer_storage[idx])) return -ENOMEM;
        }

        pvr2_stream_set_callback(pvr->video_stream.stream,
                                 pvr2_dvb_notify, adap);

        ret = pvr2_stream_set_buffer_count(stream, PVR2_DVB_BUFFER_COUNT);
        if (ret < 0) return ret;

        for (idx = 0; idx < PVR2_DVB_BUFFER_COUNT; idx++) {
                bp = pvr2_stream_get_buffer(stream, idx);
                pvr2_buffer_set_buffer(bp,
                                       adap->buffer_storage[idx],
                                       PVR2_DVB_BUFFER_SIZE);
        }

        ret = pvr2_hdw_set_streaming(adap->channel.hdw, 1);
        if (ret < 0) return ret;

        while ((bp = pvr2_stream_get_idle_buffer(stream)) != NULL) {
                ret = pvr2_buffer_queue(bp);
                if (ret < 0) return ret;
        }

        adap->thread = kthread_run(pvr2_dvb_feed_thread, adap, "pvrusb2-dvb");

        if (IS_ERR(adap->thread)) {
                ret = PTR_ERR(adap->thread);
                adap->thread = NULL;
                return ret;
        }

        adap->stream_run = !0;

        return 0;
}

static int pvr2_dvb_stream_start(struct pvr2_dvb_adapter *adap)
{
        int ret = pvr2_dvb_stream_do_start(adap);
        if (ret < 0) pvr2_dvb_stream_end(adap);
        return ret;
}

static int pvr2_dvb_ctrl_feed(struct dvb_demux_feed *dvbdmxfeed, int onoff)
{
        struct pvr2_dvb_adapter *adap = dvbdmxfeed->demux->priv;
        int ret = 0;

        if (adap == NULL) return -ENODEV;

        mutex_lock(&adap->lock);
        do {
                if (onoff) {
                        if (!adap->feedcount) {
                                pvr2_trace(PVR2_TRACE_DVB_FEED,
                                           "start feeding demux");
                                ret = pvr2_dvb_stream_start(adap);
                                if (ret < 0) break;
                        }
                        (adap->feedcount)++;
                } else if (adap->feedcount > 0) {
                        (adap->feedcount)--;
                        if (!adap->feedcount) {
                                pvr2_trace(PVR2_TRACE_DVB_FEED,
                                           "stop feeding demux");
                                pvr2_dvb_stream_end(adap);
                        }
                }
        } while (0);
        mutex_unlock(&adap->lock);

        return ret;
}

static int pvr2_dvb_start_feed(struct dvb_demux_feed *dvbdmxfeed)
{
        pvr2_trace(PVR2_TRACE_DVB_FEED, "start pid: 0x%04x", dvbdmxfeed->pid);
        return pvr2_dvb_ctrl_feed(dvbdmxfeed, 1);
}

static int pvr2_dvb_stop_feed(struct dvb_demux_feed *dvbdmxfeed)
{
        pvr2_trace(PVR2_TRACE_DVB_FEED, "stop pid: 0x%04x", dvbdmxfeed->pid);
        return pvr2_dvb_ctrl_feed(dvbdmxfeed, 0);
}

static int pvr2_dvb_bus_ctrl(struct dvb_frontend *fe, int acquire)
{
        struct pvr2_dvb_adapter *adap = fe->dvb->priv;
        return pvr2_channel_limit_inputs(
            &adap->channel,
            (acquire ? (1 << PVR2_CVAL_INPUT_DTV) : 0));
}

static int pvr2_dvb_adapter_init(struct pvr2_dvb_adapter *adap)
{
        int ret;

        ret = dvb_register_adapter(&adap->dvb_adap, "pvrusb2-dvb",
                                   THIS_MODULE/*&hdw->usb_dev->owner*/,
                                   &adap->channel.hdw->usb_dev->dev,
                                   adapter_nr);
        if (ret < 0) {
                pvr2_trace(PVR2_TRACE_ERROR_LEGS,
                           "dvb_register_adapter failed: error %d", ret);
                goto err;
        }
        adap->dvb_adap.priv = adap;

        adap->demux.dmx.capabilities = DMX_TS_FILTERING |
                                       DMX_SECTION_FILTERING |
                                       DMX_MEMORY_BASED_FILTERING;
        adap->demux.priv             = adap;
        adap->demux.filternum        = 256;
        adap->demux.feednum          = 256;
        adap->demux.start_feed       = pvr2_dvb_start_feed;
        adap->demux.stop_feed        = pvr2_dvb_stop_feed;
        adap->demux.write_to_decoder = NULL;

        ret = dvb_dmx_init(&adap->demux);
        if (ret < 0) {
                pvr2_trace(PVR2_TRACE_ERROR_LEGS,
                           "dvb_dmx_init failed: error %d", ret);
                goto err_dmx;
        }

        adap->dmxdev.filternum       = adap->demux.filternum;
        adap->dmxdev.demux           = &adap->demux.dmx;
        adap->dmxdev.capabilities    = 0;

        ret = dvb_dmxdev_init(&adap->dmxdev, &adap->dvb_adap);
        if (ret < 0) {
                pvr2_trace(PVR2_TRACE_ERROR_LEGS,
                           "dvb_dmxdev_init failed: error %d", ret);
                goto err_dmx_dev;
        }

        dvb_net_init(&adap->dvb_adap, &adap->dvb_net, &adap->demux.dmx);

        return 0;

err_dmx_dev:
        dvb_dmx_release(&adap->demux);
err_dmx:
        dvb_unregister_adapter(&adap->dvb_adap);
err:
        return ret;
}

static int pvr2_dvb_adapter_exit(struct pvr2_dvb_adapter *adap)
{
        pvr2_trace(PVR2_TRACE_INFO, "unregistering DVB devices");
        dvb_net_release(&adap->dvb_net);
        adap->demux.dmx.close(&adap->demux.dmx);
        dvb_dmxdev_release(&adap->dmxdev);
        dvb_dmx_release(&adap->demux);
        dvb_unregister_adapter(&adap->dvb_adap);
        return 0;
}

static int pvr2_dvb_frontend_init(struct pvr2_dvb_adapter *adap)
{
        struct pvr2_hdw *hdw = adap->channel.hdw;
        const struct pvr2_dvb_props *dvb_props = hdw->hdw_desc->dvb_props;
        int ret = 0;

        if (dvb_props == NULL) {
                pvr2_trace(PVR2_TRACE_ERROR_LEGS, "fe_props not defined!");
                return -EINVAL;
        }

        ret = pvr2_channel_limit_inputs(
            &adap->channel,
            (1 << PVR2_CVAL_INPUT_DTV));
        if (ret) {
                pvr2_trace(PVR2_TRACE_ERROR_LEGS,
                           "failed to grab control of dtv input (code=%d)",
                    ret);
                return ret;
        }

        if (dvb_props->frontend_attach == NULL) {
                pvr2_trace(PVR2_TRACE_ERROR_LEGS,
                           "frontend_attach not defined!");
                ret = -EINVAL;
                goto done;
        }

        if (dvb_props->frontend_attach(adap) == 0 && adap->fe[0]) {
                if (dvb_register_frontend(&adap->dvb_adap, adap->fe[0])) {
                        pvr2_trace(PVR2_TRACE_ERROR_LEGS,
                                   "frontend registration failed!");
                        ret = -ENODEV;
                        goto fail_frontend0;
                }
                if (adap->fe[0]->ops.analog_ops.standby)
                        adap->fe[0]->ops.analog_ops.standby(adap->fe[0]);

                pvr2_trace(PVR2_TRACE_INFO, "transferring fe[%d] ts_bus_ctrl() to pvr2_dvb_bus_ctrl()",
                           adap->fe[0]->id);
                adap->fe[0]->ops.ts_bus_ctrl = pvr2_dvb_bus_ctrl;
        } else {
                pvr2_trace(PVR2_TRACE_ERROR_LEGS,
                           "no frontend was attached!");
                ret = -ENODEV;
                return ret;
        }

        if (dvb_props->tuner_attach && dvb_props->tuner_attach(adap)) {
                pvr2_trace(PVR2_TRACE_ERROR_LEGS, "tuner attach failed");
                ret = -ENODEV;
                goto fail_tuner;
        }

        if (adap->fe[1]) {
                adap->fe[1]->id = 1;
                adap->fe[1]->tuner_priv = adap->fe[0]->tuner_priv;
                memcpy(&adap->fe[1]->ops.tuner_ops,
                       &adap->fe[0]->ops.tuner_ops,
                       sizeof(struct dvb_tuner_ops));

                if (dvb_register_frontend(&adap->dvb_adap, adap->fe[1])) {
                        pvr2_trace(PVR2_TRACE_ERROR_LEGS,
                                   "frontend registration failed!");
                        ret = -ENODEV;
                        goto fail_frontend1;
                }
                /* MFE lock */
                adap->dvb_adap.mfe_shared = 1;

                if (adap->fe[1]->ops.analog_ops.standby)
                        adap->fe[1]->ops.analog_ops.standby(adap->fe[1]);

                pvr2_trace(PVR2_TRACE_INFO, "transferring fe[%d] ts_bus_ctrl() to pvr2_dvb_bus_ctrl()",
                           adap->fe[1]->id);
                adap->fe[1]->ops.ts_bus_ctrl = pvr2_dvb_bus_ctrl;
        }
done:
        pvr2_channel_limit_inputs(&adap->channel, 0);
        return ret;

fail_frontend1:
        dvb_frontend_detach(adap->fe[1]);
        adap->fe[1] = NULL;
fail_tuner:
        dvb_unregister_frontend(adap->fe[0]);
fail_frontend0:
        dvb_frontend_detach(adap->fe[0]);
        adap->fe[0] = NULL;
        dvb_module_release(adap->i2c_client_tuner);
        dvb_module_release(adap->i2c_client_demod[1]);
        dvb_module_release(adap->i2c_client_demod[0]);

        return ret;
}

static int pvr2_dvb_frontend_exit(struct pvr2_dvb_adapter *adap)
{
        if (adap->fe[1]) {
                dvb_unregister_frontend(adap->fe[1]);
                dvb_frontend_detach(adap->fe[1]);
                adap->fe[1] = NULL;
        }
        if (adap->fe[0]) {
                dvb_unregister_frontend(adap->fe[0]);
                dvb_frontend_detach(adap->fe[0]);
                adap->fe[0] = NULL;
        }

        dvb_module_release(adap->i2c_client_tuner);
        adap->i2c_client_tuner = NULL;
        dvb_module_release(adap->i2c_client_demod[1]);
        adap->i2c_client_demod[1] = NULL;
        dvb_module_release(adap->i2c_client_demod[0]);
        adap->i2c_client_demod[0] = NULL;

        return 0;
}

static void pvr2_dvb_destroy(struct pvr2_dvb_adapter *adap)
{
        pvr2_dvb_stream_end(adap);
        pvr2_dvb_frontend_exit(adap);
        pvr2_dvb_adapter_exit(adap);
        pvr2_channel_done(&adap->channel);
        kfree(adap);
}

static void pvr2_dvb_internal_check(struct pvr2_channel *chp)
{
        struct pvr2_dvb_adapter *adap;
        adap = container_of(chp, struct pvr2_dvb_adapter, channel);
        if (!adap->channel.mc_head->disconnect_flag) return;
        pvr2_dvb_destroy(adap);
}

struct pvr2_dvb_adapter *pvr2_dvb_create(struct pvr2_context *pvr)
{
        int ret = 0;
        struct pvr2_dvb_adapter *adap;
        if (!pvr->hdw->hdw_desc->dvb_props) {
                /* Device lacks a digital interface so don't set up
                   the DVB side of the driver either.  For now. */
                return NULL;
        }
        adap = kzalloc_obj(*adap);
        if (!adap) return adap;
        pvr2_channel_init(&adap->channel, pvr);
        adap->channel.check_func = pvr2_dvb_internal_check;
        init_waitqueue_head(&adap->buffer_wait_data);
        mutex_init(&adap->lock);
        ret = pvr2_dvb_adapter_init(adap);
        if (ret < 0) goto fail1;
        ret = pvr2_dvb_frontend_init(adap);
        if (ret < 0) goto fail2;
        return adap;

fail2:
        pvr2_dvb_adapter_exit(adap);
fail1:
        pvr2_channel_done(&adap->channel);
        return NULL;
}