/*
 * oxfw_stream.c - a part of driver for OXFW970/971 based devices
 *
 * Copyright (c) 2014 Takashi Sakamoto
 *
 * Licensed under the terms of the GNU General Public License, version 2.
 */

#include "oxfw.h"
#include <linux/delay.h>

#define AVC_GENERIC_FRAME_MAXIMUM_BYTES 512
#define CALLBACK_TIMEOUT        200

/*
 * According to datasheet of Oxford Semiconductor:
 *  OXFW970: 32.0/44.1/48.0/96.0 Khz, 8 audio channels I/O
 *  OXFW971: 32.0/44.1/48.0/88.2/96.0/192.0 kHz, 16 audio channels I/O, MIDI I/O
 */
static const unsigned int oxfw_rate_table[] = {
        [0] = 32000,
        [1] = 44100,
        [2] = 48000,
        [3] = 88200,
        [4] = 96000,
        [5] = 192000,
};

/*
 * See Table 5.7 – Sampling frequency for Multi-bit Audio
 * in AV/C Stream Format Information Specification 1.1 (Apr 2005, 1394TA)
 */
static const unsigned int avc_stream_rate_table[] = {
        [0] = 0x02,
        [1] = 0x03,
        [2] = 0x04,
        [3] = 0x0a,
        [4] = 0x05,
        [5] = 0x07,
};

static int set_rate(struct snd_oxfw *oxfw, unsigned int rate)
{
        int err;

        err = avc_general_set_sig_fmt(oxfw->unit, rate,
                                      AVC_GENERAL_PLUG_DIR_IN, 0);
        if (err < 0)
                goto end;

        if (oxfw->has_output)
                err = avc_general_set_sig_fmt(oxfw->unit, rate,
                                              AVC_GENERAL_PLUG_DIR_OUT, 0);
end:
        return err;
}

static int set_stream_format(struct snd_oxfw *oxfw, struct amdtp_stream *s,
                             unsigned int rate, unsigned int pcm_channels)
{
        u8 **formats;
        struct snd_oxfw_stream_formation formation;
        enum avc_general_plug_dir dir;
        unsigned int len;
        int i, err;

        if (s == &oxfw->tx_stream) {
                formats = oxfw->tx_stream_formats;
                dir = AVC_GENERAL_PLUG_DIR_OUT;
        } else {
                formats = oxfw->rx_stream_formats;
                dir = AVC_GENERAL_PLUG_DIR_IN;
        }

        /* Seek stream format for requirements. */
        for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) {
                err = snd_oxfw_stream_parse_format(formats[i], &formation);
                if (err < 0)
                        return err;

                if ((formation.rate == rate) && (formation.pcm == pcm_channels))
                        break;
        }
        if (i == SND_OXFW_STREAM_FORMAT_ENTRIES)
                return -EINVAL;

        /* If assumed, just change rate. */
        if (oxfw->assumed)
                return set_rate(oxfw, rate);

        /* Calculate format length. */
        len = 5 + formats[i][4] * 2;

        err = avc_stream_set_format(oxfw->unit, dir, 0, formats[i], len);
        if (err < 0)
                return err;

        /* Some requests just after changing format causes freezing. */
        msleep(100);

        return 0;
}

static void stop_stream(struct snd_oxfw *oxfw, struct amdtp_stream *stream)
{
        amdtp_stream_pcm_abort(stream);
        amdtp_stream_stop(stream);

        if (stream == &oxfw->tx_stream)
                cmp_connection_break(&oxfw->out_conn);
        else
                cmp_connection_break(&oxfw->in_conn);
}

static int start_stream(struct snd_oxfw *oxfw, struct amdtp_stream *stream,
                        unsigned int rate, unsigned int pcm_channels)
{
        u8 **formats;
        struct cmp_connection *conn;
        struct snd_oxfw_stream_formation formation;
        unsigned int i, midi_ports;
        int err;

        if (stream == &oxfw->rx_stream) {
                formats = oxfw->rx_stream_formats;
                conn = &oxfw->in_conn;
        } else {
                formats = oxfw->tx_stream_formats;
                conn = &oxfw->out_conn;
        }

        /* Get stream format */
        for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) {
                if (formats[i] == NULL)
                        break;

                err = snd_oxfw_stream_parse_format(formats[i], &formation);
                if (err < 0)
                        goto end;
                if (rate != formation.rate)
                        continue;
                if (pcm_channels == 0 ||  pcm_channels == formation.pcm)
                        break;
        }
        if (i == SND_OXFW_STREAM_FORMAT_ENTRIES) {
                err = -EINVAL;
                goto end;
        }

        pcm_channels = formation.pcm;
        midi_ports = DIV_ROUND_UP(formation.midi, 8);

        /* The stream should have one pcm channels at least */
        if (pcm_channels == 0) {
                err = -EINVAL;
                goto end;
        }
        amdtp_stream_set_parameters(stream, rate, pcm_channels, midi_ports);

        err = cmp_connection_establish(conn,
                                       amdtp_stream_get_max_payload(stream));
        if (err < 0)
                goto end;

        err = amdtp_stream_start(stream,
                                 conn->resources.channel,
                                 conn->speed);
        if (err < 0) {
                cmp_connection_break(conn);
                goto end;
        }

        /* Wait first packet */
        if (!amdtp_stream_wait_callback(stream, CALLBACK_TIMEOUT)) {
                stop_stream(oxfw, stream);
                err = -ETIMEDOUT;
        }
end:
        return err;
}

static int check_connection_used_by_others(struct snd_oxfw *oxfw,
                                           struct amdtp_stream *stream)
{
        struct cmp_connection *conn;
        bool used;
        int err;

        if (stream == &oxfw->tx_stream)
                conn = &oxfw->out_conn;
        else
                conn = &oxfw->in_conn;

        err = cmp_connection_check_used(conn, &used);
        if ((err >= 0) && used && !amdtp_stream_running(stream)) {
                dev_err(&oxfw->unit->device,
                        "Connection established by others: %cPCR[%d]\n",
                        (conn->direction == CMP_OUTPUT) ? 'o' : 'i',
                        conn->pcr_index);
                err = -EBUSY;
        }

        return err;
}

int snd_oxfw_stream_init_simplex(struct snd_oxfw *oxfw,
                                 struct amdtp_stream *stream)
{
        struct cmp_connection *conn;
        enum cmp_direction c_dir;
        enum amdtp_stream_direction s_dir;
        int err;

        if (stream == &oxfw->tx_stream) {
                conn = &oxfw->out_conn;
                c_dir = CMP_OUTPUT;
                s_dir = AMDTP_IN_STREAM;
        } else {
                conn = &oxfw->in_conn;
                c_dir = CMP_INPUT;
                s_dir = AMDTP_OUT_STREAM;
        }

        err = cmp_connection_init(conn, oxfw->unit, c_dir, 0);
        if (err < 0)
                goto end;

        err = amdtp_stream_init(stream, oxfw->unit, s_dir, CIP_NONBLOCKING);
        if (err < 0) {
                amdtp_stream_destroy(stream);
                cmp_connection_destroy(conn);
                goto end;
        }

        /*
         * OXFW starts to transmit packets with non-zero dbc.
         * OXFW postpone transferring packets till handling any asynchronous
         * packets. As a result, next isochronous packet includes more data
         * blocks than IEC 61883-6 defines.
         */
        if (stream == &oxfw->tx_stream)
                oxfw->tx_stream.flags |= CIP_SKIP_INIT_DBC_CHECK |
                                         CIP_JUMBO_PAYLOAD;
end:
        return err;
}

int snd_oxfw_stream_start_simplex(struct snd_oxfw *oxfw,
                                  struct amdtp_stream *stream,
                                  unsigned int rate, unsigned int pcm_channels)
{
        struct amdtp_stream *opposite;
        struct snd_oxfw_stream_formation formation;
        enum avc_general_plug_dir dir;
        unsigned int substreams, opposite_substreams;
        int err = 0;

        if (stream == &oxfw->tx_stream) {
                substreams = oxfw->capture_substreams;
                opposite = &oxfw->rx_stream;
                opposite_substreams = oxfw->playback_substreams;
                dir = AVC_GENERAL_PLUG_DIR_OUT;
        } else {
                substreams = oxfw->playback_substreams;
                opposite_substreams = oxfw->capture_substreams;

                if (oxfw->has_output)
                        opposite = &oxfw->rx_stream;
                else
                        opposite = NULL;

                dir = AVC_GENERAL_PLUG_DIR_IN;
        }

        if (substreams == 0)
                goto end;

        /*
         * Considering JACK/FFADO streaming:
         * TODO: This can be removed hwdep functionality becomes popular.
         */
        err = check_connection_used_by_others(oxfw, stream);
        if (err < 0)
                goto end;

        /* packet queueing error */
        if (amdtp_streaming_error(stream))
                stop_stream(oxfw, stream);

        err = snd_oxfw_stream_get_current_formation(oxfw, dir, &formation);
        if (err < 0)
                goto end;
        if (rate == 0)
                rate = formation.rate;
        if (pcm_channels == 0)
                pcm_channels = formation.pcm;

        if ((formation.rate != rate) || (formation.pcm != pcm_channels)) {
                if (opposite != NULL) {
                        err = check_connection_used_by_others(oxfw, opposite);
                        if (err < 0)
                                goto end;
                        stop_stream(oxfw, opposite);
                }
                stop_stream(oxfw, stream);

                err = set_stream_format(oxfw, stream, rate, pcm_channels);
                if (err < 0) {
                        dev_err(&oxfw->unit->device,
                                "fail to set stream format: %d\n", err);
                        goto end;
                }

                /* Start opposite stream if needed. */
                if (opposite && !amdtp_stream_running(opposite) &&
                    (opposite_substreams > 0)) {
                        err = start_stream(oxfw, opposite, rate, 0);
                        if (err < 0) {
                                dev_err(&oxfw->unit->device,
                                        "fail to restart stream: %d\n", err);
                                goto end;
                        }
                }
        }

        /* Start requested stream. */
        if (!amdtp_stream_running(stream)) {
                err = start_stream(oxfw, stream, rate, pcm_channels);
                if (err < 0)
                        dev_err(&oxfw->unit->device,
                                "fail to start stream: %d\n", err);
        }
end:
        return err;
}

void snd_oxfw_stream_stop_simplex(struct snd_oxfw *oxfw,
                                  struct amdtp_stream *stream)
{
        if (((stream == &oxfw->tx_stream) && (oxfw->capture_substreams > 0)) ||
            ((stream == &oxfw->rx_stream) && (oxfw->playback_substreams > 0)))
                return;

        stop_stream(oxfw, stream);
}

/*
 * This function should be called before starting the stream or after stopping
 * the streams.
 */
void snd_oxfw_stream_destroy_simplex(struct snd_oxfw *oxfw,
                                     struct amdtp_stream *stream)
{
        struct cmp_connection *conn;

        if (stream == &oxfw->tx_stream)
                conn = &oxfw->out_conn;
        else
                conn = &oxfw->in_conn;

        amdtp_stream_destroy(stream);
        cmp_connection_destroy(conn);
}

void snd_oxfw_stream_update_simplex(struct snd_oxfw *oxfw,
                                    struct amdtp_stream *stream)
{
        struct cmp_connection *conn;

        if (stream == &oxfw->tx_stream)
                conn = &oxfw->out_conn;
        else
                conn = &oxfw->in_conn;

        if (cmp_connection_update(conn) < 0)
                stop_stream(oxfw, stream);
        else
                amdtp_stream_update(stream);
}

int snd_oxfw_stream_get_current_formation(struct snd_oxfw *oxfw,
                                enum avc_general_plug_dir dir,
                                struct snd_oxfw_stream_formation *formation)
{
        u8 *format;
        unsigned int len;
        int err;

        len = AVC_GENERIC_FRAME_MAXIMUM_BYTES;
        format = kmalloc(len, GFP_KERNEL);
        if (format == NULL)
                return -ENOMEM;

        err = avc_stream_get_format_single(oxfw->unit, dir, 0, format, &len);
        if (err < 0)
                goto end;
        if (len < 3) {
                err = -EIO;
                goto end;
        }

        err = snd_oxfw_stream_parse_format(format, formation);
end:
        kfree(format);
        return err;
}

/*
 * See Table 6.16 - AM824 Stream Format
 *     Figure 6.19 - format_information field for AM824 Compound
 * in AV/C Stream Format Information Specification 1.1 (Apr 2005, 1394TA)
 * Also 'Clause 12 AM824 sequence adaption layers' in IEC 61883-6:2005
 */
int snd_oxfw_stream_parse_format(u8 *format,
                                 struct snd_oxfw_stream_formation *formation)
{
        unsigned int i, e, channels, type;

        memset(formation, 0, sizeof(struct snd_oxfw_stream_formation));

        /*
         * this module can support a hierarchy combination that:
         *  Root:       Audio and Music (0x90)
         *  Level 1:    AM824 Compound  (0x40)
         */
        if ((format[0] != 0x90) || (format[1] != 0x40))
                return -ENOSYS;

        /* check the sampling rate */
        for (i = 0; i < ARRAY_SIZE(avc_stream_rate_table); i++) {
                if (format[2] == avc_stream_rate_table[i])
                        break;
        }
        if (i == ARRAY_SIZE(avc_stream_rate_table))
                return -ENOSYS;

        formation->rate = oxfw_rate_table[i];

        for (e = 0; e < format[4]; e++) {
                channels = format[5 + e * 2];
                type = format[6 + e * 2];

                switch (type) {
                /* IEC 60958 Conformant, currently handled as MBLA */
                case 0x00:
                /* Multi Bit Linear Audio (Raw) */
                case 0x06:
                        formation->pcm += channels;
                        break;
                /* MIDI Conformant */
                case 0x0d:
                        formation->midi = channels;
                        break;
                /* IEC 61937-3 to 7 */
                case 0x01:
                case 0x02:
                case 0x03:
                case 0x04:
                case 0x05:
                /* Multi Bit Linear Audio */
                case 0x07:      /* DVD-Audio */
                case 0x0c:      /* High Precision */
                /* One Bit Audio */
                case 0x08:      /* (Plain) Raw */
                case 0x09:      /* (Plain) SACD */
                case 0x0a:      /* (Encoded) Raw */
                case 0x0b:      /* (Encoded) SACD */
                /* SMPTE Time-Code conformant */
                case 0x0e:
                /* Sample Count */
                case 0x0f:
                /* Anciliary Data */
                case 0x10:
                /* Synchronization Stream (Stereo Raw audio) */
                case 0x40:
                /* Don't care */
                case 0xff:
                default:
                        return -ENOSYS; /* not supported */
                }
        }

        if (formation->pcm  > AMDTP_MAX_CHANNELS_FOR_PCM ||
            formation->midi > AMDTP_MAX_CHANNELS_FOR_MIDI)
                return -ENOSYS;

        return 0;
}

static int
assume_stream_formats(struct snd_oxfw *oxfw, enum avc_general_plug_dir dir,
                      unsigned int pid, u8 *buf, unsigned int *len,
                      u8 **formats)
{
        struct snd_oxfw_stream_formation formation;
        unsigned int i, eid;
        int err;

        /* get format at current sampling rate */
        err = avc_stream_get_format_single(oxfw->unit, dir, pid, buf, len);
        if (err < 0) {
                dev_err(&oxfw->unit->device,
                "fail to get current stream format for isoc %s plug %d:%d\n",
                        (dir == AVC_GENERAL_PLUG_DIR_IN) ? "in" : "out",
                        pid, err);
                goto end;
        }

        /* parse and set stream format */
        eid = 0;
        err = snd_oxfw_stream_parse_format(buf, &formation);
        if (err < 0)
                goto end;

        formats[eid] = kmalloc(*len, GFP_KERNEL);
        if (formats[eid] == NULL) {
                err = -ENOMEM;
                goto end;
        }
        memcpy(formats[eid], buf, *len);

        /* apply the format for each available sampling rate */
        for (i = 0; i < ARRAY_SIZE(oxfw_rate_table); i++) {
                if (formation.rate == oxfw_rate_table[i])
                        continue;

                err = avc_general_inquiry_sig_fmt(oxfw->unit,
                                                  oxfw_rate_table[i],
                                                  dir, pid);
                if (err < 0)
                        continue;

                eid++;
                formats[eid] = kmalloc(*len, GFP_KERNEL);
                if (formats[eid] == NULL) {
                        err = -ENOMEM;
                        goto end;
                }
                memcpy(formats[eid], buf, *len);
                formats[eid][2] = avc_stream_rate_table[i];
        }

        err = 0;
        oxfw->assumed = true;
end:
        return err;
}

static int fill_stream_formats(struct snd_oxfw *oxfw,
                               enum avc_general_plug_dir dir,
                               unsigned short pid)
{
        u8 *buf, **formats;
        unsigned int len, eid = 0;
        struct snd_oxfw_stream_formation dummy;
        int err;

        buf = kmalloc(AVC_GENERIC_FRAME_MAXIMUM_BYTES, GFP_KERNEL);
        if (buf == NULL)
                return -ENOMEM;

        if (dir == AVC_GENERAL_PLUG_DIR_OUT)
                formats = oxfw->tx_stream_formats;
        else
                formats = oxfw->rx_stream_formats;

        /* get first entry */
        len = AVC_GENERIC_FRAME_MAXIMUM_BYTES;
        err = avc_stream_get_format_list(oxfw->unit, dir, 0, buf, &len, 0);
        if (err == -ENOSYS) {
                /* LIST subfunction is not implemented */
                len = AVC_GENERIC_FRAME_MAXIMUM_BYTES;
                err = assume_stream_formats(oxfw, dir, pid, buf, &len,
                                            formats);
                goto end;
        } else if (err < 0) {
                dev_err(&oxfw->unit->device,
                        "fail to get stream format %d for isoc %s plug %d:%d\n",
                        eid, (dir == AVC_GENERAL_PLUG_DIR_IN) ? "in" : "out",
                        pid, err);
                goto end;
        }

        /* LIST subfunction is implemented */
        while (eid < SND_OXFW_STREAM_FORMAT_ENTRIES) {
                /* The format is too short. */
                if (len < 3) {
                        err = -EIO;
                        break;
                }

                /* parse and set stream format */
                err = snd_oxfw_stream_parse_format(buf, &dummy);
                if (err < 0)
                        break;

                formats[eid] = kmalloc(len, GFP_KERNEL);
                if (formats[eid] == NULL) {
                        err = -ENOMEM;
                        break;
                }
                memcpy(formats[eid], buf, len);

                /* get next entry */
                len = AVC_GENERIC_FRAME_MAXIMUM_BYTES;
                err = avc_stream_get_format_list(oxfw->unit, dir, 0,
                                                 buf, &len, ++eid);
                /* No entries remained. */
                if (err == -EINVAL) {
                        err = 0;
                        break;
                } else if (err < 0) {
                        dev_err(&oxfw->unit->device,
                        "fail to get stream format %d for isoc %s plug %d:%d\n",
                                eid, (dir == AVC_GENERAL_PLUG_DIR_IN) ? "in" :
                                                                        "out",
                                pid, err);
                        break;
                }
        }
end:
        kfree(buf);
        return err;
}

int snd_oxfw_stream_discover(struct snd_oxfw *oxfw)
{
        u8 plugs[AVC_PLUG_INFO_BUF_BYTES];
        int err;

        /* the number of plugs for isoc in/out, ext in/out  */
        err = avc_general_get_plug_info(oxfw->unit, 0x1f, 0x07, 0x00, plugs);
        if (err < 0) {
                dev_err(&oxfw->unit->device,
                "fail to get info for isoc/external in/out plugs: %d\n",
                        err);
                goto end;
        } else if ((plugs[0] == 0) && (plugs[1] == 0)) {
                err = -ENOSYS;
                goto end;
        }

        /* use oPCR[0] if exists */
        if (plugs[1] > 0) {
                err = fill_stream_formats(oxfw, AVC_GENERAL_PLUG_DIR_OUT, 0);
                if (err < 0)
                        goto end;
                oxfw->has_output = true;
        }

        /* use iPCR[0] if exists */
        if (plugs[0] > 0)
                err = fill_stream_formats(oxfw, AVC_GENERAL_PLUG_DIR_IN, 0);
end:
        return err;
}

void snd_oxfw_stream_lock_changed(struct snd_oxfw *oxfw)
{
        oxfw->dev_lock_changed = true;
        wake_up(&oxfw->hwdep_wait);
}

int snd_oxfw_stream_lock_try(struct snd_oxfw *oxfw)
{
        int err;

        spin_lock_irq(&oxfw->lock);

        /* user land lock this */
        if (oxfw->dev_lock_count < 0) {
                err = -EBUSY;
                goto end;
        }

        /* this is the first time */
        if (oxfw->dev_lock_count++ == 0)
                snd_oxfw_stream_lock_changed(oxfw);
        err = 0;
end:
        spin_unlock_irq(&oxfw->lock);
        return err;
}

void snd_oxfw_stream_lock_release(struct snd_oxfw *oxfw)
{
        spin_lock_irq(&oxfw->lock);

        if (WARN_ON(oxfw->dev_lock_count <= 0))
                goto end;
        if (--oxfw->dev_lock_count == 0)
                snd_oxfw_stream_lock_changed(oxfw);
end:
        spin_unlock_irq(&oxfw->lock);
}