// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
 *                   Uros Bizjak <uros@kss-loka.si>
 *
 *  Routines for control of 8-bit SoundBlaster cards and clones
 *  Please note: I don't have access to old SB8 soundcards.
 *
 * --
 *
 * Thu Apr 29 20:36:17 BST 1999 George David Morrison <gdm@gedamo.demon.co.uk>
 *   DSP can't respond to commands whilst in "high speed" mode. Caused 
 *   glitching during playback. Fixed.
 *
 * Wed Jul 12 22:02:55 CEST 2000 Uros Bizjak <uros@kss-loka.si>
 *   Cleaned up and rewrote lowlevel routines.
 */

#include <linux/io.h>
#include <asm/dma.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/module.h>
#include <sound/core.h>
#include <sound/sb.h>

MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Uros Bizjak <uros@kss-loka.si>");
MODULE_DESCRIPTION("Routines for control of 8-bit SoundBlaster cards and clones");
MODULE_LICENSE("GPL");

#define SB8_CLOCK       1000000
#define SB8_DEN(v)      ((SB8_CLOCK + (v) / 2) / (v))
#define SB8_RATE(v)     (SB8_CLOCK / SB8_DEN(v))

static const struct snd_ratnum clock = {
        .num = SB8_CLOCK,
        .den_min = 1,
        .den_max = 256,
        .den_step = 1,
};

static const struct snd_pcm_hw_constraint_ratnums hw_constraints_clock = {
        .nrats = 1,
        .rats = &clock,
};

static const struct snd_ratnum stereo_clocks[] = {
        {
                .num = SB8_CLOCK,
                .den_min = SB8_DEN(22050),
                .den_max = SB8_DEN(22050),
                .den_step = 1,
        },
        {
                .num = SB8_CLOCK,
                .den_min = SB8_DEN(11025),
                .den_max = SB8_DEN(11025),
                .den_step = 1,
        }
};

static int snd_sb8_hw_constraint_rate_channels(struct snd_pcm_hw_params *params,
                                               struct snd_pcm_hw_rule *rule)
{
        struct snd_interval *c = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
        if (c->min > 1) {
                unsigned int num = 0, den = 0;
                int err = snd_interval_ratnum(hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE),
                                          2, stereo_clocks, &num, &den);
                if (err >= 0 && den) {
                        params->rate_num = num;
                        params->rate_den = den;
                }
                return err;
        }
        return 0;
}

static int snd_sb8_hw_constraint_channels_rate(struct snd_pcm_hw_params *params,
                                               struct snd_pcm_hw_rule *rule)
{
        struct snd_interval *r = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
        if (r->min > SB8_RATE(22050) || r->max <= SB8_RATE(11025)) {
                struct snd_interval t = { .min = 1, .max = 1 };
                return snd_interval_refine(hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS), &t);
        }
        return 0;
}

static int snd_sb8_playback_prepare(struct snd_pcm_substream *substream)
{
        struct snd_sb *chip = snd_pcm_substream_chip(substream);
        struct snd_pcm_runtime *runtime = substream->runtime;
        unsigned int mixreg, rate, size, count;
        unsigned char format;
        unsigned char stereo = runtime->channels > 1;
        int dma;

        rate = runtime->rate;
        switch (chip->hardware) {
        case SB_HW_JAZZ16:
                if (runtime->format == SNDRV_PCM_FORMAT_S16_LE) {
                        if (chip->mode & SB_MODE_CAPTURE_16)
                                return -EBUSY;
                        else
                                chip->mode |= SB_MODE_PLAYBACK_16;
                }
                chip->playback_format = SB_DSP_LO_OUTPUT_AUTO;
                break;
        case SB_HW_PRO:
                if (runtime->channels > 1) {
                        if (snd_BUG_ON(rate != SB8_RATE(11025) &&
                                       rate != SB8_RATE(22050)))
                                return -EINVAL;
                        chip->playback_format = SB_DSP_HI_OUTPUT_AUTO;
                        break;
                }
                fallthrough;
        case SB_HW_201:
                if (rate > 23000) {
                        chip->playback_format = SB_DSP_HI_OUTPUT_AUTO;
                        break;
                }
                fallthrough;
        case SB_HW_20:
                chip->playback_format = SB_DSP_LO_OUTPUT_AUTO;
                break;
        case SB_HW_10:
                chip->playback_format = SB_DSP_OUTPUT;
                break;
        default:
                return -EINVAL;
        }
        if (chip->mode & SB_MODE_PLAYBACK_16) {
                format = stereo ? SB_DSP_STEREO_16BIT : SB_DSP_MONO_16BIT;
                dma = chip->dma16;
        } else {
                format = stereo ? SB_DSP_STEREO_8BIT : SB_DSP_MONO_8BIT;
                chip->mode |= SB_MODE_PLAYBACK_8;
                dma = chip->dma8;
        }
        size = chip->p_dma_size = snd_pcm_lib_buffer_bytes(substream);
        count = chip->p_period_size = snd_pcm_lib_period_bytes(substream);
        scoped_guard(spinlock_irqsave, &chip->reg_lock) {
                snd_sbdsp_command(chip, SB_DSP_SPEAKER_ON);
                if (chip->hardware == SB_HW_JAZZ16)
                        snd_sbdsp_command(chip, format);
                else if (stereo) {
                        /* set playback stereo mode */
                        scoped_guard(spinlock, &chip->mixer_lock) {
                                mixreg = snd_sbmixer_read(chip, SB_DSP_STEREO_SW);
                                snd_sbmixer_write(chip, SB_DSP_STEREO_SW, mixreg | 0x02);
                        }

                        /* Soundblaster hardware programming reference guide, 3-23 */
                        snd_sbdsp_command(chip, SB_DSP_DMA8_EXIT);
                        runtime->dma_area[0] = 0x80;
                        snd_dma_program(dma, runtime->dma_addr, 1, DMA_MODE_WRITE);
                        /* force interrupt */
                        snd_sbdsp_command(chip, SB_DSP_OUTPUT);
                        snd_sbdsp_command(chip, 0);
                        snd_sbdsp_command(chip, 0);
                }
                snd_sbdsp_command(chip, SB_DSP_SAMPLE_RATE);
                if (stereo) {
                        snd_sbdsp_command(chip, 256 - runtime->rate_den / 2);
                        scoped_guard(spinlock, &chip->mixer_lock) {
                                /* save output filter status and turn it off */
                                mixreg = snd_sbmixer_read(chip, SB_DSP_PLAYBACK_FILT);
                                snd_sbmixer_write(chip, SB_DSP_PLAYBACK_FILT, mixreg | 0x20);
                        }
                        /* just use force_mode16 for temporary storate... */
                        chip->force_mode16 = mixreg;
                } else {
                        snd_sbdsp_command(chip, 256 - runtime->rate_den);
                }
                if (chip->playback_format != SB_DSP_OUTPUT) {
                        if (chip->mode & SB_MODE_PLAYBACK_16)
                                count /= 2;
                        count--;
                        snd_sbdsp_command(chip, SB_DSP_BLOCK_SIZE);
                        snd_sbdsp_command(chip, count & 0xff);
                        snd_sbdsp_command(chip, count >> 8);
                }
        }
        snd_dma_program(dma, runtime->dma_addr,
                        size, DMA_MODE_WRITE | DMA_AUTOINIT);
        return 0;
}

static int snd_sb8_playback_trigger(struct snd_pcm_substream *substream,
                                    int cmd)
{
        struct snd_sb *chip = snd_pcm_substream_chip(substream);
        unsigned int count;

        guard(spinlock_irqsave)(&chip->reg_lock);
        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
                snd_sbdsp_command(chip, chip->playback_format);
                if (chip->playback_format == SB_DSP_OUTPUT) {
                        count = chip->p_period_size - 1;
                        snd_sbdsp_command(chip, count & 0xff);
                        snd_sbdsp_command(chip, count >> 8);
                }
                break;
        case SNDRV_PCM_TRIGGER_STOP:
                if (chip->playback_format == SB_DSP_HI_OUTPUT_AUTO) {
                        struct snd_pcm_runtime *runtime = substream->runtime;
                        snd_sbdsp_reset(chip);
                        if (runtime->channels > 1) {
                                guard(spinlock)(&chip->mixer_lock);
                                /* restore output filter and set hardware to mono mode */ 
                                snd_sbmixer_write(chip, SB_DSP_STEREO_SW, chip->force_mode16 & ~0x02);
                        }
                } else {
                        snd_sbdsp_command(chip, SB_DSP_DMA8_OFF);
                }
                snd_sbdsp_command(chip, SB_DSP_SPEAKER_OFF);
        }
        return 0;
}

static int snd_sb8_capture_prepare(struct snd_pcm_substream *substream)
{
        struct snd_sb *chip = snd_pcm_substream_chip(substream);
        struct snd_pcm_runtime *runtime = substream->runtime;
        unsigned int mixreg, rate, size, count;
        unsigned char format;
        unsigned char stereo = runtime->channels > 1;
        int dma;

        rate = runtime->rate;
        switch (chip->hardware) {
        case SB_HW_JAZZ16:
                if (runtime->format == SNDRV_PCM_FORMAT_S16_LE) {
                        if (chip->mode & SB_MODE_PLAYBACK_16)
                                return -EBUSY;
                        else
                                chip->mode |= SB_MODE_CAPTURE_16;
                }
                chip->capture_format = SB_DSP_LO_INPUT_AUTO;
                break;
        case SB_HW_PRO:
                if (runtime->channels > 1) {
                        if (snd_BUG_ON(rate != SB8_RATE(11025) &&
                                       rate != SB8_RATE(22050)))
                                return -EINVAL;
                        chip->capture_format = SB_DSP_HI_INPUT_AUTO;
                        break;
                }
                chip->capture_format = (rate > 23000) ? SB_DSP_HI_INPUT_AUTO : SB_DSP_LO_INPUT_AUTO;
                break;
        case SB_HW_201:
                if (rate > 13000) {
                        chip->capture_format = SB_DSP_HI_INPUT_AUTO;
                        break;
                }
                fallthrough;
        case SB_HW_20:
                chip->capture_format = SB_DSP_LO_INPUT_AUTO;
                break;
        case SB_HW_10:
                chip->capture_format = SB_DSP_INPUT;
                break;
        default:
                return -EINVAL;
        }
        if (chip->mode & SB_MODE_CAPTURE_16) {
                format = stereo ? SB_DSP_STEREO_16BIT : SB_DSP_MONO_16BIT;
                dma = chip->dma16;
        } else {
                format = stereo ? SB_DSP_STEREO_8BIT : SB_DSP_MONO_8BIT;
                chip->mode |= SB_MODE_CAPTURE_8;
                dma = chip->dma8;
        }
        size = chip->c_dma_size = snd_pcm_lib_buffer_bytes(substream);
        count = chip->c_period_size = snd_pcm_lib_period_bytes(substream);
        scoped_guard(spinlock_irqsave, &chip->reg_lock) {
                snd_sbdsp_command(chip, SB_DSP_SPEAKER_OFF);
                if (chip->hardware == SB_HW_JAZZ16)
                        snd_sbdsp_command(chip, format);
                else if (stereo)
                        snd_sbdsp_command(chip, SB_DSP_STEREO_8BIT);
                snd_sbdsp_command(chip, SB_DSP_SAMPLE_RATE);
                if (stereo) {
                        snd_sbdsp_command(chip, 256 - runtime->rate_den / 2);
                        scoped_guard(spinlock, &chip->mixer_lock) {
                                /* save input filter status and turn it off */
                                mixreg = snd_sbmixer_read(chip, SB_DSP_CAPTURE_FILT);
                                snd_sbmixer_write(chip, SB_DSP_CAPTURE_FILT, mixreg | 0x20);
                        }
                        /* just use force_mode16 for temporary storate... */
                        chip->force_mode16 = mixreg;
                } else {
                        snd_sbdsp_command(chip, 256 - runtime->rate_den);
                }
                if (chip->capture_format != SB_DSP_INPUT) {
                        if (chip->mode & SB_MODE_PLAYBACK_16)
                                count /= 2;
                        count--;
                        snd_sbdsp_command(chip, SB_DSP_BLOCK_SIZE);
                        snd_sbdsp_command(chip, count & 0xff);
                        snd_sbdsp_command(chip, count >> 8);
                }
        }
        snd_dma_program(dma, runtime->dma_addr,
                        size, DMA_MODE_READ | DMA_AUTOINIT);
        return 0;
}

static int snd_sb8_capture_trigger(struct snd_pcm_substream *substream,
                                   int cmd)
{
        struct snd_sb *chip = snd_pcm_substream_chip(substream);
        unsigned int count;

        guard(spinlock_irqsave)(&chip->reg_lock);
        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
                snd_sbdsp_command(chip, chip->capture_format);
                if (chip->capture_format == SB_DSP_INPUT) {
                        count = chip->c_period_size - 1;
                        snd_sbdsp_command(chip, count & 0xff);
                        snd_sbdsp_command(chip, count >> 8);
                }
                break;
        case SNDRV_PCM_TRIGGER_STOP:
                if (chip->capture_format == SB_DSP_HI_INPUT_AUTO) {
                        struct snd_pcm_runtime *runtime = substream->runtime;
                        snd_sbdsp_reset(chip);
                        if (runtime->channels > 1) {
                                /* restore input filter status */
                                scoped_guard(spinlock, &chip->mixer_lock) {
                                        snd_sbmixer_write(chip, SB_DSP_CAPTURE_FILT, chip->force_mode16);
                                }
                                /* set hardware to mono mode */
                                snd_sbdsp_command(chip, SB_DSP_MONO_8BIT);
                        }
                } else {
                        snd_sbdsp_command(chip, SB_DSP_DMA8_OFF);
                }
                snd_sbdsp_command(chip, SB_DSP_SPEAKER_OFF);
        }
        return 0;
}

irqreturn_t snd_sb8dsp_interrupt(struct snd_sb *chip)
{
        struct snd_pcm_substream *substream;

        snd_sb_ack_8bit(chip);
        switch (chip->mode) {
        case SB_MODE_PLAYBACK_16:       /* ok.. playback is active */
                if (chip->hardware != SB_HW_JAZZ16)
                        break;
                fallthrough;
        case SB_MODE_PLAYBACK_8:
                substream = chip->playback_substream;
                if (chip->playback_format == SB_DSP_OUTPUT)
                        snd_sb8_playback_trigger(substream, SNDRV_PCM_TRIGGER_START);
                snd_pcm_period_elapsed(substream);
                break;
        case SB_MODE_CAPTURE_16:
                if (chip->hardware != SB_HW_JAZZ16)
                        break;
                fallthrough;
        case SB_MODE_CAPTURE_8:
                substream = chip->capture_substream;
                if (chip->capture_format == SB_DSP_INPUT)
                        snd_sb8_capture_trigger(substream, SNDRV_PCM_TRIGGER_START);
                snd_pcm_period_elapsed(substream);
                break;
        }
        return IRQ_HANDLED;
}

static snd_pcm_uframes_t snd_sb8_playback_pointer(struct snd_pcm_substream *substream)
{
        struct snd_sb *chip = snd_pcm_substream_chip(substream);
        size_t ptr;
        int dma;

        if (chip->mode & SB_MODE_PLAYBACK_8)
                dma = chip->dma8;
        else if (chip->mode & SB_MODE_PLAYBACK_16)
                dma = chip->dma16;
        else
                return 0;
        ptr = snd_dma_pointer(dma, chip->p_dma_size);
        return bytes_to_frames(substream->runtime, ptr);
}

static snd_pcm_uframes_t snd_sb8_capture_pointer(struct snd_pcm_substream *substream)
{
        struct snd_sb *chip = snd_pcm_substream_chip(substream);
        size_t ptr;
        int dma;

        if (chip->mode & SB_MODE_CAPTURE_8)
                dma = chip->dma8;
        else if (chip->mode & SB_MODE_CAPTURE_16)
                dma = chip->dma16;
        else
                return 0;
        ptr = snd_dma_pointer(dma, chip->c_dma_size);
        return bytes_to_frames(substream->runtime, ptr);
}

/*

 */

static const struct snd_pcm_hardware snd_sb8_playback =
{
        .info =                 (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
                                 SNDRV_PCM_INFO_MMAP_VALID),
        .formats =               SNDRV_PCM_FMTBIT_U8,
        .rates =                (SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000 |
                                 SNDRV_PCM_RATE_11025 | SNDRV_PCM_RATE_22050),
        .rate_min =             4000,
        .rate_max =             23000,
        .channels_min =         1,
        .channels_max =         1,
        .buffer_bytes_max =     65536,
        .period_bytes_min =     64,
        .period_bytes_max =     65536,
        .periods_min =          1,
        .periods_max =          1024,
        .fifo_size =            0,
};

static const struct snd_pcm_hardware snd_sb8_capture =
{
        .info =                 (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
                                 SNDRV_PCM_INFO_MMAP_VALID),
        .formats =              SNDRV_PCM_FMTBIT_U8,
        .rates =                (SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000 |
                                 SNDRV_PCM_RATE_11025),
        .rate_min =             4000,
        .rate_max =             13000,
        .channels_min =         1,
        .channels_max =         1,
        .buffer_bytes_max =     65536,
        .period_bytes_min =     64,
        .period_bytes_max =     65536,
        .periods_min =          1,
        .periods_max =          1024,
        .fifo_size =            0,
};

/*
 *
 */
 
static int snd_sb8_open(struct snd_pcm_substream *substream)
{
        struct snd_sb *chip = snd_pcm_substream_chip(substream);
        struct snd_pcm_runtime *runtime = substream->runtime;

        scoped_guard(spinlock_irqsave, &chip->open_lock) {
                if (chip->open)
                        return -EAGAIN;
                chip->open |= SB_OPEN_PCM;
        }
        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                chip->playback_substream = substream;
                runtime->hw = snd_sb8_playback;
        } else {
                chip->capture_substream = substream;
                runtime->hw = snd_sb8_capture;
        }
        switch (chip->hardware) {
        case SB_HW_JAZZ16:
                if (chip->dma16 == 5 || chip->dma16 == 7)
                        runtime->hw.formats |= SNDRV_PCM_FMTBIT_S16_LE;
                runtime->hw.rates |= SNDRV_PCM_RATE_8000_48000;
                runtime->hw.rate_min = 4000;
                runtime->hw.rate_max = 50000;
                runtime->hw.channels_max = 2;
                break;
        case SB_HW_PRO:
                runtime->hw.rate_max = 44100;
                runtime->hw.channels_max = 2;
                snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
                                    snd_sb8_hw_constraint_rate_channels, NULL,
                                    SNDRV_PCM_HW_PARAM_CHANNELS,
                                    SNDRV_PCM_HW_PARAM_RATE, -1);
                snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
                                     snd_sb8_hw_constraint_channels_rate, NULL,
                                     SNDRV_PCM_HW_PARAM_RATE, -1);
                break;
        case SB_HW_201:
                if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                        runtime->hw.rate_max = 44100;
                } else {
                        runtime->hw.rate_max = 15000;
                }
                break;
        default:
                break;
        }
        snd_pcm_hw_constraint_ratnums(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
                                      &hw_constraints_clock);
        if (chip->dma8 > 3 || chip->dma16 >= 0) {
                snd_pcm_hw_constraint_step(runtime, 0,
                                           SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 2);
                snd_pcm_hw_constraint_step(runtime, 0,
                                           SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 2);
                runtime->hw.buffer_bytes_max = 128 * 1024 * 1024;
                runtime->hw.period_bytes_max = 128 * 1024 * 1024;
        }
        return 0;       
}

static int snd_sb8_close(struct snd_pcm_substream *substream)
{
        struct snd_sb *chip = snd_pcm_substream_chip(substream);

        chip->playback_substream = NULL;
        chip->capture_substream = NULL;
        guard(spinlock_irqsave)(&chip->open_lock);
        chip->open &= ~SB_OPEN_PCM;
        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                chip->mode &= ~SB_MODE_PLAYBACK;
        else
                chip->mode &= ~SB_MODE_CAPTURE;
        return 0;
}

/*
 *  Initialization part
 */
 
static const struct snd_pcm_ops snd_sb8_playback_ops = {
        .open =                 snd_sb8_open,
        .close =                snd_sb8_close,
        .prepare =              snd_sb8_playback_prepare,
        .trigger =              snd_sb8_playback_trigger,
        .pointer =              snd_sb8_playback_pointer,
};

static const struct snd_pcm_ops snd_sb8_capture_ops = {
        .open =                 snd_sb8_open,
        .close =                snd_sb8_close,
        .prepare =              snd_sb8_capture_prepare,
        .trigger =              snd_sb8_capture_trigger,
        .pointer =              snd_sb8_capture_pointer,
};

int snd_sb8dsp_pcm(struct snd_sb *chip, int device)
{
        struct snd_card *card = chip->card;
        struct snd_pcm *pcm;
        int err;
        size_t max_prealloc = 64 * 1024;

        err = snd_pcm_new(card, "SB8 DSP", device, 1, 1, &pcm);
        if (err < 0)
                return err;
        sprintf(pcm->name, "DSP v%i.%i", chip->version >> 8, chip->version & 0xff);
        pcm->info_flags = SNDRV_PCM_INFO_HALF_DUPLEX;
        pcm->private_data = chip;

        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_sb8_playback_ops);
        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_sb8_capture_ops);

        if (chip->dma8 > 3 || chip->dma16 >= 0)
                max_prealloc = 128 * 1024;
        snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV,
                                       card->dev, 64*1024, max_prealloc);

        return 0;
}

EXPORT_SYMBOL(snd_sb8dsp_pcm);
EXPORT_SYMBOL(snd_sb8dsp_interrupt);
  /* sb8_midi.c */
EXPORT_SYMBOL(snd_sb8dsp_midi_interrupt);
EXPORT_SYMBOL(snd_sb8dsp_midi);