source: mainline/uspace/drv/audio/sb16/dsp.c

/*
 * Copyright (c) 2025 Jiri Svoboda
 * Copyright (c) 2011 Jan Vesely
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
/** @addtogroup drvaudiosb16
 * @{
 */
/** @file
 * @brief DSP helper functions implementation
 */

#include <as.h>
#include <stdbool.h>
#include <ddf/driver.h>
#include <ddi.h>
#include <device/hw_res.h>
#include <libarch/ddi.h>
#include <barrier.h>
#include <macros.h>
#include <str_error.h>
#include <audio_pcm_iface.h>

#include "ddf_log.h"
#include "dsp_commands.h"
#include "dsp.h"

/* Maximum allowed transfer size for ISA DMA transfers is 64kB */
#define MAX_BUFFER_SIZE (64 * 1024)

#ifndef DSP_RETRY_COUNT
#define DSP_RETRY_COUNT 100
#endif

#define DSP_RESET_RESPONSE 0xaa

/* These are only for SB16 (DSP4.00+) */
#define DSP_RATE_UPPER_LIMIT 44100
#define DSP_RATE_LOWER_LIMIT 5000

#define AUTO_DMA_MODE

static inline const char *dsp_state_to_str(dsp_state_t state)
{
        static const char *state_names[] = {
                [DSP_PLAYBACK_ACTIVE_EVENTS] = "PLAYBACK w/ EVENTS",
                [DSP_CAPTURE_ACTIVE_EVENTS] = "CAPTURE w/ EVENTS",
                [DSP_PLAYBACK_NOEVENTS] = "PLAYBACK w/o EVENTS",
                [DSP_CAPTURE_NOEVENTS] = "CAPTURE w/o EVENTS",
                [DSP_PLAYBACK_TERMINATE] = "PLAYBACK TERMINATE",
                [DSP_CAPTURE_TERMINATE] = "CAPTURE TERMINATE",
                [DSP_READY] = "READY",
                [DSP_NO_BUFFER] = "NO BUFFER",
                [DSP_QUIESCED] = "QUIESCED"
        };
        if ((size_t)state < ARRAY_SIZE(state_names))
                return state_names[state];
        return "UNKNOWN";
}

static inline void dsp_change_state(sb_dsp_t *dsp, dsp_state_t state)
{
        assert(dsp);
        if (dsp->state == DSP_QUIESCED)
                return;

        ddf_log_verbose("Changing state from %s to %s",
            dsp_state_to_str(dsp->state), dsp_state_to_str(state));
        dsp->state = state;
}

static inline errno_t dsp_read(sb_dsp_t *dsp, uint8_t *data)
{
        assert(data);
        assert(dsp);
        uint8_t status;
        size_t attempts = DSP_RETRY_COUNT;
        do {
                status = pio_read_8(&dsp->regs->dsp_read_status);
        } while (--attempts && ((status & DSP_READ_READY) == 0));

        if ((status & DSP_READ_READY) == 0)
                return EIO;

        *data = pio_read_8(&dsp->regs->dsp_data_read);
        return EOK;
}

static inline errno_t dsp_write(sb_dsp_t *dsp, uint8_t data)
{
        assert(dsp);
        uint8_t status;
        size_t attempts = DSP_RETRY_COUNT;
        do {
                status = pio_read_8(&dsp->regs->dsp_write);
        } while (--attempts && ((status & DSP_WRITE_BUSY) != 0));

        if ((status & DSP_WRITE_BUSY))
                return EIO;

        pio_write_8(&dsp->regs->dsp_write, data);
        return EOK;
}

static inline void dsp_reset(sb_dsp_t *dsp)
{
        assert(dsp);
        /* Reset DSP, see Chapter 2 of Sound Blaster HW programming guide */
        pio_write_8(&dsp->regs->dsp_reset, 1);
        udelay(3); /* Keep reset for 3 us */
        pio_write_8(&dsp->regs->dsp_reset, 0);
        /* "DSP takes about 100 microseconds to initialize itself" */
        udelay(100);
}

static inline void dsp_start_current_active(sb_dsp_t *dsp, uint8_t command)
{
        dsp_write(dsp, command);
        dsp_write(dsp, dsp->active.mode);
        dsp_write(dsp, (dsp->active.samples - 1) & 0xff);
        dsp_write(dsp, (dsp->active.samples - 1) >> 8);
}

static inline void dsp_set_sampling_rate(sb_dsp_t *dsp, unsigned rate)
{
        dsp_write(dsp, SET_SAMPLING_RATE_OUTPUT);
        uint8_t rate_lo = rate & 0xff;
        uint8_t rate_hi = rate >> 8;
        dsp_write(dsp, rate_hi);
        dsp_write(dsp, rate_lo);
        ddf_log_verbose("Sampling rate: %hhx:%hhx.", rate_hi, rate_lo);
}

static inline void dsp_report_event(sb_dsp_t *dsp, pcm_event_t event)
{
        assert(dsp);
        if (!dsp->event_exchange)
                ddf_log_warning("No one listening for event %u", event);
        async_msg_1(dsp->event_exchange, event, dsp->active.frame_count);
}

static inline errno_t setup_dma(sb_dsp_t *dsp, uintptr_t pa, size_t size)
{
        async_sess_t *sess = ddf_dev_parent_sess_get(dsp->sb_dev);

        return hw_res_dma_channel_setup(sess,
            dsp->dma16_channel, pa, size,
            DMA_MODE_READ | DMA_MODE_AUTO | DMA_MODE_ON_DEMAND);
}

static inline errno_t setup_buffer(sb_dsp_t *dsp, size_t size)
{
        assert(dsp);

        if ((size > MAX_BUFFER_SIZE) || (size == 0) || ((size % 2) == 1))
                size = MAX_BUFFER_SIZE;

        uintptr_t pa = 0;
        void *buffer = AS_AREA_ANY;

        errno_t ret = dmamem_map_anonymous(size, DMAMEM_16MiB | 0x0000ffff,
            AS_AREA_WRITE | AS_AREA_READ, 0, &pa, &buffer);
        if (ret != EOK) {
                ddf_log_error("Failed to allocate DMA buffer.");
                return ENOMEM;
        }

        ddf_log_verbose("Setup DMA buffer at %p (%zu) %zu.", buffer, pa, size);
        assert(pa < (1 << 24));

        /* Setup 16 bit channel */
        ret = setup_dma(dsp, pa, size);
        if (ret == EOK) {
                dsp->buffer.data = buffer;
                dsp->buffer.size = size;
        } else {
                ddf_log_error("Failed to setup DMA16 channel: %s.",
                    str_error(ret));
                dmamem_unmap_anonymous(buffer);
        }

        return ret;
}

errno_t sb_dsp_init(sb_dsp_t *dsp, sb16_regs_t *regs, ddf_dev_t *dev,
    int dma8, int dma16)
{
        assert(dsp);
        dsp->regs = regs;
        dsp->dma8_channel = dma8;
        dsp->dma16_channel = dma16;
        dsp->event_session = NULL;
        dsp->event_exchange = NULL;
        dsp->sb_dev = dev;
        dsp->state = DSP_NO_BUFFER;
        dsp_reset(dsp);
        uint8_t response;
        const errno_t ret = dsp_read(dsp, &response);
        if (ret != EOK) {
                ddf_log_error("Failed to read DSP reset response value.");
                return ret;
        }
        if (response != DSP_RESET_RESPONSE) {
                ddf_log_error("Invalid DSP reset response: %x.", response);
                return EIO;
        }

        /* Get DSP version number */
        dsp_write(dsp, DSP_VERSION);
        dsp_read(dsp, &dsp->version.major);
        dsp_read(dsp, &dsp->version.minor);

        return ret;
}

void sb_dsp_quiesce(sb_dsp_t *dsp)
{
        dsp->state = DSP_QUIESCED;
        dsp_reset(dsp);
}

void sb_dsp_interrupt(sb_dsp_t *dsp)
{
        assert(dsp);

        dsp->active.frame_count +=
            dsp->active.samples / ((dsp->active.mode & DSP_MODE_STEREO) ? 2 : 1);

        switch (dsp->state) {
        case DSP_PLAYBACK_ACTIVE_EVENTS:
                dsp_report_event(dsp, PCM_EVENT_FRAMES_PLAYED);
        case DSP_PLAYBACK_NOEVENTS:
#ifndef AUTO_DMA_MODE
                dsp_start_current_active(dsp, SINGLE_DMA_16B_DA);
#endif
                break;
        case DSP_CAPTURE_ACTIVE_EVENTS:
                dsp_report_event(dsp, PCM_EVENT_FRAMES_CAPTURED);
        case DSP_CAPTURE_NOEVENTS:
#ifndef AUTO_DMA_MODE
                dsp_start_current_active(dsp, SINGLE_DMA_16B_DA);
#endif
                break;
        case DSP_CAPTURE_TERMINATE:
                dsp_change_state(dsp, DSP_READY);
                dsp_report_event(dsp, PCM_EVENT_CAPTURE_TERMINATED);
                async_exchange_end(dsp->event_exchange);
                dsp->event_exchange = NULL;
                break;
        case DSP_PLAYBACK_TERMINATE:
                dsp_change_state(dsp, DSP_READY);
                dsp_report_event(dsp, PCM_EVENT_PLAYBACK_TERMINATED);
                async_exchange_end(dsp->event_exchange);
                dsp->event_exchange = NULL;
                break;
        default:
                ddf_log_warning("Interrupt while DSP not active (%s)",
                    dsp_state_to_str(dsp->state));
        }
}

unsigned sb_dsp_query_cap(sb_dsp_t *dsp, audio_cap_t cap)
{
        ddf_log_verbose("Querying cap %s", audio_pcm_cap_str(cap));
        switch (cap) {
        case AUDIO_CAP_CAPTURE:
        case AUDIO_CAP_PLAYBACK:
        case AUDIO_CAP_INTERRUPT:
        case AUDIO_CAP_BUFFER_POS:
                return 1;
        case AUDIO_CAP_MAX_BUFFER:
                return MAX_BUFFER_SIZE;
        case AUDIO_CAP_INTERRUPT_MIN_FRAMES:
                return 1;
        case AUDIO_CAP_INTERRUPT_MAX_FRAMES:
                return 16535;
        default:
                return -1;
        }
}

errno_t sb_dsp_get_buffer_position(sb_dsp_t *dsp, size_t *pos)
{
        if (dsp->state == DSP_NO_BUFFER)
                return ENOENT;

        assert(dsp->buffer.data);
        async_sess_t *sess = ddf_dev_parent_sess_get(dsp->sb_dev);

        // TODO: Assumes DMA 16
        size_t remain;
        errno_t rc = hw_res_dma_channel_remain(sess, dsp->dma16_channel, &remain);
        if (rc == EOK) {
                *pos = dsp->buffer.size - remain;
        }
        return rc;
}

errno_t sb_dsp_test_format(sb_dsp_t *dsp, unsigned *channels, unsigned *rate,
    pcm_sample_format_t *format)
{
        errno_t ret = EOK;
        if (*channels == 0 || *channels > 2) {
                *channels = 2;
                ret = ELIMIT;
        }
        //TODO 8bit DMA supports 8bit formats
        if (*format != PCM_SAMPLE_SINT16_LE && *format != PCM_SAMPLE_UINT16_LE) {
                *format = pcm_sample_format_is_signed(*format) ?
                    PCM_SAMPLE_SINT16_LE : PCM_SAMPLE_UINT16_LE;
                ret = ELIMIT;
        }
        if (*rate > DSP_RATE_UPPER_LIMIT) {
                *rate = DSP_RATE_UPPER_LIMIT;
                ret = ELIMIT;
        }
        if (*rate < DSP_RATE_LOWER_LIMIT) {
                *rate = DSP_RATE_LOWER_LIMIT;
                ret = ELIMIT;
        }
        return ret;
}

errno_t sb_dsp_set_event_session(sb_dsp_t *dsp, async_sess_t *session)
{
        assert(dsp);
        if (dsp->event_session && session)
                return EBUSY;
        dsp->event_session = session;
        ddf_log_debug("Set event session to %p.", session);
        return EOK;
}

async_sess_t *sb_dsp_get_event_session(sb_dsp_t *dsp)
{
        assert(dsp);
        ddf_log_debug("Get event session: %p.", dsp->event_session);
        return dsp->event_session;
}

errno_t sb_dsp_get_buffer(sb_dsp_t *dsp, void **buffer, size_t *size)
{
        assert(dsp);
        assert(size);

        /*
         * buffer is already setup by for someone, refuse to work until
         * it's released
         */
        if (dsp->state != DSP_NO_BUFFER)
                return EBUSY;
        assert(dsp->buffer.data == NULL);

        const errno_t ret = setup_buffer(dsp, *size);
        if (ret == EOK) {
                ddf_log_debug("Providing buffer: %p, %zu B.",
                    dsp->buffer.data, dsp->buffer.size);

                if (buffer)
                        *buffer = dsp->buffer.data;
                if (size)
                        *size = dsp->buffer.size;
                dsp_change_state(dsp, DSP_READY);
        }
        return ret;
}

errno_t sb_dsp_release_buffer(sb_dsp_t *dsp)
{
        assert(dsp);
        if (dsp->state != DSP_READY)
                return EINVAL;
        assert(dsp->buffer.data);
        dmamem_unmap_anonymous(dsp->buffer.data);
        dsp->buffer.data = NULL;
        dsp->buffer.size = 0;
        ddf_log_debug("DSP buffer released.");
        dsp_change_state(dsp, DSP_NO_BUFFER);
        return EOK;
}

errno_t sb_dsp_start_playback(sb_dsp_t *dsp, unsigned frames,
    unsigned channels, unsigned sampling_rate, pcm_sample_format_t format)
{
        assert(dsp);

        if (!dsp->buffer.data || dsp->state != DSP_READY)
                return EINVAL;

        /* Check supported parameters */
        ddf_log_debug("Requested playback: %u frames, %uHz, %s, %u channel(s).",
            frames, sampling_rate, pcm_sample_format_str(format), channels);
        if (sb_dsp_test_format(dsp, &channels, &sampling_rate, &format) != EOK)
                return ENOTSUP;

        /* Client requested regular events */
        if (frames && !dsp->event_session)
                return EINVAL;

        if (dsp->event_session) {
                dsp->event_exchange = async_exchange_begin(dsp->event_session);
                if (!dsp->event_exchange)
                        return ENOMEM;
        }

        dsp->active.mode = 0 |
            (pcm_sample_format_is_signed(format) ? DSP_MODE_SIGNED : 0) |
            (channels == 2 ? DSP_MODE_STEREO : 0);
        dsp->active.samples = frames * channels;
        dsp->active.frame_count = 0;

        dsp_set_sampling_rate(dsp, sampling_rate);

#ifdef AUTO_DMA_MODE
        dsp_start_current_active(dsp, AUTO_DMA_16B_DA_FIFO);
#else
        dsp_start_current_active(dsp, SINGLE_DMA_16B_DA);
#endif

        ddf_log_verbose("Playback started, event every %u samples",
            dsp->active.samples);

        dsp_change_state(dsp,
            frames ? DSP_PLAYBACK_ACTIVE_EVENTS : DSP_PLAYBACK_NOEVENTS);
        if (dsp->state == DSP_PLAYBACK_ACTIVE_EVENTS)
                dsp_report_event(dsp, PCM_EVENT_PLAYBACK_STARTED);

        return EOK;
}

errno_t sb_dsp_stop_playback(sb_dsp_t *dsp, bool immediate)
{
        assert(dsp);
        if ((dsp->state == DSP_PLAYBACK_NOEVENTS ||
            dsp->state == DSP_PLAYBACK_ACTIVE_EVENTS) &&
            immediate) {
                dsp_write(dsp, DMA_16B_PAUSE);
                dsp_reset(dsp);
                ddf_log_debug("Stopped playback");
                dsp_change_state(dsp, DSP_READY);
                if (dsp->event_exchange) {
                        dsp_report_event(dsp, PCM_EVENT_PLAYBACK_TERMINATED);
                        async_exchange_end(dsp->event_exchange);
                        dsp->event_exchange = NULL;
                }
                return EOK;
        }
        if (dsp->state == DSP_PLAYBACK_ACTIVE_EVENTS) {
                /* Stop after current fragment */
                assert(!immediate);
                dsp_write(dsp, DMA_16B_EXIT);
                ddf_log_debug("Last playback fragment");
                dsp_change_state(dsp, DSP_PLAYBACK_TERMINATE);
                return EOK;
        }
        return EINVAL;
}

errno_t sb_dsp_start_capture(sb_dsp_t *dsp, unsigned frames,
    unsigned channels, unsigned sampling_rate, pcm_sample_format_t format)
{
        assert(dsp);
        if (!dsp->buffer.data || dsp->state != DSP_READY)
                return EINVAL;

        /* Check supported parameters */
        ddf_log_debug("Requested capture: %u frames, %uHz, %s, %u channel(s).",
            frames, sampling_rate, pcm_sample_format_str(format), channels);
        if (sb_dsp_test_format(dsp, &channels, &sampling_rate, &format) != EOK)
                return ENOTSUP;

        /* Client requested regular events */
        if (frames && !dsp->event_session)
                return EINVAL;

        if (dsp->event_session) {
                dsp->event_exchange = async_exchange_begin(dsp->event_session);
                if (!dsp->event_exchange)
                        return ENOMEM;
        }

        dsp->active.mode = 0 |
            (pcm_sample_format_is_signed(format) ? DSP_MODE_SIGNED : 0) |
            (channels == 2 ? DSP_MODE_STEREO : 0);
        dsp->active.samples = frames * channels;
        dsp->active.frame_count = 0;

        dsp_set_sampling_rate(dsp, sampling_rate);

#ifdef AUTO_DMA_MODE
        dsp_start_current_active(dsp, AUTO_DMA_16B_AD_FIFO);
#else
        dsp_start_current_active(dsp, SINGLE_DMA_16B_AD);
#endif

        ddf_log_verbose("Capture started started, event every %u samples",
            dsp->active.samples);
        dsp_change_state(dsp,
            frames ? DSP_CAPTURE_ACTIVE_EVENTS : DSP_CAPTURE_NOEVENTS);
        if (dsp->state == DSP_CAPTURE_ACTIVE_EVENTS)
                dsp_report_event(dsp, PCM_EVENT_CAPTURE_STARTED);
        return EOK;
}

errno_t sb_dsp_stop_capture(sb_dsp_t *dsp, bool immediate)
{
        assert(dsp);
        if ((dsp->state == DSP_CAPTURE_NOEVENTS ||
            dsp->state == DSP_CAPTURE_ACTIVE_EVENTS) &&
            immediate) {
                dsp_write(dsp, DMA_16B_PAUSE);
                dsp_reset(dsp);
                ddf_log_debug("Stopped capture fragment");
                dsp_change_state(dsp, DSP_READY);
                if (dsp->event_exchange) {
                        dsp_report_event(dsp, PCM_EVENT_CAPTURE_TERMINATED);
                        async_exchange_end(dsp->event_exchange);
                        dsp->event_exchange = NULL;
                }
                return EOK;
        }
        if (dsp->state == DSP_CAPTURE_ACTIVE_EVENTS) {
                /* Stop after current fragment */
                assert(!immediate);
                dsp_write(dsp, DMA_16B_EXIT);
                ddf_log_debug("Last capture fragment");
                dsp_change_state(dsp, DSP_CAPTURE_TERMINATE);
                return EOK;
        }
        return EINVAL;
}
/**
 * @}
 */