source: mainline/uspace/drv/audio/sb16/dsp.c@ 0f2e7c1

/*
 * 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 <libarch/ddi.h>

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


#ifndef DSP_RETRY_COUNT
#define DSP_RETRY_COUNT 100
#endif

#define DSP_RESET_RESPONSE 0xaa

static inline int sb_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 int sb_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 sb_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);
}
/*----------------------------------------------------------------------------*/
int sb_dsp_init(sb_dsp_t *dsp, sb16_regs_t *regs)
{
        assert(dsp);
        dsp->regs = regs;
        sb_dsp_reset(dsp);
        /* "DSP takes about 100 microseconds to initialize itself" */
        udelay(100);
        uint8_t response;
        const int ret = sb_dsp_read(dsp, &response);
        if (ret != EOK) {
                ddf_log_error("Failed to read DSP reset response value.\n");
                return ret;
        }
        if (response != DSP_RESET_RESPONSE) {
                ddf_log_error("Invalid DSP reset response: %x.\n", response);
                return EIO;
        }

        /* Get DSP version number */
        sb_dsp_write(dsp, DSP_VERSION);
        sb_dsp_read(dsp, &dsp->version.major);
        sb_dsp_read(dsp, &dsp->version.minor);
        return EOK;
}
/*----------------------------------------------------------------------------*/
int sb_dsp_play_direct(sb_dsp_t *dsp, const uint8_t *data, size_t size,
    unsigned sampling_rate, unsigned channels, unsigned bit_depth)
{
        assert(dsp);
        if (channels != 1 || bit_depth != 8)
                return EIO;
        /* In microseconds */
        const unsigned wait_period = 1000000 / sampling_rate;
        while (size--) {
                pio_write_8(&dsp->regs->dsp_write, DIRECT_8B_OUTPUT);
                pio_write_8(&dsp->regs->dsp_write, *data++);
                udelay(wait_period);
        }
        return EOK;
}
/**
 * @}
 */