/*
 * Driver for Digigram VX soundcards
 *
 * IEC958 stuff
 *
 * Copyright (c) 2002 by Takashi Iwai <tiwai@suse.de>
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */

#include <linux/delay.h>
#include <sound/core.h>
#include <sound/vx_core.h>
#include "vx_cmd.h"


/*
 * vx_modify_board_clock - tell the board that its clock has been modified
 * @sync: DSP needs to resynchronize its FIFO
 */
static int vx_modify_board_clock(struct vx_core *chip, int sync)
{
        struct vx_rmh rmh;

        vx_init_rmh(&rmh, CMD_MODIFY_CLOCK);
        /* Ask the DSP to resynchronize its FIFO. */
        if (sync)
                rmh.Cmd[0] |= CMD_MODIFY_CLOCK_S_BIT;
        return vx_send_msg(chip, &rmh);
}

/*
 * vx_modify_board_inputs - resync audio inputs
 */
static int vx_modify_board_inputs(struct vx_core *chip)
{
        struct vx_rmh rmh;

        vx_init_rmh(&rmh, CMD_RESYNC_AUDIO_INPUTS);
        rmh.Cmd[0] |= 1 << 0; /* reference: AUDIO 0 */
        return vx_send_msg(chip, &rmh);
}

/*
 * vx_read_one_cbit - read one bit from UER config
 * @index: the bit index
 * returns 0 or 1.
 */
static int vx_read_one_cbit(struct vx_core *chip, int index)
{
        int val;

        mutex_lock(&chip->lock);
        if (chip->type >= VX_TYPE_VXPOCKET) {
                vx_outb(chip, CSUER, 1); /* read */
                vx_outb(chip, RUER, index & XX_UER_CBITS_OFFSET_MASK);
                val = (vx_inb(chip, RUER) >> 7) & 0x01;
        } else {
                vx_outl(chip, CSUER, 1); /* read */
                vx_outl(chip, RUER, index & XX_UER_CBITS_OFFSET_MASK);
                val = (vx_inl(chip, RUER) >> 7) & 0x01;
        }
        mutex_unlock(&chip->lock);
        return val;
}

/*
 * vx_write_one_cbit - write one bit to UER config
 * @index: the bit index
 * @val: bit value, 0 or 1
 */
static void vx_write_one_cbit(struct vx_core *chip, int index, int val)
{
        val = !!val;    /* 0 or 1 */
        mutex_lock(&chip->lock);
        if (vx_is_pcmcia(chip)) {
                vx_outb(chip, CSUER, 0); /* write */
                vx_outb(chip, RUER, (val << 7) | (index & XX_UER_CBITS_OFFSET_MASK));
        } else {
                vx_outl(chip, CSUER, 0); /* write */
                vx_outl(chip, RUER, (val << 7) | (index & XX_UER_CBITS_OFFSET_MASK));
        }
        mutex_unlock(&chip->lock);
}

/*
 * vx_read_uer_status - read the current UER status
 * @mode: pointer to store the UER mode, VX_UER_MODE_XXX
 *
 * returns the frequency of UER, or 0 if not sync,
 * or a negative error code.
 */
static int vx_read_uer_status(struct vx_core *chip, unsigned int *mode)
{
        int val, freq;

        /* Default values */
        freq = 0;

        /* Read UER status */
        if (vx_is_pcmcia(chip))
            val = vx_inb(chip, CSUER);
        else
            val = vx_inl(chip, CSUER);
        if (val < 0)
                return val;
        /* If clock is present, read frequency */
        if (val & VX_SUER_CLOCK_PRESENT_MASK) {
                switch (val & VX_SUER_FREQ_MASK) {
                case VX_SUER_FREQ_32KHz_MASK:
                        freq = 32000;
                        break;
                case VX_SUER_FREQ_44KHz_MASK:
                        freq = 44100;
                        break;
                case VX_SUER_FREQ_48KHz_MASK:
                        freq = 48000;
                        break;
                }
        }
        if (val & VX_SUER_DATA_PRESENT_MASK)
                /* bit 0 corresponds to consumer/professional bit */
                *mode = vx_read_one_cbit(chip, 0) ?
                        VX_UER_MODE_PROFESSIONAL : VX_UER_MODE_CONSUMER;
        else
                *mode = VX_UER_MODE_NOT_PRESENT;

        return freq;
}


/*
 * compute the sample clock value from frequency
 *
 * The formula is as follows:
 *
 *    HexFreq = (dword) ((double) ((double) 28224000 / (double) Frequency))
 *    switch ( HexFreq & 0x00000F00 )
 *    case 0x00000100: ;
 *    case 0x00000200:
 *    case 0x00000300: HexFreq -= 0x00000201 ;
 *    case 0x00000400:
 *    case 0x00000500:
 *    case 0x00000600:
 *    case 0x00000700: HexFreq = (dword) (((double) 28224000 / (double) (Frequency*2)) - 1)
 *    default        : HexFreq = (dword) ((double) 28224000 / (double) (Frequency*4)) - 0x000001FF
 */

static int vx_calc_clock_from_freq(struct vx_core *chip, int freq)
{
        int hexfreq;

        if (snd_BUG_ON(freq <= 0))
                return 0;

        hexfreq = (28224000 * 10) / freq;
        hexfreq = (hexfreq + 5) / 10;

        /* max freq = 55125 Hz */
        if (snd_BUG_ON(hexfreq <= 0x00000200))
                return 0;

        if (hexfreq <= 0x03ff)
                return hexfreq - 0x00000201;
        if (hexfreq <= 0x07ff) 
                return (hexfreq / 2) - 1;
        if (hexfreq <= 0x0fff)
                return (hexfreq / 4) + 0x000001ff;

        return 0x5fe;   /* min freq = 6893 Hz */
}


/*
 * vx_change_clock_source - change the clock source
 * @source: the new source
 */
static void vx_change_clock_source(struct vx_core *chip, int source)
{
        /* we mute DAC to prevent clicks */
        vx_toggle_dac_mute(chip, 1);
        mutex_lock(&chip->lock);
        chip->ops->set_clock_source(chip, source);
        chip->clock_source = source;
        mutex_unlock(&chip->lock);
        /* unmute */
        vx_toggle_dac_mute(chip, 0);
}


/*
 * set the internal clock
 */
void vx_set_internal_clock(struct vx_core *chip, unsigned int freq)
{
        int clock;

        /* Get real clock value */
        clock = vx_calc_clock_from_freq(chip, freq);
        snd_printdd(KERN_DEBUG "set internal clock to 0x%x from freq %d\n", clock, freq);
        mutex_lock(&chip->lock);
        if (vx_is_pcmcia(chip)) {
                vx_outb(chip, HIFREQ, (clock >> 8) & 0x0f);
                vx_outb(chip, LOFREQ, clock & 0xff);
        } else {
                vx_outl(chip, HIFREQ, (clock >> 8) & 0x0f);
                vx_outl(chip, LOFREQ, clock & 0xff);
        }
        mutex_unlock(&chip->lock);
}


/*
 * set the iec958 status bits
 * @bits: 32-bit status bits
 */
void vx_set_iec958_status(struct vx_core *chip, unsigned int bits)
{
        int i;

        if (chip->chip_status & VX_STAT_IS_STALE)
                return;

        for (i = 0; i < 32; i++)
                vx_write_one_cbit(chip, i, bits & (1 << i));
}


/*
 * vx_set_clock - change the clock and audio source if necessary
 */
int vx_set_clock(struct vx_core *chip, unsigned int freq)
{
        int src_changed = 0;

        if (chip->chip_status & VX_STAT_IS_STALE)
                return 0;

        /* change the audio source if possible */
        vx_sync_audio_source(chip);

        if (chip->clock_mode == VX_CLOCK_MODE_EXTERNAL ||
            (chip->clock_mode == VX_CLOCK_MODE_AUTO &&
             chip->audio_source == VX_AUDIO_SRC_DIGITAL)) {
                if (chip->clock_source != UER_SYNC) {
                        vx_change_clock_source(chip, UER_SYNC);
                        mdelay(6);
                        src_changed = 1;
                }
        } else if (chip->clock_mode == VX_CLOCK_MODE_INTERNAL ||
                   (chip->clock_mode == VX_CLOCK_MODE_AUTO &&
                    chip->audio_source != VX_AUDIO_SRC_DIGITAL)) {
                if (chip->clock_source != INTERNAL_QUARTZ) {
                        vx_change_clock_source(chip, INTERNAL_QUARTZ);
                        src_changed = 1;
                }
                if (chip->freq == freq)
                        return 0;
                vx_set_internal_clock(chip, freq);
                if (src_changed)
                        vx_modify_board_inputs(chip);
        }
        if (chip->freq == freq)
                return 0;
        chip->freq = freq;
        vx_modify_board_clock(chip, 1);
        return 0;
}


/*
 * vx_change_frequency - called from interrupt handler
 */
int vx_change_frequency(struct vx_core *chip)
{
        int freq;

        if (chip->chip_status & VX_STAT_IS_STALE)
                return 0;

        if (chip->clock_source == INTERNAL_QUARTZ)
                return 0;
        /*
         * Read the real UER board frequency
         */
        freq = vx_read_uer_status(chip, &chip->uer_detected);
        if (freq < 0)
                return freq;
        /*
         * The frequency computed by the DSP is good and
         * is different from the previous computed.
         */
        if (freq == 48000 || freq == 44100 || freq == 32000)
                chip->freq_detected = freq;

        return 0;
}