pmac.c

Go to the documentation of this file.

/*
 * PMac DBDMA lowlevel functions
 *
 * Copyright (c) by Takashi Iwai <[email protected]>
 * code based on dmasound.c.
 *
 *   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 <asm/io.h>
#include <asm/irq.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/dma-mapping.h>
#include <sound/core.h>
#include "pmac.h"
#include <sound/pcm_params.h>
#include <asm/pmac_feature.h>
#include <asm/pci-bridge.h>


/* fixed frequency table for awacs, screamer, burgundy, DACA (44100 max) */
static int awacs_freqs[8] = {
    44100, 29400, 22050, 17640, 14700, 11025, 8820, 7350
};
/* fixed frequency table for tumbler */
static int tumbler_freqs[1] = {
    44100
};


/*
 * we will allocate a single 'emergency' dbdma cmd block to use if the
 * tx status comes up "DEAD".  This happens on some PowerComputing Pmac
 * clones, either owing to a bug in dbdma or some interaction between
 * IDE and sound.  However, this measure would deal with DEAD status if
 * it appeared elsewhere.
 */
static struct pmac_dbdma emergency_dbdma;
static int emergency_in_use;


/*
 * allocate DBDMA command arrays
 */
static int snd_pmac_dbdma_alloc(struct snd_pmac *chip, struct pmac_dbdma *rec, int size)
{
    unsigned int rsize = sizeof(struct dbdma_cmd) * (size + 1);

    rec->space = dma_alloc_coherent(&chip->pdev->dev, rsize,
                    &rec->dma_base, GFP_KERNEL);
    if (rec->space == NULL)
        return -ENOMEM;
    rec->size = size;
    memset(rec->space, 0, rsize);
    rec->cmds = (void __iomem *)DBDMA_ALIGN(rec->space);
    rec->addr = rec->dma_base + (unsigned long)((char *)rec->cmds - (char *)rec->space);

    return 0;
}

static void snd_pmac_dbdma_free(struct snd_pmac *chip, struct pmac_dbdma *rec)
{
    if (rec->space) {
        unsigned int rsize = sizeof(struct dbdma_cmd) * (rec->size + 1);

        dma_free_coherent(&chip->pdev->dev, rsize, rec->space, rec->dma_base);
    }
}


/*
 * pcm stuff
 */

/*
 * look up frequency table
 */

unsigned int snd_pmac_rate_index(struct snd_pmac *chip, struct pmac_stream *rec, unsigned int rate)
{
    int i, ok, found;

    ok = rec->cur_freqs;
    if (rate > chip->freq_table[0])
        return 0;
    found = 0;
    for (i = 0; i < chip->num_freqs; i++, ok >>= 1) {
        if (! (ok & 1)) continue;
        found = i;
        if (rate >= chip->freq_table[i])
            break;
    }
    return found;
}

/*
 * check whether another stream is active
 */
static inline int another_stream(int stream)
{
    return (stream == SNDRV_PCM_STREAM_PLAYBACK) ?
        SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
}

/*
 * allocate buffers
 */
static int snd_pmac_pcm_hw_params(struct snd_pcm_substream *subs,
                  struct snd_pcm_hw_params *hw_params)
{
    return snd_pcm_lib_malloc_pages(subs, params_buffer_bytes(hw_params));
}

/*
 * release buffers
 */
static int snd_pmac_pcm_hw_free(struct snd_pcm_substream *subs)
{
    snd_pcm_lib_free_pages(subs);
    return 0;
}

/*
 * get a stream of the opposite direction
 */
static struct pmac_stream *snd_pmac_get_stream(struct snd_pmac *chip, int stream)
{
    switch (stream) {
    case SNDRV_PCM_STREAM_PLAYBACK:
        return &chip->playback;
    case SNDRV_PCM_STREAM_CAPTURE:
        return &chip->capture;
    default:
        snd_BUG();
        return NULL;
    }
}

/*
 * wait while run status is on
 */
static inline void
snd_pmac_wait_ack(struct pmac_stream *rec)
{
    int timeout = 50000;
    while ((in_le32(&rec->dma->status) & RUN) && timeout-- > 0)
        udelay(1);
}

/*
 * set the format and rate to the chip.
 * call the lowlevel function if defined (e.g. for AWACS).
 */
static void snd_pmac_pcm_set_format(struct snd_pmac *chip)
{
    /* set up frequency and format */
    out_le32(&chip->awacs->control, chip->control_mask | (chip->rate_index << 8));
    out_le32(&chip->awacs->byteswap, chip->format == SNDRV_PCM_FORMAT_S16_LE ? 1 : 0);
    if (chip->set_format)
        chip->set_format(chip);
}

/*
 * stop the DMA transfer
 */
static inline void snd_pmac_dma_stop(struct pmac_stream *rec)
{
    out_le32(&rec->dma->control, (RUN|WAKE|FLUSH|PAUSE) << 16);
    snd_pmac_wait_ack(rec);
}

/*
 * set the command pointer address
 */
static inline void snd_pmac_dma_set_command(struct pmac_stream *rec, struct pmac_dbdma *cmd)
{
    out_le32(&rec->dma->cmdptr, cmd->addr);
}

/*
 * start the DMA
 */
static inline void snd_pmac_dma_run(struct pmac_stream *rec, int status)
{
    out_le32(&rec->dma->control, status | (status << 16));
}


/*
 * prepare playback/capture stream
 */
static int snd_pmac_pcm_prepare(struct snd_pmac *chip, struct pmac_stream *rec, struct snd_pcm_substream *subs)
{
    int i;
    volatile struct dbdma_cmd __iomem *cp;
    struct snd_pcm_runtime *runtime = subs->runtime;
    int rate_index;
    long offset;
    struct pmac_stream *astr;

    rec->dma_size = snd_pcm_lib_buffer_bytes(subs);
    rec->period_size = snd_pcm_lib_period_bytes(subs);
    rec->nperiods = rec->dma_size / rec->period_size;
    rec->cur_period = 0;
    rate_index = snd_pmac_rate_index(chip, rec, runtime->rate);

    /* set up constraints */
    astr = snd_pmac_get_stream(chip, another_stream(rec->stream));
    if (! astr)
        return -EINVAL;
    astr->cur_freqs = 1 << rate_index;
    astr->cur_formats = 1 << runtime->format;
    chip->rate_index = rate_index;
    chip->format = runtime->format;

    /* We really want to execute a DMA stop command, after the AWACS
     * is initialized.
     * For reasons I don't understand, it stops the hissing noise
     * common to many PowerBook G3 systems and random noise otherwise
     * captured on iBook2's about every third time. -ReneR
     */
    spin_lock_irq(&chip->reg_lock);
    snd_pmac_dma_stop(rec);
    st_le16(&chip->extra_dma.cmds->command, DBDMA_STOP);
    snd_pmac_dma_set_command(rec, &chip->extra_dma);
    snd_pmac_dma_run(rec, RUN);
    spin_unlock_irq(&chip->reg_lock);
    mdelay(5);
    spin_lock_irq(&chip->reg_lock);
    /* continuous DMA memory type doesn't provide the physical address,
     * so we need to resolve the address here...
     */
    offset = runtime->dma_addr;
    for (i = 0, cp = rec->cmd.cmds; i < rec->nperiods; i++, cp++) {
        st_le32(&cp->phy_addr, offset);
        st_le16(&cp->req_count, rec->period_size);
        /*st_le16(&cp->res_count, 0);*/
        st_le16(&cp->xfer_status, 0);
        offset += rec->period_size;
    }
    /* make loop */
    st_le16(&cp->command, DBDMA_NOP + BR_ALWAYS);
    st_le32(&cp->cmd_dep, rec->cmd.addr);

    snd_pmac_dma_stop(rec);
    snd_pmac_dma_set_command(rec, &rec->cmd);
    spin_unlock_irq(&chip->reg_lock);

    return 0;
}


/*
 * PCM trigger/stop
 */
static int snd_pmac_pcm_trigger(struct snd_pmac *chip, struct pmac_stream *rec,
                struct snd_pcm_substream *subs, int cmd)
{
    volatile struct dbdma_cmd __iomem *cp;
    int i, command;

    switch (cmd) {
    case SNDRV_PCM_TRIGGER_START:
    case SNDRV_PCM_TRIGGER_RESUME:
        if (rec->running)
            return -EBUSY;
        command = (subs->stream == SNDRV_PCM_STREAM_PLAYBACK ?
               OUTPUT_MORE : INPUT_MORE) + INTR_ALWAYS;
        spin_lock(&chip->reg_lock);
        snd_pmac_beep_stop(chip);
        snd_pmac_pcm_set_format(chip);
        for (i = 0, cp = rec->cmd.cmds; i < rec->nperiods; i++, cp++)
            out_le16(&cp->command, command);
        snd_pmac_dma_set_command(rec, &rec->cmd);
        (void)in_le32(&rec->dma->status);
        snd_pmac_dma_run(rec, RUN|WAKE);
        rec->running = 1;
        spin_unlock(&chip->reg_lock);
        break;

    case SNDRV_PCM_TRIGGER_STOP:
    case SNDRV_PCM_TRIGGER_SUSPEND:
        spin_lock(&chip->reg_lock);
        rec->running = 0;
        /*printk(KERN_DEBUG "stopped!!\n");*/
        snd_pmac_dma_stop(rec);
        for (i = 0, cp = rec->cmd.cmds; i < rec->nperiods; i++, cp++)
            out_le16(&cp->command, DBDMA_STOP);
        spin_unlock(&chip->reg_lock);
        break;

    default:
        return -EINVAL;
    }

    return 0;
}

/*
 * return the current pointer
 */
inline
static snd_pcm_uframes_t snd_pmac_pcm_pointer(struct snd_pmac *chip,
                          struct pmac_stream *rec,
                          struct snd_pcm_substream *subs)
{
    int count = 0;

#if 1 /* hmm.. how can we get the current dma pointer?? */
    int stat;
    volatile struct dbdma_cmd __iomem *cp = &rec->cmd.cmds[rec->cur_period];
    stat = ld_le16(&cp->xfer_status);
    if (stat & (ACTIVE|DEAD)) {
        count = in_le16(&cp->res_count);
        if (count)
            count = rec->period_size - count;
    }
#endif
    count += rec->cur_period * rec->period_size;
    /*printk(KERN_DEBUG "pointer=%d\n", count);*/
    return bytes_to_frames(subs->runtime, count);
}

/*
 * playback
 */

static int snd_pmac_playback_prepare(struct snd_pcm_substream *subs)
{
    struct snd_pmac *chip = snd_pcm_substream_chip(subs);
    return snd_pmac_pcm_prepare(chip, &chip->playback, subs);
}

static int snd_pmac_playback_trigger(struct snd_pcm_substream *subs,
                     int cmd)
{
    struct snd_pmac *chip = snd_pcm_substream_chip(subs);
    return snd_pmac_pcm_trigger(chip, &chip->playback, subs, cmd);
}

static snd_pcm_uframes_t snd_pmac_playback_pointer(struct snd_pcm_substream *subs)
{
    struct snd_pmac *chip = snd_pcm_substream_chip(subs);
    return snd_pmac_pcm_pointer(chip, &chip->playback, subs);
}


/*
 * capture
 */

static int snd_pmac_capture_prepare(struct snd_pcm_substream *subs)
{
    struct snd_pmac *chip = snd_pcm_substream_chip(subs);
    return snd_pmac_pcm_prepare(chip, &chip->capture, subs);
}

static int snd_pmac_capture_trigger(struct snd_pcm_substream *subs,
                    int cmd)
{
    struct snd_pmac *chip = snd_pcm_substream_chip(subs);
    return snd_pmac_pcm_trigger(chip, &chip->capture, subs, cmd);
}

static snd_pcm_uframes_t snd_pmac_capture_pointer(struct snd_pcm_substream *subs)
{
    struct snd_pmac *chip = snd_pcm_substream_chip(subs);
    return snd_pmac_pcm_pointer(chip, &chip->capture, subs);
}


/*
 * Handle DEAD DMA transfers:
 * if the TX status comes up "DEAD" - reported on some Power Computing machines
 * we need to re-start the dbdma - but from a different physical start address
 * and with a different transfer length.  It would get very messy to do this
 * with the normal dbdma_cmd blocks - we would have to re-write the buffer start
 * addresses each time.  So, we will keep a single dbdma_cmd block which can be
 * fiddled with.
 * When DEAD status is first reported the content of the faulted dbdma block is
 * copied into the emergency buffer and we note that the buffer is in use.
 * we then bump the start physical address by the amount that was successfully
 * output before it died.
 * On any subsequent DEAD result we just do the bump-ups (we know that we are
 * already using the emergency dbdma_cmd).
 * CHECK: this just tries to "do it".  It is possible that we should abandon
 * xfers when the number of residual bytes gets below a certain value - I can
 * see that this might cause a loop-forever if a too small transfer causes
 * DEAD status.  However this is a TODO for now - we'll see what gets reported.
 * When we get a successful transfer result with the emergency buffer we just
 * pretend that it completed using the original dmdma_cmd and carry on.  The
 * 'next_cmd' field will already point back to the original loop of blocks.
 */
static inline void snd_pmac_pcm_dead_xfer(struct pmac_stream *rec,
                      volatile struct dbdma_cmd __iomem *cp)
{
    unsigned short req, res ;
    unsigned int phy ;

    /* printk(KERN_WARNING "snd-powermac: DMA died - patching it up!\n"); */

    /* to clear DEAD status we must first clear RUN
       set it to quiescent to be on the safe side */
    (void)in_le32(&rec->dma->status);
    out_le32(&rec->dma->control, (RUN|PAUSE|FLUSH|WAKE) << 16);

    if (!emergency_in_use) { /* new problem */
        memcpy((void *)emergency_dbdma.cmds, (void *)cp,
               sizeof(struct dbdma_cmd));
        emergency_in_use = 1;
        st_le16(&cp->xfer_status, 0);
        st_le16(&cp->req_count, rec->period_size);
        cp = emergency_dbdma.cmds;
    }

    /* now bump the values to reflect the amount
       we haven't yet shifted */
    req = ld_le16(&cp->req_count);
    res = ld_le16(&cp->res_count);
    phy = ld_le32(&cp->phy_addr);
    phy += (req - res);
    st_le16(&cp->req_count, res);
    st_le16(&cp->res_count, 0);
    st_le16(&cp->xfer_status, 0);
    st_le32(&cp->phy_addr, phy);

    st_le32(&cp->cmd_dep, rec->cmd.addr
        + sizeof(struct dbdma_cmd)*((rec->cur_period+1)%rec->nperiods));

    st_le16(&cp->command, OUTPUT_MORE | BR_ALWAYS | INTR_ALWAYS);

    /* point at our patched up command block */
    out_le32(&rec->dma->cmdptr, emergency_dbdma.addr);

    /* we must re-start the controller */
    (void)in_le32(&rec->dma->status);
    /* should complete clearing the DEAD status */
    out_le32(&rec->dma->control, ((RUN|WAKE) << 16) + (RUN|WAKE));
}

/*
 * update playback/capture pointer from interrupts
 */
static void snd_pmac_pcm_update(struct snd_pmac *chip, struct pmac_stream *rec)
{
    volatile struct dbdma_cmd __iomem *cp;
    int c;
    int stat;

    spin_lock(&chip->reg_lock);
    if (rec->running) {
        for (c = 0; c < rec->nperiods; c++) { /* at most all fragments */

            if (emergency_in_use)   /* already using DEAD xfer? */
                cp = emergency_dbdma.cmds;
            else
                cp = &rec->cmd.cmds[rec->cur_period];

            stat = ld_le16(&cp->xfer_status);

            if (stat & DEAD) {
                snd_pmac_pcm_dead_xfer(rec, cp);
                break; /* this block is still going */
            }

            if (emergency_in_use)
                emergency_in_use = 0 ; /* done that */

            if (! (stat & ACTIVE))
                break;

            /*printk(KERN_DEBUG "update frag %d\n", rec->cur_period);*/
            st_le16(&cp->xfer_status, 0);
            st_le16(&cp->req_count, rec->period_size);
            /*st_le16(&cp->res_count, 0);*/
            rec->cur_period++;
            if (rec->cur_period >= rec->nperiods) {
                rec->cur_period = 0;
            }

            spin_unlock(&chip->reg_lock);
            snd_pcm_period_elapsed(rec->substream);
            spin_lock(&chip->reg_lock);
        }
    }
    spin_unlock(&chip->reg_lock);
}


/*
 * hw info
 */

static struct snd_pcm_hardware snd_pmac_playback =
{
    .info =         (SNDRV_PCM_INFO_INTERLEAVED |
                 SNDRV_PCM_INFO_MMAP |
                 SNDRV_PCM_INFO_MMAP_VALID |
                 SNDRV_PCM_INFO_RESUME),
    .formats =      SNDRV_PCM_FMTBIT_S16_BE | SNDRV_PCM_FMTBIT_S16_LE,
    .rates =        SNDRV_PCM_RATE_8000_44100,
    .rate_min =     7350,
    .rate_max =     44100,
    .channels_min =     2,
    .channels_max =     2,
    .buffer_bytes_max = 131072,
    .period_bytes_min = 256,
    .period_bytes_max = 16384,
    .periods_min =      3,
    .periods_max =      PMAC_MAX_FRAGS,
};

static struct snd_pcm_hardware snd_pmac_capture =
{
    .info =         (SNDRV_PCM_INFO_INTERLEAVED |
                 SNDRV_PCM_INFO_MMAP |
                 SNDRV_PCM_INFO_MMAP_VALID |
                 SNDRV_PCM_INFO_RESUME),
    .formats =      SNDRV_PCM_FMTBIT_S16_BE | SNDRV_PCM_FMTBIT_S16_LE,
    .rates =        SNDRV_PCM_RATE_8000_44100,
    .rate_min =     7350,
    .rate_max =     44100,
    .channels_min =     2,
    .channels_max =     2,
    .buffer_bytes_max = 131072,
    .period_bytes_min = 256,
    .period_bytes_max = 16384,
    .periods_min =      3,
    .periods_max =      PMAC_MAX_FRAGS,
};


#if 0 // NYI
static int snd_pmac_hw_rule_rate(struct snd_pcm_hw_params *params,
                 struct snd_pcm_hw_rule *rule)
{
    struct snd_pmac *chip = rule->private;
    struct pmac_stream *rec = snd_pmac_get_stream(chip, rule->deps[0]);
    int i, freq_table[8], num_freqs;

    if (! rec)
        return -EINVAL;
    num_freqs = 0;
    for (i = chip->num_freqs - 1; i >= 0; i--) {
        if (rec->cur_freqs & (1 << i))
            freq_table[num_freqs++] = chip->freq_table[i];
    }

    return snd_interval_list(hw_param_interval(params, rule->var),
                 num_freqs, freq_table, 0);
}

static int snd_pmac_hw_rule_format(struct snd_pcm_hw_params *params,
                   struct snd_pcm_hw_rule *rule)
{
    struct snd_pmac *chip = rule->private;
    struct pmac_stream *rec = snd_pmac_get_stream(chip, rule->deps[0]);

    if (! rec)
        return -EINVAL;
    return snd_mask_refine_set(hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT),
                   rec->cur_formats);
}
#endif // NYI

static int snd_pmac_pcm_open(struct snd_pmac *chip, struct pmac_stream *rec,
                 struct snd_pcm_substream *subs)
{
    struct snd_pcm_runtime *runtime = subs->runtime;
    int i;

    /* look up frequency table and fill bit mask */
    runtime->hw.rates = 0;
    for (i = 0; i < chip->num_freqs; i++)
        if (chip->freqs_ok & (1 << i))
            runtime->hw.rates |=
                snd_pcm_rate_to_rate_bit(chip->freq_table[i]);

    /* check for minimum and maximum rates */
    for (i = 0; i < chip->num_freqs; i++) {
        if (chip->freqs_ok & (1 << i)) {
            runtime->hw.rate_max = chip->freq_table[i];
            break;
        }
    }
    for (i = chip->num_freqs - 1; i >= 0; i--) {
        if (chip->freqs_ok & (1 << i)) {
            runtime->hw.rate_min = chip->freq_table[i];
            break;
        }
    }
    runtime->hw.formats = chip->formats_ok;
    if (chip->can_capture) {
        if (! chip->can_duplex)
            runtime->hw.info |= SNDRV_PCM_INFO_HALF_DUPLEX;
        runtime->hw.info |= SNDRV_PCM_INFO_JOINT_DUPLEX;
    }
    runtime->private_data = rec;
    rec->substream = subs;

#if 0 /* FIXME: still under development.. */
    snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
                snd_pmac_hw_rule_rate, chip, rec->stream, -1);
    snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
                snd_pmac_hw_rule_format, chip, rec->stream, -1);
#endif

    runtime->hw.periods_max = rec->cmd.size - 1;

    /* constraints to fix choppy sound */
    snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
    return 0;
}

static int snd_pmac_pcm_close(struct snd_pmac *chip, struct pmac_stream *rec,
                  struct snd_pcm_substream *subs)
{
    struct pmac_stream *astr;

    snd_pmac_dma_stop(rec);

    astr = snd_pmac_get_stream(chip, another_stream(rec->stream));
    if (! astr)
        return -EINVAL;

    /* reset constraints */
    astr->cur_freqs = chip->freqs_ok;
    astr->cur_formats = chip->formats_ok;

    return 0;
}

static int snd_pmac_playback_open(struct snd_pcm_substream *subs)
{
    struct snd_pmac *chip = snd_pcm_substream_chip(subs);

    subs->runtime->hw = snd_pmac_playback;
    return snd_pmac_pcm_open(chip, &chip->playback, subs);
}

static int snd_pmac_capture_open(struct snd_pcm_substream *subs)
{
    struct snd_pmac *chip = snd_pcm_substream_chip(subs);

    subs->runtime->hw = snd_pmac_capture;
    return snd_pmac_pcm_open(chip, &chip->capture, subs);
}

static int snd_pmac_playback_close(struct snd_pcm_substream *subs)
{
    struct snd_pmac *chip = snd_pcm_substream_chip(subs);

    return snd_pmac_pcm_close(chip, &chip->playback, subs);
}

static int snd_pmac_capture_close(struct snd_pcm_substream *subs)
{
    struct snd_pmac *chip = snd_pcm_substream_chip(subs);

    return snd_pmac_pcm_close(chip, &chip->capture, subs);
}

/*
 */

static struct snd_pcm_ops snd_pmac_playback_ops = {
    .open =     snd_pmac_playback_open,
    .close =    snd_pmac_playback_close,
    .ioctl =    snd_pcm_lib_ioctl,
    .hw_params =    snd_pmac_pcm_hw_params,
    .hw_free =  snd_pmac_pcm_hw_free,
    .prepare =  snd_pmac_playback_prepare,
    .trigger =  snd_pmac_playback_trigger,
    .pointer =  snd_pmac_playback_pointer,
};

static struct snd_pcm_ops snd_pmac_capture_ops = {
    .open =     snd_pmac_capture_open,
    .close =    snd_pmac_capture_close,
    .ioctl =    snd_pcm_lib_ioctl,
    .hw_params =    snd_pmac_pcm_hw_params,
    .hw_free =  snd_pmac_pcm_hw_free,
    .prepare =  snd_pmac_capture_prepare,
    .trigger =  snd_pmac_capture_trigger,
    .pointer =  snd_pmac_capture_pointer,
};

int __devinit snd_pmac_pcm_new(struct snd_pmac *chip)
{
    struct snd_pcm *pcm;
    int err;
    int num_captures = 1;

    if (! chip->can_capture)
        num_captures = 0;
    err = snd_pcm_new(chip->card, chip->card->driver, 0, 1, num_captures, &pcm);
    if (err < 0)
        return err;

    snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_pmac_playback_ops);
    if (chip->can_capture)
        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_pmac_capture_ops);

    pcm->private_data = chip;
    pcm->info_flags = SNDRV_PCM_INFO_JOINT_DUPLEX;
    strcpy(pcm->name, chip->card->shortname);
    chip->pcm = pcm;

    chip->formats_ok = SNDRV_PCM_FMTBIT_S16_BE;
    if (chip->can_byte_swap)
        chip->formats_ok |= SNDRV_PCM_FMTBIT_S16_LE;

    chip->playback.cur_formats = chip->formats_ok;
    chip->capture.cur_formats = chip->formats_ok;
    chip->playback.cur_freqs = chip->freqs_ok;
    chip->capture.cur_freqs = chip->freqs_ok;

    /* preallocate 64k buffer */
    snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
                          &chip->pdev->dev,
                          64 * 1024, 64 * 1024);

    return 0;
}


static void snd_pmac_dbdma_reset(struct snd_pmac *chip)
{
    out_le32(&chip->playback.dma->control, (RUN|PAUSE|FLUSH|WAKE|DEAD) << 16);
    snd_pmac_wait_ack(&chip->playback);
    out_le32(&chip->capture.dma->control, (RUN|PAUSE|FLUSH|WAKE|DEAD) << 16);
    snd_pmac_wait_ack(&chip->capture);
}


/*
 * handling beep
 */
void snd_pmac_beep_dma_start(struct snd_pmac *chip, int bytes, unsigned long addr, int speed)
{
    struct pmac_stream *rec = &chip->playback;

    snd_pmac_dma_stop(rec);
    st_le16(&chip->extra_dma.cmds->req_count, bytes);
    st_le16(&chip->extra_dma.cmds->xfer_status, 0);
    st_le32(&chip->extra_dma.cmds->cmd_dep, chip->extra_dma.addr);
    st_le32(&chip->extra_dma.cmds->phy_addr, addr);
    st_le16(&chip->extra_dma.cmds->command, OUTPUT_MORE + BR_ALWAYS);
    out_le32(&chip->awacs->control,
         (in_le32(&chip->awacs->control) & ~0x1f00)
         | (speed << 8));
    out_le32(&chip->awacs->byteswap, 0);
    snd_pmac_dma_set_command(rec, &chip->extra_dma);
    snd_pmac_dma_run(rec, RUN);
}

void snd_pmac_beep_dma_stop(struct snd_pmac *chip)
{
    snd_pmac_dma_stop(&chip->playback);
    st_le16(&chip->extra_dma.cmds->command, DBDMA_STOP);
    snd_pmac_pcm_set_format(chip); /* reset format */
}


/*
 * interrupt handlers
 */
static irqreturn_t
snd_pmac_tx_intr(int irq, void *devid)
{
    struct snd_pmac *chip = devid;
    snd_pmac_pcm_update(chip, &chip->playback);
    return IRQ_HANDLED;
}


static irqreturn_t
snd_pmac_rx_intr(int irq, void *devid)
{
    struct snd_pmac *chip = devid;
    snd_pmac_pcm_update(chip, &chip->capture);
    return IRQ_HANDLED;
}


static irqreturn_t
snd_pmac_ctrl_intr(int irq, void *devid)
{
    struct snd_pmac *chip = devid;
    int ctrl = in_le32(&chip->awacs->control);

    /*printk(KERN_DEBUG "pmac: control interrupt.. 0x%x\n", ctrl);*/
    if (ctrl & MASK_PORTCHG) {
        /* do something when headphone is plugged/unplugged? */
        if (chip->update_automute)
            chip->update_automute(chip, 1);
    }
    if (ctrl & MASK_CNTLERR) {
        int err = (in_le32(&chip->awacs->codec_stat) & MASK_ERRCODE) >> 16;
        if (err && chip->model <= PMAC_SCREAMER)
            snd_printk(KERN_DEBUG "error %x\n", err);
    }
    /* Writing 1s to the CNTLERR and PORTCHG bits clears them... */
    out_le32(&chip->awacs->control, ctrl);
    return IRQ_HANDLED;
}


/*
 * a wrapper to feature call for compatibility
 */
static void snd_pmac_sound_feature(struct snd_pmac *chip, int enable)
{
    if (ppc_md.feature_call)
        ppc_md.feature_call(PMAC_FTR_SOUND_CHIP_ENABLE, chip->node, 0, enable);
}

/*
 * release resources
 */

static int snd_pmac_free(struct snd_pmac *chip)
{
    /* stop sounds */
    if (chip->initialized) {
        snd_pmac_dbdma_reset(chip);
        /* disable interrupts from awacs interface */
        out_le32(&chip->awacs->control, in_le32(&chip->awacs->control) & 0xfff);
    }

    if (chip->node)
        snd_pmac_sound_feature(chip, 0);

    /* clean up mixer if any */
    if (chip->mixer_free)
        chip->mixer_free(chip);

    snd_pmac_detach_beep(chip);

    /* release resources */
    if (chip->irq >= 0)
        free_irq(chip->irq, (void*)chip);
    if (chip->tx_irq >= 0)
        free_irq(chip->tx_irq, (void*)chip);
    if (chip->rx_irq >= 0)
        free_irq(chip->rx_irq, (void*)chip);
    snd_pmac_dbdma_free(chip, &chip->playback.cmd);
    snd_pmac_dbdma_free(chip, &chip->capture.cmd);
    snd_pmac_dbdma_free(chip, &chip->extra_dma);
    snd_pmac_dbdma_free(chip, &emergency_dbdma);
    if (chip->macio_base)
        iounmap(chip->macio_base);
    if (chip->latch_base)
        iounmap(chip->latch_base);
    if (chip->awacs)
        iounmap(chip->awacs);
    if (chip->playback.dma)
        iounmap(chip->playback.dma);
    if (chip->capture.dma)
        iounmap(chip->capture.dma);

    if (chip->node) {
        int i;
        for (i = 0; i < 3; i++) {
            if (chip->requested & (1 << i))
                release_mem_region(chip->rsrc[i].start,
                           resource_size(&chip->rsrc[i]));
        }
    }

    if (chip->pdev)
        pci_dev_put(chip->pdev);
    of_node_put(chip->node);
    kfree(chip);
    return 0;
}


/*
 * free the device
 */
static int snd_pmac_dev_free(struct snd_device *device)
{
    struct snd_pmac *chip = device->device_data;
    return snd_pmac_free(chip);
}


/*
 * check the machine support byteswap (little-endian)
 */

static void __devinit detect_byte_swap(struct snd_pmac *chip)
{
    struct device_node *mio;

    /* if seems that Keylargo can't byte-swap  */
    for (mio = chip->node->parent; mio; mio = mio->parent) {
        if (strcmp(mio->name, "mac-io") == 0) {
            if (of_device_is_compatible(mio, "Keylargo"))
                chip->can_byte_swap = 0;
            break;
        }
    }

    /* it seems the Pismo & iBook can't byte-swap in hardware. */
    if (of_machine_is_compatible("PowerBook3,1") ||
        of_machine_is_compatible("PowerBook2,1"))
        chip->can_byte_swap = 0 ;

    if (of_machine_is_compatible("PowerBook2,1"))
        chip->can_duplex = 0;
}


/*
 * detect a sound chip
 */
static int __devinit snd_pmac_detect(struct snd_pmac *chip)
{
    struct device_node *sound;
    struct device_node *dn;
    const unsigned int *prop;
    unsigned int l;
    struct macio_chip* macio;

    if (!machine_is(powermac))
        return -ENODEV;

    chip->subframe = 0;
    chip->revision = 0;
    chip->freqs_ok = 0xff; /* all ok */
    chip->model = PMAC_AWACS;
    chip->can_byte_swap = 1;
    chip->can_duplex = 1;
    chip->can_capture = 1;
    chip->num_freqs = ARRAY_SIZE(awacs_freqs);
    chip->freq_table = awacs_freqs;
    chip->pdev = NULL;

    chip->control_mask = MASK_IEPC | MASK_IEE | 0x11; /* default */

    /* check machine type */
    if (of_machine_is_compatible("AAPL,3400/2400")
        || of_machine_is_compatible("AAPL,3500"))
        chip->is_pbook_3400 = 1;
    else if (of_machine_is_compatible("PowerBook1,1")
         || of_machine_is_compatible("AAPL,PowerBook1998"))
        chip->is_pbook_G3 = 1;
    chip->node = of_find_node_by_name(NULL, "awacs");
    sound = of_node_get(chip->node);

    /*
     * powermac G3 models have a node called "davbus"
     * with a child called "sound".
     */
    if (!chip->node)
        chip->node = of_find_node_by_name(NULL, "davbus");
    /*
     * if we didn't find a davbus device, try 'i2s-a' since
     * this seems to be what iBooks have
     */
    if (! chip->node) {
        chip->node = of_find_node_by_name(NULL, "i2s-a");
        if (chip->node && chip->node->parent &&
            chip->node->parent->parent) {
            if (of_device_is_compatible(chip->node->parent->parent,
                         "K2-Keylargo"))
                chip->is_k2 = 1;
        }
    }
    if (! chip->node)
        return -ENODEV;

    if (!sound) {
        sound = of_find_node_by_name(NULL, "sound");
        while (sound && sound->parent != chip->node)
            sound = of_find_node_by_name(sound, "sound");
    }
    if (! sound) {
        of_node_put(chip->node);
        chip->node = NULL;
        return -ENODEV;
    }
    prop = of_get_property(sound, "sub-frame", NULL);
    if (prop && *prop < 16)
        chip->subframe = *prop;
    prop = of_get_property(sound, "layout-id", NULL);
    if (prop) {
        /* partly deprecate snd-powermac, for those machines
         * that have a layout-id property for now */
        printk(KERN_INFO "snd-powermac no longer handles any "
                 "machines with a layout-id property "
                 "in the device-tree, use snd-aoa.\n");
        of_node_put(sound);
        of_node_put(chip->node);
        chip->node = NULL;
        return -ENODEV;
    }
    /* This should be verified on older screamers */
    if (of_device_is_compatible(sound, "screamer")) {
        chip->model = PMAC_SCREAMER;
        // chip->can_byte_swap = 0; /* FIXME: check this */
    }
    if (of_device_is_compatible(sound, "burgundy")) {
        chip->model = PMAC_BURGUNDY;
        chip->control_mask = MASK_IEPC | 0x11; /* disable IEE */
    }
    if (of_device_is_compatible(sound, "daca")) {
        chip->model = PMAC_DACA;
        chip->can_capture = 0;  /* no capture */
        chip->can_duplex = 0;
        // chip->can_byte_swap = 0; /* FIXME: check this */
        chip->control_mask = MASK_IEPC | 0x11; /* disable IEE */
    }
    if (of_device_is_compatible(sound, "tumbler")) {
        chip->model = PMAC_TUMBLER;
        chip->can_capture = of_machine_is_compatible("PowerMac4,2")
                || of_machine_is_compatible("PowerBook3,2")
                || of_machine_is_compatible("PowerBook3,3")
                || of_machine_is_compatible("PowerBook4,1")
                || of_machine_is_compatible("PowerBook4,2")
                || of_machine_is_compatible("PowerBook4,3");
        chip->can_duplex = 0;
        // chip->can_byte_swap = 0; /* FIXME: check this */
        chip->num_freqs = ARRAY_SIZE(tumbler_freqs);
        chip->freq_table = tumbler_freqs;
        chip->control_mask = MASK_IEPC | 0x11; /* disable IEE */
    }
    if (of_device_is_compatible(sound, "snapper")) {
        chip->model = PMAC_SNAPPER;
        // chip->can_byte_swap = 0; /* FIXME: check this */
        chip->num_freqs = ARRAY_SIZE(tumbler_freqs);
        chip->freq_table = tumbler_freqs;
        chip->control_mask = MASK_IEPC | 0x11; /* disable IEE */
    }
    prop = of_get_property(sound, "device-id", NULL);
    if (prop)
        chip->device_id = *prop;
    dn = of_find_node_by_name(NULL, "perch");
    chip->has_iic = (dn != NULL);
    of_node_put(dn);

    /* We need the PCI device for DMA allocations, let's use a crude method
     * for now ...
     */
    macio = macio_find(chip->node, macio_unknown);
    if (macio == NULL)
        printk(KERN_WARNING "snd-powermac: can't locate macio !\n");
    else {
        struct pci_dev *pdev = NULL;

        for_each_pci_dev(pdev) {
            struct device_node *np = pci_device_to_OF_node(pdev);
            if (np && np == macio->of_node) {
                chip->pdev = pdev;
                break;
            }
        }
    }
    if (chip->pdev == NULL)
        printk(KERN_WARNING "snd-powermac: can't locate macio PCI"
               " device !\n");

    detect_byte_swap(chip);

    /* look for a property saying what sample rates
       are available */
    prop = of_get_property(sound, "sample-rates", &l);
    if (! prop)
        prop = of_get_property(sound, "output-frame-rates", &l);
    if (prop) {
        int i;
        chip->freqs_ok = 0;
        for (l /= sizeof(int); l > 0; --l) {
            unsigned int r = *prop++;
            /* Apple 'Fixed' format */
            if (r >= 0x10000)
                r >>= 16;
            for (i = 0; i < chip->num_freqs; ++i) {
                if (r == chip->freq_table[i]) {
                    chip->freqs_ok |= (1 << i);
                    break;
                }
            }
        }
    } else {
        /* assume only 44.1khz */
        chip->freqs_ok = 1;
    }

    of_node_put(sound);
    return 0;
}

#ifdef PMAC_SUPPORT_AUTOMUTE
/*
 * auto-mute
 */
static int pmac_auto_mute_get(struct snd_kcontrol *kcontrol,
                  struct snd_ctl_elem_value *ucontrol)
{
    struct snd_pmac *chip = snd_kcontrol_chip(kcontrol);
    ucontrol->value.integer.value[0] = chip->auto_mute;
    return 0;
}

static int pmac_auto_mute_put(struct snd_kcontrol *kcontrol,
                  struct snd_ctl_elem_value *ucontrol)
{
    struct snd_pmac *chip = snd_kcontrol_chip(kcontrol);
    if (ucontrol->value.integer.value[0] != chip->auto_mute) {
        chip->auto_mute = !!ucontrol->value.integer.value[0];
        if (chip->update_automute)
            chip->update_automute(chip, 1);
        return 1;
    }
    return 0;
}

static int pmac_hp_detect_get(struct snd_kcontrol *kcontrol,
                  struct snd_ctl_elem_value *ucontrol)
{
    struct snd_pmac *chip = snd_kcontrol_chip(kcontrol);
    if (chip->detect_headphone)
        ucontrol->value.integer.value[0] = chip->detect_headphone(chip);
    else
        ucontrol->value.integer.value[0] = 0;
    return 0;
}

static struct snd_kcontrol_new auto_mute_controls[] __devinitdata = {
    { .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
      .name = "Auto Mute Switch",
      .info = snd_pmac_boolean_mono_info,
      .get = pmac_auto_mute_get,
      .put = pmac_auto_mute_put,
    },
    { .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
      .name = "Headphone Detection",
      .access = SNDRV_CTL_ELEM_ACCESS_READ,
      .info = snd_pmac_boolean_mono_info,
      .get = pmac_hp_detect_get,
    },
};

int __devinit snd_pmac_add_automute(struct snd_pmac *chip)
{
    int err;
    chip->auto_mute = 1;
    err = snd_ctl_add(chip->card, snd_ctl_new1(&auto_mute_controls[0], chip));
    if (err < 0) {
        printk(KERN_ERR "snd-powermac: Failed to add automute control\n");
        return err;
    }
    chip->hp_detect_ctl = snd_ctl_new1(&auto_mute_controls[1], chip);
    return snd_ctl_add(chip->card, chip->hp_detect_ctl);
}
#endif /* PMAC_SUPPORT_AUTOMUTE */

/*
 * create and detect a pmac chip record
 */
int __devinit snd_pmac_new(struct snd_card *card, struct snd_pmac **chip_return)
{
    struct snd_pmac *chip;
    struct device_node *np;
    int i, err;
    unsigned int irq;
    unsigned long ctrl_addr, txdma_addr, rxdma_addr;
    static struct snd_device_ops ops = {
        .dev_free = snd_pmac_dev_free,
    };

    *chip_return = NULL;

    chip = kzalloc(sizeof(*chip), GFP_KERNEL);
    if (chip == NULL)
        return -ENOMEM;
    chip->card = card;

    spin_lock_init(&chip->reg_lock);
    chip->irq = chip->tx_irq = chip->rx_irq = -1;

    chip->playback.stream = SNDRV_PCM_STREAM_PLAYBACK;
    chip->capture.stream = SNDRV_PCM_STREAM_CAPTURE;

    if ((err = snd_pmac_detect(chip)) < 0)
        goto __error;

    if (snd_pmac_dbdma_alloc(chip, &chip->playback.cmd, PMAC_MAX_FRAGS + 1) < 0 ||
        snd_pmac_dbdma_alloc(chip, &chip->capture.cmd, PMAC_MAX_FRAGS + 1) < 0 ||
        snd_pmac_dbdma_alloc(chip, &chip->extra_dma, 2) < 0 ||
        snd_pmac_dbdma_alloc(chip, &emergency_dbdma, 2) < 0) {
        err = -ENOMEM;
        goto __error;
    }

    np = chip->node;
    chip->requested = 0;
    if (chip->is_k2) {
        static char *rnames[] = {
            "Sound Control", "Sound DMA" };
        for (i = 0; i < 2; i ++) {
            if (of_address_to_resource(np->parent, i,
                           &chip->rsrc[i])) {
                printk(KERN_ERR "snd: can't translate rsrc "
                       " %d (%s)\n", i, rnames[i]);
                err = -ENODEV;
                goto __error;
            }
            if (request_mem_region(chip->rsrc[i].start,
                           resource_size(&chip->rsrc[i]),
                           rnames[i]) == NULL) {
                printk(KERN_ERR "snd: can't request rsrc "
                       " %d (%s: %pR)\n",
                       i, rnames[i], &chip->rsrc[i]);
                err = -ENODEV;
                goto __error;
            }
            chip->requested |= (1 << i);
        }
        ctrl_addr = chip->rsrc[0].start;
        txdma_addr = chip->rsrc[1].start;
        rxdma_addr = txdma_addr + 0x100;
    } else {
        static char *rnames[] = {
            "Sound Control", "Sound Tx DMA", "Sound Rx DMA" };
        for (i = 0; i < 3; i ++) {
            if (of_address_to_resource(np, i,
                           &chip->rsrc[i])) {
                printk(KERN_ERR "snd: can't translate rsrc "
                       " %d (%s)\n", i, rnames[i]);
                err = -ENODEV;
                goto __error;
            }
            if (request_mem_region(chip->rsrc[i].start,
                           resource_size(&chip->rsrc[i]),
                           rnames[i]) == NULL) {
                printk(KERN_ERR "snd: can't request rsrc "
                       " %d (%s: %pR)\n",
                       i, rnames[i], &chip->rsrc[i]);
                err = -ENODEV;
                goto __error;
            }
            chip->requested |= (1 << i);
        }
        ctrl_addr = chip->rsrc[0].start;
        txdma_addr = chip->rsrc[1].start;
        rxdma_addr = chip->rsrc[2].start;
    }

    chip->awacs = ioremap(ctrl_addr, 0x1000);
    chip->playback.dma = ioremap(txdma_addr, 0x100);
    chip->capture.dma = ioremap(rxdma_addr, 0x100);
    if (chip->model <= PMAC_BURGUNDY) {
        irq = irq_of_parse_and_map(np, 0);
        if (request_irq(irq, snd_pmac_ctrl_intr, 0,
                "PMac", (void*)chip)) {
            snd_printk(KERN_ERR "pmac: unable to grab IRQ %d\n",
                   irq);
            err = -EBUSY;
            goto __error;
        }
        chip->irq = irq;
    }
    irq = irq_of_parse_and_map(np, 1);
    if (request_irq(irq, snd_pmac_tx_intr, 0, "PMac Output", (void*)chip)){
        snd_printk(KERN_ERR "pmac: unable to grab IRQ %d\n", irq);
        err = -EBUSY;
        goto __error;
    }
    chip->tx_irq = irq;
    irq = irq_of_parse_and_map(np, 2);
    if (request_irq(irq, snd_pmac_rx_intr, 0, "PMac Input", (void*)chip)) {
        snd_printk(KERN_ERR "pmac: unable to grab IRQ %d\n", irq);
        err = -EBUSY;
        goto __error;
    }
    chip->rx_irq = irq;

    snd_pmac_sound_feature(chip, 1);

    /* reset & enable interrupts */
    if (chip->model <= PMAC_BURGUNDY)
        out_le32(&chip->awacs->control, chip->control_mask);

    /* Powerbooks have odd ways of enabling inputs such as
       an expansion-bay CD or sound from an internal modem
       or a PC-card modem. */
    if (chip->is_pbook_3400) {
        /* Enable CD and PC-card sound inputs. */
        /* This is done by reading from address
         * f301a000, + 0x10 to enable the expansion-bay
         * CD sound input, + 0x80 to enable the PC-card
         * sound input.  The 0x100 enables the SCSI bus
         * terminator power.
         */
        chip->latch_base = ioremap (0xf301a000, 0x1000);
        in_8(chip->latch_base + 0x190);
    } else if (chip->is_pbook_G3) {
        struct device_node* mio;
        for (mio = chip->node->parent; mio; mio = mio->parent) {
            if (strcmp(mio->name, "mac-io") == 0) {
                struct resource r;
                if (of_address_to_resource(mio, 0, &r) == 0)
                    chip->macio_base =
                        ioremap(r.start, 0x40);
                break;
            }
        }
        /* Enable CD sound input. */
        /* The relevant bits for writing to this byte are 0x8f.
         * I haven't found out what the 0x80 bit does.
         * For the 0xf bits, writing 3 or 7 enables the CD
         * input, any other value disables it.  Values
         * 1, 3, 5, 7 enable the microphone.  Values 0, 2,
         * 4, 6, 8 - f enable the input from the modem.
         */
        if (chip->macio_base)
            out_8(chip->macio_base + 0x37, 3);
    }

    /* Reset dbdma channels */
    snd_pmac_dbdma_reset(chip);

    if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops)) < 0)
        goto __error;

    *chip_return = chip;
    return 0;

 __error:
    snd_pmac_free(chip);
    return err;
}


/*
 * sleep notify for powerbook
 */

#ifdef CONFIG_PM

/*
 * Save state when going to sleep, restore it afterwards.
 */

void snd_pmac_suspend(struct snd_pmac *chip)
{
    unsigned long flags;

    snd_power_change_state(chip->card, SNDRV_CTL_POWER_D3hot);
    if (chip->suspend)
        chip->suspend(chip);
    snd_pcm_suspend_all(chip->pcm);
    spin_lock_irqsave(&chip->reg_lock, flags);
    snd_pmac_beep_stop(chip);
    spin_unlock_irqrestore(&chip->reg_lock, flags);
    if (chip->irq >= 0)
        disable_irq(chip->irq);
    if (chip->tx_irq >= 0)
        disable_irq(chip->tx_irq);
    if (chip->rx_irq >= 0)
        disable_irq(chip->rx_irq);
    snd_pmac_sound_feature(chip, 0);
}

void snd_pmac_resume(struct snd_pmac *chip)
{
    snd_pmac_sound_feature(chip, 1);
    if (chip->resume)
        chip->resume(chip);
    /* enable CD sound input */
    if (chip->macio_base && chip->is_pbook_G3)
        out_8(chip->macio_base + 0x37, 3);
    else if (chip->is_pbook_3400)
        in_8(chip->latch_base + 0x190);

    snd_pmac_pcm_set_format(chip);

    if (chip->irq >= 0)
        enable_irq(chip->irq);
    if (chip->tx_irq >= 0)
        enable_irq(chip->tx_irq);
    if (chip->rx_irq >= 0)
        enable_irq(chip->rx_irq);

    snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);
}

#endif /* CONFIG_PM */