pcm.c

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/*
 * i2sbus driver -- pcm routines
 *
 * Copyright 2006 Johannes Berg <[email protected]>
 *
 * GPL v2, can be found in COPYING.
 */

#include <asm/io.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <sound/core.h>
#include <asm/macio.h>
#include <linux/pci.h>
#include <linux/module.h>
#include "../soundbus.h"
#include "i2sbus.h"

static inline void get_pcm_info(struct i2sbus_dev *i2sdev, int in,
                struct pcm_info **pi, struct pcm_info **other)
{
    if (in) {
        if (pi)
            *pi = &i2sdev->in;
        if (other)
            *other = &i2sdev->out;
    } else {
        if (pi)
            *pi = &i2sdev->out;
        if (other)
            *other = &i2sdev->in;
    }
}

static int clock_and_divisors(int mclk, int sclk, int rate, int *out)
{
    /* sclk must be derived from mclk! */
    if (mclk % sclk)
        return -1;
    /* derive sclk register value */
    if (i2s_sf_sclkdiv(mclk / sclk, out))
        return -1;

    if (I2S_CLOCK_SPEED_18MHz % (rate * mclk) == 0) {
        if (!i2s_sf_mclkdiv(I2S_CLOCK_SPEED_18MHz / (rate * mclk), out)) {
            *out |= I2S_SF_CLOCK_SOURCE_18MHz;
            return 0;
        }
    }
    if (I2S_CLOCK_SPEED_45MHz % (rate * mclk) == 0) {
        if (!i2s_sf_mclkdiv(I2S_CLOCK_SPEED_45MHz / (rate * mclk), out)) {
            *out |= I2S_SF_CLOCK_SOURCE_45MHz;
            return 0;
        }
    }
    if (I2S_CLOCK_SPEED_49MHz % (rate * mclk) == 0) {
        if (!i2s_sf_mclkdiv(I2S_CLOCK_SPEED_49MHz / (rate * mclk), out)) {
            *out |= I2S_SF_CLOCK_SOURCE_49MHz;
            return 0;
        }
    }
    return -1;
}

#define CHECK_RATE(rate)                        \
    do { if (rates & SNDRV_PCM_RATE_ ##rate) {          \
        int dummy;                      \
        if (clock_and_divisors(sysclock_factor,         \
                       bus_factor, rate, &dummy))   \
            rates &= ~SNDRV_PCM_RATE_ ##rate;       \
    } } while (0)

static int i2sbus_pcm_open(struct i2sbus_dev *i2sdev, int in)
{
    struct pcm_info *pi, *other;
    struct soundbus_dev *sdev;
    int masks_inited = 0, err;
    struct codec_info_item *cii, *rev;
    struct snd_pcm_hardware *hw;
    u64 formats = 0;
    unsigned int rates = 0;
    struct transfer_info v;
    int result = 0;
    int bus_factor = 0, sysclock_factor = 0;
    int found_this;

    mutex_lock(&i2sdev->lock);

    get_pcm_info(i2sdev, in, &pi, &other);

    hw = &pi->substream->runtime->hw;
    sdev = &i2sdev->sound;

    if (pi->active) {
        /* alsa messed up */
        result = -EBUSY;
        goto out_unlock;
    }

    /* we now need to assign the hw */
    list_for_each_entry(cii, &sdev->codec_list, list) {
        struct transfer_info *ti = cii->codec->transfers;
        bus_factor = cii->codec->bus_factor;
        sysclock_factor = cii->codec->sysclock_factor;
        while (ti->formats && ti->rates) {
            v = *ti;
            if (ti->transfer_in == in
                && cii->codec->usable(cii, ti, &v)) {
                if (masks_inited) {
                    formats &= v.formats;
                    rates &= v.rates;
                } else {
                    formats = v.formats;
                    rates = v.rates;
                    masks_inited = 1;
                }
            }
            ti++;
        }
    }
    if (!masks_inited || !bus_factor || !sysclock_factor) {
        result = -ENODEV;
        goto out_unlock;
    }
    /* bus dependent stuff */
    hw->info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
           SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_RESUME |
           SNDRV_PCM_INFO_JOINT_DUPLEX;

    CHECK_RATE(5512);
    CHECK_RATE(8000);
    CHECK_RATE(11025);
    CHECK_RATE(16000);
    CHECK_RATE(22050);
    CHECK_RATE(32000);
    CHECK_RATE(44100);
    CHECK_RATE(48000);
    CHECK_RATE(64000);
    CHECK_RATE(88200);
    CHECK_RATE(96000);
    CHECK_RATE(176400);
    CHECK_RATE(192000);
    hw->rates = rates;

    /* well. the codec might want 24 bits only, and we'll
     * ever only transfer 24 bits, but they are top-aligned!
     * So for alsa, we claim that we're doing full 32 bit
     * while in reality we'll ignore the lower 8 bits of
     * that when doing playback (they're transferred as 0
     * as far as I know, no codecs we have are 32-bit capable
     * so I can't really test) and when doing recording we'll
     * always have those lower 8 bits recorded as 0 */
    if (formats & SNDRV_PCM_FMTBIT_S24_BE)
        formats |= SNDRV_PCM_FMTBIT_S32_BE;
    if (formats & SNDRV_PCM_FMTBIT_U24_BE)
        formats |= SNDRV_PCM_FMTBIT_U32_BE;
    /* now mask off what we can support. I suppose we could
     * also support S24_3LE and some similar formats, but I
     * doubt there's a codec that would be able to use that,
     * so we don't support it here. */
    hw->formats = formats & (SNDRV_PCM_FMTBIT_S16_BE |
                 SNDRV_PCM_FMTBIT_U16_BE |
                 SNDRV_PCM_FMTBIT_S32_BE |
                 SNDRV_PCM_FMTBIT_U32_BE);

    /* we need to set the highest and lowest rate possible.
     * These are the highest and lowest rates alsa can
     * support properly in its bitfield.
     * Below, we'll use that to restrict to the rate
     * currently in use (if any). */
    hw->rate_min = 5512;
    hw->rate_max = 192000;
    /* if the other stream is active, then we can only
     * support what it is currently using.
     * FIXME: I lied. This comment is wrong. We can support
     * anything that works with the same serial format, ie.
     * when recording 24 bit sound we can well play 16 bit
     * sound at the same time iff using the same transfer mode.
     */
    if (other->active) {
        /* FIXME: is this guaranteed by the alsa api? */
        hw->formats &= (1ULL << i2sdev->format);
        /* see above, restrict rates to the one we already have */
        hw->rate_min = i2sdev->rate;
        hw->rate_max = i2sdev->rate;
    }

    hw->channels_min = 2;
    hw->channels_max = 2;
    /* these are somewhat arbitrary */
    hw->buffer_bytes_max = 131072;
    hw->period_bytes_min = 256;
    hw->period_bytes_max = 16384;
    hw->periods_min = 3;
    hw->periods_max = MAX_DBDMA_COMMANDS;
    err = snd_pcm_hw_constraint_integer(pi->substream->runtime,
                        SNDRV_PCM_HW_PARAM_PERIODS);
    if (err < 0) {
        result = err;
        goto out_unlock;
    }
    list_for_each_entry(cii, &sdev->codec_list, list) {
        if (cii->codec->open) {
            err = cii->codec->open(cii, pi->substream);
            if (err) {
                result = err;
                /* unwind */
                found_this = 0;
                list_for_each_entry_reverse(rev,
                    &sdev->codec_list, list) {
                    if (found_this && rev->codec->close) {
                        rev->codec->close(rev,
                                pi->substream);
                    }
                    if (rev == cii)
                        found_this = 1;
                }
                goto out_unlock;
            }
        }
    }

 out_unlock:
    mutex_unlock(&i2sdev->lock);
    return result;
}

#undef CHECK_RATE

static int i2sbus_pcm_close(struct i2sbus_dev *i2sdev, int in)
{
    struct codec_info_item *cii;
    struct pcm_info *pi;
    int err = 0, tmp;

    mutex_lock(&i2sdev->lock);

    get_pcm_info(i2sdev, in, &pi, NULL);

    list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
        if (cii->codec->close) {
            tmp = cii->codec->close(cii, pi->substream);
            if (tmp)
                err = tmp;
        }
    }

    pi->substream = NULL;
    pi->active = 0;
    mutex_unlock(&i2sdev->lock);
    return err;
}

static void i2sbus_wait_for_stop(struct i2sbus_dev *i2sdev,
                 struct pcm_info *pi)
{
    unsigned long flags;
    struct completion done;
    long timeout;

    spin_lock_irqsave(&i2sdev->low_lock, flags);
    if (pi->dbdma_ring.stopping) {
        init_completion(&done);
        pi->stop_completion = &done;
        spin_unlock_irqrestore(&i2sdev->low_lock, flags);
        timeout = wait_for_completion_timeout(&done, HZ);
        spin_lock_irqsave(&i2sdev->low_lock, flags);
        pi->stop_completion = NULL;
        if (timeout == 0) {
            /* timeout expired, stop dbdma forcefully */
            printk(KERN_ERR "i2sbus_wait_for_stop: timed out\n");
            /* make sure RUN, PAUSE and S0 bits are cleared */
            out_le32(&pi->dbdma->control, (RUN | PAUSE | 1) << 16);
            pi->dbdma_ring.stopping = 0;
            timeout = 10;
            while (in_le32(&pi->dbdma->status) & ACTIVE) {
                if (--timeout <= 0)
                    break;
                udelay(1);
            }
        }
    }
    spin_unlock_irqrestore(&i2sdev->low_lock, flags);
}

#ifdef CONFIG_PM
void i2sbus_wait_for_stop_both(struct i2sbus_dev *i2sdev)
{
    struct pcm_info *pi;

    get_pcm_info(i2sdev, 0, &pi, NULL);
    i2sbus_wait_for_stop(i2sdev, pi);
    get_pcm_info(i2sdev, 1, &pi, NULL);
    i2sbus_wait_for_stop(i2sdev, pi);
}
#endif

static int i2sbus_hw_params(struct snd_pcm_substream *substream,
                struct snd_pcm_hw_params *params)
{
    return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
}

static inline int i2sbus_hw_free(struct snd_pcm_substream *substream, int in)
{
    struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
    struct pcm_info *pi;

    get_pcm_info(i2sdev, in, &pi, NULL);
    if (pi->dbdma_ring.stopping)
        i2sbus_wait_for_stop(i2sdev, pi);
    snd_pcm_lib_free_pages(substream);
    return 0;
}

static int i2sbus_playback_hw_free(struct snd_pcm_substream *substream)
{
    return i2sbus_hw_free(substream, 0);
}

static int i2sbus_record_hw_free(struct snd_pcm_substream *substream)
{
    return i2sbus_hw_free(substream, 1);
}

static int i2sbus_pcm_prepare(struct i2sbus_dev *i2sdev, int in)
{
    /* whee. Hard work now. The user has selected a bitrate
     * and bit format, so now we have to program our
     * I2S controller appropriately. */
    struct snd_pcm_runtime *runtime;
    struct dbdma_cmd *command;
    int i, periodsize, nperiods;
    dma_addr_t offset;
    struct bus_info bi;
    struct codec_info_item *cii;
    int sfr = 0;        /* serial format register */
    int dws = 0;        /* data word sizes reg */
    int input_16bit;
    struct pcm_info *pi, *other;
    int cnt;
    int result = 0;
    unsigned int cmd, stopaddr;

    mutex_lock(&i2sdev->lock);

    get_pcm_info(i2sdev, in, &pi, &other);

    if (pi->dbdma_ring.running) {
        result = -EBUSY;
        goto out_unlock;
    }
    if (pi->dbdma_ring.stopping)
        i2sbus_wait_for_stop(i2sdev, pi);

    if (!pi->substream || !pi->substream->runtime) {
        result = -EINVAL;
        goto out_unlock;
    }

    runtime = pi->substream->runtime;
    pi->active = 1;
    if (other->active &&
        ((i2sdev->format != runtime->format)
         || (i2sdev->rate != runtime->rate))) {
        result = -EINVAL;
        goto out_unlock;
    }

    i2sdev->format = runtime->format;
    i2sdev->rate = runtime->rate;

    periodsize = snd_pcm_lib_period_bytes(pi->substream);
    nperiods = pi->substream->runtime->periods;
    pi->current_period = 0;

    /* generate dbdma command ring first */
    command = pi->dbdma_ring.cmds;
    memset(command, 0, (nperiods + 2) * sizeof(struct dbdma_cmd));

    /* commands to DMA to/from the ring */
    /*
     * For input, we need to do a graceful stop; if we abort
     * the DMA, we end up with leftover bytes that corrupt
     * the next recording.  To do this we set the S0 status
     * bit and wait for the DMA controller to stop.  Each
     * command has a branch condition to
     * make it branch to a stop command if S0 is set.
     * On input we also need to wait for the S7 bit to be
     * set before turning off the DMA controller.
     * In fact we do the graceful stop for output as well.
     */
    offset = runtime->dma_addr;
    cmd = (in? INPUT_MORE: OUTPUT_MORE) | BR_IFSET | INTR_ALWAYS;
    stopaddr = pi->dbdma_ring.bus_cmd_start +
        (nperiods + 1) * sizeof(struct dbdma_cmd);
    for (i = 0; i < nperiods; i++, command++, offset += periodsize) {
        command->command = cpu_to_le16(cmd);
        command->cmd_dep = cpu_to_le32(stopaddr);
        command->phy_addr = cpu_to_le32(offset);
        command->req_count = cpu_to_le16(periodsize);
    }

    /* branch back to beginning of ring */
    command->command = cpu_to_le16(DBDMA_NOP | BR_ALWAYS);
    command->cmd_dep = cpu_to_le32(pi->dbdma_ring.bus_cmd_start);
    command++;

    /* set stop command */
    command->command = cpu_to_le16(DBDMA_STOP);

    /* ok, let's set the serial format and stuff */
    switch (runtime->format) {
    /* 16 bit formats */
    case SNDRV_PCM_FORMAT_S16_BE:
    case SNDRV_PCM_FORMAT_U16_BE:
        /* FIXME: if we add different bus factors we need to
         * do more here!! */
        bi.bus_factor = 0;
        list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
            bi.bus_factor = cii->codec->bus_factor;
            break;
        }
        if (!bi.bus_factor) {
            result = -ENODEV;
            goto out_unlock;
        }
        input_16bit = 1;
        break;
    case SNDRV_PCM_FORMAT_S32_BE:
    case SNDRV_PCM_FORMAT_U32_BE:
        /* force 64x bus speed, otherwise the data cannot be
         * transferred quickly enough! */
        bi.bus_factor = 64;
        input_16bit = 0;
        break;
    default:
        result = -EINVAL;
        goto out_unlock;
    }
    /* we assume all sysclocks are the same! */
    list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
        bi.sysclock_factor = cii->codec->sysclock_factor;
        break;
    }

    if (clock_and_divisors(bi.sysclock_factor,
                   bi.bus_factor,
                   runtime->rate,
                   &sfr) < 0) {
        result = -EINVAL;
        goto out_unlock;
    }
    switch (bi.bus_factor) {
    case 32:
        sfr |= I2S_SF_SERIAL_FORMAT_I2S_32X;
        break;
    case 64:
        sfr |= I2S_SF_SERIAL_FORMAT_I2S_64X;
        break;
    }
    /* FIXME: THIS ASSUMES MASTER ALL THE TIME */
    sfr |= I2S_SF_SCLK_MASTER;

    list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
        int err = 0;
        if (cii->codec->prepare)
            err = cii->codec->prepare(cii, &bi, pi->substream);
        if (err) {
            result = err;
            goto out_unlock;
        }
    }
    /* codecs are fine with it, so set our clocks */
    if (input_16bit)
        dws =   (2 << I2S_DWS_NUM_CHANNELS_IN_SHIFT) |
            (2 << I2S_DWS_NUM_CHANNELS_OUT_SHIFT) |
            I2S_DWS_DATA_IN_16BIT | I2S_DWS_DATA_OUT_16BIT;
    else
        dws =   (2 << I2S_DWS_NUM_CHANNELS_IN_SHIFT) |
            (2 << I2S_DWS_NUM_CHANNELS_OUT_SHIFT) |
            I2S_DWS_DATA_IN_24BIT | I2S_DWS_DATA_OUT_24BIT;

    /* early exit if already programmed correctly */
    /* not locking these is fine since we touch them only in this function */
    if (in_le32(&i2sdev->intfregs->serial_format) == sfr
     && in_le32(&i2sdev->intfregs->data_word_sizes) == dws)
        goto out_unlock;

    /* let's notify the codecs about clocks going away.
     * For now we only do mastering on the i2s cell... */
    list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
        if (cii->codec->switch_clock)
            cii->codec->switch_clock(cii, CLOCK_SWITCH_PREPARE_SLAVE);

    i2sbus_control_enable(i2sdev->control, i2sdev);
    i2sbus_control_cell(i2sdev->control, i2sdev, 1);

    out_le32(&i2sdev->intfregs->intr_ctl, I2S_PENDING_CLOCKS_STOPPED);

    i2sbus_control_clock(i2sdev->control, i2sdev, 0);

    msleep(1);

    /* wait for clock stopped. This can apparently take a while... */
    cnt = 100;
    while (cnt-- &&
        !(in_le32(&i2sdev->intfregs->intr_ctl) & I2S_PENDING_CLOCKS_STOPPED)) {
        msleep(5);
    }
    out_le32(&i2sdev->intfregs->intr_ctl, I2S_PENDING_CLOCKS_STOPPED);

    /* not locking these is fine since we touch them only in this function */
    out_le32(&i2sdev->intfregs->serial_format, sfr);
    out_le32(&i2sdev->intfregs->data_word_sizes, dws);

        i2sbus_control_enable(i2sdev->control, i2sdev);
        i2sbus_control_cell(i2sdev->control, i2sdev, 1);
        i2sbus_control_clock(i2sdev->control, i2sdev, 1);
    msleep(1);

    list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
        if (cii->codec->switch_clock)
            cii->codec->switch_clock(cii, CLOCK_SWITCH_SLAVE);

 out_unlock:
    mutex_unlock(&i2sdev->lock);
    return result;
}

#ifdef CONFIG_PM
void i2sbus_pcm_prepare_both(struct i2sbus_dev *i2sdev)
{
    i2sbus_pcm_prepare(i2sdev, 0);
    i2sbus_pcm_prepare(i2sdev, 1);
}
#endif

static int i2sbus_pcm_trigger(struct i2sbus_dev *i2sdev, int in, int cmd)
{
    struct codec_info_item *cii;
    struct pcm_info *pi;
    int result = 0;
    unsigned long flags;

    spin_lock_irqsave(&i2sdev->low_lock, flags);

    get_pcm_info(i2sdev, in, &pi, NULL);

    switch (cmd) {
    case SNDRV_PCM_TRIGGER_START:
    case SNDRV_PCM_TRIGGER_RESUME:
        if (pi->dbdma_ring.running) {
            result = -EALREADY;
            goto out_unlock;
        }
        list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
            if (cii->codec->start)
                cii->codec->start(cii, pi->substream);
        pi->dbdma_ring.running = 1;

        if (pi->dbdma_ring.stopping) {
            /* Clear the S0 bit, then see if we stopped yet */
            out_le32(&pi->dbdma->control, 1 << 16);
            if (in_le32(&pi->dbdma->status) & ACTIVE) {
                /* possible race here? */
                udelay(10);
                if (in_le32(&pi->dbdma->status) & ACTIVE) {
                    pi->dbdma_ring.stopping = 0;
                    goto out_unlock; /* keep running */
                }
            }
        }

        /* make sure RUN, PAUSE and S0 bits are cleared */
        out_le32(&pi->dbdma->control, (RUN | PAUSE | 1) << 16);

        /* set branch condition select register */
        out_le32(&pi->dbdma->br_sel, (1 << 16) | 1);

        /* write dma command buffer address to the dbdma chip */
        out_le32(&pi->dbdma->cmdptr, pi->dbdma_ring.bus_cmd_start);

        /* initialize the frame count and current period */
        pi->current_period = 0;
        pi->frame_count = in_le32(&i2sdev->intfregs->frame_count);

        /* set the DMA controller running */
        out_le32(&pi->dbdma->control, (RUN << 16) | RUN);

        /* off you go! */
        break;

    case SNDRV_PCM_TRIGGER_STOP:
    case SNDRV_PCM_TRIGGER_SUSPEND:
        if (!pi->dbdma_ring.running) {
            result = -EALREADY;
            goto out_unlock;
        }
        pi->dbdma_ring.running = 0;

        /* Set the S0 bit to make the DMA branch to the stop cmd */
        out_le32(&pi->dbdma->control, (1 << 16) | 1);
        pi->dbdma_ring.stopping = 1;

        list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
            if (cii->codec->stop)
                cii->codec->stop(cii, pi->substream);
        break;
    default:
        result = -EINVAL;
        goto out_unlock;
    }

 out_unlock:
    spin_unlock_irqrestore(&i2sdev->low_lock, flags);
    return result;
}

static snd_pcm_uframes_t i2sbus_pcm_pointer(struct i2sbus_dev *i2sdev, int in)
{
    struct pcm_info *pi;
    u32 fc;

    get_pcm_info(i2sdev, in, &pi, NULL);

    fc = in_le32(&i2sdev->intfregs->frame_count);
    fc = fc - pi->frame_count;

    if (fc >= pi->substream->runtime->buffer_size)
        fc %= pi->substream->runtime->buffer_size;
    return fc;
}

static inline void handle_interrupt(struct i2sbus_dev *i2sdev, int in)
{
    struct pcm_info *pi;
    u32 fc, nframes;
    u32 status;
    int timeout, i;
    int dma_stopped = 0;
    struct snd_pcm_runtime *runtime;

    spin_lock(&i2sdev->low_lock);
    get_pcm_info(i2sdev, in, &pi, NULL);
    if (!pi->dbdma_ring.running && !pi->dbdma_ring.stopping)
        goto out_unlock;

    i = pi->current_period;
    runtime = pi->substream->runtime;
    while (pi->dbdma_ring.cmds[i].xfer_status) {
        if (le16_to_cpu(pi->dbdma_ring.cmds[i].xfer_status) & BT)
            /*
             * BT is the branch taken bit.  If it took a branch
             * it is because we set the S0 bit to make it
             * branch to the stop command.
             */
            dma_stopped = 1;
        pi->dbdma_ring.cmds[i].xfer_status = 0;

        if (++i >= runtime->periods) {
            i = 0;
            pi->frame_count += runtime->buffer_size;
        }
        pi->current_period = i;

        /*
         * Check the frame count.  The DMA tends to get a bit
         * ahead of the frame counter, which confuses the core.
         */
        fc = in_le32(&i2sdev->intfregs->frame_count);
        nframes = i * runtime->period_size;
        if (fc < pi->frame_count + nframes)
            pi->frame_count = fc - nframes;
    }

    if (dma_stopped) {
        timeout = 1000;
        for (;;) {
            status = in_le32(&pi->dbdma->status);
            if (!(status & ACTIVE) && (!in || (status & 0x80)))
                break;
            if (--timeout <= 0) {
                printk(KERN_ERR "i2sbus: timed out "
                       "waiting for DMA to stop!\n");
                break;
            }
            udelay(1);
        }

        /* Turn off DMA controller, clear S0 bit */
        out_le32(&pi->dbdma->control, (RUN | PAUSE | 1) << 16);

        pi->dbdma_ring.stopping = 0;
        if (pi->stop_completion)
            complete(pi->stop_completion);
    }

    if (!pi->dbdma_ring.running)
        goto out_unlock;
    spin_unlock(&i2sdev->low_lock);
    /* may call _trigger again, hence needs to be unlocked */
    snd_pcm_period_elapsed(pi->substream);
    return;

 out_unlock:
    spin_unlock(&i2sdev->low_lock);
}

irqreturn_t i2sbus_tx_intr(int irq, void *devid)
{
    handle_interrupt((struct i2sbus_dev *)devid, 0);
    return IRQ_HANDLED;
}

irqreturn_t i2sbus_rx_intr(int irq, void *devid)
{
    handle_interrupt((struct i2sbus_dev *)devid, 1);
    return IRQ_HANDLED;
}

static int i2sbus_playback_open(struct snd_pcm_substream *substream)
{
    struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);

    if (!i2sdev)
        return -EINVAL;
    i2sdev->out.substream = substream;
    return i2sbus_pcm_open(i2sdev, 0);
}

static int i2sbus_playback_close(struct snd_pcm_substream *substream)
{
    struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
    int err;

    if (!i2sdev)
        return -EINVAL;
    if (i2sdev->out.substream != substream)
        return -EINVAL;
    err = i2sbus_pcm_close(i2sdev, 0);
    if (!err)
        i2sdev->out.substream = NULL;
    return err;
}

static int i2sbus_playback_prepare(struct snd_pcm_substream *substream)
{
    struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);

    if (!i2sdev)
        return -EINVAL;
    if (i2sdev->out.substream != substream)
        return -EINVAL;
    return i2sbus_pcm_prepare(i2sdev, 0);
}

static int i2sbus_playback_trigger(struct snd_pcm_substream *substream, int cmd)
{
    struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);

    if (!i2sdev)
        return -EINVAL;
    if (i2sdev->out.substream != substream)
        return -EINVAL;
    return i2sbus_pcm_trigger(i2sdev, 0, cmd);
}

static snd_pcm_uframes_t i2sbus_playback_pointer(struct snd_pcm_substream
                         *substream)
{
    struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);

    if (!i2sdev)
        return -EINVAL;
    if (i2sdev->out.substream != substream)
        return 0;
    return i2sbus_pcm_pointer(i2sdev, 0);
}

static struct snd_pcm_ops i2sbus_playback_ops = {
    .open =     i2sbus_playback_open,
    .close =    i2sbus_playback_close,
    .ioctl =    snd_pcm_lib_ioctl,
    .hw_params =    i2sbus_hw_params,
    .hw_free =  i2sbus_playback_hw_free,
    .prepare =  i2sbus_playback_prepare,
    .trigger =  i2sbus_playback_trigger,
    .pointer =  i2sbus_playback_pointer,
};

static int i2sbus_record_open(struct snd_pcm_substream *substream)
{
    struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);

    if (!i2sdev)
        return -EINVAL;
    i2sdev->in.substream = substream;
    return i2sbus_pcm_open(i2sdev, 1);
}

static int i2sbus_record_close(struct snd_pcm_substream *substream)
{
    struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
    int err;

    if (!i2sdev)
        return -EINVAL;
    if (i2sdev->in.substream != substream)
        return -EINVAL;
    err = i2sbus_pcm_close(i2sdev, 1);
    if (!err)
        i2sdev->in.substream = NULL;
    return err;
}

static int i2sbus_record_prepare(struct snd_pcm_substream *substream)
{
    struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);

    if (!i2sdev)
        return -EINVAL;
    if (i2sdev->in.substream != substream)
        return -EINVAL;
    return i2sbus_pcm_prepare(i2sdev, 1);
}

static int i2sbus_record_trigger(struct snd_pcm_substream *substream, int cmd)
{
    struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);

    if (!i2sdev)
        return -EINVAL;
    if (i2sdev->in.substream != substream)
        return -EINVAL;
    return i2sbus_pcm_trigger(i2sdev, 1, cmd);
}

static snd_pcm_uframes_t i2sbus_record_pointer(struct snd_pcm_substream
                           *substream)
{
    struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);

    if (!i2sdev)
        return -EINVAL;
    if (i2sdev->in.substream != substream)
        return 0;
    return i2sbus_pcm_pointer(i2sdev, 1);
}

static struct snd_pcm_ops i2sbus_record_ops = {
    .open =     i2sbus_record_open,
    .close =    i2sbus_record_close,
    .ioctl =    snd_pcm_lib_ioctl,
    .hw_params =    i2sbus_hw_params,
    .hw_free =  i2sbus_record_hw_free,
    .prepare =  i2sbus_record_prepare,
    .trigger =  i2sbus_record_trigger,
    .pointer =  i2sbus_record_pointer,
};

static void i2sbus_private_free(struct snd_pcm *pcm)
{
    struct i2sbus_dev *i2sdev = snd_pcm_chip(pcm);
    struct codec_info_item *p, *tmp;

    i2sdev->sound.pcm = NULL;
    i2sdev->out.created = 0;
    i2sdev->in.created = 0;
    list_for_each_entry_safe(p, tmp, &i2sdev->sound.codec_list, list) {
        printk(KERN_ERR "i2sbus: a codec didn't unregister!\n");
        list_del(&p->list);
        module_put(p->codec->owner);
        kfree(p);
    }
    soundbus_dev_put(&i2sdev->sound);
    module_put(THIS_MODULE);
}

int
i2sbus_attach_codec(struct soundbus_dev *dev, struct snd_card *card,
            struct codec_info *ci, void *data)
{
    int err, in = 0, out = 0;
    struct transfer_info *tmp;
    struct i2sbus_dev *i2sdev = soundbus_dev_to_i2sbus_dev(dev);
    struct codec_info_item *cii;

    if (!dev->pcmname || dev->pcmid == -1) {
        printk(KERN_ERR "i2sbus: pcm name and id must be set!\n");
        return -EINVAL;
    }

    list_for_each_entry(cii, &dev->codec_list, list) {
        if (cii->codec_data == data)
            return -EALREADY;
    }

    if (!ci->transfers || !ci->transfers->formats
        || !ci->transfers->rates || !ci->usable)
        return -EINVAL;

    /* we currently code the i2s transfer on the clock, and support only
     * 32 and 64 */
    if (ci->bus_factor != 32 && ci->bus_factor != 64)
        return -EINVAL;

    /* If you want to fix this, you need to keep track of what transport infos
     * are to be used, which codecs they belong to, and then fix all the
     * sysclock/busclock stuff above to depend on which is usable */
    list_for_each_entry(cii, &dev->codec_list, list) {
        if (cii->codec->sysclock_factor != ci->sysclock_factor) {
            printk(KERN_DEBUG
                   "cannot yet handle multiple different sysclocks!\n");
            return -EINVAL;
        }
        if (cii->codec->bus_factor != ci->bus_factor) {
            printk(KERN_DEBUG
                   "cannot yet handle multiple different bus clocks!\n");
            return -EINVAL;
        }
    }

    tmp = ci->transfers;
    while (tmp->formats && tmp->rates) {
        if (tmp->transfer_in)
            in = 1;
        else
            out = 1;
        tmp++;
    }

    cii = kzalloc(sizeof(struct codec_info_item), GFP_KERNEL);
    if (!cii) {
        printk(KERN_DEBUG "i2sbus: failed to allocate cii\n");
        return -ENOMEM;
    }

    /* use the private data to point to the codec info */
    cii->sdev = soundbus_dev_get(dev);
    cii->codec = ci;
    cii->codec_data = data;

    if (!cii->sdev) {
        printk(KERN_DEBUG
               "i2sbus: failed to get soundbus dev reference\n");
        err = -ENODEV;
        goto out_free_cii;
    }

    if (!try_module_get(THIS_MODULE)) {
        printk(KERN_DEBUG "i2sbus: failed to get module reference!\n");
        err = -EBUSY;
        goto out_put_sdev;
    }

    if (!try_module_get(ci->owner)) {
        printk(KERN_DEBUG
               "i2sbus: failed to get module reference to codec owner!\n");
        err = -EBUSY;
        goto out_put_this_module;
    }

    if (!dev->pcm) {
        err = snd_pcm_new(card, dev->pcmname, dev->pcmid, 0, 0,
                  &dev->pcm);
        if (err) {
            printk(KERN_DEBUG "i2sbus: failed to create pcm\n");
            goto out_put_ci_module;
        }
        dev->pcm->dev = &dev->ofdev.dev;
    }

    /* ALSA yet again sucks.
     * If it is ever fixed, remove this line. See below. */
    out = in = 1;

    if (!i2sdev->out.created && out) {
        if (dev->pcm->card != card) {
            /* eh? */
            printk(KERN_ERR
                   "Can't attach same bus to different cards!\n");
            err = -EINVAL;
            goto out_put_ci_module;
        }
        err = snd_pcm_new_stream(dev->pcm, SNDRV_PCM_STREAM_PLAYBACK, 1);
        if (err)
            goto out_put_ci_module;
        snd_pcm_set_ops(dev->pcm, SNDRV_PCM_STREAM_PLAYBACK,
                &i2sbus_playback_ops);
        i2sdev->out.created = 1;
    }

    if (!i2sdev->in.created && in) {
        if (dev->pcm->card != card) {
            printk(KERN_ERR
                   "Can't attach same bus to different cards!\n");
            err = -EINVAL;
            goto out_put_ci_module;
        }
        err = snd_pcm_new_stream(dev->pcm, SNDRV_PCM_STREAM_CAPTURE, 1);
        if (err)
            goto out_put_ci_module;
        snd_pcm_set_ops(dev->pcm, SNDRV_PCM_STREAM_CAPTURE,
                &i2sbus_record_ops);
        i2sdev->in.created = 1;
    }

    /* so we have to register the pcm after adding any substream
     * to it because alsa doesn't create the devices for the
     * substreams when we add them later.
     * Therefore, force in and out on both busses (above) and
     * register the pcm now instead of just after creating it.
     */
    err = snd_device_register(card, dev->pcm);
    if (err) {
        printk(KERN_ERR "i2sbus: error registering new pcm\n");
        goto out_put_ci_module;
    }
    /* no errors any more, so let's add this to our list */
    list_add(&cii->list, &dev->codec_list);

    dev->pcm->private_data = i2sdev;
    dev->pcm->private_free = i2sbus_private_free;

    /* well, we really should support scatter/gather DMA */
    snd_pcm_lib_preallocate_pages_for_all(
        dev->pcm, SNDRV_DMA_TYPE_DEV,
        snd_dma_pci_data(macio_get_pci_dev(i2sdev->macio)),
        64 * 1024, 64 * 1024);

    return 0;
 out_put_ci_module:
    module_put(ci->owner);
 out_put_this_module:
    module_put(THIS_MODULE);
 out_put_sdev:
    soundbus_dev_put(dev);
 out_free_cii:
    kfree(cii);
    return err;
}

void i2sbus_detach_codec(struct soundbus_dev *dev, void *data)
{
    struct codec_info_item *cii = NULL, *i;

    list_for_each_entry(i, &dev->codec_list, list) {
        if (i->codec_data == data) {
            cii = i;
            break;
        }
    }
    if (cii) {
        list_del(&cii->list);
        module_put(cii->codec->owner);
        kfree(cii);
    }
    /* no more codecs, but still a pcm? */
    if (list_empty(&dev->codec_list) && dev->pcm) {
        /* the actual cleanup is done by the callback above! */
        snd_device_free(dev->pcm->card, dev->pcm);
    }
}