aica.c

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/*
* This code is licenced under 
* the General Public Licence
* version 2
*
* Copyright Adrian McMenamin 2005, 2006, 2007
* <[email protected]>
* Requires firmware (BSD licenced) available from:
* http://linuxdc.cvs.sourceforge.net/linuxdc/linux-sh-dc/sound/oss/aica/firmware/
* or the maintainer
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as published by
* the Free Software Foundation.
*
* 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/init.h>
#include <linux/jiffies.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/wait.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/firmware.h>
#include <linux/timer.h>
#include <linux/delay.h>
#include <linux/workqueue.h>
#include <sound/core.h>
#include <sound/control.h>
#include <sound/pcm.h>
#include <sound/initval.h>
#include <sound/info.h>
#include <asm/io.h>
#include <asm/dma.h>
#include <mach/sysasic.h>
#include "aica.h"

MODULE_AUTHOR("Adrian McMenamin <[email protected]>");
MODULE_DESCRIPTION("Dreamcast AICA sound (pcm) driver");
MODULE_LICENSE("GPL");
MODULE_SUPPORTED_DEVICE("{{Yamaha/SEGA, AICA}}");
MODULE_FIRMWARE("aica_firmware.bin");

/* module parameters */
#define CARD_NAME "AICA"
static int index = -1;
static char *id;
static bool enable = 1;
module_param(index, int, 0444);
MODULE_PARM_DESC(index, "Index value for " CARD_NAME " soundcard.");
module_param(id, charp, 0444);
MODULE_PARM_DESC(id, "ID string for " CARD_NAME " soundcard.");
module_param(enable, bool, 0644);
MODULE_PARM_DESC(enable, "Enable " CARD_NAME " soundcard.");

/* Use workqueue */
static struct workqueue_struct *aica_queue;

/* Simple platform device */
static struct platform_device *pd;
static struct resource aica_memory_space[2] = {
    {
     .name = "AICA ARM CONTROL",
     .start = ARM_RESET_REGISTER,
     .flags = IORESOURCE_MEM,
     .end = ARM_RESET_REGISTER + 3,
     },
    {
     .name = "AICA Sound RAM",
     .start = SPU_MEMORY_BASE,
     .flags = IORESOURCE_MEM,
     .end = SPU_MEMORY_BASE + 0x200000 - 1,
     },
};

/* SPU specific functions */
/* spu_write_wait - wait for G2-SH FIFO to clear */
static void spu_write_wait(void)
{
    int time_count;
    time_count = 0;
    while (1) {
        if (!(readl(G2_FIFO) & 0x11))
            break;
        /* To ensure hardware failure doesn't wedge kernel */
        time_count++;
        if (time_count > 0x10000) {
            snd_printk
                ("WARNING: G2 FIFO appears to be blocked.\n");
            break;
        }
    }
}

/* spu_memset - write to memory in SPU address space */
static void spu_memset(u32 toi, u32 what, int length)
{
    int i;
    unsigned long flags;
    if (snd_BUG_ON(length % 4))
        return;
    for (i = 0; i < length; i++) {
        if (!(i % 8))
            spu_write_wait();
        local_irq_save(flags);
        writel(what, toi + SPU_MEMORY_BASE);
        local_irq_restore(flags);
        toi++;
    }
}

/* spu_memload - write to SPU address space */
static void spu_memload(u32 toi, void *from, int length)
{
    unsigned long flags;
    u32 *froml = from;
    u32 __iomem *to = (u32 __iomem *) (SPU_MEMORY_BASE + toi);
    int i;
    u32 val;
    length = DIV_ROUND_UP(length, 4);
    spu_write_wait();
    for (i = 0; i < length; i++) {
        if (!(i % 8))
            spu_write_wait();
        val = *froml;
        local_irq_save(flags);
        writel(val, to);
        local_irq_restore(flags);
        froml++;
        to++;
    }
}

/* spu_disable - set spu registers to stop sound output */
static void spu_disable(void)
{
    int i;
    unsigned long flags;
    u32 regval;
    spu_write_wait();
    regval = readl(ARM_RESET_REGISTER);
    regval |= 1;
    spu_write_wait();
    local_irq_save(flags);
    writel(regval, ARM_RESET_REGISTER);
    local_irq_restore(flags);
    for (i = 0; i < 64; i++) {
        spu_write_wait();
        regval = readl(SPU_REGISTER_BASE + (i * 0x80));
        regval = (regval & ~0x4000) | 0x8000;
        spu_write_wait();
        local_irq_save(flags);
        writel(regval, SPU_REGISTER_BASE + (i * 0x80));
        local_irq_restore(flags);
    }
}

/* spu_enable - set spu registers to enable sound output */
static void spu_enable(void)
{
    unsigned long flags;
    u32 regval = readl(ARM_RESET_REGISTER);
    regval &= ~1;
    spu_write_wait();
    local_irq_save(flags);
    writel(regval, ARM_RESET_REGISTER);
    local_irq_restore(flags);
}

/* 
 * Halt the sound processor, clear the memory,
 * load some default ARM7 code, and then restart ARM7
*/
static void spu_reset(void)
{
    unsigned long flags;
    spu_disable();
    spu_memset(0, 0, 0x200000 / 4);
    /* Put ARM7 in endless loop */
    local_irq_save(flags);
    __raw_writel(0xea000002, SPU_MEMORY_BASE);
    local_irq_restore(flags);
    spu_enable();
}

/* aica_chn_start - write to spu to start playback */
static void aica_chn_start(void)
{
    unsigned long flags;
    spu_write_wait();
    local_irq_save(flags);
    writel(AICA_CMD_KICK | AICA_CMD_START, (u32 *) AICA_CONTROL_POINT);
    local_irq_restore(flags);
}

/* aica_chn_halt - write to spu to halt playback */
static void aica_chn_halt(void)
{
    unsigned long flags;
    spu_write_wait();
    local_irq_save(flags);
    writel(AICA_CMD_KICK | AICA_CMD_STOP, (u32 *) AICA_CONTROL_POINT);
    local_irq_restore(flags);
}

/* ALSA code below */
static struct snd_pcm_hardware snd_pcm_aica_playback_hw = {
    .info = (SNDRV_PCM_INFO_NONINTERLEAVED),
    .formats =
        (SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_LE |
         SNDRV_PCM_FMTBIT_IMA_ADPCM),
    .rates = SNDRV_PCM_RATE_8000_48000,
    .rate_min = 8000,
    .rate_max = 48000,
    .channels_min = 1,
    .channels_max = 2,
    .buffer_bytes_max = AICA_BUFFER_SIZE,
    .period_bytes_min = AICA_PERIOD_SIZE,
    .period_bytes_max = AICA_PERIOD_SIZE,
    .periods_min = AICA_PERIOD_NUMBER,
    .periods_max = AICA_PERIOD_NUMBER,
};

static int aica_dma_transfer(int channels, int buffer_size,
                 struct snd_pcm_substream *substream)
{
    int q, err, period_offset;
    struct snd_card_aica *dreamcastcard;
    struct snd_pcm_runtime *runtime;
    unsigned long flags;
    err = 0;
    dreamcastcard = substream->pcm->private_data;
    period_offset = dreamcastcard->clicks;
    period_offset %= (AICA_PERIOD_NUMBER / channels);
    runtime = substream->runtime;
    for (q = 0; q < channels; q++) {
        local_irq_save(flags);
        err = dma_xfer(AICA_DMA_CHANNEL,
                   (unsigned long) (runtime->dma_area +
                        (AICA_BUFFER_SIZE * q) /
                        channels +
                        AICA_PERIOD_SIZE *
                        period_offset),
                   AICA_CHANNEL0_OFFSET + q * CHANNEL_OFFSET +
                   AICA_PERIOD_SIZE * period_offset,
                   buffer_size / channels, AICA_DMA_MODE);
        if (unlikely(err < 0)) {
            local_irq_restore(flags);
            break;
        }
        dma_wait_for_completion(AICA_DMA_CHANNEL);
        local_irq_restore(flags);
    }
    return err;
}

static void startup_aica(struct snd_card_aica *dreamcastcard)
{
    spu_memload(AICA_CHANNEL0_CONTROL_OFFSET,
            dreamcastcard->channel, sizeof(struct aica_channel));
    aica_chn_start();
}

static void run_spu_dma(struct work_struct *work)
{
    int buffer_size;
    struct snd_pcm_runtime *runtime;
    struct snd_card_aica *dreamcastcard;
    dreamcastcard =
        container_of(work, struct snd_card_aica, spu_dma_work);
    runtime = dreamcastcard->substream->runtime;
    if (unlikely(dreamcastcard->dma_check == 0)) {
        buffer_size =
            frames_to_bytes(runtime, runtime->buffer_size);
        if (runtime->channels > 1)
            dreamcastcard->channel->flags |= 0x01;
        aica_dma_transfer(runtime->channels, buffer_size,
                  dreamcastcard->substream);
        startup_aica(dreamcastcard);
        dreamcastcard->clicks =
            buffer_size / (AICA_PERIOD_SIZE * runtime->channels);
        return;
    } else {
        aica_dma_transfer(runtime->channels,
                  AICA_PERIOD_SIZE * runtime->channels,
                  dreamcastcard->substream);
        snd_pcm_period_elapsed(dreamcastcard->substream);
        dreamcastcard->clicks++;
        if (unlikely(dreamcastcard->clicks >= AICA_PERIOD_NUMBER))
            dreamcastcard->clicks %= AICA_PERIOD_NUMBER;
        mod_timer(&dreamcastcard->timer, jiffies + 1);
    }
}

static void aica_period_elapsed(unsigned long timer_var)
{
    /*timer function - so cannot sleep */
    int play_period;
    struct snd_pcm_runtime *runtime;
    struct snd_pcm_substream *substream;
    struct snd_card_aica *dreamcastcard;
    substream = (struct snd_pcm_substream *) timer_var;
    runtime = substream->runtime;
    dreamcastcard = substream->pcm->private_data;
    /* Have we played out an additional period? */
    play_period =
        frames_to_bytes(runtime,
                readl
                (AICA_CONTROL_CHANNEL_SAMPLE_NUMBER)) /
        AICA_PERIOD_SIZE;
    if (play_period == dreamcastcard->current_period) {
        /* reschedule the timer */
        mod_timer(&(dreamcastcard->timer), jiffies + 1);
        return;
    }
    if (runtime->channels > 1)
        dreamcastcard->current_period = play_period;
    if (unlikely(dreamcastcard->dma_check == 0))
        dreamcastcard->dma_check = 1;
    queue_work(aica_queue, &(dreamcastcard->spu_dma_work));
}

static void spu_begin_dma(struct snd_pcm_substream *substream)
{
    struct snd_card_aica *dreamcastcard;
    struct snd_pcm_runtime *runtime;
    runtime = substream->runtime;
    dreamcastcard = substream->pcm->private_data;
    /*get the queue to do the work */
    queue_work(aica_queue, &(dreamcastcard->spu_dma_work));
    /* Timer may already be running */
    if (unlikely(dreamcastcard->timer.data)) {
        mod_timer(&dreamcastcard->timer, jiffies + 4);
        return;
    }
    init_timer(&(dreamcastcard->timer));
    dreamcastcard->timer.data = (unsigned long) substream;
    dreamcastcard->timer.function = aica_period_elapsed;
    dreamcastcard->timer.expires = jiffies + 4;
    add_timer(&(dreamcastcard->timer));
}

static int snd_aicapcm_pcm_open(struct snd_pcm_substream
                *substream)
{
    struct snd_pcm_runtime *runtime;
    struct aica_channel *channel;
    struct snd_card_aica *dreamcastcard;
    if (!enable)
        return -ENOENT;
    dreamcastcard = substream->pcm->private_data;
    channel = kmalloc(sizeof(struct aica_channel), GFP_KERNEL);
    if (!channel)
        return -ENOMEM;
    /* set defaults for channel */
    channel->sfmt = SM_8BIT;
    channel->cmd = AICA_CMD_START;
    channel->vol = dreamcastcard->master_volume;
    channel->pan = 0x80;
    channel->pos = 0;
    channel->flags = 0; /* default to mono */
    dreamcastcard->channel = channel;
    runtime = substream->runtime;
    runtime->hw = snd_pcm_aica_playback_hw;
    spu_enable();
    dreamcastcard->clicks = 0;
    dreamcastcard->current_period = 0;
    dreamcastcard->dma_check = 0;
    return 0;
}

static int snd_aicapcm_pcm_close(struct snd_pcm_substream
                 *substream)
{
    struct snd_card_aica *dreamcastcard = substream->pcm->private_data;
    flush_workqueue(aica_queue);
    if (dreamcastcard->timer.data)
        del_timer(&dreamcastcard->timer);
    kfree(dreamcastcard->channel);
    spu_disable();
    return 0;
}

static int snd_aicapcm_pcm_hw_free(struct snd_pcm_substream
                   *substream)
{
    /* Free the DMA buffer */
    return snd_pcm_lib_free_pages(substream);
}

static int snd_aicapcm_pcm_hw_params(struct snd_pcm_substream
                     *substream, struct snd_pcm_hw_params
                     *hw_params)
{
    /* Allocate a DMA buffer using ALSA built-ins */
    return
        snd_pcm_lib_malloc_pages(substream,
                     params_buffer_bytes(hw_params));
}

static int snd_aicapcm_pcm_prepare(struct snd_pcm_substream
                   *substream)
{
    struct snd_card_aica *dreamcastcard = substream->pcm->private_data;
    if ((substream->runtime)->format == SNDRV_PCM_FORMAT_S16_LE)
        dreamcastcard->channel->sfmt = SM_16BIT;
    dreamcastcard->channel->freq = substream->runtime->rate;
    dreamcastcard->substream = substream;
    return 0;
}

static int snd_aicapcm_pcm_trigger(struct snd_pcm_substream
                   *substream, int cmd)
{
    switch (cmd) {
    case SNDRV_PCM_TRIGGER_START:
        spu_begin_dma(substream);
        break;
    case SNDRV_PCM_TRIGGER_STOP:
        aica_chn_halt();
        break;
    default:
        return -EINVAL;
    }
    return 0;
}

static unsigned long snd_aicapcm_pcm_pointer(struct snd_pcm_substream
                         *substream)
{
    return readl(AICA_CONTROL_CHANNEL_SAMPLE_NUMBER);
}

static struct snd_pcm_ops snd_aicapcm_playback_ops = {
    .open = snd_aicapcm_pcm_open,
    .close = snd_aicapcm_pcm_close,
    .ioctl = snd_pcm_lib_ioctl,
    .hw_params = snd_aicapcm_pcm_hw_params,
    .hw_free = snd_aicapcm_pcm_hw_free,
    .prepare = snd_aicapcm_pcm_prepare,
    .trigger = snd_aicapcm_pcm_trigger,
    .pointer = snd_aicapcm_pcm_pointer,
};

/* TO DO: set up to handle more than one pcm instance */
static int __init snd_aicapcmchip(struct snd_card_aica
                  *dreamcastcard, int pcm_index)
{
    struct snd_pcm *pcm;
    int err;
    /* AICA has no capture ability */
    err =
        snd_pcm_new(dreamcastcard->card, "AICA PCM", pcm_index, 1, 0,
            &pcm);
    if (unlikely(err < 0))
        return err;
    pcm->private_data = dreamcastcard;
    strcpy(pcm->name, "AICA PCM");
    snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
            &snd_aicapcm_playback_ops);
    /* Allocate the DMA buffers */
    err =
        snd_pcm_lib_preallocate_pages_for_all(pcm,
                          SNDRV_DMA_TYPE_CONTINUOUS,
                          snd_dma_continuous_data
                          (GFP_KERNEL),
                          AICA_BUFFER_SIZE,
                          AICA_BUFFER_SIZE);
    return err;
}

/* Mixer controls */
#define aica_pcmswitch_info     snd_ctl_boolean_mono_info

static int aica_pcmswitch_get(struct snd_kcontrol *kcontrol,
                  struct snd_ctl_elem_value *ucontrol)
{
    ucontrol->value.integer.value[0] = 1;   /* TO DO: Fix me */
    return 0;
}

static int aica_pcmswitch_put(struct snd_kcontrol *kcontrol,
                  struct snd_ctl_elem_value *ucontrol)
{
    if (ucontrol->value.integer.value[0] == 1)
        return 0;   /* TO DO: Fix me */
    else
        aica_chn_halt();
    return 0;
}

static int aica_pcmvolume_info(struct snd_kcontrol *kcontrol,
                   struct snd_ctl_elem_info *uinfo)
{
    uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
    uinfo->count = 1;
    uinfo->value.integer.min = 0;
    uinfo->value.integer.max = 0xFF;
    return 0;
}

static int aica_pcmvolume_get(struct snd_kcontrol *kcontrol,
                  struct snd_ctl_elem_value *ucontrol)
{
    struct snd_card_aica *dreamcastcard;
    dreamcastcard = kcontrol->private_data;
    if (unlikely(!dreamcastcard->channel))
        return -ETXTBSY;    /* we've not yet been set up */
    ucontrol->value.integer.value[0] = dreamcastcard->channel->vol;
    return 0;
}

static int aica_pcmvolume_put(struct snd_kcontrol *kcontrol,
                  struct snd_ctl_elem_value *ucontrol)
{
    struct snd_card_aica *dreamcastcard;
    unsigned int vol;
    dreamcastcard = kcontrol->private_data;
    if (unlikely(!dreamcastcard->channel))
        return -ETXTBSY;
    vol = ucontrol->value.integer.value[0];
    if (vol > 0xff)
        return -EINVAL;
    if (unlikely(dreamcastcard->channel->vol == vol))
        return 0;
    dreamcastcard->channel->vol = ucontrol->value.integer.value[0];
    dreamcastcard->master_volume = ucontrol->value.integer.value[0];
    spu_memload(AICA_CHANNEL0_CONTROL_OFFSET,
            dreamcastcard->channel, sizeof(struct aica_channel));
    return 1;
}

static struct snd_kcontrol_new snd_aica_pcmswitch_control __devinitdata = {
    .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
    .name = "PCM Playback Switch",
    .index = 0,
    .info = aica_pcmswitch_info,
    .get = aica_pcmswitch_get,
    .put = aica_pcmswitch_put
};

static struct snd_kcontrol_new snd_aica_pcmvolume_control __devinitdata = {
    .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
    .name = "PCM Playback Volume",
    .index = 0,
    .info = aica_pcmvolume_info,
    .get = aica_pcmvolume_get,
    .put = aica_pcmvolume_put
};

static int load_aica_firmware(void)
{
    int err;
    const struct firmware *fw_entry;
    spu_reset();
    err = request_firmware(&fw_entry, "aica_firmware.bin", &pd->dev);
    if (unlikely(err))
        return err;
    /* write firmware into memory */
    spu_disable();
    spu_memload(0, fw_entry->data, fw_entry->size);
    spu_enable();
    release_firmware(fw_entry);
    return err;
}

static int __devinit add_aicamixer_controls(struct snd_card_aica
                        *dreamcastcard)
{
    int err;
    err = snd_ctl_add
        (dreamcastcard->card,
         snd_ctl_new1(&snd_aica_pcmvolume_control, dreamcastcard));
    if (unlikely(err < 0))
        return err;
    err = snd_ctl_add
        (dreamcastcard->card,
         snd_ctl_new1(&snd_aica_pcmswitch_control, dreamcastcard));
    if (unlikely(err < 0))
        return err;
    return 0;
}

static int __devexit snd_aica_remove(struct platform_device *devptr)
{
    struct snd_card_aica *dreamcastcard;
    dreamcastcard = platform_get_drvdata(devptr);
    if (unlikely(!dreamcastcard))
        return -ENODEV;
    snd_card_free(dreamcastcard->card);
    kfree(dreamcastcard);
    platform_set_drvdata(devptr, NULL);
    return 0;
}

static int __devinit snd_aica_probe(struct platform_device *devptr)
{
    int err;
    struct snd_card_aica *dreamcastcard;
    dreamcastcard = kmalloc(sizeof(struct snd_card_aica), GFP_KERNEL);
    if (unlikely(!dreamcastcard))
        return -ENOMEM;
    err = snd_card_create(index, SND_AICA_DRIVER, THIS_MODULE, 0,
                  &dreamcastcard->card);
    if (unlikely(err < 0)) {
        kfree(dreamcastcard);
        return err;
    }
    strcpy(dreamcastcard->card->driver, "snd_aica");
    strcpy(dreamcastcard->card->shortname, SND_AICA_DRIVER);
    strcpy(dreamcastcard->card->longname,
           "Yamaha AICA Super Intelligent Sound Processor for SEGA Dreamcast");
    /* Prepare to use the queue */
    INIT_WORK(&(dreamcastcard->spu_dma_work), run_spu_dma);
    /* Load the PCM 'chip' */
    err = snd_aicapcmchip(dreamcastcard, 0);
    if (unlikely(err < 0))
        goto freedreamcast;
    snd_card_set_dev(dreamcastcard->card, &devptr->dev);
    dreamcastcard->timer.data = 0;
    dreamcastcard->channel = NULL;
    /* Add basic controls */
    err = add_aicamixer_controls(dreamcastcard);
    if (unlikely(err < 0))
        goto freedreamcast;
    /* Register the card with ALSA subsystem */
    err = snd_card_register(dreamcastcard->card);
    if (unlikely(err < 0))
        goto freedreamcast;
    platform_set_drvdata(devptr, dreamcastcard);
    aica_queue = create_workqueue(CARD_NAME);
    if (unlikely(!aica_queue))
        goto freedreamcast;
    snd_printk
        ("ALSA Driver for Yamaha AICA Super Intelligent Sound Processor\n");
    return 0;
      freedreamcast:
    snd_card_free(dreamcastcard->card);
    kfree(dreamcastcard);
    return err;
}

static struct platform_driver snd_aica_driver = {
    .probe = snd_aica_probe,
    .remove = __devexit_p(snd_aica_remove),
    .driver = {
        .name = SND_AICA_DRIVER,
        .owner  = THIS_MODULE,
    },
};

static int __init aica_init(void)
{
    int err;
    err = platform_driver_register(&snd_aica_driver);
    if (unlikely(err < 0))
        return err;
    pd = platform_device_register_simple(SND_AICA_DRIVER, -1,
                         aica_memory_space, 2);
    if (IS_ERR(pd)) {
        platform_driver_unregister(&snd_aica_driver);
        return PTR_ERR(pd);
    }
    /* Load the firmware */
    return load_aica_firmware();
}

static void __exit aica_exit(void)
{
    /* Destroy the aica kernel thread            *
     * being extra cautious to check if it exists*/
    if (likely(aica_queue))
        destroy_workqueue(aica_queue);
    platform_device_unregister(pd);
    platform_driver_unregister(&snd_aica_driver);
    /* Kill any sound still playing and reset ARM7 to safe state */
    spu_reset();
}

module_init(aica_init);
module_exit(aica_exit);