core.c

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/*
 * i2sbus driver
 *
 * Copyright 2006-2008 Johannes Berg <[email protected]>
 *
 * GPL v2, can be found in COPYING.
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/dma-mapping.h>

#include <sound/core.h>

#include <asm/macio.h>
#include <asm/dbdma.h>

#include "../soundbus.h"
#include "i2sbus.h"

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Johannes Berg <[email protected]>");
MODULE_DESCRIPTION("Apple Soundbus: I2S support");

static int force;
module_param(force, int, 0444);
MODULE_PARM_DESC(force, "Force loading i2sbus even when"
            " no layout-id property is present");

static struct of_device_id i2sbus_match[] = {
    { .name = "i2s" },
    { }
};

MODULE_DEVICE_TABLE(of, i2sbus_match);

static int alloc_dbdma_descriptor_ring(struct i2sbus_dev *i2sdev,
                       struct dbdma_command_mem *r,
                       int numcmds)
{
    /* one more for rounding, one for branch back, one for stop command */
    r->size = (numcmds + 3) * sizeof(struct dbdma_cmd);
    /* We use the PCI APIs for now until the generic one gets fixed
     * enough or until we get some macio-specific versions
     */
    r->space = dma_alloc_coherent(
            &macio_get_pci_dev(i2sdev->macio)->dev,
            r->size,
            &r->bus_addr,
            GFP_KERNEL);

    if (!r->space) return -ENOMEM;

    memset(r->space, 0, r->size);
    r->cmds = (void*)DBDMA_ALIGN(r->space);
    r->bus_cmd_start = r->bus_addr +
               (dma_addr_t)((char*)r->cmds - (char*)r->space);

    return 0;
}

static void free_dbdma_descriptor_ring(struct i2sbus_dev *i2sdev,
                       struct dbdma_command_mem *r)
{
    if (!r->space) return;

    dma_free_coherent(&macio_get_pci_dev(i2sdev->macio)->dev,
                r->size, r->space, r->bus_addr);
}

static void i2sbus_release_dev(struct device *dev)
{
    struct i2sbus_dev *i2sdev;
    int i;

    i2sdev = container_of(dev, struct i2sbus_dev, sound.ofdev.dev);

    if (i2sdev->intfregs) iounmap(i2sdev->intfregs);
    if (i2sdev->out.dbdma) iounmap(i2sdev->out.dbdma);
    if (i2sdev->in.dbdma) iounmap(i2sdev->in.dbdma);
    for (i = aoa_resource_i2smmio; i <= aoa_resource_rxdbdma; i++)
        if (i2sdev->allocated_resource[i])
            release_and_free_resource(i2sdev->allocated_resource[i]);
    free_dbdma_descriptor_ring(i2sdev, &i2sdev->out.dbdma_ring);
    free_dbdma_descriptor_ring(i2sdev, &i2sdev->in.dbdma_ring);
    for (i = aoa_resource_i2smmio; i <= aoa_resource_rxdbdma; i++)
        free_irq(i2sdev->interrupts[i], i2sdev);
    i2sbus_control_remove_dev(i2sdev->control, i2sdev);
    mutex_destroy(&i2sdev->lock);
    kfree(i2sdev);
}

static irqreturn_t i2sbus_bus_intr(int irq, void *devid)
{
    struct i2sbus_dev *dev = devid;
    u32 intreg;

    spin_lock(&dev->low_lock);
    intreg = in_le32(&dev->intfregs->intr_ctl);

    /* acknowledge interrupt reasons */
    out_le32(&dev->intfregs->intr_ctl, intreg);

    spin_unlock(&dev->low_lock);

    return IRQ_HANDLED;
}


/*
 * XXX FIXME: We test the layout_id's here to get the proper way of
 * mapping in various registers, thanks to bugs in Apple device-trees.
 * We could instead key off the machine model and the name of the i2s
 * node (i2s-a). This we'll do when we move it all to macio_asic.c
 * and have that export items for each sub-node too.
 */
static int i2sbus_get_and_fixup_rsrc(struct device_node *np, int index,
                     int layout, struct resource *res)
{
    struct device_node *parent;
    int pindex, rc = -ENXIO;
    const u32 *reg;

    /* Machines with layout 76 and 36 (K2 based) have a weird device
     * tree what we need to special case.
     * Normal machines just fetch the resource from the i2s-X node.
     * Darwin further divides normal machines into old and new layouts
     * with a subtely different code path but that doesn't seem necessary
     * in practice, they just bloated it. In addition, even on our K2
     * case the i2s-modem node, if we ever want to handle it, uses the
     * normal layout
     */
    if (layout != 76 && layout != 36)
        return of_address_to_resource(np, index, res);

    parent = of_get_parent(np);
    pindex = (index == aoa_resource_i2smmio) ? 0 : 1;
    rc = of_address_to_resource(parent, pindex, res);
    if (rc)
        goto bail;
    reg = of_get_property(np, "reg", NULL);
    if (reg == NULL) {
        rc = -ENXIO;
        goto bail;
    }
    res->start += reg[index * 2];
    res->end = res->start + reg[index * 2 + 1] - 1;
 bail:
    of_node_put(parent);
    return rc;
}

/* FIXME: look at device node refcounting */
static int i2sbus_add_dev(struct macio_dev *macio,
              struct i2sbus_control *control,
              struct device_node *np)
{
    struct i2sbus_dev *dev;
    struct device_node *child = NULL, *sound = NULL;
    struct resource *r;
    int i, layout = 0, rlen, ok = force;
    static const char *rnames[] = { "i2sbus: %s (control)",
                    "i2sbus: %s (tx)",
                    "i2sbus: %s (rx)" };
    static irq_handler_t ints[] = {
        i2sbus_bus_intr,
        i2sbus_tx_intr,
        i2sbus_rx_intr
    };

    if (strlen(np->name) != 5)
        return 0;
    if (strncmp(np->name, "i2s-", 4))
        return 0;

    dev = kzalloc(sizeof(struct i2sbus_dev), GFP_KERNEL);
    if (!dev)
        return 0;

    i = 0;
    while ((child = of_get_next_child(np, child))) {
        if (strcmp(child->name, "sound") == 0) {
            i++;
            sound = child;
        }
    }
    if (i == 1) {
        const u32 *id = of_get_property(sound, "layout-id", NULL);

        if (id) {
            layout = *id;
            snprintf(dev->sound.modalias, 32,
                 "sound-layout-%d", layout);
            ok = 1;
        } else {
            id = of_get_property(sound, "device-id", NULL);
            /*
             * We probably cannot handle all device-id machines,
             * so restrict to those we do handle for now.
             */
            if (id && (*id == 22 || *id == 14 || *id == 35)) {
                snprintf(dev->sound.modalias, 32,
                     "aoa-device-id-%d", *id);
                ok = 1;
                layout = -1;
            }
        }
    }
    /* for the time being, until we can handle non-layout-id
     * things in some fabric, refuse to attach if there is no
     * layout-id property or we haven't been forced to attach.
     * When there are two i2s busses and only one has a layout-id,
     * then this depends on the order, but that isn't important
     * either as the second one in that case is just a modem. */
    if (!ok) {
        kfree(dev);
        return -ENODEV;
    }

    mutex_init(&dev->lock);
    spin_lock_init(&dev->low_lock);
    dev->sound.ofdev.archdata.dma_mask = macio->ofdev.archdata.dma_mask;
    dev->sound.ofdev.dev.of_node = np;
    dev->sound.ofdev.dev.dma_mask = &dev->sound.ofdev.archdata.dma_mask;
    dev->sound.ofdev.dev.parent = &macio->ofdev.dev;
    dev->sound.ofdev.dev.release = i2sbus_release_dev;
    dev->sound.attach_codec = i2sbus_attach_codec;
    dev->sound.detach_codec = i2sbus_detach_codec;
    dev->sound.pcmid = -1;
    dev->macio = macio;
    dev->control = control;
    dev->bus_number = np->name[4] - 'a';
    INIT_LIST_HEAD(&dev->sound.codec_list);

    for (i = aoa_resource_i2smmio; i <= aoa_resource_rxdbdma; i++) {
        dev->interrupts[i] = -1;
        snprintf(dev->rnames[i], sizeof(dev->rnames[i]),
             rnames[i], np->name);
    }
    for (i = aoa_resource_i2smmio; i <= aoa_resource_rxdbdma; i++) {
        int irq = irq_of_parse_and_map(np, i);
        if (request_irq(irq, ints[i], 0, dev->rnames[i], dev))
            goto err;
        dev->interrupts[i] = irq;
    }


    /* Resource handling is problematic as some device-trees contain
     * useless crap (ugh ugh ugh). We work around that here by calling
     * specific functions for calculating the appropriate resources.
     *
     * This will all be moved to macio_asic.c at one point
     */
    for (i = aoa_resource_i2smmio; i <= aoa_resource_rxdbdma; i++) {
        if (i2sbus_get_and_fixup_rsrc(np,i,layout,&dev->resources[i]))
            goto err;
        /* If only we could use our resource dev->resources[i]...
         * but request_resource doesn't know about parents and
         * contained resources...
         */
        dev->allocated_resource[i] =
            request_mem_region(dev->resources[i].start,
                       resource_size(&dev->resources[i]),
                       dev->rnames[i]);
        if (!dev->allocated_resource[i]) {
            printk(KERN_ERR "i2sbus: failed to claim resource %d!\n", i);
            goto err;
        }
    }

    r = &dev->resources[aoa_resource_i2smmio];
    rlen = resource_size(r);
    if (rlen < sizeof(struct i2s_interface_regs))
        goto err;
    dev->intfregs = ioremap(r->start, rlen);

    r = &dev->resources[aoa_resource_txdbdma];
    rlen = resource_size(r);
    if (rlen < sizeof(struct dbdma_regs))
        goto err;
    dev->out.dbdma = ioremap(r->start, rlen);

    r = &dev->resources[aoa_resource_rxdbdma];
    rlen = resource_size(r);
    if (rlen < sizeof(struct dbdma_regs))
        goto err;
    dev->in.dbdma = ioremap(r->start, rlen);

    if (!dev->intfregs || !dev->out.dbdma || !dev->in.dbdma)
        goto err;

    if (alloc_dbdma_descriptor_ring(dev, &dev->out.dbdma_ring,
                    MAX_DBDMA_COMMANDS))
        goto err;
    if (alloc_dbdma_descriptor_ring(dev, &dev->in.dbdma_ring,
                    MAX_DBDMA_COMMANDS))
        goto err;

    if (i2sbus_control_add_dev(dev->control, dev)) {
        printk(KERN_ERR "i2sbus: control layer didn't like bus\n");
        goto err;
    }

    if (soundbus_add_one(&dev->sound)) {
        printk(KERN_DEBUG "i2sbus: device registration error!\n");
        goto err;
    }

    /* enable this cell */
    i2sbus_control_cell(dev->control, dev, 1);
    i2sbus_control_enable(dev->control, dev);
    i2sbus_control_clock(dev->control, dev, 1);

    return 1;
 err:
    for (i=0;i<3;i++)
        if (dev->interrupts[i] != -1)
            free_irq(dev->interrupts[i], dev);
    free_dbdma_descriptor_ring(dev, &dev->out.dbdma_ring);
    free_dbdma_descriptor_ring(dev, &dev->in.dbdma_ring);
    if (dev->intfregs) iounmap(dev->intfregs);
    if (dev->out.dbdma) iounmap(dev->out.dbdma);
    if (dev->in.dbdma) iounmap(dev->in.dbdma);
    for (i=0;i<3;i++)
        if (dev->allocated_resource[i])
            release_and_free_resource(dev->allocated_resource[i]);
    mutex_destroy(&dev->lock);
    kfree(dev);
    return 0;
}

static int i2sbus_probe(struct macio_dev* dev, const struct of_device_id *match)
{
    struct device_node *np = NULL;
    int got = 0, err;
    struct i2sbus_control *control = NULL;

    err = i2sbus_control_init(dev, &control);
    if (err)
        return err;
    if (!control) {
        printk(KERN_ERR "i2sbus_control_init API breakage\n");
        return -ENODEV;
    }

    while ((np = of_get_next_child(dev->ofdev.dev.of_node, np))) {
        if (of_device_is_compatible(np, "i2sbus") ||
            of_device_is_compatible(np, "i2s-modem")) {
            got += i2sbus_add_dev(dev, control, np);
        }
    }

    if (!got) {
        /* found none, clean up */
        i2sbus_control_destroy(control);
        return -ENODEV;
    }

    dev_set_drvdata(&dev->ofdev.dev, control);

    return 0;
}

static int i2sbus_remove(struct macio_dev* dev)
{
    struct i2sbus_control *control = dev_get_drvdata(&dev->ofdev.dev);
    struct i2sbus_dev *i2sdev, *tmp;

    list_for_each_entry_safe(i2sdev, tmp, &control->list, item)
        soundbus_remove_one(&i2sdev->sound);

    return 0;
}

#ifdef CONFIG_PM
static int i2sbus_suspend(struct macio_dev* dev, pm_message_t state)
{
    struct i2sbus_control *control = dev_get_drvdata(&dev->ofdev.dev);
    struct codec_info_item *cii;
    struct i2sbus_dev* i2sdev;
    int err, ret = 0;

    list_for_each_entry(i2sdev, &control->list, item) {
        /* Notify Alsa */
        if (i2sdev->sound.pcm) {
            /* Suspend PCM streams */
            snd_pcm_suspend_all(i2sdev->sound.pcm);
        }

        /* Notify codecs */
        list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
            err = 0;
            if (cii->codec->suspend)
                err = cii->codec->suspend(cii, state);
            if (err)
                ret = err;
        }

        /* wait until streams are stopped */
        i2sbus_wait_for_stop_both(i2sdev);
    }

    return ret;
}

static int i2sbus_resume(struct macio_dev* dev)
{
    struct i2sbus_control *control = dev_get_drvdata(&dev->ofdev.dev);
    struct codec_info_item *cii;
    struct i2sbus_dev* i2sdev;
    int err, ret = 0;

    list_for_each_entry(i2sdev, &control->list, item) {
        /* reset i2s bus format etc. */
        i2sbus_pcm_prepare_both(i2sdev);

        /* Notify codecs so they can re-initialize */
        list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
            err = 0;
            if (cii->codec->resume)
                err = cii->codec->resume(cii);
            if (err)
                ret = err;
        }
    }

    return ret;
}
#endif /* CONFIG_PM */

static int i2sbus_shutdown(struct macio_dev* dev)
{
    return 0;
}

static struct macio_driver i2sbus_drv = {
    .driver = {
        .name = "soundbus-i2s",
        .owner = THIS_MODULE,
        .of_match_table = i2sbus_match,
    },
    .probe = i2sbus_probe,
    .remove = i2sbus_remove,
#ifdef CONFIG_PM
    .suspend = i2sbus_suspend,
    .resume = i2sbus_resume,
#endif
    .shutdown = i2sbus_shutdown,
};

static int __init soundbus_i2sbus_init(void)
{
    return macio_register_driver(&i2sbus_drv);
}

static void __exit soundbus_i2sbus_exit(void)
{
    macio_unregister_driver(&i2sbus_drv);
}

module_init(soundbus_i2sbus_init);
module_exit(soundbus_i2sbus_exit);