/*
 * i2sbus driver
 *
 * Copyright 2006-2008 Johannes Berg <johannes@sipsolutions.net>
 *
 * 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 <linux/of_address.h>
#include <linux/of_irq.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 <johannes@sipsolutions.net>");
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 const 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_zalloc_coherent(&macio_get_pci_dev(i2sdev->macio)->dev,
                                       r->size, &r->bus_addr, GFP_KERNEL);
        if (!r->space)
                return -ENOMEM;

        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);
        iounmap(i2sdev->intfregs);
        iounmap(i2sdev->out.dbdma);
        iounmap(i2sdev->in.dbdma);
        for (i = aoa_resource_i2smmio; i <= aoa_resource_rxdbdma; 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 ||
                                   *id == 44)) {
                                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);
        iounmap(dev->intfregs);
        iounmap(dev->out.dbdma);
        iounmap(dev->in.dbdma);
        for (i=0;i<3;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 */
                /* 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);