mailbox.c

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/*
 * Mailbox reservation modules for OMAP1
 *
 * Copyright (C) 2006-2009 Nokia Corporation
 * Written by: Hiroshi DOYU <[email protected]>
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <plat/mailbox.h>

#define MAILBOX_ARM2DSP1        0x00
#define MAILBOX_ARM2DSP1b       0x04
#define MAILBOX_DSP2ARM1        0x08
#define MAILBOX_DSP2ARM1b       0x0c
#define MAILBOX_DSP2ARM2        0x10
#define MAILBOX_DSP2ARM2b       0x14
#define MAILBOX_ARM2DSP1_Flag       0x18
#define MAILBOX_DSP2ARM1_Flag       0x1c
#define MAILBOX_DSP2ARM2_Flag       0x20

static void __iomem *mbox_base;

struct omap_mbox1_fifo {
    unsigned long cmd;
    unsigned long data;
    unsigned long flag;
};

struct omap_mbox1_priv {
    struct omap_mbox1_fifo tx_fifo;
    struct omap_mbox1_fifo rx_fifo;
};

static inline int mbox_read_reg(size_t ofs)
{
    return __raw_readw(mbox_base + ofs);
}

static inline void mbox_write_reg(u32 val, size_t ofs)
{
    __raw_writew(val, mbox_base + ofs);
}

/* msg */
static mbox_msg_t omap1_mbox_fifo_read(struct omap_mbox *mbox)
{
    struct omap_mbox1_fifo *fifo =
        &((struct omap_mbox1_priv *)mbox->priv)->rx_fifo;
    mbox_msg_t msg;

    msg = mbox_read_reg(fifo->data);
    msg |= ((mbox_msg_t) mbox_read_reg(fifo->cmd)) << 16;

    return msg;
}

static void
omap1_mbox_fifo_write(struct omap_mbox *mbox, mbox_msg_t msg)
{
    struct omap_mbox1_fifo *fifo =
        &((struct omap_mbox1_priv *)mbox->priv)->tx_fifo;

    mbox_write_reg(msg & 0xffff, fifo->data);
    mbox_write_reg(msg >> 16, fifo->cmd);
}

static int omap1_mbox_fifo_empty(struct omap_mbox *mbox)
{
    return 0;
}

static int omap1_mbox_fifo_full(struct omap_mbox *mbox)
{
    struct omap_mbox1_fifo *fifo =
        &((struct omap_mbox1_priv *)mbox->priv)->rx_fifo;

    return mbox_read_reg(fifo->flag);
}

/* irq */
static void
omap1_mbox_enable_irq(struct omap_mbox *mbox, omap_mbox_type_t irq)
{
    if (irq == IRQ_RX)
        enable_irq(mbox->irq);
}

static void
omap1_mbox_disable_irq(struct omap_mbox *mbox, omap_mbox_type_t irq)
{
    if (irq == IRQ_RX)
        disable_irq(mbox->irq);
}

static int
omap1_mbox_is_irq(struct omap_mbox *mbox, omap_mbox_type_t irq)
{
    if (irq == IRQ_TX)
        return 0;
    return 1;
}

static struct omap_mbox_ops omap1_mbox_ops = {
    .type       = OMAP_MBOX_TYPE1,
    .fifo_read  = omap1_mbox_fifo_read,
    .fifo_write = omap1_mbox_fifo_write,
    .fifo_empty = omap1_mbox_fifo_empty,
    .fifo_full  = omap1_mbox_fifo_full,
    .enable_irq = omap1_mbox_enable_irq,
    .disable_irq    = omap1_mbox_disable_irq,
    .is_irq     = omap1_mbox_is_irq,
};

/* FIXME: the following struct should be created automatically by the user id */

/* DSP */
static struct omap_mbox1_priv omap1_mbox_dsp_priv = {
    .tx_fifo = {
        .cmd    = MAILBOX_ARM2DSP1b,
        .data   = MAILBOX_ARM2DSP1,
        .flag   = MAILBOX_ARM2DSP1_Flag,
    },
    .rx_fifo = {
        .cmd    = MAILBOX_DSP2ARM1b,
        .data   = MAILBOX_DSP2ARM1,
        .flag   = MAILBOX_DSP2ARM1_Flag,
    },
};

static struct omap_mbox mbox_dsp_info = {
    .name   = "dsp",
    .ops    = &omap1_mbox_ops,
    .priv   = &omap1_mbox_dsp_priv,
};

static struct omap_mbox *omap1_mboxes[] = { &mbox_dsp_info, NULL };

static int __devinit omap1_mbox_probe(struct platform_device *pdev)
{
    struct resource *mem;
    int ret;
    struct omap_mbox **list;

    list = omap1_mboxes;
    list[0]->irq = platform_get_irq_byname(pdev, "dsp");

    mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    mbox_base = ioremap(mem->start, resource_size(mem));
    if (!mbox_base)
        return -ENOMEM;

    ret = omap_mbox_register(&pdev->dev, list);
    if (ret) {
        iounmap(mbox_base);
        return ret;
    }

    return 0;
}

static int __devexit omap1_mbox_remove(struct platform_device *pdev)
{
    omap_mbox_unregister();
    iounmap(mbox_base);
    return 0;
}

static struct platform_driver omap1_mbox_driver = {
    .probe  = omap1_mbox_probe,
    .remove = __devexit_p(omap1_mbox_remove),
    .driver = {
        .name   = "omap-mailbox",
    },
};

static int __init omap1_mbox_init(void)
{
    return platform_driver_register(&omap1_mbox_driver);
}

static void __exit omap1_mbox_exit(void)
{
    platform_driver_unregister(&omap1_mbox_driver);
}

module_init(omap1_mbox_init);
module_exit(omap1_mbox_exit);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("omap mailbox: omap1 architecture specific functions");
MODULE_AUTHOR("Hiroshi DOYU <[email protected]>");
MODULE_ALIAS("platform:omap1-mailbox");