Merge tag 'for-linus-5.0-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git...

[mirror_ubuntu-focal-kernel.git] / drivers / mailbox / omap-mailbox.c

// SPDX-License-Identifier: GPL-2.0
/*
 * OMAP mailbox driver
 *
 * Copyright (C) 2006-2009 Nokia Corporation. All rights reserved.
 * Copyright (C) 2013-2016 Texas Instruments Incorporated - http://www.ti.com
 *
 * Contact: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
 *          Suman Anna <s-anna@ti.com>
 */

#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/kfifo.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/omap-mailbox.h>
#include <linux/mailbox_controller.h>
#include <linux/mailbox_client.h>

#include "mailbox.h"

#define MAILBOX_REVISION                0x000
#define MAILBOX_MESSAGE(m)              (0x040 + 4 * (m))
#define MAILBOX_FIFOSTATUS(m)           (0x080 + 4 * (m))
#define MAILBOX_MSGSTATUS(m)            (0x0c0 + 4 * (m))

#define OMAP2_MAILBOX_IRQSTATUS(u)      (0x100 + 8 * (u))
#define OMAP2_MAILBOX_IRQENABLE(u)      (0x104 + 8 * (u))

#define OMAP4_MAILBOX_IRQSTATUS(u)      (0x104 + 0x10 * (u))
#define OMAP4_MAILBOX_IRQENABLE(u)      (0x108 + 0x10 * (u))
#define OMAP4_MAILBOX_IRQENABLE_CLR(u)  (0x10c + 0x10 * (u))

#define MAILBOX_IRQSTATUS(type, u)      (type ? OMAP4_MAILBOX_IRQSTATUS(u) : \
                                                OMAP2_MAILBOX_IRQSTATUS(u))
#define MAILBOX_IRQENABLE(type, u)      (type ? OMAP4_MAILBOX_IRQENABLE(u) : \
                                                OMAP2_MAILBOX_IRQENABLE(u))
#define MAILBOX_IRQDISABLE(type, u)     (type ? OMAP4_MAILBOX_IRQENABLE_CLR(u) \
                                                : OMAP2_MAILBOX_IRQENABLE(u))

#define MAILBOX_IRQ_NEWMSG(m)           (1 << (2 * (m)))
#define MAILBOX_IRQ_NOTFULL(m)          (1 << (2 * (m) + 1))

/* Interrupt register configuration types */
#define MBOX_INTR_CFG_TYPE1             0
#define MBOX_INTR_CFG_TYPE2             1

struct omap_mbox_fifo {
        unsigned long msg;
        unsigned long fifo_stat;
        unsigned long msg_stat;
        unsigned long irqenable;
        unsigned long irqstatus;
        unsigned long irqdisable;
        u32 intr_bit;
};

struct omap_mbox_queue {
        spinlock_t              lock;
        struct kfifo            fifo;
        struct work_struct      work;
        struct omap_mbox        *mbox;
        bool full;
};

struct omap_mbox_match_data {
        u32 intr_type;
};

struct omap_mbox_device {
        struct device *dev;
        struct mutex cfg_lock;
        void __iomem *mbox_base;
        u32 *irq_ctx;
        u32 num_users;
        u32 num_fifos;
        u32 intr_type;
        struct omap_mbox **mboxes;
        struct mbox_controller controller;
        struct list_head elem;
};

struct omap_mbox_fifo_info {
        int tx_id;
        int tx_usr;
        int tx_irq;

        int rx_id;
        int rx_usr;
        int rx_irq;

        const char *name;
        bool send_no_irq;
};

struct omap_mbox {
        const char              *name;
        int                     irq;
        struct omap_mbox_queue  *rxq;
        struct device           *dev;
        struct omap_mbox_device *parent;
        struct omap_mbox_fifo   tx_fifo;
        struct omap_mbox_fifo   rx_fifo;
        u32                     intr_type;
        struct mbox_chan        *chan;
        bool                    send_no_irq;
};

/* global variables for the mailbox devices */
static DEFINE_MUTEX(omap_mbox_devices_lock);
static LIST_HEAD(omap_mbox_devices);

static unsigned int mbox_kfifo_size = CONFIG_OMAP_MBOX_KFIFO_SIZE;
module_param(mbox_kfifo_size, uint, S_IRUGO);
MODULE_PARM_DESC(mbox_kfifo_size, "Size of omap's mailbox kfifo (bytes)");

static struct omap_mbox *mbox_chan_to_omap_mbox(struct mbox_chan *chan)
{
        if (!chan || !chan->con_priv)
                return NULL;

        return (struct omap_mbox *)chan->con_priv;
}

static inline
unsigned int mbox_read_reg(struct omap_mbox_device *mdev, size_t ofs)
{
        return __raw_readl(mdev->mbox_base + ofs);
}

static inline
void mbox_write_reg(struct omap_mbox_device *mdev, u32 val, size_t ofs)
{
        __raw_writel(val, mdev->mbox_base + ofs);
}

/* Mailbox FIFO handle functions */
static mbox_msg_t mbox_fifo_read(struct omap_mbox *mbox)
{
        struct omap_mbox_fifo *fifo = &mbox->rx_fifo;

        return (mbox_msg_t)mbox_read_reg(mbox->parent, fifo->msg);
}

static void mbox_fifo_write(struct omap_mbox *mbox, mbox_msg_t msg)
{
        struct omap_mbox_fifo *fifo = &mbox->tx_fifo;

        mbox_write_reg(mbox->parent, msg, fifo->msg);
}

static int mbox_fifo_empty(struct omap_mbox *mbox)
{
        struct omap_mbox_fifo *fifo = &mbox->rx_fifo;

        return (mbox_read_reg(mbox->parent, fifo->msg_stat) == 0);
}

static int mbox_fifo_full(struct omap_mbox *mbox)
{
        struct omap_mbox_fifo *fifo = &mbox->tx_fifo;

        return mbox_read_reg(mbox->parent, fifo->fifo_stat);
}

/* Mailbox IRQ handle functions */
static void ack_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
{
        struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
                                &mbox->tx_fifo : &mbox->rx_fifo;
        u32 bit = fifo->intr_bit;
        u32 irqstatus = fifo->irqstatus;

        mbox_write_reg(mbox->parent, bit, irqstatus);

        /* Flush posted write for irq status to avoid spurious interrupts */
        mbox_read_reg(mbox->parent, irqstatus);
}

static int is_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
{
        struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
                                &mbox->tx_fifo : &mbox->rx_fifo;
        u32 bit = fifo->intr_bit;
        u32 irqenable = fifo->irqenable;
        u32 irqstatus = fifo->irqstatus;

        u32 enable = mbox_read_reg(mbox->parent, irqenable);
        u32 status = mbox_read_reg(mbox->parent, irqstatus);

        return (int)(enable & status & bit);
}

static void _omap_mbox_enable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
{
        u32 l;
        struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
                                &mbox->tx_fifo : &mbox->rx_fifo;
        u32 bit = fifo->intr_bit;
        u32 irqenable = fifo->irqenable;

        l = mbox_read_reg(mbox->parent, irqenable);
        l |= bit;
        mbox_write_reg(mbox->parent, l, irqenable);
}

static void _omap_mbox_disable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
{
        struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
                                &mbox->tx_fifo : &mbox->rx_fifo;
        u32 bit = fifo->intr_bit;
        u32 irqdisable = fifo->irqdisable;

        /*
         * Read and update the interrupt configuration register for pre-OMAP4.
         * OMAP4 and later SoCs have a dedicated interrupt disabling register.
         */
        if (!mbox->intr_type)
                bit = mbox_read_reg(mbox->parent, irqdisable) & ~bit;

        mbox_write_reg(mbox->parent, bit, irqdisable);
}

void omap_mbox_enable_irq(struct mbox_chan *chan, omap_mbox_irq_t irq)
{
        struct omap_mbox *mbox = mbox_chan_to_omap_mbox(chan);

        if (WARN_ON(!mbox))
                return;

        _omap_mbox_enable_irq(mbox, irq);
}
EXPORT_SYMBOL(omap_mbox_enable_irq);

void omap_mbox_disable_irq(struct mbox_chan *chan, omap_mbox_irq_t irq)
{
        struct omap_mbox *mbox = mbox_chan_to_omap_mbox(chan);

        if (WARN_ON(!mbox))
                return;

        _omap_mbox_disable_irq(mbox, irq);
}
EXPORT_SYMBOL(omap_mbox_disable_irq);

/*
 * Message receiver(workqueue)
 */
static void mbox_rx_work(struct work_struct *work)
{
        struct omap_mbox_queue *mq =
                        container_of(work, struct omap_mbox_queue, work);
        mbox_msg_t msg;
        int len;

        while (kfifo_len(&mq->fifo) >= sizeof(msg)) {
                len = kfifo_out(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
                WARN_ON(len != sizeof(msg));

                mbox_chan_received_data(mq->mbox->chan, (void *)msg);
                spin_lock_irq(&mq->lock);
                if (mq->full) {
                        mq->full = false;
                        _omap_mbox_enable_irq(mq->mbox, IRQ_RX);
                }
                spin_unlock_irq(&mq->lock);
        }
}

/*
 * Mailbox interrupt handler
 */
static void __mbox_tx_interrupt(struct omap_mbox *mbox)
{
        _omap_mbox_disable_irq(mbox, IRQ_TX);
        ack_mbox_irq(mbox, IRQ_TX);
        mbox_chan_txdone(mbox->chan, 0);
}

static void __mbox_rx_interrupt(struct omap_mbox *mbox)
{
        struct omap_mbox_queue *mq = mbox->rxq;
        mbox_msg_t msg;
        int len;

        while (!mbox_fifo_empty(mbox)) {
                if (unlikely(kfifo_avail(&mq->fifo) < sizeof(msg))) {
                        _omap_mbox_disable_irq(mbox, IRQ_RX);
                        mq->full = true;
                        goto nomem;
                }

                msg = mbox_fifo_read(mbox);

                len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
                WARN_ON(len != sizeof(msg));
        }

        /* no more messages in the fifo. clear IRQ source. */
        ack_mbox_irq(mbox, IRQ_RX);
nomem:
        schedule_work(&mbox->rxq->work);
}

static irqreturn_t mbox_interrupt(int irq, void *p)
{
        struct omap_mbox *mbox = p;

        if (is_mbox_irq(mbox, IRQ_TX))
                __mbox_tx_interrupt(mbox);

        if (is_mbox_irq(mbox, IRQ_RX))
                __mbox_rx_interrupt(mbox);

        return IRQ_HANDLED;
}

static struct omap_mbox_queue *mbox_queue_alloc(struct omap_mbox *mbox,
                                        void (*work)(struct work_struct *))
{
        struct omap_mbox_queue *mq;

        if (!work)
                return NULL;

        mq = kzalloc(sizeof(*mq), GFP_KERNEL);
        if (!mq)
                return NULL;

        spin_lock_init(&mq->lock);

        if (kfifo_alloc(&mq->fifo, mbox_kfifo_size, GFP_KERNEL))
                goto error;

        INIT_WORK(&mq->work, work);
        return mq;

error:
        kfree(mq);
        return NULL;
}

static void mbox_queue_free(struct omap_mbox_queue *q)
{
        kfifo_free(&q->fifo);
        kfree(q);
}

static int omap_mbox_startup(struct omap_mbox *mbox)
{
        int ret = 0;
        struct omap_mbox_queue *mq;

        mq = mbox_queue_alloc(mbox, mbox_rx_work);
        if (!mq)
                return -ENOMEM;
        mbox->rxq = mq;
        mq->mbox = mbox;

        ret = request_irq(mbox->irq, mbox_interrupt, IRQF_SHARED,
                          mbox->name, mbox);
        if (unlikely(ret)) {
                pr_err("failed to register mailbox interrupt:%d\n", ret);
                goto fail_request_irq;
        }

        if (mbox->send_no_irq)
                mbox->chan->txdone_method = TXDONE_BY_ACK;

        _omap_mbox_enable_irq(mbox, IRQ_RX);

        return 0;

fail_request_irq:
        mbox_queue_free(mbox->rxq);
        return ret;
}

static void omap_mbox_fini(struct omap_mbox *mbox)
{
        _omap_mbox_disable_irq(mbox, IRQ_RX);
        free_irq(mbox->irq, mbox);
        flush_work(&mbox->rxq->work);
        mbox_queue_free(mbox->rxq);
}

static struct omap_mbox *omap_mbox_device_find(struct omap_mbox_device *mdev,
                                               const char *mbox_name)
{
        struct omap_mbox *_mbox, *mbox = NULL;
        struct omap_mbox **mboxes = mdev->mboxes;
        int i;

        if (!mboxes)
                return NULL;

        for (i = 0; (_mbox = mboxes[i]); i++) {
                if (!strcmp(_mbox->name, mbox_name)) {
                        mbox = _mbox;
                        break;
                }
        }
        return mbox;
}

struct mbox_chan *omap_mbox_request_channel(struct mbox_client *cl,
                                            const char *chan_name)
{
        struct device *dev = cl->dev;
        struct omap_mbox *mbox = NULL;
        struct omap_mbox_device *mdev;
        struct mbox_chan *chan;
        unsigned long flags;
        int ret;

        if (!dev)
                return ERR_PTR(-ENODEV);

        if (dev->of_node) {
                pr_err("%s: please use mbox_request_channel(), this API is supported only for OMAP non-DT usage\n",
                       __func__);
                return ERR_PTR(-ENODEV);
        }

        mutex_lock(&omap_mbox_devices_lock);
        list_for_each_entry(mdev, &omap_mbox_devices, elem) {
                mbox = omap_mbox_device_find(mdev, chan_name);
                if (mbox)
                        break;
        }
        mutex_unlock(&omap_mbox_devices_lock);

        if (!mbox || !mbox->chan)
                return ERR_PTR(-ENOENT);

        chan = mbox->chan;
        spin_lock_irqsave(&chan->lock, flags);
        chan->msg_free = 0;
        chan->msg_count = 0;
        chan->active_req = NULL;
        chan->cl = cl;
        init_completion(&chan->tx_complete);
        spin_unlock_irqrestore(&chan->lock, flags);

        ret = chan->mbox->ops->startup(chan);
        if (ret) {
                pr_err("Unable to startup the chan (%d)\n", ret);
                mbox_free_channel(chan);
                chan = ERR_PTR(ret);
        }

        return chan;
}
EXPORT_SYMBOL(omap_mbox_request_channel);

static struct class omap_mbox_class = { .name = "mbox", };

static int omap_mbox_register(struct omap_mbox_device *mdev)
{
        int ret;
        int i;
        struct omap_mbox **mboxes;

        if (!mdev || !mdev->mboxes)
                return -EINVAL;

        mboxes = mdev->mboxes;
        for (i = 0; mboxes[i]; i++) {
                struct omap_mbox *mbox = mboxes[i];

                mbox->dev = device_create(&omap_mbox_class, mdev->dev,
                                        0, mbox, "%s", mbox->name);
                if (IS_ERR(mbox->dev)) {
                        ret = PTR_ERR(mbox->dev);
                        goto err_out;
                }
        }

        mutex_lock(&omap_mbox_devices_lock);
        list_add(&mdev->elem, &omap_mbox_devices);
        mutex_unlock(&omap_mbox_devices_lock);

        ret = devm_mbox_controller_register(mdev->dev, &mdev->controller);

err_out:
        if (ret) {
                while (i--)
                        device_unregister(mboxes[i]->dev);
        }
        return ret;
}

static int omap_mbox_unregister(struct omap_mbox_device *mdev)
{
        int i;
        struct omap_mbox **mboxes;

        if (!mdev || !mdev->mboxes)
                return -EINVAL;

        mutex_lock(&omap_mbox_devices_lock);
        list_del(&mdev->elem);
        mutex_unlock(&omap_mbox_devices_lock);

        mboxes = mdev->mboxes;
        for (i = 0; mboxes[i]; i++)
                device_unregister(mboxes[i]->dev);
        return 0;
}

static int omap_mbox_chan_startup(struct mbox_chan *chan)
{
        struct omap_mbox *mbox = mbox_chan_to_omap_mbox(chan);
        struct omap_mbox_device *mdev = mbox->parent;
        int ret = 0;

        mutex_lock(&mdev->cfg_lock);
        pm_runtime_get_sync(mdev->dev);
        ret = omap_mbox_startup(mbox);
        if (ret)
                pm_runtime_put_sync(mdev->dev);
        mutex_unlock(&mdev->cfg_lock);
        return ret;
}

static void omap_mbox_chan_shutdown(struct mbox_chan *chan)
{
        struct omap_mbox *mbox = mbox_chan_to_omap_mbox(chan);
        struct omap_mbox_device *mdev = mbox->parent;

        mutex_lock(&mdev->cfg_lock);
        omap_mbox_fini(mbox);
        pm_runtime_put_sync(mdev->dev);
        mutex_unlock(&mdev->cfg_lock);
}

static int omap_mbox_chan_send_noirq(struct omap_mbox *mbox, void *data)
{
        int ret = -EBUSY;

        if (!mbox_fifo_full(mbox)) {
                _omap_mbox_enable_irq(mbox, IRQ_RX);
                mbox_fifo_write(mbox, (mbox_msg_t)data);
                ret = 0;
                _omap_mbox_disable_irq(mbox, IRQ_RX);

                /* we must read and ack the interrupt directly from here */
                mbox_fifo_read(mbox);
                ack_mbox_irq(mbox, IRQ_RX);
        }

        return ret;
}

static int omap_mbox_chan_send(struct omap_mbox *mbox, void *data)
{
        int ret = -EBUSY;

        if (!mbox_fifo_full(mbox)) {
                mbox_fifo_write(mbox, (mbox_msg_t)data);
                ret = 0;
        }

        /* always enable the interrupt */
        _omap_mbox_enable_irq(mbox, IRQ_TX);
        return ret;
}

static int omap_mbox_chan_send_data(struct mbox_chan *chan, void *data)
{
        struct omap_mbox *mbox = mbox_chan_to_omap_mbox(chan);
        int ret;

        if (!mbox)
                return -EINVAL;

        if (mbox->send_no_irq)
                ret = omap_mbox_chan_send_noirq(mbox, data);
        else
                ret = omap_mbox_chan_send(mbox, data);

        return ret;
}

static const struct mbox_chan_ops omap_mbox_chan_ops = {
        .startup        = omap_mbox_chan_startup,
        .send_data      = omap_mbox_chan_send_data,
        .shutdown       = omap_mbox_chan_shutdown,
};

#ifdef CONFIG_PM_SLEEP
static int omap_mbox_suspend(struct device *dev)
{
        struct omap_mbox_device *mdev = dev_get_drvdata(dev);
        u32 usr, fifo, reg;

        if (pm_runtime_status_suspended(dev))
                return 0;

        for (fifo = 0; fifo < mdev->num_fifos; fifo++) {
                if (mbox_read_reg(mdev, MAILBOX_MSGSTATUS(fifo))) {
                        dev_err(mdev->dev, "fifo %d has unexpected unread messages\n",
                                fifo);
                        return -EBUSY;
                }
        }

        for (usr = 0; usr < mdev->num_users; usr++) {
                reg = MAILBOX_IRQENABLE(mdev->intr_type, usr);
                mdev->irq_ctx[usr] = mbox_read_reg(mdev, reg);
        }

        return 0;
}

static int omap_mbox_resume(struct device *dev)
{
        struct omap_mbox_device *mdev = dev_get_drvdata(dev);
        u32 usr, reg;

        if (pm_runtime_status_suspended(dev))
                return 0;

        for (usr = 0; usr < mdev->num_users; usr++) {
                reg = MAILBOX_IRQENABLE(mdev->intr_type, usr);
                mbox_write_reg(mdev, mdev->irq_ctx[usr], reg);
        }

        return 0;
}
#endif

static const struct dev_pm_ops omap_mbox_pm_ops = {
        SET_SYSTEM_SLEEP_PM_OPS(omap_mbox_suspend, omap_mbox_resume)
};

static const struct omap_mbox_match_data omap2_data = { MBOX_INTR_CFG_TYPE1 };
static const struct omap_mbox_match_data omap4_data = { MBOX_INTR_CFG_TYPE2 };

static const struct of_device_id omap_mailbox_of_match[] = {
        {
                .compatible     = "ti,omap2-mailbox",
                .data           = &omap2_data,
        },
        {
                .compatible     = "ti,omap3-mailbox",
                .data           = &omap2_data,
        },
        {
                .compatible     = "ti,omap4-mailbox",
                .data           = &omap4_data,
        },
        {
                /* end */
        },
};
MODULE_DEVICE_TABLE(of, omap_mailbox_of_match);

static struct mbox_chan *omap_mbox_of_xlate(struct mbox_controller *controller,
                                            const struct of_phandle_args *sp)
{
        phandle phandle = sp->args[0];
        struct device_node *node;
        struct omap_mbox_device *mdev;
        struct omap_mbox *mbox;

        mdev = container_of(controller, struct omap_mbox_device, controller);
        if (WARN_ON(!mdev))
                return ERR_PTR(-EINVAL);

        node = of_find_node_by_phandle(phandle);
        if (!node) {
                pr_err("%s: could not find node phandle 0x%x\n",
                       __func__, phandle);
                return ERR_PTR(-ENODEV);
        }

        mbox = omap_mbox_device_find(mdev, node->name);
        of_node_put(node);
        return mbox ? mbox->chan : ERR_PTR(-ENOENT);
}

static int omap_mbox_probe(struct platform_device *pdev)
{
        struct resource *mem;
        int ret;
        struct mbox_chan *chnls;
        struct omap_mbox **list, *mbox, *mboxblk;
        struct omap_mbox_fifo_info *finfo, *finfoblk;
        struct omap_mbox_device *mdev;
        struct omap_mbox_fifo *fifo;
        struct device_node *node = pdev->dev.of_node;
        struct device_node *child;
        const struct omap_mbox_match_data *match_data;
        u32 intr_type, info_count;
        u32 num_users, num_fifos;
        u32 tmp[3];
        u32 l;
        int i;

        if (!node) {
                pr_err("%s: only DT-based devices are supported\n", __func__);
                return -ENODEV;
        }

        match_data = of_device_get_match_data(&pdev->dev);
        if (!match_data)
                return -ENODEV;
        intr_type = match_data->intr_type;

        if (of_property_read_u32(node, "ti,mbox-num-users", &num_users))
                return -ENODEV;

        if (of_property_read_u32(node, "ti,mbox-num-fifos", &num_fifos))
                return -ENODEV;

        info_count = of_get_available_child_count(node);
        if (!info_count) {
                dev_err(&pdev->dev, "no available mbox devices found\n");
                return -ENODEV;
        }

        finfoblk = devm_kcalloc(&pdev->dev, info_count, sizeof(*finfoblk),
                                GFP_KERNEL);
        if (!finfoblk)
                return -ENOMEM;

        finfo = finfoblk;
        child = NULL;
        for (i = 0; i < info_count; i++, finfo++) {
                child = of_get_next_available_child(node, child);
                ret = of_property_read_u32_array(child, "ti,mbox-tx", tmp,
                                                 ARRAY_SIZE(tmp));
                if (ret)
                        return ret;
                finfo->tx_id = tmp[0];
                finfo->tx_irq = tmp[1];
                finfo->tx_usr = tmp[2];

                ret = of_property_read_u32_array(child, "ti,mbox-rx", tmp,
                                                 ARRAY_SIZE(tmp));
                if (ret)
                        return ret;
                finfo->rx_id = tmp[0];
                finfo->rx_irq = tmp[1];
                finfo->rx_usr = tmp[2];

                finfo->name = child->name;

                if (of_find_property(child, "ti,mbox-send-noirq", NULL))
                        finfo->send_no_irq = true;

                if (finfo->tx_id >= num_fifos || finfo->rx_id >= num_fifos ||
                    finfo->tx_usr >= num_users || finfo->rx_usr >= num_users)
                        return -EINVAL;
        }

        mdev = devm_kzalloc(&pdev->dev, sizeof(*mdev), GFP_KERNEL);
        if (!mdev)
                return -ENOMEM;

        mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        mdev->mbox_base = devm_ioremap_resource(&pdev->dev, mem);
        if (IS_ERR(mdev->mbox_base))
                return PTR_ERR(mdev->mbox_base);

        mdev->irq_ctx = devm_kcalloc(&pdev->dev, num_users, sizeof(u32),
                                     GFP_KERNEL);
        if (!mdev->irq_ctx)
                return -ENOMEM;

        /* allocate one extra for marking end of list */
        list = devm_kcalloc(&pdev->dev, info_count + 1, sizeof(*list),
                            GFP_KERNEL);
        if (!list)
                return -ENOMEM;

        chnls = devm_kcalloc(&pdev->dev, info_count + 1, sizeof(*chnls),
                             GFP_KERNEL);
        if (!chnls)
                return -ENOMEM;

        mboxblk = devm_kcalloc(&pdev->dev, info_count, sizeof(*mbox),
                               GFP_KERNEL);
        if (!mboxblk)
                return -ENOMEM;

        mbox = mboxblk;
        finfo = finfoblk;
        for (i = 0; i < info_count; i++, finfo++) {
                fifo = &mbox->tx_fifo;
                fifo->msg = MAILBOX_MESSAGE(finfo->tx_id);
                fifo->fifo_stat = MAILBOX_FIFOSTATUS(finfo->tx_id);
                fifo->intr_bit = MAILBOX_IRQ_NOTFULL(finfo->tx_id);
                fifo->irqenable = MAILBOX_IRQENABLE(intr_type, finfo->tx_usr);
                fifo->irqstatus = MAILBOX_IRQSTATUS(intr_type, finfo->tx_usr);
                fifo->irqdisable = MAILBOX_IRQDISABLE(intr_type, finfo->tx_usr);

                fifo = &mbox->rx_fifo;
                fifo->msg = MAILBOX_MESSAGE(finfo->rx_id);
                fifo->msg_stat =  MAILBOX_MSGSTATUS(finfo->rx_id);
                fifo->intr_bit = MAILBOX_IRQ_NEWMSG(finfo->rx_id);
                fifo->irqenable = MAILBOX_IRQENABLE(intr_type, finfo->rx_usr);
                fifo->irqstatus = MAILBOX_IRQSTATUS(intr_type, finfo->rx_usr);
                fifo->irqdisable = MAILBOX_IRQDISABLE(intr_type, finfo->rx_usr);

                mbox->send_no_irq = finfo->send_no_irq;
                mbox->intr_type = intr_type;

                mbox->parent = mdev;
                mbox->name = finfo->name;
                mbox->irq = platform_get_irq(pdev, finfo->tx_irq);
                if (mbox->irq < 0)
                        return mbox->irq;
                mbox->chan = &chnls[i];
                chnls[i].con_priv = mbox;
                list[i] = mbox++;
        }

        mutex_init(&mdev->cfg_lock);
        mdev->dev = &pdev->dev;
        mdev->num_users = num_users;
        mdev->num_fifos = num_fifos;
        mdev->intr_type = intr_type;
        mdev->mboxes = list;

        /* OMAP does not have a Tx-Done IRQ, but rather a Tx-Ready IRQ */
        mdev->controller.txdone_irq = true;
        mdev->controller.dev = mdev->dev;
        mdev->controller.ops = &omap_mbox_chan_ops;
        mdev->controller.chans = chnls;
        mdev->controller.num_chans = info_count;
        mdev->controller.of_xlate = omap_mbox_of_xlate;
        ret = omap_mbox_register(mdev);
        if (ret)
                return ret;

        platform_set_drvdata(pdev, mdev);
        pm_runtime_enable(mdev->dev);

        ret = pm_runtime_get_sync(mdev->dev);
        if (ret < 0) {
                pm_runtime_put_noidle(mdev->dev);
                goto unregister;
        }

        /*
         * just print the raw revision register, the format is not
         * uniform across all SoCs
         */
        l = mbox_read_reg(mdev, MAILBOX_REVISION);
        dev_info(mdev->dev, "omap mailbox rev 0x%x\n", l);

        ret = pm_runtime_put_sync(mdev->dev);
        if (ret < 0)
                goto unregister;

        devm_kfree(&pdev->dev, finfoblk);
        return 0;

unregister:
        pm_runtime_disable(mdev->dev);
        omap_mbox_unregister(mdev);
        return ret;
}

static int omap_mbox_remove(struct platform_device *pdev)
{
        struct omap_mbox_device *mdev = platform_get_drvdata(pdev);

        pm_runtime_disable(mdev->dev);
        omap_mbox_unregister(mdev);

        return 0;
}

static struct platform_driver omap_mbox_driver = {
        .probe  = omap_mbox_probe,
        .remove = omap_mbox_remove,
        .driver = {
                .name = "omap-mailbox",
                .pm = &omap_mbox_pm_ops,
                .of_match_table = of_match_ptr(omap_mailbox_of_match),
        },
};

static int __init omap_mbox_init(void)
{
        int err;

        err = class_register(&omap_mbox_class);
        if (err)
                return err;

        /* kfifo size sanity check: alignment and minimal size */
        mbox_kfifo_size = ALIGN(mbox_kfifo_size, sizeof(mbox_msg_t));
        mbox_kfifo_size = max_t(unsigned int, mbox_kfifo_size,
                                                        sizeof(mbox_msg_t));

        err = platform_driver_register(&omap_mbox_driver);
        if (err)
                class_unregister(&omap_mbox_class);

        return err;
}
subsys_initcall(omap_mbox_init);

static void __exit omap_mbox_exit(void)
{
        platform_driver_unregister(&omap_mbox_driver);
        class_unregister(&omap_mbox_class);
}
module_exit(omap_mbox_exit);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("omap mailbox: interrupt driven messaging");
MODULE_AUTHOR("Toshihiro Kobayashi");
MODULE_AUTHOR("Hiroshi DOYU");