/*
 *  linux/arch/arm/common/amba.c
 *
 *  Copyright (C) 2003 Deep Blue Solutions Ltd, All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>

#include <asm/io.h>
#include <asm/irq.h>
#include <asm/hardware/amba.h>
#include <asm/sizes.h>

#define to_amba_device(d)       container_of(d, struct amba_device, dev)
#define to_amba_driver(d)       container_of(d, struct amba_driver, drv)

static struct amba_id *
amba_lookup(struct amba_id *table, struct amba_device *dev)
{
        int ret = 0;

        while (table->mask) {
                ret = (dev->periphid & table->mask) == table->id;
                if (ret)
                        break;
                table++;
        }

        return ret ? table : NULL;
}

static int amba_match(struct device *dev, struct device_driver *drv)
{
        struct amba_device *pcdev = to_amba_device(dev);
        struct amba_driver *pcdrv = to_amba_driver(drv);

        return amba_lookup(pcdrv->id_table, pcdev) != NULL;
}

#ifdef CONFIG_HOTPLUG
static int amba_hotplug(struct device *dev, char **envp, int nr_env, char *buf, int bufsz)
{
        struct amba_device *pcdev = to_amba_device(dev);

        if (nr_env < 2)
                return -ENOMEM;

        snprintf(buf, bufsz, "AMBA_ID=%08x", pcdev->periphid);
        *envp++ = buf;
        *envp++ = NULL;
        return 0;
}
#else
#define amba_hotplug NULL
#endif

static int amba_suspend(struct device *dev, pm_message_t state)
{
        struct amba_driver *drv = to_amba_driver(dev->driver);
        int ret = 0;

        if (dev->driver && drv->suspend)
                ret = drv->suspend(to_amba_device(dev), state);
        return ret;
}

static int amba_resume(struct device *dev)
{
        struct amba_driver *drv = to_amba_driver(dev->driver);
        int ret = 0;

        if (dev->driver && drv->resume)
                ret = drv->resume(to_amba_device(dev));
        return ret;
}

/*
 * Primecells are part of the Advanced Microcontroller Bus Architecture,
 * so we call the bus "amba".
 */
static struct bus_type amba_bustype = {
        .name           = "amba",
        .match          = amba_match,
        .hotplug        = amba_hotplug,
        .suspend        = amba_suspend,
        .resume         = amba_resume,
};

static int __init amba_init(void)
{
        return bus_register(&amba_bustype);
}

postcore_initcall(amba_init);

/*
 * These are the device model conversion veneers; they convert the
 * device model structures to our more specific structures.
 */
static int amba_probe(struct device *dev)
{
        struct amba_device *pcdev = to_amba_device(dev);
        struct amba_driver *pcdrv = to_amba_driver(dev->driver);
        struct amba_id *id;

        id = amba_lookup(pcdrv->id_table, pcdev);

        return pcdrv->probe(pcdev, id);
}

static int amba_remove(struct device *dev)
{
        struct amba_driver *drv = to_amba_driver(dev->driver);
        return drv->remove(to_amba_device(dev));
}

static void amba_shutdown(struct device *dev)
{
        struct amba_driver *drv = to_amba_driver(dev->driver);
        drv->shutdown(to_amba_device(dev));
}

/**
 *      amba_driver_register - register an AMBA device driver
 *      @drv: amba device driver structure
 *
 *      Register an AMBA device driver with the Linux device model
 *      core.  If devices pre-exist, the drivers probe function will
 *      be called.
 */
int amba_driver_register(struct amba_driver *drv)
{
        drv->drv.bus = &amba_bustype;

#define SETFN(fn)       if (drv->fn) drv->drv.fn = amba_##fn
        SETFN(probe);
        SETFN(remove);
        SETFN(shutdown);

        return driver_register(&drv->drv);
}

/**
 *      amba_driver_unregister - remove an AMBA device driver
 *      @drv: AMBA device driver structure to remove
 *
 *      Unregister an AMBA device driver from the Linux device
 *      model.  The device model will call the drivers remove function
 *      for each device the device driver is currently handling.
 */
void amba_driver_unregister(struct amba_driver *drv)
{
        driver_unregister(&drv->drv);
}


static void amba_device_release(struct device *dev)
{
        struct amba_device *d = to_amba_device(dev);

        if (d->res.parent)
                release_resource(&d->res);
        kfree(d);
}

#define amba_attr(name,fmt,arg...)                              \
static ssize_t show_##name(struct device *_dev, char *buf)      \
{                                                               \
        struct amba_device *dev = to_amba_device(_dev);         \
        return sprintf(buf, fmt, arg);                          \
}                                                               \
static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)

amba_attr(id, "%08x\n", dev->periphid);
amba_attr(irq0, "%u\n", dev->irq[0]);
amba_attr(irq1, "%u\n", dev->irq[1]);
amba_attr(resource, "\t%08lx\t%08lx\t%08lx\n",
          dev->res.start, dev->res.end, dev->res.flags);

/**
 *      amba_device_register - register an AMBA device
 *      @dev: AMBA device to register
 *      @parent: parent memory resource
 *
 *      Setup the AMBA device, reading the cell ID if present.
 *      Claim the resource, and register the AMBA device with
 *      the Linux device manager.
 */
int amba_device_register(struct amba_device *dev, struct resource *parent)
{
        u32 pid, cid;
        void __iomem *tmp;
        int i, ret;

        dev->dev.release = amba_device_release;
        dev->dev.bus = &amba_bustype;
        dev->dev.dma_mask = &dev->dma_mask;
        dev->res.name = dev->dev.bus_id;

        if (!dev->dev.coherent_dma_mask && dev->dma_mask)
                dev_warn(&dev->dev, "coherent dma mask is unset\n");

        ret = request_resource(parent, &dev->res);
        if (ret == 0) {
                tmp = ioremap(dev->res.start, SZ_4K);
                if (!tmp) {
                        ret = -ENOMEM;
                        goto out;
                }

                for (pid = 0, i = 0; i < 4; i++)
                        pid |= (readl(tmp + 0xfe0 + 4 * i) & 255) << (i * 8);
                for (cid = 0, i = 0; i < 4; i++)
                        cid |= (readl(tmp + 0xff0 + 4 * i) & 255) << (i * 8);

                iounmap(tmp);

                if (cid == 0xb105f00d)
                        dev->periphid = pid;

                if (dev->periphid)
                        ret = device_register(&dev->dev);
                else
                        ret = -ENODEV;

                if (ret == 0) {
                        device_create_file(&dev->dev, &dev_attr_id);
                        if (dev->irq[0] != NO_IRQ)
                                device_create_file(&dev->dev, &dev_attr_irq0);
                        if (dev->irq[1] != NO_IRQ)
                                device_create_file(&dev->dev, &dev_attr_irq1);
                        device_create_file(&dev->dev, &dev_attr_resource);
                } else {
 out:
                        release_resource(&dev->res);
                }
        }
        return ret;
}

/**
 *      amba_device_unregister - unregister an AMBA device
 *      @dev: AMBA device to remove
 *
 *      Remove the specified AMBA device from the Linux device
 *      manager.  All files associated with this object will be
 *      destroyed, and device drivers notified that the device has
 *      been removed.  The AMBA device's resources including
 *      the amba_device structure will be freed once all
 *      references to it have been dropped.
 */
void amba_device_unregister(struct amba_device *dev)
{
        device_unregister(&dev->dev);
}


struct find_data {
        struct amba_device *dev;
        struct device *parent;
        const char *busid;
        unsigned int id;
        unsigned int mask;
};

static int amba_find_match(struct device *dev, void *data)
{
        struct find_data *d = data;
        struct amba_device *pcdev = to_amba_device(dev);
        int r;

        r = (pcdev->periphid & d->mask) == d->id;
        if (d->parent)
                r &= d->parent == dev->parent;
        if (d->busid)
                r &= strcmp(dev->bus_id, d->busid) == 0;

        if (r) {
                get_device(dev);
                d->dev = pcdev;
        }

        return r;
}

/**
 *      amba_find_device - locate an AMBA device given a bus id
 *      @busid: bus id for device (or NULL)
 *      @parent: parent device (or NULL)
 *      @id: peripheral ID (or 0)
 *      @mask: peripheral ID mask (or 0)
 *
 *      Return the AMBA device corresponding to the supplied parameters.
 *      If no device matches, returns NULL.
 *
 *      NOTE: When a valid device is found, its refcount is
 *      incremented, and must be decremented before the returned
 *      reference.
 */
struct amba_device *
amba_find_device(const char *busid, struct device *parent, unsigned int id,
                 unsigned int mask)
{
        struct find_data data;

        data.dev = NULL;
        data.parent = parent;
        data.busid = busid;
        data.id = id;
        data.mask = mask;

        bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match);

        return data.dev;
}

/**
 *      amba_request_regions - request all mem regions associated with device
 *      @dev: amba_device structure for device
 *      @name: name, or NULL to use driver name
 */
int amba_request_regions(struct amba_device *dev, const char *name)
{
        int ret = 0;

        if (!name)
                name = dev->dev.driver->name;

        if (!request_mem_region(dev->res.start, SZ_4K, name))
                ret = -EBUSY;

        return ret;
}

/**
 *      amba_release_regions - release mem regions assoicated with device
 *      @dev: amba_device structure for device
 *
 *      Release regions claimed by a successful call to amba_request_regions.
 */
void amba_release_regions(struct amba_device *dev)
{
        release_mem_region(dev->res.start, SZ_4K);
}

EXPORT_SYMBOL(amba_driver_register);
EXPORT_SYMBOL(amba_driver_unregister);
EXPORT_SYMBOL(amba_device_register);
EXPORT_SYMBOL(amba_device_unregister);
EXPORT_SYMBOL(amba_find_device);
EXPORT_SYMBOL(amba_request_regions);
EXPORT_SYMBOL(amba_release_regions);