/*
 * platform.c - platform 'pseudo' bus for legacy devices
 *
 * Copyright (c) 2002-3 Patrick Mochel
 * Copyright (c) 2002-3 Open Source Development Labs
 *
 * This file is released under the GPLv2
 *
 * Please see Documentation/driver-model/platform.txt for more
 * information.
 */

#include <linux/device.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/dma-mapping.h>
#include <linux/bootmem.h>
#include <linux/err.h>

struct device platform_bus = {
        .bus_id         = "platform",
};

/**
 *      platform_get_resource - get a resource for a device
 *      @dev: platform device
 *      @type: resource type
 *      @num: resource index
 */
struct resource *
platform_get_resource(struct platform_device *dev, unsigned int type,
                      unsigned int num)
{
        int i;

        for (i = 0; i < dev->num_resources; i++) {
                struct resource *r = &dev->resource[i];

                if ((r->flags & (IORESOURCE_IO|IORESOURCE_MEM|
                                 IORESOURCE_IRQ|IORESOURCE_DMA))
                    == type)
                        if (num-- == 0)
                                return r;
        }
        return NULL;
}

/**
 *      platform_get_irq - get an IRQ for a device
 *      @dev: platform device
 *      @num: IRQ number index
 */
int platform_get_irq(struct platform_device *dev, unsigned int num)
{
        struct resource *r = platform_get_resource(dev, IORESOURCE_IRQ, num);

        return r ? r->start : 0;
}

/**
 *      platform_get_resource_byname - get a resource for a device by name
 *      @dev: platform device
 *      @type: resource type
 *      @name: resource name
 */
struct resource *
platform_get_resource_byname(struct platform_device *dev, unsigned int type,
                      char *name)
{
        int i;

        for (i = 0; i < dev->num_resources; i++) {
                struct resource *r = &dev->resource[i];

                if ((r->flags & (IORESOURCE_IO|IORESOURCE_MEM|
                                 IORESOURCE_IRQ|IORESOURCE_DMA)) == type)
                        if (!strcmp(r->name, name))
                                return r;
        }
        return NULL;
}

/**
 *      platform_get_irq - get an IRQ for a device
 *      @dev: platform device
 *      @name: IRQ name
 */
int platform_get_irq_byname(struct platform_device *dev, char *name)
{
        struct resource *r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name);

        return r ? r->start : 0;
}

/**
 *      platform_add_devices - add a numbers of platform devices
 *      @devs: array of platform devices to add
 *      @num: number of platform devices in array
 */
int platform_add_devices(struct platform_device **devs, int num)
{
        int i, ret = 0;

        for (i = 0; i < num; i++) {
                ret = platform_device_register(devs[i]);
                if (ret) {
                        while (--i >= 0)
                                platform_device_unregister(devs[i]);
                        break;
                }
        }

        return ret;
}

/**
 *      platform_device_register - add a platform-level device
 *      @dev:   platform device we're adding
 *
 */
int platform_device_register(struct platform_device * pdev)
{
        int i, ret = 0;

        if (!pdev)
                return -EINVAL;

        if (!pdev->dev.parent)
                pdev->dev.parent = &platform_bus;

        pdev->dev.bus = &platform_bus_type;

        if (pdev->id != -1)
                snprintf(pdev->dev.bus_id, BUS_ID_SIZE, "%s%u", pdev->name, pdev->id);
        else
                strlcpy(pdev->dev.bus_id, pdev->name, BUS_ID_SIZE);

        for (i = 0; i < pdev->num_resources; i++) {
                struct resource *p, *r = &pdev->resource[i];

                if (r->name == NULL)
                        r->name = pdev->dev.bus_id;

                p = r->parent;
                if (!p) {
                        if (r->flags & IORESOURCE_MEM)
                                p = &iomem_resource;
                        else if (r->flags & IORESOURCE_IO)
                                p = &ioport_resource;
                }

                if (p && request_resource(p, r)) {
                        printk(KERN_ERR
                               "%s: failed to claim resource %d\n",
                               pdev->dev.bus_id, i);
                        ret = -EBUSY;
                        goto failed;
                }
        }

        pr_debug("Registering platform device '%s'. Parent at %s\n",
                 pdev->dev.bus_id, pdev->dev.parent->bus_id);

        ret = device_register(&pdev->dev);
        if (ret == 0)
                return ret;

 failed:
        while (--i >= 0)
                if (pdev->resource[i].flags & (IORESOURCE_MEM|IORESOURCE_IO))
                        release_resource(&pdev->resource[i]);
        return ret;
}

/**
 *      platform_device_unregister - remove a platform-level device
 *      @dev:   platform device we're removing
 *
 *      Note that this function will also release all memory- and port-based
 *      resources owned by the device (@dev->resource).
 */
void platform_device_unregister(struct platform_device * pdev)
{
        int i;

        if (pdev) {
                for (i = 0; i < pdev->num_resources; i++) {
                        struct resource *r = &pdev->resource[i];
                        if (r->flags & (IORESOURCE_MEM|IORESOURCE_IO))
                                release_resource(r);
                }

                device_unregister(&pdev->dev);
        }
}

struct platform_object {
        struct platform_device pdev;
        struct resource resources[0];
};

static void platform_device_release_simple(struct device *dev)
{
        struct platform_device *pdev = to_platform_device(dev);

        kfree(container_of(pdev, struct platform_object, pdev));
}

/**
 *      platform_device_register_simple
 *      @name:  base name of the device we're adding
 *      @id:    instance id
 *      @res:   set of resources that needs to be allocated for the device
 *      @num:   number of resources
 *
 *      This function creates a simple platform device that requires minimal
 *      resource and memory management. Canned release function freeing
 *      memory allocated for the device allows drivers using such devices
 *      to be unloaded iwithout waiting for the last reference to the device
 *      to be dropped.
 */
struct platform_device *platform_device_register_simple(char *name, unsigned int id,
                                                        struct resource *res, unsigned int num)
{
        struct platform_object *pobj;
        int retval;

        pobj = kmalloc(sizeof(struct platform_object) + sizeof(struct resource) * num, GFP_KERNEL);
        if (!pobj) {
                retval = -ENOMEM;
                goto error;
        }

        memset(pobj, 0, sizeof(*pobj));
        pobj->pdev.name = name;
        pobj->pdev.id = id;
        pobj->pdev.dev.release = platform_device_release_simple;

        if (num) {
                memcpy(pobj->resources, res, sizeof(struct resource) * num);
                pobj->pdev.resource = pobj->resources;
                pobj->pdev.num_resources = num;
        }

        retval = platform_device_register(&pobj->pdev);
        if (retval)
                goto error;

        return &pobj->pdev;

error:
        kfree(pobj);
        return ERR_PTR(retval);
}


/**
 *      platform_match - bind platform device to platform driver.
 *      @dev:   device.
 *      @drv:   driver.
 *
 *      Platform device IDs are assumed to be encoded like this:
 *      "<name><instance>", where <name> is a short description of the
 *      type of device, like "pci" or "floppy", and <instance> is the
 *      enumerated instance of the device, like '0' or '42'.
 *      Driver IDs are simply "<name>".
 *      So, extract the <name> from the platform_device structure,
 *      and compare it against the name of the driver. Return whether
 *      they match or not.
 */

static int platform_match(struct device * dev, struct device_driver * drv)
{
        struct platform_device *pdev = container_of(dev, struct platform_device, dev);

        return (strncmp(pdev->name, drv->name, BUS_ID_SIZE) == 0);
}

static int platform_suspend(struct device * dev, pm_message_t state)
{
        int ret = 0;

        if (dev->driver && dev->driver->suspend) {
                ret = dev->driver->suspend(dev, state, SUSPEND_DISABLE);
                if (ret == 0)
                        ret = dev->driver->suspend(dev, state, SUSPEND_SAVE_STATE);
                if (ret == 0)
                        ret = dev->driver->suspend(dev, state, SUSPEND_POWER_DOWN);
        }
        return ret;
}

static int platform_resume(struct device * dev)
{
        int ret = 0;

        if (dev->driver && dev->driver->resume) {
                ret = dev->driver->resume(dev, RESUME_POWER_ON);
                if (ret == 0)
                        ret = dev->driver->resume(dev, RESUME_RESTORE_STATE);
                if (ret == 0)
                        ret = dev->driver->resume(dev, RESUME_ENABLE);
        }
        return ret;
}

struct bus_type platform_bus_type = {
        .name           = "platform",
        .match          = platform_match,
        .suspend        = platform_suspend,
        .resume         = platform_resume,
};

int __init platform_bus_init(void)
{
        device_register(&platform_bus);
        return bus_register(&platform_bus_type);
}

#ifndef ARCH_HAS_DMA_GET_REQUIRED_MASK
u64 dma_get_required_mask(struct device *dev)
{
        u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT);
        u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT));
        u64 mask;

        if (!high_totalram) {
                /* convert to mask just covering totalram */
                low_totalram = (1 << (fls(low_totalram) - 1));
                low_totalram += low_totalram - 1;
                mask = low_totalram;
        } else {
                high_totalram = (1 << (fls(high_totalram) - 1));
                high_totalram += high_totalram - 1;
                mask = (((u64)high_totalram) << 32) + 0xffffffff;
        }
        return mask & *dev->dma_mask;
}
EXPORT_SYMBOL_GPL(dma_get_required_mask);
#endif

EXPORT_SYMBOL_GPL(platform_bus);
EXPORT_SYMBOL_GPL(platform_bus_type);
EXPORT_SYMBOL_GPL(platform_device_register);
EXPORT_SYMBOL_GPL(platform_device_register_simple);
EXPORT_SYMBOL_GPL(platform_device_unregister);
EXPORT_SYMBOL_GPL(platform_get_irq);
EXPORT_SYMBOL_GPL(platform_get_resource);
EXPORT_SYMBOL_GPL(platform_get_irq_byname);
EXPORT_SYMBOL_GPL(platform_get_resource_byname);