/*
 * IBM PowerPC IBM eBus Infrastructure Support.
 *
 * Copyright (c) 2005 IBM Corporation
 *  Joachim Fenkes <fenkes@de.ibm.com>
 *  Heiko J Schick <schickhj@de.ibm.com>
 *
 * All rights reserved.
 *
 * This source code is distributed under a dual license of GPL v2.0 and OpenIB
 * BSD.
 *
 * OpenIB BSD License
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials
 * provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <linux/init.h>
#include <linux/export.h>
#include <linux/console.h>
#include <linux/kobject.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/of_platform.h>
#include <asm/ibmebus.h>

static struct device ibmebus_bus_device = { /* fake "parent" device */
        .init_name = "ibmebus",
};

struct bus_type ibmebus_bus_type;

/* These devices will automatically be added to the bus during init */
static const struct of_device_id ibmebus_matches[] __initconst = {
        { .compatible = "IBM,lhca" },
        { .compatible = "IBM,lhea" },
        {},
};

static void *ibmebus_alloc_coherent(struct device *dev,
                                    size_t size,
                                    dma_addr_t *dma_handle,
                                    gfp_t flag,
                                    struct dma_attrs *attrs)
{
        void *mem;

        mem = kmalloc(size, flag);
        *dma_handle = (dma_addr_t)mem;

        return mem;
}

static void ibmebus_free_coherent(struct device *dev,
                                  size_t size, void *vaddr,
                                  dma_addr_t dma_handle,
                                  struct dma_attrs *attrs)
{
        kfree(vaddr);
}

static dma_addr_t ibmebus_map_page(struct device *dev,
                                   struct page *page,
                                   unsigned long offset,
                                   size_t size,
                                   enum dma_data_direction direction,
                                   struct dma_attrs *attrs)
{
        return (dma_addr_t)(page_address(page) + offset);
}

static void ibmebus_unmap_page(struct device *dev,
                               dma_addr_t dma_addr,
                               size_t size,
                               enum dma_data_direction direction,
                               struct dma_attrs *attrs)
{
        return;
}

static int ibmebus_map_sg(struct device *dev,
                          struct scatterlist *sgl,
                          int nents, enum dma_data_direction direction,
                          struct dma_attrs *attrs)
{
        struct scatterlist *sg;
        int i;

        for_each_sg(sgl, sg, nents, i) {
                sg->dma_address = (dma_addr_t) sg_virt(sg);
                sg->dma_length = sg->length;
        }

        return nents;
}

static void ibmebus_unmap_sg(struct device *dev,
                             struct scatterlist *sg,
                             int nents, enum dma_data_direction direction,
                             struct dma_attrs *attrs)
{
        return;
}

static int ibmebus_dma_supported(struct device *dev, u64 mask)
{
        return mask == DMA_BIT_MASK(64);
}

static u64 ibmebus_dma_get_required_mask(struct device *dev)
{
        return DMA_BIT_MASK(64);
}

static struct dma_map_ops ibmebus_dma_ops = {
        .alloc              = ibmebus_alloc_coherent,
        .free               = ibmebus_free_coherent,
        .map_sg             = ibmebus_map_sg,
        .unmap_sg           = ibmebus_unmap_sg,
        .dma_supported      = ibmebus_dma_supported,
        .get_required_mask  = ibmebus_dma_get_required_mask,
        .map_page           = ibmebus_map_page,
        .unmap_page         = ibmebus_unmap_page,
};

static int ibmebus_match_path(struct device *dev, void *data)
{
        struct device_node *dn = to_platform_device(dev)->dev.of_node;
        return (dn->full_name &&
                (strcasecmp((char *)data, dn->full_name) == 0));
}

static int ibmebus_match_node(struct device *dev, void *data)
{
        return to_platform_device(dev)->dev.of_node == data;
}

static int ibmebus_create_device(struct device_node *dn)
{
        struct platform_device *dev;
        int ret;

        dev = of_device_alloc(dn, NULL, &ibmebus_bus_device);
        if (!dev)
                return -ENOMEM;

        dev->dev.bus = &ibmebus_bus_type;
        dev->dev.archdata.dma_ops = &ibmebus_dma_ops;

        ret = of_device_add(dev);
        if (ret)
                platform_device_put(dev);
        return ret;
}

static int ibmebus_create_devices(const struct of_device_id *matches)
{
        struct device_node *root, *child;
        int ret = 0;

        root = of_find_node_by_path("/");

        for_each_child_of_node(root, child) {
                if (!of_match_node(matches, child))
                        continue;

                if (bus_find_device(&ibmebus_bus_type, NULL, child,
                                    ibmebus_match_node))
                        continue;

                ret = ibmebus_create_device(child);
                if (ret) {
                        printk(KERN_ERR "%s: failed to create device (%i)",
                               __func__, ret);
                        of_node_put(child);
                        break;
                }
        }

        of_node_put(root);
        return ret;
}

int ibmebus_register_driver(struct platform_driver *drv)
{
        /* If the driver uses devices that ibmebus doesn't know, add them */
        ibmebus_create_devices(drv->driver.of_match_table);

        drv->driver.bus = &ibmebus_bus_type;
        return driver_register(&drv->driver);
}
EXPORT_SYMBOL(ibmebus_register_driver);

void ibmebus_unregister_driver(struct platform_driver *drv)
{
        driver_unregister(&drv->driver);
}
EXPORT_SYMBOL(ibmebus_unregister_driver);

int ibmebus_request_irq(u32 ist, irq_handler_t handler,
                        unsigned long irq_flags, const char *devname,
                        void *dev_id)
{
        unsigned int irq = irq_create_mapping(NULL, ist);

        if (irq == NO_IRQ)
                return -EINVAL;

        return request_irq(irq, handler, irq_flags, devname, dev_id);
}
EXPORT_SYMBOL(ibmebus_request_irq);

void ibmebus_free_irq(u32 ist, void *dev_id)
{
        unsigned int irq = irq_find_mapping(NULL, ist);

        free_irq(irq, dev_id);
        irq_dispose_mapping(irq);
}
EXPORT_SYMBOL(ibmebus_free_irq);

static char *ibmebus_chomp(const char *in, size_t count)
{
        char *out = kmalloc(count + 1, GFP_KERNEL);

        if (!out)
                return NULL;

        memcpy(out, in, count);
        out[count] = '\0';
        if (out[count - 1] == '\n')
                out[count - 1] = '\0';

        return out;
}

static ssize_t ibmebus_store_probe(struct bus_type *bus,
                                   const char *buf, size_t count)
{
        struct device_node *dn = NULL;
        char *path;
        ssize_t rc = 0;

        path = ibmebus_chomp(buf, count);
        if (!path)
                return -ENOMEM;

        if (bus_find_device(&ibmebus_bus_type, NULL, path,
                            ibmebus_match_path)) {
                printk(KERN_WARNING "%s: %s has already been probed\n",
                       __func__, path);
                rc = -EEXIST;
                goto out;
        }

        if ((dn = of_find_node_by_path(path))) {
                rc = ibmebus_create_device(dn);
                of_node_put(dn);
        } else {
                printk(KERN_WARNING "%s: no such device node: %s\n",
                       __func__, path);
                rc = -ENODEV;
        }

out:
        kfree(path);
        if (rc)
                return rc;
        return count;
}
static BUS_ATTR(probe, S_IWUSR, NULL, ibmebus_store_probe);

static ssize_t ibmebus_store_remove(struct bus_type *bus,
                                    const char *buf, size_t count)
{
        struct device *dev;
        char *path;

        path = ibmebus_chomp(buf, count);
        if (!path)
                return -ENOMEM;

        if ((dev = bus_find_device(&ibmebus_bus_type, NULL, path,
                                   ibmebus_match_path))) {
                of_device_unregister(to_platform_device(dev));

                kfree(path);
                return count;
        } else {
                printk(KERN_WARNING "%s: %s not on the bus\n",
                       __func__, path);

                kfree(path);
                return -ENODEV;
        }
}
static BUS_ATTR(remove, S_IWUSR, NULL, ibmebus_store_remove);

static struct attribute *ibmbus_bus_attrs[] = {
        &bus_attr_probe.attr,
        &bus_attr_remove.attr,
        NULL,
};
ATTRIBUTE_GROUPS(ibmbus_bus);

static int ibmebus_bus_bus_match(struct device *dev, struct device_driver *drv)
{
        const struct of_device_id *matches = drv->of_match_table;

        if (!matches)
                return 0;

        return of_match_device(matches, dev) != NULL;
}

static int ibmebus_bus_device_probe(struct device *dev)
{
        int error = -ENODEV;
        struct platform_driver *drv;
        struct platform_device *of_dev;

        drv = to_platform_driver(dev->driver);
        of_dev = to_platform_device(dev);

        if (!drv->probe)
                return error;

        of_dev_get(of_dev);

        if (of_driver_match_device(dev, dev->driver))
                error = drv->probe(of_dev);
        if (error)
                of_dev_put(of_dev);

        return error;
}

static int ibmebus_bus_device_remove(struct device *dev)
{
        struct platform_device *of_dev = to_platform_device(dev);
        struct platform_driver *drv = to_platform_driver(dev->driver);

        if (dev->driver && drv->remove)
                drv->remove(of_dev);
        return 0;
}

static void ibmebus_bus_device_shutdown(struct device *dev)
{
        struct platform_device *of_dev = to_platform_device(dev);
        struct platform_driver *drv = to_platform_driver(dev->driver);

        if (dev->driver && drv->shutdown)
                drv->shutdown(of_dev);
}

/*
 * ibmebus_bus_device_attrs
 */
static ssize_t devspec_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct platform_device *ofdev;

        ofdev = to_platform_device(dev);
        return sprintf(buf, "%s\n", ofdev->dev.of_node->full_name);
}

static ssize_t name_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct platform_device *ofdev;

        ofdev = to_platform_device(dev);
        return sprintf(buf, "%s\n", ofdev->dev.of_node->name);
}

static ssize_t modalias_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        ssize_t len = of_device_get_modalias(dev, buf, PAGE_SIZE - 2);
        buf[len] = '\n';
        buf[len+1] = 0;
        return len+1;
}

struct device_attribute ibmebus_bus_device_attrs[] = {
        __ATTR_RO(devspec),
        __ATTR_RO(name),
        __ATTR_RO(modalias),
        __ATTR_NULL
};

#ifdef CONFIG_PM_SLEEP
static int ibmebus_bus_legacy_suspend(struct device *dev, pm_message_t mesg)
{
        struct platform_device *of_dev = to_platform_device(dev);
        struct platform_driver *drv = to_platform_driver(dev->driver);
        int ret = 0;

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

static int ibmebus_bus_legacy_resume(struct device *dev)
{
        struct platform_device *of_dev = to_platform_device(dev);
        struct platform_driver *drv = to_platform_driver(dev->driver);
        int ret = 0;

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

static int ibmebus_bus_pm_prepare(struct device *dev)
{
        struct device_driver *drv = dev->driver;
        int ret = 0;

        if (drv && drv->pm && drv->pm->prepare)
                ret = drv->pm->prepare(dev);

        return ret;
}

static void ibmebus_bus_pm_complete(struct device *dev)
{
        struct device_driver *drv = dev->driver;

        if (drv && drv->pm && drv->pm->complete)
                drv->pm->complete(dev);
}

#ifdef CONFIG_SUSPEND

static int ibmebus_bus_pm_suspend(struct device *dev)
{
        struct device_driver *drv = dev->driver;
        int ret = 0;

        if (!drv)
                return 0;

        if (drv->pm) {
                if (drv->pm->suspend)
                        ret = drv->pm->suspend(dev);
        } else {
                ret = ibmebus_bus_legacy_suspend(dev, PMSG_SUSPEND);
        }

        return ret;
}

static int ibmebus_bus_pm_suspend_noirq(struct device *dev)
{
        struct device_driver *drv = dev->driver;
        int ret = 0;

        if (!drv)
                return 0;

        if (drv->pm) {
                if (drv->pm->suspend_noirq)
                        ret = drv->pm->suspend_noirq(dev);
        }

        return ret;
}

static int ibmebus_bus_pm_resume(struct device *dev)
{
        struct device_driver *drv = dev->driver;
        int ret = 0;

        if (!drv)
                return 0;

        if (drv->pm) {
                if (drv->pm->resume)
                        ret = drv->pm->resume(dev);
        } else {
                ret = ibmebus_bus_legacy_resume(dev);
        }

        return ret;
}

static int ibmebus_bus_pm_resume_noirq(struct device *dev)
{
        struct device_driver *drv = dev->driver;
        int ret = 0;

        if (!drv)
                return 0;

        if (drv->pm) {
                if (drv->pm->resume_noirq)
                        ret = drv->pm->resume_noirq(dev);
        }

        return ret;
}

#else /* !CONFIG_SUSPEND */

#define ibmebus_bus_pm_suspend          NULL
#define ibmebus_bus_pm_resume           NULL
#define ibmebus_bus_pm_suspend_noirq    NULL
#define ibmebus_bus_pm_resume_noirq     NULL

#endif /* !CONFIG_SUSPEND */

#ifdef CONFIG_HIBERNATE_CALLBACKS

static int ibmebus_bus_pm_freeze(struct device *dev)
{
        struct device_driver *drv = dev->driver;
        int ret = 0;

        if (!drv)
                return 0;

        if (drv->pm) {
                if (drv->pm->freeze)
                        ret = drv->pm->freeze(dev);
        } else {
                ret = ibmebus_bus_legacy_suspend(dev, PMSG_FREEZE);
        }

        return ret;
}

static int ibmebus_bus_pm_freeze_noirq(struct device *dev)
{
        struct device_driver *drv = dev->driver;
        int ret = 0;

        if (!drv)
                return 0;

        if (drv->pm) {
                if (drv->pm->freeze_noirq)
                        ret = drv->pm->freeze_noirq(dev);
        }

        return ret;
}

static int ibmebus_bus_pm_thaw(struct device *dev)
{
        struct device_driver *drv = dev->driver;
        int ret = 0;

        if (!drv)
                return 0;

        if (drv->pm) {
                if (drv->pm->thaw)
                        ret = drv->pm->thaw(dev);
        } else {
                ret = ibmebus_bus_legacy_resume(dev);
        }

        return ret;
}

static int ibmebus_bus_pm_thaw_noirq(struct device *dev)
{
        struct device_driver *drv = dev->driver;
        int ret = 0;

        if (!drv)
                return 0;

        if (drv->pm) {
                if (drv->pm->thaw_noirq)
                        ret = drv->pm->thaw_noirq(dev);
        }

        return ret;
}

static int ibmebus_bus_pm_poweroff(struct device *dev)
{
        struct device_driver *drv = dev->driver;
        int ret = 0;

        if (!drv)
                return 0;

        if (drv->pm) {
                if (drv->pm->poweroff)
                        ret = drv->pm->poweroff(dev);
        } else {
                ret = ibmebus_bus_legacy_suspend(dev, PMSG_HIBERNATE);
        }

        return ret;
}

static int ibmebus_bus_pm_poweroff_noirq(struct device *dev)
{
        struct device_driver *drv = dev->driver;
        int ret = 0;

        if (!drv)
                return 0;

        if (drv->pm) {
                if (drv->pm->poweroff_noirq)
                        ret = drv->pm->poweroff_noirq(dev);
        }

        return ret;
}

static int ibmebus_bus_pm_restore(struct device *dev)
{
        struct device_driver *drv = dev->driver;
        int ret = 0;

        if (!drv)
                return 0;

        if (drv->pm) {
                if (drv->pm->restore)
                        ret = drv->pm->restore(dev);
        } else {
                ret = ibmebus_bus_legacy_resume(dev);
        }

        return ret;
}

static int ibmebus_bus_pm_restore_noirq(struct device *dev)
{
        struct device_driver *drv = dev->driver;
        int ret = 0;

        if (!drv)
                return 0;

        if (drv->pm) {
                if (drv->pm->restore_noirq)
                        ret = drv->pm->restore_noirq(dev);
        }

        return ret;
}

#else /* !CONFIG_HIBERNATE_CALLBACKS */

#define ibmebus_bus_pm_freeze           NULL
#define ibmebus_bus_pm_thaw             NULL
#define ibmebus_bus_pm_poweroff         NULL
#define ibmebus_bus_pm_restore          NULL
#define ibmebus_bus_pm_freeze_noirq     NULL
#define ibmebus_bus_pm_thaw_noirq               NULL
#define ibmebus_bus_pm_poweroff_noirq   NULL
#define ibmebus_bus_pm_restore_noirq    NULL

#endif /* !CONFIG_HIBERNATE_CALLBACKS */

static struct dev_pm_ops ibmebus_bus_dev_pm_ops = {
        .prepare = ibmebus_bus_pm_prepare,
        .complete = ibmebus_bus_pm_complete,
        .suspend = ibmebus_bus_pm_suspend,
        .resume = ibmebus_bus_pm_resume,
        .freeze = ibmebus_bus_pm_freeze,
        .thaw = ibmebus_bus_pm_thaw,
        .poweroff = ibmebus_bus_pm_poweroff,
        .restore = ibmebus_bus_pm_restore,
        .suspend_noirq = ibmebus_bus_pm_suspend_noirq,
        .resume_noirq = ibmebus_bus_pm_resume_noirq,
        .freeze_noirq = ibmebus_bus_pm_freeze_noirq,
        .thaw_noirq = ibmebus_bus_pm_thaw_noirq,
        .poweroff_noirq = ibmebus_bus_pm_poweroff_noirq,
        .restore_noirq = ibmebus_bus_pm_restore_noirq,
};

#define IBMEBUS_BUS_PM_OPS_PTR  (&ibmebus_bus_dev_pm_ops)

#else /* !CONFIG_PM_SLEEP */

#define IBMEBUS_BUS_PM_OPS_PTR  NULL

#endif /* !CONFIG_PM_SLEEP */

struct bus_type ibmebus_bus_type = {
        .name      = "ibmebus",
        .uevent    = of_device_uevent_modalias,
        .bus_groups = ibmbus_bus_groups,
        .match     = ibmebus_bus_bus_match,
        .probe     = ibmebus_bus_device_probe,
        .remove    = ibmebus_bus_device_remove,
        .shutdown  = ibmebus_bus_device_shutdown,
        .dev_attrs = ibmebus_bus_device_attrs,
        .pm        = IBMEBUS_BUS_PM_OPS_PTR,
};
EXPORT_SYMBOL(ibmebus_bus_type);

static int __init ibmebus_bus_init(void)
{
        int err;

        printk(KERN_INFO "IBM eBus Device Driver\n");

        err = bus_register(&ibmebus_bus_type);
        if (err) {
                printk(KERN_ERR "%s: failed to register IBM eBus.\n",
                       __func__);
                return err;
        }

        err = device_register(&ibmebus_bus_device);
        if (err) {
                printk(KERN_WARNING "%s: device_register returned %i\n",
                       __func__, err);
                bus_unregister(&ibmebus_bus_type);

                return err;
        }

        err = ibmebus_create_devices(ibmebus_matches);
        if (err) {
                device_unregister(&ibmebus_bus_device);
                bus_unregister(&ibmebus_bus_type);
                return err;
        }

        return 0;
}
postcore_initcall(ibmebus_bus_init);