/*
 * IBM PowerPC Virtual I/O Infrastructure Support.
 *
 *    Copyright (c) 2003-2005 IBM Corp.
 *     Dave Engebretsen engebret@us.ibm.com
 *     Santiago Leon santil@us.ibm.com
 *     Hollis Blanchard <hollisb@us.ibm.com>
 *     Stephen Rothwell
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#include <linux/types.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/dma-mapping.h>
#include <linux/kobject.h>

#include <asm/iommu.h>
#include <asm/dma.h>
#include <asm/vio.h>
#include <asm/prom.h>
#include <asm/firmware.h>
#include <asm/tce.h>
#include <asm/abs_addr.h>
#include <asm/page.h>
#include <asm/hvcall.h>
#include <asm/iseries/vio.h>
#include <asm/iseries/hv_types.h>
#include <asm/iseries/hv_lp_config.h>
#include <asm/iseries/hv_call_xm.h>
#include <asm/iseries/iommu.h>

extern struct kset devices_subsys; /* needed for vio_find_name() */

static struct bus_type vio_bus_type;

static struct vio_dev vio_bus_device  = { /* fake "parent" device */
        .name = vio_bus_device.dev.bus_id,
        .type = "",
        .dev.bus_id = "vio",
        .dev.bus = &vio_bus_type,
};

static struct iommu_table *vio_build_iommu_table(struct vio_dev *dev)
{
        const unsigned char *dma_window;
        struct iommu_table *tbl;
        unsigned long offset, size;

        if (firmware_has_feature(FW_FEATURE_ISERIES))
                return vio_build_iommu_table_iseries(dev);

        dma_window = of_get_property(dev->dev.archdata.of_node,
                                  "ibm,my-dma-window", NULL);
        if (!dma_window)
                return NULL;

        tbl = kmalloc(sizeof(*tbl), GFP_KERNEL);

        of_parse_dma_window(dev->dev.archdata.of_node, dma_window,
                            &tbl->it_index, &offset, &size);

        /* TCE table size - measured in tce entries */
        tbl->it_size = size >> IOMMU_PAGE_SHIFT;
        /* offset for VIO should always be 0 */
        tbl->it_offset = offset >> IOMMU_PAGE_SHIFT;
        tbl->it_busno = 0;
        tbl->it_type = TCE_VB;

        return iommu_init_table(tbl, -1);
}

/**
 * vio_match_device: - Tell if a VIO device has a matching
 *                      VIO device id structure.
 * @ids:        array of VIO device id structures to search in
 * @dev:        the VIO device structure to match against
 *
 * Used by a driver to check whether a VIO device present in the
 * system is in its list of supported devices. Returns the matching
 * vio_device_id structure or NULL if there is no match.
 */
static const struct vio_device_id *vio_match_device(
                const struct vio_device_id *ids, const struct vio_dev *dev)
{
        while (ids->type[0] != '\0') {
                if ((strncmp(dev->type, ids->type, strlen(ids->type)) == 0) &&
                    of_device_is_compatible(dev->dev.archdata.of_node,
                                         ids->compat))
                        return ids;
                ids++;
        }
        return NULL;
}

/*
 * Convert from struct device to struct vio_dev and pass to driver.
 * dev->driver has already been set by generic code because vio_bus_match
 * succeeded.
 */
static int vio_bus_probe(struct device *dev)
{
        struct vio_dev *viodev = to_vio_dev(dev);
        struct vio_driver *viodrv = to_vio_driver(dev->driver);
        const struct vio_device_id *id;
        int error = -ENODEV;

        if (!viodrv->probe)
                return error;

        id = vio_match_device(viodrv->id_table, viodev);
        if (id)
                error = viodrv->probe(viodev, id);

        return error;
}

/* convert from struct device to struct vio_dev and pass to driver. */
static int vio_bus_remove(struct device *dev)
{
        struct vio_dev *viodev = to_vio_dev(dev);
        struct vio_driver *viodrv = to_vio_driver(dev->driver);

        if (viodrv->remove)
                return viodrv->remove(viodev);

        /* driver can't remove */
        return 1;
}

/**
 * vio_register_driver: - Register a new vio driver
 * @drv:        The vio_driver structure to be registered.
 */
int vio_register_driver(struct vio_driver *viodrv)
{
        printk(KERN_DEBUG "%s: driver %s registering\n", __FUNCTION__,
                viodrv->driver.name);

        /* fill in 'struct driver' fields */
        viodrv->driver.bus = &vio_bus_type;

        return driver_register(&viodrv->driver);
}
EXPORT_SYMBOL(vio_register_driver);

/**
 * vio_unregister_driver - Remove registration of vio driver.
 * @driver:     The vio_driver struct to be removed form registration
 */
void vio_unregister_driver(struct vio_driver *viodrv)
{
        driver_unregister(&viodrv->driver);
}
EXPORT_SYMBOL(vio_unregister_driver);

/* vio_dev refcount hit 0 */
static void __devinit vio_dev_release(struct device *dev)
{
        /* XXX should free TCE table */
        of_node_put(dev->archdata.of_node);
        kfree(to_vio_dev(dev));
}

/**
 * vio_register_device_node: - Register a new vio device.
 * @of_node:    The OF node for this device.
 *
 * Creates and initializes a vio_dev structure from the data in
 * of_node and adds it to the list of virtual devices.
 * Returns a pointer to the created vio_dev or NULL if node has
 * NULL device_type or compatible fields.
 */
struct vio_dev * __devinit vio_register_device_node(struct device_node *of_node)
{
        struct vio_dev *viodev;
        const unsigned int *unit_address;

        /* we need the 'device_type' property, in order to match with drivers */
        if (of_node->type == NULL) {
                printk(KERN_WARNING "%s: node %s missing 'device_type'\n",
                                __FUNCTION__,
                                of_node->name ? of_node->name : "<unknown>");
                return NULL;
        }

        unit_address = of_get_property(of_node, "reg", NULL);
        if (unit_address == NULL) {
                printk(KERN_WARNING "%s: node %s missing 'reg'\n",
                                __FUNCTION__,
                                of_node->name ? of_node->name : "<unknown>");
                return NULL;
        }

        /* allocate a vio_dev for this node */
        viodev = kzalloc(sizeof(struct vio_dev), GFP_KERNEL);
        if (viodev == NULL)
                return NULL;

        viodev->irq = irq_of_parse_and_map(of_node, 0);

        snprintf(viodev->dev.bus_id, BUS_ID_SIZE, "%x", *unit_address);
        viodev->name = of_node->name;
        viodev->type = of_node->type;
        viodev->unit_address = *unit_address;
        if (firmware_has_feature(FW_FEATURE_ISERIES)) {
                unit_address = of_get_property(of_node,
                                "linux,unit_address", NULL);
                if (unit_address != NULL)
                        viodev->unit_address = *unit_address;
        }
        viodev->dev.archdata.of_node = of_node_get(of_node);
        viodev->dev.archdata.dma_ops = &dma_iommu_ops;
        viodev->dev.archdata.dma_data = vio_build_iommu_table(viodev);
        viodev->dev.archdata.numa_node = of_node_to_nid(of_node);

        /* init generic 'struct device' fields: */
        viodev->dev.parent = &vio_bus_device.dev;
        viodev->dev.bus = &vio_bus_type;
        viodev->dev.release = vio_dev_release;

        /* register with generic device framework */
        if (device_register(&viodev->dev)) {
                printk(KERN_ERR "%s: failed to register device %s\n",
                                __FUNCTION__, viodev->dev.bus_id);
                /* XXX free TCE table */
                kfree(viodev);
                return NULL;
        }

        return viodev;
}
EXPORT_SYMBOL(vio_register_device_node);

/**
 * vio_bus_init: - Initialize the virtual IO bus
 */
static int __init vio_bus_init(void)
{
        int err;
        struct device_node *node_vroot;

        err = bus_register(&vio_bus_type);
        if (err) {
                printk(KERN_ERR "failed to register VIO bus\n");
                return err;
        }

        /*
         * The fake parent of all vio devices, just to give us
         * a nice directory
         */
        err = device_register(&vio_bus_device.dev);
        if (err) {
                printk(KERN_WARNING "%s: device_register returned %i\n",
                                __FUNCTION__, err);
                return err;
        }

        node_vroot = of_find_node_by_name(NULL, "vdevice");
        if (node_vroot) {
                struct device_node *of_node;

                /*
                 * Create struct vio_devices for each virtual device in
                 * the device tree. Drivers will associate with them later.
                 */
                for (of_node = node_vroot->child; of_node != NULL;
                                of_node = of_node->sibling)
                        vio_register_device_node(of_node);
                of_node_put(node_vroot);
        }

        return 0;
}
__initcall(vio_bus_init);

static ssize_t name_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        return sprintf(buf, "%s\n", to_vio_dev(dev)->name);
}

static ssize_t devspec_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct device_node *of_node = dev->archdata.of_node;

        return sprintf(buf, "%s\n", of_node ? of_node->full_name : "none");
}

static struct device_attribute vio_dev_attrs[] = {
        __ATTR_RO(name),
        __ATTR_RO(devspec),
        __ATTR_NULL
};

void __devinit vio_unregister_device(struct vio_dev *viodev)
{
        device_unregister(&viodev->dev);
}
EXPORT_SYMBOL(vio_unregister_device);

static int vio_bus_match(struct device *dev, struct device_driver *drv)
{
        const struct vio_dev *vio_dev = to_vio_dev(dev);
        struct vio_driver *vio_drv = to_vio_driver(drv);
        const struct vio_device_id *ids = vio_drv->id_table;

        return (ids != NULL) && (vio_match_device(ids, vio_dev) != NULL);
}

static int vio_hotplug(struct device *dev, struct kobj_uevent_env *env)
{
        const struct vio_dev *vio_dev = to_vio_dev(dev);
        struct device_node *dn;
        const char *cp;

        dn = dev->archdata.of_node;
        if (!dn)
                return -ENODEV;
        cp = of_get_property(dn, "compatible", NULL);
        if (!cp)
                return -ENODEV;

        add_uevent_var(env, "MODALIAS=vio:T%sS%s", vio_dev->type, cp);
        return 0;
}

static struct bus_type vio_bus_type = {
        .name = "vio",
        .dev_attrs = vio_dev_attrs,
        .uevent = vio_hotplug,
        .match = vio_bus_match,
        .probe = vio_bus_probe,
        .remove = vio_bus_remove,
};

/**
 * vio_get_attribute: - get attribute for virtual device
 * @vdev:       The vio device to get property.
 * @which:      The property/attribute to be extracted.
 * @length:     Pointer to length of returned data size (unused if NULL).
 *
 * Calls prom.c's of_get_property() to return the value of the
 * attribute specified by @which
*/
const void *vio_get_attribute(struct vio_dev *vdev, char *which, int *length)
{
        return of_get_property(vdev->dev.archdata.of_node, which, length);
}
EXPORT_SYMBOL(vio_get_attribute);

#ifdef CONFIG_PPC_PSERIES
/* vio_find_name() - internal because only vio.c knows how we formatted the
 * kobject name
 * XXX once vio_bus_type.devices is actually used as a kset in
 * drivers/base/bus.c, this function should be removed in favor of
 * "device_find(kobj_name, &vio_bus_type)"
 */
static struct vio_dev *vio_find_name(const char *kobj_name)
{
        struct kobject *found;

        found = kset_find_obj(&devices_subsys, kobj_name);
        if (!found)
                return NULL;

        return to_vio_dev(container_of(found, struct device, kobj));
}

/**
 * vio_find_node - find an already-registered vio_dev
 * @vnode: device_node of the virtual device we're looking for
 */
struct vio_dev *vio_find_node(struct device_node *vnode)
{
        const uint32_t *unit_address;
        char kobj_name[BUS_ID_SIZE];

        /* construct the kobject name from the device node */
        unit_address = of_get_property(vnode, "reg", NULL);
        if (!unit_address)
                return NULL;
        snprintf(kobj_name, BUS_ID_SIZE, "%x", *unit_address);

        return vio_find_name(kobj_name);
}
EXPORT_SYMBOL(vio_find_node);

int vio_enable_interrupts(struct vio_dev *dev)
{
        int rc = h_vio_signal(dev->unit_address, VIO_IRQ_ENABLE);
        if (rc != H_SUCCESS)
                printk(KERN_ERR "vio: Error 0x%x enabling interrupts\n", rc);
        return rc;
}
EXPORT_SYMBOL(vio_enable_interrupts);

int vio_disable_interrupts(struct vio_dev *dev)
{
        int rc = h_vio_signal(dev->unit_address, VIO_IRQ_DISABLE);
        if (rc != H_SUCCESS)
                printk(KERN_ERR "vio: Error 0x%x disabling interrupts\n", rc);
        return rc;
}
EXPORT_SYMBOL(vio_disable_interrupts);
#endif /* CONFIG_PPC_PSERIES */