// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Bus & driver management routines for devices within
 * a MacIO ASIC. Interface to new driver model mostly
 * stolen from the PCI version.
 * 
 *  Copyright (C) 2005 Ben. Herrenschmidt (benh@kernel.crashing.org)
 *
 * TODO:
 * 
 *  - Don't probe below media bay by default, but instead provide
 *    some hooks for media bay to dynamically add/remove it's own
 *    sub-devices.
 */
 
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/of_irq.h>

#include <asm/machdep.h>
#include <asm/macio.h>
#include <asm/pmac_feature.h>

#undef DEBUG

#define MAX_NODE_NAME_SIZE (20 - 12)

static struct macio_chip      *macio_on_hold;

static int macio_bus_match(struct device *dev, const 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;
}

struct macio_dev *macio_dev_get(struct macio_dev *dev)
{
        struct device *tmp;

        if (!dev)
                return NULL;
        tmp = get_device(&dev->ofdev.dev);
        if (tmp)
                return to_macio_device(tmp);
        else
                return NULL;
}

void macio_dev_put(struct macio_dev *dev)
{
        if (dev)
                put_device(&dev->ofdev.dev);
}


static int macio_device_probe(struct device *dev)
{
        int error = -ENODEV;
        struct macio_driver *drv;
        struct macio_dev *macio_dev;
        const struct of_device_id *match;

        drv = to_macio_driver(dev->driver);
        macio_dev = to_macio_device(dev);

        if (!drv->probe)
                return error;

        macio_dev_get(macio_dev);

        match = of_match_device(drv->driver.of_match_table, dev);
        if (match)
                error = drv->probe(macio_dev, match);
        if (error)
                macio_dev_put(macio_dev);

        return error;
}

static void macio_device_remove(struct device *dev)
{
        struct macio_dev * macio_dev = to_macio_device(dev);
        struct macio_driver * drv = to_macio_driver(dev->driver);

        if (dev->driver && drv->remove)
                drv->remove(macio_dev);
        macio_dev_put(macio_dev);
}

static void macio_device_shutdown(struct device *dev)
{
        struct macio_dev * macio_dev = to_macio_device(dev);
        struct macio_driver * drv = to_macio_driver(dev->driver);

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

static int macio_device_suspend(struct device *dev, pm_message_t state)
{
        struct macio_dev * macio_dev = to_macio_device(dev);
        struct macio_driver * drv = to_macio_driver(dev->driver);

        if (dev->driver && drv->suspend)
                return drv->suspend(macio_dev, state);
        return 0;
}

static int macio_device_resume(struct device * dev)
{
        struct macio_dev * macio_dev = to_macio_device(dev);
        struct macio_driver * drv = to_macio_driver(dev->driver);

        if (dev->driver && drv->resume)
                return drv->resume(macio_dev);
        return 0;
}

static int macio_device_modalias(const struct device *dev, struct kobj_uevent_env *env)
{
        return of_device_uevent_modalias(dev, env);
}

extern const struct attribute_group *macio_dev_groups[];

const struct bus_type macio_bus_type = {
       .name    = "macio",
       .match   = macio_bus_match,
       .uevent  = macio_device_modalias,
       .probe   = macio_device_probe,
       .remove  = macio_device_remove,
       .shutdown = macio_device_shutdown,
       .suspend = macio_device_suspend,
       .resume  = macio_device_resume,
       .dev_groups = macio_dev_groups,
};

static int __init macio_bus_driver_init(void)
{
        return bus_register(&macio_bus_type);
}

postcore_initcall(macio_bus_driver_init);


/**
 * macio_release_dev - free a macio device structure when all users of it are
 * finished.
 * @dev: device that's been disconnected
 *
 * Will be called only by the device core when all users of this macio device
 * are done. This currently means never as we don't hot remove any macio
 * device yet, though that will happen with mediabay based devices in a later
 * implementation.
 */
static void macio_release_dev(struct device *dev)
{
        struct macio_dev *mdev;

        mdev = to_macio_device(dev);
        kfree(mdev);
}

/**
 * macio_resource_quirks - tweak or skip some resources for a device
 * @np: pointer to the device node
 * @res: resulting resource
 * @index: index of resource in node
 *
 * If this routine returns non-null, then the resource is completely
 * skipped.
 */
static int macio_resource_quirks(struct device_node *np, struct resource *res,
                                 int index)
{
        /* Only quirks for memory resources for now */
        if ((res->flags & IORESOURCE_MEM) == 0)
                return 0;

        /* Grand Central has too large resource 0 on some machines */
        if (index == 0 && of_node_name_eq(np, "gc"))
                res->end = res->start + 0x1ffff;

        /* Airport has bogus resource 2 */
        if (index >= 2 && of_node_name_eq(np, "radio"))
                return 1;

#ifndef CONFIG_PPC64
        /* DBDMAs may have bogus sizes */
        if ((res->start & 0x0001f000) == 0x00008000)
                res->end = res->start + 0xff;
#endif /* CONFIG_PPC64 */

        /* ESCC parent eats child resources. We could have added a
         * level of hierarchy, but I don't really feel the need
         * for it
         */
        if (of_node_name_eq(np, "escc"))
                return 1;

        /* ESCC has bogus resources >= 3 */
        if (index >= 3 && (of_node_name_eq(np, "ch-a") ||
                           of_node_name_eq(np, "ch-b")))
                return 1;

        /* Media bay has too many resources, keep only first one */
        if (index > 0 && of_node_name_eq(np, "media-bay"))
                return 1;

        /* Some older IDE resources have bogus sizes */
        if (of_node_name_eq(np, "IDE") || of_node_name_eq(np, "ATA") ||
            of_node_is_type(np, "ide") || of_node_is_type(np, "ata")) {
                if (index == 0 && (res->end - res->start) > 0xfff)
                        res->end = res->start + 0xfff;
                if (index == 1 && (res->end - res->start) > 0xff)
                        res->end = res->start + 0xff;
        }
        return 0;
}

static void macio_create_fixup_irq(struct macio_dev *dev, int index,
                                   unsigned int line)
{
        unsigned int irq;

        irq = irq_create_mapping(NULL, line);
        if (!irq) {
                dev->interrupt[index].start = irq;
                dev->interrupt[index].flags = IORESOURCE_IRQ;
                dev->interrupt[index].name = dev_name(&dev->ofdev.dev);
        }
        if (dev->n_interrupts <= index)
                dev->n_interrupts = index + 1;
}

static void macio_add_missing_resources(struct macio_dev *dev)
{
        struct device_node *np = dev->ofdev.dev.of_node;
        unsigned int irq_base;

        /* Gatwick has some missing interrupts on child nodes */
        if (dev->bus->chip->type != macio_gatwick)
                return;

        /* irq_base is always 64 on gatwick. I have no cleaner way to get
         * that value from here at this point
         */
        irq_base = 64;

        /* Fix SCC */
        if (of_node_name_eq(np, "ch-a")) {
                macio_create_fixup_irq(dev, 0, 15 + irq_base);
                macio_create_fixup_irq(dev, 1,  4 + irq_base);
                macio_create_fixup_irq(dev, 2,  5 + irq_base);
                printk(KERN_INFO "macio: fixed SCC irqs on gatwick\n");
        }

        /* Fix media-bay */
        if (of_node_name_eq(np, "media-bay")) {
                macio_create_fixup_irq(dev, 0, 29 + irq_base);
                printk(KERN_INFO "macio: fixed media-bay irq on gatwick\n");
        }

        /* Fix left media bay childs */
        if (dev->media_bay != NULL && of_node_name_eq(np, "floppy")) {
                macio_create_fixup_irq(dev, 0, 19 + irq_base);
                macio_create_fixup_irq(dev, 1,  1 + irq_base);
                printk(KERN_INFO "macio: fixed left floppy irqs\n");
        }
        if (dev->media_bay != NULL && of_node_name_eq(np, "ata4")) {
                macio_create_fixup_irq(dev, 0, 14 + irq_base);
                macio_create_fixup_irq(dev, 0,  3 + irq_base);
                printk(KERN_INFO "macio: fixed left ide irqs\n");
        }
}

static void macio_setup_interrupts(struct macio_dev *dev)
{
        struct device_node *np = dev->ofdev.dev.of_node;
        unsigned int irq;
        int i = 0, j = 0;

        for (;;) {
                struct resource *res;

                if (j >= MACIO_DEV_COUNT_IRQS)
                        break;
                res = &dev->interrupt[j];
                irq = irq_of_parse_and_map(np, i++);
                if (!irq)
                        break;
                res->start = irq;
                res->flags = IORESOURCE_IRQ;
                res->name = dev_name(&dev->ofdev.dev);
                if (macio_resource_quirks(np, res, i - 1)) {
                        memset(res, 0, sizeof(struct resource));
                        continue;
                } else
                        j++;
        }
        dev->n_interrupts = j;
}

static void macio_setup_resources(struct macio_dev *dev,
                                  struct resource *parent_res)
{
        struct device_node *np = dev->ofdev.dev.of_node;
        struct resource r;
        int index;

        for (index = 0; of_address_to_resource(np, index, &r) == 0; index++) {
                struct resource *res;
                if (index >= MACIO_DEV_COUNT_RESOURCES)
                        break;
                res = &dev->resource[index];
                *res = r;
                res->name = dev_name(&dev->ofdev.dev);

                if (macio_resource_quirks(np, res, index)) {
                        memset(res, 0, sizeof(struct resource));
                        continue;
                }
                /* Currently, we consider failure as harmless, this may
                 * change in the future, once I've found all the device
                 * tree bugs in older machines & worked around them
                 */
                if (insert_resource(parent_res, res)) {
                        printk(KERN_WARNING "Can't request resource "
                               "%d for MacIO device %s\n",
                               index, dev_name(&dev->ofdev.dev));
                }
        }
        dev->n_resources = index;
}

/**
 * macio_add_one_device - Add one device from OF node to the device tree
 * @chip: pointer to the macio_chip holding the device
 * @np: pointer to the device node in the OF tree
 * @in_bay: set to 1 if device is part of a media-bay
 *
 * When media-bay is changed to hotswap drivers, this function will
 * be exposed to the bay driver some way...
 */
static struct macio_dev * macio_add_one_device(struct macio_chip *chip,
                                               struct device *parent,
                                               struct device_node *np,
                                               struct macio_dev *in_bay,
                                               struct resource *parent_res)
{
        char name[MAX_NODE_NAME_SIZE + 1];
        struct macio_dev *dev;
        const u32 *reg;

        if (np == NULL)
                return NULL;

        dev = kzalloc_obj(*dev);
        if (!dev)
                return NULL;

        dev->bus = &chip->lbus;
        dev->media_bay = in_bay;
        dev->ofdev.dev.of_node = np;
        dev->ofdev.archdata.dma_mask = 0xffffffffUL;
        dev->ofdev.dev.dma_mask = &dev->ofdev.archdata.dma_mask;
        dev->ofdev.dev.coherent_dma_mask = dev->ofdev.archdata.dma_mask;
        dev->ofdev.dev.parent = parent;
        dev->ofdev.dev.bus = &macio_bus_type;
        dev->ofdev.dev.release = macio_release_dev;
        dev->ofdev.dev.dma_parms = &dev->dma_parms;

        /* Standard DMA paremeters */
        dma_set_max_seg_size(&dev->ofdev.dev, 65536);
        dma_set_seg_boundary(&dev->ofdev.dev, 0xffffffff);

#if defined(CONFIG_PCI) && defined(CONFIG_ARCH_HAS_DMA_OPS)
        /* Set the DMA ops to the ones from the PCI device, this could be
         * fishy if we didn't know that on PowerMac it's always direct ops
         * or iommu ops that will work fine
         *
         * To get all the fields, copy all archdata
         */
        dev->ofdev.dev.archdata = chip->lbus.pdev->dev.archdata;
        dev->ofdev.dev.dma_ops = chip->lbus.pdev->dev.dma_ops;
#endif /* CONFIG_PCI && CONFIG_ARCH_HAS_DMA_OPS */

#ifdef DEBUG
        printk("preparing mdev @%p, ofdev @%p, dev @%p, kobj @%p\n",
               dev, &dev->ofdev, &dev->ofdev.dev, &dev->ofdev.dev.kobj);
#endif

        /* MacIO itself has a different reg, we use it's PCI base */
        snprintf(name, sizeof(name), "%pOFn", np);
        if (np == chip->of_node) {
                dev_set_name(&dev->ofdev.dev, "%1d.%08x:%.*s",
                             chip->lbus.index,
#ifdef CONFIG_PCI
                        (unsigned int)pci_resource_start(chip->lbus.pdev, 0),
#else
                        0, /* NuBus may want to do something better here */
#endif
                        MAX_NODE_NAME_SIZE, name);
        } else {
                reg = of_get_property(np, "reg", NULL);
                dev_set_name(&dev->ofdev.dev, "%1d.%08x:%.*s",
                             chip->lbus.index,
                             reg ? *reg : 0, MAX_NODE_NAME_SIZE, name);
        }

        /* Setup interrupts & resources */
        macio_setup_interrupts(dev);
        macio_setup_resources(dev, parent_res);
        macio_add_missing_resources(dev);

        /* Register with core */
        if (of_device_register(&dev->ofdev) != 0) {
                printk(KERN_DEBUG"macio: device registration error for %s!\n",
                       dev_name(&dev->ofdev.dev));
                put_device(&dev->ofdev.dev);
                return NULL;
        }

        return dev;
}

static int macio_skip_device(struct device_node *np)
{
        return of_node_name_prefix(np, "battery") ||
               of_node_name_prefix(np, "escc-legacy");
}

/**
 * macio_pci_add_devices - Adds sub-devices of mac-io to the device tree
 * @chip: pointer to the macio_chip holding the devices
 * 
 * This function will do the job of extracting devices from the
 * Open Firmware device tree, build macio_dev structures and add
 * them to the Linux device tree.
 * 
 * For now, childs of media-bay are added now as well. This will
 * change rsn though.
 */
static void macio_pci_add_devices(struct macio_chip *chip)
{
        struct device_node *np, *pnode;
        struct macio_dev *rdev, *mdev, *mbdev = NULL, *sdev = NULL;
        struct device *parent = NULL;
        struct resource *root_res = &iomem_resource;
        
        /* Add a node for the macio bus itself */
#ifdef CONFIG_PCI
        if (chip->lbus.pdev) {
                parent = &chip->lbus.pdev->dev;
                root_res = &chip->lbus.pdev->resource[0];
        }
#endif
        pnode = of_node_get(chip->of_node);
        if (pnode == NULL)
                return;

        /* Add macio itself to hierarchy */
        rdev = macio_add_one_device(chip, parent, pnode, NULL, root_res);
        if (rdev == NULL)
                return;
        root_res = &rdev->resource[0];

        /* First scan 1st level */
        for_each_child_of_node(pnode, np) {
                if (macio_skip_device(np))
                        continue;
                of_node_get(np);
                mdev = macio_add_one_device(chip, &rdev->ofdev.dev, np, NULL,
                                            root_res);
                if (mdev == NULL)
                        of_node_put(np);
                else if (of_node_name_prefix(np, "media-bay"))
                        mbdev = mdev;
                else if (of_node_name_prefix(np, "escc"))
                        sdev = mdev;
        }

        /* Add media bay devices if any */
        if (mbdev) {
                pnode = mbdev->ofdev.dev.of_node;
                for_each_child_of_node(pnode, np) {
                        if (macio_skip_device(np))
                                continue;
                        of_node_get(np);
                        if (macio_add_one_device(chip, &mbdev->ofdev.dev, np,
                                                 mbdev,  root_res) == NULL)
                                of_node_put(np);
                }
        }

        /* Add serial ports if any */
        if (sdev) {
                pnode = sdev->ofdev.dev.of_node;
                for_each_child_of_node(pnode, np) {
                        if (macio_skip_device(np))
                                continue;
                        of_node_get(np);
                        if (macio_add_one_device(chip, &sdev->ofdev.dev, np,
                                                 NULL, root_res) == NULL)
                                of_node_put(np);
                }
        }
}


/**
 * macio_register_driver - Registers a new MacIO device driver
 * @drv: pointer to the driver definition structure
 */
int macio_register_driver(struct macio_driver *drv)
{
        /* initialize common driver fields */
        drv->driver.bus = &macio_bus_type;

        /* register with core */
        return driver_register(&drv->driver);
}

/**
 * macio_unregister_driver - Unregisters a new MacIO device driver
 * @drv: pointer to the driver definition structure
 */
void macio_unregister_driver(struct macio_driver *drv)
{
        driver_unregister(&drv->driver);
}

/* Managed MacIO resources */
struct macio_devres {
        u32     res_mask;
};

static void maciom_release(struct device *gendev, void *res)
{
        struct macio_dev *dev = to_macio_device(gendev);
        struct macio_devres *dr = res;
        int i, max;

        max = min(dev->n_resources, 32);
        for (i = 0; i < max; i++) {
                if (dr->res_mask & (1 << i))
                        macio_release_resource(dev, i);
        }
}

int macio_enable_devres(struct macio_dev *dev)
{
        struct macio_devres *dr;

        dr = devres_find(&dev->ofdev.dev, maciom_release, NULL, NULL);
        if (!dr) {
                dr = devres_alloc(maciom_release, sizeof(*dr), GFP_KERNEL);
                if (!dr)
                        return -ENOMEM;
        }
        return devres_get(&dev->ofdev.dev, dr, NULL, NULL) != NULL;
}

static struct macio_devres * find_macio_dr(struct macio_dev *dev)
{
        return devres_find(&dev->ofdev.dev, maciom_release, NULL, NULL);
}

/**
 *      macio_request_resource - Request an MMIO resource
 *      @dev: pointer to the device holding the resource
 *      @resource_no: resource number to request
 *      @name: resource name
 *
 *      Mark  memory region number @resource_no associated with MacIO
 *      device @dev as being reserved by owner @name.  Do not access
 *      any address inside the memory regions unless this call returns
 *      successfully.
 *
 *      Returns 0 on success, or %EBUSY on error.  A warning
 *      message is also printed on failure.
 */
int macio_request_resource(struct macio_dev *dev, int resource_no,
                           const char *name)
{
        struct macio_devres *dr = find_macio_dr(dev);

        if (macio_resource_len(dev, resource_no) == 0)
                return 0;
                
        if (!request_mem_region(macio_resource_start(dev, resource_no),
                                macio_resource_len(dev, resource_no),
                                name))
                goto err_out;

        if (dr && resource_no < 32)
                dr->res_mask |= 1 << resource_no;
        
        return 0;

err_out:
        printk (KERN_WARNING "MacIO: Unable to reserve resource #%d:%lx@%lx"
                " for device %s\n",
                resource_no,
                macio_resource_len(dev, resource_no),
                macio_resource_start(dev, resource_no),
                dev_name(&dev->ofdev.dev));
        return -EBUSY;
}

/**
 * macio_release_resource - Release an MMIO resource
 * @dev: pointer to the device holding the resource
 * @resource_no: resource number to release
 */
void macio_release_resource(struct macio_dev *dev, int resource_no)
{
        struct macio_devres *dr = find_macio_dr(dev);

        if (macio_resource_len(dev, resource_no) == 0)
                return;
        release_mem_region(macio_resource_start(dev, resource_no),
                           macio_resource_len(dev, resource_no));
        if (dr && resource_no < 32)
                dr->res_mask &= ~(1 << resource_no);
}

/**
 *      macio_request_resources - Reserve all memory resources
 *      @dev: MacIO device whose resources are to be reserved
 *      @name: Name to be associated with resource.
 *
 *      Mark all memory regions associated with MacIO device @dev as
 *      being reserved by owner @name.  Do not access any address inside
 *      the memory regions unless this call returns successfully.
 *
 *      Returns 0 on success, or %EBUSY on error.  A warning
 *      message is also printed on failure.
 */
int macio_request_resources(struct macio_dev *dev, const char *name)
{
        int i;
        
        for (i = 0; i < dev->n_resources; i++)
                if (macio_request_resource(dev, i, name))
                        goto err_out;
        return 0;

err_out:
        while(--i >= 0)
                macio_release_resource(dev, i);
                
        return -EBUSY;
}

/**
 *      macio_release_resources - Release reserved memory resources
 *      @dev: MacIO device whose resources were previously reserved
 */

void macio_release_resources(struct macio_dev *dev)
{
        int i;
        
        for (i = 0; i < dev->n_resources; i++)
                macio_release_resource(dev, i);
}


#ifdef CONFIG_PCI

static int macio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
{
        struct device_node* np;
        struct macio_chip* chip;
        
        if (ent->vendor != PCI_VENDOR_ID_APPLE)
                return -ENODEV;

        /* Note regarding refcounting: We assume pci_device_to_OF_node() is
         * ported to new OF APIs and returns a node with refcount incremented.
         */
        np = pci_device_to_OF_node(pdev);
        if (np == NULL)
                return -ENODEV;

        /* The above assumption is wrong !!!
         * fix that here for now until I fix the arch code
         */
        of_node_get(np);

        /* We also assume that pmac_feature will have done a get() on nodes
         * stored in the macio chips array
         */
        chip = macio_find(np, macio_unknown);
        of_node_put(np);
        if (chip == NULL)
                return -ENODEV;

        /* XXX Need locking ??? */
        if (chip->lbus.pdev == NULL) {
                chip->lbus.pdev = pdev;
                chip->lbus.chip = chip;
                pci_set_drvdata(pdev, &chip->lbus);
                pci_set_master(pdev);
        }

        printk(KERN_INFO "MacIO PCI driver attached to %s chipset\n",
                chip->name);

        /*
         * HACK ALERT: The WallStreet PowerBook and some OHare based machines
         * have 2 macio ASICs. I must probe the "main" one first or IDE
         * ordering will be incorrect. So I put on "hold" the second one since
         * it seem to appear first on PCI
         */
        if (chip->type == macio_gatwick || chip->type == macio_ohareII)
                if (macio_chips[0].lbus.pdev == NULL) {
                        macio_on_hold = chip;
                        return 0;
                }

        macio_pci_add_devices(chip);
        if (macio_on_hold && macio_chips[0].lbus.pdev != NULL) {
                macio_pci_add_devices(macio_on_hold);
                macio_on_hold = NULL;
        }

        return 0;
}

static void macio_pci_remove(struct pci_dev* pdev)
{
        panic("removing of macio-asic not supported !\n");
}

/*
 * MacIO is matched against any Apple ID, it's probe() function
 * will then decide wether it applies or not
 */
static const struct pci_device_id pci_ids[] = { {
        .vendor         = PCI_VENDOR_ID_APPLE,
        .device         = PCI_ANY_ID,
        .subvendor      = PCI_ANY_ID,
        .subdevice      = PCI_ANY_ID,

        }, { /* end: all zeroes */ }
};
MODULE_DEVICE_TABLE (pci, pci_ids);

/* pci driver glue; this is a "new style" PCI driver module */
static struct pci_driver macio_pci_driver = {
        .name           = "macio",
        .id_table       = pci_ids,

        .probe          = macio_pci_probe,
        .remove         = macio_pci_remove,
};

#endif /* CONFIG_PCI */

static int __init macio_module_init (void) 
{
#ifdef CONFIG_PCI
        int rc;

        rc = pci_register_driver(&macio_pci_driver);
        if (rc)
                return rc;
#endif /* CONFIG_PCI */
        return 0;
}

module_init(macio_module_init);

EXPORT_SYMBOL(macio_register_driver);
EXPORT_SYMBOL(macio_unregister_driver);
EXPORT_SYMBOL(macio_dev_get);
EXPORT_SYMBOL(macio_dev_put);
EXPORT_SYMBOL(macio_request_resource);
EXPORT_SYMBOL(macio_release_resource);
EXPORT_SYMBOL(macio_request_resources);
EXPORT_SYMBOL(macio_release_resources);
EXPORT_SYMBOL(macio_enable_devres);