// SPDX-License-Identifier: GPL-2.0-only
/*
 * EISA bus support functions for sysfs.
 *
 * (C) 2002, 2003 Marc Zyngier <maz@wild-wind.fr.eu.org>
 */

#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/eisa.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <asm/io.h>

#define SLOT_ADDRESS(r,n) (r->bus_base_addr + (0x1000 * n))

#define EISA_DEVINFO(i,s) { .id = { .sig = i }, .name = s }

struct eisa_device_info {
        struct eisa_device_id id;
        char name[EISA_DEVICE_INFO_NAME_SIZE];
};

#ifdef CONFIG_EISA_NAMES
static struct eisa_device_info __initdata eisa_table[] = {
#include "devlist.h"
};
#define EISA_INFOS (sizeof (eisa_table) / (sizeof (struct eisa_device_info)))
#endif

#define EISA_MAX_FORCED_DEV 16

static int enable_dev[EISA_MAX_FORCED_DEV];
static unsigned int enable_dev_count;
static int disable_dev[EISA_MAX_FORCED_DEV];
static unsigned int disable_dev_count;

static int is_forced_dev(int *forced_tab,
                         int forced_count,
                         struct eisa_root_device *root,
                         struct eisa_device *edev)
{
        int i, x;

        for (i = 0; i < forced_count; i++) {
                x = (root->bus_nr << 8) | edev->slot;
                if (forced_tab[i] == x)
                        return 1;
        }

        return 0;
}

static void __init eisa_name_device(struct eisa_device *edev)
{
#ifdef CONFIG_EISA_NAMES
        int i;
        for (i = 0; i < EISA_INFOS; i++) {
                if (!strcmp(edev->id.sig, eisa_table[i].id.sig)) {
                        strscpy(edev->pretty_name,
                                eisa_table[i].name,
                                sizeof(edev->pretty_name));
                        return;
                }
        }

        /* No name was found */
        sprintf(edev->pretty_name, "EISA device %.7s", edev->id.sig);
#endif
}

static char __init *decode_eisa_sig(unsigned long addr)
{
        static char sig_str[EISA_SIG_LEN];
        u8 sig[4];
        u16 rev;
        int i;

        for (i = 0; i < 4; i++) {
#ifdef CONFIG_EISA_VLB_PRIMING
                /*
                 * This ugly stuff is used to wake up VL-bus cards
                 * (AHA-284x is the only known example), so we can
                 * read the EISA id.
                 *
                 * Thankfully, this only exists on x86...
                 */
                outb(0x80 + i, addr);
#endif
                sig[i] = inb(addr + i);

                if (!i && (sig[0] & 0x80))
                        return NULL;
        }

        sig_str[0] = ((sig[0] >> 2) & 0x1f) + ('A' - 1);
        sig_str[1] = (((sig[0] & 3) << 3) | (sig[1] >> 5)) + ('A' - 1);
        sig_str[2] = (sig[1] & 0x1f) + ('A' - 1);
        rev = (sig[2] << 8) | sig[3];
        sprintf(sig_str + 3, "%04X", rev);

        return sig_str;
}

static int eisa_bus_match(struct device *dev, const struct device_driver *drv)
{
        struct eisa_device *edev = to_eisa_device(dev);
        const struct eisa_driver *edrv = to_eisa_driver(drv);
        const struct eisa_device_id *eids = edrv->id_table;

        if (!eids)
                return 0;

        while (strlen(eids->sig)) {
                if (!strcmp(eids->sig, edev->id.sig) &&
                    edev->state & EISA_CONFIG_ENABLED) {
                        edev->id.driver_data = eids->driver_data;
                        return 1;
                }

                eids++;
        }

        return 0;
}

static int eisa_bus_uevent(const struct device *dev, struct kobj_uevent_env *env)
{
        const struct eisa_device *edev = to_eisa_device(dev);

        add_uevent_var(env, "MODALIAS=" EISA_DEVICE_MODALIAS_FMT, edev->id.sig);
        return 0;
}

const struct bus_type eisa_bus_type = {
        .name  = "eisa",
        .match = eisa_bus_match,
        .uevent = eisa_bus_uevent,
};
EXPORT_SYMBOL(eisa_bus_type);

int eisa_driver_register(struct eisa_driver *edrv)
{
        edrv->driver.bus = &eisa_bus_type;
        return driver_register(&edrv->driver);
}
EXPORT_SYMBOL(eisa_driver_register);

void eisa_driver_unregister(struct eisa_driver *edrv)
{
        driver_unregister(&edrv->driver);
}
EXPORT_SYMBOL(eisa_driver_unregister);

static ssize_t signature_show(struct device *dev,
                              struct device_attribute *attr, char *buf)
{
        struct eisa_device *edev = to_eisa_device(dev);
        return sprintf(buf, "%s\n", edev->id.sig);
}
static DEVICE_ATTR_RO(signature);

static ssize_t enabled_show(struct device *dev,
                            struct device_attribute *attr, char *buf)
{
        struct eisa_device *edev = to_eisa_device(dev);
        return sprintf(buf, "%d\n", edev->state & EISA_CONFIG_ENABLED);
}
static DEVICE_ATTR_RO(enabled);

static ssize_t modalias_show(struct device *dev,
                             struct device_attribute *attr, char *buf)
{
        struct eisa_device *edev = to_eisa_device(dev);
        return sprintf(buf, EISA_DEVICE_MODALIAS_FMT "\n", edev->id.sig);
}
static DEVICE_ATTR_RO(modalias);

static int __init eisa_init_device(struct eisa_root_device *root,
                                   struct eisa_device *edev,
                                   int slot)
{
        char *sig;
        unsigned long sig_addr;
        int i;

        sig_addr = SLOT_ADDRESS(root, slot) + EISA_VENDOR_ID_OFFSET;

        sig = decode_eisa_sig(sig_addr);
        if (!sig)
                return -1;      /* No EISA device here */

        memcpy(edev->id.sig, sig, EISA_SIG_LEN);
        edev->slot = slot;
        edev->state = inb(SLOT_ADDRESS(root, slot) + EISA_CONFIG_OFFSET)
                      & EISA_CONFIG_ENABLED;
        edev->base_addr = SLOT_ADDRESS(root, slot);
        edev->dma_mask = root->dma_mask; /* Default DMA mask */
        eisa_name_device(edev);
        edev->dev.parent = root->dev;
        edev->dev.bus = &eisa_bus_type;
        edev->dev.dma_mask = &edev->dma_mask;
        edev->dev.coherent_dma_mask = edev->dma_mask;
        dev_set_name(&edev->dev, "%02X:%02X", root->bus_nr, slot);

        for (i = 0; i < EISA_MAX_RESOURCES; i++) {
#ifdef CONFIG_EISA_NAMES
                edev->res[i].name = edev->pretty_name;
#else
                edev->res[i].name = edev->id.sig;
#endif
        }

        if (is_forced_dev(enable_dev, enable_dev_count, root, edev))
                edev->state = EISA_CONFIG_ENABLED | EISA_CONFIG_FORCED;

        if (is_forced_dev(disable_dev, disable_dev_count, root, edev))
                edev->state = EISA_CONFIG_FORCED;

        return 0;
}

static int __init eisa_register_device(struct eisa_device *edev)
{
        int rc = device_register(&edev->dev);
        if (rc) {
                put_device(&edev->dev);
                return rc;
        }

        rc = device_create_file(&edev->dev, &dev_attr_signature);
        if (rc)
                goto err_devreg;
        rc = device_create_file(&edev->dev, &dev_attr_enabled);
        if (rc)
                goto err_sig;
        rc = device_create_file(&edev->dev, &dev_attr_modalias);
        if (rc)
                goto err_enab;

        return 0;

err_enab:
        device_remove_file(&edev->dev, &dev_attr_enabled);
err_sig:
        device_remove_file(&edev->dev, &dev_attr_signature);
err_devreg:
        device_unregister(&edev->dev);
        return rc;
}

static int __init eisa_request_resources(struct eisa_root_device *root,
                                         struct eisa_device *edev,
                                         int slot)
{
        int i;

        for (i = 0; i < EISA_MAX_RESOURCES; i++) {
                /* Don't register resource for slot 0, since this is
                 * very likely to fail... :-( Instead, grab the EISA
                 * id, now we can display something in /proc/ioports.
                 */

                /* Only one region for mainboard */
                if (!slot && i > 0) {
                        edev->res[i].start = edev->res[i].end = 0;
                        continue;
                }

                if (slot) {
                        edev->res[i].name  = NULL;
                        edev->res[i].start = SLOT_ADDRESS(root, slot)
                                             + (i * 0x400);
                        edev->res[i].end   = edev->res[i].start + 0xff;
                        edev->res[i].flags = IORESOURCE_IO;
                } else {
                        edev->res[i].name  = NULL;
                        edev->res[i].start = SLOT_ADDRESS(root, slot)
                                             + EISA_VENDOR_ID_OFFSET;
                        edev->res[i].end   = edev->res[i].start + 3;
                        edev->res[i].flags = IORESOURCE_IO | IORESOURCE_BUSY;
                }

                if (request_resource(root->res, &edev->res[i]))
                        goto failed;
        }

        return 0;

 failed:
        while (--i >= 0)
                release_resource(&edev->res[i]);

        return -1;
}

static void __init eisa_release_resources(struct eisa_device *edev)
{
        int i;

        for (i = 0; i < EISA_MAX_RESOURCES; i++)
                if (edev->res[i].start || edev->res[i].end)
                        release_resource(&edev->res[i]);
}

static int __init eisa_probe(struct eisa_root_device *root)
{
        int i, c;
        struct eisa_device *edev;
        char *enabled_str;

        dev_info(root->dev, "Probing EISA bus %d\n", root->bus_nr);

        /* First try to get hold of slot 0. If there is no device
         * here, simply fail, unless root->force_probe is set. */

        edev = kzalloc_obj(*edev);
        if (!edev)
                return -ENOMEM;

        if (eisa_request_resources(root, edev, 0)) {
                dev_warn(root->dev,
                         "EISA: Cannot allocate resource for mainboard\n");
                kfree(edev);
                if (!root->force_probe)
                        return -EBUSY;
                goto force_probe;
        }

        if (eisa_init_device(root, edev, 0)) {
                eisa_release_resources(edev);
                kfree(edev);
                if (!root->force_probe)
                        return -ENODEV;
                goto force_probe;
        }

        dev_info(&edev->dev, "EISA: Mainboard %s detected\n", edev->id.sig);

        if (eisa_register_device(edev)) {
                dev_err(&edev->dev, "EISA: Failed to register %s\n",
                        edev->id.sig);
                eisa_release_resources(edev);
                kfree(edev);
        }

 force_probe:

        for (c = 0, i = 1; i <= root->slots; i++) {
                edev = kzalloc_obj(*edev);
                if (!edev) {
                        dev_err(root->dev, "EISA: Out of memory for slot %d\n",
                                i);
                        continue;
                }

                if (eisa_request_resources(root, edev, i)) {
                        dev_warn(root->dev,
                                 "Cannot allocate resource for EISA slot %d\n",
                                 i);
                        kfree(edev);
                        continue;
                }

                if (eisa_init_device(root, edev, i)) {
                        eisa_release_resources(edev);
                        kfree(edev);
                        continue;
                }

                if (edev->state == (EISA_CONFIG_ENABLED | EISA_CONFIG_FORCED))
                        enabled_str = " (forced enabled)";
                else if (edev->state == EISA_CONFIG_FORCED)
                        enabled_str = " (forced disabled)";
                else if (edev->state == 0)
                        enabled_str = " (disabled)";
                else
                        enabled_str = "";

                dev_info(&edev->dev, "EISA: slot %d: %s detected%s\n", i,
                         edev->id.sig, enabled_str);

                c++;

                if (eisa_register_device(edev)) {
                        dev_err(&edev->dev, "EISA: Failed to register %s\n",
                                edev->id.sig);
                        eisa_release_resources(edev);
                        kfree(edev);
                }
        }

        dev_info(root->dev, "EISA: Detected %d card%s\n", c, c == 1 ? "" : "s");
        return 0;
}

static struct resource eisa_root_res = {
        .name  = "EISA root resource",
        .start = 0,
        .end   = 0xffffffff,
        .flags = IORESOURCE_IO,
};

static int eisa_bus_count;

int __init eisa_root_register(struct eisa_root_device *root)
{
        int err;

        /* Use our own resources to check if this bus base address has
         * been already registered. This prevents the virtual root
         * device from registering after the real one has, for
         * example... */

        root->eisa_root_res.name  = eisa_root_res.name;
        root->eisa_root_res.start = root->res->start;
        root->eisa_root_res.end   = root->res->end;
        root->eisa_root_res.flags = IORESOURCE_BUSY;

        err = request_resource(&eisa_root_res, &root->eisa_root_res);
        if (err)
                return err;

        root->bus_nr = eisa_bus_count++;

        err = eisa_probe(root);
        if (err)
                release_resource(&root->eisa_root_res);

        return err;
}

static int __init eisa_init(void)
{
        int r;

        r = bus_register(&eisa_bus_type);
        if (r)
                return r;

        printk(KERN_INFO "EISA bus registered\n");
        return 0;
}

module_param_array(enable_dev, int, &enable_dev_count, 0444);
module_param_array(disable_dev, int, &disable_dev_count, 0444);

postcore_initcall(eisa_init);

int EISA_bus;           /* for legacy drivers */
EXPORT_SYMBOL(EISA_bus);