eisa-bus.c

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/*
 * EISA bus support functions for sysfs.
 *
 * (C) 2002, 2003 Marc Zyngier <[email protected]>
 *
 * This code is released under the GPL version 2.
 */

#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[50];
};

#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)) {
            strlcpy(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, struct device_driver *drv)
{
    struct eisa_device *edev = to_eisa_device(dev);
    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(struct device *dev, struct kobj_uevent_env *env)
{
    struct eisa_device *edev = to_eisa_device(dev);

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

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 eisa_show_sig(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(signature, S_IRUGO, eisa_show_sig, NULL);

static ssize_t eisa_show_state(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(enabled, S_IRUGO, eisa_show_state, NULL);

static ssize_t eisa_show_modalias(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(modalias, S_IRUGO, eisa_show_modalias, NULL);

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)
        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_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;

    printk(KERN_INFO "EISA: Probing bus %d at %s\n",
           root->bus_nr, dev_name(root->dev));

    /* First try to get hold of slot 0. If there is no device
     * here, simply fail, unless root->force_probe is set. */
    
    edev = kzalloc(sizeof(*edev), GFP_KERNEL);
    if (!edev) {
        printk(KERN_ERR "EISA: Couldn't allocate mainboard slot\n");
        return -ENOMEM;
    }
        
    if (eisa_request_resources(root, edev, 0)) {
        printk(KERN_WARNING \
               "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;
    }

    printk(KERN_INFO "EISA: Mainboard %s detected.\n", edev->id.sig);

    if (eisa_register_device(edev)) {
        printk(KERN_ERR "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(sizeof(*edev), GFP_KERNEL);
        if (!edev) {
            printk(KERN_ERR "EISA: Out of memory for slot %d\n", i);
            continue;
        }

        if (eisa_request_resources(root, edev, i)) {
            printk(KERN_WARNING \
                   "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;
        }
        
        printk(KERN_INFO "EISA: slot %d : %s detected",
               i, edev->id.sig);
            
        switch (edev->state) {
        case EISA_CONFIG_ENABLED | EISA_CONFIG_FORCED:
            printk(" (forced enabled)");
            break;

        case EISA_CONFIG_FORCED:
            printk(" (forced disabled)");
            break;

        case 0:
            printk(" (disabled)");
            break;
        }
            
        printk (".\n");

        c++;

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

    printk(KERN_INFO "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);