eisa-bus.c

// 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[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(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;
}

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(sizeof(*edev), GFP_KERNEL);
	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(sizeof(*edev), GFP_KERNEL);
		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);