arch/mips/sgi-ip22/ip22-gio.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 #include <linux/export.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/slab.h>

 #include <asm/addrspace.h>
 #include <asm/paccess.h>
 #include <asm/gio_device.h>
 #include <asm/sgi/gio.h>
 #include <asm/sgi/hpc3.h>
 #include <asm/sgi/mc.h>
 #include <asm/sgi/ip22.h>

 static const struct bus_type gio_bus_type;

 static struct {
 	const char *name;
 	__u8	   id;
 } gio_name_table[] = {
 	{ .name = "SGI Impact", .id = 0x10 },
 	{ .name = "Phobos G160", .id = 0x35 },
 	{ .name = "Phobos G130", .id = 0x36 },
 	{ .name = "Phobos G100", .id = 0x37 },
 	{ .name = "Set Engineering GFE", .id = 0x38 },
 	/* fake IDs */
 	{ .name = "SGI Newport", .id = 0x7e },
 	{ .name = "SGI GR2/GR3", .id = 0x7f },
 };

 static void gio_bus_release(struct device *dev)
 {
 	kfree(dev);
 }

 static struct device gio_bus = {
 	.init_name = "gio",
 	.release = &gio_bus_release,
 };

 /**
  * gio_match_device - Tell if an of_device structure has a matching
  * gio_match structure
  * @ids: array of of device match structures to search in
  * @dev: the of device structure to match against
  *
  * Used by a driver to check whether an of_device present in the
  * system is in its list of supported devices.
  */
 static const struct gio_device_id *
 gio_match_device(const struct gio_device_id *match,
 		 const struct gio_device *dev)
 {
 	const struct gio_device_id *ids;

 	for (ids = match; ids->id != 0xff; ids++)
 		if (ids->id == dev->id.id)
 			return ids;

 	return NULL;
 }

 struct gio_device *gio_dev_get(struct gio_device *dev)
 {
 	struct device *tmp;

 	if (!dev)
 		return NULL;
 	tmp = get_device(&dev->dev);
 	if (tmp)
 		return to_gio_device(tmp);
 	else
 		return NULL;
 }
 EXPORT_SYMBOL_GPL(gio_dev_get);

 void gio_dev_put(struct gio_device *dev)
 {
 	if (dev)
 		put_device(&dev->dev);
 }
 EXPORT_SYMBOL_GPL(gio_dev_put);

 /**
  * gio_release_dev - free an gio 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 gio device are
  * done.
  */
 void gio_release_dev(struct device *dev)
 {
 	struct gio_device *giodev;

 	giodev = to_gio_device(dev);
 	kfree(giodev);
 }
 EXPORT_SYMBOL_GPL(gio_release_dev);

 int gio_device_register(struct gio_device *giodev)
 {
 	giodev->dev.bus = &gio_bus_type;
 	giodev->dev.parent = &gio_bus;
 	return device_register(&giodev->dev);
 }
 EXPORT_SYMBOL_GPL(gio_device_register);

 void gio_device_unregister(struct gio_device *giodev)
 {
 	device_unregister(&giodev->dev);
 }
 EXPORT_SYMBOL_GPL(gio_device_unregister);

 static int gio_bus_match(struct device *dev, const struct device_driver *drv)
 {
 	struct gio_device *gio_dev = to_gio_device(dev);
 	struct gio_driver *gio_drv = to_gio_driver(drv);

 	return gio_match_device(gio_drv->id_table, gio_dev) != NULL;
 }

 static int gio_device_probe(struct device *dev)
 {
 	int error = -ENODEV;
 	struct gio_driver *drv;
 	struct gio_device *gio_dev;
 	const struct gio_device_id *match;

 	drv = to_gio_driver(dev->driver);
 	gio_dev = to_gio_device(dev);

 	if (!drv->probe)
 		return error;

 	gio_dev_get(gio_dev);

 	match = gio_match_device(drv->id_table, gio_dev);
 	if (match)
 		error = drv->probe(gio_dev, match);
 	if (error)
 		gio_dev_put(gio_dev);

 	return error;
 }

 static void gio_device_remove(struct device *dev)
 {
 	struct gio_device *gio_dev = to_gio_device(dev);
 	struct gio_driver *drv = to_gio_driver(dev->driver);

 	if (drv->remove)
 		drv->remove(gio_dev);
 }

 static void gio_device_shutdown(struct device *dev)
 {
 	struct gio_device *gio_dev = to_gio_device(dev);
 	struct gio_driver *drv = to_gio_driver(dev->driver);

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

 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
 			     char *buf)
 {
 	struct gio_device *gio_dev = to_gio_device(dev);
 	int len = snprintf(buf, PAGE_SIZE, "gio:%x\n", gio_dev->id.id);

 	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
 }
 static DEVICE_ATTR_RO(modalias);

 static ssize_t name_show(struct device *dev,
 			 struct device_attribute *attr, char *buf)
 {
 	struct gio_device *giodev;

 	giodev = to_gio_device(dev);
 	return sprintf(buf, "%s", giodev->name);
 }
 static DEVICE_ATTR_RO(name);

 static ssize_t id_show(struct device *dev,
 		       struct device_attribute *attr, char *buf)
 {
 	struct gio_device *giodev;

 	giodev = to_gio_device(dev);
 	return sprintf(buf, "%x", giodev->id.id);
 }
 static DEVICE_ATTR_RO(id);

 static struct attribute *gio_dev_attrs[] = {
 	&dev_attr_modalias.attr,
 	&dev_attr_name.attr,
 	&dev_attr_id.attr,
 	NULL,
 };
 ATTRIBUTE_GROUPS(gio_dev);

 static int gio_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
 {
 	const struct gio_device *gio_dev = to_gio_device(dev);

 	add_uevent_var(env, "MODALIAS=gio:%x", gio_dev->id.id);
 	return 0;
 }

 int gio_register_driver(struct gio_driver *drv)
 {
 	/* initialize common driver fields */
 	if (!drv->driver.name)
 		drv->driver.name = drv->name;
 	if (!drv->driver.owner)
 		drv->driver.owner = drv->owner;
 	drv->driver.bus = &gio_bus_type;

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

 void gio_unregister_driver(struct gio_driver *drv)
 {
 	driver_unregister(&drv->driver);
 }
 EXPORT_SYMBOL_GPL(gio_unregister_driver);

 void gio_set_master(struct gio_device *dev)
 {
 	u32 tmp = sgimc->giopar;

 	switch (dev->slotno) {
 	case 0:
 		tmp |= SGIMC_GIOPAR_MASTERGFX;
 		break;
 	case 1:
 		tmp |= SGIMC_GIOPAR_MASTEREXP0;
 		break;
 	case 2:
 		tmp |= SGIMC_GIOPAR_MASTEREXP1;
 		break;
 	}
 	sgimc->giopar = tmp;
 }
 EXPORT_SYMBOL_GPL(gio_set_master);

 static void ip22_gio_set_64bit(int slotno)
 {
 	u32 tmp = sgimc->giopar;

 	switch (slotno) {
 	case 0:
 		tmp |= SGIMC_GIOPAR_GFX64;
 		break;
 	case 1:
 		tmp |= SGIMC_GIOPAR_EXP064;
 		break;
 	case 2:
 		tmp |= SGIMC_GIOPAR_EXP164;
 		break;
 	}
 	sgimc->giopar = tmp;
 }

 static int ip22_gio_id(unsigned long addr, u32 *res)
 {
 	u8 tmp8;
 	u8 tmp16;
 	u32 tmp32;
 	u8 *ptr8;
 	u16 *ptr16;
 	u32 *ptr32;

 	ptr32 = (void *)CKSEG1ADDR(addr);
 	if (!get_dbe(tmp32, ptr32)) {
 		/*
 		 * We got no DBE, but this doesn't mean anything.
 		 * If GIO is pipelined (which can't be disabled
 		 * for GFX slot) we don't get a DBE, but we see
 		 * the transfer size as data. So we do an 8bit
 		 * and a 16bit access and check whether the common
 		 * data matches
 		 */
 		ptr8 = (void *)CKSEG1ADDR(addr + 3);
 		if (get_dbe(tmp8, ptr8)) {
 			/*
 			 * 32bit access worked, but 8bit doesn't
 			 * so we don't see phantom reads on
 			 * a pipelined bus, but a real card which
 			 * doesn't support 8 bit reads
 			 */
 			*res = tmp32;
 			return 1;
 		}
 		ptr16 = (void *)CKSEG1ADDR(addr + 2);
 		get_dbe(tmp16, ptr16);
 		if (tmp8 == (tmp16 & 0xff) &&
 		    tmp8 == (tmp32 & 0xff) &&
 		    tmp16 == (tmp32 & 0xffff)) {
 			*res = tmp32;
 			return 1;
 		}
 	}
 	return 0; /* nothing here */
 }

 #define HQ2_MYSTERY_OFFS       0x6A07C
 #define NEWPORT_USTATUS_OFFS   0xF133C

 static int ip22_is_gr2(unsigned long addr)
 {
 	u32 tmp;
 	u32 *ptr;

 	/* HQ2 only allows 32bit accesses */
 	ptr = (void *)CKSEG1ADDR(addr + HQ2_MYSTERY_OFFS);
 	if (!get_dbe(tmp, ptr)) {
 		if (tmp == 0xdeadbeef)
 			return 1;
 	}
 	return 0;
 }


 static void ip22_check_gio(int slotno, unsigned long addr, int irq)
 {
 	const char *name = "Unknown";
 	struct gio_device *gio_dev;
 	u32 tmp;
 	__u8 id;
 	int i;

 	/* first look for GR2/GR3 by checking mystery register */
 	if (ip22_is_gr2(addr))
 		tmp = 0x7f;
 	else {
 		if (!ip22_gio_id(addr, &tmp)) {
 			/*
 			 * no GIO signature at start address of slot
 			 * since Newport doesn't have one, we check if
 			 * user status register is readable
 			 */
 			if (ip22_gio_id(addr + NEWPORT_USTATUS_OFFS, &tmp))
 				tmp = 0x7e;
 			else
 				tmp = 0;
 		}
 	}
 	if (tmp) {
 		id = GIO_ID(tmp);
 		if (tmp & GIO_32BIT_ID) {
 			if (tmp & GIO_64BIT_IFACE)
 				ip22_gio_set_64bit(slotno);
 		}
 		for (i = 0; i < ARRAY_SIZE(gio_name_table); i++) {
 			if (id == gio_name_table[i].id) {
 				name = gio_name_table[i].name;
 				break;
 			}
 		}
 		printk(KERN_INFO "GIO: slot %d : %s (id %x)\n",
 		       slotno, name, id);
 		gio_dev = kzalloc(sizeof *gio_dev, GFP_KERNEL);
 		if (!gio_dev)
 			return;
 		gio_dev->name = name;
 		gio_dev->slotno = slotno;
 		gio_dev->id.id = id;
 		gio_dev->resource.start = addr;
 		gio_dev->resource.end = addr + 0x3fffff;
 		gio_dev->resource.flags = IORESOURCE_MEM;
 		gio_dev->irq = irq;
 		dev_set_name(&gio_dev->dev, "%d", slotno);
 		gio_device_register(gio_dev);
 	} else
 		printk(KERN_INFO "GIO: slot %d : Empty\n", slotno);
 }

 static const struct bus_type gio_bus_type = {
 	.name	   = "gio",
 	.dev_groups = gio_dev_groups,
 	.match	   = gio_bus_match,
 	.probe	   = gio_device_probe,
 	.remove	   = gio_device_remove,
 	.shutdown  = gio_device_shutdown,
 	.uevent	   = gio_device_uevent,
 };

 static struct resource gio_bus_resource = {
 	.start = GIO_SLOT_GFX_BASE,
 	.end   = GIO_SLOT_GFX_BASE + 0x9fffff,
 	.name  = "GIO Bus",
 	.flags = IORESOURCE_MEM,
 };

 static int __init ip22_gio_init(void)
 {
 	unsigned int pbdma __maybe_unused;
 	int ret;

 	ret = device_register(&gio_bus);
 	if (ret) {
 		put_device(&gio_bus);
 		return ret;
 	}

 	ret = bus_register(&gio_bus_type);
 	if (!ret) {
 		request_resource(&iomem_resource, &gio_bus_resource);
 		printk(KERN_INFO "GIO: Probing bus...\n");

 		if (ip22_is_fullhouse()) {
 			/* Indigo2 */
 			ip22_check_gio(0, GIO_SLOT_GFX_BASE, SGI_GIO_1_IRQ);
 			ip22_check_gio(1, GIO_SLOT_EXP0_BASE, SGI_GIO_1_IRQ);
 		} else {
 			/* Indy/Challenge S */
 			if (get_dbe(pbdma, (unsigned int *)&hpc3c1->pbdma[1]))
 				ip22_check_gio(0, GIO_SLOT_GFX_BASE,
 					       SGI_GIO_0_IRQ);
 			ip22_check_gio(1, GIO_SLOT_EXP0_BASE, SGI_GIOEXP0_IRQ);
 			ip22_check_gio(2, GIO_SLOT_EXP1_BASE, SGI_GIOEXP1_IRQ);
 		}
 	} else
 		device_unregister(&gio_bus);

 	return ret;
 }

 subsys_initcall(ip22_gio_init);
	// SPDX-License-Identifier: GPL-2.0-only
	#include <linux/export.h>
	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <linux/slab.h>

	#include <asm/addrspace.h>
	#include <asm/paccess.h>
	#include <asm/gio_device.h>
	#include <asm/sgi/gio.h>
	#include <asm/sgi/hpc3.h>
	#include <asm/sgi/mc.h>
	#include <asm/sgi/ip22.h>

	static const struct bus_type gio_bus_type;

	static struct {
	const char *name;
	__u8 id;
	} gio_name_table[] = {
	{ .name = "SGI Impact", .id = 0x10 },
	{ .name = "Phobos G160", .id = 0x35 },
	{ .name = "Phobos G130", .id = 0x36 },
	{ .name = "Phobos G100", .id = 0x37 },
	{ .name = "Set Engineering GFE", .id = 0x38 },
	/* fake IDs */
	{ .name = "SGI Newport", .id = 0x7e },
	{ .name = "SGI GR2/GR3", .id = 0x7f },
	};

	static void gio_bus_release(struct device *dev)
	{
	kfree(dev);
	}

	static struct device gio_bus = {
	.init_name = "gio",
	.release = &gio_bus_release,
	};

	/**
	* gio_match_device - Tell if an of_device structure has a matching
	* gio_match structure
	* @ids: array of of device match structures to search in
	* @dev: the of device structure to match against
	*
	* Used by a driver to check whether an of_device present in the
	* system is in its list of supported devices.
	*/
	static const struct gio_device_id *
	gio_match_device(const struct gio_device_id *match,
	const struct gio_device *dev)
	{
	const struct gio_device_id *ids;

	for (ids = match; ids->id != 0xff; ids++)
	if (ids->id == dev->id.id)
	return ids;

	return NULL;
	}

	struct gio_device gio_dev_get(struct gio_device dev)
	{
	struct device *tmp;

	if (!dev)
	return NULL;
	tmp = get_device(&dev->dev);
	if (tmp)
	return to_gio_device(tmp);
	else
	return NULL;
	}
	EXPORT_SYMBOL_GPL(gio_dev_get);

	void gio_dev_put(struct gio_device *dev)
	{
	if (dev)
	put_device(&dev->dev);
	}
	EXPORT_SYMBOL_GPL(gio_dev_put);

	/**
	* gio_release_dev - free an gio 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 gio device are
	* done.
	*/
	void gio_release_dev(struct device *dev)
	{
	struct gio_device *giodev;

	giodev = to_gio_device(dev);
	kfree(giodev);
	}
	EXPORT_SYMBOL_GPL(gio_release_dev);

	int gio_device_register(struct gio_device *giodev)
	{
	giodev->dev.bus = &gio_bus_type;
	giodev->dev.parent = &gio_bus;
	return device_register(&giodev->dev);
	}
	EXPORT_SYMBOL_GPL(gio_device_register);

	void gio_device_unregister(struct gio_device *giodev)
	{
	device_unregister(&giodev->dev);
	}
	EXPORT_SYMBOL_GPL(gio_device_unregister);

	static int gio_bus_match(struct device dev, const struct device_driver drv)
	{
	struct gio_device *gio_dev = to_gio_device(dev);
	struct gio_driver *gio_drv = to_gio_driver(drv);

	return gio_match_device(gio_drv->id_table, gio_dev) != NULL;
	}

	static int gio_device_probe(struct device *dev)
	{
	int error = -ENODEV;
	struct gio_driver *drv;
	struct gio_device *gio_dev;
	const struct gio_device_id *match;

	drv = to_gio_driver(dev->driver);
	gio_dev = to_gio_device(dev);

	if (!drv->probe)
	return error;

	gio_dev_get(gio_dev);

	match = gio_match_device(drv->id_table, gio_dev);
	if (match)
	error = drv->probe(gio_dev, match);
	if (error)
	gio_dev_put(gio_dev);

	return error;
	}

	static void gio_device_remove(struct device *dev)
	{
	struct gio_device *gio_dev = to_gio_device(dev);
	struct gio_driver *drv = to_gio_driver(dev->driver);

	if (drv->remove)
	drv->remove(gio_dev);
	}

	static void gio_device_shutdown(struct device *dev)
	{
	struct gio_device *gio_dev = to_gio_device(dev);
	struct gio_driver *drv = to_gio_driver(dev->driver);

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

	static ssize_t modalias_show(struct device dev, struct device_attribute a,
	char *buf)
	{
	struct gio_device *gio_dev = to_gio_device(dev);
	int len = snprintf(buf, PAGE_SIZE, "gio:%x\n", gio_dev->id.id);

	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
	}
	static DEVICE_ATTR_RO(modalias);

	static ssize_t name_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct gio_device *giodev;

	giodev = to_gio_device(dev);
	return sprintf(buf, "%s", giodev->name);
	}
	static DEVICE_ATTR_RO(name);

	static ssize_t id_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct gio_device *giodev;

	giodev = to_gio_device(dev);
	return sprintf(buf, "%x", giodev->id.id);
	}
	static DEVICE_ATTR_RO(id);

	static struct attribute *gio_dev_attrs[] = {
	&dev_attr_modalias.attr,
	&dev_attr_name.attr,
	&dev_attr_id.attr,
	NULL,
	};
	ATTRIBUTE_GROUPS(gio_dev);

	static int gio_device_uevent(const struct device dev, struct kobj_uevent_env env)
	{
	const struct gio_device *gio_dev = to_gio_device(dev);

	add_uevent_var(env, "MODALIAS=gio:%x", gio_dev->id.id);
	return 0;
	}

	int gio_register_driver(struct gio_driver *drv)
	{
	/* initialize common driver fields */
	if (!drv->driver.name)
	drv->driver.name = drv->name;
	if (!drv->driver.owner)
	drv->driver.owner = drv->owner;
	drv->driver.bus = &gio_bus_type;

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

	void gio_unregister_driver(struct gio_driver *drv)
	{
	driver_unregister(&drv->driver);
	}
	EXPORT_SYMBOL_GPL(gio_unregister_driver);

	void gio_set_master(struct gio_device *dev)
	{
	u32 tmp = sgimc->giopar;

	switch (dev->slotno) {
	case 0:
	tmp \|= SGIMC_GIOPAR_MASTERGFX;
	break;
	case 1:
	tmp \|= SGIMC_GIOPAR_MASTEREXP0;
	break;
	case 2:
	tmp \|= SGIMC_GIOPAR_MASTEREXP1;
	break;
	}
	sgimc->giopar = tmp;
	}
	EXPORT_SYMBOL_GPL(gio_set_master);

	static void ip22_gio_set_64bit(int slotno)
	{
	u32 tmp = sgimc->giopar;

	switch (slotno) {
	case 0:
	tmp \|= SGIMC_GIOPAR_GFX64;
	break;
	case 1:
	tmp \|= SGIMC_GIOPAR_EXP064;
	break;
	case 2:
	tmp \|= SGIMC_GIOPAR_EXP164;
	break;
	}
	sgimc->giopar = tmp;
	}

	static int ip22_gio_id(unsigned long addr, u32 *res)
	{
	u8 tmp8;
	u8 tmp16;
	u32 tmp32;
	u8 *ptr8;
	u16 *ptr16;
	u32 *ptr32;

	ptr32 = (void *)CKSEG1ADDR(addr);
	if (!get_dbe(tmp32, ptr32)) {
	/*
	* We got no DBE, but this doesn't mean anything.
	* If GIO is pipelined (which can't be disabled
	* for GFX slot) we don't get a DBE, but we see
	* the transfer size as data. So we do an 8bit
	* and a 16bit access and check whether the common
	* data matches
	*/
	ptr8 = (void *)CKSEG1ADDR(addr + 3);
	if (get_dbe(tmp8, ptr8)) {
	/*
	* 32bit access worked, but 8bit doesn't
	* so we don't see phantom reads on
	* a pipelined bus, but a real card which
	* doesn't support 8 bit reads
	*/
	*res = tmp32;
	return 1;
	}
	ptr16 = (void *)CKSEG1ADDR(addr + 2);
	get_dbe(tmp16, ptr16);
	if (tmp8 == (tmp16 & 0xff) &&
	tmp8 == (tmp32 & 0xff) &&
	tmp16 == (tmp32 & 0xffff)) {
	*res = tmp32;
	return 1;
	}
	}
	return 0; /* nothing here */
	}

	#define HQ2_MYSTERY_OFFS 0x6A07C
	#define NEWPORT_USTATUS_OFFS 0xF133C

	static int ip22_is_gr2(unsigned long addr)
	{
	u32 tmp;
	u32 *ptr;

	/* HQ2 only allows 32bit accesses */
	ptr = (void *)CKSEG1ADDR(addr + HQ2_MYSTERY_OFFS);
	if (!get_dbe(tmp, ptr)) {
	if (tmp == 0xdeadbeef)
	return 1;
	}
	return 0;
	}


	static void ip22_check_gio(int slotno, unsigned long addr, int irq)
	{
	const char *name = "Unknown";
	struct gio_device *gio_dev;
	u32 tmp;
	__u8 id;
	int i;

	/* first look for GR2/GR3 by checking mystery register */
	if (ip22_is_gr2(addr))
	tmp = 0x7f;
	else {
	if (!ip22_gio_id(addr, &tmp)) {
	/*
	* no GIO signature at start address of slot
	* since Newport doesn't have one, we check if
	* user status register is readable
	*/
	if (ip22_gio_id(addr + NEWPORT_USTATUS_OFFS, &tmp))
	tmp = 0x7e;
	else
	tmp = 0;
	}
	}
	if (tmp) {
	id = GIO_ID(tmp);
	if (tmp & GIO_32BIT_ID) {
	if (tmp & GIO_64BIT_IFACE)
	ip22_gio_set_64bit(slotno);
	}
	for (i = 0; i < ARRAY_SIZE(gio_name_table); i++) {
	if (id == gio_name_table[i].id) {
	name = gio_name_table[i].name;
	break;
	}
	}
	printk(KERN_INFO "GIO: slot %d : %s (id %x)\n",
	slotno, name, id);
	gio_dev = kzalloc(sizeof *gio_dev, GFP_KERNEL);
	if (!gio_dev)
	return;
	gio_dev->name = name;
	gio_dev->slotno = slotno;
	gio_dev->id.id = id;
	gio_dev->resource.start = addr;
	gio_dev->resource.end = addr + 0x3fffff;
	gio_dev->resource.flags = IORESOURCE_MEM;
	gio_dev->irq = irq;
	dev_set_name(&gio_dev->dev, "%d", slotno);
	gio_device_register(gio_dev);
	} else
	printk(KERN_INFO "GIO: slot %d : Empty\n", slotno);
	}

	static const struct bus_type gio_bus_type = {
	.name = "gio",
	.dev_groups = gio_dev_groups,
	.match = gio_bus_match,
	.probe = gio_device_probe,
	.remove = gio_device_remove,
	.shutdown = gio_device_shutdown,
	.uevent = gio_device_uevent,
	};

	static struct resource gio_bus_resource = {
	.start = GIO_SLOT_GFX_BASE,
	.end = GIO_SLOT_GFX_BASE + 0x9fffff,
	.name = "GIO Bus",
	.flags = IORESOURCE_MEM,
	};

	static int __init ip22_gio_init(void)
	{
	unsigned int pbdma __maybe_unused;
	int ret;

	ret = device_register(&gio_bus);
	if (ret) {
	put_device(&gio_bus);
	return ret;
	}

	ret = bus_register(&gio_bus_type);
	if (!ret) {
	request_resource(&iomem_resource, &gio_bus_resource);
	printk(KERN_INFO "GIO: Probing bus...\n");

	if (ip22_is_fullhouse()) {
	/* Indigo2 */
	ip22_check_gio(0, GIO_SLOT_GFX_BASE, SGI_GIO_1_IRQ);
	ip22_check_gio(1, GIO_SLOT_EXP0_BASE, SGI_GIO_1_IRQ);
	} else {
	/* Indy/Challenge S */
	if (get_dbe(pbdma, (unsigned int *)&hpc3c1->pbdma[1]))
	ip22_check_gio(0, GIO_SLOT_GFX_BASE,
	SGI_GIO_0_IRQ);
	ip22_check_gio(1, GIO_SLOT_EXP0_BASE, SGI_GIOEXP0_IRQ);
	ip22_check_gio(2, GIO_SLOT_EXP1_BASE, SGI_GIOEXP1_IRQ);
	}
	} else
	device_unregister(&gio_bus);

	return ret;
	}

	subsys_initcall(ip22_gio_init);