arch/powerpc/platforms/pseries/ibmebus.c - kernel/msm-4.19 - Gitiles

 /*
  * IBM PowerPC IBM eBus Infrastructure Support.
  *
  * Copyright (c) 2005 IBM Corporation
  *  Joachim Fenkes <fenkes@de.ibm.com>
  *  Heiko J Schick <schickhj@de.ibm.com>
  *
  * All rights reserved.
  *
  * This source code is distributed under a dual license of GPL v2.0 and OpenIB
  * BSD.
  *
  * OpenIB BSD License
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  * Redistributions of source code must retain the above copyright notice, this
  * list of conditions and the following disclaimer.
  *
  * Redistributions in binary form must reproduce the above copyright notice,
  * this list of conditions and the following disclaimer in the documentation
  * and/or other materials
  * provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */

 #include <linux/init.h>
 #include <linux/export.h>
 #include <linux/console.h>
 #include <linux/kobject.h>
 #include <linux/dma-mapping.h>
 #include <linux/interrupt.h>
 #include <linux/of.h>
 #include <linux/slab.h>
 #include <linux/stat.h>
 #include <linux/of_platform.h>
 #include <asm/ibmebus.h>

 static struct device ibmebus_bus_device = { /* fake "parent" device */
 	.init_name = "ibmebus",
 };

 struct bus_type ibmebus_bus_type;

 /* These devices will automatically be added to the bus during init */
 static const struct of_device_id ibmebus_matches[] __initconst = {
 	{ .compatible = "IBM,lhca" },
 	{ .compatible = "IBM,lhea" },
 	{},
 };

 static void *ibmebus_alloc_coherent(struct device *dev,
 				    size_t size,
 				    dma_addr_t *dma_handle,
 				    gfp_t flag,
 				    unsigned long attrs)
 {
 	void *mem;

 	mem = kmalloc(size, flag);
 	*dma_handle = (dma_addr_t)mem;

 	return mem;
 }

 static void ibmebus_free_coherent(struct device *dev,
 				  size_t size, void *vaddr,
 				  dma_addr_t dma_handle,
 				  unsigned long attrs)
 {
 	kfree(vaddr);
 }

 static dma_addr_t ibmebus_map_page(struct device *dev,
 				   struct page *page,
 				   unsigned long offset,
 				   size_t size,
 				   enum dma_data_direction direction,
 				   unsigned long attrs)
 {
 	return (dma_addr_t)(page_address(page) + offset);
 }

 static void ibmebus_unmap_page(struct device *dev,
 			       dma_addr_t dma_addr,
 			       size_t size,
 			       enum dma_data_direction direction,
 			       unsigned long attrs)
 {
 	return;
 }

 static int ibmebus_map_sg(struct device *dev,
 			  struct scatterlist *sgl,
 			  int nents, enum dma_data_direction direction,
 			  unsigned long attrs)
 {
 	struct scatterlist *sg;
 	int i;

 	for_each_sg(sgl, sg, nents, i) {
 		sg->dma_address = (dma_addr_t) sg_virt(sg);
 		sg->dma_length = sg->length;
 	}

 	return nents;
 }

 static void ibmebus_unmap_sg(struct device *dev,
 			     struct scatterlist *sg,
 			     int nents, enum dma_data_direction direction,
 			     unsigned long attrs)
 {
 	return;
 }

 static int ibmebus_dma_supported(struct device *dev, u64 mask)
 {
 	return mask == DMA_BIT_MASK(64);
 }

 static u64 ibmebus_dma_get_required_mask(struct device *dev)
 {
 	return DMA_BIT_MASK(64);
 }

 static const struct dma_map_ops ibmebus_dma_ops = {
 	.alloc              = ibmebus_alloc_coherent,
 	.free               = ibmebus_free_coherent,
 	.map_sg             = ibmebus_map_sg,
 	.unmap_sg           = ibmebus_unmap_sg,
 	.dma_supported      = ibmebus_dma_supported,
 	.get_required_mask  = ibmebus_dma_get_required_mask,
 	.map_page           = ibmebus_map_page,
 	.unmap_page         = ibmebus_unmap_page,
 };

 static int ibmebus_match_path(struct device *dev, void *data)
 {
 	struct device_node *dn = to_platform_device(dev)->dev.of_node;
 	return (dn->full_name &&
 		(strcasecmp((char *)data, dn->full_name) == 0));
 }

 static int ibmebus_match_node(struct device *dev, void *data)
 {
 	return to_platform_device(dev)->dev.of_node == data;
 }

 static int ibmebus_create_device(struct device_node *dn)
 {
 	struct platform_device *dev;
 	int ret;

 	dev = of_device_alloc(dn, NULL, &ibmebus_bus_device);
 	if (!dev)
 		return -ENOMEM;

 	dev->dev.bus = &ibmebus_bus_type;
 	dev->dev.dma_ops = &ibmebus_dma_ops;

 	ret = of_device_add(dev);
 	if (ret)
 		platform_device_put(dev);
 	return ret;
 }

 static int ibmebus_create_devices(const struct of_device_id *matches)
 {
 	struct device_node *root, *child;
 	struct device *dev;
 	int ret = 0;

 	root = of_find_node_by_path("/");

 	for_each_child_of_node(root, child) {
 		if (!of_match_node(matches, child))
 			continue;

 		dev = bus_find_device(&ibmebus_bus_type, NULL, child,
 				      ibmebus_match_node);
 		if (dev) {
 			put_device(dev);
 			continue;
 		}

 		ret = ibmebus_create_device(child);
 		if (ret) {
 			printk(KERN_ERR "%s: failed to create device (%i)",
 			       __func__, ret);
 			of_node_put(child);
 			break;
 		}
 	}

 	of_node_put(root);
 	return ret;
 }

 int ibmebus_register_driver(struct platform_driver *drv)
 {
 	/* If the driver uses devices that ibmebus doesn't know, add them */
 	ibmebus_create_devices(drv->driver.of_match_table);

 	drv->driver.bus = &ibmebus_bus_type;
 	return driver_register(&drv->driver);
 }
 EXPORT_SYMBOL(ibmebus_register_driver);

 void ibmebus_unregister_driver(struct platform_driver *drv)
 {
 	driver_unregister(&drv->driver);
 }
 EXPORT_SYMBOL(ibmebus_unregister_driver);

 int ibmebus_request_irq(u32 ist, irq_handler_t handler,
 			unsigned long irq_flags, const char *devname,
 			void *dev_id)
 {
 	unsigned int irq = irq_create_mapping(NULL, ist);

 	if (!irq)
 		return -EINVAL;

 	return request_irq(irq, handler, irq_flags, devname, dev_id);
 }
 EXPORT_SYMBOL(ibmebus_request_irq);

 void ibmebus_free_irq(u32 ist, void *dev_id)
 {
 	unsigned int irq = irq_find_mapping(NULL, ist);

 	free_irq(irq, dev_id);
 	irq_dispose_mapping(irq);
 }
 EXPORT_SYMBOL(ibmebus_free_irq);

 static char *ibmebus_chomp(const char *in, size_t count)
 {
 	char *out = kmalloc(count + 1, GFP_KERNEL);

 	if (!out)
 		return NULL;

 	memcpy(out, in, count);
 	out[count] = '\0';
 	if (out[count - 1] == '\n')
 		out[count - 1] = '\0';

 	return out;
 }

 static ssize_t ibmebus_store_probe(struct bus_type *bus,
 				   const char *buf, size_t count)
 {
 	struct device_node *dn = NULL;
 	struct device *dev;
 	char *path;
 	ssize_t rc = 0;

 	path = ibmebus_chomp(buf, count);
 	if (!path)
 		return -ENOMEM;

 	dev = bus_find_device(&ibmebus_bus_type, NULL, path,
 			      ibmebus_match_path);
 	if (dev) {
 		put_device(dev);
 		printk(KERN_WARNING "%s: %s has already been probed\n",
 		       __func__, path);
 		rc = -EEXIST;
 		goto out;
 	}

 	if ((dn = of_find_node_by_path(path))) {
 		rc = ibmebus_create_device(dn);
 		of_node_put(dn);
 	} else {
 		printk(KERN_WARNING "%s: no such device node: %s\n",
 		       __func__, path);
 		rc = -ENODEV;
 	}

 out:
 	kfree(path);
 	if (rc)
 		return rc;
 	return count;
 }
 static BUS_ATTR(probe, S_IWUSR, NULL, ibmebus_store_probe);

 static ssize_t ibmebus_store_remove(struct bus_type *bus,
 				    const char *buf, size_t count)
 {
 	struct device *dev;
 	char *path;

 	path = ibmebus_chomp(buf, count);
 	if (!path)
 		return -ENOMEM;

 	if ((dev = bus_find_device(&ibmebus_bus_type, NULL, path,
 				   ibmebus_match_path))) {
 		of_device_unregister(to_platform_device(dev));
 		put_device(dev);

 		kfree(path);
 		return count;
 	} else {
 		printk(KERN_WARNING "%s: %s not on the bus\n",
 		       __func__, path);

 		kfree(path);
 		return -ENODEV;
 	}
 }
 static BUS_ATTR(remove, S_IWUSR, NULL, ibmebus_store_remove);

 static struct attribute *ibmbus_bus_attrs[] = {
 	&bus_attr_probe.attr,
 	&bus_attr_remove.attr,
 	NULL,
 };
 ATTRIBUTE_GROUPS(ibmbus_bus);

 static int ibmebus_bus_bus_match(struct device *dev, 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;
 }

 static int ibmebus_bus_device_probe(struct device *dev)
 {
 	int error = -ENODEV;
 	struct platform_driver *drv;
 	struct platform_device *of_dev;

 	drv = to_platform_driver(dev->driver);
 	of_dev = to_platform_device(dev);

 	if (!drv->probe)
 		return error;

 	of_dev_get(of_dev);

 	if (of_driver_match_device(dev, dev->driver))
 		error = drv->probe(of_dev);
 	if (error)
 		of_dev_put(of_dev);

 	return error;
 }

 static int ibmebus_bus_device_remove(struct device *dev)
 {
 	struct platform_device *of_dev = to_platform_device(dev);
 	struct platform_driver *drv = to_platform_driver(dev->driver);

 	if (dev->driver && drv->remove)
 		drv->remove(of_dev);
 	return 0;
 }

 static void ibmebus_bus_device_shutdown(struct device *dev)
 {
 	struct platform_device *of_dev = to_platform_device(dev);
 	struct platform_driver *drv = to_platform_driver(dev->driver);

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

 /*
  * ibmebus_bus_device_attrs
  */
 static ssize_t devspec_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	struct platform_device *ofdev;

 	ofdev = to_platform_device(dev);
 	return sprintf(buf, "%s\n", ofdev->dev.of_node->full_name);
 }

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

 	ofdev = to_platform_device(dev);
 	return sprintf(buf, "%s\n", ofdev->dev.of_node->name);
 }

 static ssize_t modalias_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	return of_device_modalias(dev, buf, PAGE_SIZE);
 }

 static struct device_attribute ibmebus_bus_device_attrs[] = {
 	__ATTR_RO(devspec),
 	__ATTR_RO(name),
 	__ATTR_RO(modalias),
 	__ATTR_NULL
 };

 struct bus_type ibmebus_bus_type = {
 	.name      = "ibmebus",
 	.uevent    = of_device_uevent_modalias,
 	.bus_groups = ibmbus_bus_groups,
 	.match     = ibmebus_bus_bus_match,
 	.probe     = ibmebus_bus_device_probe,
 	.remove    = ibmebus_bus_device_remove,
 	.shutdown  = ibmebus_bus_device_shutdown,
 	.dev_attrs = ibmebus_bus_device_attrs,
 };
 EXPORT_SYMBOL(ibmebus_bus_type);

 static int __init ibmebus_bus_init(void)
 {
 	int err;

 	printk(KERN_INFO "IBM eBus Device Driver\n");

 	err = bus_register(&ibmebus_bus_type);
 	if (err) {
 		printk(KERN_ERR "%s: failed to register IBM eBus.\n",
 		       __func__);
 		return err;
 	}

 	err = device_register(&ibmebus_bus_device);
 	if (err) {
 		printk(KERN_WARNING "%s: device_register returned %i\n",
 		       __func__, err);
 		bus_unregister(&ibmebus_bus_type);

 		return err;
 	}

 	err = ibmebus_create_devices(ibmebus_matches);
 	if (err) {
 		device_unregister(&ibmebus_bus_device);
 		bus_unregister(&ibmebus_bus_type);
 		return err;
 	}

 	return 0;
 }
 postcore_initcall(ibmebus_bus_init);
	/*
	* IBM PowerPC IBM eBus Infrastructure Support.
	*
	* Copyright (c) 2005 IBM Corporation
	* Joachim Fenkes <fenkes@de.ibm.com>
	* Heiko J Schick <schickhj@de.ibm.com>
	*
	* All rights reserved.
	*
	* This source code is distributed under a dual license of GPL v2.0 and OpenIB
	* BSD.
	*
	* OpenIB BSD License
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are met:
	*
	* Redistributions of source code must retain the above copyright notice, this
	* list of conditions and the following disclaimer.
	*
	* Redistributions in binary form must reproduce the above copyright notice,
	* this list of conditions and the following disclaimer in the documentation
	* and/or other materials
	* provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
	* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
	* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
	* IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	* POSSIBILITY OF SUCH DAMAGE.
	*/

	#include <linux/init.h>
	#include <linux/export.h>
	#include <linux/console.h>
	#include <linux/kobject.h>
	#include <linux/dma-mapping.h>
	#include <linux/interrupt.h>
	#include <linux/of.h>
	#include <linux/slab.h>
	#include <linux/stat.h>
	#include <linux/of_platform.h>
	#include <asm/ibmebus.h>

	static struct device ibmebus_bus_device = { /* fake "parent" device */
	.init_name = "ibmebus",
	};

	struct bus_type ibmebus_bus_type;

	/* These devices will automatically be added to the bus during init */
	static const struct of_device_id ibmebus_matches[] __initconst = {
	{ .compatible = "IBM,lhca" },
	{ .compatible = "IBM,lhea" },
	{},
	};

	static void ibmebus_alloc_coherent(struct device dev,
	size_t size,
	dma_addr_t *dma_handle,
	gfp_t flag,
	unsigned long attrs)
	{
	void *mem;

	mem = kmalloc(size, flag);
	*dma_handle = (dma_addr_t)mem;

	return mem;
	}

	static void ibmebus_free_coherent(struct device *dev,
	size_t size, void *vaddr,
	dma_addr_t dma_handle,
	unsigned long attrs)
	{
	kfree(vaddr);
	}

	static dma_addr_t ibmebus_map_page(struct device *dev,
	struct page *page,
	unsigned long offset,
	size_t size,
	enum dma_data_direction direction,
	unsigned long attrs)
	{
	return (dma_addr_t)(page_address(page) + offset);
	}

	static void ibmebus_unmap_page(struct device *dev,
	dma_addr_t dma_addr,
	size_t size,
	enum dma_data_direction direction,
	unsigned long attrs)
	{
	return;
	}

	static int ibmebus_map_sg(struct device *dev,
	struct scatterlist *sgl,
	int nents, enum dma_data_direction direction,
	unsigned long attrs)
	{
	struct scatterlist *sg;
	int i;

	for_each_sg(sgl, sg, nents, i) {
	sg->dma_address = (dma_addr_t) sg_virt(sg);
	sg->dma_length = sg->length;
	}

	return nents;
	}

	static void ibmebus_unmap_sg(struct device *dev,
	struct scatterlist *sg,
	int nents, enum dma_data_direction direction,
	unsigned long attrs)
	{
	return;
	}

	static int ibmebus_dma_supported(struct device *dev, u64 mask)
	{
	return mask == DMA_BIT_MASK(64);
	}

	static u64 ibmebus_dma_get_required_mask(struct device *dev)
	{
	return DMA_BIT_MASK(64);
	}

	static const struct dma_map_ops ibmebus_dma_ops = {
	.alloc = ibmebus_alloc_coherent,
	.free = ibmebus_free_coherent,
	.map_sg = ibmebus_map_sg,
	.unmap_sg = ibmebus_unmap_sg,
	.dma_supported = ibmebus_dma_supported,
	.get_required_mask = ibmebus_dma_get_required_mask,
	.map_page = ibmebus_map_page,
	.unmap_page = ibmebus_unmap_page,
	};

	static int ibmebus_match_path(struct device dev, void data)
	{
	struct device_node *dn = to_platform_device(dev)->dev.of_node;
	return (dn->full_name &&
	(strcasecmp((char *)data, dn->full_name) == 0));
	}

	static int ibmebus_match_node(struct device dev, void data)
	{
	return to_platform_device(dev)->dev.of_node == data;
	}

	static int ibmebus_create_device(struct device_node *dn)
	{
	struct platform_device *dev;
	int ret;

	dev = of_device_alloc(dn, NULL, &ibmebus_bus_device);
	if (!dev)
	return -ENOMEM;

	dev->dev.bus = &ibmebus_bus_type;
	dev->dev.dma_ops = &ibmebus_dma_ops;

	ret = of_device_add(dev);
	if (ret)
	platform_device_put(dev);
	return ret;
	}

	static int ibmebus_create_devices(const struct of_device_id *matches)
	{
	struct device_node root, child;
	struct device *dev;
	int ret = 0;

	root = of_find_node_by_path("/");

	for_each_child_of_node(root, child) {
	if (!of_match_node(matches, child))
	continue;

	dev = bus_find_device(&ibmebus_bus_type, NULL, child,
	ibmebus_match_node);
	if (dev) {
	put_device(dev);
	continue;
	}

	ret = ibmebus_create_device(child);
	if (ret) {
	printk(KERN_ERR "%s: failed to create device (%i)",
	__func__, ret);
	of_node_put(child);
	break;
	}
	}

	of_node_put(root);
	return ret;
	}

	int ibmebus_register_driver(struct platform_driver *drv)
	{
	/* If the driver uses devices that ibmebus doesn't know, add them */
	ibmebus_create_devices(drv->driver.of_match_table);

	drv->driver.bus = &ibmebus_bus_type;
	return driver_register(&drv->driver);
	}
	EXPORT_SYMBOL(ibmebus_register_driver);

	void ibmebus_unregister_driver(struct platform_driver *drv)
	{
	driver_unregister(&drv->driver);
	}
	EXPORT_SYMBOL(ibmebus_unregister_driver);

	int ibmebus_request_irq(u32 ist, irq_handler_t handler,
	unsigned long irq_flags, const char *devname,
	void *dev_id)
	{
	unsigned int irq = irq_create_mapping(NULL, ist);

	if (!irq)
	return -EINVAL;

	return request_irq(irq, handler, irq_flags, devname, dev_id);
	}
	EXPORT_SYMBOL(ibmebus_request_irq);

	void ibmebus_free_irq(u32 ist, void *dev_id)
	{
	unsigned int irq = irq_find_mapping(NULL, ist);

	free_irq(irq, dev_id);
	irq_dispose_mapping(irq);
	}
	EXPORT_SYMBOL(ibmebus_free_irq);

	static char ibmebus_chomp(const char in, size_t count)
	{
	char *out = kmalloc(count + 1, GFP_KERNEL);

	if (!out)
	return NULL;

	memcpy(out, in, count);
	out[count] = '\0';
	if (out[count - 1] == '\n')
	out[count - 1] = '\0';

	return out;
	}

	static ssize_t ibmebus_store_probe(struct bus_type *bus,
	const char *buf, size_t count)
	{
	struct device_node *dn = NULL;
	struct device *dev;
	char *path;
	ssize_t rc = 0;

	path = ibmebus_chomp(buf, count);
	if (!path)
	return -ENOMEM;

	dev = bus_find_device(&ibmebus_bus_type, NULL, path,
	ibmebus_match_path);
	if (dev) {
	put_device(dev);
	printk(KERN_WARNING "%s: %s has already been probed\n",
	__func__, path);
	rc = -EEXIST;
	goto out;
	}

	if ((dn = of_find_node_by_path(path))) {
	rc = ibmebus_create_device(dn);
	of_node_put(dn);
	} else {
	printk(KERN_WARNING "%s: no such device node: %s\n",
	__func__, path);
	rc = -ENODEV;
	}

	out:
	kfree(path);
	if (rc)
	return rc;
	return count;
	}
	static BUS_ATTR(probe, S_IWUSR, NULL, ibmebus_store_probe);

	static ssize_t ibmebus_store_remove(struct bus_type *bus,
	const char *buf, size_t count)
	{
	struct device *dev;
	char *path;

	path = ibmebus_chomp(buf, count);
	if (!path)
	return -ENOMEM;

	if ((dev = bus_find_device(&ibmebus_bus_type, NULL, path,
	ibmebus_match_path))) {
	of_device_unregister(to_platform_device(dev));
	put_device(dev);

	kfree(path);
	return count;
	} else {
	printk(KERN_WARNING "%s: %s not on the bus\n",
	__func__, path);

	kfree(path);
	return -ENODEV;
	}
	}
	static BUS_ATTR(remove, S_IWUSR, NULL, ibmebus_store_remove);

	static struct attribute *ibmbus_bus_attrs[] = {
	&bus_attr_probe.attr,
	&bus_attr_remove.attr,
	NULL,
	};
	ATTRIBUTE_GROUPS(ibmbus_bus);

	static int ibmebus_bus_bus_match(struct device dev, 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;
	}

	static int ibmebus_bus_device_probe(struct device *dev)
	{
	int error = -ENODEV;
	struct platform_driver *drv;
	struct platform_device *of_dev;

	drv = to_platform_driver(dev->driver);
	of_dev = to_platform_device(dev);

	if (!drv->probe)
	return error;

	of_dev_get(of_dev);

	if (of_driver_match_device(dev, dev->driver))
	error = drv->probe(of_dev);
	if (error)
	of_dev_put(of_dev);

	return error;
	}

	static int ibmebus_bus_device_remove(struct device *dev)
	{
	struct platform_device *of_dev = to_platform_device(dev);
	struct platform_driver *drv = to_platform_driver(dev->driver);

	if (dev->driver && drv->remove)
	drv->remove(of_dev);
	return 0;
	}

	static void ibmebus_bus_device_shutdown(struct device *dev)
	{
	struct platform_device *of_dev = to_platform_device(dev);
	struct platform_driver *drv = to_platform_driver(dev->driver);

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

	/*
	* ibmebus_bus_device_attrs
	*/
	static ssize_t devspec_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct platform_device *ofdev;

	ofdev = to_platform_device(dev);
	return sprintf(buf, "%s\n", ofdev->dev.of_node->full_name);
	}

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

	ofdev = to_platform_device(dev);
	return sprintf(buf, "%s\n", ofdev->dev.of_node->name);
	}

	static ssize_t modalias_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	return of_device_modalias(dev, buf, PAGE_SIZE);
	}

	static struct device_attribute ibmebus_bus_device_attrs[] = {
	__ATTR_RO(devspec),
	__ATTR_RO(name),
	__ATTR_RO(modalias),
	__ATTR_NULL
	};

	struct bus_type ibmebus_bus_type = {
	.name = "ibmebus",
	.uevent = of_device_uevent_modalias,
	.bus_groups = ibmbus_bus_groups,
	.match = ibmebus_bus_bus_match,
	.probe = ibmebus_bus_device_probe,
	.remove = ibmebus_bus_device_remove,
	.shutdown = ibmebus_bus_device_shutdown,
	.dev_attrs = ibmebus_bus_device_attrs,
	};
	EXPORT_SYMBOL(ibmebus_bus_type);

	static int __init ibmebus_bus_init(void)
	{
	int err;

	printk(KERN_INFO "IBM eBus Device Driver\n");

	err = bus_register(&ibmebus_bus_type);
	if (err) {
	printk(KERN_ERR "%s: failed to register IBM eBus.\n",
	__func__);
	return err;
	}

	err = device_register(&ibmebus_bus_device);
	if (err) {
	printk(KERN_WARNING "%s: device_register returned %i\n",
	__func__, err);
	bus_unregister(&ibmebus_bus_type);

	return err;
	}

	err = ibmebus_create_devices(ibmebus_matches);
	if (err) {
	device_unregister(&ibmebus_bus_device);
	bus_unregister(&ibmebus_bus_type);
	return err;
	}

	return 0;
	}
	postcore_initcall(ibmebus_bus_init);