arch/powerpc/sysdev/axonram.c - kernel/msm-5.4 - Gitiles

 /*
  * (C) Copyright IBM Deutschland Entwicklung GmbH 2006
  *
  * Author: Maxim Shchetynin <maxim@de.ibm.com>
  *
  * Axon DDR2 device driver.
  * It registers one block device per Axon's DDR2 memory bank found on a system.
  * Block devices are called axonram?, their major and minor numbers are
  * available in /proc/devices, /proc/partitions or in /sys/block/axonram?/dev.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2, or (at your option)
  * any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */

 #include <linux/bio.h>
 #include <linux/blkdev.h>
 #include <linux/dax.h>
 #include <linux/device.h>
 #include <linux/errno.h>
 #include <linux/fs.h>
 #include <linux/genhd.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/ioport.h>
 #include <linux/irq.h>
 #include <linux/irqreturn.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/types.h>
 #include <linux/of_device.h>
 #include <linux/of_platform.h>
 #include <linux/pfn_t.h>
 #include <linux/uio.h>

 #include <asm/page.h>
 #include <asm/prom.h>

 #define AXON_RAM_MODULE_NAME		"axonram"
 #define AXON_RAM_DEVICE_NAME		"axonram"
 #define AXON_RAM_MINORS_PER_DISK	16
 #define AXON_RAM_BLOCK_SHIFT		PAGE_SHIFT
 #define AXON_RAM_BLOCK_SIZE		1 << AXON_RAM_BLOCK_SHIFT
 #define AXON_RAM_SECTOR_SHIFT		9
 #define AXON_RAM_SECTOR_SIZE		1 << AXON_RAM_SECTOR_SHIFT
 #define AXON_RAM_IRQ_FLAGS		IRQF_SHARED | IRQF_TRIGGER_RISING

 static int azfs_major, azfs_minor;

 struct axon_ram_bank {
 	struct platform_device	*device;
 	struct gendisk		*disk;
 	struct dax_device	*dax_dev;
 	unsigned int		irq_id;
 	unsigned long		ph_addr;
 	unsigned long		io_addr;
 	unsigned long		size;
 	unsigned long		ecc_counter;
 };

 static ssize_t
 axon_ram_sysfs_ecc(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct platform_device *device = to_platform_device(dev);
 	struct axon_ram_bank *bank = device->dev.platform_data;

 	BUG_ON(!bank);

 	return sprintf(buf, "%ld\n", bank->ecc_counter);
 }

 static DEVICE_ATTR(ecc, S_IRUGO, axon_ram_sysfs_ecc, NULL);

 /**
  * axon_ram_irq_handler - interrupt handler for Axon RAM ECC
  * @irq: interrupt ID
  * @dev: pointer to of_device
  */
 static irqreturn_t
 axon_ram_irq_handler(int irq, void *dev)
 {
 	struct platform_device *device = dev;
 	struct axon_ram_bank *bank = device->dev.platform_data;

 	BUG_ON(!bank);

 	dev_err(&device->dev, "Correctable memory error occurred\n");
 	bank->ecc_counter++;
 	return IRQ_HANDLED;
 }

 /**
  * axon_ram_make_request - make_request() method for block device
  * @queue, @bio: see blk_queue_make_request()
  */
 static blk_qc_t
 axon_ram_make_request(struct request_queue *queue, struct bio *bio)
 {
 	struct axon_ram_bank *bank = bio->bi_bdev->bd_disk->private_data;
 	unsigned long phys_mem, phys_end;
 	void *user_mem;
 	struct bio_vec vec;
 	unsigned int transfered;
 	struct bvec_iter iter;

 	phys_mem = bank->io_addr + (bio->bi_iter.bi_sector <<
 				    AXON_RAM_SECTOR_SHIFT);
 	phys_end = bank->io_addr + bank->size;
 	transfered = 0;
 	bio_for_each_segment(vec, bio, iter) {
 		if (unlikely(phys_mem + vec.bv_len > phys_end)) {
 			bio_io_error(bio);
 			return BLK_QC_T_NONE;
 		}

 		user_mem = page_address(vec.bv_page) + vec.bv_offset;
 		if (bio_data_dir(bio) == READ)
 			memcpy(user_mem, (void *) phys_mem, vec.bv_len);
 		else
 			memcpy((void *) phys_mem, user_mem, vec.bv_len);

 		phys_mem += vec.bv_len;
 		transfered += vec.bv_len;
 	}
 	bio_endio(bio);
 	return BLK_QC_T_NONE;
 }

 static const struct block_device_operations axon_ram_devops = {
 	.owner		= THIS_MODULE,
 };

 static long
 __axon_ram_direct_access(struct axon_ram_bank *bank, pgoff_t pgoff, long nr_pages,
 		       void **kaddr, pfn_t *pfn)
 {
 	resource_size_t offset = pgoff * PAGE_SIZE;

 	*kaddr = (void *) bank->io_addr + offset;
 	*pfn = phys_to_pfn_t(bank->ph_addr + offset, PFN_DEV);
 	return (bank->size - offset) / PAGE_SIZE;
 }

 static long
 axon_ram_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
 		       void **kaddr, pfn_t *pfn)
 {
 	struct axon_ram_bank *bank = dax_get_private(dax_dev);

 	return __axon_ram_direct_access(bank, pgoff, nr_pages, kaddr, pfn);
 }

 static size_t axon_ram_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
 		void *addr, size_t bytes, struct iov_iter *i)
 {
 	return copy_from_iter(addr, bytes, i);
 }

 static const struct dax_operations axon_ram_dax_ops = {
 	.direct_access = axon_ram_dax_direct_access,
 	.copy_from_iter = axon_ram_copy_from_iter,
 };

 /**
  * axon_ram_probe - probe() method for platform driver
  * @device: see platform_driver method
  */
 static int axon_ram_probe(struct platform_device *device)
 {
 	static int axon_ram_bank_id = -1;
 	struct axon_ram_bank *bank;
 	struct resource resource;
 	int rc = 0;

 	axon_ram_bank_id++;

 	dev_info(&device->dev, "Found memory controller on %s\n",
 			device->dev.of_node->full_name);

 	bank = kzalloc(sizeof(struct axon_ram_bank), GFP_KERNEL);
 	if (bank == NULL) {
 		dev_err(&device->dev, "Out of memory\n");
 		rc = -ENOMEM;
 		goto failed;
 	}

 	device->dev.platform_data = bank;

 	bank->device = device;

 	if (of_address_to_resource(device->dev.of_node, 0, &resource) != 0) {
 		dev_err(&device->dev, "Cannot access device tree\n");
 		rc = -EFAULT;
 		goto failed;
 	}

 	bank->size = resource_size(&resource);

 	if (bank->size == 0) {
 		dev_err(&device->dev, "No DDR2 memory found for %s%d\n",
 				AXON_RAM_DEVICE_NAME, axon_ram_bank_id);
 		rc = -ENODEV;
 		goto failed;
 	}

 	dev_info(&device->dev, "Register DDR2 memory device %s%d with %luMB\n",
 			AXON_RAM_DEVICE_NAME, axon_ram_bank_id, bank->size >> 20);

 	bank->ph_addr = resource.start;
 	bank->io_addr = (unsigned long) ioremap_prot(
 			bank->ph_addr, bank->size, _PAGE_NO_CACHE);
 	if (bank->io_addr == 0) {
 		dev_err(&device->dev, "ioremap() failed\n");
 		rc = -EFAULT;
 		goto failed;
 	}

 	bank->disk = alloc_disk(AXON_RAM_MINORS_PER_DISK);
 	if (bank->disk == NULL) {
 		dev_err(&device->dev, "Cannot register disk\n");
 		rc = -EFAULT;
 		goto failed;
 	}


 	bank->disk->major = azfs_major;
 	bank->disk->first_minor = azfs_minor;
 	bank->disk->fops = &axon_ram_devops;
 	bank->disk->private_data = bank;

 	sprintf(bank->disk->disk_name, "%s%d",
 			AXON_RAM_DEVICE_NAME, axon_ram_bank_id);

 	bank->dax_dev = alloc_dax(bank, bank->disk->disk_name,
 			&axon_ram_dax_ops);
 	if (!bank->dax_dev) {
 		rc = -ENOMEM;
 		goto failed;
 	}

 	bank->disk->queue = blk_alloc_queue(GFP_KERNEL);
 	if (bank->disk->queue == NULL) {
 		dev_err(&device->dev, "Cannot register disk queue\n");
 		rc = -EFAULT;
 		goto failed;
 	}

 	set_capacity(bank->disk, bank->size >> AXON_RAM_SECTOR_SHIFT);
 	blk_queue_make_request(bank->disk->queue, axon_ram_make_request);
 	blk_queue_logical_block_size(bank->disk->queue, AXON_RAM_SECTOR_SIZE);
 	device_add_disk(&device->dev, bank->disk);

 	bank->irq_id = irq_of_parse_and_map(device->dev.of_node, 0);
 	if (!bank->irq_id) {
 		dev_err(&device->dev, "Cannot access ECC interrupt ID\n");
 		rc = -EFAULT;
 		goto failed;
 	}

 	rc = request_irq(bank->irq_id, axon_ram_irq_handler,
 			AXON_RAM_IRQ_FLAGS, bank->disk->disk_name, device);
 	if (rc != 0) {
 		dev_err(&device->dev, "Cannot register ECC interrupt handler\n");
 		bank->irq_id = 0;
 		rc = -EFAULT;
 		goto failed;
 	}

 	rc = device_create_file(&device->dev, &dev_attr_ecc);
 	if (rc != 0) {
 		dev_err(&device->dev, "Cannot create sysfs file\n");
 		rc = -EFAULT;
 		goto failed;
 	}

 	azfs_minor += bank->disk->minors;

 	return 0;

 failed:
 	if (bank != NULL) {
 		if (bank->irq_id)
 			free_irq(bank->irq_id, device);
 		if (bank->disk != NULL) {
 			if (bank->disk->major > 0)
 				unregister_blkdev(bank->disk->major,
 						bank->disk->disk_name);
 			if (bank->disk->flags & GENHD_FL_UP)
 				del_gendisk(bank->disk);
 			put_disk(bank->disk);
 		}
 		kill_dax(bank->dax_dev);
 		put_dax(bank->dax_dev);
 		device->dev.platform_data = NULL;
 		if (bank->io_addr != 0)
 			iounmap((void __iomem *) bank->io_addr);
 		kfree(bank);
 	}

 	return rc;
 }

 /**
  * axon_ram_remove - remove() method for platform driver
  * @device: see of_platform_driver method
  */
 static int
 axon_ram_remove(struct platform_device *device)
 {
 	struct axon_ram_bank *bank = device->dev.platform_data;

 	BUG_ON(!bank || !bank->disk);

 	device_remove_file(&device->dev, &dev_attr_ecc);
 	free_irq(bank->irq_id, device);
 	kill_dax(bank->dax_dev);
 	put_dax(bank->dax_dev);
 	del_gendisk(bank->disk);
 	put_disk(bank->disk);
 	iounmap((void __iomem *) bank->io_addr);
 	kfree(bank);

 	return 0;
 }

 static const struct of_device_id axon_ram_device_id[] = {
 	{
 		.type	= "dma-memory"
 	},
 	{}
 };
 MODULE_DEVICE_TABLE(of, axon_ram_device_id);

 static struct platform_driver axon_ram_driver = {
 	.probe		= axon_ram_probe,
 	.remove		= axon_ram_remove,
 	.driver = {
 		.name = AXON_RAM_MODULE_NAME,
 		.of_match_table = axon_ram_device_id,
 	},
 };

 /**
  * axon_ram_init
  */
 static int __init
 axon_ram_init(void)
 {
 	azfs_major = register_blkdev(azfs_major, AXON_RAM_DEVICE_NAME);
 	if (azfs_major < 0) {
 		printk(KERN_ERR "%s cannot become block device major number\n",
 				AXON_RAM_MODULE_NAME);
 		return -EFAULT;
 	}
 	azfs_minor = 0;

 	return platform_driver_register(&axon_ram_driver);
 }

 /**
  * axon_ram_exit
  */
 static void __exit
 axon_ram_exit(void)
 {
 	platform_driver_unregister(&axon_ram_driver);
 	unregister_blkdev(azfs_major, AXON_RAM_DEVICE_NAME);
 }

 module_init(axon_ram_init);
 module_exit(axon_ram_exit);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Maxim Shchetynin <maxim@de.ibm.com>");
 MODULE_DESCRIPTION("Axon DDR2 RAM device driver for IBM Cell BE");
	/*
	* (C) Copyright IBM Deutschland Entwicklung GmbH 2006
	*
	* Author: Maxim Shchetynin <maxim@de.ibm.com>
	*
	* Axon DDR2 device driver.
	* It registers one block device per Axon's DDR2 memory bank found on a system.
	* Block devices are called axonram?, their major and minor numbers are
	* available in /proc/devices, /proc/partitions or in /sys/block/axonram?/dev.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2, or (at your option)
	* any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	*/

	#include <linux/bio.h>
	#include <linux/blkdev.h>
	#include <linux/dax.h>
	#include <linux/device.h>
	#include <linux/errno.h>
	#include <linux/fs.h>
	#include <linux/genhd.h>
	#include <linux/interrupt.h>
	#include <linux/io.h>
	#include <linux/ioport.h>
	#include <linux/irq.h>
	#include <linux/irqreturn.h>
	#include <linux/kernel.h>
	#include <linux/mm.h>
	#include <linux/mod_devicetable.h>
	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/string.h>
	#include <linux/types.h>
	#include <linux/of_device.h>
	#include <linux/of_platform.h>
	#include <linux/pfn_t.h>
	#include <linux/uio.h>

	#include <asm/page.h>
	#include <asm/prom.h>

	#define AXON_RAM_MODULE_NAME "axonram"
	#define AXON_RAM_DEVICE_NAME "axonram"
	#define AXON_RAM_MINORS_PER_DISK 16
	#define AXON_RAM_BLOCK_SHIFT PAGE_SHIFT
	#define AXON_RAM_BLOCK_SIZE 1 << AXON_RAM_BLOCK_SHIFT
	#define AXON_RAM_SECTOR_SHIFT 9
	#define AXON_RAM_SECTOR_SIZE 1 << AXON_RAM_SECTOR_SHIFT
	#define AXON_RAM_IRQ_FLAGS IRQF_SHARED \| IRQF_TRIGGER_RISING

	static int azfs_major, azfs_minor;

	struct axon_ram_bank {
	struct platform_device *device;
	struct gendisk *disk;
	struct dax_device *dax_dev;
	unsigned int irq_id;
	unsigned long ph_addr;
	unsigned long io_addr;
	unsigned long size;
	unsigned long ecc_counter;
	};

	static ssize_t
	axon_ram_sysfs_ecc(struct device dev, struct device_attribute attr, char *buf)
	{
	struct platform_device *device = to_platform_device(dev);
	struct axon_ram_bank *bank = device->dev.platform_data;

	BUG_ON(!bank);

	return sprintf(buf, "%ld\n", bank->ecc_counter);
	}

	static DEVICE_ATTR(ecc, S_IRUGO, axon_ram_sysfs_ecc, NULL);

	/**
	* axon_ram_irq_handler - interrupt handler for Axon RAM ECC
	* @irq: interrupt ID
	* @dev: pointer to of_device
	*/
	static irqreturn_t
	axon_ram_irq_handler(int irq, void *dev)
	{
	struct platform_device *device = dev;
	struct axon_ram_bank *bank = device->dev.platform_data;

	BUG_ON(!bank);

	dev_err(&device->dev, "Correctable memory error occurred\n");
	bank->ecc_counter++;
	return IRQ_HANDLED;
	}

	/**
	* axon_ram_make_request - make_request() method for block device
	* @queue, @bio: see blk_queue_make_request()
	*/
	static blk_qc_t
	axon_ram_make_request(struct request_queue queue, struct bio bio)
	{
	struct axon_ram_bank *bank = bio->bi_bdev->bd_disk->private_data;
	unsigned long phys_mem, phys_end;
	void *user_mem;
	struct bio_vec vec;
	unsigned int transfered;
	struct bvec_iter iter;

	phys_mem = bank->io_addr + (bio->bi_iter.bi_sector <<
	AXON_RAM_SECTOR_SHIFT);
	phys_end = bank->io_addr + bank->size;
	transfered = 0;
	bio_for_each_segment(vec, bio, iter) {
	if (unlikely(phys_mem + vec.bv_len > phys_end)) {
	bio_io_error(bio);
	return BLK_QC_T_NONE;
	}

	user_mem = page_address(vec.bv_page) + vec.bv_offset;
	if (bio_data_dir(bio) == READ)
	memcpy(user_mem, (void *) phys_mem, vec.bv_len);
	else
	memcpy((void *) phys_mem, user_mem, vec.bv_len);

	phys_mem += vec.bv_len;
	transfered += vec.bv_len;
	}
	bio_endio(bio);
	return BLK_QC_T_NONE;
	}

	static const struct block_device_operations axon_ram_devops = {
	.owner = THIS_MODULE,
	};

	static long
	__axon_ram_direct_access(struct axon_ram_bank *bank, pgoff_t pgoff, long nr_pages,
	void *kaddr, pfn_t pfn)
	{
	resource_size_t offset = pgoff * PAGE_SIZE;

	kaddr = (void ) bank->io_addr + offset;
	*pfn = phys_to_pfn_t(bank->ph_addr + offset, PFN_DEV);
	return (bank->size - offset) / PAGE_SIZE;
	}

	static long
	axon_ram_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
	void *kaddr, pfn_t pfn)
	{
	struct axon_ram_bank *bank = dax_get_private(dax_dev);

	return __axon_ram_direct_access(bank, pgoff, nr_pages, kaddr, pfn);
	}

	static size_t axon_ram_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
	void addr, size_t bytes, struct iov_iter i)
	{
	return copy_from_iter(addr, bytes, i);
	}

	static const struct dax_operations axon_ram_dax_ops = {
	.direct_access = axon_ram_dax_direct_access,
	.copy_from_iter = axon_ram_copy_from_iter,
	};

	/**
	* axon_ram_probe - probe() method for platform driver
	* @device: see platform_driver method
	*/
	static int axon_ram_probe(struct platform_device *device)
	{
	static int axon_ram_bank_id = -1;
	struct axon_ram_bank *bank;
	struct resource resource;
	int rc = 0;

	axon_ram_bank_id++;

	dev_info(&device->dev, "Found memory controller on %s\n",
	device->dev.of_node->full_name);

	bank = kzalloc(sizeof(struct axon_ram_bank), GFP_KERNEL);
	if (bank == NULL) {
	dev_err(&device->dev, "Out of memory\n");
	rc = -ENOMEM;
	goto failed;
	}

	device->dev.platform_data = bank;

	bank->device = device;

	if (of_address_to_resource(device->dev.of_node, 0, &resource) != 0) {
	dev_err(&device->dev, "Cannot access device tree\n");
	rc = -EFAULT;
	goto failed;
	}

	bank->size = resource_size(&resource);

	if (bank->size == 0) {
	dev_err(&device->dev, "No DDR2 memory found for %s%d\n",
	AXON_RAM_DEVICE_NAME, axon_ram_bank_id);
	rc = -ENODEV;
	goto failed;
	}

	dev_info(&device->dev, "Register DDR2 memory device %s%d with %luMB\n",
	AXON_RAM_DEVICE_NAME, axon_ram_bank_id, bank->size >> 20);

	bank->ph_addr = resource.start;
	bank->io_addr = (unsigned long) ioremap_prot(
	bank->ph_addr, bank->size, _PAGE_NO_CACHE);
	if (bank->io_addr == 0) {
	dev_err(&device->dev, "ioremap() failed\n");
	rc = -EFAULT;
	goto failed;
	}

	bank->disk = alloc_disk(AXON_RAM_MINORS_PER_DISK);
	if (bank->disk == NULL) {
	dev_err(&device->dev, "Cannot register disk\n");
	rc = -EFAULT;
	goto failed;
	}


	bank->disk->major = azfs_major;
	bank->disk->first_minor = azfs_minor;
	bank->disk->fops = &axon_ram_devops;
	bank->disk->private_data = bank;

	sprintf(bank->disk->disk_name, "%s%d",
	AXON_RAM_DEVICE_NAME, axon_ram_bank_id);

	bank->dax_dev = alloc_dax(bank, bank->disk->disk_name,
	&axon_ram_dax_ops);
	if (!bank->dax_dev) {
	rc = -ENOMEM;
	goto failed;
	}

	bank->disk->queue = blk_alloc_queue(GFP_KERNEL);
	if (bank->disk->queue == NULL) {
	dev_err(&device->dev, "Cannot register disk queue\n");
	rc = -EFAULT;
	goto failed;
	}

	set_capacity(bank->disk, bank->size >> AXON_RAM_SECTOR_SHIFT);
	blk_queue_make_request(bank->disk->queue, axon_ram_make_request);
	blk_queue_logical_block_size(bank->disk->queue, AXON_RAM_SECTOR_SIZE);
	device_add_disk(&device->dev, bank->disk);

	bank->irq_id = irq_of_parse_and_map(device->dev.of_node, 0);
	if (!bank->irq_id) {
	dev_err(&device->dev, "Cannot access ECC interrupt ID\n");
	rc = -EFAULT;
	goto failed;
	}

	rc = request_irq(bank->irq_id, axon_ram_irq_handler,
	AXON_RAM_IRQ_FLAGS, bank->disk->disk_name, device);
	if (rc != 0) {
	dev_err(&device->dev, "Cannot register ECC interrupt handler\n");
	bank->irq_id = 0;
	rc = -EFAULT;
	goto failed;
	}

	rc = device_create_file(&device->dev, &dev_attr_ecc);
	if (rc != 0) {
	dev_err(&device->dev, "Cannot create sysfs file\n");
	rc = -EFAULT;
	goto failed;
	}

	azfs_minor += bank->disk->minors;

	return 0;

	failed:
	if (bank != NULL) {
	if (bank->irq_id)
	free_irq(bank->irq_id, device);
	if (bank->disk != NULL) {
	if (bank->disk->major > 0)
	unregister_blkdev(bank->disk->major,
	bank->disk->disk_name);
	if (bank->disk->flags & GENHD_FL_UP)
	del_gendisk(bank->disk);
	put_disk(bank->disk);
	}
	kill_dax(bank->dax_dev);
	put_dax(bank->dax_dev);
	device->dev.platform_data = NULL;
	if (bank->io_addr != 0)
	iounmap((void __iomem *) bank->io_addr);
	kfree(bank);
	}

	return rc;
	}

	/**
	* axon_ram_remove - remove() method for platform driver
	* @device: see of_platform_driver method
	*/
	static int
	axon_ram_remove(struct platform_device *device)
	{
	struct axon_ram_bank *bank = device->dev.platform_data;

	BUG_ON(!bank \|\| !bank->disk);

	device_remove_file(&device->dev, &dev_attr_ecc);
	free_irq(bank->irq_id, device);
	kill_dax(bank->dax_dev);
	put_dax(bank->dax_dev);
	del_gendisk(bank->disk);
	put_disk(bank->disk);
	iounmap((void __iomem *) bank->io_addr);
	kfree(bank);

	return 0;
	}

	static const struct of_device_id axon_ram_device_id[] = {
	{
	.type = "dma-memory"
	},
	{}
	};
	MODULE_DEVICE_TABLE(of, axon_ram_device_id);

	static struct platform_driver axon_ram_driver = {
	.probe = axon_ram_probe,
	.remove = axon_ram_remove,
	.driver = {
	.name = AXON_RAM_MODULE_NAME,
	.of_match_table = axon_ram_device_id,
	},
	};

	/**
	* axon_ram_init
	*/
	static int __init
	axon_ram_init(void)
	{
	azfs_major = register_blkdev(azfs_major, AXON_RAM_DEVICE_NAME);
	if (azfs_major < 0) {
	printk(KERN_ERR "%s cannot become block device major number\n",
	AXON_RAM_MODULE_NAME);
	return -EFAULT;
	}
	azfs_minor = 0;

	return platform_driver_register(&axon_ram_driver);
	}

	/**
	* axon_ram_exit
	*/
	static void __exit
	axon_ram_exit(void)
	{
	platform_driver_unregister(&axon_ram_driver);
	unregister_blkdev(azfs_major, AXON_RAM_DEVICE_NAME);
	}

	module_init(axon_ram_init);
	module_exit(axon_ram_exit);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Maxim Shchetynin <maxim@de.ibm.com>");
	MODULE_DESCRIPTION("Axon DDR2 RAM device driver for IBM Cell BE");