[deliverable/linux.git] / drivers / char / bsr.c

/* IBM POWER Barrier Synchronization Register Driver
 *
 * Copyright IBM Corporation 2008
 *
 * Author: Sonny Rao <sonnyrao@us.ibm.com>
 *
 * 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 of the License, 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */

#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/cdev.h>
#include <linux/list.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <asm/pgtable.h>
#include <asm/io.h>

/*
 This driver exposes a special register which can be used for fast
 synchronization across a large SMP machine.  The hardware is exposed
 as an array of bytes where each process will write to one of the bytes to
 indicate it has finished the current stage and this update is broadcast to
 all processors without having to bounce a cacheline between them. In
 POWER5 and POWER6 there is one of these registers per SMP,  but it is
 presented in two forms; first, it is given as a whole and then as a number
 of smaller registers which alias to parts of the single whole register.
 This can potentially allow multiple groups of processes to each have their
 own private synchronization device.

 Note that this hardware *must* be written to using *only* single byte writes.
 It may be read using 1, 2, 4, or 8 byte loads which must be aligned since
 this region is treated as cache-inhibited  processes should also use a
 full sync before and after writing to the BSR to ensure all stores and
 the BSR update have made it to all chips in the system
*/

/* This is arbitrary number, up to Power6 it's been 17 or fewer  */
#define BSR_MAX_DEVS (32)

struct bsr_dev {
	u64      bsr_addr;     /* Real address */
	u64      bsr_len;      /* length of mem region we can map */
	unsigned bsr_bytes;    /* size of the BSR reg itself */
	unsigned bsr_stride;   /* interval at which BSR repeats in the page */
	unsigned bsr_type;     /* maps to enum below */
	unsigned bsr_num;      /* bsr id number for its type */
	int      bsr_minor;

	struct list_head bsr_list;

	dev_t    bsr_dev;
	struct cdev bsr_cdev;
	struct device *bsr_device;
	char     bsr_name[32];

};

static unsigned total_bsr_devs;
static struct list_head bsr_devs = LIST_HEAD_INIT(bsr_devs);
static struct class *bsr_class;
static int bsr_major;

enum {
	BSR_8    = 0,
	BSR_16   = 1,
	BSR_64   = 2,
	BSR_128  = 3,
	BSR_4096 = 4,
	BSR_UNKNOWN = 5,
	BSR_MAX  = 6,
};

static unsigned bsr_types[BSR_MAX];

static ssize_t
bsr_size_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct bsr_dev *bsr_dev = dev_get_drvdata(dev);
	return sprintf(buf, "%u\n", bsr_dev->bsr_bytes);
}
static DEVICE_ATTR_RO(bsr_size);

static ssize_t
bsr_stride_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct bsr_dev *bsr_dev = dev_get_drvdata(dev);
	return sprintf(buf, "%u\n", bsr_dev->bsr_stride);
}
static DEVICE_ATTR_RO(bsr_stride);

static ssize_t
bsr_length_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct bsr_dev *bsr_dev = dev_get_drvdata(dev);
	return sprintf(buf, "%llu\n", bsr_dev->bsr_len);
}
static DEVICE_ATTR_RO(bsr_length);

static struct attribute *bsr_dev_attrs[] = {
	&dev_attr_bsr_size.attr,
	&dev_attr_bsr_stride.attr,
	&dev_attr_bsr_length.attr,
	NULL,
};
ATTRIBUTE_GROUPS(bsr_dev);

static int bsr_mmap(struct file *filp, struct vm_area_struct *vma)
{
	unsigned long size   = vma->vm_end - vma->vm_start;
	struct bsr_dev *dev = filp->private_data;
	int ret;

	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);

	/* check for the case of a small BSR device and map one 4k page for it*/
	if (dev->bsr_len < PAGE_SIZE && size == PAGE_SIZE)
		ret = remap_4k_pfn(vma, vma->vm_start, dev->bsr_addr >> 12,
				   vma->vm_page_prot);
	else if (size <= dev->bsr_len)
		ret = io_remap_pfn_range(vma, vma->vm_start,
					 dev->bsr_addr >> PAGE_SHIFT,
					 size, vma->vm_page_prot);
	else
		return -EINVAL;

	if (ret)
		return -EAGAIN;

	return 0;
}

static int bsr_open(struct inode * inode, struct file * filp)
{
	struct cdev *cdev = inode->i_cdev;
	struct bsr_dev *dev = container_of(cdev, struct bsr_dev, bsr_cdev);

	filp->private_data = dev;
	return 0;
}

static const struct file_operations bsr_fops = {
	.owner = THIS_MODULE,
	.mmap  = bsr_mmap,
	.open  = bsr_open,
	.llseek = noop_llseek,
};

static void bsr_cleanup_devs(void)
{
	struct bsr_dev *cur, *n;

	list_for_each_entry_safe(cur, n, &bsr_devs, bsr_list) {
		if (cur->bsr_device) {
			cdev_del(&cur->bsr_cdev);
			device_del(cur->bsr_device);
		}
		list_del(&cur->bsr_list);
		kfree(cur);
	}
}

static int bsr_add_node(struct device_node *bn)
{
	int bsr_stride_len, bsr_bytes_len, num_bsr_devs;
	const u32 *bsr_stride;
	const u32 *bsr_bytes;
	unsigned i;
	int ret = -ENODEV;

	bsr_stride = of_get_property(bn, "ibm,lock-stride", &bsr_stride_len);
	bsr_bytes  = of_get_property(bn, "ibm,#lock-bytes", &bsr_bytes_len);

	if (!bsr_stride || !bsr_bytes ||
	    (bsr_stride_len != bsr_bytes_len)) {
		printk(KERN_ERR "bsr of-node has missing/incorrect property\n");
		return ret;
	}

	num_bsr_devs = bsr_bytes_len / sizeof(u32);

	for (i = 0 ; i < num_bsr_devs; i++) {
		struct bsr_dev *cur = kzalloc(sizeof(struct bsr_dev),
					      GFP_KERNEL);
		struct resource res;
		int result;

		if (!cur) {
			printk(KERN_ERR "Unable to alloc bsr dev\n");
			ret = -ENOMEM;
			goto out_err;
		}

		result = of_address_to_resource(bn, i, &res);
		if (result < 0) {
			printk(KERN_ERR "bsr of-node has invalid reg property, skipping\n");
			kfree(cur);
			continue;
		}

		cur->bsr_minor  = i + total_bsr_devs;
		cur->bsr_addr   = res.start;
		cur->bsr_len    = resource_size(&res);
		cur->bsr_bytes  = bsr_bytes[i];
		cur->bsr_stride = bsr_stride[i];
		cur->bsr_dev    = MKDEV(bsr_major, i + total_bsr_devs);

		/* if we have a bsr_len of > 4k and less then PAGE_SIZE (64k pages) */
		/* we can only map 4k of it, so only advertise the 4k in sysfs */
		if (cur->bsr_len > 4096 && cur->bsr_len < PAGE_SIZE)
			cur->bsr_len = 4096;

		switch(cur->bsr_bytes) {
		case 8:
			cur->bsr_type = BSR_8;
			break;
		case 16:
			cur->bsr_type = BSR_16;
			break;
		case 64:
			cur->bsr_type = BSR_64;
			break;
		case 128:
			cur->bsr_type = BSR_128;
			break;
		case 4096:
			cur->bsr_type = BSR_4096;
			break;
		default:
			cur->bsr_type = BSR_UNKNOWN;
		}

		cur->bsr_num = bsr_types[cur->bsr_type];
		snprintf(cur->bsr_name, 32, "bsr%d_%d",
			 cur->bsr_bytes, cur->bsr_num);

		cdev_init(&cur->bsr_cdev, &bsr_fops);
		result = cdev_add(&cur->bsr_cdev, cur->bsr_dev, 1);
		if (result) {
			kfree(cur);
			goto out_err;
		}

		cur->bsr_device = device_create(bsr_class, NULL, cur->bsr_dev,
						cur, cur->bsr_name);
		if (IS_ERR(cur->bsr_device)) {
			printk(KERN_ERR "device_create failed for %s\n",
			       cur->bsr_name);
			cdev_del(&cur->bsr_cdev);
			kfree(cur);
			goto out_err;
		}

		bsr_types[cur->bsr_type] = cur->bsr_num + 1;
		list_add_tail(&cur->bsr_list, &bsr_devs);
	}

	total_bsr_devs += num_bsr_devs;

	return 0;

 out_err:

	bsr_cleanup_devs();
	return ret;
}

static int bsr_create_devs(struct device_node *bn)
{
	int ret;

	while (bn) {
		ret = bsr_add_node(bn);
		if (ret) {
			of_node_put(bn);
			return ret;
		}
		bn = of_find_compatible_node(bn, NULL, "ibm,bsr");
	}
	return 0;
}

static int __init bsr_init(void)
{
	struct device_node *np;
	dev_t bsr_dev;
	int ret = -ENODEV;

	np = of_find_compatible_node(NULL, NULL, "ibm,bsr");
	if (!np)
		goto out_err;

	bsr_class = class_create(THIS_MODULE, "bsr");
	if (IS_ERR(bsr_class)) {
		printk(KERN_ERR "class_create() failed for bsr_class\n");
		ret = PTR_ERR(bsr_class);
		goto out_err_1;
	}
	bsr_class->dev_groups = bsr_dev_groups;

	ret = alloc_chrdev_region(&bsr_dev, 0, BSR_MAX_DEVS, "bsr");
	bsr_major = MAJOR(bsr_dev);
	if (ret < 0) {
		printk(KERN_ERR "alloc_chrdev_region() failed for bsr\n");
		goto out_err_2;
	}

	if ((ret = bsr_create_devs(np)) < 0) {
		np = NULL;
		goto out_err_3;
	}

	return 0;

 out_err_3:
	unregister_chrdev_region(bsr_dev, BSR_MAX_DEVS);

 out_err_2:
	class_destroy(bsr_class);

 out_err_1:
	of_node_put(np);

 out_err:

	return ret;
}

static void __exit  bsr_exit(void)
{

	bsr_cleanup_devs();

	if (bsr_class)
		class_destroy(bsr_class);

	if (bsr_major)
		unregister_chrdev_region(MKDEV(bsr_major, 0), BSR_MAX_DEVS);
}

module_init(bsr_init);
module_exit(bsr_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Sonny Rao <sonnyrao@us.ibm.com>");
Commit	Line	Data
fe9e8d53 SR	1	/* IBM POWER Barrier Synchronization Register Driver
	2	*
	3	* Copyright IBM Corporation 2008
	4	*
	5	* Author: Sonny Rao <sonnyrao@us.ibm.com>
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License as published by
	9	* the Free Software Foundation; either version 2 of the License, or
	10	* (at your option) any later version.
	11	*
	12	* This program is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this program; if not, write to the Free Software
	19	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	20	*/
	21
	22	#include <linux/kernel.h>
	23	#include <linux/of.h>
	24	#include <linux/of_device.h>
	25	#include <linux/of_platform.h>
22ae782f	26	#include <linux/fs.h>
fe9e8d53 SR	27	#include <linux/module.h>
	28	#include <linux/cdev.h>
	29	#include <linux/list.h>
	30	#include <linux/mm.h>
5a0e3ad6	31	#include <linux/slab.h>
04a85d12	32	#include <asm/pgtable.h>
fe9e8d53 SR	33	#include <asm/io.h>
	34
	35	/*
	36	This driver exposes a special register which can be used for fast
	37	synchronization across a large SMP machine. The hardware is exposed
	38	as an array of bytes where each process will write to one of the bytes to
	39	indicate it has finished the current stage and this update is broadcast to
	40	all processors without having to bounce a cacheline between them. In
	41	POWER5 and POWER6 there is one of these registers per SMP, but it is
	42	presented in two forms; first, it is given as a whole and then as a number
	43	of smaller registers which alias to parts of the single whole register.
	44	This can potentially allow multiple groups of processes to each have their
	45	own private synchronization device.
	46
	47	Note that this hardware must be written to using only single byte writes.
	48	It may be read using 1, 2, 4, or 8 byte loads which must be aligned since
	49	this region is treated as cache-inhibited processes should also use a
	50	full sync before and after writing to the BSR to ensure all stores and
	51	the BSR update have made it to all chips in the system
	52	*/
	53
	54	/* This is arbitrary number, up to Power6 it's been 17 or fewer */
	55	#define BSR_MAX_DEVS (32)
	56
	57	struct bsr_dev {
	58	u64 bsr_addr; /* Real address */
	59	u64 bsr_len; /* length of mem region we can map */
	60	unsigned bsr_bytes; /* size of the BSR reg itself */
	61	unsigned bsr_stride; /* interval at which BSR repeats in the page */
	62	unsigned bsr_type; /* maps to enum below */
	63	unsigned bsr_num; /* bsr id number for its type */
	64	int bsr_minor;
	65
a0e2f9f4 SR	66	struct list_head bsr_list;
a0e2f9f4 SR	67
fe9e8d53 SR	68	dev_t bsr_dev;
	69	struct cdev bsr_cdev;
	70	struct device *bsr_device;
	71	char bsr_name[32];
	72
	73	};
	74
a0e2f9f4 SR	75	static unsigned total_bsr_devs;
a0e2f9f4 SR	76	static struct list_head bsr_devs = LIST_HEAD_INIT(bsr_devs);
fe9e8d53 SR	77	static struct class *bsr_class;
	78	static int bsr_major;
	79
	80	enum {
e4031d52 SR	81	BSR_8 = 0,
	82	BSR_16 = 1,
	83	BSR_64 = 2,
	84	BSR_128 = 3,
	85	BSR_4096 = 4,
	86	BSR_UNKNOWN = 5,
	87	BSR_MAX = 6,
fe9e8d53 SR	88	};
	89
	90	static unsigned bsr_types[BSR_MAX];
	91
	92	static ssize_t
	93	bsr_size_show(struct device dev, struct device_attribute attr, char *buf)
	94	{
	95	struct bsr_dev *bsr_dev = dev_get_drvdata(dev);
	96	return sprintf(buf, "%u\n", bsr_dev->bsr_bytes);
	97	}
62e13505	98	static DEVICE_ATTR_RO(bsr_size);
fe9e8d53 SR	99
	100	static ssize_t
	101	bsr_stride_show(struct device dev, struct device_attribute attr, char *buf)
	102	{
	103	struct bsr_dev *bsr_dev = dev_get_drvdata(dev);
	104	return sprintf(buf, "%u\n", bsr_dev->bsr_stride);
	105	}
62e13505	106	static DEVICE_ATTR_RO(bsr_stride);
fe9e8d53 SR	107
fe9e8d53 SR	108	static ssize_t
62e13505	109	bsr_length_show(struct device dev, struct device_attribute attr, char *buf)
fe9e8d53 SR	110	{
fe9e8d53 SR	111	struct bsr_dev *bsr_dev = dev_get_drvdata(dev);
1901515c	112	return sprintf(buf, "%llu\n", bsr_dev->bsr_len);
fe9e8d53	113	}
62e13505	114	static DEVICE_ATTR_RO(bsr_length);
fe9e8d53	115
62e13505 GKH	116	static struct attribute *bsr_dev_attrs[] = {
	117	&dev_attr_bsr_size.attr,
	118	&dev_attr_bsr_stride.attr,
	119	&dev_attr_bsr_length.attr,
	120	NULL,
fe9e8d53	121	};
62e13505	122	ATTRIBUTE_GROUPS(bsr_dev);
fe9e8d53 SR	123
	124	static int bsr_mmap(struct file filp, struct vm_area_struct vma)
	125	{
	126	unsigned long size = vma->vm_end - vma->vm_start;
	127	struct bsr_dev *dev = filp->private_data;
04a85d12	128	int ret;
fe9e8d53	129
fe9e8d53 SR	130	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
fe9e8d53 SR	131
04a85d12 SR	132	/* check for the case of a small BSR device and map one 4k page for it*/
	133	if (dev->bsr_len < PAGE_SIZE && size == PAGE_SIZE)
	134	ret = remap_4k_pfn(vma, vma->vm_start, dev->bsr_addr >> 12,
	135	vma->vm_page_prot);
	136	else if (size <= dev->bsr_len)
	137	ret = io_remap_pfn_range(vma, vma->vm_start,
	138	dev->bsr_addr >> PAGE_SHIFT,
	139	size, vma->vm_page_prot);
	140	else
	141	return -EINVAL;
	142
	143	if (ret)
fe9e8d53 SR	144	return -EAGAIN;
	145
	146	return 0;
	147	}
	148
	149	static int bsr_open(struct inode * inode, struct file * filp)
	150	{
	151	struct cdev *cdev = inode->i_cdev;
	152	struct bsr_dev *dev = container_of(cdev, struct bsr_dev, bsr_cdev);
	153
	154	filp->private_data = dev;
	155	return 0;
	156	}
	157
27157a70	158	static const struct file_operations bsr_fops = {
fe9e8d53 SR	159	.owner = THIS_MODULE,
	160	.mmap = bsr_mmap,
	161	.open = bsr_open,
6038f373	162	.llseek = noop_llseek,
fe9e8d53 SR	163	};
	164
	165	static void bsr_cleanup_devs(void)
	166	{
a0e2f9f4 SR	167	struct bsr_dev cur, n;
	168
	169	list_for_each_entry_safe(cur, n, &bsr_devs, bsr_list) {
fe9e8d53 SR	170	if (cur->bsr_device) {
	171	cdev_del(&cur->bsr_cdev);
	172	device_del(cur->bsr_device);
	173	}
a0e2f9f4 SR	174	list_del(&cur->bsr_list);
a0e2f9f4 SR	175	kfree(cur);
fe9e8d53	176	}
fe9e8d53 SR	177	}
fe9e8d53 SR	178
a0e2f9f4	179	static int bsr_add_node(struct device_node *bn)
fe9e8d53	180	{
a0e2f9f4	181	int bsr_stride_len, bsr_bytes_len, num_bsr_devs;
fe9e8d53 SR	182	const u32 *bsr_stride;
	183	const u32 *bsr_bytes;
	184	unsigned i;
a0e2f9f4	185	int ret = -ENODEV;
fe9e8d53 SR	186
	187	bsr_stride = of_get_property(bn, "ibm,lock-stride", &bsr_stride_len);
	188	bsr_bytes = of_get_property(bn, "ibm,#lock-bytes", &bsr_bytes_len);
	189
	190	if (!bsr_stride \|\| !bsr_bytes \|\|
	191	(bsr_stride_len != bsr_bytes_len)) {
	192	printk(KERN_ERR "bsr of-node has missing/incorrect property\n");
a0e2f9f4	193	return ret;
fe9e8d53 SR	194	}
	195
	196	num_bsr_devs = bsr_bytes_len / sizeof(u32);
	197
fe9e8d53	198	for (i = 0 ; i < num_bsr_devs; i++) {
a0e2f9f4 SR	199	struct bsr_dev *cur = kzalloc(sizeof(struct bsr_dev),
a0e2f9f4 SR	200	GFP_KERNEL);
fe9e8d53 SR	201	struct resource res;
	202	int result;
	203
a0e2f9f4 SR	204	if (!cur) {
	205	printk(KERN_ERR "Unable to alloc bsr dev\n");
	206	ret = -ENOMEM;
	207	goto out_err;
	208	}
	209
fe9e8d53 SR	210	result = of_address_to_resource(bn, i, &res);
fe9e8d53 SR	211	if (result < 0) {
a0e2f9f4 SR	212	printk(KERN_ERR "bsr of-node has invalid reg property, skipping\n");
	213	kfree(cur);
	214	continue;
fe9e8d53 SR	215	}
fe9e8d53 SR	216
a0e2f9f4	217	cur->bsr_minor = i + total_bsr_devs;
fe9e8d53	218	cur->bsr_addr = res.start;
28f65c11	219	cur->bsr_len = resource_size(&res);
fe9e8d53 SR	220	cur->bsr_bytes = bsr_bytes[i];
fe9e8d53 SR	221	cur->bsr_stride = bsr_stride[i];
a0e2f9f4	222	cur->bsr_dev = MKDEV(bsr_major, i + total_bsr_devs);
fe9e8d53	223
04a85d12 SR	224	/* if we have a bsr_len of > 4k and less then PAGE_SIZE (64k pages) */
	225	/* we can only map 4k of it, so only advertise the 4k in sysfs */
	226	if (cur->bsr_len > 4096 && cur->bsr_len < PAGE_SIZE)
	227	cur->bsr_len = 4096;
	228
fe9e8d53 SR	229	switch(cur->bsr_bytes) {
	230	case 8:
	231	cur->bsr_type = BSR_8;
	232	break;
	233	case 16:
	234	cur->bsr_type = BSR_16;
	235	break;
	236	case 64:
	237	cur->bsr_type = BSR_64;
	238	break;
	239	case 128:
	240	cur->bsr_type = BSR_128;
	241	break;
e4031d52 SR	242	case 4096:
	243	cur->bsr_type = BSR_4096;
	244	break;
fe9e8d53 SR	245	default:
fe9e8d53 SR	246	cur->bsr_type = BSR_UNKNOWN;
fe9e8d53 SR	247	}
	248
	249	cur->bsr_num = bsr_types[cur->bsr_type];
fe9e8d53 SR	250	snprintf(cur->bsr_name, 32, "bsr%d_%d",
	251	cur->bsr_bytes, cur->bsr_num);
	252
	253	cdev_init(&cur->bsr_cdev, &bsr_fops);
	254	result = cdev_add(&cur->bsr_cdev, cur->bsr_dev, 1);
a0e2f9f4 SR	255	if (result) {
a0e2f9f4 SR	256	kfree(cur);
fe9e8d53	257	goto out_err;
a0e2f9f4	258	}
fe9e8d53	259
03457cd4 GKH	260	cur->bsr_device = device_create(bsr_class, NULL, cur->bsr_dev,
03457cd4 GKH	261	cur, cur->bsr_name);
30c96ce5	262	if (IS_ERR(cur->bsr_device)) {
fe9e8d53 SR	263	printk(KERN_ERR "device_create failed for %s\n",
	264	cur->bsr_name);
	265	cdev_del(&cur->bsr_cdev);
a0e2f9f4	266	kfree(cur);
fe9e8d53 SR	267	goto out_err;
fe9e8d53 SR	268	}
a0e2f9f4 SR	269
	270	bsr_types[cur->bsr_type] = cur->bsr_num + 1;
	271	list_add_tail(&cur->bsr_list, &bsr_devs);
fe9e8d53 SR	272	}
fe9e8d53 SR	273
a0e2f9f4 SR	274	total_bsr_devs += num_bsr_devs;
a0e2f9f4 SR	275
fe9e8d53 SR	276	return 0;
	277
	278	out_err:
	279
	280	bsr_cleanup_devs();
a0e2f9f4 SR	281	return ret;
	282	}
	283
	284	static int bsr_create_devs(struct device_node *bn)
	285	{
	286	int ret;
	287
	288	while (bn) {
	289	ret = bsr_add_node(bn);
	290	if (ret) {
	291	of_node_put(bn);
	292	return ret;
	293	}
	294	bn = of_find_compatible_node(bn, NULL, "ibm,bsr");
	295	}
	296	return 0;
fe9e8d53 SR	297	}
	298
	299	static int __init bsr_init(void)
	300	{
	301	struct device_node *np;
cce36444	302	dev_t bsr_dev;
fe9e8d53	303	int ret = -ENODEV;
fe9e8d53	304
a0e2f9f4	305	np = of_find_compatible_node(NULL, NULL, "ibm,bsr");
fe9e8d53 SR	306	if (!np)
	307	goto out_err;
	308
	309	bsr_class = class_create(THIS_MODULE, "bsr");
	310	if (IS_ERR(bsr_class)) {
	311	printk(KERN_ERR "class_create() failed for bsr_class\n");
8397c76a	312	ret = PTR_ERR(bsr_class);
fe9e8d53 SR	313	goto out_err_1;
fe9e8d53 SR	314	}
62e13505	315	bsr_class->dev_groups = bsr_dev_groups;
fe9e8d53	316
8397c76a	317	ret = alloc_chrdev_region(&bsr_dev, 0, BSR_MAX_DEVS, "bsr");
fe9e8d53	318	bsr_major = MAJOR(bsr_dev);
8397c76a	319	if (ret < 0) {
fe9e8d53 SR	320	printk(KERN_ERR "alloc_chrdev_region() failed for bsr\n");
	321	goto out_err_2;
	322	}
	323
a0e2f9f4 SR	324	if ((ret = bsr_create_devs(np)) < 0) {
a0e2f9f4 SR	325	np = NULL;
fe9e8d53	326	goto out_err_3;
a0e2f9f4	327	}
fe9e8d53 SR	328
	329	return 0;
	330
	331	out_err_3:
	332	unregister_chrdev_region(bsr_dev, BSR_MAX_DEVS);
	333
	334	out_err_2:
	335	class_destroy(bsr_class);
	336
	337	out_err_1:
	338	of_node_put(np);
	339
	340	out_err:
	341
	342	return ret;
	343	}
	344
	345	static void __exit bsr_exit(void)
	346	{
	347
	348	bsr_cleanup_devs();
	349
	350	if (bsr_class)
	351	class_destroy(bsr_class);
	352
	353	if (bsr_major)
	354	unregister_chrdev_region(MKDEV(bsr_major, 0), BSR_MAX_DEVS);
	355	}
	356
	357	module_init(bsr_init);
	358	module_exit(bsr_exit);
	359	MODULE_LICENSE("GPL");
	360	MODULE_AUTHOR("Sonny Rao <sonnyrao@us.ibm.com>");