[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / s390 / cio / ccwgroup.c

/*
 *  drivers/s390/cio/ccwgroup.c
 *  bus driver for ccwgroup
 *
 *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
 *                       IBM Corporation
 *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
 *               Cornelia Huck (cornelia.huck@de.ibm.com)
 */
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/ctype.h>
#include <linux/dcache.h>

#include <asm/semaphore.h>
#include <asm/ccwdev.h>
#include <asm/ccwgroup.h>

/* In Linux 2.4, we had a channel device layer called "chandev"
 * that did all sorts of obscure stuff for networking devices.
 * This is another driver that serves as a replacement for just
 * one of its functions, namely the translation of single subchannels
 * to devices that use multiple subchannels.
 */

/* a device matches a driver if all its slave devices match the same
 * entry of the driver */
static int
ccwgroup_bus_match (struct device * dev, struct device_driver * drv)
{
	struct ccwgroup_device *gdev;
	struct ccwgroup_driver *gdrv;

	gdev = container_of(dev, struct ccwgroup_device, dev);
	gdrv = container_of(drv, struct ccwgroup_driver, driver);

	if (gdev->creator_id == gdrv->driver_id)
		return 1;

	return 0;
}
static int
ccwgroup_uevent (struct device *dev, char **envp, int num_envp, char *buffer,
		  int buffer_size)
{
	/* TODO */
	return 0;
}

static struct bus_type ccwgroup_bus_type;

static inline void
__ccwgroup_remove_symlinks(struct ccwgroup_device *gdev)
{
	int i;
	char str[8];

	for (i = 0; i < gdev->count; i++) {
		sprintf(str, "cdev%d", i);
		sysfs_remove_link(&gdev->dev.kobj, str);
		sysfs_remove_link(&gdev->cdev[i]->dev.kobj, "group_device");
	}
	
}

/*
 * Provide an 'ungroup' attribute so the user can remove group devices no
 * longer needed or accidentially created. Saves memory :)
 */
static ssize_t
ccwgroup_ungroup_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	struct ccwgroup_device *gdev;

	gdev = to_ccwgroupdev(dev);

	if (gdev->state != CCWGROUP_OFFLINE)
		return -EINVAL;

	__ccwgroup_remove_symlinks(gdev);
	device_unregister(dev);

	return count;
}

static DEVICE_ATTR(ungroup, 0200, NULL, ccwgroup_ungroup_store);

static void
ccwgroup_release (struct device *dev)
{
	struct ccwgroup_device *gdev;
	int i;

	gdev = to_ccwgroupdev(dev);

	for (i = 0; i < gdev->count; i++) {
		gdev->cdev[i]->dev.driver_data = NULL;
		put_device(&gdev->cdev[i]->dev);
	}
	kfree(gdev);
}

static inline int
__ccwgroup_create_symlinks(struct ccwgroup_device *gdev)
{
	char str[8];
	int i, rc;

	for (i = 0; i < gdev->count; i++) {
		rc = sysfs_create_link(&gdev->cdev[i]->dev.kobj, &gdev->dev.kobj,
				       "group_device");
		if (rc) {
			for (--i; i >= 0; i--)
				sysfs_remove_link(&gdev->cdev[i]->dev.kobj,
						  "group_device");
			return rc;
		}
	}
	for (i = 0; i < gdev->count; i++) {
		sprintf(str, "cdev%d", i);
		rc = sysfs_create_link(&gdev->dev.kobj, &gdev->cdev[i]->dev.kobj,
				       str);
		if (rc) {
			for (--i; i >= 0; i--) {
				sprintf(str, "cdev%d", i);
				sysfs_remove_link(&gdev->dev.kobj, str);
			}
			for (i = 0; i < gdev->count; i++)
				sysfs_remove_link(&gdev->cdev[i]->dev.kobj,
						  "group_device");
			return rc;
		}
	}
	return 0;
}

/*
 * try to add a new ccwgroup device for one driver
 * argc and argv[] are a list of bus_id's of devices
 * belonging to the driver.
 */
int
ccwgroup_create(struct device *root,
		unsigned int creator_id,
		struct ccw_driver *cdrv,
		int argc, char *argv[])
{
	struct ccwgroup_device *gdev;
	int i;
	int rc;
	int del_drvdata;

	if (argc > 256) /* disallow dumb users */
		return -EINVAL;

	gdev = kmalloc(sizeof(*gdev) + argc*sizeof(gdev->cdev[0]), GFP_KERNEL);
	if (!gdev)
		return -ENOMEM;

	memset(gdev, 0, sizeof(*gdev) + argc*sizeof(gdev->cdev[0]));
	atomic_set(&gdev->onoff, 0);

	del_drvdata = 0;
	for (i = 0; i < argc; i++) {
		gdev->cdev[i] = get_ccwdev_by_busid(cdrv, argv[i]);

		/* all devices have to be of the same type in
		 * order to be grouped */
		if (!gdev->cdev[i]
		    || gdev->cdev[i]->id.driver_info !=
		    gdev->cdev[0]->id.driver_info) {
			rc = -EINVAL;
			goto free_dev;
		}
		/* Don't allow a device to belong to more than one group. */
		if (gdev->cdev[i]->dev.driver_data) {
			rc = -EINVAL;
			goto free_dev;
		}
	}
	for (i = 0; i < argc; i++)
		gdev->cdev[i]->dev.driver_data = gdev;
	del_drvdata = 1;

	gdev->creator_id = creator_id;
	gdev->count = argc;
	gdev->dev = (struct device ) {
		.bus = &ccwgroup_bus_type,
		.parent = root,
		.release = ccwgroup_release,
	};

	snprintf (gdev->dev.bus_id, BUS_ID_SIZE, "%s",
			gdev->cdev[0]->dev.bus_id);

	rc = device_register(&gdev->dev);
	
	if (rc)
		goto free_dev;
	get_device(&gdev->dev);
	rc = device_create_file(&gdev->dev, &dev_attr_ungroup);

	if (rc) {
		device_unregister(&gdev->dev);
		goto error;
	}

	rc = __ccwgroup_create_symlinks(gdev);
	if (!rc) {
		put_device(&gdev->dev);
		return 0;
	}
	device_remove_file(&gdev->dev, &dev_attr_ungroup);
	device_unregister(&gdev->dev);
error:
	for (i = 0; i < argc; i++)
		if (gdev->cdev[i]) {
			put_device(&gdev->cdev[i]->dev);
			gdev->cdev[i]->dev.driver_data = NULL;
		}
	put_device(&gdev->dev);
	return rc;
free_dev:
	for (i = 0; i < argc; i++)
		if (gdev->cdev[i]) {
			put_device(&gdev->cdev[i]->dev);
			if (del_drvdata)
				gdev->cdev[i]->dev.driver_data = NULL;
		}
	kfree(gdev);
	return rc;
}

static int __init
init_ccwgroup (void)
{
	return bus_register (&ccwgroup_bus_type);
}

static void __exit
cleanup_ccwgroup (void)
{
	bus_unregister (&ccwgroup_bus_type);
}

module_init(init_ccwgroup);
module_exit(cleanup_ccwgroup);

/************************** driver stuff ******************************/

static int
ccwgroup_set_online(struct ccwgroup_device *gdev)
{
	struct ccwgroup_driver *gdrv;
	int ret;

	if (atomic_cmpxchg(&gdev->onoff, 0, 1) != 0)
		return -EAGAIN;
	if (gdev->state == CCWGROUP_ONLINE) {
		ret = 0;
		goto out;
	}
	if (!gdev->dev.driver) {
		ret = -EINVAL;
		goto out;
	}
	gdrv = to_ccwgroupdrv (gdev->dev.driver);
	if ((ret = gdrv->set_online ? gdrv->set_online(gdev) : 0))
		goto out;

	gdev->state = CCWGROUP_ONLINE;
 out:
	atomic_set(&gdev->onoff, 0);
	return ret;
}

static int
ccwgroup_set_offline(struct ccwgroup_device *gdev)
{
	struct ccwgroup_driver *gdrv;
	int ret;

	if (atomic_cmpxchg(&gdev->onoff, 0, 1) != 0)
		return -EAGAIN;
	if (gdev->state == CCWGROUP_OFFLINE) {
		ret = 0;
		goto out;
	}
	if (!gdev->dev.driver) {
		ret = -EINVAL;
		goto out;
	}
	gdrv = to_ccwgroupdrv (gdev->dev.driver);
	if ((ret = gdrv->set_offline ? gdrv->set_offline(gdev) : 0))
		goto out;

	gdev->state = CCWGROUP_OFFLINE;
 out:
	atomic_set(&gdev->onoff, 0);
	return ret;
}

static ssize_t
ccwgroup_online_store (struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	struct ccwgroup_device *gdev;
	struct ccwgroup_driver *gdrv;
	unsigned int value;
	int ret;

	gdev = to_ccwgroupdev(dev);
	if (!dev->driver)
		return count;

	gdrv = to_ccwgroupdrv (gdev->dev.driver);
	if (!try_module_get(gdrv->owner))
		return -EINVAL;

	value = simple_strtoul(buf, 0, 0);
	ret = count;
	if (value == 1)
		ccwgroup_set_online(gdev);
	else if (value == 0)
		ccwgroup_set_offline(gdev);
	else
		ret = -EINVAL;
	module_put(gdrv->owner);
	return ret;
}

static ssize_t
ccwgroup_online_show (struct device *dev, struct device_attribute *attr, char *buf)
{
	int online;

	online = (to_ccwgroupdev(dev)->state == CCWGROUP_ONLINE);

	return sprintf(buf, online ? "1\n" : "0\n");
}

static DEVICE_ATTR(online, 0644, ccwgroup_online_show, ccwgroup_online_store);

static int
ccwgroup_probe (struct device *dev)
{
	struct ccwgroup_device *gdev;
	struct ccwgroup_driver *gdrv;

	int ret;

	gdev = to_ccwgroupdev(dev);
	gdrv = to_ccwgroupdrv(dev->driver);

	if ((ret = device_create_file(dev, &dev_attr_online)))
		return ret;

	pr_debug("%s: device %s\n", __func__, gdev->dev.bus_id);
	ret = gdrv->probe ? gdrv->probe(gdev) : -ENODEV;
	if (ret)
		device_remove_file(dev, &dev_attr_online);

	return ret;
}

static int
ccwgroup_remove (struct device *dev)
{
	struct ccwgroup_device *gdev;
	struct ccwgroup_driver *gdrv;

	gdev = to_ccwgroupdev(dev);
	gdrv = to_ccwgroupdrv(dev->driver);

	pr_debug("%s: device %s\n", __func__, gdev->dev.bus_id);

	device_remove_file(dev, &dev_attr_online);

	if (gdrv && gdrv->remove)
		gdrv->remove(gdev);
	return 0;
}

static struct bus_type ccwgroup_bus_type = {
	.name   = "ccwgroup",
	.match  = ccwgroup_bus_match,
	.uevent = ccwgroup_uevent,
	.probe  = ccwgroup_probe,
	.remove = ccwgroup_remove,
};

int
ccwgroup_driver_register (struct ccwgroup_driver *cdriver)
{
	/* register our new driver with the core */
	cdriver->driver = (struct device_driver) {
		.bus = &ccwgroup_bus_type,
		.name = cdriver->name,
	};

	return driver_register(&cdriver->driver);
}

static int
__ccwgroup_driver_unregister_device(struct device *dev, void *data)
{
	__ccwgroup_remove_symlinks(to_ccwgroupdev(dev));
	device_unregister(dev);
	put_device(dev);
	return 0;
}

void
ccwgroup_driver_unregister (struct ccwgroup_driver *cdriver)
{
	/* We don't want ccwgroup devices to live longer than their driver. */
	get_driver(&cdriver->driver);
	driver_for_each_device(&cdriver->driver, NULL, NULL,
			       __ccwgroup_driver_unregister_device);
	put_driver(&cdriver->driver);
	driver_unregister(&cdriver->driver);
}

int
ccwgroup_probe_ccwdev(struct ccw_device *cdev)
{
	return 0;
}

static inline struct ccwgroup_device *
__ccwgroup_get_gdev_by_cdev(struct ccw_device *cdev)
{
	struct ccwgroup_device *gdev;

	if (cdev->dev.driver_data) {
		gdev = (struct ccwgroup_device *)cdev->dev.driver_data;
		if (get_device(&gdev->dev)) {
			if (device_is_registered(&gdev->dev))
				return gdev;
			put_device(&gdev->dev);
		}
		return NULL;
	}
	return NULL;
}

void
ccwgroup_remove_ccwdev(struct ccw_device *cdev)
{
	struct ccwgroup_device *gdev;

	/* Ignore offlining errors, device is gone anyway. */
	ccw_device_set_offline(cdev);
	/* If one of its devices is gone, the whole group is done for. */
	gdev = __ccwgroup_get_gdev_by_cdev(cdev);
	if (gdev) {
		__ccwgroup_remove_symlinks(gdev);
		device_unregister(&gdev->dev);
		put_device(&gdev->dev);
	}
}

MODULE_LICENSE("GPL");
EXPORT_SYMBOL(ccwgroup_driver_register);
EXPORT_SYMBOL(ccwgroup_driver_unregister);
EXPORT_SYMBOL(ccwgroup_create);
EXPORT_SYMBOL(ccwgroup_probe_ccwdev);
EXPORT_SYMBOL(ccwgroup_remove_ccwdev);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* drivers/s390/cio/ccwgroup.c
	3	* bus driver for ccwgroup
1da177e4 LT	4	*
	5	* Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
	6	* IBM Corporation
	7	* Author(s): Arnd Bergmann (arndb@de.ibm.com)
4ce3b30c	8	* Cornelia Huck (cornelia.huck@de.ibm.com)
1da177e4 LT	9	*/
	10	#include <linux/module.h>
	11	#include <linux/errno.h>
	12	#include <linux/slab.h>
	13	#include <linux/list.h>
	14	#include <linux/device.h>
	15	#include <linux/init.h>
	16	#include <linux/ctype.h>
	17	#include <linux/dcache.h>
	18
	19	#include <asm/semaphore.h>
	20	#include <asm/ccwdev.h>
	21	#include <asm/ccwgroup.h>
	22
	23	/* In Linux 2.4, we had a channel device layer called "chandev"
	24	* that did all sorts of obscure stuff for networking devices.
	25	* This is another driver that serves as a replacement for just
	26	* one of its functions, namely the translation of single subchannels
	27	* to devices that use multiple subchannels.
	28	*/
	29
	30	/* a device matches a driver if all its slave devices match the same
	31	* entry of the driver */
	32	static int
	33	ccwgroup_bus_match (struct device * dev, struct device_driver * drv)
	34	{
	35	struct ccwgroup_device *gdev;
	36	struct ccwgroup_driver *gdrv;
	37
	38	gdev = container_of(dev, struct ccwgroup_device, dev);
	39	gdrv = container_of(drv, struct ccwgroup_driver, driver);
	40
	41	if (gdev->creator_id == gdrv->driver_id)
	42	return 1;
	43
	44	return 0;
	45	}
	46	static int
6d20b035	47	ccwgroup_uevent (struct device dev, char envp, int num_envp, char buffer,
1da177e4 LT	48	int buffer_size)
	49	{
	50	/* TODO */
	51	return 0;
	52	}
	53
f9ccf456	54	static struct bus_type ccwgroup_bus_type;
1da177e4 LT	55
	56	static inline void
	57	__ccwgroup_remove_symlinks(struct ccwgroup_device *gdev)
	58	{
	59	int i;
	60	char str[8];
	61
	62	for (i = 0; i < gdev->count; i++) {
	63	sprintf(str, "cdev%d", i);
	64	sysfs_remove_link(&gdev->dev.kobj, str);
	65	sysfs_remove_link(&gdev->cdev[i]->dev.kobj, "group_device");
	66	}
	67
	68	}
	69
	70	/*
	71	* Provide an 'ungroup' attribute so the user can remove group devices no
	72	* longer needed or accidentially created. Saves memory :)
	73	*/
	74	static ssize_t
3fd3c0a5	75	ccwgroup_ungroup_store(struct device dev, struct device_attribute attr, const char *buf, size_t count)
1da177e4 LT	76	{
	77	struct ccwgroup_device *gdev;
	78
	79	gdev = to_ccwgroupdev(dev);
	80
	81	if (gdev->state != CCWGROUP_OFFLINE)
	82	return -EINVAL;
	83
	84	__ccwgroup_remove_symlinks(gdev);
	85	device_unregister(dev);
	86
	87	return count;
	88	}
	89
	90	static DEVICE_ATTR(ungroup, 0200, NULL, ccwgroup_ungroup_store);
	91
	92	static void
	93	ccwgroup_release (struct device *dev)
	94	{
	95	struct ccwgroup_device *gdev;
	96	int i;
	97
	98	gdev = to_ccwgroupdev(dev);
	99
	100	for (i = 0; i < gdev->count; i++) {
	101	gdev->cdev[i]->dev.driver_data = NULL;
	102	put_device(&gdev->cdev[i]->dev);
	103	}
	104	kfree(gdev);
	105	}
	106
	107	static inline int
	108	__ccwgroup_create_symlinks(struct ccwgroup_device *gdev)
	109	{
	110	char str[8];
	111	int i, rc;
	112
	113	for (i = 0; i < gdev->count; i++) {
	114	rc = sysfs_create_link(&gdev->cdev[i]->dev.kobj, &gdev->dev.kobj,
	115	"group_device");
	116	if (rc) {
	117	for (--i; i >= 0; i--)
	118	sysfs_remove_link(&gdev->cdev[i]->dev.kobj,
	119	"group_device");
	120	return rc;
	121	}
	122	}
	123	for (i = 0; i < gdev->count; i++) {
	124	sprintf(str, "cdev%d", i);
	125	rc = sysfs_create_link(&gdev->dev.kobj, &gdev->cdev[i]->dev.kobj,
	126	str);
	127	if (rc) {
	128	for (--i; i >= 0; i--) {
	129	sprintf(str, "cdev%d", i);
	130	sysfs_remove_link(&gdev->dev.kobj, str);
	131	}
	132	for (i = 0; i < gdev->count; i++)
	133	sysfs_remove_link(&gdev->cdev[i]->dev.kobj,
	134	"group_device");
	135	return rc;
	136	}
	137	}
	138	return 0;
	139	}
140
141	/*
142	* try to add a new ccwgroup device for one driver
143	* argc and argv[] are a list of bus_id's of devices
144	* belonging to the driver.
145	*/
146	int
147	ccwgroup_create(struct device *root,
148	unsigned int creator_id,
149	struct ccw_driver *cdrv,
150	int argc, char *argv[])
151	{
152	struct ccwgroup_device *gdev;
153	int i;
154	int rc;
155	int del_drvdata;
156
157	if (argc > 256) /* disallow dumb users */
158	return -EINVAL;
159
160	gdev = kmalloc(sizeof(gdev) + argcsizeof(gdev->cdev[0]), GFP_KERNEL);
161	if (!gdev)
162	return -ENOMEM;
163
164	memset(gdev, 0, sizeof(gdev) + argcsizeof(gdev->cdev[0]));
165	atomic_set(&gdev->onoff, 0);
166
167	del_drvdata = 0;
168	for (i = 0; i < argc; i++) {
169	gdev->cdev[i] = get_ccwdev_by_busid(cdrv, argv[i]);
170
171	/* all devices have to be of the same type in
172	* order to be grouped */
173	if (!gdev->cdev[i]
174	\|\| gdev->cdev[i]->id.driver_info !=
175	gdev->cdev[0]->id.driver_info) {
176	rc = -EINVAL;
177	goto free_dev;
178	}
179	/* Don't allow a device to belong to more than one group. */
180	if (gdev->cdev[i]->dev.driver_data) {
181	rc = -EINVAL;
182	goto free_dev;
183	}
184	}
185	for (i = 0; i < argc; i++)
186	gdev->cdev[i]->dev.driver_data = gdev;
187	del_drvdata = 1;
188
189	gdev->creator_id = creator_id;
190	gdev->count = argc;
191	gdev->dev = (struct device ) {
192	.bus = &ccwgroup_bus_type,
193	.parent = root,
194	.release = ccwgroup_release,
195	};
196
197	snprintf (gdev->dev.bus_id, BUS_ID_SIZE, "%s",
198	gdev->cdev[0]->dev.bus_id);
199
200	rc = device_register(&gdev->dev);
201
202	if (rc)
203	goto free_dev;
204	get_device(&gdev->dev);
205	rc = device_create_file(&gdev->dev, &dev_attr_ungroup);
206
207	if (rc) {
208	device_unregister(&gdev->dev);
209	goto error;
210	}
211
212	rc = __ccwgroup_create_symlinks(gdev);
213	if (!rc) {
214	put_device(&gdev->dev);
215	return 0;
216	}
217	device_remove_file(&gdev->dev, &dev_attr_ungroup);
218	device_unregister(&gdev->dev);
219	error:
220	for (i = 0; i < argc; i++)
221	if (gdev->cdev[i]) {
222	put_device(&gdev->cdev[i]->dev);
223	gdev->cdev[i]->dev.driver_data = NULL;
224	}
225	put_device(&gdev->dev);
226	return rc;
227	free_dev:
228	for (i = 0; i < argc; i++)
229	if (gdev->cdev[i]) {
230	put_device(&gdev->cdev[i]->dev);
231	if (del_drvdata)
232	gdev->cdev[i]->dev.driver_data = NULL;
233	}
234	kfree(gdev);
235	return rc;
236	}
237
238	static int __init
239	init_ccwgroup (void)
240	{
241	return bus_register (&ccwgroup_bus_type);
242	}
243
244	static void __exit
245	cleanup_ccwgroup (void)
246	{
247	bus_unregister (&ccwgroup_bus_type);
248	}
249
250	module_init(init_ccwgroup);
251	module_exit(cleanup_ccwgroup);
252
253	/************************ driver stuff ****************************/
254
255	static int
256	ccwgroup_set_online(struct ccwgroup_device *gdev)
257	{
258	struct ccwgroup_driver *gdrv;
259	int ret;
260
973bd993	261	if (atomic_cmpxchg(&gdev->onoff, 0, 1) != 0)
1da177e4 LT	262	return -EAGAIN;
	263	if (gdev->state == CCWGROUP_ONLINE) {
	264	ret = 0;
	265	goto out;
	266	}
	267	if (!gdev->dev.driver) {
	268	ret = -EINVAL;
	269	goto out;
	270	}
	271	gdrv = to_ccwgroupdrv (gdev->dev.driver);
a0016408	272	if ((ret = gdrv->set_online ? gdrv->set_online(gdev) : 0))
1da177e4 LT	273	goto out;
	274
	275	gdev->state = CCWGROUP_ONLINE;
	276	out:
	277	atomic_set(&gdev->onoff, 0);
	278	return ret;
	279	}
	280
	281	static int
	282	ccwgroup_set_offline(struct ccwgroup_device *gdev)
	283	{
	284	struct ccwgroup_driver *gdrv;
	285	int ret;
	286
973bd993	287	if (atomic_cmpxchg(&gdev->onoff, 0, 1) != 0)
1da177e4 LT	288	return -EAGAIN;
	289	if (gdev->state == CCWGROUP_OFFLINE) {
	290	ret = 0;
	291	goto out;
	292	}
	293	if (!gdev->dev.driver) {
	294	ret = -EINVAL;
	295	goto out;
	296	}
	297	gdrv = to_ccwgroupdrv (gdev->dev.driver);
a0016408	298	if ((ret = gdrv->set_offline ? gdrv->set_offline(gdev) : 0))
1da177e4 LT	299	goto out;
	300
	301	gdev->state = CCWGROUP_OFFLINE;
	302	out:
	303	atomic_set(&gdev->onoff, 0);
	304	return ret;
	305	}
	306
	307	static ssize_t
3fd3c0a5	308	ccwgroup_online_store (struct device dev, struct device_attribute attr, const char *buf, size_t count)
1da177e4 LT	309	{
	310	struct ccwgroup_device *gdev;
	311	struct ccwgroup_driver *gdrv;
	312	unsigned int value;
	313	int ret;
	314
	315	gdev = to_ccwgroupdev(dev);
	316	if (!dev->driver)
	317	return count;
	318
	319	gdrv = to_ccwgroupdrv (gdev->dev.driver);
	320	if (!try_module_get(gdrv->owner))
	321	return -EINVAL;
	322
	323	value = simple_strtoul(buf, 0, 0);
	324	ret = count;
	325	if (value == 1)
	326	ccwgroup_set_online(gdev);
	327	else if (value == 0)
	328	ccwgroup_set_offline(gdev);
	329	else
	330	ret = -EINVAL;
	331	module_put(gdrv->owner);
	332	return ret;
	333	}
	334
	335	static ssize_t
3fd3c0a5	336	ccwgroup_online_show (struct device dev, struct device_attribute attr, char *buf)
1da177e4 LT	337	{
	338	int online;
	339
	340	online = (to_ccwgroupdev(dev)->state == CCWGROUP_ONLINE);
	341
	342	return sprintf(buf, online ? "1\n" : "0\n");
	343	}
	344
	345	static DEVICE_ATTR(online, 0644, ccwgroup_online_show, ccwgroup_online_store);
	346
	347	static int
	348	ccwgroup_probe (struct device *dev)
	349	{
	350	struct ccwgroup_device *gdev;
	351	struct ccwgroup_driver *gdrv;
	352
	353	int ret;
	354
	355	gdev = to_ccwgroupdev(dev);
	356	gdrv = to_ccwgroupdrv(dev->driver);
	357
	358	if ((ret = device_create_file(dev, &dev_attr_online)))
	359	return ret;
	360
	361	pr_debug("%s: device %s\n", __func__, gdev->dev.bus_id);
	362	ret = gdrv->probe ? gdrv->probe(gdev) : -ENODEV;
	363	if (ret)
	364	device_remove_file(dev, &dev_attr_online);
	365
	366	return ret;
	367	}
	368
	369	static int
	370	ccwgroup_remove (struct device *dev)
	371	{
	372	struct ccwgroup_device *gdev;
	373	struct ccwgroup_driver *gdrv;
	374
	375	gdev = to_ccwgroupdev(dev);
	376	gdrv = to_ccwgroupdrv(dev->driver);
	377
	378	pr_debug("%s: device %s\n", __func__, gdev->dev.bus_id);
	379
	380	device_remove_file(dev, &dev_attr_online);
	381
	382	if (gdrv && gdrv->remove)
	383	gdrv->remove(gdev);
	384	return 0;
	385	}
	386
f9ccf456 RK	387	static struct bus_type ccwgroup_bus_type = {
	388	.name = "ccwgroup",
	389	.match = ccwgroup_bus_match,
	390	.uevent = ccwgroup_uevent,
	391	.probe = ccwgroup_probe,
	392	.remove = ccwgroup_remove,
	393	};
	394
1da177e4 LT	395	int
	396	ccwgroup_driver_register (struct ccwgroup_driver *cdriver)
	397	{
	398	/* register our new driver with the core */
	399	cdriver->driver = (struct device_driver) {
	400	.bus = &ccwgroup_bus_type,
	401	.name = cdriver->name,
1da177e4 LT	402	};
	403
	404	return driver_register(&cdriver->driver);
	405	}
	406
b0744bd2 CH	407	static int
b0744bd2 CH	408	__ccwgroup_driver_unregister_device(struct device dev, void data)
1da177e4	409	{
b0744bd2 CH	410	__ccwgroup_remove_symlinks(to_ccwgroupdev(dev));
	411	device_unregister(dev);
	412	put_device(dev);
	413	return 0;
1da177e4 LT	414	}
	415
	416	void
	417	ccwgroup_driver_unregister (struct ccwgroup_driver *cdriver)
	418	{
1da177e4 LT	419	/* We don't want ccwgroup devices to live longer than their driver. */
1da177e4 LT	420	get_driver(&cdriver->driver);
b0744bd2 CH	421	driver_for_each_device(&cdriver->driver, NULL, NULL,
b0744bd2 CH	422	__ccwgroup_driver_unregister_device);
1da177e4 LT	423	put_driver(&cdriver->driver);
	424	driver_unregister(&cdriver->driver);
	425	}
	426
	427	int
	428	ccwgroup_probe_ccwdev(struct ccw_device *cdev)
	429	{
	430	return 0;
	431	}
	432
	433	static inline struct ccwgroup_device *
	434	__ccwgroup_get_gdev_by_cdev(struct ccw_device *cdev)
	435	{
	436	struct ccwgroup_device *gdev;
	437
	438	if (cdev->dev.driver_data) {
	439	gdev = (struct ccwgroup_device *)cdev->dev.driver_data;
	440	if (get_device(&gdev->dev)) {
d305ef5d	441	if (device_is_registered(&gdev->dev))
1da177e4 LT	442	return gdev;
	443	put_device(&gdev->dev);
	444	}
	445	return NULL;
	446	}
	447	return NULL;
	448	}
	449
	450	void
	451	ccwgroup_remove_ccwdev(struct ccw_device *cdev)
	452	{
	453	struct ccwgroup_device *gdev;
	454
	455	/* Ignore offlining errors, device is gone anyway. */
	456	ccw_device_set_offline(cdev);
	457	/* If one of its devices is gone, the whole group is done for. */
	458	gdev = __ccwgroup_get_gdev_by_cdev(cdev);
	459	if (gdev) {
	460	__ccwgroup_remove_symlinks(gdev);
	461	device_unregister(&gdev->dev);
	462	put_device(&gdev->dev);
	463	}
	464	}
	465
	466	MODULE_LICENSE("GPL");
	467	EXPORT_SYMBOL(ccwgroup_driver_register);
	468	EXPORT_SYMBOL(ccwgroup_driver_unregister);
	469	EXPORT_SYMBOL(ccwgroup_create);
	470	EXPORT_SYMBOL(ccwgroup_probe_ccwdev);
	471	EXPORT_SYMBOL(ccwgroup_remove_ccwdev);