[net-next-2.6.git] / drivers / w1 / w1_int.c

/*
 *	w1_int.c
 *
 * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
 *
 *
 * 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/list.h>
#include <linux/delay.h>

#include "w1.h"
#include "w1_log.h"
#include "w1_netlink.h"
#include "w1_int.h"

static u32 w1_ids = 1;

static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
				       struct device_driver *driver,
				       struct device *device)
{
	struct w1_master *dev;
	int err;

	/*
	 * We are in process context(kernel thread), so can sleep.
	 */
	dev = kmalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL);
	if (!dev) {
		printk(KERN_ERR
			"Failed to allocate %zd bytes for new w1 device.\n",
			sizeof(struct w1_master));
		return NULL;
	}

	memset(dev, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master));

	dev->bus_master = (struct w1_bus_master *)(dev + 1);

	dev->owner		= THIS_MODULE;
	dev->max_slave_count	= slave_count;
	dev->slave_count	= 0;
	dev->attempts		= 0;
	dev->kpid		= -1;
	dev->initialized	= 0;
	dev->id			= id;
	dev->slave_ttl		= slave_ttl;
        dev->search_count	= -1; /* continual scan */

	atomic_set(&dev->refcnt, 2);

	INIT_LIST_HEAD(&dev->slist);
	init_MUTEX(&dev->mutex);

	init_completion(&dev->dev_exited);

	memcpy(&dev->dev, device, sizeof(struct device));
	snprintf(dev->dev.bus_id, sizeof(dev->dev.bus_id),
		  "w1_bus_master%u", dev->id);
	snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id);

	dev->driver = driver;

	dev->groups = 1;
	dev->seq = 1;
	dev_init_netlink(dev);

	err = device_register(&dev->dev);
	if (err) {
		printk(KERN_ERR "Failed to register master device. err=%d\n", err);

		dev_fini_netlink(dev);

		memset(dev, 0, sizeof(struct w1_master));
		kfree(dev);
		dev = NULL;
	}

	return dev;
}

static void w1_free_dev(struct w1_master *dev)
{
	device_unregister(&dev->dev);
}

int w1_add_master_device(struct w1_bus_master *master)
{
	struct w1_master *dev;
	int retval = 0;
	struct w1_netlink_msg msg;

        /* validate minimum functionality */
        if (!(master->touch_bit && master->reset_bus) &&
            !(master->write_bit && master->read_bit)) {
		printk(KERN_ERR "w1_add_master_device: invalid function set\n");
		return(-EINVAL);
        }

	dev = w1_alloc_dev(w1_ids++, w1_max_slave_count, w1_max_slave_ttl, &w1_master_driver, &w1_master_device);
	if (!dev)
		return -ENOMEM;

	dev->kpid = kernel_thread(&w1_process, dev, 0);
	if (dev->kpid < 0) {
		dev_err(&dev->dev,
			 "Failed to create new kernel thread. err=%d\n",
			 dev->kpid);
		retval = dev->kpid;
		goto err_out_free_dev;
	}

	retval =  w1_create_master_attributes(dev);
	if (retval)
		goto err_out_kill_thread;

	memcpy(dev->bus_master, master, sizeof(struct w1_bus_master));

	dev->initialized = 1;

	spin_lock(&w1_mlock);
	list_add(&dev->w1_master_entry, &w1_masters);
	spin_unlock(&w1_mlock);

	msg.id.mst.id = dev->id;
	msg.id.mst.pid = dev->kpid;
	msg.type = W1_MASTER_ADD;
	w1_netlink_send(dev, &msg);

	return 0;

err_out_kill_thread:
	set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
	if (kill_proc(dev->kpid, SIGTERM, 1))
		dev_err(&dev->dev,
			 "Failed to send signal to w1 kernel thread %d.\n",
			 dev->kpid);
	wait_for_completion(&dev->dev_exited);

err_out_free_dev:
	w1_free_dev(dev);

	return retval;
}

void __w1_remove_master_device(struct w1_master *dev)
{
	int err;
	struct w1_netlink_msg msg;

	set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
	err = kill_proc(dev->kpid, SIGTERM, 1);
	if (err)
		dev_err(&dev->dev,
			 "%s: Failed to send signal to w1 kernel thread %d.\n",
			 __func__, dev->kpid);

	while (atomic_read(&dev->refcnt)) {
		dev_dbg(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n",
				dev->name, atomic_read(&dev->refcnt));

		if (msleep_interruptible(1000))
			flush_signals(current);
	}

	msg.id.mst.id = dev->id;
	msg.id.mst.pid = dev->kpid;
	msg.type = W1_MASTER_REMOVE;
	w1_netlink_send(dev, &msg);

	w1_free_dev(dev);
}

void w1_remove_master_device(struct w1_bus_master *bm)
{
	struct w1_master *dev = NULL;

	list_for_each_entry(dev, &w1_masters, w1_master_entry) {
		if (!dev->initialized)
			continue;

		if (dev->bus_master->data == bm->data)
			break;
	}

	if (!dev) {
		printk(KERN_ERR "Device doesn't exist.\n");
		return;
	}

	__w1_remove_master_device(dev);
}

EXPORT_SYMBOL(w1_add_master_device);
EXPORT_SYMBOL(w1_remove_master_device);
Commit	Line	Data
1da177e4	1	/*
7785925d	2	* w1_int.c
1da177e4 LT	3	*
1da177e4 LT	4	* Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
7785925d	5	*
1da177e4 LT	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/list.h>
	24	#include <linux/delay.h>
	25
	26	#include "w1.h"
	27	#include "w1_log.h"
	28	#include "w1_netlink.h"
a9fb1c7b	29	#include "w1_int.h"
1da177e4 LT	30
	31	static u32 w1_ids = 1;
	32
7785925d EP	33	static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
	34	struct device_driver *driver,
	35	struct device *device)
1da177e4 LT	36	{
	37	struct w1_master *dev;
	38	int err;
	39
	40	/*
	41	* We are in process context(kernel thread), so can sleep.
	42	*/
	43	dev = kmalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL);
	44	if (!dev) {
	45	printk(KERN_ERR
	46	"Failed to allocate %zd bytes for new w1 device.\n",
	47	sizeof(struct w1_master));
	48	return NULL;
	49	}
	50
	51	memset(dev, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master));
	52
	53	dev->bus_master = (struct w1_bus_master *)(dev + 1);
	54
7785925d EP	55	dev->owner = THIS_MODULE;
	56	dev->max_slave_count = slave_count;
	57	dev->slave_count = 0;
	58	dev->attempts = 0;
	59	dev->kpid = -1;
	60	dev->initialized = 0;
	61	dev->id = id;
1da177e4	62	dev->slave_ttl = slave_ttl;
2a9d0c17	63	dev->search_count = -1; /* continual scan */
1da177e4 LT	64
	65	atomic_set(&dev->refcnt, 2);
	66
	67	INIT_LIST_HEAD(&dev->slist);
	68	init_MUTEX(&dev->mutex);
	69
1da177e4 LT	70	init_completion(&dev->dev_exited);
	71
	72	memcpy(&dev->dev, device, sizeof(struct device));
	73	snprintf(dev->dev.bus_id, sizeof(dev->dev.bus_id),
	74	"w1_bus_master%u", dev->id);
	75	snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id);
	76
	77	dev->driver = driver;
	78
ad93e266	79	dev->groups = 1;
1da177e4	80	dev->seq = 1;
2d833179	81	dev_init_netlink(dev);
1da177e4 LT	82
	83	err = device_register(&dev->dev);
	84	if (err) {
	85	printk(KERN_ERR "Failed to register master device. err=%d\n", err);
2d833179 EP	86
	87	dev_fini_netlink(dev);
	88
1da177e4 LT	89	memset(dev, 0, sizeof(struct w1_master));
	90	kfree(dev);
	91	dev = NULL;
	92	}
	93
	94	return dev;
	95	}
	96
a9fb1c7b	97	static void w1_free_dev(struct w1_master *dev)
1da177e4 LT	98	{
1da177e4 LT	99	device_unregister(&dev->dev);
1da177e4 LT	100	}
	101
	102	int w1_add_master_device(struct w1_bus_master *master)
	103	{
	104	struct w1_master *dev;
	105	int retval = 0;
	106	struct w1_netlink_msg msg;
	107
be57ce26 EP	108	/* validate minimum functionality */
be57ce26 EP	109	if (!(master->touch_bit && master->reset_bus) &&
6adf87bd EP	110	!(master->write_bit && master->read_bit)) {
	111	printk(KERN_ERR "w1_add_master_device: invalid function set\n");
	112	return(-EINVAL);
be57ce26 EP	113	}
be57ce26 EP	114
7f772ed8	115	dev = w1_alloc_dev(w1_ids++, w1_max_slave_count, w1_max_slave_ttl, &w1_master_driver, &w1_master_device);
1da177e4 LT	116	if (!dev)
	117	return -ENOMEM;
	118
	119	dev->kpid = kernel_thread(&w1_process, dev, 0);
	120	if (dev->kpid < 0) {
	121	dev_err(&dev->dev,
	122	"Failed to create new kernel thread. err=%d\n",
	123	dev->kpid);
	124	retval = dev->kpid;
	125	goto err_out_free_dev;
	126	}
	127
	128	retval = w1_create_master_attributes(dev);
	129	if (retval)
	130	goto err_out_kill_thread;
	131
	132	memcpy(dev->bus_master, master, sizeof(struct w1_bus_master));
	133
	134	dev->initialized = 1;
	135
	136	spin_lock(&w1_mlock);
	137	list_add(&dev->w1_master_entry, &w1_masters);
	138	spin_unlock(&w1_mlock);
	139
	140	msg.id.mst.id = dev->id;
	141	msg.id.mst.pid = dev->kpid;
	142	msg.type = W1_MASTER_ADD;
	143	w1_netlink_send(dev, &msg);
	144
	145	return 0;
	146
	147	err_out_kill_thread:
6adf87bd	148	set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
1da177e4 LT	149	if (kill_proc(dev->kpid, SIGTERM, 1))
	150	dev_err(&dev->dev,
	151	"Failed to send signal to w1 kernel thread %d.\n",
	152	dev->kpid);
	153	wait_for_completion(&dev->dev_exited);
	154
	155	err_out_free_dev:
	156	w1_free_dev(dev);
	157
	158	return retval;
	159	}
	160
	161	void __w1_remove_master_device(struct w1_master *dev)
	162	{
	163	int err;
	164	struct w1_netlink_msg msg;
	165
6adf87bd	166	set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
1da177e4 LT	167	err = kill_proc(dev->kpid, SIGTERM, 1);
	168	if (err)
	169	dev_err(&dev->dev,
	170	"%s: Failed to send signal to w1 kernel thread %d.\n",
	171	__func__, dev->kpid);
	172
	173	while (atomic_read(&dev->refcnt)) {
3aca692d	174	dev_dbg(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n",
1da177e4 LT	175	dev->name, atomic_read(&dev->refcnt));
	176
	177	if (msleep_interruptible(1000))
	178	flush_signals(current);
	179	}
	180
	181	msg.id.mst.id = dev->id;
	182	msg.id.mst.pid = dev->kpid;
	183	msg.type = W1_MASTER_REMOVE;
	184	w1_netlink_send(dev, &msg);
	185
	186	w1_free_dev(dev);
	187	}
	188
	189	void w1_remove_master_device(struct w1_bus_master *bm)
	190	{
	191	struct w1_master *dev = NULL;
1da177e4	192
7785925d	193	list_for_each_entry(dev, &w1_masters, w1_master_entry) {
1da177e4 LT	194	if (!dev->initialized)
	195	continue;
	196
	197	if (dev->bus_master->data == bm->data)
	198	break;
	199	}
	200
	201	if (!dev) {
	202	printk(KERN_ERR "Device doesn't exist.\n");
	203	return;
	204	}
	205
	206	__w1_remove_master_device(dev);
	207	}
	208
	209	EXPORT_SYMBOL(w1_add_master_device);
	210	EXPORT_SYMBOL(w1_remove_master_device);