path: root/drivers/w1/w1.c

/*
 *	w1.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/delay.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/list.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/timer.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/sched.h>

#include <asm/atomic.h>

#include "w1.h"
#include "w1_io.h"
#include "w1_log.h"
#include "w1_int.h"
#include "w1_family.h"
#include "w1_netlink.h"

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol.");

static int w1_timeout = 10;
static int w1_control_timeout = 1;
int w1_max_slave_count = 10;
int w1_max_slave_ttl = 10;

module_param_named(timeout, w1_timeout, int, 0);
module_param_named(control_timeout, w1_control_timeout, int, 0);
module_param_named(max_slave_count, w1_max_slave_count, int, 0);
module_param_named(slave_ttl, w1_max_slave_ttl, int, 0);

DEFINE_SPINLOCK(w1_mlock);
LIST_HEAD(w1_masters);

static pid_t control_thread;
static int control_needs_exit;
static DECLARE_COMPLETION(w1_control_complete);

static int w1_master_match(struct device *dev, struct device_driver *drv)
{
	return 1;
}

static int w1_master_probe(struct device *dev)
{
	return -ENODEV;
}

static void w1_master_release(struct device *dev)
{
	struct w1_master *md = dev_to_w1_master(dev);

	dev_dbg(dev, "%s: Releasing %s.\n", __func__, md->name);

	if (md->nls && md->nls->sk_socket)
		sock_release(md->nls->sk_socket);
	memset(md, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master));
	kfree(md);
}

static void w1_slave_release(struct device *dev)
{
	struct w1_slave *sl = dev_to_w1_slave(dev);

	dev_dbg(dev, "%s: Releasing %s.\n", __func__, sl->name);

	while (atomic_read(&sl->refcnt)) {
		dev_dbg(dev, "Waiting for %s to become free: refcnt=%d.\n",
				sl->name, atomic_read(&sl->refcnt));
		if (msleep_interruptible(1000))
			flush_signals(current);
	}

	w1_family_put(sl->family);
	sl->master->slave_count--;

	complete(&sl->released);
}

static ssize_t w1_slave_read_name(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct w1_slave *sl = dev_to_w1_slave(dev);

	return sprintf(buf, "%s\n", sl->name);
}

static ssize_t w1_slave_read_id(struct kobject *kobj, char *buf, loff_t off, size_t count)
{
	struct w1_slave *sl = kobj_to_w1_slave(kobj);

	atomic_inc(&sl->refcnt);
	if (off > 8) {
		count = 0;
	} else {
		if (off + count > 8)
			count = 8 - off;

		memcpy(buf, (u8 *)&sl->reg_num, count);
	}
	atomic_dec(&sl->refcnt);

	return count;
}

static struct device_attribute w1_slave_attr_name =
	__ATTR(name, S_IRUGO, w1_slave_read_name, NULL);

static struct bin_attribute w1_slave_attr_bin_id = {
      .attr = {
              .name = "id",
              .mode = S_IRUGO,
              .owner = THIS_MODULE,
      },
      .size = 8,
      .read = w1_slave_read_id,
};

/* Default family */
static struct w1_family w1_default_family;

static int w1_hotplug(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size);

static struct bus_type w1_bus_type = {
	.name = "w1",
	.match = w1_master_match,
	.hotplug = w1_hotplug,
};

struct device_driver w1_master_driver = {
	.name = "w1_master_driver",
	.bus = &w1_bus_type,
	.probe = w1_master_probe,
};

struct device w1_master_device = {
	.parent = NULL,
	.bus = &w1_bus_type,
	.bus_id = "w1 bus master",
	.driver = &w1_master_driver,
	.release = &w1_master_release
};

struct device_driver w1_slave_driver = {
	.name = "w1_slave_driver",