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 <linux/kthread.h>
#include <linux/freezer.h>

#include <asm/atomic.h>

#include "w1.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;
int w1_max_slave_count = 10;
int w1_max_slave_ttl = 10;

module_param_named(timeout, w1_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_MUTEX(w1_mlock);
LIST_HEAD(w1_masters);

static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn);

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);
	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 device *dev,
	struct device_attribute *attr, char *buf)
{
	struct w1_slave *sl = dev_to_w1_slave(dev);
	ssize_t count = sizeof(sl->reg_num);

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

static struct device_attribute w1_slave_attr_name =
	__ATTR(name, S_IRUGO, w1_slave_read_name, NULL);
static struct device_attribute w1_slave_attr_id =
	__ATTR(id, S_IRUGO, w1_slave_read_id, NULL);

/* Default family */

static ssize_t w1_default_write(struct file *filp, struct kobject *kobj,
				struct bin_attribute *bin_attr,
				char *buf, loff_t off, size_t count)
{
	struct w1_slave *sl = kobj_to_w1_slave(kobj);

	mutex_lock(&sl->master->mutex);
	if (w1_reset_select_slave(sl)) {
		count = 0;
		goto out_up;
	}

	w1_write_block(sl->master, buf, count);

out_up:
	mutex_unlock(&sl->master->mutex);
	return count