path: root/drivers/w1/w1.c

/*
 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
 *
 * 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.
 */

#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 <linux/hwmon.h>
#include <linux/of.h>

#include <linux/atomic.h>

#include "w1_internal.h"
#include "w1_netlink.h"

#define W1_FAMILY_DEFAULT	0

static int w1_timeout = 10;
module_param_named(timeout, w1_timeout, int, 0);
MODULE_PARM_DESC(timeout, "time in seconds between automatic slave searches");

static int w1_timeout_us = 0;
module_param_named(timeout_us, w1_timeout_us, int, 0);
MODULE_PARM_DESC(timeout_us,
		 "time in microseconds between automatic slave searches");

/* A search stops when w1_max_slave_count devices have been found in that
 * search.  The next search will start over and detect the same set of devices
 * on a static 1-wire bus.  Memory is not allocated based on this number, just
 * on the number of devices known to the kernel.  Having a high number does not
 * consume additional resources.  As a special case, if there is only one
 * device on the network and w1_max_slave_count is set to 1, the device id can
 * be read directly skipping the normal slower search process.
 */
int w1_max_slave_count = 64;
module_param_named(max_slave_count, w1_max_slave_count, int, 0);
MODULE_PARM_DESC(max_slave_count,
	"maximum number of slaves detected in a search");

int w1_max_slave_ttl = 10;
module_param_named(slave_ttl, w1_max_slave_ttl, int, 0);
MODULE_PARM_DESC(slave_ttl,
	"Number of searches not seeing a slave before it will be removed");

DEFINE_MUTEX(w1_mlock);
LIST_HEAD(w1_masters);

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 [%p]\n", __func__, sl->name, sl);

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

static ssize_t name_show(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 DEVICE_ATTR_RO(name);

static ssize_t id_show(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 DEVICE_ATTR_RO(id);

static struct attribute *w1_slave_attrs[] = {
	&dev_attr_name.attr,
	&dev_attr_id.attr,
	NULL,
};