/*
- * 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
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/sched.h>
+#include <linux/kthread.h>
#include <asm/atomic.h>
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 struct task_struct *w1_control_thread;
static int w1_master_match(struct device *dev, struct device_driver *drv)
{
return -ENODEV;
}
-static int w1_master_remove(struct device *dev)
-{
- return 0;
-}
-
static void w1_master_release(struct device *dev)
{
- struct w1_master *md = container_of(dev, struct w1_master, dev);
+ struct w1_master *md = dev_to_w1_master(dev);
+
+ dev_dbg(dev, "%s: Releasing %s.\n", __func__, md->name);
- complete(&md->dev_released);
+ dev_fini_netlink(md);
+ 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 = container_of(dev, struct w1_slave, 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->dev_released);
+ complete(&sl->released);
}
-static ssize_t w1_default_read_name(struct device *dev, char *buf)
+static ssize_t w1_slave_read_name(struct device *dev, struct device_attribute *attr, char *buf)
{
- return sprintf(buf, "No family registered.\n");
+ struct w1_slave *sl = dev_to_w1_slave(dev);
+
+ return sprintf(buf, "%s\n", sl->name);
}
-static ssize_t w1_default_read_bin(struct kobject *kobj, char *buf, loff_t off,
- size_t count)
+static ssize_t w1_slave_read_id(struct kobject *kobj, char *buf, loff_t off, size_t count)
{
- return sprintf(buf, "No family registered.\n");
+ 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_uevent(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,
+ .uevent = w1_uevent,
};
-struct device_driver w1_driver = {
- .name = "w1_driver",
+struct device_driver w1_master_driver = {
+ .name = "w1_master_driver",
.bus = &w1_bus_type,
.probe = w1_master_probe,
- .remove = w1_master_remove,
};
-struct device w1_device = {
+struct device w1_master_device = {
.parent = NULL,
.bus = &w1_bus_type,
.bus_id = "w1 bus master",
- .driver = &w1_driver,
+ .driver = &w1_master_driver,
.release = &w1_master_release
};
-static struct device_attribute w1_slave_attribute = {
- .attr = {
- .name = "name",
- .mode = S_IRUGO,
- .owner = THIS_MODULE
- },
- .show = &w1_default_read_name,
+static struct device_driver w1_slave_driver = {
+ .name = "w1_slave_driver",
+ .bus = &w1_bus_type,
};
-static struct device_attribute w1_slave_attribute_val = {
- .attr = {
- .name = "value",
- .mode = S_IRUGO,
- .owner = THIS_MODULE
- },
- .show = &w1_default_read_name,
+#if 0
+struct device w1_slave_device = {
+ .parent = NULL,
+ .bus = &w1_bus_type,
+ .bus_id = "w1 bus slave",
+ .driver = &w1_slave_driver,
+ .release = &w1_slave_release
};
+#endif /* 0 */
-static ssize_t w1_master_attribute_show_name(struct device *dev, char *buf)
+static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf)
{
- struct w1_master *md = container_of (dev, struct w1_master, dev);
+ struct w1_master *md = dev_to_w1_master(dev);
ssize_t count;
-
+
if (down_interruptible (&md->mutex))
return -EBUSY;
count = sprintf(buf, "%s\n", md->name);
-
+
up(&md->mutex);
return count;
}
-static ssize_t w1_master_attribute_show_pointer(struct device *dev, char *buf)
+static ssize_t w1_master_attribute_store_search(struct device * dev,
+ struct device_attribute *attr,
+ const char * buf, size_t count)
{
- struct w1_master *md = container_of(dev, struct w1_master, dev);
+ struct w1_master *md = dev_to_w1_master(dev);
+
+ if (down_interruptible (&md->mutex))
+ return -EBUSY;
+
+ md->search_count = simple_strtol(buf, NULL, 0);
+
+ up(&md->mutex);
+
+ return count;
+}
+
+static ssize_t w1_master_attribute_show_search(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct w1_master *md = dev_to_w1_master(dev);
ssize_t count;
-
+
+ if (down_interruptible (&md->mutex))
+ return -EBUSY;
+
+ count = sprintf(buf, "%d\n", md->search_count);
+
+ up(&md->mutex);
+
+ return count;
+}
+
+static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct w1_master *md = dev_to_w1_master(dev);
+ ssize_t count;
+
if (down_interruptible(&md->mutex))
return -EBUSY;
count = sprintf(buf, "0x%p\n", md->bus_master);
-
+
up(&md->mutex);
return count;
}
-static ssize_t w1_master_attribute_show_timeout(struct device *dev, char *buf)
+static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct device_attribute *attr, char *buf)
{
ssize_t count;
count = sprintf(buf, "%d\n", w1_timeout);
return count;
}
-static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, char *buf)
+static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
{
- struct w1_master *md = container_of(dev, struct w1_master, dev);
+ struct w1_master *md = dev_to_w1_master(dev);
ssize_t count;
-
+
if (down_interruptible(&md->mutex))
return -EBUSY;
count = sprintf(buf, "%d\n", md->max_slave_count);
-
+
up(&md->mutex);
return count;
}
-static ssize_t w1_master_attribute_show_attempts(struct device *dev, char *buf)
+static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct device_attribute *attr, char *buf)
{
- struct w1_master *md = container_of(dev, struct w1_master, dev);
+ struct w1_master *md = dev_to_w1_master(dev);
ssize_t count;
-
+
if (down_interruptible(&md->mutex))
return -EBUSY;
count = sprintf(buf, "%lu\n", md->attempts);
-
+
up(&md->mutex);
return count;
}
-static ssize_t w1_master_attribute_show_slave_count(struct device *dev, char *buf)
+static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
{
- struct w1_master *md = container_of(dev, struct w1_master, dev);
+ struct w1_master *md = dev_to_w1_master(dev);
ssize_t count;
-
+
if (down_interruptible(&md->mutex))
return -EBUSY;
count = sprintf(buf, "%d\n", md->slave_count);
-
+
up(&md->mutex);
return count;
}
-static ssize_t w1_master_attribute_show_slaves(struct device *dev, char *buf)
-
+static ssize_t w1_master_attribute_show_slaves(struct device *dev, struct device_attribute *attr, char *buf)
{
- struct w1_master *md = container_of(dev, struct w1_master, dev);
+ struct w1_master *md = dev_to_w1_master(dev);
int c = PAGE_SIZE;
if (down_interruptible(&md->mutex))
list_for_each_safe(ent, n, &md->slist) {
sl = list_entry(ent, struct w1_slave, w1_slave_entry);
- c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
+ c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
}
}
return PAGE_SIZE - c;
}
-static struct device_attribute w1_master_attribute_slaves = {
- .attr = {
- .name = "w1_master_slaves",
- .mode = S_IRUGO,
- .owner = THIS_MODULE,
- },
- .show = &w1_master_attribute_show_slaves,
-};
-static struct device_attribute w1_master_attribute_slave_count = {
- .attr = {
- .name = "w1_master_slave_count",
- .mode = S_IRUGO,
- .owner = THIS_MODULE
- },
- .show = &w1_master_attribute_show_slave_count,
-};
-static struct device_attribute w1_master_attribute_attempts = {
- .attr = {
- .name = "w1_master_attempts",
- .mode = S_IRUGO,
- .owner = THIS_MODULE
- },
- .show = &w1_master_attribute_show_attempts,
-};
-static struct device_attribute w1_master_attribute_max_slave_count = {
- .attr = {
- .name = "w1_master_max_slave_count",
- .mode = S_IRUGO,
- .owner = THIS_MODULE
- },
- .show = &w1_master_attribute_show_max_slave_count,
+#define W1_MASTER_ATTR_RO(_name, _mode) \
+ struct device_attribute w1_master_attribute_##_name = \
+ __ATTR(w1_master_##_name, _mode, \
+ w1_master_attribute_show_##_name, NULL)
+
+#define W1_MASTER_ATTR_RW(_name, _mode) \
+ struct device_attribute w1_master_attribute_##_name = \
+ __ATTR(w1_master_##_name, _mode, \
+ w1_master_attribute_show_##_name, \
+ w1_master_attribute_store_##_name)
+
+static W1_MASTER_ATTR_RO(name, S_IRUGO);
+static W1_MASTER_ATTR_RO(slaves, S_IRUGO);
+static W1_MASTER_ATTR_RO(slave_count, S_IRUGO);
+static W1_MASTER_ATTR_RO(max_slave_count, S_IRUGO);
+static W1_MASTER_ATTR_RO(attempts, S_IRUGO);
+static W1_MASTER_ATTR_RO(timeout, S_IRUGO);
+static W1_MASTER_ATTR_RO(pointer, S_IRUGO);
+static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUGO);
+
+static struct attribute *w1_master_default_attrs[] = {
+ &w1_master_attribute_name.attr,
+ &w1_master_attribute_slaves.attr,
+ &w1_master_attribute_slave_count.attr,
+ &w1_master_attribute_max_slave_count.attr,
+ &w1_master_attribute_attempts.attr,
+ &w1_master_attribute_timeout.attr,
+ &w1_master_attribute_pointer.attr,
+ &w1_master_attribute_search.attr,
+ NULL
};
-static struct device_attribute w1_master_attribute_timeout = {
- .attr = {
- .name = "w1_master_timeout",
- .mode = S_IRUGO,
- .owner = THIS_MODULE
- },
- .show = &w1_master_attribute_show_timeout,
-};
-static struct device_attribute w1_master_attribute_pointer = {
- .attr = {
- .name = "w1_master_pointer",
- .mode = S_IRUGO,
- .owner = THIS_MODULE
- },
- .show = &w1_master_attribute_show_pointer,
-};
-static struct device_attribute w1_master_attribute_name = {
- .attr = {
- .name = "w1_master_name",
- .mode = S_IRUGO,
- .owner = THIS_MODULE
- },
- .show = &w1_master_attribute_show_name,
+
+static struct attribute_group w1_master_defattr_group = {
+ .attrs = w1_master_default_attrs,
};
-static struct bin_attribute w1_slave_bin_attribute = {
- .attr = {
- .name = "w1_slave",
- .mode = S_IRUGO,
- .owner = THIS_MODULE,
- },
- .size = W1_SLAVE_DATA_SIZE,
- .read = &w1_default_read_bin,
+int w1_create_master_attributes(struct w1_master *master)
+{
+ return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group);
+}
+
+static void w1_destroy_master_attributes(struct w1_master *master)
+{
+ sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group);
+}
+
+#ifdef CONFIG_HOTPLUG
+static int w1_uevent(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size)
+{
+ struct w1_master *md = NULL;
+ struct w1_slave *sl = NULL;
+ char *event_owner, *name;
+ int err, cur_index=0, cur_len=0;
+
+ if (dev->driver == &w1_master_driver) {
+ md = container_of(dev, struct w1_master, dev);
+ event_owner = "master";
+ name = md->name;
+ } else if (dev->driver == &w1_slave_driver) {
+ sl = container_of(dev, struct w1_slave, dev);
+ event_owner = "slave";
+ name = sl->name;
+ } else {
+ dev_dbg(dev, "Unknown event.\n");
+ return -EINVAL;
+ }
+
+ dev_dbg(dev, "Hotplug event for %s %s, bus_id=%s.\n", event_owner, name, dev->bus_id);
+
+ if (dev->driver != &w1_slave_driver || !sl)
+ return 0;
+
+ err = add_uevent_var(envp, num_envp, &cur_index, buffer, buffer_size,
+ &cur_len, "W1_FID=%02X", sl->reg_num.family);
+ if (err)
+ return err;
+
+ err = add_uevent_var(envp, num_envp, &cur_index, buffer, buffer_size,
+ &cur_len, "W1_SLAVE_ID=%024LX",
+ (unsigned long long)sl->reg_num.id);
+ if (err)
+ return err;
+
+ return 0;
};
+#else
+static int w1_uevent(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size)
+{
+ return 0;
+}
+#endif
static int __w1_attach_slave_device(struct w1_slave *sl)
{
int err;
sl->dev.parent = &sl->master->dev;
- sl->dev.driver = sl->master->driver;
+ sl->dev.driver = &w1_slave_driver;
sl->dev.bus = &w1_bus_type;
sl->dev.release = &w1_slave_release;
snprintf(&sl->dev.bus_id[0], sizeof(sl->dev.bus_id),
- "%02x-%012llx",
- (unsigned int) sl->reg_num.family,
- (unsigned long long) sl->reg_num.id);
- snprintf (&sl->name[0], sizeof(sl->name),
- "%02x-%012llx",
- (unsigned int) sl->reg_num.family,
- (unsigned long long) sl->reg_num.id);
+ "%02x-%012llx",
+ (unsigned int) sl->reg_num.family,
+ (unsigned long long) sl->reg_num.id);
+ snprintf(&sl->name[0], sizeof(sl->name),
+ "%02x-%012llx",
+ (unsigned int) sl->reg_num.family,
+ (unsigned long long) sl->reg_num.id);
- dev_dbg(&sl->dev, "%s: registering %s.\n", __func__,
- &sl->dev.bus_id[0]);
+ dev_dbg(&sl->dev, "%s: registering %s as %p.\n", __func__, &sl->dev.bus_id[0]);
err = device_register(&sl->dev);
if (err < 0) {
dev_err(&sl->dev,
- "Device registration [%s] failed. err=%d\n",
- sl->dev.bus_id, err);
+ "Device registration [%s] failed. err=%d\n",
+ sl->dev.bus_id, err);
return err;
}
- memcpy(&sl->attr_bin, &w1_slave_bin_attribute, sizeof(sl->attr_bin));
- memcpy(&sl->attr_name, &w1_slave_attribute, sizeof(sl->attr_name));
- memcpy(&sl->attr_val, &w1_slave_attribute_val, sizeof(sl->attr_val));
-
- sl->attr_bin.read = sl->family->fops->rbin;
- sl->attr_name.show = sl->family->fops->rname;
- sl->attr_val.show = sl->family->fops->rval;
- sl->attr_val.attr.name = sl->family->fops->rvalname;
-
- err = device_create_file(&sl->dev, &sl->attr_name);
+ /* Create "name" entry */
+ err = device_create_file(&sl->dev, &w1_slave_attr_name);
if (err < 0) {
dev_err(&sl->dev,
- "sysfs file creation for [%s] failed. err=%d\n",
- sl->dev.bus_id, err);
- device_unregister(&sl->dev);
- return err;
+ "sysfs file creation for [%s] failed. err=%d\n",
+ sl->dev.bus_id, err);
+ goto out_unreg;
}
- err = device_create_file(&sl->dev, &sl->attr_val);
+ /* Create "id" entry */
+ err = sysfs_create_bin_file(&sl->dev.kobj, &w1_slave_attr_bin_id);
if (err < 0) {
dev_err(&sl->dev,
- "sysfs file creation for [%s] failed. err=%d\n",
- sl->dev.bus_id, err);
- device_remove_file(&sl->dev, &sl->attr_name);
- device_unregister(&sl->dev);
- return err;
+ "sysfs file creation for [%s] failed. err=%d\n",
+ sl->dev.bus_id, err);
+ goto out_rem1;
}
- err = sysfs_create_bin_file(&sl->dev.kobj, &sl->attr_bin);
- if (err < 0) {
+ /* if the family driver needs to initialize something... */
+ if (sl->family->fops && sl->family->fops->add_slave &&
+ ((err = sl->family->fops->add_slave(sl)) < 0)) {
dev_err(&sl->dev,
- "sysfs file creation for [%s] failed. err=%d\n",
- sl->dev.bus_id, err);
- device_remove_file(&sl->dev, &sl->attr_name);
- device_remove_file(&sl->dev, &sl->attr_val);
- device_unregister(&sl->dev);
- return err;
+ "sysfs file creation for [%s] failed. err=%d\n",
+ sl->dev.bus_id, err);
+ goto out_rem2;
}
list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
return 0;
+
+out_rem2:
+ sysfs_remove_bin_file(&sl->dev.kobj, &w1_slave_attr_bin_id);
+out_rem1:
+ device_remove_file(&sl->dev, &w1_slave_attr_name);
+out_unreg:
+ device_unregister(&sl->dev);
+ return err;
}
static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
atomic_set(&sl->refcnt, 0);
- init_completion(&sl->dev_released);
+ init_completion(&sl->released);
spin_lock(&w1_flock);
f = w1_family_registered(rn->family);
if (!f) {
- spin_unlock(&w1_flock);
+ f= &w1_default_family;
dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n",
rn->family, rn->family,
(unsigned long long)rn->id, rn->crc);
- kfree(sl);
- return -ENODEV;
}
__w1_family_get(f);
spin_unlock(&w1_flock);
static void w1_slave_detach(struct w1_slave *sl)
{
struct w1_netlink_msg msg;
-
- dev_info(&sl->dev, "%s: detaching %s.\n", __func__, sl->name);
- while (atomic_read(&sl->refcnt)) {
- printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n",
- sl->name, atomic_read(&sl->refcnt));
+ dev_dbg(&sl->dev, "%s: detaching %s [%p].\n", __func__, sl->name, sl);
- if (msleep_interruptible(1000))
- flush_signals(current);
- }
+ list_del(&sl->w1_slave_entry);
- sysfs_remove_bin_file (&sl->dev.kobj, &sl->attr_bin);
- device_remove_file(&sl->dev, &sl->attr_name);
- device_remove_file(&sl->dev, &sl->attr_val);
- device_unregister(&sl->dev);
- w1_family_put(sl->family);
+ if (sl->family->fops && sl->family->fops->remove_slave)
+ sl->family->fops->remove_slave(sl);
memcpy(&msg.id.id, &sl->reg_num, sizeof(msg.id.id));
msg.type = W1_SLAVE_REMOVE;
w1_netlink_send(sl->master, &msg);
+
+ sysfs_remove_bin_file(&sl->dev.kobj, &w1_slave_attr_bin_id);
+ device_remove_file(&sl->dev, &w1_slave_attr_name);
+ device_unregister(&sl->dev);
+
+ wait_for_completion(&sl->released);
+ kfree(sl);
}
-static struct w1_master *w1_search_master(unsigned long data)
+static struct w1_master *w1_search_master(void *data)
{
struct w1_master *dev;
int found = 0;
-
- spin_lock_irq(&w1_mlock);
+
+ spin_lock_bh(&w1_mlock);
list_for_each_entry(dev, &w1_masters, w1_master_entry) {
if (dev->bus_master->data == data) {
found = 1;
break;
}
}
- spin_unlock_irq(&w1_mlock);
+ spin_unlock_bh(&w1_mlock);
return (found)?dev:NULL;
}
-void w1_slave_found(unsigned long data, u64 rn)
+void w1_reconnect_slaves(struct w1_family *f)
+{
+ struct w1_master *dev;
+
+ spin_lock_bh(&w1_mlock);
+ list_for_each_entry(dev, &w1_masters, w1_master_entry) {
+ dev_dbg(&dev->dev, "Reconnecting slaves in %s into new family %02x.\n",
+ dev->name, f->fid);
+ set_bit(W1_MASTER_NEED_RECONNECT, &dev->flags);
+ }
+ spin_unlock_bh(&w1_mlock);
+}
+
+static void w1_slave_found(void *data, u64 rn)
{
int slave_count;
struct w1_slave *sl;
struct w1_reg_num *tmp;
int family_found = 0;
struct w1_master *dev;
+ u64 rn_le = cpu_to_le64(rn);
dev = w1_search_master(data);
if (!dev) {
- printk(KERN_ERR "Failed to find w1 master device for data %08lx, it is impossible.\n",
- data);
+ printk(KERN_ERR "Failed to find w1 master device for data %p, "
+ "it is impossible.\n", data);
return;
}
-
+
tmp = (struct w1_reg_num *) &rn;
slave_count = 0;
sl->reg_num.crc == tmp->crc) {
set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
break;
- }
- else if (sl->reg_num.family == tmp->family) {
+ } else if (sl->reg_num.family == tmp->family) {
family_found = 1;
break;
}
slave_count++;
}
- rn = cpu_to_le64(rn);
-
if (slave_count == dev->slave_count &&
- rn && ((le64_to_cpu(rn) >> 56) & 0xff) == w1_calc_crc8((u8 *)&rn, 7)) {
+ rn && ((rn >> 56) & 0xff) == w1_calc_crc8((u8 *)&rn_le, 7)) {
w1_attach_slave_device(dev, tmp);
}
-
+
atomic_dec(&dev->refcnt);
}
-void w1_search(struct w1_master *dev)
+/**
+ * Performs a ROM Search & registers any devices found.
+ * The 1-wire search is a simple binary tree search.
+ * For each bit of the address, we read two bits and write one bit.
+ * The bit written will put to sleep all devies that don't match that bit.
+ * When the two reads differ, the direction choice is obvious.
+ * When both bits are 0, we must choose a path to take.
+ * When we can scan all 64 bits without having to choose a path, we are done.
+ *
+ * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com
+ *
+ * @dev The master device to search
+ * @cb Function to call when a device is found
+ */
+void w1_search(struct w1_master *dev, w1_slave_found_callback cb)
{
- u64 last, rn, tmp;
- int i, count = 0;
- int last_family_desc, last_zero, last_device;
- int search_bit, id_bit, comp_bit, desc_bit;
+ u64 last_rn, rn, tmp64;
+ int i, slave_count = 0;
+ int last_zero, last_device;
+ int search_bit, desc_bit;
+ u8 triplet_ret = 0;
- search_bit = id_bit = comp_bit = 0;
- rn = tmp = last = 0;
- last_device = last_zero = last_family_desc = 0;
+ search_bit = 0;
+ rn = last_rn = 0;
+ last_device = 0;
+ last_zero = -1;
desc_bit = 64;
- while (!(id_bit && comp_bit) && !last_device
- && count++ < dev->max_slave_count) {
- last = rn;
+ while ( !last_device && (slave_count++ < dev->max_slave_count) ) {
+ last_rn = rn;
rn = 0;
- last_family_desc = 0;
-
/*
* Reset bus and all 1-wire device state machines
* so they can respond to our requests.
* Return 0 - device(s) present, 1 - no devices present.
*/
if (w1_reset_bus(dev)) {
- dev_info(&dev->dev, "No devices present on the wire.\n");
+ //dev_dbg(&dev->dev, "No devices present on the wire.\n");
break;
}
-#if 1
+ /* Start the search */
w1_write_8(dev, W1_SEARCH);
for (i = 0; i < 64; ++i) {
- /*
- * Read 2 bits from bus.
- * All who don't sleep must send ID bit and COMPLEMENT ID bit.
- * They actually are ANDed between all senders.
- */
- id_bit = w1_touch_bit(dev, 1);
- comp_bit = w1_touch_bit(dev, 1);
-
- if (id_bit && comp_bit)
- break;
-
- if (id_bit == 0 && comp_bit == 0) {
- if (i == desc_bit)
- search_bit = 1;
- else if (i > desc_bit)
- search_bit = 0;
- else
- search_bit = ((last >> i) & 0x1);
-
- if (search_bit == 0) {
- last_zero = i;
- if (last_zero < 9)
- last_family_desc = last_zero;
- }
-
- }
+ /* Determine the direction/search bit */
+ if (i == desc_bit)
+ search_bit = 1; /* took the 0 path last time, so take the 1 path */
+ else if (i > desc_bit)
+ search_bit = 0; /* take the 0 path on the next branch */
else
- search_bit = id_bit;
+ search_bit = ((last_rn >> i) & 0x1);
- tmp = search_bit;
- rn |= (tmp << i);
+ /** Read two bits and write one bit */
+ triplet_ret = w1_triplet(dev, search_bit);
- /*
- * Write 1 bit to bus
- * and make all who don't have "search_bit" in "i"'th position
- * in it's registration number sleep.
- */
- if (dev->bus_master->touch_bit)
- w1_touch_bit(dev, search_bit);
- else
- w1_write_bit(dev, search_bit);
+ /* quit if no device responded */
+ if ( (triplet_ret & 0x03) == 0x03 )
+ break;
- }
-#endif
+ /* If both directions were valid, and we took the 0 path... */
+ if (triplet_ret == 0)
+ last_zero = i;
- if (desc_bit == last_zero)
- last_device = 1;
+ /* extract the direction taken & update the device number */
+ tmp64 = (triplet_ret >> 2);
+ rn |= (tmp64 << i);
+ }
- desc_bit = last_zero;
-
- w1_slave_found(dev->bus_master->data, rn);
+ if ( (triplet_ret & 0x03) != 0x03 ) {
+ if ( (desc_bit == last_zero) || (last_zero < 0))
+ last_device = 1;
+ desc_bit = last_zero;
+ cb(dev->bus_master->data, rn);
+ }
}
}
-int w1_create_master_attributes(struct w1_master *dev)
+static int w1_control(void *data)
{
- if ( device_create_file(&dev->dev, &w1_master_attribute_slaves) < 0 ||
- device_create_file(&dev->dev, &w1_master_attribute_slave_count) < 0 ||
- device_create_file(&dev->dev, &w1_master_attribute_attempts) < 0 ||
- device_create_file(&dev->dev, &w1_master_attribute_max_slave_count) < 0 ||
- device_create_file(&dev->dev, &w1_master_attribute_timeout) < 0||
- device_create_file(&dev->dev, &w1_master_attribute_pointer) < 0||
- device_create_file(&dev->dev, &w1_master_attribute_name) < 0)
- return -EINVAL;
+ struct w1_slave *sl, *sln;
+ struct w1_master *dev, *n;
+ int have_to_wait = 0;
- return 0;
-}
-
-void w1_destroy_master_attributes(struct w1_master *dev)
-{
- device_remove_file(&dev->dev, &w1_master_attribute_slaves);
- device_remove_file(&dev->dev, &w1_master_attribute_slave_count);
- device_remove_file(&dev->dev, &w1_master_attribute_attempts);
- device_remove_file(&dev->dev, &w1_master_attribute_max_slave_count);
- device_remove_file(&dev->dev, &w1_master_attribute_timeout);
- device_remove_file(&dev->dev, &w1_master_attribute_pointer);
- device_remove_file(&dev->dev, &w1_master_attribute_name);
-}
-
-
-int w1_control(void *data)
-{
- struct w1_slave *sl;
- struct w1_master *dev;
- struct list_head *ent, *ment, *n, *mn;
- int err, have_to_wait = 0;
-
- daemonize("w1_control");
- allow_signal(SIGTERM);
-
- while (!control_needs_exit || have_to_wait) {
+ while (!kthread_should_stop() || have_to_wait) {
have_to_wait = 0;
- try_to_freeze(PF_FREEZE);
- msleep_interruptible(w1_timeout * 1000);
-
- if (signal_pending(current))
- flush_signals(current);
+ try_to_freeze();
+ msleep_interruptible(w1_control_timeout * 1000);
- list_for_each_safe(ment, mn, &w1_masters) {
- dev = list_entry(ment, struct w1_master, w1_master_entry);
-
- if (!control_needs_exit && !dev->need_exit)
+ list_for_each_entry_safe(dev, n, &w1_masters, w1_master_entry) {
+ if (!kthread_should_stop() && !dev->flags)
continue;
/*
* Little race: we can create thread but not set the flag.
continue;
}
- spin_lock(&w1_mlock);
- list_del(&dev->w1_master_entry);
- spin_unlock(&w1_mlock);
+ if (kthread_should_stop() || test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {
+ set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
- if (control_needs_exit) {
- dev->need_exit = 1;
+ spin_lock(&w1_mlock);
+ list_del(&dev->w1_master_entry);
+ spin_unlock(&w1_mlock);
- err = kill_proc(dev->kpid, SIGTERM, 1);
- if (err)
- dev_err(&dev->dev,
- "Failed to send signal to w1 kernel thread %d.\n",
- dev->kpid);
+ down(&dev->mutex);
+ list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
+ w1_slave_detach(sl);
+ }
+ w1_destroy_master_attributes(dev);
+ up(&dev->mutex);
+ atomic_dec(&dev->refcnt);
+ continue;
}
- wait_for_completion(&dev->dev_exited);
-
- list_for_each_safe(ent, n, &dev->slist) {
- sl = list_entry(ent, struct w1_slave, w1_slave_entry);
+ if (test_bit(W1_MASTER_NEED_RECONNECT, &dev->flags)) {
+ dev_dbg(&dev->dev, "Reconnecting slaves in device %s.\n", dev->name);
+ down(&dev->mutex);
+ list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
+ if (sl->family->fid == W1_FAMILY_DEFAULT) {
+ struct w1_reg_num rn;
- if (!sl)
- dev_warn(&dev->dev,
- "%s: slave entry is NULL.\n",
- __func__);
- else {
- list_del(&sl->w1_slave_entry);
+ memcpy(&rn, &sl->reg_num, sizeof(rn));
+ w1_slave_detach(sl);
- w1_slave_detach(sl);
- kfree(sl);
+ w1_attach_slave_device(dev, &rn);
+ }
}
+ dev_dbg(&dev->dev, "Reconnecting slaves in device %s has been finished.\n", dev->name);
+ clear_bit(W1_MASTER_NEED_RECONNECT, &dev->flags);
+ up(&dev->mutex);
}
- w1_destroy_master_attributes(dev);
- atomic_dec(&dev->refcnt);
}
}
- complete_and_exit(&w1_control_complete, 0);
+ return 0;
}
int w1_process(void *data)
{
struct w1_master *dev = (struct w1_master *) data;
- struct list_head *ent, *n;
- struct w1_slave *sl;
+ struct w1_slave *sl, *sln;
- daemonize("%s", dev->name);
- allow_signal(SIGTERM);
-
- while (!dev->need_exit) {
- try_to_freeze(PF_FREEZE);
+ while (!kthread_should_stop() && !test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {
+ try_to_freeze();
msleep_interruptible(w1_timeout * 1000);
- if (signal_pending(current))
- flush_signals(current);
-
- if (dev->need_exit)
+ if (kthread_should_stop() || test_bit(W1_MASTER_NEED_EXIT, &dev->flags))
break;
if (!dev->initialized)
continue;
+ if (dev->search_count == 0)
+ continue;
+
if (down_interruptible(&dev->mutex))
continue;
- list_for_each_safe(ent, n, &dev->slist) {
- sl = list_entry(ent, struct w1_slave, w1_slave_entry);
+ list_for_each_entry(sl, &dev->slist, w1_slave_entry)
+ clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
- if (sl)
- clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
- }
-
w1_search_devices(dev, w1_slave_found);
- list_for_each_safe(ent, n, &dev->slist) {
- sl = list_entry(ent, struct w1_slave, w1_slave_entry);
-
- if (sl && !test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags) && !--sl->ttl) {
- list_del (&sl->w1_slave_entry);
-
- w1_slave_detach (sl);
- kfree (sl);
+ list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
+ if (!test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags) && !--sl->ttl) {
+ w1_slave_detach(sl);
dev->slave_count--;
- }
- else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags))
+ } else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags))
sl->ttl = dev->slave_ttl;
}
+
+ if (dev->search_count > 0)
+ dev->search_count--;
+
up(&dev->mutex);
}
atomic_dec(&dev->refcnt);
- complete_and_exit(&dev->dev_exited, 0);
return 0;
}
-int w1_init(void)
+static int w1_init(void)
{
int retval;
goto err_out_exit_init;
}
- retval = driver_register(&w1_driver);
+ retval = driver_register(&w1_master_driver);
if (retval) {
printk(KERN_ERR
"Failed to register master driver. err=%d.\n",
goto err_out_bus_unregister;
}
- control_thread = kernel_thread(&w1_control, NULL, 0);
- if (control_thread < 0) {
+ retval = driver_register(&w1_slave_driver);
+ if (retval) {
+ printk(KERN_ERR
+ "Failed to register master driver. err=%d.\n",
+ retval);
+ goto err_out_master_unregister;
+ }
+
+ w1_control_thread = kthread_run(w1_control, NULL, "w1_control");
+ if (IS_ERR(w1_control_thread)) {
+ retval = PTR_ERR(w1_control_thread);
printk(KERN_ERR "Failed to create control thread. err=%d\n",
- control_thread);
- retval = control_thread;
- goto err_out_driver_unregister;
+ retval);
+ goto err_out_slave_unregister;
}
return 0;
-err_out_driver_unregister:
- driver_unregister(&w1_driver);
+err_out_slave_unregister:
+ driver_unregister(&w1_slave_driver);
+
+err_out_master_unregister:
+ driver_unregister(&w1_master_driver);
err_out_bus_unregister:
bus_unregister(&w1_bus_type);
return retval;
}
-void w1_fini(void)
+static void w1_fini(void)
{
struct w1_master *dev;
- struct list_head *ent, *n;
- list_for_each_safe(ent, n, &w1_masters) {
- dev = list_entry(ent, struct w1_master, w1_master_entry);
+ list_for_each_entry(dev, &w1_masters, w1_master_entry)
__w1_remove_master_device(dev);
- }
-
- control_needs_exit = 1;
- wait_for_completion(&w1_control_complete);
+ kthread_stop(w1_control_thread);
- driver_unregister(&w1_driver);
+ driver_unregister(&w1_slave_driver);
+ driver_unregister(&w1_master_driver);
bus_unregister(&w1_bus_type);
}
git://git.onelab.eu / linux-2.6.git / blobdiff