summaryrefslogtreecommitdiff
path: root/drivers/w1/w1.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/w1/w1.c')
-rw-r--r--drivers/w1/w1.c1069
1 files changed, 1069 insertions, 0 deletions
diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
new file mode 100644
index 00000000..97619506
--- /dev/null
+++ b/drivers/w1/w1.c
@@ -0,0 +1,1069 @@
+/*
+ * 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.
+ *
+ * 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 <linux/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 <zbr@ioremap.net>");
+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;
+}
+
+static ssize_t w1_default_read(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);
+ w1_read_block(sl->master, buf, count);
+ mutex_unlock(&sl->master->mutex);
+ return count;
+}
+
+static struct bin_attribute w1_default_attr = {
+ .attr = {
+ .name = "rw",
+ .mode = S_IRUGO | S_IWUSR,
+ },
+ .size = PAGE_SIZE,
+ .read = w1_default_read,
+ .write = w1_default_write,
+};
+
+static int w1_default_add_slave(struct w1_slave *sl)
+{
+ return sysfs_create_bin_file(&sl->dev.kobj, &w1_default_attr);
+}
+
+static void w1_default_remove_slave(struct w1_slave *sl)
+{
+ sysfs_remove_bin_file(&sl->dev.kobj, &w1_default_attr);
+}
+
+static struct w1_family_ops w1_default_fops = {
+ .add_slave = w1_default_add_slave,
+ .remove_slave = w1_default_remove_slave,
+};
+
+static struct w1_family w1_default_family = {
+ .fops = &w1_default_fops,
+};
+
+static int w1_uevent(struct device *dev, struct kobj_uevent_env *env);
+
+static struct bus_type w1_bus_type = {
+ .name = "w1",
+ .match = w1_master_match,
+ .uevent = w1_uevent,
+};
+
+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,
+ .init_name = "w1 bus master",
+ .driver = &w1_master_driver,
+ .release = &w1_master_release
+};
+
+static struct device_driver w1_slave_driver = {
+ .name = "w1_slave_driver",
+ .bus = &w1_bus_type,
+};
+
+#if 0
+struct device w1_slave_device = {
+ .parent = NULL,
+ .bus = &w1_bus_type,
+ .init_name = "w1 bus slave",
+ .driver = &w1_slave_driver,
+ .release = &w1_slave_release
+};
+#endif /* 0 */
+
+static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct w1_master *md = dev_to_w1_master(dev);
+ ssize_t count;
+
+ mutex_lock(&md->mutex);
+ count = sprintf(buf, "%s\n", md->name);
+ mutex_unlock(&md->mutex);
+
+ return count;
+}
+
+static ssize_t w1_master_attribute_store_search(struct device * dev,
+ struct device_attribute *attr,
+ const char * buf, size_t count)
+{
+ long tmp;
+ struct w1_master *md = dev_to_w1_master(dev);
+
+ if (strict_strtol(buf, 0, &tmp) == -EINVAL)
+ return -EINVAL;
+
+ mutex_lock(&md->mutex);
+ md->search_count = tmp;
+ mutex_unlock(&md->mutex);
+ wake_up_process(md->thread);
+
+ 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;
+
+ mutex_lock(&md->mutex);
+ count = sprintf(buf, "%d\n", md->search_count);
+ mutex_unlock(&md->mutex);
+
+ return count;
+}
+
+static ssize_t w1_master_attribute_store_pullup(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ long tmp;
+ struct w1_master *md = dev_to_w1_master(dev);
+
+ if (strict_strtol(buf, 0, &tmp) == -EINVAL)
+ return -EINVAL;
+
+ mutex_lock(&md->mutex);
+ md->enable_pullup = tmp;
+ mutex_unlock(&md->mutex);
+ wake_up_process(md->thread);
+
+ return count;
+}
+
+static ssize_t w1_master_attribute_show_pullup(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct w1_master *md = dev_to_w1_master(dev);
+ ssize_t count;
+
+ mutex_lock(&md->mutex);
+ count = sprintf(buf, "%d\n", md->enable_pullup);
+ mutex_unlock(&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;
+
+ mutex_lock(&md->mutex);
+ count = sprintf(buf, "0x%p\n", md->bus_master);
+ mutex_unlock(&md->mutex);
+ return count;
+}
+
+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, struct device_attribute *attr, char *buf)
+{
+ struct w1_master *md = dev_to_w1_master(dev);
+ ssize_t count;
+
+ mutex_lock(&md->mutex);
+ count = sprintf(buf, "%d\n", md->max_slave_count);
+ mutex_unlock(&md->mutex);
+ return count;
+}
+
+static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct w1_master *md = dev_to_w1_master(dev);
+ ssize_t count;
+
+ mutex_lock(&md->mutex);
+ count = sprintf(buf, "%lu\n", md->attempts);
+ mutex_unlock(&md->mutex);
+ return count;
+}
+
+static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct w1_master *md = dev_to_w1_master(dev);
+ ssize_t count;
+
+ mutex_lock(&md->mutex);
+ count = sprintf(buf, "%d\n", md->slave_count);
+ mutex_unlock(&md->mutex);
+ return count;
+}
+
+static ssize_t w1_master_attribute_show_slaves(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct w1_master *md = dev_to_w1_master(dev);
+ int c = PAGE_SIZE;
+
+ mutex_lock(&md->mutex);
+
+ if (md->slave_count == 0)
+ c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
+ else {
+ struct list_head *ent, *n;
+ struct w1_slave *sl;
+
+ 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);
+ }
+ }
+
+ mutex_unlock(&md->mutex);
+
+ return PAGE_SIZE - c;
+}
+
+static ssize_t w1_master_attribute_show_add(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ int c = PAGE_SIZE;
+ c -= snprintf(buf+PAGE_SIZE - c, c,
+ "write device id xx-xxxxxxxxxxxx to add slave\n");
+ return PAGE_SIZE - c;
+}
+
+static int w1_atoreg_num(struct device *dev, const char *buf, size_t count,
+ struct w1_reg_num *rn)
+{
+ unsigned int family;
+ unsigned long long id;
+ int i;
+ u64 rn64_le;
+
+ /* The CRC value isn't read from the user because the sysfs directory
+ * doesn't include it and most messages from the bus search don't
+ * print it either. It would be unreasonable for the user to then
+ * provide it.
+ */
+ const char *error_msg = "bad slave string format, expecting "
+ "ff-dddddddddddd\n";
+
+ if (buf[2] != '-') {
+ dev_err(dev, "%s", error_msg);
+ return -EINVAL;
+ }
+ i = sscanf(buf, "%02x-%012llx", &family, &id);
+ if (i != 2) {
+ dev_err(dev, "%s", error_msg);
+ return -EINVAL;
+ }
+ rn->family = family;
+ rn->id = id;
+
+ rn64_le = cpu_to_le64(*(u64 *)rn);
+ rn->crc = w1_calc_crc8((u8 *)&rn64_le, 7);
+
+#if 0
+ dev_info(dev, "With CRC device is %02x.%012llx.%02x.\n",
+ rn->family, (unsigned long long)rn->id, rn->crc);
+#endif
+
+ return 0;
+}
+
+/* Searches the slaves in the w1_master and returns a pointer or NULL.
+ * Note: must hold the mutex
+ */
+static struct w1_slave *w1_slave_search_device(struct w1_master *dev,
+ struct w1_reg_num *rn)
+{
+ struct w1_slave *sl;
+ list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
+ if (sl->reg_num.family == rn->family &&
+ sl->reg_num.id == rn->id &&
+ sl->reg_num.crc == rn->crc) {
+ return sl;
+ }
+ }
+ return NULL;
+}
+
+static ssize_t w1_master_attribute_store_add(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct w1_master *md = dev_to_w1_master(dev);
+ struct w1_reg_num rn;
+ struct w1_slave *sl;
+ ssize_t result = count;
+
+ if (w1_atoreg_num(dev, buf, count, &rn))
+ return -EINVAL;
+
+ mutex_lock(&md->mutex);
+ sl = w1_slave_search_device(md, &rn);
+ /* It would be nice to do a targeted search one the one-wire bus
+ * for the new device to see if it is out there or not. But the
+ * current search doesn't support that.
+ */
+ if (sl) {
+ dev_info(dev, "Device %s already exists\n", sl->name);
+ result = -EINVAL;
+ } else {
+ w1_attach_slave_device(md, &rn);
+ }
+ mutex_unlock(&md->mutex);
+
+ return result;
+}
+
+static ssize_t w1_master_attribute_show_remove(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ int c = PAGE_SIZE;
+ c -= snprintf(buf+PAGE_SIZE - c, c,
+ "write device id xx-xxxxxxxxxxxx to remove slave\n");
+ return PAGE_SIZE - c;
+}
+
+static ssize_t w1_master_attribute_store_remove(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct w1_master *md = dev_to_w1_master(dev);
+ struct w1_reg_num rn;
+ struct w1_slave *sl;
+ ssize_t result = count;
+
+ if (w1_atoreg_num(dev, buf, count, &rn))
+ return -EINVAL;
+
+ mutex_lock(&md->mutex);
+ sl = w1_slave_search_device(md, &rn);
+ if (sl) {
+ w1_slave_detach(sl);
+ } else {
+ dev_info(dev, "Device %02x-%012llx doesn't exists\n", rn.family,
+ (unsigned long long)rn.id);
+ result = -EINVAL;
+ }
+ mutex_unlock(&md->mutex);
+
+ return result;
+}
+
+#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_IWUSR | S_IWGRP);
+static W1_MASTER_ATTR_RW(pullup, S_IRUGO | S_IWUSR | S_IWGRP);
+static W1_MASTER_ATTR_RW(add, S_IRUGO | S_IWUSR | S_IWGRP);
+static W1_MASTER_ATTR_RW(remove, S_IRUGO | S_IWUSR | S_IWGRP);
+
+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,
+ &w1_master_attribute_pullup.attr,
+ &w1_master_attribute_add.attr,
+ &w1_master_attribute_remove.attr,
+ NULL
+};
+
+static struct attribute_group w1_master_defattr_group = {
+ .attrs = w1_master_default_attrs,
+};
+
+int w1_create_master_attributes(struct w1_master *master)
+{
+ return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group);
+}
+
+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, struct kobj_uevent_env *env)
+{
+ struct w1_master *md = NULL;
+ struct w1_slave *sl = NULL;
+ char *event_owner, *name;
+ int err;
+
+ 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_name(dev));
+
+ if (dev->driver != &w1_slave_driver || !sl)
+ return 0;
+
+ err = add_uevent_var(env, "W1_FID=%02X", sl->reg_num.family);
+ if (err)
+ return err;
+
+ err = add_uevent_var(env, "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, struct kobj_uevent_env *env)
+{
+ return 0;
+}
+#endif
+
+static int __w1_attach_slave_device(struct w1_slave *sl)
+{
+ int err;
+
+ sl->dev.parent = &sl->master->dev;
+ sl->dev.driver = &w1_slave_driver;
+ sl->dev.bus = &w1_bus_type;
+ sl->dev.release = &w1_slave_release;
+
+ dev_set_name(&sl->dev, "%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 as %p.\n", __func__,
+ dev_name(&sl->dev), sl);
+
+ err = device_register(&sl->dev);
+ if (err < 0) {
+ dev_err(&sl->dev,
+ "Device registration [%s] failed. err=%d\n",
+ dev_name(&sl->dev), err);
+ return err;
+ }
+
+ /* 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",
+ dev_name(&sl->dev), err);
+ goto out_unreg;
+ }
+
+ /* Create "id" entry */
+ err = device_create_file(&sl->dev, &w1_slave_attr_id);
+ if (err < 0) {
+ dev_err(&sl->dev,
+ "sysfs file creation for [%s] failed. err=%d\n",
+ dev_name(&sl->dev), err);
+ goto out_rem1;
+ }
+
+ /* 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",
+ dev_name(&sl->dev), err);
+ goto out_rem2;
+ }
+
+ list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
+
+ return 0;
+
+out_rem2:
+ device_remove_file(&sl->dev, &w1_slave_attr_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)
+{
+ struct w1_slave *sl;
+ struct w1_family *f;
+ int err;
+ struct w1_netlink_msg msg;
+
+ sl = kzalloc(sizeof(struct w1_slave), GFP_KERNEL);
+ if (!sl) {
+ dev_err(&dev->dev,
+ "%s: failed to allocate new slave device.\n",
+ __func__);
+ return -ENOMEM;
+ }
+
+
+ sl->owner = THIS_MODULE;
+ sl->master = dev;
+ set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
+
+ memset(&msg, 0, sizeof(msg));
+ memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
+ atomic_set(&sl->refcnt, 0);
+ init_completion(&sl->released);
+
+ spin_lock(&w1_flock);
+ f = w1_family_registered(rn->family);
+ if (!f) {
+ 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);
+ }
+ __w1_family_get(f);
+ spin_unlock(&w1_flock);
+
+ sl->family = f;
+
+
+ err = __w1_attach_slave_device(sl);
+ if (err < 0) {
+ dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
+ sl->name);
+ w1_family_put(sl->family);
+ kfree(sl);
+ return err;
+ }
+
+ sl->ttl = dev->slave_ttl;
+ dev->slave_count++;
+
+ memcpy(msg.id.id, rn, sizeof(msg.id));
+ msg.type = W1_SLAVE_ADD;
+ w1_netlink_send(dev, &msg);
+
+ return 0;
+}
+
+void w1_slave_detach(struct w1_slave *sl)
+{
+ struct w1_netlink_msg msg;
+
+ dev_dbg(&sl->dev, "%s: detaching %s [%p].\n", __func__, sl->name, sl);
+
+ list_del(&sl->w1_slave_entry);
+
+ if (sl->family->fops && sl->family->fops->remove_slave)
+ sl->family->fops->remove_slave(sl);
+
+ memset(&msg, 0, sizeof(msg));
+ memcpy(msg.id.id, &sl->reg_num, sizeof(msg.id));
+ msg.type = W1_SLAVE_REMOVE;
+ w1_netlink_send(sl->master, &msg);
+
+ device_remove_file(&sl->dev, &w1_slave_attr_id);
+ device_remove_file(&sl->dev, &w1_slave_attr_name);
+ device_unregister(&sl->dev);
+
+ wait_for_completion(&sl->released);
+ kfree(sl);
+}
+
+struct w1_master *w1_search_master_id(u32 id)
+{
+ struct w1_master *dev;
+ int found = 0;
+
+ mutex_lock(&w1_mlock);
+ list_for_each_entry(dev, &w1_masters, w1_master_entry) {
+ if (dev->id == id) {
+ found = 1;
+ atomic_inc(&dev->refcnt);
+ break;
+ }
+ }
+ mutex_unlock(&w1_mlock);
+
+ return (found)?dev:NULL;
+}
+
+struct w1_slave *w1_search_slave(struct w1_reg_num *id)
+{
+ struct w1_master *dev;
+ struct w1_slave *sl = NULL;
+ int found = 0;
+
+ mutex_lock(&w1_mlock);
+ list_for_each_entry(dev, &w1_masters, w1_master_entry) {
+ mutex_lock(&dev->mutex);
+ list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
+ if (sl->reg_num.family == id->family &&
+ sl->reg_num.id == id->id &&
+ sl->reg_num.crc == id->crc) {
+ found = 1;
+ atomic_inc(&dev->refcnt);
+ atomic_inc(&sl->refcnt);
+ break;
+ }
+ }
+ mutex_unlock(&dev->mutex);
+
+ if (found)
+ break;
+ }
+ mutex_unlock(&w1_mlock);
+
+ return (found)?sl:NULL;
+}
+
+void w1_reconnect_slaves(struct w1_family *f, int attach)
+{
+ struct w1_slave *sl, *sln;
+ struct w1_master *dev;
+
+ mutex_lock(&w1_mlock);
+ list_for_each_entry(dev, &w1_masters, w1_master_entry) {
+ dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
+ "for family %02x.\n", dev->name, f->fid);
+ mutex_lock(&dev->mutex);
+ list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
+ /* If it is a new family, slaves with the default
+ * family driver and are that family will be
+ * connected. If the family is going away, devices
+ * matching that family are reconneced.
+ */
+ if ((attach && sl->family->fid == W1_FAMILY_DEFAULT
+ && sl->reg_num.family == f->fid) ||
+ (!attach && sl->family->fid == f->fid)) {
+ struct w1_reg_num rn;
+
+ memcpy(&rn, &sl->reg_num, sizeof(rn));
+ w1_slave_detach(sl);
+
+ w1_attach_slave_device(dev, &rn);
+ }
+ }
+ dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
+ "has been finished.\n", dev->name);
+ mutex_unlock(&dev->mutex);
+ }
+ mutex_unlock(&w1_mlock);
+}
+
+void w1_slave_found(struct w1_master *dev, u64 rn)
+{
+ struct w1_slave *sl;
+ struct w1_reg_num *tmp;
+ u64 rn_le = cpu_to_le64(rn);
+
+ atomic_inc(&dev->refcnt);
+
+ tmp = (struct w1_reg_num *) &rn;
+
+ sl = w1_slave_search_device(dev, tmp);
+ if (sl) {
+ set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
+ } else {
+ if (rn && tmp->crc == w1_calc_crc8((u8 *)&rn_le, 7))
+ w1_attach_slave_device(dev, tmp);
+ }
+
+ atomic_dec(&dev->refcnt);
+}
+
+/**
+ * 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, u8 search_type, w1_slave_found_callback cb)
+{
+ 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 = 0;
+ rn = last_rn = 0;
+ last_device = 0;
+ last_zero = -1;
+
+ desc_bit = 64;
+
+ while ( !last_device && (slave_count++ < dev->max_slave_count) ) {
+ last_rn = rn;
+ rn = 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_dbg(&dev->dev, "No devices present on the wire.\n");
+ break;
+ }
+
+ /* Do fast search on single slave bus */
+ if (dev->max_slave_count == 1) {
+ w1_write_8(dev, W1_READ_ROM);
+
+ if (w1_read_block(dev, (u8 *)&rn, 8) == 8 && rn)
+ cb(dev, rn);
+
+ break;
+ }
+
+ /* Start the search */
+ w1_write_8(dev, search_type);
+ for (i = 0; i < 64; ++i) {
+ /* 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 = ((last_rn >> i) & 0x1);
+
+ /** Read two bits and write one bit */
+ triplet_ret = w1_triplet(dev, search_bit);
+
+ /* quit if no device responded */
+ if ( (triplet_ret & 0x03) == 0x03 )
+ break;
+
+ /* If both directions were valid, and we took the 0 path... */
+ if (triplet_ret == 0)
+ last_zero = i;
+
+ /* extract the direction taken & update the device number */
+ tmp64 = (triplet_ret >> 2);
+ rn |= (tmp64 << i);
+
+ if (kthread_should_stop()) {
+ dev_dbg(&dev->dev, "Abort w1_search\n");
+ return;
+ }
+ }
+
+ if ( (triplet_ret & 0x03) != 0x03 ) {
+ if ( (desc_bit == last_zero) || (last_zero < 0))
+ last_device = 1;
+ desc_bit = last_zero;
+ cb(dev, rn);
+ }
+ }
+}
+
+void w1_search_process_cb(struct w1_master *dev, u8 search_type,
+ w1_slave_found_callback cb)
+{
+ struct w1_slave *sl, *sln;
+
+ list_for_each_entry(sl, &dev->slist, w1_slave_entry)
+ clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
+
+ w1_search_devices(dev, search_type, cb);
+
+ 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);
+ else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags))
+ sl->ttl = dev->slave_ttl;
+ }
+
+ if (dev->search_count > 0)
+ dev->search_count--;
+}
+
+static void w1_search_process(struct w1_master *dev, u8 search_type)
+{
+ w1_search_process_cb(dev, search_type, w1_slave_found);
+}
+
+int w1_process(void *data)
+{
+ struct w1_master *dev = (struct w1_master *) data;
+ /* As long as w1_timeout is only set by a module parameter the sleep
+ * time can be calculated in jiffies once.
+ */
+ const unsigned long jtime = msecs_to_jiffies(w1_timeout * 1000);
+
+ while (!kthread_should_stop()) {
+ if (dev->search_count) {
+ mutex_lock(&dev->mutex);
+ w1_search_process(dev, W1_SEARCH);
+ mutex_unlock(&dev->mutex);
+ }
+
+ try_to_freeze();
+ __set_current_state(TASK_INTERRUPTIBLE);
+
+ if (kthread_should_stop())
+ break;
+
+ /* Only sleep when the search is active. */
+ if (dev->search_count)
+ schedule_timeout(jtime);
+ else
+ schedule();
+ }
+
+ atomic_dec(&dev->refcnt);
+
+ return 0;
+}
+
+static int __init w1_init(void)
+{
+ int retval;
+
+ printk(KERN_INFO "Driver for 1-wire Dallas network protocol.\n");
+
+ w1_init_netlink();
+
+ retval = bus_register(&w1_bus_type);
+ if (retval) {
+ printk(KERN_ERR "Failed to register bus. err=%d.\n", retval);
+ goto err_out_exit_init;
+ }
+
+ retval = driver_register(&w1_master_driver);
+ if (retval) {
+ printk(KERN_ERR
+ "Failed to register master driver. err=%d.\n",
+ retval);
+ goto err_out_bus_unregister;
+ }
+
+ 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;
+ }
+
+ return 0;
+
+#if 0
+/* For undoing the slave register if there was a step after it. */
+err_out_slave_unregister:
+ driver_unregister(&w1_slave_driver);
+#endif
+
+err_out_master_unregister:
+ driver_unregister(&w1_master_driver);
+
+err_out_bus_unregister:
+ bus_unregister(&w1_bus_type);
+
+err_out_exit_init:
+ return retval;
+}
+
+static void __exit w1_fini(void)
+{
+ struct w1_master *dev;
+
+ /* Set netlink removal messages and some cleanup */
+ list_for_each_entry(dev, &w1_masters, w1_master_entry)
+ __w1_remove_master_device(dev);
+
+ w1_fini_netlink();
+
+ driver_unregister(&w1_slave_driver);
+ driver_unregister(&w1_master_driver);
+ bus_unregister(&w1_bus_type);
+}
+
+module_init(w1_init);
+module_exit(w1_fini);
generated by cgit (git 2.34.1) at 2025-02-24 19:04:54 +0000