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![Alexey Khoroshilov](/assets/img/avatar_default.png)
w1_process_callbacks() expects to be called with dev->list_mutex held, but it is the fact only in w1_process(). __w1_remove_master_device() calls w1_process_callbacks() after it releases list_mutex. The patch fixes __w1_remove_master_device() to acquire list_mutex for w1_process_callbacks(). Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Acked-by: David Fries <david@fries.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Cc: stable <stable@vger.kernel.org> # 3.15 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1225 lines
30 KiB
C
1225 lines
30 KiB
C
/*
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* w1.c
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*
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* Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
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*
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/delay.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/list.h>
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#include <linux/interrupt.h>
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#include <linux/spinlock.h>
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#include <linux/timer.h>
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#include <linux/device.h>
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#include <linux/slab.h>
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#include <linux/sched.h>
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#include <linux/kthread.h>
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#include <linux/freezer.h>
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#include <linux/atomic.h>
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#include "w1.h"
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#include "w1_log.h"
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#include "w1_int.h"
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#include "w1_family.h"
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#include "w1_netlink.h"
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
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MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol.");
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static int w1_timeout = 10;
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int w1_max_slave_count = 64;
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int w1_max_slave_ttl = 10;
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module_param_named(timeout, w1_timeout, int, 0);
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MODULE_PARM_DESC(timeout, "time in seconds between automatic slave searches");
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/* A search stops when w1_max_slave_count devices have been found in that
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* search. The next search will start over and detect the same set of devices
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* on a static 1-wire bus. Memory is not allocated based on this number, just
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* on the number of devices known to the kernel. Having a high number does not
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* consume additional resources. As a special case, if there is only one
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* device on the network and w1_max_slave_count is set to 1, the device id can
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* be read directly skipping the normal slower search process.
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*/
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module_param_named(max_slave_count, w1_max_slave_count, int, 0);
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MODULE_PARM_DESC(max_slave_count,
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"maximum number of slaves detected in a search");
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module_param_named(slave_ttl, w1_max_slave_ttl, int, 0);
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MODULE_PARM_DESC(slave_ttl,
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"Number of searches not seeing a slave before it will be removed");
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DEFINE_MUTEX(w1_mlock);
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LIST_HEAD(w1_masters);
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static int w1_master_match(struct device *dev, struct device_driver *drv)
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{
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return 1;
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}
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static int w1_master_probe(struct device *dev)
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{
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return -ENODEV;
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}
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static void w1_master_release(struct device *dev)
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{
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struct w1_master *md = dev_to_w1_master(dev);
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dev_dbg(dev, "%s: Releasing %s.\n", __func__, md->name);
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memset(md, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master));
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kfree(md);
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}
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static void w1_slave_release(struct device *dev)
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{
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struct w1_slave *sl = dev_to_w1_slave(dev);
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dev_dbg(dev, "%s: Releasing %s [%p]\n", __func__, sl->name, sl);
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w1_family_put(sl->family);
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sl->master->slave_count--;
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}
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static ssize_t name_show(struct device *dev, struct device_attribute *attr, char *buf)
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{
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struct w1_slave *sl = dev_to_w1_slave(dev);
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return sprintf(buf, "%s\n", sl->name);
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}
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static DEVICE_ATTR_RO(name);
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static ssize_t id_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct w1_slave *sl = dev_to_w1_slave(dev);
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ssize_t count = sizeof(sl->reg_num);
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memcpy(buf, (u8 *)&sl->reg_num, count);
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return count;
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}
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static DEVICE_ATTR_RO(id);
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static struct attribute *w1_slave_attrs[] = {
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&dev_attr_name.attr,
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&dev_attr_id.attr,
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NULL,
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};
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ATTRIBUTE_GROUPS(w1_slave);
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/* Default family */
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static ssize_t rw_write(struct file *filp, struct kobject *kobj,
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struct bin_attribute *bin_attr, char *buf, loff_t off,
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size_t count)
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{
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struct w1_slave *sl = kobj_to_w1_slave(kobj);
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mutex_lock(&sl->master->mutex);
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if (w1_reset_select_slave(sl)) {
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count = 0;
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goto out_up;
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}
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w1_write_block(sl->master, buf, count);
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out_up:
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mutex_unlock(&sl->master->mutex);
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return count;
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}
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static ssize_t rw_read(struct file *filp, struct kobject *kobj,
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struct bin_attribute *bin_attr, char *buf, loff_t off,
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size_t count)
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{
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struct w1_slave *sl = kobj_to_w1_slave(kobj);
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mutex_lock(&sl->master->mutex);
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w1_read_block(sl->master, buf, count);
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mutex_unlock(&sl->master->mutex);
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return count;
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}
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static BIN_ATTR_RW(rw, PAGE_SIZE);
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static struct bin_attribute *w1_slave_bin_attrs[] = {
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&bin_attr_rw,
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NULL,
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};
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static const struct attribute_group w1_slave_default_group = {
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.bin_attrs = w1_slave_bin_attrs,
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};
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static const struct attribute_group *w1_slave_default_groups[] = {
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&w1_slave_default_group,
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NULL,
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};
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static struct w1_family_ops w1_default_fops = {
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.groups = w1_slave_default_groups,
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};
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static struct w1_family w1_default_family = {
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.fops = &w1_default_fops,
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};
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static int w1_uevent(struct device *dev, struct kobj_uevent_env *env);
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static struct bus_type w1_bus_type = {
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.name = "w1",
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.match = w1_master_match,
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.uevent = w1_uevent,
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};
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struct device_driver w1_master_driver = {
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.name = "w1_master_driver",
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.bus = &w1_bus_type,
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.probe = w1_master_probe,
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};
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struct device w1_master_device = {
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.parent = NULL,
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.bus = &w1_bus_type,
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.init_name = "w1 bus master",
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.driver = &w1_master_driver,
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.release = &w1_master_release
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};
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static struct device_driver w1_slave_driver = {
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.name = "w1_slave_driver",
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.bus = &w1_bus_type,
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};
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#if 0
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struct device w1_slave_device = {
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.parent = NULL,
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.bus = &w1_bus_type,
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.init_name = "w1 bus slave",
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.driver = &w1_slave_driver,
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.release = &w1_slave_release
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};
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#endif /* 0 */
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static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf)
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{
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struct w1_master *md = dev_to_w1_master(dev);
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ssize_t count;
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mutex_lock(&md->mutex);
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count = sprintf(buf, "%s\n", md->name);
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mutex_unlock(&md->mutex);
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return count;
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}
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static ssize_t w1_master_attribute_store_search(struct device * dev,
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struct device_attribute *attr,
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const char * buf, size_t count)
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{
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long tmp;
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struct w1_master *md = dev_to_w1_master(dev);
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int ret;
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ret = kstrtol(buf, 0, &tmp);
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if (ret)
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return ret;
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mutex_lock(&md->mutex);
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md->search_count = tmp;
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mutex_unlock(&md->mutex);
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/* Only wake if it is going to be searching. */
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if (tmp)
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wake_up_process(md->thread);
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return count;
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}
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static ssize_t w1_master_attribute_show_search(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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struct w1_master *md = dev_to_w1_master(dev);
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ssize_t count;
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mutex_lock(&md->mutex);
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count = sprintf(buf, "%d\n", md->search_count);
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mutex_unlock(&md->mutex);
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return count;
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}
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static ssize_t w1_master_attribute_store_pullup(struct device *dev,
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struct device_attribute *attr,
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const char *buf, size_t count)
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{
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long tmp;
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struct w1_master *md = dev_to_w1_master(dev);
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int ret;
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ret = kstrtol(buf, 0, &tmp);
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if (ret)
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return ret;
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mutex_lock(&md->mutex);
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md->enable_pullup = tmp;
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mutex_unlock(&md->mutex);
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return count;
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}
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static ssize_t w1_master_attribute_show_pullup(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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struct w1_master *md = dev_to_w1_master(dev);
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ssize_t count;
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mutex_lock(&md->mutex);
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count = sprintf(buf, "%d\n", md->enable_pullup);
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mutex_unlock(&md->mutex);
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return count;
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}
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static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf)
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{
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struct w1_master *md = dev_to_w1_master(dev);
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ssize_t count;
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mutex_lock(&md->mutex);
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count = sprintf(buf, "0x%p\n", md->bus_master);
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mutex_unlock(&md->mutex);
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return count;
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}
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static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct device_attribute *attr, char *buf)
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{
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ssize_t count;
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count = sprintf(buf, "%d\n", w1_timeout);
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return count;
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}
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static ssize_t w1_master_attribute_store_max_slave_count(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t count)
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{
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int tmp;
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struct w1_master *md = dev_to_w1_master(dev);
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if (kstrtoint(buf, 0, &tmp) == -EINVAL || tmp < 1)
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return -EINVAL;
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mutex_lock(&md->mutex);
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md->max_slave_count = tmp;
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/* allow each time the max_slave_count is updated */
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clear_bit(W1_WARN_MAX_COUNT, &md->flags);
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mutex_unlock(&md->mutex);
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return count;
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}
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static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
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{
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struct w1_master *md = dev_to_w1_master(dev);
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ssize_t count;
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mutex_lock(&md->mutex);
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count = sprintf(buf, "%d\n", md->max_slave_count);
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mutex_unlock(&md->mutex);
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return count;
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}
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static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct device_attribute *attr, char *buf)
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{
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struct w1_master *md = dev_to_w1_master(dev);
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ssize_t count;
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mutex_lock(&md->mutex);
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count = sprintf(buf, "%lu\n", md->attempts);
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mutex_unlock(&md->mutex);
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return count;
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}
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static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
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{
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struct w1_master *md = dev_to_w1_master(dev);
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ssize_t count;
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mutex_lock(&md->mutex);
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count = sprintf(buf, "%d\n", md->slave_count);
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mutex_unlock(&md->mutex);
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return count;
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}
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static ssize_t w1_master_attribute_show_slaves(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct w1_master *md = dev_to_w1_master(dev);
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int c = PAGE_SIZE;
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struct list_head *ent, *n;
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struct w1_slave *sl = NULL;
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mutex_lock(&md->list_mutex);
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list_for_each_safe(ent, n, &md->slist) {
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sl = list_entry(ent, struct w1_slave, w1_slave_entry);
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c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
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}
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if (!sl)
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c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
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mutex_unlock(&md->list_mutex);
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return PAGE_SIZE - c;
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}
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static ssize_t w1_master_attribute_show_add(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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int c = PAGE_SIZE;
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c -= snprintf(buf+PAGE_SIZE - c, c,
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"write device id xx-xxxxxxxxxxxx to add slave\n");
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return PAGE_SIZE - c;
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}
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static int w1_atoreg_num(struct device *dev, const char *buf, size_t count,
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struct w1_reg_num *rn)
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{
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unsigned int family;
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unsigned long long id;
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int i;
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u64 rn64_le;
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/* The CRC value isn't read from the user because the sysfs directory
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* doesn't include it and most messages from the bus search don't
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* print it either. It would be unreasonable for the user to then
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* provide it.
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*/
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const char *error_msg = "bad slave string format, expecting "
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"ff-dddddddddddd\n";
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if (buf[2] != '-') {
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dev_err(dev, "%s", error_msg);
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return -EINVAL;
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}
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i = sscanf(buf, "%02x-%012llx", &family, &id);
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if (i != 2) {
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dev_err(dev, "%s", error_msg);
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return -EINVAL;
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}
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rn->family = family;
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rn->id = id;
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rn64_le = cpu_to_le64(*(u64 *)rn);
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rn->crc = w1_calc_crc8((u8 *)&rn64_le, 7);
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#if 0
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dev_info(dev, "With CRC device is %02x.%012llx.%02x.\n",
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rn->family, (unsigned long long)rn->id, rn->crc);
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#endif
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return 0;
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}
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/* Searches the slaves in the w1_master and returns a pointer or NULL.
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* Note: must not hold list_mutex
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*/
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struct w1_slave *w1_slave_search_device(struct w1_master *dev,
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struct w1_reg_num *rn)
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{
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struct w1_slave *sl;
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mutex_lock(&dev->list_mutex);
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list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
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if (sl->reg_num.family == rn->family &&
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sl->reg_num.id == rn->id &&
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sl->reg_num.crc == rn->crc) {
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mutex_unlock(&dev->list_mutex);
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return sl;
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}
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}
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mutex_unlock(&dev->list_mutex);
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return NULL;
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}
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static ssize_t w1_master_attribute_store_add(struct device *dev,
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struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct w1_master *md = dev_to_w1_master(dev);
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struct w1_reg_num rn;
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struct w1_slave *sl;
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ssize_t result = count;
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if (w1_atoreg_num(dev, buf, count, &rn))
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return -EINVAL;
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mutex_lock(&md->mutex);
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sl = w1_slave_search_device(md, &rn);
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/* It would be nice to do a targeted search one the one-wire bus
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* for the new device to see if it is out there or not. But the
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* current search doesn't support that.
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*/
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if (sl) {
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dev_info(dev, "Device %s already exists\n", sl->name);
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result = -EINVAL;
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} else {
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w1_attach_slave_device(md, &rn);
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}
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mutex_unlock(&md->mutex);
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return result;
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}
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static ssize_t w1_master_attribute_show_remove(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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int c = PAGE_SIZE;
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c -= snprintf(buf+PAGE_SIZE - c, c,
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"write device id xx-xxxxxxxxxxxx to remove slave\n");
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return PAGE_SIZE - c;
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}
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|
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) {
|
|
result = w1_slave_detach(sl);
|
|
/* refcnt 0 means it was detached in the call */
|
|
if (result == 0)
|
|
result = count;
|
|
} 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_RW(max_slave_count, S_IRUGO | S_IWUSR | S_IWGRP);
|
|
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);
|
|
}
|
|
|
|
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 = 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_name(dev));
|
|
|
|
if (dev->driver != &w1_slave_driver || !sl)
|
|
goto end;
|
|
|
|
err = add_uevent_var(env, "W1_FID=%02X", sl->reg_num.family);
|
|
if (err)
|
|
goto end;
|
|
|
|
err = add_uevent_var(env, "W1_SLAVE_ID=%024LX",
|
|
(unsigned long long)sl->reg_num.id);
|
|
end:
|
|
return err;
|
|
}
|
|
|
|
static int w1_family_notify(unsigned long action, struct w1_slave *sl)
|
|
{
|
|
struct w1_family_ops *fops;
|
|
int err;
|
|
|
|
fops = sl->family->fops;
|
|
|
|
if (!fops)
|
|
return 0;
|
|
|
|
switch (action) {
|
|
case BUS_NOTIFY_ADD_DEVICE:
|
|
/* if the family driver needs to initialize something... */
|
|
if (fops->add_slave) {
|
|
err = fops->add_slave(sl);
|
|
if (err < 0) {
|
|
dev_err(&sl->dev,
|
|
"add_slave() call failed. err=%d\n",
|
|
err);
|
|
return err;
|
|
}
|
|
}
|
|
if (fops->groups) {
|
|
err = sysfs_create_groups(&sl->dev.kobj, fops->groups);
|
|
if (err) {
|
|
dev_err(&sl->dev,
|
|
"sysfs group creation failed. err=%d\n",
|
|
err);
|
|
return err;
|
|
}
|
|
}
|
|
|
|
break;
|
|
case BUS_NOTIFY_DEL_DEVICE:
|
|
if (fops->remove_slave)
|
|
sl->family->fops->remove_slave(sl);
|
|
if (fops->groups)
|
|
sysfs_remove_groups(&sl->dev.kobj, fops->groups);
|
|
break;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
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;
|
|
sl->dev.groups = w1_slave_groups;
|
|
|
|
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);
|
|
|
|
/* suppress for w1_family_notify before sending KOBJ_ADD */
|
|
dev_set_uevent_suppress(&sl->dev, true);
|
|
|
|
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;
|
|
}
|
|
w1_family_notify(BUS_NOTIFY_ADD_DEVICE, sl);
|
|
|
|
dev_set_uevent_suppress(&sl->dev, false);
|
|
kobject_uevent(&sl->dev.kobj, KOBJ_ADD);
|
|
|
|
mutex_lock(&sl->master->list_mutex);
|
|
list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
|
|
mutex_unlock(&sl->master->list_mutex);
|
|
|
|
return 0;
|
|
}
|
|
|
|
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, &sl->flags);
|
|
|
|
memset(&msg, 0, sizeof(msg));
|
|
memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
|
|
atomic_set(&sl->refcnt, 1);
|
|
atomic_inc(&sl->master->refcnt);
|
|
|
|
/* slave modules need to be loaded in a context with unlocked mutex */
|
|
mutex_unlock(&dev->mutex);
|
|
request_module("w1-family-0x%0x", rn->family);
|
|
mutex_lock(&dev->mutex);
|
|
|
|
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;
|
|
}
|
|
|
|
int w1_unref_slave(struct w1_slave *sl)
|
|
{
|
|
struct w1_master *dev = sl->master;
|
|
int refcnt;
|
|
mutex_lock(&dev->list_mutex);
|
|
refcnt = atomic_sub_return(1, &sl->refcnt);
|
|
if (refcnt == 0) {
|
|
struct w1_netlink_msg msg;
|
|
|
|
dev_dbg(&sl->dev, "%s: detaching %s [%p].\n", __func__,
|
|
sl->name, sl);
|
|
|
|
list_del(&sl->w1_slave_entry);
|
|
|
|
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);
|
|
|
|
w1_family_notify(BUS_NOTIFY_DEL_DEVICE, sl);
|
|
device_unregister(&sl->dev);
|
|
#ifdef DEBUG
|
|
memset(sl, 0, sizeof(*sl));
|
|
#endif
|
|
kfree(sl);
|
|
}
|
|
atomic_dec(&dev->refcnt);
|
|
mutex_unlock(&dev->list_mutex);
|
|
return refcnt;
|
|
}
|
|
|
|
int w1_slave_detach(struct w1_slave *sl)
|
|
{
|
|
/* Only detach a slave once as it decreases the refcnt each time. */
|
|
int destroy_now;
|
|
mutex_lock(&sl->master->list_mutex);
|
|
destroy_now = !test_bit(W1_SLAVE_DETACH, &sl->flags);
|
|
set_bit(W1_SLAVE_DETACH, &sl->flags);
|
|
mutex_unlock(&sl->master->list_mutex);
|
|
|
|
if (destroy_now)
|
|
destroy_now = !w1_unref_slave(sl);
|
|
return destroy_now ? 0 : -EBUSY;
|
|
}
|
|
|
|
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->list_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->list_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);
|
|
mutex_lock(&dev->list_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;
|
|
|
|
mutex_unlock(&dev->list_mutex);
|
|
memcpy(&rn, &sl->reg_num, sizeof(rn));
|
|
/* If it was already in use let the automatic
|
|
* scan pick it up again later.
|
|
*/
|
|
if (!w1_slave_detach(sl))
|
|
w1_attach_slave_device(dev, &rn);
|
|
mutex_lock(&dev->list_mutex);
|
|
}
|
|
}
|
|
dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
|
|
"has been finished.\n", dev->name);
|
|
mutex_unlock(&dev->list_mutex);
|
|
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, &sl->flags);
|
|
} else {
|
|
if (rn && tmp->crc == w1_calc_crc8((u8 *)&rn_le, 7))
|
|
w1_attach_slave_device(dev, tmp);
|
|
}
|
|
|
|
atomic_dec(&dev->refcnt);
|
|
}
|
|
|
|
/**
|
|
* w1_search() - Performs a ROM Search & registers any devices found.
|
|
* @dev: The master device to search
|
|
* @search_type: W1_SEARCH to search all devices, or W1_ALARM_SEARCH
|
|
* to return only devices in the alarmed state
|
|
* @cb: Function to call when a device is 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
|
|
*
|
|
*/
|
|
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 = dev->search_id;
|
|
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.
|
|
*/
|
|
mutex_lock(&dev->bus_mutex);
|
|
if (w1_reset_bus(dev)) {
|
|
mutex_unlock(&dev->bus_mutex);
|
|
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) {
|
|
int rv;
|
|
w1_write_8(dev, W1_READ_ROM);
|
|
rv = w1_read_block(dev, (u8 *)&rn, 8);
|
|
mutex_unlock(&dev->bus_mutex);
|
|
|
|
if (rv == 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 (test_bit(W1_ABORT_SEARCH, &dev->flags)) {
|
|
mutex_unlock(&dev->bus_mutex);
|
|
dev_dbg(&dev->dev, "Abort w1_search\n");
|
|
return;
|
|
}
|
|
}
|
|
mutex_unlock(&dev->bus_mutex);
|
|
|
|
if ( (triplet_ret & 0x03) != 0x03 ) {
|
|
if ((desc_bit == last_zero) || (last_zero < 0)) {
|
|
last_device = 1;
|
|
dev->search_id = 0;
|
|
} else {
|
|
dev->search_id = rn;
|
|
}
|
|
desc_bit = last_zero;
|
|
cb(dev, rn);
|
|
}
|
|
|
|
if (!last_device && slave_count == dev->max_slave_count &&
|
|
!test_bit(W1_WARN_MAX_COUNT, &dev->flags)) {
|
|
/* Only max_slave_count will be scanned in a search,
|
|
* but it will start where it left off next search
|
|
* until all ids are identified and then it will start
|
|
* over. A continued search will report the previous
|
|
* last id as the first id (provided it is still on the
|
|
* bus).
|
|
*/
|
|
dev_info(&dev->dev, "%s: max_slave_count %d reached, "
|
|
"will continue next search.\n", __func__,
|
|
dev->max_slave_count);
|
|
set_bit(W1_WARN_MAX_COUNT, &dev->flags);
|
|
}
|
|
}
|
|
}
|
|
|
|
void w1_search_process_cb(struct w1_master *dev, u8 search_type,
|
|
w1_slave_found_callback cb)
|
|
{
|
|
struct w1_slave *sl, *sln;
|
|
|
|
mutex_lock(&dev->list_mutex);
|
|
list_for_each_entry(sl, &dev->slist, w1_slave_entry)
|
|
clear_bit(W1_SLAVE_ACTIVE, &sl->flags);
|
|
mutex_unlock(&dev->list_mutex);
|
|
|
|
w1_search_devices(dev, search_type, cb);
|
|
|
|
mutex_lock(&dev->list_mutex);
|
|
list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
|
|
if (!test_bit(W1_SLAVE_ACTIVE, &sl->flags) && !--sl->ttl) {
|
|
mutex_unlock(&dev->list_mutex);
|
|
w1_slave_detach(sl);
|
|
mutex_lock(&dev->list_mutex);
|
|
}
|
|
else if (test_bit(W1_SLAVE_ACTIVE, &sl->flags))
|
|
sl->ttl = dev->slave_ttl;
|
|
}
|
|
mutex_unlock(&dev->list_mutex);
|
|
|
|
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);
|
|
}
|
|
|
|
/**
|
|
* w1_process_callbacks() - execute each dev->async_list callback entry
|
|
* @dev: w1_master device
|
|
*
|
|
* The w1 master list_mutex must be held.
|
|
*
|
|
* Return: 1 if there were commands to executed 0 otherwise
|
|
*/
|
|
int w1_process_callbacks(struct w1_master *dev)
|
|
{
|
|
int ret = 0;
|
|
struct w1_async_cmd *async_cmd, *async_n;
|
|
|
|
/* The list can be added to in another thread, loop until it is empty */
|
|
while (!list_empty(&dev->async_list)) {
|
|
list_for_each_entry_safe(async_cmd, async_n, &dev->async_list,
|
|
async_entry) {
|
|
/* drop the lock, if it is a search it can take a long
|
|
* time */
|
|
mutex_unlock(&dev->list_mutex);
|
|
async_cmd->cb(dev, async_cmd);
|
|
ret = 1;
|
|
mutex_lock(&dev->list_mutex);
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
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);
|
|
/* remainder if it woke up early */
|
|
unsigned long jremain = 0;
|
|
|
|
for (;;) {
|
|
|
|
if (!jremain && dev->search_count) {
|
|
mutex_lock(&dev->mutex);
|
|
w1_search_process(dev, W1_SEARCH);
|
|
mutex_unlock(&dev->mutex);
|
|
}
|
|
|
|
mutex_lock(&dev->list_mutex);
|
|
/* Note, w1_process_callback drops the lock while processing,
|
|
* but locks it again before returning.
|
|
*/
|
|
if (!w1_process_callbacks(dev) && jremain) {
|
|
/* a wake up is either to stop the thread, process
|
|
* callbacks, or search, it isn't process callbacks, so
|
|
* schedule a search.
|
|
*/
|
|
jremain = 1;
|
|
}
|
|
|
|
try_to_freeze();
|
|
__set_current_state(TASK_INTERRUPTIBLE);
|
|
|
|
/* hold list_mutex until after interruptible to prevent loosing
|
|
* the wakeup signal when async_cmd is added.
|
|
*/
|
|
mutex_unlock(&dev->list_mutex);
|
|
|
|
if (kthread_should_stop())
|
|
break;
|
|
|
|
/* Only sleep when the search is active. */
|
|
if (dev->search_count) {
|
|
if (!jremain)
|
|
jremain = jtime;
|
|
jremain = schedule_timeout(jremain);
|
|
}
|
|
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 slave 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);
|