diff options
Diffstat (limited to 'drivers/w1/w1.c')
| -rw-r--r-- | drivers/w1/w1.c | 661 |
1 files changed, 432 insertions, 229 deletions
diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c index 0459df843c58..002d2639aa12 100644 --- a/drivers/w1/w1.c +++ b/drivers/w1/w1.c @@ -1,22 +1,6 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* - * 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> @@ -32,37 +16,48 @@ #include <linux/sched.h> #include <linux/kthread.h> #include <linux/freezer.h> +#include <linux/hwmon.h> +#include <linux/of.h> #include <linux/atomic.h> -#include "w1.h" -#include "w1_log.h" -#include "w1_int.h" -#include "w1_family.h" +#include "w1_internal.h" #include "w1_netlink.h" -MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>"); -MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol."); +#define W1_FAMILY_DEFAULT 0 +#define W1_FAMILY_DS28E04 0x1C /* for crc quirk */ -static int w1_timeout = 10; -int w1_max_slave_count = 10; -int w1_max_slave_ttl = 10; +static int w1_timeout = 10; module_param_named(timeout, w1_timeout, int, 0); +MODULE_PARM_DESC(timeout, "time in seconds between automatic slave searches"); + +static int w1_timeout_us; +module_param_named(timeout_us, w1_timeout_us, int, 0); +MODULE_PARM_DESC(timeout_us, + "time in microseconds between automatic slave searches"); + +/* A search stops when w1_max_slave_count devices have been found in that + * search. The next search will start over and detect the same set of devices + * on a static 1-wire bus. Memory is not allocated based on this number, just + * on the number of devices known to the kernel. Having a high number does not + * consume additional resources. As a special case, if there is only one + * device on the network and w1_max_slave_count is set to 1, the device id can + * be read directly skipping the normal slower search process. + */ +int w1_max_slave_count = 64; module_param_named(max_slave_count, w1_max_slave_count, int, 0); +MODULE_PARM_DESC(max_slave_count, + "maximum number of slaves detected in a search"); + +int w1_max_slave_ttl = 10; module_param_named(slave_ttl, w1_max_slave_ttl, int, 0); +MODULE_PARM_DESC(slave_ttl, + "Number of searches not seeing a slave before it will be removed"); DEFINE_MUTEX(w1_mlock); LIST_HEAD(w1_masters); -static int w1_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; @@ -81,29 +76,21 @@ 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); - } + dev_dbg(dev, "%s: Releasing %s [%p]\n", __func__, sl->name, sl); 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) +static ssize_t name_show(struct device *dev, struct device_attribute *attr, char *buf) { struct w1_slave *sl = dev_to_w1_slave(dev); - return sprintf(buf, "%s\n", sl->name); + return sysfs_emit(buf, "%s\n", sl->name); } +static DEVICE_ATTR_RO(name); -static ssize_t w1_slave_read_id(struct device *dev, +static ssize_t id_show(struct device *dev, struct device_attribute *attr, char *buf) { struct w1_slave *sl = dev_to_w1_slave(dev); @@ -112,17 +99,20 @@ static ssize_t w1_slave_read_id(struct device *dev, memcpy(buf, (u8 *)&sl->reg_num, count); return count; } +static DEVICE_ATTR_RO(id); -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); +static struct attribute *w1_slave_attrs[] = { + &dev_attr_name.attr, + &dev_attr_id.attr, + NULL, +}; +ATTRIBUTE_GROUPS(w1_slave); /* 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) +static ssize_t rw_write(struct file *filp, struct kobject *kobj, + const struct bin_attribute *bin_attr, char *buf, loff_t off, + size_t count) { struct w1_slave *sl = kobj_to_w1_slave(kobj); @@ -139,9 +129,9 @@ out_up: 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) +static ssize_t rw_read(struct file *filp, struct kobject *kobj, + const struct bin_attribute *bin_attr, char *buf, + loff_t off, size_t count) { struct w1_slave *sl = kobj_to_w1_slave(kobj); @@ -151,40 +141,34 @@ static ssize_t w1_default_read(struct file *filp, struct kobject *kobj, 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 const BIN_ATTR_RW(rw, PAGE_SIZE); + +static const struct bin_attribute *const w1_slave_bin_attrs[] = { + &bin_attr_rw, + NULL, }; -static int w1_default_add_slave(struct w1_slave *sl) -{ - return sysfs_create_bin_file(&sl->dev.kobj, &w1_default_attr); -} +static const struct attribute_group w1_slave_default_group = { + .bin_attrs = w1_slave_bin_attrs, +}; -static void w1_default_remove_slave(struct w1_slave *sl) -{ - sysfs_remove_bin_file(&sl->dev.kobj, &w1_default_attr); -} +static const struct attribute_group *w1_slave_default_groups[] = { + &w1_slave_default_group, + NULL, +}; -static struct w1_family_ops w1_default_fops = { - .add_slave = w1_default_add_slave, - .remove_slave = w1_default_remove_slave, +static const struct w1_family_ops w1_default_fops = { + .groups = w1_slave_default_groups, }; static struct w1_family w1_default_family = { .fops = &w1_default_fops, }; -static int w1_uevent(struct device *dev, struct kobj_uevent_env *env); +static int w1_uevent(const struct device *dev, struct kobj_uevent_env *env); -static struct bus_type w1_bus_type = { +static const struct bus_type w1_bus_type = { .name = "w1", - .match = w1_master_match, .uevent = w1_uevent, }; @@ -223,7 +207,7 @@ static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_a ssize_t count; mutex_lock(&md->mutex); - count = sprintf(buf, "%s\n", md->name); + count = sysfs_emit(buf, "%s\n", md->name); mutex_unlock(&md->mutex); return count; @@ -235,14 +219,18 @@ static ssize_t w1_master_attribute_store_search(struct device * dev, { long tmp; struct w1_master *md = dev_to_w1_master(dev); + int ret; - if (strict_strtol(buf, 0, &tmp) == -EINVAL) - return -EINVAL; + ret = kstrtol(buf, 0, &tmp); + if (ret) + return ret; mutex_lock(&md->mutex); md->search_count = tmp; mutex_unlock(&md->mutex); - wake_up_process(md->thread); + /* Only wake if it is going to be searching. */ + if (tmp) + wake_up_process(md->thread); return count; } @@ -255,7 +243,7 @@ static ssize_t w1_master_attribute_show_search(struct device *dev, ssize_t count; mutex_lock(&md->mutex); - count = sprintf(buf, "%d\n", md->search_count); + count = sysfs_emit(buf, "%d\n", md->search_count); mutex_unlock(&md->mutex); return count; @@ -267,14 +255,15 @@ static ssize_t w1_master_attribute_store_pullup(struct device *dev, { long tmp; struct w1_master *md = dev_to_w1_master(dev); + int ret; - if (strict_strtol(buf, 0, &tmp) == -EINVAL) - return -EINVAL; + ret = kstrtol(buf, 0, &tmp); + if (ret) + return ret; mutex_lock(&md->mutex); md->enable_pullup = tmp; mutex_unlock(&md->mutex); - wake_up_process(md->thread); return count; } @@ -287,7 +276,7 @@ static ssize_t w1_master_attribute_show_pullup(struct device *dev, ssize_t count; mutex_lock(&md->mutex); - count = sprintf(buf, "%d\n", md->enable_pullup); + count = sysfs_emit(buf, "%d\n", md->enable_pullup); mutex_unlock(&md->mutex); return count; @@ -299,15 +288,37 @@ static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct devic ssize_t count; mutex_lock(&md->mutex); - count = sprintf(buf, "0x%p\n", md->bus_master); + count = sysfs_emit(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 sysfs_emit(buf, "%d\n", w1_timeout); +} + +static ssize_t w1_master_attribute_show_timeout_us(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%d\n", w1_timeout_us); +} + +static ssize_t w1_master_attribute_store_max_slave_count(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + int tmp; + struct w1_master *md = dev_to_w1_master(dev); + + if (kstrtoint(buf, 0, &tmp) || tmp < 1) + return -EINVAL; + + mutex_lock(&md->mutex); + md->max_slave_count = tmp; + /* allow each time the max_slave_count is updated */ + clear_bit(W1_WARN_MAX_COUNT, &md->flags); + mutex_unlock(&md->mutex); + return count; } @@ -317,7 +328,7 @@ static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, stru ssize_t count; mutex_lock(&md->mutex); - count = sprintf(buf, "%d\n", md->max_slave_count); + count = sysfs_emit(buf, "%d\n", md->max_slave_count); mutex_unlock(&md->mutex); return count; } @@ -328,7 +339,7 @@ static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct devi ssize_t count; mutex_lock(&md->mutex); - count = sprintf(buf, "%lu\n", md->attempts); + count = sysfs_emit(buf, "%lu\n", md->attempts); mutex_unlock(&md->mutex); return count; } @@ -339,7 +350,7 @@ static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct d ssize_t count; mutex_lock(&md->mutex); - count = sprintf(buf, "%d\n", md->slave_count); + count = sysfs_emit(buf, "%d\n", md->slave_count); mutex_unlock(&md->mutex); return count; } @@ -349,23 +360,20 @@ static ssize_t w1_master_attribute_show_slaves(struct device *dev, { struct w1_master *md = dev_to_w1_master(dev); int c = PAGE_SIZE; + struct list_head *ent, *n; + struct w1_slave *sl = NULL; - 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; + mutex_lock(&md->list_mutex); - list_for_each_safe(ent, n, &md->slist) { - sl = list_entry(ent, struct w1_slave, w1_slave_entry); + 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); } + if (!sl) + c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n"); - mutex_unlock(&md->mutex); + mutex_unlock(&md->list_mutex); return PAGE_SIZE - c; } @@ -419,19 +427,22 @@ static int w1_atoreg_num(struct device *dev, const char *buf, size_t count, } /* Searches the slaves in the w1_master and returns a pointer or NULL. - * Note: must hold the mutex + * Note: must not hold list_mutex */ -static struct w1_slave *w1_slave_search_device(struct w1_master *dev, +struct w1_slave *w1_slave_search_device(struct w1_master *dev, struct w1_reg_num *rn) { struct w1_slave *sl; + mutex_lock(&dev->list_mutex); 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) { + mutex_unlock(&dev->list_mutex); return sl; } } + mutex_unlock(&dev->list_mutex); return NULL; } @@ -480,7 +491,7 @@ static ssize_t w1_master_attribute_store_remove(struct device *dev, struct w1_master *md = dev_to_w1_master(dev); struct w1_reg_num rn; struct w1_slave *sl; - ssize_t result = count; + ssize_t result; if (w1_atoreg_num(dev, buf, count, &rn)) return -EINVAL; @@ -488,9 +499,12 @@ static ssize_t w1_master_attribute_store_remove(struct device *dev, mutex_lock(&md->mutex); sl = w1_slave_search_device(md, &rn); if (sl) { - w1_slave_detach(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, + dev_info(dev, "Device %02x-%012llx doesn't exist\n", rn.family, (unsigned long long)rn.id); result = -EINVAL; } @@ -513,9 +527,10 @@ static ssize_t w1_master_attribute_store_remove(struct device *dev, 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_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(timeout_us, 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); @@ -529,6 +544,7 @@ static struct attribute *w1_master_default_attrs[] = { &w1_master_attribute_max_slave_count.attr, &w1_master_attribute_attempts.attr, &w1_master_attribute_timeout.attr, + &w1_master_attribute_timeout_us.attr, &w1_master_attribute_pointer.attr, &w1_master_attribute_search.attr, &w1_master_attribute_pullup.attr, @@ -537,7 +553,7 @@ static struct attribute *w1_master_default_attrs[] = { NULL }; -static struct attribute_group w1_master_defattr_group = { +static const struct attribute_group w1_master_defattr_group = { .attrs = w1_master_default_attrs, }; @@ -551,11 +567,11 @@ 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) +static int w1_uevent(const struct device *dev, struct kobj_uevent_env *env) { - struct w1_master *md = NULL; - struct w1_slave *sl = NULL; - char *event_owner, *name; + const struct w1_master *md = NULL; + const struct w1_slave *sl = NULL; + const char *event_owner, *name; int err = 0; if (dev->driver == &w1_master_driver) { @@ -587,6 +603,64 @@ end: return err; } +static int w1_family_notify(unsigned long action, struct w1_slave *sl) +{ + const 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; + } + } + if (IS_REACHABLE(CONFIG_HWMON) && fops->chip_info) { + struct device *hwmon + = hwmon_device_register_with_info(&sl->dev, + "w1_slave_temp", sl, + fops->chip_info, + NULL); + if (IS_ERR(hwmon)) { + dev_warn(&sl->dev, + "could not create hwmon device\n"); + } else { + sl->hwmon = hwmon; + } + } + break; + case BUS_NOTIFY_DEL_DEVICE: + if (IS_REACHABLE(CONFIG_HWMON) && fops->chip_info && + sl->hwmon) + hwmon_device_unregister(sl->hwmon); + 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; @@ -595,6 +669,9 @@ static int __w1_attach_slave_device(struct w1_slave *sl) sl->dev.driver = &w1_slave_driver; sl->dev.bus = &w1_bus_type; sl->dev.release = &w1_slave_release; + sl->dev.groups = w1_slave_groups; + sl->dev.of_node = of_find_matching_node(sl->master->dev.of_node, + sl->family->of_match_table); dev_set_name(&sl->dev, "%02x-%012llx", (unsigned int) sl->reg_num.family, @@ -607,55 +684,31 @@ static int __w1_attach_slave_device(struct w1_slave *sl) 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); + of_node_put(sl->dev.of_node); + put_device(&sl->dev); return err; } + w1_family_notify(BUS_NOTIFY_ADD_DEVICE, sl); - /* 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; - } + 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; - -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) +int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn) { struct w1_slave *sl; struct w1_family *f; @@ -673,14 +726,20 @@ static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn) sl->owner = THIS_MODULE; sl->master = dev; - set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags); + 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, 0); - init_completion(&sl->released); + atomic_set(&sl->refcnt, 1); + atomic_inc(&sl->master->refcnt); + dev->slave_count++; + dev_info(&dev->dev, "Attaching one wire slave %02x.%012llx crc %02x\n", + rn->family, (unsigned long long)rn->id, rn->crc); - request_module("w1-family-0x%0x", rn->family); + /* slave modules need to be loaded in a context with unlocked mutex */ + mutex_unlock(&dev->mutex); + request_module("w1-family-0x%02X", rn->family); + mutex_lock(&dev->mutex); spin_lock(&w1_flock); f = w1_family_registered(rn->family); @@ -695,18 +754,18 @@ static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn) sl->family = f; - err = __w1_attach_slave_device(sl); if (err < 0) { dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__, sl->name); + dev->slave_count--; w1_family_put(sl->family); + atomic_dec(&sl->master->refcnt); 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; @@ -715,75 +774,94 @@ static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn) return 0; } -void w1_slave_detach(struct w1_slave *sl) +int w1_unref_slave(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); + 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; +} - wait_for_completion(&sl->released); - kfree(sl); +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; + struct w1_master *dev = NULL, *iter; mutex_lock(&w1_mlock); - list_for_each_entry(dev, &w1_masters, w1_master_entry) { - if (dev->id == id) { - found = 1; - atomic_inc(&dev->refcnt); + list_for_each_entry(iter, &w1_masters, w1_master_entry) { + if (iter->id == id) { + dev = iter; + atomic_inc(&iter->refcnt); break; } } mutex_unlock(&w1_mlock); - return (found)?dev:NULL; + return dev; } struct w1_slave *w1_search_slave(struct w1_reg_num *id) { struct w1_master *dev; - struct w1_slave *sl = NULL; - int found = 0; + struct w1_slave *sl = NULL, *iter; 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; + mutex_lock(&dev->list_mutex); + list_for_each_entry(iter, &dev->slist, w1_slave_entry) { + if (iter->reg_num.family == id->family && + iter->reg_num.id == id->id && + iter->reg_num.crc == id->crc) { + sl = iter; atomic_inc(&dev->refcnt); - atomic_inc(&sl->refcnt); + atomic_inc(&iter->refcnt); break; } } - mutex_unlock(&dev->mutex); + mutex_unlock(&dev->list_mutex); - if (found) + if (sl) break; } mutex_unlock(&w1_mlock); - return (found)?sl:NULL; + return sl; } void w1_reconnect_slaves(struct w1_family *f, int attach) @@ -796,6 +874,7 @@ void w1_reconnect_slaves(struct w1_family *f, int attach) 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 @@ -807,24 +886,62 @@ void w1_reconnect_slaves(struct w1_family *f, int attach) (!attach && sl->family->fid == f->fid)) { struct w1_reg_num rn; + mutex_unlock(&dev->list_mutex); memcpy(&rn, &sl->reg_num, sizeof(rn)); - w1_slave_detach(sl); - - w1_attach_slave_device(dev, &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); } +static int w1_addr_crc_is_valid(struct w1_master *dev, u64 rn) +{ + u64 rn_le = cpu_to_le64(rn); + struct w1_reg_num *tmp = (struct w1_reg_num *)&rn; + u8 crc; + + crc = w1_calc_crc8((u8 *)&rn_le, 7); + + /* quirk: + * DS28E04 (1w eeprom) has strapping pins to change + * address, but will not update the crc. So normal rules + * for consistent w1 addresses are violated. We test + * with the 7 LSBs of the address forced high. + * + * (char*)&rn_le = { family, addr_lsb, ..., addr_msb, crc }. + */ + if (crc != tmp->crc && tmp->family == W1_FAMILY_DS28E04) { + u64 corr_le = rn_le; + + ((u8 *)&corr_le)[1] |= 0x7f; + crc = w1_calc_crc8((u8 *)&corr_le, 7); + + dev_info(&dev->dev, "DS28E04 crc workaround on %02x.%012llx.%02x\n", + tmp->family, (unsigned long long)tmp->id, tmp->crc); + } + + if (crc != tmp->crc) { + dev_dbg(&dev->dev, "w1 addr crc mismatch: %02x.%012llx.%02x != 0x%02x.\n", + tmp->family, (unsigned long long)tmp->id, tmp->crc, crc); + return 0; + } + return 1; +} + 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); @@ -832,9 +949,9 @@ void w1_slave_found(struct w1_master *dev, u64 rn) sl = w1_slave_search_device(dev, tmp); if (sl) { - set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags); + set_bit(W1_SLAVE_ACTIVE, &sl->flags); } else { - if (rn && tmp->crc == w1_calc_crc8((u8 *)&rn_le, 7)) + if (rn && w1_addr_crc_is_valid(dev, rn)) w1_attach_slave_device(dev, tmp); } @@ -842,7 +959,12 @@ void w1_slave_found(struct w1_master *dev, u64 rn) } /** - * Performs a ROM Search & registers any devices found. + * 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. @@ -852,8 +974,6 @@ void w1_slave_found(struct w1_master *dev, u64 rn) * * 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) { @@ -864,7 +984,8 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb u8 triplet_ret = 0; search_bit = 0; - rn = last_rn = 0; + rn = dev->search_id; + last_rn = 0; last_device = 0; last_zero = -1; @@ -911,7 +1032,7 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb else search_bit = ((last_rn >> i) & 0x1); - /** Read two bits and write one bit */ + /* Read two bits and write one bit */ triplet_ret = w1_triplet(dev, search_bit); /* quit if no device responded */ @@ -926,8 +1047,7 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb tmp64 = (triplet_ret >> 2); rn |= (tmp64 << i); - /* ensure we're called from kthread and not by netlink callback */ - if (!dev->priv && kthread_should_stop()) { + if (test_bit(W1_ABORT_SEARCH, &dev->flags)) { mutex_unlock(&dev->bus_mutex); dev_dbg(&dev->dev, "Abort w1_search\n"); return; @@ -936,11 +1056,30 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb mutex_unlock(&dev->bus_mutex); if ( (triplet_ret & 0x03) != 0x03 ) { - if ( (desc_bit == last_zero) || (last_zero < 0)) + 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); + } } } @@ -949,17 +1088,24 @@ void w1_search_process_cb(struct w1_master *dev, u8 search_type, { 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, (long *)&sl->flags); + 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, (unsigned long *)&sl->flags) && !--sl->ttl) + if (!test_bit(W1_SLAVE_ACTIVE, &sl->flags) && !--sl->ttl) { + mutex_unlock(&dev->list_mutex); w1_slave_detach(sl); - else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags)) + 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--; @@ -970,30 +1116,85 @@ 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); + const unsigned long jtime = + usecs_to_jiffies(w1_timeout * 1000000 + w1_timeout_us); + /* remainder if it woke up early */ + unsigned long jremain = 0; - while (!kthread_should_stop()) { - if (dev->search_count) { + atomic_inc(&dev->refcnt); + + for (;;) { + + if (!jremain && dev->search_count) { mutex_lock(&dev->mutex); w1_search_process(dev, W1_SEARCH); mutex_unlock(&dev->mutex); } - try_to_freeze(); + 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; + } + __set_current_state(TASK_INTERRUPTIBLE); - if (kthread_should_stop()) + /* 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()) { + __set_current_state(TASK_RUNNING); break; + } /* Only sleep when the search is active. */ - if (dev->search_count) - schedule_timeout(jtime); + if (dev->search_count) { + if (!jremain) + jremain = jtime; + jremain = schedule_timeout(jremain); + } else schedule(); } @@ -1007,28 +1208,26 @@ static int __init w1_init(void) { int retval; - printk(KERN_INFO "Driver for 1-wire Dallas network protocol.\n"); + pr_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); + pr_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", + pr_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", + pr_err("Failed to register slave driver. err=%d.\n", retval); goto err_out_master_unregister; } @@ -1053,10 +1252,10 @@ err_out_exit_init: static void __exit w1_fini(void) { - struct w1_master *dev; + struct w1_master *dev, *n; /* Set netlink removal messages and some cleanup */ - list_for_each_entry(dev, &w1_masters, w1_master_entry) + list_for_each_entry_safe(dev, n, &w1_masters, w1_master_entry) __w1_remove_master_device(dev); w1_fini_netlink(); @@ -1068,3 +1267,7 @@ static void __exit w1_fini(void) module_init(w1_init); module_exit(w1_fini); + +MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>"); +MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol."); +MODULE_LICENSE("GPL"); |