diff options
Diffstat (limited to 'drivers/w1/w1.c')
| -rw-r--r-- | drivers/w1/w1.c | 858 |
1 files changed, 554 insertions, 304 deletions
diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c index 7293c9b11f9..5d734152054 100644 --- a/drivers/w1/w1.c +++ b/drivers/w1/w1.c @@ -1,7 +1,7 @@ /* * w1.c * - * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru> + * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net> * * * This program is free software; you can redistribute it and/or modify @@ -33,7 +33,7 @@ #include <linux/kthread.h> #include <linux/freezer.h> -#include <asm/atomic.h> +#include <linux/atomic.h> #include "w1.h" #include "w1_log.h" @@ -42,24 +42,33 @@ #include "w1_netlink.h" MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>"); +MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>"); MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol."); static int w1_timeout = 10; -static int w1_control_timeout = 1; -int w1_max_slave_count = 10; +int w1_max_slave_count = 64; int w1_max_slave_ttl = 10; module_param_named(timeout, w1_timeout, int, 0); -module_param_named(control_timeout, w1_control_timeout, int, 0); +MODULE_PARM_DESC(timeout, "time in seconds 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. + */ 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"); 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 struct task_struct *w1_control_thread; - static int w1_master_match(struct device *dev, struct device_driver *drv) { return 1; @@ -83,63 +92,43 @@ static void w1_slave_release(struct device *dev) { struct w1_slave *sl = dev_to_w1_slave(dev); - printk("%s: Releasing %s.\n", __func__, sl->name); - - while (atomic_read(&sl->refcnt)) { - printk("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); } +static DEVICE_ATTR_RO(name); -static ssize_t w1_slave_read_id(struct kobject *kobj, - struct bin_attribute *bin_attr, - char *buf, loff_t off, size_t count) +static ssize_t id_show(struct device *dev, + struct device_attribute *attr, char *buf) { - struct w1_slave *sl = kobj_to_w1_slave(kobj); - - if (off > 8) { - count = 0; - } else { - if (off + count > 8) - count = 8 - off; - - memcpy(buf, (u8 *)&sl->reg_num, count); - } + struct w1_slave *sl = dev_to_w1_slave(dev); + ssize_t count = sizeof(sl->reg_num); + memcpy(buf, (u8 *)&sl->reg_num, count); return count; } +static DEVICE_ATTR_RO(id); -static struct device_attribute w1_slave_attr_name = - __ATTR(name, S_IRUGO, w1_slave_read_name, NULL); - -static struct bin_attribute w1_slave_attr_bin_id = { - .attr = { - .name = "id", - .mode = S_IRUGO, - }, - .size = 8, - .read = w1_slave_read_id, +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 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, + struct bin_attribute *bin_attr, char *buf, loff_t off, + size_t count) { struct w1_slave *sl = kobj_to_w1_slave(kobj); @@ -156,9 +145,9 @@ out_up: return count; } -static ssize_t w1_default_read(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, + struct bin_attribute *bin_attr, char *buf, loff_t off, + size_t count) { struct w1_slave *sl = kobj_to_w1_slave(kobj); @@ -168,29 +157,24 @@ static ssize_t w1_default_read(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 BIN_ATTR_RW(rw, PAGE_SIZE); + +static struct bin_attribute *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, + .groups = w1_slave_default_groups, }; static struct w1_family w1_default_family = { @@ -214,7 +198,7 @@ struct device_driver w1_master_driver = { struct device w1_master_device = { .parent = NULL, .bus = &w1_bus_type, - .bus_id = "w1 bus master", + .init_name = "w1 bus master", .driver = &w1_master_driver, .release = &w1_master_release }; @@ -228,7 +212,7 @@ static struct device_driver w1_slave_driver = { struct device w1_slave_device = { .parent = NULL, .bus = &w1_bus_type, - .bus_id = "w1 bus slave", + .init_name = "w1 bus slave", .driver = &w1_slave_driver, .release = &w1_slave_release }; @@ -250,11 +234,20 @@ 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); + int ret; + + ret = kstrtol(buf, 0, &tmp); + if (ret) + return ret; mutex_lock(&md->mutex); - md->search_count = simple_strtol(buf, NULL, 0); + md->search_count = tmp; mutex_unlock(&md->mutex); + /* Only wake if it is going to be searching. */ + if (tmp) + wake_up_process(md->thread); return count; } @@ -273,6 +266,39 @@ static ssize_t w1_master_attribute_show_search(struct device *dev, 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); + int ret; + + ret = kstrtol(buf, 0, &tmp); + if (ret) + return ret; + + mutex_lock(&md->mutex); + md->enable_pullup = tmp; + mutex_unlock(&md->mutex); + + 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); @@ -291,6 +317,24 @@ static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct devic return count; } +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) == -EINVAL || 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; +} + 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); @@ -324,31 +368,164 @@ static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct d return count; } -static ssize_t w1_master_attribute_show_slaves(struct device *dev, struct device_attribute *attr, char *buf) +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; + struct list_head *ent, *n; + struct w1_slave *sl = NULL; - mutex_lock(&md->mutex); + mutex_lock(&md->list_mutex); + + list_for_each_safe(ent, n, &md->slist) { + sl = list_entry(ent, struct w1_slave, w1_slave_entry); - if (md->slave_count == 0) + c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name); + } + if (!sl) 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); + mutex_unlock(&md->list_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 - c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name); + return 0; +} + +/* Searches the slaves in the w1_master and returns a pointer or NULL. + * Note: must not hold list_mutex + */ +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; +} +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) { + 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, \ @@ -363,11 +540,14 @@ static ssize_t w1_master_attribute_show_slaves(struct device *dev, struct device 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(pointer, S_IRUGO); -static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUGO); +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, @@ -378,6 +558,9 @@ static struct attribute *w1_master_default_attrs[] = { &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 }; @@ -390,18 +573,17 @@ int w1_create_master_attributes(struct w1_master *master) return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group); } -static void w1_destroy_master_attributes(struct w1_master *master) +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; + int err = 0; if (dev->driver == &w1_master_driver) { md = container_of(dev, struct w1_master, dev); @@ -417,28 +599,63 @@ static int w1_uevent(struct device *dev, struct kobj_uevent_env *env) } dev_dbg(dev, "Hotplug event for %s %s, bus_id=%s.\n", - event_owner, name, dev->bus_id); + event_owner, name, dev_name(dev)); if (dev->driver != &w1_slave_driver || !sl) - return 0; + goto end; err = add_uevent_var(env, "W1_FID=%02X", sl->reg_num.family); if (err) - return err; + goto end; err = add_uevent_var(env, "W1_SLAVE_ID=%024LX", (unsigned long long)sl->reg_num.id); - if (err) - return err; +end: + return err; +} - return 0; -}; -#else -static int w1_uevent(struct device *dev, struct kobj_uevent_env *env) +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; } -#endif static int __w1_attach_slave_device(struct w1_slave *sl) { @@ -448,9 +665,9 @@ 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; - snprintf(&sl->dev.bus_id[0], sizeof(sl->dev.bus_id), - "%02x-%012llx", + 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), @@ -459,57 +676,31 @@ static int __w1_attach_slave_device(struct w1_slave *sl) (unsigned long long) sl->reg_num.id); dev_dbg(&sl->dev, "%s: registering %s as %p.\n", __func__, - &sl->dev.bus_id[0], sl); + 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", - sl->dev.bus_id, err); + dev_name(&sl->dev), err); 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", - sl->dev.bus_id, err); - goto out_unreg; - } - - /* Create "id" entry */ - err = sysfs_create_bin_file(&sl->dev.kobj, &w1_slave_attr_bin_id); - if (err < 0) { - dev_err(&sl->dev, - "sysfs file creation for [%s] failed. err=%d\n", - sl->dev.bus_id, err); - 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", - sl->dev.bus_id, 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: - sysfs_remove_bin_file(&sl->dev.kobj, &w1_slave_attr_bin_id); -out_rem1: - device_remove_file(&sl->dev, &w1_slave_attr_name); -out_unreg: - device_unregister(&sl->dev); - return err; } -static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn) +int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn) { struct w1_slave *sl; struct w1_family *f; @@ -527,12 +718,17 @@ 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); + + /* 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); @@ -567,46 +763,49 @@ static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn) return 0; } -static 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); - - sysfs_remove_bin_file(&sl->dev.kobj, &w1_slave_attr_bin_id); - device_remove_file(&sl->dev, &w1_slave_attr_name); - device_unregister(&sl->dev); - - wait_for_completion(&sl->released); - kfree(sl); + 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; } -static struct w1_master *w1_search_master(void *data) +int w1_slave_detach(struct w1_slave *sl) { - struct w1_master *dev; - int found = 0; - - mutex_lock(&w1_mlock); - list_for_each_entry(dev, &w1_masters, w1_master_entry) { - if (dev->bus_master->data == data) { - found = 1; - atomic_inc(&dev->refcnt); - break; - } - } - mutex_unlock(&w1_mlock); - - return (found)?dev:NULL; + /* 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) @@ -635,7 +834,7 @@ struct w1_slave *w1_search_slave(struct w1_reg_num *id) mutex_lock(&w1_mlock); list_for_each_entry(dev, &w1_masters, w1_master_entry) { - mutex_lock(&dev->mutex); + 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 && @@ -646,7 +845,7 @@ struct w1_slave *w1_search_slave(struct w1_reg_num *id) break; } } - mutex_unlock(&dev->mutex); + mutex_unlock(&dev->list_mutex); if (found) break; @@ -656,62 +855,74 @@ struct w1_slave *w1_search_slave(struct w1_reg_num *id) return (found)?sl:NULL; } -void w1_reconnect_slaves(struct w1_family *f) +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 %s into new family %02x.\n", - dev->name, f->fid); - set_bit(W1_MASTER_NEED_RECONNECT, &dev->flags); + 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); } -static void w1_slave_found(void *data, u64 rn) +void w1_slave_found(struct w1_master *dev, u64 rn) { - int slave_count; struct w1_slave *sl; - struct list_head *ent; struct w1_reg_num *tmp; - struct w1_master *dev; u64 rn_le = cpu_to_le64(rn); - dev = w1_search_master(data); - if (!dev) { - printk(KERN_ERR "Failed to find w1 master device for data %p, " - "it is impossible.\n", data); - return; - } + atomic_inc(&dev->refcnt); tmp = (struct w1_reg_num *) &rn; - slave_count = 0; - list_for_each(ent, &dev->slist) { - - sl = list_entry(ent, struct w1_slave, w1_slave_entry); - - if (sl->reg_num.family == tmp->family && - sl->reg_num.id == tmp->id && - sl->reg_num.crc == tmp->crc) { - set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags); - break; - } - - slave_count++; - } - - if (slave_count == dev->slave_count && - rn && ((rn >> 56) & 0xff) == w1_calc_crc8((u8 *)&rn_le, 7)) { - w1_attach_slave_device(dev, tmp); + 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); } /** - * 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. @@ -721,8 +932,6 @@ static void w1_slave_found(void *data, 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) { @@ -733,7 +942,8 @@ 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; @@ -749,11 +959,26 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb * * 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) { @@ -765,7 +990,7 @@ 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 */ @@ -779,122 +1004,153 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb /* 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)) + 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->bus_master->data, rn); + cb(dev, rn); } - } -} - -static int w1_control(void *data) -{ - struct w1_slave *sl, *sln; - struct w1_master *dev, *n; - int have_to_wait = 0; - - set_freezable(); - while (!kthread_should_stop() || have_to_wait) { - have_to_wait = 0; - try_to_freeze(); - msleep_interruptible(w1_control_timeout * 1000); - - list_for_each_entry_safe(dev, n, &w1_masters, w1_master_entry) { - if (!kthread_should_stop() && !dev->flags) - continue; - /* - * Little race: we can create thread but not set the flag. - * Get a chance for external process to set flag up. + 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). */ - if (!dev->initialized) { - have_to_wait = 1; - continue; - } - - if (kthread_should_stop() || test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) { - set_bit(W1_MASTER_NEED_EXIT, &dev->flags); - - mutex_lock(&w1_mlock); - list_del(&dev->w1_master_entry); - mutex_unlock(&w1_mlock); - - mutex_lock(&dev->mutex); - list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) { - w1_slave_detach(sl); - } - w1_destroy_master_attributes(dev); - mutex_unlock(&dev->mutex); - atomic_dec(&dev->refcnt); - continue; - } - - if (test_bit(W1_MASTER_NEED_RECONNECT, &dev->flags)) { - dev_dbg(&dev->dev, "Reconnecting slaves in device %s.\n", dev->name); - mutex_lock(&dev->mutex); - list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) { - if (sl->family->fid == W1_FAMILY_DEFAULT) { - struct w1_reg_num rn; - - 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); - clear_bit(W1_MASTER_NEED_RECONNECT, &dev->flags); - mutex_unlock(&dev->mutex); - } + 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); } } - - return 0; } -void w1_search_process(struct w1_master *dev, u8 search_type) +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, (long *)&sl->flags); + clear_bit(W1_SLAVE_ACTIVE, &sl->flags); + mutex_unlock(&dev->list_mutex); - w1_search_devices(dev, search_type, w1_slave_found); + 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--; } +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); + } - while (!kthread_should_stop() && !test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) { - try_to_freeze(); - msleep_interruptible(w1_timeout * 1000); + 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; + } - if (kthread_should_stop() || test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) - break; + try_to_freeze(); + __set_current_state(TASK_INTERRUPTIBLE); - if (!dev->initialized) - continue; + /* hold list_mutex until after interruptible to prevent loosing + * the wakeup signal when async_cmd is added. + */ + mutex_unlock(&dev->list_mutex); - if (dev->search_count == 0) - continue; + if (kthread_should_stop()) + break; - mutex_lock(&dev->mutex); - w1_search_process(dev, W1_SEARCH); - mutex_unlock(&dev->mutex); + /* 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); @@ -902,7 +1158,7 @@ int w1_process(void *data) return 0; } -static int w1_init(void) +static int __init w1_init(void) { int retval; @@ -927,23 +1183,18 @@ static int w1_init(void) retval = driver_register(&w1_slave_driver); if (retval) { printk(KERN_ERR - "Failed to register master driver. err=%d.\n", + "Failed to register slave driver. err=%d.\n", retval); goto err_out_master_unregister; } - w1_control_thread = kthread_run(w1_control, NULL, "w1_control"); - if (IS_ERR(w1_control_thread)) { - retval = PTR_ERR(w1_control_thread); - printk(KERN_ERR "Failed to create control thread. err=%d\n", - retval); - goto err_out_slave_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); @@ -955,17 +1206,16 @@ err_out_exit_init: return retval; } -static void w1_fini(void) +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(); - kthread_stop(w1_control_thread); - driver_unregister(&w1_slave_driver); driver_unregister(&w1_master_driver); bus_unregister(&w1_bus_type); |