1 // SPDX-License-Identifier: GPL-2.0-or-later
6 #include <linux/kernel.h>
18 static int w1_search_count = -1; /* Default is continual scan */
32 	 * We are in process context(kernel thread), so can sleep.  in w1_alloc_dev()
42 	dev->bus_master = (struct w1_bus_master *)(dev + 1);  in w1_alloc_dev()
44 	dev->owner		= THIS_MODULE;  in w1_alloc_dev()
45 	dev->max_slave_count	= slave_count;  in w1_alloc_dev()
46 	dev->slave_count	= 0;  in w1_alloc_dev()
47 	dev->attempts		= 0;  in w1_alloc_dev()
48 	dev->initialized	= 0;  in w1_alloc_dev()
49 	dev->id			= id;  in w1_alloc_dev()
50 	dev->slave_ttl		= slave_ttl;  in w1_alloc_dev()
51 	dev->search_count	= w1_search_count;  in w1_alloc_dev()
52 	dev->enable_pullup	= w1_enable_pullup;  in w1_alloc_dev()
57 	atomic_set(&dev->refcnt, 2);  in w1_alloc_dev()
59 	INIT_LIST_HEAD(&dev->slist);  in w1_alloc_dev()
60 	INIT_LIST_HEAD(&dev->async_list);  in w1_alloc_dev()
61 	mutex_init(&dev->mutex);  in w1_alloc_dev()
62 	mutex_init(&dev->bus_mutex);  in w1_alloc_dev()
63 	mutex_init(&dev->list_mutex);  in w1_alloc_dev()
65 	memcpy(&dev->dev, device, sizeof(struct device));  in w1_alloc_dev()
66 	dev_set_name(&dev->dev, "w1_bus_master%u", dev->id);  in w1_alloc_dev()
67 	snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id);  in w1_alloc_dev()
68 	dev->dev.init_name = dev->name;  in w1_alloc_dev()
70 	dev->driver = driver;  in w1_alloc_dev()
72 	dev->seq = 1;  in w1_alloc_dev()
74 	err = device_register(&dev->dev);  in w1_alloc_dev()
76 		pr_err("Failed to register master device. err=%d\n", err);  in w1_alloc_dev()
77 		put_device(&dev->dev);  in w1_alloc_dev()
86 	device_unregister(&dev->dev);  in w1_free_dev()
90  * w1_add_master_device() - registers a new master device
91  * @master:	master bus device to register
93 int w1_add_master_device(struct w1_bus_master *master)  in w1_add_master_device()  argument
101 	if (!(master->touch_bit && master->reset_bus) &&  in w1_add_master_device()
102 	    !(master->write_bit && master->read_bit) &&  in w1_add_master_device()
103 	    !(master->write_byte && master->read_byte && master->reset_bus)) {  in w1_add_master_device()
105 		return(-EINVAL);  in w1_add_master_device()
116 			if (entry->id == id) {  in w1_add_master_device()
127 		return -ENOMEM;  in w1_add_master_device()
136 	memcpy(dev->bus_master, master, sizeof(struct w1_bus_master));  in w1_add_master_device()
138 	dev->initialized = 1;  in w1_add_master_device()
140 	dev->thread = kthread_run(&w1_process, dev, "%s", dev->name);  in w1_add_master_device()
141 	if (IS_ERR(dev->thread)) {  in w1_add_master_device()
142 		retval = PTR_ERR(dev->thread);  in w1_add_master_device()
143 		dev_err(&dev->dev,  in w1_add_master_device()
144 			 "Failed to create new kernel thread. err=%d\n",  in w1_add_master_device()
150 	list_add(&dev->w1_master_entry, &w1_masters);  in w1_add_master_device()
154 	msg.id.mst.id = dev->id;  in w1_add_master_device()
162 	set_bit(W1_ABORT_SEARCH, &dev->flags);  in w1_add_master_device()
163 	kthread_stop(dev->thread);  in w1_add_master_device()
180 	list_del(&dev->w1_master_entry);  in __w1_remove_master_device()
183 	set_bit(W1_ABORT_SEARCH, &dev->flags);  in __w1_remove_master_device()
184 	kthread_stop(dev->thread);  in __w1_remove_master_device()
186 	mutex_lock(&dev->mutex);  in __w1_remove_master_device()
187 	mutex_lock(&dev->list_mutex);  in __w1_remove_master_device()
188 	list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {  in __w1_remove_master_device()
189 		mutex_unlock(&dev->list_mutex);  in __w1_remove_master_device()
191 		mutex_lock(&dev->list_mutex);  in __w1_remove_master_device()
194 	mutex_unlock(&dev->list_mutex);  in __w1_remove_master_device()
195 	mutex_unlock(&dev->mutex);  in __w1_remove_master_device()
196 	atomic_dec(&dev->refcnt);  in __w1_remove_master_device()
198 	while (atomic_read(&dev->refcnt)) {  in __w1_remove_master_device()
199 		dev_info(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n",  in __w1_remove_master_device()
200 				dev->name, atomic_read(&dev->refcnt));  in __w1_remove_master_device()
204 		mutex_lock(&dev->list_mutex);  in __w1_remove_master_device()
206 		mutex_unlock(&dev->list_mutex);  in __w1_remove_master_device()
208 	mutex_lock(&dev->list_mutex);  in __w1_remove_master_device()
210 	mutex_unlock(&dev->list_mutex);  in __w1_remove_master_device()
213 	msg.id.mst.id = dev->id;  in __w1_remove_master_device()
221  * w1_remove_master_device() - unregister a master device
222  * @bm:	master bus device to remove
229 		if (!dev->initialized)  in w1_remove_master_device()
232 		if (dev->bus_master->data == bm->data) {  in w1_remove_master_device()