Commit | Line | Data |
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c942fddf | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 | 2 | /* |
a8018766 | 3 | * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net> |
1da177e4 LT |
4 | */ |
5 | ||
6 | #include <linux/kernel.h> | |
7 | #include <linux/list.h> | |
8 | #include <linux/delay.h> | |
674a396c | 9 | #include <linux/kthread.h> |
5a0e3ad6 | 10 | #include <linux/slab.h> |
3f07c014 | 11 | #include <linux/sched/signal.h> |
9623932c | 12 | #include <linux/export.h> |
4d184129 | 13 | #include <linux/moduleparam.h> |
1da177e4 | 14 | |
de0d6dbd | 15 | #include "w1_internal.h" |
1da177e4 LT |
16 | #include "w1_netlink.h" |
17 | ||
9141f57c DF |
18 | static int w1_search_count = -1; /* Default is continual scan */ |
19 | module_param_named(search_count, w1_search_count, int, 0); | |
1da177e4 | 20 | |
6a158c0d DF |
21 | static int w1_enable_pullup = 1; |
22 | module_param_named(enable_pullup, w1_enable_pullup, int, 0); | |
23 | ||
7242d42a | 24 | static struct w1_master *w1_alloc_dev(u32 id, int slave_count, int slave_ttl, |
7785925d EP |
25 | struct device_driver *driver, |
26 | struct device *device) | |
1da177e4 LT |
27 | { |
28 | struct w1_master *dev; | |
29 | int err; | |
30 | ||
31 | /* | |
32 | * We are in process context(kernel thread), so can sleep. | |
33 | */ | |
dd00cc48 | 34 | dev = kzalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL); |
1da177e4 | 35 | if (!dev) { |
fdc9167a | 36 | pr_err("Failed to allocate %zd bytes for new w1 device.\n", |
1da177e4 LT |
37 | sizeof(struct w1_master)); |
38 | return NULL; | |
39 | } | |
40 | ||
1da177e4 LT |
41 | |
42 | dev->bus_master = (struct w1_bus_master *)(dev + 1); | |
43 | ||
7785925d EP |
44 | dev->owner = THIS_MODULE; |
45 | dev->max_slave_count = slave_count; | |
46 | dev->slave_count = 0; | |
47 | dev->attempts = 0; | |
7785925d EP |
48 | dev->initialized = 0; |
49 | dev->id = id; | |
1da177e4 | 50 | dev->slave_ttl = slave_ttl; |
9141f57c | 51 | dev->search_count = w1_search_count; |
6a158c0d | 52 | dev->enable_pullup = w1_enable_pullup; |
1da177e4 | 53 | |
25d56488 | 54 | /* For __w1_remove_master_device to decrement |
01e14d6d | 55 | */ |
25d56488 | 56 | atomic_set(&dev->refcnt, 1); |
1da177e4 LT |
57 | |
58 | INIT_LIST_HEAD(&dev->slist); | |
9fcbbac5 | 59 | INIT_LIST_HEAD(&dev->async_list); |
abd52a13 | 60 | mutex_init(&dev->mutex); |
b02f8bed | 61 | mutex_init(&dev->bus_mutex); |
9fcbbac5 | 62 | mutex_init(&dev->list_mutex); |
1da177e4 | 63 | |
1da177e4 | 64 | memcpy(&dev->dev, device, sizeof(struct device)); |
40f91de6 | 65 | dev_set_name(&dev->dev, "w1_bus_master%u", dev->id); |
1da177e4 | 66 | snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id); |
68a436ae | 67 | dev->dev.init_name = dev->name; |
1da177e4 LT |
68 | |
69 | dev->driver = driver; | |
70 | ||
1da177e4 | 71 | dev->seq = 1; |
1da177e4 LT |
72 | |
73 | err = device_register(&dev->dev); | |
74 | if (err) { | |
fdc9167a | 75 | pr_err("Failed to register master device. err=%d\n", err); |
5052436d | 76 | put_device(&dev->dev); |
1da177e4 LT |
77 | dev = NULL; |
78 | } | |
79 | ||
80 | return dev; | |
81 | } | |
82 | ||
2c5bfdac | 83 | static void w1_free_dev(struct w1_master *dev) |
1da177e4 LT |
84 | { |
85 | device_unregister(&dev->dev); | |
1da177e4 LT |
86 | } |
87 | ||
b3be177a DF |
88 | /** |
89 | * w1_add_master_device() - registers a new master device | |
90 | * @master: master bus device to register | |
91 | */ | |
1da177e4 LT |
92 | int w1_add_master_device(struct w1_bus_master *master) |
93 | { | |
af00a2d5 | 94 | struct w1_master *dev, *entry; |
1da177e4 LT |
95 | int retval = 0; |
96 | struct w1_netlink_msg msg; | |
af00a2d5 | 97 | int id, found; |
1da177e4 | 98 | |
7242d42a TW |
99 | /* validate minimum functionality */ |
100 | if (!(master->touch_bit && master->reset_bus) && | |
101 | !(master->write_bit && master->read_bit) && | |
c1f858b7 | 102 | !(master->write_byte && master->read_byte && master->reset_bus)) { |
fdc9167a | 103 | pr_err("w1_add_master_device: invalid function set\n"); |
6adf87bd | 104 | return(-EINVAL); |
7242d42a | 105 | } |
be57ce26 | 106 | |
af00a2d5 DF |
107 | /* Lock until the device is added (or not) to w1_masters. */ |
108 | mutex_lock(&w1_mlock); | |
109 | /* Search for the first available id (starting at 1). */ | |
110 | id = 0; | |
111 | do { | |
112 | ++id; | |
113 | found = 0; | |
114 | list_for_each_entry(entry, &w1_masters, w1_master_entry) { | |
115 | if (entry->id == id) { | |
116 | found = 1; | |
117 | break; | |
118 | } | |
119 | } | |
120 | } while (found); | |
121 | ||
122 | dev = w1_alloc_dev(id, w1_max_slave_count, w1_max_slave_ttl, | |
123 | &w1_master_driver, &w1_master_device); | |
124 | if (!dev) { | |
125 | mutex_unlock(&w1_mlock); | |
1da177e4 | 126 | return -ENOMEM; |
af00a2d5 | 127 | } |
1da177e4 | 128 | |
01e14d6d | 129 | retval = w1_create_master_attributes(dev); |
af00a2d5 DF |
130 | if (retval) { |
131 | mutex_unlock(&w1_mlock); | |
01e14d6d | 132 | goto err_out_free_dev; |
af00a2d5 | 133 | } |
01e14d6d DF |
134 | |
135 | memcpy(dev->bus_master, master, sizeof(struct w1_bus_master)); | |
136 | ||
137 | dev->initialized = 1; | |
138 | ||
674a396c EP |
139 | dev->thread = kthread_run(&w1_process, dev, "%s", dev->name); |
140 | if (IS_ERR(dev->thread)) { | |
141 | retval = PTR_ERR(dev->thread); | |
1da177e4 LT |
142 | dev_err(&dev->dev, |
143 | "Failed to create new kernel thread. err=%d\n", | |
674a396c | 144 | retval); |
af00a2d5 | 145 | mutex_unlock(&w1_mlock); |
01e14d6d | 146 | goto err_out_rm_attr; |
1da177e4 LT |
147 | } |
148 | ||
1da177e4 | 149 | list_add(&dev->w1_master_entry, &w1_masters); |
abd52a13 | 150 | mutex_unlock(&w1_mlock); |
1da177e4 | 151 | |
12003375 | 152 | memset(&msg, 0, sizeof(msg)); |
1da177e4 | 153 | msg.id.mst.id = dev->id; |
1da177e4 LT |
154 | msg.type = W1_MASTER_ADD; |
155 | w1_netlink_send(dev, &msg); | |
156 | ||
157 | return 0; | |
158 | ||
01e14d6d | 159 | #if 0 /* Thread cleanup code, not required currently. */ |
1da177e4 | 160 | err_out_kill_thread: |
42105698 | 161 | set_bit(W1_ABORT_SEARCH, &dev->flags); |
674a396c | 162 | kthread_stop(dev->thread); |
01e14d6d DF |
163 | #endif |
164 | err_out_rm_attr: | |
165 | w1_destroy_master_attributes(dev); | |
1da177e4 LT |
166 | err_out_free_dev: |
167 | w1_free_dev(dev); | |
168 | ||
169 | return retval; | |
170 | } | |
50fa2951 | 171 | EXPORT_SYMBOL(w1_add_master_device); |
1da177e4 LT |
172 | |
173 | void __w1_remove_master_device(struct w1_master *dev) | |
174 | { | |
1da177e4 | 175 | struct w1_netlink_msg msg; |
c30c9b15 | 176 | struct w1_slave *sl, *sln; |
1da177e4 | 177 | |
c30c9b15 DF |
178 | mutex_lock(&w1_mlock); |
179 | list_del(&dev->w1_master_entry); | |
180 | mutex_unlock(&w1_mlock); | |
181 | ||
9fcbbac5 DF |
182 | set_bit(W1_ABORT_SEARCH, &dev->flags); |
183 | kthread_stop(dev->thread); | |
184 | ||
c30c9b15 | 185 | mutex_lock(&dev->mutex); |
9fcbbac5 DF |
186 | mutex_lock(&dev->list_mutex); |
187 | list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) { | |
188 | mutex_unlock(&dev->list_mutex); | |
c30c9b15 | 189 | w1_slave_detach(sl); |
9fcbbac5 DF |
190 | mutex_lock(&dev->list_mutex); |
191 | } | |
c30c9b15 | 192 | w1_destroy_master_attributes(dev); |
9fcbbac5 | 193 | mutex_unlock(&dev->list_mutex); |
c30c9b15 DF |
194 | mutex_unlock(&dev->mutex); |
195 | atomic_dec(&dev->refcnt); | |
196 | ||
1da177e4 | 197 | while (atomic_read(&dev->refcnt)) { |
674a396c | 198 | dev_info(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n", |
1da177e4 LT |
199 | dev->name, atomic_read(&dev->refcnt)); |
200 | ||
201 | if (msleep_interruptible(1000)) | |
202 | flush_signals(current); | |
a0f10464 | 203 | mutex_lock(&dev->list_mutex); |
9fcbbac5 | 204 | w1_process_callbacks(dev); |
a0f10464 | 205 | mutex_unlock(&dev->list_mutex); |
1da177e4 | 206 | } |
a0f10464 | 207 | mutex_lock(&dev->list_mutex); |
9fcbbac5 | 208 | w1_process_callbacks(dev); |
a0f10464 | 209 | mutex_unlock(&dev->list_mutex); |
1da177e4 | 210 | |
12003375 | 211 | memset(&msg, 0, sizeof(msg)); |
1da177e4 | 212 | msg.id.mst.id = dev->id; |
1da177e4 LT |
213 | msg.type = W1_MASTER_REMOVE; |
214 | w1_netlink_send(dev, &msg); | |
215 | ||
216 | w1_free_dev(dev); | |
217 | } | |
218 | ||
b3be177a DF |
219 | /** |
220 | * w1_remove_master_device() - unregister a master device | |
221 | * @bm: master bus device to remove | |
222 | */ | |
1da177e4 LT |
223 | void w1_remove_master_device(struct w1_bus_master *bm) |
224 | { | |
59d9445e | 225 | struct w1_master *dev, *found = NULL; |
1da177e4 | 226 | |
7785925d | 227 | list_for_each_entry(dev, &w1_masters, w1_master_entry) { |
1da177e4 LT |
228 | if (!dev->initialized) |
229 | continue; | |
230 | ||
59d9445e EP |
231 | if (dev->bus_master->data == bm->data) { |
232 | found = dev; | |
1da177e4 | 233 | break; |
59d9445e | 234 | } |
1da177e4 LT |
235 | } |
236 | ||
59d9445e | 237 | if (!found) { |
fdc9167a | 238 | pr_err("Device doesn't exist.\n"); |
1da177e4 LT |
239 | return; |
240 | } | |
241 | ||
59d9445e | 242 | __w1_remove_master_device(found); |
1da177e4 | 243 | } |
1da177e4 | 244 | EXPORT_SYMBOL(w1_remove_master_device); |