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22#include <linux/kernel.h>
23#include <linux/list.h>
24#include <linux/delay.h>
25#include <linux/kthread.h>
26#include <linux/slab.h>
27#include <linux/export.h>
28#include <linux/moduleparam.h>
29
30#include "w1.h"
31#include "w1_log.h"
32#include "w1_netlink.h"
33#include "w1_int.h"
34
35static int w1_search_count = -1;
36module_param_named(search_count, w1_search_count, int, 0);
37
38static int w1_enable_pullup = 1;
39module_param_named(enable_pullup, w1_enable_pullup, int, 0);
40
41static struct w1_master *w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
42 struct device_driver *driver,
43 struct device *device)
44{
45 struct w1_master *dev;
46 int err;
47
48
49
50
51 dev = kzalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL);
52 if (!dev) {
53 pr_err("Failed to allocate %zd bytes for new w1 device.\n",
54 sizeof(struct w1_master));
55 return NULL;
56 }
57
58
59 dev->bus_master = (struct w1_bus_master *)(dev + 1);
60
61 dev->owner = THIS_MODULE;
62 dev->max_slave_count = slave_count;
63 dev->slave_count = 0;
64 dev->attempts = 0;
65 dev->initialized = 0;
66 dev->id = id;
67 dev->slave_ttl = slave_ttl;
68 dev->search_count = w1_search_count;
69 dev->enable_pullup = w1_enable_pullup;
70
71
72
73
74 atomic_set(&dev->refcnt, 2);
75
76 INIT_LIST_HEAD(&dev->slist);
77 INIT_LIST_HEAD(&dev->async_list);
78 mutex_init(&dev->mutex);
79 mutex_init(&dev->bus_mutex);
80 mutex_init(&dev->list_mutex);
81
82 memcpy(&dev->dev, device, sizeof(struct device));
83 dev_set_name(&dev->dev, "w1_bus_master%u", dev->id);
84 snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id);
85 dev->dev.init_name = dev->name;
86
87 dev->driver = driver;
88
89 dev->seq = 1;
90
91 err = device_register(&dev->dev);
92 if (err) {
93 pr_err("Failed to register master device. err=%d\n", err);
94 memset(dev, 0, sizeof(struct w1_master));
95 kfree(dev);
96 dev = NULL;
97 }
98
99 return dev;
100}
101
102static void w1_free_dev(struct w1_master *dev)
103{
104 device_unregister(&dev->dev);
105}
106
107
108
109
110
111int w1_add_master_device(struct w1_bus_master *master)
112{
113 struct w1_master *dev, *entry;
114 int retval = 0;
115 struct w1_netlink_msg msg;
116 int id, found;
117
118
119 if (!(master->touch_bit && master->reset_bus) &&
120 !(master->write_bit && master->read_bit) &&
121 !(master->write_byte && master->read_byte && master->reset_bus)) {
122 pr_err("w1_add_master_device: invalid function set\n");
123 return(-EINVAL);
124 }
125
126
127 mutex_lock(&w1_mlock);
128
129 id = 0;
130 do {
131 ++id;
132 found = 0;
133 list_for_each_entry(entry, &w1_masters, w1_master_entry) {
134 if (entry->id == id) {
135 found = 1;
136 break;
137 }
138 }
139 } while (found);
140
141 dev = w1_alloc_dev(id, w1_max_slave_count, w1_max_slave_ttl,
142 &w1_master_driver, &w1_master_device);
143 if (!dev) {
144 mutex_unlock(&w1_mlock);
145 return -ENOMEM;
146 }
147
148 retval = w1_create_master_attributes(dev);
149 if (retval) {
150 mutex_unlock(&w1_mlock);
151 goto err_out_free_dev;
152 }
153
154 memcpy(dev->bus_master, master, sizeof(struct w1_bus_master));
155
156 dev->initialized = 1;
157
158 dev->thread = kthread_run(&w1_process, dev, "%s", dev->name);
159 if (IS_ERR(dev->thread)) {
160 retval = PTR_ERR(dev->thread);
161 dev_err(&dev->dev,
162 "Failed to create new kernel thread. err=%d\n",
163 retval);
164 mutex_unlock(&w1_mlock);
165 goto err_out_rm_attr;
166 }
167
168 list_add(&dev->w1_master_entry, &w1_masters);
169 mutex_unlock(&w1_mlock);
170
171 memset(&msg, 0, sizeof(msg));
172 msg.id.mst.id = dev->id;
173 msg.type = W1_MASTER_ADD;
174 w1_netlink_send(dev, &msg);
175
176 return 0;
177
178#if 0
179err_out_kill_thread:
180 set_bit(W1_ABORT_SEARCH, &dev->flags);
181 kthread_stop(dev->thread);
182#endif
183err_out_rm_attr:
184 w1_destroy_master_attributes(dev);
185err_out_free_dev:
186 w1_free_dev(dev);
187
188 return retval;
189}
190
191void __w1_remove_master_device(struct w1_master *dev)
192{
193 struct w1_netlink_msg msg;
194 struct w1_slave *sl, *sln;
195
196 mutex_lock(&w1_mlock);
197 list_del(&dev->w1_master_entry);
198 mutex_unlock(&w1_mlock);
199
200 set_bit(W1_ABORT_SEARCH, &dev->flags);
201 kthread_stop(dev->thread);
202
203 mutex_lock(&dev->mutex);
204 mutex_lock(&dev->list_mutex);
205 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
206 mutex_unlock(&dev->list_mutex);
207 w1_slave_detach(sl);
208 mutex_lock(&dev->list_mutex);
209 }
210 w1_destroy_master_attributes(dev);
211 mutex_unlock(&dev->list_mutex);
212 mutex_unlock(&dev->mutex);
213 atomic_dec(&dev->refcnt);
214
215 while (atomic_read(&dev->refcnt)) {
216 dev_info(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n",
217 dev->name, atomic_read(&dev->refcnt));
218
219 if (msleep_interruptible(1000))
220 flush_signals(current);
221 mutex_lock(&dev->list_mutex);
222 w1_process_callbacks(dev);
223 mutex_unlock(&dev->list_mutex);
224 }
225 mutex_lock(&dev->list_mutex);
226 w1_process_callbacks(dev);
227 mutex_unlock(&dev->list_mutex);
228
229 memset(&msg, 0, sizeof(msg));
230 msg.id.mst.id = dev->id;
231 msg.type = W1_MASTER_REMOVE;
232 w1_netlink_send(dev, &msg);
233
234 w1_free_dev(dev);
235}
236
237
238
239
240
241void w1_remove_master_device(struct w1_bus_master *bm)
242{
243 struct w1_master *dev, *found = NULL;
244
245 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
246 if (!dev->initialized)
247 continue;
248
249 if (dev->bus_master->data == bm->data) {
250 found = dev;
251 break;
252 }
253 }
254
255 if (!found) {
256 pr_err("Device doesn't exist.\n");
257 return;
258 }
259
260 __w1_remove_master_device(found);
261}
262
263EXPORT_SYMBOL(w1_add_master_device);
264EXPORT_SYMBOL(w1_remove_master_device);
265