Loading...
1/*
2 * w1_int.c
3 *
4 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
5 *
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
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; /* Default is continual scan */
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 * We are in process context(kernel thread), so can sleep.
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 /* 1 for w1_process to decrement
72 * 1 for __w1_remove_master_device to decrement
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 put_device(&dev->dev);
95 dev = NULL;
96 }
97
98 return dev;
99}
100
101static void w1_free_dev(struct w1_master *dev)
102{
103 device_unregister(&dev->dev);
104}
105
106/**
107 * w1_add_master_device() - registers a new master device
108 * @master: master bus device to register
109 */
110int w1_add_master_device(struct w1_bus_master *master)
111{
112 struct w1_master *dev, *entry;
113 int retval = 0;
114 struct w1_netlink_msg msg;
115 int id, found;
116
117 /* validate minimum functionality */
118 if (!(master->touch_bit && master->reset_bus) &&
119 !(master->write_bit && master->read_bit) &&
120 !(master->write_byte && master->read_byte && master->reset_bus)) {
121 pr_err("w1_add_master_device: invalid function set\n");
122 return(-EINVAL);
123 }
124
125 /* Lock until the device is added (or not) to w1_masters. */
126 mutex_lock(&w1_mlock);
127 /* Search for the first available id (starting at 1). */
128 id = 0;
129 do {
130 ++id;
131 found = 0;
132 list_for_each_entry(entry, &w1_masters, w1_master_entry) {
133 if (entry->id == id) {
134 found = 1;
135 break;
136 }
137 }
138 } while (found);
139
140 dev = w1_alloc_dev(id, w1_max_slave_count, w1_max_slave_ttl,
141 &w1_master_driver, &w1_master_device);
142 if (!dev) {
143 mutex_unlock(&w1_mlock);
144 return -ENOMEM;
145 }
146
147 retval = w1_create_master_attributes(dev);
148 if (retval) {
149 mutex_unlock(&w1_mlock);
150 goto err_out_free_dev;
151 }
152
153 memcpy(dev->bus_master, master, sizeof(struct w1_bus_master));
154
155 dev->initialized = 1;
156
157 dev->thread = kthread_run(&w1_process, dev, "%s", dev->name);
158 if (IS_ERR(dev->thread)) {
159 retval = PTR_ERR(dev->thread);
160 dev_err(&dev->dev,
161 "Failed to create new kernel thread. err=%d\n",
162 retval);
163 mutex_unlock(&w1_mlock);
164 goto err_out_rm_attr;
165 }
166
167 list_add(&dev->w1_master_entry, &w1_masters);
168 mutex_unlock(&w1_mlock);
169
170 memset(&msg, 0, sizeof(msg));
171 msg.id.mst.id = dev->id;
172 msg.type = W1_MASTER_ADD;
173 w1_netlink_send(dev, &msg);
174
175 return 0;
176
177#if 0 /* Thread cleanup code, not required currently. */
178err_out_kill_thread:
179 set_bit(W1_ABORT_SEARCH, &dev->flags);
180 kthread_stop(dev->thread);
181#endif
182err_out_rm_attr:
183 w1_destroy_master_attributes(dev);
184err_out_free_dev:
185 w1_free_dev(dev);
186
187 return retval;
188}
189
190void __w1_remove_master_device(struct w1_master *dev)
191{
192 struct w1_netlink_msg msg;
193 struct w1_slave *sl, *sln;
194
195 mutex_lock(&w1_mlock);
196 list_del(&dev->w1_master_entry);
197 mutex_unlock(&w1_mlock);
198
199 set_bit(W1_ABORT_SEARCH, &dev->flags);
200 kthread_stop(dev->thread);
201
202 mutex_lock(&dev->mutex);
203 mutex_lock(&dev->list_mutex);
204 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
205 mutex_unlock(&dev->list_mutex);
206 w1_slave_detach(sl);
207 mutex_lock(&dev->list_mutex);
208 }
209 w1_destroy_master_attributes(dev);
210 mutex_unlock(&dev->list_mutex);
211 mutex_unlock(&dev->mutex);
212 atomic_dec(&dev->refcnt);
213
214 while (atomic_read(&dev->refcnt)) {
215 dev_info(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n",
216 dev->name, atomic_read(&dev->refcnt));
217
218 if (msleep_interruptible(1000))
219 flush_signals(current);
220 mutex_lock(&dev->list_mutex);
221 w1_process_callbacks(dev);
222 mutex_unlock(&dev->list_mutex);
223 }
224 mutex_lock(&dev->list_mutex);
225 w1_process_callbacks(dev);
226 mutex_unlock(&dev->list_mutex);
227
228 memset(&msg, 0, sizeof(msg));
229 msg.id.mst.id = dev->id;
230 msg.type = W1_MASTER_REMOVE;
231 w1_netlink_send(dev, &msg);
232
233 w1_free_dev(dev);
234}
235
236/**
237 * w1_remove_master_device() - unregister a master device
238 * @bm: master bus device to remove
239 */
240void w1_remove_master_device(struct w1_bus_master *bm)
241{
242 struct w1_master *dev, *found = NULL;
243
244 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
245 if (!dev->initialized)
246 continue;
247
248 if (dev->bus_master->data == bm->data) {
249 found = dev;
250 break;
251 }
252 }
253
254 if (!found) {
255 pr_err("Device doesn't exist.\n");
256 return;
257 }
258
259 __w1_remove_master_device(found);
260}
261
262EXPORT_SYMBOL(w1_add_master_device);
263EXPORT_SYMBOL(w1_remove_master_device);
1/*
2 * w1_int.c
3 *
4 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
5 *
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
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; /* Default is continual scan */
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 * We are in process context(kernel thread), so can sleep.
50 */
51 dev = kzalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL);
52 if (!dev) {
53 printk(KERN_ERR
54 "Failed to allocate %zd bytes for new w1 device.\n",
55 sizeof(struct w1_master));
56 return NULL;
57 }
58
59
60 dev->bus_master = (struct w1_bus_master *)(dev + 1);
61
62 dev->owner = THIS_MODULE;
63 dev->max_slave_count = slave_count;
64 dev->slave_count = 0;
65 dev->attempts = 0;
66 dev->initialized = 0;
67 dev->id = id;
68 dev->slave_ttl = slave_ttl;
69 dev->search_count = w1_search_count;
70 dev->enable_pullup = w1_enable_pullup;
71
72 /* 1 for w1_process to decrement
73 * 1 for __w1_remove_master_device to decrement
74 */
75 atomic_set(&dev->refcnt, 2);
76
77 INIT_LIST_HEAD(&dev->slist);
78 mutex_init(&dev->mutex);
79
80 memcpy(&dev->dev, device, sizeof(struct device));
81 dev_set_name(&dev->dev, "w1_bus_master%u", dev->id);
82 snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id);
83 dev->dev.init_name = dev->name;
84
85 dev->driver = driver;
86
87 dev->seq = 1;
88
89 err = device_register(&dev->dev);
90 if (err) {
91 printk(KERN_ERR "Failed to register master device. err=%d\n", err);
92 memset(dev, 0, sizeof(struct w1_master));
93 kfree(dev);
94 dev = NULL;
95 }
96
97 return dev;
98}
99
100static void w1_free_dev(struct w1_master *dev)
101{
102 device_unregister(&dev->dev);
103}
104
105int w1_add_master_device(struct w1_bus_master *master)
106{
107 struct w1_master *dev, *entry;
108 int retval = 0;
109 struct w1_netlink_msg msg;
110 int id, found;
111
112 /* validate minimum functionality */
113 if (!(master->touch_bit && master->reset_bus) &&
114 !(master->write_bit && master->read_bit) &&
115 !(master->write_byte && master->read_byte && master->reset_bus)) {
116 printk(KERN_ERR "w1_add_master_device: invalid function set\n");
117 return(-EINVAL);
118 }
119 /* While it would be electrically possible to make a device that
120 * generated a strong pullup in bit bang mode, only hardare that
121 * controls 1-wire time frames are even expected to support a strong
122 * pullup. w1_io.c would need to support calling set_pullup before
123 * the last write_bit operation of a w1_write_8 which it currently
124 * doesn't.
125 */
126 if (!master->write_byte && !master->touch_bit && master->set_pullup) {
127 printk(KERN_ERR "w1_add_master_device: set_pullup requires "
128 "write_byte or touch_bit, disabling\n");
129 master->set_pullup = NULL;
130 }
131
132 /* Lock until the device is added (or not) to w1_masters. */
133 mutex_lock(&w1_mlock);
134 /* Search for the first available id (starting at 1). */
135 id = 0;
136 do {
137 ++id;
138 found = 0;
139 list_for_each_entry(entry, &w1_masters, w1_master_entry) {
140 if (entry->id == id) {
141 found = 1;
142 break;
143 }
144 }
145 } while (found);
146
147 dev = w1_alloc_dev(id, w1_max_slave_count, w1_max_slave_ttl,
148 &w1_master_driver, &w1_master_device);
149 if (!dev) {
150 mutex_unlock(&w1_mlock);
151 return -ENOMEM;
152 }
153
154 retval = w1_create_master_attributes(dev);
155 if (retval) {
156 mutex_unlock(&w1_mlock);
157 goto err_out_free_dev;
158 }
159
160 memcpy(dev->bus_master, master, sizeof(struct w1_bus_master));
161
162 dev->initialized = 1;
163
164 dev->thread = kthread_run(&w1_process, dev, "%s", dev->name);
165 if (IS_ERR(dev->thread)) {
166 retval = PTR_ERR(dev->thread);
167 dev_err(&dev->dev,
168 "Failed to create new kernel thread. err=%d\n",
169 retval);
170 mutex_unlock(&w1_mlock);
171 goto err_out_rm_attr;
172 }
173
174 list_add(&dev->w1_master_entry, &w1_masters);
175 mutex_unlock(&w1_mlock);
176
177 memset(&msg, 0, sizeof(msg));
178 msg.id.mst.id = dev->id;
179 msg.type = W1_MASTER_ADD;
180 w1_netlink_send(dev, &msg);
181
182 return 0;
183
184#if 0 /* Thread cleanup code, not required currently. */
185err_out_kill_thread:
186 kthread_stop(dev->thread);
187#endif
188err_out_rm_attr:
189 w1_destroy_master_attributes(dev);
190err_out_free_dev:
191 w1_free_dev(dev);
192
193 return retval;
194}
195
196void __w1_remove_master_device(struct w1_master *dev)
197{
198 struct w1_netlink_msg msg;
199 struct w1_slave *sl, *sln;
200
201 kthread_stop(dev->thread);
202
203 mutex_lock(&w1_mlock);
204 list_del(&dev->w1_master_entry);
205 mutex_unlock(&w1_mlock);
206
207 mutex_lock(&dev->mutex);
208 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry)
209 w1_slave_detach(sl);
210 w1_destroy_master_attributes(dev);
211 mutex_unlock(&dev->mutex);
212 atomic_dec(&dev->refcnt);
213
214 while (atomic_read(&dev->refcnt)) {
215 dev_info(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n",
216 dev->name, atomic_read(&dev->refcnt));
217
218 if (msleep_interruptible(1000))
219 flush_signals(current);
220 }
221
222 memset(&msg, 0, sizeof(msg));
223 msg.id.mst.id = dev->id;
224 msg.type = W1_MASTER_REMOVE;
225 w1_netlink_send(dev, &msg);
226
227 w1_free_dev(dev);
228}
229
230void w1_remove_master_device(struct w1_bus_master *bm)
231{
232 struct w1_master *dev, *found = NULL;
233
234 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
235 if (!dev->initialized)
236 continue;
237
238 if (dev->bus_master->data == bm->data) {
239 found = dev;
240 break;
241 }
242 }
243
244 if (!found) {
245 printk(KERN_ERR "Device doesn't exist.\n");
246 return;
247 }
248
249 __w1_remove_master_device(found);
250}
251
252EXPORT_SYMBOL(w1_add_master_device);
253EXPORT_SYMBOL(w1_remove_master_device);