Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Evgeniy Polyakov | 7785925 | 2005-05-20 22:33:25 +0400 | [diff] [blame] | 2 | * w1_int.c |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3 | * |
Evgeniy Polyakov | a801876 | 2011-08-25 15:59:06 -0700 | [diff] [blame] | 4 | * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net> |
Evgeniy Polyakov | 7785925 | 2005-05-20 22:33:25 +0400 | [diff] [blame] | 5 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Evgeniy Polyakov | 674a396c | 2006-02-20 11:15:37 +0300 | [diff] [blame] | 25 | #include <linux/kthread.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 26 | #include <linux/slab.h> |
Paul Gortmaker | 9623932 | 2011-07-10 13:21:52 -0400 | [diff] [blame] | 27 | #include <linux/export.h> |
Paul Gortmaker | 4d18412 | 2011-09-15 23:09:52 -0400 | [diff] [blame] | 28 | #include <linux/moduleparam.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | |
| 30 | #include "w1.h" |
| 31 | #include "w1_log.h" |
| 32 | #include "w1_netlink.h" |
Evgeniy Polyakov | 70d484b | 2006-04-24 10:46:14 +0400 | [diff] [blame] | 33 | #include "w1_int.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | |
David Fries | 9141f57 | 2008-10-15 22:04:45 -0700 | [diff] [blame] | 35 | static int w1_search_count = -1; /* Default is continual scan */ |
| 36 | module_param_named(search_count, w1_search_count, int, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | |
David Fries | 6a158c0 | 2008-10-15 22:04:42 -0700 | [diff] [blame] | 38 | static int w1_enable_pullup = 1; |
| 39 | module_param_named(enable_pullup, w1_enable_pullup, int, 0); |
| 40 | |
Evgeniy Polyakov | 7785925 | 2005-05-20 22:33:25 +0400 | [diff] [blame] | 41 | static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl, |
| 42 | struct device_driver *driver, |
| 43 | struct device *device) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | { |
| 45 | struct w1_master *dev; |
| 46 | int err; |
| 47 | |
| 48 | /* |
| 49 | * We are in process context(kernel thread), so can sleep. |
| 50 | */ |
Yoann Padioleau | dd00cc4 | 2007-07-19 01:49:03 -0700 | [diff] [blame] | 51 | dev = kzalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | |
| 60 | dev->bus_master = (struct w1_bus_master *)(dev + 1); |
| 61 | |
Evgeniy Polyakov | 7785925 | 2005-05-20 22:33:25 +0400 | [diff] [blame] | 62 | dev->owner = THIS_MODULE; |
| 63 | dev->max_slave_count = slave_count; |
| 64 | dev->slave_count = 0; |
| 65 | dev->attempts = 0; |
Evgeniy Polyakov | 7785925 | 2005-05-20 22:33:25 +0400 | [diff] [blame] | 66 | dev->initialized = 0; |
| 67 | dev->id = id; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | dev->slave_ttl = slave_ttl; |
David Fries | 9141f57 | 2008-10-15 22:04:45 -0700 | [diff] [blame] | 69 | dev->search_count = w1_search_count; |
David Fries | 6a158c0 | 2008-10-15 22:04:42 -0700 | [diff] [blame] | 70 | dev->enable_pullup = w1_enable_pullup; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | |
David Fries | 01e14d6 | 2008-10-15 22:04:40 -0700 | [diff] [blame] | 72 | /* 1 for w1_process to decrement |
| 73 | * 1 for __w1_remove_master_device to decrement |
| 74 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | atomic_set(&dev->refcnt, 2); |
| 76 | |
| 77 | INIT_LIST_HEAD(&dev->slist); |
Evgeniy Polyakov | abd52a1 | 2006-04-03 12:04:27 +0400 | [diff] [blame] | 78 | mutex_init(&dev->mutex); |
NeilBrown | b02f8be | 2012-05-18 15:59:52 +1000 | [diff] [blame] | 79 | mutex_init(&dev->bus_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | memcpy(&dev->dev, device, sizeof(struct device)); |
Kay Sievers | 40f91de | 2009-01-06 10:44:34 -0800 | [diff] [blame] | 82 | dev_set_name(&dev->dev, "w1_bus_master%u", dev->id); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id); |
Florian Faber | 68a436a | 2011-11-02 13:39:59 -0700 | [diff] [blame] | 84 | dev->dev.init_name = dev->name; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | |
| 86 | dev->driver = driver; |
| 87 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | dev->seq = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | |
| 90 | err = device_register(&dev->dev); |
| 91 | if (err) { |
| 92 | printk(KERN_ERR "Failed to register master device. err=%d\n", err); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 93 | memset(dev, 0, sizeof(struct w1_master)); |
| 94 | kfree(dev); |
| 95 | dev = NULL; |
| 96 | } |
| 97 | |
| 98 | return dev; |
| 99 | } |
| 100 | |
Evgeniy Polyakov | 2c5bfda | 2006-04-04 20:35:22 +0400 | [diff] [blame] | 101 | static void w1_free_dev(struct w1_master *dev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | { |
| 103 | device_unregister(&dev->dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 104 | } |
| 105 | |
| 106 | int w1_add_master_device(struct w1_bus_master *master) |
| 107 | { |
David Fries | af00a2d | 2008-10-15 22:04:53 -0700 | [diff] [blame] | 108 | struct w1_master *dev, *entry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | int retval = 0; |
| 110 | struct w1_netlink_msg msg; |
David Fries | af00a2d | 2008-10-15 22:04:53 -0700 | [diff] [blame] | 111 | int id, found; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | |
Evgeniy Polyakov | be57ce2 | 2005-06-04 01:21:46 +0400 | [diff] [blame] | 113 | /* validate minimum functionality */ |
| 114 | if (!(master->touch_bit && master->reset_bus) && |
Evgeniy Polyakov | c1f858b | 2007-05-08 00:31:20 -0700 | [diff] [blame] | 115 | !(master->write_bit && master->read_bit) && |
| 116 | !(master->write_byte && master->read_byte && master->reset_bus)) { |
Evgeniy Polyakov | 6adf87b | 2005-06-04 01:29:25 +0400 | [diff] [blame] | 117 | printk(KERN_ERR "w1_add_master_device: invalid function set\n"); |
| 118 | return(-EINVAL); |
Evgeniy Polyakov | be57ce2 | 2005-06-04 01:21:46 +0400 | [diff] [blame] | 119 | } |
| 120 | |
David Fries | af00a2d | 2008-10-15 22:04:53 -0700 | [diff] [blame] | 121 | /* Lock until the device is added (or not) to w1_masters. */ |
| 122 | mutex_lock(&w1_mlock); |
| 123 | /* Search for the first available id (starting at 1). */ |
| 124 | id = 0; |
| 125 | do { |
| 126 | ++id; |
| 127 | found = 0; |
| 128 | list_for_each_entry(entry, &w1_masters, w1_master_entry) { |
| 129 | if (entry->id == id) { |
| 130 | found = 1; |
| 131 | break; |
| 132 | } |
| 133 | } |
| 134 | } while (found); |
| 135 | |
| 136 | dev = w1_alloc_dev(id, w1_max_slave_count, w1_max_slave_ttl, |
| 137 | &w1_master_driver, &w1_master_device); |
| 138 | if (!dev) { |
| 139 | mutex_unlock(&w1_mlock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | return -ENOMEM; |
David Fries | af00a2d | 2008-10-15 22:04:53 -0700 | [diff] [blame] | 141 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | |
David Fries | 01e14d6 | 2008-10-15 22:04:40 -0700 | [diff] [blame] | 143 | retval = w1_create_master_attributes(dev); |
David Fries | af00a2d | 2008-10-15 22:04:53 -0700 | [diff] [blame] | 144 | if (retval) { |
| 145 | mutex_unlock(&w1_mlock); |
David Fries | 01e14d6 | 2008-10-15 22:04:40 -0700 | [diff] [blame] | 146 | goto err_out_free_dev; |
David Fries | af00a2d | 2008-10-15 22:04:53 -0700 | [diff] [blame] | 147 | } |
David Fries | 01e14d6 | 2008-10-15 22:04:40 -0700 | [diff] [blame] | 148 | |
| 149 | memcpy(dev->bus_master, master, sizeof(struct w1_bus_master)); |
| 150 | |
| 151 | dev->initialized = 1; |
| 152 | |
Evgeniy Polyakov | 674a396c | 2006-02-20 11:15:37 +0300 | [diff] [blame] | 153 | dev->thread = kthread_run(&w1_process, dev, "%s", dev->name); |
| 154 | if (IS_ERR(dev->thread)) { |
| 155 | retval = PTR_ERR(dev->thread); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | dev_err(&dev->dev, |
| 157 | "Failed to create new kernel thread. err=%d\n", |
Evgeniy Polyakov | 674a396c | 2006-02-20 11:15:37 +0300 | [diff] [blame] | 158 | retval); |
David Fries | af00a2d | 2008-10-15 22:04:53 -0700 | [diff] [blame] | 159 | mutex_unlock(&w1_mlock); |
David Fries | 01e14d6 | 2008-10-15 22:04:40 -0700 | [diff] [blame] | 160 | goto err_out_rm_attr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | } |
| 162 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | list_add(&dev->w1_master_entry, &w1_masters); |
Evgeniy Polyakov | abd52a1 | 2006-04-03 12:04:27 +0400 | [diff] [blame] | 164 | mutex_unlock(&w1_mlock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | |
Evgeniy Polyakov | 1200337 | 2006-03-23 19:11:58 +0300 | [diff] [blame] | 166 | memset(&msg, 0, sizeof(msg)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | msg.id.mst.id = dev->id; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | msg.type = W1_MASTER_ADD; |
| 169 | w1_netlink_send(dev, &msg); |
| 170 | |
| 171 | return 0; |
| 172 | |
David Fries | 01e14d6 | 2008-10-15 22:04:40 -0700 | [diff] [blame] | 173 | #if 0 /* Thread cleanup code, not required currently. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 174 | err_out_kill_thread: |
Evgeniy Polyakov | 674a396c | 2006-02-20 11:15:37 +0300 | [diff] [blame] | 175 | kthread_stop(dev->thread); |
David Fries | 01e14d6 | 2008-10-15 22:04:40 -0700 | [diff] [blame] | 176 | #endif |
| 177 | err_out_rm_attr: |
| 178 | w1_destroy_master_attributes(dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 179 | err_out_free_dev: |
| 180 | w1_free_dev(dev); |
| 181 | |
| 182 | return retval; |
| 183 | } |
| 184 | |
| 185 | void __w1_remove_master_device(struct w1_master *dev) |
| 186 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | struct w1_netlink_msg msg; |
David Fries | c30c9b1 | 2008-10-15 22:04:38 -0700 | [diff] [blame] | 188 | struct w1_slave *sl, *sln; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 189 | |
Evgeniy Polyakov | 674a396c | 2006-02-20 11:15:37 +0300 | [diff] [blame] | 190 | kthread_stop(dev->thread); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | |
David Fries | c30c9b1 | 2008-10-15 22:04:38 -0700 | [diff] [blame] | 192 | mutex_lock(&w1_mlock); |
| 193 | list_del(&dev->w1_master_entry); |
| 194 | mutex_unlock(&w1_mlock); |
| 195 | |
| 196 | mutex_lock(&dev->mutex); |
| 197 | list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) |
| 198 | w1_slave_detach(sl); |
| 199 | w1_destroy_master_attributes(dev); |
| 200 | mutex_unlock(&dev->mutex); |
| 201 | atomic_dec(&dev->refcnt); |
| 202 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | while (atomic_read(&dev->refcnt)) { |
Evgeniy Polyakov | 674a396c | 2006-02-20 11:15:37 +0300 | [diff] [blame] | 204 | dev_info(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | dev->name, atomic_read(&dev->refcnt)); |
| 206 | |
| 207 | if (msleep_interruptible(1000)) |
| 208 | flush_signals(current); |
| 209 | } |
| 210 | |
Evgeniy Polyakov | 1200337 | 2006-03-23 19:11:58 +0300 | [diff] [blame] | 211 | memset(&msg, 0, sizeof(msg)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | msg.id.mst.id = dev->id; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | msg.type = W1_MASTER_REMOVE; |
| 214 | w1_netlink_send(dev, &msg); |
| 215 | |
| 216 | w1_free_dev(dev); |
| 217 | } |
| 218 | |
| 219 | void w1_remove_master_device(struct w1_bus_master *bm) |
| 220 | { |
Evgeniy Polyakov | 59d9445 | 2007-08-22 14:01:51 -0700 | [diff] [blame] | 221 | struct w1_master *dev, *found = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 222 | |
Evgeniy Polyakov | 7785925 | 2005-05-20 22:33:25 +0400 | [diff] [blame] | 223 | list_for_each_entry(dev, &w1_masters, w1_master_entry) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 224 | if (!dev->initialized) |
| 225 | continue; |
| 226 | |
Evgeniy Polyakov | 59d9445 | 2007-08-22 14:01:51 -0700 | [diff] [blame] | 227 | if (dev->bus_master->data == bm->data) { |
| 228 | found = dev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 229 | break; |
Evgeniy Polyakov | 59d9445 | 2007-08-22 14:01:51 -0700 | [diff] [blame] | 230 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 231 | } |
| 232 | |
Evgeniy Polyakov | 59d9445 | 2007-08-22 14:01:51 -0700 | [diff] [blame] | 233 | if (!found) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 234 | printk(KERN_ERR "Device doesn't exist.\n"); |
| 235 | return; |
| 236 | } |
| 237 | |
Evgeniy Polyakov | 59d9445 | 2007-08-22 14:01:51 -0700 | [diff] [blame] | 238 | __w1_remove_master_device(found); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 239 | } |
| 240 | |
| 241 | EXPORT_SYMBOL(w1_add_master_device); |
| 242 | EXPORT_SYMBOL(w1_remove_master_device); |