11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * w1_int.c 31da177e4SLinus Torvalds * 4a8018766SEvgeniy Polyakov * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net> 51da177e4SLinus Torvalds * 61da177e4SLinus Torvalds * 71da177e4SLinus Torvalds * This program is free software; you can redistribute it and/or modify 81da177e4SLinus Torvalds * it under the terms of the GNU General Public License as published by 91da177e4SLinus Torvalds * the Free Software Foundation; either version 2 of the License, or 101da177e4SLinus Torvalds * (at your option) any later version. 111da177e4SLinus Torvalds * 121da177e4SLinus Torvalds * This program is distributed in the hope that it will be useful, 131da177e4SLinus Torvalds * but WITHOUT ANY WARRANTY; without even the implied warranty of 141da177e4SLinus Torvalds * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 151da177e4SLinus Torvalds * GNU General Public License for more details. 161da177e4SLinus Torvalds * 171da177e4SLinus Torvalds * You should have received a copy of the GNU General Public License 181da177e4SLinus Torvalds * along with this program; if not, write to the Free Software 191da177e4SLinus Torvalds * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 201da177e4SLinus Torvalds */ 211da177e4SLinus Torvalds 221da177e4SLinus Torvalds #include <linux/kernel.h> 231da177e4SLinus Torvalds #include <linux/list.h> 241da177e4SLinus Torvalds #include <linux/delay.h> 25674a396cSEvgeniy Polyakov #include <linux/kthread.h> 265a0e3ad6STejun Heo #include <linux/slab.h> 279623932cSPaul Gortmaker #include <linux/export.h> 284d184129SPaul Gortmaker #include <linux/moduleparam.h> 291da177e4SLinus Torvalds 301da177e4SLinus Torvalds #include "w1.h" 311da177e4SLinus Torvalds #include "w1_log.h" 321da177e4SLinus Torvalds #include "w1_netlink.h" 3370d484bfSEvgeniy Polyakov #include "w1_int.h" 341da177e4SLinus Torvalds 359141f57cSDavid Fries static int w1_search_count = -1; /* Default is continual scan */ 369141f57cSDavid Fries module_param_named(search_count, w1_search_count, int, 0); 371da177e4SLinus Torvalds 386a158c0dSDavid Fries static int w1_enable_pullup = 1; 396a158c0dSDavid Fries module_param_named(enable_pullup, w1_enable_pullup, int, 0); 406a158c0dSDavid Fries 417785925dSEvgeniy Polyakov static struct w1_master *w1_alloc_dev(u32 id, int slave_count, int slave_ttl, 427785925dSEvgeniy Polyakov struct device_driver *driver, 437785925dSEvgeniy Polyakov struct device *device) 441da177e4SLinus Torvalds { 451da177e4SLinus Torvalds struct w1_master *dev; 461da177e4SLinus Torvalds int err; 471da177e4SLinus Torvalds 481da177e4SLinus Torvalds /* 491da177e4SLinus Torvalds * We are in process context(kernel thread), so can sleep. 501da177e4SLinus Torvalds */ 51dd00cc48SYoann Padioleau dev = kzalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL); 521da177e4SLinus Torvalds if (!dev) { 53fdc9167aSFjodor Schelichow pr_err("Failed to allocate %zd bytes for new w1 device.\n", 541da177e4SLinus Torvalds sizeof(struct w1_master)); 551da177e4SLinus Torvalds return NULL; 561da177e4SLinus Torvalds } 571da177e4SLinus Torvalds 581da177e4SLinus Torvalds 591da177e4SLinus Torvalds dev->bus_master = (struct w1_bus_master *)(dev + 1); 601da177e4SLinus Torvalds 611da177e4SLinus Torvalds dev->owner = THIS_MODULE; 621da177e4SLinus Torvalds dev->max_slave_count = slave_count; 631da177e4SLinus Torvalds dev->slave_count = 0; 641da177e4SLinus Torvalds dev->attempts = 0; 651da177e4SLinus Torvalds dev->initialized = 0; 661da177e4SLinus Torvalds dev->id = id; 671da177e4SLinus Torvalds dev->slave_ttl = slave_ttl; 689141f57cSDavid Fries dev->search_count = w1_search_count; 696a158c0dSDavid Fries dev->enable_pullup = w1_enable_pullup; 701da177e4SLinus Torvalds 7101e14d6dSDavid Fries /* 1 for w1_process to decrement 7201e14d6dSDavid Fries * 1 for __w1_remove_master_device to decrement 7301e14d6dSDavid Fries */ 741da177e4SLinus Torvalds atomic_set(&dev->refcnt, 2); 751da177e4SLinus Torvalds 761da177e4SLinus Torvalds INIT_LIST_HEAD(&dev->slist); 779fcbbac5SDavid Fries INIT_LIST_HEAD(&dev->async_list); 78abd52a13SEvgeniy Polyakov mutex_init(&dev->mutex); 79b02f8bedSNeilBrown mutex_init(&dev->bus_mutex); 809fcbbac5SDavid Fries mutex_init(&dev->list_mutex); 811da177e4SLinus Torvalds 821da177e4SLinus Torvalds memcpy(&dev->dev, device, sizeof(struct device)); 8340f91de6SKay Sievers dev_set_name(&dev->dev, "w1_bus_master%u", dev->id); 841da177e4SLinus Torvalds snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id); 8568a436aeSFlorian Faber dev->dev.init_name = dev->name; 861da177e4SLinus Torvalds 871da177e4SLinus Torvalds dev->driver = driver; 881da177e4SLinus Torvalds 891da177e4SLinus Torvalds dev->seq = 1; 901da177e4SLinus Torvalds 911da177e4SLinus Torvalds err = device_register(&dev->dev); 921da177e4SLinus Torvalds if (err) { 93fdc9167aSFjodor Schelichow pr_err("Failed to register master device. err=%d\n", err); 945052436dSLevente Kurusa put_device(&dev->dev); 951da177e4SLinus Torvalds dev = NULL; 961da177e4SLinus Torvalds } 971da177e4SLinus Torvalds 981da177e4SLinus Torvalds return dev; 991da177e4SLinus Torvalds } 1001da177e4SLinus Torvalds 1012c5bfdacSEvgeniy Polyakov static void w1_free_dev(struct w1_master *dev) 1021da177e4SLinus Torvalds { 1031da177e4SLinus Torvalds device_unregister(&dev->dev); 1041da177e4SLinus Torvalds } 1051da177e4SLinus Torvalds 106b3be177aSDavid Fries /** 107b3be177aSDavid Fries * w1_add_master_device() - registers a new master device 108b3be177aSDavid Fries * @master: master bus device to register 109b3be177aSDavid Fries */ 1101da177e4SLinus Torvalds int w1_add_master_device(struct w1_bus_master *master) 1111da177e4SLinus Torvalds { 112af00a2d5SDavid Fries struct w1_master *dev, *entry; 1131da177e4SLinus Torvalds int retval = 0; 1141da177e4SLinus Torvalds struct w1_netlink_msg msg; 115af00a2d5SDavid Fries int id, found; 1161da177e4SLinus Torvalds 117be57ce26SEvgeniy Polyakov /* validate minimum functionality */ 118be57ce26SEvgeniy Polyakov if (!(master->touch_bit && master->reset_bus) && 119c1f858b7SEvgeniy Polyakov !(master->write_bit && master->read_bit) && 120c1f858b7SEvgeniy Polyakov !(master->write_byte && master->read_byte && master->reset_bus)) { 121fdc9167aSFjodor Schelichow pr_err("w1_add_master_device: invalid function set\n"); 122be57ce26SEvgeniy Polyakov return(-EINVAL); 123be57ce26SEvgeniy Polyakov } 124be57ce26SEvgeniy Polyakov 125af00a2d5SDavid Fries /* Lock until the device is added (or not) to w1_masters. */ 126af00a2d5SDavid Fries mutex_lock(&w1_mlock); 127af00a2d5SDavid Fries /* Search for the first available id (starting at 1). */ 128af00a2d5SDavid Fries id = 0; 129af00a2d5SDavid Fries do { 130af00a2d5SDavid Fries ++id; 131af00a2d5SDavid Fries found = 0; 132af00a2d5SDavid Fries list_for_each_entry(entry, &w1_masters, w1_master_entry) { 133af00a2d5SDavid Fries if (entry->id == id) { 134af00a2d5SDavid Fries found = 1; 135af00a2d5SDavid Fries break; 136af00a2d5SDavid Fries } 137af00a2d5SDavid Fries } 138af00a2d5SDavid Fries } while (found); 139af00a2d5SDavid Fries 140af00a2d5SDavid Fries dev = w1_alloc_dev(id, w1_max_slave_count, w1_max_slave_ttl, 141af00a2d5SDavid Fries &w1_master_driver, &w1_master_device); 142af00a2d5SDavid Fries if (!dev) { 143af00a2d5SDavid Fries mutex_unlock(&w1_mlock); 1441da177e4SLinus Torvalds return -ENOMEM; 145af00a2d5SDavid Fries } 1461da177e4SLinus Torvalds 14701e14d6dSDavid Fries retval = w1_create_master_attributes(dev); 148af00a2d5SDavid Fries if (retval) { 149af00a2d5SDavid Fries mutex_unlock(&w1_mlock); 15001e14d6dSDavid Fries goto err_out_free_dev; 151af00a2d5SDavid Fries } 15201e14d6dSDavid Fries 15301e14d6dSDavid Fries memcpy(dev->bus_master, master, sizeof(struct w1_bus_master)); 15401e14d6dSDavid Fries 15501e14d6dSDavid Fries dev->initialized = 1; 15601e14d6dSDavid Fries 157674a396cSEvgeniy Polyakov dev->thread = kthread_run(&w1_process, dev, "%s", dev->name); 158674a396cSEvgeniy Polyakov if (IS_ERR(dev->thread)) { 159674a396cSEvgeniy Polyakov retval = PTR_ERR(dev->thread); 1601da177e4SLinus Torvalds dev_err(&dev->dev, 1611da177e4SLinus Torvalds "Failed to create new kernel thread. err=%d\n", 162674a396cSEvgeniy Polyakov retval); 163af00a2d5SDavid Fries mutex_unlock(&w1_mlock); 16401e14d6dSDavid Fries goto err_out_rm_attr; 1651da177e4SLinus Torvalds } 1661da177e4SLinus Torvalds 1671da177e4SLinus Torvalds list_add(&dev->w1_master_entry, &w1_masters); 168abd52a13SEvgeniy Polyakov mutex_unlock(&w1_mlock); 1691da177e4SLinus Torvalds 17012003375SEvgeniy Polyakov memset(&msg, 0, sizeof(msg)); 1711da177e4SLinus Torvalds msg.id.mst.id = dev->id; 1721da177e4SLinus Torvalds msg.type = W1_MASTER_ADD; 1731da177e4SLinus Torvalds w1_netlink_send(dev, &msg); 1741da177e4SLinus Torvalds 1751da177e4SLinus Torvalds return 0; 1761da177e4SLinus Torvalds 17701e14d6dSDavid Fries #if 0 /* Thread cleanup code, not required currently. */ 1781da177e4SLinus Torvalds err_out_kill_thread: 17942105698SDavid Fries set_bit(W1_ABORT_SEARCH, &dev->flags); 180674a396cSEvgeniy Polyakov kthread_stop(dev->thread); 18101e14d6dSDavid Fries #endif 18201e14d6dSDavid Fries err_out_rm_attr: 18301e14d6dSDavid Fries w1_destroy_master_attributes(dev); 1841da177e4SLinus Torvalds err_out_free_dev: 1851da177e4SLinus Torvalds w1_free_dev(dev); 1861da177e4SLinus Torvalds 1871da177e4SLinus Torvalds return retval; 1881da177e4SLinus Torvalds } 1891da177e4SLinus Torvalds 1901da177e4SLinus Torvalds void __w1_remove_master_device(struct w1_master *dev) 1911da177e4SLinus Torvalds { 1921da177e4SLinus Torvalds struct w1_netlink_msg msg; 193c30c9b15SDavid Fries struct w1_slave *sl, *sln; 1941da177e4SLinus Torvalds 195c30c9b15SDavid Fries mutex_lock(&w1_mlock); 196c30c9b15SDavid Fries list_del(&dev->w1_master_entry); 197c30c9b15SDavid Fries mutex_unlock(&w1_mlock); 198c30c9b15SDavid Fries 1999fcbbac5SDavid Fries set_bit(W1_ABORT_SEARCH, &dev->flags); 2009fcbbac5SDavid Fries kthread_stop(dev->thread); 2019fcbbac5SDavid Fries 202c30c9b15SDavid Fries mutex_lock(&dev->mutex); 2039fcbbac5SDavid Fries mutex_lock(&dev->list_mutex); 2049fcbbac5SDavid Fries list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) { 2059fcbbac5SDavid Fries mutex_unlock(&dev->list_mutex); 206c30c9b15SDavid Fries w1_slave_detach(sl); 2079fcbbac5SDavid Fries mutex_lock(&dev->list_mutex); 2089fcbbac5SDavid Fries } 209c30c9b15SDavid Fries w1_destroy_master_attributes(dev); 2109fcbbac5SDavid Fries mutex_unlock(&dev->list_mutex); 211c30c9b15SDavid Fries mutex_unlock(&dev->mutex); 212c30c9b15SDavid Fries atomic_dec(&dev->refcnt); 213c30c9b15SDavid Fries 2141da177e4SLinus Torvalds while (atomic_read(&dev->refcnt)) { 215674a396cSEvgeniy Polyakov dev_info(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n", 2161da177e4SLinus Torvalds dev->name, atomic_read(&dev->refcnt)); 2171da177e4SLinus Torvalds 2181da177e4SLinus Torvalds if (msleep_interruptible(1000)) 2191da177e4SLinus Torvalds flush_signals(current); 220a0f10464SAlexey Khoroshilov mutex_lock(&dev->list_mutex); 2219fcbbac5SDavid Fries w1_process_callbacks(dev); 222a0f10464SAlexey Khoroshilov mutex_unlock(&dev->list_mutex); 2231da177e4SLinus Torvalds } 224a0f10464SAlexey Khoroshilov mutex_lock(&dev->list_mutex); 2259fcbbac5SDavid Fries w1_process_callbacks(dev); 226a0f10464SAlexey Khoroshilov mutex_unlock(&dev->list_mutex); 2271da177e4SLinus Torvalds 22812003375SEvgeniy Polyakov memset(&msg, 0, sizeof(msg)); 2291da177e4SLinus Torvalds msg.id.mst.id = dev->id; 2301da177e4SLinus Torvalds msg.type = W1_MASTER_REMOVE; 2311da177e4SLinus Torvalds w1_netlink_send(dev, &msg); 2321da177e4SLinus Torvalds 2331da177e4SLinus Torvalds w1_free_dev(dev); 2341da177e4SLinus Torvalds } 2351da177e4SLinus Torvalds 236b3be177aSDavid Fries /** 237b3be177aSDavid Fries * w1_remove_master_device() - unregister a master device 238b3be177aSDavid Fries * @bm: master bus device to remove 239b3be177aSDavid Fries */ 2401da177e4SLinus Torvalds void w1_remove_master_device(struct w1_bus_master *bm) 2411da177e4SLinus Torvalds { 24259d9445eSEvgeniy Polyakov struct w1_master *dev, *found = NULL; 2431da177e4SLinus Torvalds 2447785925dSEvgeniy Polyakov list_for_each_entry(dev, &w1_masters, w1_master_entry) { 2451da177e4SLinus Torvalds if (!dev->initialized) 2461da177e4SLinus Torvalds continue; 2471da177e4SLinus Torvalds 24859d9445eSEvgeniy Polyakov if (dev->bus_master->data == bm->data) { 24959d9445eSEvgeniy Polyakov found = dev; 2501da177e4SLinus Torvalds break; 2511da177e4SLinus Torvalds } 25259d9445eSEvgeniy Polyakov } 2531da177e4SLinus Torvalds 25459d9445eSEvgeniy Polyakov if (!found) { 255fdc9167aSFjodor Schelichow pr_err("Device doesn't exist.\n"); 2561da177e4SLinus Torvalds return; 2571da177e4SLinus Torvalds } 2581da177e4SLinus Torvalds 25959d9445eSEvgeniy Polyakov __w1_remove_master_device(found); 2601da177e4SLinus Torvalds } 2611da177e4SLinus Torvalds 2621da177e4SLinus Torvalds EXPORT_SYMBOL(w1_add_master_device); 2631da177e4SLinus Torvalds EXPORT_SYMBOL(w1_remove_master_device); 264