diff options
Diffstat (limited to 'drivers/w1/w1_int.c')
| -rw-r--r-- | drivers/w1/w1_int.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/drivers/w1/w1_int.c b/drivers/w1/w1_int.c new file mode 100644 index 000000000000..5f0bafbbd575 --- /dev/null +++ b/drivers/w1/w1_int.c @@ -0,0 +1,220 @@ +/* + * w1_int.c + * + * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru> + * + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/delay.h> + +#include "w1.h" +#include "w1_log.h" +#include "w1_netlink.h" + +static u32 w1_ids = 1; + +extern struct device_driver w1_driver; +extern struct bus_type w1_bus_type; +extern struct device w1_device; +extern int w1_max_slave_count; +extern int w1_max_slave_ttl; +extern struct list_head w1_masters; +extern spinlock_t w1_mlock; + +extern int w1_process(void *); + +struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl, + struct device_driver *driver, struct device *device) +{ + struct w1_master *dev; + int err; + + /* + * We are in process context(kernel thread), so can sleep. + */ + dev = kmalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL); + if (!dev) { + printk(KERN_ERR + "Failed to allocate %zd bytes for new w1 device.\n", + sizeof(struct w1_master)); + return NULL; + } + + memset(dev, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master)); + + dev->bus_master = (struct w1_bus_master *)(dev + 1); + + dev->owner = THIS_MODULE; + dev->max_slave_count = slave_count; + dev->slave_count = 0; + dev->attempts = 0; + dev->kpid = -1; + dev->initialized = 0; + dev->id = id; + dev->slave_ttl = slave_ttl; + + atomic_set(&dev->refcnt, 2); + + INIT_LIST_HEAD(&dev->slist); + init_MUTEX(&dev->mutex); + + init_completion(&dev->dev_released); + init_completion(&dev->dev_exited); + + memcpy(&dev->dev, device, sizeof(struct device)); + snprintf(dev->dev.bus_id, sizeof(dev->dev.bus_id), + "w1_bus_master%u", dev->id); + snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id); + + dev->driver = driver; + + dev->groups = 23; + dev->seq = 1; + dev->nls = netlink_kernel_create(NETLINK_NFLOG, NULL); + if (!dev->nls) { + printk(KERN_ERR "Failed to create new netlink socket(%u) for w1 master %s.\n", + NETLINK_NFLOG, dev->dev.bus_id); + } + + err = device_register(&dev->dev); + if (err) { + printk(KERN_ERR "Failed to register master device. err=%d\n", err); + if (dev->nls && dev->nls->sk_socket) + sock_release(dev->nls->sk_socket); + memset(dev, 0, sizeof(struct w1_master)); + kfree(dev); + dev = NULL; + } + + return dev; +} + +void w1_free_dev(struct w1_master *dev) +{ + device_unregister(&dev->dev); + if (dev->nls && dev->nls->sk_socket) + sock_release(dev->nls->sk_socket); + memset(dev, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master)); + kfree(dev); +} + +int w1_add_master_device(struct w1_bus_master *master) +{ + struct w1_master *dev; + int retval = 0; + struct w1_netlink_msg msg; + + dev = w1_alloc_dev(w1_ids++, w1_max_slave_count, w1_max_slave_ttl, &w1_driver, &w1_device); + if (!dev) + return -ENOMEM; + + dev->kpid = kernel_thread(&w1_process, dev, 0); + if (dev->kpid < 0) { + dev_err(&dev->dev, + "Failed to create new kernel thread. err=%d\n", + dev->kpid); + retval = dev->kpid; + goto err_out_free_dev; + } + + retval = w1_create_master_attributes(dev); + if (retval) + goto err_out_kill_thread; + + memcpy(dev->bus_master, master, sizeof(struct w1_bus_master)); + + dev->initialized = 1; + + spin_lock(&w1_mlock); + list_add(&dev->w1_master_entry, &w1_masters); + spin_unlock(&w1_mlock); + + msg.id.mst.id = dev->id; + msg.id.mst.pid = dev->kpid; + msg.type = W1_MASTER_ADD; + w1_netlink_send(dev, &msg); + + return 0; + +err_out_kill_thread: + dev->need_exit = 1; + if (kill_proc(dev->kpid, SIGTERM, 1)) + dev_err(&dev->dev, + "Failed to send signal to w1 kernel thread %d.\n", + dev->kpid); + wait_for_completion(&dev->dev_exited); + +err_out_free_dev: + w1_free_dev(dev); + + return retval; +} + +void __w1_remove_master_device(struct w1_master *dev) +{ + int err; + struct w1_netlink_msg msg; + + dev->need_exit = 1; + err = kill_proc(dev->kpid, SIGTERM, 1); + if (err) + dev_err(&dev->dev, + "%s: Failed to send signal to w1 kernel thread %d.\n", + __func__, dev->kpid); + + while (atomic_read(&dev->refcnt)) { + printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n", + dev->name, atomic_read(&dev->refcnt)); + + if (msleep_interruptible(1000)) + flush_signals(current); + } + + msg.id.mst.id = dev->id; + msg.id.mst.pid = dev->kpid; + msg.type = W1_MASTER_REMOVE; + w1_netlink_send(dev, &msg); + + w1_free_dev(dev); +} + +void w1_remove_master_device(struct w1_bus_master *bm) +{ + struct w1_master *dev = NULL; + struct list_head *ent, *n; + + list_for_each_safe(ent, n, &w1_masters) { + dev = list_entry(ent, struct w1_master, w1_master_entry); + if (!dev->initialized) + continue; + + if (dev->bus_master->data == bm->data) + break; + } + + if (!dev) { + printk(KERN_ERR "Device doesn't exist.\n"); + return; + } + + __w1_remove_master_device(dev); +} + +EXPORT_SYMBOL(w1_add_master_device); +EXPORT_SYMBOL(w1_remove_master_device); |