earlysuspend: add verbose debug flag
[linux-2.6.git] / drivers / w1 / w1_int.c
index 280f140..d220bce 100644 (file)
@@ -1,7 +1,7 @@
 /*
  *     w1_int.c
  *
- * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
+ * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
  *
  *
  * This program is free software; you can redistribute it and/or modify
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/delay.h>
+#include <linux/kthread.h>
+#include <linux/slab.h>
 
 #include "w1.h"
 #include "w1_log.h"
 #include "w1_netlink.h"
+#include "w1_int.h"
 
-static u32 w1_ids = 1;
+static int w1_search_count = -1; /* Default is continual scan */
+module_param_named(search_count, w1_search_count, int, 0);
 
-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 *);
+static int w1_enable_pullup = 1;
+module_param_named(enable_pullup, w1_enable_pullup, int, 0);
 
 static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
                                       struct device_driver *driver,
@@ -49,7 +46,7 @@ static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
        /*
         * We are in process context(kernel thread), so can sleep.
         */
-       dev = kmalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL);
+       dev = kzalloc(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",
@@ -57,7 +54,6 @@ static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
                return NULL;
        }
 
-       memset(dev, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master));
 
        dev->bus_master = (struct w1_bus_master *)(dev + 1);
 
@@ -65,39 +61,31 @@ static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
        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;
+       dev->search_count       = w1_search_count;
+       dev->enable_pullup      = w1_enable_pullup;
 
+       /* 1 for w1_process to decrement
+        * 1 for __w1_remove_master_device to decrement
+        */
        atomic_set(&dev->refcnt, 2);
 
        INIT_LIST_HEAD(&dev->slist);
-       init_MUTEX(&dev->mutex);
-
-       init_completion(&dev->dev_released);
-       init_completion(&dev->dev_exited);
+       mutex_init(&dev->mutex);
 
        memcpy(&dev->dev, device, sizeof(struct device));
-       snprintf(dev->dev.bus_id, sizeof(dev->dev.bus_id),
-                 "w1_bus_master%u", dev->id);
+       dev_set_name(&dev->dev, "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;
@@ -109,66 +97,93 @@ static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
 static 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;
+       struct w1_master *dev, *entry;
        int retval = 0;
        struct w1_netlink_msg msg;
+       int id, found;
 
         /* validate minimum functionality */
         if (!(master->touch_bit && master->reset_bus) &&
-            !(master->write_bit && master->read_bit))
-        {
-           printk(KERN_ERR "w1_add_master_device: invalid function set\n");
-           return(-EINVAL);
+            !(master->write_bit && master->read_bit) &&
+           !(master->write_byte && master->read_byte && master->reset_bus)) {
+               printk(KERN_ERR "w1_add_master_device: invalid function set\n");
+               return(-EINVAL);
         }
+       /* While it would be electrically possible to make a device that
+        * generated a strong pullup in bit bang mode, only hardare that
+        * controls 1-wire time frames are even expected to support a strong
+        * pullup.  w1_io.c would need to support calling set_pullup before
+        * the last write_bit operation of a w1_write_8 which it currently
+        * doesn't.
+        */
+       if (!master->write_byte && !master->touch_bit && master->set_pullup) {
+               printk(KERN_ERR "w1_add_master_device: set_pullup requires "
+                       "write_byte or touch_bit, disabling\n");
+               master->set_pullup = NULL;
+       }
 
-       dev = w1_alloc_dev(w1_ids++, w1_max_slave_count, w1_max_slave_ttl, &w1_driver, &w1_device);
-       if (!dev)
+       /* Lock until the device is added (or not) to w1_masters. */
+       mutex_lock(&w1_mlock);
+       /* Search for the first available id (starting at 1). */
+       id = 0;
+       do {
+               ++id;
+               found = 0;
+               list_for_each_entry(entry, &w1_masters, w1_master_entry) {
+                       if (entry->id == id) {
+                               found = 1;
+                               break;
+                       }
+               }
+       } while (found);
+
+       dev = w1_alloc_dev(id, w1_max_slave_count, w1_max_slave_ttl,
+               &w1_master_driver, &w1_master_device);
+       if (!dev) {
+               mutex_unlock(&w1_mlock);
                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;
+       if (retval) {
+               mutex_unlock(&w1_mlock);
+               goto err_out_free_dev;
+       }
 
        memcpy(dev->bus_master, master, sizeof(struct w1_bus_master));
 
        dev->initialized = 1;
 
-       spin_lock(&w1_mlock);
+       dev->thread = kthread_run(&w1_process, dev, "%s", dev->name);
+       if (IS_ERR(dev->thread)) {
+               retval = PTR_ERR(dev->thread);
+               dev_err(&dev->dev,
+                        "Failed to create new kernel thread. err=%d\n",
+                        retval);
+               mutex_unlock(&w1_mlock);
+               goto err_out_rm_attr;
+       }
+
        list_add(&dev->w1_master_entry, &w1_masters);
-       spin_unlock(&w1_mlock);
+       mutex_unlock(&w1_mlock);
 
+       memset(&msg, 0, sizeof(msg));
        msg.id.mst.id = dev->id;
-       msg.id.mst.pid = dev->kpid;
        msg.type = W1_MASTER_ADD;
        w1_netlink_send(dev, &msg);
 
        return 0;
 
+#if 0 /* Thread cleanup code, not required currently. */
 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);
-
+       kthread_stop(dev->thread);
+#endif
+err_out_rm_attr:
+       w1_destroy_master_attributes(dev);
 err_out_free_dev:
        w1_free_dev(dev);
 
@@ -177,26 +192,32 @@ err_out_free_dev:
 
 void __w1_remove_master_device(struct w1_master *dev)
 {
-       int err;
        struct w1_netlink_msg msg;
+       struct w1_slave *sl, *sln;
 
-       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);
+       kthread_stop(dev->thread);
+
+       mutex_lock(&w1_mlock);
+       list_del(&dev->w1_master_entry);
+       mutex_unlock(&w1_mlock);
+
+       mutex_lock(&dev->mutex);
+       list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry)
+               w1_slave_detach(sl);
+       w1_destroy_master_attributes(dev);
+       mutex_unlock(&dev->mutex);
+       atomic_dec(&dev->refcnt);
 
        while (atomic_read(&dev->refcnt)) {
-               printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n",
+               dev_info(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n",
                                dev->name, atomic_read(&dev->refcnt));
 
                if (msleep_interruptible(1000))
                        flush_signals(current);
        }
 
+       memset(&msg, 0, sizeof(msg));
        msg.id.mst.id = dev->id;
-       msg.id.mst.pid = dev->kpid;
        msg.type = W1_MASTER_REMOVE;
        w1_netlink_send(dev, &msg);
 
@@ -205,22 +226,24 @@ void __w1_remove_master_device(struct w1_master *dev)
 
 void w1_remove_master_device(struct w1_bus_master *bm)
 {
-       struct w1_master *dev = NULL;
+       struct w1_master *dev, *found = NULL;
 
        list_for_each_entry(dev, &w1_masters, w1_master_entry) {
                if (!dev->initialized)
                        continue;
 
-               if (dev->bus_master->data == bm->data)
+               if (dev->bus_master->data == bm->data) {
+                       found = dev;
                        break;
+               }
        }
 
-       if (!dev) {
+       if (!found) {
                printk(KERN_ERR "Device doesn't exist.\n");
                return;
        }
 
-       __w1_remove_master_device(dev);
+       __w1_remove_master_device(found);
 }
 
 EXPORT_SYMBOL(w1_add_master_device);