]> nv-tegra.nvidia Code Review - linux-2.6.git/blobdiff - drivers/w1/w1.c
W1: feature, enable hardware strong pullup
[linux-2.6.git] / drivers / w1 / w1.c
index 7293c9b11f9160e2b80f89e8e9c63d6bdfd6553f..32418d4e555a0add94001c8c8d2a4db8b19308aa 100644 (file)
@@ -46,20 +46,16 @@ MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol.");
 
 static int w1_timeout = 10;
-static int w1_control_timeout = 1;
 int w1_max_slave_count = 10;
 int w1_max_slave_ttl = 10;
 
 module_param_named(timeout, w1_timeout, int, 0);
-module_param_named(control_timeout, w1_control_timeout, int, 0);
 module_param_named(max_slave_count, w1_max_slave_count, int, 0);
 module_param_named(slave_ttl, w1_max_slave_ttl, int, 0);
 
 DEFINE_MUTEX(w1_mlock);
 LIST_HEAD(w1_masters);
 
-static struct task_struct *w1_control_thread;
-
 static int w1_master_match(struct device *dev, struct device_driver *drv)
 {
        return 1;
@@ -250,11 +246,16 @@ static ssize_t w1_master_attribute_store_search(struct device * dev,
                                                struct device_attribute *attr,
                                                const char * buf, size_t count)
 {
+       long tmp;
        struct w1_master *md = dev_to_w1_master(dev);
 
+       if (strict_strtol(buf, 0, &tmp) == -EINVAL)
+               return -EINVAL;
+
        mutex_lock(&md->mutex);
-       md->search_count = simple_strtol(buf, NULL, 0);
+       md->search_count = tmp;
        mutex_unlock(&md->mutex);
+       wake_up_process(md->thread);
 
        return count;
 }
@@ -273,6 +274,38 @@ static ssize_t w1_master_attribute_show_search(struct device *dev,
        return count;
 }
 
+static ssize_t w1_master_attribute_store_pullup(struct device *dev,
+                                               struct device_attribute *attr,
+                                               const char *buf, size_t count)
+{
+       long tmp;
+       struct w1_master *md = dev_to_w1_master(dev);
+
+       if (strict_strtol(buf, 0, &tmp) == -EINVAL)
+               return -EINVAL;
+
+       mutex_lock(&md->mutex);
+       md->enable_pullup = tmp;
+       mutex_unlock(&md->mutex);
+       wake_up_process(md->thread);
+
+       return count;
+}
+
+static ssize_t w1_master_attribute_show_pullup(struct device *dev,
+                                              struct device_attribute *attr,
+                                              char *buf)
+{
+       struct w1_master *md = dev_to_w1_master(dev);
+       ssize_t count;
+
+       mutex_lock(&md->mutex);
+       count = sprintf(buf, "%d\n", md->enable_pullup);
+       mutex_unlock(&md->mutex);
+
+       return count;
+}
+
 static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf)
 {
        struct w1_master *md = dev_to_w1_master(dev);
@@ -368,6 +401,7 @@ static W1_MASTER_ATTR_RO(attempts, S_IRUGO);
 static W1_MASTER_ATTR_RO(timeout, S_IRUGO);
 static W1_MASTER_ATTR_RO(pointer, S_IRUGO);
 static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUGO);
+static W1_MASTER_ATTR_RW(pullup, S_IRUGO | S_IWUGO);
 
 static struct attribute *w1_master_default_attrs[] = {
        &w1_master_attribute_name.attr,
@@ -378,6 +412,7 @@ static struct attribute *w1_master_default_attrs[] = {
        &w1_master_attribute_timeout.attr,
        &w1_master_attribute_pointer.attr,
        &w1_master_attribute_search.attr,
+       &w1_master_attribute_pullup.attr,
        NULL
 };
 
@@ -390,7 +425,7 @@ int w1_create_master_attributes(struct w1_master *master)
        return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group);
 }
 
-static void w1_destroy_master_attributes(struct w1_master *master)
+void w1_destroy_master_attributes(struct w1_master *master)
 {
        sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group);
 }
@@ -567,7 +602,7 @@ static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
        return 0;
 }
 
-static void w1_slave_detach(struct w1_slave *sl)
+void w1_slave_detach(struct w1_slave *sl)
 {
        struct w1_netlink_msg msg;
 
@@ -591,24 +626,6 @@ static void w1_slave_detach(struct w1_slave *sl)
        kfree(sl);
 }
 
-static struct w1_master *w1_search_master(void *data)
-{
-       struct w1_master *dev;
-       int found = 0;
-
-       mutex_lock(&w1_mlock);
-       list_for_each_entry(dev, &w1_masters, w1_master_entry) {
-               if (dev->bus_master->data == data) {
-                       found = 1;
-                       atomic_inc(&dev->refcnt);
-                       break;
-               }
-       }
-       mutex_unlock(&w1_mlock);
-
-       return (found)?dev:NULL;
-}
-
 struct w1_master *w1_search_master_id(u32 id)
 {
        struct w1_master *dev;
@@ -656,34 +673,49 @@ struct w1_slave *w1_search_slave(struct w1_reg_num *id)
        return (found)?sl:NULL;
 }
 
-void w1_reconnect_slaves(struct w1_family *f)
+void w1_reconnect_slaves(struct w1_family *f, int attach)
 {
+       struct w1_slave *sl, *sln;
        struct w1_master *dev;
 
        mutex_lock(&w1_mlock);
        list_for_each_entry(dev, &w1_masters, w1_master_entry) {
-               dev_dbg(&dev->dev, "Reconnecting slaves in %s into new family %02x.\n",
-                               dev->name, f->fid);
-               set_bit(W1_MASTER_NEED_RECONNECT, &dev->flags);
+               dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
+                       "for family %02x.\n", dev->name, f->fid);
+               mutex_lock(&dev->mutex);
+               list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
+                       /* If it is a new family, slaves with the default
+                        * family driver and are that family will be
+                        * connected.  If the family is going away, devices
+                        * matching that family are reconneced.
+                        */
+                       if ((attach && sl->family->fid == W1_FAMILY_DEFAULT
+                               && sl->reg_num.family == f->fid) ||
+                               (!attach && sl->family->fid == f->fid)) {
+                               struct w1_reg_num rn;
+
+                               memcpy(&rn, &sl->reg_num, sizeof(rn));
+                               w1_slave_detach(sl);
+
+                               w1_attach_slave_device(dev, &rn);
+                       }
+               }
+               dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
+                       "has been finished.\n", dev->name);
+               mutex_unlock(&dev->mutex);
        }
        mutex_unlock(&w1_mlock);
 }
 
-static void w1_slave_found(void *data, u64 rn)
+static void w1_slave_found(struct w1_master *dev, u64 rn)
 {
        int slave_count;
        struct w1_slave *sl;
        struct list_head *ent;
        struct w1_reg_num *tmp;
-       struct w1_master *dev;
        u64 rn_le = cpu_to_le64(rn);
 
-       dev = w1_search_master(data);
-       if (!dev) {
-               printk(KERN_ERR "Failed to find w1 master device for data %p, "
-                      "it is impossible.\n", data);
-               return;
-       }
+       atomic_inc(&dev->refcnt);
 
        tmp = (struct w1_reg_num *) &rn;
 
@@ -779,82 +811,22 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb
                        /* extract the direction taken & update the device number */
                        tmp64 = (triplet_ret >> 2);
                        rn |= (tmp64 << i);
+
+                       if (kthread_should_stop()) {
+                               printk(KERN_INFO "Abort w1_search (exiting)\n");
+                               return;
+                       }
                }
 
                if ( (triplet_ret & 0x03) != 0x03 ) {
                        if ( (desc_bit == last_zero) || (last_zero < 0))
                                last_device = 1;
                        desc_bit = last_zero;
-                       cb(dev->bus_master->data, rn);
+                       cb(dev, rn);
                }
        }
 }
 
-static int w1_control(void *data)
-{
-       struct w1_slave *sl, *sln;
-       struct w1_master *dev, *n;
-       int have_to_wait = 0;
-
-       set_freezable();
-       while (!kthread_should_stop() || have_to_wait) {
-               have_to_wait = 0;
-
-               try_to_freeze();
-               msleep_interruptible(w1_control_timeout * 1000);
-
-               list_for_each_entry_safe(dev, n, &w1_masters, w1_master_entry) {
-                       if (!kthread_should_stop() && !dev->flags)
-                               continue;
-                       /*
-                        * Little race: we can create thread but not set the flag.
-                        * Get a chance for external process to set flag up.
-                        */
-                       if (!dev->initialized) {
-                               have_to_wait = 1;
-                               continue;
-                       }
-
-                       if (kthread_should_stop() || test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {
-                               set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
-
-                               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);
-                               continue;
-                       }
-
-                       if (test_bit(W1_MASTER_NEED_RECONNECT, &dev->flags)) {
-                               dev_dbg(&dev->dev, "Reconnecting slaves in device %s.\n", dev->name);
-                               mutex_lock(&dev->mutex);
-                               list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
-                                       if (sl->family->fid == W1_FAMILY_DEFAULT) {
-                                               struct w1_reg_num rn;
-
-                                               memcpy(&rn, &sl->reg_num, sizeof(rn));
-                                               w1_slave_detach(sl);
-
-                                               w1_attach_slave_device(dev, &rn);
-                                       }
-                               }
-                               dev_dbg(&dev->dev, "Reconnecting slaves in device %s has been finished.\n", dev->name);
-                               clear_bit(W1_MASTER_NEED_RECONNECT, &dev->flags);
-                               mutex_unlock(&dev->mutex);
-                       }
-               }
-       }
-
-       return 0;
-}
-
 void w1_search_process(struct w1_master *dev, u8 search_type)
 {
        struct w1_slave *sl, *sln;
@@ -878,23 +850,29 @@ void w1_search_process(struct w1_master *dev, u8 search_type)
 int w1_process(void *data)
 {
        struct w1_master *dev = (struct w1_master *) data;
+       /* As long as w1_timeout is only set by a module parameter the sleep
+        * time can be calculated in jiffies once.
+        */
+       const unsigned long jtime = msecs_to_jiffies(w1_timeout * 1000);
+
+       while (!kthread_should_stop()) {
+               if (dev->search_count) {
+                       mutex_lock(&dev->mutex);
+                       w1_search_process(dev, W1_SEARCH);
+                       mutex_unlock(&dev->mutex);
+               }
 
-       while (!kthread_should_stop() && !test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {
                try_to_freeze();
-               msleep_interruptible(w1_timeout * 1000);
+               __set_current_state(TASK_INTERRUPTIBLE);
 
-               if (kthread_should_stop() || test_bit(W1_MASTER_NEED_EXIT, &dev->flags))
+               if (kthread_should_stop())
                        break;
 
-               if (!dev->initialized)
-                       continue;
-
-               if (dev->search_count == 0)
-                       continue;
-
-               mutex_lock(&dev->mutex);
-               w1_search_process(dev, W1_SEARCH);
-               mutex_unlock(&dev->mutex);
+               /* Only sleep when the search is active. */
+               if (dev->search_count)
+                       schedule_timeout(jtime);
+               else
+                       schedule();
        }
 
        atomic_dec(&dev->refcnt);
@@ -932,18 +910,13 @@ static int w1_init(void)
                goto err_out_master_unregister;
        }
 
-       w1_control_thread = kthread_run(w1_control, NULL, "w1_control");
-       if (IS_ERR(w1_control_thread)) {
-               retval = PTR_ERR(w1_control_thread);
-               printk(KERN_ERR "Failed to create control thread. err=%d\n",
-                       retval);
-               goto err_out_slave_unregister;
-       }
-
        return 0;
 
+#if 0
+/* For undoing the slave register if there was a step after it. */
 err_out_slave_unregister:
        driver_unregister(&w1_slave_driver);
+#endif
 
 err_out_master_unregister:
        driver_unregister(&w1_master_driver);
@@ -959,13 +932,12 @@ static void w1_fini(void)
 {
        struct w1_master *dev;
 
+       /* Set netlink removal messages and some cleanup */
        list_for_each_entry(dev, &w1_masters, w1_master_entry)
                __w1_remove_master_device(dev);
 
        w1_fini_netlink();
 
-       kthread_stop(w1_control_thread);
-
        driver_unregister(&w1_slave_driver);
        driver_unregister(&w1_master_driver);
        bus_unregister(&w1_bus_type);