[PATCH] w1: Userspace communication protocol over connector.

There are three types of messages between w1 core and userspace:
1. Events. They are generated each time new master or slave device found
	either due to automatic or requested search.
2. Userspace commands. Includes read/write and search/alarm search comamnds.
3. Replies to userspace commands.

From: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 93 insertions, 44 deletions

diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index c9486c168505..32d8de881f11 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -35,7 +35,6 @@
 #include <asm/atomic.h>
 
 #include "w1.h"
-#include "w1_io.h"
 #include "w1_log.h"
 #include "w1_int.h"
 #include "w1_family.h"
@@ -55,7 +54,7 @@ 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_SPINLOCK(w1_mlock);
+DECLARE_MUTEX(w1_mlock);
 LIST_HEAD(w1_masters);
 
 static struct task_struct *w1_control_thread;
@@ -75,8 +74,6 @@ static void w1_master_release(struct device *dev)
         struct w1_master *md = dev_to_w1_master(dev);
 
         dev_dbg(dev, "%s: Releasing %s.\n", __func__, md->name);
-
-        dev_fini_netlink(md);
         memset(md, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master));
         kfree(md);
 }
@@ -85,10 +82,10 @@ static void w1_slave_release(struct device *dev)
 {
         struct w1_slave *sl = dev_to_w1_slave(dev);
 
-        dev_dbg(dev, "%s: Releasing %s.\n", __func__, sl->name);
+        printk("%s: Releasing %s.\n", __func__, sl->name);
 
         while (atomic_read(&sl->refcnt)) {
-                dev_dbg(dev, "Waiting for %s to become free: refcnt=%d.\n",
+                printk("Waiting for %s to become free: refcnt=%d.\n",
                                 sl->name, atomic_read(&sl->refcnt));
                 if (msleep_interruptible(1000))
                         flush_signals(current);
@@ -111,7 +108,6 @@ static ssize_t w1_slave_read_id(struct kobject *kobj, char *buf, loff_t off, siz
 {
         struct w1_slave *sl = kobj_to_w1_slave(kobj);
 
-        atomic_inc(&sl->refcnt);
         if (off > 8) {
                 count = 0;
         } else {
@@ -120,7 +116,6 @@ static ssize_t w1_slave_read_id(struct kobject *kobj, char *buf, loff_t off, siz
 
                 memcpy(buf, (u8 *)&sl->reg_num, count);
         }
-        atomic_dec(&sl->refcnt);
 
         return count;
 }
@@ -230,12 +225,11 @@ struct device w1_master_device = {
         .release = &w1_master_release
 };
 
-static struct device_driver w1_slave_driver = {
+struct device_driver w1_slave_driver = {
         .name = "w1_slave_driver",
         .bus = &w1_bus_type,
 };
 
-#if 0
 struct device w1_slave_device = {
         .parent = NULL,
         .bus = &w1_bus_type,
@@ -243,7 +237,6 @@ struct device w1_slave_device = {
         .driver = &w1_slave_driver,
         .release = &w1_slave_release
 };
-#endif  /*  0  */
 
 static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf)
 {
@@ -423,7 +416,7 @@ 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);
 }
@@ -454,14 +447,11 @@ static int w1_uevent(struct device *dev, char **envp, int num_envp, char *buffer
         if (dev->driver != &w1_slave_driver || !sl)
                 return 0;
 
-        err = add_uevent_var(envp, num_envp, &cur_index, buffer, buffer_size,
-                        &cur_len, "W1_FID=%02X", sl->reg_num.family);
+        err = add_uevent_var(envp, num_envp, &cur_index, buffer, buffer_size, &cur_len, "W1_FID=%02X", sl->reg_num.family);
         if (err)
                 return err;
 
-        err = add_uevent_var(envp, num_envp, &cur_index, buffer, buffer_size,
-                        &cur_len, "W1_SLAVE_ID=%024LX",
-                        (unsigned long long)sl->reg_num.id);
+        err = add_uevent_var(envp, num_envp, &cur_index, buffer, buffer_size, &cur_len, "W1_SLAVE_ID=%024LX", (u64)sl->reg_num.id);
         if (err)
                 return err;
 
@@ -563,6 +553,7 @@ static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
         sl->master = dev;
         set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
 
+        memset(&msg, 0, sizeof(msg));
         memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
         atomic_set(&sl->refcnt, 0);
         init_completion(&sl->released);
@@ -593,7 +584,7 @@ static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
         sl->ttl = dev->slave_ttl;
         dev->slave_count++;
 
-        memcpy(&msg.id.id, rn, sizeof(msg.id.id));
+        memcpy(msg.id.id, rn, sizeof(msg.id));
         msg.type = W1_SLAVE_ADD;
         w1_netlink_send(dev, &msg);
 
@@ -611,7 +602,8 @@ static void w1_slave_detach(struct w1_slave *sl)
         if (sl->family->fops && sl->family->fops->remove_slave)
                 sl->family->fops->remove_slave(sl);
 
-        memcpy(&msg.id.id, &sl->reg_num, sizeof(msg.id.id));
+        memset(&msg, 0, sizeof(msg));
+        memcpy(msg.id.id, &sl->reg_num, sizeof(msg.id));
         msg.type = W1_SLAVE_REMOVE;
         w1_netlink_send(sl->master, &msg);
 
@@ -628,7 +620,7 @@ static struct w1_master *w1_search_master(void *data)
         struct w1_master *dev;
         int found = 0;
 
-        spin_lock_bh(&w1_mlock);
+        down(&w1_mlock);
         list_for_each_entry(dev, &w1_masters, w1_master_entry) {
                 if (dev->bus_master->data == data) {
                         found = 1;
@@ -636,22 +628,69 @@ static struct w1_master *w1_search_master(void *data)
                         break;
                 }
         }
-        spin_unlock_bh(&w1_mlock);
+        up(&w1_mlock);
 
         return (found)?dev:NULL;
 }
 
+struct w1_master *w1_search_master_id(u32 id)
+{
+        struct w1_master *dev;
+        int found = 0;
+
+        down(&w1_mlock);
+        list_for_each_entry(dev, &w1_masters, w1_master_entry) {
+                if (dev->id == id) {
+                        found = 1;
+                        atomic_inc(&dev->refcnt);
+                        break;
+                }
+        }
+        up(&w1_mlock);
+
+        return (found)?dev:NULL;
+}
+
+struct w1_slave *w1_search_slave(struct w1_reg_num *id)
+{
+        struct w1_master *dev;
+        struct w1_slave *sl = NULL;
+        int found = 0;
+
+        down(&w1_mlock);
+        list_for_each_entry(dev, &w1_masters, w1_master_entry) {
+                down(&dev->mutex);
+                list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
+                        if (sl->reg_num.family == id->family &&
+                                        sl->reg_num.id == id->id &&
+                                        sl->reg_num.crc == id->crc) {
+                                found = 1;
+                                atomic_inc(&dev->refcnt);
+                                atomic_inc(&sl->refcnt);
+                                break;
+                        }
+                }
+                up(&dev->mutex);
+
+                if (found)
+                        break;
+        }
+        up(&w1_mlock);
+
+        return (found)?sl:NULL;
+}
+
 void w1_reconnect_slaves(struct w1_family *f)
 {
         struct w1_master *dev;
 
-        spin_lock_bh(&w1_mlock);
+        down(&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);
         }
-        spin_unlock_bh(&w1_mlock);
+        up(&w1_mlock);
 }
 
 static void w1_slave_found(void *data, u64 rn)
@@ -713,7 +752,7 @@ static void w1_slave_found(void *data, u64 rn)
  * @dev        The master device to search
  * @cb         Function to call when a device is found
  */
-void w1_search(struct w1_master *dev, w1_slave_found_callback cb)
+void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb)
 {
         u64 last_rn, rn, tmp64;
         int i, slave_count = 0;
@@ -744,7 +783,7 @@ void w1_search(struct w1_master *dev, w1_slave_found_callback cb)
                 }
 
                 /* Start the search */
-                w1_write_8(dev, W1_SEARCH);
+                w1_write_8(dev, search_type);
                 for (i = 0; i < 64; ++i) {
                         /* Determine the direction/search bit */
                         if (i == desc_bit)
@@ -806,9 +845,9 @@ static int w1_control(void *data)
                         if (kthread_should_stop() || test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {
                                 set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
 
-                                spin_lock(&w1_mlock);
+                                down(&w1_mlock);
                                 list_del(&dev->w1_master_entry);
-                                spin_unlock(&w1_mlock);
+                                up(&w1_mlock);
 
                                 down(&dev->mutex);
                                 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
@@ -843,10 +882,31 @@ static int w1_control(void *data)
         return 0;
 }
 
+void w1_search_process(struct w1_master *dev, u8 search_type)
+{
+        struct w1_slave *sl, *sln;
+
+        list_for_each_entry(sl, &dev->slist, w1_slave_entry)
+                clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
+
+        w1_search_devices(dev, search_type, w1_slave_found);
+
+        list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
+                if (!test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags) && !--sl->ttl) {
+                        w1_slave_detach(sl);
+
+                        dev->slave_count--;
+                } else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags))
+                        sl->ttl = dev->slave_ttl;
+        }
+
+        if (dev->search_count > 0)
+                dev->search_count--;
+}
+
 int w1_process(void *data)
 {
         struct w1_master *dev = (struct w1_master *) data;
-        struct w1_slave *sl, *sln;
 
         while (!kthread_should_stop() && !test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {
                 try_to_freeze();
@@ -864,22 +924,7 @@ int w1_process(void *data)
                 if (down_interruptible(&dev->mutex))
                         continue;
 
-                list_for_each_entry(sl, &dev->slist, w1_slave_entry)
-                        clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
-
-                w1_search_devices(dev, w1_slave_found);
-
-                list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
-                        if (!test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags) && !--sl->ttl) {
-                                w1_slave_detach(sl);
-
-                                dev->slave_count--;
-                        } else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags))
-                                sl->ttl = dev->slave_ttl;
-                }
-
-                if (dev->search_count > 0)
-                        dev->search_count--;
+                w1_search_process(dev, W1_SEARCH);
 
                 up(&dev->mutex);
         }
@@ -895,6 +940,8 @@ static int w1_init(void)
 
         printk(KERN_INFO "Driver for 1-wire Dallas network protocol.\n");
 
+        w1_init_netlink();
+
         retval = bus_register(&w1_bus_type);
         if (retval) {
                 printk(KERN_ERR "Failed to register bus. err=%d.\n", retval);
@@ -947,6 +994,8 @@ static void w1_fini(void)
         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);