[PATCH] w1: hotplug support.

Here is W1 hotplug in addition to netlink notifications.

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

2 files changed, 82 insertions, 14 deletions

diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index 0bbf029b1ef1..9c7777b6bbdc 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -125,27 +125,41 @@ static struct bin_attribute w1_slave_bin_attribute = {
         .read = &w1_default_read_bin,
 };
 
+static int w1_hotplug(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size);
 
 static struct bus_type w1_bus_type = {
         .name = "w1",
         .match = w1_master_match,
+        .hotplug = w1_hotplug,
 };
 
-struct device_driver w1_driver = {
-        .name = "w1_driver",
+struct device_driver w1_master_driver = {
+        .name = "w1_master_driver",
         .bus = &w1_bus_type,
         .probe = w1_master_probe,
         .remove = w1_master_remove,
 };
 
-struct device w1_device = {
+struct device w1_master_device = {
         .parent = NULL,
         .bus = &w1_bus_type,
         .bus_id = "w1 bus master",
-        .driver = &w1_driver,
+        .driver = &w1_master_driver,
         .release = &w1_master_release
 };
 
+struct device_driver w1_slave_driver = {
+        .name = "w1_slave_driver",
+        .bus = &w1_bus_type,
+};
+
+struct device w1_slave_device = {
+        .parent = NULL,
+        .bus = &w1_bus_type,
+        .bus_id = "w1 bus slave",
+        .driver = &w1_slave_driver,
+};
+
 static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf)
 {
         struct w1_master *md = container_of(dev, struct w1_master, dev);
@@ -329,12 +343,55 @@ void w1_destroy_master_attributes(struct w1_master *master)
         sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group);
 }
 
+#ifdef CONFIG_HOTPLUG
+static int w1_hotplug(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size)
+{
+        struct w1_master *md = NULL;
+        struct w1_slave *sl = NULL;
+        char *event_owner, *name;
+        int err, cur_index=0, cur_len=0;
+
+        if (dev->driver == &w1_master_driver) {
+                md = container_of(dev, struct w1_master, dev);
+                event_owner = "master";
+                name = md->name;
+        } else if (dev->driver == &w1_slave_driver) {
+                sl = container_of(dev, struct w1_slave, dev);
+                event_owner = "slave";
+                name = sl->name;
+        } else {
+                dev_dbg(dev, "Unknown hotplug event.\n");
+                return -EINVAL;
+        }
+
+        dev_dbg(dev, "Hotplug event for %s %s, bus_id=%s.\n", event_owner, name, dev->bus_id);
+
+        if (dev->driver != &w1_slave_driver || !sl)
+                return 0;
+
+        err = add_hotplug_env_var(envp, num_envp, &cur_index, buffer, buffer_size, &cur_len, "W1_FID=%02X", sl->reg_num.family);
+        if (err)
+                return err;
+
+        err = add_hotplug_env_var(envp, num_envp, &cur_index, buffer, buffer_size, &cur_len, "W1_SLAVE_ID=%024llX", sl->reg_num.id);
+        if (err)
+                return err;
+
+        return 0;
+};
+#else
+static int w1_hotplug(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size)
+{
+        return 0;
+}
+#endif
+
 static int __w1_attach_slave_device(struct w1_slave *sl)
 {
         int err;
 
         sl->dev.parent = &sl->master->dev;
-        sl->dev.driver = sl->master->driver;
+        sl->dev.driver = &w1_slave_driver;
         sl->dev.bus = &w1_bus_type;
         sl->dev.release = &w1_slave_release;
 
@@ -507,7 +564,6 @@ void w1_reconnect_slaves(struct w1_family *f)
         spin_unlock_bh(&w1_mlock);
 }
 
-
 static void w1_slave_found(unsigned long data, u64 rn)
 {
         int slave_count;
@@ -783,7 +839,7 @@ static int w1_init(void)
                 goto err_out_exit_init;
         }
 
-        retval = driver_register(&w1_driver);
+        retval = driver_register(&w1_master_driver);
         if (retval) {
                 printk(KERN_ERR
                         "Failed to register master driver. err=%d.\n",
@@ -791,18 +847,29 @@ static int w1_init(void)
                 goto err_out_bus_unregister;
         }
 
+        retval = driver_register(&w1_slave_driver);
+        if (retval) {
+                printk(KERN_ERR
+                        "Failed to register master driver. err=%d.\n",
+                        retval);
+                goto err_out_master_unregister;
+        }
+
         control_thread = kernel_thread(&w1_control, NULL, 0);
         if (control_thread < 0) {
                 printk(KERN_ERR "Failed to create control thread. err=%d\n",
                         control_thread);
                 retval = control_thread;
-                goto err_out_driver_unregister;
+                goto err_out_slave_unregister;
         }
 
         return 0;
 
-err_out_driver_unregister:
-        driver_unregister(&w1_driver);
+err_out_slave_unregister:
+        driver_unregister(&w1_slave_driver);
+
+err_out_master_unregister:
+        driver_unregister(&w1_master_driver);
 
 err_out_bus_unregister:
         bus_unregister(&w1_bus_type);
@@ -821,7 +888,8 @@ static void w1_fini(void)
         control_needs_exit = 1;
         wait_for_completion(&w1_control_complete);
 
-        driver_unregister(&w1_driver);
+        driver_unregister(&w1_slave_driver);
+        driver_unregister(&w1_master_driver);
         bus_unregister(&w1_bus_type);
 }
 
diff --git a/drivers/w1/w1_int.c b/drivers/w1/w1_int.c
index 2a538d012194..c13724fd0971 100644
--- a/drivers/w1/w1_int.c
+++ b/drivers/w1/w1_int.c
@@ -29,9 +29,9 @@
 
 static u32 w1_ids = 1;
 
-extern struct device_driver w1_driver;
+extern struct device_driver w1_master_driver;
 extern struct bus_type w1_bus_type;
-extern struct device w1_device;
+extern struct device w1_master_device;
 extern int w1_max_slave_count;
 extern int w1_max_slave_ttl;
 extern struct list_head w1_masters;
@@ -125,7 +125,7 @@ int w1_add_master_device(struct w1_bus_master *master)
                 return(-EINVAL);
         }
 
-        dev = w1_alloc_dev(w1_ids++, w1_max_slave_count, w1_max_slave_ttl, &w1_driver, &w1_device);
+        dev = w1_alloc_dev(w1_ids++, w1_max_slave_count, w1_max_slave_ttl, &w1_master_driver, &w1_master_device);
         if (!dev)
                 return -ENOMEM;