Merge branch 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging

* 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
  i2c: New macro to initialize i2c address lists on the fly
  i2c: Don't advertise i2c functions when not available
  i2c: Use rwsem instead of mutex for board info
  i2c: Add a sysfs interface to instantiate devices
  i2c: Limit core locking to the necessary sections
  i2c: Kill the redundant client list
  i2c: Kill is_newstyle_driver
  i2c: Merge i2c_attach_client into i2c_new_device
  i2c: Drop i2c_probe function
  i2c: Get rid of the legacy binding model
  i2c: Kill client_register and client_unregister methods

3 files changed, 205 insertions, 363 deletions

diff --git a/drivers/i2c/i2c-boardinfo.c b/drivers/i2c/i2c-boardinfo.c
index ffb35f09df03..a26a34a06641 100644
--- a/drivers/i2c/i2c-boardinfo.c
+++ b/drivers/i2c/i2c-boardinfo.c
@@ -18,6 +18,7 @@
 
 #include <linux/kernel.h>
 #include <linux/i2c.h>
+#include <linux/rwsem.h>
 
 #include "i2c-core.h"
 
@@ -25,7 +26,7 @@
 /* These symbols are exported ONLY FOR the i2c core.
  * No other users will be supported.
  */
-DEFINE_MUTEX(__i2c_board_lock);
+DECLARE_RWSEM(__i2c_board_lock);
 EXPORT_SYMBOL_GPL(__i2c_board_lock);
 
 LIST_HEAD(__i2c_board_list);
@@ -63,7 +64,7 @@ i2c_register_board_info(int busnum,
 {
         int status;
 
-        mutex_lock(&__i2c_board_lock);
+        down_write(&__i2c_board_lock);
 
         /* dynamic bus numbers will be assigned after the last static one */
         if (busnum >= __i2c_first_dynamic_bus_num)
@@ -84,7 +85,7 @@ i2c_register_board_info(int busnum,
                 list_add_tail(&devinfo->list, &__i2c_board_list);
         }
 
-        mutex_unlock(&__i2c_board_lock);
+        up_write(&__i2c_board_lock);
 
         return status;
 }
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 5ed622ee65c3..0e45c296d3d2 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -33,16 +33,20 @@
 #include <linux/completion.h>
 #include <linux/hardirq.h>
 #include <linux/irqflags.h>
+#include <linux/rwsem.h>
 #include <asm/uaccess.h>
 
 #include "i2c-core.h"
 
 
+/* core_lock protects i2c_adapter_idr, userspace_devices, and guarantees
+   that device detection, deletion of detected devices, and attach_adapter
+   and detach_adapter calls are serialized */
 static DEFINE_MUTEX(core_lock);
 static DEFINE_IDR(i2c_adapter_idr);
+static LIST_HEAD(userspace_devices);
 
-#define is_newstyle_driver(d) ((d)->probe || (d)->remove || (d)->detect)
-
+static int i2c_check_addr(struct i2c_adapter *adapter, int addr);
 static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);
 
 /* ------------------------------------------------------------------------- */
@@ -63,12 +67,6 @@ static int i2c_device_match(struct device *dev, struct device_driver *drv)
         struct i2c_client       *client = to_i2c_client(dev);
         struct i2c_driver       *driver = to_i2c_driver(drv);
 
-        /* make legacy i2c drivers bypass driver model probing entirely;
-         * such drivers scan each i2c adapter/bus themselves.
-         */
-        if (!is_newstyle_driver(driver))
-                return 0;
-
         /* match on an id table if there is one */
         if (driver->id_table)
                 return i2c_match_id(driver->id_table, client) != NULL;
@@ -83,10 +81,6 @@ static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
         struct i2c_client       *client = to_i2c_client(dev);
 
-        /* by definition, legacy drivers can't hotplug */
-        if (dev->driver)
-                return 0;
-
         if (add_uevent_var(env, "MODALIAS=%s%s",
                            I2C_MODULE_PREFIX, client->name))
                 return -ENOMEM;
@@ -175,12 +169,6 @@ static int i2c_device_resume(struct device *dev)
         return driver->resume(to_i2c_client(dev));
 }
 
-static void i2c_client_release(struct device *dev)
-{
-        struct i2c_client *client = to_i2c_client(dev);
-        complete(&client->released);
-}
-
 static void i2c_client_dev_release(struct device *dev)
 {
         kfree(to_i2c_client(dev));
@@ -240,15 +228,17 @@ EXPORT_SYMBOL(i2c_verify_client);
 
 
 /**
- * i2c_new_device - instantiate an i2c device for use with a new style driver
+ * i2c_new_device - instantiate an i2c device
  * @adap: the adapter managing the device
  * @info: describes one I2C device; bus_num is ignored
  * Context: can sleep
  *
- * Create a device to work with a new style i2c driver, where binding is
- * handled through driver model probe()/remove() methods.  This call is not
- * appropriate for use by mainboad initialization logic, which usually runs
- * during an arch_initcall() long before any i2c_adapter could exist.
+ * Create an i2c device. Binding is handled through driver model
+ * probe()/remove() methods.  A driver may be bound to this device when we
+ * return from this function, or any later moment (e.g. maybe hotplugging will
+ * load the driver module).  This call is not appropriate for use by mainboard
+ * initialization logic, which usually runs during an arch_initcall() long
+ * before any i2c_adapter could exist.
  *
  * This returns the new i2c client, which may be saved for later use with
  * i2c_unregister_device(); or NULL to indicate an error.
@@ -276,17 +266,31 @@ i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
 
         strlcpy(client->name, info->type, sizeof(client->name));
 
-        /* a new style driver may be bound to this device when we
-         * return from this function, or any later moment (e.g. maybe
-         * hotplugging will load the driver module).  and the device
-         * refcount model is the standard driver model one.
-         */
-        status = i2c_attach_client(client);
-        if (status < 0) {
-                kfree(client);
-                client = NULL;
-        }
+        /* Check for address business */
+        status = i2c_check_addr(adap, client->addr);
+        if (status)
+                goto out_err;
+
+        client->dev.parent = &client->adapter->dev;
+        client->dev.bus = &i2c_bus_type;
+        client->dev.release = i2c_client_dev_release;
+
+        dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
+                     client->addr);
+        status = device_register(&client->dev);
+        if (status)
+                goto out_err;
+
+        dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n",
+                client->name, dev_name(&client->dev));
+
         return client;
+
+out_err:
+        dev_err(&adap->dev, "Failed to register i2c client %s at 0x%02x "
+                "(%d)\n", client->name, client->addr, status);
+        kfree(client);
+        return NULL;
 }
 EXPORT_SYMBOL_GPL(i2c_new_device);
 
@@ -298,28 +302,6 @@ EXPORT_SYMBOL_GPL(i2c_new_device);
  */
 void i2c_unregister_device(struct i2c_client *client)
 {
-        struct i2c_adapter      *adapter = client->adapter;
-        struct i2c_driver       *driver = client->driver;
-
-        if (driver && !is_newstyle_driver(driver)) {
-                dev_err(&client->dev, "can't unregister devices "
-                        "with legacy drivers\n");
-                WARN_ON(1);
-                return;
-        }
-
-        if (adapter->client_unregister) {
-                if (adapter->client_unregister(client)) {
-                        dev_warn(&client->dev,
-                                 "client_unregister [%s] failed\n",
-                                 client->name);
-                }
-        }
-
-        mutex_lock(&adapter->clist_lock);
-        list_del(&client->list);
-        mutex_unlock(&adapter->clist_lock);
-
         device_unregister(&client->dev);
 }
 EXPORT_SYMBOL_GPL(i2c_unregister_device);
@@ -393,8 +375,128 @@ show_adapter_name(struct device *dev, struct device_attribute *attr, char *buf)
         return sprintf(buf, "%s\n", adap->name);
 }
 
+/*
+ * Let users instantiate I2C devices through sysfs. This can be used when
+ * platform initialization code doesn't contain the proper data for
+ * whatever reason. Also useful for drivers that do device detection and
+ * detection fails, either because the device uses an unexpected address,
+ * or this is a compatible device with different ID register values.
+ *
+ * Parameter checking may look overzealous, but we really don't want
+ * the user to provide incorrect parameters.
+ */
+static ssize_t
+i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr,
+                     const char *buf, size_t count)
+{
+        struct i2c_adapter *adap = to_i2c_adapter(dev);
+        struct i2c_board_info info;
+        struct i2c_client *client;
+        char *blank, end;
+        int res;
+
+        dev_warn(dev, "The new_device interface is still experimental "
+                 "and may change in a near future\n");
+        memset(&info, 0, sizeof(struct i2c_board_info));
+
+        blank = strchr(buf, ' ');
+        if (!blank) {
+                dev_err(dev, "%s: Missing parameters\n", "new_device");
+                return -EINVAL;
+        }
+        if (blank - buf > I2C_NAME_SIZE - 1) {
+                dev_err(dev, "%s: Invalid device name\n", "new_device");
+                return -EINVAL;
+        }
+        memcpy(info.type, buf, blank - buf);
+
+        /* Parse remaining parameters, reject extra parameters */
+        res = sscanf(++blank, "%hi%c", &info.addr, &end);
+        if (res < 1) {
+                dev_err(dev, "%s: Can't parse I2C address\n", "new_device");
+                return -EINVAL;
+        }
+        if (res > 1  && end != '\n') {
+                dev_err(dev, "%s: Extra parameters\n", "new_device");
+                return -EINVAL;
+        }
+
+        if (info.addr < 0x03 || info.addr > 0x77) {
+                dev_err(dev, "%s: Invalid I2C address 0x%hx\n", "new_device",
+                        info.addr);
+                return -EINVAL;
+        }
+
+        client = i2c_new_device(adap, &info);
+        if (!client)
+                return -EEXIST;
+
+        /* Keep track of the added device */
+        mutex_lock(&core_lock);
+        list_add_tail(&client->detected, &userspace_devices);
+        mutex_unlock(&core_lock);
+        dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device",
+                 info.type, info.addr);
+
+        return count;
+}
+
+/*
+ * And of course let the users delete the devices they instantiated, if
+ * they got it wrong. This interface can only be used to delete devices
+ * instantiated by i2c_sysfs_new_device above. This guarantees that we
+ * don't delete devices to which some kernel code still has references.
+ *
+ * Parameter checking may look overzealous, but we really don't want
+ * the user to delete the wrong device.
+ */
+static ssize_t
+i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr,
+                        const char *buf, size_t count)
+{
+        struct i2c_adapter *adap = to_i2c_adapter(dev);
+        struct i2c_client *client, *next;
+        unsigned short addr;
+        char end;
+        int res;
+
+        /* Parse parameters, reject extra parameters */
+        res = sscanf(buf, "%hi%c", &addr, &end);
+        if (res < 1) {
+                dev_err(dev, "%s: Can't parse I2C address\n", "delete_device");
+                return -EINVAL;
+        }
+        if (res > 1  && end != '\n') {
+                dev_err(dev, "%s: Extra parameters\n", "delete_device");
+                return -EINVAL;
+        }
+
+        /* Make sure the device was added through sysfs */
+        res = -ENOENT;
+        mutex_lock(&core_lock);
+        list_for_each_entry_safe(client, next, &userspace_devices, detected) {
+                if (client->addr == addr && client->adapter == adap) {
+                        dev_info(dev, "%s: Deleting device %s at 0x%02hx\n",
+                                 "delete_device", client->name, client->addr);
+
+                        list_del(&client->detected);
+                        i2c_unregister_device(client);
+                        res = count;
+                        break;
+                }
+        }
+        mutex_unlock(&core_lock);
+
+        if (res < 0)
+                dev_err(dev, "%s: Can't find device in list\n",
+                        "delete_device");
+        return res;
+}
+
 static struct device_attribute i2c_adapter_attrs[] = {
         __ATTR(name, S_IRUGO, show_adapter_name, NULL),
+        __ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device),
+        __ATTR(delete_device, S_IWUSR, NULL, i2c_sysfs_delete_device),
         { },
 };
 
@@ -408,7 +510,7 @@ static void i2c_scan_static_board_info(struct i2c_adapter *adapter)
 {
         struct i2c_devinfo      *devinfo;
 
-        mutex_lock(&__i2c_board_lock);
+        down_read(&__i2c_board_lock);
         list_for_each_entry(devinfo, &__i2c_board_list, list) {
                 if (devinfo->busnum == adapter->nr
                                 && !i2c_new_device(adapter,
@@ -417,7 +519,7 @@ static void i2c_scan_static_board_info(struct i2c_adapter *adapter)
                                 "Can't create device at 0x%02x\n",
                                 devinfo->board_info.addr);
         }
-        mutex_unlock(&__i2c_board_lock);
+        up_read(&__i2c_board_lock);
 }
 
 static int i2c_do_add_adapter(struct device_driver *d, void *data)
@@ -441,14 +543,12 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
         int res = 0, dummy;
 
         /* Can't register until after driver model init */
-        if (unlikely(WARN_ON(!i2c_bus_type.p)))
-                return -EAGAIN;
+        if (unlikely(WARN_ON(!i2c_bus_type.p))) {
+                res = -EAGAIN;
+                goto out_list;
+        }
 
         mutex_init(&adap->bus_lock);
-        mutex_init(&adap->clist_lock);
-        INIT_LIST_HEAD(&adap->clients);
-
-        mutex_lock(&core_lock);
 
         /* Set default timeout to 1 second if not already set */
         if (adap->timeout == 0)
@@ -463,21 +563,23 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
 
         dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
 
-        /* create pre-declared device nodes for new-style drivers */
+        /* create pre-declared device nodes */
         if (adap->nr < __i2c_first_dynamic_bus_num)
                 i2c_scan_static_board_info(adap);
 
         /* Notify drivers */
+        mutex_lock(&core_lock);
         dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap,
                                  i2c_do_add_adapter);
-
-out_unlock:
         mutex_unlock(&core_lock);
-        return res;
+
+        return 0;
 
 out_list:
+        mutex_lock(&core_lock);
         idr_remove(&i2c_adapter_idr, adap->nr);
-        goto out_unlock;
+        mutex_unlock(&core_lock);
+        return res;
 }
 
 /**
@@ -596,6 +698,14 @@ static int i2c_do_del_adapter(struct device_driver *d, void *data)
         return res;
 }
 
+static int __unregister_client(struct device *dev, void *dummy)
+{
+        struct i2c_client *client = i2c_verify_client(dev);
+        if (client)
+                i2c_unregister_device(client);
+        return 0;
+}
+
 /**
  * i2c_del_adapter - unregister I2C adapter
  * @adap: the adapter being unregistered
@@ -606,46 +716,30 @@ static int i2c_do_del_adapter(struct device_driver *d, void *data)
  */
 int i2c_del_adapter(struct i2c_adapter *adap)
 {
-        struct i2c_client *client, *_n;
         int res = 0;
-
-        mutex_lock(&core_lock);
+        struct i2c_adapter *found;
 
         /* First make sure that this adapter was ever added */
-        if (idr_find(&i2c_adapter_idr, adap->nr) != adap) {
+        mutex_lock(&core_lock);
+        found = idr_find(&i2c_adapter_idr, adap->nr);
+        mutex_unlock(&core_lock);
+        if (found != adap) {
                 pr_debug("i2c-core: attempting to delete unregistered "
                          "adapter [%s]\n", adap->name);
-                res = -EINVAL;
-                goto out_unlock;
+                return -EINVAL;
         }
 
         /* Tell drivers about this removal */
+        mutex_lock(&core_lock);
         res = bus_for_each_drv(&i2c_bus_type, NULL, adap,
                                i2c_do_del_adapter);
+        mutex_unlock(&core_lock);
         if (res)
-                goto out_unlock;
-
-        /* detach any active clients. This must be done first, because
-         * it can fail; in which case we give up. */
-        list_for_each_entry_safe_reverse(client, _n, &adap->clients, list) {
-                struct i2c_driver       *driver;
-
-                driver = client->driver;
-
-                /* new style, follow standard driver model */
-                if (!driver || is_newstyle_driver(driver)) {
-                        i2c_unregister_device(client);
-                        continue;
-                }
+                return res;
 
-                /* legacy drivers create and remove clients themselves */
-                if ((res = driver->detach_client(client))) {
-                        dev_err(&adap->dev, "detach_client failed for client "
-                                "[%s] at address 0x%02x\n", client->name,
-                                client->addr);
-                        goto out_unlock;
-                }
-        }
+        /* Detach any active clients. This can't fail, thus we do not
+           checking the returned value. */
+        res = device_for_each_child(&adap->dev, NULL, __unregister_client);
 
         /* clean up the sysfs representation */
         init_completion(&adap->dev_released);
@@ -655,7 +749,9 @@ int i2c_del_adapter(struct i2c_adapter *adap)
         wait_for_completion(&adap->dev_released);
 
         /* free bus id */
+        mutex_lock(&core_lock);
         idr_remove(&i2c_adapter_idr, adap->nr);
+        mutex_unlock(&core_lock);
 
         dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
 
@@ -663,9 +759,7 @@ int i2c_del_adapter(struct i2c_adapter *adap)
            added again */
         memset(&adap->dev, 0, sizeof(adap->dev));
 
- out_unlock:
-        mutex_unlock(&core_lock);
-        return res;
+        return 0;
 }
 EXPORT_SYMBOL(i2c_del_adapter);
 
@@ -688,11 +782,7 @@ static int __attach_adapter(struct device *dev, void *data)
 
 /*
  * An i2c_driver is used with one or more i2c_client (device) nodes to access
- * i2c slave chips, on a bus instance associated with some i2c_adapter.  There
- * are two models for binding the driver to its device:  "new style" drivers
- * follow the standard Linux driver model and just respond to probe() calls
- * issued if the driver core sees they match(); "legacy" drivers create device
- * nodes themselves.
+ * i2c slave chips, on a bus instance associated with some i2c_adapter.
  */
 
 int i2c_register_driver(struct module *owner, struct i2c_driver *driver)
@@ -703,37 +793,26 @@ int i2c_register_driver(struct module *owner, struct i2c_driver *driver)
         if (unlikely(WARN_ON(!i2c_bus_type.p)))
                 return -EAGAIN;
 
-        /* new style driver methods can't mix with legacy ones */
-        if (is_newstyle_driver(driver)) {
-                if (driver->detach_adapter || driver->detach_client) {
-                        printk(KERN_WARNING
-                                        "i2c-core: driver [%s] is confused\n",
-                                        driver->driver.name);
-                        return -EINVAL;
-                }
-        }
-
         /* add the driver to the list of i2c drivers in the driver core */
         driver->driver.owner = owner;
         driver->driver.bus = &i2c_bus_type;
 
-        /* for new style drivers, when registration returns the driver core
+        /* When registration returns, the driver core
          * will have called probe() for all matching-but-unbound devices.
          */
         res = driver_register(&driver->driver);
         if (res)
                 return res;
 
-        mutex_lock(&core_lock);
-
         pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name);
 
         INIT_LIST_HEAD(&driver->clients);
         /* Walk the adapters that are already present */
+        mutex_lock(&core_lock);
         class_for_each_device(&i2c_adapter_class, NULL, driver,
                               __attach_adapter);
-
         mutex_unlock(&core_lock);
+
         return 0;
 }
 EXPORT_SYMBOL(i2c_register_driver);
@@ -753,32 +832,11 @@ static int __detach_adapter(struct device *dev, void *data)
                 i2c_unregister_device(client);
         }
 
-        if (is_newstyle_driver(driver))
-                return 0;
-
-        /* Have a look at each adapter, if clients of this driver are still
-         * attached. If so, detach them to be able to kill the driver
-         * afterwards.
-         */
         if (driver->detach_adapter) {
                 if (driver->detach_adapter(adapter))
                         dev_err(&adapter->dev,
                                 "detach_adapter failed for driver [%s]\n",
                                 driver->driver.name);
-        } else {
-                struct i2c_client *client, *_n;
-
-                list_for_each_entry_safe(client, _n, &adapter->clients, list) {
-                        if (client->driver != driver)
-                                continue;
-                        dev_dbg(&adapter->dev,
-                                "detaching client [%s] at 0x%02x\n",
-                                client->name, client->addr);
-                        if (driver->detach_client(client))
-                                dev_err(&adapter->dev, "detach_client "
-                                        "failed for client [%s] at 0x%02x\n",
-                                        client->name, client->addr);
-                }
         }
 
         return 0;
@@ -792,14 +850,12 @@ static int __detach_adapter(struct device *dev, void *data)
 void i2c_del_driver(struct i2c_driver *driver)
 {
         mutex_lock(&core_lock);
-
         class_for_each_device(&i2c_adapter_class, NULL, driver,
                               __detach_adapter);
+        mutex_unlock(&core_lock);
 
         driver_unregister(&driver->driver);
         pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name);
-
-        mutex_unlock(&core_lock);
 }
 EXPORT_SYMBOL(i2c_del_driver);
 
@@ -820,86 +876,6 @@ static int i2c_check_addr(struct i2c_adapter *adapter, int addr)
         return device_for_each_child(&adapter->dev, &addr, __i2c_check_addr);
 }
 
-int i2c_attach_client(struct i2c_client *client)
-{
-        struct i2c_adapter *adapter = client->adapter;
-        int res;
-
-        /* Check for address business */
-        res = i2c_check_addr(adapter, client->addr);
-        if (res)
-                return res;
-
-        client->dev.parent = &client->adapter->dev;
-        client->dev.bus = &i2c_bus_type;
-
-        if (client->driver)
-                client->dev.driver = &client->driver->driver;
-
-        if (client->driver && !is_newstyle_driver(client->driver)) {
-                client->dev.release = i2c_client_release;
-                dev_set_uevent_suppress(&client->dev, 1);
-        } else
-                client->dev.release = i2c_client_dev_release;
-
-        dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adapter),
-                     client->addr);
-        res = device_register(&client->dev);
-        if (res)
-                goto out_err;
-
-        mutex_lock(&adapter->clist_lock);
-        list_add_tail(&client->list, &adapter->clients);
-        mutex_unlock(&adapter->clist_lock);
-
-        dev_dbg(&adapter->dev, "client [%s] registered with bus id %s\n",
-                client->name, dev_name(&client->dev));
-
-        if (adapter->client_register)  {
-                if (adapter->client_register(client)) {
-                        dev_dbg(&adapter->dev, "client_register "
-                                "failed for client [%s] at 0x%02x\n",
-                                client->name, client->addr);
-                }
-        }
-
-        return 0;
-
-out_err:
-        dev_err(&adapter->dev, "Failed to attach i2c client %s at 0x%02x "
-                "(%d)\n", client->name, client->addr, res);
-        return res;
-}
-EXPORT_SYMBOL(i2c_attach_client);
-
-int i2c_detach_client(struct i2c_client *client)
-{
-        struct i2c_adapter *adapter = client->adapter;
-        int res = 0;
-
-        if (adapter->client_unregister)  {
-                res = adapter->client_unregister(client);
-                if (res) {
-                        dev_err(&client->dev,
-                                "client_unregister [%s] failed, "
-                                "client not detached\n", client->name);
-                        goto out;
-                }
-        }
-
-        mutex_lock(&adapter->clist_lock);
-        list_del(&client->list);
-        mutex_unlock(&adapter->clist_lock);
-
-        init_completion(&client->released);
-        device_unregister(&client->dev);
-        wait_for_completion(&client->released);
-
- out:
-        return res;
-}
-EXPORT_SYMBOL(i2c_detach_client);
-
 /**
  * i2c_use_client - increments the reference count of the i2c client structure
  * @client: the client being referenced
@@ -1129,144 +1105,7 @@ EXPORT_SYMBOL(i2c_master_recv);
  * Will not work for 10-bit addresses!
  * ----------------------------------------------------
  */
-static int i2c_probe_address(struct i2c_adapter *adapter, int addr, int kind,
-                             int (*found_proc) (struct i2c_adapter *, int, int))
-{
-        int err;
-
-        /* Make sure the address is valid */
-        if (addr < 0x03 || addr > 0x77) {
-                dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",
-                         addr);
-                return -EINVAL;
-        }
-
-        /* Skip if already in use */
-        if (i2c_check_addr(adapter, addr))
-                return 0;
-
-        /* Make sure there is something at this address, unless forced */
-        if (kind < 0) {
-                if (i2c_smbus_xfer(adapter, addr, 0, 0, 0,
-                                   I2C_SMBUS_QUICK, NULL) < 0)
-                        return 0;
-
-                /* prevent 24RF08 corruption */
-                if ((addr & ~0x0f) == 0x50)
-                        i2c_smbus_xfer(adapter, addr, 0, 0, 0,
-                                       I2C_SMBUS_QUICK, NULL);
-        }
-
-        /* Finally call the custom detection function */
-        err = found_proc(adapter, addr, kind);
-        /* -ENODEV can be returned if there is a chip at the given address
-           but it isn't supported by this chip driver. We catch it here as
-           this isn't an error. */
-        if (err == -ENODEV)
-                err = 0;
-
-        if (err)
-                dev_warn(&adapter->dev, "Client creation failed at 0x%x (%d)\n",
-                         addr, err);
-        return err;
-}
-
-int i2c_probe(struct i2c_adapter *adapter,
-              const struct i2c_client_address_data *address_data,
-              int (*found_proc) (struct i2c_adapter *, int, int))
-{
-        int i, err;
-        int adap_id = i2c_adapter_id(adapter);
-
-        /* Force entries are done first, and are not affected by ignore
-           entries */
-        if (address_data->forces) {
-                const unsigned short * const *forces = address_data->forces;
-                int kind;
-
-                for (kind = 0; forces[kind]; kind++) {
-                        for (i = 0; forces[kind][i] != I2C_CLIENT_END;
-                             i += 2) {
-                                if (forces[kind][i] == adap_id
-                                 || forces[kind][i] == ANY_I2C_BUS) {
-                                        dev_dbg(&adapter->dev, "found force "
-                                                "parameter for adapter %d, "
-                                                "addr 0x%02x, kind %d\n",
-                                                adap_id, forces[kind][i + 1],
-                                                kind);
-                                        err = i2c_probe_address(adapter,
-                                                forces[kind][i + 1],
-                                                kind, found_proc);
-                                        if (err)
-                                                return err;
-                                }
-                        }
-                }
-        }
-
-        /* Stop here if we can't use SMBUS_QUICK */
-        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK)) {
-                if (address_data->probe[0] == I2C_CLIENT_END
-                 && address_data->normal_i2c[0] == I2C_CLIENT_END)
-                        return 0;
-
-                dev_dbg(&adapter->dev, "SMBus Quick command not supported, "
-                        "can't probe for chips\n");
-                return -EOPNOTSUPP;
-        }
-
-        /* Probe entries are done second, and are not affected by ignore
-           entries either */
-        for (i = 0; address_data->probe[i] != I2C_CLIENT_END; i += 2) {
-                if (address_data->probe[i] == adap_id
-                 || address_data->probe[i] == ANY_I2C_BUS) {
-                        dev_dbg(&adapter->dev, "found probe parameter for "
-                                "adapter %d, addr 0x%02x\n", adap_id,
-                                address_data->probe[i + 1]);
-                        err = i2c_probe_address(adapter,
-                                                address_data->probe[i + 1],
-                                                -1, found_proc);
-                        if (err)
-                                return err;
-                }
-        }
-
-        /* Normal entries are done last, unless shadowed by an ignore entry */
-        for (i = 0; address_data->normal_i2c[i] != I2C_CLIENT_END; i += 1) {
-                int j, ignore;
-
-                ignore = 0;
-                for (j = 0; address_data->ignore[j] != I2C_CLIENT_END;
-                     j += 2) {
-                        if ((address_data->ignore[j] == adap_id ||
-                             address_data->ignore[j] == ANY_I2C_BUS)
-                         && address_data->ignore[j + 1]
-                            == address_data->normal_i2c[i]) {
-                                dev_dbg(&adapter->dev, "found ignore "
-                                        "parameter for adapter %d, "
-                                        "addr 0x%02x\n", adap_id,
-                                        address_data->ignore[j + 1]);
-                                ignore = 1;
-                                break;
-                        }
-                }
-                if (ignore)
-                        continue;
-
-                dev_dbg(&adapter->dev, "found normal entry for adapter %d, "
-                        "addr 0x%02x\n", adap_id,
-                        address_data->normal_i2c[i]);
-                err = i2c_probe_address(adapter, address_data->normal_i2c[i],
-                                        -1, found_proc);
-                if (err)
-                        return err;
-        }
-
-        return 0;
-}
-EXPORT_SYMBOL(i2c_probe);
 
-/* Separate detection function for new-style drivers */
 static int i2c_detect_address(struct i2c_client *temp_client, int kind,
                               struct i2c_driver *driver)
 {
diff --git a/drivers/i2c/i2c-core.h b/drivers/i2c/i2c-core.h
index cd5bff874855..9f9c57ff6708 100644
--- a/drivers/i2c/i2c-core.h
+++ b/drivers/i2c/i2c-core.h
@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include <linux/rwsem.h>
+
 struct i2c_devinfo {
         struct list_head        list;
         int                     busnum;
@@ -25,7 +27,7 @@ struct i2c_devinfo {
 /* board_lock protects board_list and first_dynamic_bus_num.
  * only i2c core components are allowed to use these symbols.
  */
-extern struct mutex     __i2c_board_lock;
+extern struct rw_semaphore      __i2c_board_lock;
 extern struct list_head __i2c_board_list;
 extern int              __i2c_first_dynamic_bus_num;