diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index a7dcdc69b9e76bb59ec8d9b2e9704e588abd7102..c50229bd9f85b95be01930721e4e08109352d478 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -320,38 +320,19 @@ static void i2c_scan_static_board_info(struct i2c_adapter *adapter)
mutex_unlock(&__i2c_board_lock);
}
-
-/* -----
- * i2c_add_adapter is called from within the algorithm layer,
- * when a new hw adapter registers. A new device is register to be
- * available for clients.
- */
-int i2c_add_adapter(struct i2c_adapter *adap)
+static int i2c_register_adapter(struct i2c_adapter *adap)
{
- int id, res = 0;
+ int res = 0;
struct list_head *item;
struct i2c_driver *driver;
- mutex_lock(&core_lists);
-
- if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) {
- res = -ENOMEM;
- goto out_unlock;
- }
-
- res = idr_get_new(&i2c_adapter_idr, adap, &id);
- if (res < 0) {
- if (res == -EAGAIN)
- res = -ENOMEM;
- goto out_unlock;
- }
-
- adap->nr = id & MAX_ID_MASK;
mutex_init(&adap->bus_lock);
mutex_init(&adap->clist_lock);
- list_add_tail(&adap->list,&adapters);
INIT_LIST_HEAD(&adap->clients);
+ mutex_lock(&core_lists);
+ list_add_tail(&adap->list, &adapters);
+
/* Add the adapter to the driver core.
* If the parent pointer is not set up,
* we add this adapter to the host bus.
@@ -370,6 +351,10 @@ int i2c_add_adapter(struct i2c_adapter *adap)
dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
+ /* create pre-declared device nodes for new-style drivers */
+ if (adap->nr < __i2c_first_dynamic_bus_num)
+ i2c_scan_static_board_info(adap);
+
/* let legacy drivers scan this bus for matching devices */
list_for_each(item,&drivers) {
driver = list_entry(item, struct i2c_driver, list);
@@ -388,6 +373,93 @@ int i2c_add_adapter(struct i2c_adapter *adap)
goto out_unlock;
}
+/**
+ * i2c_add_adapter - declare i2c adapter, use dynamic bus number
+ * @adapter: the adapter to add
+ *
+ * This routine is used to declare an I2C adapter when its bus number
+ * doesn't matter. Examples: for I2C adapters dynamically added by
+ * USB links or PCI plugin cards.
+ *
+ * When this returns zero, a new bus number was allocated and stored
+ * in adap->nr, and the specified adapter became available for clients.
+ * Otherwise, a negative errno value is returned.
+ */
+int i2c_add_adapter(struct i2c_adapter *adapter)
+{
+ int id, res = 0;
+
+retry:
+ if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0)
+ return -ENOMEM;
+
+ mutex_lock(&core_lists);
+ /* "above" here means "above or equal to", sigh */
+ res = idr_get_new_above(&i2c_adapter_idr, adapter,
+ __i2c_first_dynamic_bus_num, &id);
+ mutex_unlock(&core_lists);
+
+ if (res < 0) {
+ if (res == -EAGAIN)
+ goto retry;
+ return res;
+ }
+
+ adapter->nr = id;
+ return i2c_register_adapter(adapter);
+}
+EXPORT_SYMBOL(i2c_add_adapter);
+
+/**
+ * i2c_add_numbered_adapter - declare i2c adapter, use static bus number
+ * @adap: the adapter to register (with adap->nr initialized)
+ *
+ * This routine is used to declare an I2C adapter when its bus number
+ * matters. Example: for I2C adapters from system-on-chip CPUs, or
+ * otherwise built in to the system's mainboard, and where i2c_board_info
+ * is used to properly configure I2C devices.
+ *
+ * If no devices have pre-been declared for this bus, then be sure to
+ * register the adapter before any dynamically allocated ones. Otherwise
+ * the required bus ID may not be available.
+ *
+ * When this returns zero, the specified adapter became available for
+ * clients using the bus number provided in adap->nr. Also, the table
+ * of I2C devices pre-declared using i2c_register_board_info() is scanned,
+ * and the appropriate driver model device nodes are created. Otherwise, a
+ * negative errno value is returned.
+ */
+int i2c_add_numbered_adapter(struct i2c_adapter *adap)
+{
+ int id;
+ int status;
+
+ if (adap->nr & ~MAX_ID_MASK)
+ return -EINVAL;
+
+retry:
+ if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0)
+ return -ENOMEM;
+
+ mutex_lock(&core_lists);
+ /* "above" here means "above or equal to", sigh;
+ * we need the "equal to" result to force the result
+ */
+ status = idr_get_new_above(&i2c_adapter_idr, adap, adap->nr, &id);
+ if (status == 0 && id != adap->nr) {
+ status = -EBUSY;
+ idr_remove(&i2c_adapter_idr, id);
+ }
+ mutex_unlock(&core_lists);
+ if (status == -EAGAIN)
+ goto retry;
+
+ if (status == 0)
+ status = i2c_register_adapter(adap);
+ return status;
+}
+EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter);
+
int i2c_del_adapter(struct i2c_adapter *adap)
{
struct list_head *item, *_n;
@@ -452,7 +524,7 @@ int i2c_del_adapter(struct i2c_adapter *adap)
/* wait for sysfs to drop all references */
wait_for_completion(&adap->dev_released);
- /* free dynamically allocated bus id */
+ /* free bus id */
idr_remove(&i2c_adapter_idr, adap->nr);
dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
@@ -493,6 +565,9 @@ int i2c_register_driver(struct module *owner, struct i2c_driver *driver)
driver->driver.owner = owner;
driver->driver.bus = &i2c_bus_type;
+ /* for new style drivers, 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;
@@ -1377,7 +1452,6 @@ EXPORT_SYMBOL_GPL(i2c_adapter_dev_release);
EXPORT_SYMBOL_GPL(i2c_adapter_class);
EXPORT_SYMBOL_GPL(i2c_bus_type);
-EXPORT_SYMBOL(i2c_add_adapter);
EXPORT_SYMBOL(i2c_del_adapter);
EXPORT_SYMBOL(i2c_del_driver);
EXPORT_SYMBOL(i2c_attach_client);
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 382a43bf3ad581414acd50e3a1d0f9fb8ffb152f..36d6814a6df42485e5220a55e203ecbeb04f3a81 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -363,6 +363,7 @@ struct i2c_client_address_data {
*/
extern int i2c_add_adapter(struct i2c_adapter *);
extern int i2c_del_adapter(struct i2c_adapter *);
+extern int i2c_add_numbered_adapter(struct i2c_adapter *);
extern int i2c_register_driver(struct module *, struct i2c_driver *);
extern int i2c_del_driver(struct i2c_driver *);