diff options
| -rw-r--r-- | drivers/i2c/i2c-core.c | 45 |
1 files changed, 34 insertions, 11 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 991d38daa87d..f7dfe878a51b 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -921,13 +921,35 @@ out_list: } /** + * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1 + * @adap: the adapter to register (with adap->nr initialized) + * Context: can sleep + * + * See i2c_add_numbered_adapter() for details. + */ +static int __i2c_add_numbered_adapter(struct i2c_adapter *adap) +{ + int id; + + mutex_lock(&core_lock); + id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, + GFP_KERNEL); + mutex_unlock(&core_lock); + if (id < 0) + return id == -ENOSPC ? -EBUSY : id; + + return i2c_register_adapter(adap); +} + +/** * i2c_add_adapter - declare i2c adapter, use dynamic bus number * @adapter: the adapter to add * Context: can sleep * * 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. + * doesn't matter or when its bus number is specified by an dt alias. + * Examples of bases when the bus number doesn't matter: 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. @@ -935,8 +957,17 @@ out_list: */ int i2c_add_adapter(struct i2c_adapter *adapter) { + struct device *dev = &adapter->dev; int id; + if (dev->of_node) { + id = of_alias_get_id(dev->of_node, "i2c"); + if (id >= 0) { + adapter->nr = id; + return __i2c_add_numbered_adapter(adapter); + } + } + mutex_lock(&core_lock); id = idr_alloc(&i2c_adapter_idr, adapter, __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); @@ -975,18 +1006,10 @@ EXPORT_SYMBOL(i2c_add_adapter); */ int i2c_add_numbered_adapter(struct i2c_adapter *adap) { - int id; - if (adap->nr == -1) /* -1 means dynamically assign bus id */ return i2c_add_adapter(adap); - mutex_lock(&core_lock); - id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, - GFP_KERNEL); - mutex_unlock(&core_lock); - if (id < 0) - return id == -ENOSPC ? -EBUSY : id; - return i2c_register_adapter(adap); + return __i2c_add_numbered_adapter(adap); } EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); |