diff options
Diffstat (limited to 'drivers/i2c/i2c.c')
-rw-r--r-- | drivers/i2c/i2c.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/drivers/i2c/i2c.c b/drivers/i2c/i2c.c index 32fd026de5..1fa114a31c 100644 --- a/drivers/i2c/i2c.c +++ b/drivers/i2c/i2c.c @@ -39,7 +39,7 @@ struct boardinfo { }; static LIST_HEAD(board_list); - +static LIST_HEAD(adapter_list); /** * i2c_transfer - execute a single or combined I2C message @@ -327,6 +327,23 @@ static void scan_boardinfo(struct i2c_adapter *adapter) } /** + * + * i2c_get_adapter - get an i2c adapter from its busnum + * + * @param busnum the desired bus number + * + */ +struct i2c_adapter *i2c_get_adapter(int busnum) +{ + struct i2c_adapter *adap; + + list_for_each_entry(adap, &adapter_list, list) + if (adap->nr == busnum) + return adap; + return NULL; +} + +/** * i2c_register_master - register I2C master controller * * @param master initialized master, originally from i2c_alloc_master() @@ -345,6 +362,11 @@ static void scan_boardinfo(struct i2c_adapter *adapter) */ int i2c_add_numbered_adapter(struct i2c_adapter *adapter) { + if (i2c_get_adapter(adapter->nr)) + return -EBUSY; + + list_add_tail(&adapter_list, &adapter->list); + /* populate children from any i2c device tables */ scan_boardinfo(adapter); |