diff options
| -rw-r--r-- | doc/driver-model/README.txt | 4 | ||||
| -rw-r--r-- | include/dm/device.h | 3 |
2 files changed, 5 insertions, 2 deletions
diff --git a/doc/driver-model/README.txt b/doc/driver-model/README.txt index c435cdc..8dfcf75 100644 --- a/doc/driver-model/README.txt +++ b/doc/driver-model/README.txt @@ -359,7 +359,9 @@ Device Sequence Numbers U-Boot numbers devices from 0 in many situations, such as in the command line for I2C and SPI buses, and the device names for serial ports (serial0, serial1, ...). Driver model supports this numbering and permits devices -to be locating by their 'sequence'. +to be locating by their 'sequence'. This numbering unique identifies a +device in its uclass, so no two devices within a particular uclass can have +the same sequence number. Sequence numbers start from 0 but gaps are permitted. For example, a board may have I2C buses 0, 1, 4, 5 but no 2 or 3. The choice of how devices are diff --git a/include/dm/device.h b/include/dm/device.h index 56862d3..9ce95a8 100644 --- a/include/dm/device.h +++ b/include/dm/device.h @@ -57,7 +57,8 @@ struct driver_info; * @sibling_node: Next device in list of all devices * @flags: Flags for this device DM_FLAG_... * @req_seq: Requested sequence number for this device (-1 = any) - * @seq: Allocated sequence number for this device (-1 = none) + * @seq: Allocated sequence number for this device (-1 = none). This is set up + * when the device is probed and will be unique within the device's uclass. */ struct udevice { struct driver *driver; |