dm: core: Add a clarifying comment on struct udevice's seq member

The sequence number is unique within the uclass, so state this clearly.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>

diff --git a/doc/driver-model/README.txt b/doc/driver-model/README.txt
index c435cdc6db10c9888a231a26d6806375186c141b..8dfcf75c3d369219b8cbc15782723013b94b0129 100644 (file)
--- 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
 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
 
 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 56862d32efc465de11113bdd7c4768128535eeef..9ce95a834e75ee54d6d7edefb21ee0f848f97e0f 100644 (file)
--- 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)
  * @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;
  */
 struct udevice {
        struct driver *driver;