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-rw-r--r--Documentation/ABI/testing/sysfs-bus-i3c20
1 files changed, 20 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-i3c b/Documentation/ABI/testing/sysfs-bus-i3c
index c1e048957a01..19f5cf8b1b11 100644
--- a/Documentation/ABI/testing/sysfs-bus-i3c
+++ b/Documentation/ABI/testing/sysfs-bus-i3c
@@ -172,3 +172,23 @@ Description:
the automatic retries. Exist only when I3C constroller supports
this retry on nack feature.
+What: /sys/bus/i3c/devices/i3c-<bus-id>/do_daa
+KernelVersion: 7.0
+Contact: linux-i3c@vger.kernel.org
+Description:
+ Write-only attribute that triggers a Dynamic Address Assignment
+ (DAA) procedure which discovers new I3C devices on the bus.
+ Writing a boolean true value (1, y, yes, true, on) to this
+ attribute causes the master controller to perform DAA, which
+ includes broadcasting an ENTDAA (Enter Dynamic Address Assignment)
+ Common Command Code (CCC) on the bus. Writing a false value
+ returns -EINVAL.
+
+ This is useful for discovering I3C devices that were not present
+ during initial bus initialization and are unable to issue
+ Hot-Join. Only devices without a currently assigned dynamic address
+ will respond to the ENTDAA broadcast and be assigned addresses.
+
+ Note that this mechanism is distinct from Hot-Join, since this is
+ controller-initiated discovery, while Hot-Join is device-initiated
+ method to provoke controller discovery procedure.