i3c: mipi-i3c-hci: Add Hot-Join support

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Wire the MIPI I3C HCI driver into the I3C core Hot-Join framework to
allow targets to dynamically join the bus after initial DAA.

HCI hardware ACKs or NACKs Hot-Join requests based on
HC_CONTROL.HOT_JOIN_CTRL.  This was previously left in the
NACK-and-DISEC state, effectively preventing Hot-Join.  Implement
the ->enable_hotjoin() and ->disable_hotjoin() master operations
so the core and user space can control this policy at runtime.

Also issue broadcast ENEC HJ when enabling Hot-Join.  This is required
because the controller may have previously DISEC'ed the Hot-Join
event, causing targets that were NACKed once to never retry.

Acknowledged Hot-Join requests are delivered as IBIs on the reserved
address 0x02.  Update both the DMA and PIO IBI paths to recognise this
address and forward the event to i3c_master_queue_hotjoin().

To make Hot-Join usable by default, enable it once after the initial
DAA.  This is gated by rpm_ibi_allowed, since otherwise keeping Hot-Join
enabled prevents runtime suspend.  A new hj_init_done flag ensures this
one-time enablement is not repeated on subsequent DAAs.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260608054312.10604-9-adrian.hunter@intel.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

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This commit is contained in:

Adrian Hunter 2026-06-08 08:43:12 +03:00 • committed by Alexandre Belloni

parent 4bfba7b360

commit 32fcf00398

4 changed files with 58 additions and 3 deletions

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52

drivers/i3c/master/mipi-i3c-hci/core.c

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5

drivers/i3c/master/mipi-i3c-hci/dma.c

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1

drivers/i3c/master/mipi-i3c-hci/hci.h

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5

drivers/i3c/master/mipi-i3c-hci/pio.c

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