linux-stable.git/include/linux/i3c/master.h, branch v7.3-rc2

i3c: master: dw-i3c-master: fix OD timing for first broadcast

2026-08-08T13:10:34+00:00

Implement ->set_speed() so the I3C core can switch open-drain timing for
the first broadcast address per spec: I3C_OPEN_DRAIN_SLOW_SPEED programs
tHIGH_INIT (200 ns) before RSTDAA, and I3C_OPEN_DRAIN_NORMAL_SPEED restores
normal OD timing afterward. Cache the normal OD register value during bus
init and use a separate od_hcnt for the slow path so SDR extended timing
remains derived from the normal PP hcnt.

For AMD_I3C_OD_PP_TIMING, cache AMD_I3C_OD_TIMING as the normal OD
baseline and stop rewriting OD timing in send_ccc_cmd()/runtime resume so
I3C_OPEN_DRAIN_SLOW_SPEED is preserved through RSTDAA.

Use PM_RUNTIME_ACQUIRE_AUTOSUSPEND() in set_speed(). Compute od_hcnt with
DIV_ROUND_UP_ULL() for 32-bit safety and clamp it to U8_MAX to match the
8-bit I3C_OD_HCNT field.

Fixes I2C devices with spike filters not being detected on mixed buses.

Signed-off-by: Tze Yee Ng 
Reviewed-by: Frank Li 
Link: https://patch.msgid.link/d789219ca0418898a1ef2bf9295b4f96ca7b4209.1785484707.git.tze.yee.ng@altera.com
Signed-off-by: Alexandre Belloni

i3c: master: Add helper to query bus wakeup requirements

2026-08-08T13:04:20+00:00

Add i3c_master_has_wakeup_enabled_devs(), which iterates over the devices
on an I3C bus and reports whether any of them are enabled for system
wakeup and have IBI enabled.

Controller drivers can use this helper to determine whether wakeup
support must remain available while the system is suspended.

Acked-by : Mukesh Savaliya 

Signed-off-by: Adrian Hunter 
Reviewed-by: Frank Li 
Link: https://patch.msgid.link/20260807145638.168865-11-adrian.hunter@intel.com
Signed-off-by: Alexandre Belloni

i3c: master: Support IBI-based wakeup capability

2026-08-08T13:04:19+00:00

An I3C controller acts as a bus controller for one or more I3C devices.
If the controller can wake the system in response to an In-Band
Interrupt (IBI), then any device on that bus that is capable of
generating IBIs can potentially be used as a wakeup source.

Add an ibi_wakeup flag to struct i3c_master_controller so controller
drivers can advertise support for IBI-based wakeup.

If set, mark IBI-capable I3C devices as wakeup capable when they are
registered, allowing wakeup management through the standard device
wakeup framework.

Signed-off-by: Adrian Hunter 
Reviewed-by: Frank Li 
Acked-by: Mukesh Savaliya 
Link: https://patch.msgid.link/20260807145638.168865-9-adrian.hunter@intel.com
Signed-off-by: Alexandre Belloni

i3c: master: Fix recursive locking during device registration

2026-08-08T13:02:50+00:00

i3c_master_register_new_i3c_devs() registers newly discovered devices
while holding i3c_bus_normaluse_lock(), a down_read().  device_register()
can immediately probe the device, and probe callbacks typically invoke
I3C helpers that take i3c_bus_normaluse_lock() again, leading to a
recursive acquisition of the same rwsem.  rwsems do not support recursive
read locking and can deadlock when a writer is waiting.  See the
"Recursive read locks" section of Documentation/locking/lockdep-design.rst.

For example, with Intel LPSS I3C, LOCKDEP generates a WARNING like:
  # echo intel-lpss-i3c.0 > /sys/bus/platform/drivers/mipi-i3c-hci/unbind
  # echo intel-lpss-i3c.0 > /sys/bus/platform/drivers/mipi-i3c-hci/bind
  WARNING: possible recursive locking detected
  kworker/5:1/94 is trying to acquire lock:
  ffff88811c810d78 (&i3cbus->lock){++++}-{4:4}, at: i3c_device_match_id+0x45/0x370
  but task is already holding lock:
  ffff88811c810d78 (&i3cbus->lock){++++}-{4:4}, at: i3c_master_reg_work_fn+0x21/0x5f0

Fix this by separating device creation from device registration.
Populate desc->dev under the maintenance lock, collect the devices that
still need registration into a local list, then release the lock before
calling device_register().  Finally retake the lock and clean up any
devices that failed to register.

Use the maintenance lock rather than the normal-use lock while adding
device objects.  A write-side maintenance lock prevents readers from
observing a partially initialized desc->dev during initial device
population, or desc->dev disappearing if registration fails.

The local list requires a list node, so add a list node member to struct
i3c_device.

Fixes: 3a379bbcea0a ("i3c: Add core I3C infrastructure")
Cc: stable@vger.kernel.org
Signed-off-by: Adrian Hunter 
Reviewed-by: Frank Li 
Link: https://patch.msgid.link/20260807145638.168865-2-adrian.hunter@intel.com
Signed-off-by: Alexandre Belloni

i3c: master: Add support for devices using SETAASA

2026-07-31T07:28:14+00:00

Add support for devices using SETAASA, such as SPD5118 and SPD5108
attached to DDR5 memory modules that do not support ENTDAA. Follow the
guidelines proposed by the MIPI Discovery and Configuration
Specification [1] for discovering such devices.

SETAASA (Set All Addresses to Static Address) differs from standard I3C
address assignment that uses ENTDAA or SETDASA to assign dynamic
addresses. Devices using SETAASA assign their pre-defined static addresses
as their dynamic addresses during DAA, and it is not mandatory for these
devices to implement standard CCC commands like GETPID, GETDCR, or GETBCR.
For such devices, it is generally recommended to issue SETHID (specified
by JEDEC JESD300) as a prerequisite for SETAASA to stop HID bit flipping.

[1] https://www.mipi.org/mipi-disco-for-i3c-download

Signed-off-by: Akhil R 
Link: https://www.mipi.org/mipi-disco-for-i3c-download
Link: https://patch.msgid.link/20260728065955.809445-5-akhilrajeev@nvidia.com
Signed-off-by: Alexandre Belloni

i3c: master: Use unified device property interface

2026-07-31T07:28:14+00:00

Replace all OF-specific functions with unified device property functions
as a prerequisite to support both ACPI and device tree.

Reviewed-by: Frank Li 
Signed-off-by: Akhil R 
Link: https://patch.msgid.link/20260728065955.809445-3-akhilrajeev@nvidia.com
Signed-off-by: Alexandre Belloni

i3c: master: Use unsigned int for dev_nack_retry_count consistently

2026-06-16T21:19:19+00:00

Use unsigned int for dev_nack_retry_count across the core and
controller drivers to match the type of master->dev_nack_retry_count.

Update the sysfs store path to use kstrtouint() and adjust the
 ->set_dev_nack_retry() callback prototype and callers accordingly.

Signed-off-by: Adrian Hunter 
Reviewed-by: Frank Li 
Link: https://patch.msgid.link/20260616113752.196140-4-adrian.hunter@intel.com
Signed-off-by: Alexandre Belloni

i3c: master: Expose the APIs to support I3C hub

2026-06-15T23:27:25+00:00

Change the below internal static functions to APIs to allow new I3C hub
driver to use them

1) i3c_dev_enable_ibi_locked()
2) i3c_dev_disable_ibi_locked()
3) i3c_dev_request_ibi_locked()
4) i3c_dev_free_ibi_locked()
5) i3c_master_reattach_i3c_dev_locked()

Signed-off-by: Aman Kumar Pandey 
Signed-off-by: Lakshay Piplani 
Reviewed-by: Frank Li 
Link: https://patch.msgid.link/20260612111816.3688240-3-lakshay.piplani@nxp.com
Signed-off-by: Alexandre Belloni

i3c: master: Make i3c_master_add_i3c_dev_locked() return void

2026-06-14T19:49:11+00:00

The return value of i3c_master_add_i3c_dev_locked() is not used by any
caller, and callers are not in a position to recover from failures in
this path.

Change the function to return void.  Amend the kernel-doc accordingly,
fix some grammar and remove a stale paragraph.

Signed-off-by: Adrian Hunter 
Reviewed-by: Frank Li 
Link: https://patch.msgid.link/20260612080107.11606-6-adrian.hunter@intel.com
Signed-off-by: Alexandre Belloni

i3c: master: Export i3c_master_enec_disec_locked()

2026-06-14T19:40:10+00:00

The existing i3c_master_enec_locked() wrapper always treats a NACKed
ENEC CCC as a failure (M2 error).  However, broadcasting ENEC to enable
Hot-Join is legitimately useful even when no I3C devices are currently
present on the bus, in which case the broadcast will be NACKed and
should not be reported as an error.

The underlying helper i3c_master_enec_disec_locked() already accepts a
suppress_m2 flag that lets callers ignore such NACKs.  Expose it so that
a subsequent patch enabling Hot-Join events can issue ENEC with M2
suppression.

Signed-off-by: Adrian Hunter 
Reviewed-by: Frank Li 
Link: https://patch.msgid.link/20260608054312.10604-8-adrian.hunter@intel.com
Signed-off-by: Alexandre Belloni