* [PATCH v14 0/8] Add support for NXP P3H2x4x I3C hub driver
@ 2026-07-14 9:20 Lakshay Piplani
2026-07-14 9:20 ` [PATCH v14 1/8] i3c: master: Add APIs for I3C hub support Lakshay Piplani
` (7 more replies)
0 siblings, 8 replies; 19+ messages in thread
From: Lakshay Piplani @ 2026-07-14 9:20 UTC (permalink / raw)
To: linux-kernel, linux-i3c, alexandre.belloni, krzk+dt, robh,
conor+dt, devicetree, broonie, lee, Frank.Li, lgirdwood
Cc: vikash.bansal, priyanka.jain, aman.kumarpandey, Lakshay Piplani
This is an MFD driver integrating I3C hub and on-die regulators.
The series introduces:
- Core I3C master enhancements required for hub support
- Generic I3C hub framework
- MFD driver with regulator and I3C hub child drivers for the P3H2x4x I3C hub
Below patches from v11 have already been applied to i3c/next branch:
- 79c41666b397 ("i3c: master: rename i3c_master_reattach_i3c_dev() to *_locked")
https://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux.git/commit/?id=79c41666b397
- 8d8afa428318 ("i3c: master: Expose the APIs to support I3C hub")
https://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux.git/commit/?id=8d8afa428318
This v14 series is rebased on top of those commits.
Changes in v14:
- Add i3c_master_register_fwnode() for virtual I3C masters and use it instead of temporarily changing
parent dev->of_node
- Add runtime PM handling in i3c_master_send_ccc_cmd()
- Export i3c_bus_maintenance_lock()/unlock() and use them in hub paths
- Fix IBI request/free cleanup to handle forwarded callbacks that clear dev->ibi, and destroy the
allocated IBI workqueue on request failure
- Add a shared MFD protected_reg_lock and use it for protected register accesses across P3H2X4X
child drivers
- Rework regulator protected-register handling to restore the original protection state after
each operation
- Serialize hub route selection around DAA, CCC, private transfer and IBI paths
- Hold the parent maintenance lock across temporary hub address reattach, transfer and address
restore
- Fix SMBus polling interval calculation
- Clean up already registered SMBus adapters on adapter allocation or registration failure
- Fix SMBus slave receive status handling by clearing receive flags on error paths, using FIELD_GET()
and explicitly clearing overflow status
- Link to v13: https://lore.kernel.org/linux-i3c/20260701065755.2067793-1-lakshay.piplani@nxp.com/T/#u
Changes in v13:
- Fix I3C master address management in direct attach/detach paths by using i3c_master_get_i3c_addrs()
adding rollback on failure, skipping master self attach/detach, and properly releasing addresses to
avoid stale state and use-after-free issues.
- Export and document address slot helper APIs for I3C hub support.
- Reserve parent bus address slots for downstream devices with identical static and assigned addresses
by parsing target-port DT nodes prior to virtual controller registration, preventing DAA conflicts.
- Keep broadcast RSTDAA blocked with added documentation, and clarify intentional no-op callbacks
and pending TODOs (e.g., IBI slot recycle).
- Rework SMBus transaction handling to use polling instead of fixed delays
avoiding premature reads and data corruption.
- Fix DT handling issues by preventing duplicate target-port node leaks and restoring dev->of_node
after temporary modification.
- Improve resource management using devm-based cleanup for DT nodes, IBI setup, adapter unregister
and register relock paths.
- Make IBI setup optional and robust to avoid probe failures on unsupported platforms, with proper cleanup.
- Fix SMBus slave receive path by improving buffer handling, event delivery, and handling of unregistered ports.
- Strengthen concurrency handling with proper locking around shared state.
- Link to v12: https://lore.kernel.org/linux-i3c/20260617110355.1591844-1-lakshay.piplani@nxp.com/T/#u
Changes in v12:
- Rebased on i3c/next
- Dropped patches 1/9 and 2/9 from v11 as they are already applied
- Add address check in i3c_master_direct_detach_i3c_dev_locked() to skip
detach for unaddressed devices
- Drop redundant depends on I3C from config I3C_HUB
- Return -EOPNOTSUPP for unsupported I2C transfers in the generic hub ops
- Correct default pull-up and drive-strength values
- Add devm cleanup for the IBI request/enable path
- Remove dead code and simplify cleanup by relying on devm-managed resources
- Fix SMBus slave client NULL handling and unregister cleanup
- Link to v11: https://lore.kernel.org/linux-i3c/20260612111816.3688240-1-lakshay.piplani@nxp.com/T/#u
Changes in v11:
- Convert i3c_master_supports_ccc_cmd() to return bool and align
semantics with CCC support checks used by the I3C core
- Use MFD_CELL_NAME() for child device registration
- Rename driver names to follow subsystem conventions:
- Use '-' instead of '_' in driver names
- Drop the "_drv" suffix from driver names
- Fix virtual hub address reattach handling and parent bus locking
- Fix IBI request and cleanup error paths
- Improve SMBus slave mode payload validation and parsing
- Link to v10: https://lore.kernel.org/linux-i3c/20260525064209.2263045-1-lakshay.piplani@nxp.com/T/#u
Changes in v10:
- Rename i3c_master_reattach_i3c_dev() to *_locked to reflect required
bus locking
- Rename i3c_master_direct_attach_i3c_dev() and i3c_master_direct_detach_i3c_dev()
to *_locked, as these APIs must be called with the bus lock held for write
- Drop redundant is_p3h2x4x_in_i3c flag from p3h2840.h
- Remove unnecessary ibi_lock handling in request/enable/disable/free
IBI APIs
- Remove redundant parent pointer from struct i3c_hub and derive upstream
master from hub_dev
- Split SMBus target/slave mode support, including IBI and MCTP receive handling,
into a separate patch
- Link to v9: https://lore.kernel.org/linux-i3c/20260420105222.1562243-1-lakshay.piplani@nxp.com/T/#u
Changes in v9:
- Renamed macros to follow consistent uppercase naming conventions
- Made REGMAP selects in the P3H2X4X MFD Kconfig conditional, to avoid I3C/I2C dependency issues
- Referenced i3c.yaml and i2c-controller.yaml for child bus nodes
- Dropped unnecessary #address-cells and #size-cells from child nodes
- Added CONFIG_I2C_SLAVE guards where necessary to avoid build errors when I2C slave support is disabled
- Link to v8: https://lore.kernel.org/linux-i3c/20260323062737.886728-1-lakshay.piplani@nxp.com/T/#u
Changes in v8:
- Add compatible in i3c example
- Link to v7: https://lore.kernel.org/linux-i3c/20260319112441.3888957-1-lakshay.piplani@nxp.com/T/#u
Changes in v7:
- Fix kernel-doc warnings across I3C core and hub code
- Rework DT binding schema and examples to pass dt_binding_check
- Update MFD Kconfig to use I3C_OR_I2C
- Convert CONFIG_I3C_HUB to tristate
- Remove unnecessary CONFIG_I2C_SLAVE guards
- Replace custom helpers with find_closest()
- Use devm_regulator_get_enable_optional()
- Link to v6: https://lore.kernel.org/linux-i3c/64c5070c-aa9e-427a-933e-91e168f0510c@kernel.org/T/#u
Changes in v6:
- Update DT binding with vendor-prefixed properties
- Add generic I3C hub support
- Remove generic code from P3H2x4x driver
- Link to v5: https://lore.kernel.org/linux-i3c/20260206120121.856471-1-aman.kumarpandey@nxp.com/T/#u
Changes in v5:
- Update supply naming and descriptions
- Improve MFD Kconfig/Makefile ordering
- Link to v4: https://lore.kernel.org/linux-i3c/20260113114529.1692213-2-aman.kumarpandey@nxp.com/T/#u
Changes in v4:
- Split driver into MFD, regulator and I3C hub parts
- Update I3C master for hub support
- Fix DT binding issues
- Link to v3: https://lore.kernel.org/linux-i3c/20250811-bittern-of-abstract-prestige-aaeda9@kuoka/T/#u
Changes in v3:
- Add MFD support for hub and regulators
- Add regulator integration
- Link to v2: https://lore.kernel.org/linux-i3c/17145d2f-5d07-4939-8381-74e27cde303c@kernel.org/T/#u
Changes in v2:
- Fix DT binding warnings
- Refine DT parsing logic
- Link to v1: https://lore.kernel.org/linux-i3c/822d6dca-b2c6-4439-ade5-219620ebc435@kernel.org/T/#u
Aman Kumar Pandey (5):
i3c: master: Add APIs for I3C hub support
dt-bindings: i3c: Add NXP P3H2x4x i3c-hub support
mfd: p3h2x4x: Add driver for NXP P3H2x4x i3c hub and on-die regulator
regulator: p3h2x4x: Add driver for on-die regulators in NXP P3H2x4x
i3c hub
i3c: hub: p3h2x4x: Add support for NXP P3H2x4x I3C hub functionality
Lakshay Piplani (3):
i3c: master: Fix IBI request and free cleanup paths
i3c: hub: Add support for the I3C interface in the I3C hub
i3c: hub: p3h2x4x: Add SMBus slave mode support
.../devicetree/bindings/i3c/nxp,p3h2840.yaml | 291 +++++++++
MAINTAINERS | 15 +
drivers/i3c/Kconfig | 15 +
drivers/i3c/Makefile | 2 +
drivers/i3c/hub.c | 607 ++++++++++++++++++
drivers/i3c/hub/Kconfig | 11 +
drivers/i3c/hub/Makefile | 4 +
drivers/i3c/hub/p3h2840_i3c_hub.h | 345 ++++++++++
drivers/i3c/hub/p3h2840_i3c_hub_common.c | 379 +++++++++++
drivers/i3c/hub/p3h2840_i3c_hub_i3c.c | 164 +++++
drivers/i3c/hub/p3h2840_i3c_hub_smbus.c | 573 +++++++++++++++++
drivers/i3c/master.c | 250 +++++++-
drivers/mfd/Kconfig | 13 +
drivers/mfd/Makefile | 1 +
drivers/mfd/p3h2840.c | 139 ++++
drivers/regulator/Kconfig | 10 +
drivers/regulator/Makefile | 1 +
drivers/regulator/p3h2840_i3c_hub_regulator.c | 284 ++++++++
include/linux/i3c/device.h | 2 +
include/linux/i3c/hub.h | 102 +++
include/linux/i3c/master.h | 20 +
include/linux/mfd/p3h2840.h | 25 +
22 files changed, 3228 insertions(+), 25 deletions(-)
create mode 100644 Documentation/devicetree/bindings/i3c/nxp,p3h2840.yaml
create mode 100644 drivers/i3c/hub.c
create mode 100644 drivers/i3c/hub/Kconfig
create mode 100644 drivers/i3c/hub/Makefile
create mode 100644 drivers/i3c/hub/p3h2840_i3c_hub.h
create mode 100644 drivers/i3c/hub/p3h2840_i3c_hub_common.c
create mode 100644 drivers/i3c/hub/p3h2840_i3c_hub_i3c.c
create mode 100644 drivers/i3c/hub/p3h2840_i3c_hub_smbus.c
create mode 100644 drivers/mfd/p3h2840.c
create mode 100644 drivers/regulator/p3h2840_i3c_hub_regulator.c
create mode 100644 include/linux/i3c/hub.h
create mode 100644 include/linux/mfd/p3h2840.h
--
2.25.1
^ permalink raw reply [flat|nested] 19+ messages in thread
* [PATCH v14 1/8] i3c: master: Add APIs for I3C hub support
2026-07-14 9:20 [PATCH v14 0/8] Add support for NXP P3H2x4x I3C hub driver Lakshay Piplani
@ 2026-07-14 9:20 ` Lakshay Piplani
2026-07-14 10:03 ` sashiko-bot
2026-07-14 9:20 ` [PATCH v14 2/8] i3c: master: Fix IBI request and free cleanup paths Lakshay Piplani
` (6 subsequent siblings)
7 siblings, 1 reply; 19+ messages in thread
From: Lakshay Piplani @ 2026-07-14 9:20 UTC (permalink / raw)
To: linux-kernel, linux-i3c, alexandre.belloni, krzk+dt, robh,
conor+dt, devicetree, broonie, lee, Frank.Li, lgirdwood
Cc: vikash.bansal, priyanka.jain, aman.kumarpandey, Lakshay Piplani
From: Aman Kumar Pandey <aman.kumarpandey@nxp.com>
Add helpers for attaching and detaching I3C devices and CCC helpers
to check CCC support and send CCC commands, address slot helpers to
query and update I3C bus address slot state, registering virtual
masters with an explicit firmware node, and exposing the bus maintenance
lock helpers.
These additions prepare for I3C hub support. A hub driver needs to attach
downstream devices temporarily to the parent controller, reserve/query
parent bus address slots, forward CCC commands, register virtual target
port controllers using the target-port firmware node, and serialize
operations against the parent bus maintenance lock.
i3c_master_register_fwnode() allows virtual I3C masters to register using a
firmware node different from their parent device node without temporarily
modifying parent->of_node.
The attach and detach helpers must be called with the bus lock held in
write mode.
The new helpers are:
1) i3c_master_direct_attach_i3c_dev_locked()
2) i3c_master_direct_detach_i3c_dev_locked()
3) i3c_master_send_ccc_cmd()
4) i3c_master_supports_ccc_cmd()
5) i3c_bus_get_addr_slot_status()
6) i3c_bus_set_addr_slot_status()
7) i3c_bus_maintenance_lock()
8) i3c_bus_maintenance_unlock()
9) i3c_master_register_fwnode()
Signed-off-by: Aman Kumar Pandey <aman.kumarpandey@nxp.com>
Signed-off-by: Lakshay Piplani <lakshay.piplani@nxp.com>
Signed-off-by: Vikash Bansal <vikash.bansal@nxp.com>
---
Changes in v14:
- Add i3c_master_register_fwnode() to register virtual I3C masters with an
explicit firmware node
- Export i3c_bus_maintenance_lock() and i3c_bus_maintenance_unlock()
- Add runtime PM get/put around i3c_master_send_ccc_cmd()
- Make i3c_master_supports_ccc_cmd() return false when the controller does
not implement send_ccc_cmd()
Changes in v13:
- Fix address handling in direct attach by using i3c_master_get_i3c_addrs() and
adding rollback on failure to prevent bus address collisions
- Fix detach path by clearing master_priv and releasing addresses to avoid use-after-free
and stale state issues
- Export address slot helper APIs and add kernel-doc for them
Changes in v12:
- Add address check in i3c_master_direct_detach_i3c_dev_locked() to skip
detach for unaddressed devices.
Changes in v11:
- Convert i3c_master_supports_ccc_cmd() to return bool and align
semantics with CCC support checks used by the I3C core
Changes in v10:
- Rename i3c_master_direct_attach_i3c_dev and i3c_master_direct_detach_i3c_dev
APIs to *_locked, as these APIs must be called with the bus lock held in
write mode
Changes in v9:
- No change
Changes in v8:
- No change
Changes in v7:
- Update commit message to clarify purpose (prepare for I3C hub support)
Changes in v6:
- Split the patch into two parts:
1) expose the existing API
2) add new APIs.
---
---
drivers/i3c/master.c | 229 +++++++++++++++++++++++++++++++++----
include/linux/i3c/master.h | 20 ++++
2 files changed, 226 insertions(+), 23 deletions(-)
diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index dbb4d8119b5f..2cb94face156 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -42,10 +42,11 @@ static BLOCKING_NOTIFIER_HEAD(i3c_bus_notifier);
* logic to rely on I3C device information that could be changed behind their
* back.
*/
-static void i3c_bus_maintenance_lock(struct i3c_bus *bus)
+void i3c_bus_maintenance_lock(struct i3c_bus *bus)
{
down_write(&bus->lock);
}
+EXPORT_SYMBOL_GPL(i3c_bus_maintenance_lock);
/**
* i3c_bus_maintenance_unlock - Release the bus lock after a maintenance
@@ -56,10 +57,11 @@ static void i3c_bus_maintenance_lock(struct i3c_bus *bus)
* i3c_bus_maintenance_lock() for more details on what these maintenance
* operations are.
*/
-static void i3c_bus_maintenance_unlock(struct i3c_bus *bus)
+void i3c_bus_maintenance_unlock(struct i3c_bus *bus)
{
up_write(&bus->lock);
}
+EXPORT_SYMBOL_GPL(i3c_bus_maintenance_unlock);
/**
* i3c_bus_normaluse_lock - Lock the bus for a normal operation
@@ -391,11 +393,19 @@ i3c_bus_get_addr_slot_status_mask(struct i3c_bus *bus, u16 addr, u32 mask)
return status & mask;
}
-static enum i3c_addr_slot_status
+/**
+ * i3c_bus_get_addr_slot_status() - Get I3C bus address slot status
+ * @bus: I3C bus.
+ * @addr: I3C address to query.
+ *
+ * Return: Address slot status for @addr.
+ */
+enum i3c_addr_slot_status
i3c_bus_get_addr_slot_status(struct i3c_bus *bus, u16 addr)
{
return i3c_bus_get_addr_slot_status_mask(bus, addr, I3C_ADDR_SLOT_STATUS_MASK);
}
+EXPORT_SYMBOL_GPL(i3c_bus_get_addr_slot_status);
static void i3c_bus_set_addr_slot_status_mask(struct i3c_bus *bus, u16 addr,
enum i3c_addr_slot_status status, u32 mask)
@@ -411,11 +421,18 @@ static void i3c_bus_set_addr_slot_status_mask(struct i3c_bus *bus, u16 addr,
*ptr |= ((unsigned long)status & mask) << (bitpos % BITS_PER_LONG);
}
-static void i3c_bus_set_addr_slot_status(struct i3c_bus *bus, u16 addr,
- enum i3c_addr_slot_status status)
+/**
+ * i3c_bus_set_addr_slot_status() - Set I3C bus address slot status
+ * @bus: I3C bus.
+ * @addr: I3C address to update.
+ * @status: Address slot status to set.
+ */
+void i3c_bus_set_addr_slot_status(struct i3c_bus *bus, u16 addr,
+ enum i3c_addr_slot_status status)
{
i3c_bus_set_addr_slot_status_mask(bus, addr, status, I3C_ADDR_SLOT_STATUS_MASK);
}
+EXPORT_SYMBOL_GPL(i3c_bus_set_addr_slot_status);
static bool i3c_bus_dev_addr_is_avail(struct i3c_bus *bus, u8 addr)
{
@@ -1652,6 +1669,83 @@ static int i3c_master_attach_i3c_dev(struct i3c_master_controller *master,
return 0;
}
+/**
+ * i3c_master_direct_attach_i3c_dev_locked() - Attach an I3C device to a master
+ * @master: I3C master controller to attach the device to
+ * @dev: I3C device descriptor representing the device
+ *
+ * Attach an I3C device to its master controller after reserving the device
+ * addresses on the bus. The device must belong to @master.
+ *
+ * The master device itself is not passed to the controller driver's
+ * ->attach_i3c_dev() callback.
+ *
+ * Context: Caller must hold @master->bus.lock in write mode.
+ *
+ * Return: 0 on success, or a negative error code if address reservation fails
+ * or if the master controller driver's ->attach_i3c_dev() callback fails.
+ */
+int i3c_master_direct_attach_i3c_dev_locked(struct i3c_master_controller *master,
+ struct i3c_dev_desc *dev)
+{
+ int ret;
+
+ if (WARN_ON(i3c_dev_get_master(dev) != master))
+ return -EINVAL;
+
+ ret = i3c_master_get_i3c_addrs(dev);
+ if (ret)
+ return ret;
+
+ /* Do not attach the master device itself. */
+ if (master->this != dev && master->ops->attach_i3c_dev) {
+ ret = master->ops->attach_i3c_dev(dev);
+ if (ret) {
+ i3c_master_put_i3c_addrs(dev);
+ return ret;
+ }
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(i3c_master_direct_attach_i3c_dev_locked);
+
+/**
+ * i3c_master_direct_detach_i3c_dev_locked() - Detach an I3C device from a master
+ * @dev: I3C device descriptor to detach
+ *
+ * Detach an addressed I3C device from its master controller. Devices without
+ * either a static or dynamic address are skipped because they were not attached
+ * to the controller.
+ *
+ * The master device itself is not passed to the controller driver's
+ * ->detach_i3c_dev() callback. For other devices, the callback is invoked when
+ * provided by the master controller driver.
+ *
+ * The controller-private data is cleared and the device addresses are released
+ * from the bus address slot table.
+ *
+ * Context: Caller must hold the device master's bus lock in write mode.
+ */
+void i3c_master_direct_detach_i3c_dev_locked(struct i3c_dev_desc *dev)
+{
+ struct i3c_master_controller *master = i3c_dev_get_master(dev);
+
+ /*
+ * We don't attach devices to the controller until they are
+ * addressable on the bus, so skip detach for unaddressed devices.
+ */
+ if (!dev->info.static_addr && !dev->info.dyn_addr)
+ return;
+
+ /* Do not detach the master device itself. */
+ if (master->this != dev && master->ops->detach_i3c_dev)
+ master->ops->detach_i3c_dev(dev);
+
+ dev->common.master_priv = NULL;
+ i3c_master_put_i3c_addrs(dev);
+}
+EXPORT_SYMBOL_GPL(i3c_master_direct_detach_i3c_dev_locked);
+
/**
* i3c_master_reattach_i3c_dev_locked() - reattach an I3C device with a new address
* @dev: I3C device descriptor to reattach
@@ -1815,6 +1909,59 @@ i3c_master_register_new_i3c_devs(struct i3c_master_controller *master)
}
}
+/**
+ * i3c_master_supports_ccc_cmd() - check CCC command support
+ * @master: I3C master controller
+ * @cmd: CCC command to verify
+ *
+ * Return: true if @cmd is supported, false otherwise.
+ */
+bool i3c_master_supports_ccc_cmd(struct i3c_master_controller *master,
+ const struct i3c_ccc_cmd *cmd)
+{
+ if (!master || !cmd)
+ return false;
+
+ if (!master->ops->send_ccc_cmd)
+ return false;
+
+ if (!master->ops->supports_ccc_cmd)
+ return true;
+
+ return master->ops->supports_ccc_cmd(master, cmd);
+}
+EXPORT_SYMBOL_GPL(i3c_master_supports_ccc_cmd);
+
+/**
+ * i3c_master_send_ccc_cmd() - send a CCC command
+ * @master: I3C master controller issuing the command
+ * @cmd: CCC command to be sent
+ *
+ * This function sends a Common Command Code (CCC) command to devices on the
+ * I3C bus. It acquires the bus maintenance lock, executes the command, and
+ * then releases the lock to ensure safe access to the bus.
+ *
+ * Return: 0 on success, or a negative error code on failure.
+ */
+int i3c_master_send_ccc_cmd(struct i3c_master_controller *master,
+ struct i3c_ccc_cmd *cmd)
+{
+ int ret;
+
+ ret = i3c_master_rpm_get(master);
+ if (ret)
+ return ret;
+
+ i3c_bus_maintenance_lock(&master->bus);
+ ret = i3c_master_send_ccc_cmd_locked(master, cmd);
+ i3c_bus_maintenance_unlock(&master->bus);
+
+ i3c_master_rpm_put(master);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(i3c_master_send_ccc_cmd);
+
/**
* i3c_master_do_daa_ext() - Dynamic Address Assignment (extended version)
* @master: controller
@@ -2998,34 +3145,31 @@ static int i3c_master_check_ops(const struct i3c_master_controller_ops *ops)
}
/**
- * i3c_master_register() - register an I3C master
+ * i3c_master_register_fwnode() - register an I3C master with a custom fwnode
* @master: master used to send frames on the bus
- * @parent: the parent device (the one that provides this I3C master
- * controller)
+ * @parent: the parent device providing this I3C master controller
+ * @fwnode: firmware node describing this I3C bus, or NULL
* @ops: the master controller operations
- * @secondary: true if you are registering a secondary master. Will return
- * -EOPNOTSUPP if set to true since secondary masters are not yet
- * supported
+ * @secondary: true if registering a secondary master
*
- * This function takes care of everything for you:
+ * This helper is useful for virtual I3C masters whose firmware node is not
+ * the same as @parent's firmware node.
*
- * - creates and initializes the I3C bus
- * - populates the bus with static I2C devs if @parent->of_node is not
- * NULL
- * - registers all I3C devices added by the controller during bus
- * initialization
- * - registers the I2C adapter and all I2C devices
+ * Only OF-backed fwnodes are supported for now, because the I3C core still
+ * stores the bus node in master->dev.of_node and populates the bus using OF.
*
* Return: 0 in case of success, a negative error code otherwise.
*/
-int i3c_master_register(struct i3c_master_controller *master,
- struct device *parent,
- const struct i3c_master_controller_ops *ops,
- bool secondary)
+int i3c_master_register_fwnode(struct i3c_master_controller *master,
+ struct device *parent,
+ struct fwnode_handle *fwnode,
+ const struct i3c_master_controller_ops *ops,
+ bool secondary)
{
unsigned long i2c_scl_rate = I3C_BUS_I2C_FM_PLUS_SCL_MAX_RATE;
struct i3c_bus *i3cbus = i3c_master_get_bus(master);
enum i3c_bus_mode mode = I3C_BUS_MODE_PURE;
+ struct device_node *np = NULL;
struct i2c_dev_boardinfo *i2cbi;
int ret;
@@ -3037,8 +3181,14 @@ int i3c_master_register(struct i3c_master_controller *master,
if (ret)
return ret;
+ if (fwnode) {
+ np = to_of_node(fwnode);
+ if (!np)
+ return -EINVAL;
+ }
+
master->dev.parent = parent;
- master->dev.of_node = of_node_get(parent->of_node);
+ master->dev.of_node = of_node_get(np);
master->dev.bus = &i3c_bus_type;
master->dev.type = &i3c_masterdev_type;
master->dev.release = i3c_masterdev_release;
@@ -3150,6 +3300,39 @@ int i3c_master_register(struct i3c_master_controller *master,
return ret;
}
+EXPORT_SYMBOL_GPL(i3c_master_register_fwnode);
+
+/**
+ * i3c_master_register() - register an I3C master
+ * @master: master used to send frames on the bus
+ * @parent: the parent device (the one that provides this I3C master
+ * controller)
+ * @ops: the master controller operations
+ * @secondary: true if you are registering a secondary master. Will return
+ * -EOPNOTSUPP if set to true since secondary masters are not yet
+ * supported
+ *
+ * This function takes care of everything for you:
+ *
+ * - creates and initializes the I3C bus
+ * - populates the bus with static I2C devs if @parent->of_node is not
+ * NULL
+ * - registers all I3C devices added by the controller during bus
+ * initialization
+ * - registers the I2C adapter and all I2C devices
+ *
+ * Return: 0 in case of success, a negative error code otherwise.
+ */
+int i3c_master_register(struct i3c_master_controller *master,
+ struct device *parent,
+ const struct i3c_master_controller_ops *ops,
+ bool secondary)
+{
+ return i3c_master_register_fwnode(master, parent,
+ parent->of_node ?
+ of_fwnode_handle(parent->of_node) : NULL,
+ ops, secondary);
+}
EXPORT_SYMBOL_GPL(i3c_master_register);
/**
diff --git a/include/linux/i3c/master.h b/include/linux/i3c/master.h
index 355e9b3d9ae3..64f4c39793ea 100644
--- a/include/linux/i3c/master.h
+++ b/include/linux/i3c/master.h
@@ -615,9 +615,21 @@ DEFINE_FREE(i3c_master_dma_unmap_single, void *,
int i3c_master_reattach_i3c_dev_locked(struct i3c_dev_desc *dev,
u8 old_dyn_addr);
+int i3c_master_direct_attach_i3c_dev_locked(struct i3c_master_controller *master,
+ struct i3c_dev_desc *dev);
+void i3c_master_direct_detach_i3c_dev_locked(struct i3c_dev_desc *dev);
+int i3c_master_send_ccc_cmd(struct i3c_master_controller *master,
+ struct i3c_ccc_cmd *cmd);
+bool i3c_master_supports_ccc_cmd(struct i3c_master_controller *master,
+ const struct i3c_ccc_cmd *cmd);
int i3c_master_set_info(struct i3c_master_controller *master,
const struct i3c_device_info *info);
+int i3c_master_register_fwnode(struct i3c_master_controller *master,
+ struct device *parent,
+ struct fwnode_handle *fwnode,
+ const struct i3c_master_controller_ops *ops,
+ bool secondary);
int i3c_master_register(struct i3c_master_controller *master,
struct device *parent,
const struct i3c_master_controller_ops *ops,
@@ -739,4 +751,12 @@ void i3c_for_each_bus_locked(int (*fn)(struct i3c_bus *bus, void *data),
int i3c_register_notifier(struct notifier_block *nb);
int i3c_unregister_notifier(struct notifier_block *nb);
+enum i3c_addr_slot_status
+i3c_bus_get_addr_slot_status(struct i3c_bus *bus, u16 addr);
+
+void i3c_bus_set_addr_slot_status(struct i3c_bus *bus, u16 addr,
+ enum i3c_addr_slot_status status);
+
+void i3c_bus_maintenance_lock(struct i3c_bus *bus);
+void i3c_bus_maintenance_unlock(struct i3c_bus *bus);
#endif /* I3C_MASTER_H */
--
2.25.1
^ permalink raw reply related [flat|nested] 19+ messages in thread
* [PATCH v14 2/8] i3c: master: Fix IBI request and free cleanup paths
2026-07-14 9:20 [PATCH v14 0/8] Add support for NXP P3H2x4x I3C hub driver Lakshay Piplani
2026-07-14 9:20 ` [PATCH v14 1/8] i3c: master: Add APIs for I3C hub support Lakshay Piplani
@ 2026-07-14 9:20 ` Lakshay Piplani
2026-07-14 10:20 ` sashiko-bot
2026-07-14 9:20 ` [PATCH v14 3/8] dt-bindings: i3c: Add NXP P3H2x4x i3c-hub support Lakshay Piplani
` (5 subsequent siblings)
7 siblings, 1 reply; 19+ messages in thread
From: Lakshay Piplani @ 2026-07-14 9:20 UTC (permalink / raw)
To: linux-kernel, linux-i3c, alexandre.belloni, krzk+dt, robh,
conor+dt, devicetree, broonie, lee, Frank.Li, lgirdwood
Cc: vikash.bansal, priyanka.jain, aman.kumarpandey, Lakshay Piplani
i3c_dev_request_ibi_locked() allocates the generic IBI object and its
workqueue before calling the controller request_ibi() callback. If the
callback fails, destroy the workqueue before freeing the IBI object.
Also, a controller callback may clear dev->ibi while forwarding the request
or free operation to another controller. Avoid touching dev->ibi after the
callback if it has already been cleared.
This prevents a workqueue leak in the request failure path and avoids NULL
pointer dereference in the free path when the callback has already released
the IBI object.
Signed-off-by: Lakshay Piplani <lakshay.piplani@nxp.com>
Signed-off-by: Vikash Bansal <vikash.bansal@nxp.com>
Signed-off-by: Aman Kumar Pandey <aman.kumarpandey@nxp.com>
---
Changes in v14:
- Destroy the allocated IBI workqueue when request_ibi() callback fails
- Avoid touching dev->ibi after request/free callbacks if a forwarding
controller callback has already cleared it
---
---
drivers/i3c/master.c | 21 +++++++++++++++++++--
1 file changed, 19 insertions(+), 2 deletions(-)
diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 2cb94face156..01c6e048485c 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -3499,8 +3499,18 @@ int i3c_dev_request_ibi_locked(struct i3c_dev_desc *dev,
dev->ibi = ibi;
ret = master->ops->request_ibi(dev, req);
- if (ret) {
- kfree(ibi);
+
+ /*
+ * The controller callback may have already released and cleared dev->ibi
+ * when the request is forwarded by a virtual controller. Only clean up the
+ * IBI object if the callback left dev->ibi valid.
+ */
+ if (ret && dev->ibi) {
+ /* Avoid leaking the workqueue allocated for this IBI request. */
+ if (dev->ibi->wq)
+ destroy_workqueue(dev->ibi->wq);
+
+ kfree(dev->ibi);
dev->ibi = NULL;
}
@@ -3540,6 +3550,13 @@ void i3c_dev_free_ibi_locked(struct i3c_dev_desc *dev)
master->ops->free_ibi(dev);
+ /*
+ * The controller callback may have already released dev->ibi, for example
+ * when the request was forwarded by a virtual controller.
+ */
+ if (!dev->ibi)
+ return;
+
if (dev->ibi->wq) {
destroy_workqueue(dev->ibi->wq);
dev->ibi->wq = NULL;
--
2.25.1
^ permalink raw reply related [flat|nested] 19+ messages in thread
* [PATCH v14 3/8] dt-bindings: i3c: Add NXP P3H2x4x i3c-hub support
2026-07-14 9:20 [PATCH v14 0/8] Add support for NXP P3H2x4x I3C hub driver Lakshay Piplani
2026-07-14 9:20 ` [PATCH v14 1/8] i3c: master: Add APIs for I3C hub support Lakshay Piplani
2026-07-14 9:20 ` [PATCH v14 2/8] i3c: master: Fix IBI request and free cleanup paths Lakshay Piplani
@ 2026-07-14 9:20 ` Lakshay Piplani
2026-07-14 10:30 ` sashiko-bot
2026-07-14 9:20 ` [PATCH v14 4/8] mfd: p3h2x4x: Add driver for NXP P3H2x4x i3c hub and on-die regulator Lakshay Piplani
` (4 subsequent siblings)
7 siblings, 1 reply; 19+ messages in thread
From: Lakshay Piplani @ 2026-07-14 9:20 UTC (permalink / raw)
To: linux-kernel, linux-i3c, alexandre.belloni, krzk+dt, robh,
conor+dt, devicetree, broonie, lee, Frank.Li, lgirdwood
Cc: vikash.bansal, priyanka.jain, aman.kumarpandey, Lakshay Piplani
From: Aman Kumar Pandey <aman.kumarpandey@nxp.com>
Add bindings for the NXP P3H2x4x (P3H2440/P3H2441/P3H2840/P3H2841)
multiport I3C hub family. These devices connect to a host via
I3C/I2C/SMBus and allow communication with multiple downstream
peripherals.
Signed-off-by: Aman Kumar Pandey <aman.kumarpandey@nxp.com>
Signed-off-by: Vikash Bansal <vikash.bansal@nxp.com>
Signed-off-by: Lakshay Piplani <lakshay.piplani@nxp.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
---
Changes in v14:
- No change
Changes in v13:
- Fix mismatch between example unit-address and reg property by correcting the reg value
to match the node name
Changes in v12:
- No change, added Reviewed-By tag
Changes in v11:
- No change
Changes in v10:
- No change, added Reviewed-By tag
Changes in v9:
- Referenced i3c.yaml and i2c-controller.yaml for child nodes
- Dropped unnecessary #address-cells and #size-cells from child nodes
Changes in v8:
- Add compatible in i3c example
Changes in v7:
- Fix schema validation issues
- Adjust required properties
- Add I2C example
Changes in v6:
- Use a vendor prefix for the attributes
Changes in v5:
- Removed SW properties: cp0-ldo-microvolt,cp1-ldo-microvolt,
tp0145-ldo-microvolt, tp2367-ldo-microvolt
- Changed supply entries and its descriptions
Changes in v4:
- Fixed DT binding check warning
- Removed SW properties: ibi-enable, local-dev, and always-enable
Changes in v3:
- Added MFD (Multi-Function Device) support for I3C hub and on-die regulator
- Added Regulator supply node
Changes in v2:
- Fixed DT binding check warning
- Revised logic for parsing DTS nodes
---
---
.../devicetree/bindings/i3c/nxp,p3h2840.yaml | 291 ++++++++++++++++++
MAINTAINERS | 9 +
2 files changed, 300 insertions(+)
create mode 100644 Documentation/devicetree/bindings/i3c/nxp,p3h2840.yaml
diff --git a/Documentation/devicetree/bindings/i3c/nxp,p3h2840.yaml b/Documentation/devicetree/bindings/i3c/nxp,p3h2840.yaml
new file mode 100644
index 000000000000..f7f0752de533
--- /dev/null
+++ b/Documentation/devicetree/bindings/i3c/nxp,p3h2840.yaml
@@ -0,0 +1,291 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright 2025 NXP
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/i3c/nxp,p3h2840.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NXP P3H2X4X I3C HUB
+
+maintainers:
+ - Aman Kumar Pandey <aman.kumarpandey@nxp.com>
+ - Vikash Bansal <vikash.bansal@nxp.com>
+ - Lakshay Piplani <lakshay.piplani@nxp.com>
+
+description: |
+ P3H2x4x (P3H2440/P3H2441/P3H2840/P3H2841) is a family of multiport I3C
+ hub devices that connect to:-
+ 1. A host CPU via I3C/I2C/SMBus bus on upstream side and connect to multiple
+ peripheral devices on the downstream side.
+ 2. Have two Controller Ports which can support either
+ I2C/SMBus or I3C buses and connect to a CPU, BMC or SOC.
+ 3. P3H2840/ P3H2841 are 8 port I3C hub with eight I3C/I2C Target Port.
+ 4. P3H2440/ P3H2441 are 4 port I3C hub with four I3C/I2C Target Port.
+ Target ports can be configured as I2C/SMBus, I3C or GPIO and connect to
+ peripherals.
+
+properties:
+ compatible:
+ const: nxp,p3h2840
+
+ reg:
+ maxItems: 1
+
+ '#address-cells':
+ const: 1
+
+ '#size-cells':
+ const: 0
+
+ assigned-address:
+ maximum: 0x7f
+
+ nxp,tp0145-pullup-ohms:
+ description:
+ Selects the pull up resistance for target Port 0/1/4/5, in ohms.
+ enum: [250, 500, 1000, 2000]
+ default: 500
+
+ nxp,tp2367-pullup-ohms:
+ description:
+ Selects the pull up resistance for target Port 2/3/6/7, in ohms.
+ enum: [250, 500, 1000, 2000]
+ default: 500
+
+ nxp,cp0-io-strength-ohms:
+ description:
+ Selects the IO drive strength for controller Port 0, in ohms.
+ enum: [20, 30, 40, 50]
+ default: 20
+
+ nxp,cp1-io-strength-ohms:
+ description:
+ Selects the IO drive strength for controller Port 1, in ohms.
+ enum: [20, 30, 40, 50]
+ default: 20
+
+ nxp,tp0145-io-strength-ohms:
+ description:
+ Selects the IO drive strength for target port 0/1/4/5, in ohms.
+ enum: [20, 30, 40, 50]
+ default: 20
+
+ nxp,tp2367-io-strength-ohms:
+ description:
+ Selects the IO drive strength for target port 2/3/6/7, in ohms.
+ enum: [20, 30, 40, 50]
+ default: 20
+
+ vcc1-supply:
+ description: Controller port 0 power supply.
+
+ vcc2-supply:
+ description: Controller port 1 power supply.
+
+ vcc3-supply:
+ description: Target port 0/1/4/5 power supply.
+
+ vcc4-supply:
+ description: Target port 2/3/6/7 power supply.
+
+ regulators:
+ type: object
+ additionalProperties: false
+
+ properties:
+ ldo-cp0:
+ type: object
+ $ref: /schemas/regulator/regulator.yaml#
+ unevaluatedProperties: false
+
+ ldo-cp1:
+ type: object
+ $ref: /schemas/regulator/regulator.yaml#
+ unevaluatedProperties: false
+
+ ldo-tpg0:
+ type: object
+ $ref: /schemas/regulator/regulator.yaml#
+ unevaluatedProperties: false
+
+ ldo-tpg1:
+ type: object
+ $ref: /schemas/regulator/regulator.yaml#
+ unevaluatedProperties: false
+
+required:
+ - reg
+
+patternProperties:
+ "^i3c@[0-7]$":
+ type: object
+ $ref: /schemas/i3c/i3c.yaml#
+ unevaluatedProperties: false
+
+ properties:
+ reg:
+ description:
+ The I3C HUB Target Port number.
+ maximum: 7
+
+ nxp,pullup-enable:
+ type: boolean
+ description:
+ Enables the on-die pull-up for Target Port.
+
+ required:
+ - reg
+
+ "^(i2c|smbus)@[0-7]$":
+ type: object
+ $ref: /schemas/i2c/i2c-controller.yaml#
+ unevaluatedProperties: false
+
+ properties:
+ reg:
+ description:
+ The I3C HUB Target Port number.
+ maximum: 7
+
+ nxp,pullup-enable:
+ type: boolean
+ description:
+ Enables the on-die pull-up for Target Port.
+
+ required:
+ - reg
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ i3c {
+ #address-cells = <3>;
+ #size-cells = <0>;
+
+ hub@70,236153000c2 {
+ reg = <0x70 0x236 0x153000c2>;
+ compatible = "nxp,p3h2840";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ assigned-address = <0x50>;
+
+ nxp,tp0145-pullup-ohms = <1000>;
+ nxp,tp2367-pullup-ohms = <1000>;
+ nxp,cp0-io-strength-ohms = <50>;
+ nxp,cp1-io-strength-ohms = <50>;
+ nxp,tp0145-io-strength-ohms = <50>;
+ nxp,tp2367-io-strength-ohms = <50>;
+ vcc3-supply = <®_tpg0>;
+ vcc4-supply = <®_tpg1>;
+
+ regulators {
+ reg_cp0: ldo-cp0 {
+ regulator-name = "ldo-cp0";
+ regulator-min-microvolt = <1800000>;
+ regulator-max-microvolt = <1800000>;
+ };
+
+ reg_cp1: ldo-cp1 {
+ regulator-name = "ldo-cp1";
+ regulator-min-microvolt = <1800000>;
+ regulator-max-microvolt = <1800000>;
+ };
+
+ reg_tpg0: ldo-tpg0 {
+ regulator-name = "ldo-tpg0";
+ regulator-min-microvolt = <1800000>;
+ regulator-max-microvolt = <1800000>;
+ };
+
+ reg_tpg1: ldo-tpg1 {
+ regulator-name = "ldo-tpg1";
+ regulator-min-microvolt = <1800000>;
+ regulator-max-microvolt = <1800000>;
+ };
+ };
+
+ smbus@0 {
+ reg = <0x0>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ nxp,pullup-enable;
+ };
+
+ i2c@1 {
+ reg = <0x1>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ nxp,pullup-enable;
+ };
+
+ i3c@2 {
+ reg = <0x2>;
+ #address-cells = <3>;
+ #size-cells = <0>;
+ nxp,pullup-enable;
+ };
+ };
+ };
+
+ - |
+ i2c {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ hub@70 {
+ reg = <0x70>;
+ compatible = "nxp,p3h2840";
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ nxp,tp0145-pullup-ohms = <1000>;
+ nxp,tp2367-pullup-ohms = <1000>;
+ nxp,cp0-io-strength-ohms = <50>;
+ nxp,cp1-io-strength-ohms = <50>;
+ nxp,tp0145-io-strength-ohms = <50>;
+ nxp,tp2367-io-strength-ohms = <50>;
+ vcc3-supply = <®_tpg0_i2c>;
+ vcc4-supply = <®_tpg1_i2c>;
+
+ regulators {
+ reg_cp0_i2c: ldo-cp0 {
+ regulator-name = "ldo-cp0";
+ regulator-min-microvolt = <1800000>;
+ regulator-max-microvolt = <1800000>;
+ };
+
+ reg_cp1_i2c: ldo-cp1 {
+ regulator-name = "ldo-cp1";
+ regulator-min-microvolt = <1800000>;
+ regulator-max-microvolt = <1800000>;
+ };
+
+ reg_tpg0_i2c: ldo-tpg0 {
+ regulator-name = "ldo-tpg0";
+ regulator-min-microvolt = <1800000>;
+ regulator-max-microvolt = <1800000>;
+ };
+
+ reg_tpg1_i2c: ldo-tpg1 {
+ regulator-name = "ldo-tpg1";
+ regulator-min-microvolt = <1800000>;
+ regulator-max-microvolt = <1800000>;
+ };
+ };
+
+ smbus@0 {
+ reg = <0x0>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ nxp,pullup-enable;
+ };
+
+ i2c@1 {
+ reg = <0x1>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ nxp,pullup-enable;
+ };
+ };
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index c2c6d79275c6..ba65ae5a008b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19303,6 +19303,15 @@ S: Maintained
F: Documentation/devicetree/bindings/ptp/nxp,ptp-netc.yaml
F: drivers/ptp/ptp_netc.c
+NXP P3H2X4X I3C-HUB DRIVER
+M: Vikash Bansal <vikash.bansal@nxp.com>
+M: Aman Kumar Pandey <aman.kumarpandey@nxp.com>
+M: Lakshay Piplani <lakshay.piplani@nxp.com>
+L: linux-kernel@vger.kernel.org
+L: linux-i3c@lists.infradead.org
+S: Maintained
+F: Documentation/devicetree/bindings/i3c/nxp,p3h2840.yaml
+
NXP PF5300/PF5301/PF5302 PMIC REGULATOR DEVICE DRIVER
M: Woodrow Douglass <wdouglass@carnegierobotics.com>
S: Maintained
--
2.25.1
^ permalink raw reply related [flat|nested] 19+ messages in thread
* [PATCH v14 4/8] mfd: p3h2x4x: Add driver for NXP P3H2x4x i3c hub and on-die regulator
2026-07-14 9:20 [PATCH v14 0/8] Add support for NXP P3H2x4x I3C hub driver Lakshay Piplani
` (2 preceding siblings ...)
2026-07-14 9:20 ` [PATCH v14 3/8] dt-bindings: i3c: Add NXP P3H2x4x i3c-hub support Lakshay Piplani
@ 2026-07-14 9:20 ` Lakshay Piplani
2026-07-14 10:49 ` sashiko-bot
2026-07-14 9:20 ` [PATCH v14 5/8] regulator: p3h2x4x: Add driver for on-die regulators in NXP P3H2x4x i3c hub Lakshay Piplani
` (3 subsequent siblings)
7 siblings, 1 reply; 19+ messages in thread
From: Lakshay Piplani @ 2026-07-14 9:20 UTC (permalink / raw)
To: linux-kernel, linux-i3c, alexandre.belloni, krzk+dt, robh,
conor+dt, devicetree, broonie, lee, Frank.Li, lgirdwood
Cc: vikash.bansal, priyanka.jain, aman.kumarpandey, Lakshay Piplani
From: Aman Kumar Pandey <aman.kumarpandey@nxp.com>
Add core MFD support for the NXP P3H2x4x (P3H2440/P3H2441/P3H2840/P3H2841)
family of multiport I3C hub devices. These devices connect to a host via
I3C/I2C/SMBus and expose multiple downstream target ports.
Signed-off-by: Aman Kumar Pandey <aman.kumarpandey@nxp.com>
Signed-off-by: Vikash Bansal <vikash.bansal@nxp.com>
Signed-off-by: Lakshay Piplani <lakshay.piplani@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
---
Changes in v14:
- Clean up MFD driver comments, formatting, variable names and author
information
- Define and document the I3C hub DCR value in hexadecimal form
- Use direct regmap bit-width values instead of local macros
- Add a shared protected_reg_lock for protected register accesses across
P3H2X4X child drivers
Changes in v13:
- Use i3c_device helpers (i3cdev_to_dev()) instead of direct struct access
to maintain API abstraction
- Avoid including internal I3C headers and use public device headers instead
- Ensure proper device matching by relying on manufacturer ID checks in probe
Changes in v12:
- No change, added Reviewed-By tag
Changes in v11:
- Use MFD_CELL_NAME() for child device registration
- Rename local variables for consistency
- Rename driver names to follow subsystem conventions:
- Use '-' instead of '_' in driver names
- Drop the "_drv" suffix from driver names
Changes in v10:
- Drop redundant is_p3h2x4x_in_i3c flag
Changes in v9:
- Renamed macros to follow consistent uppercase naming conventions
- Made REGMAP selects in the P3H2X4X MFD Kconfig conditional,
to avoid I3C/I2C dependency issues
Changes in v8:
- No change
Changes in v7:
- Use new config I3C_OR_I2C
Changes in v6:
- No change
Changes in v5:
- Corrected the ordering in the Makefile and Kconfig for MFD_P3H2X4X
- Updated dev_err_probe() for regmap_init failure.
- Updated module description
Changes in v4:
- Split the driver into three separate patches(mfd, regulator and I3C hub)
- Added support for NXP P3H2x4x MFD functionality
---
---
MAINTAINERS | 2 +
drivers/mfd/Kconfig | 13 ++++
drivers/mfd/Makefile | 1 +
drivers/mfd/p3h2840.c | 139 ++++++++++++++++++++++++++++++++++++
include/linux/i3c/device.h | 2 +
include/linux/mfd/p3h2840.h | 25 +++++++
6 files changed, 182 insertions(+)
create mode 100644 drivers/mfd/p3h2840.c
create mode 100644 include/linux/mfd/p3h2840.h
diff --git a/MAINTAINERS b/MAINTAINERS
index ba65ae5a008b..3420701a75c5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19311,6 +19311,8 @@ L: linux-kernel@vger.kernel.org
L: linux-i3c@lists.infradead.org
S: Maintained
F: Documentation/devicetree/bindings/i3c/nxp,p3h2840.yaml
+F: drivers/mfd/p3h2840.c
+F: include/linux/mfd/p3h2840.h
NXP PF5300/PF5301/PF5302 PMIC REGULATOR DEVICE DRIVER
M: Woodrow Douglass <wdouglass@carnegierobotics.com>
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 7192c9d1d268..405b50c3c77b 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -617,6 +617,19 @@ config MFD_MX25_TSADC
i.MX25 processors. They consist of a conversion queue for general
purpose ADC and a queue for Touchscreens.
+config MFD_P3H2X4X
+ tristate "NXP P3H2X4X I3C Hub Device"
+ depends on I3C_OR_I2C
+ select MFD_CORE
+ select REGMAP_I3C if I3C
+ select REGMAP_I2C if I2C
+ help
+ Enable Support for NXP P3H244x/P3H284x I3C HUB device using I3C/I2C
+ communication interface.
+
+ This driver provides support for I3C hub and regulator, each subdriver
+ can be enabled independently depending on the required functionality.
+
config MFD_PF1550
tristate "NXP PF1550 PMIC Support"
depends on I2C=y && OF
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index e75e8045c28a..a284b22c7b13 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -122,6 +122,7 @@ obj-$(CONFIG_MFD_MC13XXX) += mc13xxx-core.o
obj-$(CONFIG_MFD_MC13XXX_SPI) += mc13xxx-spi.o
obj-$(CONFIG_MFD_MC13XXX_I2C) += mc13xxx-i2c.o
+obj-$(CONFIG_MFD_P3H2X4X) += p3h2840.o
obj-$(CONFIG_MFD_PF1550) += pf1550.o
obj-$(CONFIG_MFD_NCT6694) += nct6694.o
diff --git a/drivers/mfd/p3h2840.c b/drivers/mfd/p3h2840.c
new file mode 100644
index 000000000000..652077408dbd
--- /dev/null
+++ b/drivers/mfd/p3h2840.c
@@ -0,0 +1,139 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2025-2026 NXP
+ *
+ * Authors:
+ * Aman Kumar Pandey <aman.kumarpandey@nxp.com>
+ * Vikash Bansal <vikash.bansal@nxp.com>
+ * Lakshay Piplani <lakshay.piplani@nxp.com>
+ *
+ * P3H2X4X multi-function device driver.
+ */
+#include <linux/i2c.h>
+#include <linux/i3c/device.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/p3h2840.h>
+#include <linux/regmap.h>
+
+static const struct mfd_cell p3h2x4x_devs[] = {
+ MFD_CELL_NAME("p3h2x4x-regulator"),
+ MFD_CELL_NAME("p3h2x4x-i3c-hub"),
+};
+
+static const struct regmap_config p3h2x4x_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = 0xFF,
+};
+
+static int p3h2x4x_device_probe_i3c(struct i3c_device *i3cdev)
+{
+ struct device *dev = i3cdev_to_dev(i3cdev);
+ struct i3c_device_info devinfo;
+ struct p3h2x4x *ddata;
+ int ret;
+
+ i3c_device_get_info(i3cdev, &devinfo);
+
+ if (I3C_PID_MANUF_ID(devinfo.pid) != I3C_MANUF_ID_NXP)
+ return -ENODEV;
+
+ ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
+ if (!ddata)
+ return -ENOMEM;
+
+ ret = devm_mutex_init(dev, &ddata->protected_reg_lock);
+ if (ret)
+ return ret;
+
+ i3cdev_set_drvdata(i3cdev, ddata);
+
+ ddata->regmap = devm_regmap_init_i3c(i3cdev, &p3h2x4x_regmap_config);
+ if (IS_ERR(ddata->regmap))
+ return dev_err_probe(dev, PTR_ERR(ddata->regmap),
+ "Failed to register HUB regmap\n");
+
+ /* The hub child driver retrieves information from i3cdev. */
+ ddata->i3cdev = i3cdev;
+
+ ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO,
+ p3h2x4x_devs, ARRAY_SIZE(p3h2x4x_devs),
+ NULL, 0, NULL);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to add sub devices\n");
+
+ return 0;
+}
+
+static int p3h2x4x_device_probe_i2c(struct i2c_client *client)
+{
+ struct p3h2x4x *ddata;
+ int ret;
+
+ ddata = devm_kzalloc(&client->dev, sizeof(*ddata), GFP_KERNEL);
+ if (!ddata)
+ return -ENOMEM;
+
+ ret = devm_mutex_init(&client->dev, &ddata->protected_reg_lock);
+ if (ret)
+ return ret;
+
+ i2c_set_clientdata(client, ddata);
+
+ ddata->regmap = devm_regmap_init_i2c(client, &p3h2x4x_regmap_config);
+ if (IS_ERR(ddata->regmap))
+ return dev_err_probe(&client->dev, PTR_ERR(ddata->regmap),
+ "Failed to register HUB regmap\n");
+
+ ddata->i3cdev = NULL;
+
+ ret = devm_mfd_add_devices(&client->dev, PLATFORM_DEVID_AUTO,
+ p3h2x4x_devs, ARRAY_SIZE(p3h2x4x_devs),
+ NULL, 0, NULL);
+ if (ret)
+ return dev_err_probe(&client->dev, ret, "Failed to add sub devices\n");
+
+ return 0;
+}
+
+static const struct i3c_device_id p3h2x4x_i3c_ids[] = {
+ I3C_CLASS(I3C_DCR_HUB, NULL),
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(i3c, p3h2x4x_i3c_ids);
+
+static const struct i2c_device_id p3h2x4x_i2c_id_table[] = {
+ { "nxp-i3c-hub" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(i2c, p3h2x4x_i2c_id_table);
+
+static const struct of_device_id p3h2x4x_i2c_of_match[] = {
+ { .compatible = "nxp,p3h2840", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, p3h2x4x_i2c_of_match);
+
+static struct i3c_driver p3h2x4x_i3c = {
+ .driver = {
+ .name = "p3h2x4x-i3c",
+ },
+ .probe = p3h2x4x_device_probe_i3c,
+ .id_table = p3h2x4x_i3c_ids,
+};
+
+static struct i2c_driver p3h2x4x_i2c = {
+ .driver = {
+ .name = "p3h2x4x-i2c",
+ .of_match_table = p3h2x4x_i2c_of_match,
+ },
+ .probe = p3h2x4x_device_probe_i2c,
+ .id_table = p3h2x4x_i2c_id_table,
+};
+module_i3c_i2c_driver(p3h2x4x_i3c, &p3h2x4x_i2c);
+
+MODULE_AUTHOR("Aman Kumar Pandey <aman.kumarpandey@nxp.com>");
+MODULE_AUTHOR("Vikash Bansal <vikash.bansal@nxp.com>");
+MODULE_AUTHOR("Lakshay Piplani <lakshay.piplani@nxp.com>");
+MODULE_DESCRIPTION("NXP P3H2X4X I3C HUB multi function driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/i3c/device.h b/include/linux/i3c/device.h
index 971d53349b6f..1dcfc4cc1cef 100644
--- a/include/linux/i3c/device.h
+++ b/include/linux/i3c/device.h
@@ -82,9 +82,11 @@ struct i3c_xfer {
/**
* enum i3c_dcr - I3C DCR values
* @I3C_DCR_GENERIC_DEVICE: generic I3C device
+ * @I3C_DCR_HUB: I3C hub device
*/
enum i3c_dcr {
I3C_DCR_GENERIC_DEVICE = 0,
+ I3C_DCR_HUB = 0xC2,
};
#define I3C_PID_MANUF_ID(pid) (((pid) & GENMASK_ULL(47, 33)) >> 33)
diff --git a/include/linux/mfd/p3h2840.h b/include/linux/mfd/p3h2840.h
new file mode 100644
index 000000000000..ba9a38756ecb
--- /dev/null
+++ b/include/linux/mfd/p3h2840.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2025-2026 NXP
+ */
+
+#ifndef _LINUX_MFD_P3H2840_H
+#define _LINUX_MFD_P3H2840_H
+
+#include <linux/mutex.h>
+#include <linux/types.h>
+
+/* Device Configuration Registers */
+#define P3H2X4X_DEV_REG_PROTECTION_CODE 0x10
+#define P3H2X4X_REGISTERS_LOCK_CODE 0x00
+#define P3H2X4X_REGISTERS_UNLOCK_CODE 0x69
+#define P3H2X4X_CP1_REGISTERS_UNLOCK_CODE 0x6a
+
+#define I3C_MANUF_ID_NXP 0x011b
+
+struct p3h2x4x {
+ struct i3c_device *i3cdev;
+ struct regmap *regmap;
+ struct mutex protected_reg_lock; /* Serializes protected register unlock/lock sequences. */
+};
+#endif /* _LINUX_MFD_P3H2840_H */
--
2.25.1
^ permalink raw reply related [flat|nested] 19+ messages in thread
* [PATCH v14 5/8] regulator: p3h2x4x: Add driver for on-die regulators in NXP P3H2x4x i3c hub
2026-07-14 9:20 [PATCH v14 0/8] Add support for NXP P3H2x4x I3C hub driver Lakshay Piplani
` (3 preceding siblings ...)
2026-07-14 9:20 ` [PATCH v14 4/8] mfd: p3h2x4x: Add driver for NXP P3H2x4x i3c hub and on-die regulator Lakshay Piplani
@ 2026-07-14 9:20 ` Lakshay Piplani
2026-07-14 10:57 ` sashiko-bot
2026-07-14 9:20 ` [PATCH v14 6/8] i3c: hub: Add support for the I3C interface in the I3C hub Lakshay Piplani
` (2 subsequent siblings)
7 siblings, 1 reply; 19+ messages in thread
From: Lakshay Piplani @ 2026-07-14 9:20 UTC (permalink / raw)
To: linux-kernel, linux-i3c, alexandre.belloni, krzk+dt, robh,
conor+dt, devicetree, broonie, lee, Frank.Li, lgirdwood
Cc: vikash.bansal, priyanka.jain, aman.kumarpandey, Lakshay Piplani,
Frank Li
From: Aman Kumar Pandey <aman.kumarpandey@nxp.com>
The NXP P3H2x4x family integrates on-die regulators alongside I3C hub
functionality. This driver registers the regulators using the MFD
framework and exposes them via the regulator subsystem.
Signed-off-by: Aman Kumar Pandey <aman.kumarpandey@nxp.com>
Signed-off-by: Vikash Bansal <vikash.bansal@nxp.com>
Signed-off-by: Lakshay Piplani <lakshay.piplani@nxp.com>
Reviewed-by: Frank Li <frank.li@nxp.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
---
Changes in v14:
- Use the shared MFD protected_reg_lock instead of a regulator-private mutex
to serialize protected register access across P3H2X4X child drivers
- Rework protected register handling into explicit unprotect/protect helpers
and restore the original protection state after each regulator operation
- Ensure protected registers are restored even if enable, disable or
set_voltage_sel fails
Changes in v13:
- Serialize register unlock/modify/lock sequences using a device-level mutex to
avoid races between regulators.
- Ensure proper module auto-loading by adding platform device ID table.
- Improve error handling in register guard paths to avoid operating on locked hub.
Changes in v12:
- No change
Changes in v11:
- No change, added Reviewed-By tag
Changes in v10:
- No change
Changes in v9:
- No change
Changes in v8:
- No change
Changes in v7:
- No change, added Reviewed-By tag
Changes in v6:
- Use DEFINE_LOCK_GUARD_1 for reg lock/unlock
Changes in v5:
- Updated dev_err_probe() for regmap_init failure.
- Updated module description
Changes in v4:
- Split the driver into three separate patches (mfd, regulator and I3C hub)
- Introduced driver for on-die regulators in NXP P3H2x4x I3C hub
---
---
MAINTAINERS | 1 +
drivers/regulator/Kconfig | 10 +
drivers/regulator/Makefile | 1 +
drivers/regulator/p3h2840_i3c_hub_regulator.c | 284 ++++++++++++++++++
4 files changed, 296 insertions(+)
create mode 100644 drivers/regulator/p3h2840_i3c_hub_regulator.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 3420701a75c5..fcb3917aa096 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19312,6 +19312,7 @@ L: linux-i3c@lists.infradead.org
S: Maintained
F: Documentation/devicetree/bindings/i3c/nxp,p3h2840.yaml
F: drivers/mfd/p3h2840.c
+F: drivers/regulator/p3h2840_i3c_hub_regulator.c
F: include/linux/mfd/p3h2840.h
NXP PF5300/PF5301/PF5302 PMIC REGULATOR DEVICE DRIVER
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index d71dac9436e3..88809f493fd4 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -1019,6 +1019,16 @@ config REGULATOR_MTK_DVFSRC
of Mediatek. It allows for voting on regulator state
between multiple users.
+config REGULATOR_P3H2X4X
+ tristate "NXP P3H2X4X regulator support"
+ depends on MFD_P3H2X4X
+ help
+ This driver provides support for the voltage regulators of the
+ P3H244x/P3H284x multi-function I3C Hub device.
+
+ Say M here if you want to include support for this regulator as
+ a module. The module will be named "p3h2840_i3c_hub_regulator".
+
config REGULATOR_PALMAS
tristate "TI Palmas PMIC Regulators"
depends on MFD_PALMAS
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 35639f3115fd..46f586ccde63 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -128,6 +128,7 @@ obj-$(CONFIG_REGULATOR_QCOM_RPMH) += qcom-rpmh-regulator.o
obj-$(CONFIG_REGULATOR_QCOM_SMD_RPM) += qcom_smd-regulator.o
obj-$(CONFIG_REGULATOR_QCOM_SPMI) += qcom_spmi-regulator.o
obj-$(CONFIG_REGULATOR_QCOM_USB_VBUS) += qcom_usb_vbus-regulator.o
+obj-$(CONFIG_REGULATOR_P3H2X4X) += p3h2840_i3c_hub_regulator.o
obj-$(CONFIG_REGULATOR_PALMAS) += palmas-regulator.o
obj-$(CONFIG_REGULATOR_PCA9450) += pca9450-regulator.o
obj-$(CONFIG_REGULATOR_PF0900) += pf0900-regulator.o
diff --git a/drivers/regulator/p3h2840_i3c_hub_regulator.c b/drivers/regulator/p3h2840_i3c_hub_regulator.c
new file mode 100644
index 000000000000..645d46ad7c2f
--- /dev/null
+++ b/drivers/regulator/p3h2840_i3c_hub_regulator.c
@@ -0,0 +1,284 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2025-2026 NXP
+ * NXP P3H2X4X regulator driver file contain functions for enable/disable regulator
+ * and voltage set/get.
+ */
+#include <linux/bitfield.h>
+#include <linux/cleanup.h>
+#include <linux/mfd/p3h2840.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+
+#define P3H2X4X_LDO_AND_PULLUP_CONF 0x19
+#define P3H2X4X_LDO_ENABLE_DISABLE_MASK GENMASK(3, 0)
+#define P3H2X4X_CP0_EN_LDO BIT(0)
+#define P3H2X4X_CP1_EN_LDO BIT(1)
+#define P3H2X4X_TP0145_EN_LDO BIT(2)
+#define P3H2X4X_TP2367_EN_LDO BIT(3)
+
+#define P3H2X4X_NET_OPER_MODE_CONF 0x15
+#define P3H2X4X_VCCIO_LDO_CONF 0x16
+#define P3H2X4X_CP0_VCCIO_LDO_VOLTAGE_MASK GENMASK(1, 0)
+#define P3H2X4X_CP0_VCCIO_LDO_VOLTAGE(x) \
+ FIELD_PREP(P3H2X4X_CP0_VCCIO_LDO_VOLTAGE_MASK, x)
+#define P3H2X4X_CP1_VCCIO_LDO_VOLTAGE_MASK GENMASK(3, 2)
+#define P3H2X4X_CP1_VCCIO_LDO_VOLTAGE(x) \
+ FIELD_PREP(P3H2X4X_CP1_VCCIO_LDO_VOLTAGE_MASK, x)
+#define P3H2X4X_TP0145_VCCIO_LDO_VOLTAGE_MASK GENMASK(5, 4)
+#define P3H2X4X_TP0145_VCCIO_LDO_VOLTAGE(x) \
+ FIELD_PREP(P3H2X4X_TP0145_VCCIO_LDO_VOLTAGE_MASK, x)
+#define P3H2X4X_TP2367_VCCIO_LDO_VOLTAGE_MASK GENMASK(7, 6)
+#define P3H2X4X_TP2367_VCCIO_LDO_VOLTAGE(x) \
+ FIELD_PREP(P3H2X4X_TP2367_VCCIO_LDO_VOLTAGE_MASK, x)
+#define P3H2X4X_LDO_COUNT 4
+
+struct p3h2x4x_regulator_dev {
+ struct regulator_dev *rp3h2x4x_dev[P3H2X4X_LDO_COUNT];
+ struct p3h2x4x *p3h2x4x;
+ struct regmap *regmap;
+};
+
+struct p3h2x4x_reg_state {
+ unsigned int orig;
+ bool restore;
+};
+
+static void p3h2x4x_reg_guard_enter(struct regulator_dev *rdev)
+{
+ struct p3h2x4x_regulator_dev *priv = rdev_get_drvdata(rdev);
+
+ mutex_lock(&priv->p3h2x4x->protected_reg_lock);
+}
+
+static void p3h2x4x_reg_guard_exit(struct regulator_dev *rdev)
+{
+ struct p3h2x4x_regulator_dev *priv = rdev_get_drvdata(rdev);
+
+ mutex_unlock(&priv->p3h2x4x->protected_reg_lock);
+}
+
+DEFINE_LOCK_GUARD_1(p3h2x4x_reg, struct regulator_dev,
+ p3h2x4x_reg_guard_enter(_T->lock),
+ p3h2x4x_reg_guard_exit(_T->lock));
+
+static int p3h2x4x_reg_unprotect(struct regulator_dev *rdev,
+ struct p3h2x4x_reg_state *state)
+{
+ int ret;
+
+ state->restore = false;
+
+ ret = regmap_read(rdev->regmap, P3H2X4X_DEV_REG_PROTECTION_CODE,
+ &state->orig);
+ if (ret)
+ return ret;
+
+ if (state->orig == P3H2X4X_REGISTERS_UNLOCK_CODE)
+ return 0;
+
+ ret = regmap_write(rdev->regmap, P3H2X4X_DEV_REG_PROTECTION_CODE,
+ P3H2X4X_REGISTERS_UNLOCK_CODE);
+ if (ret)
+ return ret;
+
+ state->restore = true;
+
+ return 0;
+}
+
+static int p3h2x4x_reg_protect(struct regulator_dev *rdev,
+ struct p3h2x4x_reg_state *state)
+{
+ if (!state->restore)
+ return 0;
+
+ return regmap_write(rdev->regmap, P3H2X4X_DEV_REG_PROTECTION_CODE,
+ state->orig);
+}
+
+static int p3h2x4x_regulator_enable(struct regulator_dev *rdev)
+{
+ struct p3h2x4x_reg_state state;
+ int ret, ret2;
+
+ guard(p3h2x4x_reg)(rdev);
+
+ ret = p3h2x4x_reg_unprotect(rdev, &state);
+ if (ret)
+ return ret;
+
+ ret = regulator_enable_regmap(rdev);
+ ret2 = p3h2x4x_reg_protect(rdev, &state);
+
+ return ret ? ret : ret2;
+}
+
+static int p3h2x4x_regulator_disable(struct regulator_dev *rdev)
+{
+ struct p3h2x4x_reg_state state;
+ int ret, ret2;
+
+ guard(p3h2x4x_reg)(rdev);
+
+ ret = p3h2x4x_reg_unprotect(rdev, &state);
+ if (ret)
+ return ret;
+
+ ret = regulator_disable_regmap(rdev);
+ ret2 = p3h2x4x_reg_protect(rdev, &state);
+
+ return ret ? ret : ret2;
+}
+
+static int p3h2x4x_regulator_set_voltage_sel(struct regulator_dev *rdev,
+ unsigned int sel)
+{
+ struct p3h2x4x_reg_state state;
+ int ret, ret2;
+
+ guard(p3h2x4x_reg)(rdev);
+
+ ret = p3h2x4x_reg_unprotect(rdev, &state);
+ if (ret)
+ return ret;
+
+ ret = regulator_set_voltage_sel_regmap(rdev, sel);
+ ret2 = p3h2x4x_reg_protect(rdev, &state);
+
+ return ret ? ret : ret2;
+}
+
+static const struct regulator_ops p3h2x4x_ldo_ops = {
+ .list_voltage = regulator_list_voltage_table,
+ .map_voltage = regulator_map_voltage_iterate,
+ .set_voltage_sel = p3h2x4x_regulator_set_voltage_sel,
+ .get_voltage_sel = regulator_get_voltage_sel_regmap,
+ .enable = p3h2x4x_regulator_enable,
+ .disable = p3h2x4x_regulator_disable,
+ .is_enabled = regulator_is_enabled_regmap,
+};
+
+static const unsigned int p3h2x4x_voltage_table[] = {
+ 1000000,
+ 1100000,
+ 1200000,
+ 1800000,
+};
+
+static struct regulator_desc p3h2x4x_regulators[] = {
+ {
+ .name = "ldo-cp0",
+ .of_match = of_match_ptr("ldo-cp0"),
+ .regulators_node = of_match_ptr("regulators"),
+ .volt_table = p3h2x4x_voltage_table,
+ .n_voltages = ARRAY_SIZE(p3h2x4x_voltage_table),
+ .ops = &p3h2x4x_ldo_ops,
+ .type = REGULATOR_VOLTAGE,
+ .owner = THIS_MODULE,
+ .enable_reg = P3H2X4X_LDO_AND_PULLUP_CONF,
+ .enable_mask = P3H2X4X_CP0_EN_LDO,
+ .vsel_reg = P3H2X4X_VCCIO_LDO_CONF,
+ .vsel_mask = P3H2X4X_CP0_VCCIO_LDO_VOLTAGE_MASK,
+ },
+ {
+ .name = "ldo-cp1",
+ .of_match = of_match_ptr("ldo-cp1"),
+ .regulators_node = of_match_ptr("regulators"),
+ .volt_table = p3h2x4x_voltage_table,
+ .n_voltages = ARRAY_SIZE(p3h2x4x_voltage_table),
+ .ops = &p3h2x4x_ldo_ops,
+ .type = REGULATOR_VOLTAGE,
+ .owner = THIS_MODULE,
+ .enable_reg = P3H2X4X_LDO_AND_PULLUP_CONF,
+ .enable_mask = P3H2X4X_CP1_EN_LDO,
+ .vsel_reg = P3H2X4X_VCCIO_LDO_CONF,
+ .vsel_mask = P3H2X4X_CP1_VCCIO_LDO_VOLTAGE_MASK,
+ },
+ {
+ .name = "ldo-tpg0",
+ .of_match = of_match_ptr("ldo-tpg0"),
+ .regulators_node = of_match_ptr("regulators"),
+ .volt_table = p3h2x4x_voltage_table,
+ .n_voltages = ARRAY_SIZE(p3h2x4x_voltage_table),
+ .ops = &p3h2x4x_ldo_ops,
+ .type = REGULATOR_VOLTAGE,
+ .owner = THIS_MODULE,
+ .enable_reg = P3H2X4X_LDO_AND_PULLUP_CONF,
+ .enable_mask = P3H2X4X_TP0145_EN_LDO,
+ .vsel_reg = P3H2X4X_VCCIO_LDO_CONF,
+ .vsel_mask = P3H2X4X_TP0145_VCCIO_LDO_VOLTAGE_MASK,
+ },
+ {
+ .name = "ldo-tpg1",
+ .of_match = of_match_ptr("ldo-tpg1"),
+ .regulators_node = of_match_ptr("regulators"),
+ .volt_table = p3h2x4x_voltage_table,
+ .n_voltages = ARRAY_SIZE(p3h2x4x_voltage_table),
+ .ops = &p3h2x4x_ldo_ops,
+ .type = REGULATOR_VOLTAGE,
+ .owner = THIS_MODULE,
+ .enable_reg = P3H2X4X_LDO_AND_PULLUP_CONF,
+ .enable_mask = P3H2X4X_TP2367_EN_LDO,
+ .vsel_reg = P3H2X4X_VCCIO_LDO_CONF,
+ .vsel_mask = P3H2X4X_TP2367_VCCIO_LDO_VOLTAGE_MASK,
+ },
+};
+
+static int p3h2x4x_regulator_probe(struct platform_device *pdev)
+{
+ struct p3h2x4x *p3h2x4x = dev_get_drvdata(pdev->dev.parent);
+ struct p3h2x4x_regulator_dev *p3h2x4x_regulator;
+ struct regulator_config rcfg = { };
+ struct device *dev = &pdev->dev;
+ struct regulator_dev *rdev;
+ int i;
+
+ p3h2x4x_regulator = devm_kzalloc(dev, sizeof(*p3h2x4x_regulator), GFP_KERNEL);
+ if (!p3h2x4x_regulator)
+ return -ENOMEM;
+
+ p3h2x4x_regulator->p3h2x4x = p3h2x4x;
+ p3h2x4x_regulator->regmap = p3h2x4x->regmap;
+
+ platform_set_drvdata(pdev, p3h2x4x_regulator);
+
+ device_set_of_node_from_dev(dev, dev->parent);
+
+ rcfg.dev = dev;
+ rcfg.regmap = p3h2x4x_regulator->regmap;
+ rcfg.driver_data = p3h2x4x_regulator;
+
+ for (i = 0; i < ARRAY_SIZE(p3h2x4x_regulators); i++) {
+ rdev = devm_regulator_register(&pdev->dev, &p3h2x4x_regulators[i], &rcfg);
+ if (IS_ERR(rdev))
+ return dev_err_probe(dev, PTR_ERR(rdev), "Failed to register %s\n",
+ p3h2x4x_regulators[i].name);
+ p3h2x4x_regulator->rp3h2x4x_dev[i] = rdev;
+ }
+ return 0;
+}
+
+static const struct platform_device_id p3h2x4x_regulator_id[] = {
+ { "p3h2x4x-regulator" },
+ { }
+};
+MODULE_DEVICE_TABLE(platform, p3h2x4x_regulator_id);
+
+static struct platform_driver p3h2x4x_regulator_driver = {
+ .driver = {
+ .name = "p3h2x4x-regulator",
+ .probe_type = PROBE_PREFER_ASYNCHRONOUS,
+ },
+ .probe = p3h2x4x_regulator_probe,
+ .id_table = p3h2x4x_regulator_id,
+};
+module_platform_driver(p3h2x4x_regulator_driver);
+
+MODULE_AUTHOR("Aman Kumar Pandey <aman.kumarpandey@nxp.com>");
+MODULE_AUTHOR("Vikash Bansal <vikash.bansal@nxp.com>");
+MODULE_AUTHOR("Lakshay Piplani <lakshay.piplani@nxp.com>");
+MODULE_DESCRIPTION("NXP P3H2X4X I3C HUB Regulator driver");
+MODULE_LICENSE("GPL");
--
2.25.1
^ permalink raw reply related [flat|nested] 19+ messages in thread
* [PATCH v14 6/8] i3c: hub: Add support for the I3C interface in the I3C hub
2026-07-14 9:20 [PATCH v14 0/8] Add support for NXP P3H2x4x I3C hub driver Lakshay Piplani
` (4 preceding siblings ...)
2026-07-14 9:20 ` [PATCH v14 5/8] regulator: p3h2x4x: Add driver for on-die regulators in NXP P3H2x4x i3c hub Lakshay Piplani
@ 2026-07-14 9:20 ` Lakshay Piplani
2026-07-14 11:14 ` sashiko-bot
2026-07-14 9:20 ` [PATCH v14 7/8] i3c: hub: p3h2x4x: Add support for NXP P3H2x4x I3C hub functionality Lakshay Piplani
2026-07-14 9:20 ` [PATCH v14 8/8] i3c: hub: p3h2x4x: Add SMBus slave mode support Lakshay Piplani
7 siblings, 1 reply; 19+ messages in thread
From: Lakshay Piplani @ 2026-07-14 9:20 UTC (permalink / raw)
To: linux-kernel, linux-i3c, alexandre.belloni, krzk+dt, robh,
conor+dt, devicetree, broonie, lee, Frank.Li, lgirdwood
Cc: vikash.bansal, priyanka.jain, aman.kumarpandey, Lakshay Piplani
Add virtual I3C bus support for the hub and provide interface to enable
or disable downstream ports.
Signed-off-by: Aman Kumar Pandey <aman.kumarpandey@nxp.com>
Signed-off-by: Vikash Bansal <vikash.bansal@nxp.com>
Signed-off-by: Lakshay Piplani <lakshay.piplani@nxp.com>
---
Changes in v14:
- Add hub route serialization around DAA, CCC, private transfer and IBI paths
- Add comments explaining that downstream devices behind hub target ports
share the parent controller address space
- Use i3c_bus_maintenance_lock()/unlock() instead of raw parent bus lock
operations
- Hold the parent maintenance lock across temporary hub address reattach,
transfer and address restore
- Rework IBI request/free forwarding, so downstream devices are temporarily
attached to the parent controller for IBI setup
- Clean up the preallocated virtual IBI object and workqueue before forwarding
the IBI request to the parent controller
- Avoid NULL dereference in the core IBI free path when the forwarding
callback has already cleared dev->ibi
Changes in v13:
- Reserve parent I3C bus address slots for downstream devices with matching static and
assigned addresses by parsing target-port DT nodes
- Keep broadcast RSTDAA blocked and add explanatory comment
- Add TODO for empty IBI slot recycle callback
- Add comments for intentional no-op callbacks
Changes in v12:
- Drop redundant depends on I3C from config I3C_HUB
- Return -EOPNOTSUPP for unsupported I2C transfers instead of reporting
success.
Changes in v11:
- Fix virtual hub address reattach handling
- Fix parent bus locking during address reattach operations
- Improve transfer and IBI request error handling
Changes in v10:
- Remove unnecessary ibi_lock handling in request/enable/disable/free
IBI APIs
- Remove redundant parent pointer from struct i3c_hub and derive upstream
master from hub_dev
Changes in v9:
- No change
Changes in v8:
- No change
Changes in v7:
- Convert Kconfig option to tristate
- Fix signedness issue in return value
- Fix kernel-doc warnings
Changes in v6:
- Add support for the generic I3C interface in the I3C Hub
---
---
MAINTAINERS | 2 +
drivers/i3c/Kconfig | 14 +
drivers/i3c/Makefile | 1 +
drivers/i3c/hub.c | 607 ++++++++++++++++++++++++++++++++++++++++
include/linux/i3c/hub.h | 102 +++++++
5 files changed, 726 insertions(+)
create mode 100644 drivers/i3c/hub.c
create mode 100644 include/linux/i3c/hub.h
diff --git a/MAINTAINERS b/MAINTAINERS
index fcb3917aa096..a0b7fd85f8e3 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19311,8 +19311,10 @@ L: linux-kernel@vger.kernel.org
L: linux-i3c@lists.infradead.org
S: Maintained
F: Documentation/devicetree/bindings/i3c/nxp,p3h2840.yaml
+F: drivers/i3c/hub.c
F: drivers/mfd/p3h2840.c
F: drivers/regulator/p3h2840_i3c_hub_regulator.c
+F: include/linux/i3c/hub.h
F: include/linux/mfd/p3h2840.h
NXP PF5300/PF5301/PF5302 PMIC REGULATOR DEVICE DRIVER
diff --git a/drivers/i3c/Kconfig b/drivers/i3c/Kconfig
index 626c54b386d5..7536f3740c94 100644
--- a/drivers/i3c/Kconfig
+++ b/drivers/i3c/Kconfig
@@ -21,6 +21,20 @@ menuconfig I3C
if I3C
source "drivers/i3c/master/Kconfig"
+
+config I3C_HUB
+ tristate "I3C Hub Support"
+ help
+ Enable support for the I3C interface in hub devices.
+
+ This option adds virtual I3C bus support for hubs by creating
+ virtual master controllers for downstream ports and forwarding
+ bus operations through the hub device. It also provides an
+ interface used by hub drivers to enable or disable downstream
+ ports during bus transactions.
+
+ Say Y here if your platform includes an I3C hub device
+
endif # I3C
config I3C_OR_I2C
diff --git a/drivers/i3c/Makefile b/drivers/i3c/Makefile
index 11982efbc6d9..9ddee56a6338 100644
--- a/drivers/i3c/Makefile
+++ b/drivers/i3c/Makefile
@@ -2,3 +2,4 @@
i3c-y := device.o master.o
obj-$(CONFIG_I3C) += i3c.o
obj-$(CONFIG_I3C) += master/
+obj-$(CONFIG_I3C_HUB) += hub.o
diff --git a/drivers/i3c/hub.c b/drivers/i3c/hub.c
new file mode 100644
index 000000000000..6105bb710be6
--- /dev/null
+++ b/drivers/i3c/hub.c
@@ -0,0 +1,607 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2026 NXP
+ * Generic I3C Hub core implementing virtual controller operations.
+ */
+#include <linux/i3c/device.h>
+#include <linux/i3c/hub.h>
+
+#include "internals.h"
+
+/**
+ * i3c_hub_master_bus_init() - Bind controller to hub device
+ * @controller: Virtual controller for a hub port
+ *
+ * Associates the virtual controller with the hub device descriptor so that
+ * transfers are executed through the hub on the parent bus.
+ */
+static int i3c_hub_master_bus_init(struct i3c_master_controller *controller)
+{
+ struct i3c_hub_controller *hub_controller;
+ struct i3c_hub *hub;
+
+ hub_controller = dev_get_drvdata(&controller->dev);
+ if (!hub_controller || !hub_controller->hub)
+ return -ENODEV;
+
+ hub = hub_controller->hub;
+
+ if (!hub->hub_dev)
+ return -ENODEV;
+
+ controller->this = hub->hub_dev->desc;
+ return 0;
+}
+
+static void i3c_hub_master_bus_cleanup(struct i3c_master_controller *controller)
+{
+ controller->this = NULL;
+}
+
+/*
+ * Devices behind the hub are not attached to the virtual bus.
+ *
+ * Instead, i3c_hub_master_priv_xfers() temporarily updates the hub dynamic
+ * address with the target device address before issuing the transfer. Once the
+ * transfer completes, the hub address is restored back to its original value.
+ *
+ * Therefore, no per-device attach, reattach, or detach handling is required for
+ * the virtual bus.
+ */
+static int i3c_hub_attach_i3c_dev(struct i3c_dev_desc *dev)
+{
+ return 0;
+}
+
+static int i3c_hub_reattach_i3c_dev(struct i3c_dev_desc *dev, u8 old_dyn_addr)
+{
+ return 0;
+}
+
+static void i3c_hub_detach_i3c_dev(struct i3c_dev_desc *dev)
+{
+}
+
+/**
+ * i3c_hub_do_daa() - Perform DAA via hub port
+ * @hub: Hub instance
+ * @controller: Virtual controller for a hub port
+ *
+ * Enables the port connection, performs DAA on the parent controller,
+ * then disables the connection.
+ */
+static int i3c_hub_do_daa(struct i3c_hub *hub,
+ struct i3c_master_controller *controller)
+{
+ struct i3c_master_controller *parent;
+ int ret;
+
+ if (!hub || !hub->hub_dev)
+ return -ENODEV;
+
+ parent = i3c_dev_get_master(hub->hub_dev->desc);
+ if (!parent)
+ return -ENODEV;
+
+ mutex_lock(&hub->lock);
+ i3c_hub_enable_port(controller);
+
+ /*
+ * Downstream devices reachable through hub target-port routes share the
+ * parent controller's I3C address space. The hub gates access to a
+ * target-port network, but it does not create an independent dynamic
+ * address domain per virtual bus.
+ *
+ * Run DAA on the parent controller so dynamic addresses remain unique
+ * across all downstream devices, even when they are behind different
+ * target ports.
+ */
+ ret = i3c_master_do_daa(parent);
+ i3c_hub_disable_port(controller);
+ mutex_unlock(&hub->lock);
+
+ return ret;
+}
+
+static bool i3c_hub_supports_ccc_cmd(struct i3c_hub *hub,
+ const struct i3c_ccc_cmd *cmd)
+{
+ struct i3c_master_controller *parent;
+
+ if (!hub || !hub->hub_dev)
+ return false;
+
+ parent = i3c_dev_get_master(hub->hub_dev->desc);
+ if (!parent)
+ return false;
+
+ return i3c_master_supports_ccc_cmd(parent, cmd);
+}
+
+/**
+ * i3c_hub_send_ccc_cmd() - Send CCC through hub port
+ * @hub: Hub instance
+ * @controller: Virtual controller
+ * @cmd: CCC command
+ *
+ * Enables the port connection while issuing CCC on the parent controller.
+ */
+static int i3c_hub_send_ccc_cmd(struct i3c_hub *hub,
+ struct i3c_master_controller *controller,
+ struct i3c_ccc_cmd *cmd)
+{
+ struct i3c_master_controller *parent;
+ int ret;
+
+ if (!hub || !hub->hub_dev)
+ return -ENODEV;
+
+ parent = i3c_dev_get_master(hub->hub_dev->desc);
+ if (!parent)
+ return -ENODEV;
+
+ mutex_lock(&hub->lock);
+ i3c_hub_enable_port(controller);
+ ret = i3c_master_send_ccc_cmd(parent, cmd);
+ i3c_hub_disable_port(controller);
+ mutex_unlock(&hub->lock);
+
+ return ret;
+}
+
+/**
+ * i3c_hub_master_priv_xfers() - Execute private transfers via hub
+ * @dev: Target device descriptor
+ * @xfers: Transfer array
+ * @nxfers: Number of transfers
+ * @mode: transfer mode (SDR, HDR, etc.)
+ *
+ * Handles address adjustment and forwards private transfers through the hub
+ * device.
+ */
+static int i3c_hub_master_priv_xfers(struct i3c_dev_desc *dev,
+ struct i3c_xfer *xfers,
+ int nxfers,
+ enum i3c_xfer_mode mode)
+{
+ struct i3c_master_controller *controller = i3c_dev_get_master(dev);
+ struct i3c_hub_controller *hub_controller;
+ struct i3c_dev_desc *hub_dev;
+ struct i3c_master_controller *parent;
+ u8 hub_addr, target_addr;
+ struct i3c_hub *hub;
+ int ret, xfer_ret;
+
+ hub_controller = dev_get_drvdata(&controller->dev);
+ if (!hub_controller || !hub_controller->hub)
+ return -ENODEV;
+
+ hub = hub_controller->hub;
+
+ if (!hub->hub_dev)
+ return -ENODEV;
+
+ hub_dev = hub->hub_dev->desc;
+
+ parent = i3c_dev_get_master(hub_dev);
+ if (!parent)
+ return -ENODEV;
+
+ mutex_lock(&hub->lock);
+
+ i3c_hub_enable_port(controller);
+
+ i3c_bus_maintenance_lock(&parent->bus);
+
+ hub_addr = hub_dev->info.dyn_addr ?
+ hub_dev->info.dyn_addr : hub_dev->info.static_addr;
+
+ target_addr = dev->info.dyn_addr ?
+ dev->info.dyn_addr : dev->info.static_addr;
+
+ if (hub_addr != target_addr) {
+ hub_dev->info.dyn_addr = target_addr;
+
+ ret = i3c_master_reattach_i3c_dev_locked(hub_dev, hub_addr);
+ if (ret) {
+ hub_dev->info.dyn_addr = hub_addr;
+ goto out_unlock_parent;
+ }
+ }
+
+ ret = i3c_dev_do_xfers_locked(hub_dev, xfers, nxfers, mode);
+
+ if (hub_addr != target_addr) {
+ hub_dev->info.dyn_addr = hub_addr;
+
+ xfer_ret = i3c_master_reattach_i3c_dev_locked(hub_dev,
+ target_addr);
+ if (!ret)
+ ret = xfer_ret;
+ }
+out_unlock_parent:
+ i3c_bus_maintenance_unlock(&parent->bus);
+ i3c_hub_disable_port(controller);
+ mutex_unlock(&hub->lock);
+
+ return ret;
+}
+
+static int i3c_hub_attach_i2c_dev(struct i2c_dev_desc *dev)
+{
+ return -EOPNOTSUPP;
+}
+
+static void i3c_hub_detach_i2c_dev(struct i2c_dev_desc *dev)
+{
+}
+
+static int i3c_hub_i2c_xfers(struct i2c_dev_desc *dev,
+ struct i2c_msg *xfers, int nxfers)
+{
+ return -EOPNOTSUPP;
+}
+
+static int i3c_hub_master_do_daa(struct i3c_master_controller *controller)
+{
+ struct i3c_hub_controller *hub_controller;
+ struct i3c_hub *hub;
+
+ hub_controller = dev_get_drvdata(&controller->dev);
+ if (!hub_controller || !hub_controller->hub)
+ return -ENODEV;
+
+ hub = hub_controller->hub;
+
+ return i3c_hub_do_daa(hub, controller);
+}
+
+static int i3c_hub_master_send_ccc_cmd(struct i3c_master_controller *controller,
+ struct i3c_ccc_cmd *cmd)
+{
+ struct i3c_hub_controller *hub_controller;
+ struct i3c_hub *hub;
+
+ hub_controller = dev_get_drvdata(&controller->dev);
+ if (!hub_controller || !hub_controller->hub)
+ return -ENODEV;
+
+ hub = hub_controller->hub;
+
+ if (!hub->hub_dev)
+ return -ENODEV;
+
+ /*
+ * Do not forward broadcast RSTDAA through the hub. The hub itself
+ * is visible on the parent bus, so forwarding RSTDAA would also
+ * reset the hub dynamic address. Downstream RSTDAA is not supported
+ * by the hub virtual-controller model.
+ */
+ if (cmd->id == I3C_CCC_RSTDAA(true))
+ return 0;
+
+ return i3c_hub_send_ccc_cmd(hub, controller, cmd);
+}
+
+static bool i3c_hub_master_supports_ccc_cmd(struct i3c_master_controller *controller,
+ const struct i3c_ccc_cmd *cmd)
+{
+ struct i3c_hub_controller *hub_controller;
+ struct i3c_hub *hub;
+
+ hub_controller = dev_get_drvdata(&controller->dev);
+ if (!hub_controller || !hub_controller->hub)
+ return false;
+
+ hub = hub_controller->hub;
+
+ return i3c_hub_supports_ccc_cmd(hub, cmd);
+}
+
+/**
+ * i3c_hub_request_ibi() - Request IBI through parent controller
+ * @desc: Target device descriptor
+ * @req: IBI setup
+ *
+ * Temporarily updates parent controller context to request IBI for a device
+ * connected through the hub.
+ */
+static int i3c_hub_request_ibi(struct i3c_dev_desc *desc,
+ const struct i3c_ibi_setup *req)
+{
+ struct i3c_master_controller *controller = i3c_dev_get_master(desc);
+ struct i3c_hub_controller *hub_controller;
+ struct i3c_master_controller *orig_parent;
+ struct i3c_master_controller *parent;
+ struct i3c_hub *hub;
+ int ret;
+
+ hub_controller = dev_get_drvdata(&controller->dev);
+ if (!hub_controller || !hub_controller->hub)
+ return -ENODEV;
+
+ hub = hub_controller->hub;
+
+ if (!hub->hub_dev)
+ return -ENODEV;
+
+ parent = i3c_dev_get_master(hub->hub_dev->desc);
+
+ i3c_bus_maintenance_lock(&parent->bus);
+
+ orig_parent = i3c_hub_update_desc_parent(&desc->common, parent);
+
+ /*
+ * Downstream devices are exposed through the virtual hub controller.
+ * Private transfers only use the hub device temporarily with the
+ * downstream device's dynamic address; they do not attach the downstream
+ * device to the parent controller.
+ *
+ * Attach the device to the parent controller before requesting IBI so
+ * the parent can allocate any controller-private IBI state.
+ */
+ ret = i3c_master_direct_attach_i3c_dev_locked(parent, desc);
+ if (ret) {
+ i3c_hub_update_desc_parent(&desc->common, orig_parent);
+ i3c_bus_maintenance_unlock(&parent->bus);
+ return ret;
+ }
+
+ if (desc->ibi) {
+ if (desc->ibi->wq) {
+ destroy_workqueue(desc->ibi->wq);
+ desc->ibi->wq = NULL;
+ }
+
+ kfree(desc->ibi);
+ desc->ibi = NULL;
+ }
+ ret = i3c_dev_request_ibi_locked(desc, req);
+ if (ret)
+ i3c_master_direct_detach_i3c_dev_locked(desc);
+
+ i3c_hub_update_desc_parent(&desc->common, orig_parent);
+
+ i3c_bus_maintenance_unlock(&parent->bus);
+
+ return ret;
+}
+
+static void i3c_hub_free_ibi(struct i3c_dev_desc *desc)
+{
+ struct i3c_master_controller *controller = i3c_dev_get_master(desc);
+ struct i3c_hub_controller *hub_controller;
+ struct i3c_master_controller *orig_parent;
+ struct i3c_master_controller *parent;
+ struct i3c_hub *hub;
+
+ hub_controller = dev_get_drvdata(&controller->dev);
+ if (!hub_controller || !hub_controller->hub)
+ return;
+
+ hub = hub_controller->hub;
+
+ if (!hub->hub_dev)
+ return;
+
+ parent = i3c_dev_get_master(hub->hub_dev->desc);
+
+ mutex_lock(&hub->lock);
+ i3c_hub_enable_port(controller);
+
+ i3c_bus_maintenance_lock(&parent->bus);
+ orig_parent = i3c_hub_update_desc_parent(&desc->common, parent);
+ i3c_dev_free_ibi_locked(desc);
+
+ /*
+ * Drop the temporary parent attachment created for IBI setup.
+ * The downstream device remains exposed through the virtual hub
+ * controller.
+ */
+ i3c_master_direct_detach_i3c_dev_locked(desc);
+ i3c_hub_update_desc_parent(&desc->common, orig_parent);
+ i3c_bus_maintenance_unlock(&parent->bus);
+
+ i3c_hub_disable_port(controller);
+ mutex_unlock(&hub->lock);
+}
+
+/**
+ * i3c_hub_enable_ibi() - Enable IBI via hub port
+ * @desc: Target device descriptor
+ *
+ * Enables port connection and forwards the IBI enable request to the parent
+ * controller.
+ */
+static int i3c_hub_enable_ibi(struct i3c_dev_desc *desc)
+{
+ struct i3c_master_controller *controller = i3c_dev_get_master(desc);
+ struct i3c_hub_controller *hub_controller;
+ struct i3c_master_controller *orig_parent;
+ struct i3c_master_controller *parent;
+ struct i3c_hub *hub;
+ int ret;
+
+ hub_controller = dev_get_drvdata(&controller->dev);
+ if (!hub_controller || !hub_controller->hub)
+ return -ENODEV;
+
+ hub = hub_controller->hub;
+
+ if (!hub->hub_dev)
+ return -ENODEV;
+
+ parent = i3c_dev_get_master(hub->hub_dev->desc);
+
+ mutex_lock(&hub->lock);
+ i3c_hub_enable_port(controller);
+
+ orig_parent = i3c_hub_update_desc_parent(&desc->common, parent);
+
+ i3c_bus_maintenance_lock(&parent->bus);
+ ret = i3c_dev_enable_ibi_locked(desc);
+ i3c_bus_maintenance_unlock(&parent->bus);
+
+ i3c_hub_update_desc_parent(&desc->common, orig_parent);
+
+ i3c_hub_disable_port(controller);
+ mutex_unlock(&hub->lock);
+
+ return ret;
+}
+
+/**
+ * i3c_hub_disable_ibi() - Disable IBI via hub port
+ * @desc: Target device descriptor
+ *
+ * Enables port connection and forwards the IBI disable request to the parent
+ * controller.
+ */
+static int i3c_hub_disable_ibi(struct i3c_dev_desc *desc)
+{
+ struct i3c_master_controller *controller = i3c_dev_get_master(desc);
+ struct i3c_hub_controller *hub_controller;
+ struct i3c_master_controller *orig_parent;
+ struct i3c_master_controller *parent;
+ struct i3c_hub *hub;
+ int ret;
+
+ hub_controller = dev_get_drvdata(&controller->dev);
+ if (!hub_controller || !hub_controller->hub)
+ return -ENODEV;
+
+ hub = hub_controller->hub;
+
+ if (!hub->hub_dev)
+ return -ENODEV;
+
+ parent = i3c_dev_get_master(hub->hub_dev->desc);
+
+ mutex_lock(&hub->lock);
+ i3c_hub_enable_port(controller);
+
+ orig_parent = i3c_hub_update_desc_parent(&desc->common, parent);
+
+ i3c_bus_maintenance_lock(&parent->bus);
+ ret = i3c_dev_disable_ibi_locked(desc);
+ i3c_bus_maintenance_unlock(&parent->bus);
+
+ i3c_hub_update_desc_parent(&desc->common, orig_parent);
+
+ i3c_hub_disable_port(controller);
+ mutex_unlock(&hub->lock);
+
+ return ret;
+}
+
+static void i3c_hub_recycle_ibi_slot(struct i3c_dev_desc *desc,
+ struct i3c_ibi_slot *slot)
+{
+ /*
+ * TODO: Forward IBI slot recycling to the parent controller when
+ * downstream-device IBI support is fully enabled. Current users only
+ * rely on the hub device IBI path for SMBus-agent events, so no parent
+ * hardware slot is recycled through this virtual callback currently.
+ */
+}
+
+static const struct i3c_master_controller_ops i3c_hub_master_ops_data = {
+ .bus_init = i3c_hub_master_bus_init,
+ .bus_cleanup = i3c_hub_master_bus_cleanup,
+ .attach_i3c_dev = i3c_hub_attach_i3c_dev,
+ .reattach_i3c_dev = i3c_hub_reattach_i3c_dev,
+ .detach_i3c_dev = i3c_hub_detach_i3c_dev,
+ .do_daa = i3c_hub_master_do_daa,
+ .supports_ccc_cmd = i3c_hub_master_supports_ccc_cmd,
+ .send_ccc_cmd = i3c_hub_master_send_ccc_cmd,
+ .i3c_xfers = i3c_hub_master_priv_xfers,
+ .attach_i2c_dev = i3c_hub_attach_i2c_dev,
+ .detach_i2c_dev = i3c_hub_detach_i2c_dev,
+ .i2c_xfers = i3c_hub_i2c_xfers,
+ .request_ibi = i3c_hub_request_ibi,
+ .free_ibi = i3c_hub_free_ibi,
+ .enable_ibi = i3c_hub_enable_ibi,
+ .disable_ibi = i3c_hub_disable_ibi,
+ .recycle_ibi_slot = i3c_hub_recycle_ibi_slot,
+};
+
+/**
+ * i3c_hub_init() - Initialize hub context
+ * @hub: Hub instance
+ * @ops: Vendor callbacks
+ * @hub_dev: I3C hub device
+ */
+void i3c_hub_init(struct i3c_hub *hub,
+ const struct i3c_hub_ops *ops,
+ struct i3c_device *hub_dev)
+{
+ hub->ops = ops;
+ hub->hub_dev = hub_dev;
+ mutex_init(&hub->lock);
+}
+EXPORT_SYMBOL_GPL(i3c_hub_init);
+
+const struct i3c_master_controller_ops *i3c_hub_master_ops(void)
+{
+ return &i3c_hub_master_ops_data;
+}
+EXPORT_SYMBOL_GPL(i3c_hub_master_ops);
+
+/**
+ * i3c_hub_reserve_parent_addrslots_from_dt() - Reserve child addresses in parent bus.
+ * @hubc: I3C hub controller for a target-port virtual bus.
+ * @node: Target-port bus Device Tree node.
+ *
+ * Reserve parent bus address slots for downstream I3C devices that keep the
+ * same static and assigned dynamic address, so parent DAA does not reuse them.
+ *
+ * Return: 0 on success, or a negative error code.
+ */
+int i3c_hub_reserve_parent_addrslots_from_dt(struct i3c_hub_controller *hubc,
+ struct device_node *node)
+{
+ struct i3c_master_controller *parent = hubc->parent;
+ enum i3c_addr_slot_status status;
+ u32 assigned_addr;
+ u8 static_addr;
+ u32 reg[3];
+ int ret;
+
+ if (!parent || !node)
+ return -ENODEV;
+
+ for_each_available_child_of_node_scoped(node, child) {
+ ret = of_property_read_variable_u32_array(child, "reg", reg, 1, 3);
+ if (ret < 0)
+ continue;
+
+ ret = of_property_read_u32(child, "assigned-address", &assigned_addr);
+ if (ret)
+ continue;
+
+ static_addr = reg[0];
+
+ if (!static_addr || !assigned_addr)
+ continue;
+
+ if (static_addr != assigned_addr)
+ continue;
+
+ i3c_bus_maintenance_lock(&parent->bus);
+ status = i3c_bus_get_addr_slot_status(&parent->bus,
+ assigned_addr);
+ if (status == I3C_ADDR_SLOT_FREE)
+ i3c_bus_set_addr_slot_status(&parent->bus,
+ assigned_addr,
+ I3C_ADDR_SLOT_I3C_DEV);
+ i3c_bus_maintenance_unlock(&parent->bus);
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(i3c_hub_reserve_parent_addrslots_from_dt);
+
+MODULE_AUTHOR("Aman Kumar Pandey <aman.kumarpandey@nxp.com>");
+MODULE_AUTHOR("Vikash Bansal <vikash.bansal@nxp.com>");
+MODULE_AUTHOR("Lakshay Piplani <lakshay.piplani@nxp.com>");
+MODULE_DESCRIPTION("Generic I3C hub support");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/i3c/hub.h b/include/linux/i3c/hub.h
new file mode 100644
index 000000000000..8ad2cf3c9d5b
--- /dev/null
+++ b/include/linux/i3c/hub.h
@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2026 NXP
+ * Generic hub definitions and helper interfaces.
+ */
+#ifndef _LINUX_I3C_HUB_H
+#define _LINUX_I3C_HUB_H
+
+#include <linux/i3c/master.h>
+#include <linux/mutex.h>
+
+static inline struct i3c_master_controller *
+i3c_hub_update_desc_parent(struct i3c_i2c_dev_desc *desc,
+ struct i3c_master_controller *parent)
+{
+ struct i3c_master_controller *orig_parent = desc->master;
+
+ desc->master = parent;
+ return orig_parent;
+}
+
+/**
+ * struct i3c_hub - Generic I3C hub context
+ * @ops: Vendor callbacks for port connection control
+ * @hub_dev: I3C device representing the hub on the parent bus
+ */
+struct i3c_hub {
+ const struct i3c_hub_ops *ops;
+ struct i3c_device *hub_dev;
+ struct mutex lock; /* Serializes hub port routing. */
+};
+
+struct i3c_hub_controller {
+ struct i3c_master_controller *parent;
+ struct i3c_master_controller controller;
+ struct i3c_hub *hub;
+};
+
+struct i3c_hub_ops {
+ void (*enable_port)(struct i3c_master_controller *controller);
+ void (*disable_port)(struct i3c_master_controller *controller);
+};
+
+/**
+ * i3c_hub_enable_port() - Enable hub connection for a controller
+ * @controller: Virtual controller representing a hub port
+ *
+ * Retrieves hub context from controller drvdata and invokes the vendor
+ * callback to enable the associated port connection.
+ */
+static inline void i3c_hub_enable_port(struct i3c_master_controller *controller)
+{
+ struct i3c_hub_controller *hub_controller;
+ struct i3c_hub *hub;
+
+ hub_controller = dev_get_drvdata(&controller->dev);
+ if (!hub_controller || !hub_controller->hub)
+ return;
+
+ hub = hub_controller->hub;
+
+ if (hub && hub->ops && hub->ops->enable_port)
+ hub->ops->enable_port(controller);
+}
+
+/**
+ * i3c_hub_disable_port() - Disable hub connection for a controller
+ * @controller: Virtual controller representing a hub port
+ *
+ * Retrieves hub context from controller drvdata and invokes the vendor
+ * callback to disable the associated port connection.
+ */
+static inline void i3c_hub_disable_port(struct i3c_master_controller *controller)
+{
+ struct i3c_hub_controller *hub_controller;
+ struct i3c_hub *hub;
+
+ hub_controller = dev_get_drvdata(&controller->dev);
+ if (!hub_controller || !hub_controller->hub)
+ return;
+
+ hub = hub_controller->hub;
+
+ if (hub && hub->ops && hub->ops->disable_port)
+ hub->ops->disable_port(controller);
+}
+
+/**
+ * i3c_hub_master_ops() - Return virtual controller ops for hub ports
+ *
+ * Provides i3c_master_controller_ops used by controllers created for hub
+ * ports.
+ */
+const struct i3c_master_controller_ops *i3c_hub_master_ops(void);
+
+void i3c_hub_init(struct i3c_hub *hub,
+ const struct i3c_hub_ops *ops,
+ struct i3c_device *hub_dev);
+
+int i3c_hub_reserve_parent_addrslots_from_dt(struct i3c_hub_controller *hubc,
+ struct device_node *node);
+#endif
--
2.25.1
^ permalink raw reply related [flat|nested] 19+ messages in thread
* [PATCH v14 7/8] i3c: hub: p3h2x4x: Add support for NXP P3H2x4x I3C hub functionality
2026-07-14 9:20 [PATCH v14 0/8] Add support for NXP P3H2x4x I3C hub driver Lakshay Piplani
` (5 preceding siblings ...)
2026-07-14 9:20 ` [PATCH v14 6/8] i3c: hub: Add support for the I3C interface in the I3C hub Lakshay Piplani
@ 2026-07-14 9:20 ` Lakshay Piplani
2026-07-14 11:31 ` sashiko-bot
2026-07-14 9:20 ` [PATCH v14 8/8] i3c: hub: p3h2x4x: Add SMBus slave mode support Lakshay Piplani
7 siblings, 1 reply; 19+ messages in thread
From: Lakshay Piplani @ 2026-07-14 9:20 UTC (permalink / raw)
To: linux-kernel, linux-i3c, alexandre.belloni, krzk+dt, robh,
conor+dt, devicetree, broonie, lee, Frank.Li, lgirdwood
Cc: vikash.bansal, priyanka.jain, aman.kumarpandey, Lakshay Piplani
From: Aman Kumar Pandey <aman.kumarpandey@nxp.com>
Add I3C hub functionality for the NXP P3H2x4x family of multiport hubs.
These devices support downstream target ports that can be configured
as I3C, I2C, or SMBus.
This driver enables:
- I3C/I2C communication between host and hub
- Transparent communication with downstream devices
- Target port configuration (I3C/I2C/SMBus)
P3H2440/P3H2441 support 4 target ports.
P3H2840/P3H2841 support 8 target ports.
Signed-off-by: Aman Kumar Pandey <aman.kumarpandey@nxp.com>
Signed-off-by: Vikash Bansal <vikash.bansal@nxp.com>
Signed-off-by: Lakshay Piplani <lakshay.piplani@nxp.com>
---
Changes in v14:
- Replace temporary parent dev->of_node reassignment with
i3c_master_register_fwnode()
- Use the shared MFD protected_reg_lock for protected hub configuration
writes
- Fix SMBus polling interval calculation to avoid oversleeping the computed
transaction timeout
- Change SMBus transfer loop counters from u8 to int
- Clean up already registered SMBus adapters on adapter allocation or
registration failure
Changes in v13:
- Fix SMBus transaction handling by replacing fixed delay with polling (read_poll_timeout)
to avoid premature reads and data corruption
- Fix DT and of_node handling: prevent duplicate target-port node leaks and avoid corrupting
parent dev->of_node by restoring it after registration
- Add proper cleanup using devm actions (relock registers, release DT nodes, unregister adapters)
and fix minor comment mismatch
Changes in v12:
- Fix target-port configuration register updates
- Correct default pull-up and drive-strength values
- Improve OF node and SMBus adapter cleanup
- Remove dead code and simplify cleanup by relying on devm-managed resources
Changes in v11:
- Fix IBI resource cleanup on error paths
- Fix adapter unregister cleanup handling
Changes in v10:
- Split SMBus target/slave mode support, including IBI and MCTP receive
handling, into a separate patch
Changes in v9:
- Added CONFIG_I2C_SLAVE guards where necessary to avoid build issues
when I2C slave support is disabled.
Changes in v8:
- No change
Changes in v7:
- Remove CONFIG_I2C_SLAVE guards
- Use Kernel API find_closest instead of custom helper
- Use devm_regulator_get_enable_optional()
- Fix kernel-doc warnings
Changes in v6:
- Remove generic I3C code and keep reg dependent code only.
Changes in v5:
- Updated supply names.
Changes in v4:
- Split the driver into three separate patches (mfd, regulator and I3C hub)
- Added support for NXP P3H2x4x I3C hub functionality
- Integrated hub driver with its on-die regulator
Changes in v3:
- Added MFD (Multi-Function Device) support for I3C hub and on-die regulator
Changes in v2:
- Refined coding style and incorporated review feedback
- Updated directory structure
- Revised logic for parsing DTS nodes
---
---
MAINTAINERS | 1 +
drivers/i3c/Kconfig | 1 +
drivers/i3c/Makefile | 1 +
drivers/i3c/hub/Kconfig | 11 +
drivers/i3c/hub/Makefile | 4 +
drivers/i3c/hub/p3h2840_i3c_hub.h | 327 +++++++++++++++++++
drivers/i3c/hub/p3h2840_i3c_hub_common.c | 379 +++++++++++++++++++++++
drivers/i3c/hub/p3h2840_i3c_hub_i3c.c | 118 +++++++
drivers/i3c/hub/p3h2840_i3c_hub_smbus.c | 322 +++++++++++++++++++
9 files changed, 1164 insertions(+)
create mode 100644 drivers/i3c/hub/Kconfig
create mode 100644 drivers/i3c/hub/Makefile
create mode 100644 drivers/i3c/hub/p3h2840_i3c_hub.h
create mode 100644 drivers/i3c/hub/p3h2840_i3c_hub_common.c
create mode 100644 drivers/i3c/hub/p3h2840_i3c_hub_i3c.c
create mode 100644 drivers/i3c/hub/p3h2840_i3c_hub_smbus.c
diff --git a/MAINTAINERS b/MAINTAINERS
index a0b7fd85f8e3..718c5fca4746 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19312,6 +19312,7 @@ L: linux-i3c@lists.infradead.org
S: Maintained
F: Documentation/devicetree/bindings/i3c/nxp,p3h2840.yaml
F: drivers/i3c/hub.c
+F: drivers/i3c/hub/*
F: drivers/mfd/p3h2840.c
F: drivers/regulator/p3h2840_i3c_hub_regulator.c
F: include/linux/i3c/hub.h
diff --git a/drivers/i3c/Kconfig b/drivers/i3c/Kconfig
index 7536f3740c94..81d5ebd8025c 100644
--- a/drivers/i3c/Kconfig
+++ b/drivers/i3c/Kconfig
@@ -35,6 +35,7 @@ config I3C_HUB
Say Y here if your platform includes an I3C hub device
+source "drivers/i3c/hub/Kconfig"
endif # I3C
config I3C_OR_I2C
diff --git a/drivers/i3c/Makefile b/drivers/i3c/Makefile
index 9ddee56a6338..2950820db9ea 100644
--- a/drivers/i3c/Makefile
+++ b/drivers/i3c/Makefile
@@ -3,3 +3,4 @@ i3c-y := device.o master.o
obj-$(CONFIG_I3C) += i3c.o
obj-$(CONFIG_I3C) += master/
obj-$(CONFIG_I3C_HUB) += hub.o
+obj-$(CONFIG_I3C_HUB) += hub/
diff --git a/drivers/i3c/hub/Kconfig b/drivers/i3c/hub/Kconfig
new file mode 100644
index 000000000000..816879fda326
--- /dev/null
+++ b/drivers/i3c/hub/Kconfig
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0
+# Copyright 2025 NXP
+config P3H2X4X_I3C_HUB
+ tristate "NXP P3H2X4X I3C HUB support"
+ depends on MFD_P3H2X4X
+ select I3C_HUB
+ help
+ This enables support for NXP P3H244x/P3H284x I3C HUB. These hubs
+ connect to a host via I3C/I2C/SMBus and allow communication with
+ multiple downstream peripherals. Say Y or M here to enable the
+ P3H2x4x I3C HUB driver.
diff --git a/drivers/i3c/hub/Makefile b/drivers/i3c/hub/Makefile
new file mode 100644
index 000000000000..9dbd8a7b4184
--- /dev/null
+++ b/drivers/i3c/hub/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
+# Copyright 2025 NXP
+p3h2840_i3c_hub-y := p3h2840_i3c_hub_common.o p3h2840_i3c_hub_i3c.o p3h2840_i3c_hub_smbus.o
+obj-$(CONFIG_P3H2X4X_I3C_HUB) += p3h2840_i3c_hub.o
diff --git a/drivers/i3c/hub/p3h2840_i3c_hub.h b/drivers/i3c/hub/p3h2840_i3c_hub.h
new file mode 100644
index 000000000000..e7ab243bbfff
--- /dev/null
+++ b/drivers/i3c/hub/p3h2840_i3c_hub.h
@@ -0,0 +1,327 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2025-2026 NXP
+ * Private definitions for the NXP P3H2X4X I3C hub driver.
+ */
+
+#ifndef P3H2840_I3C_HUB_H
+#define P3H2840_I3C_HUB_H
+
+#include <linux/bitfield.h>
+#include <linux/i2c.h>
+#include <linux/i3c/device.h>
+#include <linux/i3c/hub.h>
+#include <linux/i3c/master.h>
+#include <linux/regulator/consumer.h>
+#include <linux/regmap.h>
+
+/* I3C HUB REGISTERS */
+
+/* Device Information Registers */
+#define P3H2X4X_DEV_INFO_0 0x00
+#define P3H2X4X_DEV_INFO_1 0x01
+#define P3H2X4X_PID_5 0x02
+#define P3H2X4X_PID_4 0x03
+#define P3H2X4X_PID_3 0x04
+#define P3H2X4X_PID_2 0x05
+#define P3H2X4X_PID_1 0x06
+#define P3H2X4X_PID_0 0x07
+#define P3H2X4X_BCR 0x08
+#define P3H2X4X_DCR 0x09
+#define P3H2X4X_DEV_CAPAB 0x0a
+#define P3H2X4X_DEV_REV 0x0b
+
+/* Device Configuration Registers */
+#define P3H2X4X_CP_CONF 0x11
+#define P3H2X4X_TP_ENABLE 0x12
+
+#define P3H2X4X_DEV_CONF 0x13
+#define P3H2X4X_IO_STRENGTH 0x14
+#define P3H2X4X_TP0145_IO_STRENGTH_MASK GENMASK(1, 0)
+#define P3H2X4X_TP0145_IO_STRENGTH(x) \
+ FIELD_PREP(P3H2X4X_TP0145_IO_STRENGTH_MASK, x)
+#define P3H2X4X_TP2367_IO_STRENGTH_MASK GENMASK(3, 2)
+#define P3H2X4X_TP2367_IO_STRENGTH(x) \
+ FIELD_PREP(P3H2X4X_TP2367_IO_STRENGTH_MASK, x)
+#define P3H2X4X_CP0_IO_STRENGTH_MASK GENMASK(5, 4)
+#define P3H2X4X_CP0_IO_STRENGTH(x) \
+ FIELD_PREP(P3H2X4X_CP0_IO_STRENGTH_MASK, x)
+#define P3H2X4X_CP1_IO_STRENGTH_MASK GENMASK(7, 6)
+#define P3H2X4X_CP1_IO_STRENGTH(x) \
+ FIELD_PREP(P3H2X4X_CP1_IO_STRENGTH_MASK, x)
+#define P3H2X4X_IO_STRENGTH_MASK GENMASK(7, 0)
+
+#define P3H2X4X_TP_IO_MODE_CONF 0x17
+#define P3H2X4X_TP_SMBUS_AGNT_EN 0x18
+
+#define P3H2X4X_LDO_AND_PULLUP_CONF 0x19
+
+#define P3H2X4X_TP0145_PULLUP_CONF_MASK GENMASK(7, 6)
+#define P3H2X4X_TP0145_PULLUP_CONF(x) \
+ FIELD_PREP(P3H2X4X_TP0145_PULLUP_CONF_MASK, x)
+#define P3H2X4X_TP2367_PULLUP_CONF_MASK GENMASK(5, 4)
+#define P3H2X4X_TP2367_PULLUP_CONF(x) \
+ FIELD_PREP(P3H2X4X_TP2367_PULLUP_CONF_MASK, x)
+#define P3H2X4X_PULLUP_CONF_MASK GENMASK(7, 4)
+
+#define P3H2X4X_CP_IBI_CONF 0x1a
+
+#define P3H2X4X_TP_SMBUS_AGNT_IBI_CONFIG 0x1b
+
+#define P3H2X4X_IBI_MDB_CUSTOM 0x1c
+#define P3H2X4X_JEDEC_CONTEXT_ID 0x1d
+#define P3H2X4X_TP_GPIO_MODE_EN 0x1e
+
+/* Device Status and IBI Registers */
+#define P3H2X4X_DEV_AND_IBI_STS 0x20
+#define P3H2X4X_TP_SMBUS_AGNT_IBI_STS 0x21
+#define P3H2X4X_SMBUS_AGENT_EVENT_FLAG_STATUS BIT(4)
+
+/* Controller Port Control/Status Registers */
+#define P3H2X4X_CP_MUX_SET 0x38
+#define P3H2X4X_CONTROLLER_PORT_MUX_REQ BIT(0)
+#define P3H2X4X_CP_MUX_STS 0x39
+#define P3H2X4X_CONTROLLER_PORT_MUX_CONNECTION_STATUS BIT(0)
+
+/* Target Ports Control Registers */
+#define P3H2X4X_TP_SMBUS_AGNT_TRANS_START 0x50
+#define P3H2X4X_TP_NET_CON_CONF 0x51
+
+#define P3H2X4X_TP_PULLUP_EN 0x53
+
+#define P3H2X4X_TP_SCL_OUT_EN 0x54
+#define P3H2X4X_TP_SDA_OUT_EN 0x55
+#define P3H2X4X_TP_SCL_OUT_LEVEL 0x56
+#define P3H2X4X_TP_SDA_OUT_LEVEL 0x57
+#define P3H2X4X_TP_IN_DETECT_MODE_CONF 0x58
+#define P3H2X4X_TP_SCL_IN_DETECT_IBI_EN 0x59
+#define P3H2X4X_TP_SDA_IN_DETECT_IBI_EN 0x5a
+
+/* Target Ports Status Registers */
+#define P3H2X4X_TP_SCL_IN_LEVEL_STS 0x60
+#define P3H2X4X_TP_SDA_IN_LEVEL_STS 0x61
+#define P3H2X4X_TP_SCL_IN_DETECT_FLG 0x62
+#define P3H2X4X_TP_SDA_IN_DETECT_FLG 0x63
+
+/* SMBus Agent Configuration and Status Registers */
+#define P3H2X4X_TP0_SMBUS_AGNT_STS 0x64
+#define P3H2X4X_TP1_SMBUS_AGNT_STS 0x65
+#define P3H2X4X_TP2_SMBUS_AGNT_STS 0x66
+#define P3H2X4X_TP3_SMBUS_AGNT_STS 0x67
+#define P3H2X4X_TP4_SMBUS_AGNT_STS 0x68
+#define P3H2X4X_TP5_SMBUS_AGNT_STS 0x69
+#define P3H2X4X_TP6_SMBUS_AGNT_STS 0x6a
+#define P3H2X4X_TP7_SMBUS_AGNT_STS 0x6b
+#define P3H2X4X_ONCHIP_TD_AND_SMBUS_AGNT_CONF 0x6c
+
+/* buf receive flag set */
+#define P3H2X4X_TARGET_BUF_CA_TF BIT(0)
+#define P3H2X4X_TARGET_BUF_0_RECEIVE BIT(1)
+#define P3H2X4X_TARGET_BUF_1_RECEIVE BIT(2)
+#define P3H2X4X_TARGET_BUF_0_1_RECEIVE GENMASK(2, 1)
+#define P3H2X4X_TARGET_BUF_OVRFL GENMASK(3, 1)
+#define BUF_RECEIVED_FLAG_MASK GENMASK(3, 1)
+#define BUF_RECEIVED_FLAG_TF_MASK GENMASK(3, 0)
+
+#define P3H2X4X_TARGET_AGENT_LOCAL_DEV 0x11
+#define P3H2X4X_TARGET_BUFF_0_PAGE 0x12
+#define P3H2X4X_TARGET_BUFF_1_PAGE 0x13
+
+/* Special Function Registers */
+#define P3H2X4X_LDO_AND_CPSEL_STS 0x79
+#define P3H2X4X_CP_SDA1_LEVEL BIT(7)
+#define P3H2X4X_CP_SCL1_LEVEL BIT(6)
+
+#define P3H2X4X_CP_SEL_PIN_INPUT_CODE_MASK GENMASK(5, 4)
+#define P3H2X4X_CP_SEL_PIN_INPUT_CODE_GET(x) \
+ (((x) & P3H2X4X_CP_SEL_PIN_INPUT_CODE_MASK) >> 4)
+#define P3H2X4X_CP_SDA1_SCL1_PINS_CODE_MASK GENMASK(7, 6)
+#define P3H2X4X_CP_SDA1_SCL1_PINS_CODE_GET(x) \
+ (((x) & P3H2X4X_CP_SDA1_SCL1_PINS_CODE_MASK) >> 6)
+#define P3H2X4X_VCCIO1_PWR_GOOD BIT(3)
+#define P3H2X4X_VCCIO0_PWR_GOOD BIT(2)
+#define P3H2X4X_CP1_VCCIO_PWR_GOOD BIT(1)
+#define P3H2X4X_CP0_VCCIO_PWR_GOOD BIT(0)
+
+#define P3H2X4X_BUS_RESET_SCL_TIMEOUT 0x7a
+#define P3H2X4X_ONCHIP_TD_PROTO_ERR_FLG 0x7b
+#define P3H2X4X_DEV_CMD 0x7c
+#define P3H2X4X_ONCHIP_TD_STS 0x7d
+#define P3H2X4X_ONCHIP_TD_ADDR_CONF 0x7e
+#define P3H2X4X_PAGE_PTR 0x7f
+
+/* Paged Transaction Registers */
+#define P3H2X4X_CONTROLLER_BUFFER_PAGE 0x10
+#define P3H2X4X_CONTROLLER_AGENT_BUFF 0x80
+#define P3H2X4X_CONTROLLER_AGENT_BUFF_DATA 0x84
+
+#define P3H2X4X_TARGET_BUFF_LENGTH 0x80
+#define P3H2X4X_TARGET_BUFF_ADDRESS 0x81
+#define P3H2X4X_TARGET_BUFF_DATA 0x82
+
+#define P3H2X4X_TP_MAX_COUNT 0x08
+#define P3H2X4X_CP_MAX_COUNT 0x02
+#define P3H2X4X_TP_LOCAL_DEV 0x08
+
+/* LDO Disable/Enable DT settings */
+#define P3H2X4X_LDO_VOLT_1_0V 0x00
+#define P3H2X4X_LDO_VOLT_1_1V 0x01
+#define P3H2X4X_LDO_VOLT_1_2V 0x02
+#define P3H2X4X_LDO_VOLT_1_8V 0x03
+
+#define P3H2X4X_LDO_DISABLED 0x00
+#define P3H2X4X_LDO_ENABLED 0x01
+
+#define P3H2X4X_IBI_DISABLED 0x00
+#define P3H2X4X_IBI_ENABLED 0x01
+
+#define P3H2X4X_TP_PULLUP_DISABLED 0x00
+#define P3H2X4X_TP_PULLUP_ENABLED 0x01
+
+#define P3H2X4X_TP_MODE_I3C 0x00
+#define P3H2X4X_TP_MODE_SMBUS 0x01
+#define P3H2X4X_TP_MODE_GPIO 0x02
+#define P3H2X4X_TP_MODE_I2C 0x03
+
+#define ONE_BYTE_SIZE 0x01
+
+/* holding SDA low when both SMBus Target Agent received data buffers are full.
+ * This feature can be used as a flow-control mechanism for MCTP applications to
+ * avoid MCTP transmitters on Target Ports time out when the SMBus agent buffers
+ * are not serviced in time by upstream controller and only receives write message
+ * from its downstream ports.
+ * SMBUS_AGENT_TX_RX_LOOPBACK_EN/TARGET_AGENT_BUF_FULL_SDA_LOW_EN
+ */
+
+#define P3H2X4X_TARGET_AGENT_DFT_IBI_CONF 0x20
+#define P3H2X4X_TARGET_AGENT_DFT_IBI_CONF_MASK 0x21
+
+/* Transaction status checking mask */
+#define P3H2X4X_SMBUS_TRANSACTION_FINISH_FLAG 1
+#define P3H2X4X_SMBUS_CNTRL_STATUS_TXN_SHIFT 4
+
+#define P3H2X4X_SMBUS_CNTRL_STATUS_TXN_OK 0
+#define P3H2X4X_SMBUS_CNTRL_STATUS_TXN_ADDR_NAK 1
+#define P3H2X4X_SMBUS_CNTRL_STATUS_TXN_DATA_NAK 2
+#define P3H2X4X_SMBUS_CNTRL_STATUS_TXN_WTR_NAK 3
+#define P3H2X4X_SMBUS_CNTRL_STATUS_TXN_SYNC_RCV 4
+#define P3H2X4X_SMBUS_CNTRL_STATUS_TXN_SYNC_RCVCLR 5
+#define P3H2X4X_SMBUS_CNTRL_STATUS_TXN_FAULT 6
+#define P3H2X4X_SMBUS_CNTRL_STATUS_TXN_ARB_LOSS 7
+#define P3H2X4X_SMBUS_CNTRL_STATUS_TXN_SCL_TO 8
+
+#define P3H2X4X_TP_BUFFER_STATUS_MASK 0x0f
+#define P3H2X4X_TP_TRANSACTION_CODE_MASK 0xf0
+
+/* SMBus transaction types fields */
+#define P3H2X4X_SMBUS_400kHz BIT(2)
+
+/* SMBus polling */
+#define P3H2X4X_SMBUS_POLL_COUNT 10
+#define P3H2X4X_SMBUS_POLL_INTERVAL_MIN_US 20
+#define P3H2X4X_SMBUS_POLL_INTERVAL_MAX_US 150
+
+/* Hub buffer size */
+#define P3H2X4X_CONTROLLER_BUFFER_SIZE 88
+#define P3H2X4X_TARGET_BUFFER_SIZE 80
+#define P3H2X4X_SMBUS_DESCRIPTOR_SIZE 4
+#define P3H2X4X_SMBUS_PAYLOAD_SIZE \
+ (P3H2X4X_CONTROLLER_BUFFER_SIZE - P3H2X4X_SMBUS_DESCRIPTOR_SIZE)
+#define P3H2X4X_SMBUS_TARGET_PAYLOAD_SIZE (P3H2X4X_TARGET_BUFFER_SIZE - 2)
+
+/* Hub SMBus transaction time */
+#define P3H2X4X_SMBUS_400kHz_TRANSFER_TIMEOUT(x) ((20 * (x)) + 80)
+
+#define P3H2X4X_NO_PAGE_PER_TP 4
+
+#define P3H2X4X_MAX_PAYLOAD_LEN 2
+#define P3H2X4X_NUM_SLOTS 6
+
+#define P3H2X4X_HUB_ID 0
+
+#define P3H2X4X_SET_BIT(n) BIT(n)
+
+#define P3H2X4X_TP_MASK GENMASK(P3H2X4X_TP_MAX_COUNT - 1, 0)
+
+#define P3H2X4X_DFT_TP_PULLUP_OHMS 500
+#define P3H2X4X_DFT_IO_STRENGTH_OHMS 20
+enum p3h2x4x_tp {
+ TP_0,
+ TP_1,
+ TP_2,
+ TP_3,
+ TP_4,
+ TP_5,
+ TP_6,
+ TP_7,
+};
+
+enum p3h2x4x_rcv_buf {
+ RCV_BUF_0,
+ RCV_BUF_1,
+ RCV_BUF_OF,
+};
+
+struct tp_configuration {
+ bool pullup_en;
+ bool ibi_en;
+ bool always_enable;
+ int mode;
+};
+
+struct hub_configuration {
+ int tp0145_pullup;
+ int tp2367_pullup;
+ int cp0_io_strength;
+ int cp1_io_strength;
+ int tp0145_io_strength;
+ int tp2367_io_strength;
+ struct tp_configuration tp_config[P3H2X4X_TP_MAX_COUNT];
+};
+
+struct tp_bus {
+ bool is_registered; /* bus was registered in the framework. */
+ u8 tp_mask;
+ u8 tp_port;
+ struct mutex port_mutex; /* per port mutex */
+ struct device_node *of_node;
+ struct i2c_client *tp_smbus_client;
+ struct i2c_adapter *tp_smbus_adapter;
+ struct i3c_hub_controller hub_controller;
+ struct p3h2x4x_i3c_hub_dev *p3h2x4x_i3c_hub;
+};
+
+struct p3h2x4x_i3c_hub_dev {
+ struct device *dev;
+ struct regmap *regmap;
+ struct mutex etx_mutex; /* all port mutex */
+ struct i3c_device *i3cdev;
+ struct i2c_client *i2c_client;
+ struct hub_configuration hub_config;
+ struct tp_bus tp_bus[P3H2X4X_TP_MAX_COUNT];
+ struct i3c_hub *hub;
+};
+
+/**
+ * p3h2x4x_unregister_smbus_adapters() - unregister SMBus adapters
+ * @hub: P3H2x4x hub device
+ */
+void p3h2x4x_unregister_smbus_adapters(struct p3h2x4x_i3c_hub_dev *hub);
+
+/**
+ * p3h2x4x_tp_smbus_algo - add i2c adapter for target port configured as SMBus.
+ * @p3h2x4x_i3c_hub: P3H2x4x hub device.
+ *
+ * Return: 0 in case of success, negative error code on failure.
+ */
+int p3h2x4x_tp_smbus_algo(struct p3h2x4x_i3c_hub_dev *p3h2x4x_i3c_hub);
+
+/**
+ * p3h2x4x_tp_i3c_algo - register i3c controller for target port configured as I3C.
+ * @p3h2x4x_i3c_hub: P3H2x4x hub device.
+ *
+ * Return: 0 in case of success, negative error code on failure.
+ */
+int p3h2x4x_tp_i3c_algo(struct p3h2x4x_i3c_hub_dev *p3h2x4x_i3c_hub);
+
+#endif /* P3H2840_I3C_HUB_H */
diff --git a/drivers/i3c/hub/p3h2840_i3c_hub_common.c b/drivers/i3c/hub/p3h2840_i3c_hub_common.c
new file mode 100644
index 000000000000..2fd9723da60d
--- /dev/null
+++ b/drivers/i3c/hub/p3h2840_i3c_hub_common.c
@@ -0,0 +1,379 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2025-2026 NXP
+ * This P3H2X4X driver file implements functions for Hub probe and DT parsing.
+ */
+
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/p3h2840.h>
+#include <linux/util_macros.h>
+
+#include "p3h2840_i3c_hub.h"
+
+/* LDO voltage DT settings */
+#define P3H2X4X_DT_LDO_VOLT_1_0V 1000000
+#define P3H2X4X_DT_LDO_VOLT_1_1V 1100000
+#define P3H2X4X_DT_LDO_VOLT_1_2V 1200000
+#define P3H2X4X_DT_LDO_VOLT_1_8V 1800000
+
+static const int p3h2x4x_pullup_tbl[] = {
+ 250, 500, 1000, 2000
+};
+
+static const int p3h2x4x_io_strength_tbl[] = {
+ 20, 30, 40, 50
+};
+
+static u8 p3h2x4x_pullup_dt_to_reg(int dt_value)
+{
+ return find_closest(dt_value, p3h2x4x_pullup_tbl,
+ ARRAY_SIZE(p3h2x4x_pullup_tbl));
+}
+
+static u8 p3h2x4x_io_strength_dt_to_reg(int dt_value)
+{
+ return find_closest(dt_value, p3h2x4x_io_strength_tbl,
+ ARRAY_SIZE(p3h2x4x_io_strength_tbl));
+}
+
+static int p3h2x4x_configure_pullup(struct device *dev)
+{
+ struct p3h2x4x_i3c_hub_dev *p3h2x4x_i3c_hub = dev_get_drvdata(dev);
+ u8 pullup;
+
+ pullup = P3H2X4X_TP0145_PULLUP_CONF(p3h2x4x_pullup_dt_to_reg
+ (p3h2x4x_i3c_hub->hub_config.tp0145_pullup));
+
+ pullup |= P3H2X4X_TP2367_PULLUP_CONF(p3h2x4x_pullup_dt_to_reg
+ (p3h2x4x_i3c_hub->hub_config.tp2367_pullup));
+
+ return regmap_update_bits(p3h2x4x_i3c_hub->regmap, P3H2X4X_LDO_AND_PULLUP_CONF,
+ P3H2X4X_PULLUP_CONF_MASK, pullup);
+}
+
+static int p3h2x4x_configure_io_strength(struct device *dev)
+{
+ struct p3h2x4x_i3c_hub_dev *p3h2x4x_i3c_hub = dev_get_drvdata(dev);
+ u8 io_strength;
+
+ io_strength = P3H2X4X_CP0_IO_STRENGTH(p3h2x4x_io_strength_dt_to_reg
+ (p3h2x4x_i3c_hub->hub_config.cp0_io_strength));
+
+ io_strength |= P3H2X4X_CP1_IO_STRENGTH(p3h2x4x_io_strength_dt_to_reg
+ (p3h2x4x_i3c_hub->hub_config.cp1_io_strength));
+
+ io_strength |= P3H2X4X_TP0145_IO_STRENGTH(p3h2x4x_io_strength_dt_to_reg
+ (p3h2x4x_i3c_hub->hub_config.tp0145_io_strength));
+
+ io_strength |= P3H2X4X_TP2367_IO_STRENGTH(p3h2x4x_io_strength_dt_to_reg
+ (p3h2x4x_i3c_hub->hub_config.tp2367_io_strength));
+
+ return regmap_update_bits(p3h2x4x_i3c_hub->regmap, P3H2X4X_IO_STRENGTH,
+ P3H2X4X_IO_STRENGTH_MASK, io_strength);
+}
+
+static int p3h2x4x_configure_ldo(struct device *dev)
+{
+ static const char * const supplies[] = {
+ "vcc1",
+ "vcc2",
+ "vcc3",
+ "vcc4"
+ };
+ int ret, i;
+
+ for (i = 0; i < ARRAY_SIZE(supplies); i++) {
+ ret = devm_regulator_get_enable_optional(dev, supplies[i]);
+ if (ret == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+
+ if (ret && ret != -ENODEV)
+ dev_warn(dev, "Failed to enable %s (%d)\n",
+ supplies[i], ret);
+ }
+
+ /* This delay is required for the regulator to stabilize its output voltage */
+ fsleep(5000);
+
+ return 0;
+}
+
+static int p3h2x4x_configure_tp(struct device *dev)
+{
+ struct p3h2x4x_i3c_hub_dev *hub = dev_get_drvdata(dev);
+ u8 mode = 0, smbus = 0, pullup = 0, target_port = 0;
+ int tp, ret;
+
+ for (tp = 0; tp < P3H2X4X_TP_MAX_COUNT; tp++) {
+ pullup |= hub->hub_config.tp_config[tp].pullup_en ? P3H2X4X_SET_BIT(tp) : 0;
+ mode |= (hub->hub_config.tp_config[tp].mode != P3H2X4X_TP_MODE_I3C) ?
+ P3H2X4X_SET_BIT(tp) : 0;
+ smbus |= (hub->hub_config.tp_config[tp].mode == P3H2X4X_TP_MODE_SMBUS) ?
+ P3H2X4X_SET_BIT(tp) : 0;
+ target_port |= (hub->tp_bus[tp].tp_mask == P3H2X4X_SET_BIT(tp)) ?
+ hub->tp_bus[tp].tp_mask : 0;
+ }
+
+ ret = regmap_update_bits(hub->regmap, P3H2X4X_TP_PULLUP_EN, P3H2X4X_TP_MASK, pullup);
+ if (ret)
+ return ret;
+
+ ret = regmap_update_bits(hub->regmap, P3H2X4X_TP_IO_MODE_CONF, P3H2X4X_TP_MASK, mode);
+ if (ret)
+ return ret;
+
+ ret = regmap_update_bits(hub->regmap, P3H2X4X_TP_SMBUS_AGNT_EN, P3H2X4X_TP_MASK, smbus);
+ if (ret)
+ return ret;
+
+ if (target_port & ~smbus) {
+ ret = regmap_write(hub->regmap, P3H2X4X_CP_MUX_SET,
+ P3H2X4X_CONTROLLER_PORT_MUX_REQ);
+ if (ret)
+ return ret;
+ }
+
+ return regmap_update_bits(hub->regmap, P3H2X4X_TP_ENABLE, P3H2X4X_TP_MASK, target_port);
+}
+
+static int p3h2x4x_configure_hw(struct device *dev)
+{
+ struct p3h2x4x_i3c_hub_dev *hub = dev_get_drvdata(dev);
+ struct p3h2x4x *p3h2x4x = dev_get_drvdata(dev->parent);
+ int ret, ret2;
+
+ ret = p3h2x4x_configure_ldo(dev);
+ if (ret)
+ return ret;
+
+ /* Protect the unlock-modify-lock sequence with the shared MFD lock */
+ mutex_lock(&p3h2x4x->protected_reg_lock);
+
+ ret = regmap_write(hub->regmap, P3H2X4X_DEV_REG_PROTECTION_CODE,
+ P3H2X4X_REGISTERS_UNLOCK_CODE);
+ if (ret)
+ goto out_unlock_mutex;
+
+ ret = p3h2x4x_configure_pullup(dev);
+ if (ret)
+ goto out_lock;
+
+ ret = p3h2x4x_configure_io_strength(dev);
+ if (ret)
+ goto out_lock;
+
+ ret = p3h2x4x_configure_tp(dev);
+ if (ret)
+ goto out_lock;
+
+out_lock:
+ ret2 = regmap_write(hub->regmap, P3H2X4X_DEV_REG_PROTECTION_CODE,
+ P3H2X4X_REGISTERS_LOCK_CODE);
+ if (!ret && ret2)
+ ret = ret2;
+
+out_unlock_mutex:
+ mutex_unlock(&p3h2x4x->protected_reg_lock);
+ return ret;
+}
+
+static void p3h2x4x_get_target_port_dt_conf(struct device *dev,
+ const struct device_node *node)
+{
+ struct p3h2x4x_i3c_hub_dev *p3h2x4x_i3c_hub = dev_get_drvdata(dev);
+ u64 tp_port;
+
+ for_each_available_child_of_node_scoped(node, dev_node) {
+ if (of_property_read_reg(dev_node, 0, &tp_port, NULL))
+ continue;
+
+ if (tp_port < P3H2X4X_TP_MAX_COUNT) {
+ if (p3h2x4x_i3c_hub->tp_bus[tp_port].of_node) {
+ dev_warn(dev, "Duplicate target port %llu in DT\n", tp_port);
+ continue;
+ }
+
+ p3h2x4x_i3c_hub->tp_bus[tp_port].of_node = of_node_get(dev_node);
+ p3h2x4x_i3c_hub->tp_bus[tp_port].tp_mask = P3H2X4X_SET_BIT(tp_port);
+ p3h2x4x_i3c_hub->tp_bus[tp_port].p3h2x4x_i3c_hub = p3h2x4x_i3c_hub;
+ p3h2x4x_i3c_hub->tp_bus[tp_port].tp_port = tp_port;
+ }
+ }
+}
+
+static void p3h2x4x_parse_tp_dt_settings(struct device *dev,
+ const struct device_node *node,
+ struct tp_configuration tp_config[])
+{
+ u64 id;
+
+ for_each_available_child_of_node_scoped(node, tp_node) {
+ if (of_property_read_reg(tp_node, 0, &id, NULL))
+ continue;
+
+ if (id >= P3H2X4X_TP_MAX_COUNT) {
+ dev_warn(dev, "Invalid target port index found in DT: %lli\n", id);
+ continue;
+ }
+
+ if (strcmp(tp_node->name, "i3c") == 0)
+ tp_config[id].mode = P3H2X4X_TP_MODE_I3C;
+
+ if (strcmp(tp_node->name, "i2c") == 0)
+ tp_config[id].mode = P3H2X4X_TP_MODE_I2C;
+
+ if (strcmp(tp_node->name, "smbus") == 0)
+ tp_config[id].mode = P3H2X4X_TP_MODE_SMBUS;
+
+ tp_config[id].pullup_en =
+ of_property_read_bool(tp_node, "nxp,pullup-enable");
+ }
+}
+
+static void p3h2x4x_get_hub_dt_conf(struct device *dev,
+ const struct device_node *node)
+{
+ struct p3h2x4x_i3c_hub_dev *p3h2x4x_i3c_hub = dev_get_drvdata(dev);
+
+ of_property_read_u32(node, "nxp,tp0145-pullup-ohms",
+ &p3h2x4x_i3c_hub->hub_config.tp0145_pullup);
+ of_property_read_u32(node, "nxp,tp2367-pullup-ohms",
+ &p3h2x4x_i3c_hub->hub_config.tp2367_pullup);
+ of_property_read_u32(node, "nxp,cp0-io-strength-ohms",
+ &p3h2x4x_i3c_hub->hub_config.cp0_io_strength);
+ of_property_read_u32(node, "nxp,cp1-io-strength-ohms",
+ &p3h2x4x_i3c_hub->hub_config.cp1_io_strength);
+ of_property_read_u32(node, "nxp,tp0145-io-strength-ohms",
+ &p3h2x4x_i3c_hub->hub_config.tp0145_io_strength);
+ of_property_read_u32(node, "nxp,tp2367-io-strength-ohms",
+ &p3h2x4x_i3c_hub->hub_config.tp2367_io_strength);
+
+ p3h2x4x_parse_tp_dt_settings(dev, node, p3h2x4x_i3c_hub->hub_config.tp_config);
+}
+
+static void p3h2x4x_default_configuration(struct device *dev)
+{
+ struct p3h2x4x_i3c_hub_dev *p3h2x4x_i3c_hub = dev_get_drvdata(dev);
+ int tp_count;
+
+ p3h2x4x_i3c_hub->hub_config.tp0145_pullup = P3H2X4X_DFT_TP_PULLUP_OHMS;
+ p3h2x4x_i3c_hub->hub_config.tp2367_pullup = P3H2X4X_DFT_TP_PULLUP_OHMS;
+ p3h2x4x_i3c_hub->hub_config.cp0_io_strength = P3H2X4X_DFT_IO_STRENGTH_OHMS;
+ p3h2x4x_i3c_hub->hub_config.cp1_io_strength = P3H2X4X_DFT_IO_STRENGTH_OHMS;
+ p3h2x4x_i3c_hub->hub_config.tp0145_io_strength = P3H2X4X_DFT_IO_STRENGTH_OHMS;
+ p3h2x4x_i3c_hub->hub_config.tp2367_io_strength = P3H2X4X_DFT_IO_STRENGTH_OHMS;
+
+ for (tp_count = 0; tp_count < P3H2X4X_TP_MAX_COUNT; ++tp_count)
+ p3h2x4x_i3c_hub->hub_config.tp_config[tp_count].mode = P3H2X4X_TP_MODE_I3C;
+}
+
+static void p3h2x4x_unregister_smbus_adapters_action(void *data)
+{
+ p3h2x4x_unregister_smbus_adapters(data);
+}
+
+static void p3h2x4x_put_target_port_of_nodes(void *data)
+{
+ struct p3h2x4x_i3c_hub_dev *hub = data;
+ int tp;
+
+ for (tp = 0; tp < P3H2X4X_TP_MAX_COUNT; tp++) {
+ of_node_put(hub->tp_bus[tp].of_node);
+ hub->tp_bus[tp].of_node = NULL;
+ }
+}
+
+static int p3h2x4x_i3c_hub_probe(struct platform_device *pdev)
+{
+ struct p3h2x4x *p3h2x4x = dev_get_drvdata(pdev->dev.parent);
+ struct p3h2x4x_i3c_hub_dev *p3h2x4x_i3c_hub;
+ struct device *dev = &pdev->dev;
+ struct device_node *node;
+ int ret, i;
+
+ p3h2x4x_i3c_hub = devm_kzalloc(dev, sizeof(*p3h2x4x_i3c_hub), GFP_KERNEL);
+ if (!p3h2x4x_i3c_hub)
+ return -ENOMEM;
+
+ p3h2x4x_i3c_hub->regmap = p3h2x4x->regmap;
+ p3h2x4x_i3c_hub->dev = dev;
+
+ platform_set_drvdata(pdev, p3h2x4x_i3c_hub);
+ device_set_of_node_from_dev(dev, dev->parent);
+
+ p3h2x4x_default_configuration(dev);
+
+ ret = devm_mutex_init(dev, &p3h2x4x_i3c_hub->etx_mutex);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < P3H2X4X_TP_MAX_COUNT; i++) {
+ ret = devm_mutex_init(dev, &p3h2x4x_i3c_hub->tp_bus[i].port_mutex);
+ if (ret)
+ return ret;
+ }
+
+ /* get hub node from DT */
+ node = dev_of_node(dev);
+ if (!node)
+ return dev_err_probe(dev, -ENODEV, "No Device Tree entry found\n");
+
+ p3h2x4x_get_hub_dt_conf(dev, node);
+ p3h2x4x_get_target_port_dt_conf(dev, node);
+
+ ret = devm_add_action_or_reset(dev,
+ p3h2x4x_put_target_port_of_nodes,
+ p3h2x4x_i3c_hub);
+ if (ret)
+ return ret;
+
+ ret = p3h2x4x_configure_hw(dev);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to configure the HUB\n");
+
+ /* Register virtual I3C master controllers for I3C target ports */
+ if (p3h2x4x->i3cdev) {
+ p3h2x4x_i3c_hub->i3cdev = p3h2x4x->i3cdev;
+ i3cdev_set_drvdata(p3h2x4x->i3cdev, p3h2x4x_i3c_hub);
+ ret = p3h2x4x_tp_i3c_algo(p3h2x4x_i3c_hub);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to register i3c bus\n");
+ }
+
+ /* Register virtual I2C adapters for SMBus target ports */
+ ret = p3h2x4x_tp_smbus_algo(p3h2x4x_i3c_hub);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to add i2c adapter\n");
+
+ ret = devm_add_action_or_reset(dev,
+ p3h2x4x_unregister_smbus_adapters_action,
+ p3h2x4x_i3c_hub);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static const struct platform_device_id p3h2x4x_i3c_hub_id[] = {
+ { "p3h2x4x-i3c-hub" },
+ { }
+};
+MODULE_DEVICE_TABLE(platform, p3h2x4x_i3c_hub_id);
+
+static struct platform_driver p3h2x4x_i3c_hub_driver = {
+ .driver = {
+ .name = "p3h2x4x-i3c-hub",
+ .probe_type = PROBE_PREFER_ASYNCHRONOUS,
+ },
+ .probe = p3h2x4x_i3c_hub_probe,
+ .id_table = p3h2x4x_i3c_hub_id,
+};
+module_platform_driver(p3h2x4x_i3c_hub_driver);
+
+MODULE_AUTHOR("Aman Kumar Pandey <aman.kumarpandey@nxp.com>");
+MODULE_AUTHOR("Vikash Bansal <vikash.bansal@nxp.com>");
+MODULE_AUTHOR("Lakshay Piplani <lakshay.piplani@nxp.com>");
+MODULE_DESCRIPTION("P3H2X4X I3C HUB driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/i3c/hub/p3h2840_i3c_hub_i3c.c b/drivers/i3c/hub/p3h2840_i3c_hub_i3c.c
new file mode 100644
index 000000000000..0e5bf7eb3cf7
--- /dev/null
+++ b/drivers/i3c/hub/p3h2840_i3c_hub_i3c.c
@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2025-2026 NXP
+ * This P3H2X4X driver file contain functions for I3C virtual Bus creation, connect/disconnect
+ * hub network and read/write.
+ */
+#include <linux/i3c/hub.h>
+#include <linux/mfd/p3h2840.h>
+#include <linux/regmap.h>
+
+#include "p3h2840_i3c_hub.h"
+
+static inline struct tp_bus *
+p3h2x4x_bus_from_controller(struct i3c_master_controller *controller)
+{
+ struct i3c_hub_controller *hub_controller;
+
+ hub_controller = container_of(controller, struct i3c_hub_controller, controller);
+
+ return container_of(hub_controller, struct tp_bus, hub_controller);
+}
+
+static void p3h2x4x_hub_enable_port(struct i3c_master_controller *controller)
+{
+ struct tp_bus *bus = p3h2x4x_bus_from_controller(controller);
+ struct p3h2x4x_i3c_hub_dev *p3h2x4x_i3c_hub = bus->p3h2x4x_i3c_hub;
+
+ if (p3h2x4x_i3c_hub->hub_config.tp_config[bus->tp_port].always_enable)
+ return;
+
+ regmap_set_bits(p3h2x4x_i3c_hub->regmap, P3H2X4X_TP_NET_CON_CONF, bus->tp_mask);
+}
+
+static void p3h2x4x_hub_disable_port(struct i3c_master_controller *controller)
+{
+ struct tp_bus *bus = p3h2x4x_bus_from_controller(controller);
+ struct p3h2x4x_i3c_hub_dev *p3h2x4x_i3c_hub = bus->p3h2x4x_i3c_hub;
+
+ if (p3h2x4x_i3c_hub->hub_config.tp_config[bus->tp_port].always_enable)
+ return;
+
+ regmap_clear_bits(p3h2x4x_i3c_hub->regmap, P3H2X4X_TP_NET_CON_CONF, bus->tp_mask);
+}
+
+static const struct i3c_hub_ops p3h2x4x_hub_ops = {
+ .enable_port = p3h2x4x_hub_enable_port,
+ .disable_port = p3h2x4x_hub_disable_port,
+};
+
+static void p3h2x4x_unregister_i3c_master(void *data)
+{
+ struct i3c_master_controller *controller = data;
+
+ i3c_master_unregister(controller);
+}
+
+/**
+ * p3h2x4x_tp_i3c_algo - Register I3C virtual masters for I3C target ports.
+ * @p3h2x4x_hub: p3h2x4x device structure.
+ * Return: 0 in case of success, negative error code on failure.
+ */
+int p3h2x4x_tp_i3c_algo(struct p3h2x4x_i3c_hub_dev *p3h2x4x_hub)
+{
+ struct i3c_master_controller *parent = i3c_dev_get_master(p3h2x4x_hub->i3cdev->desc);
+ u8 tp, ntwk_mask = 0;
+ int ret;
+
+ p3h2x4x_hub->hub = devm_kzalloc(p3h2x4x_hub->dev,
+ sizeof(*p3h2x4x_hub->hub),
+ GFP_KERNEL);
+
+ if (!p3h2x4x_hub->hub)
+ return -ENOMEM;
+
+ i3c_hub_init(p3h2x4x_hub->hub,
+ &p3h2x4x_hub_ops,
+ p3h2x4x_hub->i3cdev);
+
+ for (tp = 0; tp < P3H2X4X_TP_MAX_COUNT; tp++) {
+ if (!p3h2x4x_hub->tp_bus[tp].of_node ||
+ p3h2x4x_hub->hub_config.tp_config[tp].mode != P3H2X4X_TP_MODE_I3C)
+ continue;
+
+ struct i3c_hub_controller *hub_controller =
+ &p3h2x4x_hub->tp_bus[tp].hub_controller;
+ struct i3c_master_controller *controller = &hub_controller->controller;
+
+ hub_controller->parent = parent;
+ hub_controller->hub = p3h2x4x_hub->hub;
+
+ dev_set_drvdata(&controller->dev, hub_controller);
+
+ ret = i3c_hub_reserve_parent_addrslots_from_dt(hub_controller,
+ p3h2x4x_hub->tp_bus[tp].of_node);
+ if (ret)
+ return ret;
+
+ ret = i3c_master_register_fwnode(controller,
+ p3h2x4x_hub->dev,
+ of_fwnode_handle(p3h2x4x_hub->tp_bus[tp].of_node),
+ i3c_hub_master_ops(),
+ false);
+
+ if (ret)
+ return ret;
+
+ ret = devm_add_action_or_reset(p3h2x4x_hub->dev,
+ p3h2x4x_unregister_i3c_master,
+ controller);
+ if (ret)
+ return ret;
+
+ ntwk_mask |= p3h2x4x_hub->tp_bus[tp].tp_mask;
+ p3h2x4x_hub->tp_bus[tp].is_registered = true;
+ p3h2x4x_hub->hub_config.tp_config[tp].always_enable = true;
+ }
+ return regmap_write(p3h2x4x_hub->regmap, P3H2X4X_TP_NET_CON_CONF, ntwk_mask);
+}
diff --git a/drivers/i3c/hub/p3h2840_i3c_hub_smbus.c b/drivers/i3c/hub/p3h2840_i3c_hub_smbus.c
new file mode 100644
index 000000000000..b991c46f3ed5
--- /dev/null
+++ b/drivers/i3c/hub/p3h2840_i3c_hub_smbus.c
@@ -0,0 +1,322 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2025-2026 NXP
+ * This P3H2X4X driver file contain functions for SMBus/I2C virtual Bus creation and read/write.
+ */
+#include <linux/mfd/p3h2840.h>
+#include <linux/regmap.h>
+
+#include "p3h2840_i3c_hub.h"
+
+enum p3h2x4x_smbus_desc_idx {
+ P3H2X4X_DESC_ADDR,
+ P3H2X4X_DESC_TYPE,
+ P3H2X4X_DESC_WRITE_LEN,
+ P3H2X4X_DESC_READ_LEN,
+};
+
+static int p3h2x4x_read_smbus_transaction_status(struct p3h2x4x_i3c_hub_dev *hub,
+ u8 target_port_status,
+ u8 data_length)
+{
+ unsigned int timeout_us, sleep_us;
+ u32 status_read;
+ u8 status;
+ int ret;
+
+ timeout_us = P3H2X4X_SMBUS_400kHz_TRANSFER_TIMEOUT(data_length);
+ sleep_us = clamp(timeout_us / P3H2X4X_SMBUS_POLL_COUNT,
+ P3H2X4X_SMBUS_POLL_INTERVAL_MIN_US,
+ P3H2X4X_SMBUS_POLL_INTERVAL_MAX_US);
+
+ ret = regmap_read_poll_timeout(hub->regmap, target_port_status,
+ status_read,
+ status_read & P3H2X4X_SMBUS_TRANSACTION_FINISH_FLAG,
+ sleep_us,
+ timeout_us);
+ if (ret)
+ return ret;
+
+ status = (u8)status_read;
+
+ status = (status & P3H2X4X_TP_TRANSACTION_CODE_MASK)
+ >> P3H2X4X_SMBUS_CNTRL_STATUS_TXN_SHIFT;
+
+ switch (status) {
+ case P3H2X4X_SMBUS_CNTRL_STATUS_TXN_OK:
+ return 0;
+ case P3H2X4X_SMBUS_CNTRL_STATUS_TXN_ADDR_NAK:
+ return -ENXIO;
+ case P3H2X4X_SMBUS_CNTRL_STATUS_TXN_DATA_NAK:
+ return -EIO;
+ case P3H2X4X_SMBUS_CNTRL_STATUS_TXN_SCL_TO:
+ return -ETIMEDOUT;
+ case P3H2X4X_SMBUS_CNTRL_STATUS_TXN_ARB_LOSS:
+ return -EAGAIN;
+ default:
+ return -EIO;
+ }
+}
+
+/*
+ * p3h2x4x_tp_i2c_xfer_msg() - This starts a SMBus write transaction by writing a descriptor
+ * and a message to the p3h2x4x registers. Controller buffer page is determined by multiplying the
+ * target port index by four and adding the base page number to it.
+ */
+static int p3h2x4x_tp_i2c_xfer_msg(struct p3h2x4x_i3c_hub_dev *p3h2x4x_i3c_hub,
+ struct i2c_msg *xfers,
+ u8 target_port,
+ int nxfers_i, u8 rw)
+{
+ u8 controller_buffer_page = P3H2X4X_CONTROLLER_BUFFER_PAGE + 4 * target_port;
+ u8 target_port_status = P3H2X4X_TP0_SMBUS_AGNT_STS + target_port;
+ u8 desc[P3H2X4X_SMBUS_DESCRIPTOR_SIZE] = { 0 };
+ u8 transaction_type = P3H2X4X_SMBUS_400kHz;
+ int write_length, read_length;
+ u8 addr = xfers[nxfers_i].addr;
+ u8 rw_address = 2 * addr;
+ int ret, ret2;
+
+ if (rw == 2) { /* write and read */
+ write_length = xfers[nxfers_i].len;
+ read_length = xfers[nxfers_i + 1].len;
+ } else if (rw == 1) {
+ rw_address |= P3H2X4X_SET_BIT(0);
+ write_length = 0;
+ read_length = xfers[nxfers_i].len;
+ } else {
+ write_length = xfers[nxfers_i].len;
+ read_length = 0;
+ }
+
+ desc[P3H2X4X_DESC_ADDR] = rw_address;
+ if (rw == 2)
+ desc[P3H2X4X_DESC_TYPE] = transaction_type | P3H2X4X_SET_BIT(0);
+ else
+ desc[P3H2X4X_DESC_TYPE] = transaction_type;
+ desc[P3H2X4X_DESC_WRITE_LEN] = write_length;
+ desc[P3H2X4X_DESC_READ_LEN] = read_length;
+
+ ret = regmap_write(p3h2x4x_i3c_hub->regmap, target_port_status,
+ P3H2X4X_TP_BUFFER_STATUS_MASK);
+ if (ret)
+ goto out;
+
+ ret = regmap_write(p3h2x4x_i3c_hub->regmap, P3H2X4X_PAGE_PTR, controller_buffer_page);
+
+ if (ret)
+ goto out;
+
+ ret = regmap_bulk_write(p3h2x4x_i3c_hub->regmap, P3H2X4X_CONTROLLER_AGENT_BUFF,
+ desc, P3H2X4X_SMBUS_DESCRIPTOR_SIZE);
+
+ if (ret)
+ goto out;
+
+ if (!(rw % 2) && xfers[nxfers_i].len) {
+ ret = regmap_bulk_write(p3h2x4x_i3c_hub->regmap,
+ P3H2X4X_CONTROLLER_AGENT_BUFF_DATA,
+ xfers[nxfers_i].buf, xfers[nxfers_i].len);
+ if (ret)
+ goto out;
+ }
+
+ ret = regmap_write(p3h2x4x_i3c_hub->regmap, P3H2X4X_TP_SMBUS_AGNT_TRANS_START,
+ p3h2x4x_i3c_hub->tp_bus[target_port].tp_mask);
+
+ if (ret)
+ goto out;
+
+ ret = p3h2x4x_read_smbus_transaction_status(p3h2x4x_i3c_hub,
+ target_port_status,
+ (write_length + read_length));
+ if (ret)
+ goto out;
+
+ if (rw) {
+ if (rw == 2)
+ nxfers_i += 1;
+
+ if (xfers[nxfers_i].len) {
+ ret = regmap_bulk_read(p3h2x4x_i3c_hub->regmap,
+ P3H2X4X_CONTROLLER_AGENT_BUFF_DATA + write_length,
+ xfers[nxfers_i].buf, xfers[nxfers_i].len);
+ if (ret)
+ goto out;
+ }
+ }
+out:
+ ret2 = regmap_write(p3h2x4x_i3c_hub->regmap,
+ P3H2X4X_PAGE_PTR, 0x00);
+ if (!ret && ret2)
+ ret = ret2;
+
+ return ret;
+}
+
+/*
+ * This function will be called whenever you call I2C read, write APIs like
+ * i2c_master_send(), i2c_master_recv() etc.
+ */
+static s32 p3h2x4x_tp_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+ int ret_sum = 0, ret, msg_count;
+ u8 rw;
+
+ struct tp_bus *bus = i2c_get_adapdata(adap);
+ struct p3h2x4x_i3c_hub_dev *p3h2x4x_i3c_hub = bus->p3h2x4x_i3c_hub;
+
+ guard(mutex)(&p3h2x4x_i3c_hub->etx_mutex);
+ guard(mutex)(&bus->port_mutex);
+
+ for (msg_count = 0; msg_count < num; msg_count++) {
+ if (msgs[msg_count].len > P3H2X4X_SMBUS_PAYLOAD_SIZE) {
+ dev_err(p3h2x4x_i3c_hub->dev,
+ "Message nr. %d not sent - length over %d bytes.\n",
+ msg_count, P3H2X4X_SMBUS_PAYLOAD_SIZE);
+ return -EINVAL;
+ }
+
+ rw = (msgs[msg_count].flags & I2C_M_RD) ? 1 : 0;
+ if (!rw) {
+ /* If a write message is immediately followed by a read message to
+ * the same address, consider combining them into a single transaction.
+ */
+ if (msg_count + 1 < num &&
+ msgs[msg_count].addr == msgs[msg_count + 1].addr &&
+ (msgs[msg_count + 1].flags & I2C_M_RD)) {
+ if (msgs[msg_count].len + msgs[msg_count + 1].len >
+ P3H2X4X_SMBUS_PAYLOAD_SIZE)
+ return -EINVAL;
+
+ rw = 2;
+ msg_count += 1;
+ ret_sum += 1;
+ }
+ }
+
+ ret = p3h2x4x_tp_i2c_xfer_msg(p3h2x4x_i3c_hub,
+ msgs,
+ bus->tp_port,
+ (rw == 2) ? (msg_count - 1) : msg_count,
+ rw);
+ if (ret)
+ return ret;
+
+ ret_sum++;
+ }
+ return ret_sum;
+}
+
+static u32 p3h2x4x_tp_smbus_funcs(struct i2c_adapter *adapter)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_BLOCK_DATA;
+}
+
+/*
+ * I2C algorithm Structure
+ */
+static struct i2c_algorithm p3h2x4x_tp_i2c_algorithm = {
+ .master_xfer = p3h2x4x_tp_i2c_xfer,
+ .functionality = p3h2x4x_tp_smbus_funcs,
+};
+
+void p3h2x4x_unregister_smbus_adapters(struct p3h2x4x_i3c_hub_dev *hub)
+{
+ u8 tp;
+
+ for (tp = 0; tp < P3H2X4X_TP_MAX_COUNT; tp++) {
+ if (!hub->tp_bus[tp].tp_smbus_adapter)
+ continue;
+
+ i2c_del_adapter(hub->tp_bus[tp].tp_smbus_adapter);
+
+ guard(mutex)(&hub->etx_mutex);
+ hub->tp_bus[tp].tp_smbus_adapter = NULL;
+ hub->tp_bus[tp].is_registered = false;
+ }
+}
+
+/**
+ * p3h2x4x_tp_smbus_algo - Register I2C adapters for SMBus target ports.
+ * @hub: p3h2x4x device structure.
+ * Return: 0 in case of success, negative error code on failure.
+ */
+int p3h2x4x_tp_smbus_algo(struct p3h2x4x_i3c_hub_dev *hub)
+{
+ struct p3h2x4x *p3h2x4x = dev_get_drvdata(hub->dev->parent);
+ int ret, ret2;
+ u8 tp;
+
+ mutex_lock(&p3h2x4x->protected_reg_lock);
+
+ ret = regmap_write(hub->regmap, P3H2X4X_DEV_REG_PROTECTION_CODE,
+ P3H2X4X_REGISTERS_UNLOCK_CODE);
+ if (ret)
+ goto out_unlock_mutex;
+
+ ret = regmap_write(hub->regmap, P3H2X4X_TP_SMBUS_AGNT_IBI_CONFIG, P3H2X4X_IBI_DISABLED);
+
+ ret2 = regmap_write(hub->regmap, P3H2X4X_DEV_REG_PROTECTION_CODE,
+ P3H2X4X_REGISTERS_LOCK_CODE);
+ if (!ret && ret2)
+ ret = ret2;
+
+out_unlock_mutex:
+ mutex_unlock(&p3h2x4x->protected_reg_lock);
+ if (ret)
+ return ret;
+
+ for (tp = 0; tp < P3H2X4X_TP_MAX_COUNT; tp++) {
+ if (!hub->tp_bus[tp].of_node ||
+ hub->hub_config.tp_config[tp].mode != P3H2X4X_TP_MODE_SMBUS)
+ continue;
+
+ /* Allocate adapter */
+ struct i2c_adapter *smbus_adapter =
+ devm_kzalloc(hub->dev, sizeof(*smbus_adapter), GFP_KERNEL);
+ if (!smbus_adapter) {
+ p3h2x4x_unregister_smbus_adapters(hub);
+ return -ENOMEM;
+ }
+
+ /* Initialize adapter */
+ smbus_adapter->owner = THIS_MODULE;
+ smbus_adapter->class = I2C_CLASS_HWMON;
+ smbus_adapter->algo = &p3h2x4x_tp_i2c_algorithm;
+ smbus_adapter->dev.parent = hub->dev;
+ smbus_adapter->dev.of_node = hub->tp_bus[tp].of_node;
+ snprintf(smbus_adapter->name, sizeof(smbus_adapter->name),
+ "p3h2x4x-i3c-hub.tp-port-%d", tp);
+
+ i2c_set_adapdata(smbus_adapter, &hub->tp_bus[tp]);
+
+ /* Register adapter */
+ ret = i2c_add_adapter(smbus_adapter);
+ if (ret) {
+ p3h2x4x_unregister_smbus_adapters(hub);
+ return ret;
+ }
+
+ hub->tp_bus[tp].is_registered = true;
+ hub->hub_config.tp_config[tp].ibi_en = false;
+ hub->tp_bus[tp].tp_smbus_adapter = smbus_adapter;
+ }
+
+ /*
+ * holding SDA low when both SMBus Target Agent received data buffers are full.
+ * This feature can be used as a flow-control mechanism for MCTP applications to
+ * avoid MCTP transmitters on Target Ports time out when the SMBus agent buffers
+ * are not serviced in time by upstream controller and only receives write message
+ * from its downstream ports.
+ */
+ ret = regmap_update_bits(hub->regmap, P3H2X4X_ONCHIP_TD_AND_SMBUS_AGNT_CONF,
+ P3H2X4X_TARGET_AGENT_DFT_IBI_CONF_MASK,
+ P3H2X4X_TARGET_AGENT_DFT_IBI_CONF);
+ if (ret) {
+ p3h2x4x_unregister_smbus_adapters(hub);
+ return ret;
+ }
+
+ return 0;
+}
--
2.25.1
^ permalink raw reply related [flat|nested] 19+ messages in thread
* [PATCH v14 8/8] i3c: hub: p3h2x4x: Add SMBus slave mode support
2026-07-14 9:20 [PATCH v14 0/8] Add support for NXP P3H2x4x I3C hub driver Lakshay Piplani
` (6 preceding siblings ...)
2026-07-14 9:20 ` [PATCH v14 7/8] i3c: hub: p3h2x4x: Add support for NXP P3H2x4x I3C hub functionality Lakshay Piplani
@ 2026-07-14 9:20 ` Lakshay Piplani
2026-07-14 11:56 ` sashiko-bot
7 siblings, 1 reply; 19+ messages in thread
From: Lakshay Piplani @ 2026-07-14 9:20 UTC (permalink / raw)
To: linux-kernel, linux-i3c, alexandre.belloni, krzk+dt, robh,
conor+dt, devicetree, broonie, lee, Frank.Li, lgirdwood
Cc: vikash.bansal, priyanka.jain, aman.kumarpandey, Lakshay Piplani
Add SMBus slave mode support for the P3H2x4x hub SMBus target ports.
The hub SMBus slave agent can receive downstream payloads into target
buffers and report receive events through IBI. Add CONFIG_I2C_SLAVE
to support the receive path and forward the received payloads to the
registered I2C slave client through i2c_slave_event().
Signed-off-by: Lakshay Piplani <lakshay.piplani@nxp.com>
Signed-off-by: Aman Kumar Pandey <aman.kumarpandey@nxp.com>
Signed-off-by: Vikash Bansal <vikash.bansal@nxp.com>
---
Changes in v14:
- Clear receive-buffer flags even on SMBus receive error paths to avoid
repeated IBI storms
- Decode receive-buffer status using FIELD_GET()
- Fix overflow status value and explicitly clear overflow after reading both
target buffers
Changes in v13:
- Make IBI setup optional and robust: avoid probe failure when IBI is unsupported and add proper
cleanup using devm actions
- Fix SMBus slave receive path: avoid over-clearing buffer status, handle unregistered ports,
and ensure correct event delivery
- Improve safety by adding proper locking around shared state
Changes in v12:
- Add devm cleanup for IBI request/enable path
- Fix NULL pointer dereference before tp_smbus_client check
- Clear tp_smbus_client before disabling SMBus-agent IBI in unreg_slave()
Changes in v11:
- Improve SMBus slave mode payload validation and parsing
Changes in v10:
- Split SMBus slave mode support into a separate patch
---
---
drivers/i3c/hub/p3h2840_i3c_hub.h | 18 ++
drivers/i3c/hub/p3h2840_i3c_hub_i3c.c | 48 ++++-
drivers/i3c/hub/p3h2840_i3c_hub_smbus.c | 251 ++++++++++++++++++++++++
3 files changed, 316 insertions(+), 1 deletion(-)
diff --git a/drivers/i3c/hub/p3h2840_i3c_hub.h b/drivers/i3c/hub/p3h2840_i3c_hub.h
index e7ab243bbfff..a7cb83dcf1e8 100644
--- a/drivers/i3c/hub/p3h2840_i3c_hub.h
+++ b/drivers/i3c/hub/p3h2840_i3c_hub.h
@@ -123,6 +123,11 @@
#define BUF_RECEIVED_FLAG_MASK GENMASK(3, 1)
#define BUF_RECEIVED_FLAG_TF_MASK GENMASK(3, 0)
+#define P3H2X4X_TARGET_BUF_0_RECEIVE_VAL 1
+#define P3H2X4X_TARGET_BUF_1_RECEIVE_VAL 2
+#define P3H2X4X_TARGET_BUF_0_1_RECEIVE_VAL 3
+#define P3H2X4X_TARGET_BUF_OVRFL_VAL 7
+
#define P3H2X4X_TARGET_AGENT_LOCAL_DEV 0x11
#define P3H2X4X_TARGET_BUFF_0_PAGE 0x12
#define P3H2X4X_TARGET_BUFF_1_PAGE 0x13
@@ -299,6 +304,9 @@ struct p3h2x4x_i3c_hub_dev {
struct i2c_client *i2c_client;
struct hub_configuration hub_config;
struct tp_bus tp_bus[P3H2X4X_TP_MAX_COUNT];
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ bool ibi_ready;
+#endif
struct i3c_hub *hub;
};
@@ -324,4 +332,14 @@ int p3h2x4x_tp_smbus_algo(struct p3h2x4x_i3c_hub_dev *p3h2x4x_i3c_hub);
*/
int p3h2x4x_tp_i3c_algo(struct p3h2x4x_i3c_hub_dev *p3h2x4x_i3c_hub);
+/**
+ * p3h2x4x_ibi_handler - IBI handler.
+ * @i3cdev: i3c device.
+ * @payload: two byte IBI payload data.
+ */
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+void p3h2x4x_ibi_handler(struct i3c_device *i3cdev,
+ const struct i3c_ibi_payload *payload);
+#endif
+
#endif /* P3H2840_I3C_HUB_H */
diff --git a/drivers/i3c/hub/p3h2840_i3c_hub_i3c.c b/drivers/i3c/hub/p3h2840_i3c_hub_i3c.c
index 0e5bf7eb3cf7..b47859a2dd14 100644
--- a/drivers/i3c/hub/p3h2840_i3c_hub_i3c.c
+++ b/drivers/i3c/hub/p3h2840_i3c_hub_i3c.c
@@ -10,6 +10,14 @@
#include "p3h2840_i3c_hub.h"
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+static const struct i3c_ibi_setup p3h2x4x_ibireq = {
+ .handler = p3h2x4x_ibi_handler,
+ .max_payload_len = P3H2X4X_MAX_PAYLOAD_LEN,
+ .num_slots = P3H2X4X_NUM_SLOTS,
+};
+#endif
+
static inline struct tp_bus *
p3h2x4x_bus_from_controller(struct i3c_master_controller *controller)
{
@@ -54,6 +62,16 @@ static void p3h2x4x_unregister_i3c_master(void *data)
i3c_master_unregister(controller);
}
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+static void p3h2x4x_free_ibi(void *data)
+{
+ struct i3c_device *i3cdev = data;
+
+ i3c_device_disable_ibi(i3cdev);
+ i3c_device_free_ibi(i3cdev);
+}
+#endif
+
/**
* p3h2x4x_tp_i3c_algo - Register I3C virtual masters for I3C target ports.
* @p3h2x4x_hub: p3h2x4x device structure.
@@ -114,5 +132,33 @@ int p3h2x4x_tp_i3c_algo(struct p3h2x4x_i3c_hub_dev *p3h2x4x_hub)
p3h2x4x_hub->tp_bus[tp].is_registered = true;
p3h2x4x_hub->hub_config.tp_config[tp].always_enable = true;
}
- return regmap_write(p3h2x4x_hub->regmap, P3H2X4X_TP_NET_CON_CONF, ntwk_mask);
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ ret = i3c_device_request_ibi(p3h2x4x_hub->i3cdev, &p3h2x4x_ibireq);
+ if (ret) {
+ dev_warn(p3h2x4x_hub->dev,
+ "IBI not available, SMBus slave mode disabled\n");
+ p3h2x4x_hub->ibi_ready = false;
+ } else {
+ ret = i3c_device_enable_ibi(p3h2x4x_hub->i3cdev);
+ if (ret) {
+ i3c_device_free_ibi(p3h2x4x_hub->i3cdev);
+ dev_warn(p3h2x4x_hub->dev,
+ "Failed to enable IBI, SMBus slave mode disabled\n");
+ p3h2x4x_hub->ibi_ready = false;
+ } else {
+ p3h2x4x_hub->ibi_ready = true;
+
+ ret = devm_add_action_or_reset(p3h2x4x_hub->dev,
+ p3h2x4x_free_ibi,
+ p3h2x4x_hub->i3cdev);
+ if (ret) {
+ p3h2x4x_hub->ibi_ready = false;
+ return ret;
+ }
+ }
+ }
+#endif
+ ret = regmap_write(p3h2x4x_hub->regmap, P3H2X4X_TP_NET_CON_CONF, ntwk_mask);
+
+ return ret;
}
diff --git a/drivers/i3c/hub/p3h2840_i3c_hub_smbus.c b/drivers/i3c/hub/p3h2840_i3c_hub_smbus.c
index b991c46f3ed5..89e94f551b31 100644
--- a/drivers/i3c/hub/p3h2840_i3c_hub_smbus.c
+++ b/drivers/i3c/hub/p3h2840_i3c_hub_smbus.c
@@ -3,6 +3,7 @@
* Copyright 2025-2026 NXP
* This P3H2X4X driver file contain functions for SMBus/I2C virtual Bus creation and read/write.
*/
+#include <linux/bitfield.h>
#include <linux/mfd/p3h2840.h>
#include <linux/regmap.h>
@@ -15,6 +16,168 @@ enum p3h2x4x_smbus_desc_idx {
P3H2X4X_DESC_READ_LEN,
};
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+static void p3h2x4x_read_smbus_agent_rx_buf(struct i3c_device *i3cdev, enum p3h2x4x_rcv_buf rfbuf,
+ enum p3h2x4x_tp tp)
+{
+ struct p3h2x4x_i3c_hub_dev *p3h2x4x_i3c_hub = i3cdev_get_drvdata(i3cdev);
+ u8 slave_rx_buffer[P3H2X4X_SMBUS_TARGET_PAYLOAD_SIZE] = { 0 };
+ u8 target_buffer_page, flag_clear, temp = 0, i, addr;
+ u32 packet_len, slave_address, ret;
+ struct i2c_client *client;
+
+ switch (rfbuf) {
+ case RCV_BUF_0:
+ target_buffer_page = P3H2X4X_TARGET_BUFF_0_PAGE;
+ flag_clear = P3H2X4X_TARGET_BUF_0_RECEIVE;
+ break;
+ case RCV_BUF_1:
+ target_buffer_page = P3H2X4X_TARGET_BUFF_1_PAGE;
+ flag_clear = P3H2X4X_TARGET_BUF_1_RECEIVE;
+ break;
+ default:
+ return;
+ }
+
+ target_buffer_page += P3H2X4X_NO_PAGE_PER_TP * tp;
+
+ ret = regmap_write(p3h2x4x_i3c_hub->regmap, P3H2X4X_PAGE_PTR, target_buffer_page);
+ if (ret)
+ goto ibi_err;
+
+ /* read buffer length */
+ ret = regmap_read(p3h2x4x_i3c_hub->regmap, P3H2X4X_TARGET_BUFF_LENGTH, &packet_len);
+ if (ret)
+ goto ibi_err;
+
+ if (packet_len)
+ packet_len = packet_len - 1;
+
+ if (packet_len > P3H2X4X_SMBUS_TARGET_PAYLOAD_SIZE) {
+ dev_err(&i3cdev->dev, "Received message too big for p3h2x4x buffer\n");
+ goto ibi_err;
+ }
+
+ /* read slave address */
+ ret = regmap_read(p3h2x4x_i3c_hub->regmap, P3H2X4X_TARGET_BUFF_ADDRESS, &slave_address);
+ if (ret)
+ goto ibi_err;
+
+ /* read data */
+ if (packet_len) {
+ ret = regmap_bulk_read(p3h2x4x_i3c_hub->regmap, P3H2X4X_TARGET_BUFF_DATA,
+ slave_rx_buffer, packet_len);
+ if (ret)
+ goto ibi_err;
+ }
+
+ client = p3h2x4x_i3c_hub->tp_bus[tp].tp_smbus_client;
+ if (!client)
+ goto ibi_err;
+
+ /* notify slave driver about received data */
+ if ((client->addr & 0x7f) == (slave_address >> 1)) {
+ addr = slave_address >> 1;
+ i2c_slave_event(client,
+ I2C_SLAVE_WRITE_REQUESTED, &addr);
+ for (i = 0; i < packet_len; i++) {
+ temp = slave_rx_buffer[i];
+ i2c_slave_event(client,
+ I2C_SLAVE_WRITE_RECEIVED, &temp);
+ }
+ i2c_slave_event(client, I2C_SLAVE_STOP, &temp);
+ }
+
+ibi_err:
+ regmap_write(p3h2x4x_i3c_hub->regmap, P3H2X4X_PAGE_PTR, 0x00);
+
+ regmap_write(p3h2x4x_i3c_hub->regmap, P3H2X4X_TP0_SMBUS_AGNT_STS + tp, flag_clear);
+}
+
+/**
+ * p3h2x4x_ibi_handler - IBI handler.
+ * @i3cdev: i3c device.
+ * @payload: two byte IBI payload data.
+ *
+ */
+void p3h2x4x_ibi_handler(struct i3c_device *i3cdev,
+ const struct i3c_ibi_payload *payload)
+{
+ struct p3h2x4x_i3c_hub_dev *p3h2x4x_i3c_hub;
+ u8 payload_byte_one, payload_byte_two;
+ u32 target_port_status, ret, i;
+ const u8 *data;
+
+ if (!payload || payload->len < P3H2X4X_MAX_PAYLOAD_LEN)
+ return;
+
+ data = payload->data;
+ payload_byte_one = data[0];
+
+ if (!(payload_byte_one & P3H2X4X_SMBUS_AGENT_EVENT_FLAG_STATUS))
+ return;
+
+ p3h2x4x_i3c_hub = i3cdev_get_drvdata(i3cdev);
+
+ if (!p3h2x4x_i3c_hub || !p3h2x4x_i3c_hub->regmap)
+ return;
+
+ payload_byte_two = data[1];
+ guard(mutex)(&p3h2x4x_i3c_hub->etx_mutex);
+
+ for (i = 0; i < P3H2X4X_TP_MAX_COUNT; ++i) {
+ if (!((payload_byte_two >> i) & 0x01))
+ continue;
+
+ if (!p3h2x4x_i3c_hub->tp_bus[i].is_registered) {
+ dev_dbg(&i3cdev->dev, "IBI for unregistered SMBus port %u\n", i);
+ regmap_write(p3h2x4x_i3c_hub->regmap,
+ P3H2X4X_TP0_SMBUS_AGNT_STS + i,
+ BUF_RECEIVED_FLAG_TF_MASK);
+ continue;
+ }
+
+ ret = regmap_read(p3h2x4x_i3c_hub->regmap, P3H2X4X_TP0_SMBUS_AGNT_STS + i,
+ &target_port_status);
+ if (ret) {
+ dev_err(&i3cdev->dev, "target port read status failed %d\n", ret);
+ continue;
+ }
+
+ if (target_port_status & P3H2X4X_TARGET_BUF_CA_TF)
+ regmap_write(p3h2x4x_i3c_hub->regmap,
+ P3H2X4X_TP0_SMBUS_AGNT_STS + i,
+ P3H2X4X_TARGET_BUF_CA_TF);
+
+ /* process data receive buffer */
+ switch (FIELD_GET(BUF_RECEIVED_FLAG_MASK, target_port_status)) {
+ case P3H2X4X_TARGET_BUF_0_RECEIVE_VAL:
+ p3h2x4x_read_smbus_agent_rx_buf(i3cdev, RCV_BUF_0, i);
+ break;
+ case P3H2X4X_TARGET_BUF_1_RECEIVE_VAL:
+ p3h2x4x_read_smbus_agent_rx_buf(i3cdev, RCV_BUF_1, i);
+ break;
+ case P3H2X4X_TARGET_BUF_0_1_RECEIVE_VAL:
+ p3h2x4x_read_smbus_agent_rx_buf(i3cdev, RCV_BUF_0, i);
+ p3h2x4x_read_smbus_agent_rx_buf(i3cdev, RCV_BUF_1, i);
+ break;
+ case P3H2X4X_TARGET_BUF_OVRFL_VAL:
+ p3h2x4x_read_smbus_agent_rx_buf(i3cdev, RCV_BUF_0, i);
+ p3h2x4x_read_smbus_agent_rx_buf(i3cdev, RCV_BUF_1, i);
+ regmap_write(p3h2x4x_i3c_hub->regmap, P3H2X4X_TP0_SMBUS_AGNT_STS + i,
+ P3H2X4X_TARGET_BUF_OVRFL);
+ dev_err(&i3cdev->dev, "Overflow, reading buffer zero and one\n");
+ break;
+ default:
+ regmap_write(p3h2x4x_i3c_hub->regmap,
+ P3H2X4X_TP0_SMBUS_AGNT_STS + i,
+ target_port_status & BUF_RECEIVED_FLAG_MASK);
+ break;
+ }
+ }
+}
+#endif
+
static int p3h2x4x_read_smbus_transaction_status(struct p3h2x4x_i3c_hub_dev *hub,
u8 target_port_status,
u8 data_length)
@@ -213,11 +376,99 @@ static u32 p3h2x4x_tp_smbus_funcs(struct i2c_adapter *adapter)
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_BLOCK_DATA;
}
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+static int p3h2x4x_tp_i2c_reg_slave(struct i2c_client *slave)
+{
+ struct tp_bus *bus = i2c_get_adapdata(slave->adapter);
+ struct p3h2x4x_i3c_hub_dev *hub = bus->p3h2x4x_i3c_hub;
+ struct p3h2x4x *p3h2x4x = dev_get_drvdata(hub->dev->parent);
+ int ret, ret2;
+
+ guard(mutex)(&hub->etx_mutex);
+
+ if (!hub->i3cdev || !hub->ibi_ready)
+ return -EOPNOTSUPP;
+
+ if (bus->tp_smbus_client)
+ return -EBUSY;
+
+ mutex_lock(&p3h2x4x->protected_reg_lock);
+
+ /* Unlock access to protected registers */
+ ret = regmap_write(hub->regmap, P3H2X4X_DEV_REG_PROTECTION_CODE,
+ P3H2X4X_REGISTERS_UNLOCK_CODE);
+ if (ret)
+ goto out_unlock_mutex;
+
+ ret = regmap_set_bits(hub->regmap,
+ P3H2X4X_TP_SMBUS_AGNT_IBI_CONFIG,
+ bus->tp_mask);
+
+ /* Lock access to protected registers */
+ ret2 = regmap_write(hub->regmap, P3H2X4X_DEV_REG_PROTECTION_CODE,
+ P3H2X4X_REGISTERS_LOCK_CODE);
+ if (!ret && ret2)
+ ret = ret2;
+
+out_unlock_mutex:
+ mutex_unlock(&p3h2x4x->protected_reg_lock);
+
+ if (!ret) {
+ bus->tp_smbus_client = slave;
+ hub->hub_config.tp_config[bus->tp_port].ibi_en = true;
+ }
+
+ return ret;
+}
+
+static int p3h2x4x_tp_i2c_unreg_slave(struct i2c_client *slave)
+{
+ struct tp_bus *bus = i2c_get_adapdata(slave->adapter);
+ struct p3h2x4x_i3c_hub_dev *hub = bus->p3h2x4x_i3c_hub;
+ struct p3h2x4x *p3h2x4x = dev_get_drvdata(hub->dev->parent);
+ int ret, ret2;
+
+ guard(mutex)(&hub->etx_mutex);
+
+ if (bus->tp_smbus_client != slave)
+ return -EINVAL;
+
+ bus->tp_smbus_client = NULL;
+ hub->hub_config.tp_config[bus->tp_port].ibi_en = false;
+
+ mutex_lock(&p3h2x4x->protected_reg_lock);
+
+ /* Unlock access to protected registers */
+ ret = regmap_write(hub->regmap, P3H2X4X_DEV_REG_PROTECTION_CODE,
+ P3H2X4X_REGISTERS_UNLOCK_CODE);
+ if (ret)
+ goto out_unlock_mutex;
+
+ ret = regmap_clear_bits(hub->regmap,
+ P3H2X4X_TP_SMBUS_AGNT_IBI_CONFIG,
+ bus->tp_mask);
+
+ /* Lock access to protected registers */
+ ret2 = regmap_write(hub->regmap, P3H2X4X_DEV_REG_PROTECTION_CODE,
+ P3H2X4X_REGISTERS_LOCK_CODE);
+ if (!ret && ret2)
+ ret = ret2;
+
+out_unlock_mutex:
+ mutex_unlock(&p3h2x4x->protected_reg_lock);
+ return ret;
+}
+#endif
+
/*
* I2C algorithm Structure
*/
static struct i2c_algorithm p3h2x4x_tp_i2c_algorithm = {
.master_xfer = p3h2x4x_tp_i2c_xfer,
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ .reg_slave = p3h2x4x_tp_i2c_reg_slave,
+ .unreg_slave = p3h2x4x_tp_i2c_unreg_slave,
+#endif
.functionality = p3h2x4x_tp_smbus_funcs,
};
--
2.25.1
^ permalink raw reply related [flat|nested] 19+ messages in thread
* Re: [PATCH v14 1/8] i3c: master: Add APIs for I3C hub support
2026-07-14 9:20 ` [PATCH v14 1/8] i3c: master: Add APIs for I3C hub support Lakshay Piplani
@ 2026-07-14 10:03 ` sashiko-bot
2026-07-14 19:04 ` Frank Li
0 siblings, 1 reply; 19+ messages in thread
From: sashiko-bot @ 2026-07-14 10:03 UTC (permalink / raw)
To: Lakshay Piplani
Cc: linux-i3c, Frank.Li, Alexandre Belloni, robh, conor+dt,
devicetree
Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:
New issues:
- [High] Asymmetrical cleanup in `i3c_master_direct_detach_i3c_dev_locked` leaks resources for unaddressed devices.
Pre-existing issues:
- [High] IDR entry deletion on `i3c_bus_init` failure causes ID corruption and sysfs collisions.
- [High] Missing NULL check for `dev->boardinfo` in `i3c_master_get_i3c_addrs` leads to kernel panic.
--
--- Patch [1]: [PATCH v14 1/8] i3c: master: Add APIs for I3C hub support ---
commit 1db519c7da22819d977429d77c0d05ba94daedf9
Author: Aman Kumar Pandey <aman.kumarpandey@nxp.com>
i3c: master: Add APIs for I3C hub support
Add helpers for attaching and detaching I3C devices and CCC helpers
to check CCC support and send CCC commands, address slot helpers to
query and update I3C bus address slot state, registering virtual
masters with an explicit firmware node, and exposing the bus maintenance
lock helpers.
> diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
> index f1be38a640ca1..3b1c342be2bc5 100644
> --- a/drivers/i3c/master.c
> +++ b/drivers/i3c/master.c
[ ... ]
> @@ -1775,6 +1792,83 @@ static int i3c_master_attach_i3c_dev(struct i3c_master_controller *master,
> return 0;
> }
>
> +/**
> + * i3c_master_direct_attach_i3c_dev_locked() - Attach an I3C device to a master
> + * @master: I3C master controller to attach the device to
> + * @dev: I3C device descriptor representing the device
> + *
> + * Attach an I3C device to its master controller after reserving the device
> + * addresses on the bus. The device must belong to @master.
> + *
> + * The master device itself is not passed to the controller driver's
> + * ->attach_i3c_dev() callback.
> + *
> + * Context: Caller must hold @master->bus.lock in write mode.
> + *
> + * Return: 0 on success, or a negative error code if address reservation fails
> + * or if the master controller driver's ->attach_i3c_dev() callback fails.
> + */
> +int i3c_master_direct_attach_i3c_dev_locked(struct i3c_master_controller *master,
> + struct i3c_dev_desc *dev)
> +{
> + int ret;
> +
> + if (WARN_ON(i3c_dev_get_master(dev) != master))
> + return -EINVAL;
> +
> + ret = i3c_master_get_i3c_addrs(dev);
[Severity: High]
This is a pre-existing issue, but does exposing this new API introduce a
potential NULL pointer dereference?
If a caller manually constructs a virtual I3C device without an OF node
where dev->boardinfo is NULL, but it has a static_addr, calling this
function will invoke i3c_master_get_i3c_addrs(). Inside that function,
if the static address slot is not free:
i3c_master_get_i3c_addrs() {
...
status = i3c_bus_get_addr_slot_status(&master->bus,
dev->info.static_addr);
if (status != I3C_ADDR_SLOT_FREE &&
dev->info.static_addr != dev->boardinfo->init_dyn_addr)
return -EBUSY;
...
}
Could this dereference dev->boardinfo without checking if it is NULL, leading
to a kernel panic?
> + if (ret)
> + return ret;
> +
> + /* Do not attach the master device itself. */
> + if (master->this != dev && master->ops->attach_i3c_dev) {
> + ret = master->ops->attach_i3c_dev(dev);
[Severity: High]
Could this cause an asymmetrical resource leak for unaddressed devices?
The original i3c_master_attach_i3c_dev() function includes a check at the
beginning to return early if the device has no static or dynamic address:
if (!dev->info.static_addr && !dev->info.dyn_addr)
return 0;
This new attach function lacks that check, meaning it invokes the master
controller's attach_i3c_dev() hook even for unaddressed devices.
However, the new i3c_master_direct_detach_i3c_dev_locked() function
explicitly skips detach for unaddressed devices:
if (!dev->info.static_addr && !dev->info.dyn_addr)
return;
Will any resources allocated by the controller driver during the attach
hook be permanently leaked when the device is detached?
> + if (ret) {
> + i3c_master_put_i3c_addrs(dev);
> + return ret;
> + }
> + }
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(i3c_master_direct_attach_i3c_dev_locked);
[ ... ]
> @@ -3195,34 +3342,31 @@ static int i3c_master_check_ops(const struct i3c_master_controller_ops *ops)
[ ... ]
> +int i3c_master_register_fwnode(struct i3c_master_controller *master,
> + struct device *parent,
> + struct fwnode_handle *fwnode,
> + const struct i3c_master_controller_ops *ops,
> + bool secondary)
> +{
> + unsigned long i2c_scl_rate = I3C_BUS_I2C_FM_PLUS_SCL_MAX_RATE;
> + struct i3c_bus *i3cbus = i3c_master_get_bus(master);
> + enum i3c_bus_mode mode = I3C_BUS_MODE_PURE;
> + struct device_node *np = NULL;
> + struct i2c_dev_boardinfo *i2cbi;
> + int ret;
[ ... ]
> + ret = i3c_bus_init(i3cbus, master->dev.of_node);
> + if (ret)
> + goto err_put_dev;
[Severity: High]
This isn't a bug introduced by this patch, but does an error here cause
global IDR corruption?
If i3c_bus_init() fails during idr_alloc(), it returns an error with
i3cbus->id still set to 0. Taking the err_put_dev path calls put_device() on
master->dev, which invokes i3c_masterdev_release().
i3c_masterdev_release() unconditionally calls i3c_bus_cleanup(), which runs:
i3c_bus_cleanup() {
...
idr_remove(&i3c_bus_idr, i3cbus->id);
...
}
If i3cbus->id is uninitialized (0), does this mistakenly remove ID 0 from
the global i3c_bus_idr? If a valid bus was already registered with ID 0, it
seems it would lose its IDR entry, causing a subsequent bus registration to
be assigned ID 0 again and triggering sysfs collisions (i3c-0).
> +
> + dev_set_name(&master->dev, "i3c-%d", i3cbus->id);
> +
> + ret = of_populate_i3c_bus(master);
> + if (ret)
> + goto err_put_dev;
[ ... ]
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260714092053.2461482-1-lakshay.piplani@nxp.com?part=1
^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH v14 2/8] i3c: master: Fix IBI request and free cleanup paths
2026-07-14 9:20 ` [PATCH v14 2/8] i3c: master: Fix IBI request and free cleanup paths Lakshay Piplani
@ 2026-07-14 10:20 ` sashiko-bot
2026-07-14 19:10 ` Frank Li
0 siblings, 1 reply; 19+ messages in thread
From: sashiko-bot @ 2026-07-14 10:20 UTC (permalink / raw)
To: Lakshay Piplani
Cc: conor+dt, linux-i3c, Alexandre Belloni, robh, Frank.Li,
devicetree
Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
New issues:
- [High] Bypassing the core cleanup paths when `dev->ibi` is cleared by a controller callback causes a permanent leak of the IBI workqueue (including its rescuer kthread) and potentially the `ibi` object itself.
Pre-existing issues:
- [High] Potential use-after-free of IBI pool during workqueue destruction if IBI disable fails.
--
--- Patch [2]: [PATCH v14 2/8] i3c: master: Fix IBI request and free cleanup paths ---
commit e0d1c57d2924f66898a40232f7e52ca0e1be0aea
Author: Lakshay Piplani <lakshay.piplani@nxp.com>
i3c: master: Fix IBI request and free cleanup paths
This commit attempts to fix a workqueue leak in the IBI request failure path
by destroying the workqueue before freeing the IBI object. It also adds checks
to avoid touching dev->ibi after controller callbacks if they have already
cleared it, aiming to prevent NULL pointer dereferences.
> diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
> index 3b1c342be2bc5..ba37f71badac8 100644
> --- a/drivers/i3c/master.c
> +++ b/drivers/i3c/master.c
> @@ -3702,8 +3702,18 @@ int i3c_dev_request_ibi_locked(struct i3c_dev_desc *dev,
>
> dev->ibi = ibi;
> ret = master->ops->request_ibi(dev, req);
> - if (ret) {
> - kfree(ibi);
> +
> + /*
> + * The controller callback may have already released and cleared dev->ibi
> + * when the request is forwarded by a virtual controller. Only clean up the
> + * IBI object if the callback left dev->ibi valid.
> + */
> + if (ret && dev->ibi) {
> + /* Avoid leaking the workqueue allocated for this IBI request. */
> + if (dev->ibi->wq)
> + destroy_workqueue(dev->ibi->wq);
> +
> + kfree(dev->ibi);
> dev->ibi = NULL;
> }
[Severity: High]
Does this logic introduce a permanent leak of the IBI workqueue and the local
ibi object?
Since the core framework dynamically allocated ibi and ibi->wq earlier in
i3c_dev_request_ibi_locked(), if master->ops->request_ibi() fails and the
callback cleared dev->ibi, the check if (ret && dev->ibi) will be false.
Because the callback does not own these resources and cannot safely destroy
the framework's workqueue, the workqueue (including its rescuer kthread) and
the ibi object will be skipped during cleanup and leak permanently.
[ ... ]
> @@ -3743,6 +3753,13 @@ void i3c_dev_free_ibi_locked(struct i3c_dev_desc *dev)
>
> master->ops->free_ibi(dev);
[Severity: High]
This isn't a bug introduced by this patch, but can this lead to a
use-after-free of the IBI pool memory if disabling the IBI fails?
Earlier in i3c_dev_free_ibi_locked(), if the IBI is still enabled, it tries
to disable it via i3c_dev_disable_ibi_locked(). If that disable fails
(e.g., due to a hardware timeout), it returns an error without waiting for
pending IBIs to finish, and we proceed directly to master->ops->free_ibi(dev).
This callback immediately frees the generic IBI pool. Subsequently,
destroy_workqueue() is called below, which synchronously drains
any executing IBI handler works. Since these pending work items reside inside
the newly-freed pool, won't the rescuer thread dereference freed memory as
the workqueue drains?
> + /*
> + * The controller callback may have already released dev->ibi, for example
> + * when the request was forwarded by a virtual controller.
> + */
> + if (!dev->ibi)
> + return;
[Severity: High]
Similar to the request path above, does this early return bypass the
destruction of the workqueue and cause a resource leak?
If the controller callback cleared dev->ibi on the free path, we return
early and skip the destroy_workqueue(dev->ibi->wq) step, leaking the
workqueue and its rescuer thread.
> +
> if (dev->ibi->wq) {
> destroy_workqueue(dev->ibi->wq);
> dev->ibi->wq = NULL;
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260714092053.2461482-1-lakshay.piplani@nxp.com?part=2
^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH v14 3/8] dt-bindings: i3c: Add NXP P3H2x4x i3c-hub support
2026-07-14 9:20 ` [PATCH v14 3/8] dt-bindings: i3c: Add NXP P3H2x4x i3c-hub support Lakshay Piplani
@ 2026-07-14 10:30 ` sashiko-bot
0 siblings, 0 replies; 19+ messages in thread
From: sashiko-bot @ 2026-07-14 10:30 UTC (permalink / raw)
To: Lakshay Piplani
Cc: linux-i3c, Frank.Li, Alexandre Belloni, robh, conor+dt,
devicetree
Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:
- [Medium] The binding documents GPIO provider capabilities for the target ports but omits the corresponding required standard properties (`gpio-controller`, `#gpio-cells`) from the schema.
- [Medium] The schema artificially restricts the compatible string to a single part number (`nxp,p3h2840`), failing to support the full hardware family declared in the commit message.
- [Low] The `maximum: 7` constraint is incorrectly applied directly to the `reg` property for child nodes, rendering it ineffective.
--
--- Patch [3]: [PATCH v14 3/8] dt-bindings: i3c: Add NXP P3H2x4x i3c-hub support ---
commit de643e91ed7cd5797dc3f49d8564e4fab44c0789
Author: Aman Kumar Pandey <aman.kumarpandey@nxp.com>
dt-bindings: i3c: Add NXP P3H2x4x i3c-hub support
Add bindings for the NXP P3H2x4x (P3H2440/P3H2441/P3H2840/P3H2841)
multiport I3C hub family. These devices connect to a host via
I3C/I2C/SMBus and allow communication with multiple downstream
peripherals.
> diff --git a/Documentation/devicetree/bindings/i3c/nxp,p3h2840.yaml b/Documentation/devicetree/bindings/i3c/nxp,p3h2840.yaml
> new file mode 100644
> index 0000000000000..f7f0752de5333
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/i3c/nxp,p3h2840.yaml
> @@ -0,0 +1,291 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright 2025 NXP
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/i3c/nxp,p3h2840.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: NXP P3H2X4X I3C HUB
> +
> +maintainers:
> + - Aman Kumar Pandey <aman.kumarpandey@nxp.com>
> + - Vikash Bansal <vikash.bansal@nxp.com>
> + - Lakshay Piplani <lakshay.piplani@nxp.com>
> +
> +description: |
> + P3H2x4x (P3H2440/P3H2441/P3H2840/P3H2841) is a family of multiport I3C
> + hub devices that connect to:-
> + 1. A host CPU via I3C/I2C/SMBus bus on upstream side and connect to multiple
> + peripheral devices on the downstream side.
> + 2. Have two Controller Ports which can support either
> + I2C/SMBus or I3C buses and connect to a CPU, BMC or SOC.
> + 3. P3H2840/ P3H2841 are 8 port I3C hub with eight I3C/I2C Target Port.
> + 4. P3H2440/ P3H2441 are 4 port I3C hub with four I3C/I2C Target Port.
> + Target ports can be configured as I2C/SMBus, I3C or GPIO and connect to
> + peripherals.
[Severity: Medium]
The description notes that target ports can be configured as GPIO providers,
but the schema does not seem to include the corresponding required standard
properties. Should gpio-controller and #gpio-cells be added to the schema
to support this capability and avoid incomplete device trees passing validation?
> +
> +properties:
> + compatible:
> + const: nxp,p3h2840
[Severity: Medium]
The commit message indicates this binding supports the broader P3H2x4x family
(P3H2440, P3H2441, P3H2840, P3H2841), but this strictly restricts the
compatible string to a single part number. Should this be an enum allowing
the other family members, or use an enum alongside a fallback?
[ ... ]
> +patternProperties:
> + "^i3c@[0-7]$":
> + type: object
> + $ref: /schemas/i3c/i3c.yaml#
> + unevaluatedProperties: false
> +
> + properties:
> + reg:
> + description:
> + The I3C HUB Target Port number.
> + maximum: 7
[Severity: Low]
Is this maximum: 7 constraint effective here? The reg property structurally
evaluates as an array, whereas the maximum keyword only applies to numeric
scalar types in JSON schema validation. Does this limit need to be structured
differently (for example, applying it to items) to be evaluated?
[ ... ]
> + "^(i2c|smbus)@[0-7]$":
> + type: object
> + $ref: /schemas/i2c/i2c-controller.yaml#
> + unevaluatedProperties: false
> +
> + properties:
> + reg:
> + description:
> + The I3C HUB Target Port number.
> + maximum: 7
[Severity: Low]
Similarly for the i2c/smbus nodes, is applying maximum: 7 directly to the
reg property array valid for JSON schema validation?
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260714092053.2461482-1-lakshay.piplani@nxp.com?part=3
^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH v14 4/8] mfd: p3h2x4x: Add driver for NXP P3H2x4x i3c hub and on-die regulator
2026-07-14 9:20 ` [PATCH v14 4/8] mfd: p3h2x4x: Add driver for NXP P3H2x4x i3c hub and on-die regulator Lakshay Piplani
@ 2026-07-14 10:49 ` sashiko-bot
0 siblings, 0 replies; 19+ messages in thread
From: sashiko-bot @ 2026-07-14 10:49 UTC (permalink / raw)
To: Lakshay Piplani
Cc: Alexandre Belloni, robh, devicetree, linux-i3c, Frank.Li,
conor+dt
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Architecture / Layering Violation: Driver-specific header file is incorrectly placed in the global `include/linux/mfd/` directory.
--
--- Patch [4]: [PATCH v14 4/8] mfd: p3h2x4x: Add driver for NXP P3H2x4x i3c hub and on-die regulator ---
commit 2a59167d38bc0c8607cf16c05249be2d7d9c9354
Author: Aman Kumar Pandey <aman.kumarpandey@nxp.com>
mfd: p3h2x4x: Add driver for NXP P3H2x4x i3c hub and on-die regulator
This commit adds core MFD support for the NXP P3H2x4x family of multiport
I3C hub devices. These devices connect to a host via I3C/I2C/SMBus and
expose multiple downstream target ports.
[ ... ]
> diff --git a/include/linux/mfd/p3h2840.h b/include/linux/mfd/p3h2840.h
> new file mode 100644
> index 0000000000000..ba9a38756ecb8
> --- /dev/null
> +++ b/include/linux/mfd/p3h2840.h
> @@ -0,0 +1,25 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
[ ... ]
> +#define I3C_MANUF_ID_NXP 0x011b
> +
> +struct p3h2x4x {
> + struct i3c_device *i3cdev;
> + struct regmap *regmap;
> + struct mutex protected_reg_lock; /* Serializes protected register unlock/lock sequences. */
> +};
[Severity: Low]
This isn't a bug, but since this header file defines driver-specific
structures solely intended for the parent and its immediate children, should
it be kept locally in drivers/mfd/ rather than being placed in the global
include/linux/mfd/ directory?
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260714092053.2461482-1-lakshay.piplani@nxp.com?part=4
^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH v14 5/8] regulator: p3h2x4x: Add driver for on-die regulators in NXP P3H2x4x i3c hub
2026-07-14 9:20 ` [PATCH v14 5/8] regulator: p3h2x4x: Add driver for on-die regulators in NXP P3H2x4x i3c hub Lakshay Piplani
@ 2026-07-14 10:57 ` sashiko-bot
0 siblings, 0 replies; 19+ messages in thread
From: sashiko-bot @ 2026-07-14 10:57 UTC (permalink / raw)
To: Lakshay Piplani
Cc: linux-i3c, Frank.Li, Alexandre Belloni, robh, conor+dt,
devicetree
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] The driver-specific header `p3h2840.h` is improperly placed in the global `include/linux/mfd/` directory in violation of MFD subsystem guidelines.
--
--- Patch [5]: [PATCH v14 5/8] regulator: p3h2x4x: Add driver for on-die regulators in NXP P3H2x4x i3c hub ---
commit dee1faf4c21dfa7f5c815bfdc8376ffa3158fbfe
Author: Aman Kumar Pandey <aman.kumarpandey@nxp.com>
regulator: p3h2x4x: Add driver for on-die regulators in NXP P3H2x4x i3c hub
The NXP P3H2x4x family integrates on-die regulators alongside I3C hub
functionality. This driver registers the regulators using the MFD
framework and exposes them via the regulator subsystem.
> diff --git a/drivers/regulator/p3h2840_i3c_hub_regulator.c b/drivers/regulator/p3h2840_i3c_hub_regulator.c
> new file mode 100644
> index 0000000000000..645d46ad7c2f2
> --- /dev/null
> +++ b/drivers/regulator/p3h2840_i3c_hub_regulator.c
> @@ -0,0 +1,284 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright 2025-2026 NXP
> + * NXP P3H2X4X regulator driver file contain functions for enable/disable regulator
> + * and voltage set/get.
> + */
> +#include <linux/bitfield.h>
> +#include <linux/cleanup.h>
> +#include <linux/mfd/p3h2840.h>
[Severity: Low]
According to the MFD subsystem guidelines, driver-specific header files that
are only used by the parent and its immediate children should not be placed
in the global include/linux/mfd/ directory.
Could p3h2840.h be kept local to drivers/mfd/ instead of being exposed in the
global include path?
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260714092053.2461482-1-lakshay.piplani@nxp.com?part=5
^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH v14 6/8] i3c: hub: Add support for the I3C interface in the I3C hub
2026-07-14 9:20 ` [PATCH v14 6/8] i3c: hub: Add support for the I3C interface in the I3C hub Lakshay Piplani
@ 2026-07-14 11:14 ` sashiko-bot
0 siblings, 0 replies; 19+ messages in thread
From: sashiko-bot @ 2026-07-14 11:14 UTC (permalink / raw)
To: Lakshay Piplani
Cc: linux-i3c, Alexandre Belloni, conor+dt, Frank.Li, devicetree,
robh
Thank you for your contribution! Sashiko AI review found 8 potential issue(s) to consider:
- [High] Temporary hub address swapping in `i3c_hub_master_priv_xfers` permanently frees downstream address slots.
- [High] Detaching the downstream device in IBI request/free paths unconditionally frees its parent bus address slots.
- [High] Forwarding DAA directly to the parent controller attaches downstream devices to the wrong bus topology.
- [High] The no-op `recycle_ibi_slot` callback permanently leaks hardware IBI slots allocated by the parent controller.
- [High] `i3c_hub_request_ibi()` fails with `-EBUSY` due to conflicting address reservations or corrupts parent DAT.
- [High] Recursive lock acquisition of `hub->lock` causes deadlocks with IBI workqueue handlers.
- [High] Modifying the device descriptor's master pointer under a shared read-lock causes data races, misrouting private transfers.
- [High] Forwarding direct CCC commands unmodified through the hub causes a NULL pointer dereference in the parent driver.
--
--- Patch [6]: [PATCH v14 6/8] i3c: hub: Add support for the I3C interface in the I3C hub ---
commit 02e794653daf2b554f0c962c355d0bb7abb26374
Author: Lakshay Piplani <lakshay.piplani@nxp.com>
Subject: i3c: hub: Add support for the I3C interface in the I3C hub
This commit adds virtual I3C bus support for the hub, creating virtual
master controllers for downstream ports and forwarding operations through
the parent controller.
> diff --git a/drivers/i3c/hub.c b/drivers/i3c/hub.c
> index 0000000000000..6105bb710be69
> --- /dev/null
> +++ b/drivers/i3c/hub.c
[ ... ]
> +static int i3c_hub_do_daa(struct i3c_hub *hub,
> + struct i3c_master_controller *controller)
> +{
[ ... ]
> + /*
> + * Downstream devices reachable through hub target-port routes share the
> + * parent controller's I3C address space. The hub gates access to a
> + * target-port network, but it does not create an independent dynamic
> + * address domain per virtual bus.
> + *
> + * Run DAA on the parent controller so dynamic addresses remain unique
> + * across all downstream devices, even when they are behind different
> + * target ports.
> + */
> + ret = i3c_master_do_daa(parent);
[Severity: High]
Does forwarding DAA directly to the parent controller attach dynamically
discovered downstream devices directly to the parent bus instead of the
virtual hub controller?
If these devices are bound to the physical parent, subsequent transfers
might bypass i3c_hub_master_priv_xfers() entirely, leaving the hub port
closed and causing communication to fail.
[ ... ]
> +static int i3c_hub_send_ccc_cmd(struct i3c_hub *hub,
> + struct i3c_master_controller *controller,
> + struct i3c_ccc_cmd *cmd)
> +{
[ ... ]
> + mutex_lock(&hub->lock);
> + i3c_hub_enable_port(controller);
> + ret = i3c_master_send_ccc_cmd(parent, cmd);
[Severity: High]
When forwarding direct CCC commands to the parent controller, the command
structure still contains virtual bus descriptors in its dests array.
Since virtual devices do not allocate a physical master_priv context, can
the physical parent controller driver dereference a NULL pointer here when
it assumes these devices are natively attached?
> + i3c_hub_disable_port(controller);
> + mutex_unlock(&hub->lock);
> +
> + return ret;
> +}
[ ... ]
> +static int i3c_hub_master_priv_xfers(struct i3c_dev_desc *dev,
> + struct i3c_xfer *xfers,
> + int nxfers,
> + enum i3c_xfer_mode mode)
> +{
[ ... ]
> + if (hub_addr != target_addr) {
> + hub_dev->info.dyn_addr = target_addr;
> +
> + ret = i3c_master_reattach_i3c_dev_locked(hub_dev, hub_addr);
[Severity: High]
When the hub address is temporarily swapped here, does
i3c_master_reattach_i3c_dev_locked() unconditionally mark the original
address (old_dyn_addr) as free?
This appears to permanently free downstream address slots and could lead
to address collisions on the parent bus.
> + if (ret) {
> + hub_dev->info.dyn_addr = hub_addr;
> + goto out_unlock_parent;
> + }
> + }
[ ... ]
> +static int i3c_hub_request_ibi(struct i3c_dev_desc *desc,
> + const struct i3c_ibi_setup *req)
> +{
[ ... ]
> + i3c_bus_maintenance_lock(&parent->bus);
> +
> + orig_parent = i3c_hub_update_desc_parent(&desc->common, parent);
[Severity: High]
Is it safe to modify desc->master here while only holding a read lock
on the bus?
A concurrent private transfer might read desc->master and resolve it to
the physical parent controller, misrouting the transfer and bypassing
hub routing entirely.
> +
> + /*
> + * Downstream devices are exposed through the virtual hub controller.
> + * Private transfers only use the hub device temporarily with the
> + * downstream device's dynamic address; they do not attach the downstream
> + * device to the parent controller.
> + *
> + * Attach the device to the parent controller before requesting IBI so
> + * the parent can allocate any controller-private IBI state.
> + */
> + ret = i3c_master_direct_attach_i3c_dev_locked(parent, desc);
[Severity: High]
Could attaching the downstream device directly to the parent controller
fail with -EBUSY if the address was already reserved?
Additionally, if it succeeds, might this leave duplicate DAT entries in
the parent hardware when the hub later masquerades as this target address?
> + if (ret) {
> + i3c_hub_update_desc_parent(&desc->common, orig_parent);
> + i3c_bus_maintenance_unlock(&parent->bus);
> + return ret;
> + }
> +
> + if (desc->ibi) {
> + if (desc->ibi->wq) {
> + destroy_workqueue(desc->ibi->wq);
> + desc->ibi->wq = NULL;
> + }
> +
> + kfree(desc->ibi);
> + desc->ibi = NULL;
> + }
> + ret = i3c_dev_request_ibi_locked(desc, req);
> + if (ret)
> + i3c_master_direct_detach_i3c_dev_locked(desc);
[Severity: High]
Does detaching the downstream device here unconditionally free its static
and dynamic addresses on the parent bus?
The device is still physically present and using those addresses, so freeing
them could lead to address collisions.
> +
> + i3c_hub_update_desc_parent(&desc->common, orig_parent);
> +
> + i3c_bus_maintenance_unlock(&parent->bus);
> +
> + return ret;
> +}
> +
> +static void i3c_hub_free_ibi(struct i3c_dev_desc *desc)
> +{
[ ... ]
> + mutex_lock(&hub->lock);
> + i3c_hub_enable_port(controller);
> +
> + i3c_bus_maintenance_lock(&parent->bus);
> + orig_parent = i3c_hub_update_desc_parent(&desc->common, parent);
> + i3c_dev_free_ibi_locked(desc);
[Severity: High]
Can holding hub->lock here cause a deadlock if there are pending IBI work
handlers?
Calling i3c_dev_free_ibi_locked() blocks while destroying the workqueue.
If an active IBI handler attempts to read the IBI payload, it will invoke
i3c_hub_master_priv_xfers(), which attempts to acquire this exact same lock.
> +
> + /*
> + * Drop the temporary parent attachment created for IBI setup.
> + * The downstream device remains exposed through the virtual hub
> + * controller.
> + */
> + i3c_master_direct_detach_i3c_dev_locked(desc);
[Severity: High]
Does detaching the device on this path also incorrectly free the
downstream device's addresses on the parent bus?
> + i3c_hub_update_desc_parent(&desc->common, orig_parent);
> + i3c_bus_maintenance_unlock(&parent->bus);
> +
> + i3c_hub_disable_port(controller);
> + mutex_unlock(&hub->lock);
> +}
[ ... ]
> +static int i3c_hub_disable_ibi(struct i3c_dev_desc *desc)
> +{
[ ... ]
> + mutex_lock(&hub->lock);
> + i3c_hub_enable_port(controller);
> +
> + orig_parent = i3c_hub_update_desc_parent(&desc->common, parent);
> +
> + i3c_bus_maintenance_lock(&parent->bus);
> + ret = i3c_dev_disable_ibi_locked(desc);
[Severity: High]
Could holding hub->lock while calling i3c_dev_disable_ibi_locked() also
lead to the same ABBA deadlock with pending IBI workers trying to acquire
hub->lock via i3c_hub_master_priv_xfers()?
> + i3c_bus_maintenance_unlock(&parent->bus);
> +
> + i3c_hub_update_desc_parent(&desc->common, orig_parent);
> +
> + i3c_hub_disable_port(controller);
> + mutex_unlock(&hub->lock);
> +
> + return ret;
> +}
> +
> +static void i3c_hub_recycle_ibi_slot(struct i3c_dev_desc *desc,
> + struct i3c_ibi_slot *slot)
> +{
> + /*
> + * TODO: Forward IBI slot recycling to the parent controller when
> + * downstream-device IBI support is fully enabled. Current users only
> + * rely on the hub device IBI path for SMBus-agent events, so no parent
> + * hardware slot is recycled through this virtual callback currently.
> + */
> +}
[Severity: High]
Does this empty implementation permanently leak hardware IBI slots
allocated by the parent controller?
Over time, failing to return these slots could exhaust the pool and prevent
further IBI reception.
> +
> +static const struct i3c_master_controller_ops i3c_hub_master_ops_data = {
> + .bus_init = i3c_hub_master_bus_init,
[ ... ]
> diff --git a/include/linux/i3c/hub.h b/include/linux/i3c/hub.h
> index 0000000000000..8ad2cf3c9d5b8
> --- /dev/null
> +++ b/include/linux/i3c/hub.h
> @@ -0,0 +1,102 @@
[ ... ]
> +static inline struct i3c_master_controller *
> +i3c_hub_update_desc_parent(struct i3c_i2c_dev_desc *desc,
> + struct i3c_master_controller *parent)
> +{
> + struct i3c_master_controller *orig_parent = desc->master;
> +
> + desc->master = parent;
[Severity: High]
Does modifying desc->master here create a data race with concurrent
transfers using the I3C core transfer functions?
> + return orig_parent;
> +}
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260714092053.2461482-1-lakshay.piplani@nxp.com?part=6
^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH v14 7/8] i3c: hub: p3h2x4x: Add support for NXP P3H2x4x I3C hub functionality
2026-07-14 9:20 ` [PATCH v14 7/8] i3c: hub: p3h2x4x: Add support for NXP P3H2x4x I3C hub functionality Lakshay Piplani
@ 2026-07-14 11:31 ` sashiko-bot
0 siblings, 0 replies; 19+ messages in thread
From: sashiko-bot @ 2026-07-14 11:31 UTC (permalink / raw)
To: Lakshay Piplani
Cc: robh, devicetree, linux-i3c, Frank.Li, conor+dt,
Alexandre Belloni
Thank you for your contribution! Sashiko AI review found 5 potential issue(s) to consider:
- [High] Child driver illegaly overwrites the parent MFD device's private data, causing type confusion and kernel panics.
- [High] The SMBus timeout formula underestimates minimum physical wire time, causing large block transfers to inevitably fail with -ETIMEDOUT.
- [High] Target ports configured as "i2c" are left completely disconnected and functionally dead.
- [High] Use-After-Free of device structure embedded in devm-allocated memory during driver unbind.
- [Medium] Missing I2C adapter quirks causes undocumented rigid transfer size limits.
--
--- Patch [7]: [PATCH v14 7/8] i3c: hub: p3h2x4x: Add support for NXP P3H2x4x I3C hub functionality ---
commit cfe07c5ef0a917e7757bc31fa34e458df22a78ed
Author: Aman Kumar Pandey <aman.kumarpandey@nxp.com>
i3c: hub: p3h2x4x: Add support for NXP P3H2x4x I3C hub functionality
Add I3C hub functionality for the NXP P3H2x4x family of multiport hubs.
These devices support downstream target ports that can be configured
as I3C, I2C, or SMBus.
> diff --git a/drivers/i3c/hub/p3h2840_i3c_hub.h b/drivers/i3c/hub/p3h2840_i3c_hub.h
> index 0000000000000..e7ab243bbfff6
> --- /dev/null
> +++ b/drivers/i3c/hub/p3h2840_i3c_hub.h
[ ... ]
> +/* Hub SMBus transaction time */
> +#define P3H2X4X_SMBUS_400kHz_TRANSFER_TIMEOUT(x) ((20 * (x)) + 80)
[Severity: High]
Is this timeout formula sufficient for large SMBus block transfers?
At 400kHz, each 9-bit I2C byte takes 22.5 us. For a 32-byte payload plus a
1-byte address, the minimum physical wire time is 33 * 22.5 = 742.5 us.
However, the formula 20 * x + 80 allocates only 720 us for a 32-byte payload.
If a large payload message is sent, the timeout will trigger in
p3h2x4x_read_smbus_transaction_status() before the transfer can complete on
the wire, causing it to fail with a timeout.
[ ... ]
> diff --git a/drivers/i3c/hub/p3h2840_i3c_hub_common.c b/drivers/i3c/hub/p3h2840_i3c_hub_common.c
> index 0000000000000..2fd9723da60d9
> --- /dev/null
> +++ b/drivers/i3c/hub/p3h2840_i3c_hub_common.c
[ ... ]
> +static int p3h2x4x_i3c_hub_probe(struct platform_device *pdev)
> +{
> + struct p3h2x4x *p3h2x4x = dev_get_drvdata(pdev->dev.parent);
> + struct p3h2x4x_i3c_hub_dev *p3h2x4x_i3c_hub;
> + struct device *dev = &pdev->dev;
> + struct device_node *node;
> + int ret, i;
> +
> + p3h2x4x_i3c_hub = devm_kzalloc(dev, sizeof(*p3h2x4x_i3c_hub), GFP_KERNEL);
[Severity: High]
Could this lead to a use-after-free during driver unbind?
The p3h2x4x_i3c_hub structure is allocated via devm_kzalloc() and contains
struct i3c_master_controller instances, which in turn embed struct device.
When the devm action calls i3c_master_unregister() on driver unbind, it
invokes device_unregister(). Because device_unregister() does not block to
wait for all sysfs references to drop, userspace might still hold references.
When devm subsequently frees the containing p3h2x4x_i3c_hub_dev structure,
accessing those remaining references will cause a use-after-free.
> + if (!p3h2x4x_i3c_hub)
> + return -ENOMEM;
[ ... ]
> + /* Register virtual I3C master controllers for I3C target ports */
> + if (p3h2x4x->i3cdev) {
> + p3h2x4x_i3c_hub->i3cdev = p3h2x4x->i3cdev;
> + i3cdev_set_drvdata(p3h2x4x->i3cdev, p3h2x4x_i3c_hub);
[Severity: High]
Does this code safely manage the parent device's private data?
By calling i3cdev_set_drvdata() on p3h2x4x->i3cdev here in
p3h2x4x_i3c_hub_probe(), it replaces the MFD parent's drvdata with the child
driver's context. If any parent callbacks try to retrieve their data, they
will incorrectly cast struct p3h2x4x_i3c_hub_dev to struct p3h2x4x, leading
to type confusion and data corruption.
> + ret = p3h2x4x_tp_i3c_algo(p3h2x4x_i3c_hub);
> + if (ret)
> + return dev_err_probe(dev, ret, "Failed to register i3c bus\n");
> + }
[ ... ]
> diff --git a/drivers/i3c/hub/p3h2840_i3c_hub_i3c.c b/drivers/i3c/hub/p3h2840_i3c_hub_i3c.c
> index 0000000000000..0e5bf7eb3cf7f
> --- /dev/null
> +++ b/drivers/i3c/hub/p3h2840_i3c_hub_i3c.c
[ ... ]
> +int p3h2x4x_tp_i3c_algo(struct p3h2x4x_i3c_hub_dev *p3h2x4x_hub)
> +{
[ ... ]
> + for (tp = 0; tp < P3H2X4X_TP_MAX_COUNT; tp++) {
> + if (!p3h2x4x_hub->tp_bus[tp].of_node ||
> + p3h2x4x_hub->hub_config.tp_config[tp].mode != P3H2X4X_TP_MODE_I3C)
> + continue;
[Severity: High]
Will target ports configured as i2c in the device tree be registered?
The p3h2x4x_tp_i3c_algo() function explicitly skips ports unless they are in
I3C mode. Similarly, p3h2x4x_tp_smbus_algo() skips ports unless they are in
SMBus mode. As a result, ports configured as i2c are ignored entirely and
never registered or enabled in the hardware's network configuration mask.
> +
> + struct i3c_hub_controller *hub_controller =
> + &p3h2x4x_hub->tp_bus[tp].hub_controller;
[ ... ]
> diff --git a/drivers/i3c/hub/p3h2840_i3c_hub_smbus.c b/drivers/i3c/hub/p3h2840_i3c_hub_smbus.c
> index 0000000000000..b991c46f3ed59
> --- /dev/null
> +++ b/drivers/i3c/hub/p3h2840_i3c_hub_smbus.c
[ ... ]
> +static s32 p3h2x4x_tp_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
> +{
[ ... ]
> + for (msg_count = 0; msg_count < num; msg_count++) {
> + if (msgs[msg_count].len > P3H2X4X_SMBUS_PAYLOAD_SIZE) {
> + dev_err(p3h2x4x_i3c_hub->dev,
> + "Message nr. %d not sent - length over %d bytes.\n",
> + msg_count, P3H2X4X_SMBUS_PAYLOAD_SIZE);
> + return -EINVAL;
> + }
[Severity: Medium]
Would it be better to expose this size limitation to the I2C subsystem?
By enforcing a hard boundary here dynamically in p3h2x4x_tp_i2c_xfer()
without populating the i2c_adapter_quirks structure, the I2C subsystem
cannot automatically split up oversized reads and writes for the client.
This will result in unexpected failures for standard transactions that exceed
84 bytes.
> +
> + rw = (msgs[msg_count].flags & I2C_M_RD) ? 1 : 0;
[ ... ]
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260714092053.2461482-1-lakshay.piplani@nxp.com?part=7
^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH v14 8/8] i3c: hub: p3h2x4x: Add SMBus slave mode support
2026-07-14 9:20 ` [PATCH v14 8/8] i3c: hub: p3h2x4x: Add SMBus slave mode support Lakshay Piplani
@ 2026-07-14 11:56 ` sashiko-bot
0 siblings, 0 replies; 19+ messages in thread
From: sashiko-bot @ 2026-07-14 11:56 UTC (permalink / raw)
To: Lakshay Piplani
Cc: Alexandre Belloni, Frank.Li, devicetree, conor+dt, robh,
linux-i3c
Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [High] Unprotected shared state modification after exposing the I2C adapter creates a race condition that can overwrite slave registration state and drop IBI data
- [Medium] Mixing goto-based error handling with scope-based guard() cleanup
--
--- Patch [8]: [PATCH v14 8/8] i3c: hub: p3h2x4x: Add SMBus slave mode support ---
commit 8afab6d0ec8653574d5df430584d53ab5ca6d8cb
Author: Lakshay Piplani <lakshay.piplani@nxp.com>
Subject: i3c: hub: p3h2x4x: Add SMBus slave mode support
This commit adds SMBus slave mode support for the P3H2x4x hub SMBus target
ports. It sets up the receive path via IBI and forwards payloads to the
registered I2C slave client.
> diff --git a/drivers/i3c/hub/p3h2840_i3c_hub_smbus.c b/drivers/i3c/hub/p3h2840_i3c_hub_smbus.c
> index b991c46f3ed59..89e94f551b31f 100644
> --- a/drivers/i3c/hub/p3h2840_i3c_hub_smbus.c
> +++ b/drivers/i3c/hub/p3h2840_i3c_hub_smbus.c
[ ... ]
> +void p3h2x4x_ibi_handler(struct i3c_device *i3cdev,
> + const struct i3c_ibi_payload *payload)
> +{
[ ... ]
> + for (i = 0; i < P3H2X4X_TP_MAX_COUNT; ++i) {
> + if (!((payload_byte_two >> i) & 0x01))
> + continue;
> +
> + if (!p3h2x4x_i3c_hub->tp_bus[i].is_registered) {
> + dev_dbg(&i3cdev->dev, "IBI for unregistered SMBus port %u\n", i);
> + regmap_write(p3h2x4x_i3c_hub->regmap,
> + P3H2X4X_TP0_SMBUS_AGNT_STS + i,
> + BUF_RECEIVED_FLAG_TF_MASK);
> + continue;
> + }
[Severity: High]
Could there be a race condition with synchronous slave binding here?
When the I2C adapter is exposed to the system in p3h2x4x_tp_smbus_algo(),
a slave driver can bind synchronously and invoke p3h2x4x_tp_i2c_reg_slave().
This would enable IBI in hardware and set ibi_en to true.
However, right after i2c_add_adapter() returns, p3h2x4x_tp_smbus_algo()
overwrites ibi_en to false and sets is_registered to true without any locks:
drivers/i3c/hub/p3h2840_i3c_hub_smbus.c:p3h2x4x_tp_smbus_algo() {
...
ret = i2c_add_adapter(smbus_adapter);
if (ret) {
p3h2x4x_unregister_smbus_adapters(hub);
return ret;
}
hub->tp_bus[tp].is_registered = true;
hub->hub_config.tp_config[tp].ibi_en = false;
...
}
If an IBI arrives during this tiny window, wouldn't the handler drop the data
because is_registered is still false? Also, won't the blind overwrite of
ibi_en to false corrupt the newly registered slave's state?
[ ... ]
> +static int p3h2x4x_tp_i2c_reg_slave(struct i2c_client *slave)
> +{
[ ... ]
> + guard(mutex)(&hub->etx_mutex);
> +
> + if (!hub->i3cdev || !hub->ibi_ready)
> + return -EOPNOTSUPP;
> +
> + if (bus->tp_smbus_client)
> + return -EBUSY;
> +
> + mutex_lock(&p3h2x4x->protected_reg_lock);
> +
> + /* Unlock access to protected registers */
> + ret = regmap_write(hub->regmap, P3H2X4X_DEV_REG_PROTECTION_CODE,
> + P3H2X4X_REGISTERS_UNLOCK_CODE);
> + if (ret)
> + goto out_unlock_mutex;
[ ... ]
> +out_unlock_mutex:
> + mutex_unlock(&p3h2x4x->protected_reg_lock);
> +
> + if (!ret) {
> + bus->tp_smbus_client = slave;
> + hub->hub_config.tp_config[bus->tp_port].ibi_en = true;
> + }
> +
> + return ret;
> +}
[Severity: Medium]
The cleanup subsystem guidelines suggest avoiding mixing goto-based error
handling with scope-based guard() cleanup in the same function. Could this
mix create confusing ownership semantics here?
> +
> +static int p3h2x4x_tp_i2c_unreg_slave(struct i2c_client *slave)
> +{
[ ... ]
> + guard(mutex)(&hub->etx_mutex);
> +
> + if (bus->tp_smbus_client != slave)
> + return -EINVAL;
> +
> + bus->tp_smbus_client = NULL;
> + hub->hub_config.tp_config[bus->tp_port].ibi_en = false;
> +
> + mutex_lock(&p3h2x4x->protected_reg_lock);
> +
> + /* Unlock access to protected registers */
> + ret = regmap_write(hub->regmap, P3H2X4X_DEV_REG_PROTECTION_CODE,
> + P3H2X4X_REGISTERS_UNLOCK_CODE);
> + if (ret)
> + goto out_unlock_mutex;
[ ... ]
> +out_unlock_mutex:
> + mutex_unlock(&p3h2x4x->protected_reg_lock);
> + return ret;
> +}
[Severity: Medium]
Similar to the registration function above, does the use of both guard(mutex)
and goto out_unlock_mutex in this function violate the cleanup guidelines?
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260714092053.2461482-1-lakshay.piplani@nxp.com?part=8
^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH v14 1/8] i3c: master: Add APIs for I3C hub support
2026-07-14 10:03 ` sashiko-bot
@ 2026-07-14 19:04 ` Frank Li
0 siblings, 0 replies; 19+ messages in thread
From: Frank Li @ 2026-07-14 19:04 UTC (permalink / raw)
To: sashiko-reviews
Cc: Lakshay Piplani, linux-i3c, Frank.Li, Alexandre Belloni, robh,
conor+dt, devicetree
On Tue, Jul 14, 2026 at 10:03:22AM +0000, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:
>
> New issues:
> - [High] Asymmetrical cleanup in `i3c_master_direct_detach_i3c_dev_locked` leaks resources for unaddressed devices.
>
> Pre-existing issues:
> - [High] IDR entry deletion on `i3c_bus_init` failure causes ID corruption and sysfs collisions.
> - [High] Missing NULL check for `dev->boardinfo` in `i3c_master_get_i3c_addrs` leads to kernel panic.
> --
>
> --- Patch [1]: [PATCH v14 1/8] i3c: master: Add APIs for I3C hub support ---
> commit 1db519c7da22819d977429d77c0d05ba94daedf9
> Author: Aman Kumar Pandey <aman.kumarpandey@nxp.com>
>
> i3c: master: Add APIs for I3C hub support
>
> Add helpers for attaching and detaching I3C devices and CCC helpers
> to check CCC support and send CCC commands, address slot helpers to
> query and update I3C bus address slot state, registering virtual
> masters with an explicit firmware node, and exposing the bus maintenance
> lock helpers.
>
> > diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
> > index f1be38a640ca1..3b1c342be2bc5 100644
> > --- a/drivers/i3c/master.c
> > +++ b/drivers/i3c/master.c
>
> [ ... ]
>
> > @@ -1775,6 +1792,83 @@ static int i3c_master_attach_i3c_dev(struct i3c_master_controller *master,
> > return 0;
> > }
> >
> > +/**
> > + * i3c_master_direct_attach_i3c_dev_locked() - Attach an I3C device to a master
> > + * @master: I3C master controller to attach the device to
> > + * @dev: I3C device descriptor representing the device
> > + *
> > + * Attach an I3C device to its master controller after reserving the device
> > + * addresses on the bus. The device must belong to @master.
> > + *
> > + * The master device itself is not passed to the controller driver's
> > + * ->attach_i3c_dev() callback.
> > + *
> > + * Context: Caller must hold @master->bus.lock in write mode.
> > + *
> > + * Return: 0 on success, or a negative error code if address reservation fails
> > + * or if the master controller driver's ->attach_i3c_dev() callback fails.
> > + */
> > +int i3c_master_direct_attach_i3c_dev_locked(struct i3c_master_controller *master,
> > + struct i3c_dev_desc *dev)
> > +{
> > + int ret;
> > +
> > + if (WARN_ON(i3c_dev_get_master(dev) != master))
> > + return -EINVAL;
> > +
> > + ret = i3c_master_get_i3c_addrs(dev);
>
> [Severity: High]
> This is a pre-existing issue, but does exposing this new API introduce a
> potential NULL pointer dereference?
>
> If a caller manually constructs a virtual I3C device without an OF node
> where dev->boardinfo is NULL, but it has a static_addr, calling this
> function will invoke i3c_master_get_i3c_addrs(). Inside that function,
> if the static address slot is not free:
>
> i3c_master_get_i3c_addrs() {
> ...
> status = i3c_bus_get_addr_slot_status(&master->bus,
> dev->info.static_addr);
> if (status != I3C_ADDR_SLOT_FREE &&
> dev->info.static_addr != dev->boardinfo->init_dyn_addr)
> return -EBUSY;
> ...
> }
>
> Could this dereference dev->boardinfo without checking if it is NULL, leading
> to a kernel panic?
>
> > + if (ret)
> > + return ret;
> > +
> > + /* Do not attach the master device itself. */
> > + if (master->this != dev && master->ops->attach_i3c_dev) {
> > + ret = master->ops->attach_i3c_dev(dev);
>
> [Severity: High]
> Could this cause an asymmetrical resource leak for unaddressed devices?
>
> The original i3c_master_attach_i3c_dev() function includes a check at the
> beginning to return early if the device has no static or dynamic address:
>
> if (!dev->info.static_addr && !dev->info.dyn_addr)
> return 0;
>
> This new attach function lacks that check, meaning it invokes the master
> controller's attach_i3c_dev() hook even for unaddressed devices.
Please check it ?
Frank
>
> However, the new i3c_master_direct_detach_i3c_dev_locked() function
> explicitly skips detach for unaddressed devices:
>
> if (!dev->info.static_addr && !dev->info.dyn_addr)
> return;
>
> Will any resources allocated by the controller driver during the attach
> hook be permanently leaked when the device is detached?
>
> > + if (ret) {
> > + i3c_master_put_i3c_addrs(dev);
> > + return ret;
> > + }
> > + }
> > + return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(i3c_master_direct_attach_i3c_dev_locked);
>
> [ ... ]
>
> > @@ -3195,34 +3342,31 @@ static int i3c_master_check_ops(const struct i3c_master_controller_ops *ops)
>
> [ ... ]
>
> > +int i3c_master_register_fwnode(struct i3c_master_controller *master,
> > + struct device *parent,
> > + struct fwnode_handle *fwnode,
> > + const struct i3c_master_controller_ops *ops,
> > + bool secondary)
> > +{
> > + unsigned long i2c_scl_rate = I3C_BUS_I2C_FM_PLUS_SCL_MAX_RATE;
> > + struct i3c_bus *i3cbus = i3c_master_get_bus(master);
> > + enum i3c_bus_mode mode = I3C_BUS_MODE_PURE;
> > + struct device_node *np = NULL;
> > + struct i2c_dev_boardinfo *i2cbi;
> > + int ret;
>
> [ ... ]
>
> > + ret = i3c_bus_init(i3cbus, master->dev.of_node);
> > + if (ret)
> > + goto err_put_dev;
>
> [Severity: High]
> This isn't a bug introduced by this patch, but does an error here cause
> global IDR corruption?
>
> If i3c_bus_init() fails during idr_alloc(), it returns an error with
> i3cbus->id still set to 0. Taking the err_put_dev path calls put_device() on
> master->dev, which invokes i3c_masterdev_release().
>
> i3c_masterdev_release() unconditionally calls i3c_bus_cleanup(), which runs:
>
> i3c_bus_cleanup() {
> ...
> idr_remove(&i3c_bus_idr, i3cbus->id);
> ...
> }
>
> If i3cbus->id is uninitialized (0), does this mistakenly remove ID 0 from
> the global i3c_bus_idr? If a valid bus was already registered with ID 0, it
> seems it would lose its IDR entry, causing a subsequent bus registration to
> be assigned ID 0 again and triggering sysfs collisions (i3c-0).
>
> > +
> > + dev_set_name(&master->dev, "i3c-%d", i3cbus->id);
> > +
> > + ret = of_populate_i3c_bus(master);
> > + if (ret)
> > + goto err_put_dev;
>
> [ ... ]
>
> --
> Sashiko AI review · https://sashiko.dev/#/patchset/20260714092053.2461482-1-lakshay.piplani@nxp.com?part=1
^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH v14 2/8] i3c: master: Fix IBI request and free cleanup paths
2026-07-14 10:20 ` sashiko-bot
@ 2026-07-14 19:10 ` Frank Li
0 siblings, 0 replies; 19+ messages in thread
From: Frank Li @ 2026-07-14 19:10 UTC (permalink / raw)
To: sashiko-reviews
Cc: Lakshay Piplani, conor+dt, linux-i3c, Alexandre Belloni, robh,
Frank.Li, devicetree
On Tue, Jul 14, 2026 at 10:20:25AM +0000, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
>
> New issues:
> - [High] Bypassing the core cleanup paths when `dev->ibi` is cleared by a controller callback causes a permanent leak of the IBI workqueue (including its rescuer kthread) and potentially the `ibi` object itself.
>
> Pre-existing issues:
> - [High] Potential use-after-free of IBI pool during workqueue destruction if IBI disable fails.
> --
>
> --- Patch [2]: [PATCH v14 2/8] i3c: master: Fix IBI request and free cleanup paths ---
> commit e0d1c57d2924f66898a40232f7e52ca0e1be0aea
> Author: Lakshay Piplani <lakshay.piplani@nxp.com>
>
> i3c: master: Fix IBI request and free cleanup paths
>
> This commit attempts to fix a workqueue leak in the IBI request failure path
> by destroying the workqueue before freeing the IBI object. It also adds checks
> to avoid touching dev->ibi after controller callbacks if they have already
> cleared it, aiming to prevent NULL pointer dereferences.
>
> > diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
> > index 3b1c342be2bc5..ba37f71badac8 100644
> > --- a/drivers/i3c/master.c
> > +++ b/drivers/i3c/master.c
> > @@ -3702,8 +3702,18 @@ int i3c_dev_request_ibi_locked(struct i3c_dev_desc *dev,
> >
> > dev->ibi = ibi;
> > ret = master->ops->request_ibi(dev, req);
> > - if (ret) {
> > - kfree(ibi);
> > +
> > + /*
> > + * The controller callback may have already released and cleared dev->ibi
> > + * when the request is forwarded by a virtual controller. Only clean up the
> > + * IBI object if the callback left dev->ibi valid.
> > + */
> > + if (ret && dev->ibi) {
> > + /* Avoid leaking the workqueue allocated for this IBI request. */
> > + if (dev->ibi->wq)
> > + destroy_workqueue(dev->ibi->wq);
> > +
> > + kfree(dev->ibi);
> > dev->ibi = NULL;
> > }
>
> [Severity: High]
> Does this logic introduce a permanent leak of the IBI workqueue and the local
> ibi object?
>
> Since the core framework dynamically allocated ibi and ibi->wq earlier in
> i3c_dev_request_ibi_locked(), if master->ops->request_ibi() fails and the
> callback cleared dev->ibi, the check if (ret && dev->ibi) will be false.
>
> Because the callback does not own these resources and cannot safely destroy
> the framework's workqueue, the workqueue (including its rescuer kthread) and
> the ibi object will be skipped during cleanup and leak permanently.
look like make sense
if (ret) {
if (ibi=>wq)
destroy_workqueue(...);
kfree(ibi)
dev->ibi = NULL;
}
>
> [ ... ]
>
> > @@ -3743,6 +3753,13 @@ void i3c_dev_free_ibi_locked(struct i3c_dev_desc *dev)
> >
> > master->ops->free_ibi(dev);
>
> [Severity: High]
> This isn't a bug introduced by this patch, but can this lead to a
> use-after-free of the IBI pool memory if disabling the IBI fails?
>
> Earlier in i3c_dev_free_ibi_locked(), if the IBI is still enabled, it tries
> to disable it via i3c_dev_disable_ibi_locked(). If that disable fails
> (e.g., due to a hardware timeout), it returns an error without waiting for
> pending IBIs to finish, and we proceed directly to master->ops->free_ibi(dev).
>
> This callback immediately frees the generic IBI pool. Subsequently,
> destroy_workqueue() is called below, which synchronously drains
> any executing IBI handler works. Since these pending work items reside inside
> the newly-freed pool, won't the rescuer thread dereference freed memory as
> the workqueue drains?
>
> > + /*
> > + * The controller callback may have already released dev->ibi, for example
> > + * when the request was forwarded by a virtual controller.
> > + */
> > + if (!dev->ibi)
> > + return;
>
> [Severity: High]
> Similar to the request path above, does this early return bypass the
> destruction of the workqueue and cause a resource leak?
>
> If the controller callback cleared dev->ibi on the free path, we return
> early and skip the destroy_workqueue(dev->ibi->wq) step, leaking the
> workqueue and its rescuer thread.
make sense
Frank
>
> > +
> > if (dev->ibi->wq) {
> > destroy_workqueue(dev->ibi->wq);
> > dev->ibi->wq = NULL;
>
> --
> Sashiko AI review · https://sashiko.dev/#/patchset/20260714092053.2461482-1-lakshay.piplani@nxp.com?part=2
^ permalink raw reply [flat|nested] 19+ messages in thread
end of thread, other threads:[~2026-07-14 19:10 UTC | newest]
Thread overview: 19+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-07-14 9:20 [PATCH v14 0/8] Add support for NXP P3H2x4x I3C hub driver Lakshay Piplani
2026-07-14 9:20 ` [PATCH v14 1/8] i3c: master: Add APIs for I3C hub support Lakshay Piplani
2026-07-14 10:03 ` sashiko-bot
2026-07-14 19:04 ` Frank Li
2026-07-14 9:20 ` [PATCH v14 2/8] i3c: master: Fix IBI request and free cleanup paths Lakshay Piplani
2026-07-14 10:20 ` sashiko-bot
2026-07-14 19:10 ` Frank Li
2026-07-14 9:20 ` [PATCH v14 3/8] dt-bindings: i3c: Add NXP P3H2x4x i3c-hub support Lakshay Piplani
2026-07-14 10:30 ` sashiko-bot
2026-07-14 9:20 ` [PATCH v14 4/8] mfd: p3h2x4x: Add driver for NXP P3H2x4x i3c hub and on-die regulator Lakshay Piplani
2026-07-14 10:49 ` sashiko-bot
2026-07-14 9:20 ` [PATCH v14 5/8] regulator: p3h2x4x: Add driver for on-die regulators in NXP P3H2x4x i3c hub Lakshay Piplani
2026-07-14 10:57 ` sashiko-bot
2026-07-14 9:20 ` [PATCH v14 6/8] i3c: hub: Add support for the I3C interface in the I3C hub Lakshay Piplani
2026-07-14 11:14 ` sashiko-bot
2026-07-14 9:20 ` [PATCH v14 7/8] i3c: hub: p3h2x4x: Add support for NXP P3H2x4x I3C hub functionality Lakshay Piplani
2026-07-14 11:31 ` sashiko-bot
2026-07-14 9:20 ` [PATCH v14 8/8] i3c: hub: p3h2x4x: Add SMBus slave mode support Lakshay Piplani
2026-07-14 11:56 ` sashiko-bot
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