Merge tag 'scmi-updates-6.16' of https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into soc/drivers

Arm SCMI updates for v6.16

1. Quirk framework to handle buggy firmware

With SCMI gaining broader adoption across arm64 platforms, it's
increasingly important to address how we consistently manage out-of-spec
SCMI firmware already deployed in the field. This change introduces a
lightweight quirk framework built around static_keys, enabling developers to:
- Define quirks and their match criteria, which can include:
o A list of compatibles ({ comp, comp2, NULL })
o Vendor ID / Sub-Vendor ID
o Firmware implementation version ranges ([Min_Vers, Max_Vers])

Matching proceeds from the most specific (longest match) to the least
specific. NULL entries are treated as wildcards (i.e., match any value).
This flexibility allows matching very specific combinations or just a
general compatible string.

The quirk code blocks/snippets implementing the workaround are placed near
their intended usage and guarded by a static_key that's tied to the quirk.
Once the SCMI core stack is initialized and retrieves platform info via the
base protocol, any matching quirks will have their associated static_keys
enabled.

2. Quirk for Qualcomm X1E platforms

On some Qualcomm X1E platforms, such as the Lenovo ThinkPad T14s, the
SCMI firmware fails to set the FastChannel support bit for PERF_LEVEL_GET,
yet it crashes when the driver attempts to fall back to standard messaging
which is clearly out-of-spec behavior.

To work around this, the new SCMI quirk framework is used to
unconditionally enable FC initialization for this firmware version.

In the future, once the fixed firmware version is identified, an upper
version bound can be added to the quirk match criteria. Alternatively,
matching can be further restricted using a SoC-specific compatible string
if always enabling FC proves problematic elsewhere.

3. Support for NXP i.MX LMM/CPU vendor protocol extensions

The i.MX95 System Manager (SM) implements Logical Machine Management (LMM)
and a CPU protocol to manage Logical Machines (LM) and CPUs (e.g., M7).

These changes integrate the vendor-specific protocol extensions
implementing the LMM and CPU protocols for the i.MX95, facilitating
standardized communication between the operating system and the platform's
firmware, which will be used by remoteproc drivers. The changes also
include the necessary device tree bindings.

4. Miscellaneous cleanups/changes

These mainly include polling support in SCMI raw mode. The cleanups
centralize error logging for SCMI device creation into a single helper
function, consolidate the device matching logic into a single function, and
ensure that devices must have a name for registration—removing support for
unnamed devices when matching drivers and devices for probing. Transport
devices are now excluded from bus matching, and the correct assignment of
the parent device for the arm-scmi platform device is ensured in the
transport drivers.

* tag 'scmi-updates-6.16' of https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
firmware: arm_scmi: quirk: Force perf level get fastchannel
firmware: arm_scmi: quirk: Fix CLOCK_DESCRIBE_RATES triplet
firmware: arm_scmi: Add common framework to handle firmware quirks
firmware: arm_scmi: Ensure that the message-id supports fastchannel
MAINTAINERS: add entry for i.MX SCMI extensions
firmware: imx: Add i.MX95 SCMI CPU driver
firmware: imx: Add i.MX95 SCMI LMM driver
firmware: arm_scmi: imx: Add i.MX95 CPU Protocol
firmware: arm_scmi: imx: Add i.MX95 LMM protocol
dt-bindings: firmware: Add i.MX95 SCMI LMM and CPU protocol
firmware: arm_scmi: imx: Add LMM and CPU documentation
firmware: arm_scmi: Add polling support to raw mode
firmware: arm_scmi: Exclude transport devices from bus matching
firmware: arm_scmi: Assign correct parent to arm-scmi platform device
firmware: arm_scmi: Refactor error logging from SCMI device creation to single helper
firmware: arm_scmi: Refactor device matching logic to eliminate duplication
firmware: arm_scmi: Ensure scmi_devices are always matched by name as well

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnd Bergmann <[e-mail]>

Documentation/ABI/testing/debugfs-scmi-raw

···
 		(receiving an EOF at each message boundary).
 Users:		Debugging, any userspace test suite
 
+What:		/sys/kernel/debug/scmi/<n>/raw/message_poll
+Date:		June 2025
+KernelVersion:	6.16
+Contact:	[e-mail]
+Description:	SCMI Raw message injection/snooping facility using polling mode;
+		write a complete SCMI command message (header included) in
+		little-endian binary format to have it sent to the configured
+		backend SCMI server for instance <n>, using polling mode on
+		the reception path. (if transport is polling capable)
+		Any subsequently received response can be read from this same
+		entry if it arrived within the configured timeout.
+		Each write to the entry causes one command request to be built
+		and sent while the replies are read back one message at time
+		(receiving an EOF at each message boundary).
+Users:		Debugging, any userspace test suite
+
+What:		/sys/kernel/debug/scmi/<n>/raw/message_poll_async
+Date:		June 2025
+KernelVersion:	6.16
+Contact:	[e-mail]
+Description:	SCMI Raw asynchronous message injection/snooping facility using
+		polling-mode; write a complete SCMI asynchronous command message
+		(header included) in little-endian binary format to have it sent
+		to the configured backend SCMI server for instance <n>, using
+		polling-mode on the reception path of the immediate part of the
+		asynchronous command. (if transport is polling capable)
+		Any subsequently received response can be read from this same
+		entry if it arrived within the configured timeout.
+		Any additional delayed response received afterwards can be read
+		from this same entry too if it arrived within the configured
+		timeout.
+		Each write to the entry causes one command request to be built
+		and sent while the replies are read back one message at time
+		(receiving an EOF at each message boundary).
+Users:		Debugging, any userspace test suite
+
 What:		/sys/kernel/debug/scmi/<n>/raw/errors
 Date:		March 2023
 KernelVersion:	6.3
···
 		in little-endian binary format to have it sent to the configured
 		backend SCMI server for instance <n> through the <m> transport
 		channel.
+		Any subsequently received response can be read from this same
+		entry if it arrived on channel <m> within the configured
+		timeout.
+		Any additional delayed response received afterwards can be read
+		from this same entry too if it arrived within the configured
+		timeout.
+		Each write to the entry causes one command request to be built
+		and sent while the replies are read back one message at time
+		(receiving an EOF at each message boundary).
+		Channel identifier <m> matches the SCMI protocol number which
+		has been associated with this transport channel in the DT
+		description, with base protocol number 0x10 being the default
+		channel for this instance.
+		Note that these per-channel entries rooted at <..>/channels
+		exist only if the transport is configured to have more than
+		one default channel.
+Users:		Debugging, any userspace test suite
+
+
+What:		/sys/kernel/debug/scmi/<n>/raw/channels/<m>/message_poll
+Date:		June 2025
+KernelVersion:	6.16
+Contact:	[e-mail]
+Description:	SCMI Raw message injection/snooping facility using polling mode;
+		write a complete SCMI command message (header included) in
+		little-endian binary format to have it sent to the configured
+		backend SCMI server for instance <n> through the <m> transport
+		channel, using polling mode on the reception path.
+		(if transport is polling capable)
+		Any subsequently received response can be read from this same
+		entry if it arrived on channel <m> within the configured
+		timeout.
+		Each write to the entry causes one command request to be built
+		and sent while the replies are read back one message at time
+		(receiving an EOF at each message boundary).
+		Channel identifier <m> matches the SCMI protocol number which
+		has been associated with this transport channel in the DT
+		description, with base protocol number 0x10 being the default
+		channel for this instance.
+		Note that these per-channel entries rooted at <..>/channels
+		exist only if the transport is configured to have more than
+		one default channel.
+Users:		Debugging, any userspace test suite
+
+What:		/sys/kernel/debug/scmi/<n>/raw/channels/<m>/message_poll_async
+Date:		June 2025
+KernelVersion:	6.16
+Contact:	[e-mail]
+Description:	SCMI Raw asynchronous message injection/snooping facility using
+		polling-mode; write a complete SCMI asynchronous command message
+		(header included) in little-endian binary format to have it sent
+		to the configured backend SCMI server for instance <n> through
+		the <m> transport channel, using polling mode on the reception
+		path of the immediate part of the asynchronous command.
+		(if transport is polling capable)
 		Any subsequently received response can be read from this same
 		entry if it arrived on channel <m> within the configured
 		timeout.

Documentation/devicetree/bindings/firmware/nxp,imx95-scmi.yaml

···
   - Peng Fan <[e-mail]>
 
 properties:
+  protocol@80:
+    description:
+      SCMI LMM protocol which is for boot, shutdown, and reset of other logical
+      machines (LM). It is usually used to allow one LM to manage another used
+      as an offload or accelerator engine.
+    $ref: '/schemas/firmware/arm,scmi.yaml#/$defs/protocol-node'
+    unevaluatedProperties: false
+
+    properties:
+      reg:
+        const: 0x80
+
   protocol@81:
     $ref: '/schemas/firmware/arm,scmi.yaml#/$defs/protocol-node'
     unevaluatedProperties: false
···
     properties:
       reg:
         const: 0x81
+
+  protocol@82:
+    description:
+      SCMI CPU Protocol which allows an agent to start or stop a CPU. It is
+      used to manage auxiliary CPUs in a LM.
+    $ref: '/schemas/firmware/arm,scmi.yaml#/$defs/protocol-node'
+    unevaluatedProperties: false
+
+    properties:
+      reg:
+        const: 0x82
 
   protocol@84:
     $ref: '/schemas/firmware/arm,scmi.yaml#/$defs/protocol-node'

MAINTAINERS

···
 F:	include/trace/events/scmi.h
 F:	include/uapi/linux/virtio_scmi.h
 
+SYSTEM CONTROL MANAGEMENT INTERFACE (SCMI) i.MX Extension Message Protocol drivers
+M:	Peng Fan <[e-mail]>
+L:	[e-mail]
+L:	[e-mail]
+L:	[e-mail] (moderated for non-subscribers)
+S:	Maintained
+F:	Documentation/devicetree/bindings/firmware/nxp,*scmi.yaml
+F:	drivers/firmware/arm_scmi/vendors/imx/
+
 SYSTEM RESET/SHUTDOWN DRIVERS
 M:	Sebastian Reichel <[e-mail]>
 L:	[e-mail]

drivers/firmware/arm_scmi/Kconfig

···
 	  such useful debug counters. This can be helpful for debugging and
 	  SCMI monitoring.
 
+config ARM_SCMI_QUIRKS
+	bool "Enable SCMI Quirks framework"
+	depends on JUMP_LABEL || COMPILE_TEST
+	default y
+	help
+	  Enables support for SCMI Quirks framework to workaround SCMI platform
+	  firmware bugs on system already deployed in the wild.
+
+	  The framework allows the definition of platform-specific code quirks
+	  that will be associated and enabled only on the desired platforms
+	  depending on the SCMI firmware advertised versions and/or machine
+	  compatibles.
+
 source "drivers/firmware/arm_scmi/transports/Kconfig"
 source "drivers/firmware/arm_scmi/vendors/imx/Kconfig"
 

drivers/firmware/arm_scmi/Makefile

···
 scmi-core-objs := $(scmi-bus-y)
 
 scmi-driver-y = driver.o notify.o
+scmi-driver-$(CONFIG_ARM_SCMI_QUIRKS) += quirks.o
 scmi-driver-$(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT) += raw_mode.o
 scmi-transport-$(CONFIG_ARM_SCMI_HAVE_SHMEM) = shmem.o
 scmi-transport-$(CONFIG_ARM_SCMI_HAVE_MSG) += msg.o

drivers/firmware/arm_scmi/bus.c

···
 		scmi_protocol_device_unrequest(entry);
 }
 
-static const struct scmi_device_id *
-scmi_dev_match_id(struct scmi_device *scmi_dev, const struct scmi_driver *scmi_drv)
+static int scmi_dev_match_by_id_table(struct scmi_device *scmi_dev,
+				      const struct scmi_device_id *id_table)
 {
-	const struct scmi_device_id *id = scmi_drv->id_table;
+	if (!id_table || !id_table->name)
+		return 0;
 
-	if (!id)
-		return NULL;
+	/* Always skip transport devices from matching */
+	for (; id_table->protocol_id && id_table->name; id_table++)
+		if (id_table->protocol_id == scmi_dev->protocol_id &&
+		    strncmp(scmi_dev->name, "__scmi_transport_device", 23) &&
+		    !strcmp(id_table->name, scmi_dev->name))
+			return 1;
+	return 0;
+}
 
-	for (; id->protocol_id; id++)
-		if (id->protocol_id == scmi_dev->protocol_id) {
-			if (!id->name)
-				return id;
-			else if (!strcmp(id->name, scmi_dev->name))
-				return id;
-		}
-
-	return NULL;
+static int scmi_dev_match_id(struct scmi_device *scmi_dev,
+			     const struct scmi_driver *scmi_drv)
+{
+	return scmi_dev_match_by_id_table(scmi_dev, scmi_drv->id_table);
 }
 
 static int scmi_dev_match(struct device *dev, const struct device_driver *drv)
 {
 	const struct scmi_driver *scmi_drv = to_scmi_driver(drv);
 	struct scmi_device *scmi_dev = to_scmi_dev(dev);
-	const struct scmi_device_id *id;
 
-	id = scmi_dev_match_id(scmi_dev, scmi_drv);
-	if (id)
-		return 1;
-
-	return 0;
+	return scmi_dev_match_id(scmi_dev, scmi_drv);
 }
 
 static int scmi_match_by_id_table(struct device *dev, const void *data)
 {
-	struct scmi_device *sdev = to_scmi_dev(dev);
+	struct scmi_device *scmi_dev = to_scmi_dev(dev);
 	const struct scmi_device_id *id_table = data;
 
-	return sdev->protocol_id == id_table->protocol_id &&
-		(id_table->name && !strcmp(sdev->name, id_table->name));
+	return scmi_dev_match_by_id_table(scmi_dev, id_table);
 }
 
 static struct scmi_device *scmi_child_dev_find(struct device *parent,
 					       int prot_id, const char *name)
 {
-	struct scmi_device_id id_table;
+	struct scmi_device_id id_table[2] = { 0 };
 	struct device *dev;
 
-	id_table.protocol_id = prot_id;
-	id_table.name = name;
+	id_table[0].protocol_id = prot_id;
+	id_table[0].name = name;
 
 	dev = device_find_child(parent, &id_table, scmi_match_by_id_table);
 	if (!dev)
···
 	return NULL;
 }
 
+static struct scmi_device *
+_scmi_device_create(struct device_node *np, struct device *parent,
+		    int protocol, const char *name)
+{
+	struct scmi_device *sdev;
+
+	sdev = __scmi_device_create(np, parent, protocol, name);
+	if (!sdev)
+		pr_err("(%s) Failed to create device for protocol 0x%x (%s)\n",
+		       of_node_full_name(parent->of_node), protocol, name);
+
+	return sdev;
+}
+
 /**
  * scmi_device_create  - A method to create one or more SCMI devices
  *
···
 	struct scmi_device *scmi_dev = NULL;
 
 	if (name)
-		return __scmi_device_create(np, parent, protocol, name);
+		return _scmi_device_create(np, parent, protocol, name);
 
 	mutex_lock(&scmi_requested_devices_mtx);
 	phead = idr_find(&scmi_requested_devices, protocol);
···
 	list_for_each_entry(rdev, phead, node) {
 		struct scmi_device *sdev;
 
-		sdev = __scmi_device_create(np, parent,
-					    rdev->id_table->protocol_id,
-					    rdev->id_table->name);
-		/* Report errors and carry on... */
+		sdev = _scmi_device_create(np, parent,
+					   rdev->id_table->protocol_id,
+					   rdev->id_table->name);
 		if (sdev)
 			scmi_dev = sdev;
-		else
-			pr_err("(%s) Failed to create device for protocol 0x%x (%s)\n",
-			       of_node_full_name(parent->of_node),
-			       rdev->id_table->protocol_id,
-			       rdev->id_table->name);
 	}
+
 	mutex_unlock(&scmi_requested_devices_mtx);
 
 	return scmi_dev;

drivers/firmware/arm_scmi/clock.c

···
 
 #include "protocols.h"
 #include "notify.h"
+#include "quirks.h"
 
 /* Updated only after ALL the mandatory features for that version are merged */
 #define SCMI_PROTOCOL_SUPPORTED_VERSION		0x30000
···
 	msg->rate_index = cpu_to_le32(desc_index);
 }
 
+#define QUIRK_OUT_OF_SPEC_TRIPLET					       \
+	({								       \
+		/*							       \
+		 * A known quirk: a triplet is returned but num_returned != 3  \
+		 * Check for a safe payload size and fix.		       \
+		 */							       \
+		if (st->num_returned != 3 && st->num_remaining == 0 &&	       \
+		    st->rx_len == sizeof(*r) + sizeof(__le32) * 2 * 3) {       \
+			st->num_returned = 3;				       \
+			st->num_remaining = 0;				       \
+		} else {						       \
+			dev_err(p->dev,					       \
+				"Cannot fix out-of-spec reply !\n");	       \
+			return -EPROTO;					       \
+		}							       \
+	})
+
 static int
 iter_clk_describe_update_state(struct scmi_iterator_state *st,
 			       const void *response, void *priv)
···
 			 p->clk->name, st->num_returned, st->num_remaining,
 			 st->rx_len);
 
-		/*
-		 * A known quirk: a triplet is returned but num_returned != 3
-		 * Check for a safe payload size and fix.
-		 */
-		if (st->num_returned != 3 && st->num_remaining == 0 &&
-		    st->rx_len == sizeof(*r) + sizeof(__le32) * 2 * 3) {
-			st->num_returned = 3;
-			st->num_remaining = 0;
-		} else {
-			dev_err(p->dev,
-				"Cannot fix out-of-spec reply !\n");
-			return -EPROTO;
-		}
+		SCMI_QUIRK(clock_rates_triplet_out_of_spec,
+			   QUIRK_OUT_OF_SPEC_TRIPLET);
 	}
 
 	return 0;

drivers/firmware/arm_scmi/common.h

···
 	if (ret)							       \
 		goto err;						       \
 									       \
+	spdev->dev.parent = dev;					       \
 	ret = platform_device_add(spdev);				       \
 	if (ret)							       \
 		goto err;						       \

drivers/firmware/arm_scmi/driver.c

···
  * various power domain DVFS including the core/cluster, certain system
  * clocks configuration, thermal sensors and many others.
  *
- * Copyright (C) 2018-2024 ARM Ltd.
+ * Copyright (C) 2018-2025 ARM Ltd.
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
···
 
 #include "common.h"
 #include "notify.h"
+#include "quirks.h"
 
 #include "raw_mode.h"
 
···
 					 struct scmi_info *info,
 					 int prot_id, const char *name)
 {
-	struct scmi_device *sdev;
-
 	mutex_lock(&info->devreq_mtx);
-	sdev = scmi_device_create(np, info->dev, prot_id, name);
-	if (name && !sdev)
-		dev_err(info->dev,
-			"failed to create device for protocol 0x%X (%s)\n",
-			prot_id, name);
+	scmi_device_create(np, info->dev, prot_id, name);
 	mutex_unlock(&info->devreq_mtx);
 }
 
···
 		 * RX path since it will be already queued at the end of the TX
 		 * poll loop.
 		 */
-		if (!xfer->hdr.poll_completion)
+		if (!xfer->hdr.poll_completion ||
+		    xfer->hdr.type == MSG_TYPE_DELAYED_RESP)
 			scmi_raw_message_report(info->raw, xfer,
 						SCMI_RAW_REPLY_QUEUE,
 						cinfo->id);
···
 }
 
 /**
+ * scmi_protocol_msg_check  - Check protocol message attributes
+ *
+ * @ph: A reference to the protocol handle.
+ * @message_id: The ID of the message to check.
+ * @attributes: A parameter to optionally return the retrieved message
+ *		attributes, in case of Success.
+ *
+ * An helper to check protocol message attributes for a specific protocol
+ * and message pair.
+ *
+ * Return: 0 on SUCCESS
+ */
+static int scmi_protocol_msg_check(const struct scmi_protocol_handle *ph,
+				   u32 message_id, u32 *attributes)
+{
+	int ret;
+	struct scmi_xfer *t;
+
+	ret = xfer_get_init(ph, PROTOCOL_MESSAGE_ATTRIBUTES,
+			    sizeof(__le32), 0, &t);
+	if (ret)
+		return ret;
+
+	put_unaligned_le32(message_id, t->tx.buf);
+	ret = do_xfer(ph, t);
+	if (!ret && attributes)
+		*attributes = get_unaligned_le32(t->rx.buf);
+	xfer_put(ph, t);
+
+	return ret;
+}
+
+/**
  * struct scmi_iterator  - Iterator descriptor
  * @msg: A reference to the message TX buffer; filled by @prepare_message with
  *	 a proper custom command payload for each multi-part command request.
···
 	__le32 db_preserve_hmask;
 };
 
+#define QUIRK_PERF_FC_FORCE						\
+	({								\
+		if (pi->proto->id == SCMI_PROTOCOL_PERF &&		\
+		    message_id == 0x8 /* PERF_LEVEL_GET */)		\
+			attributes |= BIT(0);				\
+	})
+
 static void
 scmi_common_fastchannel_init(const struct scmi_protocol_handle *ph,
 			     u8 describe_id, u32 message_id, u32 valid_size,
···
 	int ret;
 	u32 flags;
 	u64 phys_addr;
+	u32 attributes;
 	u8 size;
 	void __iomem *addr;
 	struct scmi_xfer *t;
···
 	struct scmi_msg_get_fc_info *info;
 	struct scmi_msg_resp_desc_fc *resp;
 	const struct scmi_protocol_instance *pi = ph_to_pi(ph);
+
+	/* Check if the MSG_ID supports fastchannel */
+	ret = scmi_protocol_msg_check(ph, message_id, &attributes);
+	SCMI_QUIRK(perf_level_get_fc_force, QUIRK_PERF_FC_FORCE);
+	if (ret || !MSG_SUPPORTS_FASTCHANNEL(attributes)) {
+		dev_dbg(ph->dev,
+			"Skip FC init for 0x%02X/%d  domain:%d - ret:%d\n",
+			pi->proto->id, message_id, domain, ret);
+		return;
+	}
 
 	if (!p_addr) {
 		ret = -EINVAL;
···
 		SCMI_PROTO_FC_RING_DB(32);
 	else /* db->width == 8 */
 		SCMI_PROTO_FC_RING_DB(64);
-}
-
-/**
- * scmi_protocol_msg_check  - Check protocol message attributes
- *
- * @ph: A reference to the protocol handle.
- * @message_id: The ID of the message to check.
- * @attributes: A parameter to optionally return the retrieved message
- *		attributes, in case of Success.
- *
- * An helper to check protocol message attributes for a specific protocol
- * and message pair.
- *
- * Return: 0 on SUCCESS
- */
-static int scmi_protocol_msg_check(const struct scmi_protocol_handle *ph,
-				   u32 message_id, u32 *attributes)
-{
-	int ret;
-	struct scmi_xfer *t;
-
-	ret = xfer_get_init(ph, PROTOCOL_MESSAGE_ATTRIBUTES,
-			    sizeof(__le32), 0, &t);
-	if (ret)
-		return ret;
-
-	put_unaligned_le32(message_id, t->tx.buf);
-	ret = do_xfer(ph, t);
-	if (!ret && attributes)
-		*attributes = get_unaligned_le32(t->rx.buf);
-	xfer_put(ph, t);
-
-	return ret;
 }
 
 static const struct scmi_proto_helpers_ops helpers_ops = {
···
 	struct scmi_info *info = bus_nb_to_scmi_info(nb);
 	struct scmi_device *sdev = to_scmi_dev(data);
 
-	/* Skip transport devices and devices of different SCMI instances */
-	if (!strncmp(sdev->name, "__scmi_transport_device", 23) ||
-	    sdev->dev.parent != info->dev)
+	/* Skip devices of different SCMI instances */
+	if (sdev->dev.parent != info->dev)
 		return NOTIFY_DONE;
 
 	switch (action) {
···
 	return &trans->desc;
 }
 
+static void scmi_enable_matching_quirks(struct scmi_info *info)
+{
+	struct scmi_revision_info *rev = &info->version;
+
+	dev_dbg(info->dev, "Looking for quirks matching: %s/%s/0x%08X\n",
+		rev->vendor_id, rev->sub_vendor_id, rev->impl_ver);
+
+	/* Enable applicable quirks */
+	scmi_quirks_enable(info->dev, rev->vendor_id,
+			   rev->sub_vendor_id, rev->impl_ver);
+}
+
 static int scmi_probe(struct platform_device *pdev)
 {
 	int ret;
···
 	mutex_lock(&scmi_list_mutex);
 	list_add_tail(&info->node, &scmi_list);
 	mutex_unlock(&scmi_list_mutex);
+
+	scmi_enable_matching_quirks(info);
 
 	for_each_available_child_of_node(np, child) {
 		u32 prot_id;
···
 
 static int __init scmi_driver_init(void)
 {
+	scmi_quirks_initialize();
+
 	/* Bail out if no SCMI transport was configured */
 	if (WARN_ON(!IS_ENABLED(CONFIG_ARM_SCMI_HAVE_TRANSPORT)))
 		return -EINVAL;

drivers/firmware/arm_scmi/protocols.h

···
 
 #define SCMI_PROTOCOL_VENDOR_BASE	0x80
 
+#define MSG_SUPPORTS_FASTCHANNEL(x)	((x) & BIT(0))
+
 enum scmi_common_cmd {
 	PROTOCOL_VERSION = 0x0,
 	PROTOCOL_ATTRIBUTES = 0x1,

drivers/firmware/arm_scmi/quirks.c

···
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Management Interface (SCMI) Message Protocol Quirks
+ *
+ * Copyright (C) 2025 ARM Ltd.
+ */
+
+/**
+ * DOC: Theory of operation
+ *
+ * A framework to define SCMI quirks and their activation conditions based on
+ * existing static_keys kernel facilities.
+ *
+ * Quirks are named and their activation conditions defined using the macro
+ * DEFINE_SCMI_QUIRK() in this file.
+ *
+ * After a quirk is defined, a corresponding entry must also be added to the
+ * global @scmi_quirks_table in this file using __DECLARE_SCMI_QUIRK_ENTRY().
+ *
+ * Additionally a corresponding quirk declaration must be added also to the
+ * quirk.h file using DECLARE_SCMI_QUIRK().
+ *
+ * The needed quirk code-snippet itself will be defined local to the SCMI code
+ * that is meant to fix and will be associated to the previously defined quirk
+ * and related activation conditions using the macro SCMI_QUIRK().
+ *
+ * At runtime, during the SCMI stack probe sequence, once the SCMI Server had
+ * advertised the running platform Vendor, SubVendor and Implementation Version
+ * data, all the defined quirks matching the activation conditions will be
+ * enabled.
+ *
+ * Example
+ *
+ * quirk.c
+ * -------
+ *  DEFINE_SCMI_QUIRK(fix_me, "vendor", "subvend", "0x12000-0x30000",
+ *		      "someone,plat_A", "another,plat_b", "vend,sku");
+ *
+ *  static struct scmi_quirk *scmi_quirks_table[] = {
+ *	...
+ *	__DECLARE_SCMI_QUIRK_ENTRY(fix_me),
+ *	NULL
+ *  };
+ *
+ * quirk.h
+ * -------
+ *  DECLARE_SCMI_QUIRK(fix_me);
+ *
+ * <somewhere_in_the_scmi_stack.c>
+ * ------------------------------
+ *
+ *  #define QUIRK_CODE_SNIPPET_FIX_ME()		\
+ *  ({						\
+ *	if (p->condition)			\
+ *		a_ptr->calculated_val = 123;	\
+ *  })
+ *
+ *
+ *  int some_function_to_fix(int param, struct something *p)
+ *  {
+ *	struct some_strut *a_ptr;
+ *
+ *	a_ptr = some_load_func(p);
+ *	SCMI_QUIRK(fix_me, QUIRK_CODE_SNIPPET_FIX_ME);
+ *	some_more_func(a_ptr);
+ *	...
+ *
+ *	return 0;
+ *  }
+ *
+ */
+
+#include <linux/ctype.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/hashtable.h>
+#include <linux/kstrtox.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/static_key.h>
+#include <linux/string.h>
+#include <linux/stringhash.h>
+#include <linux/types.h>
+
+#include "quirks.h"
+
+#define SCMI_QUIRKS_HT_SZ	4
+
+struct scmi_quirk {
+	bool enabled;
+	const char *name;
+	char *vendor;
+	char *sub_vendor_id;
+	char *impl_ver_range;
+	u32 start_range;
+	u32 end_range;
+	struct static_key_false *key;
+	struct hlist_node hash;
+	unsigned int hkey;
+	const char *const compats[];
+};
+
+#define __DEFINE_SCMI_QUIRK_ENTRY(_qn, _ven, _sub, _impl, ...)	\
+	static struct scmi_quirk scmi_quirk_entry_ ## _qn = {		\
+		.name = __stringify(quirk_ ## _qn),			\
+		.vendor = _ven,						\
+		.sub_vendor_id = _sub,					\
+		.impl_ver_range = _impl,				\
+		.key = &(scmi_quirk_ ## _qn),				\
+		.compats = { __VA_ARGS__ __VA_OPT__(,) NULL },		\
+	}
+
+#define __DECLARE_SCMI_QUIRK_ENTRY(_qn)		(&(scmi_quirk_entry_ ## _qn))
+
+/*
+ * Define a quirk by name and provide the matching tokens where:
+ *
+ *  _qn: A string which will be used to build the quirk and the global
+ *	 static_key names.
+ *  _ven : SCMI Vendor ID string match, NULL means any.
+ *  _sub : SCMI SubVendor ID string match, NULL means any.
+ *  _impl : SCMI Implementation Version string match, NULL means any.
+ *          This string can be used to express version ranges which will be
+ *          interpreted as follows:
+ *
+ *			NULL		[0, 0xFFFFFFFF]
+ *			"X"		[X, X]
+ *			"X-"		[X, 0xFFFFFFFF]
+ *			"-X"		[0, X]
+ *			"X-Y"		[X, Y]
+ *
+ *          with X <= Y and <v> in [X, Y] meaning X <= <v> <= Y
+ *
+ *  ... : An optional variadic macros argument used to provide a comma-separated
+ *	  list of compatible strings matches; when no variadic argument is
+ *	  provided, ANY compatible will match this quirk.
+ *
+ *  This implicitly define also a properly named global static-key that
+ *  will be used to dynamically enable the quirk at initialization time.
+ *
+ *  Note that it is possible to associate multiple quirks to the same
+ *  matching pattern, if your firmware quality is really astounding :P
+ *
+ * Example:
+ *
+ * Compatibles list NOT provided, so ANY compatible will match:
+ *
+ *  DEFINE_SCMI_QUIRK(my_new_issue, "Vend", "SVend", "0x12000-0x30000");
+ *
+ *
+ * A few compatibles provided to match against:
+ *
+ *  DEFINE_SCMI_QUIRK(my_new_issue, "Vend", "SVend", "0x12000-0x30000",
+ *		      "xvend,plat_a", "xvend,plat_b", "xvend,sku_name");
+ */
+#define DEFINE_SCMI_QUIRK(_qn, _ven, _sub, _impl, ...)			\
+	DEFINE_STATIC_KEY_FALSE(scmi_quirk_ ## _qn);			\
+	__DEFINE_SCMI_QUIRK_ENTRY(_qn, _ven, _sub, _impl, ##__VA_ARGS__)
+
+/*
+ * Same as DEFINE_SCMI_QUIRK but EXPORTED: this is meant to address quirks
+ * that possibly reside in code that is included in loadable kernel modules
+ * that needs to be able to access the global static keys at runtime to
+ * determine if enabled or not. (see SCMI_QUIRK to understand usage)
+ */
+#define DEFINE_SCMI_QUIRK_EXPORTED(_qn, _ven, _sub, _impl, ...)		\
+	DEFINE_STATIC_KEY_FALSE(scmi_quirk_ ## _qn);			\
+	EXPORT_SYMBOL_GPL(scmi_quirk_ ## _qn);				\
+	__DEFINE_SCMI_QUIRK_ENTRY(_qn, _ven, _sub, _impl, ##__VA_ARGS__)
+
+/* Global Quirks Definitions */
+DEFINE_SCMI_QUIRK(clock_rates_triplet_out_of_spec, NULL, NULL, NULL);
+DEFINE_SCMI_QUIRK(perf_level_get_fc_force, "Qualcomm", NULL, "0x20000-");
+
+/*
+ * Quirks Pointers Array
+ *
+ * This is filled at compile-time with the list of pointers to all the currently
+ * defined quirks descriptors.
+ */
+static struct scmi_quirk *scmi_quirks_table[] = {
+	__DECLARE_SCMI_QUIRK_ENTRY(clock_rates_triplet_out_of_spec),
+	__DECLARE_SCMI_QUIRK_ENTRY(perf_level_get_fc_force),
+	NULL
+};
+
+/*
+ * Quirks HashTable
+ *
+ * A run-time populated hashtable containing all the defined quirks descriptors
+ * hashed by matching pattern.
+ */
+static DEFINE_READ_MOSTLY_HASHTABLE(scmi_quirks_ht, SCMI_QUIRKS_HT_SZ);
+
+static unsigned int scmi_quirk_signature(const char *vend, const char *sub_vend)
+{
+	char *signature, *p;
+	unsigned int hash32;
+	unsigned long hash = 0;
+
+	/* vendor_id/sub_vendor_id guaranteed <= SCMI_SHORT_NAME_MAX_SIZE */
+	signature = kasprintf(GFP_KERNEL, "|%s|%s|", vend ?: "", sub_vend ?: "");
+	if (!signature)
+		return 0;
+
+	pr_debug("SCMI Quirk Signature >>>%s<<<\n", signature);
+
+	p = signature;
+	while (*p)
+		hash = partial_name_hash(tolower(*p++), hash);
+	hash32 = end_name_hash(hash);
+
+	kfree(signature);
+
+	return hash32;
+}
+
+static int scmi_quirk_range_parse(struct scmi_quirk *quirk)
+{
+	const char *last, *first = quirk->impl_ver_range;
+	size_t len;
+	char *sep;
+	int ret;
+
+	quirk->start_range = 0;
+	quirk->end_range = 0xFFFFFFFF;
+	len = quirk->impl_ver_range ? strlen(quirk->impl_ver_range) : 0;
+	if (!len)
+		return 0;
+
+	last = first + len - 1;
+	sep = strchr(quirk->impl_ver_range, '-');
+	if (sep)
+		*sep = '\0';
+
+	if (sep == first) /* -X */
+		ret = kstrtouint(first + 1, 0, &quirk->end_range);
+	else /* X OR X- OR X-y */
+		ret = kstrtouint(first, 0, &quirk->start_range);
+	if (ret)
+		return ret;
+
+	if (!sep)
+		quirk->end_range = quirk->start_range;
+	else if (sep != last) /* x-Y */
+		ret = kstrtouint(sep + 1, 0, &quirk->end_range);
+
+	if (quirk->start_range > quirk->end_range)
+		return -EINVAL;
+
+	return ret;
+}
+
+void scmi_quirks_initialize(void)
+{
+	struct scmi_quirk *quirk;
+	int i;
+
+	for (i = 0, quirk = scmi_quirks_table[0]; quirk;
+	     i++, quirk = scmi_quirks_table[i]) {
+		int ret;
+
+		ret = scmi_quirk_range_parse(quirk);
+		if (ret) {
+			pr_err("SCMI skip QUIRK [%s] - BAD RANGE - |%s|\n",
+			       quirk->name, quirk->impl_ver_range);
+			continue;
+		}
+		quirk->hkey = scmi_quirk_signature(quirk->vendor,
+						   quirk->sub_vendor_id);
+
+		hash_add(scmi_quirks_ht, &quirk->hash, quirk->hkey);
+
+		pr_debug("Registered SCMI QUIRK [%s] -- %p - Key [0x%08X] - %s/%s/[0x%08X-0x%08X]\n",
+			 quirk->name, quirk, quirk->hkey,
+			 quirk->vendor, quirk->sub_vendor_id,
+			 quirk->start_range, quirk->end_range);
+	}
+
+	pr_debug("SCMI Quirks initialized\n");
+}
+
+void scmi_quirks_enable(struct device *dev, const char *vend,
+			const char *subv, const u32 impl)
+{
+	for (int i = 3; i >= 0; i--) {
+		struct scmi_quirk *quirk;
+		unsigned int hkey;
+
+		hkey = scmi_quirk_signature(i > 1 ? vend : NULL,
+					    i > 2 ? subv : NULL);
+
+		/*
+		 * Note that there could be multiple matches so we
+		 * will enable multiple quirk part of a hash collision
+		 * domain...BUT we cannot assume that ALL quirks on the
+		 * same collision domain are a full match.
+		 */
+		hash_for_each_possible(scmi_quirks_ht, quirk, hash, hkey) {
+			if (quirk->enabled || quirk->hkey != hkey ||
+			    impl < quirk->start_range ||
+			    impl > quirk->end_range)
+				continue;
+
+			if (quirk->compats[0] &&
+			    !of_machine_compatible_match(quirk->compats))
+				continue;
+
+			dev_info(dev, "Enabling SCMI Quirk [%s]\n",
+				 quirk->name);
+
+			dev_dbg(dev,
+				"Quirk matched on: %s/%s/%s/[0x%08X-0x%08X]\n",
+				quirk->compats[0], quirk->vendor,
+				quirk->sub_vendor_id,
+				quirk->start_range, quirk->end_range);
+
+			static_branch_enable(quirk->key);
+			quirk->enabled = true;
+		}
+	}
+}

drivers/firmware/arm_scmi/quirks.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * System Control and Management Interface (SCMI) Message Protocol Quirks
+ *
+ * Copyright (C) 2025 ARM Ltd.
+ */
+#ifndef _SCMI_QUIRKS_H
+#define _SCMI_QUIRKS_H
+
+#include <linux/static_key.h>
+#include <linux/types.h>
+
+#ifdef CONFIG_ARM_SCMI_QUIRKS
+
+#define DECLARE_SCMI_QUIRK(_qn)						\
+	DECLARE_STATIC_KEY_FALSE(scmi_quirk_ ## _qn)
+
+/*
+ * A helper to associate the actual code snippet to use as a quirk
+ * named as _qn.
+ */
+#define SCMI_QUIRK(_qn, _blk)						\
+	do {								\
+		if (static_branch_unlikely(&(scmi_quirk_ ## _qn)))	\
+			(_blk);						\
+	} while (0)
+
+void scmi_quirks_initialize(void);
+void scmi_quirks_enable(struct device *dev, const char *vend,
+			const char *subv, const u32 impl);
+
+#else
+
+#define DECLARE_SCMI_QUIRK(_qn)
+/* Force quirks compilation even when SCMI Quirks are disabled */
+#define SCMI_QUIRK(_qn, _blk)						\
+	do {								\
+		if (0)							\
+			(_blk);						\
+	} while (0)
+
+static inline void scmi_quirks_initialize(void) { }
+static inline void scmi_quirks_enable(struct device *dev, const char *vend,
+				      const char *sub_vend, const u32 impl) { }
+
+#endif /* CONFIG_ARM_SCMI_QUIRKS */
+
+/* Quirk delarations */
+DECLARE_SCMI_QUIRK(clock_rates_triplet_out_of_spec);
+DECLARE_SCMI_QUIRK(perf_level_get_fc_force);
+
+#endif /* _SCMI_QUIRKS_H */

drivers/firmware/arm_scmi/raw_mode.c

···
  * @len: Length of the message in @buf.
  * @chan_id: The channel ID to use.
  * @async: A flag stating if an asynchronous command is required.
+ * @poll: A flag stating if a polling transmission is required.
  *
  * Return: 0 on Success
  */
 static int scmi_raw_message_send(struct scmi_raw_mode_info *raw,
-				 void *buf, size_t len, u8 chan_id, bool async)
+				 void *buf, size_t len, u8 chan_id,
+				 bool async, bool poll)
 {
 	int ret;
 	struct scmi_xfer *xfer;
···
 	ret = scmi_xfer_raw_get_init(raw, buf, len, &xfer);
 	if (ret)
 		return ret;
+
+	if (poll) {
+		if (is_transport_polling_capable(raw->desc)) {
+			xfer->hdr.poll_completion = true;
+		} else {
+			dev_err(raw->handle->dev,
+				"Failed to send RAW message - Polling NOT supported\n");
+			return -EINVAL;
+		}
+	}
 
 	ret = scmi_do_xfer_raw_start(raw, xfer, chan_id, async);
 	if (ret)
···
 static ssize_t scmi_dbg_raw_mode_common_write(struct file *filp,
 					      const char __user *buf,
 					      size_t count, loff_t *ppos,
-					      bool async)
+					      bool async, bool poll)
 {
 	int ret;
 	struct scmi_dbg_raw_data *rd = filp->private_data;
···
 	}
 
 	ret = scmi_raw_message_send(rd->raw, rd->tx.buf, rd->tx_size,
-				    rd->chan_id, async);
+				    rd->chan_id, async, poll);
 
 	/* Reset ppos for next message ... */
 	rd->tx_size = 0;
···
 					       const char __user *buf,
 					       size_t count, loff_t *ppos)
 {
-	return scmi_dbg_raw_mode_common_write(filp, buf, count, ppos, false);
+	return scmi_dbg_raw_mode_common_write(filp, buf, count, ppos,
+					      false, false);
 }
 
 static __poll_t scmi_dbg_raw_mode_message_poll(struct file *filp,
···
 						     const char __user *buf,
 						     size_t count, loff_t *ppos)
 {
-	return scmi_dbg_raw_mode_common_write(filp, buf, count, ppos, true);
+	return scmi_dbg_raw_mode_common_write(filp, buf, count, ppos,
+					      true, false);
 }
 
 static const struct file_operations scmi_dbg_raw_mode_message_async_fops = {
···
 	.release = scmi_dbg_raw_mode_release,
 	.read = scmi_dbg_raw_mode_message_read,
 	.write = scmi_dbg_raw_mode_message_async_write,
+	.poll = scmi_dbg_raw_mode_message_poll,
+	.owner = THIS_MODULE,
+};
+
+static ssize_t scmi_dbg_raw_mode_message_poll_write(struct file *filp,
+						    const char __user *buf,
+						    size_t count, loff_t *ppos)
+{
+	return scmi_dbg_raw_mode_common_write(filp, buf, count, ppos,
+					      false, true);
+}
+
+static const struct file_operations scmi_dbg_raw_mode_message_poll_fops = {
+	.open = scmi_dbg_raw_mode_open,
+	.release = scmi_dbg_raw_mode_release,
+	.read = scmi_dbg_raw_mode_message_read,
+	.write = scmi_dbg_raw_mode_message_poll_write,
+	.poll = scmi_dbg_raw_mode_message_poll,
+	.owner = THIS_MODULE,
+};
+
+static ssize_t scmi_dbg_raw_mode_message_poll_async_write(struct file *filp,
+							  const char __user *buf,
+							  size_t count, loff_t *ppos)
+{
+	return scmi_dbg_raw_mode_common_write(filp, buf, count, ppos,
+					      true, true);
+}
+
+static const struct file_operations scmi_dbg_raw_mode_message_poll_async_fops = {
+	.open = scmi_dbg_raw_mode_open,
+	.release = scmi_dbg_raw_mode_release,
+	.read = scmi_dbg_raw_mode_message_read,
+	.write = scmi_dbg_raw_mode_message_poll_async_write,
 	.poll = scmi_dbg_raw_mode_message_poll,
 	.owner = THIS_MODULE,
 };
···
 	debugfs_create_file("message_async", 0600, raw->dentry, raw,
 			    &scmi_dbg_raw_mode_message_async_fops);
 
+	debugfs_create_file("message_poll", 0600, raw->dentry, raw,
+			    &scmi_dbg_raw_mode_message_poll_fops);
+
+	debugfs_create_file("message_poll_async", 0600, raw->dentry, raw,
+			    &scmi_dbg_raw_mode_message_poll_async_fops);
+
 	debugfs_create_file("notification", 0400, raw->dentry, raw,
 			    &scmi_dbg_raw_mode_notification_fops);
 
···
 			debugfs_create_file_aux_num("message_async", 0600, chd,
 					    raw, channels[i],
 					    &scmi_dbg_raw_mode_message_async_fops);
+
+			debugfs_create_file_aux_num("message_poll", 0600, chd,
+						    raw, channels[i],
+						    &scmi_dbg_raw_mode_message_poll_fops);
+
+			debugfs_create_file_aux_num("message_poll_async", 0600,
+						    chd, raw, channels[i],
+						    &scmi_dbg_raw_mode_message_poll_async_fops);
 		}
 	}
 

drivers/firmware/arm_scmi/vendors/imx/Kconfig

···
 	  To compile this driver as a module, choose M here: the
 	  module will be called imx-sm-bbm.
 
+config IMX_SCMI_CPU_EXT
+	tristate "i.MX SCMI CPU EXTENSION"
+	depends on ARM_SCMI_PROTOCOL || (COMPILE_TEST && OF)
+	depends on IMX_SCMI_CPU_DRV
+	default y if ARCH_MXC
+	help
+	  This enables i.MX System CPU Protocol to manage cpu
+	  start, stop and etc.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called imx-sm-cpu.
+
+config IMX_SCMI_LMM_EXT
+	tristate "i.MX SCMI LMM EXTENSION"
+	depends on ARM_SCMI_PROTOCOL || (COMPILE_TEST && OF)
+	depends on IMX_SCMI_LMM_DRV
+	default y if ARCH_MXC
+	help
+	  This enables i.MX System Logical Machine Protocol to
+	  manage Logical Machines boot, shutdown and etc.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called imx-sm-lmm.
+
 config IMX_SCMI_MISC_EXT
 	tristate "i.MX SCMI MISC EXTENSION"
 	depends on ARM_SCMI_PROTOCOL || (COMPILE_TEST && OF)

drivers/firmware/arm_scmi/vendors/imx/Makefile

···
 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_IMX_SCMI_BBM_EXT) += imx-sm-bbm.o
+obj-$(CONFIG_IMX_SCMI_CPU_EXT) += imx-sm-cpu.o
+obj-$(CONFIG_IMX_SCMI_LMM_EXT) += imx-sm-lmm.o
 obj-$(CONFIG_IMX_SCMI_MISC_EXT) += imx-sm-misc.o

drivers/firmware/arm_scmi/vendors/imx/imx-sm-cpu.c

···
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System control and Management Interface (SCMI) NXP CPU Protocol
+ *
+ * Copyright 2025 NXP
+ */
+
+#include <linux/bits.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/scmi_protocol.h>
+#include <linux/scmi_imx_protocol.h>
+
+#include "../../protocols.h"
+#include "../../notify.h"
+
+#define SCMI_PROTOCOL_SUPPORTED_VERSION		0x10000
+
+enum scmi_imx_cpu_protocol_cmd {
+	SCMI_IMX_CPU_ATTRIBUTES	= 0x3,
+	SCMI_IMX_CPU_START = 0x4,
+	SCMI_IMX_CPU_STOP = 0x5,
+	SCMI_IMX_CPU_RESET_VECTOR_SET = 0x6,
+	SCMI_IMX_CPU_INFO_GET = 0xC,
+};
+
+struct scmi_imx_cpu_info {
+	u32 nr_cpu;
+};
+
+#define SCMI_IMX_CPU_NR_CPU_MASK	GENMASK(15, 0)
+struct scmi_msg_imx_cpu_protocol_attributes {
+	__le32 attributes;
+};
+
+struct scmi_msg_imx_cpu_attributes_out {
+	__le32 attributes;
+#define	CPU_MAX_NAME	16
+	u8 name[CPU_MAX_NAME];
+};
+
+struct scmi_imx_cpu_reset_vector_set_in {
+	__le32 cpuid;
+#define	CPU_VEC_FLAGS_RESUME	BIT(31)
+#define	CPU_VEC_FLAGS_START	BIT(30)
+#define	CPU_VEC_FLAGS_BOOT	BIT(29)
+	__le32 flags;
+	__le32 resetvectorlow;
+	__le32 resetvectorhigh;
+};
+
+struct scmi_imx_cpu_info_get_out {
+#define	CPU_RUN_MODE_START	0
+#define	CPU_RUN_MODE_HOLD	1
+#define	CPU_RUN_MODE_STOP	2
+#define	CPU_RUN_MODE_SLEEP	3
+	__le32 runmode;
+	__le32 sleepmode;
+	__le32 resetvectorlow;
+	__le32 resetvectorhigh;
+};
+
+static int scmi_imx_cpu_validate_cpuid(const struct scmi_protocol_handle *ph,
+				       u32 cpuid)
+{
+	struct scmi_imx_cpu_info *info = ph->get_priv(ph);
+
+	if (cpuid >= info->nr_cpu)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int scmi_imx_cpu_start(const struct scmi_protocol_handle *ph,
+			      u32 cpuid, bool start)
+{
+	struct scmi_xfer *t;
+	u8 msg_id;
+	int ret;
+
+	ret = scmi_imx_cpu_validate_cpuid(ph, cpuid);
+	if (ret)
+		return ret;
+
+	if (start)
+		msg_id = SCMI_IMX_CPU_START;
+	else
+		msg_id = SCMI_IMX_CPU_STOP;
+
+	ret = ph->xops->xfer_get_init(ph, msg_id, sizeof(u32), 0, &t);
+	if (ret)
+		return ret;
+
+	put_unaligned_le32(cpuid, t->tx.buf);
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_cpu_reset_vector_set(const struct scmi_protocol_handle *ph,
+					 u32 cpuid, u64 vector, bool start,
+					 bool boot, bool resume)
+{
+	struct scmi_imx_cpu_reset_vector_set_in *in;
+	struct scmi_xfer *t;
+	int ret;
+
+	ret = scmi_imx_cpu_validate_cpuid(ph, cpuid);
+	if (ret)
+		return ret;
+
+	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_CPU_RESET_VECTOR_SET, sizeof(*in),
+				      0, &t);
+	if (ret)
+		return ret;
+
+	in = t->tx.buf;
+	in->cpuid = cpu_to_le32(cpuid);
+	in->flags = cpu_to_le32(0);
+	if (start)
+		in->flags |= le32_encode_bits(1, CPU_VEC_FLAGS_START);
+	if (boot)
+		in->flags |= le32_encode_bits(1, CPU_VEC_FLAGS_BOOT);
+	if (resume)
+		in->flags |= le32_encode_bits(1, CPU_VEC_FLAGS_RESUME);
+	in->resetvectorlow = cpu_to_le32(lower_32_bits(vector));
+	in->resetvectorhigh = cpu_to_le32(upper_32_bits(vector));
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_cpu_started(const struct scmi_protocol_handle *ph, u32 cpuid,
+				bool *started)
+{
+	struct scmi_imx_cpu_info_get_out *out;
+	struct scmi_xfer *t;
+	u32 mode;
+	int ret;
+
+	if (!started)
+		return -EINVAL;
+
+	*started = false;
+	ret = scmi_imx_cpu_validate_cpuid(ph, cpuid);
+	if (ret)
+		return ret;
+
+	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_CPU_INFO_GET, sizeof(u32),
+				      0, &t);
+	if (ret)
+		return ret;
+
+	put_unaligned_le32(cpuid, t->tx.buf);
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		out = t->rx.buf;
+		mode = le32_to_cpu(out->runmode);
+		if (mode == CPU_RUN_MODE_START || mode == CPU_RUN_MODE_SLEEP)
+			*started = true;
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static const struct scmi_imx_cpu_proto_ops scmi_imx_cpu_proto_ops = {
+	.cpu_reset_vector_set = scmi_imx_cpu_reset_vector_set,
+	.cpu_start = scmi_imx_cpu_start,
+	.cpu_started = scmi_imx_cpu_started,
+};
+
+static int scmi_imx_cpu_protocol_attributes_get(const struct scmi_protocol_handle *ph,
+						struct scmi_imx_cpu_info *info)
+{
+	struct scmi_msg_imx_cpu_protocol_attributes *attr;
+	struct scmi_xfer *t;
+	int ret;
+
+	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES, 0,
+				      sizeof(*attr), &t);
+	if (ret)
+		return ret;
+
+	attr = t->rx.buf;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		info->nr_cpu = le32_get_bits(attr->attributes, SCMI_IMX_CPU_NR_CPU_MASK);
+		dev_info(ph->dev, "i.MX SM CPU: %d cpus\n",
+			 info->nr_cpu);
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_cpu_attributes_get(const struct scmi_protocol_handle *ph,
+				       u32 cpuid)
+{
+	struct scmi_msg_imx_cpu_attributes_out *out;
+	char name[SCMI_SHORT_NAME_MAX_SIZE] = {'\0'};
+	struct scmi_xfer *t;
+	int ret;
+
+	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_CPU_ATTRIBUTES, sizeof(u32), 0, &t);
+	if (ret)
+		return ret;
+
+	put_unaligned_le32(cpuid, t->tx.buf);
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		out = t->rx.buf;
+		strscpy(name, out->name, SCMI_SHORT_NAME_MAX_SIZE);
+		dev_info(ph->dev, "i.MX CPU: name: %s\n", name);
+	} else {
+		dev_err(ph->dev, "i.MX cpu: Failed to get info of cpu(%u)\n", cpuid);
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_cpu_protocol_init(const struct scmi_protocol_handle *ph)
+{
+	struct scmi_imx_cpu_info *info;
+	u32 version;
+	int ret, i;
+
+	ret = ph->xops->version_get(ph, &version);
+	if (ret)
+		return ret;
+
+	dev_info(ph->dev, "NXP SM CPU Protocol Version %d.%d\n",
+		 PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
+
+	info = devm_kzalloc(ph->dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	ret = scmi_imx_cpu_protocol_attributes_get(ph, info);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < info->nr_cpu; i++) {
+		ret = scmi_imx_cpu_attributes_get(ph, i);
+		if (ret)
+			return ret;
+	}
+
+	return ph->set_priv(ph, info, version);
+}
+
+static const struct scmi_protocol scmi_imx_cpu = {
+	.id = SCMI_PROTOCOL_IMX_CPU,
+	.owner = THIS_MODULE,
+	.instance_init = &scmi_imx_cpu_protocol_init,
+	.ops = &scmi_imx_cpu_proto_ops,
+	.supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION,
+	.vendor_id = SCMI_IMX_VENDOR,
+	.sub_vendor_id = SCMI_IMX_SUBVENDOR,
+};
+module_scmi_protocol(scmi_imx_cpu);
+
+MODULE_ALIAS("scmi-protocol-" __stringify(SCMI_PROTOCOL_IMX_CPU) "-" SCMI_IMX_VENDOR);
+MODULE_DESCRIPTION("i.MX SCMI CPU driver");
+MODULE_LICENSE("GPL");

drivers/firmware/arm_scmi/vendors/imx/imx-sm-lmm.c

···
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System control and Management Interface (SCMI) NXP LMM Protocol
+ *
+ * Copyright 2025 NXP
+ */
+
+#include <linux/bits.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/scmi_protocol.h>
+#include <linux/scmi_imx_protocol.h>
+
+#include "../../protocols.h"
+#include "../../notify.h"
+
+#define SCMI_PROTOCOL_SUPPORTED_VERSION		0x10000
+
+enum scmi_imx_lmm_protocol_cmd {
+	SCMI_IMX_LMM_ATTRIBUTES	= 0x3,
+	SCMI_IMX_LMM_BOOT = 0x4,
+	SCMI_IMX_LMM_RESET = 0x5,
+	SCMI_IMX_LMM_SHUTDOWN = 0x6,
+	SCMI_IMX_LMM_WAKE = 0x7,
+	SCMI_IMX_LMM_SUSPEND = 0x8,
+	SCMI_IMX_LMM_NOTIFY = 0x9,
+	SCMI_IMX_LMM_RESET_REASON = 0xA,
+	SCMI_IMX_LMM_POWER_ON = 0xB,
+	SCMI_IMX_LMM_RESET_VECTOR_SET = 0xC,
+};
+
+struct scmi_imx_lmm_priv {
+	u32 nr_lmm;
+};
+
+#define SCMI_IMX_LMM_NR_LM_MASK	GENMASK(5, 0)
+#define SCMI_IMX_LMM_NR_MAX	16
+struct scmi_msg_imx_lmm_protocol_attributes {
+	__le32 attributes;
+};
+
+struct scmi_msg_imx_lmm_attributes_out {
+	__le32 lmid;
+	__le32 attributes;
+	__le32 state;
+	__le32 errstatus;
+	u8 name[LMM_MAX_NAME];
+};
+
+struct scmi_imx_lmm_reset_vector_set_in {
+	__le32 lmid;
+	__le32 cpuid;
+	__le32 flags; /* reserved for future extension */
+	__le32 resetvectorlow;
+	__le32 resetvectorhigh;
+};
+
+struct scmi_imx_lmm_shutdown_in {
+	__le32 lmid;
+#define SCMI_IMX_LMM_SHUTDOWN_GRACEFUL	BIT(0)
+	__le32 flags;
+};
+
+static int scmi_imx_lmm_validate_lmid(const struct scmi_protocol_handle *ph, u32 lmid)
+{
+	struct scmi_imx_lmm_priv *priv = ph->get_priv(ph);
+
+	if (lmid >= priv->nr_lmm)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int scmi_imx_lmm_attributes(const struct scmi_protocol_handle *ph,
+				   u32 lmid, struct scmi_imx_lmm_info *info)
+{
+	struct scmi_msg_imx_lmm_attributes_out *out;
+	struct scmi_xfer *t;
+	int ret;
+
+	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_LMM_ATTRIBUTES, sizeof(u32), 0, &t);
+	if (ret)
+		return ret;
+
+	put_unaligned_le32(lmid, t->tx.buf);
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		out = t->rx.buf;
+		info->lmid = le32_to_cpu(out->lmid);
+		info->state = le32_to_cpu(out->state);
+		info->errstatus = le32_to_cpu(out->errstatus);
+		strscpy(info->name, out->name);
+		dev_dbg(ph->dev, "i.MX LMM: Logical Machine(%d), name: %s\n",
+			info->lmid, info->name);
+	} else {
+		dev_err(ph->dev, "i.MX LMM: Failed to get info of Logical Machine(%u)\n", lmid);
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int
+scmi_imx_lmm_power_boot(const struct scmi_protocol_handle *ph, u32 lmid, bool boot)
+{
+	struct scmi_xfer *t;
+	u8 msg_id;
+	int ret;
+
+	ret = scmi_imx_lmm_validate_lmid(ph, lmid);
+	if (ret)
+		return ret;
+
+	if (boot)
+		msg_id = SCMI_IMX_LMM_BOOT;
+	else
+		msg_id = SCMI_IMX_LMM_POWER_ON;
+
+	ret = ph->xops->xfer_get_init(ph, msg_id, sizeof(u32), 0, &t);
+	if (ret)
+		return ret;
+
+	put_unaligned_le32(lmid, t->tx.buf);
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_lmm_reset_vector_set(const struct scmi_protocol_handle *ph,
+					 u32 lmid, u32 cpuid, u32 flags, u64 vector)
+{
+	struct scmi_imx_lmm_reset_vector_set_in *in;
+	struct scmi_xfer *t;
+	int ret;
+
+	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_LMM_RESET_VECTOR_SET, sizeof(*in),
+				      0, &t);
+	if (ret)
+		return ret;
+
+	in = t->tx.buf;
+	in->lmid = cpu_to_le32(lmid);
+	in->cpuid = cpu_to_le32(cpuid);
+	in->flags = cpu_to_le32(0);
+	in->resetvectorlow = cpu_to_le32(lower_32_bits(vector));
+	in->resetvectorhigh = cpu_to_le32(upper_32_bits(vector));
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_lmm_shutdown(const struct scmi_protocol_handle *ph, u32 lmid,
+				 u32 flags)
+{
+	struct scmi_imx_lmm_shutdown_in *in;
+	struct scmi_xfer *t;
+	int ret;
+
+	ret = scmi_imx_lmm_validate_lmid(ph, lmid);
+	if (ret)
+		return ret;
+
+	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_LMM_SHUTDOWN, sizeof(*in),
+				      0, &t);
+	if (ret)
+		return ret;
+
+	in = t->tx.buf;
+	in->lmid = cpu_to_le32(lmid);
+	if (flags & SCMI_IMX_LMM_SHUTDOWN_GRACEFUL)
+		in->flags = cpu_to_le32(SCMI_IMX_LMM_SHUTDOWN_GRACEFUL);
+	else
+		in->flags = cpu_to_le32(0);
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static const struct scmi_imx_lmm_proto_ops scmi_imx_lmm_proto_ops = {
+	.lmm_power_boot = scmi_imx_lmm_power_boot,
+	.lmm_info = scmi_imx_lmm_attributes,
+	.lmm_reset_vector_set = scmi_imx_lmm_reset_vector_set,
+	.lmm_shutdown = scmi_imx_lmm_shutdown,
+};
+
+static int scmi_imx_lmm_protocol_attributes_get(const struct scmi_protocol_handle *ph,
+						struct scmi_imx_lmm_priv *priv)
+{
+	struct scmi_msg_imx_lmm_protocol_attributes *attr;
+	struct scmi_xfer *t;
+	int ret;
+
+	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES, 0,
+				      sizeof(*attr), &t);
+	if (ret)
+		return ret;
+
+	attr = t->rx.buf;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		priv->nr_lmm = le32_get_bits(attr->attributes, SCMI_IMX_LMM_NR_LM_MASK);
+		if (priv->nr_lmm > SCMI_IMX_LMM_NR_MAX) {
+			dev_err(ph->dev, "i.MX LMM: %d:Exceed max supported Logical Machines\n",
+				priv->nr_lmm);
+			ret = -EINVAL;
+		} else {
+			dev_info(ph->dev, "i.MX LMM: %d Logical Machines\n", priv->nr_lmm);
+		}
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_lmm_protocol_init(const struct scmi_protocol_handle *ph)
+{
+	struct scmi_imx_lmm_priv *info;
+	u32 version;
+	int ret;
+
+	ret = ph->xops->version_get(ph, &version);
+	if (ret)
+		return ret;
+
+	dev_info(ph->dev, "NXP SM LMM Version %d.%d\n",
+		 PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
+
+	info = devm_kzalloc(ph->dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	ret = scmi_imx_lmm_protocol_attributes_get(ph, info);
+	if (ret)
+		return ret;
+
+	return ph->set_priv(ph, info, version);
+}
+
+static const struct scmi_protocol scmi_imx_lmm = {
+	.id = SCMI_PROTOCOL_IMX_LMM,
+	.owner = THIS_MODULE,
+	.instance_init = &scmi_imx_lmm_protocol_init,
+	.ops = &scmi_imx_lmm_proto_ops,
+	.supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION,
+	.vendor_id = SCMI_IMX_VENDOR,
+	.sub_vendor_id = SCMI_IMX_SUBVENDOR,
+};
+module_scmi_protocol(scmi_imx_lmm);
+
+MODULE_ALIAS("scmi-protocol-" __stringify(SCMI_PROTOCOL_IMX_LMM) "-" SCMI_IMX_VENDOR);
+MODULE_DESCRIPTION("i.MX SCMI LMM driver");
+MODULE_LICENSE("GPL");

drivers/firmware/arm_scmi/vendors/imx/imx95.rst

···
 The SM implements an interface compliant with the Arm SCMI Specification
 with additional vendor specific extensions.
 
+System Control and Management Logical Machine Management Vendor Protocol
+========================================================================
+
+The SM adds the concept of logical machines (LMs). These are analogous to
+VMs and each has its own instance of SCMI. All normal SCMI calls only apply
+the LM running the calling agent. That includes boot, shutdown, reset,
+suspend, wake, etc. If a caller makes the SCMI base call to get a list
+of agents, it will only get those on that LM. Each LM is completely isolated
+from the others. This is mandatory for these to operate independently.
+
+This protocol is intended to support boot, shutdown, and reset of other logical
+machines (LM). It is usually used to allow one LM(e.g. OSPM) to manage
+another LM which is usually an offload or accelerator engine. Notifications
+from this protocol can also be used to manage a communication link to another
+LM. The LMM protocol provides commands to:
+
+- Describe the protocol version.
+- Discover implementation attributes.
+- Discover all the LMs defined in the system.
+- Boot a target LM.
+- Shutdown a target LM (gracefully or forcibly).
+- Reset a target LM (gracefully or forcibly).
+- Wake a target LM from suspend.
+- Suspend a target LM (gracefully).
+- Read boot/shutdown/reset information for a target LM.
+- Get notifications when a target LM boots or shuts down (e.g. LM 'X' requested
+  notification of LM 'Y' boots or shuts down, when LM 'Y' boots or shuts down,
+  SCMI firmware will send notification to LM 'X').
+
+'Graceful' means asking LM itself to shutdown/reset/etc (e.g. sending
+notification to Linux, Then Linux reboots or powers down itself). It is async
+command that the SUCCESS of the command just means the command successfully
+return, not means reboot/reset successfully finished.
+
+'Forceful' means the SM will force shutdown/reset/etc the LM. It is sync
+command that the SUCCESS of the command means the LM has been successfully
+shutdown/reset/etc.
+If the commands not have Graceful/Forceful flag settings, such as WAKE, SUSEND,
+it is a Graceful command.
+
+Commands:
+_________
+
+PROTOCOL_VERSION
+~~~~~~~~~~~~~~~~
+
+message_id: 0x0
+protocol_id: 0x80
+This command is mandatory.
+
++---------------+--------------------------------------------------------------+
+|Return values                                                                 |
++---------------+--------------------------------------------------------------+
+|Name           |Description                                                   |
++---------------+--------------------------------------------------------------+
+|int32 status   | See ARM SCMI Specification for status code definitions.      |
++---------------+--------------------------------------------------------------+
+|uint32 version | For this revision of the specification, this value must be   |
+|               | 0x10000.                                                     |
++---------------+--------------------------------------------------------------+
+
+PROTOCOL_ATTRIBUTES
+~~~~~~~~~~~~~~~~~~~
+
+message_id: 0x1
+protocol_id: 0x80
+This command is mandatory.
+
++------------------+-----------------------------------------------------------+
+|Return values                                                                 |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|int32 status      | See ARM SCMI Specification for status code definitions.   |
++------------------+-----------------------------------------------------------+
+|uint32 attributes |Protocol attributes:                                       |
+|                  |Bits[31:5] Reserved, must be zero.                         |
+|                  |Bits[4:0] Number of Logical Machines                       |
+|                  |Note that due to both hardware limitations and reset reason|
+|                  |field limitations, the max number of LM is 16. The minimum |
+|                  |is 1.                                                      |
++------------------+-----------------------------------------------------------+
+
+PROTOCOL_MESSAGE_ATTRIBUTES
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+message_id: 0x2
+protocol_id: 0x80
+This command is mandatory.
+
++------------------+-----------------------------------------------------------+
+|Return values                                                                 |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|int32 status      |SUCCESS: in case the message is implemented and available  |
+|                  |to use.                                                    |
+|                  |NOT_FOUND: if the message identified by message_id is      |
+|                  |invalid or not implemented                                 |
++------------------+-----------------------------------------------------------+
+|uint32 attributes |Flags that are associated with a specific command in the   |
+|                  |protocol. For all commands in this protocol, this          |
+|                  |parameter has a value of 0                                 |
++------------------+-----------------------------------------------------------+
+
+LMM_ATTRIBUTES
+~~~~~~~~~~~~~~
+
+message_id: 0x3
+protocol_id: 0x80
+This command is mandatory.
+
++------------------+-----------------------------------------------------------+
+|Parameters                                                                    |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|uint32 lmid       |ID of the Logical Machine                                  |
++------------------+-----------------------------------------------------------+
+|Return values                                                                 |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|int32 status      |SUCCESS: if valid attributes are returned.                 |
+|                  |NOT_FOUND: if lmid not points to a valid logical machine.  |
+|                  |DENIED: if the agent does not have permission to get info  |
+|                  |for the LM specified by lmid.                              |
++------------------+-----------------------------------------------------------+
+|uint32 lmid       |Identifier of the LM whose identification is requested.    |
+|                  |This field is: Populated with the lmid of the calling      |
+|                  |agent, when the lmid parameter passed via the command is   |
+|                  |0xFFFFFFFF. Identical to the lmid field passed via the     |
+|                  |calling parameters, in all other cases                     |
++------------------+-----------------------------------------------------------+
+|uint32 attributes | Bits[31:0] reserved. must be zero                         |
++------------------+-----------------------------------------------------------+
+|uint32 state      | Current state of the LM                                   |
++------------------+-----------------------------------------------------------+
+|uint32 errStatus  | Last error status recorded                                |
++------------------+-----------------------------------------------------------+
+|char name[16]     | A NULL terminated ASCII string with the LM name, of up    |
+|                  | to 16 bytes                                               |
++------------------+-----------------------------------------------------------+
+
+LMM_BOOT
+~~~~~~~~
+
+message_id: 0x4
+protocol_id: 0x80
+This command is mandatory.
+
++------------------+-----------------------------------------------------------+
+|Parameters                                                                    |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|uint32 lmid       |ID of the Logical Machine                                  |
++------------------+-----------------------------------------------------------+
+|Return values                                                                 |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|int32 status      |SUCCESS: if LM boots successfully started.                 |
+|                  |NOT_FOUND: if lmid not points to a valid logical machine.  |
+|                  |INVALID_PARAMETERS: if lmid is same as the caller.         |
+|                  |DENIED: if the agent does not have permission to manage the|
+|                  |the LM specified by lmid.                                  |
++------------------+-----------------------------------------------------------+
+
+LMM_RESET
+~~~~~~~~~
+
+message_id: 0x5
+protocol_id: 0x80
+This command is mandatory.
+
++------------------+-----------------------------------------------------------+
+|Parameters                                                                    |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|uint32 lmid       |ID of the Logical Machine                                  |
++------------------+-----------------------------------------------------------+
+|uint32 flags      |Reset flags:                                               |
+|                  |Bits[31:1] Reserved, must be zero.                         |
+|                  |Bit[0] Graceful request:                                   |
+|                  |Set to 1 if the request is a graceful request.             |
+|                  |Set to 0 if the request is a forceful request.             |
++------------------+-----------------------------------------------------------+
+|Return values                                                                 |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|int32 status      |SUCCESS: The LMM RESET command finished successfully in    |
+|                  |graceful reset or LM successfully resets in forceful reset.|
+|                  |NOT_FOUND: if lmid not points to a valid logical machine.  |
+|                  |INVALID_PARAMETERS: if lmid is same as the caller.         |
+|                  |DENIED: if the agent does not have permission to manage the|
+|                  |the LM specified by lmid.                                  |
++------------------+-----------------------------------------------------------+
+
+LMM_SHUTDOWN
+~~~~~~~~~~~~
+
+message_id: 0x6
+protocol_id: 0x80
+This command is mandatory.
+
++------------------+-----------------------------------------------------------+
+|Parameters                                                                    |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|uint32 lmid       |ID of the Logical Machine                                  |
++------------------+-----------------------------------------------------------+
+|uint32 flags      |Reset flags:                                               |
+|                  |Bits[31:1] Reserved, must be zero.                         |
+|                  |Bit[0] Graceful request:                                   |
+|                  |Set to 1 if the request is a graceful request.             |
+|                  |Set to 0 if the request is a forceful request.             |
++------------------+-----------------------------------------------------------+
+|Return values                                                                 |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|int32 status      |SUCCESS: The LMM shutdown command finished successfully in |
+|                  |graceful request or LM successfully shutdown in forceful   |
+|                  |request.                                                   |
+|                  |NOT_FOUND: if lmid not points to a valid logical machine.  |
+|                  |INVALID_PARAMETERS: if lmid is same as the caller.         |
+|                  |DENIED: if the agent does not have permission to manage the|
+|                  |the LM specified by lmid.                                  |
++------------------+-----------------------------------------------------------+
+
+LMM_WAKE
+~~~~~~~~
+
+message_id: 0x7
+protocol_id: 0x80
+This command is mandatory.
+
++------------------+-----------------------------------------------------------+
+|Parameters                                                                    |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|uint32 lmid       |ID of the Logical Machine                                  |
++------------------+-----------------------------------------------------------+
+|Return values                                                                 |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|int32 status      |SUCCESS: if LM wake command successfully returns.          |
+|                  |NOT_FOUND: if lmid not points to a valid logical machine.  |
+|                  |INVALID_PARAMETERS: if lmid is same as the caller.         |
+|                  |DENIED: if the agent does not have permission to manage the|
+|                  |the LM specified by lmid.                                  |
++------------------+-----------------------------------------------------------+
+
+LMM_SUSPEND
+~~~~~~~~~~~
+
+message_id: 0x8
+protocol_id: 0x80
+This command is mandatory.
+
++------------------+-----------------------------------------------------------+
+|Parameters                                                                    |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|uint32 lmid       |ID of the Logical Machine                                  |
++------------------+-----------------------------------------------------------+
+|Return values                                                                 |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|int32 status      |SUCCESS: if LM suspend command successfully returns.       |
+|                  |NOT_FOUND: if lmid not points to a valid logical machine.  |
+|                  |INVALID_PARAMETERS: if lmid is same as the caller.         |
+|                  |DENIED: if the agent does not have permission to manage the|
+|                  |the LM specified by lmid.                                  |
++------------------+-----------------------------------------------------------+
+
+LMM_NOTIFY
+~~~~~~~~~~
+
+message_id: 0x9
+protocol_id: 0x80
+This command is mandatory.
+
++------------------+-----------------------------------------------------------+
+|Parameters                                                                    |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|uint32 lmid       |ID of the Logical Machine                                  |
++------------------+-----------------------------------------------------------+
+|uint32 flags      |Notification flags:                                        |
+|                  |Bits[31:3] Reserved, must be zero.                         |
+|                  |Bit[3] Wake (resume) notification:                         |
+|                  |Set to 1 to send notification.                             |
+|                  |Set to 0 if no notification.                               |
+|                  |Bit[2] Suspend (sleep) notification:                       |
+|                  |Set to 1 to send notification.                             |
+|                  |Set to 0 if no notification.                               |
+|                  |Bit[1] Shutdown (off) notification:                        |
+|                  |Set to 1 to send notification.                             |
+|                  |Set to 0 if no notification.                               |
+|                  |Bit[0] Boot (on) notification:                             |
+|                  |Set to 1 to send notification.                             |
+|                  |Set to 0 if no notification                                |
++------------------+-----------------------------------------------------------+
+|Return values                                                                 |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|int32 status      |SUCCESS: if the notification state successfully updated.   |
+|                  |NOT_FOUND: if lmid not points to a valid logical machine.  |
+|                  |INVALID_PARAMETERS: if input attributes flag specifies     |
+|                  |unsupported or invalid configurations.                     |
+|                  |DENIED: if the agent does not have permission to request   |
+|                  |the notification.                                          |
++------------------+-----------------------------------------------------------+
+
+LMM_RESET_REASON
+~~~~~~~~~~~~~~~~
+
+message_id: 0xA
+protocol_id: 0x80
+This command is mandatory.
+
+This command is to return the reset reason that caused the last reset, such as
+POR, WDOG, JTAG and etc.
+
++---------------------+--------------------------------------------------------+
+|Parameters                                                                    |
++---------------------+--------------------------------------------------------+
+|Name                 |Description                                             |
++---------------------+--------------------------------------------------------+
+|uint32 lmid          |ID of the Logical Machine                               |
++---------------------+--------------------------------------------------------+
+|Return values                                                                 |
++---------------------+--------------------------------------------------------+
+|Name                 |Description                                             |
++---------------------+--------------------------------------------------------+
+|int32 status         |SUCCESS: if the reset reason of the LM successfully     |
+|                     |updated.                                                |
+|                     |NOT_FOUND: if lmid not points to a valid logical machine|
+|                     |DENIED: if the agent does not have permission to request|
+|                     |the reset reason.                                       |
++---------------------+--------------------------------------------------------+
+|uint32 bootflags     |Boot reason flags. This parameter has the format:       |
+|                     |Bits[31] Valid.                                         |
+|                     |Set to 1 if the entire reason is valid.                 |
+|                     |Set to 0 if the entire reason is not valid.             |
+|                     |Bits[30:29] Reserved, must be zero.                     |
+|                     |Bit[28] Valid origin:                                   |
+|                     |Set to 1 if the origin field is valid.                  |
+|                     |Set to 0 if the origin field is not valid.              |
+|                     |Bits[27:24] Origin.                                     |
+|                     |Logical Machine(LM) ID that causes the BOOT of this LM  |
+|                     |Bit[23] Valid err ID:                                   |
+|                     |Set to 1 if the error ID field is valid.                |
+|                     |Set to 0 if the error ID field is not valid.            |
+|                     |Bits[22:8] Error ID(Agent ID of the system).            |
+|                     |Bit[7:0] Reason(WDOG, POR, FCCU and etc):               |
+|                     |See the SRESR register description in the System        |
+|                     |Reset Controller (SRC) section in SoC reference mannual |
+|                     |One reason maps to BIT(reason) in SRESR                 |
++---------------------+--------------------------------------------------------+
+|uint32 shutdownflags |Shutdown reason flags. This parameter has the format:   |
+|                     |Bits[31] Valid.                                         |
+|                     |Set to 1 if the entire reason is valid.                 |
+|                     |Set to 0 if the entire reason is not valid.             |
+|                     |Bits[30:29] Number of valid extended info words.        |
+|                     |Bit[28] Valid origin:                                   |
+|                     |Set to 1 if the origin field is valid.                  |
+|                     |Set to 0 if the origin field is not valid.              |
+|                     |Bits[27:24] Origin.                                     |
+|                     |Logical Machine(LM) ID that causes the BOOT of this LM  |
+|                     |Bit[23] Valid err ID:                                   |
+|                     |Set to 1 if the error ID field is valid.                |
+|                     |Set to 0 if the error ID field is not valid.            |
+|                     |Bits[22:8] Error ID(Agent ID of the System).            |
+|                     |Bit[7:0] Reason                                         |
+|                     |See the SRESR register description in the System        |
+|                     |Reset Controller (SRC) section in SoC reference mannual |
+|                     |One reason maps to BIT(reason) in SRESR                 |
++---------------------+--------------------------------------------------------+
+|uint32 extinfo[3]    |Array of extended info words(e.g. fault pc)             |
++---------------------+--------------------------------------------------------+
+
+LMM_POWER_ON
+~~~~~~~~~~~~
+
+message_id: 0xB
+protocol_id: 0x80
+This command is mandatory.
+
++------------------+-----------------------------------------------------------+
+|Parameters                                                                    |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|uint32 lmid       |ID of the Logical Machine                                  |
++------------------+-----------------------------------------------------------+
+|Return values                                                                 |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|int32 status      |SUCCESS: if LM successfully powers on.                     |
+|                  |NOT_FOUND: if lmid not points to a valid logical machine.  |
+|                  |INVALID_PARAMETERS: if lmid is same as the caller.         |
+|                  |DENIED: if the agent does not have permission to manage the|
+|                  |the LM specified by lmid.                                  |
++------------------+-----------------------------------------------------------+
+
+LMM_RESET_VECTOR_SET
+~~~~~~~~~~~~~~~~~~~~
+
+message_id: 0xC
+protocol_id: 0x80
+This command is mandatory.
+
++-----------------------+------------------------------------------------------+
+|Parameters                                                                    |
++-----------------------+------------------------------------------------------+
+|Name                   |Description                                           |
++-----------------------+------------------------------------------------------+
+|uint32 lmid            |ID of the Logical Machine                             |
++-----------------------+------------------------------------------------------+
+|uint32 cpuid           |ID of the CPU inside the LM                           |
++-----------------------+------------------------------------------------------+
+|uint32 flags           |Reset vector flags                                    |
+|                       |Bits[31:0] Reserved, must be zero.                    |
++-----------------------+------------------------------------------------------+
+|uint32 resetVectorLow  |Lower vector                                          |
++-----------------------+------------------------------------------------------+
+|uint32 resetVectorHigh |Higher vector                                         |
++-----------------------+------------------------------------------------------+
+|Return values                                                                 |
++-----------------------+------------------------------------------------------+
+|Name                   |Description                                           |
++-----------------------+------------------------------------------------------+
+|int32 status           |SUCCESS: If reset vector is set successfully.         |
+|                       |NOT_FOUND: if lmid not points to a valid logical      |
+|                       |machine, or cpuId is not valid.                       |
+|                       |INVALID_PARAMETERS: if reset vector is invalid.       |
+|                       |DENIED: if the agent does not have permission to set  |
+|                       |the reset vector for the CPU in the LM.               |
++-----------------------+------------------------------------------------------+
+
+NEGOTIATE_PROTOCOL_VERSION
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+message_id: 0x10
+protocol_id: 0x80
+This command is mandatory.
+
++--------------------+---------------------------------------------------------+
+|Parameters                                                                    |
++--------------------+---------------------------------------------------------+
+|Name                |Description                                              |
++--------------------+---------------------------------------------------------+
+|uint32 version      |The negotiated protocol version the agent intends to use |
++--------------------+---------------------------------------------------------+
+|Return values                                                                 |
++--------------------+---------------------------------------------------------+
+|Name                |Description                                              |
++--------------------+---------------------------------------------------------+
+|int32 status        |SUCCESS: if the negotiated protocol version is supported |
+|                    |by the platform. All commands, responses, and            |
+|                    |notifications post successful return of this command must|
+|                    |comply with the negotiated version.                      |
+|                    |NOT_SUPPORTED: if the protocol version is not supported. |
++--------------------+---------------------------------------------------------+
+
+Notifications
+_____________
+
+LMM_EVENT
+~~~~~~~~~
+
+message_id: 0x0
+protocol_id: 0x80
+
++------------------+-----------------------------------------------------------+
+|Parameters                                                                    |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|uint32 lmid       |Identifier for the LM that caused the transition.          |
++------------------+-----------------------------------------------------------+
+|uint32 eventlm    |Identifier of the LM this event refers to.                 |
++------------------+-----------------------------------------------------------+
+|uint32 flags      |LM events:                                                 |
+|                  |Bits[31:3] Reserved, must be zero.                         |
+|                  |Bit[3] Wake (resume) event:                                |
+|                  |1 LM has awakened.                                         |
+|                  |0 not a wake event.                                        |
+|                  |Bit[2] Suspend (sleep) event:                              |
+|                  |1 LM has suspended.                                        |
+|                  |0 not a suspend event.                                     |
+|                  |Bit[1] Shutdown (off) event:                               |
+|                  |1 LM has shutdown.                                         |
+|                  |0 not a shutdown event.                                    |
+|                  |Bit[0] Boot (on) event:                                    |
+|                  |1 LM has booted.                                           |
+|                  |0 not a boot event.                                        |
++------------------+-----------------------------------------------------------+
+
 SCMI_BBM: System Control and Management BBM Vendor Protocol
 ==============================================================
 
···
 |                  |1 button change detected.                                  |
 |                  |0 no button change detected.                               |
 +------------------+-----------------------------------------------------------+
+
+System Control and Management CPU Vendor Protocol
+=================================================
+
+This protocol allows an agent to start or stop a CPU. It is used to manage
+auxiliary CPUs in a target LM (e.g. additional cores in an AP cluster or
+Cortex-M cores).
+Note:
+ - For cores in AP cluster, PSCI should be used and PSCI firmware will use CPU
+   protocol to handle them. For cores in non-AP cluster, Operating System(e.g.
+   Linux OS) could use CPU protocols to control Cortex-M7 cores.
+ - CPU indicates the core and its auxiliary peripherals(e.g. TCM) inside
+   i.MX SoC
+
+There are cases where giving an agent full control of a CPU via the CPU
+protocol is not desired. The LMM protocol is more restricted to just boot,
+shutdown, etc. So an agent might boot another logical machine but not be
+able to directly mess the state of its CPUs. Its also the reason there is an
+LMM power on command even though that could have been done through the
+power protocol.
+
+The CPU protocol provides commands to:
+
+- Describe the protocol version.
+- Discover implementation attributes.
+- Discover the CPUs defined in the system.
+- Start a CPU.
+- Stop a CPU.
+- Set the boot and resume addresses for a CPU.
+- Set the sleep mode of a CPU.
+- Configure wake-up sources for a CPU.
+- Configure power domain reactions (LPM mode and retention mask) for a CPU.
+- The CPU IDs can be found in the CPU section of the SoC DEVICE: SM Device
+  Interface. They can also be found in the SoC RM. See the CPU Mode Control
+  (CMC) list in General Power Controller (GPC) section.
+
+CPU settings are not aggregated and setting their state is normally exclusive
+to one client.
+
+Commands:
+_________
+
+PROTOCOL_VERSION
+~~~~~~~~~~~~~~~~
+
+message_id: 0x0
+protocol_id: 0x82
+This command is mandatory.
+
++---------------+--------------------------------------------------------------+
+|Return values                                                                 |
++---------------+--------------------------------------------------------------+
+|Name           |Description                                                   |
++---------------+--------------------------------------------------------------+
+|int32 status   | See ARM SCMI Specification for status code definitions.      |
++---------------+--------------------------------------------------------------+
+|uint32 version | For this revision of the specification, this value must be   |
+|               | 0x10000.                                                     |
++---------------+--------------------------------------------------------------+
+
+PROTOCOL_ATTRIBUTES
+~~~~~~~~~~~~~~~~~~~
+
+message_id: 0x1
+protocol_id: 0x82
+This command is mandatory.
+
++---------------+--------------------------------------------------------------+
+|Return values                                                                 |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|int32 status      | See ARM SCMI Specification for status code definitions.   |
++------------------+-----------------------------------------------------------+
+|uint32 attributes |Protocol attributes:                                       |
+|                  |Bits[31:16] Reserved, must be zero.                        |
+|                  |Bits[15:0] Number of CPUs                                  |
++------------------+-----------------------------------------------------------+
+
+PROTOCOL_MESSAGE_ATTRIBUTES
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+message_id: 0x2
+protocol_id: 0x82
+This command is mandatory.
+
++---------------+--------------------------------------------------------------+
+|Return values                                                                 |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|int32 status      |SUCCESS: in case the message is implemented and available  |
+|                  |to use.                                                    |
+|                  |NOT_FOUND: if the message identified by message_id is      |
+|                  |invalid or not implemented                                 |
++------------------+-----------------------------------------------------------+
+|uint32 attributes |Flags that are associated with a specific command in the   |
+|                  |protocol. For all commands in this protocol, this          |
+|                  |parameter has a value of 0                                 |
++------------------+-----------------------------------------------------------+
+
+CPU_ATTRIBUTES
+~~~~~~~~~~~~~~
+
+message_id: 0x4
+protocol_id: 0x82
+This command is mandatory.
+
++------------------+-----------------------------------------------------------+
+|Parameters                                                                    |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|uint32 cpuid      |Identifier for the CPU                                     |
++------------------+-----------------------------------------------------------+
+|Return values                                                                 |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|int32 status      |SUCCESS: if valid attributes are returned successfully.    |
+|                  |NOT_FOUND: if the cpuid is not valid.                      |
++------------------+-----------------------------------------------------------+
+|uint32 attributes |Bits[31:0] Reserved, must be zero                          |
++------------------+-----------------------------------------------------------+
+|char name[16]     |NULL terminated ASCII string with CPU name up to 16 bytes  |
++------------------+-----------------------------------------------------------+
+
+CPU_START
+~~~~~~~~~
+
+message_id: 0x4
+protocol_id: 0x82
+This command is mandatory.
+
++------------------+-----------------------------------------------------------+
+|Parameters                                                                    |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|uint32 cpuid      |Identifier for the CPU                                     |
++------------------+-----------------------------------------------------------+
+|Return values                                                                 |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|int32 status      |SUCCESS: if the cpu is started successfully.               |
+|                  |NOT_FOUND: if cpuid is not valid.                          |
+|                  |DENIED: the calling agent is not allowed to start this CPU.|
++------------------+-----------------------------------------------------------+
+
+CPU_STOP
+~~~~~~~~
+
+message_id: 0x5
+protocol_id: 0x82
+This command is mandatory.
+
++------------------+-----------------------------------------------------------+
+|Parameters                                                                    |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|uint32 cpuid      |Identifier for the CPU                                     |
++------------------+-----------------------------------------------------------+
+|Return values                                                                 |
++------------------+-----------------------------------------------------------+
+|Name              |Description                                                |
++------------------+-----------------------------------------------------------+
+|int32 status      |SUCCESS: if the cpu is started successfully.               |
+|                  |NOT_FOUND: if cpuid is not valid.                          |
+|                  |DENIED: the calling agent is not allowed to stop this CPU. |
++------------------+-----------------------------------------------------------+
+
+CPU_RESET_VECTOR_SET
+~~~~~~~~~~~~~~~~~~~~
+
+message_id: 0x6
+protocol_id: 0x82
+This command is mandatory.
+
++----------------------+-------------------------------------------------------+
+|Parameters                                                                    |
++----------------------+-------------------------------------------------------+
+|Name                  |Description                                            |
++----------------------+-------------------------------------------------------+
+|uint32 cpuid          |Identifier for the CPU                                 |
++----------------------+-------------------------------------------------------+
+|uint32 flags          |Reset vector flags:                                    |
+|                      |Bit[31] Resume flag.                                   |
+|                      |Set to 1 to update the reset vector used on resume.    |
+|                      |Bit[30] Boot flag.                                     |
+|                      |Set to 1 to update the reset vector used for boot.     |
+|                      |Bits[29:1] Reserved, must be zero.                     |
+|                      |Bit[0] Table flag.                                     |
+|                      |Set to 1 if vector is the vector table base address.   |
++----------------------+-------------------------------------------------------+
+|uint32 resetVectorLow |Lower vector:                                          |
+|                      |If bit[0] of flags is 0, the lower 32 bits of the      |
+|                      |physical address where the CPU should execute from on  |
+|                      |reset. If bit[0] of flags is 1, the lower 32 bits of   |
+|                      |the vector table base address                          |
++----------------------+-------------------------------------------------------+
+|uint32 resetVectorhigh|Upper vector:                                          |
+|                      |If bit[0] of flags is 0, the upper 32 bits of the      |
+|                      |physical address where the CPU should execute from on  |
+|                      |reset. If bit[0] of flags is 1, the upper 32 bits of   |
+|                      |the vector table base address                          |
++----------------------+-------------------------------------------------------+
+|Return values                                                                 |
++----------------------+-------------------------------------------------------+
+|Name                  |Description                                            |
++----------------------+-------------------------------------------------------+
+|int32 status          |SUCCESS: if the CPU reset vector is set successfully.  |
+|                      |NOT_FOUND: if cpuId does not point to a valid CPU.     |
+|                      |INVALID_PARAMETERS: the requested vector type is not   |
+|                      |supported by this CPU.                                 |
+|                      |DENIED: the calling agent is not allowed to set the    |
+|                      |reset vector of this CPU                               |
++----------------------+-------------------------------------------------------+
+
+CPU_SLEEP_MODE_SET
+~~~~~~~~~~~~~~~~~~
+
+message_id: 0x7
+protocol_id: 0x82
+This command is mandatory.
+
++----------------------+-------------------------------------------------------+
+|Parameters                                                                    |
++----------------------+-------------------------------------------------------+
+|Name                  |Description                                            |
++----------------------+-------------------------------------------------------+
+|uint32 cpuid          |Identifier for the CPU                                 |
++----------------------+-------------------------------------------------------+
+|uint32 flags          |Sleep mode flags:                                      |
+|                      |Bits[31:1] Reserved, must be zero.                     |
+|                      |Bit[0] IRQ mux:                                        |
+|                      |If set to 1 the wakeup mux source is the GIC, else if 0|
+|                      |then the GPC                                           |
++----------------------+-------------------------------------------------------+
+|uint32 sleepmode      |target sleep mode. When CPU runs into WFI, the GPC mode|
+|                      |will be triggered to be in below modes:                |
+|                      |RUN:     (0)                                           |
+|                      |WAIT:    (1)                                           |
+|                      |STOP:    (2)                                           |
+|                      |SUSPEND: (3)                                           |
++----------------------+-------------------------------------------------------+
+|Return values                                                                 |
++----------------------+-------------------------------------------------------+
+|Name                  |Description                                            |
++----------------------+-------------------------------------------------------+
+|int32 status          |SUCCESS: if the CPU sleep mode is set successfully.    |
+|                      |NOT_FOUND: if cpuId does not point to a valid CPU.     |
+|                      |INVALID_PARAMETERS: the sleepmode or flags is invalid. |
+|                      |DENIED: the calling agent is not allowed to configure  |
+|                      |the CPU                                                |
++----------------------+-------------------------------------------------------+
+
+CPU_INFO_GET
+~~~~~~~~~~~~
+
+message_id: 0xC
+protocol_id: 0x82
+This command is mandatory.
+
++----------------------+-------------------------------------------------------+
+|Parameters                                                                    |
++----------------------+-------------------------------------------------------+
+|Name                  |Description                                            |
++----------------------+-------------------------------------------------------+
+|uint32 cpuid          |Identifier for the CPU                                 |
++----------------------+-------------------------------------------------------+
+|Return values                                                                 |
++----------------------+-------------------------------------------------------+
+|Name                  |Description                                            |
++----------------------+-------------------------------------------------------+
+|int32 status          |SUCCESS: if valid attributes are returned successfully.|
+|                      |NOT_FOUND: if the cpuid is not valid.                  |
++----------------------+-------------------------------------------------------+
+|uint32 runmode        |Run mode for the CPU                                   |
+|                      |RUN(0):cpu started                                     |
+|                      |HOLD(1):cpu powered up and reset asserted              |
+|                      |STOP(2):cpu reseted and hold cpu                       |
+|                      |SUSPEND(3):in cpuidle state                            |
++----------------------+-------------------------------------------------------+
+|uint32 sleepmode      |Sleep mode for the CPU, see CPU_SLEEP_MODE_SET         |
++----------------------+-------------------------------------------------------+
+|uint32 resetvectorlow |Reset vector low 32 bits for the CPU                   |
++----------------------+-------------------------------------------------------+
+|uint32 resetvecothigh |Reset vector high 32 bits for the CPU                  |
++----------------------+-------------------------------------------------------+
+
+NEGOTIATE_PROTOCOL_VERSION
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+message_id: 0x10
+protocol_id: 0x82
+This command is mandatory.
+
++--------------------+---------------------------------------------------------+
+|Parameters                                                                    |
++--------------------+---------------------------------------------------------+
+|Name                |Description                                              |
++--------------------+---------------------------------------------------------+
+|uint32 version      |The negotiated protocol version the agent intends to use |
++--------------------+---------------------------------------------------------+
+|Return values                                                                 |
++--------------------+---------------------------------------------------------+
+|Name                |Description                                              |
++--------------------+---------------------------------------------------------+
+|int32 status        |SUCCESS: if the negotiated protocol version is supported |
+|                    |by the platform. All commands, responses, and            |
+|                    |notifications post successful return of this command must|
+|                    |comply with the negotiated version.                      |
+|                    |NOT_SUPPORTED: if the protocol version is not supported. |
++--------------------+---------------------------------------------------------+
 
 SCMI_MISC: System Control and Management MISC Vendor Protocol
 ================================================================

drivers/firmware/imx/Kconfig

···
 	  This driver manages the IPC interface between host CPU and the
 	  SCU firmware running on M4.
 
+config IMX_SCMI_CPU_DRV
+	tristate "IMX SCMI CPU Protocol driver"
+	depends on ARCH_MXC || COMPILE_TEST
+	default y if ARCH_MXC
+	help
+	  The System Controller Management Interface firmware (SCMI FW) is
+	  a low-level system function which runs on a dedicated Cortex-M
+	  core that could provide cpu management features.
+
+	  This driver can also be built as a module.
+
+config IMX_SCMI_LMM_DRV
+	tristate "IMX SCMI LMM Protocol driver"
+	depends on ARCH_MXC || COMPILE_TEST
+	default y if ARCH_MXC
+	help
+	  The System Controller Management Interface firmware (SCMI FW) is
+	  a low-level system function which runs on a dedicated Cortex-M
+	  core that could provide Logical Machine management features.
+
+	  This driver can also be built as a module.
+
 config IMX_SCMI_MISC_DRV
 	tristate "IMX SCMI MISC Protocol driver"
 	depends on ARCH_MXC || COMPILE_TEST

drivers/firmware/imx/Makefile

···
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_IMX_DSP)		+= imx-dsp.o
 obj-$(CONFIG_IMX_SCU)		+= imx-scu.o misc.o imx-scu-irq.o rm.o imx-scu-soc.o
+obj-${CONFIG_IMX_SCMI_CPU_DRV}	+= sm-cpu.o
 obj-${CONFIG_IMX_SCMI_MISC_DRV}	+= sm-misc.o
+obj-${CONFIG_IMX_SCMI_LMM_DRV}	+= sm-lmm.o

drivers/firmware/imx/sm-cpu.c

···
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2025 NXP
+ */
+
+#include <linux/firmware/imx/sm.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/scmi_protocol.h>
+#include <linux/scmi_imx_protocol.h>
+
+static const struct scmi_imx_cpu_proto_ops *imx_cpu_ops;
+static struct scmi_protocol_handle *ph;
+
+int scmi_imx_cpu_reset_vector_set(u32 cpuid, u64 vector, bool start, bool boot,
+				  bool resume)
+{
+	if (!ph)
+		return -EPROBE_DEFER;
+
+	return imx_cpu_ops->cpu_reset_vector_set(ph, cpuid, vector, start,
+						 boot, resume);
+}
+EXPORT_SYMBOL(scmi_imx_cpu_reset_vector_set);
+
+int scmi_imx_cpu_start(u32 cpuid, bool start)
+{
+	if (!ph)
+		return -EPROBE_DEFER;
+
+	if (start)
+		return imx_cpu_ops->cpu_start(ph, cpuid, true);
+
+	return imx_cpu_ops->cpu_start(ph, cpuid, false);
+};
+EXPORT_SYMBOL(scmi_imx_cpu_start);
+
+int scmi_imx_cpu_started(u32 cpuid, bool *started)
+{
+	if (!ph)
+		return -EPROBE_DEFER;
+
+	if (!started)
+		return -EINVAL;
+
+	return imx_cpu_ops->cpu_started(ph, cpuid, started);
+};
+EXPORT_SYMBOL(scmi_imx_cpu_started);
+
+static int scmi_imx_cpu_probe(struct scmi_device *sdev)
+{
+	const struct scmi_handle *handle = sdev->handle;
+
+	if (!handle)
+		return -ENODEV;
+
+	if (imx_cpu_ops) {
+		dev_err(&sdev->dev, "sm cpu already initialized\n");
+		return -EEXIST;
+	}
+
+	imx_cpu_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_IMX_CPU, &ph);
+	if (IS_ERR(imx_cpu_ops))
+		return PTR_ERR(imx_cpu_ops);
+
+	return 0;
+}
+
+static const struct scmi_device_id scmi_id_table[] = {
+	{ SCMI_PROTOCOL_IMX_CPU, "imx-cpu" },
+	{ },
+};
+MODULE_DEVICE_TABLE(scmi, scmi_id_table);
+
+static struct scmi_driver scmi_imx_cpu_driver = {
+	.name = "scmi-imx-cpu",
+	.probe = scmi_imx_cpu_probe,
+	.id_table = scmi_id_table,
+};
+module_scmi_driver(scmi_imx_cpu_driver);
+
+MODULE_AUTHOR("Peng Fan <[e-mail]>");
+MODULE_DESCRIPTION("IMX SM CPU driver");
+MODULE_LICENSE("GPL");

drivers/firmware/imx/sm-lmm.c

···
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2025 NXP
+ */
+
+#include <linux/firmware/imx/sm.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/scmi_protocol.h>
+#include <linux/scmi_imx_protocol.h>
+
+static const struct scmi_imx_lmm_proto_ops *imx_lmm_ops;
+static struct scmi_protocol_handle *ph;
+
+int scmi_imx_lmm_info(u32 lmid, struct scmi_imx_lmm_info *info)
+{
+	if (!ph)
+		return -EPROBE_DEFER;
+
+	if (!info)
+		return -EINVAL;
+
+	return imx_lmm_ops->lmm_info(ph, lmid, info);
+};
+EXPORT_SYMBOL(scmi_imx_lmm_info);
+
+int scmi_imx_lmm_reset_vector_set(u32 lmid, u32 cpuid, u32 flags, u64 vector)
+{
+	if (!ph)
+		return -EPROBE_DEFER;
+
+	return imx_lmm_ops->lmm_reset_vector_set(ph, lmid, cpuid, flags, vector);
+}
+EXPORT_SYMBOL(scmi_imx_lmm_reset_vector_set);
+
+int scmi_imx_lmm_operation(u32 lmid, enum scmi_imx_lmm_op op, u32 flags)
+{
+	if (!ph)
+		return -EPROBE_DEFER;
+
+	switch (op) {
+	case SCMI_IMX_LMM_BOOT:
+		return imx_lmm_ops->lmm_power_boot(ph, lmid, true);
+	case SCMI_IMX_LMM_POWER_ON:
+		return imx_lmm_ops->lmm_power_boot(ph, lmid, false);
+	case SCMI_IMX_LMM_SHUTDOWN:
+		return imx_lmm_ops->lmm_shutdown(ph, lmid, flags);
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL(scmi_imx_lmm_operation);
+
+static int scmi_imx_lmm_probe(struct scmi_device *sdev)
+{
+	const struct scmi_handle *handle = sdev->handle;
+
+	if (!handle)
+		return -ENODEV;
+
+	if (imx_lmm_ops) {
+		dev_err(&sdev->dev, "lmm already initialized\n");
+		return -EEXIST;
+	}
+
+	imx_lmm_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_IMX_LMM, &ph);
+	if (IS_ERR(imx_lmm_ops))
+		return PTR_ERR(imx_lmm_ops);
+
+	return 0;
+}
+
+static const struct scmi_device_id scmi_id_table[] = {
+	{ SCMI_PROTOCOL_IMX_LMM, "imx-lmm" },
+	{ },
+};
+MODULE_DEVICE_TABLE(scmi, scmi_id_table);
+
+static struct scmi_driver scmi_imx_lmm_driver = {
+	.name = "scmi-imx-lmm",
+	.probe = scmi_imx_lmm_probe,
+	.id_table = scmi_id_table,
+};
+module_scmi_driver(scmi_imx_lmm_driver);
+
+MODULE_AUTHOR("Peng Fan <[e-mail]>");
+MODULE_DESCRIPTION("IMX SM LMM driver");
+MODULE_LICENSE("GPL");

include/linux/firmware/imx/sm.h

···
 
 #include <linux/bitfield.h>
 #include <linux/errno.h>
+#include <linux/scmi_imx_protocol.h>
 #include <linux/types.h>
 
 #define SCMI_IMX_CTRL_PDM_CLK_SEL	0	/* AON PDM clock sel */
···
 int scmi_imx_misc_ctrl_get(u32 id, u32 *num, u32 *val);
 int scmi_imx_misc_ctrl_set(u32 id, u32 val);
 
+int scmi_imx_cpu_start(u32 cpuid, bool start);
+int scmi_imx_cpu_started(u32 cpuid, bool *started);
+int scmi_imx_cpu_reset_vector_set(u32 cpuid, u64 vector, bool start, bool boot,
+				  bool resume);
+
+enum scmi_imx_lmm_op {
+	SCMI_IMX_LMM_BOOT,
+	SCMI_IMX_LMM_POWER_ON,
+	SCMI_IMX_LMM_SHUTDOWN,
+};
+
+/* For shutdown pperation */
+#define SCMI_IMX_LMM_OP_FORCEFUL	0
+#define SCMI_IMX_LMM_OP_GRACEFUL	BIT(0)
+
+int scmi_imx_lmm_operation(u32 lmid, enum scmi_imx_lmm_op op, u32 flags);
+int scmi_imx_lmm_info(u32 lmid, struct scmi_imx_lmm_info *info);
+int scmi_imx_lmm_reset_vector_set(u32 lmid, u32 cpuid, u32 flags, u64 vector);
 #endif

include/linux/scmi_imx_protocol.h

···
 #include <linux/bitfield.h>
 #include <linux/device.h>
 #include <linux/notifier.h>
+#include <linux/scmi_protocol.h>
 #include <linux/types.h>
 
+#define SCMI_PROTOCOL_IMX_LMM	0x80
 #define	SCMI_PROTOCOL_IMX_BBM	0x81
+#define SCMI_PROTOCOL_IMX_CPU	0x82
 #define	SCMI_PROTOCOL_IMX_MISC	0x84
 
 #define SCMI_IMX_VENDOR		"NXP"
···
 			     u32 *num, u32 *val);
 	int (*misc_ctrl_req_notify)(const struct scmi_protocol_handle *ph,
 				    u32 ctrl_id, u32 evt_id, u32 flags);
+};
+
+/* See LMM_ATTRIBUTES in imx95.rst */
+#define	LMM_ID_DISCOVER	0xFFFFFFFFU
+#define	LMM_MAX_NAME	16
+
+enum scmi_imx_lmm_state {
+	LMM_STATE_LM_OFF,
+	LMM_STATE_LM_ON,
+	LMM_STATE_LM_SUSPEND,
+	LMM_STATE_LM_POWERED,
+};
+
+struct scmi_imx_lmm_info {
+	u32 lmid;
+	enum scmi_imx_lmm_state state;
+	u32 errstatus;
+	u8 name[LMM_MAX_NAME];
+};
+
+struct scmi_imx_lmm_proto_ops {
+	int (*lmm_power_boot)(const struct scmi_protocol_handle *ph, u32 lmid,
+			      bool boot);
+	int (*lmm_info)(const struct scmi_protocol_handle *ph, u32 lmid,
+			struct scmi_imx_lmm_info *info);
+	int (*lmm_reset_vector_set)(const struct scmi_protocol_handle *ph,
+				    u32 lmid, u32 cpuid, u32 flags, u64 vector);
+	int (*lmm_shutdown)(const struct scmi_protocol_handle *ph, u32 lmid,
+			    u32 flags);
+};
+
+struct scmi_imx_cpu_proto_ops {
+	int (*cpu_reset_vector_set)(const struct scmi_protocol_handle *ph,
+				    u32 cpuid, u64 vector, bool start,
+				    bool boot, bool resume);
+	int (*cpu_start)(const struct scmi_protocol_handle *ph, u32 cpuid,
+			 bool start);
+	int (*cpu_started)(const struct scmi_protocol_handle *ph, u32 cpuid,
+			   bool *started);
 };
 #endif