[PATCH 2/5] firmware: arm_scmi: imx: Add i.MX95 CPU Protocol

Peng Fan (OSS)
2025-01-21T15:09:03Z

From: Peng Fan <peng.fan@nxp.com>

This protocol allows an agent to start, stop a CPU or set reset vector. It
is used to manage auxiliary CPUs in an LM (e.g. additional cores in an AP
cluster).

Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
drivers/firmware/arm_scmi/vendors/imx/Kconfig | 13 +-
drivers/firmware/arm_scmi/vendors/imx/Makefile | 1 +
drivers/firmware/arm_scmi/vendors/imx/imx-sm-cpu.c | 283 +++++++++++++++++++++
include/linux/scmi_imx_protocol.h | 10 +
4 files changed, 306 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/arm_scmi/vendors/imx/Kconfig b/drivers/firmware/arm_scmi/vendors/imx/Kconfig
index 1a936fc87d2350e2a21bccd45dfbeebfa3b90286..9070522510e4d3f3d7276a7581f8676006d20f90 100644
--- a/drivers/firmware/arm_scmi/vendors/imx/Kconfig
+++ b/drivers/firmware/arm_scmi/vendors/imx/Kconfig
@@ -12,6 +12,17 @@ config IMX_SCMI_BBM_EXT
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)
+ 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)
@@ -21,7 +32,7 @@ config IMX_SCMI_LMM_EXT
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.
+ module will be called imx-sm-cpu.

config IMX_SCMI_MISC_EXT
tristate "i.MX SCMI MISC EXTENSION"
diff --git a/drivers/firmware/arm_scmi/vendors/imx/Makefile b/drivers/firmware/arm_scmi/vendors/imx/Makefile
index f39a99ccaf9af757475e8b112d224669444d7ddc..e3a5ea46345c89da1afae25e55698044672b7c28 100644
--- a/drivers/firmware/arm_scmi/vendors/imx/Makefile
+++ b/drivers/firmware/arm_scmi/vendors/imx/Makefile
@@ -1,4 +1,5 @@
# 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
diff --git a/drivers/firmware/arm_scmi/vendors/imx/imx-sm-cpu.c b/drivers/firmware/arm_scmi/vendors/imx/imx-sm-cpu.c
new file mode 100644
index 0000000000000000000000000000000000000000..e3f294c2cb69a5b5a916d55984f4a63539937d02
--- /dev/null
+++ b/drivers/firmware/arm_scmi/vendors/imx/imx-sm-cpu.c
@@ -0,0 +1,283 @@
+// 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_PROTO_ATTR_NUM_CPUS(x) ((x) & 0xFFFF)
+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)
+{
+ 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_START, 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_stop(const struct scmi_protocol_handle *ph, u32 cpuid)
+{
+ 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_STOP, 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 = start ? CPU_VEC_FLAGS_START : 0;
+ in->flags |= boot ? CPU_VEC_FLAGS_BOOT : 0;
+ in->flags |= resume ? CPU_VEC_FLAGS_BOOT : 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_cpu_started(const struct scmi_protocol_handle *ph, u32 cpuid,
+ bool *started)
+{
+ struct scmi_imx_cpu_info_get_out *out;
+ struct scmi_xfer *t;
+ int ret;
+
+ *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;
+ if ((out->runmode == CPU_RUN_MODE_START) ||
+ (out->runmode == 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,
+ .cpu_stop = scmi_imx_cpu_stop,
+};
+
+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 = SCMI_IMX_CPU_PROTO_ATTR_NUM_CPUS(attr->attributes);
+ 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_imx_cpu_info *info)
+{
+ struct scmi_msg_imx_cpu_attributes_out *out;
+ 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;
+ dev_info(ph->dev, "i.MX CPU: name: %s\n", out->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, info);
+ 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_DESCRIPTION("i.MX SCMI CPU driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/scmi_imx_protocol.h b/include/linux/scmi_imx_protocol.h
index 456559f021696ae51f40ed11e6f85089d430ce71..6521199cdab67c7e751e850def221d89898cd0f2 100644
--- a/include/linux/scmi_imx_protocol.h
+++ b/include/linux/scmi_imx_protocol.h
@@ -16,6 +16,7 @@

#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"
@@ -86,4 +87,13 @@ struct scmi_imx_lmm_proto_ops {
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);
+ int (*cpu_started)(const struct scmi_protocol_handle *ph, u32 cpuid,
+ bool *started);
+ int (*cpu_stop)(const struct scmi_protocol_handle *ph, u32 cpuid);
+};
#endif

--
2.37.1