[PATCH v2 6/7] firmware: imx: Add i.MX95 SCMI CPU driver

["Peng Fan (OSS)" <peng.fan@oss.nxp.com>]

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

The i.MX95 System manager exports SCMI CPU protocol for linux to manage
cpu cores. The driver is to use the cpu Protocol interface to
start, stop a cpu cores (eg, M7).

Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
 drivers/firmware/imx/Kconfig    | 11 +++++
 drivers/firmware/imx/Makefile   |  1 +
 drivers/firmware/imx/sm-cpu.c   | 91 +++++++++++++++++++++++++++++++++++++++++
 include/linux/firmware/imx/sm.h | 29 +++++++++++++
 4 files changed, 132 insertions(+)

diff --git a/drivers/firmware/imx/Kconfig b/drivers/firmware/imx/Kconfig
index c3e344d6ecc645df1f0e3ee8078934c47f347fd7..91c753921dffbe16ced8c10565d44c15b66b2797 100644
--- a/drivers/firmware/imx/Kconfig
+++ b/drivers/firmware/imx/Kconfig
@@ -23,6 +23,17 @@ config IMX_SCU
 	  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 IMX_SCMI_CPU_EXT || 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 IMX_SCMI_LMM_EXT || COMPILE_TEST
diff --git a/drivers/firmware/imx/Makefile b/drivers/firmware/imx/Makefile
index 7762855d2a771169d4f1867d27e0d51be7c9ad03..3bbaffa6e3478112638ed031375602389f18ef09 100644
--- a/drivers/firmware/imx/Makefile
+++ b/drivers/firmware/imx/Makefile
@@ -1,5 +1,6 @@
 # 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
diff --git a/drivers/firmware/imx/sm-cpu.c b/drivers/firmware/imx/sm-cpu.c
new file mode 100644
index 0000000000000000000000000000000000000000..1ce694a34b22843db5c1697ecb33c0479edb2ed9
--- /dev/null
+++ b/drivers/firmware/imx/sm-cpu.c
@@ -0,0 +1,91 @@
+// 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)
+{
+	if (!ph)
+		return -EPROBE_DEFER;
+
+	return imx_cpu_ops->cpu_start(ph, cpuid);
+};
+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);
+
+int scmi_imx_cpu_stop(u32 cpuid)
+{
+	if (!ph)
+		return -EPROBE_DEFER;
+
+	return imx_cpu_ops->cpu_stop(ph, cpuid);
+};
+EXPORT_SYMBOL(scmi_imx_cpu_stop);
+
+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 <peng.fan@nxp.com>");
+MODULE_DESCRIPTION("IMX SM CPU driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/firmware/imx/sm.h b/include/linux/firmware/imx/sm.h
index e02b7b558afb6f430f6fbeeaf3ee1f59feea3c1b..0eff427e5ba2cb3f93c26f7d055c346a1d1433f0 100644
--- a/include/linux/firmware/imx/sm.h
+++ b/include/linux/firmware/imx/sm.h
@@ -21,6 +21,35 @@
 int scmi_imx_misc_ctrl_get(u32 id, u32 *num, u32 *val);
 int scmi_imx_misc_ctrl_set(u32 id, u32 val);
 
+#if IS_ENABLED(CONFIG_IMX_SCMI_CPU_DRV) || IS_ENABLED(CONFIG_COMPILE_TEST)
+int scmi_imx_cpu_start(u32 cpuid);
+int scmi_imx_cpu_started(u32 cpuid, bool *started);
+int scmi_imx_cpu_stop(u32 cpuid);
+int scmi_imx_cpu_reset_vector_set(u32 cpuid, u64 vector, bool start, bool boot,
+				  bool resume);
+#else
+static inline int scmi_imx_cpu_start(u32 cpuid)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int scmi_imx_cpu_started(u32 cpuid, bool *started)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int scmi_imx_cpu_stop(u32 cpuid)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int scmi_imx_cpu_reset_vector_set(u32 cpuid, u64 vector,
+						bool start, bool boot, bool resume)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
 #if IS_ENABLED(CONFIG_IMX_SCMI_LMM_DRV) || IS_ENABLED(CONFIG_COMPILE_TEST)
 int scmi_imx_lmm_boot(u32 lmid);
 int scmi_imx_lmm_info(u32 lmid, struct scmi_imx_lmm_info *info);

-- 
2.37.1