drivers: misc: Add nxp,rtxxx-dsp-ctrl

Add the nxp,rtxxx-dsp-ctrl driver.

Responsibility of this driver is to load code executed by Xtensa-family
cores on NXP i.MX RTxxx microcontrollers and to control their run.

Signed-off-by: Vit Stanicek <vit.stanicek@nxp.com>

drivers/misc/CMakeLists.txt

@@ -11,4 +11,6 @@ add_subdirectory_ifdef(CONFIG_DEVMUX devmux)
 add_subdirectory_ifdef(CONFIG_NORDIC_VPR_LAUNCHER nordic_vpr_launcher)
 add_subdirectory_ifdef(CONFIG_MCUX_FLEXIO mcux_flexio)
 add_subdirectory_ifdef(CONFIG_RENESAS_RA_EXTERNAL_INTERRUPT renesas_ra_external_interrupt)
+add_subdirectory_ifdef(CONFIG_NXP_RTXXX_DSP_CTRL nxp_rtxxx_dsp_ctrl)
+
 add_subdirectory(coresight)

drivers/misc/Kconfig

@@ -16,5 +16,6 @@ source "drivers/misc/nordic_vpr_launcher/Kconfig"
 source "drivers/misc/mcux_flexio/Kconfig"
 source "drivers/misc/coresight/Kconfig"
 source "drivers/misc/renesas_ra_external_interrupt/Kconfig"
+source "drivers/misc/nxp_rtxxx_dsp_ctrl/Kconfig"
 
 endmenu

drivers/misc/nxp_rtxxx_dsp_ctrl/CMakeLists.txt

@@ -0,0 +1,10 @@
+# Copyright 2025 NXP
+# SPDX-License-Identifier: Apache-2.0
+
+zephyr_syscall_header(${ZEPHYR_BASE}/include/zephyr/drivers/misc/nxp_rtxxx_dsp_ctrl/nxp_rtxxx_dsp_ctrl.h)
+
+zephyr_library()
+
+zephyr_library_sources_ifdef(CONFIG_NXP_RTXXX_DSP_CTRL
+  nxp_rtxxx_dsp_ctrl.c
+)

drivers/misc/nxp_rtxxx_dsp_ctrl/Kconfig

@@ -0,0 +1,9 @@
+# Copyright 2025 NXP
+# SPDX-License-Identifier: Apache-2.0
+
+config NXP_RTXXX_DSP_CTRL
+	bool "NXP i.MX RTxxx DSP control"
+	depends on DT_HAS_NXP_RTXXX_DSP_CTRL_ENABLED
+	default y
+	help
+	  Enables a DSP control driver for NXP i.MX RTxxx devices.

drivers/misc/nxp_rtxxx_dsp_ctrl/nxp_rtxxx_dsp_ctrl.c

@@ -0,0 +1,118 @@
+/*
+ * Copyright 2025 NXP
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT nxp_rtxxx_dsp_ctrl
+
+#include <zephyr/drivers/misc/nxp_rtxxx_dsp_ctrl/nxp_rtxxx_dsp_ctrl.h>
+#include <zephyr/dt-bindings/misc/nxp_rtxxx_dsp_ctrl.h>
+
+#include <fsl_device_registers.h>
+#include <fsl_dsp.h>
+#include <fsl_clock.h>
+
+#include <errno.h>
+#include <zephyr/init.h>
+#include <zephyr/device.h>
+#include <zephyr/devicetree.h>
+
+struct nxp_rtxxx_dsp_ctrl_region {
+	void *base;
+	int32_t length;
+};
+
+struct nxp_rtxxx_dsp_ctrl_config {
+	SYSCTL0_Type *sysctl;
+	struct nxp_rtxxx_dsp_ctrl_region regions[NXP_RTXXX_DSP_REGION_MAX];
+};
+
+static void dsp_ctrl_enable(const struct device *dev)
+{
+	SYSCTL0_Type *sysctl = ((struct nxp_rtxxx_dsp_ctrl_config *)dev->config)->sysctl;
+
+	sysctl->DSPSTALL = 0;
+}
+
+static void dsp_ctrl_disable(const struct device *dev)
+{
+	SYSCTL0_Type *sysctl = ((struct nxp_rtxxx_dsp_ctrl_config *)dev->config)->sysctl;
+
+	sysctl->DSPSTALL = 1;
+}
+
+static int dsp_ctrl_load_section(const struct device *dev, const void *base, size_t length,
+				  enum nxp_rtxxx_dsp_ctrl_section_type section)
+{
+	if (section >= NXP_RTXXX_DSP_REGION_MAX) {
+		return -EINVAL;
+	}
+
+	const struct nxp_rtxxx_dsp_ctrl_config *cfg =
+		(const struct nxp_rtxxx_dsp_ctrl_config *)dev->config;
+
+	if (cfg->regions[section].base == NULL) {
+		return -EINVAL;
+	}
+
+	if (length > cfg->regions[section].length) {
+		return -ENOMEM;
+	}
+
+	/*
+	 * Custom memcpy implementation is needed because the DSP TCMs can be accessed
+	 * only by 32 bits.
+	 */
+	const uint32_t *src = (const uint32_t *)base;
+	uint32_t *dst = cfg->regions[section].base;
+
+	for (size_t remaining = length; remaining > 0; remaining -= sizeof(uint32_t)) {
+		*dst++ = *src++;
+
+		if (remaining < sizeof(uint32_t)) {
+			break;
+		}
+	}
+
+	return 0;
+}
+
+static int nxp_rtxxx_dsp_ctrl_init(const struct device *dev)
+{
+	/*
+	 * Initialize clocks associated with the DSP.
+	 * Taken from DSP examples for the MIMXRT685-EVK in the MCUXpresso SDK.
+	 */
+	CLOCK_InitSysPfd(kCLOCK_Pfd1, 16);
+	CLOCK_AttachClk(kDSP_PLL_to_DSP_MAIN_CLK);
+	CLOCK_SetClkDiv(kCLOCK_DivDspCpuClk, 1);
+	CLOCK_SetClkDiv(kCLOCK_DivDspRamClk, 2);
+
+	DSP_Init();
+
+	return 0;
+}
+
+static struct nxp_rtxxx_dsp_ctrl_api nxp_rtxxx_dsp_ctrl_api = {
+	.load_section = dsp_ctrl_load_section,
+	.enable = dsp_ctrl_enable,
+	.disable = dsp_ctrl_disable
+};
+
+#define NXP_RTXXX_DSP_SECTION(child_node_id, n)					\
+	[DT_PROP(child_node_id, type)] = {							\
+		.base = (void *)DT_REG_ADDR(child_node_id),				\
+		.length = DT_REG_SIZE(child_node_id)					\
+	},
+
+#define NXP_RTXXX_DSP_CTRL(n)                                                                     \
+	static const struct nxp_rtxxx_dsp_ctrl_config nxp_rtxxx_dsp_ctrl_##n##_config = {        \
+		.sysctl = (SYSCTL0_Type *)DT_REG_ADDR(DT_INST_PHANDLE(n, sysctl)),                 \
+		.regions = {DT_INST_FOREACH_CHILD_VARGS(n, NXP_RTXXX_DSP_SECTION, n)}};           \
+                                                                                                   \
+	DEVICE_DT_INST_DEFINE(n, nxp_rtxxx_dsp_ctrl_init, NULL, NULL,                             \
+			      &nxp_rtxxx_dsp_ctrl_##n##_config, PRE_KERNEL_1,                     \
+			      CONFIG_KERNEL_INIT_PRIORITY_DEFAULT, &nxp_rtxxx_dsp_ctrl_api);
+
+DT_INST_FOREACH_STATUS_OKAY(NXP_RTXXX_DSP_CTRL);

dts/bindings/misc/nxp,rtxxx-dsp-ctrl.yaml

@@ -0,0 +1,31 @@
+# Copyright (c) 2025 NXP
+# SPDX-License-Identifier: Apache-2.0
+
+include: [base.yaml]
+
+compatible: "nxp,rtxxx-dsp-ctrl"
+description: NXP i.MX RTxxx DSP control driver
+
+properties:
+  "#address-cells":
+    const: 1
+  "#size-cells":
+    const: 1
+  sysctl:
+    required: true
+    type: phandle
+    description: phandle to a SYSCTL node
+
+child-binding:
+  description: Memory region definition
+
+  properties:
+    reg:
+      required: true
+      type: array
+      description: Base address and length of a memory region
+
+    type:
+      required: true
+      type: int
+      description: Memory region type (NXP_RTXXX_DSP_REGION_*)

include/zephyr/drivers/misc/nxp_rtxxx_dsp_ctrl/nxp_rtxxx_dsp_ctrl.h

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2025 NXP
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/device.h>
+#include <zephyr/dt-bindings/misc/nxp_rtxxx_dsp_ctrl.h>
+
+#ifndef __NXP_RTXXX_DSP_CTRL_H__
+#define __NXP_RTXXX_DSP_CTRL_H__
+
+/**
+ * @brief Describes an image section type selection.
+ */
+enum nxp_rtxxx_dsp_ctrl_section_type {
+	NXP_RTXXX_DSP_CTRL_SECTION_RESET = NXP_RTXXX_DSP_REGION_RESET,
+	NXP_RTXXX_DSP_CTRL_SECTION_TEXT = NXP_RTXXX_DSP_REGION_TEXT,
+	NXP_RTXXX_DSP_CTRL_SECTION_DATA = NXP_RTXXX_DSP_REGION_DATA
+};
+
+typedef int (*nxp_rtxxx_dsp_ctrl_api_load_section)(
+	const struct device *,
+	const void *,
+	size_t,
+	enum nxp_rtxxx_dsp_ctrl_section_type
+);
+typedef void (*nxp_rtxxx_dsp_ctrl_api_enable)(const struct device *dev);
+typedef void (*nxp_rtxxx_dsp_ctrl_api_disable)(const struct device *dev);
+
+struct nxp_rtxxx_dsp_ctrl_api {
+	nxp_rtxxx_dsp_ctrl_api_load_section load_section;
+	nxp_rtxxx_dsp_ctrl_api_enable enable;
+	nxp_rtxxx_dsp_ctrl_api_disable disable;
+};
+
+/**
+ * @brief Loads a specified image representing a specified section to a particular region in the
+ * DSP's memory.
+ *
+ * @param dev DSP device
+ * @param base Base pointer of the image to load
+ * @param length Length of the image
+ * @param section Section type which specified image represents
+ * @return int 0 on success, -EINVAL for invalid parameters, -ENOMEM for image bigger than the
+ * target region
+ */
+static inline int nxp_rtxxx_dsp_ctrl_load_section(
+	const struct device *dev,
+	const void *base,
+	size_t length,
+	enum nxp_rtxxx_dsp_ctrl_section_type section
+)
+{
+	return ((struct nxp_rtxxx_dsp_ctrl_api *)dev->api)
+		->load_section(dev, base, length, section);
+}
+
+/**
+ * @brief Starts (unstalls) the DSP.
+ *
+ * @param dev DSP device
+ */
+static inline void nxp_rtxxx_dsp_ctrl_enable(const struct device *dev)
+{
+	((struct nxp_rtxxx_dsp_ctrl_api *)dev->api)->enable(dev);
+}
+
+/**
+ * @brief Stops (stalls) the DSP.
+ *
+ * @param dev DSP device
+ */
+static inline void nxp_rtxxx_dsp_ctrl_disable(const struct device *dev)
+{
+	((struct nxp_rtxxx_dsp_ctrl_api *)dev->api)->disable(dev);
+}
+
+#endif

include/zephyr/dt-bindings/misc/nxp_rtxxx_dsp_ctrl.h

@@ -0,0 +1,15 @@
+/*
+ * Copyright 2025 NXP
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef __NXP_RTXXX_DSP_CTRL_DT_CONST_H__
+#define __NXP_RTXXX_DSP_CTRL_DT_CONST_H__
+
+#define NXP_RTXXX_DSP_REGION_RESET 0
+#define NXP_RTXXX_DSP_REGION_TEXT  1
+#define NXP_RTXXX_DSP_REGION_DATA  2
+#define NXP_RTXXX_DSP_REGION_MAX   3
+
+#endif