drivers: interrupt_controller: Add arm v8m nvic device driver

Adds naive nvic device driver implementation for demo
purposes

Signed-off-by: Bjarki Arge Andreasen <bjarki@arge-andreasen.me>

drivers/CMakeLists.txt

@@ -47,6 +47,7 @@ add_subdirectory_ifdef(CONFIG_I2S i2s)
 add_subdirectory_ifdef(CONFIG_I3C i3c)
 add_subdirectory_ifdef(CONFIG_IEEE802154 ieee802154)
 add_subdirectory_ifdef(CONFIG_INPUT input)
+add_subdirectory_ifdef(CONFIG_INTC intc)
 add_subdirectory_ifdef(CONFIG_IPM ipm)
 add_subdirectory_ifdef(CONFIG_KSCAN kscan)
 add_subdirectory_ifdef(CONFIG_LED led)

drivers/Kconfig

@@ -41,6 +41,7 @@ source "drivers/i2s/Kconfig"
 source "drivers/i3c/Kconfig"
 source "drivers/ieee802154/Kconfig"
 source "drivers/input/Kconfig"
+source "drivers/intc/Kconfig"
 source "drivers/interrupt_controller/Kconfig"
 source "drivers/interrupt_controller/Kconfig.shared_irq"
 source "drivers/ipm/Kconfig"

drivers/intc/CMakeLists.txt

@@ -0,0 +1,6 @@
+# Copyright (c) 2023 Bjarki Arge Andreasen
+# SPDX-License-Identifier: Apache-2.0
+
+zephyr_library()
+
+zephyr_library_sources_ifdef(CONFIG_INTC_ARM_V8M_NVIC intc_arm_v8m_nvic.c)

drivers/intc/Kconfig

@@ -0,0 +1,11 @@
+# Copyright (c) 2023 Bjarki Arge Andreasen
+# SPDX-License-Identifier: Apache-2.0
+
+menuconfig INTC
+	bool "INTC (INTerrupt Controller) drivers"
+
+if INTC
+
+rsource "Kconfig.arm_v8m_nvic"
+
+endif # INTC

drivers/intc/Kconfig.arm_v8m_nvic

@@ -0,0 +1,7 @@
+# Copyright (c) 2023 Bjarki Arge Andreasen
+# SPDX-License-Identifier: Apache-2.0
+
+config INTC_ARM_V8M_NVIC
+	bool "Arm V8M Nested Vector Interrupt Controller"
+	default y
+	depends on DT_HAS_ARM_V8M_NVIC_ENABLED

drivers/intc/intc_arm_v8m_nvic.c

@@ -0,0 +1,223 @@
+/*
+ * Copyright (c) 2023 Bjarki Arge Andreasen
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/kernel.h>
+#include <zephyr/drivers/intc.h>
+#include <zephyr/drivers/intc/direct_irq_handler.h>
+#include <cmsis_core.h>
+#include <zephyr/sys/barrier.h>
+#include <zephyr/arch/cpu.h>
+#include <zephyr/linker/sections.h>
+
+#define DT_DRV_COMPAT arm_v8m_nvic
+
+struct intc_arm_v8m_nvic_data {
+	struct k_spinlock lock;
+};
+
+struct intc_arm_v8m_nvic_config {
+	uint8_t max_irq_priority;
+	uint16_t num_irqs;
+	struct intc_irq **irqs;
+};
+
+typedef void (*intc_arm_v8m_nvic_vth_t)(void);
+
+static int arm_v8m_nvic_request_irq(struct intc_irq *irq)
+{
+	const struct intc_irq_spec *spec = irq->spec;
+	const struct device *intc = spec->intc;
+	struct intc_arm_v8m_nvic_data *data = intc->data;
+	const struct intc_arm_v8m_nvic_config *config = intc->config;
+
+	if (spec->irq >= config->num_irqs) {
+		return -ENODEV;
+	}
+
+	if (spec->priority > config->max_irq_priority) {
+		return -EINVAL;
+	}
+
+	K_SPINLOCK(&data->lock) {
+		NVIC_DisableIRQ(spec->irq);
+		NVIC_ClearPendingIRQ(spec->irq);
+		NVIC_SetPriority(spec->irq, spec->priority);
+		config->irqs[spec->irq] = irq;
+	}
+
+	return 0;
+}
+
+static int arm_v8m_nvic_enable_irq(const struct intc_irq_spec *spec)
+{
+	const struct device *intc = spec->intc;
+	struct intc_arm_v8m_nvic_data *data = intc->data;
+	const struct intc_arm_v8m_nvic_config *config = intc->config;
+
+	if (spec->irq >= config->num_irqs) {
+		return -ENODEV;
+	}
+
+	K_SPINLOCK(&data->lock) {
+		NVIC_EnableIRQ(spec->irq);
+	}
+
+	return 0;
+}
+
+static int arm_v8m_nvic_disable_irq(const struct intc_irq_spec *spec)
+{
+	const struct device *intc = spec->intc;
+	struct intc_arm_v8m_nvic_data *data = intc->data;
+	const struct intc_arm_v8m_nvic_config *config = intc->config;
+
+	if (spec->irq >= config->num_irqs) {
+		return -ENODEV;
+	}
+
+	K_SPINLOCK(&data->lock) {
+		NVIC_DisableIRQ(spec->irq);
+	}
+
+	return 0;
+}
+
+static int arm_v8m_nvic_irq_is_enabled(const struct intc_irq_spec *spec)
+{
+	const struct device *intc = spec->intc;
+	struct intc_arm_v8m_nvic_data *data = intc->data;
+	const struct intc_arm_v8m_nvic_config *config = intc->config;
+	int ret;
+
+	if (spec->irq >= config->num_irqs) {
+		return -ENODEV;
+	}
+
+	K_SPINLOCK(&data->lock) {
+		ret = NVIC_GetEnableIRQ(spec->irq);
+	}
+
+	return ret;
+}
+
+static int arm_v8m_nvic_trigger_irq(const struct intc_irq_spec *spec)
+{
+	const struct device *intc = spec->intc;
+	struct intc_arm_v8m_nvic_data *data = intc->data;
+	const struct intc_arm_v8m_nvic_config *config = intc->config;
+
+	if (spec->irq >= config->num_irqs) {
+		return -ENODEV;
+	}
+
+	K_SPINLOCK(&data->lock) {
+		NVIC_SetPendingIRQ(spec->irq);
+	}
+
+	return 0;
+}
+
+static int arm_v8m_nvic_release_irq(struct intc_irq *irq)
+{
+	const struct intc_irq_spec *spec = irq->spec;
+	const struct device *intc = spec->intc;
+	struct intc_arm_v8m_nvic_data *data = intc->data;
+	const struct intc_arm_v8m_nvic_config *config = intc->config;
+
+	if (spec->irq >= config->num_irqs) {
+		return -ENODEV;
+	}
+
+	K_SPINLOCK(&data->lock) {
+		NVIC_DisableIRQ(spec->irq);
+		config->irqs[spec->irq] = NULL;
+	}
+
+	return 0;
+}
+
+static const struct intc_driver_api arm_v8m_nvic_api = {
+	.request_irq = arm_v8m_nvic_request_irq,
+	.enable_irq = arm_v8m_nvic_enable_irq,
+	.disable_irq = arm_v8m_nvic_disable_irq,
+	.irq_enabled = arm_v8m_nvic_irq_is_enabled,
+	.trigger_irq = arm_v8m_nvic_trigger_irq,
+	.release_irq = arm_v8m_nvic_release_irq,
+};
+
+static inline uint32_t arm_v8m_nvic_get_active_irq_num(void)
+{
+	return __get_IPSR() - 16;
+}
+
+#define ARM_V8M_NVIC_DEFAULT_IRQ_HANDLER_DEFINE(inst)						\
+	INTC_DT_ARM_V8M_NVIC_DIRECT_IRQ_HANDLER_DEFINE(arm_v8m_nvic_default_handler##inst)	\
+	{											\
+		uint32_t irq_num = arm_v8m_nvic_get_active_irq_num();				\
+		struct intc_irq **irqs = arm_v8m_nvic_irqs##inst;				\
+		struct intc_irq *irq = irqs[irq_num];						\
+												\
+		if (irq != NULL) {								\
+			irq->handler(irq);							\
+		} else {									\
+			while (1) {								\
+												\
+			}									\
+		}										\
+												\
+		return (INTC_DIRECT_IRQ_HANDLER_FLAG_PM | INTC_DIRECT_IRQ_HANDLER_FLAG_SWAP);	\
+	}
+
+#define ARM_V8M_NVIC_IRQ_HANDLER_DEFINE(i, inst)						\
+	__weak void INTC_DT_INST_IRQ_HANDLER_NAME(inst, i)(void)				\
+	{											\
+		UTIL_CAT(arm_v8m_nvic_default_handler, inst)();					\
+	}
+
+#define ARM_V8M_NVIC_IRQ_HANDLERS_DEFINE(inst, n)						\
+	LISTIFY(n,										\
+		ARM_V8M_NVIC_IRQ_HANDLER_DEFINE,						\
+		(),										\
+		inst										\
+	)
+
+#define ARM_V8M_NVIC_VECTOR_DEFINE(i, inst) \
+	INTC_DT_INST_IRQ_HANDLER_NAME(inst, i)
+
+#define ARM_V8M_NVIC_VECTORS_DEFINE(inst, n)							\
+	LISTIFY(n,										\
+		ARM_V8M_NVIC_VECTOR_DEFINE,							\
+		(,),										\
+		inst										\
+	)
+
+#define ARM_V8M_NVIC_VECTOR_TABLE_DEFINE(inst, n)						\
+	intc_arm_v8m_nvic_vth_t __irq_vector_table _irq_vector_table[] = {			\
+		ARM_V8M_NVIC_VECTORS_DEFINE(inst, n)						\
+	};
+
+#define ARM_V8M_NVIC_DEVICE(inst)								\
+	static struct intc_irq *arm_v8m_nvic_irqs##inst[DT_INST_PROP(inst, arm_num_irq)];	\
+												\
+	static struct intc_arm_v8m_nvic_data arm_v8m_nvic_data##inst;				\
+												\
+	static struct intc_arm_v8m_nvic_config arm_v8m_nvic_config##inst = {			\
+		.max_irq_priority = BIT_MASK(DT_INST_PROP(inst, arm_num_irq_priority_bits)),	\
+		.num_irqs = DT_INST_PROP(inst, arm_num_irq),					\
+		.irqs = arm_v8m_nvic_irqs##inst,						\
+	};											\
+												\
+	ARM_V8M_NVIC_DEFAULT_IRQ_HANDLER_DEFINE(inst)						\
+												\
+	ARM_V8M_NVIC_IRQ_HANDLERS_DEFINE(inst, DT_INST_PROP(inst, arm_num_irq))			\
+												\
+	ARM_V8M_NVIC_VECTOR_TABLE_DEFINE(inst, DT_INST_PROP(inst, arm_num_irq))			\
+												\
+	DEVICE_DT_INST_DEFINE(inst, NULL, NULL, &arm_v8m_nvic_data##inst,			\
+			      &arm_v8m_nvic_config##inst, PRE_KERNEL_1, 0,			\
+			      &arm_v8m_nvic_api);
+
+DT_INST_FOREACH_STATUS_OKAY(ARM_V8M_NVIC_DEVICE)

dts/bindings/interrupt-controller/arm,v8m-nvic.yaml

@@ -13,6 +13,10 @@ properties:
     type: int
     description: number of bits of IRQ priorities
 
+  arm,num-irq:
+    type: int
+    description: number of connected interrupt lines
+
   "#interrupt-cells":
     const: 2
 

include/zephyr/drivers/intc/arm_v8m_nvic.h

@@ -0,0 +1,58 @@
+/*
+ * Copyright 2023 Bjarki Arge Andreasen
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+extern void z_arm_int_exit(void);
+
+#ifdef CONFIG_TRACING_ISR
+extern void sys_trace_isr_enter(void);
+extern void sys_trace_isr_exit(void);
+#endif
+
+#ifdef CONFIG_PM
+extern void _arch_isr_direct_pm(void);
+#endif
+
+static inline void arm_v8m_nvic_direct_header(void)
+{
+#ifdef CONFIG_TRACING_ISR
+	sys_trace_isr_enter();
+#endif
+}
+
+static inline void arm_v8m_nvic_direct_pm(uint32_t flags)
+{
+#ifdef CONFIG_PM
+	if (flags & INTC_DIRECT_IRQ_HANDLER_FLAG_PM) {
+		_arch_isr_direct_pm();
+	}
+#endif
+}
+
+static inline void arm_v8m_nvic_direct_footer(uint32_t flags)
+{
+#ifdef CONFIG_TRACING_ISR
+	sys_trace_isr_exit();
+#endif
+	if (flags & INTC_DIRECT_IRQ_HANDLER_FLAG_SWAP) {
+		z_arm_int_exit();
+	}
+}
+
+#define INTC_DT_ARM_V8M_NVIC_DIRECT_IRQ_HANDLER_DEFINE(name)	\
+	static inline uint32_t UTIL_CAT(name, _body)(void);	\
+	_Pragma("GCC diagnostic push")				\
+	_Pragma("GCC diagnostic ignored \"-Wattributes\"")	\
+	__attribute__((interrupt("IRQ")))			\
+	void name(void)						\
+	{							\
+		uint32_t flags;					\
+		arm_v8m_nvic_direct_header();			\
+		flags = UTIL_CAT(name, _body)();		\
+		arm_v8m_nvic_direct_pm(flags);			\
+		arm_v8m_nvic_direct_footer(flags);		\
+	}							\
+	_Pragma("GCC diagnostic pop")				\
+	uint32_t UTIL_CAT(name, _body)(void)

include/zephyr/drivers/intc/direct_irq_handler.h

@@ -99,5 +99,6 @@
 	INTC_DT_DIRECT_IRQ_HANDLER_DEFINE_BY_NAME(DT_DRV_INST(inst), name)
 
 /** Architecture specific implementations of direct IRQ handlers are included here */
+#include <zephyr/drivers/intc/arm_v8m_nvic.h>
 
 #endif /* ZEPHYR_INCLUDE_DRIVERS_INTC_DIRECT_IRQ_HANDLER_H_ */