driver: interrupt_controller: nuclei_eclic: fixed interrupt level

CLIC should be the first level interrupt controller because it replaces
the basic RISC-V local interrupt.
The interrupt level in CLIC controls preemption between IRQs, rather than
specifying the number of nested interrupt controllers.
Removed CONFIG_MULTI_LEVEL_INTERRUPTS and the incorrect interrupt level.

Signed-off-by: Jimmy Zheng <jimmyzhe@andestech.com>

Author: jimmyzhe

drivers/interrupt_controller/Kconfig.clic

@@ -5,7 +5,6 @@ config NUCLEI_ECLIC
 	bool "Enhanced Core Local Interrupt Controller (ECLIC)"
 	default y
 	depends on DT_HAS_NUCLEI_ECLIC_ENABLED
-	select MULTI_LEVEL_INTERRUPTS
 	select RISCV_SOC_HAS_CUSTOM_IRQ_HANDLING if !RISCV_VECTORED_MODE
 	help
 	  Interrupt controller for Nuclei SoC core.

drivers/interrupt_controller/intc_nuclei_eclic.c

@@ -12,7 +12,6 @@
 #include <zephyr/arch/cpu.h>
 #include <zephyr/sys/util.h>
 #include <zephyr/device.h>
-#include <zephyr/irq_multilevel.h>
 
 #include <zephyr/sw_isr_table.h>
 #include <zephyr/drivers/interrupt_controller/riscv_clic.h>
@@ -96,14 +95,6 @@ struct CLICCTRL {
 #define ECLIC_CTRL      ((volatile  struct CLICCTRL *)(DT_REG_ADDR_BY_IDX(DT_NODELABEL(eclic), 3)))
 #define ECLIC_CTRL_SIZE (DT_REG_SIZE_BY_IDX(DT_NODELABEL(eclic), 3))
 
-#if CONFIG_3RD_LEVEL_INTERRUPTS
-#define INTERRUPT_LEVEL 2
-#elif CONFIG_2ND_LEVEL_INTERRUPTS
-#define INTERRUPT_LEVEL 1
-#else
-#define INTERRUPT_LEVEL 0
-#endif
-
 static uint8_t nlbits;
 static uint8_t intctlbits;
 static uint8_t max_prio;
@@ -150,7 +141,7 @@ int riscv_clic_irq_is_enabled(uint32_t irq)
 void riscv_clic_irq_priority_set(uint32_t irq, uint32_t pri, uint32_t flags)
 {
 	const uint8_t prio = leftalign8(MIN(pri, max_prio), intctlbits);
-	const uint8_t level =  leftalign8(MIN((irq_get_level(irq) - 1), max_level), nlbits);
+	const uint8_t level =  leftalign8(max_level, nlbits);
 	const uint8_t intctrl = (prio | level) | (~intctrl_mask);
 
 	ECLIC_CTRL[irq].INTCTRL = intctrl;
@@ -180,12 +171,9 @@ void riscv_clic_irq_set_pending(uint32_t irq)
 
 static int nuclei_eclic_init(const struct device *dev)
 {
-	/* check hardware support required interrupt levels */
-	__ASSERT_NO_MSG(ECLIC_INFO.b.intctlbits >= INTERRUPT_LEVEL);
-
 	ECLIC_MTH.w = 0;
 	ECLIC_CFG.w = 0;
-	ECLIC_CFG.b.nlbits = INTERRUPT_LEVEL;
+	ECLIC_CFG.b.nlbits = 0;
 	for (int i = 0; i < ECLIC_CTRL_SIZE; i++) {
 		ECLIC_CTRL[i] = (struct CLICCTRL) { 0 };
 	}

soc/gd/gd32/gd32vf103/Kconfig.defconfig.gd32vf103

@@ -24,9 +24,6 @@ config NUM_IRQS
 	default 87 if  NUCLEI_ECLIC
 	default 16 if !NUCLEI_ECLIC
 
-config 2ND_LEVEL_INTERRUPTS
-	default y
-
 config ARCH_IRQ_VECTOR_TABLE_ALIGN
 	default 512 if NUCLEI_ECLIC