drivers: add the pfic interrupt controller

This commit adds the pfic interrupt controller driver for WCH CH32V003.

Signed-off-by: Michael Hope <michaelh@juju.nz>
Signed-off-by: Dhiru Kholia <dhiru.kholia@gmail.com>

drivers/interrupt_controller/CMakeLists.txt

@@ -43,6 +43,7 @@ zephyr_library_sources_ifdef(CONFIG_NXP_PINT                intc_nxp_pint.c)
 zephyr_library_sources_ifdef(CONFIG_RENESAS_RA_ICU          intc_renesas_ra_icu.c)
 zephyr_library_sources_ifdef(CONFIG_NXP_IRQSTEER            intc_nxp_irqsteer.c)
 zephyr_library_sources_ifdef(CONFIG_INTC_MTK_ADSP           intc_mtk_adsp.c)
+zephyr_library_sources_ifdef(CONFIG_WCH_PFIC                intc_wch_pfic.c)
 
 if(CONFIG_INTEL_VTD_ICTL)
   zephyr_library_include_directories(${ZEPHYR_BASE}/arch/x86/include)

drivers/interrupt_controller/Kconfig

@@ -108,4 +108,6 @@ source "drivers/interrupt_controller/Kconfig.nxp_irqsteer"
 
 source "drivers/interrupt_controller/Kconfig.mtk_adsp"
 
+source "drivers/interrupt_controller/Kconfig.wch_pfic"
+
 endmenu

drivers/interrupt_controller/Kconfig.wch_pfic

@@ -0,0 +1,9 @@
+# Copyright (c) 2024 Michael Hope
+# SPDX-License-Identifier: Apache-2.0
+
+config WCH_PFIC
+	bool "WCH Programmable Fast Interrupt Controller (PFIC)"
+	default y
+	depends on DT_HAS_WCH_PFIC_ENABLED
+	help
+	  Interrupt controller for WCH PFIC.

drivers/interrupt_controller/intc_wch_pfic.c

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2024 Michael Hope
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT wch_pfic
+
+#include <ch32fun.h>
+
+#include <zephyr/arch/cpu.h>
+#include <zephyr/init.h>
+#include <zephyr/irq.h>
+#include <zephyr/kernel.h>
+
+#define SEVONPEND (1 << 4)
+#define WFITOWFE  (1 << 3)
+
+void arch_irq_enable(unsigned int irq)
+{
+	PFIC->IENR[irq / 32] = 1 << (irq % 32);
+}
+
+void arch_irq_disable(unsigned int irq)
+{
+	PFIC->IRER[irq / 32] |= 1 << (irq % 32);
+}
+
+int arch_irq_is_enabled(unsigned int irq)
+{
+	return ((PFIC->ISR[irq >> 5] & (1 << (irq & 0x1F))) != 0);
+}
+
+static int pfic_init(void)
+{
+	/* `wfi` is called with interrupts disabled. Configure the PFIC to wake up on any event,
+	 * including any interrupt.
+	 */
+	PFIC->SCTLR = SEVONPEND | WFITOWFE;
+	return 0;
+}
+
+SYS_INIT(pfic_init, PRE_KERNEL_1, CONFIG_INTC_INIT_PRIORITY);

dts/bindings/interrupt-controller/wch,pfic.yaml

@@ -0,0 +1,18 @@
+# Copyright (c) 2024 Michael Hope
+# SPDX-License-Identifier: Apache-2.0
+
+description: WCH CH32V00x Programmable Fast Interrupt Controller (PFIC)
+
+compatible: "wch,pfic"
+
+include: [interrupt-controller.yaml, base.yaml]
+
+properties:
+  reg:
+    required: true
+
+  "#interrupt-cells":
+    const: 1
+
+interrupt-cells:
+  - irq