hw/timer: implement ESP32-S3 System Timer

Co-authored-by: Omar Chebib <omar.chebib@espressif.com>

hw/timer/esp32s3_systimer.c

@@ -0,0 +1,60 @@
+/*
+ * ESP32-S3 System Timer
+ *
+ * Copyright (c) 2024 Espressif Systems (Shanghai) Co. Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 or
+ * (at your option) any later version.
+ */
+#include "qemu/osdep.h"
+#include "hw/hw.h"
+#include "hw/sysbus.h"
+#include "hw/registerfields.h"
+#include "hw/boards.h"
+#include "hw/timer/esp32s3_systimer.h"
+
+
+static void esp32c3_systimer_write(void *opaque, hwaddr addr, uint64_t value, unsigned int size)
+{
+    ESP32S3SysTimerClass *class = ESP32S3_SYSTIMER_GET_CLASS(opaque);
+    ESP32S3SysTimerState *s = ESP32S3_SYSTIMER(opaque);
+
+    class->parent_systimer_write(opaque, addr, value, size);
+
+    if (addr == A_SYSTIMER_INT_ENA) {
+        /* If the timer virtual interrupt is enabled too late, we may miss the interrupt in QEMU
+         * and not reprogram the next iteration. */
+        class->parent_class.comparators_reprogram(&s->parent);
+    }
+}
+
+
+
+static void esp32s3_systimer_class_init(ObjectClass *klass, void *data)
+{
+    ESP32S3SysTimerClass* esp32s3 = ESP32S3_SYSTIMER_CLASS(klass);
+    ESPSysTimerClass* esp = ESP_SYSTIMER_CLASS(klass);
+
+    /* Override the register read method */
+    esp32s3->parent_systimer_write = esp->systimer_ops.write;
+    esp->systimer_ops.write = esp32c3_systimer_write;
+}
+
+
+static const TypeInfo esp32s3_systimer_info = {
+    .name = TYPE_ESP32S3_SYSTIMER,
+    .parent = TYPE_ESP_SYSTIMER,
+    .instance_size = sizeof(ESP32S3SysTimerState),
+    .class_init = esp32s3_systimer_class_init,
+    .class_size = sizeof(ESP32S3SysTimerClass),
+};
+
+
+static void esp32s3_systimer_register_types(void)
+{
+    type_register_static(&esp32s3_systimer_info);
+}
+
+
+type_init(esp32s3_systimer_register_types)

hw/timer/meson.build

@@ -38,6 +38,8 @@ system_ss.add(when: 'CONFIG_RISCV_ESP32C3', if_true: files(
 ))
 system_ss.add(when: 'CONFIG_XTENSA_ESP32S3', if_true: files(
     'esp32c3_timg.c',
+    'esp_systimer.c',
+    'esp32s3_systimer.c'
 ))
 specific_ss.add(when: 'CONFIG_IBEX', if_true: files('ibex_timer.c'))
 system_ss.add(when: 'CONFIG_SIFIVE_PWM', if_true: files('sifive_pwm.c'))

include/hw/timer/esp32s3_systimer.h

@@ -0,0 +1,32 @@
+/*
+ * ESP32-S3 System Timer emulation
+ *
+ * Copyright (c) 2024 Espressif Systems (Shanghai) Co. Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 or
+ * (at your option) any later version.
+ */
+#pragma once
+
+#include "hw/hw.h"
+#include "hw/registerfields.h"
+#include "hw/timer/esp_systimer.h"
+
+#define TYPE_ESP32S3_SYSTIMER           "esp32s3.systimer"
+#define ESP32S3_SYSTIMER(obj)           OBJECT_CHECK(ESP32S3SysTimerState, (obj), TYPE_ESP32S3_SYSTIMER)
+#define ESP32S3_SYSTIMER_GET_CLASS(obj) OBJECT_GET_CLASS(ESP32S3SysTimerClass, obj, TYPE_ESP32S3_SYSTIMER)
+#define ESP32S3_SYSTIMER_CLASS(klass)   OBJECT_CLASS_CHECK(ESP32S3SysTimerClass, (klass), TYPE_ESP32S3_SYSTIMER)
+
+
+typedef struct ESP32S3SysTimerState {
+    ESPSysTimerState parent;
+} ESP32S3SysTimerState;
+
+
+typedef struct ESP32S3SysTimerClass {
+    ESPSysTimerClass parent_class;
+
+    /* Virtual attributes/methods overriden */
+    void (*parent_systimer_write)(void *opaque, hwaddr addr, uint64_t value, unsigned int size);
+} ESP32S3SysTimerClass;