kernel/arm: implement generic timer

Change-Id: I5edb7e36013d5e5d9d45ec3cf31014f99601a4c6
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5519
Tested-by: Commit checker robot <[email protected]>
Reviewed-by: Fredrik Holmqvist <[email protected]>

src/system/kernel/arch/arm/Jamfile

@@ -36,6 +36,7 @@ KernelMergeObject kernel_arch_arm.o :
 	arch_atomic32.cpp
 
 	arch_int_gicv2.cpp
+	arch_timer_generic.cpp
 
 	# SoC minimal kernel-required support
 	# (timers, interrupts, rtc?)

src/system/kernel/arch/arm/arch_timer.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2007-2021, Haiku Inc. All rights reserved.
+ * Copyright 2007-2022, Haiku Inc. All rights reserved.
  * Distributed under the terms of the MIT License.
  *
  * Authors:
@@ -20,6 +20,7 @@
 #include <arch/cpu.h>
 
 #include <drivers/bus/FDT.h>
+#include "arch_timer_generic.h"
 #include "soc.h"
 
 #include "soc_pxa.h"
@@ -27,12 +28,11 @@
 
 //#define TRACE_ARCH_TIMER
 #ifdef TRACE_ARCH_TIMER
-#	define TRACE(x) dprintf x
+#	define TRACE(x...) dprintf(x)
 #else
-#	define TRACE(x) ;
+#	define TRACE(x...) ;
 #endif
 
-//static fdt_module_info *sFdtModule;
 
 #if 0
 static struct fdt_device_info intc_table[] = {
@@ -68,7 +68,15 @@ arch_timer_clear_hardware_timer()
 int
 arch_init_timer(kernel_args *args)
 {
-	TRACE(("%s\n", __func__));
+	TRACE("%s\n", __func__);
+
+	if (ARMGenericTimer::IsAvailable()) {
+		TRACE("init ARMv7 generic timer\n");
+		ARMGenericTimer::Init();
+	}
+
+	//TODO: use SoC-specific timer as a fallback
+	//if the generic timer is not available
 
 #if 0
 	status_t rc = get_module(B_FDT_MODULE_NAME, (module_info**)&sFdtModule);
@@ -77,12 +85,13 @@ arch_init_timer(kernel_args *args)
 
 	rc = sFdtModule->setup_devices(intc_table, intc_count, NULL);
 	if (rc != B_OK)
-		panic("No interrupt controllers found!\n");
+		panic("No hardware timer found!\n");
 #endif
 
 	return B_OK;
 }
 
+
 bigtime_t
 system_time(void)
 {

src/system/kernel/arch/arm/arch_timer_generic.cpp

@@ -0,0 +1,98 @@
+/*
+ * Copyright 2022 Haiku, Inc. All rights reserved.
+ * Distributed under the terms of the MIT License.
+ */
+
+
+#include "arch_timer_generic.h"
+
+
+#define TIMER_IRQ 30
+
+
+static uint32_t
+get_counter_freq(void)
+{
+    uint32_t freq;
+    asm volatile ("MRC p15, 0, %0, c14, c0, 0": "=r" (freq));
+    return freq;
+}
+
+
+static uint64_t
+get_counter(void)
+{
+    uint32_t counter_low;
+    uint32_t counter_high;
+
+    asm volatile ("ISB\n"
+        "MRRC p15, 0, %0, %1, c14"
+        : "=r" (counter_low), "=r" (counter_high));
+    return ((uint64_t)counter_high << 32) | counter_low;
+}
+
+
+void
+ARMGenericTimer::SetTimeout(bigtime_t timeout)
+{
+	uint32_t timeout_ticks = timeout * fTimerFrequency / 1000000;
+	asm volatile ("ISB\n"
+		"MCR p15, 0, %0, c14, c2, 0"
+		: : "r"(timeout_ticks));
+
+	uint32_t timer_ctl = 1;
+	asm volatile ("MCR p15, 0, %0, c14, c2, 1"
+		: : "r"(timer_ctl));
+}
+
+
+void
+ARMGenericTimer::Clear()
+{
+	uint32_t timer_ctl = 2;
+	asm volatile ("MCR p15, 0, %0, c14, c2, 1"
+		: : "r"(timer_ctl));
+}
+
+
+bigtime_t
+ARMGenericTimer::Time()
+{
+	return get_counter() / fTimerFrequency;
+}
+
+
+int32
+ARMGenericTimer::_InterruptWrapper(void *data)
+{
+	return ((ARMGenericTimer*)data)->HandleInterrupt();
+}
+
+
+int32
+ARMGenericTimer::HandleInterrupt()
+{
+	return timer_interrupt();
+}
+
+
+ARMGenericTimer::ARMGenericTimer()
+: HardwareTimer()
+{
+	Clear();
+
+	reserve_io_interrupt_vectors(1, TIMER_IRQ, INTERRUPT_TYPE_IRQ);
+	install_io_interrupt_handler(TIMER_IRQ,
+		&ARMGenericTimer::_InterruptWrapper, this, 0);
+
+	fTimerFrequency = get_counter_freq();
+}
+
+
+bool
+ARMGenericTimer::IsAvailable()
+{
+	uint32_t pfr1;
+	asm volatile("MRC p15, 0, %0, c0, c1, 1": "=r" (pfr1));
+	return (pfr1 & 0x000F0000) == 0x00010000;
+}

src/system/kernel/arch/arm/arch_timer_generic.h

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2022 Haiku, Inc. All rights reserved.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef ARCH_ARM_TIMER_GENERIC_H
+#define ARCH_ARM_TIMER_GENERIC_H
+
+#include <new>
+#include <SupportDefs.h>
+
+#include "soc.h"
+
+class ARMGenericTimer : public HardwareTimer {
+public:
+	void SetTimeout(bigtime_t timeout);
+	void Clear();
+	bigtime_t Time();
+
+	static status_t Init() {
+		ARMGenericTimer *timer = new(std::nothrow) ARMGenericTimer();
+		return timer != NULL ? B_OK : B_NO_MEMORY;
+	}
+
+	static bool IsAvailable();
+protected:
+	ARMGenericTimer();
+
+private:
+	static int32 _InterruptWrapper(void *data);
+	int32 HandleInterrupt();
+
+	uint32_t fTimerFrequency;
+};
+
+#endif /* ARCH_ARM_TIMER_GENERIC_H */

src/system/kernel/arch/arm/soc.h

@@ -46,20 +46,14 @@ public:
 	}
 
 protected:
-#if 0
-	HardwareTimer(fdt_module_info *fdtModule, fdt_device_node node)
-		: fFDT(fdtModule), fNode(node) {
+	HardwareTimer()
+	{
 		if (sInstance) {
 			panic("Multiple HardwareTimer objects created; that is currently unsupported!");
 		}
 		sInstance = this;
 	}
 
-	// Keep our node around as we might want to grab attributes from it
-	fdt_module_info *fFDT;
-	fdt_device_node fNode;
-#endif
-
 	static HardwareTimer *sInstance;
 };