The actual implementation of HPET timers (not used yet, as it seems not to work correctly), by Dustin Howett (GSOC)

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27135 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/system/kernel/arch/x86/timers/x86_hpet.c

@@ -1,4 +1,3 @@
-
 /*
  * Copyright 2008, Dustin Howett, [email protected]. All rights reserved.
  * Distributed under the terms of the MIT License.
@@ -8,9 +7,21 @@
 #include <arch/x86/timer.h>
 #include <arch/x86/arch_hpet.h>
 
+#include <boot/kernel_args.h>
+
+#include <arch/int.h>
+#include <arch/cpu.h>
+
 #include "hpet.h"
 
-static int32 sHPETAddr;
+#define TRACE_HPET
+#ifdef TRACE_HPET
+	#define TRACE(x) dprintf x
+#else
+	#define TRACE(x) ;
+#endif
+
+static uint32 sHPETAddr;
 static struct hpet_regs *sHPETRegs;
 
 struct timer_info gHPETTimer = {
@@ -29,9 +40,60 @@ hpet_get_prio(void)
 }
 
 
-/* TODO: Implement something similar to smp_acpi_probe from boot/.../smp.cpp-
-	we need to get the hpet base address without talking to the acpi module,
-	because there's no guarantee that it's actually present at this early point. */
+static int32
+hpet_timer_interrupt(struct hpet_timer *timer)
+{
+	return timer_interrupt();
+}
+
+
+static status_t
+hpet_set_hardware_timer(bigtime_t relativeTimeout)
+{
+	cpu_status state;
+	uint64 timerValue;
+
+	//dprintf("disabling interrupts\n");
+
+	state = disable_interrupts();
+
+	//dprintf("getting value\n");
+	timerValue = relativeTimeout;
+	timerValue *= 1000000;
+	timerValue /= sHPETRegs->period;
+	//dprintf("adding hpet counter value\n");
+	timerValue += sHPETRegs->counter;
+
+	//dprintf("setting value %d, cur is %d\n", timerValue, sHPETRegs->counter);
+	sHPETRegs->timer2.comparator = timerValue;
+
+	// Clear the interrupt (set to 0)
+	//dprintf("clearing interrupts\n");
+	sHPETRegs->timer2.config &= (~31 << 9);
+
+	// Non-periodic mode, edge triggered
+	//dprintf("edge mode\n");
+	sHPETRegs->timer2.config &= ~(0x8 & 0x2);
+
+	// Enable timer
+	//dprintf("enable\n");
+	sHPETRegs->timer2.config |= 0x4;
+
+	//dprintf("reenable interrupts\n");
+	restore_interrupts(state);
+
+	return B_OK;
+}
+
+
+static status_t
+hpet_clear_hardware_timer(void)
+{
+	// Disable timer
+	sHPETRegs->timer2.config &= ~0x4;
+	return B_OK;
+}
+
 
 static int
 hpet_set_enabled(struct hpet_regs *regs, bool enabled)
@@ -47,8 +109,8 @@ hpet_set_enabled(struct hpet_regs *regs, bool enabled)
 static int
 hpet_set_legacy(struct hpet_regs *regs, bool enabled)
 {
-	if (!HPET_IS_LEGACY_CAPABLE(regs))
-		return B_NOT_SUPPORTED;
+//	if (!HPET_IS_LEGACY_CAPABLE(regs))
+//		return B_NOT_SUPPORTED;
 
 	if (enabled)
 		regs->config |= HPET_CONF_MASK_LEGACY;
@@ -58,33 +120,47 @@ hpet_set_legacy(struct hpet_regs *regs, bool enabled)
 }
 
 
-static int32
-hpet_timer_interrupt(void *data)
-{
-	return timer_interrupt();
-}
-
-
-static status_t
-hpet_set_hardware_timer(bigtime_t relative_timeout)
-{
-	return B_ERROR;
-}
-
-
-static status_t
-hpet_clear_hardware_timer(void)
-{
-	return B_ERROR;
-}
-
-
 static status_t
 hpet_init(struct kernel_args *args)
 {
 	/* hpet_acpi_probe() through a similar "scan spots" table to that of smp.cpp.
 	   Seems to be the most elegant solution right now. */
 
-	/* There is no hpet support proper, so error out on init */
-	return B_ERROR;
+	if (args->arch_args.hpet == NULL) {
+		return B_ERROR;
+	}
+
+	if (sHPETRegs == NULL) {
+		sHPETRegs = (struct hpet_regs *)args->arch_args.hpet;
+		if (map_physical_memory("hpet", (void *)args->arch_args.hpet_phys,
+			B_PAGE_SIZE, B_EXACT_ADDRESS, B_KERNEL_READ_AREA |
+			B_KERNEL_WRITE_AREA, (void **)&sHPETRegs) < B_OK) {
+			// Would it be better to panic here?
+			dprintf("hpet_init: Failed to map memory for the HPET registers.");
+			return B_ERROR;
+		}
+	}
+
+	TRACE(("hpet_init: HPET is at %x. Vendor ID: %x.\n", sHPETRegs, HPET_GET_VENDOR_ID(sHPETRegs)));
+
+	/* There is no hpet legacy support, so error out on init */
+	if (!HPET_IS_LEGACY_CAPABLE(sHPETRegs)) {
+		dprintf("hpet_init: HPET does support legacy mode. Skipping.\n");
+		return B_ERROR;
+	}
+
+	hpet_set_legacy(sHPETRegs, true);
+	TRACE(("hpet_init: HPET does%s support legacy mode.\n", HPET_IS_LEGACY_CAPABLE(sHPETRegs) ? "" : " not"));
+	TRACE(("hpet_init: HPET supports %d timers, and is %s bits wide.\n", HPET_GET_NUM_TIMERS(sHPETRegs) + 1, HPET_IS_64BIT(sHPETRegs) ? "64" : "32"));
+
+	if (HPET_GET_NUM_TIMERS(sHPETRegs) < 2) {
+		dprintf("hpet_init: HPET does not have at least 3 timers. Skipping.\n");
+		return B_ERROR;
+	}
+
+	install_io_interrupt_handler(0xfb - ARCH_INTERRUPT_BASE, &hpet_timer_interrupt, NULL, B_NO_LOCK_VECTOR);
+	install_io_interrupt_handler(0, &hpet_timer_interrupt, NULL, B_NO_LOCK_VECTOR);
+
+	hpet_set_enabled(sHPETRegs, true);
+	return B_OK;
 }