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timer: hpet: enable level triggering

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The HPET timer was hard-coded to support only edge triggering
interrupts. This adds the necessary bits to enable level
triggering for the timer.

Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This commit is contained in:
Daniel Leung 2020-06-12 13:32:21 -07:00 • committed by Maureen Helm
commit afc1b9de13
1 changed files with 22 additions and 1 deletions
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23
drivers/timer/hpet.c
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@ -10,11 +10,14 @@
#include <spinlock.h>
#include <irq.h>
#include <dt-bindings/interrupt-controller/intel-ioapic.h>
#define HPET_REG32(off) (*(volatile uint32_t *)(long) \
(DT_INST_REG_ADDR(0) + (off)))
#define CLK_PERIOD_REG HPET_REG32(0x04) /* High dword of caps reg */
#define GENERAL_CONF_REG HPET_REG32(0x10)
#define INTR_STATUS_REG HPET_REG32(0x20)
#define MAIN_COUNTER_REG HPET_REG32(0xf0)
#define TIMER0_CONF_REG HPET_REG32(0x100)
#define TIMER0_COMPARATOR_REG HPET_REG32(0x108)
@ -23,7 +26,11 @@
#define GCONF_ENABLE BIT(0)
#define GCONF_LR BIT(1) /* legacy interrupt routing, disables PIT */
/* INTR_STATUS_REG bits */
#define TIMER0_INT_STS BIT(0)
/* TIMERn_CONF_REG bits */
#define TCONF_INT_LEVEL BIT(1)
#define TCONF_INT_ENABLE BIT(2)
#define TCONF_PERIODIC BIT(3)
#define TCONF_VAL_SET BIT(6)
@ -49,6 +56,15 @@ static void hpet_isr(void *arg)
uint32_t now = MAIN_COUNTER_REG;
#if ((DT_INST_IRQ(0, sense) & IRQ_TYPE_LEVEL) == IRQ_TYPE_LEVEL)
/*
* Clear interrupt only if level trigger is selected.
* When edge trigger is selected, spec says only 0 can
* be written.
*/
INTR_STATUS_REG = TIMER0_INT_STS;
#endif
if (IS_ENABLED(CONFIG_SMP) &&
IS_ENABLED(CONFIG_QEMU_TARGET)) {
/* Qemu in SMP mode has observed the clock going
@ -89,6 +105,11 @@ static void set_timer0_irq(unsigned int irq)
/* 5-bit IRQ field starting at bit 9 */
uint32_t val = (TIMER0_CONF_REG & ~(0x1f << 9)) | ((irq & 0x1f) << 9);
#if ((DT_INST_IRQ(0, sense) & IRQ_TYPE_LEVEL) == IRQ_TYPE_LEVEL)
/* Level trigger */
val |= TCONF_INT_LEVEL;
#endif
TIMER0_CONF_REG = val;
}
@ -99,7 +120,7 @@ int z_clock_driver_init(struct device *device)
IRQ_CONNECT(DT_INST_IRQN(0),
DT_INST_IRQ(0, priority),
hpet_isr, 0, 0);
hpet_isr, 0, DT_INST_IRQ(0, sense));
set_timer0_irq(DT_INST_IRQN(0));
irq_enable(DT_INST_IRQN(0));