coreboot-libre-fam15h-rdimm/3rdparty/chromeec/chip/mchp/watchdog.c

124 lines
3.0 KiB
C

/* Copyright 2017 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
/* Watchdog driver */
#include "hooks.h"
#include "registers.h"
#include "task.h"
#include "watchdog.h"
#include "tfdp_chip.h"
void watchdog_reload(void)
{
MCHP_WDG_KICK = 1;
#ifdef CONFIG_WATCHDOG_HELP
/* Reload the auxiliary timer */
MCHP_TMR16_CTL(0) &= ~BIT(5);
MCHP_TMR16_CNT(0) = CONFIG_AUX_TIMER_PERIOD_MS;
MCHP_TMR16_CTL(0) |= BIT(5);
#endif
}
DECLARE_HOOK(HOOK_TICK, watchdog_reload, HOOK_PRIO_DEFAULT);
int watchdog_init(void)
{
#ifdef CONFIG_WATCHDOG_HELP
uint32_t val;
/*
* Watchdog does not warn us before expiring. Let's use a 16-bit
* timer as an auxiliary timer.
*/
/* Clear 16-bit basic timer 0 PCR sleep enable */
MCHP_PCR_SLP_DIS_DEV(MCHP_PCR_BTMR16_0);
/* Stop the auxiliary timer if it's running */
MCHP_TMR16_CTL(0) &= ~BIT(5);
/* Enable auxiliary timer */
MCHP_TMR16_CTL(0) |= BIT(0);
val = MCHP_TMR16_CTL(0);
/* Pre-scale = 48000 -> 1kHz -> Period = 1ms */
val = (val & 0xffff) | (47999 << 16);
/* No auto restart */
val &= ~BIT(3);
/* Count down */
val &= ~BIT(2);
MCHP_TMR16_CTL(0) = val;
/* Enable interrupt from auxiliary timer */
MCHP_TMR16_IEN(0) |= 1;
task_enable_irq(MCHP_IRQ_TIMER16_0);
MCHP_INT_ENABLE(MCHP_TMR16_GIRQ) = MCHP_TMR16_GIRQ_BIT(0);
/* Load and start the auxiliary timer */
MCHP_TMR16_CNT(0) = CONFIG_AUX_TIMER_PERIOD_MS;
MCHP_TMR16_CNT(0) |= BIT(5);
#endif
/* Clear WDT PCR sleep enable */
MCHP_PCR_SLP_DIS_DEV(MCHP_PCR_WDT);
/* Set timeout. It takes 1007us to decrement WDG_CNT by 1. */
MCHP_WDG_LOAD = CONFIG_WATCHDOG_PERIOD_MS * 1000 / 1007;
/* Start watchdog */
#ifdef CONFIG_CHIPSET_DEBUG
/* WDT will not count if JTAG TRST# is pulled high by JTAG cable */
MCHP_WDG_CTL = BIT(4) | BIT(0);
#else
MCHP_WDG_CTL |= 1;
#endif
return EC_SUCCESS;
}
#ifdef CONFIG_WATCHDOG_HELP
void __keep watchdog_check(uint32_t excep_lr, uint32_t excep_sp)
{
trace0(0, WDT, 0, "Watchdog check from 16-bit basic timer0 ISR");
/* Clear status */
MCHP_TMR16_STS(0) |= 1;
/* clear aggregator status */
MCHP_INT_SOURCE(MCHP_TMR16_GIRQ) = MCHP_TMR16_GIRQ_BIT(0);
watchdog_trace(excep_lr, excep_sp);
}
void
IRQ_HANDLER(MCHP_IRQ_TIMER16_0)(void) __keep __attribute__((naked));
void IRQ_HANDLER(MCHP_IRQ_TIMER16_0)(void)
{
/* Naked call so we can extract raw LR and SP */
asm volatile("mov r0, lr\n"
"mov r1, sp\n"
/*
* Must push registers in pairs to keep 64-bit aligned
* stack for ARM EABI. This also conveninently saves
* R0=LR so we can pass it to task_resched_if_needed.
*/
"push {r0, lr}\n"
"bl watchdog_check\n"
"pop {r0, lr}\n"
"b task_resched_if_needed\n");
}
/*
* Put the watchdog at the highest interrupt priority.
*/
const struct irq_priority __keep IRQ_PRIORITY(MEC1322_IRQ_TIMER16_0)
__attribute__((section(".rodata.irqprio")))
= {MCHP_IRQ_TIMER16_0, 0};
#endif