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/* Copyright (c) 2014 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.
*/
#include "common.h"
#include "console.h"
#include "registers.h"
#include "system.h"
#include "task.h"
#include "util.h"
/* What to do when we're just waiting */
static enum {
IDLE_WFI, /* default */
IDLE_SLEEP,
IDLE_DEEP_SLEEP,
NUM_CHOICES
} idle_action;
static const char const *idle_name[] = {
"wfi",
"sleep",
"deep sleep",
};
BUILD_ASSERT(ARRAY_SIZE(idle_name) == NUM_CHOICES);
static int command_idle(int argc, char **argv)
{
int c, i;
if (argc > 1) {
c = tolower(argv[1][0]);
for (i = 0; i < ARRAY_SIZE(idle_name); i++)
if (idle_name[i][0] == c) {
idle_action = i;
break;
}
}
ccprintf("idle action: %s\n", idle_name[idle_action]);
return EC_SUCCESS;
}
DECLARE_CONSOLE_COMMAND(idle, command_idle,
"[w|s|d]",
"Set or show the idle action: wfi, sleep, deep sleep",
NULL);
static void prepare_to_sleep(void)
{
/* No task switching! */
interrupt_disable();
/* Enable all possible internal wake sources */
GR_PMU_EXITPD_MASK =
GC_PMU_EXITPD_MASK_PIN_PD_EXIT_MASK |
GC_PMU_EXITPD_MASK_UTMI_SUSPEND_N_MASK |
GC_PMU_EXITPD_MASK_RDD0_PD_EXIT_TIMER_MASK |
GC_PMU_EXITPD_MASK_TIMELS0_PD_EXIT_TIMER0_MASK |
GC_PMU_EXITPD_MASK_TIMELS0_PD_EXIT_TIMER1_MASK;
/* Which rails should we turn off? */
GR_PMU_LOW_POWER_DIS =
GC_PMU_LOW_POWER_DIS_VDDIOF_MASK |
GC_PMU_LOW_POWER_DIS_VDDXO_MASK |
GC_PMU_LOW_POWER_DIS_JTR_RC_MASK;
if (idle_action == IDLE_DEEP_SLEEP) {
/*
* Preserve some state prior to deep sleep. Pretty much all we
* need is the device address, since everything else can be
* reinitialized on resume.
*/
GREG32(PMU, PWRDN_SCRATCH18) = GR_USB_DCFG;
/* And the idle action */
GREG32(PMU, PWRDN_SCRATCH17) = idle_action;
/* Latch the pinmux values */
GREG32(PINMUX, HOLD) = 1;
/* Clamp the USB pins and shut the PHY down. We have to do this
* in three separate steps, or Bad Things happen. */
GWRITE_FIELD(USB, PCGCCTL, PWRCLMP, 1);
GWRITE_FIELD(USB, PCGCCTL, RSTPDWNMODULE, 1);
GWRITE_FIELD(USB, PCGCCTL, STOPPCLK, 1);
/* Shut down one more power rail for deep sleep */
GR_PMU_LOW_POWER_DIS |=
GC_PMU_LOW_POWER_DIS_VDDL_MASK;
}
/* The next "wfi" will trigger it */
GR_PMU_LOW_POWER_DIS |= GC_PMU_LOW_POWER_DIS_START_MASK;
}
/* This is for normal sleep only. Deep sleep resumes with a warm boot. */
static void resume_from_sleep(void)
{
/* Prevent accidental reentry */
GR_PMU_LOW_POWER_DIS = 0;
/* Allow task switching again */
interrupt_enable();
}
/* The time in the future at which sleeping will be allowed. */
static timestamp_t next_sleep_time;
/* Update the future sleep time. */
void delay_sleep_by(uint32_t us)
{
timestamp_t tmp = get_time();
tmp.val += us;
if (tmp.val > next_sleep_time.val)
next_sleep_time = tmp;
}
/* Wait a good long time after any console input, in case there's more. */
void clock_refresh_console_in_use(void)
{
delay_sleep_by(10 * SECOND);
}
/* Custom idle task, executed when no tasks are ready to be scheduled. */
void __idle(void)
{
int sleep_ok, sleep_delay_passed;
/* Preserved across soft reboots, but not hard */
idle_action = GREG32(PMU, PWRDN_SCRATCH17);
if (idle_action >= NUM_CHOICES)
idle_action = IDLE_WFI;
while (1) {
/* Anyone still busy? */
sleep_ok = DEEP_SLEEP_ALLOWED;
/* Wait a bit, just in case */
sleep_delay_passed = timestamp_expired(next_sleep_time, 0);
/* If it hasn't yet been long enough, check again when it is */
if (!sleep_delay_passed)
timer_arm(next_sleep_time, TASK_ID_IDLE);
/* We're allowed to sleep now, so set it up. */
if (sleep_ok && sleep_delay_passed)
if (idle_action != IDLE_WFI)
prepare_to_sleep();
/* Wait for the next irq event. This stops the CPU clock and
* may trigger sleep or deep sleep if enabled. */
asm("wfi");
/*
* Note: After resuming from normal sleep we should clear
* PMU_LOW_POWER_DIS to prevent sleeping again by accident.
* Normal sleep eventually resumes here after the waking
* interrupt has been handled, but since all the other tasks
* will get a chance to run first it might be some time before
* that happens. If we find ourselves going back into sleep
* unexpectedly, that might be why.
*/
resume_from_sleep();
}
}
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