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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 "pmu.h"
#include "system.h"
#include "task.h"
#include "util.h"
/* This function is assumed to exist, but we don't use it */
void clock_refresh_console_in_use(void)
{
}
/* 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_deep_sleep(void)
{
/* No task switching! */
interrupt_disable();
/*
* 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;
/* Latch the pinmux values */
GREG32(PINMUX, HOLD) = 1;
/*
* Specify the PINMUX pads that can wake us.
* A1 is UART RX. Idle is high, so wake on low level
* A12 is SPS_CS_L. Also wake on low.
* HEY: Use something in gpio.inc to identify these!
*/
GREG32(PINMUX, EXITEN0) =
GC_PINMUX_EXITEN0_DIOA1_MASK |
GC_PINMUX_EXITEN0_DIOA12_MASK;
GREG32(PINMUX, EXITEDGE0) = 0; /* level sensitive */
GREG32(PINMUX, EXITINV0) = /* low or falling */
GC_PINMUX_EXITINV0_DIOA1_MASK |
GC_PINMUX_EXITINV0_DIOA12_MASK;
/* 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;
/* 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);
/* Get ready... */
GR_PMU_LOW_POWER_DIS =
/* The next "wfi" will trigger it */
GC_PMU_LOW_POWER_DIS_START_MASK |
/* ... with these rails off */
GC_PMU_LOW_POWER_DIS_VDDL_MASK | /* <= this means deep sleep */
GC_PMU_LOW_POWER_DIS_VDDIOF_MASK |
GC_PMU_LOW_POWER_DIS_VDDXO_MASK |
GC_PMU_LOW_POWER_DIS_JTR_RC_MASK;
}
/* 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;
}
/* Custom idle task, executed when no tasks are ready to be scheduled. */
void __idle(void)
{
int sleep_ok, sleep_delay_passed, prev_ok = 0;
while (1) {
/* Don't even bother unless we've enabled it */
if (idle_action == IDLE_WFI)
goto wfi;
/* Anyone still busy? */
sleep_ok = DEEP_SLEEP_ALLOWED;
/*
* We'll always wait a little bit before sleeping no matter
* what. This is more likely to let any console output finish
* than calling clock_refresh_console_in_use(), because that
* function is called BEFORE waking the console task, not after
* it runs. We can't call cflush() here because that wakes a
* task to do it and so we're not idle any more.
*/
if (sleep_ok && !prev_ok)
delay_sleep_by(200 * MSEC);
prev_ok = sleep_ok;
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 deep sleep, so set it up. */
if (sleep_ok && sleep_delay_passed)
if (idle_action == IDLE_DEEP_SLEEP)
prepare_to_deep_sleep();
/* Normal sleep is not yet implemented */
wfi:
/* Wait for the next irq event. This stops the CPU clock and
* may trigger sleep or deep sleep if enabled. */
asm("wfi");
/*
* TODO: Normal sleep resumes by handling the interrupt, but we
* need to clear PMU_LOW_POWER_DIS right away or we might sleep
* again by accident. We can't do that here because we don't
* get here until the next idle, so we'll have to do it in the
* interrupt handler or when task switching. Deep sleep resumes
* with a warm boot, which handles it differently.
*/
}
}
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