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npcx: Apply deep idle bypass for hibernate

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Although probability is small, we still have chance to encounter the same
symptom which CPU's behavior is abnormal after wake-up from deep idle.
Apply the same bypass in task.c but not enable interrupt to solve it.

Modified sources:
1. system.c: Apply deep idle bypass for hibernate.

BRANCH=none
BUG=chrome-os-partner:34346
TEST=make buildall; test "hibernate"&"hibernate 10" on wheatley.

Change-Id: Ib00b9932ac34414d6a177d60668664ab31284a79
Signed-off-by: Mulin Chao <mlchao@nuvoton.com>
Reviewed-on: https://chromium-review.googlesource.com/373300
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Reviewed-by: Amit Maoz <Amit.Maoz@nuvoton.com>
This commit is contained in:
Mulin Chao
2016-08-18 13:33:07 +08:00
committed by chrome-bot
parent d614eaf1bf
commit 746eb2c600
1 changed files with 24 additions and 1 deletions
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25
chip/npcx/system.c
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@@ -255,6 +255,15 @@ void system_mpu_config(void)
void __keep __attribute__ ((section(".lowpower_ram")))
__enter_hibernate_in_lpram(void)
{
/*
* TODO (ML): Set stack pointer to upper 512B of Suspend RAM.
* Our bypass needs stack instructions but FW will turn off main ram
* later for better power consumption.
*/
asm (
"ldr r0, =0x40001800\n"
"mov sp, r0\n"
);
/* Disable Code RAM first */
SET_BIT(NPCX_PWDWN_CTL(NPCX_PMC_PWDWN_5), NPCX_PWDWN_CTL5_MRFSH_DIS);
@@ -262,8 +271,22 @@ __enter_hibernate_in_lpram(void)
/* Set deep idle mode*/
NPCX_PMCSR = 0x6;
/* Enter deep idle, wake-up by GPIOxx or RTC */
asm("wfi");
/*
* TODO (ML): Although the probability is small, it still has chance
* to meet the same symptom that CPU's behavior is abnormal after
* wake-up from deep idle.
* Workaround: Apply the same bypass of idle but don't enable interrupt.
*/
asm (
"push {r0-r5}\n" /* Save needed registers */
"ldr r0, =0x40001600\n" /* Set r0 to Suspend RAM addr */
"wfi\n" /* Wait for int to enter idle */
"ldm r0, {r0-r5}\n" /* Add a delay after WFI */
"pop {r0-r5}\n" /* Restore regs before enabling ints */
"isb\n" /* Flush the cpu pipeline */
);
/* RTC wake-up */
if (IS_BIT_SET(NPCX_WTC, NPCX_WTC_PTO))