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[PATCH] ARM: 2781/2: PXA27x Standby mode take 2

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Patch from Todd Poynor

Add support for PXA27x Standby mode, a low-power mode that retains CPU
and some peripheral state (the existing "sleep" mode is a power-power
mode that retains less state). Activated via:
echo -n standby > /sys/power/state
From: David Burrage and Todd Poynor

Signed-off-by: Todd Poynor <tpoynor@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Todd Poynor 2005-07-01 11:27:05 +01:00 committed by Russell King
parent 62351cc38d
commit 26705ca46b
4 changed files with 45 additions and 1 deletions
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4
arch/arm/mach-pxa/Makefile
View File

@ -24,3 +24,7 @@ obj-$(CONFIG_LEDS) += $(led-y)
# Misc features
obj-$(CONFIG_PM) += pm.o sleep.o
ifeq ($(CONFIG_PXA27x),y)
obj-$(CONFIG_PM) += standby.o
endif

9
arch/arm/mach-pxa/pxa27x.c
View File

@ -126,6 +126,7 @@ int pxa_cpu_pm_prepare(suspend_state_t state)
{
switch (state) {
case PM_SUSPEND_MEM:
case PM_SUSPEND_STANDBY:
return 0;
default:
return -EINVAL;
@ -138,7 +139,10 @@ void pxa_cpu_pm_enter(suspend_state_t state)
extern void pxa_cpu_suspend(unsigned int);
extern void pxa_cpu_resume(void);
CKEN = CKEN22_MEMC | CKEN9_OSTIMER;
if (state == PM_SUSPEND_STANDBY)
CKEN = CKEN22_MEMC | CKEN9_OSTIMER | CKEN16_LCD |CKEN0_PWM0;
else
CKEN = CKEN22_MEMC | CKEN9_OSTIMER;
/* ensure voltage-change sequencer not initiated, which hangs */
PCFR &= ~PCFR_FVC;
@ -147,6 +151,9 @@ void pxa_cpu_pm_enter(suspend_state_t state)
PEDR = 0xDF12FE1B;
switch (state) {
case PM_SUSPEND_STANDBY:
pxa_cpu_standby();
break;
case PM_SUSPEND_MEM:
/* set resume return address */
PSPR = virt_to_phys(pxa_cpu_resume);

32
arch/arm/mach-pxa/standby.S Normal file
View File

@ -0,0 +1,32 @@
/*
* PXA27x standby mode
*
* Author: David Burrage
*
* 2005 (c) MontaVista Software, Inc. This file is licensed under
* the terms of the GNU General Public License version 2. This program
* is licensed "as is" without any warranty of any kind, whether express
* or implied.
*/
#include <linux/config.h>
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/hardware.h>
#include <asm/arch/pxa-regs.h>
.text
ENTRY(pxa_cpu_standby)
ldr r0, =PSSR
mov r1, #(PSSR_PH | PSSR_STS)
mov r2, #2
mov r3, #UNCACHED_PHYS_0 @ Read mem context in.
ldr ip, [r3]
b 1f
.align 5
1: mcr p14, 0, r2, c7, c0, 0 @ put the system into Standby
str r1, [r0] @ make sure PSSR_PH/STS are clear
mov pc, lr

1
include/asm-arm/arch-pxa/pxa-regs.h
View File

@ -1505,6 +1505,7 @@
#define PSSR_OTGPH (1 << 6) /* OTG Peripheral control Hold */
#define PSSR_RDH (1 << 5) /* Read Disable Hold */
#define PSSR_PH (1 << 4) /* Peripheral Control Hold */
#define PSSR_STS (1 << 3) /* Standby Mode Status */
#define PSSR_VFS (1 << 2) /* VDD Fault Status */
#define PSSR_BFS (1 << 1) /* Battery Fault Status */
#define PSSR_SSS (1 << 0) /* Software Sleep Status */