Commit 26705ca4 authored by Todd Poynor's avatar Todd Poynor Committed by Russell King
Browse files

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



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: default avatarTodd Poynor <tpoynor@mvista.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 62351cc3

arch/arm/mach-pxa/Makefile

+4 −0
Original line number Diff line number Diff line
@@ -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

arch/arm/mach-pxa/pxa27x.c

+8 −1
Original line number Diff line number Diff line
@@ -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;
@@ -138,6 +139,9 @@ void pxa_cpu_pm_enter(suspend_state_t state) 
	extern void pxa_cpu_suspend(unsigned int);

	extern void pxa_cpu_resume(void);



	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 */
@@ -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);

arch/arm/mach-pxa/standby.S

0 → 100644
+32 −0
Original line number Diff line number Diff line 
/*

 * 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

include/asm-arm/arch-pxa/pxa-regs.h

+1 −0
Original line number Diff line number Diff line
@@ -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 */

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