Subject: [PATCH v2 7/7] ARM: highbank: add suspend support

From: [email-masked] (Rob Herring)
Date: Thu, 01 Sep 2011 16:39:06 -0500

Shawn,

On 09/01/2011 07:22 AM, Shawn Guo wrote:
> On Wed, Aug 31, 2011 at 08:44:06PM -0500, Rob Herring wrote:
>> From: Rob Herring <[email-masked]>
>>
>> Add the platform suspend ops for highbank.
>>
>> Signed-off-by: Rob Herring <[email-masked]>
>> ---
>> Changes in v2:
>>  - s/a9_base_addr/scu_base_addr/
>>  - use sysregs helper functions
>>  - add __init to highbank_pm_init
>>
>>  arch/arm/mach-highbank/Makefile |    1 +
>>  arch/arm/mach-highbank/pm.c     |   55 +++++++++++++++++++++++++++++++++++++++
>>  2 files changed, 56 insertions(+), 0 deletions(-)
>>  create mode 100644 arch/arm/mach-highbank/pm.c
>>
>> diff --git a/arch/arm/mach-highbank/Makefile b/arch/arm/mach-highbank/Makefile
>> index df30b0d..daeb3d8 100644
>> --- a/arch/arm/mach-highbank/Makefile
>> +++ b/arch/arm/mach-highbank/Makefile
>> @@ -3,3 +3,4 @@ obj-$(CONFIG_DEBUG_LL)			+= lluart.o
>>  obj-$(CONFIG_SMP)			+= platsmp.o
>>  obj-$(CONFIG_LOCAL_TIMERS)		+= localtimer.o
>>  obj-$(CONFIG_HOTPLUG_CPU)		+= hotplug.o
>> +obj-$(CONFIG_PM_SLEEP)			+= pm.o
>> diff --git a/arch/arm/mach-highbank/pm.c b/arch/arm/mach-highbank/pm.c
>> new file mode 100644
>> index 0000000..33b3beb
>> --- /dev/null
>> +++ b/arch/arm/mach-highbank/pm.c
>> @@ -0,0 +1,55 @@
>> +/*
>> + * Copyright 2011 Calxeda, Inc.
>> + *
>> + * This program is free software; you can redistribute it and/or modify it
>> + * under the terms and conditions of the GNU General Public License,
>> + * version 2, as published by the Free Software Foundation.
>> + *
>> + * This program is distributed in the hope it will be useful, but WITHOUT
>> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
>> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
>> + * more details.
>> + *
>> + * You should have received a copy of the GNU General Public License along with
>> + * this program.  If not, see <http://www.gnu.org/licenses/>.
>> + */
>> +
>> +#include <linux/init.h>
>> +#include <linux/io.h>
>> +#include <linux/suspend.h>
>> +
>> +#include <asm/proc-fns.h>
>> +#include <asm/smp_scu.h>
>> +#include <asm/suspend.h>
>> +
>> +#include "core.h"
>> +#include "sysregs.h"
>> +
>> +static int highbank_suspend_finish(unsigned long val)
>> +{
>> +	cpu_do_idle();
>> +	return 0;
>> +}
>> +
>> +static int highbank_pm_enter(suspend_state_t state)
>> +{
>> +	hignbank_set_pwr_suspend();
>> +	highbank_set_cpu_jump(0, cpu_resume);
>> +
>> +	scu_power_mode(scu_base_addr, SCU_PM_POWEROFF);
>> +	cpu_suspend(0, highbank_suspend_finish);
>> +
> Rob,
> 
> Just out of curiosity, how can you resume back without taking care of
> GIC, L2 and SCU which will lose power during suspend?
> 

They are not powergated yet, so it's really just wfi ATM. The L2 and SCU
will be re-initialized by boot code. The GIC will need some save and
restore.

Rob