linux-kernel - Re: [PATCH 4/4] mcpm: exynos: populate suspend and powered

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Message-ID: <CANuQgHEQ_G-fuT6_hyKQ+bT0dsnNW5QnTTLBvX+BZUr4w0Fg2Q@mail.gmail.com>
Date:	Wed, 23 Apr 2014 13:52:40 +0530
From:	Chander Kashyap <chander.kashyap@...aro.org>
To:	Daniel Lezcano <daniel.lezcano@...aro.org>
Cc:	linux-pm@...r.kernel.org,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-samsung-soc@...r.kernel.org" 
	<linux-samsung-soc@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	Kukjin Kim <kgene.kim@...sung.com>,
	Chander Kashyap <k.chander@...sung.com>
Subject: Re: [PATCH 4/4] mcpm: exynos: populate suspend and powered_up callbacks

On 22 April 2014 16:21, Daniel Lezcano <daniel.lezcano@...aro.org> wrote:
> On 04/21/2014 01:49 PM, Chander Kashyap wrote:
>>
>> In order to support cpuidle through mcpm, suspend and powered-up
>> callbacks are required in mcpm platform code.
>> Hence populate the same callbacks.
>>
>> Signed-off-by: Chander Kashyap <chander.kashyap@...aro.org>
>> Signed-off-by: Chander Kashyap <k.chander@...sung.com>
>> ---
>>   arch/arm/mach-exynos/mcpm-exynos.c |   53
>> ++++++++++++++++++++++++++++++++++++
>>   1 file changed, 53 insertions(+)
>>
>> diff --git a/arch/arm/mach-exynos/mcpm-exynos.c
>> b/arch/arm/mach-exynos/mcpm-exynos.c
>> index 46d4968..16af0bd 100644
>> --- a/arch/arm/mach-exynos/mcpm-exynos.c
>> +++ b/arch/arm/mach-exynos/mcpm-exynos.c
>> @@ -318,10 +318,63 @@ static int exynos_power_down_finish(unsigned int
>> cpu, unsigned int cluster)
>>         return 0; /* success: the CPU is halted */
>>   }
>>
>> +static void enable_coherency(void)
>> +{
>> +       unsigned long v, u;
>> +
>> +       asm volatile(
>> +               "mrc    p15, 0, %0, c1, c0, 1\n"
>> +               "orr    %0, %0, %2\n"
>> +               "ldr    %1, [%3]\n"
>> +               "and    %1, %1, #0\n"
>> +               "orr    %0, %0, %1\n"
>> +               "mcr    p15, 0, %0, c1, c0, 1\n"
>> +               : "=&r" (v), "=&r" (u)
>> +               : "Ir" (0x40), "Ir" (S5P_INFORM0)
>> +               : "cc");
>> +}
>
>
> Shouldn't this function to be used from hotplug.c also ?

Hotplug.c already taking care for this. And anyhow that will go away
for mcpm dependent SoCs

>
>
>> +
>> +void exynos_powered_up(void)
>> +{
>> +       unsigned int mpidr, cpu, cluster;
>> +
>> +       mpidr = read_cpuid_mpidr();
>> +       cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
>> +       cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
>> +
>> +       arch_spin_lock(&bl_lock);
>> +       if (cpu_use_count[cpu][cluster] == 0)
>> +               cpu_use_count[cpu][cluster] = 1;
>> +       arch_spin_unlock(&bl_lock);
>> +}
>> +
>> +static void exynos_suspend(u64 residency)
>> +{
>> +       unsigned int mpidr, cpunr;
>> +
>> +       mpidr = read_cpuid_mpidr();
>> +       cpunr = enynos_pmu_cpunr(mpidr);
>
>
> *enynos*_pmu_cpunr ?

oops, I will fix typo

>
>
>> +
>> +       __raw_writel(virt_to_phys(mcpm_entry_point), REG_ENTRY_ADDR);
>> +
>> +       exynos_power_down();
>> +
>> +       /*
>> +        * Execution reaches here only if cpu did not power down.
>> +        * Hence roll back the changes done in exynos_power_down function.
>> +       */
>> +       __raw_writel(EXYNOS_CORE_LOCAL_PWR_EN,
>> +                       EXYNOS_ARM_CORE_CONFIGURATION(cpunr));
>
>
> Why don't you use the functions defined in the
>
> patch 5/5 arm: exynos: Add MCPM call-back functions

In exynos_core_power_control it powerup the alreay powered down core.
But here i need to simply set this value as core never powered down.

>
> exynos_core_power_control() ?
>
>
>> +       set_cr(get_cr() | CR_C);
>> +       enable_coherency();
>> +}
>> +
>>   static const struct mcpm_platform_ops exynos_power_ops = {
>>         .power_up               = exynos_power_up,
>>         .power_down             = exynos_power_down,
>>         .power_down_finish      = exynos_power_down_finish,
>> +       .suspend                = exynos_suspend,
>> +       .powered_up             = exynos_powered_up,
>>   };
>>
>>   static void __init exynos_mcpm_usage_count_init(void)
>>
>
>
> --
>  <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
>
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>



-- 
with warm regards,
Chander Kashyap
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