Subject: [RFC patch 1/2] ARM: at91: cpuidle: encapsulate the standby code

From: [email-masked] (Daniel Lezcano)
Date: Mon, 15 Apr 2013 16:13:59 +0200

On 04/15/2013 03:54 PM, Nicolas Ferre wrote:
> Hi Daniel,
> 
> On 04/15/2013 03:29 PM, Daniel Lezcano :
>> In order to split the pm code from the cpuidle driver, add an ops for the
>> standby function which will be initialized by the pm init functions directly,
>> thus no need of the SoC specific headers.
>>
>> Cleanup also the headers included in this file as they are no longer needed.
>>
>> Signed-off-by: Daniel Lezcano <[email-masked]>
>> ---
>>  arch/arm/mach-at91/cpuidle.c |   19 ++++---------------
>>  arch/arm/mach-at91/pm.c      |    8 +++++++-
>>  2 files changed, 11 insertions(+), 16 deletions(-)
>>
>> diff --git a/arch/arm/mach-at91/cpuidle.c b/arch/arm/mach-at91/cpuidle.c
>> index 48f1228..b2bec92 100644
>> --- a/arch/arm/mach-at91/cpuidle.c
>> +++ b/arch/arm/mach-at91/cpuidle.c
>> @@ -13,32 +13,21 @@
>>   * #2 wait-for-interrupt and RAM self refresh
>>   */
>>  
>> -#include <linux/kernel.h>
>> +#include <linux/module.h>
>>  #include <linux/init.h>
>> -#include <linux/platform_device.h>
>>  #include <linux/cpuidle.h>
>> -#include <linux/io.h>
>> -#include <linux/export.h>
>> -#include <asm/proc-fns.h>
>>  #include <asm/cpuidle.h>
>> -#include <mach/cpu.h>
>> -
>> -#include "pm.h"
>>  
>>  #define AT91_MAX_STATES	2
>>  
>> +extern void (*at91_standby_ops)(void);
>> +
>>  /* Actual code that puts the SoC in different idle states */
>>  static int at91_enter_idle(struct cpuidle_device *dev,
>>  			struct cpuidle_driver *drv,
>>  			       int index)
>>  {
>> -	if (cpu_is_at91rm9200())
>> -		at91rm9200_standby();
>> -	else if (cpu_is_at91sam9g45())
>> -		at91sam9g45_standby();
>> -	else
>> -		at91sam9_standby();
>> -
>> +	at91_standby_ops();
>>  	return index;
>>  }
>>  
>> diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
>> index 73f1f25..f456e86 100644
>> --- a/arch/arm/mach-at91/pm.c
>> +++ b/arch/arm/mach-at91/pm.c
>> @@ -39,6 +39,8 @@
>>  #include "at91_rstc.h"
>>  #include "at91_shdwc.h"
>>  
>> +void (*at91_standby_ops)(void);
> 
> Is this a common pattern to have such a floating function pointer in the
> pm code?

Well, already seen but I agree it is not really nice.

The idea I had was to convert little by little all these pm functions
into ops, then order, group and use them to initialize the cpuidle
drivers through a single ARM driver. The correct order would have been
to convert first these to ops then move the driver but there are so many
drivers, so many code, I don't know where do I start.

Do you have a suggestion ?

>> +
>>  static void __init show_reset_status(void)
>>  {
>>  	static char reset[] __initdata = "reset";
>> @@ -321,8 +323,12 @@ static int __init at91_pm_init(void)
>>  	pr_info("AT91: Power Management%s\n", (slow_clock ? " (with slow clock mode)" : ""));
>>  
>>  	/* AT91RM9200 SDRAM low-power mode cannot be used with self-refresh. */
>> -	if (cpu_is_at91rm9200())
>> +	if (cpu_is_at91rm9200()) {
>>  		at91_ramc_write(0, AT91RM9200_SDRAMC_LPR, 0);
>> +		at91_standby_ops = at91rm9200_standby;
>> +	} else if (cpu_is_at91sam9g45())
> 
> CodingStyle: ending "{" is missing.
> 
>> +		at91_standby_ops= at91sam9g45_standby;
> 
> CodingStyle: " " is missing
> 
>> +	else at91_standby_ops = at91sam9_standby;
> 
> CodingStyle: not on the same line + "{}" missing
> 
>>  
>>  	suspend_set_ops(&at91_pm_ops);
> 
> I am in favor for the move. 

Ok, cool.

> But please rewrite a new series.

Yes, sure, that was a draft.

Thanks for the review.

  -- Daniel

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