Subject: [PATCHv4 6/8] ARM: OMAP4: PM: support ret_logic/mem_off_counters

From: [email-masked] (Kevin Hilman)
Date: Mon, 07 May 2012 17:19:39 -0700

Tero Kristo <[email-masked]> writes:

> From: Axel Haslam <[email-masked]>
>
> On OMAP4, there is no support to read previous logic state
> or previous memory state achieved when a power domain transitions
> to RET. Instead there are module level context registers.
>
> In order to support the powerdomain level logic/mem_off_counters
> on OMAP4, instead use the previous power state achieved (RET) and
> the *programmed* logic/mem RET state to derive if a powerdomain lost
> logic or did not.

OK, but this also changes the behavior for OMAP3 as well, right?  I
don't see in the changelog how this affects OMAP3 and whether it is
still expected to work on OMAP3.  When changing common code like this,
the changelog should describe the impacts on to all affected SoCs.

As suggested by Vaibhav Bedia, now might be the right time to add this
function to the SoC specific function pointers (struct pwrdm_ops.)

Doing that, the existing function could be used for OMAP3 (and OMAP4 if
the changelog describes that it can/should be used for both.)

Then, when AM33xx support is added, it will be obvious where they will
need to plugin support for that SoC.

Kevin

> If the powerdomain is programmed to enter RET state and lose logic
> in RET state, knowing that the powerdomain entered RET is good enough
> to derive that the logic was lost as well, in such cases.
>
> Signed-off-by: Axel Haslam <[email-masked]>
> [rnayak at ti.com: Updated changelog, updated patch to support mem counters]
> Signed-off-by: Rajendra Nayak <[email-masked]>
> Signed-off-by: Tero Kristo <[email-masked]>
> ---
>  arch/arm/mach-omap2/powerdomain.c |   16 ++++++++++------
>  1 files changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/powerdomain.c b/arch/arm/mach-omap2/powerdomain.c
> index 96ad3dbe..068f06b 100644
> --- a/arch/arm/mach-omap2/powerdomain.c
> +++ b/arch/arm/mach-omap2/powerdomain.c
> @@ -124,18 +124,22 @@ static int _pwrdm_register(struct powerdomain *pwrdm)
>  static void _update_logic_membank_counters(struct powerdomain *pwrdm)
>  {
>  	int i;
> -	u8 prev_logic_pwrst, prev_mem_pwrst;
> +	int logic_pwrst, mem_pwrst;
> +
> +	logic_pwrst = pwrdm_read_prev_logic_pwrst(pwrdm);
> +	if (logic_pwrst == -EINVAL)
> +		logic_pwrst = pwrdm_read_logic_retst(pwrdm);
>  
> -	prev_logic_pwrst = pwrdm_read_prev_logic_pwrst(pwrdm);
>  	if ((pwrdm->pwrsts_logic_ret == PWRSTS_OFF_RET) &&
> -	    (prev_logic_pwrst == PWRDM_POWER_OFF))
> +	    (logic_pwrst == PWRDM_POWER_OFF))
>  		pwrdm->ret_logic_off_counter++;
>  
>  	for (i = 0; i < pwrdm->banks; i++) {
> -		prev_mem_pwrst = pwrdm_read_prev_mem_pwrst(pwrdm, i);
> -
> +		mem_pwrst = pwrdm_read_prev_mem_pwrst(pwrdm, i);
> +		if (mem_pwrst == -EINVAL)
> +			mem_pwrst = pwrdm_read_mem_retst(pwrdm, i);
>  		if ((pwrdm->pwrsts_mem_ret[i] == PWRSTS_OFF_RET) &&
> -		    (prev_mem_pwrst == PWRDM_POWER_OFF))
> +		    (mem_pwrst == PWRDM_POWER_OFF))
>  			pwrdm->ret_mem_off_counter[i]++;
>  	}
>  }