[PATCH v2 1/5] OMAP4: PM: Use the low-power state change feature on OMAP4

[Kevin Hilman]

Rajendra Nayak <rnayak at ti.com> writes:

> For pwrdm's which support LOWPOWERSTATECHANGE, do not try waking
> up the domain to put it back to deeper sleep state.
>
> Signed-off-by: Rajendra Nayak <rnayak at ti.com>
> Signed-off-by: Santosh Shilimkar <santosh.shilimkar at ti.com>
> Acked-by: Benoit Cousson <b-cousson at ti.com>
> Cc: Kevin Hilman <khilman at deeprootsystems.com>
> Cc: Paul Walmsley <paul at pwsan.com>

Acked-by: Kevin Hilman <khilman at deeprootsystems.com>

> ---
> Changes in v2:
> Changed implementation for better readability and code
> reuse as suggested here
> http://marc.info/?l=linux-omap&m=129245686306262&w=2
>
> The below branch is updated with this version of the patch
> git://gitorious.org/omap-pm/linux.git for_2.6.38/power
>
>  arch/arm/mach-omap2/pm.c |   28 ++++++++++++++++++++++------
>  1 file changed, 22 insertions(+), 6 deletions(-)
>
> Index: linux/arch/arm/mach-omap2/pm.c
> ===================================================================
> --- linux.orig/arch/arm/mach-omap2/pm.c	2010-12-15 17:29:42.361228780 +0530
> +++ linux/arch/arm/mach-omap2/pm.c	2010-12-15 20:19:48.321228780 +0530
> @@ -89,6 +89,10 @@
>  	}
>  }
>  
> +/* Types of sleep_switch used in omap_set_pwrdm_state */
> +#define FORCEWAKEUP_SWITCH	0
> +#define LOWPOWERSTATE_SWITCH	1
> +
>  /*
>   * This sets pwrdm state (other than mpu & core. Currently only ON &
>   * RET are supported. Function is assuming that clkdm doesn't have
> @@ -114,9 +118,14 @@
>  		return ret;
>  
>  	if (pwrdm_read_pwrst(pwrdm) < PWRDM_POWER_ON) {
> -		omap2_clkdm_wakeup(pwrdm->pwrdm_clkdms[0]);
> -		sleep_switch = 1;
> -		pwrdm_wait_transition(pwrdm);
> +		if ((pwrdm_read_pwrst(pwrdm) > state) &&
> +			(pwrdm->flags & PWRDM_HAS_LOWPOWERSTATECHANGE)) {
> +			sleep_switch = LOWPOWERSTATE_SWITCH;
> +		} else {
> +			omap2_clkdm_wakeup(pwrdm->pwrdm_clkdms[0]);
> +			pwrdm_wait_transition(pwrdm);
> +			sleep_switch = FORCEWAKEUP_SWITCH;
> +		}
>  	}
>  
>  	ret = pwrdm_set_next_pwrst(pwrdm, state);
> @@ -126,12 +135,19 @@
>  		goto err;
>  	}
>  
> -	if (sleep_switch) {
> +	switch (sleep_switch) {
> +	case FORCEWAKEUP_SWITCH:
>  		omap2_clkdm_allow_idle(pwrdm->pwrdm_clkdms[0]);
> -		pwrdm_wait_transition(pwrdm);
> -		pwrdm_state_switch(pwrdm);
> +		break;
> +	case LOWPOWERSTATE_SWITCH:
> +		pwrdm_set_lowpwrstchange(pwrdm);
> +		break;
> +	default:
> +		return ret;
>  	}
>  
> +	pwrdm_wait_transition(pwrdm);
> +	pwrdm_state_switch(pwrdm);
>  err:
>  	return ret;
>  }