Subject: [PATCH v3 2/3] ARM: rockchip: set correct stabilization thresholds in suspend

From: [email-masked] (Chris Zhong)
Date: Wed, 05 Aug 2015 18:41:14 +0800

On 08/05/2015 06:51 AM, Heiko St?bner wrote:
> Currently the stabilization thresholds for the oscillator and external pmu
> are statically set to 30ms based on a 32kHz clock rate. This leaves out the
> case when we don't switch to the 32kHz clock when only entering the shallow
> suspend mode where the logic keeps running.
>
> So, set the correct threshold after we have determined if we switch to the
> 32kHz clock or stay with the 24MHz one. Also set the oscillator-
> stabilization to 0 if it is kept running during suspend, as it of course
> does not need to stabilize then.
>
> Reported-by: Chris Zhong <[email-masked]>
> Signed-off-by: Heiko Stuebner <[email-masked]>
> ---
> changes since v2:
> - describe 32kHz vs 24MHz
> - don't wait for oscillator stabilization if it's still running,
>    as explained by Chris Zhong in v2
> changes since v1:
> - 24MHz oriented threshold is only needed in shallow suspend, the deep
>    suspend always switches to 32kHz and only leaves the 24MHz oscillator
>    running if needed for stuff like usb wakeup
>
>   arch/arm/mach-rockchip/pm.c | 22 +++++++++++++++++++---
>   arch/arm/mach-rockchip/pm.h |  4 ----
>   2 files changed, 19 insertions(+), 7 deletions(-)
>
> diff --git a/arch/arm/mach-rockchip/pm.c b/arch/arm/mach-rockchip/pm.c
> index 2ca1170..c11a30b 100644
> --- a/arch/arm/mach-rockchip/pm.c
> +++ b/arch/arm/mach-rockchip/pm.c
> @@ -145,6 +145,19 @@ static void rk3288_slp_mode_set(int level)
>   
>   		mode_set1 |= BIT(PMU_CLR_ALIVE) | BIT(PMU_CLR_BUS) |
>   			     BIT(PMU_CLR_PERI) | BIT(PMU_CLR_DMA);
> +
> +		/*
> +		 * In deep suspend we use PMU_PMU_USE_LF to let the rk3288
> +		 * switch its main clock supply to the alternative 32kHz
> +		 * source. Therefore set 30ms on a 32kHz clock for pmic
> +		 * stabilization. Similar 30ms on 24MHz for the other
> +		 * mode below.
> +		 */
> +		regmap_write(pmu_regmap, RK3288_PMU_STABL_CNT, 32 * 30);
> +
> +		/* only wait for stabilization, if we turned the osc off */
> +		regmap_write(pmu_regmap, RK3288_PMU_OSC_CNT,
> +					 osc_disable ? 32 * 30 : 0);
>   	} else {
>   		/*
>   		 * arm off, logic normal
> @@ -152,6 +165,12 @@ static void rk3288_slp_mode_set(int level)
>   		 * wakeup will be error
>   		 */
>   		mode_set |= BIT(PMU_CLK_CORE_SRC_GATE_EN);
> +
> +		/* 30ms on a 24MHz clock for pmic stabilization */
> +		regmap_write(pmu_regmap, RK3288_PMU_STABL_CNT, 24000 * 30);
> +
> +		/* oscillator is still running, so no need to wait */
> +		regmap_write(pmu_regmap, RK3288_PMU_OSC_CNT, 0);
>   	}
>   
>   	regmap_write(pmu_regmap, RK3288_PMU_PWRMODE_CON, mode_set);
> @@ -262,9 +281,6 @@ static int rk3288_suspend_init(struct device_node *np)
>   	memcpy(rk3288_bootram_base, rockchip_slp_cpu_resume,
>   	       rk3288_bootram_sz);
>   
> -	regmap_write(pmu_regmap, RK3288_PMU_OSC_CNT, OSC_STABL_CNT_THRESH);
> -	regmap_write(pmu_regmap, RK3288_PMU_STABL_CNT, PMU_STABL_CNT_THRESH);
> -
>   	return 0;
>   }
>   
> diff --git a/arch/arm/mach-rockchip/pm.h b/arch/arm/mach-rockchip/pm.h
> index b6494c2..8a55ee2 100644
> --- a/arch/arm/mach-rockchip/pm.h
> +++ b/arch/arm/mach-rockchip/pm.h
> @@ -62,10 +62,6 @@ static inline void rockchip_suspend_init(void)
>   /* PMU_WAKEUP_CFG1 bits */
>   #define PMU_ARMINT_WAKEUP_EN		BIT(0)
>   
> -/* wait 30ms for OSC stable and 30ms for pmic stable */
> -#define OSC_STABL_CNT_THRESH	(32 * 30)
> -#define PMU_STABL_CNT_THRESH	(32 * 30)
> -
>   enum rk3288_pwr_mode_con {
>   	PMU_PWR_MODE_EN = 0,
>   	PMU_CLK_CORE_SRC_GATE_EN,
Reviewed-by: Chris Zhong <[email-masked]>
Tested-by: Chris Zhong <[email-masked]>