Re: [PATCH 11/17] Make USBHOST powerdomain go to sleep after warm reset.

[Kevin Hilman <khilman@deeprootsystems.com>]

Tero Kristo <tero.kristo@nokia.com> writes:

> From: Peter De-Schrijver <peter.de-schrijver@nokia.com>
>
> This patch makes sure the USBHOST and SGX powerdomains can go to any sleep
> state after a warm reset.

Workaround looks ok, but the changelog should describe the cause of
problem.  IOW, why weren't these domains transitioning after a warm
reset?

Kevin

> Signed-off-by: Peter 'p2' De Schrijver <peter.de-schrijver@nokia.com>
> Signed-off-by: Jouni Hogander <jouni.hogander@nokia.com>
> ---
>  arch/arm/mach-omap2/cm-regbits-34xx.h |    1 +
>  arch/arm/mach-omap2/pm34xx.c          |   18 ++++++++++++++++++
>  2 files changed, 19 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/cm-regbits-34xx.h b/arch/arm/mach-omap2/cm-regbits-34xx.h
> index 6923deb..3152553 100644
> --- a/arch/arm/mach-omap2/cm-regbits-34xx.h
> +++ b/arch/arm/mach-omap2/cm-regbits-34xx.h
> @@ -680,6 +680,7 @@
>  #define OMAP3430_CLKSEL_GPT2_SHIFT			0
>  
>  /* CM_SLEEPDEP_PER specific bits */
> +#define OMAP3430_CM_SLEEPDEP_PER_EN_MPU			(1 << 1)
>  #define OMAP3430_CM_SLEEPDEP_PER_EN_IVA2		(1 << 2)
>  
>  /* CM_CLKSTCTRL_PER */
> diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
> index 47f5738..1fa778f 100644
> --- a/arch/arm/mach-omap2/pm34xx.c
> +++ b/arch/arm/mach-omap2/pm34xx.c
> @@ -26,6 +26,7 @@
>  #include <linux/err.h>
>  #include <linux/gpio.h>
>  #include <linux/clk.h>
> +#include <linux/delay.h>
>  
>  #include <mach/sram.h>
>  #include <mach/prcm.h>
> @@ -934,6 +935,24 @@ static void __init prcm_setup_regs(void)
>  	prm_write_mod_reg(0, OMAP3430_CAM_MOD, PM_WKDEP);
>  	prm_write_mod_reg(0, OMAP3430_PER_MOD, PM_WKDEP);
>  	if (omap_rev() > OMAP3430_REV_ES1_0) {
> +
> +		/*
> +		 * This workaround is needed to prevent SGX and USBHOST from
> +		 * failing to transition to RET/OFF after a warm reset in OFF
> +		 * mode. Workaround sets a sleepdep of each of these domains
> +		 * with MPU, waits for a min 2 sysclk cycles and clears the
> +		 * sleepdep.
> +		 */
> +		cm_write_mod_reg(OMAP3430_CM_SLEEPDEP_PER_EN_MPU,
> +				OMAP3430ES2_USBHOST_MOD, OMAP3430_CM_SLEEPDEP);
> +		cm_write_mod_reg(OMAP3430_CM_SLEEPDEP_PER_EN_MPU,
> +				OMAP3430ES2_SGX_MOD, OMAP3430_CM_SLEEPDEP);
> +		udelay(100);
> +		cm_write_mod_reg(0, OMAP3430ES2_USBHOST_MOD,
> +				OMAP3430_CM_SLEEPDEP);
> +		cm_write_mod_reg(0, OMAP3430ES2_SGX_MOD,
> +				OMAP3430_CM_SLEEPDEP);
> +
>  		prm_write_mod_reg(0, OMAP3430ES2_SGX_MOD, PM_WKDEP);
>  		prm_write_mod_reg(0, OMAP3430ES2_USBHOST_MOD, PM_WKDEP);
>  	} else
> -- 
> 1.5.4.3
>
> --
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