> -----Original Message----- > From: Russell King - ARM Linux [mailto:linux@xxxxxxxxxxxxxxxx] > Sent: Friday, February 04, 2011 5:01 PM > To: Santosh Shilimkar > Cc: catalin.marinas@xxxxxxx; linus.ml.walleij@xxxxxxxxx; linux- > omap@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; > ccross@xxxxxxxxxxx > Subject: Re: [PATCH 4/5] ARM: scu: Move register defines to header > file > > On Fri, Feb 04, 2011 at 04:16:07PM +0530, Santosh Shilimkar wrote: > > > -----Original Message----- > > > From: Russell King - ARM Linux [mailto:linux@xxxxxxxxxxxxxxxx] > > > Sent: Friday, February 04, 2011 4:11 PM > > > To: Santosh Shilimkar > > > Cc: catalin.marinas@xxxxxxx; linus.ml.walleij@xxxxxxxxx; linux- > > > omap@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; > > > ccross@xxxxxxxxxxx > > > Subject: Re: [PATCH 4/5] ARM: scu: Move register defines to > header > > > file > > > > > > On Tue, Jan 25, 2011 at 11:53:35PM +0530, Santosh Shilimkar > wrote: > > > > After fixing the 3rd version for base address break, I was > able to > > > > use this patch and test it. Seems to work. SMC related stuff > can > > > > be ignored because OMAP4 ES1.0 doesn't have functional PM > hardware > > > > support. > > > > > > I think I'd prefer to do as the other functions do, and pass in > the > > > scu base address from the platform code. It's potentially more > > > efficient for platforms which have a fixed SCU base address. > > Ok. I can fix that > Thanks. Will use this version then. > 8<------ > Subject: [PATCH] ARM: smp: add function to set WFI low-power mode > for SMP CPUs > > Add a function to set the SCU low-power mode for SMP CPUs. This > centralizes this functionality rather than having to expose the > SCU register definitions to each platform. > > Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx> > --- > arch/arm/include/asm/smp_scu.h | 5 +++++ > arch/arm/kernel/smp_scu.c | 24 ++++++++++++++++++++++++ > 2 files changed, 29 insertions(+), 0 deletions(-) > > diff --git a/arch/arm/include/asm/smp_scu.h > b/arch/arm/include/asm/smp_scu.h > index 2376835..800860d 100644 > --- a/arch/arm/include/asm/smp_scu.h > +++ b/arch/arm/include/asm/smp_scu.h > @@ -1,7 +1,12 @@ > #ifndef __ASMARM_ARCH_SCU_H > #define __ASMARM_ARCH_SCU_H > > +#define SCU_PM_NORMAL 0 > +#define SCU_PM_DORMANT 2 > +#define SCU_PM_POWEROFF 3 > + > unsigned int scu_get_core_count(void __iomem *); > void scu_enable(void __iomem *); > +int scu_power_mode(void __iomem *, unsigned int); > > #endif > diff --git a/arch/arm/kernel/smp_scu.c b/arch/arm/kernel/smp_scu.c > index 9ab4149..0ba329a 100644 > --- a/arch/arm/kernel/smp_scu.c > +++ b/arch/arm/kernel/smp_scu.c > @@ -50,3 +50,27 @@ void __init scu_enable(void __iomem *scu_base) > */ > flush_cache_all(); > } > + > +/* > + * Set the executing CPUs power mode as defined. This will be in > + * preparation for it executing a WFI instruction. > + * > + * This function must be called with preemption disabled, and as it > + * has the side effect of disabling coherency, caches must have > been > + * flushed. Interrupts must also have been disabled. > + */ > +int scu_power_mode(void __iomem *scu_base, unsigned int mode) > +{ > + unsigned int val; > + int cpu = smp_processor_id(); > + int shift; > + > + if (mode > 3 || mode == 1 || cpu > 3) > + return -EINVAL; > + > + val = __raw_readb(scu_base + SCU_CPU_STATUS + cpu) & ~0x03; > + val |= mode; > + __raw_writeb(val, scu_base + SCU_CPU_STATUS + cpu); > + > + return 0; > +} > -- > 1.6.2.5 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
