Hi Amit, On Fri, Nov 11, 2011 at 06:29:33AM +0000, Amit Daniel Kachhap wrote: > This patch adds support for AFTR(ARM OFF TOP RUNNING) mode in > cpuidle driver for EXYNOS4210. L2 cache keeps their data in this mode. > This patch adds the code to the latest interfaces to > save/restore CPU state inclusive of CPU PM notifiers, l2 > resume and cpu_suspend/resume. > > Signed-off-by: Jaecheol Lee <jc.lee@xxxxxxxxxxx> > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> > Signed-off-by: Amit Daniel Kachhap <amit.kachhap@xxxxxxxxxx> > --- > arch/arm/mach-exynos/cpuidle.c | 148 ++++++++++++++++++++++++++++++- > arch/arm/mach-exynos/include/mach/pmu.h | 2 + > 2 files changed, 146 insertions(+), 4 deletions(-) > > diff --git a/arch/arm/mach-exynos/cpuidle.c b/arch/arm/mach-exynos/cpuidle.c > index c6485d3..857ccc6 100644 > --- a/arch/arm/mach-exynos/cpuidle.c > +++ b/arch/arm/mach-exynos/cpuidle.c > @@ -12,13 +12,31 @@ > #include <linux/module.h> > #include <linux/init.h> > #include <linux/cpuidle.h> > +#include <linux/cpu_pm.h> Included but not used, why ? Is GIC state kept in AFTR ? Even if it is, VFP state is certainly gone, so you must call the notifiers anyway. > #include <linux/io.h> > - > +#include <linux/suspend.h> > +#include <linux/err.h> > #include <asm/proc-fns.h> > +#include <asm/smp_scu.h> > +#include <asm/suspend.h> > +#include <asm/unified.h> > +#include <mach/regs-pmu.h> > +#include <mach/pmu.h> > + > +#include <plat/exynos4.h> > +#include <plat/cpu.h> > + > +#define REG_DIRECTGO_ADDR (samsung_rev() == EXYNOS4210_REV_1_1 ? \ > + S5P_INFORM7 : (S5P_VA_SYSRAM + 0x24)) > +#define REG_DIRECTGO_FLAG (samsung_rev() == EXYNOS4210_REV_1_1 ? \ > + S5P_INFORM6 : (S5P_VA_SYSRAM + 0x20)) > > static int exynos4_enter_idle(struct cpuidle_device *dev, > struct cpuidle_driver *drv, > int index); > +static int exynos4_enter_lowpower(struct cpuidle_device *dev, > + struct cpuidle_driver *drv, > + int index); > > static struct cpuidle_state exynos4_cpuidle_set[] = { > [0] = { > @@ -26,9 +44,17 @@ static struct cpuidle_state exynos4_cpuidle_set[] = { > .exit_latency = 1, > .target_residency = 100000, > .flags = CPUIDLE_FLAG_TIME_VALID, > - .name = "IDLE", > + .name = "C0", > .desc = "ARM clock gating(WFI)", > }, > + [1] = { > + .enter = exynos4_enter_lowpower, > + .exit_latency = 300, > + .target_residency = 100000, > + .flags = CPUIDLE_FLAG_TIME_VALID, > + .name = "C1", > + .desc = "ARM power down", > + }, > }; > > static DEFINE_PER_CPU(struct cpuidle_device, exynos4_cpuidle_device); > @@ -38,9 +64,95 @@ static struct cpuidle_driver exynos4_idle_driver = { > .owner = THIS_MODULE, > }; > > +/* Ext-GIC nIRQ/nFIQ is the only wakeup source in AFTR */ > +static void exynos4_set_wakeupmask(void) > +{ > + __raw_writel(0x0000ff3e, S5P_WAKEUP_MASK); > +} > + > +static unsigned int g_pwr_ctrl, g_diag_reg; > + > +static void save_cpu_arch_register(void) > +{ > + /*read power control register*/ > + asm("mrc p15, 0, %0, c15, c0, 0" : "=r"(g_pwr_ctrl) : : "cc"); > + /*read diagnostic register*/ > + asm("mrc p15, 0, %0, c15, c0, 1" : "=r"(g_diag_reg) : : "cc"); > + return; > +} > + > +static void restore_cpu_arch_register(void) > +{ > + /*write power control register*/ > + asm("mcr p15, 0, %0, c15, c0, 0" : : "r"(g_pwr_ctrl) : "cc"); > + /*write diagnostic register*/ > + asm("mcr p15, 0, %0, c15, c0, 1" : : "r"(g_diag_reg) : "cc"); > + return; > +} > + > +static int idle_finisher(unsigned long flags) > +{ > + cpu_do_idle(); > + return 1; > +} > + > +static int exynos4_enter_core0_aftr(struct cpuidle_device *dev, > + struct cpuidle_driver *drv, > + int index) > +{ > + struct timeval before, after; > + int idle_time; > + unsigned long tmp; > + > + local_irq_disable(); > + do_gettimeofday(&before); > + > + exynos4_set_wakeupmask(); > + > + /* Set value of power down register for aftr mode */ > + exynos4_sys_powerdown_conf(SYS_AFTR); > + > + save_cpu_arch_register(); > + You must call the notifiers here, at least cpu_pm_enter(); > + /* Setting Central Sequence Register for power down mode */ > + tmp = __raw_readl(S5P_CENTRAL_SEQ_CONFIGURATION); > + tmp &= ~S5P_CENTRAL_LOWPWR_CFG; > + __raw_writel(tmp, S5P_CENTRAL_SEQ_CONFIGURATION); > + > + cpu_suspend(0, idle_finisher); > + > + scu_enable(S5P_VA_SCU); > + Again, you need to resume (VFP, if GIC is kept) through notifiers here, I do not understand why that code has been removed. Lorenzo -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html