From d3f293656c07a1147c11e8c8774d7955a903cee0 Mon Sep 17 00:00:00 2001 From: Joseph Lo Date: Wed, 31 Oct 2012 17:41:16 +0800 Subject: [PATCH] ARM: tegra: cpuidle: add CPU resume function The CPU suspending on Tegra means CPU power gating. We add a resume function for taking care the CPUs that resume from power gating status. This function was been hooked to the reset handler. We take care everything here before go into kernel. Be aware of that, you may see the legacy power status "LP2" in the code which is exactly the same meaning of "CPU power down". Based on the work by: Scott Williams Colin Cross Gary King Signed-off-by: Joseph Lo Signed-off-by: Stephen Warren --- arch/arm/mach-tegra/headsmp.S | 60 +++++++++++++++++++++++++++++++++++ arch/arm/mach-tegra/reset.c | 6 ++++ arch/arm/mach-tegra/sleep.h | 1 + 3 files changed, 67 insertions(+) diff --git a/arch/arm/mach-tegra/headsmp.S b/arch/arm/mach-tegra/headsmp.S index 93f0370cc95b..82dc84b6b868 100644 --- a/arch/arm/mach-tegra/headsmp.S +++ b/arch/arm/mach-tegra/headsmp.S @@ -68,6 +68,55 @@ ENTRY(tegra_secondary_startup) b secondary_startup ENDPROC(tegra_secondary_startup) +#ifdef CONFIG_PM_SLEEP +/* + * tegra_resume + * + * CPU boot vector when restarting the a CPU following + * an LP2 transition. Also branched to by LP0 and LP1 resume after + * re-enabling sdram. + */ +ENTRY(tegra_resume) + bl v7_invalidate_l1 + /* Enable coresight */ + mov32 r0, 0xC5ACCE55 + mcr p14, 0, r0, c7, c12, 6 + + cpu_id r0 + cmp r0, #0 @ CPU0? + bne cpu_resume @ no + +#ifdef CONFIG_ARCH_TEGRA_3x_SOC + /* Are we on Tegra20? */ + mov32 r6, TEGRA_APB_MISC_BASE + ldr r0, [r6, #APB_MISC_GP_HIDREV] + and r0, r0, #0xff00 + cmp r0, #(0x20 << 8) + beq 1f @ Yes + /* Clear the flow controller flags for this CPU. */ + mov32 r2, TEGRA_FLOW_CTRL_BASE + FLOW_CTRL_CPU0_CSR @ CPU0 CSR + ldr r1, [r2] + /* Clear event & intr flag */ + orr r1, r1, \ + #FLOW_CTRL_CSR_INTR_FLAG | FLOW_CTRL_CSR_EVENT_FLAG + movw r0, #0x0FFD @ enable, cluster_switch, immed, & bitmaps + bic r1, r1, r0 + str r1, [r2] +1: +#endif + +#ifdef CONFIG_HAVE_ARM_SCU + /* enable SCU */ + mov32 r0, TEGRA_ARM_PERIF_BASE + ldr r1, [r0] + orr r1, r1, #1 + str r1, [r0] +#endif + + b cpu_resume +ENDPROC(tegra_resume) +#endif + .align L1_CACHE_SHIFT ENTRY(__tegra_cpu_reset_handler_start) @@ -121,6 +170,17 @@ ENTRY(__tegra_cpu_reset_handler) 1: #endif + /* Waking up from LP2? */ + ldr r9, [r12, #RESET_DATA(MASK_LP2)] + tst r9, r11 @ if in_lp2 + beq __is_not_lp2 + ldr lr, [r12, #RESET_DATA(STARTUP_LP2)] + cmp lr, #0 + bleq __die @ no LP2 startup handler + bx lr + +__is_not_lp2: + #ifdef CONFIG_SMP /* * Can only be secondary boot (initial or hotplug) but CPU 0 diff --git a/arch/arm/mach-tegra/reset.c b/arch/arm/mach-tegra/reset.c index e05da7d10c3b..3fd89ecd158e 100644 --- a/arch/arm/mach-tegra/reset.c +++ b/arch/arm/mach-tegra/reset.c @@ -25,6 +25,7 @@ #include "iomap.h" #include "irammap.h" #include "reset.h" +#include "sleep.h" #include "fuse.h" #define TEGRA_IRAM_RESET_BASE (TEGRA_IRAM_BASE + \ @@ -79,5 +80,10 @@ void __init tegra_cpu_reset_handler_init(void) virt_to_phys((void *)tegra_secondary_startup); #endif +#ifdef CONFIG_PM_SLEEP + __tegra_cpu_reset_handler_data[TEGRA_RESET_STARTUP_LP2] = + virt_to_phys((void *)tegra_resume); +#endif + tegra_cpu_reset_handler_enable(); } diff --git a/arch/arm/mach-tegra/sleep.h b/arch/arm/mach-tegra/sleep.h index 4889b281c5f9..addb83f5bc73 100644 --- a/arch/arm/mach-tegra/sleep.h +++ b/arch/arm/mach-tegra/sleep.h @@ -72,6 +72,7 @@ dsb .endm #else +void tegra_resume(void); #ifdef CONFIG_HOTPLUG_CPU void tegra20_hotplug_init(void); -- 2.20.1