[PATCH 2/7] ARM: tegra: cpuidle: add LP2 resume function
Joseph Lo
josephl at nvidia.com
Mon Oct 8 06:26:16 EDT 2012
LP2 is one of the Tegra low power states that supports power gating both
CPU cores and GICs. Adding a resume function for taking care the CPUs that
resume from LP2. This function was been hooked to reset handler. We take
care everything here before go into kernel.
Based on the work by:
Scott Williams <scwilliams at nvidia.com>
Colin Cross <ccross at android.com>
Gary King <gking at nvidia.com>
Signed-off-by: Joseph Lo <josephl at nvidia.com>
---
arch/arm/mach-tegra/headsmp.S | 58 +++++++++++++++++++++++++++++++++++++++++
arch/arm/mach-tegra/reset.c | 6 ++++
arch/arm/mach-tegra/sleep.h | 1 +
3 files changed, 65 insertions(+), 0 deletions(-)
diff --git a/arch/arm/mach-tegra/headsmp.S b/arch/arm/mach-tegra/headsmp.S
index 6addc78..abf86b3 100644
--- a/arch/arm/mach-tegra/headsmp.S
+++ b/arch/arm/mach-tegra/headsmp.S
@@ -69,6 +69,53 @@ 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
+
+ /* 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
+#ifdef CONFIG_ARCH_TEGRA_3x_SOC
+ /* 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]
+#endif
+1:
+
+ /* enable SCU */
+ mov32 r0, TEGRA_ARM_PERIF_BASE
+ ldr r1, [r0]
+ orr r1, r1, #1
+ str r1, [r0]
+
+ b cpu_resume
+ENDPROC(tegra_resume)
+#endif
+
.align L1_CACHE_SHIFT
ENTRY(__tegra_cpu_reset_handler_start)
@@ -122,6 +169,17 @@ 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 5beb7eb..c48548f 100644
--- a/arch/arm/mach-tegra/reset.c
+++ b/arch/arm/mach-tegra/reset.c
@@ -26,6 +26,7 @@
#include <mach/irammap.h>
#include "reset.h"
+#include "sleep.h"
#include "fuse.h"
#define TEGRA_IRAM_RESET_BASE (TEGRA_IRAM_BASE + \
@@ -80,5 +81,10 @@ 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 e25a7cd..c9dec37 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);
--
1.7.0.4
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