ARM: tegra: add common resume handling code for LP1 resuming

Add support to the Tegra CPU reset vector to detect whether the CPU is
resuming from LP1 suspend state. If it is, branch to the LP1-specific
resume code.

When Tegra enters the LP1 suspend state, the SDRAM controller is placed
into a self-refresh state. For this reason, we must place the LP1 resume
code into IRAM, so that it is accessible before SDRAM access has been
re-enabled.

Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>

3 files changed, 17 insertions, 0 deletions

diff --git a/arch/arm/mach-tegra/iomap.h b/arch/arm/mach-tegra/iomap.h
index 399fbca27102..f2bdcb4eac94 100644
--- a/arch/arm/mach-tegra/iomap.h
+++ b/arch/arm/mach-tegra/iomap.h
@@ -24,6 +24,8 @@
 #define TEGRA_IRAM_BASE                 0x40000000
 #define TEGRA_IRAM_SIZE                 SZ_256K
 
+#define TEGRA_IRAM_CODE_AREA            (TEGRA_IRAM_BASE + SZ_4K)
+
 #define TEGRA_HOST1X_BASE               0x50000000
 #define TEGRA_HOST1X_SIZE               0x24000
 
diff --git a/arch/arm/mach-tegra/reset-handler.S b/arch/arm/mach-tegra/reset-handler.S
index 34614bdf3f5b..f527b2c2dea7 100644
--- a/arch/arm/mach-tegra/reset-handler.S
+++ b/arch/arm/mach-tegra/reset-handler.S
@@ -182,6 +182,19 @@ after_errata:
 1:
 #endif
 
+        /* Waking up from LP1? */
+        ldr     r8, [r12, #RESET_DATA(MASK_LP1)]
+        tst     r8, r11                         @ if in_lp1
+        beq     __is_not_lp1
+        cmp     r10, #0
+        bne     __die                           @ only CPU0 can be here
+        ldr     lr, [r12, #RESET_DATA(STARTUP_LP1)]
+        cmp     lr, #0
+        bleq    __die                           @ no LP1 startup handler
+ THUMB( add     lr, lr, #1 )                    @ switch to Thumb mode
+        bx      lr
+__is_not_lp1:
+
         /* Waking up from LP2? */
         ldr     r9, [r12, #RESET_DATA(MASK_LP2)]
         tst     r9, r11                         @ if in_lp2
diff --git a/arch/arm/mach-tegra/reset.c b/arch/arm/mach-tegra/reset.c
index 1ac434e0068f..fd0bbf8a6c94 100644
--- a/arch/arm/mach-tegra/reset.c
+++ b/arch/arm/mach-tegra/reset.c
@@ -81,6 +81,8 @@ void __init tegra_cpu_reset_handler_init(void)
 #endif
 
 #ifdef CONFIG_PM_SLEEP
+        __tegra_cpu_reset_handler_data[TEGRA_RESET_STARTUP_LP1] =
+                TEGRA_IRAM_CODE_AREA;
         __tegra_cpu_reset_handler_data[TEGRA_RESET_STARTUP_LP2] =
                 virt_to_phys((void *)tegra_resume);
 #endif