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>

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
 

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

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