From 6d76e260493dc5f8c071f6330f3f6490952125f9 Mon Sep 17 00:00:00 2001
From: Yudong Tan <ytan@nvidia.com>
Date: Thu, 18 Aug 2011 15:26:52 -0700
Subject: ARM: tegra: power: implement LP1 suspend/resume for Tegra3

Bug 862502

Change-Id: If70e54fb32ce14d5f13dde1d7fb4c1f1499a6722
Reviewed-on: http://git-master/r/47398
Reviewed-by: Daniel Willemsen <dwillemsen@nvidia.com>
Tested-by: Daniel Willemsen <dwillemsen@nvidia.com>

Rebase-Id: Ra77a54e6930692bca628a97bf1de10a30408cdef
---
 arch/arm/mach-tegra/asm_macros.h |   9 +
 arch/arm/mach-tegra/pm-t3.c      |   2 +-
 arch/arm/mach-tegra/pm.c         |  26 ++-
 arch/arm/mach-tegra/pm.h         |   2 +-
 arch/arm/mach-tegra/reset.h      |   2 +-
 arch/arm/mach-tegra/sleep-t3.S   | 470 ++++++++++++++++++++++++++++++++++++++-
 arch/arm/mach-tegra/sleep.h      |   3 +-
 7 files changed, 496 insertions(+), 18 deletions(-)

(limited to 'arch')

diff --git a/arch/arm/mach-tegra/asm_macros.h b/arch/arm/mach-tegra/asm_macros.h
index 61a7028a6cc0..2463d797ce39 100644
--- a/arch/arm/mach-tegra/asm_macros.h
+++ b/arch/arm/mach-tegra/asm_macros.h
@@ -19,6 +19,15 @@
 
 #ifdef __ASSEMBLY__
 
+/* waits until the microsecond counter (base) ticks, for exact timing loops */
+.macro  wait_for_us, rd, base, tmp
+	ldr    \rd, [\base]
+1001:   ldr    \tmp, [\base]
+	cmp    \rd, \tmp
+	beq    1001b
+	mov    \tmp, \rd
+.endm
+
 /* waits until the microsecond counter (base) is > rn */
 .macro	wait_until, rn, base, tmp
 	add	\rn, \rn, #1
diff --git a/arch/arm/mach-tegra/pm-t3.c b/arch/arm/mach-tegra/pm-t3.c
index 5f0e01406f2f..959ab909bcf5 100644
--- a/arch/arm/mach-tegra/pm-t3.c
+++ b/arch/arm/mach-tegra/pm-t3.c
@@ -328,7 +328,7 @@ int tegra_cluster_control(unsigned int us, unsigned int flags)
 		if (us)
 			tegra_lp2_set_trigger(us);
 
-		tegra_suspend_dram(TEGRA_SUSPEND_LP1);
+		tegra_suspend_dram(TEGRA_SUSPEND_LP1, flags);
 
 		if (us)
 			tegra_lp2_set_trigger(0);
diff --git a/arch/arm/mach-tegra/pm.c b/arch/arm/mach-tegra/pm.c
index 688775531fe0..9211671984b0 100644
--- a/arch/arm/mach-tegra/pm.c
+++ b/arch/arm/mach-tegra/pm.c
@@ -66,6 +66,7 @@
 #include "reset.h"
 #include "sleep.h"
 #include "timer.h"
+#include "reset.h"
 
 struct suspend_context {
 	/*
@@ -99,6 +100,7 @@ static pgd_t *tegra_pgd;
 static DEFINE_SPINLOCK(tegra_lp2_lock);
 static cpumask_t tegra_in_lp2;
 static cpumask_t *iram_cpu_lp2_mask;
+static unsigned long *iram_cpu_lp1_mask;
 static u8 *iram_save;
 static unsigned long iram_save_size;
 static void __iomem *iram_code = IO_ADDRESS(TEGRA_IRAM_CODE_AREA);
@@ -664,8 +666,6 @@ static void tegra_pm_set(enum tegra_suspend_mode mode)
 		 * scratch 41 to tegra_resume
 		 */
 		writel(0x0, pmc + PMC_SCRATCH39);
-		__raw_writel(virt_to_phys(tegra_resume), pmc + PMC_SCRATCH41);
-		wmb();
 
 		/* Enable DPD sample to trigger sampling pads data and direction
 		 * in which pad will be driven during lp0 mode*/
@@ -678,8 +678,10 @@ static void tegra_pm_set(enum tegra_suspend_mode mode)
 		pmc_32kwritel(tegra_lp0_vec_start, PMC_SCRATCH1);
 
 		reg |= TEGRA_POWER_EFFECT_LP0;
-		break;
+		/* No break here. LP0 code falls through to write SCRATCH41 */
 	case TEGRA_SUSPEND_LP1:
+		__raw_writel(virt_to_phys(tegra_resume), pmc + PMC_SCRATCH41);
+		wmb();
 		break;
 	case TEGRA_SUSPEND_LP2:
 		rate = clk_get_rate(tegra_pclk);
@@ -709,7 +711,7 @@ static int tegra_suspend_enter(suspend_state_t state)
 	if (pdata && pdata->board_suspend)
 		pdata->board_suspend(current_suspend_mode, TEGRA_SUSPEND_BEFORE_PERIPHERAL);
 
-	ret = tegra_suspend_dram(current_suspend_mode);
+	ret = tegra_suspend_dram(current_suspend_mode, 0);
 
 	if (pdata && pdata->board_resume)
 		pdata->board_resume(current_suspend_mode, TEGRA_RESUME_AFTER_PERIPHERAL);
@@ -743,7 +745,7 @@ static void tegra_suspend_check_pwr_stats(void)
 	return;
 }
 
-int tegra_suspend_dram(enum tegra_suspend_mode mode)
+int tegra_suspend_dram(enum tegra_suspend_mode mode, unsigned int flags)
 {
 	BUG_ON(mode < 0 || mode >= TEGRA_MAX_SUSPEND_MODE);
 
@@ -774,7 +776,11 @@ int tegra_suspend_dram(enum tegra_suspend_mode mode)
 		tegra_lp0_suspend_mc();
 	}
 
-	suspend_cpu_complex(0);
+	suspend_cpu_complex(flags);
+
+	if (mode == TEGRA_SUSPEND_LP1)
+		*iram_cpu_lp1_mask = 1;
+
 	flush_cache_all();
 	outer_flush_all();
 	outer_disable();
@@ -789,9 +795,10 @@ int tegra_suspend_dram(enum tegra_suspend_mode mode)
 	if (mode == TEGRA_SUSPEND_LP0) {
 		tegra_lp0_resume_mc();
 		tegra_lp0_cpu_mode(false);
-	}
+	} else if (mode == TEGRA_SUSPEND_LP1)
+		*iram_cpu_lp1_mask = 0;
 
-	restore_cpu_complex(0);
+	restore_cpu_complex(flags);
 
 	cpu_complex_pm_exit();
 	cpu_pm_exit();
@@ -803,6 +810,8 @@ int tegra_suspend_dram(enum tegra_suspend_mode mode)
 
 	tegra_common_resume();
 
+	pr_info("Exited suspend state %s\n", lp_state[mode]);
+
 	return 0;
 }
 
@@ -1021,6 +1030,7 @@ out:
 	}
 
 	iram_cpu_lp2_mask = tegra_cpu_lp2_mask;
+	iram_cpu_lp1_mask = tegra_cpu_lp1_mask;
 fail:
 #endif
 	if (plat->suspend_mode == TEGRA_SUSPEND_NONE)
diff --git a/arch/arm/mach-tegra/pm.h b/arch/arm/mach-tegra/pm.h
index d375a1c595e9..4d4b8ef30d80 100644
--- a/arch/arm/mach-tegra/pm.h
+++ b/arch/arm/mach-tegra/pm.h
@@ -67,7 +67,7 @@ unsigned long tegra_cpu_lp2_min_residency(void);
 void tegra_clear_cpu_in_lp2(int cpu);
 bool tegra_set_cpu_in_lp2(int cpu);
 
-int tegra_suspend_dram(enum tegra_suspend_mode mode);
+int tegra_suspend_dram(enum tegra_suspend_mode mode, unsigned int flags);
 
 #define FLOW_CTRL_CLUSTER_CONTROL \
 	(IO_ADDRESS(TEGRA_FLOW_CTRL_BASE) + 0x2c)
diff --git a/arch/arm/mach-tegra/reset.h b/arch/arm/mach-tegra/reset.h
index 4674194547ce..08a44809e6f4 100644
--- a/arch/arm/mach-tegra/reset.h
+++ b/arch/arm/mach-tegra/reset.h
@@ -37,7 +37,7 @@ void __tegra_cpu_reset_handler_start(void);
 void tegra_secondary_startup(void);
 
 #ifdef CONFIG_PM_SLEEP
-#define tegra_cpu_lp1_map (*(unsigned long *)(IO_ADDRESS(TEGRA_RESET_HANDLER_BASE + \
+#define tegra_cpu_lp1_mask ((unsigned long *)(IO_ADDRESS(TEGRA_RESET_HANDLER_BASE + \
 		((u32)&__tegra_cpu_reset_handler_data[TEGRA_RESET_MASK_LP1] - \
 		 (u32)__tegra_cpu_reset_handler_start))))
 
diff --git a/arch/arm/mach-tegra/sleep-t3.S b/arch/arm/mach-tegra/sleep-t3.S
index 7c57e9133010..bf31812a0435 100644
--- a/arch/arm/mach-tegra/sleep-t3.S
+++ b/arch/arm/mach-tegra/sleep-t3.S
@@ -39,7 +39,77 @@
 #include "asm_macros.h"
 #include "sleep.h"
 
-#define TEGRA_ARM_PERIF_VIRT	(TEGRA_ARM_PERIF_BASE - IO_CPU_PHYS + IO_CPU_VIRT)
+#define EMC_CFG				0xc
+#define EMC_ADR_CFG			0x10
+#define EMC_TIMING_CONTROL		0x28
+#define EMC_REFRESH			0x70
+#define EMC_NOP				0xdc
+#define EMC_SELF_REF			0xe0
+#define EMC_MRW				0xe8
+#define EMC_REQ_CTRL			0x2b0
+#define EMC_EMC_STATUS			0x2b4
+#define EMC_FBIO_CFG5			0x104
+#define EMC_AUTO_CAL_CONFIG		0x2a4
+#define EMC_AUTO_CAL_INTERVAL		0x2a8
+#define EMC_AUTO_CAL_STATUS		0x2ac
+#define EMC_CFG_DIG_DLL			0x2bc
+#define EMC_ZCAL_INTERVAL		0x2e0
+#define EMC_ZQ_CAL			0x2ec
+#define EMC_XM2VTTGENPADCTRL		0x310
+#define EMC_XM2VTTGENPADCTRL2		0x314
+
+#define PMC_PWRGATE_TOGGLE		0x30
+#define PMC_REMOVE_CLAMPING_CMD		0x34
+#define PMC_PWRGATE_STATUS		0x38
+
+#define PMC_PWRGATE_PARTID_L2C		(0x5)
+
+#define PMC_IO_DPD_REQ			0x1b8
+#define PMC_IO_DPD_STATUS		0x1bc
+
+#define CLK_RESET_CCLK_BURST		0x20
+#define CLK_RESET_CCLK_DIVIDER		0x24
+#define CLK_RESET_SCLK_BURST		0x28
+#define CLK_RESET_SCLK_DIVIDER		0x2c
+
+#define CLK_RESET_PLLC_BASE		0x80
+#define CLK_RESET_PLLM_BASE		0x90
+#define CLK_RESET_PLLP_BASE		0xa0
+#define CLK_RESET_PLLA_BASE		0xb0
+#define CLK_RESET_PLLX_BASE		0xe0
+
+#define CLK_RESET_PLLC_MISC		0x8c
+#define CLK_RESET_PLLM_MISC		0x9c
+#define CLK_RESET_PLLP_MISC		0xac
+#define CLK_RESET_PLLA_MISC		0xbc
+#define CLK_RESET_PLLX_MISC		0xe4
+
+#define CLK_RESET_PLLP_OUTA		0xa4
+#define CLK_RESET_PLLP_OUTB		0xa8
+
+#define PMC_PLLP_WB0_OVERRIDE		0xf8
+
+#define CLK_RESET_CLK_SOURCE_MSELECT	0x3b4
+
+#define MSELECT_CLKM			(0x3 << 30)
+
+#define USE_PLL_LOCK_BITS 0
+
+.macro emc_device_mask, rd, base
+	ldr	\rd, [\base, #EMC_ADR_CFG]
+	tst	\rd, #(0x3<<24)
+	moveq	\rd, #(0x1<<8)		@ just 1 device
+	movne	\rd, #(0x3<<8)		@ 2 devices
+.endm
+
+.macro emc_timing_update, rd, base
+	mov	\rd, #1
+	str	\rd, [\base, #EMC_TIMING_CONTROL]
+1001:
+	ldr	\rd, [\base, #EMC_EMC_STATUS]
+	tst	\rd, #(0x1<<23)		@ wait until EMC_STATUS_TIMING_UPDATE_STALLED is clear
+	bne	1001b
+.endm
 
 #ifdef CONFIG_HOTPLUG_CPU
 /*
@@ -119,6 +189,36 @@ ENDPROC(tegra3_cpu_reset)
 #endif
 
 #ifdef CONFIG_PM_SLEEP
+
+/*
+ * tegra3_sleep_core(unsigned long v2p)
+ *
+ * enters suspend in LP0 or LP1 by turning off the mmu and jumping to
+ * tegra3_tear_down_core in IRAM
+ */
+ENTRY(tegra3_sleep_core)
+	mov	r12, pc 		@ return here is via r12
+	b	tegra_cpu_save
+
+	/* preload all the address literals that are needed for the
+	 * CPU power-gating process, to avoid loads from SDRAM (which are
+	 * not supported once SDRAM is put into self-refresh.
+	 * LP0 / LP1 use physical address, since the MMU needs to be
+	 * disabled before putting SDRAM into self-refresh to avoid
+	 * memory access due to page table walks */
+	mov32	r4, TEGRA_PMC_BASE
+	mov32	r5, TEGRA_CLK_RESET_BASE
+	mov32	r6, TEGRA_FLOW_CTRL_BASE
+	mov32	r7, TEGRA_TMRUS_BASE
+
+	mov32	r1, tegra3_tear_down_core
+	mov32	r2, tegra3_iram_start
+	sub	r1, r1, r2
+	mov32	r2, TEGRA_IRAM_CODE_AREA
+	add	r1, r1, r2
+	b	tegra_turn_off_mmu
+ENDPROC(tegra3_sleep_core)
+
 /*
  * tegra3_sleep_cpu_secondary(unsigned long v2p)
  *
@@ -140,6 +240,11 @@ ENDPROC(tegra3_sleep_cpu_secondary)
  * Switches the CPU cluster to PLL-P and enters sleep.
  */
 ENTRY(tegra3_tear_down_cpu)
+	mov32	r4, TEGRA_PMC_BASE
+	mov32	r5, TEGRA_CLK_RESET_BASE
+	mov32	r6, TEGRA_FLOW_CTRL_BASE
+	mov32	r7, TEGRA_TMRUS_BASE
+
 	bl	tegra_cpu_pllp
 	b	tegra3_enter_sleep
 ENDPROC(tegra3_tear_down_cpu)
@@ -162,8 +267,274 @@ tegra3_iram_start:
  *
  * NOTE: THIS *MUST* BE RELOCATED TO TEGRA_IRAM_CODE_AREA AND MUST BE FIRST.
  */
+.macro pll_enable, rd, car, base, misc
+	ldr	\rd, [\car, #\base]
+	tst	\rd, #(1<<30)
+	orreq	\rd, \rd, #(1<<30)
+	streq	\rd, [\car, #\base]
+#if USE_PLL_LOCK_BITS
+	ldr	\rd, [\car, #\misc]
+	orr	\rd, \rd, #(1<<18)
+	str	\rd, [\car, #\misc]
+#endif
+.endm
+
+ENTRY(tegra3_lp1_reset)
+	/* the CPU and system bus are running at 32KHz and executing from
+	 * IRAM when this code is executed; immediately switch to CLKM and
+	 * enable PLLP, PLLM, PLLC, PLLA and PLLX. */
+	mov32	r0, TEGRA_CLK_RESET_BASE
+
+	mov	r1, #(1<<28)
+	str	r1, [r0, #CLK_RESET_SCLK_BURST]
+	str	r1, [r0, #CLK_RESET_CCLK_BURST]
+	mov	r1, #0
+	str	r1, [r0, #CLK_RESET_SCLK_DIVIDER]
+	str	r1, [r0, #CLK_RESET_CCLK_DIVIDER]
+
+	/* enable PLLM via PMC */
+	mov32	r2, TEGRA_PMC_BASE
+	ldr	r1, [r2, #PMC_PLLP_WB0_OVERRIDE]
+	orr	r1, r1, #(1<<12)
+	str	r1, [r2, #PMC_PLLP_WB0_OVERRIDE]
+
+	pll_enable r1, r0, CLK_RESET_PLLP_BASE, CLK_RESET_PLLP_MISC
+	pll_enable r1, r0, CLK_RESET_PLLA_BASE, CLK_RESET_PLLA_MISC
+	pll_enable r1, r0, CLK_RESET_PLLC_BASE, CLK_RESET_PLLC_MISC
+	pll_enable r1, r0, CLK_RESET_PLLX_BASE, CLK_RESET_PLLX_MISC
+	mov32	r7, TEGRA_TMRUS_BASE
+	ldr	r1, [r7]
+
+#if USE_PLL_LOCK_BITS
+	pll_locked r1, r0, CLK_RESET_PLLM_BASE
+	pll_locked r1, r0, CLK_RESET_PLLP_BASE
+	pll_locked r1, r0, CLK_RESET_PLLA_BASE
+	pll_locked r1, r0, CLK_RESET_PLLC_BASE
+	pll_locked r1, r0, CLK_RESET_PLLX_BASE
+#else
+	add	r1, r1, #0xff	@ 255uS delay for PLL stabilization
+	wait_until r1, r7, r3
+#endif
+	add	r5, pc, #tegra3_sdram_pad_save-(.+8)	@ r5 reserved for pad base
+
+	ldr	r4, [r5, #0x18]
+	str	r4, [r0, #CLK_RESET_CLK_SOURCE_MSELECT]
+
+	ldr	r4, [r5, #0x1C]
+	str	r4, [r0, #CLK_RESET_SCLK_BURST]
+
+	mov32	r4, ((1<<28) | (8))	@ burst policy is PLLX
+	str	r4, [r0, #CLK_RESET_CCLK_BURST]
+
+#if defined (CONFIG_CACHE_L2X0)
+	/* power up L2 */
+	ldr	r0, [r2, #PMC_PWRGATE_STATUS]
+	tst	r0, #(1<<PMC_PWRGATE_PARTID_L2C)
+	bne	powerup_l2_done
+	movw	r0, #(1<<8) | PMC_PWRGATE_PARTID_L2C
+	str	r0, [r2, #PMC_PWRGATE_TOGGLE]
+powerup_l2_wait:
+	ldr	r0, [r2, #PMC_PWRGATE_STATUS]
+	tst	r0, #(1<<PMC_PWRGATE_PARTID_L2C)
+	beq	powerup_l2_wait
+powerup_l2_done:
+	mov	r0, #PMC_PWRGATE_PARTID_L2C
+	str	r0, [r2, #PMC_REMOVE_CLAMPING_CMD]
+#endif
+
+	mov32	r0, TEGRA_EMC_BASE			@ r0 reserved for emc base
+
+	ldr	r1, [r5, #0x14]	@ PMC_IO_DPD_STATUS
+	mvn	r1, r1
+	bic	r1, r1, #(0x1<<31)
+	orr	r1, r1, #(0x1<<30)
+	str	r1, [r2, #PMC_IO_DPD_REQ]
+	ldr	r1, [r5, #0xC]
+	str	r1, [r0, #EMC_XM2VTTGENPADCTRL]
+	ldr	r1, [r5, #0x10]
+	str	r1, [r0, #EMC_XM2VTTGENPADCTRL2]
+	ldr	r1, [r5, #0x8]
+	str	r1, [r0, #EMC_AUTO_CAL_INTERVAL]
+
+	ldr	r1, [r0, #EMC_CFG_DIG_DLL]
+	orr	r1, r1, #(0x1<<30)		@ set DLL_RESET
+	str	r1, [r0, #EMC_CFG_DIG_DLL]
+
+	emc_timing_update r1, r0
+
+	ldr	r1, [r0, #EMC_AUTO_CAL_CONFIG]
+	orr	r1, r1, #(0x1<<31)		@ set AUTO_CAL_ACTIVE
+	str	r1, [r0, #EMC_AUTO_CAL_CONFIG]
+
+emc_wait_audo_cal_onetime:
+	ldr	r1, [r0, #EMC_AUTO_CAL_STATUS]
+	tst	r1, #(0x1<<31)		@ wait until AUTO_CAL_ACTIVE is clear
+	bne	emc_wait_audo_cal_onetime
+
+	ldr	r1, [r0, #EMC_CFG]
+	bic	r1, r1, #(1<<31)	@ disable DRAM_CLK_STOP
+	str	r1, [r0, #EMC_CFG]
+
+	mov	r1, #0
+	str	r1, [r0, #EMC_SELF_REF]	@ take DRAM out of self refresh
+	mov	r1, #1
+	str	r1, [r0, #EMC_NOP]
+	str	r1, [r0, #EMC_NOP]
+	str	r1, [r0, #EMC_REFRESH]
+
+	emc_device_mask r1, r0
+
+exit_selfrefresh_loop:
+	ldr	r2, [r0, #EMC_EMC_STATUS]
+	ands	r2, r2, r1
+	bne	exit_selfrefresh_loop
+
+	lsr	r1, r1, #8		@ devSel, bit0:dev0 bit1:dev1
+
+	mov32	r7, TEGRA_TMRUS_BASE
+	ldr	r2, [r0, #EMC_FBIO_CFG5]
+
+	and	r2, r2, #3
+	cmp	r2, #2
+	beq	emc_lpddr2
+
+	mov32	r2, 0x80000011
+	str	r2, [r0, #EMC_ZQ_CAL]
+	ldr	r2, [r7]
+	add	r2, r2, #10
+	wait_until r2, r7, r3
 
-/* !!!FIXME!!! Add LP1/LP1 code */
+	tst	r1, #2
+	beq zcal_done
+
+	mov32	r2, 0x40000011
+	str	r2, [r0, #EMC_ZQ_CAL]
+	ldr	r2, [r7]
+	add	r2, r2, #10
+	wait_until r2, r7, r3
+	b zcal_done
+
+emc_lpddr2:
+
+	mov32	r2, 0x800A00AB
+	str	r2, [r0, #EMC_MRW]
+	ldr	r2, [r7]
+	add	r2, r2, #1
+	wait_until r2, r7, r3
+
+	tst	r1, #2
+	beq zcal_done
+
+	mov32	r2, 0x400A00AB
+	str	r2, [r0, #EMC_MRW]
+	ldr	r2, [r7]
+	add	r2, r2, #1
+	wait_until r2, r7, r3
+
+zcal_done:
+
+	mov	r1, #0
+	str	r1, [r0, #EMC_REQ_CTRL]
+	ldr	r1, [r5, #0x4]
+	str	r1, [r0, #EMC_ZCAL_INTERVAL]
+	ldr	r1, [r5, #0x0]
+	str	r1, [r0, #EMC_CFG]
+
+	mov32	r0, TEGRA_PMC_BASE
+	ldr	r0, [r0, #PMC_SCRATCH41]
+	mov	pc, r0
+ENDPROC(tegra3_lp1_reset)
+
+	.align	L1_CACHE_SHIFT
+	.type	tegra3_sdram_pad_save, %object
+tegra3_sdram_pad_save:
+	.word	0
+	.word	0
+	.word	0
+	.word	0
+	.word	0
+	.word	0
+	.word	0
+	.word	0
+
+tegra3_sdram_pad_address:
+	.word	TEGRA_EMC_BASE + EMC_CFG				@0x0
+	.word	TEGRA_EMC_BASE + EMC_ZCAL_INTERVAL			@0x4
+	.word	TEGRA_EMC_BASE + EMC_AUTO_CAL_INTERVAL			@0x8
+	.word	TEGRA_EMC_BASE + EMC_XM2VTTGENPADCTRL			@0xc
+	.word	TEGRA_EMC_BASE + EMC_XM2VTTGENPADCTRL2			@0x10
+	.word	TEGRA_PMC_BASE + PMC_IO_DPD_STATUS			@0x14
+	.word	TEGRA_CLK_RESET_BASE + CLK_RESET_CLK_SOURCE_MSELECT	@0x18
+	.word	TEGRA_CLK_RESET_BASE + CLK_RESET_SCLK_BURST		@0x1c
+
+tegra3_sdram_pad_size:
+	.word	tegra3_sdram_pad_address - tegra3_sdram_pad_save
+
+/*
+ * tegra3_tear_down_core
+ *
+ * copied into and executed from IRAM
+ * puts memory in self-refresh for LP0 and LP1
+ */
+tegra3_tear_down_core:
+	bl	tegra3_sdram_self_refresh
+	bl	tegra3_cpu_clk32k
+	b	tegra3_enter_sleep
+
+/*
+ * tegra3_cpu_clk32k
+ *
+ * In LP0 and LP1 all plls will be turned off.  Switch the CPU and system clock
+ * to the 32khz clock (clks)
+ * r4 = TEGRA_PMC_BASE
+ * r5 = TEGRA_CLK_RESET_BASE
+ * r6 = TEGRA_FLOW_CTRL_BASE
+ * r7 = TEGRA_TMRUS_BASE
+ */
+tegra3_cpu_clk32k:
+	/* start by jumping to clkm to safely disable PLLs, then jump
+	 * to clks */
+	mov	r0, #(1 << 28)
+	str	r0, [r5, #CLK_RESET_SCLK_BURST]
+	str	r0, [r5, #CLK_RESET_CCLK_BURST]
+	mov	r0, #0
+	str	r0, [r5, #CLK_RESET_CCLK_DIVIDER]
+	str	r0, [r5, #CLK_RESET_SCLK_DIVIDER]
+
+	/* switch the clock source for mselect to be CLK_M */
+	ldr	r0, [r5, #CLK_RESET_CLK_SOURCE_MSELECT]
+	orr	r0, r0, #MSELECT_CLKM
+	str	r0, [r5, #CLK_RESET_CLK_SOURCE_MSELECT]
+
+	/* 2 us delay between changing sclk and disabling PLLs */
+	wait_for_us r1, r7, r9
+	add	r1, r1, #2
+	wait_until r1, r7, r9
+
+#if 1
+	/* switch to CLKS */
+	mov	r0, #0	/* burst policy = 32KHz */
+	str	r0, [r5, #CLK_RESET_SCLK_BURST]
+#endif
+	/* disable PLLM via PMC in LP0 and LP1 states */
+	ldr	r0, [r4, #PMC_PLLP_WB0_OVERRIDE]
+	bic	r0, r0, #(1<<12)
+	str	r0, [r4, #PMC_PLLP_WB0_OVERRIDE]
+
+	/* disable PLLP, PLLA, PLLC, and PLLX in LP0 and LP1 states */
+	ldr	r0, [r5, #CLK_RESET_PLLP_BASE]
+	bic	r0, r0, #(1<<30)
+	str	r0, [r5, #CLK_RESET_PLLP_BASE]
+	ldr	r0, [r5, #CLK_RESET_PLLA_BASE]
+	bic	r0, r0, #(1<<30)
+	str	r0, [r5, #CLK_RESET_PLLA_BASE]
+	ldr	r0, [r5, #CLK_RESET_PLLC_BASE]
+	bic	r0, r0, #(1<<30)
+	str	r0, [r5, #CLK_RESET_PLLC_BASE]
+	ldr	r0, [r5, #CLK_RESET_PLLX_BASE]
+	bic	r0, r0, #(1<<30)
+	str	r0, [r5, #CLK_RESET_PLLX_BASE]
+	mov	pc, lr
 
 /*
  * tegra3_enter_sleep
@@ -171,14 +542,15 @@ tegra3_iram_start:
  * uses flow controller to enter sleep state
  * executes from IRAM with SDRAM in selfrefresh when target state is LP0 or LP1
  * executes from SDRAM with target state is LP2
+ * r4 = TEGRA_PMC_BASE
+ * r5 = TEGRA_CLK_RESET_BASE
+ * r6 = TEGRA_FLOW_CTRL_BASE
+ * r7 = TEGRA_TMRUS_BASE
  */
 tegra3_enter_sleep:
-	mov32	r7, TEGRA_TMRUS_BASE
 	ldr	r1, [r7]
-	mov32	r4, TEGRA_PMC_BASE
 	str	r1, [r4, #PMC_SCRATCH38]
 	dsb
-	mov32	r6, TEGRA_FLOW_CTRL_BASE
 	cpu_id	r1
 
 	cpu_to_csr_reg	r2, r1
@@ -201,6 +573,94 @@ halted:
 	/* !!!FIXME!!! Implement halt failure handler */
 	b	halted
 
+/*
+ * tegra3_sdram_self_refresh
+ *
+ * called with MMU off and caches disabled
+ * puts sdram in self refresh
+ * must execute from IRAM
+ * r4 = TEGRA_PMC_BASE
+ * r5 = TEGRA_CLK_RESET_BASE
+ * r6 = TEGRA_FLOW_CTRL_BASE
+ * r7 = TEGRA_TMRUS_BASE
+ */
+
+tegra3_sdram_self_refresh:
+
+	adr	r2, tegra3_sdram_pad_address
+	adr	r8, tegra3_sdram_pad_save
+	mov	r9, #0
+
+padsave:
+	ldr	r0, [r2, r9]			@ r0 is emc register address
+
+	ldr	r1, [r0]
+	str	r1, [r8, r9]			@ save emc register
+
+	add	r9, r9, #4
+	ldr	r0, tegra3_sdram_pad_size
+	cmp	r0, r9
+	bne	padsave
+padsave_done:
+
+	dsb
+
+	mov32	r0, TEGRA_EMC_BASE			@ r0 reserved for emc base
+
+	mov	r1, #0
+	str	r1, [r0, #EMC_ZCAL_INTERVAL]
+	str	r1, [r0, #EMC_AUTO_CAL_INTERVAL]
+	ldr	r1, [r0, #EMC_CFG]
+	bic	r1, r1, #(1<<28)
+	str	r1, [r0, #EMC_CFG]		@ disable DYN_SELF_REF
+
+	emc_timing_update r1, r0
+
+	ldr	r1, [r7]
+	add	r1, r1, #5
+	wait_until r1, r7, r2
+
+emc_wait_audo_cal:
+	ldr	r1, [r0, #EMC_AUTO_CAL_STATUS]
+	tst	r1, #(0x1<<31)		@ wait until AUTO_CAL_ACTIVE is clear
+	bne	emc_wait_audo_cal
+
+	mov	r1, #3
+	str	r1, [r0, #EMC_REQ_CTRL]		@ stall incoming DRAM requests
+
+emcidle:
+	ldr	r1, [r0, #EMC_EMC_STATUS]
+	tst	r1, #4
+	beq	emcidle
+
+	mov	r1, #1
+	str	r1, [r0, #EMC_SELF_REF]
+
+	emc_device_mask r1, r0
+
+emcself:
+	ldr	r2, [r0, #EMC_EMC_STATUS]
+	and	r2, r2, r1
+	cmp	r2, r1
+	bne	emcself				@ loop until DDR in self-refresh
+
+	ldr	r1, [r0, #EMC_XM2VTTGENPADCTRL]
+	mov32	r2, 0xF8F8FFFF		@ clear XM2VTTGEN_DRVUP and XM2VTTGEN_DRVDN
+	and	r1, r1, r2
+	str	r1, [r0, #EMC_XM2VTTGENPADCTRL]
+	ldr	r1, [r0, #EMC_XM2VTTGENPADCTRL2]
+	orr	r1, r1, #7			@ set E_NO_VTTGEN
+	str	r1, [r0, #EMC_XM2VTTGENPADCTRL2]
+
+	emc_timing_update r1, r0
+
+	mov32	r1, 0x8EC00000
+	str	r1, [r4, #PMC_IO_DPD_REQ]
+
+	dsb
+
+	mov	pc, lr
+
 	.ltorg
 /* dummy symbol for end of IRAM */
 	.align L1_CACHE_SHIFT
diff --git a/arch/arm/mach-tegra/sleep.h b/arch/arm/mach-tegra/sleep.h
index 8f9926fe7172..d78bac986733 100644
--- a/arch/arm/mach-tegra/sleep.h
+++ b/arch/arm/mach-tegra/sleep.h
@@ -241,8 +241,7 @@ static inline void tegra_sleep_core(unsigned long v2p)
 #ifdef CONFIG_ARCH_TEGRA_2x_SOC
 	tegra2_sleep_core(v2p);
 #else
-	/* tegra3_sleep_core(v2p);    !!!FIXME!!! not supported yet */
-	BUG();
+	tegra3_sleep_core(v2p);
 #endif
 }
 
-- 
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