Commit 731a9274 authored by Joseph Lo's avatar Joseph Lo Committed by Stephen Warren
Browse files

ARM: tegra: add LP1 suspend support for Tegra20 



The LP1 suspend mode will power off the CPU, clock gated the PLLs and put
SDRAM to self-refresh mode. Any interrupt can wake up device from LP1. The
sequence when LP1 suspending:

* tunning off L1 data cache and the MMU
* putting SDRAM into self-refresh
* storing some EMC registers and SCLK burst policy
* switching CPU to CLK_M (12MHz OSC)
* switching SCLK to CLK_S (32KHz OSC)
* tunning off PLLM, PLLP and PLLC
* shutting off the CPU rail

The sequence of LP1 resuming:

* re-enabling PLLM, PLLP, and PLLC
* restoring some EMC registers and SCLK burst policy
* setting up CCLK burst policy to PLLP
* resuming SDRAM to normal mode
* jumping to the "tegra_resume" from PMC_SCRATCH41

Due to the SDRAM will be put into self-refresh mode, the low level
procedures of LP1 suspending and resuming should be copied to
TEGRA_IRAM_CODE_AREA (TEGRA_IRAM_BASE + SZ_4K) when suspending. Before
restoring the CPU context when resuming, the SDRAM needs to be switched
back to normal mode. And the PLLs need to be re-enabled, SCLK burst policy
be restored, CCLK burst policy be set in PLLP. Then jumping to
"tegra_resume" that was expected to be stored in PMC_SCRATCH41 to restore
CPU context and back to kernel.

Based on the work by:
Colin Cross <ccross@android.com>
Gary King <gking@nvidia.com>

Signed-off-by: default avatarJoseph Lo <josephl@nvidia.com>
Signed-off-by: default avatarStephen Warren <swarren@nvidia.com>
parent e7a932b1

arch/arm/mach-tegra/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ obj-$(CONFIG_CPU_IDLE) += cpuidle.o 
obj-$(CONFIG_ARCH_TEGRA_2x_SOC)		+= tegra20_speedo.o

obj-$(CONFIG_ARCH_TEGRA_2x_SOC)		+= tegra2_emc.o

obj-$(CONFIG_ARCH_TEGRA_2x_SOC)		+= sleep-tegra20.o

obj-$(CONFIG_ARCH_TEGRA_2x_SOC)		+= pm-tegra20.o

ifeq ($(CONFIG_CPU_IDLE),y)

obj-$(CONFIG_ARCH_TEGRA_2x_SOC)		+= cpuidle-tegra20.o

endif

arch/arm/mach-tegra/pm-tegra20.c

0 → 100644
+34 −0
Original line number Diff line number Diff line 
/*

 * Copyright (c) 2013, NVIDIA Corporation. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms and conditions of the GNU General Public License,

 * version 2, as published by the Free Software Foundation.

 *

 * This program is distributed in the hope it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for

 * more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */

#include <linux/kernel.h>



#include "pm.h"



#ifdef CONFIG_PM_SLEEP

extern u32 tegra20_iram_start, tegra20_iram_end;

extern void tegra20_sleep_core_finish(unsigned long);



void tegra20_lp1_iram_hook(void)

{

	tegra_lp1_iram.start_addr = &tegra20_iram_start;

	tegra_lp1_iram.end_addr = &tegra20_iram_end;

}



void tegra20_sleep_core_init(void)

{

	tegra_sleep_core_finish = tegra20_sleep_core_finish;

}

#endif

arch/arm/mach-tegra/pm.c

+8 −0
Original line number Diff line number Diff line
@@ -210,6 +210,10 @@ static int tegra_sleep_core(unsigned long v2p) 
static bool tegra_lp1_iram_hook(void)

{

	switch (tegra_chip_id) {

	case TEGRA20:

		if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC))

			tegra20_lp1_iram_hook();

		break;

	case TEGRA30:

		if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC))

			tegra30_lp1_iram_hook();
@@ -232,6 +236,10 @@ static bool tegra_lp1_iram_hook(void) 
static bool tegra_sleep_core_init(void)

{

	switch (tegra_chip_id) {

	case TEGRA20:

		if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC))

			tegra20_sleep_core_init();

		break;

	case TEGRA30:

		if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC))

			tegra30_sleep_core_init();

arch/arm/mach-tegra/pm.h

+2 −0
Original line number Diff line number Diff line
@@ -30,6 +30,8 @@ struct tegra_lp1_iram { 
extern struct tegra_lp1_iram tegra_lp1_iram;

extern void (*tegra_sleep_core_finish)(unsigned long v2p);



void tegra20_lp1_iram_hook(void);

void tegra20_sleep_core_init(void);

void tegra30_lp1_iram_hook(void);

void tegra30_sleep_core_init(void);

arch/arm/mach-tegra/sleep-tegra20.S

+296 −0
Original line number Diff line number Diff line
@@ -23,10 +23,49 @@ 
#include <asm/assembler.h>

#include <asm/proc-fns.h>

#include <asm/cp15.h>

#include <asm/cache.h>



#include "sleep.h"

#include "flowctrl.h"



#define EMC_CFG				0xc

#define EMC_ADR_CFG			0x10

#define EMC_REFRESH			0x70

#define EMC_NOP				0xdc

#define EMC_SELF_REF			0xe0

#define EMC_REQ_CTRL			0x2b0

#define EMC_EMC_STATUS			0x2b4



#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 APB_MISC_XM2CFGCPADCTRL		0x8c8

#define APB_MISC_XM2CFGDPADCTRL		0x8cc

#define APB_MISC_XM2CLKCFGPADCTRL	0x8d0

#define APB_MISC_XM2COMPPADCTRL		0x8d4

#define APB_MISC_XM2VTTGENPADCTRL	0x8d8

#define APB_MISC_XM2CFGCPADCTRL2	0x8e4

#define APB_MISC_XM2CFGDPADCTRL2	0x8e8



.macro pll_enable, rd, r_car_base, pll_base

	ldr	\rd, [\r_car_base, #\pll_base]

	tst	\rd, #(1 << 30)

	orreq	\rd, \rd, #(1 << 30)

	streq	\rd, [\r_car_base, #\pll_base]

.endm



.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



#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PM_SLEEP)

/*

 * tegra20_hotplug_shutdown(void)
@@ -180,6 +219,28 @@ ENTRY(tegra20_cpu_is_resettable_soon) 
	mov	pc, lr

ENDPROC(tegra20_cpu_is_resettable_soon)



/*

 * tegra20_sleep_core_finish(unsigned long v2p)

 *

 * Enters suspend in LP0 or LP1 by turning off the mmu and jumping to

 * tegra20_tear_down_core in IRAM

 */

ENTRY(tegra20_sleep_core_finish)

	/* Flush, disable the L1 data cache and exit SMP */

	bl	tegra_disable_clean_inv_dcache



	mov32	r3, tegra_shut_off_mmu

	add	r3, r3, r0



	mov32	r0, tegra20_tear_down_core

	mov32	r1, tegra20_iram_start

	sub	r0, r0, r1

	mov32	r1, TEGRA_IRAM_CODE_AREA

	add	r0, r0, r1



	mov	pc, r3

ENDPROC(tegra20_sleep_core_finish)



/*

 * tegra20_sleep_cpu_secondary_finish(unsigned long v2p)

 *
@@ -251,6 +312,150 @@ ENTRY(tegra20_tear_down_cpu) 
	b	tegra20_enter_sleep

ENDPROC(tegra20_tear_down_cpu)



/* START OF ROUTINES COPIED TO IRAM */

	.align L1_CACHE_SHIFT

	.globl tegra20_iram_start

tegra20_iram_start:



/*

 * tegra20_lp1_reset

 *

 * reset vector for LP1 restore; copied into IRAM during suspend.

 * Brings the system back up to a safe staring point (SDRAM out of

 * self-refresh, PLLC, PLLM and PLLP reenabled, CPU running on PLLP,

 * system clock running on the same PLL that it suspended at), and

 * jumps to tegra_resume to restore virtual addressing and PLLX.

 * The physical address of tegra_resume expected to be stored in

 * PMC_SCRATCH41.

 *

 * NOTE: THIS *MUST* BE RELOCATED TO TEGRA_IRAM_CODE_AREA.

 */

ENTRY(tegra20_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 PLLM, PLLP, PLLC.

	 */

	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_CCLK_DIVIDER]

	str	r1, [r0, #CLK_RESET_SCLK_DIVIDER]



	pll_enable r1, r0, CLK_RESET_PLLM_BASE

	pll_enable r1, r0, CLK_RESET_PLLP_BASE

	pll_enable r1, r0, CLK_RESET_PLLC_BASE



	adr	r2, tegra20_sdram_pad_address

	adr	r4, tegra20_sdram_pad_save

	mov	r5, #0



	ldr	r6, tegra20_sdram_pad_size

padload:

	ldr	r7, [r2, r5]		@ r7 is the addr in the pad_address



	ldr	r1, [r4, r5]

	str	r1, [r7]		@ restore the value in pad_save



	add	r5, r5, #4

	cmp	r6, r5

	bne	padload



padload_done:

	/* 255uS delay for PLL stabilization */

	mov32	r7, TEGRA_TMRUS_BASE

	ldr	r1, [r7]

	add	r1, r1, #0xff

	wait_until r1, r7, r9



	adr	r4, tegra20_sclk_save

	ldr	r4, [r4]

	str	r4, [r0, #CLK_RESET_SCLK_BURST]

	mov32	r4, ((1 << 28) | (4))	@ burst policy is PLLP

	str	r4, [r0, #CLK_RESET_CCLK_BURST]



	mov32	r0, TEGRA_EMC_BASE

	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



	mov	r1, #0			@ unstall all transactions

	str	r1, [r0, #EMC_REQ_CTRL]



	mov32	r0, TEGRA_PMC_BASE

	ldr	r0, [r0, #PMC_SCRATCH41]

	mov	pc, r0			@ jump to tegra_resume

ENDPROC(tegra20_lp1_reset)



/*

 * tegra20_tear_down_core

 *

 * copied into and executed from IRAM

 * puts memory in self-refresh for LP0 and LP1

 */

tegra20_tear_down_core:

	bl	tegra20_sdram_self_refresh

	bl	tegra20_switch_cpu_to_clk32k

	b	tegra20_enter_sleep



/*

 * tegra20_switch_cpu_to_clk32k

 *

 * In LP0 and LP1 all PLLs will be turned off. Switch the CPU and system clock

 * to the 32KHz clock.

 */

tegra20_switch_cpu_to_clk32k:

	/*

	 * start by switching to CLKM to safely disable PLLs, then switch 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]



	/* 2uS delay delay between changing SCLK and disabling PLLs */

	mov32	r7, TEGRA_TMRUS_BASE

	ldr	r1, [r7]

	add	r1, r1, #2

	wait_until r1, r7, r9



	/* disable PLLM, PLLP and PLLC */

	ldr	r0, [r5, #CLK_RESET_PLLM_BASE]

	bic	r0, r0, #(1 << 30)

	str	r0, [r5, #CLK_RESET_PLLM_BASE]

	ldr	r0, [r5, #CLK_RESET_PLLP_BASE]

	bic	r0, r0, #(1 << 30)

	str	r0, [r5, #CLK_RESET_PLLP_BASE]

	ldr	r0, [r5, #CLK_RESET_PLLC_BASE]

	bic	r0, r0, #(1 << 30)

	str	r0, [r5, #CLK_RESET_PLLC_BASE]



	/* switch to CLKS */

	mov	r0, #0	/* brust policy = 32KHz */

	str	r0, [r5, #CLK_RESET_SCLK_BURST]



	mov	pc, lr



/*

 * tegra20_enter_sleep

 *
@@ -275,4 +480,95 @@ halted: 
	isb

	b	halted



/*

 * tegra20_sdram_self_refresh

 *

 * called with MMU off and caches disabled

 * puts sdram in self refresh

 * must be executed from IRAM

 */

tegra20_sdram_self_refresh:

	mov32	r1, TEGRA_EMC_BASE	@ r1 reserved for emc base addr



	mov	r2, #3

	str	r2, [r1, #EMC_REQ_CTRL]	@ stall incoming DRAM requests



emcidle:

	ldr	r2, [r1, #EMC_EMC_STATUS]

	tst	r2, #4

	beq	emcidle



	mov	r2, #1

	str	r2, [r1, #EMC_SELF_REF]



	emc_device_mask r2, r1



emcself:

	ldr	r3, [r1, #EMC_EMC_STATUS]

	and	r3, r3, r2

	cmp	r3, r2

	bne	emcself			@ loop until DDR in self-refresh



	adr	r2, tegra20_sdram_pad_address

	adr	r3, tegra20_sdram_pad_safe

	adr	r4, tegra20_sdram_pad_save

	mov	r5, #0



	ldr	r6, tegra20_sdram_pad_size

padsave:

	ldr	r0, [r2, r5]		@ r0 is the addr in the pad_address



	ldr	r1, [r0]

	str	r1, [r4, r5]		@ save the content of the addr



	ldr	r1, [r3, r5]

	str	r1, [r0]		@ set the save val to the addr



	add	r5, r5, #4

	cmp	r6, r5

	bne	padsave

padsave_done:



	mov32	r5, TEGRA_CLK_RESET_BASE

	ldr	r0, [r5, #CLK_RESET_SCLK_BURST]

	adr	r2, tegra20_sclk_save

	str	r0, [r2]

	dsb

	mov	pc, lr



tegra20_sdram_pad_address:

	.word	TEGRA_APB_MISC_BASE + APB_MISC_XM2CFGCPADCTRL

	.word	TEGRA_APB_MISC_BASE + APB_MISC_XM2CFGDPADCTRL

	.word	TEGRA_APB_MISC_BASE + APB_MISC_XM2CLKCFGPADCTRL

	.word	TEGRA_APB_MISC_BASE + APB_MISC_XM2COMPPADCTRL

	.word	TEGRA_APB_MISC_BASE + APB_MISC_XM2VTTGENPADCTRL

	.word	TEGRA_APB_MISC_BASE + APB_MISC_XM2CFGCPADCTRL2

	.word	TEGRA_APB_MISC_BASE + APB_MISC_XM2CFGDPADCTRL2



tegra20_sdram_pad_size:

	.word	tegra20_sdram_pad_size - tegra20_sdram_pad_address



tegra20_sdram_pad_safe:

	.word	0x8

	.word	0x8

	.word	0x0

	.word	0x8

	.word	0x5500

	.word	0x08080040

	.word	0x0



tegra20_sclk_save:

	.word	0x0



tegra20_sdram_pad_save:

	.rept (tegra20_sdram_pad_size - tegra20_sdram_pad_address) / 4

	.long	0

	.endr



	.ltorg

/* dummy symbol for end of IRAM */

	.align L1_CACHE_SHIFT

	.globl tegra20_iram_end

tegra20_iram_end:

	b	.

#endif

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