linux/arch/arm/mach-tegra/pm.h
Joseph Lo 731a927438 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: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
2013-08-12 13:30:11 -06:00

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1.7 KiB
C

/*
* Copyright (C) 2010 Google, Inc.
* Copyright (c) 2010-2012 NVIDIA Corporation. All rights reserved.
*
* Author:
* Colin Cross <ccross@google.com>
*
* 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/>.
*/
#ifndef _MACH_TEGRA_PM_H_
#define _MACH_TEGRA_PM_H_
#include "pmc.h"
struct tegra_lp1_iram {
void *start_addr;
void *end_addr;
};
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);
extern unsigned long l2x0_saved_regs_addr;
void save_cpu_arch_register(void);
void restore_cpu_arch_register(void);
void tegra_clear_cpu_in_lp2(void);
bool tegra_set_cpu_in_lp2(void);
void tegra_idle_lp2_last(void);
extern void (*tegra_tear_down_cpu)(void);
#ifdef CONFIG_PM_SLEEP
enum tegra_suspend_mode tegra_pm_validate_suspend_mode(
enum tegra_suspend_mode mode);
void tegra_init_suspend(void);
#else
static inline enum tegra_suspend_mode tegra_pm_validate_suspend_mode(
enum tegra_suspend_mode mode)
{
return TEGRA_SUSPEND_NONE;
}
static inline void tegra_init_suspend(void) {}
#endif
#endif /* _MACH_TEGRA_PM_H_ */