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alistair23-linux/arch/arm/mach-tegra/pm-tegra30.c

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// SPDX-License-Identifier: GPL-2.0-only
ARM: tegra: add LP1 suspend support for Tegra30 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 * storing some EMC registers, DPD (deep power down) status, clk source of mselect and SCLK burst policy * putting SDRAM into self-refresh * switching CPU to CLK_M (12MHz OSC) * tunning off PLLM, PLLP, PLLA, PLLC and PLLX * switching SCLK to CLK_S (32KHz OSC) * shutting off the CPU rail The sequence of LP1 resuming: * re-enabling PLLM, PLLP, PLLA, PLLC and PLLX * restoring the clk source of mselect and SCLK burst policy * setting up CCLK burst policy to PLLX * restoring DPD status and some EMC registers * 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 PLLX. 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: Scott Williams <scwilliams@nvidia.com> Signed-off-by: Joseph Lo <josephl@nvidia.com> Signed-off-by: Stephen Warren <swarren@nvidia.com>
2013-08-12 03:40:04 -06:00
/*
* Copyright (c) 2013, NVIDIA Corporation. All rights reserved.
*/
ARM: tegra: add LP1 suspend support for Tegra30 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 * storing some EMC registers, DPD (deep power down) status, clk source of mselect and SCLK burst policy * putting SDRAM into self-refresh * switching CPU to CLK_M (12MHz OSC) * tunning off PLLM, PLLP, PLLA, PLLC and PLLX * switching SCLK to CLK_S (32KHz OSC) * shutting off the CPU rail The sequence of LP1 resuming: * re-enabling PLLM, PLLP, PLLA, PLLC and PLLX * restoring the clk source of mselect and SCLK burst policy * setting up CCLK burst policy to PLLX * restoring DPD status and some EMC registers * 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 PLLX. 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: Scott Williams <scwilliams@nvidia.com> Signed-off-by: Joseph Lo <josephl@nvidia.com> Signed-off-by: Stephen Warren <swarren@nvidia.com>
2013-08-12 03:40:04 -06:00
#include <linux/kernel.h>
#include "pm.h"
#ifdef CONFIG_PM_SLEEP
extern u32 tegra30_iram_start, tegra30_iram_end;
extern void tegra30_sleep_core_finish(unsigned long);
void tegra30_lp1_iram_hook(void)
{
tegra_lp1_iram.start_addr = &tegra30_iram_start;
tegra_lp1_iram.end_addr = &tegra30_iram_end;
}
void tegra30_sleep_core_init(void)
{
tegra_sleep_core_finish = tegra30_sleep_core_finish;
}
#endif