5b795d051c
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>
92 lines
2.3 KiB
C
92 lines
2.3 KiB
C
/*
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* arch/arm/mach-tegra/reset.c
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*
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* Copyright (C) 2011,2012 NVIDIA Corporation.
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*
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* This software is licensed under the terms of the GNU General Public
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* License version 2, as published by the Free Software Foundation, and
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* may be copied, distributed, and modified under those terms.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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*/
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#include <linux/init.h>
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#include <linux/io.h>
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#include <linux/cpumask.h>
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#include <linux/bitops.h>
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#include <asm/cacheflush.h>
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#include <asm/hardware/cache-l2x0.h>
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#include "iomap.h"
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#include "irammap.h"
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#include "reset.h"
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#include "sleep.h"
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#include "fuse.h"
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#define TEGRA_IRAM_RESET_BASE (TEGRA_IRAM_BASE + \
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TEGRA_IRAM_RESET_HANDLER_OFFSET)
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static bool is_enabled;
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static void __init tegra_cpu_reset_handler_enable(void)
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{
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void __iomem *iram_base = IO_ADDRESS(TEGRA_IRAM_RESET_BASE);
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void __iomem *evp_cpu_reset =
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IO_ADDRESS(TEGRA_EXCEPTION_VECTORS_BASE + 0x100);
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void __iomem *sb_ctrl = IO_ADDRESS(TEGRA_SB_BASE);
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u32 reg;
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BUG_ON(is_enabled);
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BUG_ON(tegra_cpu_reset_handler_size > TEGRA_IRAM_RESET_HANDLER_SIZE);
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memcpy(iram_base, (void *)__tegra_cpu_reset_handler_start,
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tegra_cpu_reset_handler_size);
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/*
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* NOTE: This must be the one and only write to the EVP CPU reset
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* vector in the entire system.
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*/
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writel(TEGRA_IRAM_RESET_BASE + tegra_cpu_reset_handler_offset,
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evp_cpu_reset);
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wmb();
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reg = readl(evp_cpu_reset);
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/*
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* Prevent further modifications to the physical reset vector.
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* NOTE: Has no effect on chips prior to Tegra30.
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*/
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if (tegra_chip_id != TEGRA20) {
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reg = readl(sb_ctrl);
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reg |= 2;
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writel(reg, sb_ctrl);
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wmb();
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}
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is_enabled = true;
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}
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void __init tegra_cpu_reset_handler_init(void)
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{
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#ifdef CONFIG_SMP
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__tegra_cpu_reset_handler_data[TEGRA_RESET_MASK_PRESENT] =
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*((u32 *)cpu_possible_mask);
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__tegra_cpu_reset_handler_data[TEGRA_RESET_STARTUP_SECONDARY] =
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virt_to_phys((void *)tegra_secondary_startup);
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#endif
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#ifdef CONFIG_PM_SLEEP
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__tegra_cpu_reset_handler_data[TEGRA_RESET_STARTUP_LP1] =
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TEGRA_IRAM_CODE_AREA;
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__tegra_cpu_reset_handler_data[TEGRA_RESET_STARTUP_LP2] =
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virt_to_phys((void *)tegra_resume);
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#endif
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tegra_cpu_reset_handler_enable();
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}
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