d3f293656c
The CPU suspending on Tegra means CPU power gating. We add a resume function for taking care the CPUs that resume from power gating status. This function was been hooked to the reset handler. We take care everything here before go into kernel. Be aware of that, you may see the legacy power status "LP2" in the code which is exactly the same meaning of "CPU power down". Based on the work by: Scott Williams <scwilliams@nvidia.com> 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>
90 lines
2.3 KiB
C
90 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_present_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_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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