arch/arm/mach-tegra/reset.c

   1 /*
   2  * arch/arm/mach-tegra/reset.c
   3  *
   4  * Copyright (C) 2011,2012 NVIDIA Corporation.
   5  *
   6  * This software is licensed under the terms of the GNU General Public
   7  * License version 2, as published by the Free Software Foundation, and
   8  * may be copied, distributed, and modified under those terms.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  */
  16
  17 #include <linux/init.h>
  18 #include <linux/io.h>
  19 #include <linux/cpumask.h>
  20 #include <linux/bitops.h>
  21
  22 #include <asm/cacheflush.h>
  23 #include <asm/hardware/cache-l2x0.h>
  24
  25 #include "iomap.h"
  26 #include "irammap.h"
  27 #include "reset.h"
  28 #include "sleep.h"
  29 #include "fuse.h"
  30
  31 #define TEGRA_IRAM_RESET_BASE (TEGRA_IRAM_BASE + \
  32                                 TEGRA_IRAM_RESET_HANDLER_OFFSET)
  33
  34 static bool is_enabled;
  35
  36 static void __init tegra_cpu_reset_handler_enable(void)
  37 {
  38         void __iomem *iram_base = IO_ADDRESS(TEGRA_IRAM_RESET_BASE);
  39         void __iomem *evp_cpu_reset =
  40                 IO_ADDRESS(TEGRA_EXCEPTION_VECTORS_BASE + 0x100);
  41         void __iomem *sb_ctrl = IO_ADDRESS(TEGRA_SB_BASE);
  42         u32 reg;
  43
  44         BUG_ON(is_enabled);
  45         BUG_ON(tegra_cpu_reset_handler_size > TEGRA_IRAM_RESET_HANDLER_SIZE);
  46
  47         memcpy(iram_base, (void *)__tegra_cpu_reset_handler_start,
  48                         tegra_cpu_reset_handler_size);
  49
  50         /*
  51          * NOTE: This must be the one and only write to the EVP CPU reset
  52          *       vector in the entire system.
  53          */
  54         writel(TEGRA_IRAM_RESET_BASE + tegra_cpu_reset_handler_offset,
  55                         evp_cpu_reset);
  56         wmb();
  57         reg = readl(evp_cpu_reset);
  58
  59         /*
  60          * Prevent further modifications to the physical reset vector.
  61          *  NOTE: Has no effect on chips prior to Tegra30.
  62          */
  63         if (tegra_chip_id != TEGRA20) {
  64                 reg = readl(sb_ctrl);
  65                 reg |= 2;
  66                 writel(reg, sb_ctrl);
  67                 wmb();
  68         }
  69
  70         is_enabled = true;
  71 }
  72
  73 void __init tegra_cpu_reset_handler_init(void)
  74 {
  75
  76 #ifdef CONFIG_SMP
  77         __tegra_cpu_reset_handler_data[TEGRA_RESET_MASK_PRESENT] =
  78                 *((u32 *)cpu_possible_mask);
  79         __tegra_cpu_reset_handler_data[TEGRA_RESET_STARTUP_SECONDARY] =
  80                 virt_to_phys((void *)tegra_secondary_startup);
  81 #endif
  82
  83 #ifdef CONFIG_PM_SLEEP
  84         __tegra_cpu_reset_handler_data[TEGRA_RESET_STARTUP_LP2] =
  85                 virt_to_phys((void *)tegra_resume);
  86 #endif
  87
  88         tegra_cpu_reset_handler_enable();
  89 }