drivers/power/reset/arm-versatile-reboot.c

   1 /*
   2  * Copyright (C) 2014 Linaro Ltd.
   3  *
   4  * Author: Linus Walleij <linus.walleij@linaro.org>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2, as
   8  * published by the Free Software Foundation.
   9  *
  10  */
  11 #include <linux/init.h>
  12 #include <linux/mfd/syscon.h>
  13 #include <linux/reboot.h>
  14 #include <linux/regmap.h>
  15 #include <linux/of.h>
  16
  17 #define INTEGRATOR_HDR_CTRL_OFFSET      0x0C
  18 #define INTEGRATOR_HDR_LOCK_OFFSET      0x14
  19 #define INTEGRATOR_CM_CTRL_RESET        (1 << 3)
  20
  21 #define VERSATILE_SYS_LOCK_OFFSET       0x20
  22 #define VERSATILE_SYS_RESETCTL_OFFSET   0x40
  23
  24 /* Magic unlocking token used on all Versatile boards */
  25 #define VERSATILE_LOCK_VAL              0xA05F
  26
  27 /*
  28  * We detect the different syscon types from the compatible strings.
  29  */
  30 enum versatile_reboot {
  31         INTEGRATOR_REBOOT_CM,
  32         VERSATILE_REBOOT_CM,
  33         REALVIEW_REBOOT_EB,
  34         REALVIEW_REBOOT_PB1176,
  35         REALVIEW_REBOOT_PB11MP,
  36         REALVIEW_REBOOT_PBA8,
  37         REALVIEW_REBOOT_PBX,
  38 };
  39
  40 /* Pointer to the system controller */
  41 static struct regmap *syscon_regmap;
  42 static enum versatile_reboot versatile_reboot_type;
  43
  44 static const struct of_device_id versatile_reboot_of_match[] = {
  45         {
  46                 .compatible = "arm,core-module-integrator",
  47                 .data = (void *)INTEGRATOR_REBOOT_CM
  48         },
  49         {
  50                 .compatible = "arm,core-module-versatile",
  51                 .data = (void *)VERSATILE_REBOOT_CM,
  52         },
  53         {
  54                 .compatible = "arm,realview-eb-syscon",
  55                 .data = (void *)REALVIEW_REBOOT_EB,
  56         },
  57         {
  58                 .compatible = "arm,realview-pb1176-syscon",
  59                 .data = (void *)REALVIEW_REBOOT_PB1176,
  60         },
  61         {
  62                 .compatible = "arm,realview-pb11mp-syscon",
  63                 .data = (void *)REALVIEW_REBOOT_PB11MP,
  64         },
  65         {
  66                 .compatible = "arm,realview-pba8-syscon",
  67                 .data = (void *)REALVIEW_REBOOT_PBA8,
  68         },
  69         {
  70                 .compatible = "arm,realview-pbx-syscon",
  71                 .data = (void *)REALVIEW_REBOOT_PBX,
  72         },
  73         {},
  74 };
  75
  76 static int versatile_reboot(struct notifier_block *this, unsigned long mode,
  77                             void *cmd)
  78 {
  79         /* Unlock the reset register */
  80         /* Then hit reset on the different machines */
  81         switch (versatile_reboot_type) {
  82         case INTEGRATOR_REBOOT_CM:
  83                 regmap_write(syscon_regmap, INTEGRATOR_HDR_LOCK_OFFSET,
  84                              VERSATILE_LOCK_VAL);
  85                 regmap_update_bits(syscon_regmap,
  86                                    INTEGRATOR_HDR_CTRL_OFFSET,
  87                                    INTEGRATOR_CM_CTRL_RESET,
  88                                    INTEGRATOR_CM_CTRL_RESET);
  89                 break;
  90         case VERSATILE_REBOOT_CM:
  91                 regmap_write(syscon_regmap, VERSATILE_SYS_LOCK_OFFSET,
  92                              VERSATILE_LOCK_VAL);
  93                 regmap_update_bits(syscon_regmap,
  94                                    VERSATILE_SYS_RESETCTL_OFFSET,
  95                                    0x0107,
  96                                    0x0105);
  97                 regmap_write(syscon_regmap, VERSATILE_SYS_LOCK_OFFSET,
  98                              0);
  99                 break;
 100         case REALVIEW_REBOOT_EB:
 101                 regmap_write(syscon_regmap, VERSATILE_SYS_LOCK_OFFSET,
 102                              VERSATILE_LOCK_VAL);
 103                 regmap_write(syscon_regmap,
 104                              VERSATILE_SYS_RESETCTL_OFFSET, 0x0008);
 105                 break;
 106         case REALVIEW_REBOOT_PB1176:
 107                 regmap_write(syscon_regmap, VERSATILE_SYS_LOCK_OFFSET,
 108                              VERSATILE_LOCK_VAL);
 109                 regmap_write(syscon_regmap,
 110                              VERSATILE_SYS_RESETCTL_OFFSET, 0x0100);
 111                 break;
 112         case REALVIEW_REBOOT_PB11MP:
 113         case REALVIEW_REBOOT_PBA8:
 114                 regmap_write(syscon_regmap, VERSATILE_SYS_LOCK_OFFSET,
 115                              VERSATILE_LOCK_VAL);
 116                 regmap_write(syscon_regmap, VERSATILE_SYS_RESETCTL_OFFSET,
 117                              0x0000);
 118                 regmap_write(syscon_regmap, VERSATILE_SYS_RESETCTL_OFFSET,
 119                              0x0004);
 120                 break;
 121         case REALVIEW_REBOOT_PBX:
 122                 regmap_write(syscon_regmap, VERSATILE_SYS_LOCK_OFFSET,
 123                              VERSATILE_LOCK_VAL);
 124                 regmap_write(syscon_regmap, VERSATILE_SYS_RESETCTL_OFFSET,
 125                              0x00f0);
 126                 regmap_write(syscon_regmap, VERSATILE_SYS_RESETCTL_OFFSET,
 127                              0x00f4);
 128                 break;
 129         }
 130         dsb();
 131
 132         return NOTIFY_DONE;
 133 }
 134
 135 static struct notifier_block versatile_reboot_nb = {
 136         .notifier_call = versatile_reboot,
 137         .priority = 192,
 138 };
 139
 140 static int __init versatile_reboot_probe(void)
 141 {
 142         const struct of_device_id *reboot_id;
 143         struct device_node *np;
 144         int err;
 145
 146         np = of_find_matching_node_and_match(NULL, versatile_reboot_of_match,
 147                                                  &reboot_id);
 148         if (!np)
 149                 return -ENODEV;
 150         versatile_reboot_type = (enum versatile_reboot)reboot_id->data;
 151
 152         syscon_regmap = syscon_node_to_regmap(np);
 153         of_node_put(np);
 154         if (IS_ERR(syscon_regmap))
 155                 return PTR_ERR(syscon_regmap);
 156
 157         err = register_restart_handler(&versatile_reboot_nb);
 158         if (err)
 159                 return err;
 160
 161         pr_info("versatile reboot driver registered\n");
 162         return 0;
 163 }
 164 device_initcall(versatile_reboot_probe);