arch/mips/ralink/reset.c

   1 /*
   2  * This program is free software; you can redistribute it and/or modify it
   3  * under the terms of the GNU General Public License version 2 as published
   4  * by the Free Software Foundation.
   5  *
   6  * Copyright (C) 2008-2009 Gabor Juhos <juhosg@openwrt.org>
   7  * Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
   8  * Copyright (C) 2013 John Crispin <john@phrozen.org>
   9  */
  10
  11 #include <linux/pm.h>
  12 #include <linux/io.h>
  13 #include <linux/of.h>
  14 #include <linux/delay.h>
  15 #include <linux/reset-controller.h>
  16
  17 #include <asm/reboot.h>
  18
  19 #include <asm/mach-ralink/ralink_regs.h>
  20
  21 /* Reset Control */
  22 #define SYSC_REG_RESET_CTRL     0x034
  23
  24 #define RSTCTL_RESET_PCI        BIT(26)
  25 #define RSTCTL_RESET_SYSTEM     BIT(0)
  26
  27 static int ralink_assert_device(struct reset_controller_dev *rcdev,
  28                                 unsigned long id)
  29 {
  30         u32 val;
  31
  32         if (id < 8)
  33                 return -1;
  34
  35         val = rt_sysc_r32(SYSC_REG_RESET_CTRL);
  36         val |= BIT(id);
  37         rt_sysc_w32(val, SYSC_REG_RESET_CTRL);
  38
  39         return 0;
  40 }
  41
  42 static int ralink_deassert_device(struct reset_controller_dev *rcdev,
  43                                   unsigned long id)
  44 {
  45         u32 val;
  46
  47         if (id < 8)
  48                 return -1;
  49
  50         val = rt_sysc_r32(SYSC_REG_RESET_CTRL);
  51         val &= ~BIT(id);
  52         rt_sysc_w32(val, SYSC_REG_RESET_CTRL);
  53
  54         return 0;
  55 }
  56
  57 static int ralink_reset_device(struct reset_controller_dev *rcdev,
  58                                unsigned long id)
  59 {
  60         ralink_assert_device(rcdev, id);
  61         return ralink_deassert_device(rcdev, id);
  62 }
  63
  64 static const struct reset_control_ops reset_ops = {
  65         .reset = ralink_reset_device,
  66         .assert = ralink_assert_device,
  67         .deassert = ralink_deassert_device,
  68 };
  69
  70 static struct reset_controller_dev reset_dev = {
  71         .ops                    = &reset_ops,
  72         .owner                  = THIS_MODULE,
  73         .nr_resets              = 32,
  74         .of_reset_n_cells       = 1,
  75 };
  76
  77 void ralink_rst_init(void)
  78 {
  79         reset_dev.of_node = of_find_compatible_node(NULL, NULL,
  80                                                 "ralink,rt2880-reset");
  81         if (!reset_dev.of_node)
  82                 pr_err("Failed to find reset controller node");
  83         else
  84                 reset_controller_register(&reset_dev);
  85 }
  86
  87 static void ralink_restart(char *command)
  88 {
  89         if (IS_ENABLED(CONFIG_PCI)) {
  90                 rt_sysc_m32(0, RSTCTL_RESET_PCI, SYSC_REG_RESET_CTRL);
  91                 mdelay(50);
  92         }
  93
  94         local_irq_disable();
  95         rt_sysc_w32(RSTCTL_RESET_SYSTEM, SYSC_REG_RESET_CTRL);
  96         unreachable();
  97 }
  98
  99 static int __init mips_reboot_setup(void)
 100 {
 101         _machine_restart = ralink_restart;
 102
 103         return 0;
 104 }
 105
 106 arch_initcall(mips_reboot_setup);