kernel/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 <blogic@openwrt.org>
   9  */
  10
  11 #include <linux/pm.h>
  12 #include <linux/io.h>
  13 #include <linux/of.h>
  14 #include <linux/reset-controller.h>
  15
  16 #include <asm/reboot.h>
  17
  18 #include <asm/mach-ralink/ralink_regs.h>
  19
  20 /* Reset Control */
  21 #define SYSC_REG_RESET_CTRL     0x034
  22 #define RSTCTL_RESET_SYSTEM     BIT(0)
  23
  24 static int ralink_assert_device(struct reset_controller_dev *rcdev,
  25                                 unsigned long id)
  26 {
  27         u32 val;
  28
  29         if (id < 8)
  30                 return -1;
  31
  32         val = rt_sysc_r32(SYSC_REG_RESET_CTRL);
  33         val |= BIT(id);
  34         rt_sysc_w32(val, SYSC_REG_RESET_CTRL);
  35
  36         return 0;
  37 }
  38
  39 static int ralink_deassert_device(struct reset_controller_dev *rcdev,
  40                                   unsigned long id)
  41 {
  42         u32 val;
  43
  44         if (id < 8)
  45                 return -1;
  46
  47         val = rt_sysc_r32(SYSC_REG_RESET_CTRL);
  48         val &= ~BIT(id);
  49         rt_sysc_w32(val, SYSC_REG_RESET_CTRL);
  50
  51         return 0;
  52 }
  53
  54 static int ralink_reset_device(struct reset_controller_dev *rcdev,
  55                                unsigned long id)
  56 {
  57         ralink_assert_device(rcdev, id);
  58         return ralink_deassert_device(rcdev, id);
  59 }
  60
  61 static struct reset_control_ops reset_ops = {
  62         .reset = ralink_reset_device,
  63         .assert = ralink_assert_device,
  64         .deassert = ralink_deassert_device,
  65 };
  66
  67 static struct reset_controller_dev reset_dev = {
  68         .ops                    = &reset_ops,
  69         .owner                  = THIS_MODULE,
  70         .nr_resets              = 32,
  71         .of_reset_n_cells       = 1,
  72 };
  73
  74 void ralink_rst_init(void)
  75 {
  76         reset_dev.of_node = of_find_compatible_node(NULL, NULL,
  77                                                 "ralink,rt2880-reset");
  78         if (!reset_dev.of_node)
  79                 pr_err("Failed to find reset controller node");
  80         else
  81                 reset_controller_register(&reset_dev);
  82 }
  83
  84 static void ralink_restart(char *command)
  85 {
  86         local_irq_disable();
  87         rt_sysc_w32(RSTCTL_RESET_SYSTEM, SYSC_REG_RESET_CTRL);
  88         unreachable();
  89 }
  90
  91 static void ralink_halt(void)
  92 {
  93         local_irq_disable();
  94         unreachable();
  95 }
  96
  97 static int __init mips_reboot_setup(void)
  98 {
  99         _machine_restart = ralink_restart;
 100         _machine_halt = ralink_halt;
 101         pm_power_off = ralink_halt;
 102
 103         return 0;
 104 }
 105
 106 arch_initcall(mips_reboot_setup);