LXR linux/arch/mips/ralink/reset.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *
   4 * Copyright (C) 2008-2009 Gabor Juhos <juhosg@openwrt.org>
   5 * Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
   6 * Copyright (C) 2013 John Crispin <john@phrozen.org>
   7 */
   8
   9#include <linux/pm.h>
  10#include <linux/io.h>
  11#include <linux/of.h>
  12#include <linux/delay.h>
  13#include <linux/reset-controller.h>
  14
  15#include <asm/reboot.h>
  16
  17#include <asm/mach-ralink/ralink_regs.h>
  18
  19/* Reset Control */
  20#define SYSC_REG_RESET_CTRL     0x034
  21
  22#define RSTCTL_RESET_PCI        BIT(26)
  23#define RSTCTL_RESET_SYSTEM     BIT(0)
  24
  25static int ralink_assert_device(struct reset_controller_dev *rcdev,
  26                                unsigned long id)
  27{
  28        u32 val;
  29
  30        if (id == 0)
  31                return -1;
  32
  33        val = rt_sysc_r32(SYSC_REG_RESET_CTRL);
  34        val |= BIT(id);
  35        rt_sysc_w32(val, SYSC_REG_RESET_CTRL);
  36
  37        return 0;
  38}
  39
  40static int ralink_deassert_device(struct reset_controller_dev *rcdev,
  41                                  unsigned long id)
  42{
  43        u32 val;
  44
  45        if (id == 0)
  46                return -1;
  47
  48        val = rt_sysc_r32(SYSC_REG_RESET_CTRL);
  49        val &= ~BIT(id);
  50        rt_sysc_w32(val, SYSC_REG_RESET_CTRL);
  51
  52        return 0;
  53}
  54
  55static int ralink_reset_device(struct reset_controller_dev *rcdev,
  56                               unsigned long id)
  57{
  58        ralink_assert_device(rcdev, id);
  59        return ralink_deassert_device(rcdev, id);
  60}
  61
  62static const struct reset_control_ops reset_ops = {
  63        .reset = ralink_reset_device,
  64        .assert = ralink_assert_device,
  65        .deassert = ralink_deassert_device,
  66};
  67
  68static struct reset_controller_dev reset_dev = {
  69        .ops                    = &reset_ops,
  70        .owner                  = THIS_MODULE,
  71        .nr_resets              = 32,
  72        .of_reset_n_cells       = 1,
  73};
  74
  75void ralink_rst_init(void)
  76{
  77        reset_dev.of_node = of_find_compatible_node(NULL, NULL,
  78                                                "ralink,rt2880-reset");
  79        if (!reset_dev.of_node)
  80                pr_err("Failed to find reset controller node");
  81        else
  82                reset_controller_register(&reset_dev);
  83}
  84
  85static void ralink_restart(char *command)
  86{
  87        if (IS_ENABLED(CONFIG_PCI)) {
  88                rt_sysc_m32(0, RSTCTL_RESET_PCI, SYSC_REG_RESET_CTRL);
  89                mdelay(50);
  90        }
  91
  92        local_irq_disable();
  93        rt_sysc_w32(RSTCTL_RESET_SYSTEM, SYSC_REG_RESET_CTRL);
  94        unreachable();
  95}
  96
  97static int __init mips_reboot_setup(void)
  98{
  99        _machine_restart = ralink_restart;
 100
 101        return 0;
 102}
 103
 104arch_initcall(mips_reboot_setup);
 105