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
  25 static 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
  40 static 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
  55 static 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
  62 static const struct reset_control_ops reset_ops = {
  63         .reset = ralink_reset_device,
  64         .assert = ralink_assert_device,
  65         .deassert = ralink_deassert_device,
  66 };
  67
  68 static 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
  75 void 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
  85 static 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
  97 static int __init mips_reboot_setup(void)
  98 {
  99         _machine_restart = ralink_restart;
 100
 101         return 0;
 102 }
 103
 104 arch_initcall(mips_reboot_setup);