arch/mips/lantiq/xway/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) 2010 John Crispin <blogic@openwrt.org>
   7  */
   8
   9 #include <linux/init.h>
  10 #include <linux/io.h>
  11 #include <linux/ioport.h>
  12 #include <linux/pm.h>
  13 #include <linux/export.h>
  14 #include <asm/reboot.h>
  15
  16 #include <lantiq_soc.h>
  17
  18 #define ltq_rcu_w32(x, y)       ltq_w32((x), ltq_rcu_membase + (y))
  19 #define ltq_rcu_r32(x)          ltq_r32(ltq_rcu_membase + (x))
  20
  21 /* register definitions */
  22 #define LTQ_RCU_RST             0x0010
  23 #define LTQ_RCU_RST_ALL         0x40000000
  24
  25 #define LTQ_RCU_RST_STAT        0x0014
  26 #define LTQ_RCU_STAT_SHIFT      26
  27
  28 static struct resource ltq_rcu_resource = {
  29         .name   = "rcu",
  30         .start  = LTQ_RCU_BASE_ADDR,
  31         .end    = LTQ_RCU_BASE_ADDR + LTQ_RCU_SIZE - 1,
  32         .flags  = IORESOURCE_MEM,
  33 };
  34
  35 /* remapped base addr of the reset control unit */
  36 static void __iomem *ltq_rcu_membase;
  37
  38 /* This function is used by the watchdog driver */
  39 int ltq_reset_cause(void)
  40 {
  41         u32 val = ltq_rcu_r32(LTQ_RCU_RST_STAT);
  42         return val >> LTQ_RCU_STAT_SHIFT;
  43 }
  44 EXPORT_SYMBOL_GPL(ltq_reset_cause);
  45
  46 static void ltq_machine_restart(char *command)
  47 {
  48         pr_notice("System restart\n");
  49         local_irq_disable();
  50         ltq_rcu_w32(ltq_rcu_r32(LTQ_RCU_RST) | LTQ_RCU_RST_ALL, LTQ_RCU_RST);
  51         unreachable();
  52 }
  53
  54 static void ltq_machine_halt(void)
  55 {
  56         pr_notice("System halted.\n");
  57         local_irq_disable();
  58         unreachable();
  59 }
  60
  61 static void ltq_machine_power_off(void)
  62 {
  63         pr_notice("Please turn off the power now.\n");
  64         local_irq_disable();
  65         unreachable();
  66 }
  67
  68 static int __init mips_reboot_setup(void)
  69 {
  70         /* insert and request the memory region */
  71         if (insert_resource(&iomem_resource, &ltq_rcu_resource) < 0)
  72                 panic("Failed to insert rcu memory");
  73
  74         if (request_mem_region(ltq_rcu_resource.start,
  75                         resource_size(&ltq_rcu_resource), "rcu") < 0)
  76                 panic("Failed to request rcu memory");
  77
  78         /* remap rcu register range */
  79         ltq_rcu_membase = ioremap_nocache(ltq_rcu_resource.start,
  80                                 resource_size(&ltq_rcu_resource));
  81         if (!ltq_rcu_membase)
  82                 panic("Failed to remap rcu memory");
  83
  84         _machine_restart = ltq_machine_restart;
  85         _machine_halt = ltq_machine_halt;
  86         pm_power_off = ltq_machine_power_off;
  87
  88         return 0;
  89 }
  90
  91 arch_initcall(mips_reboot_setup);