arch/microblaze/kernel/reset.c

   1 /*
   2  * Copyright (C) 2009 Michal Simek <monstr@monstr.eu>
   3  * Copyright (C) 2009 PetaLogix
   4  *
   5  * This file is subject to the terms and conditions of the GNU General Public
   6  * License. See the file "COPYING" in the main directory of this archive
   7  * for more details.
   8  */
   9
  10 #include <linux/init.h>
  11 #include <linux/of_platform.h>
  12 #include <asm/prom.h>
  13
  14 /* Trigger specific functions */
  15 #ifdef CONFIG_GPIOLIB
  16
  17 #include <linux/of_gpio.h>
  18
  19 static int handle; /* reset pin handle */
  20 static unsigned int reset_val;
  21
  22 void of_platform_reset_gpio_probe(void)
  23 {
  24         int ret;
  25         handle = of_get_named_gpio(of_find_node_by_path("/"),
  26                                    "hard-reset-gpios", 0);
  27
  28         if (!gpio_is_valid(handle)) {
  29                 printk(KERN_INFO "Skipping unavailable RESET gpio %d (%s)\n",
  30                                 handle, "reset");
  31         }
  32
  33         ret = gpio_request(handle, "reset");
  34         if (ret < 0) {
  35                 printk(KERN_INFO "GPIO pin is already allocated\n");
  36                 return;
  37         }
  38
  39         /* get current setup value */
  40         reset_val = gpio_get_value(handle);
  41         /* FIXME maybe worth to perform any action */
  42         pr_debug("Reset: Gpio output state: 0x%x\n", reset_val);
  43
  44         /* Setup GPIO as output */
  45         ret = gpio_direction_output(handle, 0);
  46         if (ret < 0)
  47                 goto err;
  48
  49         /* Setup output direction */
  50         gpio_set_value(handle, 0);
  51
  52         printk(KERN_INFO "RESET: Registered gpio device: %d, current val: %d\n",
  53                                                         handle, reset_val);
  54         return;
  55 err:
  56         gpio_free(handle);
  57         return;
  58 }
  59
  60
  61 static void gpio_system_reset(void)
  62 {
  63         gpio_set_value(handle, 1 - reset_val);
  64 }
  65 #else
  66 #define gpio_system_reset() do {} while (0)
  67 void of_platform_reset_gpio_probe(void)
  68 {
  69         return;
  70 }
  71 #endif
  72
  73 void machine_restart(char *cmd)
  74 {
  75         printk(KERN_NOTICE "Machine restart...\n");
  76         gpio_system_reset();
  77         dump_stack();
  78         while (1)
  79                 ;
  80 }
  81
  82 void machine_shutdown(void)
  83 {
  84         printk(KERN_NOTICE "Machine shutdown...\n");
  85         while (1)
  86                 ;
  87 }
  88
  89 void machine_halt(void)
  90 {
  91         printk(KERN_NOTICE "Machine halt...\n");
  92         while (1)
  93                 ;
  94 }
  95
  96 void machine_power_off(void)
  97 {
  98         printk(KERN_NOTICE "Machine power off...\n");
  99         while (1)
 100                 ;
 101 }