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                 pr_info("Skipping unavailable RESET gpio %d (%s)\n",
  30                                 handle, "reset");
  31                 return;
  32         }
  33
  34         ret = gpio_request(handle, "reset");
  35         if (ret < 0) {
  36                 pr_info("GPIO pin is already allocated\n");
  37                 return;
  38         }
  39
  40         /* get current setup value */
  41         reset_val = gpio_get_value(handle);
  42         /* FIXME maybe worth to perform any action */
  43         pr_debug("Reset: Gpio output state: 0x%x\n", reset_val);
  44
  45         /* Setup GPIO as output */
  46         ret = gpio_direction_output(handle, 0);
  47         if (ret < 0)
  48                 goto err;
  49
  50         /* Setup output direction */
  51         gpio_set_value(handle, 0);
  52
  53         pr_info("RESET: Registered gpio device: %d, current val: %d\n",
  54                                                         handle, reset_val);
  55         return;
  56 err:
  57         gpio_free(handle);
  58         return;
  59 }
  60
  61
  62 static void gpio_system_reset(void)
  63 {
  64         if (gpio_is_valid(handle))
  65                 gpio_set_value(handle, 1 - reset_val);
  66         else
  67                 pr_notice("Reset GPIO unavailable - halting!\n");
  68 }
  69 #else
  70 #define gpio_system_reset() do {} while (0)
  71 void of_platform_reset_gpio_probe(void)
  72 {
  73         return;
  74 }
  75 #endif
  76
  77 void machine_restart(char *cmd)
  78 {
  79         pr_notice("Machine restart...\n");
  80         gpio_system_reset();
  81         while (1)
  82                 ;
  83 }
  84
  85 void machine_shutdown(void)
  86 {
  87         pr_notice("Machine shutdown...\n");
  88         while (1)
  89                 ;
  90 }
  91
  92 void machine_halt(void)
  93 {
  94         pr_notice("Machine halt...\n");
  95         while (1)
  96                 ;
  97 }
  98
  99 void machine_power_off(void)
 100 {
 101         pr_notice("Machine power off...\n");
 102         while (1)
 103                 ;
 104 }