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
  13 /* Trigger specific functions */
  14 #ifdef CONFIG_GPIOLIB
  15
  16 #include <linux/of_gpio.h>
  17
  18 static int handle; /* reset pin handle */
  19 static unsigned int reset_val;
  20
  21 static int of_platform_reset_gpio_probe(void)
  22 {
  23         int ret;
  24         handle = of_get_named_gpio(of_find_node_by_path("/"),
  25                                    "hard-reset-gpios", 0);
  26
  27         if (!gpio_is_valid(handle)) {
  28                 pr_info("Skipping unavailable RESET gpio %d (%s)\n",
  29                                 handle, "reset");
  30                 return -ENODEV;
  31         }
  32
  33         ret = gpio_request(handle, "reset");
  34         if (ret < 0) {
  35                 pr_info("GPIO pin is already allocated\n");
  36                 return ret;
  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         pr_info("RESET: Registered gpio device: %d, current val: %d\n",
  53                                                         handle, reset_val);
  54         return 0;
  55 err:
  56         gpio_free(handle);
  57         return ret;
  58 }
  59 device_initcall(of_platform_reset_gpio_probe);
  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 static void gpio_system_reset(void)
  71 {
  72         pr_notice("No reset GPIO present - halting!\n");
  73 }
  74
  75 void of_platform_reset_gpio_probe(void)
  76 {
  77         return;
  78 }
  79 #endif
  80
  81 void machine_restart(char *cmd)
  82 {
  83         pr_notice("Machine restart...\n");
  84         gpio_system_reset();
  85         while (1)
  86                 ;
  87 }
  88
  89 void machine_shutdown(void)
  90 {
  91         pr_notice("Machine shutdown...\n");
  92         while (1)
  93                 ;
  94 }
  95
  96 void machine_halt(void)
  97 {
  98         pr_notice("Machine halt...\n");
  99         while (1)
 100                 ;
 101 }
 102
 103 void machine_power_off(void)
 104 {
 105         pr_notice("Machine power off...\n");
 106         while (1)
 107                 ;
 108 }