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 } 109