1 /* 2 * Eurobraille/Iris power off support. 3 * 4 * Eurobraille's Iris machine is a PC with no APM or ACPI support. 5 * It is shutdown by a special I/O sequence which this module provides. 6 * 7 * Copyright (C) Shérab <Sebastien.Hinderer@ens-lyon.org> 8 * 9 * This program is free software ; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License as published by 11 * the Free Software Foundation ; either version 2 of the License, or 12 * (at your option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY ; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with the program ; if not, write to the Free Software 21 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 22 */ 23 24 #include <linux/moduleparam.h> 25 #include <linux/module.h> 26 #include <linux/platform_device.h> 27 #include <linux/kernel.h> 28 #include <linux/errno.h> 29 #include <linux/delay.h> 30 #include <linux/init.h> 31 #include <linux/pm.h> 32 #include <asm/io.h> 33 34 #define IRIS_GIO_BASE 0x340 35 #define IRIS_GIO_INPUT IRIS_GIO_BASE 36 #define IRIS_GIO_OUTPUT (IRIS_GIO_BASE + 1) 37 #define IRIS_GIO_PULSE 0x80 /* First byte to send */ 38 #define IRIS_GIO_REST 0x00 /* Second byte to send */ 39 #define IRIS_GIO_NODEV 0xff /* Likely not an Iris */ 40 41 MODULE_LICENSE("GPL"); 42 MODULE_AUTHOR("Sébastien Hinderer <Sebastien.Hinderer@ens-lyon.org>"); 43 MODULE_DESCRIPTION("A power_off handler for Iris devices from EuroBraille"); 44 MODULE_SUPPORTED_DEVICE("Eurobraille/Iris"); 45 46 static bool force; 47 48 module_param(force, bool, 0); 49 MODULE_PARM_DESC(force, "Set to one to force poweroff handler installation."); 50 51 static void (*old_pm_power_off)(void); 52 53 static void iris_power_off(void) 54 { 55 outb(IRIS_GIO_PULSE, IRIS_GIO_OUTPUT); 56 msleep(850); 57 outb(IRIS_GIO_REST, IRIS_GIO_OUTPUT); 58 } 59 60 /* 61 * Before installing the power_off handler, try to make sure the OS is 62 * running on an Iris. Since Iris does not support DMI, this is done 63 * by reading its input port and seeing whether the read value is 64 * meaningful. 65 */ 66 static int iris_probe(struct platform_device *pdev) 67 { 68 unsigned char status = inb(IRIS_GIO_INPUT); 69 if (status == IRIS_GIO_NODEV) { 70 printk(KERN_ERR "This machine does not seem to be an Iris. " 71 "Power off handler not installed.\n"); 72 return -ENODEV; 73 } 74 old_pm_power_off = pm_power_off; 75 pm_power_off = &iris_power_off; 76 printk(KERN_INFO "Iris power_off handler installed.\n"); 77 return 0; 78 } 79 80 static int iris_remove(struct platform_device *pdev) 81 { 82 pm_power_off = old_pm_power_off; 83 printk(KERN_INFO "Iris power_off handler uninstalled.\n"); 84 return 0; 85 } 86 87 static struct platform_driver iris_driver = { 88 .driver = { 89 .name = "iris", 90 .owner = THIS_MODULE, 91 }, 92 .probe = iris_probe, 93 .remove = iris_remove, 94 }; 95 96 static struct resource iris_resources[] = { 97 { 98 .start = IRIS_GIO_BASE, 99 .end = IRIS_GIO_OUTPUT, 100 .flags = IORESOURCE_IO, 101 .name = "address" 102 } 103 }; 104 105 static struct platform_device *iris_device; 106 107 static int iris_init(void) 108 { 109 int ret; 110 if (force != 1) { 111 printk(KERN_ERR "The force parameter has not been set to 1." 112 " The Iris poweroff handler will not be installed.\n"); 113 return -ENODEV; 114 } 115 ret = platform_driver_register(&iris_driver); 116 if (ret < 0) { 117 printk(KERN_ERR "Failed to register iris platform driver: %d\n", 118 ret); 119 return ret; 120 } 121 iris_device = platform_device_register_simple("iris", (-1), 122 iris_resources, ARRAY_SIZE(iris_resources)); 123 if (IS_ERR(iris_device)) { 124 printk(KERN_ERR "Failed to register iris platform device\n"); 125 platform_driver_unregister(&iris_driver); 126 return PTR_ERR(iris_device); 127 } 128 return 0; 129 } 130 131 static void iris_exit(void) 132 { 133 platform_device_unregister(iris_device); 134 platform_driver_unregister(&iris_driver); 135 } 136 137 module_init(iris_init); 138 module_exit(iris_exit); 139