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/kernel.h> 27 #include <linux/errno.h> 28 #include <linux/delay.h> 29 #include <linux/init.h> 30 #include <linux/pm.h> 31 #include <asm/io.h> 32 33 #define IRIS_GIO_BASE 0x340 34 #define IRIS_GIO_INPUT IRIS_GIO_BASE 35 #define IRIS_GIO_OUTPUT (IRIS_GIO_BASE + 1) 36 #define IRIS_GIO_PULSE 0x80 /* First byte to send */ 37 #define IRIS_GIO_REST 0x00 /* Second byte to send */ 38 #define IRIS_GIO_NODEV 0xff /* Likely not an Iris */ 39 40 MODULE_LICENSE("GPL"); 41 MODULE_AUTHOR("Sébastien Hinderer <Sebastien.Hinderer@ens-lyon.org>"); 42 MODULE_DESCRIPTION("A power_off handler for Iris devices from EuroBraille"); 43 MODULE_SUPPORTED_DEVICE("Eurobraille/Iris"); 44 45 static int force; 46 47 module_param(force, bool, 0); 48 MODULE_PARM_DESC(force, "Set to one to force poweroff handler installation."); 49 50 static void (*old_pm_power_off)(void); 51 52 static void iris_power_off(void) 53 { 54 outb(IRIS_GIO_PULSE, IRIS_GIO_OUTPUT); 55 msleep(850); 56 outb(IRIS_GIO_REST, IRIS_GIO_OUTPUT); 57 } 58 59 /* 60 * Before installing the power_off handler, try to make sure the OS is 61 * running on an Iris. Since Iris does not support DMI, this is done 62 * by reading its input port and seeing whether the read value is 63 * meaningful. 64 */ 65 static int iris_init(void) 66 { 67 unsigned char status; 68 if (force != 1) { 69 printk(KERN_ERR "The force parameter has not been set to 1 so the Iris poweroff handler will not be installed.\n"); 70 return -ENODEV; 71 } 72 status = inb(IRIS_GIO_INPUT); 73 if (status == IRIS_GIO_NODEV) { 74 printk(KERN_ERR "This machine does not seem to be an Iris. Power_off handler not installed.\n"); 75 return -ENODEV; 76 } 77 old_pm_power_off = pm_power_off; 78 pm_power_off = &iris_power_off; 79 printk(KERN_INFO "Iris power_off handler installed.\n"); 80 81 return 0; 82 } 83 84 static void iris_exit(void) 85 { 86 pm_power_off = old_pm_power_off; 87 printk(KERN_INFO "Iris power_off handler uninstalled.\n"); 88 } 89 90 module_init(iris_init); 91 module_exit(iris_exit); 92