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/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 40MODULE_LICENSE("GPL"); 41MODULE_AUTHOR("Sébastien Hinderer <Sebastien.Hinderer@ens-lyon.org>"); 42MODULE_DESCRIPTION("A power_off handler for Iris devices from EuroBraille"); 43MODULE_SUPPORTED_DEVICE("Eurobraille/Iris"); 44 45static bool force; 46 47module_param(force, bool, 0); 48MODULE_PARM_DESC(force, "Set to one to force poweroff handler installation."); 49 50static void (*old_pm_power_off)(void); 51 52static 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 */ 65static int iris_probe(struct platform_device *pdev) 66{ 67 unsigned char status = inb(IRIS_GIO_INPUT); 68 if (status == IRIS_GIO_NODEV) { 69 printk(KERN_ERR "This machine does not seem to be an Iris. " 70 "Power off handler not installed.\n"); 71 return -ENODEV; 72 } 73 old_pm_power_off = pm_power_off; 74 pm_power_off = &iris_power_off; 75 printk(KERN_INFO "Iris power_off handler installed.\n"); 76 return 0; 77} 78 79static int iris_remove(struct platform_device *pdev) 80{ 81 pm_power_off = old_pm_power_off; 82 printk(KERN_INFO "Iris power_off handler uninstalled.\n"); 83 return 0; 84} 85 86static struct platform_driver iris_driver = { 87 .driver = { 88 .name = "iris", 89 }, 90 .probe = iris_probe, 91 .remove = iris_remove, 92}; 93 94static struct resource iris_resources[] = { 95 { 96 .start = IRIS_GIO_BASE, 97 .end = IRIS_GIO_OUTPUT, 98 .flags = IORESOURCE_IO, 99 .name = "address" 100 } 101}; 102 103static struct platform_device *iris_device; 104 105static int iris_init(void) 106{ 107 int ret; 108 if (force != 1) { 109 printk(KERN_ERR "The force parameter has not been set to 1." 110 " The Iris poweroff handler will not be installed.\n"); 111 return -ENODEV; 112 } 113 ret = platform_driver_register(&iris_driver); 114 if (ret < 0) { 115 printk(KERN_ERR "Failed to register iris platform driver: %d\n", 116 ret); 117 return ret; 118 } 119 iris_device = platform_device_register_simple("iris", (-1), 120 iris_resources, ARRAY_SIZE(iris_resources)); 121 if (IS_ERR(iris_device)) { 122 printk(KERN_ERR "Failed to register iris platform device\n"); 123 platform_driver_unregister(&iris_driver); 124 return PTR_ERR(iris_device); 125 } 126 return 0; 127} 128 129static void iris_exit(void) 130{ 131 platform_device_unregister(iris_device); 132 platform_driver_unregister(&iris_driver); 133} 134 135module_init(iris_init); 136module_exit(iris_exit); 137