Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
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
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 int 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_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
84static 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
90module_init(iris_init);
91module_exit(iris_exit);