blob: 4d171e8640efe7e049a07e2b89d7dd1c5c3eb0de [file] [log] [blame]
Shérab82148d12010-09-25 06:06:57 +02001/*
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>
Shérab88d67ee2012-12-18 14:21:21 -080026#include <linux/platform_device.h>
Shérab82148d12010-09-25 06:06:57 +020027#include <linux/kernel.h>
28#include <linux/errno.h>
29#include <linux/delay.h>
Shérab82148d12010-09-25 06:06:57 +020030#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
Rusty Russell476bc002012-01-13 09:32:18 +103045static bool force;
Shérab82148d12010-09-25 06:06:57 +020046
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 */
Shérab88d67ee2012-12-18 14:21:21 -080065static int iris_probe(struct platform_device *pdev)
Shérab82148d12010-09-25 06:06:57 +020066{
Shérab88d67ee2012-12-18 14:21:21 -080067 unsigned char status = inb(IRIS_GIO_INPUT);
Shérab82148d12010-09-25 06:06:57 +020068 if (status == IRIS_GIO_NODEV) {
Shérab88d67ee2012-12-18 14:21:21 -080069 printk(KERN_ERR "This machine does not seem to be an Iris. "
70 "Power off handler not installed.\n");
Shérab82148d12010-09-25 06:06:57 +020071 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");
Shérab88d67ee2012-12-18 14:21:21 -080076 return 0;
77}
Shérab82148d12010-09-25 06:06:57 +020078
Shérab88d67ee2012-12-18 14:21:21 -080079static 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 .owner = THIS_MODULE,
90 },
91 .probe = iris_probe,
92 .remove = iris_remove,
93};
94
95static struct resource iris_resources[] = {
96 {
97 .start = IRIS_GIO_BASE,
98 .end = IRIS_GIO_OUTPUT,
99 .flags = IORESOURCE_IO,
100 .name = "address"
101 }
102};
103
104static struct platform_device *iris_device;
105
106static int iris_init(void)
107{
108 int ret;
109 if (force != 1) {
110 printk(KERN_ERR "The force parameter has not been set to 1."
111 " The Iris poweroff handler will not be installed.\n");
112 return -ENODEV;
113 }
114 ret = platform_driver_register(&iris_driver);
115 if (ret < 0) {
116 printk(KERN_ERR "Failed to register iris platform driver: %d\n",
117 ret);
118 return ret;
119 }
120 iris_device = platform_device_register_simple("iris", (-1),
121 iris_resources, ARRAY_SIZE(iris_resources));
122 if (IS_ERR(iris_device)) {
123 printk(KERN_ERR "Failed to register iris platform device\n");
124 platform_driver_unregister(&iris_driver);
125 return PTR_ERR(iris_device);
126 }
Shérab82148d12010-09-25 06:06:57 +0200127 return 0;
128}
129
130static void iris_exit(void)
131{
Shérab88d67ee2012-12-18 14:21:21 -0800132 platform_device_unregister(iris_device);
133 platform_driver_unregister(&iris_driver);
Shérab82148d12010-09-25 06:06:57 +0200134}
135
136module_init(iris_init);
137module_exit(iris_exit);