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fd26084e | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
82148d1d S |
2 | /* |
3 | * Eurobraille/Iris power off support. | |
4 | * | |
5 | * Eurobraille's Iris machine is a PC with no APM or ACPI support. | |
6 | * It is shutdown by a special I/O sequence which this module provides. | |
7 | * | |
8 | * Copyright (C) Shérab <Sebastien.Hinderer@ens-lyon.org> | |
82148d1d S |
9 | */ |
10 | ||
11 | #include <linux/moduleparam.h> | |
12 | #include <linux/module.h> | |
88d67ee3 | 13 | #include <linux/platform_device.h> |
82148d1d S |
14 | #include <linux/kernel.h> |
15 | #include <linux/errno.h> | |
16 | #include <linux/delay.h> | |
82148d1d S |
17 | #include <linux/pm.h> |
18 | #include <asm/io.h> | |
19 | ||
20 | #define IRIS_GIO_BASE 0x340 | |
21 | #define IRIS_GIO_INPUT IRIS_GIO_BASE | |
22 | #define IRIS_GIO_OUTPUT (IRIS_GIO_BASE + 1) | |
23 | #define IRIS_GIO_PULSE 0x80 /* First byte to send */ | |
24 | #define IRIS_GIO_REST 0x00 /* Second byte to send */ | |
25 | #define IRIS_GIO_NODEV 0xff /* Likely not an Iris */ | |
26 | ||
27 | MODULE_LICENSE("GPL"); | |
28 | MODULE_AUTHOR("Sébastien Hinderer <Sebastien.Hinderer@ens-lyon.org>"); | |
29 | MODULE_DESCRIPTION("A power_off handler for Iris devices from EuroBraille"); | |
82148d1d | 30 | |
476bc001 | 31 | static bool force; |
82148d1d S |
32 | |
33 | module_param(force, bool, 0); | |
34 | MODULE_PARM_DESC(force, "Set to one to force poweroff handler installation."); | |
35 | ||
36 | static void (*old_pm_power_off)(void); | |
37 | ||
38 | static void iris_power_off(void) | |
39 | { | |
40 | outb(IRIS_GIO_PULSE, IRIS_GIO_OUTPUT); | |
41 | msleep(850); | |
42 | outb(IRIS_GIO_REST, IRIS_GIO_OUTPUT); | |
43 | } | |
44 | ||
45 | /* | |
46 | * Before installing the power_off handler, try to make sure the OS is | |
47 | * running on an Iris. Since Iris does not support DMI, this is done | |
48 | * by reading its input port and seeing whether the read value is | |
49 | * meaningful. | |
50 | */ | |
88d67ee3 | 51 | static int iris_probe(struct platform_device *pdev) |
82148d1d | 52 | { |
88d67ee3 | 53 | unsigned char status = inb(IRIS_GIO_INPUT); |
82148d1d | 54 | if (status == IRIS_GIO_NODEV) { |
88d67ee3 S |
55 | printk(KERN_ERR "This machine does not seem to be an Iris. " |
56 | "Power off handler not installed.\n"); | |
82148d1d S |
57 | return -ENODEV; |
58 | } | |
59 | old_pm_power_off = pm_power_off; | |
60 | pm_power_off = &iris_power_off; | |
61 | printk(KERN_INFO "Iris power_off handler installed.\n"); | |
82148d1d S |
62 | return 0; |
63 | } | |
64 | ||
88d67ee3 | 65 | static int iris_remove(struct platform_device *pdev) |
82148d1d S |
66 | { |
67 | pm_power_off = old_pm_power_off; | |
68 | printk(KERN_INFO "Iris power_off handler uninstalled.\n"); | |
88d67ee3 S |
69 | return 0; |
70 | } | |
71 | ||
72 | static struct platform_driver iris_driver = { | |
73 | .driver = { | |
74 | .name = "iris", | |
88d67ee3 S |
75 | }, |
76 | .probe = iris_probe, | |
77 | .remove = iris_remove, | |
78 | }; | |
79 | ||
80 | static struct resource iris_resources[] = { | |
81 | { | |
82 | .start = IRIS_GIO_BASE, | |
83 | .end = IRIS_GIO_OUTPUT, | |
84 | .flags = IORESOURCE_IO, | |
85 | .name = "address" | |
86 | } | |
87 | }; | |
88 | ||
89 | static struct platform_device *iris_device; | |
90 | ||
91 | static int iris_init(void) | |
92 | { | |
93 | int ret; | |
94 | if (force != 1) { | |
95 | printk(KERN_ERR "The force parameter has not been set to 1." | |
96 | " The Iris poweroff handler will not be installed.\n"); | |
97 | return -ENODEV; | |
98 | } | |
99 | ret = platform_driver_register(&iris_driver); | |
100 | if (ret < 0) { | |
101 | printk(KERN_ERR "Failed to register iris platform driver: %d\n", | |
102 | ret); | |
103 | return ret; | |
104 | } | |
105 | iris_device = platform_device_register_simple("iris", (-1), | |
106 | iris_resources, ARRAY_SIZE(iris_resources)); | |
107 | if (IS_ERR(iris_device)) { | |
108 | printk(KERN_ERR "Failed to register iris platform device\n"); | |
109 | platform_driver_unregister(&iris_driver); | |
110 | return PTR_ERR(iris_device); | |
111 | } | |
112 | return 0; | |
113 | } | |
114 | ||
115 | static void iris_exit(void) | |
116 | { | |
117 | platform_device_unregister(iris_device); | |
118 | platform_driver_unregister(&iris_driver); | |
82148d1d S |
119 | } |
120 | ||
121 | module_init(iris_init); | |
122 | module_exit(iris_exit); |