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6
7#include <linux/err.h>
8#include <linux/io.h>
9#include <linux/kernel.h>
10#include <linux/leds.h>
11#include <linux/module.h>
12#include <linux/platform_device.h>
13#include <linux/string.h>
14
15static int force = 0;
16module_param(force, bool, 0444);
17MODULE_PARM_DESC(force, "Assume system has ALIX.2 style LEDs");
18
19struct alix_led {
20 struct led_classdev cdev;
21 unsigned short port;
22 unsigned int on_value;
23 unsigned int off_value;
24};
25
26static void alix_led_set(struct led_classdev *led_cdev,
27 enum led_brightness brightness)
28{
29 struct alix_led *led_dev =
30 container_of(led_cdev, struct alix_led, cdev);
31
32 if (brightness)
33 outl(led_dev->on_value, led_dev->port);
34 else
35 outl(led_dev->off_value, led_dev->port);
36}
37
38static struct alix_led alix_leds[] = {
39 {
40 .cdev = {
41 .name = "alix:1",
42 .brightness_set = alix_led_set,
43 },
44 .port = 0x6100,
45 .on_value = 1 << 22,
46 .off_value = 1 << 6,
47 },
48 {
49 .cdev = {
50 .name = "alix:2",
51 .brightness_set = alix_led_set,
52 },
53 .port = 0x6180,
54 .on_value = 1 << 25,
55 .off_value = 1 << 9,
56 },
57 {
58 .cdev = {
59 .name = "alix:3",
60 .brightness_set = alix_led_set,
61 },
62 .port = 0x6180,
63 .on_value = 1 << 27,
64 .off_value = 1 << 11,
65 },
66};
67
68static int __init alix_led_probe(struct platform_device *pdev)
69{
70 int i;
71 int ret;
72
73 for (i = 0; i < ARRAY_SIZE(alix_leds); i++) {
74 alix_leds[i].cdev.flags |= LED_CORE_SUSPENDRESUME;
75 ret = led_classdev_register(&pdev->dev, &alix_leds[i].cdev);
76 if (ret < 0)
77 goto fail;
78 }
79 return 0;
80
81fail:
82 while (--i >= 0)
83 led_classdev_unregister(&alix_leds[i].cdev);
84 return ret;
85}
86
87static int alix_led_remove(struct platform_device *pdev)
88{
89 int i;
90
91 for (i = 0; i < ARRAY_SIZE(alix_leds); i++)
92 led_classdev_unregister(&alix_leds[i].cdev);
93 return 0;
94}
95
96static struct platform_driver alix_led_driver = {
97 .remove = alix_led_remove,
98 .driver = {
99 .name = KBUILD_MODNAME,
100 .owner = THIS_MODULE,
101 },
102};
103
104static int __init alix_present(void)
105{
106 const unsigned long bios_phys = 0x000f0000;
107 const size_t bios_len = 0x00010000;
108 const char alix_sig[] = "PC Engines ALIX.";
109 const size_t alix_sig_len = sizeof(alix_sig) - 1;
110
111 const char *bios_virt;
112 const char *scan_end;
113 const char *p;
114 int ret = 0;
115
116 if (force) {
117 printk(KERN_NOTICE "%s: forced to skip BIOS test, "
118 "assume system has ALIX.2 style LEDs\n",
119 KBUILD_MODNAME);
120 ret = 1;
121 goto out;
122 }
123
124 bios_virt = phys_to_virt(bios_phys);
125 scan_end = bios_virt + bios_len - (alix_sig_len + 2);
126 for (p = bios_virt; p < scan_end; p++) {
127 const char *tail;
128
129 if (memcmp(p, alix_sig, alix_sig_len) != 0) {
130 continue;
131 }
132
133 tail = p + alix_sig_len;
134 if ((tail[0] == '2' || tail[0] == '3') && tail[1] == '\0') {
135 printk(KERN_INFO
136 "%s: system is recognized as \"%s\"\n",
137 KBUILD_MODNAME, p);
138 ret = 1;
139 break;
140 }
141 }
142
143out:
144 return ret;
145}
146
147static struct platform_device *pdev;
148
149static int __init alix_led_init(void)
150{
151 int ret;
152
153 if (!alix_present()) {
154 ret = -ENODEV;
155 goto out;
156 }
157
158 pdev = platform_device_register_simple(KBUILD_MODNAME, -1, NULL, 0);
159 if (!IS_ERR(pdev)) {
160 ret = platform_driver_probe(&alix_led_driver, alix_led_probe);
161 if (ret)
162 platform_device_unregister(pdev);
163 } else
164 ret = PTR_ERR(pdev);
165
166out:
167 return ret;
168}
169
170static void __exit alix_led_exit(void)
171{
172 platform_device_unregister(pdev);
173 platform_driver_unregister(&alix_led_driver);
174}
175
176module_init(alix_led_init);
177module_exit(alix_led_exit);
178
179MODULE_AUTHOR("Constantin Baranov <const@mimas.ru>");
180MODULE_DESCRIPTION("PCEngines ALIX.2 and ALIX.3 LED driver");
181MODULE_LICENSE("GPL");
182
