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Sebastian Andrzej Siewiore9a45932012-01-20 14:33:59 -08001/*
2 * Bachmann ot200 leds driver.
3 *
4 * Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
5 * Christian Gmeiner <christian.gmeiner@gmail.com>
6 *
7 * License: GPL as published by the FSF.
8 */
9
10#include <linux/kernel.h>
11#include <linux/init.h>
12#include <linux/platform_device.h>
13#include <linux/slab.h>
14#include <linux/leds.h>
15#include <linux/io.h>
16#include <linux/module.h>
17
18
19struct ot200_led {
20 struct led_classdev cdev;
21 const char *name;
22 unsigned long port;
23 u8 mask;
24};
25
26/*
27 * The device has three leds on the back panel (led_err, led_init and led_run)
28 * and can handle up to seven leds on the front panel.
29 */
30
31static struct ot200_led leds[] = {
32 {
33 .name = "led_run",
34 .port = 0x5a,
35 .mask = BIT(0),
36 },
37 {
38 .name = "led_init",
39 .port = 0x5a,
40 .mask = BIT(1),
41 },
42 {
43 .name = "led_err",
44 .port = 0x5a,
45 .mask = BIT(2),
46 },
47 {
48 .name = "led_1",
49 .port = 0x49,
50 .mask = BIT(7),
51 },
52 {
53 .name = "led_2",
54 .port = 0x49,
55 .mask = BIT(6),
56 },
57 {
58 .name = "led_3",
59 .port = 0x49,
60 .mask = BIT(5),
61 },
62 {
63 .name = "led_4",
64 .port = 0x49,
65 .mask = BIT(4),
66 },
67 {
68 .name = "led_5",
69 .port = 0x49,
70 .mask = BIT(3),
71 },
72 {
73 .name = "led_6",
74 .port = 0x49,
75 .mask = BIT(2),
76 },
77 {
78 .name = "led_7",
79 .port = 0x49,
80 .mask = BIT(1),
81 }
82};
83
84static DEFINE_SPINLOCK(value_lock);
85
86/*
87 * we need to store the current led states, as it is not
88 * possible to read the current led state via inb().
89 */
90static u8 leds_back;
91static u8 leds_front;
92
93static void ot200_led_brightness_set(struct led_classdev *led_cdev,
94 enum led_brightness value)
95{
96 struct ot200_led *led = container_of(led_cdev, struct ot200_led, cdev);
97 u8 *val;
98 unsigned long flags;
99
100 spin_lock_irqsave(&value_lock, flags);
101
102 if (led->port == 0x49)
103 val = &leds_front;
104 else if (led->port == 0x5a)
105 val = &leds_back;
106 else
107 BUG();
108
109 if (value == LED_OFF)
110 *val &= ~led->mask;
111 else
112 *val |= led->mask;
113
114 outb(*val, led->port);
115 spin_unlock_irqrestore(&value_lock, flags);
116}
117
118static int __devinit ot200_led_probe(struct platform_device *pdev)
119{
120 int i;
121 int ret;
122
123 for (i = 0; i < ARRAY_SIZE(leds); i++) {
124
125 leds[i].cdev.name = leds[i].name;
126 leds[i].cdev.brightness_set = ot200_led_brightness_set;
127
128 ret = led_classdev_register(&pdev->dev, &leds[i].cdev);
129 if (ret < 0)
130 goto err;
131 }
132
133 leds_front = 0; /* turn off all front leds */
134 leds_back = BIT(1); /* turn on init led */
135 outb(leds_front, 0x49);
136 outb(leds_back, 0x5a);
137
138 return 0;
139
140err:
141 for (i = i - 1; i >= 0; i--)
142 led_classdev_unregister(&leds[i].cdev);
143
144 return ret;
145}
146
147static int __devexit ot200_led_remove(struct platform_device *pdev)
148{
149 int i;
150
151 for (i = 0; i < ARRAY_SIZE(leds); i++)
152 led_classdev_unregister(&leds[i].cdev);
153
154 return 0;
155}
156
157static struct platform_driver ot200_led_driver = {
158 .probe = ot200_led_probe,
159 .remove = __devexit_p(ot200_led_remove),
160 .driver = {
161 .name = "leds-ot200",
162 .owner = THIS_MODULE,
163 },
164};
165
166module_platform_driver(ot200_led_driver);
167
168MODULE_AUTHOR("Sebastian A. Siewior <bigeasy@linutronix.de>");
169MODULE_DESCRIPTION("ot200 LED driver");
170MODULE_LICENSE("GPL");
171MODULE_ALIAS("platform:leds-ot200");