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