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
18struct 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
30static 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
83static 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 */
89static u8 leds_back;
90static u8 leds_front;
91
92static 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
117static 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 = led_classdev_register(&pdev->dev, &leds[i].cdev);
128		if (ret < 0)
129			goto err;
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
139err:
140	for (i = i - 1; i >= 0; i--)
141		led_classdev_unregister(&leds[i].cdev);
142
143	return ret;
144}
145
146static int ot200_led_remove(struct platform_device *pdev)
147{
148	int i;
149
150	for (i = 0; i < ARRAY_SIZE(leds); i++)
151		led_classdev_unregister(&leds[i].cdev);
152
153	return 0;
154}
155
156static struct platform_driver ot200_led_driver = {
157	.probe		= ot200_led_probe,
158	.remove		= ot200_led_remove,
159	.driver		= {
160		.name	= "leds-ot200",
161		.owner	= THIS_MODULE,
162	},
163};
164
165module_platform_driver(ot200_led_driver);
166
167MODULE_AUTHOR("Sebastian A. Siewior <bigeasy@linutronix.de>");
168MODULE_DESCRIPTION("ot200 LED driver");
169MODULE_LICENSE("GPL");
170MODULE_ALIAS("platform:leds-ot200");
171