1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2016 National Instruments Corp.
4 */
5
6#include <linux/acpi.h>
7#include <linux/leds.h>
8#include <linux/module.h>
9#include <linux/platform_device.h>
10#include <linux/spinlock.h>
11
12#define NIC78BX_USER1_LED_MASK		0x3
13#define NIC78BX_USER1_GREEN_LED		BIT(0)
14#define NIC78BX_USER1_YELLOW_LED	BIT(1)
15
16#define NIC78BX_USER2_LED_MASK		0xC
17#define NIC78BX_USER2_GREEN_LED		BIT(2)
18#define NIC78BX_USER2_YELLOW_LED	BIT(3)
19
20#define NIC78BX_LOCK_REG_OFFSET		1
21#define NIC78BX_LOCK_VALUE		0xA5
22#define NIC78BX_UNLOCK_VALUE		0x5A
23
24#define NIC78BX_USER_LED_IO_SIZE	2
25
26struct nic78bx_led_data {
27	u16 io_base;
28	spinlock_t lock;
29	struct platform_device *pdev;
30};
31
32struct nic78bx_led {
33	u8 bit;
34	u8 mask;
35	struct nic78bx_led_data *data;
36	struct led_classdev cdev;
37};
38
39static inline struct nic78bx_led *to_nic78bx_led(struct led_classdev *cdev)
40{
41	return container_of(cdev, struct nic78bx_led, cdev);
42}
43
44static void nic78bx_brightness_set(struct led_classdev *cdev,
45				  enum led_brightness brightness)
46{
47	struct nic78bx_led *nled = to_nic78bx_led(cdev);
48	unsigned long flags;
49	u8 value;
50
51	spin_lock_irqsave(&nled->data->lock, flags);
52	value = inb(nled->data->io_base);
53
54	if (brightness) {
55		value &= ~nled->mask;
56		value |= nled->bit;
57	} else {
58		value &= ~nled->bit;
59	}
60
61	outb(value, nled->data->io_base);
62	spin_unlock_irqrestore(&nled->data->lock, flags);
63}
64
65static enum led_brightness nic78bx_brightness_get(struct led_classdev *cdev)
66{
67	struct nic78bx_led *nled = to_nic78bx_led(cdev);
68	unsigned long flags;
69	u8 value;
70
71	spin_lock_irqsave(&nled->data->lock, flags);
72	value = inb(nled->data->io_base);
73	spin_unlock_irqrestore(&nled->data->lock, flags);
74
75	return (value & nled->bit) ? 1 : LED_OFF;
76}
77
78static struct nic78bx_led nic78bx_leds[] = {
79	{
80		.bit = NIC78BX_USER1_GREEN_LED,
81		.mask = NIC78BX_USER1_LED_MASK,
82		.cdev = {
83			.name = "nilrt:green:user1",
84			.max_brightness = 1,
85			.brightness_set = nic78bx_brightness_set,
86			.brightness_get = nic78bx_brightness_get,
87		}
88	},
89	{
90		.bit = NIC78BX_USER1_YELLOW_LED,
91		.mask = NIC78BX_USER1_LED_MASK,
92		.cdev = {
93			.name = "nilrt:yellow:user1",
94			.max_brightness = 1,
95			.brightness_set = nic78bx_brightness_set,
96			.brightness_get = nic78bx_brightness_get,
97		}
98	},
99	{
100		.bit = NIC78BX_USER2_GREEN_LED,
101		.mask = NIC78BX_USER2_LED_MASK,
102		.cdev = {
103			.name = "nilrt:green:user2",
104			.max_brightness = 1,
105			.brightness_set = nic78bx_brightness_set,
106			.brightness_get = nic78bx_brightness_get,
107		}
108	},
109	{
110		.bit = NIC78BX_USER2_YELLOW_LED,
111		.mask = NIC78BX_USER2_LED_MASK,
112		.cdev = {
113			.name = "nilrt:yellow:user2",
114			.max_brightness = 1,
115			.brightness_set = nic78bx_brightness_set,
116			.brightness_get = nic78bx_brightness_get,
117		}
118	}
119};
120
121static int nic78bx_probe(struct platform_device *pdev)
122{
123	struct device *dev = &pdev->dev;
124	struct nic78bx_led_data *led_data;
125	struct resource *io_rc;
126	int ret, i;
127
128	led_data = devm_kzalloc(dev, sizeof(*led_data), GFP_KERNEL);
129	if (!led_data)
130		return -ENOMEM;
131
132	led_data->pdev = pdev;
133	platform_set_drvdata(pdev, led_data);
134
135	io_rc = platform_get_resource(pdev, IORESOURCE_IO, 0);
136	if (!io_rc) {
137		dev_err(dev, "missing IO resources\n");
138		return -EINVAL;
139	}
140
141	if (resource_size(io_rc) < NIC78BX_USER_LED_IO_SIZE) {
142		dev_err(dev, "IO region too small\n");
143		return -EINVAL;
144	}
145
146	if (!devm_request_region(dev, io_rc->start, resource_size(io_rc),
147				 KBUILD_MODNAME)) {
148		dev_err(dev, "failed to get IO region\n");
149		return -EBUSY;
150	}
151
152	led_data->io_base = io_rc->start;
153	spin_lock_init(&led_data->lock);
154
155	for (i = 0; i < ARRAY_SIZE(nic78bx_leds); i++) {
156		nic78bx_leds[i].data = led_data;
157
158		ret = devm_led_classdev_register(dev, &nic78bx_leds[i].cdev);
159		if (ret)
160			return ret;
161	}
162
163	/* Unlock LED register */
164	outb(NIC78BX_UNLOCK_VALUE,
165	     led_data->io_base + NIC78BX_LOCK_REG_OFFSET);
166
167	return ret;
168}
169
170static int nic78bx_remove(struct platform_device *pdev)
171{
172	struct nic78bx_led_data *led_data = platform_get_drvdata(pdev);
173
174	/* Lock LED register */
175	outb(NIC78BX_LOCK_VALUE,
176	     led_data->io_base + NIC78BX_LOCK_REG_OFFSET);
177
178	return 0;
179}
180
181static const struct acpi_device_id led_device_ids[] = {
182	{"NIC78B3", 0},
183	{"", 0},
184};
185MODULE_DEVICE_TABLE(acpi, led_device_ids);
186
187static struct platform_driver led_driver = {
188	.probe = nic78bx_probe,
189	.remove = nic78bx_remove,
190	.driver = {
191		.name = KBUILD_MODNAME,
192		.acpi_match_table = ACPI_PTR(led_device_ids),
193	},
194};
195
196module_platform_driver(led_driver);
197
198MODULE_DESCRIPTION("National Instruments PXI User LEDs driver");
199MODULE_AUTHOR("Hui Chun Ong <hui.chun.ong@ni.com>");
200MODULE_LICENSE("GPL");
201