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 void 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
179static const struct acpi_device_id led_device_ids[] = {
180	{"NIC78B3", 0},
181	{"", 0},
182};
183MODULE_DEVICE_TABLE(acpi, led_device_ids);
184
185static struct platform_driver led_driver = {
186	.probe = nic78bx_probe,
187	.remove_new = nic78bx_remove,
188	.driver = {
189		.name = KBUILD_MODNAME,
190		.acpi_match_table = ACPI_PTR(led_device_ids),
191	},
192};
193
194module_platform_driver(led_driver);
195
196MODULE_DESCRIPTION("National Instruments PXI User LEDs driver");
197MODULE_AUTHOR("Hui Chun Ong <hui.chun.ong@ni.com>");
198MODULE_LICENSE("GPL");