linuxdebug/drivers/leds/leds-ot200.c

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2024-07-16 15:50:57 +02:00
/*
* Bachmann ot200 leds driver.
*
* Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
* Christian Gmeiner <christian.gmeiner@gmail.com>
*
* License: GPL as published by the FSF.
*/
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/leds.h>
#include <linux/io.h>
#include <linux/module.h>
struct ot200_led {
struct led_classdev cdev;
const char *name;
unsigned long port;
u8 mask;
};
/*
* The device has three leds on the back panel (led_err, led_init and led_run)
* and can handle up to seven leds on the front panel.
*/
static struct ot200_led leds[] = {
{
.name = "led_run",
.port = 0x5a,
.mask = BIT(0),
},
{
.name = "led_init",
.port = 0x5a,
.mask = BIT(1),
},
{
.name = "led_err",
.port = 0x5a,
.mask = BIT(2),
},
{
.name = "led_1",
.port = 0x49,
.mask = BIT(6),
},
{
.name = "led_2",
.port = 0x49,
.mask = BIT(5),
},
{
.name = "led_3",
.port = 0x49,
.mask = BIT(4),
},
{
.name = "led_4",
.port = 0x49,
.mask = BIT(3),
},
{
.name = "led_5",
.port = 0x49,
.mask = BIT(2),
},
{
.name = "led_6",
.port = 0x49,
.mask = BIT(1),
},
{
.name = "led_7",
.port = 0x49,
.mask = BIT(0),
}
};
static DEFINE_SPINLOCK(value_lock);
/*
* we need to store the current led states, as it is not
* possible to read the current led state via inb().
*/
static u8 leds_back;
static u8 leds_front;
static void ot200_led_brightness_set(struct led_classdev *led_cdev,
enum led_brightness value)
{
struct ot200_led *led = container_of(led_cdev, struct ot200_led, cdev);
u8 *val;
unsigned long flags;
spin_lock_irqsave(&value_lock, flags);
if (led->port == 0x49)
val = &leds_front;
else if (led->port == 0x5a)
val = &leds_back;
else
BUG();
if (value == LED_OFF)
*val &= ~led->mask;
else
*val |= led->mask;
outb(*val, led->port);
spin_unlock_irqrestore(&value_lock, flags);
}
static int ot200_led_probe(struct platform_device *pdev)
{
int i;
int ret;
for (i = 0; i < ARRAY_SIZE(leds); i++) {
leds[i].cdev.name = leds[i].name;
leds[i].cdev.brightness_set = ot200_led_brightness_set;
ret = devm_led_classdev_register(&pdev->dev, &leds[i].cdev);
if (ret < 0)
return ret;
}
leds_front = 0; /* turn off all front leds */
leds_back = BIT(1); /* turn on init led */
outb(leds_front, 0x49);
outb(leds_back, 0x5a);
return 0;
}
static struct platform_driver ot200_led_driver = {
.probe = ot200_led_probe,
.driver = {
.name = "leds-ot200",
},
};
module_platform_driver(ot200_led_driver);
MODULE_AUTHOR("Sebastian A. Siewior <bigeasy@linutronix.de>");
MODULE_DESCRIPTION("ot200 LED driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:leds-ot200");