linux/drivers/leds/leds-ot200.c
Christian Gmeiner 4b949b8af1 drivers/leds/leds-ot200.c: fix error caused by shifted mask
During the development of this driver an in-house register documentation
was used.  The last week some integration tests were done and this
problem was found.  It turned out that the released register
documentation is wrong.

The fix is very simple: shift all masks by one.

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Cc: Bryan Wu <cooloney@gmail.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-24 16:22:51 -07:00

172 lines
3.0 KiB
C

/*
* 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/init.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 = led_classdev_register(&pdev->dev, &leds[i].cdev);
if (ret < 0)
goto err;
}
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;
err:
for (i = i - 1; i >= 0; i--)
led_classdev_unregister(&leds[i].cdev);
return ret;
}
static int ot200_led_remove(struct platform_device *pdev)
{
int i;
for (i = 0; i < ARRAY_SIZE(leds); i++)
led_classdev_unregister(&leds[i].cdev);
return 0;
}
static struct platform_driver ot200_led_driver = {
.probe = ot200_led_probe,
.remove = ot200_led_remove,
.driver = {
.name = "leds-ot200",
.owner = THIS_MODULE,
},
};
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");