leds.c

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/*
 * Driver for the LED found on the EBSA110 machine
 * Based on Versatile and RealView machine LED code
 *
 * License terms: GNU General Public License (GPL) version 2
 * Author: Bryan Wu <[email protected]>
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/leds.h>

#include <asm/mach-types.h>

#include "core.h"

#if defined(CONFIG_NEW_LEDS) && defined(CONFIG_LEDS_CLASS)
static void ebsa110_led_set(struct led_classdev *cdev,
                  enum led_brightness b)
{
    u8 reg = __raw_readb(SOFT_BASE);

    if (b != LED_OFF)
        reg |= 0x80;
    else
        reg &= ~0x80;

    __raw_writeb(reg, SOFT_BASE);
}

static enum led_brightness ebsa110_led_get(struct led_classdev *cdev)
{
    u8 reg = __raw_readb(SOFT_BASE);

    return (reg & 0x80) ? LED_FULL : LED_OFF;
}

static int __init ebsa110_leds_init(void)
{

    struct led_classdev *cdev;
    int ret;

    if (!machine_is_ebsa110())
        return -ENODEV;

    cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
    if (!cdev)
        return -ENOMEM;

    cdev->name = "ebsa110:0";
    cdev->brightness_set = ebsa110_led_set;
    cdev->brightness_get = ebsa110_led_get;
    cdev->default_trigger = "heartbeat";

    ret = led_classdev_register(NULL, cdev);
    if (ret < 0) {
        kfree(cdev);
        return ret;
    }

    return 0;
}

/*
 * Since we may have triggers on any subsystem, defer registration
 * until after subsystem_init.
 */
fs_initcall(ebsa110_leds_init);
#endif