linux下点灯有关问题

linux下点灯问题
硬件平台：OMAP-L138
软件平台：linux-2.6.32+VMware

问题描述：
板子上有个CPLD，CPLD的逻辑关系开发商不给，只给了文档描述,如下：

我自己写了个字符驱动用来控制灯的状态：
代码如下：

C/C++ code


static int __init hello_init(void)
{
        unsigned long led_addr;

        led_addr = (unsigned long)ioremap(0x64000040,0x08);

        printk("nled_addr is 0x%x.n",led_addr);

        writel(0x00,led_addr);

        iounmap(led_addr);

        printk("nhelloword:: Hello module is installed!!!!!!n");

        return 0;
}

动态加载的信息如下：
root@seed:/opt# insmod first_driver_hello.ko

led_addr is 0xc4888040.

helloword:: Hello module is installed!!!!!!
root@seed:/opt#

但是灯没有点亮，已证实硬件没有问题，请高手指点~~~

不要这么直接嘛
先试试读写是否正常
先读再写再读，看看你的写入是否有效果

随便在内核里找了段代码
if (!request_mem_region(up->port.mapbase, size, "serial")) {
ret = -EBUSY;
break;
}

if (up->port.flags & UPF_IOREMAP) {
up->port.membase = ioremap_nocache(up->port.mapbase,
size);
if (!up->port.membase) {
release_mem_region(up->port.mapbase, size);
ret = -ENOMEM;
}
}

这里你应该先request_mem_region
此外建议使用ioread8 iowrite8 这样的api

C/C++ code

这个驱动，请根据你的需要进行修改。

#include <linux/config.h>

#include <linux/init.h>

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/fcntl.h>

#include <linux/fs.h>

#include <linux/types.h>

#include <linux/input.h>
#include <asm/io.h>
void *R_GPBCON;

void *R_GPBDAT;
static u32 resave_gpbcon;

static u32 resave_gpbdat;
static struct input_dev my_led_dev;
static void iomap_gpb(void)

{

    R_GPBCON = ioremap(0x56000010,0x4);

    R_GPBDAT = ioremap(0x56000014,0x4);

}
static void unmap_gpb(void)

{

    iounmap(R_GPBCON);

    iounmap(R_GPBDAT);

}
static void init_led_reg(void)

{

    u32 temp;
    resave_gpbcon = __raw_readl(R_GPBCON);

    resave_gpbdat = __raw_readl(R_GPBDAT);
    temp = resave_gpbcon & (~(0xff << 10));

    temp |= ((0x1 << 10) | (0x1 << 12)|

                     (0x1 << 14) | (0x1 << 16));

    __raw_writel(temp,R_GPBCON);
    temp = resave_gpbdat | ( 0xf << 5);

    __raw_writel(temp,R_GPBDAT);

}
static void resave_led_reg(void)

{

    __raw_writel(resave_gpbcon,R_GPBCON);

    __raw_writel(resave_gpbdat,R_GPBDAT);

}
static int my_led_event(struct input_dev *dev,

       unsigned int type, unsigned int code, int value)
{

    u32 temp;
    if (type != EV_LED)

        return -1;
    switch (code) {

        case LED_NUML:

            break;

        default:

            return -1;

    }
    temp = __raw_readl(R_GPBDAT);

    temp &= (~(0xf << 5));
    __raw_writel(temp | value,R_GPBDAT);
    return 0;

}
static int __init my_led_init(void)

{

    init_input_dev(&my_led_dev);
    my_led_dev.evbit[0] = BIT(EV_LED);

    my_led_dev.ledbit[0] = BIT(LED_NUML);

    my_led_dev.event = my_led_event;
    my_led_dev.name = "my_led_name";

    my_led_dev.phys = "my_led_phys";

    my_led_dev.id.bustype = BUS_HOST;

    my_led_dev.id.vendor = 0x001f;

    my_led_dev.id.product = 0x0001;

    my_led_dev.id.version = 0x0100;
    iomap_gpb();

    init_led_reg();
    input_register_device(&my_led_dev);

    return 0;

}
static void __exit my_led_exit(void)

{

        resave_led_reg();

        unmap_gpb();
    input_unregister_device(&my

相关文章：

你感兴趣的文章：

标签云：