11.8代码

利用gpiod子系统实现开发板六盏灯，安装驱动点亮，卸载驱动熄灭

#include 
#include 
#include 
#include 
/*
        myleds{
                core-leds{
                        leds = <&gpioz 5 0>,<&gpioz 6 0>,<&gpioz 7 0>;
                };
                extend-leds{
                led1 = <&gpioe 10 0>;
                led2 = <&gpiof 10 0>;
                led3 = <&gpioe 8 0>;
                };
        };
*/
struct device_node *node;
struct device_node *core_node;
struct device_node *extend_node;
struct gpio_desc *core_desc[3];
struct gpio_desc *extend_desc[3];
char *extend_leds[3] = {"led1", "led2", "led3"};
// 入口
static int __init demo_init(void)
{
    int i;
    // 获取父结点
    node = of_find_node_by_path("/myleds");
    if (node == NULL)
    {
        printk("of_find_node_by_path is error\n");
        return -EIO;
    }
    // 获取core子节点
    core_node = of_get_child_by_name(node, "core-leds");
    if (core_node == NULL)
    {
        printk("core of_get_child_by_name is error\n");
        return -EIO;
    }
    // 获取extend子节点
    extend_node = of_get_child_by_name(node, "extend-leds");
    if (node == NULL)
    {
        printk("extend of_get_child_by_name is error\n");
        return -EIO;
    }
    for (i = 0; i < 3; i++)
    {
        // 获取gpio结构体
        core_desc[i] = gpiod_get_from_of_node(core_node, "leds", i, GPIOD_OUT_HIGH, NULL);
        // 申请gpio编号
        gpiod_get_value(core_desc[i]);
        // 设置gpio输出为1
        gpiod_direction_output(core_desc[i], 1);
    }
    for (i = 0; i < 3; i++)
    {
        // 获取gpio结构体
        extend_desc[i] = gpiod_get_from_of_node(extend_node, extend_leds[i], 0, GPIOD_OUT_HIGH, NULL);
        // 申请gpio编号
        gpiod_get_value(extend_desc[i]);
        // 设置gpio输出为1
        gpiod_direction_output(extend_desc[i], 1);
    }
 
    return 0;
}
// 出口
static void __exit demo_exit(void)
{
    int i;
    for (i = 0; i < 3; i++)
    {
        // 设置gpio输出为0
        gpiod_direction_output(core_desc[i], 0);
        // 释放gpio编号
        gpiod_put(core_desc[i]);
    }
    for (i = 0; i < 3; i++)
    {
        // 设置gpio输出为0
        gpiod_direction_output(extend_desc[i], 0);
        // 释放gpio编号
        gpiod_put(extend_desc[i]);
    }
}
 
module_init(demo_init);
module_exit(demo_exit);
MODULE_LICENSE("GPL"); // 许可证

使用linux中断子系统完成三个按键编写

#include 
#include 
#include 
#include 
#include 
/*
    mykeys{
            interrupt-parent=<&gpiof>;
            interrupts = <9 0>,<7 0>,<8 0>;
    };
*/
irqreturn_t key1_irq_handler(int irq, void *dev)
{
    int key = (int)dev;
    switch (key)
    {
    case 0:
        printk("key1 down!!!\n");
        break;
    case 1:
        printk("key2 down!!!\n");
        break;
    case 2:
        printk("key3 down!!!\n");
        break;
    default:
        break;
    }
    return IRQ_HANDLED;
}
unsigned int irqnu[3];
char *irname[3] = {"key1", "key2", "key3"};
struct device_node *node;
 
// 入口
static int __init demo_init(void)
{
    int i;
    int ret;
    // 获取结点
    node = of_find_node_by_path("/mykeys");
    if (node == NULL)
    {
        printk("of_find_node_by_path is error\n");
        return -EIO;
    }
    for (i = 0; i < 3; i++)
    {
        // 获取软中断号
        irqnu[i] = irq_of_parse_and_map(node, i);
        // 注册中断子系统
        ret = request_irq(irqnu[i], key1_irq_handler, IRQF_TRIGGER_FALLING, irname[i], (void *)i);
        if (ret < 0)
        {
            printk("%d request_irq is error\n", irqnu[i]);
            return -EIO;
        }
    }
 
    return 0;
}
// 出口
static void __exit demo_exit(void)
{
    int i;
    for (i = 0; i < 3; i++)
    {
        // 注销中断
        free_irq(irqnu[i], NULL);
    }
}
 
module_exit(demo_exit);
module_init(demo_init);
MODULE_LICENSE("GPL"); // 许可证