在UART 16550和Linux内核中断 [英] Interrupts in UART 16550 and Linux Kernel

问题描述

我正在尝试使用中断来查看UART 16550D中是否有错误以及何时可以读取字符.

I'm trying to use interrupts to see if there are errors in an UART 16550D and when a character is available to be read.

在UART配置如下:

#define UART    0x03f8      // Endereço da Porta Serial - I (com1) 
#define UART_IER    1
#define UART_LCR    3
#define UART_LSR    5
#define UART_DLL    0   /* Out: Divisor Latch Low */
#define UART_DLM    1   /* Out: Divisor Latch High */
#define UART_LSR_THRE   0x20 /* Transmit-hold-register empty */
#define UART_LSR_DR     0x01 /* Receiver data ready */
#define UART_RX     0   /* In:  Receive buffer */ 
#define UART_TX     0   /* Out: Transmit buffer */

void UART_init(void){
    outb( 0x80 , UART + UART_LCR );     
    outb( 0x00 , UART + UART_DLM );     
    outb( 0x60 , UART + UART_DLL );     
    outb( 0x1f , UART + UART_LCR );     
    outb( 0x07 , UART + UART_IER );         
    return;
}

和所述中断

irqreturn_t short_interrupt(int irq, void *dev_id){

        printk("INTERRUPT HAPPENED. WILL NOW RETURN\n");

        return 0;
}

static int seri_init(void){
        int result, i;

        UART_init();  

        request_irq(4, short_interrupt, SA_SHIRQ, "seri", NULL);

        ....

所以现在我只想看看是否调用了处理程序. 4被定义为在我使用该虚框设置IRQ.

So for now I just want to see if the handler is called or not. 4 is defined as the IRQ in the virtual box settings I'm using.

我想知道的是，是有什么错此设置?测试时，我没有问题，阅读和处理我在读什么.的是，该处理程序没有被调用.

What I want to know is, is there something wrong about this setup? When testing, I have no problem reading and processing what I'm reading. Thing is, the handler is never called.

这的request_irq()的返回是-22.不存在任何问题编译期间.

The return from request_irq() is -22. There are no problems during compilation.

推荐答案

我知道这是一个古老的职位，但想到我会扔了一个答案.使用的 gpio_to_irq 的获得中断号.第三个参数确定何时中断发生.

I know this is an old post, but thought I would throw up an answer. use gpio_to_irq to get interrupt number. The third parameter determines when the interrupt occurs.

irqNumber = gpio_to_irq(gpioUART);

// This next call requests an interrupt line
result = request_irq(irqNumber,       // The interrupt number requested
    (irq_handler_t) short_interrupt, // The pointer to handler function below
    IRQF_TRIGGER_FALLING,            // Interrupt on FALL edge ()
    "seri",                          // For /proc/interrupts identity
    NULL);                           // The *dev_id for shared interrupt

这篇关于在UART 16550和Linux内核中断的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！