驱动里怎么设置低电平触发？不生效啊

vonnyfly

Hi experts,

I have trouble about interrupt. I need low level trigger the interrupt. My control flow is that when data is less than a threshold, it needs keeping interrupt until data is supplied.  

So I use the flag `IRQ_TYPE_LEVEL_LOW `, but it doesn’t work. I have also tried `IRQF_TRIGGER_LOW`, it also doesn’t work.

I have checked the hardware register, the interrupt GPIO is still `falling edges`, not `low level`.

My board is ARM S3C6410 tiny board.


  221        /* inkprinter */
  222        #define S3C64XX_PA_INKPRINTER (0x30000000)
  223        #define S3C64XX_SZ_INKPRINTER SZ_1M
  224        static struct resource inkprinter_resources[] = {
  225                [0] = {
  226                        .start                = S3C64XX_PA_INKPRINTER,
  227                        .end                = S3C64XX_PA_INKPRINTER + S3C64XX_SZ_INKPRINTER,
  228                        .flags                = IORESOURCE_MEM,
  229                },
  230                [1] = {
  231                        .start                = IRQ_EINT(1),
  232                        .end                = IRQ_EINT(1),
  233                        .flags = IORESOURCE_IRQ | IRQ_TYPE_LEVEL_LOW,
  234                }
  235        };
  236        static struct platform_device s3c_device_inkprinter = {
  237                .name                        = "inkprinter",
  238                .num_resources        = ARRAY_SIZE(inkprinter_resources),
  239                .resource                = inkprinter_resources,
  240        };
  241


My question is :

Is `IRQ_TYPE_LEVEL_LOW ` or `IRQF_TRIGGER_LOW `  for low level trigger? Or some other problem? Any tips?
Your response will be highly appreciated.

欢迎大家帮忙解答。

linuxlife123

感觉还是老的定义方式，现在新的都是dts了。
我觉得原因可能是你request_irq的时候没有带IRQ_TYPE_LEVEL_LOW这个标记。

vonnyfly

回复 2# linuxlife123
感谢！
后来发现是你说的问题，这里设置没什么大用。